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  1. Correlation of matrix metalloproteinase-2 single nucleotide polymorphisms with the risk of small vessel disease (SVD).

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    Zhang, Min; Zhu, Wusheng; Yun, Wenwei; Wang, Qizhang; Cheng, Maogang; Zhang, Zhizhong; Liu, Xinfeng; Zhou, Xianju; Xu, Gelin

    2015-09-15

    Maladjustment of matrix metalloproteinases (MMPs) results in cerebral vasculature and blood-brain barrier dysfunction, which is associated with small vessel disease (SVD). This study was to aim at evaluating correlations between matrix metalloproteinase-2 and 9 single nucleotide polymorphisms and the risk of SVD. A total of 178 patients with SVD were enrolled into this study via Nanjing Stroke Registry Program (NSRP) from January 2010 to November 2011. SVD patients were further subtyped as isolated lacunar infarction (ILI, absent or with mild leukoaraiosis) and ischemic leukoaraiosis (ILA, with moderate or severe leukoaraiosis) according to the Fazekas scale. 100 age- and gender-matched individuals from outpatient medical examination were recruited as the control group. The genotypes of MMP-2-1306 T/C and MMP-9-1562 C/T were determined by the TaqMan method. Of 178 SVD patients, 86 and 92 patients were classified as ILI and ILA, respectively. Comparison analysis between SVD patients and controls revealed a significant correlation between SVD and hypertension, as well as a prevalence of hypertension in ILA. Further genotype analysis showed that the frequency of MMP-2-1306 CC genotype was higher in ILA patients than in controls (P=0.009, χ(2) test; P=0.027, the multiple test with Bonferroni correction). Finally, logistic regression analysis with adjustment of age, sex and vascular risk factors showed that the MMP-2-1306 T/C polymorphism was an independent predictor for ILA (OR: 2.605; 95% confidence interval [CI], 1.067-6.364; P=0.036). Our findings suggest that the MMP-2-1306 T/C polymorphism is a direct risk factor for ILA. Copyright © 2015. Published by Elsevier B.V.

  2. Perivascular Spaces, Glymphatic Dysfunction, and Small Vessel Disease

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    Mestre, Humberto; Kostrikov, Serhii; Mehta, Rupal I.; Nedergaard, Maiken

    2017-01-01

    Cerebral small vessel diseases (SVD) range broadly in etiology but share a remarkably overlapping pathology. Features of SVD including enlarged perivascular spaces and formation of abluminal protein deposits cannot be completely explained by the putative pathophysiology. The recently discovered glymphatic system provides a new perspective to potentially address these gaps. This work provides a comprehensive review of the known factors that regulate glymphatic function and the disease mechanis...

  3. Small vessel disease is linked to disrupted structural network covariance in Alzheimer's disease.

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    Nestor, Sean M; Mišić, Bratislav; Ramirez, Joel; Zhao, Jiali; Graham, Simon J; Verhoeff, Nicolaas P L G; Stuss, Donald T; Masellis, Mario; Black, Sandra E

    2017-07-01

    Cerebral small vessel disease (SVD) is thought to contribute to Alzheimer's disease (AD) through abnormalities in white matter networks. Gray matter (GM) hub covariance networks share only partial overlap with white matter connectivity, and their relationship with SVD has not been examined in AD. We developed a multivariate analytical pipeline to elucidate the cortical GM thickness systems that covary with major network hubs and assessed whether SVD and neurodegenerative pathologic markers were associated with attenuated covariance network integrity in mild AD and normal elderly control subjects. SVD burden was associated with reduced posterior cingulate corticocortical GM network integrity and subneocorticocortical hub network integrity in AD. These findings provide evidence that SVD is linked to the selective disruption of cortical hub GM networks in AD brains and point to the need to consider GM hub covariance networks when assessing network disruption in mixed disease. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  4. Baseline Cerebral Small Vessel Disease Is Not Associated with Gait Decline After Five Years

    NARCIS (Netherlands)

    Van Der Holst, Helena M.; Van Uden, Ingeborg W.M.; de Laat, Karlijn F.; Van Leijsen, Esther M.C.; van Norden, Anouk G.W.; Norris, David G.; Van DIjk, Ewoud J.; Tuladhar, Anil M.; de Leeuw, Frank-Erik

    2017-01-01

    Background Cerebral small vessel disease (SVD) is cross-sectionally associated with gait disturbances, however, the relation between baseline SVD and gait decline over time is uncertain. Furthermore, diffusion tensor imaging (DTI) studies on gait decline are currently lacking. Objective To

  5. Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration

    NARCIS (Netherlands)

    Wardlaw, J.M.; Smith, E.E.; Biessels, G.J.; Cordonnier, C.; Fazekas, F.; Frayne, R.; Lindley, R.I.; O'Brien, J. T.; Barkhof, F.; Benavente, O.R.; Black, S.E.; Brayne, C.; Breteler, M.; Chabriat, H.; deCarli, C.; de Leeuw, F.E.; Doubal, F.; Duering, M.; Fox, N.C.; Greenberg, S.; Hachinski, V.; Kilimann, I.; Mok, V.; van Oostenbrugge, R.; Pantoni, L.; Speck, O.; Stephan, B.C.M.; Teipel, S.; Viswanathan, A.; Werring, D.; Chen, C.; Smith, C.; van Buchem, M.; Norrving, B.; Gorelick, P.B.; Dichgans, M.

    2013-01-01

    Cerebral small vessel disease (SVD) is a common accompaniment of ageing. Features seen on neuroimaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. SVD can present as a stroke or cognitive decline, or can have

  6. The renin-angiotensin-aldosterone system in cerebral small vessel disease

    NARCIS (Netherlands)

    Brenner, D.; Labreuche, J.; Pico, F.; Scheltens, P.; Poirier, O.; Cambien, F.; Amarenco, P.

    2008-01-01

    Introduction: Cerebral small vessel disease (SVD) appears on magnetic resonance imaging (MRI) as leukoaraiosis (LA), état criblé (EC), and multiple lacunar infarctions (MLI). Although the pathophysiology of SVD is poorly understood, there is evidence of a genetic contribution. We sought to analyze

  7. Apathy, but not depression, is associated with executive dysfunction in cerebral small vessel disease.

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    Lohner, Valerie; Brookes, Rebecca L; Hollocks, Matthew J; Morris, Robin G; Markus, Hugh S

    2017-01-01

    To determine the prevalence of apathy and depression in cerebral small vessel disease (SVD), and the relationships between both apathy and depression with cognition. To examine whether apathy is specifically related to impairment in executive functioning and processing speed. 196 patients with a clinical lacunar stroke and an anatomically corresponding lacunar infarct on MRI were compared to 300 stroke-free controls. Apathy and depression were measured using the Geriatric Depression Scale, and cognitive functioning was assessed using an SVD cognitive screening tool, the Brief Memory and Executive Test, which measures executive functioning/processing speed and memory/orientation. Path analysis and binary logistic regression were used to assess the relation between apathy, depression and cognitive impairment. 31 participants with SVD (15.8%) met criteria for apathy only, 23 (11.8%) for both apathy and depression, and 2 (1.0%) for depression only. In the SVD group the presence of apathy was related to global cognition, and specifically to impaired executive functioning/processing speed, but not memory/orientation. The presence of depression was not related to global cognition, impaired executive functioning/processing speed or memory/orientation. Apathy is a common feature of SVD and is associated with impaired executive functioning/processing speed suggesting the two may share biological mechanisms. Screening for apathy should be considered in SVD, and further work is required to develop and evaluate effective apathy treatment or management in SVD.

  8. Prevalence, risk factors and consequences of cerebral small vessel diseases: data from three Asian countries.

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    Hilal, Saima; Mok, Vincent; Youn, Young Chul; Wong, Adrian; Ikram, Mohammad Kamran; Chen, Christopher Li-Hsian

    2017-08-01

    Cerebral small vessel disease (SVD) has been suggested to be more common in Asians compared with Caucasians. However, data from population-based studies in Asia are lacking. We report on the prevalence, risk factors and consequences of SVD from contemporary studies in three Asian countries using 3-Tesla MRI for the evaluation of SVD. Clinical, cognitive and 3-Tesla brain MRI assessments were performed among participants of three studies from Singapore, Hong Kong and Korea. SVD markers include white matter hyperintensities (WMHs) using the modified Fazekas scale, lacunes and microbleeds. Cognition was assessed using the Mini Mental Status Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Adjustments were made for age, sex and cardiovascular risk factors. A total of 1797 subjects were available for analysis (mean age: 70.1±6.3 years and 57% women). The prevalence of confluent WMH was 36.6%, lacunes, 24.6% and microbleeds, 26.9%. Presence of all three SVD markers showed a steeper increase with increasing age rising from 1.9% in the lowest to 46.2% in the highest 5-year age strata. The major risk factors for the increased severity of SVD markers were advancing age and hypertension. Moreover, increasing severity of SVD markers was independently associated with worse performance on MMSE and MoCA. Elderly Asians have a high burden of SVD which was associated with cognitive dysfunction. This suggests that SVD markers should be a potential target for treatment in clinical trials so as to delay progression of cerebrovascular disease and potentially cognitive decline. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. [Management of cerebral small vessel disease for the diagnosis and treatment of dementia].

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    Ihara, Masafumi

    2013-07-01

    With the demographic shift in life expectancy inexorably increasing in developed countries, dementia is set to become one of the most important health problems worldwide. In recent years, cerebral small vessel disease (SVD) has received much attention as an important cause of dementia. The reason for this is twofold: firstly, arteriosclerosis (type 1 SVD) is the leading cause of vascular cognitive impairment, and secondly, cerebral amyloid angiopathy (CAA; type 2 SVD) is an almost invariable accompaniment of Alzheimer's disease. SVD is known to induce a variety of pathological changes; for example, type 1 SVD results in lacunar infarction, deep microbleeds, and white matter damage, while type 2 SVD leads to cortical microinfarcts, lobar microbleeds, and white matter damage. SVD is considered a spectrum of abnormalities, with the majority of patients experiencing symptoms from both type 1 and type 2 SVD as the disease progresses. The discouraging results of immunotherapy clinical trials for Alzheimer's disease have shifted the scientific attention from the classical neuron-centric approach towards a novel neurovascular approach. As arteries stiffen with age or with other co-morbid factors such as life-related diseases, amyloid β (Aβ) synthesis becomes upregulated, resulting in the deposition of insoluble Aβ not only in the parenchyma as senile plaques but also in the perivascular drainage pathways as CAA. Therefore, therapeutic strategies such as vasoactive drugs that enhance the patency of this Aβ drainage pathway may facilitate Aβ removal and help prevent cognitive decline in the elderly. Based on this emerging paradigm, clinical trials are warranted to investigate whether a neurovascular therapeutic approach can effectively halt cognitive decline and act as a preemptive medicine for patients at risk of dementia.

  10. Perivascular spaces, glymphatic dysfunction, and small vessel disease.

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    Mestre, Humberto; Kostrikov, Serhii; Mehta, Rupal I; Nedergaard, Maiken

    2017-09-01

    Cerebral small vessel diseases (SVDs) range broadly in etiology but share remarkably overlapping pathology. Features of SVD including enlarged perivascular spaces (EPVS) and formation of abluminal protein deposits cannot be completely explained by the putative pathophysiology. The recently discovered glymphatic system provides a new perspective to potentially address these gaps. This work provides a comprehensive review of the known factors that regulate glymphatic function and the disease mechanisms underlying glymphatic impairment emphasizing the role that aquaporin-4 (AQP4)-lined perivascular spaces (PVSs), cerebrovascular pulsatility, and metabolite clearance play in normal CNS physiology. This review also discusses the implications that glymphatic impairment may have on SVD inception and progression with the aim of exploring novel therapeutic targets and highlighting the key questions that remain to be answered. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. Cerebral White Matter Hypoperfusion Increases with Small-Vessel Disease Burden. Data From the Third International Stroke Trial.

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    Arba, Francesco; Mair, Grant; Carpenter, Trevor; Sakka, Eleni; Sandercock, Peter A G; Lindley, Richard I; Inzitari, Domenico; Wardlaw, Joanna M

    2017-07-01

    Leukoaraiosis is associated with impaired cerebral perfusion, but the effect of individual and combined small-vessel disease (SVD) features on white matter perfusion is unclear. We studied patients recruited with perfusion imaging in the Third International Stroke Trial. We rated individual SVD features (leukoaraiosis, lacunes) and brain atrophy on baseline plain computed tomography or magnetic resonance imaging. Separately, we assessed white matter at the level of the lateral ventricles in the cerebral hemisphere contralateral to the stroke for visible areas of hypoperfusion (present or absent) on 4 time-based perfusion imaging parameters. We examined associations between SVD features (individually and summed) and presence of hypoperfusion using logistic regression adjusted for age, sex, baseline National Institutes of Health Stroke Scale, hypertension, and diabetes. A total of 115 patients with median (interquartile range) age of 81 (72-86) years, 78 (52%) of which were male, had complete perfusion data. Hypoperfusion was most frequent on mean transit time (MTT; 63 patients, 55%) and least frequent on time to maximum flow (19 patients, 17%). The SVD score showed stronger independent associations with hypoperfusion (e.g., MTT, odds ratio [OR] = 2.80; 95% confidence interval [CI] = 1.56-5.03) than individual SVD markers (e.g., white matter hypoattenuation score, MTT, OR = 1.49, 95% CI = 1.09-2.04). Baseline blood pressure did not differ by presence or absence of hypoperfusion or across strata of SVD score. Presence of white matter hypoperfusion increased with SVD summed score. The SVD summed score was associated with hypoperfusion more consistently than individual SVD features, providing validity to the SVD score concept. Increasing SVD burden indicates worse perfusion in the white matter. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  12. Mechanisms of cognitive impairment in cerebral small vessel disease: multimodal MRI results from the St George's cognition and neuroimaging in stroke (SCANS study.

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    Andrew J Lawrence

    Full Text Available Cerebral small vessel disease (SVD is a common cause of vascular cognitive impairment. A number of disease features can be assessed on MRI including lacunar infarcts, T2 lesion volume, brain atrophy, and cerebral microbleeds. In addition, diffusion tensor imaging (DTI is sensitive to disruption of white matter ultrastructure, and recently it has been suggested that additional information on the pattern of damage may be obtained from axial diffusivity, a proposed marker of axonal damage, and radial diffusivity, an indicator of demyelination. We determined the contribution of these whole brain MRI markers to cognitive impairment in SVD. Consecutive patients with lacunar stroke and confluent leukoaraiosis were recruited into the ongoing SCANS study of cognitive impairment in SVD (n = 115, and underwent neuropsychological assessment and multimodal MRI. SVD subjects displayed poor performance on tests of executive function and processing speed. In the SVD group brain volume was lower, white matter hyperintensity volume higher and all diffusion characteristics differed significantly from control subjects (n = 50. On multi-predictor analysis independent predictors of executive function in SVD were lacunar infarct count and diffusivity of normal appearing white matter on DTI. Independent predictors of processing speed were lacunar infarct count and brain atrophy. Radial diffusivity was a stronger DTI predictor than axial diffusivity, suggesting ischaemic demyelination, seen neuropathologically in SVD, may be an important predictor of cognitive impairment in SVD. Our study provides information on the mechanism of cognitive impairment in SVD.

  13. Total Cerebral Small Vessel Disease MRI Score Is Associated With Cognitive Decline In Executive Function In Patients With Hypertension

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    Renske Uiterwijk

    2016-12-01

    Full Text Available Objectives: Hypertension is a major risk factor for white matter hyperintensities, lacunes, cerebral microbleeds and perivascular spaces, which are MRI markers of cerebral small vessel disease (SVD. Studies have shown associations between these individual MRI markers and cognitive functioning and decline. Recently, a total SVD score was proposed in which the different MRI markers were combined into one measure of SVD, to capture total SVD-related brain damage. We investigated if this SVD score was associated with cognitive decline over 4 years in patients with hypertension. Methods: In this longitudinal cohort study, 130 hypertensive patients (91 patients with uncomplicated hypertension and 39 hypertensive patients with a lacunar stroke were included. They underwent a neuropsychological assessment at baseline and after 4 years. The presence of white matter hyperintensities, lacunes, cerebral microbleeds, and perivascular spaces were rated on baseline MRI. Presence of each individual marker was added to calculate the total SVD score (range 0-4 in each patient. Results: Uncorrected linear regression analyses showed associations between SVD score and decline in overall cognition (p=0.017, executive functioning (p<0.001 and information processing speed (p=0.037, but not with memory (p=0.911. The association between SVD score and decline in overall cognition and executive function remained significant after adjustment for age, sex, education, anxiety and depression score, potential vascular risk factors, patient group and baseline cognitive performance.Conclusions: Our study shows that a total SVD score can predict cognitive decline, specifically in executive function, over 4 years in hypertensive patients. This emphasizes the importance of considering total brain damage due to SVD.

  14. [Small vessel cerebrovascular disease].

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    Cardona Portela, P; Escrig Avellaneda, A

    2018-05-09

    Small vessel vascular disease is a spectrum of different conditions that includes lacunar infarction, alteration of deep white matter, or microbleeds. Hypertension is the main risk factor, although the atherothrombotic lesion may be present, particularly in large-sized lacunar infarctions along with other vascular risk factors. MRI findings are characteristic and the lesions authentic biomarkers that allow differentiating the value of risk factors and defining their prognostic value. Copyright © 2018 SEH-LELHA. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Small white matter lesion detection in cerebral small vessel disease

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    Ghafoorian, Mohsen; Karssemeijer, Nico; van Uden, Inge; de Leeuw, Frank E.; Heskes, Tom; Marchiori, Elena; Platel, Bram

    2015-03-01

    Cerebral small vessel disease (SVD) is a common finding on magnetic resonance images of elderly people. White matter lesions (WML) are important markers for not only the small vessel disease, but also neuro-degenerative diseases including multiple sclerosis, Alzheimer's disease and vascular dementia. Volumetric measurements such as the "total lesion load", have been studied and related to these diseases. With respect to SVD we conjecture that small lesions are important, as they have been observed to grow over time and they form the majority of lesions in number. To study these small lesions they need to be annotated, which is a complex and time-consuming task. Existing (semi) automatic methods have been aimed at volumetric measurements and large lesions, and are not suitable for the detection of small lesions. In this research we established a supervised voxel classification CAD system, optimized and trained to exclusively detect small WMLs. To achieve this, several preprocessing steps were taken, which included a robust standardization of subject intensities to reduce inter-subject intensity variability as much as possible. A number of features that were found to be well identifying small lesions were calculated including multimodal intensities, tissue probabilities, several features for accurate location description, a number of second order derivative features as well as multi-scale annular filter for blobness detection. Only small lesions were used to learn the target concept via Adaboost using random forests as its basic classifiers. Finally the results were evaluated using Free-response receiver operating characteristic.

  16. Characterization of Heterozygous HTRA1 Mutations in Taiwanese Patients With Cerebral Small Vessel Disease.

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    Lee, Yi-Chung; Chung, Chih-Ping; Chao, Nai-Chen; Fuh, Jong-Ling; Chang, Feng-Chi; Soong, Bing-Wing; Liao, Yi-Chu

    2018-07-01

    Homozygous and compound heterozygous mutations in the high temperature requirement serine peptidase A1 gene ( HTRA1 ) cause cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy. However, heterozygous HTRA1 mutations were recently identified to be associated with autosomal dominant cerebral small vessel disease (SVD). The present study aims at investigating the clinical features, frequency, and spectrum of HTRA1 mutations in a Taiwanese cohort with SVD. Mutational analyses of HTRA1 were performed by Sanger sequencing in 222 subjects, selected from a cohort of 337 unrelated patients with SVD after excluding those harboring a NOTCH3 mutation. The influence of these mutations on HTRA1 protease activities was characterized. Seven novel heterozygous mutations in HTRA1 were identified, including p.Gly120Asp, p.Ile179Asn, p.Ala182Profs*33, p.Ile256Thr, p.Gly276Ala, p.Gln289Ter, and p.Asn324Thr, and each was identified in 1 single index patient. All mutations significantly compromise the HTRA1 protease activities. For the 7 index cases and another 2 affected siblings carrying a heterozygous HTRA1 mutation, the common clinical presentations include lacunar infarction, intracerebral hemorrhage, cognitive decline, and spondylosis at the fifth to sixth decade of life. Among the 9 patients, 4 have psychiatric symptoms as delusion, depression, and compulsive behavior, 3 have leukoencephalopathy in anterior temporal poles, and 2 patients have alopecia. Heterozygous HTRA1 mutations account for 2.08% (7 of 337) of SVD in Taiwan. The clinical and neuroradiological features of HTRA1 -related SVD and sporadic SVD are similar. These findings broaden the mutational spectrum of HTRA1 and highlight the pathogenic role of heterozygous HTRA1 mutations in SVD. © 2018 American Heart Association, Inc.

  17. Cerebral Small Vessel Disease Burden Is Associated With Poststroke Depressive Symptoms: A 15-Month Prospective Study

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    Yan Liang

    2018-02-01

    Full Text Available Objective: All types of cerebral small vessel disease (SVD markers including lacune, white matter hyperintensities (WMH, cerebral microbleeds, and perivascular spaces were found to be associated with poststroke depressive symptoms (PDS. This study explored whether the combination of the four markers constituting an overall SVD burden was associated with PDS.Methods: A cohort of 563 patients with acute ischemic stroke were followed over a 15-month period after the index stroke. A score of ≥7 on the 15-item Geriatric Depression Scale was defined as clinically significant PDS. Scores of the four SVD markers ascertained on magnetic resonance imaging were summed up to represent total SVD burden. The association between SVD burden and PDS was assessed with generalized estimating equation models.Results: The study sample had a mean age of 67.0 ± 10.2 years and mild-moderate stroke [National Institutes of Health Stroke Scale score: 3, interquartile, 1–5]. PDS were found in 18.3%, 11.6%, and 12.3% of the sample at 3, 9, and 15 months after stroke, respectively. After adjusting for demographic characteristics, vascular risk factors, social support, stroke severity, physical and cognitive functions, and size and locations of stroke, the SVD burden was associated with an increased risk of PDS [odds ratio = 1.30; 95% confidence interval = 1.07–1.58; p = 0.010]. Other significant predictors of PDS were time of assessment, female sex, smoking, number of acute infarcts, functional independence, and social support.Conclusion: SVD burden was associated with PDS examined over a 15-month follow-up in patients with mild to moderate acute ischemic stroke.

  18. Causes and consequences of cerebral small vessel disease. The RUN DMC study: a prospective cohort study. Study rationale and protocol

    NARCIS (Netherlands)

    Norden, A.G.W. van; Laat, K.F. de; Gons, R.A.R.; Uden, I.W.M. van; Dijk, E.J. van; Oudheusden, L.J.B. van; Esselink, R.A.J.; Bloem, B.R.; Engelen, B.G.M. van; Zwarts, M.J.; Tendolkar, I.; Olde-Rikkert, M.G.M.; Vlugt, M.J. van der; Zwiers, M.P.; Norris, D.G.; Leeuw, F.E. de

    2011-01-01

    BACKGROUND: Cerebral small vessel disease (SVD) is a frequent finding on CT and MRI scans of elderly people and is related to vascular risk factors and cognitive and motor impairment, ultimately leading to dementia or parkinsonism in some. In general, the relations are weak, and not all subjects

  19. Application of Texture Analysis to Study Small Vessel Disease and Blood–Brain Barrier Integrity

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    Maria del C. Valdés Hernández

    2017-07-01

    Full Text Available ObjectivesWe evaluate the alternative use of texture analysis for evaluating the role of blood–brain barrier (BBB in small vessel disease (SVD.MethodsWe used brain magnetic resonance imaging from 204 stroke patients, acquired before and 20 min after intravenous gadolinium administration. We segmented tissues, white matter hyperintensities (WMH and applied validated visual scores. We measured textural features in all tissues pre- and post-contrast and used ANCOVA to evaluate the effect of SVD indicators on the pre-/post-contrast change, Kruskal–Wallis for significance between patient groups and linear mixed models for pre-/post-contrast variations in cerebrospinal fluid (CSF with Fazekas scores.ResultsTextural “homogeneity” increase in normal tissues with higher presence of SVD indicators was consistently more overt than in abnormal tissues. Textural “homogeneity” increased with age, basal ganglia perivascular spaces scores (p < 0.01 and SVD scores (p < 0.05 and was significantly higher in hypertensive patients (p < 0.002 and lacunar stroke (p = 0.04. Hypertension (74% patients, WMH load (median = 1.5 ± 1.6% of intracranial volume, and age (mean = 65.6 years, SD = 11.3 predicted the pre/post-contrast change in normal white matter, WMH, and index stroke lesion. CSF signal increased with increasing SVD post-contrast.ConclusionA consistent general pattern of increasing textural “homogeneity” with increasing SVD and post-contrast change in CSF with increasing WMH suggest that texture analysis may be useful for the study of BBB integrity.

  20. Study of white matter at the centrum semiovale level with magnetic resonance spectroscopy and diffusion tensor imaging in cerebral small vessel disease.

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    Huang, L A; Ling, X Y; Li, C; Zhang, S J; Chi, G B; Xu, A D

    2014-04-08

    White matter lesion (WML) in magnetic resonance imaging is commonly observed in patients with cerebral small vessel disease (SVD), but the pathological mechanism of WML in SVD is still unclear. We observed the metabolism and microscopic anatomy of white matter in SVD patients. Twelve subjects clinically diagnosed with SVD and 6 normal control subjects were examined with magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI). The white matter at the centrum semiovale level was selected as the region of interest (ROI). The ROI metabolism parameters, including N-acetyl-l-aspartic acid (NAA), creatine (Cr), and choline (Cho) were measured by MRS. Microscopic parameters such as mean diffusion (MD) and fractional anisotropy (FA) in ROI were obtained by DTI. Compared with the normal control group, bilateral MD values in the SVD group were significantly elevated, whereas bilateral FA values in SVD were decreased, but the difference was not statistically significant. Additionally, NAA/Cho, Cho/Cr, and NAA/Cr showed no significant statistical differences. Our study suggests that the mechanisms of the SVD cognitive impairment are related to damage of the white matter structures rather than to brain metabolism.

  1. Association of Chronic Kidney Disease and Cerebral Small Vessel Disease with Cognitive Impairment in Elderly Patients with Type 2 Diabetes

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    Toshitaka Umemura

    2013-07-01

    Full Text Available Background/Aims: In recent years, the relationship between chronic kidney disease (CKD and cognitive impairment has been attracting attention. Cerebral small vessel disease (SVD is also associated with an increased risk of cognitive impairment. However, it is still unknown whether CKD markers are associated with cognitive impairment independently of SVD in elderly diabetic patients. Methods: Seventy-nine type 2 diabetic patients (mean age, 76.0 years were enrolled in the present study. CKD was defined as the presence of albuminuria and/or a low estimated glomerular filtration rate (eGFR 2. SVD was evaluated by the presence and severity of silent brain infarcts (SBIs and white matter lesions (WMLs on brain magnetic resonance imaging. Neuropsychological tests were assessed using four validated cognitive instruments. Results: In multiple linear regression analyses, albuminuria was associated with worse modified Stroop Color Word scores (β = 0.284, p = 0.017 and low eGFR was associated with reduced Digit Symbol Substitution scores (β = -0.224, p = 0.026 after adjustment for age, sex, education years, diabetes duration, hypertension, multiple SBIs, and advanced WMLs. In contrast, there were no significant associations between CKD markers and Mini-Mental State Examination or Word Recall scores. Conclusion: Our findings suggest that albuminuria and low eGFR are associated with frontal lobe dysfunction independently of SVD in elderly type 2 diabetic patients.

  2. Causes and consequences of cerebral small vessel disease. The RUN DMC study: a prospective cohort study. Study rationale and protocol

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    van der Vlugt Maureen J

    2011-02-01

    Full Text Available Abstract Background Cerebral small vessel disease (SVD is a frequent finding on CT and MRI scans of elderly people and is related to vascular risk factors and cognitive and motor impairment, ultimately leading to dementia or parkinsonism in some. In general, the relations are weak, and not all subjects with SVD become demented or get parkinsonism. This might be explained by the diversity of underlying pathology of both white matter lesions (WML and the normal appearing white matter (NAWM. Both cannot be properly appreciated with conventional MRI. Diffusion tensor imaging (DTI provides alternative information on microstructural white matter integrity. The association between SVD, its microstructural integrity, and incident dementia and parkinsonism has never been investigated. Methods/Design The RUN DMC study is a prospective cohort study on the risk factors and cognitive and motor consequences of brain changes among 503 non-demented elderly, aged between 50-85 years, with cerebral SVD. First follow up is being prepared for July 2011. Participants alive will be included and invited to the research centre to undergo a structured questionnaire on demographics and vascular risk factors, and a cognitive, and motor, assessment, followed by a MRI protocol including conventional MRI, DTI and resting state fMRI. Discussion The follow up of the RUN DMC study has the potential to further unravel the causes and possibly better predict the consequences of changes in white matter integrity in elderly with SVD by using relatively new imaging techniques. When proven, these changes might function as a surrogate endpoint for cognitive and motor function in future therapeutic trials. Our data could furthermore provide a better understanding of the pathophysiology of cognitive and motor disturbances in elderly with SVD. The execution and completion of the follow up of our study might ultimately unravel the role of SVD on the microstructural integrity of the white

  3. Causes and consequences of cerebral small vessel disease. The RUN DMC study: a prospective cohort study. Study rationale and protocol.

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    van Norden, Anouk Gw; de Laat, Karlijn F; Gons, Rob Ar; van Uden, Inge Wm; van Dijk, Ewoud J; van Oudheusden, Lucas Jb; Esselink, Rianne Aj; Bloem, Bastiaan R; van Engelen, Baziel Gm; Zwarts, Machiel J; Tendolkar, Indira; Olde-Rikkert, Marcel G; van der Vlugt, Maureen J; Zwiers, Marcel P; Norris, David G; de Leeuw, Frank-Erik

    2011-02-28

    Cerebral small vessel disease (SVD) is a frequent finding on CT and MRI scans of elderly people and is related to vascular risk factors and cognitive and motor impairment, ultimately leading to dementia or parkinsonism in some. In general, the relations are weak, and not all subjects with SVD become demented or get parkinsonism. This might be explained by the diversity of underlying pathology of both white matter lesions (WML) and the normal appearing white matter (NAWM). Both cannot be properly appreciated with conventional MRI. Diffusion tensor imaging (DTI) provides alternative information on microstructural white matter integrity. The association between SVD, its microstructural integrity, and incident dementia and parkinsonism has never been investigated. The RUN DMC study is a prospective cohort study on the risk factors and cognitive and motor consequences of brain changes among 503 non-demented elderly, aged between 50-85 years, with cerebral SVD. First follow up is being prepared for July 2011. Participants alive will be included and invited to the research centre to undergo a structured questionnaire on demographics and vascular risk factors, and a cognitive, and motor, assessment, followed by a MRI protocol including conventional MRI, DTI and resting state fMRI. The follow up of the RUN DMC study has the potential to further unravel the causes and possibly better predict the consequences of changes in white matter integrity in elderly with SVD by using relatively new imaging techniques. When proven, these changes might function as a surrogate endpoint for cognitive and motor function in future therapeutic trials. Our data could furthermore provide a better understanding of the pathophysiology of cognitive and motor disturbances in elderly with SVD. The execution and completion of the follow up of our study might ultimately unravel the role of SVD on the microstructural integrity of the white matter in the transition from "normal" aging to cognitive and

  4. Age-Specific Associations of Renal Impairment With Magnetic Resonance Imaging Markers of Cerebral Small Vessel Disease in Transient Ischemic Attack and Stroke.

    Science.gov (United States)

    Liu, Bian; Lau, Kui Kai; Li, Linxin; Lovelock, Caroline; Liu, Ming; Kuker, Wilhelm; Rothwell, Peter M

    2018-04-01

    It has been hypothesized that cerebral small vessel disease (SVD) and chronic renal impairment may be part of a multisystem small-vessel disorder, but their association may simply be as a result of shared risk factors (eg, hypertension) rather than to a systemic susceptibility to premature SVD. However, most previous studies were hospital based, most had inadequate adjustment for hypertension, many were confined to patients with lacunar stroke, and none stratified by age. In a population-based study of transient ischemic attack and ischemic stroke (OXVASC [Oxford Vascular Study]), we evaluated the magnetic resonance imaging markers of cerebral SVD, including lacunes, white matter hyperintensities, cerebral microbleeds, and enlarged perivascular space. We studied the age-specific associations of renal impairment (estimated glomerular filtration rate <60 mL/min per 1.73 m 2 ) and total SVD burden (total SVD score) adjusting for age, sex, vascular risk factors, and premorbid blood pressure (mean blood pressure during 15 years preevent). Of 1080 consecutive patients, 1028 (95.2%) had complete magnetic resonance imaging protocol and creatinine measured at baseline. Renal impairment was associated with total SVD score (odds ratio [OR], 2.16; 95% confidence interval [CI], 1.69-2.75; P <0.001), but only at age <60 years (<60 years: OR, 3.97; 95% CI, 1.69-9.32; P =0.002; 60-79 years: OR, 1.01; 95% CI, 0.72-1.41; P =0.963; ≥80 years: OR, 0.95; 95% CI, 0.59-1.54; P =0.832). The overall association of renal impairment and total SVD score was also attenuated after adjustment for age, sex, history of hypertension, diabetes mellitus, and premorbid average systolic blood pressure (adjusted OR, 0.76; 95% CI, 0.56-1.02; P =0.067), but the independent association of renal impairment and total SVD score at age <60 years was maintained (adjusted OR, 3.11; 95% CI, 1.21-7.98; P =0.018). Associations of renal impairment and SVD were consistent for each SVD marker at age <60 years but

  5. Neuroimaging Characteristics of Small-Vessel Disease in Older Adults with Normal Cognition, Mild Cognitive Impairment, and Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Alberto Mimenza-Alvarado

    2018-05-01

    Full Text Available Introduction: Cerebral small-vessel disease (SVD represents the most frequent type of vascular brain lesions, often coexisting with Alzheimer disease (AD. By quantifying white matter hyperintensities (WMH and hippocampal and parietal atrophy, we aimed to describe the prevalence and severity of SVD among older adults with normal cognition (NC, mild cognitive impairment (MCI, and probable AD and to describe associated risk factors. Methods: This study included 105 older adults evaluated with magnetic resonance imaging and clinical and neuropsychological tests. We used the Fazekas scale (FS for quantification of WMH, the Scheltens scale (SS for hippocampal atrophy, and the Koedam scale (KS for parietal atrophy. Logistic regression models were performed to determine the association between FS, SS, and KS scores and the presence of NC, MCI, or probable AD. Results: Compared to NC subjects, SVD was more prevalent in MCI and probable AD subjects. After adjusting for confounding factors, logistic regression showed a positive association between higher scores on the FS and probable AD (OR = 7.6, 95% CI 2.7–20, p < 0.001. With the use of the SS and KS (OR = 4.5, 95% CI 3.5–58, p = 0.003 and OR = 8.9, 95% CI 1–72, p = 0.04, respectively, the risk also remained significant for probable AD. Conclusions: These results suggest an association between severity of vascular brain lesions and neurodegeneration.

  6. Pattern and Rate of Cognitive Decline in Cerebral Small Vessel Disease: A Prospective Study.

    Directory of Open Access Journals (Sweden)

    Andrew J Lawrence

    Full Text Available Cognitive impairment, predominantly affecting processing speed and executive function, is an important consequence of cerebral small vessel disease (SVD. To date, few longitudinal studies of cognition in SVD have been conducted. We determined the pattern and rate of cognitive decline in SVD and used the results to determine sample size calculations for clinical trials of interventions reducing cognitive decline.121 patients with MRI confirmed lacunar stroke and leukoaraiosis were enrolled into the prospective St George's Cognition And Neuroimaging in Stroke (SCANS study. Patients attended one baseline and three annual cognitive assessments providing 36 month follow-up data. Neuropsychological assessment comprised a battery of tests assessing working memory, long-term (episodic memory, processing speed and executive function. We calculated annualized change in cognition for the 98 patients who completed at least two time-points.Task performance was heterogeneous, but significant cognitive decline was found for the executive function index (p<0.007. Working memory and processing speed decreased numerically, but not significantly. The executive function composite score would require the smallest samples sizes for a treatment trial with an aim of halting decline, but this would still require over 2,000 patients per arm to detect a 30% difference with power of 0.8 over a three year follow-up.The pattern of cognitive decline seen in SVD over three years is consistent with the pattern of impairments at baseline. Rates of decline were slow and sample sizes would need to be large for clinical trials aimed at halting decline beyond initial diagnosis using cognitive scores as an outcome measure. This emphasizes the importance of more sensitive surrogate markers in this disease.

  7. What is cerebral small vessel disease?

    International Nuclear Information System (INIS)

    Onodera, Osamu

    2011-01-01

    An accumulating amount of evidence suggests that the white matter hyperintensities on T 2 weighted brain magnetic resonance imaging predict an increased risk of dementia and gait disturbance. This state has been proposed as cerebral small vessel disease, including leukoaraiosis, Binswanger's disease, lacunar stroke and cerebral microbleeds. However, the concept of cerebral small vessel disease is still obscure. To understand the cerebral small vessel disease, the precise structure and function of cerebral small vessels must be clarified. Cerebral small vessels include several different arteries which have different anatomical structures and functions. Important functions of the cerebral small vessels are blood-brain barrier and perivasucular drainage of interstitial fluid from the brain parenchyma. Cerebral capillaries and glial endfeet, take an important role for these functions. However, the previous pathological investigations on cerebral small vessels have focused on larger arteries than capillaries. Therefore little is known about the pathology of capillaries in small vessel disease. The recent discoveries of genes which cause the cerebral small vessel disease indicate that the cerebral small vessel diseases are caused by a distinct molecular mechanism. One of the pathological findings in hereditary cerebral small vessel disease is the loss of smooth muscle cells, which is an also well-recognized finding in sporadic cerebral small vessel disease. Since pericytes have similar character with the smooth muscle cells, the pericytes should be investigated in these disorders. In addition, the loss of smooth muscle cells may result in dysfunction of drainage of interstitial fluid from capillaries. The precise correlation between the loss of smooth muscle cells and white matter disease is still unknown. However, the function that is specific to cerebral small vessel may be associated with the pathogenesis of cerebral small vessel disease. (author)

  8. NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease-Implications for Prevention.

    Science.gov (United States)

    McCarty, Mark F

    2015-04-15

    Cerebral small vessel disease (SVD), a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS) activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways-exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea), and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine-which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine-mediate this benefit. Ameliorating the risk factors for SVD-including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine-also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

  9. Unitary embedding for data hiding with the SVD

    Science.gov (United States)

    Bergman, Clifford; Davidson, Jennifer

    2005-03-01

    Steganography is the study of data hiding for the purpose of covert communication. A secret message is inserted into a cover file so that the very existence of the message is not apparent. Most current steganography algorithms insert data in the spatial or transform domains; common transforms include the discrete cosine transform, the discrete Fourier transform, and discrete wavelet transform. In this paper, we present a data-hiding algorithm that exploits a decomposition representation of the data instead of a frequency-based transformation of the data. The decomposition transform used is the singular value decomposition (SVD). The SVD of a matrix A is a decomposition A= USV' in which S is a nonnegative diagonal matrix and U and V are orthogonal matrices. We show how to use the orthogonal matrices in the SVD as a vessel in which to embed information. Several challenges were presented in order to accomplish this, and we give effective information-hiding using the SVD can be just as effective as using transform-based techniques. Furthermore, different problems arise when using the SVD than using a transform-based technique. We have applied the SVD to image data, but the technique can be formulated for other data types such as audio and video.

  10. Hemorrhage recurrence risk factors in cerebral amyloid angiopathy: Comparative analysis of the overall small vessel disease severity score versus individual neuroimaging markers.

    Science.gov (United States)

    Boulouis, Gregoire; Charidimou, Andreas; Pasi, Marco; Roongpiboonsopit, Duangnapa; Xiong, Li; Auriel, Eitan; van Etten, Ellis S; Martinez-Ramirez, Sergi; Ayres, Alison; Vashkevich, Anastasia; Schwab, Kristin M; Rosand, Jonathan; Goldstein, Joshua N; Gurol, M Edip; Greenberg, Steven M; Viswanathan, Anand

    2017-09-15

    An MRI-based score of total small vessel disease burden (CAA-SVD-Score) in cerebral amyloid angiopathy (CAA) has been demonstrated to correlate with severity of pathologic changes. Evidence suggests that CAA-related intracerebral hemorrhage (ICH) recurrence risk is associated with specific disease imaging manifestations rather than overall severity. We compared the correlation between the CAA-SVD-Score with the risk of recurrent CAA-related lobar ICH versus the predictive role of each of its components. Consecutive patients with CAA-related ICH from a single-center prospective cohort were analyzed. Radiological markers of CAA related SVD damage were quantified and categorized according to the CAA-SVD-Score (0-6 points). Subjects were followed prospectively for recurrent symptomatic ICH. Adjusted Cox proportional hazards models were used to investigate associations between the CAA-SVD-Score as well as each of the individual MRI signatures of CAA and the risk of recurrent ICH. In 229 CAA patients with ICH, a total of 56 recurrent ICH events occurred during a median follow-up of 2.8years [IQR 0.9-5.4years, 781 person-years). Higher CAA-SVD-Score (HR=1.26 per additional point, 95%CI [1.04-1.52], p=0.015) and older age were independently associated with higher ICH recurrence risk. Analysis of individual markers of CAA showed that CAA-SVD-Score findings were due to the independent effect of disseminated superficial siderosis (HR for disseminated cSS vs none: 2.89, 95%CI [1.47-5.5], p=0.002) and high degree of perivascular spaces enlargement (RR=3.50-95%CI [1.04-21], p=0.042). In lobar CAA-ICH patients, higher CAA-SVD-Score does predict recurrent ICH. Amongst individual elements of the score, superficial siderosis and dilated perivascular spaces are the only markers independently associated with ICH recurrence, contributing to the evidence for distinct CAA phenotypes singled out by neuro-imaging manifestations. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Vitamin D status and vascular dementia due to cerebral small vessel disease in the elderly Asian Indian population.

    Science.gov (United States)

    Prabhakar, Puttachandra; Chandra, Sadanandavalli Retnaswami; Supriya, Manjunath; Issac, Thomas Gregor; Prasad, Chandrajit; Christopher, Rita

    2015-12-15

    Vitamin D plays vital roles in human health and recent studies have shown its beneficial effect on brain functioning. The present study was designed to evaluate the association of vitamin D with vascular dementia (VaD) due to cerebral small vessel disease (SVD) in Asian Indian population. 140 VaD patients aged ≥ 60 years with neuroimaging evidence of SVD, and 132 age and gender-matched controls, were investigated. Vitamin D status was estimated by measuring serum 25-hydroxy vitamin D. Logistic regression model revealed that deficient levels of vitamin D (vitamin D deficiency and insufficiency (12-20 ng/ml), the odds were increased to 31.6-fold and 14.4-fold, respectively. However, in hypertensives with vitamin D sufficiency (>20 ng/ml), the odds of VaD were increased by 3.8-fold only. Pearson correlation showed that serum vitamin D was inversely associated with systolic and diastolic blood pressure (r=-0.401 and -0.411, pvitamin D-deficient subjects. Since the combined presence of hypertension and vitamin D deficiency increases the probability of developing VaD, screening for vitamin D status in addition to regular monitoring of blood pressure, could reduce the risk of VaD associated with cerebral SVD in the elderly Asian Indian subjects. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Impact of Strategically Located White Matter Hyperintensities on Cognition in Memory Clinic Patients with Small Vessel Disease.

    Science.gov (United States)

    Biesbroek, J Matthijs; Weaver, Nick A; Hilal, Saima; Kuijf, Hugo J; Ikram, Mohammad Kamran; Xu, Xin; Tan, Boon Yeow; Venketasubramanian, Narayanaswamy; Postma, Albert; Biessels, Geert Jan; Chen, Christopher P L H

    2016-01-01

    Studies on the impact of small vessel disease (SVD) on cognition generally focus on white matter hyperintensity (WMH) volume. The extent to which WMH location relates to cognitive performance has received less attention, but is likely to be functionally important. We examined the relation between WMH location and cognition in a memory clinic cohort of patients with sporadic SVD. A total of 167 patients with SVD were recruited from memory clinics. Assumption-free region of interest-based analyses based on major white matter tracts and voxel-wise analyses were used to determine the association between WMH location and executive functioning, visuomotor speed and memory. Region of interest-based analyses showed that WMHs located particularly within the anterior thalamic radiation and forceps minor were inversely associated with both executive functioning and visuomotor speed, independent of total WMH volume. Memory was significantly associated with WMH volume in the forceps minor, independent of total WMH volume. An independent assumption-free voxel-wise analysis identified strategic voxels in these same tracts. Region of interest-based analyses showed that WMH volume within the anterior thalamic radiation explained 6.8% of variance in executive functioning, compared to 3.9% for total WMH volume; WMH volume within the forceps minor explained 4.6% of variance in visuomotor speed and 4.2% of variance in memory, compared to 1.8% and 1.3% respectively for total WMH volume. Our findings identify the anterior thalamic radiation and forceps minor as strategic white matter tracts in which WMHs are most strongly associated with cognitive impairment in memory clinic patients with SVD. WMH volumes in individual tracts explained more variance in cognition than total WMH burden, emphasizing the importance of lesion location when addressing the functional consequences of WMHs.

  13. Accumulation of MRI markers of cerebral small vessel disease is associated with decreased cognitive function. A study in first-ever lacunar stroke and hypertensive patients.

    Directory of Open Access Journals (Sweden)

    Marjolein eHuijts

    2013-11-01

    Full Text Available Background – White matter lesions (WMLs, asymptomatic lacunar infarcts, brain microbleeds (BMBs and enlarged perivascular spaces (EPVS have been identified as silent lesions due to cerebral small vessel disease (cSVD. All these markers have been individually linked to cognitive functioning, but are also strongly correlated with each other. The combined effect of these markers on cognitive function has never been studied and would possibly provide more useful information on the effect on cognitive function. Methods – Brain MRI and extensive neuropsychological assessment were performed in 189 patients at risk for cSVD (112 hypertensive patients and 77 first-ever lacunar stroke patients. We rated the presence of any asymptomatic lacunar infarct, extensive WMLs, any deep BMB, and moderate to extensive EPVS in the basal ganglia. The presence of each marker was summed to an ordinal score between 0 and 4. Associations with domains of cognitive function (memory, executive function, information processing speed and overall cognition were analyzed with correlation analyses. Results – Correlation analyses revealed significant associations between accumulating cSVD burden and decreased performance on all cognitive domains (all p≤.001. Results remained significant for information processing speed (r=-.181, p=.013 and overall cognition (r=-.178, p=.017, after correction for age and sex. Testing of trend using linear regression analyses revealed the same results. Discussion – We tested a new approach to capture total brain damage resulting from cSVD and found that accumulation of MRI burden of cSVD is associated with decreased performance on tests of information processing speed and overall cognition, implying that accumulating brain damage is accompanied by worse cognitive functioning.

  14. Quantification of the extent and severity of myocardial ischemia in single-vessel disease using stress-redistribution thallium-201 single-photon emission computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Prigent, F.; Maddahi, J.; Garcia, E.; VanTrain, K.; Friedman, J.; Bietendorf, J.; Swan, H.J.C.; Waxman, A.; Berman, D.

    1984-01-01

    Single-vessel coronary artery (CA) disease (SVD) is not uniformly benign: long-term prognosis is likely to be related to the extent (E) and severity (S) of myocardial ischemia (isch). To assess the ability of stress thalium-201 (Tl) single photon emission computerized tomography (SPECT) to quantify E and S of isch, the authors studied 15 patients (pts) without myocardial infarction who had SVD (8 LAD, 4 RCA, and 3 LCX). SPECT cuts were analyzed using maximum count circumferential profiles (CPs) which were compared with previously established normal (nl) limits derived from 20 nl pts. E of isch was defined as the % of the CP points falling below nl, S and depth (D) of ischemia respectively expressed the total and the mean % by which the abnormal points fell below normal limits. Although all pts had SVD, the range of E, S and D of isch was wide (0 to 48% and 0 to 38% and 0 to 20% respectively). CA scores (CS) were derived using a 15-point system accounting for the distribution of the diseased CA, location, and degree of stenosis, and collateral supply. CS varied from 1.2 to 8. E and S significantly correlated with CS (r=.74,p=.001, and r=.78, p=.000, respectively). The 6 pts with a D less than or equal to .1 had 75% CA stenosis whereas 5 of the 9 pts with D <.1 had only 50-75% stenosis. Thus, the authors conclude that: 1) pts with SVD have highly differing degrees of isch; 2) E, S and D scores from Tl SPECT correlate favorably with the angiographic extent and severity of disease; and 3) SPECT offers potential for quantification of the magnitude of isch and may become a useful, noninvasive prognostic indicator.

  15. Hypercholesterolemia induced cerebral small vessel disease.

    Science.gov (United States)

    Kraft, Peter; Schuhmann, Michael K; Garz, Cornelia; Jandke, Solveig; Urlaub, Daniela; Mencl, Stine; Zernecke, Alma; Heinze, Hans-Jochen; Carare, Roxana O; Kleinschnitz, Christoph; Schreiber, Stefanie

    2017-01-01

    While hypercholesterolemia plays a causative role for the development of ischemic stroke in large vessels, its significance for cerebral small vessel disease (CSVD) remains unclear. We thus aimed to understand the detailed relationship between hypercholesterolemia and CSVD using the well described Ldlr-/- mouse model. We used Ldlr-/- mice (n = 16) and wild-type (WT) mice (n = 15) at the age of 6 and 12 months. Ldlr-/- mice develop high plasma cholesterol levels following a high fat diet. We analyzed cerebral capillaries and arterioles for intravascular erythrocyte accumulations, thrombotic vessel occlusions, blood-brain barrier (BBB) dysfunction and microbleeds. We found a significant increase in the number of erythrocyte stases in 6 months old Ldlr-/- mice compared to all other groups (P hypercholesterolemia is related to a thrombotic CSVD phenotype, which is different from hypertension-related CSVD that associates with a hemorrhagic CSVD phenotype. Our data demonstrate a relationship between hypercholesterolemia and the development of CSVD. Ldlr-/- mice appear to be an adequate animal model for research into CSVD.

  16. Qualitatively Assessing Randomness in SVD Results

    Science.gov (United States)

    Lamb, K. W.; Miller, W. P.; Kalra, A.; Anderson, S.; Rodriguez, A.

    2012-12-01

    Singular Value Decomposition (SVD) is a powerful tool for identifying regions of significant co-variability between two spatially distributed datasets. SVD has been widely used in atmospheric research to define relationships between sea surface temperatures, geopotential height, wind, precipitation and streamflow data for myriad regions across the globe. A typical application for SVD is to identify leading climate drivers (as observed in the wind or pressure data) for a particular hydrologic response variable such as precipitation, streamflow, or soil moisture. One can also investigate the lagged relationship between a climate variable and the hydrologic response variable using SVD. When performing these studies it is important to limit the spatial bounds of the climate variable to reduce the chance of random co-variance relationships being identified. On the other hand, a climate region that is too small may ignore climate signals which have more than a statistical relationship to a hydrologic response variable. The proposed research seeks to identify a qualitative method of identifying random co-variability relationships between two data sets. The research identifies the heterogeneous correlation maps from several past results and compares these results with correlation maps produced using purely random and quasi-random climate data. The comparison identifies a methodology to determine if a particular region on a correlation map may be explained by a physical mechanism or is simply statistical chance.

  17. A High Performance QDWH-SVD Solver using Hardware Accelerators

    KAUST Repository

    Sukkari, Dalal E.; Ltaief, Hatem; Keyes, David E.

    2015-01-01

    few digits of accuracy, compared to the full double precision floating point arithmetic. We further leverage the single GPU QDWH-SVD implementation by introducing the first multi-GPU SVD solver to study the scalability of the QDWH-SVD framework.

  18. Clinical manifestations of small vessel disease

    NARCIS (Netherlands)

    Kooistra, M.

    2014-01-01

    Cardiovascular disease is a major health problem worldwide. However, the mortality risk in patients with cardiovascular disease has decreased due to early detection of the disease and improved treatment possibilities. The downside of increased survival rates are higher rates of long-term functional

  19. Note on Symplectic SVD-Like Decomposition

    Directory of Open Access Journals (Sweden)

    AGOUJIL Said

    2016-02-01

    Full Text Available The aim of this study was to introduce a constructive method to compute a symplectic singular value decomposition (SVD-like decomposition of a 2n-by-m rectangular real matrix A, based on symplectic refectors.This approach used a canonical Schur form of skew-symmetric matrix and it allowed us to compute eigenvalues for the structured matrices as Hamiltonian matrix JAA^T.

  20. Diseases of the heart and main vessels

    International Nuclear Information System (INIS)

    Kiseleva, I.P.; Ivanitskij, A.V.

    1988-01-01

    The problems of roentgenoanatomy of children and adolescent heart are considered. Various methods of roentgenological examinations in diagnosis of cardo-vascular diseases (roentgenoscopy, roentgenography, tomography, roentgenokymography) are described. A scheme of data study of roentgenolocial examinations is given. Roentgenograms of children heart with various congenital and acquired heart diseases, as well as myocarditis, pericarditis, endocardium fibroelastosis are presented

  1. Hereditary cerebral small vessel disease and stroke

    DEFF Research Database (Denmark)

    Søndergaard, Christian Baastrup; Nielsen, Jørgen Erik; Hansen, Christine Krarup

    2017-01-01

    disturbances. Some also present with extra-cerebral manifestations such as microangiopathy of the eyes and kidneys. Many present with clinically recognizable syndromes. Investigations include a thorough family medical history, medical history, neurological examination, neuroimaging, often supplemented...... is important. Enzyme replacement therapy is possible in Fabry disease, but treatment options remain overall very limited....

  2. Large vessel involvement by IgG4-related disease

    Science.gov (United States)

    Perugino, Cory A.; Wallace, Zachary S.; Meyersohn, Nandini; Oliveira, George; Stone, James R.; Stone, John H.

    2016-01-01

    Abstract Objectives: IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs and lead to tumefactive, tissue-destructive lesions. Reports have described inflammatory aortitis and periaortitis, the latter in the setting of retroperitoneal fibrosis (RPF), but have not distinguished adequately between these 2 manifestations. The frequency, radiologic features, and response of vascular complications to B cell depletion remain poorly defined. We describe the clinical features, radiology findings, and treatment response in a cohort of 36 patients with IgG4-RD affecting large blood vessels. Methods: Clinical records of all patients diagnosed with IgG4-RD in our center were reviewed. All radiologic studies were reviewed. We distinguished between primary large blood vessel inflammation and secondary vascular involvement. Primary involvement was defined as inflammation in the blood vessel wall as a principal focus of disease. Secondary vascular involvement was defined as disease caused by the effects of adjacent inflammation on the blood vessel wall. Results: Of the 160 IgG4-RD patients in this cohort, 36 (22.5%) had large-vessel involvement. The mean age at disease onset of the patients with large-vessel IgG4-RD was 54.6 years. Twenty-eight patients (78%) were male and 8 (22%) were female. Thirteen patients (36%) had primary IgG4-related vasculitis and aortitis with aneurysm formation comprised the most common manifestation. This affected 5.6% of the entire IgG4-RD cohort and was observed in the thoracic aorta in 8 patients, the abdominal aorta in 4, and both the thoracic and abdominal aorta in 3. Three of these aneurysms were complicated by aortic dissection or contained perforation. Periaortitis secondary to RPF accounted for 27 of 29 patients (93%) of secondary vascular involvement by IgG4-RD. Only 5 patients demonstrated evidence of both primary and secondary blood vessel involvement. Of those treated with

  3. Machine Learning for Quantification of Small Vessel Disease Imaging Biomarkers

    NARCIS (Netherlands)

    Ghafoorian, M.

    2018-01-01

    This thesis is devoted to developing fully automated methods for quantification of small vessel disease imaging bio-markers, namely WMHs and lacunes, using vari- ous machine learning/deep learning and computer vision techniques. The rest of the thesis is organized as follows: Chapter 2 describes

  4. Trigger Timing Module for SVD2 upgrade at Belle

    International Nuclear Information System (INIS)

    Chang, M.C.; Gao, Z.W.; Guo, Y.N.; Kawasaki, T.; Ueno, K.; Velikzhanin, Y.S.

    2003-01-01

    We have developed a Trigger Timing Module (TTM2) for the control and readout electronics (CORE) of the upgraded Silicon Vertex Detector (SVD2) for use in the BELLE experiment. Eleven Trigger Timing Modules located at one VME-crate provide timing and strobe signals for the SVD2 CORE electronics and make communication between SVD2 and Global Decision Logic of the BELLE data acquisition system. The main motivation to make a new TTM design is to avoid glitches

  5. Impact of Chronic Rheumatic Valve Diseases on Large Vessels.

    Science.gov (United States)

    Altunbas, Gokhan; Yuce, Murat; Ozer, Hasan O; Davutoglu, Vedat; Ercan, Suleyman; Kizilkan, Nese; Bilici, Muhammet

    2016-01-01

    BACKGROUND AND AIM OF STUDY: Rheumatic valvular heart disease, which remains a common health problem in developing countries, has numerous consequences on the heart chambers and circulation. The study aim was to investigate the effects of chronic rheumatic valve disease on the diameters of the descending aorta (DA) and inferior vena cava (IVC). METHODS: A total of 88 patients with echocardiographically documented rheumatic valvular heart disease and 112 healthy controls were enrolled into the study. All patients underwent detailed echocardiographic examinations, while their height and body weight were recorded and adjusted to their body surface area. RESULTS: The most common involvement was mitral valve disease, followed by aortic valve disease and tricuspid valve disease. The mean diameter of the DA (indexed to BSA) was 1.79 ± 0.49 cm for patients and 1.53 ± 0.41 for controls (p Rheumatic valve disease, especially mitral stenosis, was closely related to remodeling of the great vessels.

  6. Characterising the grey matter correlates of leukoaraiosis in cerebral small vessel disease

    Directory of Open Access Journals (Sweden)

    Christian Lambert

    2015-01-01

    We demonstrate that SVD severity is associated with regional cortical thinning. Furthermore a quantitative measure of SVD severity (WMH volume can be predicted from grey matter measures, supporting an association between white and grey matter damage. The pattern of cortical thinning and volumetric decline is distinctive for SVD severity compared to ageing. These results, taken together, suggest that there is a phenotypic pattern of atrophy associated with SVD severity.

  7. Dense Deposit Disease Mimicking a Renal Small Vessel Vasculitis

    Science.gov (United States)

    Singh, Lavleen; Bhardwaj, Swati; Sinha, Aditi; Bagga, Arvind; Dinda, Amit

    2016-01-01

    Dense deposit disease is caused by fluid-phase dysregulation of the alternative complement pathway and frequently deviates from the classic membranoproliferative pattern of injury on light microscopy. Other patterns of injury described for dense deposit disease include mesangioproliferative, acute proliferative/exudative, and crescentic GN. Regardless of the histologic pattern, C3 glomerulopathy, which includes dense deposit disease and C3 GN, is defined by immunofluorescence intensity of C3c two or more orders of magnitude greater than any other immune reactant (on a 0–3 scale). Ultrastructural appearances distinguish dense deposit disease and C3 GN. Focal and segmental necrotizing glomerular lesions with crescents, mimicking a small vessel vasculitis such as ANCA-associated GN, are a very rare manifestation of dense deposit disease. We describe our experience with this unusual histologic presentation and distinct clinical course of dense deposit disease, discuss the pitfalls in diagnosis, examine differential diagnoses, and review the relevant literature. PMID:26361799

  8. Inherited neurovascular diseases affecting cerebral blood vessels and smooth muscle.

    Science.gov (United States)

    Sam, Christine; Li, Fei-Feng; Liu, Shu-Lin

    2015-10-01

    Neurovascular diseases are among the leading causes of mortality and permanent disability due to stroke, aneurysm, and other cardiovascular complications. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and Marfan syndrome are two neurovascular disorders that affect smooth muscle cells through accumulation of granule and osmiophilic materials and defective elastic fiber formations respectively. Moyamoya disease, hereditary hemorrhagic telangiectasia (HHT), microcephalic osteodysplastic primordial dwarfism type II (MOPD II), and Fabry's disease are disorders that affect the endothelium cells of blood vessels through occlusion or abnormal development. While much research has been done on mapping out mutations in these diseases, the exact mechanisms are still largely unknown. This paper briefly introduces the pathogenesis, genetics, clinical symptoms, and current methods of treatment of the diseases in the hope that it can help us better understand the mechanism of these diseases and work on ways to develop better diagnosis and treatment.

  9. Water quality assessment using SVD-based principal component ...

    African Journals Online (AJOL)

    SVD) of hydrological data was tested for water quality assessment. Using two case studies of waste- and drinking water, PCA via SVD was able to find latent variables which explain 80.8% and 83.7% of the variance, respectively. By means of ...

  10. Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease

    NARCIS (Netherlands)

    Guio, F. De; Jouvent, E.; Biessels, G.J.; Black, S.E.; Brayne, C.; Chen, C.; Cordonnier, C.; Leeuw, F.E. de; Dichgans, M.; Doubal, F.; Duering, M.; Dufouil, C.; Duzel, E.; Fazekas, F.; Hachinski, V.; Ikram, M.A.; Linn, J.; Matthews, P.M.; Mazoyer, B.; Mok, V.; Norrving, B.; O'Brien, J.T.; Pantoni, L.; Ropele, S.; Sachdev, P.; Schmidt, R.; Seshadri, S.; Smith, E.E.; Sposato, L.A.; Stephan, B.; Swartz, R.H.; Tzourio, C.; Buchem, M. van; Lugt, A. van der; Oostenbrugge, R.; Vernooij, M.W.; Viswanathan, A.; Werring, D.; Wollenweber, F.; Wardlaw, J.M.; Chabriat, H.

    2016-01-01

    Brain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility of these

  11. Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease

    NARCIS (Netherlands)

    De Guio, F. (François); Jouvent, E. (Eric); G.J. Biessels (Geert Jan); S.E. Black (Sandra); C. Brayne (Carol); C. Chen (Christopher); C. Cordonnier (Charlotte); H.F. de Leeuw (Frank); C. Kubisch (Christian); Doubal, F. (Fergus); Duering, M. (Marco); C. Dufouil (Carole); Duzel, E. (Emrah); F. Fazekas (Franz); V. Hachinski (Vladimir); M.K. Ikram (Kamran); J. Linn (Jennifer); P.M. Matthews (P.); B. Mazoyer (Bernard); Mok, V. (Vincent); B. Norrving (Bo); O'Brien, J.T. (John T.); Pantoni, L. (Leonardo); S. Ropele (Stefan); P.S. Sachdev (Perminder); R. Schmidt (Reinhold); S. Seshadri (Sudha); E.E. Smith (Eric); L.A. Sposato (Luciano A); B.C.M. Stephan; Swartz, R.H. (Richard H.); C. Tzourio (Christophe); M.A. van Buchem (Mark); A. van der Lugt (Aad); R.J. van Oostenbrugge (Robert); M.W. Vernooij (Meike); Viswanathan, A. (Anand); D.J. Werring (David); Wollenweber, F. (Frank); J.M. Wardlaw (J.); Chabriat, H. (Hugues)

    2016-01-01

    textabstractBrain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility

  12. [Morphological pathology of vessels in granulomatosis with polyangiitis (Wegener's disease)].

    Science.gov (United States)

    Zerbino, D D; Zimba, E A

    2015-01-01

    to investigate the incidence of injuries in different vascular beds and the morphopathological changes in vessels in granulomatosis with polyangiitis. The morphopathological features of vascular injuries were investigated in 11 dead patients aged 16--74 years with granulomatosis with polyangiitis. Proliferative and destructive angiitis with predominant involvement of microcirculatory vessels and with development of necrosis-prone granulomas in their walls and perivascularly was established to underlie the clinical manifestations of granulomatosis with polyangiitis. The most typical localization of the pathologic process is the vessels of the upper respiratory tract, lungs, and kidneys. Cardiopulmonary and renal failures are causes of death in the majority of cases. It should be noted that the vessels of the heart, liver, and gastrointestinal tract are frequently involved in the pathological process. Vascular changes in these organs determine the clinical features of granulomatosis with polyangiitis and lead to a number of fatal complications. Granulomatosis with polyangiitis is a systemic disease with polymorphism of clinical manifestations, which requires in-depth analysis based on current precision patient examination methods, including a histopathological study.

  13. Molecular magnetic resonance imaging of atherosclerotic vessel wall disease

    Energy Technology Data Exchange (ETDEWEB)

    Noerenberg, Dominik [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); University of Munich - Grosshadern, Department of Clinical Radiology, Munich (Germany); Ebersberger, Hans U. [Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Diederichs, Gerd; Hamm, Bernd [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); Botnar, Rene M. [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Makowski, Marcus R. [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

    2016-03-15

    Molecular imaging aims to improve the identification and characterization of pathological processes in vivo by visualizing the underlying biological mechanisms. Molecular imaging techniques are increasingly used to assess vascular inflammation, remodeling, cell migration, angioneogenesis and apoptosis. In cardiovascular diseases, molecular magnetic resonance imaging (MRI) offers new insights into the in vivo biology of pathological vessel wall processes of the coronary and carotid arteries and the aorta. This includes detection of early vascular changes preceding plaque development, visualization of unstable plaques and assessment of response to therapy. The current review focuses on recent developments in the field of molecular MRI to characterise different stages of atherosclerotic vessel wall disease. A variety of molecular MR-probes have been developed to improve the non-invasive detection and characterization of atherosclerotic plaques. Specifically targeted molecular probes allow for the visualization of key biological steps in the cascade leading to the development of arterial vessel wall lesions. Early detection of processes which lead to the development of atherosclerosis and the identification of vulnerable atherosclerotic plaques may enable the early assessment of response to therapy, improve therapy planning, foster the prevention of cardiovascular events and may open the door for the development of patient-specific treatment strategies. (orig.)

  14. Molecular magnetic resonance imaging of atherosclerotic vessel wall disease

    International Nuclear Information System (INIS)

    Noerenberg, Dominik; Ebersberger, Hans U.; Diederichs, Gerd; Hamm, Bernd; Botnar, Rene M.; Makowski, Marcus R.

    2016-01-01

    Molecular imaging aims to improve the identification and characterization of pathological processes in vivo by visualizing the underlying biological mechanisms. Molecular imaging techniques are increasingly used to assess vascular inflammation, remodeling, cell migration, angioneogenesis and apoptosis. In cardiovascular diseases, molecular magnetic resonance imaging (MRI) offers new insights into the in vivo biology of pathological vessel wall processes of the coronary and carotid arteries and the aorta. This includes detection of early vascular changes preceding plaque development, visualization of unstable plaques and assessment of response to therapy. The current review focuses on recent developments in the field of molecular MRI to characterise different stages of atherosclerotic vessel wall disease. A variety of molecular MR-probes have been developed to improve the non-invasive detection and characterization of atherosclerotic plaques. Specifically targeted molecular probes allow for the visualization of key biological steps in the cascade leading to the development of arterial vessel wall lesions. Early detection of processes which lead to the development of atherosclerosis and the identification of vulnerable atherosclerotic plaques may enable the early assessment of response to therapy, improve therapy planning, foster the prevention of cardiovascular events and may open the door for the development of patient-specific treatment strategies. (orig.)

  15. Small Vessel Cerebrovascular Disease: The Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Réza Behrouz

    2012-01-01

    Full Text Available Brain infarction due to small vessel cerebrovascular disease (SVCD—also known as small vessel infarct (SVI or “lacunar” stroke—accounts for 20% to 25% of all ischemic strokes. Historically, SVIs have been associated with a favorable short-term prognosis. However, studies over the years have demonstrated that SVCD/SVI is perhaps a more complex and less benign phenomenon than generally presumed. The currently employed diagnostic and therapeutic strategies are based upon historical and contemporary perceptions of SVCD/SVI. What is discovered in the future will unmask the true countenance of SVCD/SVI and help furnish more accurate prognostication schemes and effective treatments for this condition. This paper is an overview of SVCD/SVI with respect to the discoveries of the past, what is known now, and what will the ongoing investigations evince in the future.

  16. A High Performance QDWH-SVD Solver using Hardware Accelerators

    KAUST Repository

    Sukkari, Dalal E.

    2015-04-08

    This paper describes a new high performance implementation of the QR-based Dynamically Weighted Halley Singular Value Decomposition (QDWH-SVD) solver on multicore architecture enhanced with multiple GPUs. The standard QDWH-SVD algorithm was introduced by Nakatsukasa and Higham (SIAM SISC, 2013) and combines three successive computational stages: (1) the polar decomposition calculation of the original matrix using the QDWH algorithm, (2) the symmetric eigendecomposition of the resulting polar factor to obtain the singular values and the right singular vectors and (3) the matrix-matrix multiplication to get the associated left singular vectors. A comprehensive test suite highlights the numerical robustness of the QDWH-SVD solver. Although it performs up to two times more flops when computing all singular vectors compared to the standard SVD solver algorithm, our new high performance implementation on single GPU results in up to 3.8x improvements for asymptotic matrix sizes, compared to the equivalent routines from existing state-of-the-art open-source and commercial libraries. However, when only singular values are needed, QDWH-SVD is penalized by performing up to 14 times more flops. The singular value only implementation of QDWH-SVD on single GPU can still run up to 18% faster than the best existing equivalent routines. Integrating mixed precision techniques in the solver can additionally provide up to 40% improvement at the price of losing few digits of accuracy, compared to the full double precision floating point arithmetic. We further leverage the single GPU QDWH-SVD implementation by introducing the first multi-GPU SVD solver to study the scalability of the QDWH-SVD framework.

  17. SVD vs PCA: Comparison of Performance in an Imaging Spectrometer

    Directory of Open Access Journals (Sweden)

    Wilma Oblefias

    2004-12-01

    Full Text Available The calculation of basis spectra from a spectral library is an important prerequisite of any compact imaging spectrometer. In this paper, we compare the basis spectra computed by singular-value decomposition (SVD and principal component analysis (PCA in terms of estimation performance with respect to resolution, presence of noise, intensity variation, and quantization error. Results show that SVD is robust in intensity variation while PCA is not. However, PCA performs better with signals of low signal-to-noise ratio. No significant difference is seen between SVD and PCA in terms of resolution and quantization error.

  18. The Belle II SVD data readout system

    Energy Technology Data Exchange (ETDEWEB)

    Thalmeier, R., E-mail: Richard.Thalmeier@oeaw.ac.at [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Adamczyk, K. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Aihara, H. [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Angelini, C. [Dipartimento di Fisica, Universita’ di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Aziz, T.; Babu, V. [Tata Institute of Fundamental Research, Mumbai 400005 (India); Bacher, S. [H. Niewodniczanski Institute of Nuclear Physics, Krakow 31-342 (Poland); Bahinipati, S. [Indian Institute of Technology Bhubaneswar, Satya Nagar (India); Barberio, E.; Baroncelli, Ti.; Baroncelli, To. [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Basith, A.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Batignani, G. [Dipartimento di Fisica, Universita’ di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bauer, A. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Behera, P.K. [Indian Institute of Technology Madras, Chennai 600036 (India); Bergauer, T. [Institute of High Energy Physics, Austrian Academy of Sciences, 1050 Vienna (Austria); Bettarini, S. [Dipartimento di Fisica, Universita’ di Pisa, I-56127 Pisa (Italy); INFN Sezione di Pisa, I-56127 Pisa (Italy); Bhuyan, B. [Indian Institute of Technolog y Guwahati, Assam 781039 (India); Bilka, T. [Faculty of Mathematics and Physics, Charles University, 12116 Prague (Czech Republic); Bosi, F. [INFN Sezione di Pisa, I-56127 Pisa (Italy); and others

    2017-02-11

    The Belle II Experiment at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan, will explore the asymmetry between matter and antimatter and search for new physics beyond the standard model. 172 double-sided silicon strip detectors are arranged cylindrically in four layers around the collision point to be part of a system which measures the tracks of the collision products of electrons and positrons. A total of 1748 radiation-hard APV25 chips read out 128 silicon strips each and send the analog signals by time-division multiplexing out of the radiation zone to 48 Flash Analog Digital Converter Modules (FADC). Each of them applies processing to the data; for example, it uses a digital finite impulse response filter to compensate line signal distortions, and it extracts the peak timing and amplitude from a set of several data points for each hit, using a neural network. We present an overview of the SVD data readout system, along with front-end electronics, cabling, power supplies and data processing.

  19. LARGE VESSEL INVOLVEMENT IN BEHCET’S DISEASE

    Directory of Open Access Journals (Sweden)

    AR. Jamshidi F. Davatchi

    2004-08-01

    Full Text Available Large vessel involvement is one of the hallmarks of Behcet’s disease (BD but its prevalence varies widely due to ethnic variation or environmental factors. The aim of this study is to find the characteristics of vasculo-Behcet (VB in Iran. In a cohort of 4769 patients with BD, those with vascular involvement were selected. Different manifestations of disease were compared with the remaining group of patients. A confidence interval at 95% (CI was calculated for each item. Vascular involvement was seen in 409 cases (8.6%; CI, 0.8. Venous involvement was seen in 396 cases, deep vein thrombosis in 294 (6.2%; CI, 0.7, superficial phlebitis in 108 (2.3%; CI, 0.4 and large vein thrombosis in 45 (0.9%; CI, 0.3. Arterial involvement was seen in 28 patients (25 aneurysms and 4 thromboses. Thirteen patients showed both arterial and venous involvement. The mean age of the patients with VB was slightly higher (P<0.03, but the disease duration was significantly longer (P<0.0003. VB was more common in men. As the presenting sign, ocular lesions were less frequent in VB (P<0.0006, while skin lesions were over 2 times more common in these cases (P<0.000001. VB was associated with a higher frequency of genital aphthosis, skin involvement, joint manifestations, epididymitis, CNS lesions and GI involvement. The juvenile form was less common in VB (P<0.03. High ESR was more frequent in VB (P=0.000002, but the frequency of false positive VDRL, pathergy phenomenon, HLA-B5 or HLA-B27 showed no significant difference between the two groups. In Iranian patients with BD, vascular involvement is not common and large vessel involvement is rare. It may be sex-related, and is more common in well-established disease with multiple organ involvement and longer disease duration.

  20. Analytic robust stability analysis of SVD orbit feedback

    CERN Document Server

    Pfingstner, Jürgen

    2012-01-01

    Orbit feedback controllers are indispensable for the operation of modern particle accelerators. Many such controllers are based on the decoupling of the inputs and outputs of the system to be controlled with the help of the singular value decomposition (SVD controller). It is crucial to verify the stability of SVD controllers, also in the presence of mismatches between the used accelerator model and the real machine (robust stability problem). In this paper, analytical criteria for guaranteed stability margins of SVD orbit feedback systems for three different types of model mismatches are presented: scaling errors of actuators and BPMs (beam position monitors) and additive errors of the orbit response matrix. For the derivation of these criteria, techniques from robust control theory have been used, e.g the small gain theorem. The obtained criteria can be easily applied directly to other SVD orbit feedback systems. As an example, the criteria were applied to the orbit feedback system of the Compact Linear ...

  1. Clinical study on the value of combining neuropsychological tests with auditory event-related potential P300 for cognitive assessment in elderly patients with cerebral small vessel disease

    Directory of Open Access Journals (Sweden)

    Xiao-ling ZHAO

    2016-11-01

    Full Text Available Objective To investigate the value of combining neuropsychological tests with auditory event-related potential (ERP P300 for cognitive assessment in elderly patients with cerebral small vessel disease (cSVD.  Methods A total of 183 elderly patients with cSVD were enrolled in this study. They were divided into 3 groups according to brain MRI: lacunar infarct (LACI group (N = 62, white matter hyperintensity (WMH group (N = 60 and LACI + WMH group (N = 61. A total of 50 brain MRI normal persons were selected as control group. Montreal Cognitive Assessment (MoCA, Chinese version was used to evaluate the cognitive function, and the amplitude and latency of P300 were measured in each group.  Results Compared with control group, the MoCA total score in LACI, WMH and LACI + WMH groups were significantly lower (P = 0.042, 0.015, 0.000, and the score in LACI + WMH group was significantly lower than that in LACI and WMH groups (P = 0.001, 0.042. In the eight cognitive domains of MoCA scale, the visual space and executive function (P = 0.006, 0.041, 0.035, delayed memory (P = 0.006, 0.012, 0.048, language (P = 0.001, 0.032, 0.047 and calculation (P = 0.009, 0.001, 0.003 in LACI + WMH group were significantly lower than those in control, LACI and WMH groups. The delayed memory in LACI group was significantly lower than that in control group (P = 0.037. The delayed memory (P = 0.005 and language (P = 0.047 in WMH group were significantly lower than those in control group. Compared with control group, the amplitudes of P300 (P = 0.025, 0.033, 0.000 in LACI, WMH and LACI + WMH groups were significantly decreased, and the latencies (P = 0.018, 0.000, 0.000 were significantly prolonged. The amplitude of P300 in LACI + WMH group was significantly lower than that in LACI and WMH groups (P = 0.041, 0.018, and the latency was significantly prolonged (P = 0.000, 0.022.  Conclusions Elderly patients of cSVD all suffer from different degrees of cognitive impairment

  2. Image fusion via nonlocal sparse K-SVD dictionary learning.

    Science.gov (United States)

    Li, Ying; Li, Fangyi; Bai, Bendu; Shen, Qiang

    2016-03-01

    Image fusion aims to merge two or more images captured via various sensors of the same scene to construct a more informative image by integrating their details. Generally, such integration is achieved through the manipulation of the representations of the images concerned. Sparse representation plays an important role in the effective description of images, offering a great potential in a variety of image processing tasks, including image fusion. Supported by sparse representation, in this paper, an approach for image fusion by the use of a novel dictionary learning scheme is proposed. The nonlocal self-similarity property of the images is exploited, not only at the stage of learning the underlying description dictionary but during the process of image fusion. In particular, the property of nonlocal self-similarity is combined with the traditional sparse dictionary. This results in an improved learned dictionary, hereafter referred to as the nonlocal sparse K-SVD dictionary (where K-SVD stands for the K times singular value decomposition that is commonly used in the literature), and abbreviated to NL_SK_SVD. The performance of the NL_SK_SVD dictionary is applied for image fusion using simultaneous orthogonal matching pursuit. The proposed approach is evaluated with different types of images, and compared with a number of alternative image fusion techniques. The resultant superior fused images using the present approach demonstrates the efficacy of the NL_SK_SVD dictionary in sparse image representation.

  3. Associations Between Cerebral Small-Vessel Disease and Alzheimer Disease Pathology as Measured by Cerebrospinal Fluid Biomarkers

    NARCIS (Netherlands)

    Kester, M.I.; Goos, J.D.C.; Teunissen, C.E.; Benedictus, M.R.; Bouwman, F.H.; Wattjes, M.P.; Barkhof, F.; Scheltens, P.; van der Flier, W.M.

    2014-01-01

    IMPORTANCE: It remains unclear if and how associations between cerebral small-vessel disease and Alzheimer disease (AD) pathology lead to cognitive decline and dementia. OBJECTIVE: To determine associations between small-vessel disease and AD pathology. DESIGN, SETTING, AND PARTICIPANTS:

  4. White matters - The influence of cerebral small-vessel disease on depression, cognition and functioning

    NARCIS (Netherlands)

    Grool, A.M.

    2012-01-01

    Depression and cognitive impairment are highly prevalent in later life, and frequently co-occur. One of the possible mechanisms that may underlie both conditions is the presence of cerebral small-vessel disease. The presence of cerebral small-vessel disease is strongly associated with common

  5. New Collaborative Filtering Algorithms Based on SVD++ and Differential Privacy

    Directory of Open Access Journals (Sweden)

    Zhengzheng Xian

    2017-01-01

    Full Text Available Collaborative filtering technology has been widely used in the recommender system, and its implementation is supported by the large amount of real and reliable user data from the big-data era. However, with the increase of the users’ information-security awareness, these data are reduced or the quality of the data becomes worse. Singular Value Decomposition (SVD is one of the common matrix factorization methods used in collaborative filtering, which introduces the bias information of users and items and is realized by using algebraic feature extraction. The derivative model SVD++ of SVD achieves better predictive accuracy due to the addition of implicit feedback information. Differential privacy is defined very strictly and can be proved, which has become an effective measure to solve the problem of attackers indirectly deducing the personal privacy information by using background knowledge. In this paper, differential privacy is applied to the SVD++ model through three approaches: gradient perturbation, objective-function perturbation, and output perturbation. Through theoretical derivation and experimental verification, the new algorithms proposed can better protect the privacy of the original data on the basis of ensuring the predictive accuracy. In addition, an effective scheme is given that can measure the privacy protection strength and predictive accuracy, and a reasonable range for selection of the differential privacy parameter is provided.

  6. The clinical significance of brain microbleeds in patients with Alzheimer′s disease: Preliminary study

    Directory of Open Access Journals (Sweden)

    Jae-Hyeok Heo

    2016-01-01

    Full Text Available Background: Microbleeds (MBs are observed frequently in Alzheimer′s disease (AD and suggested to play a crucial role in the pathophysiology, but their clinical significance remains unclear. Materials and Methods: The study recruited 100 patients with AD who were diagnosed at the memory clinic in Seoul Medical Center in 2014. For each patient, baseline characteristics, neuropsychological tests, cerebrovascular risk factors, medial temporal lobe atrophy (MTLA, and severity of small vessel disease (SVD according to the existence of MBs were evaluated. Results: The prevalence of MBs in patients with AD was 33%. The percentage of male gender, the severity of SVD and MTLA were significantly increased in MB(+ group. The MB(+ group showed more severe MTLA and SVD than MB(− group. Conclusions: These results suggested that MBs might reflect the burden of amyloid and ischemic vascular pathology.

  7. Application of digital subtraction angiography in disease of large cardiac vessel

    Energy Technology Data Exchange (ETDEWEB)

    Arisawa, Jun; Sone, Shusuke; Morimoto, Shizuo; Ikezoe, Junpei; Higashibara, Tokuro; Hanayama, Masayuki

    1983-06-01

    Digital subtraction angiography (DSA) was performed in 31 cases of disease of large cardiac vessel. DSA was useful for the diagnosis of aortic aneurysm and malformation of large vessels, follow-up after A-C bypass operation and Blalock's shunt operation for tetralogy of Fallot and as an adjuvant modality in cardiac catheterization.

  8. Application of digital subtraction angiography in disease of large cardiac vessel

    International Nuclear Information System (INIS)

    Arisawa, Jun; Sone, Shusuke; Morimoto, Shizuo; Ikezoe, Junpei; Higashibara, Tokuro; Hanayama, Masayuki

    1983-01-01

    Digital subtraction angiography (DSA) was performed in 31 cases of disease of large cardiac vessel. DSA was useful for the diagnosis of aortic aneurysm and malformation of large vessels, follow-up after A-C bypass operation and Blalock's shunt operation for tetralogy of Fallot and as an adjuvant modality in cardiac catheterization. (Chiba, N.)

  9. Complete versus culprit-only revascularisation in ST elevation myocardial infarction with multi-vessel disease

    DEFF Research Database (Denmark)

    Bravo, Claudio A.; Hirji, Sameer A.; Bhatt, Deepak L.

    2017-01-01

    Background: Multi-vessel coronary disease in people with ST elevation myocardial infarction (STEMI) is common and is associated with worse prognosis after STEMI. Based on limited evidence, international guidelines recommend intervention on only the culprit vessel during STEMI. This, in turn, leaves...

  10. Platelet-vessel wall interaction in health and disease

    NARCIS (Netherlands)

    Löwenberg, E. C.; Meijers, J. C. M.; Levi, M. [=Marcel M.

    2010-01-01

    Upon vessel wall injury platelets rapidly adhere to the exposed subendothelial matrix which is mediated by several cellular receptors present on platelets or endothelial cells and various adhesive proteins such as von Willebrand factor, collagen and fibrinogen. Subsequent platelet activation results

  11. Loss of white matter integrity is associated with gait disorders in cerebral small vessel disease

    NARCIS (Netherlands)

    Laat, K.F. de; Tuladhar, A.M.; Norden, A.G.W. van; Norris, D.G.; Zwiers, M.P.; Leeuw, F.E. de

    2011-01-01

    Gait disturbances are common in the elderly. Cerebral small vessel disease, including white matter lesions and lacunars infarcts, is thought to disrupt white matter tracts that connect important motor regions, hence resulting in gait disturbances. Pathological studies have demonstrated abnormalities

  12. Genetics Home Reference: COL4A1-related brain small-vessel disease

    Science.gov (United States)

    ... hemorrhage Johns Hopkins Medicine Department of Neurology and Neurosurgery: Intracerebral Hemorrhage Johns Hopkins Medicine Department of Neurology and Neurosurgery: Stroke MalaCards: col4a1-related brain small-vessel disease ...

  13. New Collaborative Filtering Algorithms Based on SVD++ and Differential Privacy

    OpenAIRE

    Xian, Zhengzheng; Li, Qiliang; Li, Gai; Li, Lei

    2017-01-01

    Collaborative filtering technology has been widely used in the recommender system, and its implementation is supported by the large amount of real and reliable user data from the big-data era. However, with the increase of the users’ information-security awareness, these data are reduced or the quality of the data becomes worse. Singular Value Decomposition (SVD) is one of the common matrix factorization methods used in collaborative filtering, which introduces the bias information of users a...

  14. Detecting culprit vessel of coronary artery disease with SPECT 99Tcm-MIBI myocardial imaging

    International Nuclear Information System (INIS)

    Luan Zhaosheng; Zhou Wen; Peng Yong; Su Yuwen; Tian Jianhe; Gai lue; Sun Zhijun

    2002-01-01

    Objective: To assess the value of detecting culprit vessel of coronary artery disease (CAD) with SPECT 99 Tc m -MIBI myocardial imaging. Methods: Forty-six patients with CAD were studied. Every patients had multiple-vessel lesion showed by coronary arteriography and was treated by revascularization as percutaneous transluminal angioplasty (PTCA), coronary artery bypass graft (CABG) or laser holing. Exercise (EX), rest (RE) and intravenous infusion of nitroglycerine (NTG) SPECT 99 Tc m -MIBI myocardial imagings were performed before revascularization. Exercise and rest images revealed the myocardial ischemia. NTG images revealed myocardial viability. Culprit vessels were detected according to the defects showed by above mentioned images. The veracity of detected culprit vessels was tested with the outcome of the reperfusion therapy. Results: In this group, the coronary arteriography revealed 107 lesioned coronary arteries. Myocardial imaging detected 46 culprit vessels including 23 left anterior descending (LAD), 19 left circumflex coronary artery (LCX) and 4 right coronary artery (RCA). All 46 culprit vessels underwent revascularization and had nice outcome. The veracity of 99 Tc m -MIBI myocardial imaging detected culprit vessels was high according to patients' outcome. Conclusion: Exercise, rest and NTG 99 Tc m -MIBI myocardial imaging is a great method for detecting culprit vessels in multivessel coronary disease

  15. Using SVD on Clusters to Improve Precision of Interdocument Similarity Measure

    Directory of Open Access Journals (Sweden)

    Wen Zhang

    2016-01-01

    Full Text Available Recently, LSI (Latent Semantic Indexing based on SVD (Singular Value Decomposition is proposed to overcome the problems of polysemy and homonym in traditional lexical matching. However, it is usually criticized as with low discriminative power for representing documents although it has been validated as with good representative quality. In this paper, SVD on clusters is proposed to improve the discriminative power of LSI. The contribution of this paper is three manifolds. Firstly, we make a survey of existing linear algebra methods for LSI, including both SVD based methods and non-SVD based methods. Secondly, we propose SVD on clusters for LSI and theoretically explain that dimension expansion of document vectors and dimension projection using SVD are the two manipulations involved in SVD on clusters. Moreover, we develop updating processes to fold in new documents and terms in a decomposed matrix by SVD on clusters. Thirdly, two corpora, a Chinese corpus and an English corpus, are used to evaluate the performances of the proposed methods. Experiments demonstrate that, to some extent, SVD on clusters can improve the precision of interdocument similarity measure in comparison with other SVD based LSI methods.

  16. Guidelines versus reality: is coronary stent application in three-vessel disease standard or the exception?

    Science.gov (United States)

    Linder, Roland; Zeidler, J; Verheyen, F; von der Schulenburg, J-M Graf; Haverich, A; Schilling, T

    2017-08-19

    The national guidelines for treatment of chronic coronary heart disease (CHD) recommend surgical coronary aortic bypass grafting (CABG) rather than percutaneous coronary intervention (PCI) for patients with a coronary three-vessel disease. The epidemiology of three-vessel CHD and data about the application of different revascularisation strategies raise suspicion of deviation from the guidelines in the treatment of those patients. Claims data containing records of almost 10 million patients of the largest German statutory health insurance fund (Techniker Krankenkasse) were utilised to measure adherence to the guidelines for treatment of groups of patients with one-, two-, and three-vessel CHD, respectively. The impact of age, sex, and comorbidity on each patient's revascularisation procedure was investigated as well. There was no significant difference in the rate of PCI between the groups. In conclusion, the hypothesis that patients with a coronary three-vessel disease are not always treated according to the recommendations of the national guidelines could not be disproved by this study. Finally, the results of this study suggest that the best revascularisation strategy for each patient with two- and three-vessel disease should be decided upon by an interdisciplinary discussion between both cardiologists and cardiac surgeons.

  17. Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS)

    DEFF Research Database (Denmark)

    Pauls, Mathilde M H; Clarke, Natasha; Trippier, Sarah

    2017-01-01

    vascular territories. The aim of this trial is to test the hypothesis that tadalafil increases cerebral blood flow in older people with small vessel disease. METHODS/DESIGN: Perfusion by Arterial Spin labelling following Single dose Tadalafil In Small vessel disease (PASTIS) is a phase II randomised double......-blind crossover trial. In two visits, 7-30 days apart, participants undergo arterial spin labelling to measure cerebral blood flow and a battery of cognitive tests, pre- and post-dosing with oral tadalafil (20 mg) or placebo. SAMPLE SIZE: 54 participants are required to detect a 15% increase in cerebral blood...

  18. Alterations of the cerebral cortex in sporadic small vessel disease: A systematic review of in vivo MRI data.

    Science.gov (United States)

    Peres, Roxane; De Guio, François; Chabriat, Hugues; Jouvent, Eric

    2016-04-01

    Cerebral small vessel diseases of the brain are a major determinant of cognitive impairment in the elderly. In small vessel diseases, the most easily identifiable lesions, both at post-mortem evaluation and magnetic resonance imaging, lie in subcortical areas. However, recent results obtained post-mortem, particularly in severe cases, have highlighted the burden of cortex lesions such as microinfarcts and diffuse neuronal loss. The recent development of image post-processing methods allows now assessing in vivo multiple aspects of the cerebral cortex. This systematic review aimed to analyze in vivo magnetic resonance imaging studies evaluating cortex alterations at different stages of small vessel diseases. Studies assessing the relationships between small vessel disease magnetic resonance imaging markers obtained at the subcortical level and cortex estimates were reviewed both in community-dwelling elderly and in patients with symptomatic small vessel diseases. Thereafter, studies analyzing cortex estimates in small vessel disease patients compared with healthy subjects were evaluated. The results support that important cortex alterations develop along the course of small vessel diseases independently of concomitant neurodegenerative processes. Easy detection and quantification of cortex changes in small vessel diseases as well as understanding their underlying mechanisms are challenging tasks for better understanding cognitive decline in small vessel diseases. © The Author(s) 2016.

  19. Embolization of Collateral Vessels Using Mechanically Detachable Coils in Young Children with Congenital Heart Disease

    International Nuclear Information System (INIS)

    Sato, Y.; Ogino, H.; Hara, M.; Satake, M.; Oshima, H.; Banno, T.; Mizuno, K.; Mishima, A.; Shibamoto, Y.

    2003-01-01

    Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days-3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management

  20. Collateral vessels in moyamoya disease : comparison of MR and MRA with conventional angiography

    International Nuclear Information System (INIS)

    Shim, Joo Eun; Yoon, Dae Young; Yi, Jeong Geun; Kim, Ho Chul; Choi, Chul Sun; Bae, Sang Hoon

    1998-01-01

    To determine the value of magnetic resonance imaging (MR) and magnetic resonance angiography (MRA) in assessing collateral vessels of moyamoya disease. Twenty-four patients with moyamoya disease who underwent MR, 3D TOF MRA, and conventional angiography participated in this study. Two radiologists working independently and with no knowledge of the angiographic findings, interpreted the MR and MRA images. To determine the presence of parenchymal and leptomeningeal collaterals (48 hemispheres) and transdural collaterals (38 hemispheres in 19 patients were depicted by angiography of the external carotid), the findings were compared with those of angiography. Parenchymal, leptomeningeal, and transdural collaterals were depicted by conventional angiography in 34 (71%), 32 (67%), and 11 (29%) hemispheres respectively. The sensitivity and specificity of MR/MRA for collateral vessels were 79.1/88.1 % for parenchymal collaterals, 72.1/88.1 % for leptomeningeal collaterals, and 0.1/18.1 % for transdural collaterals, respectively. Respective sensitivity and specificity of MR/MRA were 88.94/94.1% for leptomeningeal collaterals, and 18.93/55.1 % for transdural collaterals, when the prominent posterior cerebral and external carotid artery were regarded as secondary signs of leptomeningeal and transdural collateral vessels. In moyamoya disease, MR and MRA are useful imaging modalities for the assessment of collateral vessels. The prominent posterior cerebral artery and external carotid artery can be useful secondary signs of leptomeningeal and transdural collateral vessels. (author). 18 refs., 2 figs

  1. Assessment of disease activity in large-vessel vasculitis

    DEFF Research Database (Denmark)

    Aydin, Sibel Z.; Direskeneli, Haner; Merkel, Peter A.

    2017-01-01

    Objective. To arrive at consensus for candidate outcomes for disease activity assessment in largevessel vasculitis (LVV) in clinical trials. Methods.A Delphi survey including 99 items was circulated among international experts for 3 rounds. Results. Fifty-seven items were accepted for both giant ...

  2. Perivascular spaces, glymphatic dysfunction, and small vessel disease

    DEFF Research Database (Denmark)

    Mestre, Humberto; Kostrikov, Serhii; Mehta, Rupal I.

    2017-01-01

    discovered glymphatic system provides a new perspective to potentially address these gaps. This work provides a comprehensive review of the known factors that regulate glymphatic function and the disease mechanisms underlying glymphatic impairment emphasizing the role that aquaporin-4 (AQP4)-lined...

  3. Lymph vessels: the forgotten second circulation in health and disease

    NARCIS (Netherlands)

    Adamczyk, Lukasz A.; Gordon, Kristiana; Kholová, Ivana; Meijer-Jorna, Lorine B.; Telinius, Niklas; Gallagher, Patrick J.; van der Wal, Allard C.; Baandrup, Ulrik

    2016-01-01

    The lymphatic circulation is still a somewhat forgotten part of the circulatory system. Despite this, novel insights in lymph angiogenesis in health and disease, application of immune markers for lymphatic growth and differentiation and also the introduction of new imaging techniques to visualize

  4. Exercise-induced ST-T changes and severity of myocardial ischemia in single-vessel coronary artery disease

    International Nuclear Information System (INIS)

    Shimonagata, Tsuyoshi; Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Takamiya, Makoto; Sumiyoshi, Tetsuya; Saito, Muneyasu.

    1986-01-01

    The purpose of this study was to evaluate how exercise-induced ST-T changes reflect the severity of myocardial ischemia in 66 patients with singlevessel disease (SVD) who underwent stress thallium scans. Quantitative assessment of myocardial ischemia was performed with thallium ischemic score (TIS) derived from circumferential profile analysis. Circumferential profiles of the initial and 4 hr redistribution myocardial image were generated for each of three views (ANT, LAO 45, LAO 70) and TIS was obtained as the average of the area between the initial and 4 hr redistribution profile for each view. In 66 patients with SVD, TIS were compared with coronary angiographic findings. TIS was correlated well with the severity of coronary artery stenosis. In addition, TIS was also correlated well with lung thallium uptake in 46 LAD disease. Therefore, these data proved that TIS was useful for the evaluation of the severity of myocardial ischemia. In 46 LAD disease, TIS, being as the indicator of the severity of myocardial ischemia, was compared precisely with results of stress electrocardiograms to evaluate how exercise-induced ST-T changes reflect the severity of myocardial ischemia. Patients with negative U wave had the highest mean TIS and those with horizontal or down sloping ST depression of 1.0 mm or more had higher mean TIS than those with slow upsloping ST depression of 1.5 mm or more, but there were no significant differences between these groups and those without ST-T change and the mean TIS was not different significantly between V 2-6 ST depression group and V 2-6 , II, III, a V F ST depression group. In conclusion, these results indicated that exercise-induced ST-T changes reflect the severity of myocardial ischemia in some degree but also has a limitation in evaluation of the severity of myocardial ischemia. (author)

  5. Strategic lacunes and their relationship to cognitive impairment in cerebral small vessel disease

    Directory of Open Access Journals (Sweden)

    Philip Benjamin

    2014-01-01

    Conclusion: Lacunes are important predictors of cognitive impairment in SVD. We highlight the importance of spatial distribution, particularly of anteromedial thalamic lacunes which are associated with impaired information processing speed and may mediate cognitive impairment via disruption of connectivity to the prefrontal cortex.

  6. Clinical and magnetic resonance observations in cerebral small-vessel disease

    NARCIS (Netherlands)

    Kwa, V.I.H.

    1999-01-01

    The study reported in this thesis tried to address the following questions: 1. Is it possible to detect genetic factors and vascular risk factors that are specifically associated with the development of small- or large-vessel disease? 2. Are the different clinical and MRI manifestations, that are

  7. Role of thalamic diffusion for disease differentiation between multiple sclerosis and ischemic cerebral small vessel disease

    International Nuclear Information System (INIS)

    Oeztoprak, Bilge; Oeztoprak, Ibrahim; Salk, Ismail; Topalkara, Kamil; Erkoc, Mustafa F.

    2015-01-01

    Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) both harbor multiple, T2-hyperintense white matter lesions on conventional magnetic resonance imaging (MRI).We aimed to determine the microstructural changes via diffusion-weighted imaging (DWI) in normal appearing thalami. We hypothesized that the apparent diffusion coefficient (ADC) values would be different in CSVD and MS, since the extent of arterial involvement is different in these two diseases. DWI was performed for 50 patients with CSVD and 35 patients with MS along with gender- and age-matched controls whose conventional MRI revealed normal findings. DWI was done with 1.5 Tesla MR devices using echo planar imaging (EPI) for b = 0, 1000 s/mm 2 . ADC values were obtained from the thalami which appeared normal on T2-weighted and FLAIR images. Standard oval regions of interest (ROIs) of 0.5 cm 2 which were oriented parallel to the long axis of the thalamus were used for this purpose. The mean ADC value of the thalamus was (0.99 ± 0.16) x 10 -3 mm 2 /s in patients with CSVD, whereas the mean ADC value was (0.78 ± 0.06) x 10 -3 mm 2 /s in the control group. The mean ADC value was significantly higher in patients with CSVD compared to the controls (p < 0.001). The mean ADC values of the thalamus were (0.78 ± 0.08) x 10 -3 mm 2 /s in MS patients, and (0.75 ± 0.08) x 10 -3 mm 2 /s in the control group, which are not significantly different (p > 0.05). Our study revealed a difference in the diffusion of the thalami between CSVD and MS. DWI may aid in the radiological disease differentiation. (orig.)

  8. Role of thalamic diffusion for disease differentiation between multiple sclerosis and ischemic cerebral small vessel disease

    Energy Technology Data Exchange (ETDEWEB)

    Oeztoprak, Bilge; Oeztoprak, Ibrahim; Salk, Ismail [Cumhuriyet University School of Medicine, Department of Radiology, Sivas (Turkey); Topalkara, Kamil [Bayindir Hospital, Department of Neurology, Ankara (Turkey); Erkoc, Mustafa F. [Bozok University School of Medicine, Department of Radiology, Yozgat (Turkey)

    2015-04-01

    Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) both harbor multiple, T2-hyperintense white matter lesions on conventional magnetic resonance imaging (MRI).We aimed to determine the microstructural changes via diffusion-weighted imaging (DWI) in normal appearing thalami. We hypothesized that the apparent diffusion coefficient (ADC) values would be different in CSVD and MS, since the extent of arterial involvement is different in these two diseases. DWI was performed for 50 patients with CSVD and 35 patients with MS along with gender- and age-matched controls whose conventional MRI revealed normal findings. DWI was done with 1.5 Tesla MR devices using echo planar imaging (EPI) for b = 0, 1000 s/mm{sup 2}. ADC values were obtained from the thalami which appeared normal on T2-weighted and FLAIR images. Standard oval regions of interest (ROIs) of 0.5 cm{sup 2} which were oriented parallel to the long axis of the thalamus were used for this purpose. The mean ADC value of the thalamus was (0.99 ± 0.16) x 10{sup -3} mm{sup 2}/s in patients with CSVD, whereas the mean ADC value was (0.78 ± 0.06) x 10{sup -3} mm{sup 2}/s in the control group. The mean ADC value was significantly higher in patients with CSVD compared to the controls (p < 0.001). The mean ADC values of the thalamus were (0.78 ± 0.08) x 10{sup -3} mm{sup 2}/s in MS patients, and (0.75 ± 0.08) x 10{sup -3} mm{sup 2}/s in the control group, which are not significantly different (p > 0.05). Our study revealed a difference in the diffusion of the thalami between CSVD and MS. DWI may aid in the radiological disease differentiation. (orig.)

  9. Distinctive Resting State Network Disruptions Among Alzheimer's Disease, Subcortical Vascular Dementia, and Mixed Dementia Patients.

    Science.gov (United States)

    Kim, Hee Jin; Cha, Jungho; Lee, Jong-Min; Shin, Ji Soo; Jung, Na-Yeon; Kim, Yeo Jin; Choe, Yearn Seong; Lee, Kyung Han; Kim, Sung Tae; Kim, Jae Seung; Lee, Jae Hong; Na, Duk L; Seo, Sang Won

    2016-01-01

    Recent advances in resting-state functional MRI have revealed altered functional networks in Alzheimer's disease (AD), especially those of the default mode network (DMN) and central executive network (CEN). However, few studies have evaluated whether small vessel disease (SVD) or combined amyloid and SVD burdens affect the DMN or CEN. The aim of this study was to evaluate whether SVD or combined amyloid and SVD burdens affect the DMN or CEN. In this cross-sectional study, we investigated the resting-state functional connectivity within DMN and CEN in 37 Pittsburgh compound-B (PiB)(+) AD, 37 PiB(-) subcortical vascular dementia (SVaD), 13 mixed dementia patients, and 65 normal controls. When the resting-state DMN of PiB(+) AD and PiB(-) SVaD patients were compared, the PiB(+) AD patients displayed lower functional connectivity in the inferior parietal lobule while the PiB(-) SVaD patients displayed lower functional connectivity in the medial frontal and superior frontal gyri. Compared to the PiB(-) SVaD or PiB(+) AD, the mixed dementia patients displayed lower functional connectivity within the DMN in the posterior cingulate gyrus. When the resting-state CEN connectivity of PiB(+) AD and PiB(-) SVaD patients were compared, the PiB(-) SVaD patients displayed lower functional connectivity in the anterior insular region. Compared to the PiB(-) SVaD or PiB(+) AD, the mixed dementia patients displayed lower functional connectivity within the CEN in the inferior frontal gyrus. Our findings suggest that in PiB(+) AD and PiB(-) SVaD, there is divergent disruptions in resting-state DMN and CEN. Furthermore, patients with combined amyloid and SVD burdens exhibited more disrupted resting-state DMN and CEN than patients with only amyloid or SVD burden.

  10. Relationship between diminution of small pulmonary vessels and emphysema in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Mashimo, Shuko; Chubachi, Shotaro; Tsutsumi, Akihiro; Kameyama, Naofumi; Sasaki, Mamoru; Jinzaki, Masahiro; Nakamura, Hidetoshi; Asano, Koichiro; Reilly, John J; Betsuyaku, Tomoko

    To investigate the relationship between small pulmonary vessels and extent of emphysema on CT in individual lungs with chronic obstructive pulmonary disease (COPD). Forty-nine patients were included. The percentage of cross-sectional area of vessels emphysema were assessed. Less than half of the COPD patients demonstrated an inverse correlation between %CSA <5 and percentage of low attenuation area (LAA%). In the remaining patients, %CSA <5 was homogeneously distributed. Not all patients with COPD demonstrated an inverse correlation of the distributions between %CSA <5 and LAA% in individual lungs. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Serum Hepatocyte Growth Factor Is Associated with Small Vessel Disease in Alzheimer’s Dementia

    Directory of Open Access Journals (Sweden)

    Yanan Zhu

    2018-01-01

    Full Text Available Background: While hepatocyte growth factor (HGF is known to exert cell growth, migration and morphogenic effects in various organs, recent studies suggest that HGF may also play a role in synaptic maintenance and cerebrovascular integrity. Although increased levels of HGF have been reported in brain and cerebrospinal fluid (CSF samples of patients with Alzheimer’s disease (AD, it is unclear whether peripheral HGF may be associated with cerebrovascular disease (CeVD and dementia. In this study, we examined the association of baseline serum HGF with neuroimaging markers of CeVD in a cohort of pre-dementia (cognitive impaired no dementia, CIND and AD patients.Methods: Serum samples from aged, Non-cognitively impaired (NCI controls, CIND and AD subjects were measured for HGF levels. CeVD (cortical infarcts, microinfarcts, lacunes, white matter hyperintensities (WMH and microbleeds were assessed by magnetic resonance imaging (MRI.Results: After controlling for covariates, higher levels of HGF were associated with both CIND and AD. Among the different CeVD MRI markers in CIND and AD, only small vessel disease, but not large vessel disease markers were associated with higher HGF levels.Conclusion: Serum HGF may be a useful peripheral biomarker for small vessel disease in subjects with cognitive impairment and AD.

  12. Mechanical Recanalization of Subacute Vessel Occlusion in Peripheral Arterial Disease with a Directional Atherectomy Catheter

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Alexander, E-mail: Alexander.Massmann@uks.eu; Katoh, Marcus [Saarland University Hospital, Department of Diagnostic and Interventional Radiology (Germany); Shayesteh-Kheslat, Roushanak [Saarland University Hospital, Department of General Surgery, Visceral, Vascular, and Pediatric Surgery (Germany); Buecker, Arno [Saarland University Hospital, Department of Diagnostic and Interventional Radiology (Germany)

    2012-10-15

    Purpose: To retrospectively examine the technical feasibility and safety of directional atherectomy for treatment of subacute infrainguinal arterial vessel occlusions. Methods: Five patients (one woman, four men, age range 51-81 years) with peripheral arterial disease who experienced sudden worsening of their peripheral arterial disease-related symptoms during the last 2-6 weeks underwent digital subtraction angiography, which revealed vessel occlusion in native popliteal artery (n = 4) and in-stent occlusion of the superficial femoral artery (n = 1). Subsequently, all patients were treated by atherectomy with the SilverHawk (ev3 Endovascular, USA) device. Results: The mean diameter of treated vessels was 5.1 {+-} 1.0 mm. The length of the occlusion ranged 2-14 cm. The primary technical success rate was 100%. One patient experienced a reocclusion during hospitalization due to heparin-induced thrombocytopenia. There were no further periprocedural complications, in particular no peripheral embolizations, until hospital discharge or during the follow-up period of 1 year. Conclusion: The recanalization of infrainguinal arterial vessel occlusions by atherectomy with the SilverHawk device is technically feasible and safe. In our limited retrospective study, it was associated with a high technical success rate and a low procedure-related complication rate.

  13. The diagnostic value of cine-MR imaging in diseases of great vessels

    International Nuclear Information System (INIS)

    Sasaki, Shigeyuki; Yoshida, Hideaki; Matsui, Yoshiro; Sakuma, Makoto; Yasuda, Keihide; Tanabe, Tatsuzo; Chouji, H.

    1990-01-01

    The diagnostic value of cine magnetic resonance imaging (cine-MRI) was evaluated in 10 patients with diseases of great vessels. The parameters necessary to decide the appropriate treatment, such as presence and extension of intimal flap, DeBakey type classification, identification of the entry, differentiation between true and false lumen, and between thrombosis and slow flow were demonstrated in all patients with dissecting aortic aneurysm. However, abdominal aortic branches could not be demonstrated enough by cine-MRI, therefore conventional AOG was necessary to choose the operative procedure in these cases. In patients with thoracic aortic aneurysm (TAA), cine-MRI was valuable in demonstrating both blood flow and thrombus in the lumen of aneurysm, and AOG was thought to be unnecessary in most cases. Cine-MRI is a promising new technique for the evaluation of diseases of great vessels. (author)

  14. Adult primary angiitis of the central nervous system: isolated small-vessel vasculitis represents distinct disease pattern.

    Science.gov (United States)

    de Boysson, Hubert; Boulouis, Grégoire; Aouba, Achille; Bienvenu, Boris; Guillevin, Loïc; Zuber, Mathieu; Touzé, Emmanuel; Naggara, Olivier; Pagnoux, Christian

    2017-03-01

    We aimed to identify whether presentations and outcomes in adult patients with isolated small-vessel primary angiitis of the CNS (PACNS) would differ from other patients with large/medium-vessel involvement. In the French PACNS cohort, we compared the characteristics, treatments and outcomes of patients with isolated small-vessel disease (normal CT, MR and/or conventional angiograms, brain biopsy positive for vasculitis) with other patients who had large/medium-vessel involvement (vessel abnormalities on CT, MR or conventional angiograms). A good functional outcome was defined as a modified Rankin scale ⩽2 at last follow-up, regardless of the occurrence of relapse. Among the 102 patients in the cohort, 26 (25%) had isolated small-vessel PACNS, whereas the 76 others demonstrated large/medium-vessel involvement. Patients with isolated small-vessel PACNS had more seizures (P adult patients with isolated small-vessel PACNS presented some distinct disease features and relapsed more often than other PACNS patients who had large/medium-vessel involvement. Functional outcomes and mortality did not differ. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  15. A SURVEY OF RETINA BASED DISEASE IDENTIFICATION USING BLOOD VESSEL SEGMENTATION

    Directory of Open Access Journals (Sweden)

    P Kuppusamy

    2016-11-01

    Full Text Available The colour retinal photography is one of the most essential features to identify the confirmation of various eye diseases. The iris is primary attribute to authenticate the human. This research work presents the survey and comparison of various blood vessel related feature identification, segmentation, extraction and enhancement methods. Additionally, this study is observed the various databases performance for storing the images and testing in minimal time. This paper is also provides the better performance techniques based on the survey.

  16. Mechanical Recanalization of Subacute Vessel Occlusion in Peripheral Arterial Disease with a Directional Atherectomy Catheter

    International Nuclear Information System (INIS)

    Massmann, Alexander; Katoh, Marcus; Shayesteh-Kheslat, Roushanak; Buecker, Arno

    2012-01-01

    Purpose: To retrospectively examine the technical feasibility and safety of directional atherectomy for treatment of subacute infrainguinal arterial vessel occlusions. Methods: Five patients (one woman, four men, age range 51–81 years) with peripheral arterial disease who experienced sudden worsening of their peripheral arterial disease–related symptoms during the last 2–6 weeks underwent digital subtraction angiography, which revealed vessel occlusion in native popliteal artery (n = 4) and in-stent occlusion of the superficial femoral artery (n = 1). Subsequently, all patients were treated by atherectomy with the SilverHawk (ev3 Endovascular, USA) device. Results: The mean diameter of treated vessels was 5.1 ± 1.0 mm. The length of the occlusion ranged 2–14 cm. The primary technical success rate was 100%. One patient experienced a reocclusion during hospitalization due to heparin-induced thrombocytopenia. There were no further periprocedural complications, in particular no peripheral embolizations, until hospital discharge or during the follow-up period of 1 year. Conclusion: The recanalization of infrainguinal arterial vessel occlusions by atherectomy with the SilverHawk device is technically feasible and safe. In our limited retrospective study, it was associated with a high technical success rate and a low procedure-related complication rate.

  17. Cerebral Small Vessel Disease: Cognition, Mood, Daily Functioning, and Imaging Findings from a Small Pilot Sample

    Directory of Open Access Journals (Sweden)

    John G. Baker

    2012-04-01

    Full Text Available Cerebral small vessel disease, a leading cause of cognitive decline, is considered a relatively homogeneous disease process, and it can co-occur with Alzheimer’s disease. Clinical reports of magnetic resonance imaging (MRI/computed tomography and single photon emission computed tomography (SPECT imaging and neuropsychology testing for a small pilot sample of 14 patients are presented to illustrate disease characteristics through findings from structural and functional imaging and cognitive assessment. Participants showed some decreases in executive functioning, attention, processing speed, and memory retrieval, consistent with previous literature. An older subgroup showed lower age-corrected scores at a single time point compared to younger participants. Performance on a computer-administered cognitive measure showed a slight overall decline over a period of 8–28 months. For a case study with mild neuropsychology findings, the MRI report was normal while the SPECT report identified perfusion abnormalities. Future research can test whether advances in imaging analysis allow for identification of cerebral small vessel disease before changes are detected in cognition.

  18. [Theoretic basis on the same therapeutic program for different degenerative brain diseases in terms of the Governor Vessel: Alzheimer's disease and Parkinson's disease].

    Science.gov (United States)

    Wu, Junyan; Wang, Jie; Zhang, Junlong

    2015-05-01

    Through the consultation of TCM ancient classical theory, the relationship of kidney essence, marrow and brain is analyzed. It is discovered that the degenerative brain diseases, represented by Alzheimer's disease (AD) and Parkinson's disease (PD) share the same etiological basis as "kidney essence deficiency and brain marrow emptiness" and have the mutual pathological outcomes as yang qi declining. The Governor Vessel gathers yang qi of the whole body and maintains the normal functional activity of zangfu organs in the human body through the storage, regulation and invigoration of yang qi. It is viewed that the theory of the Governor Vessel is applied to treat the different degenerative brain diseases, which provides the theoretic support and practice guide for the thought of TCM as the same therapeutic program for the different diseases. As a result, the degenerative brain diseases can be retarded and the approach is provided to the effective prevention and treatment of degenerative diseases in central nerve system:

  19. SVD application in image and data compression - Some case studies in oceanography (Developed in MATLAB)

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, T.V.R.; Rao, M.M.M.; SuryaPrakash, S.; Chandramouli, P.; Murthy, K.S.R.

    An integrated friendly-user interactive multiple Ocean Application Pacakage has been developed utilizing the well known statistical technique called Singular Value Decomposition (SVD) to achieve image and data compression in MATLAB environment...

  20. NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease—Implications for Prevention

    Directory of Open Access Journals (Sweden)

    Mark F. McCarty

    2015-04-01

    Full Text Available Cerebral small vessel disease (SVD, a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways—exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea, and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine—which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine—mediate this benefit. Ameliorating the risk factors for SVD—including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine—also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

  1. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  2. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Science.gov (United States)

    Kyrtsos, Christina Rose; Baras, John S

    2015-01-01

    Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  3. Excluding Noise from Short Krylov Subspace Approximations to the Truncated Singular Value Decomposition (SVD)

    Science.gov (United States)

    2017-09-27

    100 times larger for the minimal Krylov subspace. 0 5 10 15 20 25 Krylov subspace dimension 10-2 10-1 100 101 102 103 104 jjĜ ¡ 1 jj F SVD...approximation Kn (G;u(0) ) 0 5 10 15 20 25 Krylov subspace dimension 10-2 10-1 100 101 102 103 104 jjx jj fo r m in x jjĜ x ¡ bjj SVD approximation Kn (G;u(0

  4. An Implementation and Detailed Analysis of the K-SVD Image Denoising Algorithm

    Directory of Open Access Journals (Sweden)

    Marc Lebrun

    2012-05-01

    Full Text Available K-SVD is a signal representation method which, from a set of signals, can derive a dictionary able to approximate each signal with a sparse combination of the atoms. This paper focuses on the K-SVD-based image denoising algorithm. The implementation is described in detail and its parameters are analyzed and varied to come up with a reliable implementation.

  5. Impact of vessel wall lesions and vascular stenoses on cerebrovascular reactivity in patients with intracranial stenotic disease

    NARCIS (Netherlands)

    Cogswell, Petrice M; Davis, Taylor L; Strother, Megan K; Faraco, Carlos C; Scott, Allison O; Jordan, Lori C; Fusco, Matthew R; Frederick, Blaise deB; Hendrikse, Jeroen; Donahue, Manus J

    2017-01-01

    PURPOSE: To compare cerebrovascular reactivity (CVR) and CVR lagtimes in flow territories perfused by vessels with vs. without proximal arterial wall disease and/or stenosis, separately in patients with atherosclerotic and nonatherosclerotic (moyamoya) intracranial stenosis. MATERIALS AND METHODS:

  6. Altered low frequency oscillations of cortical vessels in patients with cerebrovascular occlusive disease – a NIRS study

    DEFF Research Database (Denmark)

    Phillip, Dorte; Iversen, Helle K; Schytz, Henrik W

    2013-01-01

    Analysis of cerebral autoregulation by measuring spontaneous oscillations in the low frequency spectrum of cerebral cortical vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease and stroke. Near infrared spectroscopy (NIRS...

  7. Transfemoral transcatheter aortic valve implantation in patients with small diseased peripheral vessels

    International Nuclear Information System (INIS)

    Ruparelia, Neil; Buzzatti, Nicola; Romano, Vittorio; Longoni, Matteo; Figini, Fillipo; Montorfano, Matteo; Kawamoto, Hiroyoshi; Miyazaki, Tadashi; Spagnolo, Pietro; Alfieri, Ottavio; Colombo, Antonio; Latib, Azeem

    2015-01-01

    Objectives: The aim of this study was to assess the feasibility, safety and short-term outcomes of transfemoral transcatheter aortic valve implantation (TF-TAVI) in patients with small diseased peripheral vessels. Background: The transfemoral (TF) route for transcatheter aortic valve (TAVI) is the default option due to associated advantages. However, this is limited due to the high prevalence of significant peripheral arterial disease and increased risk of vascular complications. Methods: Of 539 consecutive patients undergoing TAVI in a single Italian center, 23 patients underwent TF-TAVI in the presence of small peripheral vessels as defined by a minimal luminal diameter (MLD) of ≤ 5.5 mm [by computed tomography (CT)] and/or the inability to advance a large-bore sheath. Calcification was defined as being concentric if calcium extended more than 270° around the circumference of the artery. All patients underwent 30-day clinical follow-up. Results: 17 (73.9%) patients underwent peripheral vessel pre-dilatation with a semi-compliant balloon and 6 (26.1%) patients with a Solopath sheath. 6 (26.1%) patients suffered a peri-procedural complication, with 1 patient requiring surgical embolectomy for thrombotic occlusion and the remaining patients successfully managed percutaneously in the catheter laboratory. No patient suffered a vessel perforation or required implantation of a covered stent. At 30-day follow-up, all patients were free of symptoms and signs or symptoms of peripheral vascular disease, with well-functioning TAVI prostheses as evaluated by echocardiography. Conclusions: Performing TF-TAVI is feasible in patients with no other viable vascular access option in the presence of small MLD and calcification of the peripheral vasculature, with any anticipated acute vascular complication managed in the catheter laboratory with established percutaneous techniques. - Highlights: • Small peripheral vessels is regarded as contraindication to transfemoral TAVI.

  8. Transfemoral transcatheter aortic valve implantation in patients with small diseased peripheral vessels

    Energy Technology Data Exchange (ETDEWEB)

    Ruparelia, Neil [San Raffaele Scientific Institute, Milan (Italy); Imperial College, London (United Kingdom); Buzzatti, Nicola; Romano, Vittorio; Longoni, Matteo; Figini, Fillipo; Montorfano, Matteo; Kawamoto, Hiroyoshi; Miyazaki, Tadashi; Spagnolo, Pietro; Alfieri, Ottavio; Colombo, Antonio [San Raffaele Scientific Institute, Milan (Italy); Latib, Azeem, E-mail: info@emocolumbus.it [San Raffaele Scientific Institute, Milan (Italy)

    2015-09-15

    Objectives: The aim of this study was to assess the feasibility, safety and short-term outcomes of transfemoral transcatheter aortic valve implantation (TF-TAVI) in patients with small diseased peripheral vessels. Background: The transfemoral (TF) route for transcatheter aortic valve (TAVI) is the default option due to associated advantages. However, this is limited due to the high prevalence of significant peripheral arterial disease and increased risk of vascular complications. Methods: Of 539 consecutive patients undergoing TAVI in a single Italian center, 23 patients underwent TF-TAVI in the presence of small peripheral vessels as defined by a minimal luminal diameter (MLD) of ≤ 5.5 mm [by computed tomography (CT)] and/or the inability to advance a large-bore sheath. Calcification was defined as being concentric if calcium extended more than 270° around the circumference of the artery. All patients underwent 30-day clinical follow-up. Results: 17 (73.9%) patients underwent peripheral vessel pre-dilatation with a semi-compliant balloon and 6 (26.1%) patients with a Solopath sheath. 6 (26.1%) patients suffered a peri-procedural complication, with 1 patient requiring surgical embolectomy for thrombotic occlusion and the remaining patients successfully managed percutaneously in the catheter laboratory. No patient suffered a vessel perforation or required implantation of a covered stent. At 30-day follow-up, all patients were free of symptoms and signs or symptoms of peripheral vascular disease, with well-functioning TAVI prostheses as evaluated by echocardiography. Conclusions: Performing TF-TAVI is feasible in patients with no other viable vascular access option in the presence of small MLD and calcification of the peripheral vasculature, with any anticipated acute vascular complication managed in the catheter laboratory with established percutaneous techniques. - Highlights: • Small peripheral vessels is regarded as contraindication to transfemoral TAVI.

  9. High-resolution vessel wall MRI for the evaluation of intracranial atherosclerotic disease

    Energy Technology Data Exchange (ETDEWEB)

    De Havenon, Adam [University of Utah, Department of Neurology, Salt Lake City, UT (United States); Mossa-Basha, Mahmud [University of Washington, Department of Radiology, Seattle, WA (United States); Shah, Lubdha; Kim, Seong-Eun; Parker, Dennis; McNally, J.S. [University of Utah, Department of Radiology, Salt Lake City, UT (United States); Park, Min [University of Utah, Department of Neurosurgery, Salt Lake City, UT (United States)

    2017-12-15

    High-resolution vessel wall MRI (vwMRI) of the intracranial arteries is an emerging diagnostic imaging technique with the goal of evaluating vascular pathology. vwMRI sequences have high spatial resolution and directly image the vessel wall by suppressing blood signal. With vwMRI, it is possible to identify distinct morphologic and enhancement patterns of atherosclerosis that can provide important information about stroke etiology and recurrence risk. We present a review of vwMRI research in relation to intracranial atherosclerosis, with a focus on the relationship between ischemic stroke and atherosclerotic plaque T1 post-contrast enhancement or plaque/vessel wall morphology. The goal of this review is to provide readers with the most current understanding of the reliability, incidence, and importance of specific vwMRI findings in intracranial atherosclerosis, to guide their interpretation of vwMRI research, and help inform clinical interpretation of vwMRI. We will also provide a translational perspective on the existing vwMRI literature and insight into future vwMRI research questions and objectives. With increased use of high field strength MRI, powerful gradients, and improved pulse sequences, vwMRI will become standard-of-care in the diagnosis and prognosis of patients with cerebrovascular disease, making a firm grasp of its strengths and weakness important for neuroimagers. (orig.)

  10. High-resolution vessel wall MRI for the evaluation of intracranial atherosclerotic disease

    International Nuclear Information System (INIS)

    De Havenon, Adam; Mossa-Basha, Mahmud; Shah, Lubdha; Kim, Seong-Eun; Parker, Dennis; McNally, J.S.; Park, Min

    2017-01-01

    High-resolution vessel wall MRI (vwMRI) of the intracranial arteries is an emerging diagnostic imaging technique with the goal of evaluating vascular pathology. vwMRI sequences have high spatial resolution and directly image the vessel wall by suppressing blood signal. With vwMRI, it is possible to identify distinct morphologic and enhancement patterns of atherosclerosis that can provide important information about stroke etiology and recurrence risk. We present a review of vwMRI research in relation to intracranial atherosclerosis, with a focus on the relationship between ischemic stroke and atherosclerotic plaque T1 post-contrast enhancement or plaque/vessel wall morphology. The goal of this review is to provide readers with the most current understanding of the reliability, incidence, and importance of specific vwMRI findings in intracranial atherosclerosis, to guide their interpretation of vwMRI research, and help inform clinical interpretation of vwMRI. We will also provide a translational perspective on the existing vwMRI literature and insight into future vwMRI research questions and objectives. With increased use of high field strength MRI, powerful gradients, and improved pulse sequences, vwMRI will become standard-of-care in the diagnosis and prognosis of patients with cerebrovascular disease, making a firm grasp of its strengths and weakness important for neuroimagers. (orig.)

  11. Myofibrotic malformation vessels: unique angiodysplasia toward the progression of hemorrhoidal disease

    Science.gov (United States)

    Li, Sheng-Long; Jing, Fang-Yan; Ma, Li-Li; Guo, Li-Li; Na, Feng; An, Sheng-Li; Ye, Yan; Yang, Jun-Ming; Bao, Ming; Kang, Dong; Sun, Xiao-Lan; Deng, Yong-Jian

    2015-01-01

    Background The etiology and pathogenesis of hemorrhoids is unclear, although hemorrhoids are a worldwide disease in men and women, with peak prevalence at 45–65 years of age. Hemorrhoidal cushions as the anal venous plexi are normal anatomical structures from infancy. This study attempts to reveal the angiodysplasia and other pathological changes in association with different degrees of symptomatic hemorrhoids. Materials and methods A total of 281 patients with internal hemorrhoids from degree I to IV underwent hemorrhoidectomy. The vascular changes were analyzed by microscopic assessment and software analysis, with Masson’s trichrome, CD34, and smooth muscle actin. Results The hemorrhoidal tissues exhibited abnormal vessels in the mucosae and submucosae that we termed them as myofibrotic malformation vessels (MMVs). MMVs are not ascribed to arteries or veins because they exhibit enlarged and tortuous lumens with smooth muscle dysplasia and fibrotic deposition in the walls without overlying mucosal ulceration. The muscularis mucosae also showed smooth muscle dysplasia and fibrosis, even if it were interrupted by the intruding MMVs. The statistical data indicated that the severity of all the changes correlate positively with the progression of hemorrhoids (PHemorrhoidal patients are prone for reoccurrence even with prolapsing hemorrhoid when compared with the conventional hemorrhoidectomy. Multiple logistic regression analysis showed that MMVs in mucosal propria, mean thickness of mucosal muscularis layer, and fibrotic changes in MMV were independent risk factors for MMVs in hemorrhoidal disease. Conclusion MMVs and muscularis mucosae dysplasia reciprocally contribute to hemorrhoidal exacerbation. The novel findings of this study propose that the characteristic features of MMVs and muscularis mucosae dysplasia of the anorectal tube ultimately cause symptomatic hemorrhoids, which could affect the clinical management of hemorrhoidal disease through the use of

  12. Hypertension-Induced Cerebral Small Vessel Disease Leading to Cognitive Impairment.

    Science.gov (United States)

    Liu, Yang; Dong, Yan-Hong; Lyu, Pei-Yuan; Chen, Wei-Hong; Li, Rui

    2018-03-05

    Alzheimer's disease and vascular dementia are responsible for more than 80% of dementia cases. These two conditions share common risk factors including hypertension. Cerebral small vessel disease (CSVD) is strongly associated with both hypertension and cognitive impairment. In this review, we identify the pathophysiological changes in CSVD that are caused by hypertension and further explore the relationship between CSVD and cognitive impairment. We searched and scanned the PubMed database for recently published literatures up to December 2017. We used the keywords of "hypertension", "cerebral small vessel disease", "white matter lesions", "enlarged perivascular spaces", "lacunar infarcts", "cerebral microbleeds", and "cognitive impairment" in the database of PubMed. Articles were obtained and reviewed to analyze the hypertension-induced pathophysiological changes that occur in CSVD and the correlation between CSVD and cognitive impairment. In recent years, studies have demonstrated that hypertension-related changes (e.g., small vascular lesions, inflammatory reactions, hypoperfusion, oxidative stress, damage to autoregulatory processes and the blood-brain barrier, and cerebral amyloid angiopathy) can occur over time in cerebral small vessels, potentially leading to lower cognitive function when blood pressure (BP) control is poor or lacking. Both isolated and co-occurrent CSVD can lead to cognitive deterioration, and this effect may be attributable to a dysfunction in either the cholinergic system or the functionality of cortical and subcortical tracts. We explore the currently available evidence about the hypertensive vasculopathy and inflammatory changes that occur in CSVD. Both are vital prognostic indicators of the development of cognitive impairment. Future studies should be performed to validate the relationship between BP levels and CSVD progression and between the numbers, volumes, and anatomical locations of CSVD and cognitive impairment.

  13. Comparison of exercise electrocardiography and quantitative thallium imaging for one-vessel coronary artery disease

    International Nuclear Information System (INIS)

    Kaul, S.; Kiess, M.; Liu, P.; Guiney, T.E.; Pohost, G.M.; Okada, R.D.; Boucher, C.A.

    1985-01-01

    The relative value of exercise electrocardiography and computer analyzed thallium-201 imaging was compared in 124 patients with 1-vessel coronary artery disease (CAD). Of these, 78 had left anterior descending (LAD), 32 right and 14 left circumflex (LC) CAD. In patients with no previous myocardial infarction (MI), thallium imaging was more sensitive than the electrocardiogram (78% vs 64%, p less than 0.01), but in patients with previous MI, sensitivity was similar. Further, thallium imaging was more sensitive only in LAD and LC disease. Redistribution was compared with ST-segment depression as a marker of ischemia. Only in patients with prior MI (76% vs 44%, p less than 0.01) and only in LC and right CAD did redistribution occur more often than ST depression. Thallium imaging was more accurate in localizing stenoses than the electrocardiogram (p less than 0.001), but did not always correctly predict coronary anatomy. Septal thallium defects were associated with LAD disease in 84%, inferior defects with right CAD in 40% and posterolateral lesion defects with LC CAD in 22%. The results indicate the overall superiority of thallium imaging in 1-vessel CAD compared with exercise electrocardiography; however, there is a wide spectrum of extent and location of perfusion defects associated with each coronary artery. Thallium imaging complements coronary angiography by demonstrating the functional impact of CAD on myocardial perfusion

  14. Assessment of jeopardized myocardium in patients with one-vessel disease

    International Nuclear Information System (INIS)

    Iskandrian, A.S.; Lichtenberg, R.; Segal, B.L.; Mintz, G.S.; Mundth, E.D.; Hakki, A.-H.; Kimbiris, D.; Bemis, C.E.; Croll, M.N.; Kane, S.A.

    1982-01-01

    The size of the perfusion defect was assessed from a quantitative analysis of exercise thallium-201 images. Quantitative analysis was determined by measuring the area and the perimeter of the perfusion defect and expressing it as a percentage of the total left ventricular area or perimeter in three projections. Using this technique, we studied 50 patients with one-vessel disease of 50% or greater diameter narrowing. The planimetric and the perimetric methods correlated well (p<0.001, r=0.97). Of the 11 patients with less than 70% diameter narrowing, only one patient had abnormal exercise thallium-201 images. Of the remaining 39 patients with 70% or greater diameter narrowing, 35 had abnormal exercise images. The defects were larger in patients with left anterior descending coronary artery disease (33 +/- 10%; mean +/- SD by perimetry) than in patients with left circumflex coronary artery disease (19 +/- 14%, p<0.01) or right coronary artery disease (17 +/- 11%, p<0.01). There was also significant variation in the sizes of the defects in the three projections in patients with left circumflex and right coronary artery disease, but not in patients with left anterior descending coronary artery disease. Patients with left anterior descending coronary artery disease with collaterals had smaller defects than their counterparts without collaterals

  15. Myocardial perfusion and left ventricular function early after successful PTCA in 1-vessel coronary artery diseases

    International Nuclear Information System (INIS)

    Hoffmeister, H.M.; Kaiser, W.; Hanke, H.; Mueller-Schauenburg, W.; Karsch, K.R.; Seipel, L.

    1994-01-01

    Myocardial perfusion ( 201 Tl-ECT) and contractile function ( 99m Tc-ventriculography) were studied during exercise and rest 3 to 6 days after PTCA in 20 patients (11 with stable and 9 with unstable angina pectoris). All patients had single vessel disease and no previous myocardial infarction. During exercise after PTCA the ejection fraction increased for 3 to 5% and no regional wall motion abnormalities, ST-segment depression or perfusion defects occurred (with exception in one patient with very early restenosis). Therefore, perfusion and wall motion were completely normalized at test and during exercise within days after technically successful PTCA even in patients with previously unstable angina pectoris. Pathological stress test results after this time should thus be attributed to other causes e.g. early restenosis, multivessel disease, false positive tests) and are not due to the specific situation early after PTCA. (orig.) [de

  16. Noninvasive identification of left main and triple vessel coronary artery disease using dipyridamole thallium scintigraphy

    International Nuclear Information System (INIS)

    Chikamori, Taishiro; Doi, Yoshinori; Yonezawa, Yoshihiro; Yamada, Mitsutoshi; Seo, Hiromi; Kawai, Kazuya; Yabe, Toshikazu; Ozawa, Toshio

    1993-01-01

    The diagnostic value of dipyridamole thallium scintigraphy for the noninvasive identification of left main (LM) and triple vessel (TV) coronary artery disease (CAD) was evaluated in 615 consecutive patients with known or suspected CAD. One hundred thirty-nine patients had LM or TVCAD; the remaining 476 patients had limited CAD (double vessel CAD in 112, single vessel CAD in 235, insignificant lesions in 129). Patients with LM or TVCAD, compared to those with limited CAD, had a higher incidence of diffuse slow washout (58 vs 20%, p<0.0001), extensive fixed defects (21 vs 6%, p<0.0001) and extensive reversible defects (32 vs 8%, p<0.0001). During dipyridamole loading, the incidence of chest pain was higher (65 vs 41%, p<0.0001), and the magnitude of ST depression was greater (0.16±0.14 vs 0.04±0.07 mV, p<0.001) in patients with LM or TVCAD than in those with limited CAD. Stepwise discriminant analysis using scintigraphic imaging achieved a sensitivity of 69%, a specificity of 79%, and an accuracy of 77% for diagnosing patients with LM or TVCAD. After including clinical markers of ischemia during dipyridamole loading, multivariate analysis revealed an improved diagnosis with a sensitivity of 71%, a specificity of 85%, and an accuracy of 82%. These results clearly show the usefulness of scintigraphic imaging as well as the significance of careful assessment of clinical markers of ischemia during dipyridamole loading for the noninvasive identification of LM and TVCAD. (author)

  17. A High-Speed and Low-Energy-Consumption Processor for SVD-MIMO-OFDM Systems

    Directory of Open Access Journals (Sweden)

    Hiroki Iwaizumi

    2013-01-01

    Full Text Available A processor design for singular value decomposition (SVD and compression/decompression of feedback matrices, which are mandatory operations for SVD multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM systems, is proposed and evaluated. SVD-MIMO is a transmission method for suppressing multistream interference and improving communication quality by beamforming. An application specific instruction-set processor (ASIP architecture is adopted to achieve flexibility in terms of operations and matrix size. The proposed processor realizes a high-speed/low-power design and real-time processing by the parallelization of floating-point units (FPUs and arithmetic instructions specialized in complex matrix operations.

  18. Case of Small Vessel Disease Associated with COL4A1 Mutations following Trauma

    Directory of Open Access Journals (Sweden)

    Joao McONeil Plancher

    2015-06-01

    Full Text Available With this case report, we would like to heighten the awareness of clinicians about COL4A1 as a single-gene disorder causing cerebral small vessel disease and describe a previously unreported pathogenic missense substitution in COL4A1 (p.Gly990Val and a new clinical presentation. We identified a heterozygous putatively pathogenic mutation of COL4A1 in a 50-year-old female with a history of congenital cataracts and glaucoma who presented with multiple diffusion-positive infarcts and areas of contrast enhancement following mild head trauma. We believe that this presentation of multiple areas of acute brain and vascular injury in the setting of mild head trauma is a new manifestation of this genetic disorder. Imaging findings of multiple acute infarcts and regions of contrast enhancement with associated asymptomatic old deep microhemorrhages and leukomalacia in adults after head trauma should raise a high suspicion for a COL4A1 genetic disorder. Radiographic patterns of significant leukoaraiosis and deep microhemorrhages can also be seen in patients with long-standing vasculopathy associated with hypertension, which our patient lacked. Our findings demonstrate the utility of genetic screening for COL4A1 mutations in young patients who have small vessel vasculopathy on brain imaging but who do not have significant cardiovascular risk factors.

  19. Vessel Wall Inflammation of Takayasu Arteritis Detected by Contrast-Enhanced Magnetic Resonance Imaging: Association with Disease Distribution and Activity.

    Directory of Open Access Journals (Sweden)

    Yoko Kato

    Full Text Available The assessment of the distribution and activity of vessel wall inflammation is clinically important in patients with Takayasu arteritis. Magnetic resonance imaging (MRI is a useful tool, but the clinical utility of late gadolinium enhancement (LGE in Takayasu arteritis has yet to be determined. The aim of the present study was to evaluate the utility of LGE in assessing vessel wall inflammation and disease activity in Takayasu arteritis.We enrolled 49 patients with Takayasu arteritis who had undergone 1.5 T MRI. Patients were divided into Active (n = 19 and Inactive disease (n = 30 groups. The distribution of vessel wall inflammation using angiography and LGE was assessed by qualitative analysis. In 79% and 63% of patients in Active and Inactive groups, respectively, greater distribution of vessel wall inflammation was observed with LGE than with conventional angiography. MRI values of pre- and post-contrast signal-to-noise ratios (SNR, SNR increment (post-SNR minus pre-SNR, pre- and post-contrast contrast-to-noise ratios (CNR, and CNR increment (post-CNR minus pre-CNR were evaluated at arterial wall sites with the highest signal intensity using quantitative analysis of post-contrast LGE images. No statistically significant differences in MRI parameters were observed between Active and Inactive groups. Contrast-enhanced MRI was unable to accurately detect active disease.Contrast-enhanced MRI has utility in detecting the distribution of vessel wall inflammation but has less utility in assessing disease activity in Takayasu arteritis.

  20. A QDWH-Based SVD Software Framework on Distributed-Memory Manycore Systems

    KAUST Repository

    Sukkari, Dalal

    2017-01-01

    This paper presents a high performance software framework for computing a dense SVD on distributed- memory manycore systems. Originally introduced by Nakatsukasa et al. (Nakatsukasa et al. 2010; Nakatsukasa and Higham 2013), the SVD solver relies on the polar decomposition using the QR Dynamically-Weighted Halley algorithm (QDWH). Although the QDWH-based SVD algorithm performs a significant amount of extra floating-point operations compared to the traditional SVD with the one-stage bidiagonal reduction, the inherent high level of concurrency associated with Level 3 BLAS compute-bound kernels ultimately compensates for the arithmetic complexity overhead. Using the ScaLAPACK two-dimensional block cyclic data distribution with a rectangular processor topology, the resulting QDWH-SVD further reduces excessive communications during the panel factorization, while increasing the degree of parallelism during the update of the trailing submatrix, as opposed to relying to the default square processor grid. After detailing the algorithmic complexity and the memory footprint of the algorithm, we conduct a thorough performance analysis and study the impact of the grid topology on the performance by looking at the communication and computation profiling trade-offs. We report performance results against state-of-the-art existing QDWH software implementations (e.g., Elemental) and their SVD extensions on large-scale distributed-memory manycore systems based on commodity Intel x86 Haswell processors and Knights Landing (KNL) architecture. The QDWH-SVD framework achieves up to 3/8-fold on the Haswell/KNL-based platforms, respectively, against ScaLAPACK PDGESVD and turns out to be a competitive alternative for well and ill-conditioned matrices. We finally come up herein with a performance model based on these empirical results. Our QDWH-based polar decomposition and its SVD extension are freely available at https://github.com/ecrc/qdwh.git and https

  1. Prior blunt chest trauma may be a cause of single vessel coronary disease; hypothesis and review

    DEFF Research Database (Denmark)

    Bartels, Mette Damkjær; Nielsen, PE; Sleight, P

    2006-01-01

    Prompted by a case where a patient (with no risk factors, and single vessel disease) developed angina pectoris after previous blunt chest trauma, we searched Medline for blunt chest trauma and myocardial ischaemia. We found 77 cases describing AMI after blunt chest trauma, but only one reporting...... angina pectoris. We focused on the age and sex distribution, type of trauma, the angiography findings and the time interval between the trauma and the angiography. The age distribution was atypical, compared to AMI in general; 82% of the patients with AMI after blunt chest trauma were less than 45 years......, which strongly suggested a causal relation between the trauma and subsequent occlusion. AMI should therefore be considered in patients suffering from chest pain after blunt chest trauma. Because traumatic AMI might often be the result of an intimal tear or dissection, thrombolytic therapy might worsen...

  2. [Problems with certification of work capability for people with symptoms of functional and organic diseases of cerebral vessels].

    Science.gov (United States)

    Polakowska, B

    1993-01-01

    The problems of certifying work capability for people with the symptoms of functional and organic diseases of cerebral vessels were investigated basing on the documentation of 470 medical consultations performed at the Out-Patient Department of Occupational Diseases, the Institute of Occupational Medicine, Lodz, Poland. The certification was most difficult in people with angiogenic headache, symptoms of transient cerebral ischaemia and apoplexy with non-intensive deficiency signs. The certification criteria most appropriate for that group of diseases were formulated.

  3. Frequency of significant three vessel coronary artery disease and left main stem disease in acute coronary syndrome patients having high LDL cholesterol level

    International Nuclear Information System (INIS)

    Zeb, S.; Achakzai, A.S.; Zeb, J.; Zeb, R.; Adil, M.; Jan, H.

    2017-01-01

    Objective: To calculate the frequency of significant three-vessel coronary artery and left main stem disease in patients presenting with acute coronary syndrome having high LDL cholesterol level. Methodology: This observational study was performed in Lady Reading Hospital, Peshawar, Pakistan from June 1, 2013 to December 31, 2013. All consecutive patients undergoing coronary angiography admitted with acute coronary syndrome within past 30 days and having LDL cholesterol more than 130mg/dl were included in the study. Demographic data was noted. The data was analyzed by using software SPSS version 16. Results: A total number of 206 patients were included in the study. Mean age was 51.25+-8.4 years. Of them, 139(67.5%) were male and 67(32.5%) female. Hypertension was found in 87(42.2%) patients, diabetes was found in 71(34.5%) patients, 56(27.2%) were smokers, family history of CAD was present in 39(18.9%) patients. The incidence of significant three vessel coronary artery disease was 52(25.2%) and left main stem disease were present in 15(7.2%). Out of 67(32.4%) with severe triple vessel and Left main stem disease, males were 51(76.1%) and females were 16(23.9%). Patients with significant three vessel and left main stem disease were more frequently males and younger. Conclusion: Patients having acute coronary syndrome with High LDL levels are more frequently have significant three vessel and Left main stem disease.

  4. Classic beta-amyloid deposits cluster around large diameter blood vessels rather than capillaries in sporadic Alzheimer's disease.

    Science.gov (United States)

    Armstrong, Richard A

    2006-11-01

    Various hypotheses could explain the relationship between beta-amyloid (Abeta) deposition and the vasculature in Alzheimer's disease (AD). Amyloid deposition may reduce capillary density, affect endothelial cells of blood vessels, result in diffusion from blood vessels, or interfere with the perivascular clearance mechanism. Hence, the spatial pattern of the classic ('cored') type of Abeta deposit was studied in the upper laminae (I,II/III) of the superior frontal gyrus in nine cases of sporadic AD (SAD). Sections were immunostained with antibodies against Abeta and with collagen IV to study the relationships between the spatial distribution of the classic deposits and the blood vessel profiles. Both the classic deposits and blood vessel profiles were distributed in clusters. In all cases, there was a positive spatial correlation between the clusters of the classic deposits and the larger diameter (>10 microm) blood vessel profiles and especially the vertically penetrating arterioles. In only 1 case, was there a significant spatial correlation between the clusters of the classic deposits and the smaller diameter (upper laminae of the frontal cortex. This aggregation could result from diffusion of proteins from blood vessels or from overloading the system of perivascular clearance from the brain.

  5. Dolichoectasia and Small Vessel Disease in Young Patients With Transient Ischemic Attack and Stroke.

    Science.gov (United States)

    Thijs, Vincent; Grittner, Ulrike; Fazekas, Franz; McCabe, Dominick J H; Giese, Anne-Katrin; Kessler, Christof; Martus, Peter; Norrving, Bo; Ringelstein, Erich Bernd; Schmidt, Reinhold; Tanislav, Christian; Putaala, Jukka; Tatlisumak, Turgut; von Sarnowski, Bettina; Rolfs, Arndt; Enzinger, Christian

    2017-09-01

    We evaluated whether basilar dolichoectasia is associated with markers of cerebral small vessel disease in younger transient ischemic attack and ischemic stroke patients. We used data from the SIFAP1 study (Stroke in Young Fabry Patients), a large prospective, hospital-based, screening study for Fabry disease in young (ischemic attack/stroke patients in whom detailed clinical data and brain MRI were obtained, and stroke subtyping with TOAST classification (Trial of ORG 10172 in Acute Stroke Treatment) was performed. Dolichoectasia was found in 508 of 3850 (13.2%) of patients. Dolichoectasia was associated with older age (odds ratio per decade, 1.26; 95% confidence interval, 1.09-1.44), male sex (odds ratio, 1.96; 95% confidence interval, 1.59-2.42), and hypertension (odds ratio, 1.39; 95% confidence interval, 1.13-1.70). Dolichoectasia was more common in patients with small infarctions (33.9% versus 29.8% for acute lesions, P =0.065; 29.1% versus 16.5% for old lesions, P ischemic attack and ischemic stroke. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00414583. © 2017 American Heart Association, Inc.

  6. A Fast SVD-Hidden-nodes based Extreme Learning Machine for Large-Scale Data Analytics.

    Science.gov (United States)

    Deng, Wan-Yu; Bai, Zuo; Huang, Guang-Bin; Zheng, Qing-Hua

    2016-05-01

    Big dimensional data is a growing trend that is emerging in many real world contexts, extending from web mining, gene expression analysis, protein-protein interaction to high-frequency financial data. Nowadays, there is a growing consensus that the increasing dimensionality poses impeding effects on the performances of classifiers, which is termed as the "peaking phenomenon" in the field of machine intelligence. To address the issue, dimensionality reduction is commonly employed as a preprocessing step on the Big dimensional data before building the classifiers. In this paper, we propose an Extreme Learning Machine (ELM) approach for large-scale data analytic. In contrast to existing approaches, we embed hidden nodes that are designed using singular value decomposition (SVD) into the classical ELM. These SVD nodes in the hidden layer are shown to capture the underlying characteristics of the Big dimensional data well, exhibiting excellent generalization performances. The drawback of using SVD on the entire dataset, however, is the high computational complexity involved. To address this, a fast divide and conquer approximation scheme is introduced to maintain computational tractability on high volume data. The resultant algorithm proposed is labeled here as Fast Singular Value Decomposition-Hidden-nodes based Extreme Learning Machine or FSVD-H-ELM in short. In FSVD-H-ELM, instead of identifying the SVD hidden nodes directly from the entire dataset, SVD hidden nodes are derived from multiple random subsets of data sampled from the original dataset. Comprehensive experiments and comparisons are conducted to assess the FSVD-H-ELM against other state-of-the-art algorithms. The results obtained demonstrated the superior generalization performance and efficiency of the FSVD-H-ELM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Diagnosis of moyamoya disease using 3-T MRI and MRA: value of cisternal moyamoya vessels

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Takeshi; Yamamoto, Akira; Okada, Tomohisa; Kanagaki, Mitsunori; Kasahara, Seiko; Togashi, Kaori [Kyoto University, Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto (Japan); Miki, Yukio [Osaka City University, Department of Radiology, Graduate School of Medicine, Osaka (Japan); Kikuta, Ken-ichiro [Fukui University, Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, Fukui (Japan); Miyamoto, Susumu; Takahashi, Jun C. [Kyoto University, Department of Neurosurgery, Graduate School of Medicine, Kyoto (Japan); Fukuyama, Hidenao [Kyoto University, Human Brain Research Center, Graduate School of Medicine, Kyoto (Japan)

    2012-10-15

    The purpose of this study was to propose new magnetic resonance (MR) criteria of diagnosing moyamoya disease (MMD) from cisternal moyamoya vessels (MMVs) on 3-T magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) and compare the diagnostic accuracy of the existing MR criteria and the proposed MR criteria. Participants comprised 20 consecutive patients with MMD (4 males, 16 females) diagnosed clinically using conventional angiography and 20 controls (13 male and 7 female arteriosclerosis patients). In these participants, 3-T MRI/MRA was evaluated by the existing MR criteria, which use MMVs in the basal ganglia, and the proposed MR criteria, which use cisternal MMVs, and then these two criteria were statistically compared by McNemar's test. Diagnostic accuracy was 62.5% with the existing MR criteria and 97.5% with the proposed MR criteria. The proposed MR criteria was more sensitive (1.00) than the existing MR criteria (0.45), but less specific (0.95) than the existing MR criteria (1.00). The proposed MR criteria using cisternal MMVs showed significantly higher diagnostic accuracy than the existing MR criteria. We believe that our proposed MR criteria will be beneficial for diagnosing MMD. (orig.)

  8. Diagnosis of moyamoya disease using 3-T MRI and MRA: value of cisternal moyamoya vessels

    International Nuclear Information System (INIS)

    Sawada, Takeshi; Yamamoto, Akira; Okada, Tomohisa; Kanagaki, Mitsunori; Kasahara, Seiko; Togashi, Kaori; Miki, Yukio; Kikuta, Ken-ichiro; Miyamoto, Susumu; Takahashi, Jun C.; Fukuyama, Hidenao

    2012-01-01

    The purpose of this study was to propose new magnetic resonance (MR) criteria of diagnosing moyamoya disease (MMD) from cisternal moyamoya vessels (MMVs) on 3-T magnetic resonance imaging (MRI)/magnetic resonance angiography (MRA) and compare the diagnostic accuracy of the existing MR criteria and the proposed MR criteria. Participants comprised 20 consecutive patients with MMD (4 males, 16 females) diagnosed clinically using conventional angiography and 20 controls (13 male and 7 female arteriosclerosis patients). In these participants, 3-T MRI/MRA was evaluated by the existing MR criteria, which use MMVs in the basal ganglia, and the proposed MR criteria, which use cisternal MMVs, and then these two criteria were statistically compared by McNemar's test. Diagnostic accuracy was 62.5% with the existing MR criteria and 97.5% with the proposed MR criteria. The proposed MR criteria was more sensitive (1.00) than the existing MR criteria (0.45), but less specific (0.95) than the existing MR criteria (1.00). The proposed MR criteria using cisternal MMVs showed significantly higher diagnostic accuracy than the existing MR criteria. We believe that our proposed MR criteria will be beneficial for diagnosing MMD. (orig.)

  9. Effects of cerebrovascular disease on amyloid precursor protein metabolites in cerebrospinal fluid

    Directory of Open Access Journals (Sweden)

    Rosengren Lars

    2010-07-01

    Full Text Available Abstract Background Alzheimer's disease (AD and cerebrovascular disease (CVD including chronic small vessel disease of the brain (SVD are the most frequent causes of dementia. AD is associated with metabolism of amyloid precursor protein (APP and low levels of amyloid-β peptide (Aβ X-42 in the cerebrospinal fluid (CSF. CVD and SVD are established risk factors for AD, brain white matter lesions (WML are established surrogate markers for SVD and are also associated with reduced CSF AβX-42. A cohort survey was performed to examine whether SVD or acute CVD affects APP metabolism and to explore a potential association between WML and APP metabolism in two groups; cognitively impaired patients, subjective and mild (SCI and MCI and stroke patients. Through measurements of CSF APP metabolite levels in patients with a wide range of WML volumes, this study aimed to determine how SVD influences APP metabolism. Methods Sixty-three patients were included: 37 with subjective cognitive impairment (SCI or mild cognitive impairment (MCI without stroke, and 26 after acute stroke. Chronic and acute WML volume and infarct volume were determined by magnetic resonance imaging (MRI post-scan processing, and CSF levels of α- and β-cleaved soluble APP (sAPP-α and sAPP-β, AβX-38, AβX-40 and AβX-42 were determined. The Mann-Whitney test was used to compare the patient groups. Chronic and acute WML volumes, infarct volume, age, and sex were used as predictors for CSF biomarker levels in linear regression analysis. Results CSF levels of sAPP-α and sAPP-β were strongly correlated (r = 0.95, p p p p ≤ 0.005; p ≤ 0.01; p ≤ 0.01; p ≤ 0.05; p ≤ 0.05 respectively, but not with acute WML or infarct volumes. Conclusions Lower CSF levels of sAPP-α and sAPP-β in the stroke group than in the SCI/MCI group and an inverse correlation with chronic WML indicate that ischemia lowers the levels of CSF sAPP metabolites and suggests that APP axonal transport or

  10. The Research on Denoising of SAR Image Based on Improved K-SVD Algorithm

    Science.gov (United States)

    Tan, Linglong; Li, Changkai; Wang, Yueqin

    2018-04-01

    SAR images often receive noise interference in the process of acquisition and transmission, which can greatly reduce the quality of images and cause great difficulties for image processing. The existing complete DCT dictionary algorithm is fast in processing speed, but its denoising effect is poor. In this paper, the problem of poor denoising, proposed K-SVD (K-means and singular value decomposition) algorithm is applied to the image noise suppression. Firstly, the sparse dictionary structure is introduced in detail. The dictionary has a compact representation and can effectively train the image signal. Then, the sparse dictionary is trained by K-SVD algorithm according to the sparse representation of the dictionary. The algorithm has more advantages in high dimensional data processing. Experimental results show that the proposed algorithm can remove the speckle noise more effectively than the complete DCT dictionary and retain the edge details better.

  11. Fault diagnosis for tilting-pad journal bearing based on SVD and LMD

    Directory of Open Access Journals (Sweden)

    Zhang Xiaotao

    2016-01-01

    Full Text Available Aiming at fault diagnosis for tilting-pad journal bearing with fluid support developed recently, a new method based on singular value decomposition (SVD and local mean decomposition (LMD is proposed. First, the phase space reconstruction of Hankel matrix and SVD method are used as pre-filter process unit to reduce the random noises in the original signal. Then the purified signal is decomposed by LMD into a series of production functions (PFs. Based on PFs, time frequency map and marginal spectrum can be obtained for fault diagnosis. Finally, this method is applied to numerical simulation and practical experiment data. The results show that the proposed method can effectively detect fault features of tilting-pad journal bearing.

  12. MDCTA diagnosis of cerebral vessel disease among patients with arterial hypertension

    International Nuclear Information System (INIS)

    Romanko-Hrushchak, Nataliya

    2013-01-01

    to study changes involving cerebral vessels in patients with hypertension and various levels of total cardiovascular risk. One hundred and thirty-four patients underwent CT-angiography of intracranial vessels. Ninety-eight of them were diagnosed with hypertension. Taking into consideration high blood pressure, presence of risk factors and target organ damage subjects were divided into 4 groups: with low, medium, high and very high total cardiovascular risk. Control group included 36 patients. They were not diagnosed with hypertension at the time of examination. One hundred and five patients were examined using a 4-slice CT scanner (Toshiba Asteion 4, Toshiba Medical System, Japan), and 29 patients were examined using a 128-slice scanner (Siemens Definition AS+, Siemens Healthcare, Germany) with an injection system. We used iodine-containing contrast agents such as iodixanol and iopromide for angiography. Anatomical and topographic changes of cerebral vessels were most frequently found in hypertensive patients with high and very high total cardiovascular risk. Narrowing of vertebral vessels was the most common change (27 patients (27.55%), 21 patients (21.43%) had narrowing of the right artery, and 6 (6.12%) subjects – of the left one). Tortuous course of internal carotid arteries at the neck level was visualized in 11 patients (11.22%). Narrowing of A1 segment of anterior cerebral artery was noted in 9 patients (9.18%), of the right one – in 8 patients (8.16%), of the left one – in 1 patient (1.02%). Aneurysmal dilation of intracranial vessels was visualized in 6 patients (6.12%). Saccular aneurysm of left internal carotid artery was diagnosed in 2 patients (2.04%), one patient (1.02%) had right internal carotid artery aneurysm and one patient (1.02%) had an aneurysm of the basilar artery. the most common changes of cerebral vessels diagnosed in MDCTA among patients with hypertension included various degrees of narrowing of vertebral vessels, anterior

  13. An R-peak detection method that uses an SVD filter and a search back system.

    Science.gov (United States)

    Jung, Woo-Hyuk; Lee, Sang-Goog

    2012-12-01

    In this paper, we present a method for detecting the R-peak of an ECG signal by using an singular value decomposition (SVD) filter and a search back system. The ECG signal was detected in two phases: the pre-processing phase and the decision phase. The pre-processing phase consisted of the stages for the SVD filter, Butterworth High Pass Filter (HPF), moving average (MA), and squaring, whereas the decision phase consisted of a single stage that detected the R-peak. In the pre-processing phase, the SVD filter removed noise while the Butterworth HPF eliminated baseline wander. The MA removed the remaining noise of the signal that had gone through the SVD filter to make the signal smooth, and squaring played a role in strengthening the signal. In the decision phase, the threshold was used to set the interval before detecting the R-peak. When the latest R-R interval (RRI), suggested by Hamilton et al., was greater than 150% of the previous RRI, the method of detecting the R-peak in such an interval was modified to be 150% or greater than the smallest interval of the two most latest RRIs. When the modified search back system was used, the error rate of the peak detection decreased to 0.29%, compared to 1.34% when the modified search back system was not used. Consequently, the sensitivity was 99.47%, the positive predictivity was 99.47%, and the detection error was 1.05%. Furthermore, the quality of the signal in data with a substantial amount of noise was improved, and thus, the R-peak was detected effectively. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  14. The risk of coronary heart disease of seafarers on vessels sailing under a German flag.

    Science.gov (United States)

    Oldenburg, Marcus; Jensen, Hans-Joachim; Latza, Ute; Baur, Xaver

    2010-01-01

    This study aimed to predict the risk of coronary heart disease (CHD) among seafarers on German-flagged vessels and to assess the association of shipboard job duration at sea with the risk of CHD. During the legally required medical fitness test for nautical service, 161 seafarers in Hamburg participated in a cross-sectional study which included an interview, blood sampling, and blood pressure measurements (response 84.9%). The predicted 10-year risk of an acute coronary event of the examined German seafarers aged 35 to 64 years (n = 46) was assessed in comparison with a sample of male German employees of the same age working ashore (PROCAM study). The number of independent CHD risk factors (according to the PROCAM study) was compared in the groups with 'shorter' and 'longer' median shipboard job duration at sea (15.0 years). The examined German seafarers had a similar age-standardized predicted 10-year CHD risk as the German reference population. Nearly all independent CHD risk factors were significantly more frequent in seamen with job duration at sea of ≥ 15 years than in those with 〈 15 years. After adjusting for age, the number of CHD risk factors was associated with job duration (OR 1.08 [95% CI 1.02-1.14] per year). Seafarers on German-flagged ships have to attend a medical fitness test for nautical service every 2 years. Thus, it can be assumed that seafarers present a healthier population than employees ashore. In this study, however, CHD risk of seafarers was similar to that of the reference population. This may indicate that working onboard implies a high coronary risk. Furthermore, the study results suggest a tendency of increased risk of CHD among seafarers with longer job duration at sea.

  15. Application of EMD-Based SVD and SVM to Coal-Gangue Interface Detection

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2014-01-01

    Full Text Available Coal-gangue interface detection during top-coal caving mining is a challenging problem. This paper proposes a new vibration signal analysis approach to detecting the coal-gangue interface based on singular value decomposition (SVD techniques and support vector machines (SVMs. Due to the nonstationary characteristics in vibration signals of the tail boom support of the longwall mining machine in this complicated environment, the empirical mode decomposition (EMD is used to decompose the raw vibration signals into a number of intrinsic mode functions (IMFs by which the initial feature vector matrices can be formed automatically. By applying the SVD algorithm to the initial feature vector matrices, the singular values of matrices can be obtained and used as the input feature vectors of SVMs classifier. The analysis results of vibration signals from the tail boom support of a longwall mining machine show that the method based on EMD, SVD, and SVM is effective for coal-gangue interface detection even when the number of samples is small.

  16. Diffusion tensor image segmentation of the cerebrum provides a single measure of cerebral small vessel disease severity related to cognitive change

    Directory of Open Access Journals (Sweden)

    Owen A. Williams

    2017-01-01

    DSEG θ is a powerful tool for characterising subtle brain change in SVD that has a negative impact on cognition and remains a significant predictor of cognitive change when other MRI markers of brain change are accounted for. DSEG provides an automatic segmentation of the whole cerebrum that is sensitive to a range of SVD related structural changes and successfully predicts cognitive change. Power analysis shows DSEG θ has potential as a monitoring tool in clinical trials. As such it may provide a marker of SVD severity from a single imaging modality (i.e. DTIs.

  17. Clinical Results of Arteriovenous Fistulas Constructed Using Autologous Vessels in End-Stage Renal Disease Patients on Hemodialysis

    Directory of Open Access Journals (Sweden)

    Ki Tae Kim

    2018-04-01

    Full Text Available Background: For hemodialysis patients with end-stage renal disease (ESRD, it is important to construct an efficient vascular access with a superior patency rate. This study investigated the factors influencing the efficiency of arteriovenous fistulas (AVFs constructed using an autologous vessel and evaluated the necessity of ultrasonography as a preoperative tool for AVF construction. Methods: A retrospective analysis was performed of 250 patients in whom an AVF was constructed using an autologous vessel due to ESRD at our institution from January 2009 to April 2016. Results: The 1-, 3-, and 5-year patency rates for all subjects were 87.6%, 85.6%, and 84.4%, respectively. The patients who underwent a preoperative evaluation of their vessels via ultrasonography had better patency rates than those who did not. Superior patency rates were found in patients under 65 years of age or with an anastomotic vein diameter of 3 mm or more. The 1-year patency rate and the diameter of the anastomotic vein showed a positive relationship. Conclusion: Ultrasonography is strongly recommended for AVF construction, and efforts should be made to increase the patency rate in patients over 65. Superior clinical results can be expected when an AVF is made using an autologous vessel with an anastomotic vein diameter of at least 3 mm.

  18. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer’s Disease Pathogenesis

    Science.gov (United States)

    Kyrtsos, Christina Rose; Baras, John S.

    2015-01-01

    Alzheimer’s disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain. PMID:26448331

  19. Vessel Operating Units (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for vessels that are greater than five net tons and have a current US Coast Guard documentation number. Beginning in1979, the NMFS...

  20. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  1. Batched QR and SVD Algorithms on GPUs with Applications in Hierarchical Matrix Compression

    KAUST Repository

    Halim Boukaram, Wajih

    2017-09-14

    We present high performance implementations of the QR and the singular value decomposition of a batch of small matrices hosted on the GPU with applications in the compression of hierarchical matrices. The one-sided Jacobi algorithm is used for its simplicity and inherent parallelism as a building block for the SVD of low rank blocks using randomized methods. We implement multiple kernels based on the level of the GPU memory hierarchy in which the matrices can reside and show substantial speedups against streamed cuSOLVER SVDs. The resulting batched routine is a key component of hierarchical matrix compression, opening up opportunities to perform H-matrix arithmetic efficiently on GPUs.

  2. A Hybrid DWT-SVD Image-Coding System (HDWTSVD for Color Images

    Directory of Open Access Journals (Sweden)

    Humberto Ochoa

    2003-04-01

    Full Text Available In this paper, we propose the HDWTSVD system to encode color images. Before encoding, the color components (RGB are transformed into YCbCr. Cb and Cr components are downsampled by a factor of two, both horizontally and vertically, before sending them through the encoder. A criterion based on the average standard deviation of 8x8 subblocks of the Y component is used to choose DWT or SVD for all the components. Standard test images are compressed based on the proposed algorithm.

  3. Batched QR and SVD Algorithms on GPUs with Applications in Hierarchical Matrix Compression

    KAUST Repository

    Halim Boukaram, Wajih; Turkiyyah, George; Ltaief, Hatem; Keyes, David E.

    2017-01-01

    We present high performance implementations of the QR and the singular value decomposition of a batch of small matrices hosted on the GPU with applications in the compression of hierarchical matrices. The one-sided Jacobi algorithm is used for its simplicity and inherent parallelism as a building block for the SVD of low rank blocks using randomized methods. We implement multiple kernels based on the level of the GPU memory hierarchy in which the matrices can reside and show substantial speedups against streamed cuSOLVER SVDs. The resulting batched routine is a key component of hierarchical matrix compression, opening up opportunities to perform H-matrix arithmetic efficiently on GPUs.

  4. Rare variants of the 3’-5’ DNA exonuclease TREX1 in early onset small vessel stroke [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sarah McGlasson

    2017-11-01

    Full Text Available Background: Monoallelic and biallelic mutations in the exonuclease TREX1 cause monogenic small vessel diseases (SVD. Given recent evidence for genetic and pathophysiological overlap between monogenic and polygenic forms of SVD, evaluation of TREX1 in small vessel stroke is warranted. Methods: We sequenced the TREX1 gene in an exploratory cohort of patients with lacunar stroke (Edinburgh Stroke Study, n=290 lacunar stroke cases. We subsequently performed a fully blinded case-control study of early onset MRI-confirmed small vessel stroke within the UK Young Lacunar Stroke Resource (990 cases, 939 controls. Results: No patients with canonical disease-causing mutations of TREX1 were identified in cases or controls. Analysis of an exploratory cohort identified a potential association between rare variants of TREX1 and patients with lacunar stroke. However, subsequent controlled and blinded evaluation of TREX1 in a larger and MRI-confirmed patient cohort, the UK Young Lacunar Stroke Resource, identified heterozygous rare variants in 2.1% of cases and 2.3% of controls. No association was observed with stroke risk (odds ratio = 0.90; 95% confidence interval, 0.49-1.65 p=0.74. Similarly no association was seen with rare TREX1 variants with predicted deleterious effects on enzyme function (odds ratio = 1.05; 95% confidence interval, 0.43-2.61 p=0.91. Conclusions: No patients with early-onset lacunar stroke had genetic evidence of a TREX1-associated monogenic microangiopathy. These results show no evidence of association between rare variants of TREX1 and early onset lacunar stroke. This includes rare variants that significantly affect protein and enzyme function. Routine sequencing of the TREX1 gene in patients with early onset lacunar stroke is therefore unlikely to be of diagnostic utility, in the absence of syndromic features or family history.

  5. Acute hypertensive encephalopathy with widespread small-vessel disease at MRI in a diabetic patient: pathogenetic hypotheses

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, F. [Centre Hospitalier Lyon Sud, Department of Radiology, Pierre Benite (France); Universite Claude-Bernard Lyon-I, CREATIS, UMR CNRS (France); Universite Claude-Bernard Lyon-I, Laboratoire d' Anatomie, Laennec (France); Kamoun, S.; Rety-Jacob, F.; Tran-Minh, V.A. [Centre Hospitalier Lyon Sud, Department of Radiology, Pierre Benite (France); Nighoghossian, N. [Hopital Neurologique et Neurochirurgical, Department of Neurology, Bron (France); Universite Claude-Bernard Lyon-I, CREATIS, UMR CNRS (France); Hermier, M. [Hopital Neurologique et Neurochirurgical, Department of Neuroradiology and MRI, Bron (France); Universite Claude-Bernard Lyon-I, CREATIS, UMR CNRS (France)

    2005-08-01

    We report unusual magnetic resonance imaging (MRI) findings in a diabetic patient with neglected hypertension and hyperglycemia, presenting with seizures and coma. Outcome was fatal despite intensive care. The MRI findings included bilateral insular and temporo-occipital grey and white matter involvement, and numerous, scattered, lacunar-like lesions involving the peripheral and deep white matter, basal ganglia grey matter, and brainstem. Lesions had a low apparent diffusion coefficient, and some enhanced following contrast injection. Hypertensive encephalopathy with widespread and severe acute small-vessel disease was considered. Pathophysiology is discussed. (orig.)

  6. Acute hypertensive encephalopathy with widespread small-vessel disease at MRI in a diabetic patient: pathogenetic hypotheses

    International Nuclear Information System (INIS)

    Cotton, F.; Kamoun, S.; Rety-Jacob, F.; Tran-Minh, V.A.; Nighoghossian, N.; Hermier, M.

    2005-01-01

    We report unusual magnetic resonance imaging (MRI) findings in a diabetic patient with neglected hypertension and hyperglycemia, presenting with seizures and coma. Outcome was fatal despite intensive care. The MRI findings included bilateral insular and temporo-occipital grey and white matter involvement, and numerous, scattered, lacunar-like lesions involving the peripheral and deep white matter, basal ganglia grey matter, and brainstem. Lesions had a low apparent diffusion coefficient, and some enhanced following contrast injection. Hypertensive encephalopathy with widespread and severe acute small-vessel disease was considered. Pathophysiology is discussed. (orig.)

  7. Utilization of self-expanding stents in the treatment of intracranial atherosclerotic disease in the distal small cerebral vessels

    International Nuclear Information System (INIS)

    Turk, Aquilla S.; Niemann, David B.; Aagaard-Kienitz, Beverly; Ahmed, Azam; Brooks, Nathaniel; Levine, Ross L.

    2007-01-01

    Previously, endovascular treatment of stenosis related to intracranial atherosclerosis (ICAD) involving arteries measuring less than 2 mm in diameter was limited. To our knowledge, there are no reports in the literature addressing stent placement for treatment of stenosis in arteries of this size. Four patients aged 33 to 80 years (mean 57.5 years) with medically refractory ICAD underwent angioplasty and stenting of small (<2 mm) distal intracerebral arteries. Vessel location and length of follow-up were anterior cerebral artery (ACA) A1 segment (5 months), ACA A2 segment (18 months), middle cerebral artery M1 segment (18 months), and posterior cerebral artery P1 segment (8 months) with vessel calibers ranging from 1.2 to 1.8 mm. Clinical and imaging follow-up ranged from 5 to 18 months. All procedures were successfully performed without complications. Follow-up out to 18 months demonstrated one vessel that went on to occlusion while the other stented vessel segments remained patent. One patient died 8 months after stenting, but the death was not related to neurological disease. The remaining patients experienced resolution of the presenting symptomatology and remained asymptomatic throughout follow-up. In this small series, stenoses of distal (<2 mm) cerebral arteries were amenable to treatment using new self-expanding stents. We safely and successfully treated four arteries smaller than 2 mm in diameter with newer self-expanding stents. All patients remained clinically asymptomatic. One stent occluded at 5 months and the others remained patent during follow-up. Longer term clinical follow-up is required to determine the durability and viability of this therapy. (orig.)

  8. The clinical value and limitation of exercise electrocardiography and exercise thallium-201 myocardial scintigraphy in the diagnosis of coronary artery disease, with special reference to single vessel disease

    International Nuclear Information System (INIS)

    Fujioka, Tatsuo; Shibata, Nitaro; Shimizu, Yoichi; Itoh, Yukiyoshi; Abe, Mitsuki; Tanaka, Toshihide; Matsuda, Mitsukazu; Obunai, Yoshio

    1984-01-01

    The clinical value and limitation of exercise electrocardiography and exercise thallium-201 myocardial scintigraphy were studied in 40 patients with no previous history of myocardial infarction. Coronary angiography was performed on all the patients. Compared with thallium-201 myocardial scintigraphy, treadmill exercise electrocardiography showed greater sensitivity (84% versus 63%) in diagnosing coronary stenosis of more than 50%. In patients with single vessel discase, the results of sensitivities were similar (75% to 65%). However, the specificity of thallium-201 myocardial scintigraphy was higher than that of exercise electrocardiography (100% compared to 63%). Nine patients with evidence of significant lesions using coronary angiography, showed normal conditions using exercise electrocardiography and thallium myocardial scintigraphy examinations as well. All these patients had a history of chest pain, and 4 of them experienced chest pain during exercise. In cases with false negative exercise tests, the clinical symptoms and exercise-induced chest pain seem to be important diagnostic signs when evaluating patients with coronary artery disease. In 15 patients with isolated single vessel coronary artery disease (more than 75% stenosis of luminal diameter in only one vessel), the site of ST segment depression did not coincide with the stenotic lesion. The site of reversible perfusion defect on thallium-201 myocardial scintigraphy did, however, coincide with the site of myocardial ishemia and the stenotic lesion in most cases. (author)

  9. A Fault Diagnosis Model Based on LCD-SVD-ANN-MIV and VPMCD for Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Songrong Luo

    2016-01-01

    Full Text Available The fault diagnosis process is essentially a class discrimination problem. However, traditional class discrimination methods such as SVM and ANN fail to capitalize the interactions among the feature variables. Variable predictive model-based class discrimination (VPMCD can adequately use the interactions. But the feature extraction and selection will greatly affect the accuracy and stability of VPMCD classifier. Aiming at the nonstationary characteristics of vibration signal from rotating machinery with local fault, singular value decomposition (SVD technique based local characteristic-scale decomposition (LCD was developed to extract the feature variables. Subsequently, combining artificial neural net (ANN and mean impact value (MIV, ANN-MIV as a kind of feature selection approach was proposed to select more suitable feature variables as input vector of VPMCD classifier. In the end of this paper, a novel fault diagnosis model based on LCD-SVD-ANN-MIV and VPMCD is proposed and proved by an experimental application for roller bearing fault diagnosis. The results show that the proposed method is effective and noise tolerant. And the comparative results demonstrate that the proposed method is superior to the other methods in diagnosis speed, diagnosis success rate, and diagnosis stability.

  10. Extracting semantic representations from word co-occurrence statistics: stop-lists, stemming, and SVD.

    Science.gov (United States)

    Bullinaria, John A; Levy, Joseph P

    2012-09-01

    In a previous article, we presented a systematic computational study of the extraction of semantic representations from the word-word co-occurrence statistics of large text corpora. The conclusion was that semantic vectors of pointwise mutual information values from very small co-occurrence windows, together with a cosine distance measure, consistently resulted in the best representations across a range of psychologically relevant semantic tasks. This article extends that study by investigating the use of three further factors--namely, the application of stop-lists, word stemming, and dimensionality reduction using singular value decomposition (SVD)--that have been used to provide improved performance elsewhere. It also introduces an additional semantic task and explores the advantages of using a much larger corpus. This leads to the discovery and analysis of improved SVD-based methods for generating semantic representations (that provide new state-of-the-art performance on a standard TOEFL task) and the identification and discussion of problems and misleading results that can arise without a full systematic study.

  11. Precision PEP-II optics measurement with an SVD-enhanced Least-Square fitting

    Science.gov (United States)

    Yan, Y. T.; Cai, Y.

    2006-03-01

    A singular value decomposition (SVD)-enhanced Least-Square fitting technique is discussed. By automatic identifying, ordering, and selecting dominant SVD modes of the derivative matrix that responds to the variations of the variables, the converging process of the Least-Square fitting is significantly enhanced. Thus the fitting speed can be fast enough for a fairly large system. This technique has been successfully applied to precision PEP-II optics measurement in which we determine all quadrupole strengths (both normal and skew components) and sextupole feed-downs as well as all BPM gains and BPM cross-plane couplings through Least-Square fitting of the phase advances and the Local Green's functions as well as the coupling ellipses among BPMs. The local Green's functions are specified by 4 local transfer matrix components R12, R34, R32, R14. These measurable quantities (the Green's functions, the phase advances and the coupling ellipse tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a high-resolution model-independent analysis (MIA). Once all of the quadrupoles and sextupole feed-downs are determined, we obtain a computer virtual accelerator which matches the real accelerator in linear optics. Thus, beta functions, linear coupling parameters, and interaction point (IP) optics characteristics can be measured and displayed.

  12. The Vulnerability of Vessels Involved in the Role of Embolism and Hypoperfusion in the Mechanisms of Ischemic Cerebrovascular Diseases

    Directory of Open Access Journals (Sweden)

    Yong Peng Yu

    2016-01-01

    Full Text Available Accurate definition and better understanding of the mechanisms of stroke are crucial as this will guide the effective care and therapy. In this paper, we review the previous basic and clinical researches on the causes or mechanisms of ischemic cerebrovascular diseases (ICVD and interpret the correlation between embolism and hypoperfusion based on vascular stenosis and arterial intimal lesions. It was suggested that if there is no embolus (dynamic or in situ emboli, there might be no cerebral infarction. Three kinds of different clinical outcomes of TIA were theoretically interpreted based on its mechanisms. We suppose that there is a correlation between embolism and hypoperfusion, and which mechanisms (hypoperfusion or hypoperfusion induced microemboli playing the dominant role in each type of ICVD depends on the unique background of arterial intimal lesions (the vulnerability of vessels. That is to say, the vulnerability of vessels is involved in the role of embolism and hypoperfusion in the mechanisms of ischemic cerebrovascular diseases. This inference might enrich and provide better understandings for the underlying etiologies of ischemic cerebrovascular events.

  13. Intracranial Vascular Disease Evaluation With Combined Vessel Wall Imaging And Patient Specific Hemodynamics

    Science.gov (United States)

    Samson, Kurt; Mossa-Basha, Mahmud; Yuan, Chun; Canton, Maria De Gador; Aliseda, Alberto

    2017-11-01

    Intracranial vascular pathologies are evaluated with angiography, conventional digital subtraction angiography or non-invasive (MRI, CT). Current techniques present limitations on the resolution with which the vessel wall characteristics can be measured, presenting a major challenge to differential diagnostic of cerebral vasculopathies. A new combined approach is presented that incorporates patient-specific image-based CFD models with intracranial vessel-wall MRI (VWMRI). Comparisons of the VWMRI measurements, evaluated for the presence of wall enhancement and thin-walled regions, against CFD metrics such as wall shear stress (WSS), and oscillatory shear index (OSI) are used to understand how the new imaging technique developed can predict the influence of hemodynamics on the deterioration of the aneurysmal wall, leading to rupture. Additionally, histology of each resected aneurysm, evaluated for inflammatory infiltration and wall thickness features, is used to validate the analysis from VWMRI and CFD. This data presents a solid foundation on which to build a new framework for combined VWMRI-CFD to predict unstable wall changes in unruptured intracranial aneurysms, and support clinical monitoring and intervention decisions.

  14. Diagnostic value of Doppler assessment of the hepatic and portal vessels and ultrasound of the spleen in liver disease.

    Science.gov (United States)

    O'Donohue, John; Ng, Chaan; Catnach, Susan; Farrant, Patricia; Williams, Roger

    2004-02-01

    To investigate the clinical utility and the intra-observer and inter-observer variability of Doppler ultrasound assessment of the hepatic and portal vessels along with measurement of spleen size in the diagnosis of chronic liver disease and cirrhosis. Ultrasound measurements of portal vein diameter (PVD), portal vein velocity (PVV), hepatic arterial resistance index (HARI), hepatic vein profile (HVP), and spleen size were obtained in 49 controls and 45 patients with liver disease (23 with primary biliary cirrhosis, 22 with hepatitis C) by two experienced observers, who each performed three blinded measurements of each variable. Control values were derived from normal hospital workers. Percutaneous liver biopsies in 41 of the patients showed cirrhosis (14 patients), moderate/severe fibrosis (13 patients), and early disease (14 patients). Seventy-one percent of cirrhotic patients had splenomegaly (> 13.6 cm). The spleen size was significantly larger in cirrhotics (16.0 cm) than in non-cirrhotics (13.0 cm, P HVP was abnormal in 76.9% of cirrhotics, 57.7% of non-cirrhotics and 2.1% of controls (P HVP are useful predictors of chronic liver disease and cirrhosis, and both can be measured reliably and reproducibly. However, Doppler measurements of PVV, PVD and HARI are not useful in distinguishing patients with chronic liver disease from normal controls.

  15. Bioresorbable vascular scaffolds for LMCA with double vessel disease under IVUS guidance

    Directory of Open Access Journals (Sweden)

    Sridhar Kasturi, MD, DM, FACC

    2015-12-01

    Full Text Available An 80-year-old male patient, presented with chest pain. ECG showed ST elevation in leads V2 to V4 and T wave inversion in leads V2-V6. Check angiogram revealed ostial LMCA 70% lesion & mid-LAD 90% lesion and LCX proximal 80% lesion. Predilatation of LMCA lesion was done with 2.0 × 12 mm NC Trek balloon and the LAD lesion with 2.0 × 12 mm and 2.5 × 08 mm (NC Trek balloons. Prestenting IVUS (Intravascular ultrasound was done with Atlantis SR pro 40 MHz 3.6Fr catheter. IVUS showed the LAD to have a minimal lumen area of 2.6 sq mm with 90% fibrotic plaque and a vessel size of 2.5 mm and the LMCA to have a minimal lumen area of 8.8 sq mm with 70% fibrotic plaque and vessel size of 3.8 mm. Mid-LAD stenting was done with 2.5 × 28 mm Absorb Stent (BVS. Predilatation of LCX lesion was done with 2.5 × 08 mm NC Trek balloon. Then stenting was performed with 3.0 × 28 mm Absorb Stent (BVS. Check angiogram showed edge dissection proximal to the BVS Stent which was covered with 3.0 × 12 mm Xience Xpedtion Stent (DES. Then LMCA Stenting was done with 3.5 × 12 mm Absorb Stent. Post dilatation was done with 4.0 × 08 mm NC Trek balloon. Post Stenting LMCA - LAD IVUS was done. LMCA and LAD Stents were well opposed without any dissection or residual stenosis. TIMI III Flow was achieved in the final results.

  16. Low QRS Voltage on Presenting Electrocardiogram Predicts Multi-vessel Disease in Anterior ST-segment Elevation Myocardial Infarction.

    Science.gov (United States)

    Kobayashi, Akihiro; Misumida, Naoki; Aoi, Shunsuke; Kanei, Yumiko

    Low QRS voltage was reported to predict adverse outcomes in acute myocardial infarction in the pre-thrombolytic era. However, the association between low voltage and angiographic findings has not been fully addressed. We performed a retrospective analysis of patients with anterior ST-segment elevation myocardial infarction (STEMI). Low QRS voltage was defined as either peak to peak QRS complex voltage voltage. Patients with low voltage had a higher rate of multi-vessel disease (MVD) (76% vs. 52%, p=0.01). Patients with low voltage were more likely to undergo coronary artery bypass grafting (CABG) during admission (11% vs. 2%, p=0.028). Low voltage was an independent predictor for MVD (OR 2.50; 95% CI 1.12 to 6.03; p=0.032). Low QRS voltage was associated with MVD and in-hospital CABG in anterior STEMI. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Spatial distribution of diffuse, primitive, and classic amyloid-beta deposits and blood vessels in the upper laminae of the frontal cortex in Alzheimer disease.

    Science.gov (United States)

    Armstrong, R A; Cairns, N J; Lantos, P L

    1998-12-01

    The spatial distribution of the diffuse, primitive, and classic amyloid-beta deposits was studied in the upper laminae of the superior frontal gyrus in cases of sporadic Alzheimer disease (AD). Amyloid-beta-stained tissue was counterstained with collagen IV to determine whether the spatial distribution of the amyloid-beta deposits along the cortex was related to blood vessels. In all patients, amyloid-beta deposits and blood vessels were aggregated into distinct clusters and in many patients, the clusters were distributed with a regular periodicity along the cortex. The clusters of diffuse and primitive deposits did not coincide with the clusters of blood vessels in most patients. However, the clusters of classic amyloid-beta deposits coincided with those of the large diameter (>10 microm) blood vessels in all patients and with clusters of small-diameter (upper cortical laminae.

  18. Proton density differences in signal characteristics of multiple sclerosis plaques versus white matter lesions of small vessel disease and vasculitis on high-field strength MR images

    International Nuclear Information System (INIS)

    Peyster, R.G.; Siegal, T.L.

    1990-01-01

    This paper determines if variations in signal intensity characteristics on multi-spin-echo images obtained with a high-field-strength magnet can be useful in differentiating demyelinating plaques of multiple sclerosis from other pathologic white matter processes due to small vessel disease and vasculities. Using the first of two multi-spin-echo images obtained with a General Electric 1.5-T magnet, the investigators compared signal intensity characteristics in 30 patients with a firm clinical diagnosis of multiple sclerosis versus a control group of 30 patients with a known clinical history of small-vessel disease and vasculitis are isodense to gray matter on proton-density images

  19. A New Adaptive Gamma Correction Based Algorithm Using DWT-SVD for Non-Contrast CT Image Enhancement.

    Science.gov (United States)

    Kallel, Fathi; Ben Hamida, Ahmed

    2017-12-01

    The performances of medical image processing techniques, in particular CT scans, are usually affected by poor contrast quality introduced by some medical imaging devices. This suggests the use of contrast enhancement methods as a solution to adjust the intensity distribution of the dark image. In this paper, an advanced adaptive and simple algorithm for dark medical image enhancement is proposed. This approach is principally based on adaptive gamma correction using discrete wavelet transform with singular-value decomposition (DWT-SVD). In a first step, the technique decomposes the input medical image into four frequency sub-bands by using DWT and then estimates the singular-value matrix of the low-low (LL) sub-band image. In a second step, an enhanced LL component is generated using an adequate correction factor and inverse singular value decomposition (SVD). In a third step, for an additional improvement of LL component, obtained LL sub-band image from SVD enhancement stage is classified into two main classes (low contrast and moderate contrast classes) based on their statistical information and therefore processed using an adaptive dynamic gamma correction function. In fact, an adaptive gamma correction factor is calculated for each image according to its class. Finally, the obtained LL sub-band image undergoes inverse DWT together with the unprocessed low-high (LH), high-low (HL), and high-high (HH) sub-bands for enhanced image generation. Different types of non-contrast CT medical images are considered for performance evaluation of the proposed contrast enhancement algorithm based on adaptive gamma correction using DWT-SVD (DWT-SVD-AGC). Results show that our proposed algorithm performs better than other state-of-the-art techniques.

  20. Patterns of cortical degeneration in an elderly cohort with cerebral small vessel disease.

    NARCIS (Netherlands)

    Reid, A.T.; Norden, A.G.W. van; Laat, K.F. de; Oudheusden, L.J.B. van; Zwiers, M.P.; Evans, A.C.; Leeuw, F.E. de; Kotter, R.

    2010-01-01

    Emerging noninvasive neuroimaging techniques allow for the morphometric analysis of patterns of gray and white matter degeneration in vivo, which may help explain and predict the occurrence of cognitive impairment and Alzheimer's disease. A single center prospective follow-up study (Radboud

  1. Alzheimer's disease, cerebrovascular dysfunction and the benefits of exercise: from vessels to neurons.

    Science.gov (United States)

    Lange-Asschenfeldt, Christian; Kojda, Georg

    2008-06-01

    Exercise training promotes extensive cardiovascular changes and adaptive mechanisms in both the peripheral and cerebral vasculature, such as improved organ blood flow, induction of antioxidant pathways, and enhanced angiogenesis and vascular regeneration. Clinical studies have demonstrated a reduction of morbidity and mortality from cardiovascular disease among exercising individuals. However, evidence from recent large clinical trials also suggests a substantial reduction of dementia risk - particularly regarding Alzheimer's disease (AD) - with regular exercise. Enhanced neurogenesis and improved synaptic plasticity have been implicated in this beneficial effect. However, recent research has revealed that vascular and specifically endothelial dysfunction is essentially involved in the disease process and profoundly aggravates underlying neurodegeneration. Moreover, vascular risk factors (VRFs) are probably determinants of incidence and course of AD. In this review, we emphasize the interconnection between AD and VRFs and the impact of cerebrovascular and endothelial dysfunction on AD pathophysiology. Furthermore, we describe the molecular mechanisms of the beneficial effects of exercise on the vasculature such as activation of the vascular nitric oxide (NO)/endothelial NO synthase (eNOS) pathway, upregulation of antioxidant enzymes, and angiogenesis. Finally, recent prospective clinical studies dealing with the effect of exercise on the risk of incident AD are briefly reviewed. We conclude that, next to upholding neuronal plasticity, regular exercise may counteract AD pathophysiology by building a vascular reserve.

  2. Research vessels

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.

    The role of the research vessels as a tool for marine research and exploration is very important. Technical requirements of a suitable vessel and the laboratories needed on board are discussed. The history and the research work carried out...

  3. Exclusive use of arterial grafts in coronary artery bypass operations for three-vessel disease : Use of both thoracic arteries and the gastroepiploic artery in 256 consecutive patients

    NARCIS (Netherlands)

    Grandjean, JG; Voors, AA; Boonstra, PW; denHeyer, P; Ebels, T

    1996-01-01

    Methods: From September 1989 to September 1994 we operated on a consecutive group of 256 patients with three-vessel disease in whom we used the right gastroepiploic artery together with both internal thoracic arteries, Vein grafts were not used in these patients, This population consisted of 233 men

  4. Hospital patterns of medical management strategy use for patients with non-ST-elevation myocardial infarction and 3-vessel or left main coronary artery disease

    NARCIS (Netherlands)

    Harskamp, Ralf E.; Wang, Tracy Y.; Bhatt, Deepak L.; Wiviott, Stephen D.; Amsterdam, Ezra A.; Li, Shuang; Thomas, Laine; de Winter, Robbert J.; Roe, Matthew T.

    2014-01-01

    Patients with non-ST-elevation myocardial infarction (NSTEMI) and three-vessel or left main coronary disease (3VD/LMD) have a high risk of long-term mortality when treated with a medical management strategy (MMS) compared with revascularization. We evaluated patterns of use and patient features

  5. Higher incidence of death in multi-vessel coronary artery disease patients associated with polymorphisms in chromosome 9p21

    Directory of Open Access Journals (Sweden)

    Gioli-Pereira Luciana

    2012-08-01

    Full Text Available Abstract Background We investigated whether 9p21 polymorphisms are associated with cardiovascular events in a group of 611 patients enrolled in the Medical, Angioplasty or Surgery Study II (MASS II, a randomized trial comparing treatments for patients with coronary artery disease (CAD and preserved left ventricular function. Methods The participants of the MASS II were genotyped for 9p21 polymorphisms (rs10757274, rs2383206, rs10757278 and rs1333049. Survival curves were calculated with the Kaplan–Meier method and compared with the log-rank statistic. We assessed the relationship between baseline variables and the composite end-point of death, death from cardiac causes and myocardial infarction using a Cox proportional hazards survival model. Results We observed significant differences between patients within each polymorphism genotype group for baseline characteristics. The frequency of diabetes was lower in patients carrying GG genotype for rs10757274, rs2383206 and rs10757278 (29.4%, 32.8%, 32.0% compared to patients carrying AA or AG genotypes (49.1% and 39.2%, p = 0.01; 52.4% and 40.1%, p = 0.01; 47.8% and 37.9%, p = 0.04; respectively. Significant differences in genotype frequencies between double and triple vessel disease patients were observed for the rs10757274, rs10757278 and rs1333049. Finally, there was a higher incidence of overall mortality in patients with the GG genotype for rs2383206 compared to patients with AA and AG genotypes (19.5%, 11.9%, 11.0%, respectively; p = 0.04. Moreover, the rs2383206 was still significantly associated with a 1.75-fold increased risk of overall mortality (p = 0.02 even after adjustment of a Cox multivariate model for age, previous myocardial infarction, diabetes, smoking and type of coronary anatomy. Conclusions Our data are in accordance to previous evidence that chromosome 9p21 genetic variation may constitute a genetic modulator in the cardiovascular system in different

  6. Planning of vessel grafts for reconstructive surgery in congenital heart diseases

    Science.gov (United States)

    Rietdorf, U.; Riesenkampff, E.; Schwarz, T.; Kuehne, T.; Meinzer, H.-P.; Wolf, I.

    2010-02-01

    The Fontan operation is a surgical treatment for patients with severe congenital heart diseases, where a biventricular correction of the heart can't be achieved. In these cases, a uni-ventricular system is established. During the last step of surgery a tunnel segment is placed to connect the inferior caval vein directly with the pulmonary artery, bypassing the right atrium and ventricle. Thus, the existing ventricle works for the body circulation, while the venous blood is passively directed to the pulmonary arteries. Fontan tunnels can be placed intra- and extracardially. The location, length and shape of the tunnel must be planned accurately. Furthermore, if the tunnel is placed extracardially, it must be positioned between other anatomical structures without constraining them. We developed a software system to support planning of the tunnel location, shape, and size, making pre-operative preparation of the tunnel material possible. The system allows for interactive placement and adjustment of the tunnel, affords a three-dimensional visualization of the virtual Fontan tunnel inside the thorax, and provides a quantification of the length, circumferences and diameters of the tunnel segments. The visualization and quantification can be used to plan and prepare the tunnel material for surgery in order to reduce the intra-operative time and to improve the fit of the tunnel patch.

  7. Multi-linear sparse reconstruction for SAR imaging based on higher-order SVD

    Science.gov (United States)

    Gao, Yu-Fei; Gui, Guan; Cong, Xun-Chao; Yang, Yue; Zou, Yan-Bin; Wan, Qun

    2017-12-01

    This paper focuses on the spotlight synthetic aperture radar (SAR) imaging for point scattering targets based on tensor modeling. In a real-world scenario, scatterers usually distribute in the block sparse pattern. Such a distribution feature has been scarcely utilized by the previous studies of SAR imaging. Our work takes advantage of this structure property of the target scene, constructing a multi-linear sparse reconstruction algorithm for SAR imaging. The multi-linear block sparsity is introduced into higher-order singular value decomposition (SVD) with a dictionary constructing procedure by this research. The simulation experiments for ideal point targets show the robustness of the proposed algorithm to the noise and sidelobe disturbance which always influence the imaging quality of the conventional methods. The computational resources requirement is further investigated in this paper. As a consequence of the algorithm complexity analysis, the present method possesses the superiority on resource consumption compared with the classic matching pursuit method. The imaging implementations for practical measured data also demonstrate the effectiveness of the algorithm developed in this paper.

  8. SVD-BASED TRANSMIT BEAMFORMING FOR VARIOUS MODULATIONS WITH CONVOLUTION ENCODING

    Directory of Open Access Journals (Sweden)

    M. Raja

    2011-09-01

    Full Text Available This paper present a new beamforming technique using singular value decomposition (SVD for closed loop Multiple-input, multiple-output (MIMO wireless systems with various modulation techniques such as BPSK, 16-QAM, 16-PSK, DPSK and PAM along with convolution encoder. The channel matrix is decomposed into a number of independent orthogonal modes of excitation, which refer to as eigenmodes of the channel. Transmit precoding is performed by multiplying the input symbols with unitary matrix to produce the transmit beamforming, and the precoded symbols are transmitted over Rayleigh fading channel. At the receiver, combining process is performed by using maximum ratio combiner (MRC, and the receiver shaping is performed to retrieve the original input symbols by multiplying the received signal with conjugate transpose of the unitary matrix. Furthermore, the expressions for average bit error rate (BER for M-PSK and average BER for M-QAM are derived. The superiority of the proposed work is proved by simulation results and the proposed work is compared to the other beamforming methods.

  9. Comparison of DCT, SVD and BFOA based multimodal biometric watermarking system

    Directory of Open Access Journals (Sweden)

    S. Anu H. Nair

    2015-12-01

    Full Text Available Digital image watermarking is a major domain for hiding the biometric information, in which the watermark data are made to be concealed inside a host image imposing imperceptible change in the picture. Due to the advance in digital image watermarking, the majority of research aims to make a reliable improvement in robustness to prevent the attack. The reversible invisible watermarking scheme is used for fingerprint and iris multimodal biometric system. A novel approach is used for fusing different biometric modalities. Individual unique modalities of fingerprint and iris biometric are extracted and fused using different fusion techniques. The performance of different fusion techniques is evaluated and the Discrete Wavelet Transform fusion method is identified as the best. Then the best fused biometric template is watermarked into a cover image. The various watermarking techniques such as the Discrete Cosine Transform (DCT, Singular Value Decomposition (SVD and Bacterial Foraging Optimization Algorithm (BFOA are implemented to the fused biometric feature image. Performance of watermarking systems is compared using different metrics. It is found that the watermarked images are found robust over different attacks and they are able to reverse the biometric template for Bacterial Foraging Optimization Algorithm (BFOA watermarking technique.

  10. A Reliable Image Watermarking Scheme Based on Redistributed Image Normalization and SVD

    Directory of Open Access Journals (Sweden)

    Musrrat Ali

    2016-01-01

    Full Text Available Digital image watermarking is the process of concealing secret information in a digital image for protecting its rightful ownership. Most of the existing block based singular value decomposition (SVD digital watermarking schemes are not robust to geometric distortions, such as rotation in an integer multiple of ninety degree and image flipping, which change the locations of the pixels but don’t make any changes to the pixel’s intensity of the image. Also, the schemes have used a constant scaling factor to give the same weightage to the coefficients of different magnitudes that results in visible distortion in some regions of the watermarked image. Therefore, to overcome the problems mentioned here, this paper proposes a novel image watermarking scheme by incorporating the concepts of redistributed image normalization and variable scaling factor depending on the coefficient’s magnitude to be embedded. Furthermore, to enhance the security and robustness the watermark is shuffled by using the piecewise linear chaotic map before the embedding. To investigate the robustness of the scheme several attacks are applied to seriously distort the watermarked image. Empirical analysis of the results has demonstrated the efficiency of the proposed scheme.

  11. PERBANDINGAN QUANTUM CLUSTERING DAN SUPPORT VECTOR CLUSTERING UNTUK DATA MICROARRAY EXPRESSION YEAST CELL DALAM RUANG SINGULAR VALUE DECOMPOSITION (SVD)

    OpenAIRE

    ., Riwinoto

    2013-01-01

    Sekarang ini, metode clustering telah diimplementasikan dalam riset DNA. Data dari DNA didapat melalui teknik microarray. Dengan menggunakan metode teknik SVD, dimensi data dikurangi sehingga mempermudah proses komputasi. Dalam paper ini, ditampilkan hasil clustering tanpa pengarahan terhadap gen-gen dari data bakteri ragi dengan menggunakan metode quantum clustering. Sebagai pembanding, dilakukan juga clustering menggunakan metoda Support Vector Clustering. Selain itu juga ditampilkan data h...

  12. Altered low frequency oscillations of cortical vessels in patients with cerebrovascular occlusive disease – a NIRS study

    Directory of Open Access Journals (Sweden)

    Dorte ePhillip

    2013-12-01

    Full Text Available Analysis of cerebral autoregulation by measuring spontaneous oscillations in the low frequency spectrum of cerebral cortical vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease (CAD and stroke. Near infrared spectroscopy (NIRS is a non-invasive optical method to investigate regional changes in oxygenated (oxyHb and deoxygenated hemoglobin (deoxyHb in the outermost layers of the cerebral cortex. In the present study we examined oxyHb low frequency oscillations (LFOs, believed to reflect cortical cerebral autoregulation, in 16 patients with both symptomatic carotid occlusive disease and cerebral hypoperfusion in comparison to healthy controls. Each hemisphere was examined with 2 NIRS channels using a 3 cm source detector distance. Arterial blood pressure (ABP was measured via a finger plethysmograph. Using transfer function analysis ABP-oxyHb phase shift and gain as well as inter-hemispheric phase shift and amplitude ratio were assessed. We found that inter-hemispheric amplitude ratio was significantly altered in hypoperfusion patients compared to healthy controls (P= 0.010, because of relatively lower amplitude on the hypoperfusion side. The inter-hemispheric phase shift showed a trend (P = 0.061 towards increased phase shift in hypoperfusion patients compared to controls. We found no statistical difference between hemispheres in hypoperfusion patients for phase shift or gain values. There were no differences between the hypoperfusion side and controls for phase shift or gain values. These preliminary results suggest an impairment of autoregulation in hypoperfusion patients at the cortical level using NIRS.

  13. Cortical changes in cerebral small vessel diseases: a 3D MRI study of cortical morphology in CADASIL

    International Nuclear Information System (INIS)

    Jouvent, E.; Bousser, M.G.; Chabriat, H.; Jouvent, E.; Bousser, M.G.; Chabriat, H.; Porcher, R.; Viswanathan, A.; Viswanathan, A.; Viswanathan, A.; O'Sullivan, M.; Dichgans, M.; Guichard, J.P.

    2008-01-01

    Brain atrophy represents a key marker of disease progression in cerebrovascular disorders. The 3D changes of cortex morphology occurring during the course of small vessel diseases of the brain (SVDB) remain poorly understood. The objective of this study was to assess the changes affecting depth and surface area of cortical sulci and their clinical and radiological correlates in a cohort of patients with cerebral autosomal dominant arteriolopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a genetic SVDB. Data were obtained from a series of 69 CADASIL patients. Validated methods were used to determine depth and surface area of four cortical sulci. The ratio of brain to intracranial cavity volumes (brain parenchymal fraction-BPF), volume of lacunar lesions (LL) and of white matter hyper-intensities, number of cerebral micro-haemorrhages, and mean apparent diffusion coefficient were also measured. Association between depth and surface area of the cortical sulci and BPF, clinical status and subcortical MRI lesions were tested. Depth and surface area of cortical sulci obtained in 54 patients were strongly correlated with both cognitive score and disability scales. Depth was related to the extent of subcortical lesions, surface area was related only to age. In additional analyses, the depth of the cingular sulcus was independently associated with the volume of LL (P 0.001), and that of the superior frontal sulcus with the mean apparent diffusion coefficient (P 0.003). In CADASIL, important morphological changes of cortical sulci occur in association with clinical worsening,extension of subcortical tissue damage and progression of global cerebral atrophy. These results suggest that the examination of cortical morphology may be of high clinical relevance in SVDB. (authors)

  14. A novel strategy for signal denoising using reweighted SVD and its applications to weak fault feature enhancement of rotating machinery

    Science.gov (United States)

    Zhao, Ming; Jia, Xiaodong

    2017-09-01

    Singular value decomposition (SVD), as an effective signal denoising tool, has been attracting considerable attention in recent years. The basic idea behind SVD denoising is to preserve the singular components (SCs) with significant singular values. However, it is shown that the singular values mainly reflect the energy of decomposed SCs, therefore traditional SVD denoising approaches are essentially energy-based, which tend to highlight the high-energy regular components in the measured signal, while ignoring the weak feature caused by early fault. To overcome this issue, a reweighted singular value decomposition (RSVD) strategy is proposed for signal denoising and weak feature enhancement. In this work, a novel information index called periodic modulation intensity is introduced to quantify the diagnostic information in a mechanical signal. With this index, the decomposed SCs can be evaluated and sorted according to their information levels, rather than energy. Based on that, a truncated linear weighting function is proposed to control the contribution of each SC in the reconstruction of the denoised signal. In this way, some weak but informative SCs could be highlighted effectively. The advantages of RSVD over traditional approaches are demonstrated by both simulated signals and real vibration/acoustic data from a two-stage gearbox as well as train bearings. The results demonstrate that the proposed method can successfully extract the weak fault feature even in the presence of heavy noise and ambient interferences.

  15. The Use of the Profunda Femoral Artery as the Sole Target Vessel to Bypass Aortoiliac Disease in Patients with Critical Limb Ischemia and Concomitant Unreconstructable Infrainguinal Disease.

    Science.gov (United States)

    Kontopodis, Nikolaos; Lioudaki, Stella; Chronis, Christos; Kalogerakos, Paris; Lazopoulos, George; Papaioannou, Alexandra; Ioannou, Christos V

    2018-04-01

    Critical limb ischemia (CLI) often results from multilevel occlusive disease. There are occasions where a patent profunda femoral artery (PFA) is the only target artery that can be used as outflow during reconstruction to bypass aortoiliac disease (AOID), with no further option for infrainguinal revascularization. We aim to report results of the use of PFA as the sole target vessel for the treatment of these patients. This is a retrospective, single-center study including CLI patients treated during 36 months. All procedures were included regardless of inflow site. The outcomes examined were hemodynamic improvement, clinical status change, amputation-free and overall survival, and patency of the prosthesis. Univariate analysis was performed to identify possible predictors of adverse outcomes. Twenty-three patients and 27 limbs were included (2 female, mean age 70.6). Sixteen limbs presented rest pain and 11 tissue loss. Inflow was obtained from the axillary (n = 9), contralateral femoral (n = 8), abdominal aorta (n = 2), thoracic aorta (n = 1), ipsilateral external iliac (n = 2), and contralateral external iliac artery (n = 1). Immediately postoperatively ankle-brachial index significantly increased from 0.15 (0-0.5) to 0.50 (0.25-0.9), (P-value limbs presented clinical improvement (3 minimally, 18 moderately, and 3 markedly improved) and 3 presented no change. During a mean follow-up of 15.8 (2-36) months, we recorded 4 deaths and 4 major amputations. Mean predicted overall survival and amputation-free survival were 29.8 (95% confidence interval [CI] 24.5-35.1) and 26.5 months (95% CI 21.1-31.8), respectively. Predicted primary patency was 76% at 3 years. Univariate analysis revealed significant associations only between bypass patency and limp loss (P-value = 0.021). In the presence of CLI due to AOID and unreconstructable infrainguinal disease, the use of PFA as the sole target vessel during bypass is associated with significant rates of clinical

  16. Short-Term Blood Pressure Variability Relates to the Presence of Subclinical Brain Small Vessel Disease in Primary Hypertension.

    Science.gov (United States)

    Filomena, Josefina; Riba-Llena, Iolanda; Vinyoles, Ernest; Tovar, José L; Mundet, Xavier; Castañé, Xavier; Vilar, Andrea; López-Rueda, Antonio; Jiménez-Baladó, Joan; Cartanyà, Anna; Montaner, Joan; Delgado, Pilar

    2015-09-01

    Blood pressure (BP) variability is associated with stroke risk, but less is known about subclinical cerebral small vessel disease (CSVD). We aimed to determine whether CSVD relates to short-term BP variability independently of BP levels and also, whether they improve CSVD discrimination beyond clinical variables and office BP levels. This was a cohort study on asymptomatic hypertensives who underwent brain magnetic resonance imaging and 24-hour ambulatory BP monitoring. Office and average 24-hour, daytime and nighttime BP levels, and several metrics of BP variability (SD, weighted SD, coefficient of variation, and average real variability [ARV]) were calculated. Definition of CSVD was based on the presence of lacunar infarcts and white matter hyperintensity grades. Multivariate analysis and integrated discrimination improvement were performed to assess whether BP variability and levels were independently associated with CSVD and improved its discrimination. Four hundred eighty-seven individuals participated (median age, 64; 47% women). CSVD was identified in 18.9%, related to age, male sex, diabetes mellitus, use of treatment, ambulatory BP monitoring-defined BP levels, and ARV of systolic BP at any period. The highest prevalence (33.7%) was found in subjects with both 24-hour BP levels and ARV elevated. BP levels at any period and ARV (24 hours and nocturnal) emerged as independent predictors of CSVD, and discrimination was incrementally improved although not to a clinically significant extent (integrated discrimination improvement, 5.31%, 5.17% to 5.4%). Ambulatory BP monitoring-defined BP levels and ARV of systolic BP relate to subclinical CSVD in hypertensive individuals. © 2015 American Heart Association, Inc.

  17. Association of Aortic Compliance and Brachial Endothelial Function with Cerebral Small Vessel Disease in Type 2 Diabetes Mellitus Patients: Assessment with High-Resolution MRI

    Directory of Open Access Journals (Sweden)

    Yan Shan

    2016-01-01

    Full Text Available Objective. To assess the possible association of aortic compliance and brachial endothelial function with cerebral small vessel disease in type 2 diabetes mellitus (DM2 patients by using 3.0 T high-resolution magnetic resonance imaging. Methods. Sixty-two clinically confirmed DM2 patients (25 women and 37 men; mean age: 56.8±7.5 years were prospectively enrolled for noninvasive MR examinations of the aorta, brachial artery, and brain. Aortic arch pulse wave velocity (PWV, flow-mediated dilation (FMD of brachial artery, lacunar brain infarcts, and periventricular and deep white matter hyperintensities (WMHs were assessed. Pearson and Spearman correlation analysis were performed to analyze the association between PWV and FMD with clinical data and biochemical test results. Univariable logistic regression analyses were used to analyze the association between PWV and FMD with cerebral small vessel disease. Multiple logistic regression analyses were used to find out the independent predictive factors of cerebral small vessel disease. Results. Mean PWV was 6.73±2.00 m/s and FMD was 16.67±9.11%. After adjustment for compounding factors, PWV was found significantly associated with lacunar brain infarcts (OR = 2.00; 95% CI: 1.14–3.2; P<0.05 and FMD was significantly associated with periventricular WMHs (OR = 0.82; 95% CI: 0.71–0.95; P<0.05. Conclusions. Quantitative evaluation of aortic compliance and endothelial function by using high-resolution MRI may be potentially useful to stratify DM2 patients with risk of cerebral small vessel disease.

  18. Prediction of left main or 3-vessel disease using myocardial perfusion reserve on dynamic thallium-201 single-photon emission computed tomography with a semiconductor gamma camera.

    Science.gov (United States)

    Shiraishi, Shinya; Sakamoto, Fumi; Tsuda, Noriko; Yoshida, Morikatsu; Tomiguchi, Seiji; Utsunomiya, Daisuke; Ogawa, Hisao; Yamashita, Yasuyuki

    2015-01-01

    Myocardial perfusion imaging (MPI) may fail to detect balanced ischemia. We evaluated myocardial perfusion reserve (MPR) using Tl dynamic single-photon emission computed tomography (SPECT) and a novel cadmium zinc telluride (CZT) camera for predicting 3-vessel or left main coronary artery disease (CAD). METHODS AND RESULTS: A total of 55 consecutive patients with suspected CAD underwent SPECT-MPI and coronary angiography. The MPR index was calculated using the standard 2-compartment kinetic model. We analyzed the utility of MPR index, other SPECT findings, and various clinical variables. On multivariate analysis, MPR index and history of previous myocardial infarction (MI) predicted left main and 3-vessel disease. The area under the receiver operating characteristic curve was 0.81 for MPR index, 0.699 for history of previous MI, and 0.86 for MPR index plus history of previous MI. MPR index ≤1.5 yielded the highest diagnostic accuracy. Sensitivity, specificity, and accuracy were 86%, 78%, and 80%, respectively, for MPR index, 64%, 76%, 73% for previous MI, and 57%, 93%, and 84% for MPR index plus history of previous MI. Quantification of MPR using dynamic SPECT and a novel CZT camera may identify balanced ischemia in patients with left main or 3-vessel disease.

  19. An automated vessel segmentation of retinal images using multiscale vesselness

    International Nuclear Information System (INIS)

    Ben Abdallah, M.; Malek, J.; Tourki, R.; Krissian, K.

    2011-01-01

    The ocular fundus image can provide information on pathological changes caused by local ocular diseases and early signs of certain systemic diseases, such as diabetes and hypertension. Automated analysis and interpretation of fundus images has become a necessary and important diagnostic procedure in ophthalmology. The extraction of blood vessels from retinal images is an important and challenging task in medical analysis and diagnosis. In this paper, we introduce an implementation of the anisotropic diffusion which allows reducing the noise and better preserving small structures like vessels in 2D images. A vessel detection filter, based on a multi-scale vesselness function, is then applied to enhance vascular structures.

  20. Sparse representation of multi parametric DCE-MRI features using K-SVD for classifying gene expression based breast cancer recurrence risk

    Science.gov (United States)

    Mahrooghy, Majid; Ashraf, Ahmed B.; Daye, Dania; Mies, Carolyn; Rosen, Mark; Feldman, Michael; Kontos, Despina

    2014-03-01

    We evaluate the prognostic value of sparse representation-based features by applying the K-SVD algorithm on multiparametric kinetic, textural, and morphologic features in breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). K-SVD is an iterative dimensionality reduction method that optimally reduces the initial feature space by updating the dictionary columns jointly with the sparse representation coefficients. Therefore, by using K-SVD, we not only provide sparse representation of the features and condense the information in a few coefficients but also we reduce the dimensionality. The extracted K-SVD features are evaluated by a machine learning algorithm including a logistic regression classifier for the task of classifying high versus low breast cancer recurrence risk as determined by a validated gene expression assay. The features are evaluated using ROC curve analysis and leave one-out cross validation for different sparse representation and dimensionality reduction numbers. Optimal sparse representation is obtained when the number of dictionary elements is 4 (K=4) and maximum non-zero coefficients is 2 (L=2). We compare K-SVD with ANOVA based feature selection for the same prognostic features. The ROC results show that the AUC of the K-SVD based (K=4, L=2), the ANOVA based, and the original features (i.e., no dimensionality reduction) are 0.78, 0.71. and 0.68, respectively. From the results, it can be inferred that by using sparse representation of the originally extracted multi-parametric, high-dimensional data, we can condense the information on a few coefficients with the highest predictive value. In addition, the dimensionality reduction introduced by K-SVD can prevent models from over-fitting.

  1. Chronic kidney disease, 24-h blood pressure and small vessel diseases are independently associated with cognitive impairment in lacunar infarct patients

    International Nuclear Information System (INIS)

    Yamamoto, Yasumasa; Ohara, Tomoyuki; Nagakane, Yoshinari; Tanaka, Eijiro; Morii, Fukiko; Koizumi, Takashi; Akiguchi, Ichiro

    2011-01-01

    Although the relationships between chronic kidney disease (CKD) and cognitive impairment (CI) have been highlighted, the etiology of CI in CKD remains uncertain. Subjects comprised 224 consecutive patients with symptomatic lacunar infarction who underwent magnetic resonance imaging and ambulatory blood pressure monitoring (ABPM). Diurnal blood pressure (BP) patterns were categorized into three groups: dippers, non-dippers and risers. Lacunar infarcts (LIs), including both symptomatic and silent and diffuse white matter lesions (WMLs), were graded into three grades according to their degree. The results of kidney function were evaluated using estimated glomerular filtration rate (eGFR), categorized into three groups: stage 1, >60; stage 2, 30-60; and stage 3, -1 per 1.73 m 2 . There were 44 patients with CI. Confluent WMLs, including WML 2 and WML 3, were found in 36 patients (81.8%), and multiple lacunae including LI 2 and LI 3 were found in 30 patients (68.1%) with CI. Age >75 years (odds ratio (OR), 5.5; P -1 per 1.73 m 2 (OR, 2.9; P -1 per 1.73 m 2 (OR, 23.8; P 75 years (OR, 4.1; P -1 per 1.73 m 2 (OR, 3.7; P -1 per 1.73 m 2 (OR, 8.7; P<0.05) were independently associated with WML grade 3. Extensive small vessel diseases, CKD and non-dipping status were independently associated with CI. CKD appears to mainly contribute to vascular CI, whereas possibilities of overlapping with other mechanisms such as degenerative CI cannot be excluded. Strict night time BP control and renoprotective treatment may be warranted to prevent CI. (author)

  2. A genetic study of Factor V Leiden (G1691A) mutation in young ischemic strokes with large vessel disease in a South Indian population.

    Science.gov (United States)

    Anadure, Ravi; Christopher, Rita; Nagaraja, Dindagur; Narayanan, Coimbatore

    2017-10-01

    Factor V Leiden (FVL) has been, by far, the most investigated gene mutation, with 26 studies to date, on its role in arterial strokes. Overall, a meta-analysis of all these studies taken together showed that carriers of the Factor V Leiden allele were 1.33times more likely to develop arterial strokes when compared to controls. We subjected a highly select subset of young strokes, with large vessel infarcts, to genetic analysis for FVL mutation and compared them with matched healthy controls to look for a statistically significant association. In this prospective study, 6/120 cases (5%) and 2/120 controls (1.6%) were positive for heterozygous FVL (G1691A) mutation. The higher prevalence of FVL mutation in cases (5%) compared to controls (1.6%) did not show statistical significance with a Pearson's Chi square P value of 0.15. The Odds Ratio (OR) for risk of large vessel disease in FVL positive cases was 3.10 (95% CI of 0.61-15.7). FVL mutation (G1691A) in young Indian subjects with ischemic strokes does not seem to be significantly associated with large vessel disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Construction and test of the first Belle II SVD ladder implementing the origami chip-on-sensor design

    International Nuclear Information System (INIS)

    Irmler, C.; Bauer, A.; Bergauer, T.; Adamczyk, K.; Bacher, S.; Aihara, H.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Aziz, T.; Babu, V.; Bahinipati, S.; Barberio, E.; Baroncelli, Ti.; Baroncelli, To.; Basith, A.K.; Behera, P.K.; Bhuyan, B.; Bilka, T.

    2016-01-01

    The Belle II Silicon Vertex Detector comprises four layers of double-sided silicon strip detectors (DSSDs), consisting of ladders with two to five sensors each. All sensors are individually read out by APV25 chips with the Origami chip-on-sensor concept for the central DSSDs of the ladders. The chips sit on flexible circuits that are glued on the top of the sensors. This concept allows a low material budget and an efficient cooling of the chips by a single pipe per ladder. We present the construction of the first SVD ladders and results from precision measurements and electrical tests

  4. Ground roll attenuation using a curvelet-SVD filter: a case study from the west of Iran

    International Nuclear Information System (INIS)

    Boustani, Bahareh; Javaherian, Abdorahim; Mortazavi, Seyed Ahmad; Torabi, Siyavash

    2013-01-01

    In reflection seismology, a ground roll is a low frequency, low velocity and high amplitude surface wave. It usually has stronger amplitude than reflections, and masks valuable information carried by signals. Many filters in different domains have been used for ground roll attenuation such as tau-p and f-k filters. Recently, in many studies, the curvelet transform has been used for ground roll attenuation. The curvelet transform creates a good separation between ground roll and reflections in dip and frequency, especially in high frequency subbands. In this paper, based on the adaptive curvelet filter, a new method is introduced through a combination of the adaptive curvelet and adaptive singular value decomposition (ASVD) filters and is called a curvelet-SVD filter. In this filter, the subbands in a curvelet domain are divided into three categories based on the ground roll energy in each subband. These categories are subbands (1) with high energy containing only ground roll, (2) with medium energy that contains both ground roll and reflections, and (3) with low energy containing only reflections. The category that contains only ground roll will be muted, as in common usage of the adaptive curvelet filter. If the category that contains both ground roll and reflections is unchanged, part of the ground roll will not be attenuated. If this category is muted, part of the reflections will be damaged. To overcome this problem, ASVD is applied to attenuate ground roll in the subbands of this category. The category that contains only reflections will not be touched. This filter was applied to a synthetic and to a real data set from the west of Iran. The synthetic data contained dispersed and aliased ground roll. A curvelet-SVD filter could attenuate dispersed ground roll but it could not completely attenuate aliased ground roll. Because of the damage to the reflections, the energy threshold for applying ASVD in the curvelet domain could not be selected any lower. In real

  5. Noninvasive identification of left main and triple vessel coronary artery disease: improved accuracy using quantitative analysis of regional myocardial stress distribution and washout of thallium-201

    International Nuclear Information System (INIS)

    Maddahi, J.; Abdulla, A.; Garcia, E.V.; Swan, H.J.; Berman, D.S.

    1986-01-01

    The capabilities of visual and quantitative analysis of stress redistribution thallium-201 scintigrams, exercise electrocardiography and exercise blood pressure response were compared for correct identification of extensive coronary disease, defined as left main or triple vessel coronary artery disease, or both (50% or more luminal diameter coronary narrowing), in 105 consecutive patients with suspected coronary artery disease. Extensive disease was present in 56 patients and the remaining 49 had either less extensive coronary artery disease (n = 34) or normal coronary arteriograms (n = 15). Although exercise blood pressure response, exercise electrocardiography and visual thallium-201 analysis were highly specific (98, 88 and 96%, respectively), they were insensitive for identification of patients with extensive disease (14, 45 and 16%, respectively). Quantitative thallium-201 analysis significantly improved the sensitivity of visual thallium-201 analysis for identification of patients with extensive disease (from 16 to 63%, p less than 0.001) without a significant loss of specificity (96 versus 86%, p = NS). Eighteen (64%) of the 28 patients who were misclassified by visual analysis as having less extensive disease were correctly classified as having extensive disease by virtue of quantitative analysis of regional myocardial thallium-201 washout. When the results of quantitative thallium-201 analysis were combined with those of blood pressure and electrocardiographic response to exercise, the sensitivity and specificity for identification of patients with extensive disease was 86 and 76%, respectively, and the highest overall accuracy (0.82) was obtained

  6. An SVD-based comparison of nine whole eukaryotic genomes supports a coelomate rather than ecdysozoan lineage

    Directory of Open Access Journals (Sweden)

    Stuart Gary W

    2004-12-01

    Full Text Available Abstract Background Eukaryotic whole genome sequences are accumulating at an impressive rate. Effective methods for comparing multiple whole eukaryotic genomes on a large scale are needed. Most attempted solutions involve the production of large scale alignments, and many of these require a high stringency pre-screen for putative orthologs in order to reduce the effective size of the dataset and provide a reasonably high but unknown fraction of correctly aligned homologous sites for comparison. As an alternative, highly efficient methods that do not require the pre-alignment of operationally defined orthologs are also being explored. Results A non-alignment method based on the Singular Value Decomposition (SVD was used to compare the predicted protein complement of nine whole eukaryotic genomes ranging from yeast to man. This analysis resulted in the simultaneous identification and definition of a large number of well conserved motifs and gene families, and produced a species tree supporting one of two conflicting hypotheses of metazoan relationships. Conclusions Our SVD-based analysis of the entire protein complement of nine whole eukaryotic genomes suggests that highly conserved motifs and gene families can be identified and effectively compared in a single coherent definition space for the easy extraction of gene and species trees. While this occurs without the explicit definition of orthologs or homologous sites, the analysis can provide a basis for these definitions.

  7. On a Hopping-Points SVD and Hough Transform-Based Line Detection Algorithm for Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)

    Abhijeet Ravankar

    2016-05-01

    Full Text Available Line detection is an important problem in computer vision, graphics and autonomous robot navigation. Lines detected using a laser range sensor (LRS mounted on a robot can be used as features to build a map of the environment, and later to localize the robot in the map, in a process known as Simultaneous Localization and Mapping (SLAM. We propose an efficient algorithm for line detection from LRS data using a novel hopping-points Singular Value Decomposition (SVD and Hough transform-based algorithm, in which SVD is applied to intermittent LRS points to accelerate the algorithm. A reverse-hop mechanism ensures that the end points of the line segments are accurately extracted. Line segments extracted from the proposed algorithm are used to form a map and, subsequently, LRS data points are matched with the line segments to localize the robot. The proposed algorithm eliminates the drawbacks of point-based matching algorithms like the Iterative Closest Points (ICP algorithm, the performance of which degrades with an increasing number of points. We tested the proposed algorithm for mapping and localization in both simulated and real environments, and found it to detect lines accurately and build maps with good self-localization.

  8. Lowering risk score profile during PCI in multiple vessel disease is associated with low adverse events: The ERACI risk score.

    Science.gov (United States)

    Rodriguez, Alfredo E; Fernandez-Pereira, Carlos; Mieres, Juan; Pavlovsky, Hernan; Del Pozo, Juan; Rodriguez-Granillo, Alfredo M; Antoniucci, David

    2018-02-13

    In recent years angiographic risk scores have been introduced in clinical practice to stratify different levels of risk after percutaneous coronary interventions (PCI). The SYNTAX score included all intermediate lesions in vessels ≥1.5 mm, consequently, multiple stent implantation was required. Four years ago, we built a new angiographic score in order to guide PCI strategy avoiding stent deployment both in intermediate stenosis as in small vessels, therefore these were not scored (ERACI risk score). The purpose of this mini review is to validate the strategy of PCI guided by this scoring, taking into account long term follow up outcomes of two observational and prospective registries where this policy was used. With this new risk score we have modified risk profile of our patient's candidates for PCI or coronary artery bypass surgery lowering the risk and PCI. The simple exclusion of small vessels and intermediate stenosis from the revascularization approach resulted in clinical outcome comparable with the one of fractional flow reserve guided revascularization. Low events rate at late follow up observed in both studies was also in agreement with guided PCI by functional lesion assessment observed by Syntax II registry, where investigators found lower events rate in spite of a few number of stents implanted per patient. use of ERACI risk scores may significantly reclassify patients into a lower risk category and be associated with low adverse events rate. Copyright © 2018. Published by Elsevier Inc.

  9. White matter microstructural damage in small vessel disease is associated with Montreal cognitive assessment but not with mini mental state examination performances: vascular mild cognitive impairment Tuscany study.

    Science.gov (United States)

    Pasi, Marco; Salvadori, Emilia; Poggesi, Anna; Ciolli, Laura; Del Bene, Alessandra; Marini, Sandro; Nannucci, Serena; Pescini, Francesca; Valenti, Raffaella; Ginestroni, Andrea; Toschi, Nicola; Diciotti, Stefano; Mascalchi, Mario; Inzitari, Domenico; Pantoni, Leonardo

    2015-01-01

    Montreal Cognitive Assessment (MoCA) has been proposed as a screening tool in vascular cognitive impairment. Diffusion tensor imaging is sensitive to white matter microstructural damage. We investigated if diffusion tensor imaging-derived indices are more strongly associated with performances on MoCA or on the widely used mini mental state examination in patients with mild cognitive impairment and small vessel disease. Mild cognitive impairment patients with moderate/severe degrees of white matter hyperintensities on MRI were enrolled. Lacunar infarcts, cortical atrophy, medial temporal lobe atrophy and median values of mean diffusivity and fractional anisotropy of the cerebral white matter were studied and correlated with cognitive tests performances. Seventy-six patients (mean age 75.1±6.8 years, mean years of education 8.0±4.3) were assessed. In univariate analyses, a significant association of both MoCA and mini mental state examination scores with age, education, cortical atrophy, and medial temporal lobe atrophy was found, whereas mean diffusivity and fractional anisotropy were associated with MoCA. In partial correlation analyses, adjusting for all demographic and neuroimaging variables, both mean diffusivity and fractional anisotropy were associated only with MoCA (mean diffusivity: r= -0.275, P=0.023; fractional anisotropy: r=0.246, P=0.043). In patients with mild cognitive impairment and small vessel disease, diffusion tensor imaging-measured white matter microstructural damage is more related to MoCA than mini mental state examination performances. MoCA is suited for the cognitive screening of patients with small vessel disease. © 2014 American Heart Association, Inc.

  10. Long-term consequences of developmental vascular defects on retinal vessel homeostasis and function in a mouse model of Norrie disease.

    Directory of Open Access Journals (Sweden)

    Susanne C Beck

    Full Text Available Loss of Norrin signalling due to mutations in the Norrie disease pseudoglioma gene causes severe vascular defects in the retina, leading to visual impairment and ultimately blindness. While the emphasis of experimental work so far was on the developmental period, we focus here on disease mechanisms that induce progression into severe adult disease. The goal of this study was the comprehensive analysis of the long-term effects of the absence of Norrin on vascular homeostasis and retinal function. In a mouse model of Norrie disease retinal vascular morphology and integrity were studied by means of in vivo angiography; the vascular constituents were assessed in detailed histological analyses using quantitative retinal morphometry. Finally, electroretinographic analyses were performed to assess the retinal function in adult Norrin deficient animals. We could show that the primary developmental defects not only persisted but developed into further vascular abnormalities and microangiopathies. In particular, the overall vessel homeostasis, the vascular integrity, and also the cellular constituents of the vascular wall were affected in the adult Norrin deficient retina. Moreover, functional analyses indicated to persistent hypoxia in the neural retina which was suggested as one of the major driving forces of disease progression. In summary, our data provide evidence that the key to adult Norrie disease are ongoing vascular modifications, driven by the persistent hypoxic conditions, which are ineffective to compensate for the primary Norrin-dependent defects.

  11. Long-term consequences of developmental vascular defects on retinal vessel homeostasis and function in a mouse model of Norrie disease.

    Science.gov (United States)

    Beck, Susanne C; Feng, Yuxi; Sothilingam, Vithiyanjali; Garcia Garrido, Marina; Tanimoto, Naoyuki; Acar, Niyazi; Shan, Shenliang; Seebauer, Britta; Berger, Wolfgang; Hammes, Hans-Peter; Seeliger, Mathias W

    2017-01-01

    Loss of Norrin signalling due to mutations in the Norrie disease pseudoglioma gene causes severe vascular defects in the retina, leading to visual impairment and ultimately blindness. While the emphasis of experimental work so far was on the developmental period, we focus here on disease mechanisms that induce progression into severe adult disease. The goal of this study was the comprehensive analysis of the long-term effects of the absence of Norrin on vascular homeostasis and retinal function. In a mouse model of Norrie disease retinal vascular morphology and integrity were studied by means of in vivo angiography; the vascular constituents were assessed in detailed histological analyses using quantitative retinal morphometry. Finally, electroretinographic analyses were performed to assess the retinal function in adult Norrin deficient animals. We could show that the primary developmental defects not only persisted but developed into further vascular abnormalities and microangiopathies. In particular, the overall vessel homeostasis, the vascular integrity, and also the cellular constituents of the vascular wall were affected in the adult Norrin deficient retina. Moreover, functional analyses indicated to persistent hypoxia in the neural retina which was suggested as one of the major driving forces of disease progression. In summary, our data provide evidence that the key to adult Norrie disease are ongoing vascular modifications, driven by the persistent hypoxic conditions, which are ineffective to compensate for the primary Norrin-dependent defects.

  12. Containment vessel

    International Nuclear Information System (INIS)

    Zbirohowski-Koscia, K.F.; Roberts, A.C.

    1980-01-01

    A concrete containment vessel for nuclear reactors is disclosed that is spherical and that has prestressing tendons disposed in first, second and third sets, the tendons of each set being all substantially concentric and centred around a respective one of the three orthogonal axes of the sphere; the tendons of the first set being anchored at each end at a first anchor rib running around a circumference of the vessel, the tendons of the second set being anchored at each end at a second anchor rib running around a circumference of the sphere and disposed at 90 0 to the first rib, and the tendons of the third set being anchored some to the first rib and the remainder to the second rib. (author)

  13. SVD and Hankel matrix based de-noising approach for ball bearing fault detection and its assessment using artificial faults

    Science.gov (United States)

    Golafshan, Reza; Yuce Sanliturk, Kenan

    2016-03-01

    Ball bearings remain one of the most crucial components in industrial machines and due to their critical role, it is of great importance to monitor their conditions under operation. However, due to the background noise in acquired signals, it is not always possible to identify probable faults. This incapability in identifying the faults makes the de-noising process one of the most essential steps in the field of Condition Monitoring (CM) and fault detection. In the present study, Singular Value Decomposition (SVD) and Hankel matrix based de-noising process is successfully applied to the ball bearing time domain vibration signals as well as to their spectrums for the elimination of the background noise and the improvement the reliability of the fault detection process. The test cases conducted using experimental as well as the simulated vibration signals demonstrate the effectiveness of the proposed de-noising approach for the ball bearing fault detection.

  14. SVD identifies transcript length distribution functions from DNA microarray data and reveals evolutionary forces globally affecting GBM metabolism.

    Directory of Open Access Journals (Sweden)

    Nicolas M Bertagnolli

    Full Text Available To search for evolutionary forces that might act upon transcript length, we use the singular value decomposition (SVD to identify the length distribution functions of sets and subsets of human and yeast transcripts from profiles of mRNA abundance levels across gel electrophoresis migration distances that were previously measured by DNA microarrays. We show that the SVD identifies the transcript length distribution functions as "asymmetric generalized coherent states" from the DNA microarray data and with no a-priori assumptions. Comparing subsets of human and yeast transcripts of the same gene ontology annotations, we find that in both disparate eukaryotes, transcripts involved in protein synthesis or mitochondrial metabolism are significantly shorter than typical, and in particular, significantly shorter than those involved in glucose metabolism. Comparing the subsets of human transcripts that are overexpressed in glioblastoma multiforme (GBM or normal brain tissue samples from The Cancer Genome Atlas, we find that GBM maintains normal brain overexpression of significantly short transcripts, enriched in transcripts that are involved in protein synthesis or mitochondrial metabolism, but suppresses normal overexpression of significantly longer transcripts, enriched in transcripts that are involved in glucose metabolism and brain activity. These global relations among transcript length, cellular metabolism and tumor development suggest a previously unrecognized physical mode for tumor and normal cells to differentially regulate metabolism in a transcript length-dependent manner. The identified distribution functions support a previous hypothesis from mathematical modeling of evolutionary forces that act upon transcript length in the manner of the restoring force of the harmonic oscillator.

  15. Small vessel disease, neurovascular regulation and cognitive impairment: post-mortem studies reveal a complex relationship, still poorly understood.

    Science.gov (United States)

    Love, Seth; Miners, J Scott

    2017-07-15

    The contribution of vascular disease to cognitive impairment is under-recognized and the pathogenesis is poorly understood. This information gap has multiple causes, including a lack of post-mortem validation of clinical diagnoses of vascular cognitive impairment (VCI) or vascular dementia (VaD), the exclusion of cases with concomitant neurodegenerative disease when diagnosing VCI/VaD, and a lack of standardization of neuropathological assessment protocols for vascular disease. Other contributors include a focus on end-stage destructive lesions to the exclusion of more subtle types of diffuse brain injury, on structural abnormalities of arteries and arterioles to the exclusion of non-structural abnormalities and capillary damage, and the use of post-mortem sampling strategies that are biased towards the identification of neurodegenerative pathologies. Recent studies have demonstrated the value of detailed neuropathology in characterizing vascular contributions to cognitive impairment (e.g. in diabetes), and highlight the importance of diffuse white matter changes, capillary damage and vasoregulatory abnormalities in VCI/VaD. The use of standardized, evidence-based post-mortem assessment protocols and the inclusion of biochemical as well as morphological methods in neuropathological studies should improve the accuracy of determination of the contribution of vascular disease to cognitive impairment and clarify the relative contribution of different pathogenic processes to the tissue damage. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  16. The value of [{sup 18}F]FDG-PET in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Martin A.; Mueller-Brand, Jan; Nitzsche, Egbert U. [University Hospital Basel, Institute of Nuclear Medicine, Basel (Switzerland); Melzer, Ralph A.; Tyndall, Alan [University Hospital Basel, Division of Rheumatology (Switzerland); Schindler, Christian [University Hospital Basel, Institute of Social and Preventive Medicine (Switzerland)

    2005-06-01

    This study was performed to investigate the value of{sup 18}F-fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG-PET) in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease. Twenty-six consecutive patients (21 females, 5 males; median age - years, range 17-86 years) with giant cell arteritis or Takayasu's arteritis were examined with [{sup 18}F]FDG-PET. Follow-up scans were performed in four patients. Twenty-six age- and gender-matched controls (21 females, 5 males; median age 71 years, range 17-86 years) were included. The severity of large-vessel [{sup 18}F]FDG uptake was visually graded using a four-point scale. C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were measured and correlated with [{sup 18}F]FDG-PET results by logistic regression. [{sup 18}F]FDG-PET revealed pathological findings in 18 of 26 patients. Three scans were categorised as grade I, 12 as grade II and 3 as grade III arteritis. Visual grade was significantly correlated with both CRP and ESR levels (p=0.002 and 0.007 respectively; grade I: CRP 4.0 mg/l, ESR 6 mm/h; grade II: CRP 37 mg/l, ESR 46 mm/h; grade III: CRP 172 mg/l, ESR 90 mm/h). Overall sensitivity was 60% (95% CI 40.6-77.3%), specificity 99.8% (95% CI 89.1-100%), positive predictive value 99.7% (95% CI 77-100%), negative predictive value 67.9% (95% CI 49.8-80.9%) and accuracy 78.6% (95% CI 65.6-88.4%). In patients presenting with a CRP <12 mg/l or an ESR <12 mm/h, logistic regression revealed a sensitivity of less than 50%. In patients with high CRP/ESR levels, sensitivity was 95.5%/80.7%. [{sup 18}F]FDG-PET is highly effective in assessing the activity and the extent of large-vessel vasculitis. Visual grading was validated as representing the severity of inflammation. Its use is simple and provides high specificity, while high sensitivity is achieved by scanning in the state of active inflammation. (orig.)

  17. The value of [18F]FDG-PET in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease

    International Nuclear Information System (INIS)

    Walter, Martin A.; Mueller-Brand, Jan; Nitzsche, Egbert U.; Melzer, Ralph A.; Tyndall, Alan; Schindler, Christian

    2005-01-01

    This study was performed to investigate the value of 18 F-fluorodeoxyglucose positron emission tomography ([ 18 F]FDG-PET) in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease. Twenty-six consecutive patients (21 females, 5 males; median age - years, range 17-86 years) with giant cell arteritis or Takayasu's arteritis were examined with [ 18 F]FDG-PET. Follow-up scans were performed in four patients. Twenty-six age- and gender-matched controls (21 females, 5 males; median age 71 years, range 17-86 years) were included. The severity of large-vessel [ 18 F]FDG uptake was visually graded using a four-point scale. C-reactive protein (CRP) and the erythrocyte sedimentation rate (ESR) were measured and correlated with [ 18 F]FDG-PET results by logistic regression. [ 18 F]FDG-PET revealed pathological findings in 18 of 26 patients. Three scans were categorised as grade I, 12 as grade II and 3 as grade III arteritis. Visual grade was significantly correlated with both CRP and ESR levels (p=0.002 and 0.007 respectively; grade I: CRP 4.0 mg/l, ESR 6 mm/h; grade II: CRP 37 mg/l, ESR 46 mm/h; grade III: CRP 172 mg/l, ESR 90 mm/h). Overall sensitivity was 60% (95% CI 40.6-77.3%), specificity 99.8% (95% CI 89.1-100%), positive predictive value 99.7% (95% CI 77-100%), negative predictive value 67.9% (95% CI 49.8-80.9%) and accuracy 78.6% (95% CI 65.6-88.4%). In patients presenting with a CRP 18 F]FDG-PET is highly effective in assessing the activity and the extent of large-vessel vasculitis. Visual grading was validated as representing the severity of inflammation. Its use is simple and provides high specificity, while high sensitivity is achieved by scanning in the state of active inflammation. (orig.)

  18. Sparse coded image super-resolution using K-SVD trained dictionary based on regularized orthogonal matching pursuit.

    Science.gov (United States)

    Sajjad, Muhammad; Mehmood, Irfan; Baik, Sung Wook

    2015-01-01

    Image super-resolution (SR) plays a vital role in medical imaging that allows a more efficient and effective diagnosis process. Usually, diagnosing is difficult and inaccurate from low-resolution (LR) and noisy images. Resolution enhancement through conventional interpolation methods strongly affects the precision of consequent processing steps, such as segmentation and registration. Therefore, we propose an efficient sparse coded image SR reconstruction technique using a trained dictionary. We apply a simple and efficient regularized version of orthogonal matching pursuit (ROMP) to seek the coefficients of sparse representation. ROMP has the transparency and greediness of OMP and the robustness of the L1-minization that enhance the dictionary learning process to capture feature descriptors such as oriented edges and contours from complex images like brain MRIs. The sparse coding part of the K-SVD dictionary training procedure is modified by substituting OMP with ROMP. The dictionary update stage allows simultaneously updating an arbitrary number of atoms and vectors of sparse coefficients. In SR reconstruction, ROMP is used to determine the vector of sparse coefficients for the underlying patch. The recovered representations are then applied to the trained dictionary, and finally, an optimization leads to high-resolution output of high-quality. Experimental results demonstrate that the super-resolution reconstruction quality of the proposed scheme is comparatively better than other state-of-the-art schemes.

  19. Identification of Combined Power Quality Disturbances Using Singular Value Decomposition (SVD and Total Least Squares-Estimation of Signal Parameters via Rotational Invariance Techniques (TLS-ESPRIT

    Directory of Open Access Journals (Sweden)

    Huaishuo Xiao

    2017-11-01

    Full Text Available In order to identify various kinds of combined power quality disturbances, the singular value decomposition (SVD and the improved total least squares-estimation of signal parameters via rotational invariance techniques (TLS-ESPRIT are combined as the basis of disturbance identification in this paper. SVD is applied to identify the catastrophe points of disturbance intervals, based on which the disturbance intervals are segmented. Then the improved TLS-ESPRIT optimized by singular value norm method is used to analyze each data segment, and extract the amplitude, frequency, attenuation coefficient and initial phase of various kinds of disturbances. Multi-group combined disturbance test signals are constructed by MATLAB and the proposed method is also tested by the measured data of IEEE Power and Energy Society (PES Database. The test results show that the new method proposed has a relatively higher accuracy than conventional TLS-ESPRIT, which could be used in the identification of measured data.

  20. Aortic stiffness is associated with cardiac function and cerebral small vessel disease in patients with type 1 diabetes mellitus: assessment by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elderen, Saskia G.C. van; Brandts, A.; Westenberg, J.J.M.; Grond, J. van der; Buchem, M.A. van; Kroft, L.J.M.; Roos, A. de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Tamsma, J.T.; Romijn, J.A.; Smit, J.W.A. [Leiden University Medical Center, Department of Endocrinology, Leiden (Netherlands)

    2010-05-15

    To evaluate, with the use of magnetic resonance imaging (MRI), whether aortic pulse wave velocity (PWV) is associated with cardiac left ventricular (LV) function and mass as well as with cerebral small vessel disease in patients with type 1 diabetes mellitus (DM). We included 86 consecutive type 1 DM patients (49 male, mean age 46.9 {+-} 11.7 years) in a prospective, cross-sectional study. Exclusion criteria included aortic/heart disease and general MRI contra-indications. MRI of the aorta, heart and brain was performed for assessment of aortic PWV, as a marker of aortic stiffness, systolic LV function and mass, as well as for the presence of cerebral white matter hyperintensities (WMHs), microbleeds and lacunar infarcts. Multivariate linear or logistic regression was performed to analyse the association between aortic PWV and outcome parameters, with covariates defined as age, gender, mean arterial pressure, heart rate, BMI, smoking, DM duration and hypertension. Mean aortic PWV was 7.1 {+-} 2.5 m/s. Aortic PWV was independently associated with LV ejection fraction (ss= -0.406, P = 0.006), LV stroke volume (ss=-0.407, P = 0.001), LV cardiac output (ss= -0.458, P = 0.001), and with cerebral WMHs (P < 0.05). There were no independent associations between aortic stiffness and LV mass, cerebral microbleeds or lacunar infarcts. Aortic stiffness is independently associated with systolic LV function and cerebral WMHs in patients with type 1 DM. (orig.)

  1. Aortic stiffness is associated with cardiac function and cerebral small vessel disease in patients with type 1 diabetes mellitus: assessment by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Elderen, Saskia G.C. van; Brandts, A.; Westenberg, J.J.M.; Grond, J. van der; Buchem, M.A. van; Kroft, L.J.M.; Roos, A. de; Tamsma, J.T.; Romijn, J.A.; Smit, J.W.A.

    2010-01-01

    To evaluate, with the use of magnetic resonance imaging (MRI), whether aortic pulse wave velocity (PWV) is associated with cardiac left ventricular (LV) function and mass as well as with cerebral small vessel disease in patients with type 1 diabetes mellitus (DM). We included 86 consecutive type 1 DM patients (49 male, mean age 46.9 ± 11.7 years) in a prospective, cross-sectional study. Exclusion criteria included aortic/heart disease and general MRI contra-indications. MRI of the aorta, heart and brain was performed for assessment of aortic PWV, as a marker of aortic stiffness, systolic LV function and mass, as well as for the presence of cerebral white matter hyperintensities (WMHs), microbleeds and lacunar infarcts. Multivariate linear or logistic regression was performed to analyse the association between aortic PWV and outcome parameters, with covariates defined as age, gender, mean arterial pressure, heart rate, BMI, smoking, DM duration and hypertension. Mean aortic PWV was 7.1 ± 2.5 m/s. Aortic PWV was independently associated with LV ejection fraction (ss= -0.406, P = 0.006), LV stroke volume (ss=-0.407, P = 0.001), LV cardiac output (ss= -0.458, P = 0.001), and with cerebral WMHs (P < 0.05). There were no independent associations between aortic stiffness and LV mass, cerebral microbleeds or lacunar infarcts. Aortic stiffness is independently associated with systolic LV function and cerebral WMHs in patients with type 1 DM. (orig.)

  2. Significance of Haemodynamic and Haemostatic Factors in the Course of Different Manifestations of Cerebral Small Vessel Disease: The SHEF-CSVD Study—Study Rationale and Protocol

    Directory of Open Access Journals (Sweden)

    Jacek Staszewski

    2013-01-01

    Full Text Available Rationale. This paper describes the rationale and design of the SHEF-CSVD Study, which aims to determine the long-term clinical and radiological course of cerebral small vessel disease (CSVD and to evaluate haemostatic and haemodynamic prognostic factors of the condition. Design. This single-centre, prospective, non-interventional cohort study will follow 150 consecutive patients with different clinical manifestations of CSVD (lacunar ischaemic stroke, vascular dementia, vascular parkinsonism or spontaneous deep, intracerebral haemorrhage and 50 age- and sex-matched controls over a period of 24 months. The clinical and radiological course will be evaluated basing on a detailed neurological, neuropsychological and MRI examinations. Haemodynamic (cerebral vasoreactivity, 24 h blood pressure control and haemostatic factors (markers of endothelial and platelet dysfunction, brachial artery flow-mediated dilatation test will be determined. Discussion. The scheduled study will specifically address the issue of haemodynamic and haemostatic prognostic factors and their course over time in various clinical manifestations of CSVD. The findings may aid the development of prophylactic strategies and individualised treatment plans, which are critical during the early stages of the disease.

  3. The primary vascular dysregulation syndrome: implications for eye diseases

    Science.gov (United States)

    2013-01-01

    Vascular dysregulation refers to the regulation of blood flow that is not adapted to the needs of the respective tissue. We distinguish primary vascular dysregulation (PVD, formerly called vasospastic syndrome) and secondary vascular dysregulation (SVD). Subjects with PVD tend to have cold extremities, low blood pressure, reduced feeling of thirst, altered drug sensitivity, increased pain sensitivity, prolonged sleep onset time, altered gene expression in the lymphocytes, signs of oxidative stress, slightly increased endothelin-1 plasma level, low body mass index and often diffuse and fluctuating visual field defects. Coldness, emotional or mechanical stress and starving can provoke symptoms. Virtually all organs, particularly the eye, can be involved. In subjects with PVD, retinal vessels are stiffer and more irregular, and both neurovascular coupling and autoregulation capacity are reduced while retinal venous pressure is often increased. Subjects with PVD have increased risk for normal-tension glaucoma, optic nerve compartment syndrome, central serous choroidopathy, Susac syndrome, retinal artery and vein occlusions and anterior ischaemic neuropathy without atherosclerosis. Further characteristics are their weaker blood–brain and blood-retinal barriers and the higher prevalence of optic disc haemorrhages and activated astrocytes. Subjects with PVD tend to suffer more often from tinnitus, muscle cramps, migraine with aura and silent myocardial ischaemic and are at greater risk for altitude sickness. While the main cause of vascular dysregulation is vascular endotheliopathy, dysfunction of the autonomic nervous system is also involved. In contrast, SVD occurs in the context of other diseases such as multiple sclerosis, retrobulbar neuritis, rheumatoid arthritis, fibromyalgia and giant cell arteritis. Taking into consideration the high prevalence of PVD in the population and potentially linked pathologies, in the current article, the authors provide

  4. Correlation and SVD Analysis of Anomalous Spring Precipitation in Northwest China and Sea Surface Temperature in Key Region in Recent 50 Years

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the relationship between spring precipitation anomaly in Northwest China and sea surface temperature anomaly (SSTA) in Key region in recent 50 years. [Method] Based on monthly average precipitation in Northwest China and global monthly sea surface temperature (SST) grid data, the effects of SSTA in equatorial central and eastern Pacific on spring precipitation in Northwest China were discussed by means of correlation and SVD analysis. [Result] For spring precipitation in Nor...

  5. Dual-tree complex wavelet transform and SVD based acoustic noise reduction and its application in leak detection for natural gas pipeline

    Science.gov (United States)

    Yu, Xuchao; Liang, Wei; Zhang, Laibin; Jin, Hao; Qiu, Jingwei

    2016-05-01

    During the last decades, leak detection for natural gas pipeline has become one of the paramount concerns of pipeline operators and researchers across the globe. However, acoustic wave method has been proved to be an effective way to identify and localize leakage for gas pipeline. Considering the fact that noises inevitably exist in the acoustic signals collected, noise reduction should be enforced on the signals for subsequent data mining and analysis. Thus, an integrated acoustic noise reduction method based on DTCWT and SVD is proposed in this study. The method is put forward based on the idea that noise reduction strategy should match the characteristics of the noisy signal. According to previous studies, it is known that the energy of acoustic signals collected under leaking condition is mainly concentrated in low-frequency portion (0-100 Hz). And ultralow-frequency component (0-5 Hz), which is taken as the characteristic frequency band in this study, can propagate a relatively longer distance and be captured by sensors. Therefore, in order to filter the noises and to reserve the characteristic frequency band, DTCWT is taken as the core to conduct multilevel decomposition and refining for acoustic signals and SVD is employed to eliminate noises in non-characteristic bands. Both simulation and field experiments show that DTCWT-SVD is an excellent method for acoustic noise reduction. At the end of this study, application in leakage localization shows that it becomes much easier and a little more accurate to estimate the location of leak hole after noise reduction by DTCWT-SVD.

  6. Vessel Operator System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Operator cards are required for any operator of a charter/party boat and or a commercial vessel (including carrier and processor vessels) issued a vessel permit from...

  7. Anatomically corrected transposition of great vessels

    International Nuclear Information System (INIS)

    Ivanitskij, A.V.; Sarkisova, T.N.

    1989-01-01

    The paper is concerned with the description of rare congenital heart disease: anatomically corrected malposition of major vessels in a 9-mos 24 day old girl. The diagnosis of this disease was shown on the results of angiocardiography, concomitant congenital heart diseases were descibed. This abnormality is characterized by common atrioventricular and ventriculovascular joints and inversion position of the major vessels, it is always attended by congenital heart diseases. Surgical intervention is aimed at the elimination of concomitant heart dieseases

  8. High rebleeding risk associated with choroidal collateral vessels in hemorrhagic moyamoya disease: analysis of a nonsurgical cohort in the Japan Adult Moyamoya Trial.

    Science.gov (United States)

    Funaki, Takeshi; Takahashi, Jun C; Houkin, Kiyohiro; Kuroda, Satoshi; Takeuchi, Shigekazu; Fujimura, Miki; Tomata, Yasutake; Miyamoto, Susumu

    2018-03-02

    OBJECTIVE Choroidal collateral vessels typical of moyamoya disease have received attention as a potential bleeding source. The authors' previous angiographic cross-sectional analysis suggested a possible association between choroidal collaterals and posterior hemorrhage, indicating a high risk for rebleeding. The present longitudinal analysis is intended to determine whether choroidal collaterals are a predictor of rebleeding in hemorrhagic moyamoya disease. METHODS The Japan Adult Moyamoya Trial group designed an ancillary cohort study using 5-year follow-up data on 37 patients included in the nonsurgical arm of the original randomized controlled trial and compared the rebleeding rate of those with and those without choroidal collaterals, represented by the connection between the anterior or posterior choroidal arteries and the medullary arteries. An expert panel determined whether a choroidal collateral was present in each patient through the measurement of baseline angiography studies. The rebleeding rate comparison was adjusted for age, diagnosis of hypertension, and involvement of the posterior cerebral artery. RESULTS Choroidal collaterals were present in 21 patients (56.8%). The rebleeding rate was 13.1% per year in the collateral-positive group as compared with 1.3% in the negative group (p = 0.008, log-rank test). The adjusted hazard ratio for rebleeding in the collateral-positive group relative to the negative group remained statistically significant (HR 11.10, 95% CI 1.37-89.91). Radiographic assessment of the collateral-positive group revealed good correspondence between the distribution of collaterals and rebleeding sites. CONCLUSIONS Results of this study suggest that choroidal collaterals are a bleeding source with a high risk for hemorrhagic recurrence and a predictor of rebleeding in hemorrhagic moyamoya disease.

  9. Automatic Vessel Segmentation on Retinal Images

    Institute of Scientific and Technical Information of China (English)

    Chun-Yuan Yu; Chia-Jen Chang; Yen-Ju Yao; Shyr-Shen Yu

    2014-01-01

    Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hyper-tension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm. In this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE (digital retinal images for vessel extraction) retinal database, which is much better than other methods.

  10. SVD/MCMC Data Analysis Pipeline for Global Redshifted 21-cm Spectrum Observations of the Cosmic Dawn and Dark Ages

    Science.gov (United States)

    Burns, Jack O.; Tauscher, Keith; Rapetti, David; Mirocha, Jordan; Switzer, Eric

    2018-01-01

    We have designed a complete data analysis pipeline for constraining Cosmic Dawn physics using sky-averaged spectra in the VHF range (40-200 MHz) obtained either from the ground (e.g., the Experiment to Detect Global Epoch of Reionization Signal, EDGES; and the Cosmic Twilight Polarimeter, CTP) or from orbit above the lunar farside (e.g., the Dark Ages Radio Explorer, DARE). In the case of DARE, we avoid Earth-based RFI, ionospheric effects, and radio solar emissions (when observing at night). To extract the 21-cm spectrum, we parametrize the cosmological signal and systematics with two separate sets of modes defined through Singular Value Decomposition (SVD) of training set curves. The training set for the 21-cm spin-flip brightness temperatures is composed of theoretical models of the first stars, galaxies and black holes created by varying physical parameters within the ares code. The systematics training set is created using sky and beam data to model the beam-weighted foregrounds (which are about four orders of magnitude larger than the signal) as well as expected lab data to model receiver systematics. To constrain physical parameters determining the 21-cm spectrum, we apply to the extracted signal a series of consecutive fitting techniques including two usages of a Markov Chain Monte Carlo (MCMC) algorithm. Importantly, our pipeline efficiently utilizes the significant differences between the foreground and the 21-cm signal in spatial and spectral variations. In addition, it incorporates for the first time polarization data, dramatically improving the constraining power. We are currently validating this end-to-end pipeline using detailed simulations of the signal, foregrounds and instruments. This work was directly supported by the NASA Solar System Exploration Research Virtual Institute cooperative agreement number 80ARC017M0006 and funding from the NASA Ames Research Center cooperative agreement NNX16AF59G.

  11. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoyi; Li, Dongye [Capital Medical University and Beijing Institute for Brain Disorders, Center for Brain Disorders Research, Beijing (China); Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Zhao, Huilin [Shanghai Jiao Tong University, Department of Radiology, Renji Hospital, School of Medicine, Shanghai (China); Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Cui, Yuanyuan [PLA General Hospital, Department of Radiology, Beijing (China); Zhou, Zechen [Philips Research China, Healthcare Department, Beijing (China); Yuan, Chun [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); University of Washington, Department of Radiology, Seattle, WA (United States); Zhao, Xihai [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Beijing Institute for Brain Disorders, Center for Stroke, Beijing (China)

    2017-05-15

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  12. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    International Nuclear Information System (INIS)

    Chen, Xiaoyi; Li, Dongye; Zhao, Huilin; Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui; Cui, Yuanyuan; Zhou, Zechen; Yuan, Chun; Zhao, Xihai

    2017-01-01

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  13. The Portuguese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) in the diagnosis of subcortical vascular dementia and Alzheimer's disease.

    Science.gov (United States)

    Gonçalves, Cátia; Pinho, Maria Salomé; Cruz, Vitor; Pais, Joana; Gens, Helena; Oliveira, Fátima; Santana, Isabel; Rente, José; Santos, José Manuel

    2015-01-01

    The aim of this study was to investigate the accuracy of the Portuguese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) in detecting and differentiating early stage subcortical vascular dementia (SVD) from early stage Alzheimer's disease (AD). Ninety-two subjects (18 SVD patients, 36 AD patients, and 38 healthy controls) were assessed using the ACE-R. Between-group's differences were evaluated using the Quade's rank analysis of covariance. The diagnostic accuracy and discriminatory ability of the ACE-R were examined via receiver operating characteristic (ROC) analysis. The ACE-R was able to successfully discriminate between patients and healthy subjects. The mean ACE-R total scores differed between SVD and AD patients; there were also significant differences in attention and orientation and in memory measures between the groups. An optimal cut-off of 72/73 was found for the detection of AD (sensitivity: 97%; specificity: 92%) and SVD (sensitivity: 100%; specificity: 92%).

  14. EEG in Silent Small Vessel Disease : sLORETA Mapping Reveals Cortical Sources of Vascular Cognitive Impairment No Dementia in the Default Mode Network

    NARCIS (Netherlands)

    Sheorajpanday, Rishi V. A.; Marien, Peter; Weeren, Arie J. T. M.; Nagels, Guy; Saerens, Jos; van Putten, Michel J. A. M.; De Deyn, Peter P.

    Introduction: Vascular cognitive impairment, no dementia (vCIND) is a prevalent and potentially preventable disorder. Clinical presof the small vessel subcortical subtype may be insidious and difficult to diagnose in the initial stage. We investigated electroencephalographic sources of subcortical

  15. G-CSF and cognitive dysfunction in elderly diabetic mice with cerebral small vessel disease: Preventive intervention effects and underlying mechanisms.

    Science.gov (United States)

    Guan, Zhu-Fei; Tao, Ying-Hong; Zhang, Xiao-Ming; Guo, Qi-Lin; Liu, Ying-Chao; Zhang, Yu; Wang, Yan-Mei; Ji, Gang; Wu, Guo-Feng; Wang, Na-Na; Yang, Hao; Yu, Zhong-Yu; Guo, Jing-Chun; Zhou, Hou-Guang

    2017-06-01

    Although cognitive dysfunction is a common neurological complication in elderly patients with diabetes, the mechanisms underlying this relationship remain unclear, and effective preventive interventions have yet to be developed. Thus, this study investigated the preventive effects and mechanisms of action associated with granulocyte colony-stimulating factor (G-CSF) on cognitive dysfunction in elderly diabetic mice with cerebral small vessel disease. This study included 40 male db/db diabetic and wild-type (WT) mice that were categorized into the following four groups at the age of 3 weeks: db/db group (DG), db/db+G-CSF group (DGG), WT group (WG), and WT+G-CSF group (WGG). The mice were fed normal diets for 4 months and then given G-CSF (75 μg/kg) via intraperitoneal injections for 1 month. At 7.5 months of age, the cognitive abilities of the mice were assessed with the Y-maze test and the Social Choice Test; body weight, blood pressure (BP), and blood glucose measurements were obtained throughout the study. Brain imaging and blood oxygen level-dependent (BOLD) contrast imaging analyses were performed with a small animal magnetic resonance imaging (MRI) system, autophagosome levels were detected with a transmission electron microscope (TEM), hippocampal neurons were assessed with hematoxylin and eosin (HE) staining, and protein expressions and distributions were evaluated using immunohistochemistry and Western blot analyses. (i) The body weight and blood glucose levels of the DG and DGG mice were significantly higher than those of the WG and WGG mice; (ii) social choice and spatial memory capabilities were significantly reduced in DG mice but were recovered by G-CSF in DGG mice; (iii) the MRI scans revealed multiple lacunar lesions and apparent hippocampal atrophy in the brains of DG mice, but G-CSF reduced the number of lacunar lesions and ameliorated hippocampal atrophy; (iv) the MRI-BOLD scans showed a downward trend in whole-brain activity and reductions

  16. What is the relationship between type 2 diabetes mellitus status and the neuroradiological correlates of cerebral small vessel disease in adults? Protocol for a systematic review.

    Science.gov (United States)

    Funnell, Clark; Doyle-Waters, Mary M; Yip, Samuel; Field, Thalia

    2017-01-17

    Cerebral small vessel disease (CSVD) is a common cause of stroke, dementia, and functional decline. In recent years, neuroradiologic correlates of CSVD have been identified. These imaging findings, best characterized on magnetic resonance imaging (MRI), include some combination of white matter hyperintensities, lacunes, cerebral microbleeds, enlarged perivascular spaces, and cerebral atrophy. Though some cohorts have reported that participants with type 2 diabetes mellitus (T2DM), an important risk factor for CSVD, may have a distinct neuroradiologic phenotype, this relationship is not well-characterized. Adults with diabetes mellitus have a two- to threefold higher incidence of ischemic stroke compared to controls and are an increasingly important population given global trends of increasing diabetes prevalence. This study aims to determine if adults with CSVD and T2DM have a distinct neuroradiologic phenotype. A systematic search of the literature will be conducted to find articles that report the MRI features of CSVD in a cohort of participants including those with and without type 2 diabetes mellitus (T2DM). A number of databases will be searched including MEDLINE, Embase, CINAHL, and Web of Science. Proceedings and abstracts from key conferences will also be reviewed and relevant journals hand searched for additional papers. The references from selected papers will be scanned. Screening of potential articles, data extraction, and quality appraisal will be performed in duplicate by independent reviewers. Odds ratios and 95% confidence intervals for the presence versus absence of each neuroradiologic correlate of interest from each included study will be calculated. If sufficient homogeneity exists among studies, a meta-analysis will be performed for each neuroradiologic correlate of CSVD. If heterogeneity of studies precludes data pooling, results will be presented in narrative form. Determining whether a distinct neuroradiologic phenotype of CSVD exists in

  17. Vessel dilatation in coronary angiograms

    International Nuclear Information System (INIS)

    Hinterauer, L.; Goebel, N.

    1983-01-01

    Amongst 166 patients with aneurysms, ectasia or megaloarteries shown on coronary angiograms, 86.1% had dilated vessels as part of generalised coronary sclerosis (usually in patients with three-vessel disease). In 9%, dilatation was of iatrogenic origin and in 4.8% it was idiopathic. One patient had Marfan's syndrome. Amongst 9 000 patients, there were eight with megalo-arteries without stenosis; six of these had atypical angina and three suffered an infarct. Patients with definite dilatation of the coronary artery and stagnation of contrast flow required treatment. (orig.) [de

  18. Vessel dilatation in coronary angiograms

    Energy Technology Data Exchange (ETDEWEB)

    Hinterauer, L.; Goebel, N.

    1983-11-01

    Amongst 166 patients with aneurysms, ectasia or megaloarteries shown on coronary angiograms, 86.1% had dilated vessels as part of generalised coronary sclerosis (usually in patients with three-vessel disease). In 9%, dilatation was of iatrogenic origin and in 4.8% it was idiopathic. One patient had Marfan's syndrome. Amongst 9 000 patients, there were eight with megalo-arteries without stenosis; six of these had atypical angina and three suffered an infarct. Patients with definite dilatation of the coronary artery and stagnation of contrast flow required treatment.

  19. Multiple shell pressure vessel

    International Nuclear Information System (INIS)

    Wedellsborg, B.W.

    1988-01-01

    A method is described of fabricating a pressure vessel comprising the steps of: attaching a first inner pressure vessel having means defining inlet and outlet openings to a top flange, placing a second inner pressure vessel, having means defining inlet and outlet opening, concentric with and spaced about the first inner pressure vessel and attaching the second inner pressure vessel to the top flange, placing an outer pressure vessel, having inlet and outlet openings, concentric with and spaced apart about the second inner pressure vessel and attaching the outer pressure vessel to the top flange, attaching a generally cylindrical inner inlet conduit and a generally cylindrical inner outlet conduit respectively to the inlet and outlet openings in the first inner pressure vessel, attaching a generally cylindrical outer inlet conduit and a generally cylindrical outer outlet conduit respectively to the inlet and outlet opening in the second inner pressure vessel, heating the assembled pressure vessel to a temperature above the melting point of a material selected from the group, lead, tin, antimony, bismuth, potassium, sodium, boron and mixtures thereof, filling the space between the first inner pressure vessel and the second inner pressure vessel with material selected from the group, filling the space between the second inner pressure vessel and the outer pressure vessel with material selected from the group, and pressurizing the material filling the spaces between the pressure vessels to a predetermined pressure, the step comprising: pressurizing the spaces to a pressure whereby the wall of the first inner pressure vessel is maintained in compression during steady state operation of the pressure vessel

  20. Combined use of a field-plate and narrow p-barriers for a wide-pitch ohmic-side readout of the BELLE double-sided SVD

    International Nuclear Information System (INIS)

    Ikeda, H.; Matsuda, T.

    1997-01-01

    We explored wide-pitch ohmic-side structures for the BELLE SVD, where we proposed a field-plate structure combined with narrow p-barriers in between the readout electrodes of 90, 113, 180, and 226 μm-pitch detectors. The effect of the p-barriers was studied with a numerical model to trace the carrier trajectories. The charge collection and sharing properties were examined in practice for prototype small-size detectors with an IR pulse shining from either the junction side or the ohmic side. The channel separation capabilities were also shown to be appropriate under nominal operation conditions. (orig.)

  1. Randomized controlled trial to evaluate the effect of canola oil on blood vessel function in peripheral arterial disease: rationale and design of the Canola-PAD Study

    Directory of Open Access Journals (Sweden)

    Enns JE

    2014-10-01

    Full Text Available Jennifer E Enns,1,2 Peter Zahradka,1–3 Randolph P Guzman,4,5 Alanna Baldwin,1 Brendon Foot,1 Carla G Taylor1–31Canadian Centre for Agri-Food Research in Health and Medicine, St Boniface Research Centre, Winnipeg, Canada; 2Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada; 3Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada; 4IH Asper Clinical Research Institute, St Boniface Hospital, Winnipeg, Canada; 5Section of Vascular Surgery, Department of Surgery, St Boniface Hospital, Winnipeg, CanadaBackground: Individuals with peripheral arterial disease (PAD are at high risk for cardiac events due to atherosclerosis. Dietary fatty acid composition has been shown to modulate blood vessel properties, but whether a diet enriched in conventional canola oil can improve clinical endpoints in PAD is not known.Purpose: To describe the rationale and design of a clinical trial testing the effect of canola oil consumption on vascular function and cardiovascular risk factors in an 8-week dietary intervention in individuals with PAD.Methods: The Canola-PAD Study was a single center, prospective, double-blind, randomized controlled trial in 50 patients over 40 years old with PAD. Participants were randomized into two groups and consumed food items containing either conventional canola oil (25 g/day or an oil mixture representing the Western diet (25 g/day for 8 weeks as part of their usual diet. The primary outcome was vascular function (ankle-brachial index, arterial stiffness, endothelial dysfunction, walking capacity, and cognitive function. Secondary measurements included anthropometrics, serum lipid profile and fatty acid composition, markers of inflammation and glycemic control, and serum metabolite profile.Discussion: The Canola-PAD Study uses an innovative and noninvasive approach to evaluate the effect of canola oil on clinically relevant outcomes in individuals with PAD, including

  2. Incremental value of regional wall motion analysis immediately after exercise for the detection of single-vessel coronary artery disease. Study by separate acquisition, dual-isotope ECG-gated single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Yoda, Shunichi; Sato, Yuichi; Matsumoto, Naoya; Tani, Shigemasa; Takayama, Tadateru; Uchiyama, Takahisa; Saito, Satoshi

    2005-01-01

    Although the detection of wall motion abnormalities gives incremental value to myocardial perfusion single-photon emission computed tomography (SPECT) in the diagnosis of extensive coronary artery disease (CAD) and high-grade single-vessel CAD, whether or not it is useful in the diagnosis of mild, single-vessel CAD has not been studied previously. Separate acquisition, dual isotope electrocardiogram (ECG)-gated SPECT was performed in 97 patients with a low likelihood of CAD (Group 1) and 46 patients with single-vessel CAD (Group 2). Mild CAD was defined by stenosis of 50-75% (Group 2a, n=22) and moderate to severe CAD was defined by stenosis ≥76% (Group 2b, n=24). Myocardial perfusion and wall motion were graded by a 5 point-scale, 20-segment model. The sensitivity of myocardial perfusion alone was 50% for Group 2a, 83% for Group 2b and 67% for Group 2 as a whole. The overall specificity was 90%. When the wall motion analysis was combined, the sensitivity was increased to 82% in Group 2a and 92% in Group 2b. The ability to detect a wall motion abnormality immediately after exercise gives incremental diagnostic value to myocardial perfusion SPECT in the identification of mild, single-vessel CAD. (author)

  3. Improvement to reactor vessel

    International Nuclear Information System (INIS)

    1974-01-01

    The vessel described includes a prestressed concrete vessel containing a chamber and a removable cover closing this chamber. The cover is in concrete and is kept in its closed position by main and auxiliary retainers, comprising fittings integral with the concrete of the vessel. The auxiliary retainers pass through the concrete of the cover. This improvement may be applied to BWR, PWR and LMFBR type reactor vessel [fr

  4. ALICE HMPID Radiator Vessel

    CERN Document Server

    2003-01-01

    View of the radiator vessels of the ALICE/HMPID mounted on the support frame. Each HMPID module is equipped with 3 indipendent radiator vessels made out of neoceram and fused silica (quartz) windows glued together. The spacers inside the vessel are needed to stand the hydrostatic pressure. http://alice-hmpid.web.cern.ch/alice-hmpid

  5. CHARACTERISTICS OF MEI-YU PRECIPITATION AND SVD ANALYSIS OF PRECIPITATION OVER THE YANGTZE-HUAIHE RIVERS VALLEYS AND THE SEA SURFACE TEMPERATURE IN THE NORTHERN PACIFIC OCEAN

    Institute of Scientific and Technical Information of China (English)

    MAO Wen-shu; WANG Qian-qian; PENG Jun; LI Yong-hua

    2008-01-01

    Based on the precipitation data of Meiyu at 37 stations in the valleys of Yangtze and Huaihe Rivers from 1954 to 2001, the temporal-spatial characteristics of Meiyu precipitation and their relationships with the sea surface temperature in northern Pacific are investigated using such methods as harmonic analysis, empirical orthogonal function (EOF), composite analysis and singular value decomposition (SVD). The results show that the temporal evolution and spatial distribution of Meiyu precipitation are not homogeneous in the Yangtze-Huaihe Rivers basins but with prominent inter-annual and inter-decadal variabilities. The key region between the anomalies of Meiyu precipitation and the monthly sea surface temperature anomalies (SSTA) lies in the west wind drift of North Pacific, which influences the precipitation anomaly of Meiyu precipitation over a key period of time from January to March in the same year. When the SST in the North Pacific west wind drift is warmer (colder) than average during these months, Meiyu precipitation anomalously increases (decreases) in the concurrent year. Results of SVD are consistent with those of composite analysis which pass the significance test of Monte-Carlo at 0.05.

  6. A novel model for Time-Series Data Clustering Based on piecewise SVD and BIRCH for Stock Data Analysis on Hadoop Platform

    Directory of Open Access Journals (Sweden)

    Ibgtc Bowala

    2017-06-01

    Full Text Available With the rapid growth of financial markets, analyzers are paying more attention on predictions. Stock data are time series data, with huge amounts. Feasible solution for handling the increasing amount of data is to use a cluster for parallel processing, and Hadoop parallel computing platform is a typical representative. There are various statistical models for forecasting time series data, but accurate clusters are a pre-requirement. Clustering analysis for time series data is one of the main methods for mining time series data for many other analysis processes. However, general clustering algorithms cannot perform clustering for time series data because series data has a special structure and a high dimensionality has highly co-related values due to high noise level. A novel model for time series clustering is presented using BIRCH, based on piecewise SVD, leading to a novel dimension reduction approach. Highly co-related features are handled using SVD with a novel approach for dimensionality reduction in order to keep co-related behavior optimal and then use BIRCH for clustering. The algorithm is a novel model that can handle massive time series data. Finally, this new model is successfully applied to real stock time series data of Yahoo finance with satisfactory results.

  7. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  8. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

    ``Normalization'' of tumor blood vessels has shown promise to improve the efficacy of chemotherapeutics. In theory, anti-angiogenic drugs targeting endothelial VEGF signaling can improve vessel network structure and function, enhancing the transport of subsequent cytotoxic drugs to cancer cells. In practice, the effects are unpredictable, with varying levels of success. The predominant effects of anti-VEGF therapies are decreased vessel leakiness (hydraulic conductivity), decreased vessel diameters and pruning of the immature vessel network. It is thought that each of these can influence perfusion of the vessel network, inducing flow in regions that were previously sluggish or stagnant. Unfortunately, when anti-VEGF therapies affect vessel structure and function, the changes are dynamic and overlapping in time, and it has been difficult to identify a consistent and predictable normalization ``window'' during which perfusion and subsequent drug delivery is optimal. This is largely due to the non-linearity in the system, and the inability to distinguish the effects of decreased vessel leakiness from those due to network structural changes in clinical trials or animal studies. We have developed a mathematical model to calculate blood flow in complex tumor networks imaged by two-photon microscopy. The model incorporates the necessary and sufficient components for addressing the problem of normalization of tumor vasculature: i) lattice-Boltzmann calculations of the full flow field within the vasculature and within the tissue, ii) diffusion and convection of soluble species such as oxygen or drugs within vessels and the tissue domain, iii) distinct and spatially-resolved vessel hydraulic conductivities and permeabilities for each species, iv) erythrocyte particles advecting in the flow and delivering oxygen with real oxygen release kinetics, v) shear stress-mediated vascular remodeling. This model, guided by multi-parameter intravital imaging of tumor vessel structure

  9. Maury Journals - German Vessels

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — German vessels observations, after the 1853 Brussels Conference that set International Maritime Standards, modeled after Maury Marine Standard Observations.

  10. Roi Detection and Vessel Segmentation in Retinal Image

    Science.gov (United States)

    Sabaz, F.; Atila, U.

    2017-11-01

    Diabetes disrupts work by affecting the structure of the eye and afterwards leads to loss of vision. Depending on the stage of disease that called diabetic retinopathy, there are sudden loss of vision and blurred vision problems. Automated detection of vessels in retinal images is a useful study to diagnose eye diseases, disease classification and other clinical trials. The shape and structure of the vessels give information about the severity of the disease and the stage of the disease. Automatic and fast detection of vessels allows for a quick diagnosis of the disease and the treatment process to start shortly. ROI detection and vessel extraction methods for retinal image are mentioned in this study. It is shown that the Frangi filter used in image processing can be successfully used in detection and extraction of vessels.

  11. ROI DETECTION AND VESSEL SEGMENTATION IN RETINAL IMAGE

    Directory of Open Access Journals (Sweden)

    F. Sabaz

    2017-11-01

    Full Text Available Diabetes disrupts work by affecting the structure of the eye and afterwards leads to loss of vision. Depending on the stage of disease that called diabetic retinopathy, there are sudden loss of vision and blurred vision problems. Automated detection of vessels in retinal images is a useful study to diagnose eye diseases, disease classification and other clinical trials. The shape and structure of the vessels give information about the severity of the disease and the stage of the disease. Automatic and fast detection of vessels allows for a quick diagnosis of the disease and the treatment process to start shortly. ROI detection and vessel extraction methods for retinal image are mentioned in this study. It is shown that the Frangi filter used in image processing can be successfully used in detection and extraction of vessels.

  12. Comparison of immediate results and follow-up of patients with single-vessel and multivessel coronary artery disease younger than 50 years of age undergoing coronary stent implantation

    Directory of Open Access Journals (Sweden)

    Anello Alexandre L.

    2003-01-01

    Full Text Available OBJECTIVE: To assess the in-hospital results and clinical follow-up of young patients (< 50 years with multivessel coronary artery disease undergoing stent implantation in native coronary arteries and to compare their results with those of patients with single-vessel coronary artery disease. METHODS: We retrospectively studied 462 patients undergoing coronary stent implantation. Patients were divided into 2 groups: group I (G-I - 388 (84% patients with single-vessel coronary artery disease; and group II (G-II - 74 (16% patients with multivessel coronary artery disease. RESULTS: The mean age of the patients was 45±4.9 years, and the clinical findings at presentation and demographic data were similar in both groups. The rate of clinical success was 95% in G-I and 95.8% in G-II (P=0.96, with no difference in regard to in-hospital evolution between the groups. Death, acute myocardial infarction, and the need for myocardial revascularization during clinical follow-up occurred in 10.1% and 11.2% (P=0.92 in G-I and G-II, respectively. By the end of 24 months, the actuarial analysis showed an event-free survival of 84.6 % in G-I and 81.1% in G-II (P=0.57. CONCLUSION: Percutaneous treatment with coronary stent implantation in young patients with multivessel disease may be safe with a high rate of clinical success, a low incidence of in-hospital complications, and a favorable evolution in clinical follow-up.

  13. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    This invention relates to an apparatus and method for sealing the cold leg nozzles of a nuclear reactor pressure vessel from a remote location during maintenance and inspection of associated steam generators and pumps while the pressure vessel and refueling canal are filled with water. The apparatus includes a sealing plug for mechanically sealing the cold leg nozzle from the inside of a reactor pressure vessel. The sealing plugs include a primary and a secondary O-ring. An installation tool is suspended within the reactor vessel and carries the sealing plug. The tool telescopes to insert the sealing plug within the cold leg nozzle, and to subsequently remove the plug. Hydraulic means are used to activate the sealing plug, and support means serve to suspend the installation tool within the reactor vessel during installation and removal of the sealing plug

  14. Containment vessel drain system

    Science.gov (United States)

    Harris, Scott G.

    2018-01-30

    A system for draining a containment vessel may include a drain inlet located in a lower portion of the containment vessel. The containment vessel may be at least partially filled with a liquid, and the drain inlet may be located below a surface of the liquid. The system may further comprise an inlet located in an upper portion of the containment vessel. The inlet may be configured to insert pressurized gas into the containment vessel to form a pressurized region above the surface of the liquid, and the pressurized region may operate to apply a surface pressure that forces the liquid into the drain inlet. Additionally, a fluid separation device may be operatively connected to the drain inlet. The fluid separation device may be configured to separate the liquid from the pressurized gas that enters the drain inlet after the surface of the liquid falls below the drain inlet.

  15. An everolimus-eluting stent versus a paclitaxel-eluting stent in small vessel coronary artery disease: a pooled analysis from the SPIRIT II and SPIRIT III trials.

    Science.gov (United States)

    Bartorelli, Antonio L; Serruys, Patrick W; Miquel-Hébert, Karine; Yu, Shui; Pierson, Wes; Stone, Gregg W

    2010-07-01

    To evaluate the safety and efficacy of the XIENCE V everolimus-eluting stent compared to the TAXUS paclitaxel-eluting stent in small vessels. The XIENCE V everolimus-eluting stent (EES) has been shown to improve angiographic and clinical outcomes after percutaneous myocardial revascularization, but its performance in small coronary arteries has not been investigated. In this pooled analysis, we studied a cohort of 541 patients with small coronary vessels (reference diameter SPIRIT II and SPIRIT III studies. TAXUS Express (73% of lesions) and TAXUS Liberté (27% of lesions) paclitaxel-eluting stents (PES) were used as controls in SPIRIT II. In SPIRIT III, Taxus Express(2) PES was the control. Mean angiographic in-stent and in-segment late loss was significantly less in the EES group compared with the PES group, (0.15 +/- 0.37 mm vs. 0.30 +/- 0.44 mm; P = 0.011 for in-stent; 0.10 +/- 0.38 mm vs. 0.21 +/- 0.34 mm; P = 0.034 for in-segment). EES also resulted in a significant reduction in composite major adverse cardiac events at 1 year (19/366 [5.2%] vs. 17/159 [10.7%]; P = 0.037), due to fewer non-Q-wave myocardial infarctions and target lesion revascularizations. At 1 year, the rate of non-Q-wave myocardial infarction was significantly lower in the EES group compared with that of the PES group (6/366 [1.6%] vs. 8/159 [5.0%]; P = 0.037). In patients with small vessel coronary arteries, the XIENCE V EES was superior to the TAXUS PES. (c) 2010 Wiley-Liss, Inc.

  16. Safety and feasibility of performing staged non-culprit vessel percutaneous coronary intervention within the index hospitalization in patients with ST-segment elevation myocardial infarction and multivessel disease

    International Nuclear Information System (INIS)

    Loh, Joshua P.; Kitabata, Hironori; Torguson, Rebecca; Satler, Lowell F.; Kent, Kenneth M.; Suddath, William O.; Pichard, Augusto D.; Lindsay, Joseph; Waksman, Ron

    2013-01-01

    Objectives: To determine whether staged percutaneous coronary intervention (PCI) within the same hospitalization as primary PCI is safe. Background: In ST-segment elevation myocardial infarction (STEMI) patients with multivessel disease undergoing primary PCI, staged non-culprit vessel PCI at a separate session is recommended. Methods: We conducted a retrospective analysis of 282 consecutive STEMI patients with multivessel disease who underwent primary PCI followed by staged PCI of the non-culprit vessel. Patients were categorized into staged PCI in the same hospitalization (n = 184) and staged PCI at a separate hospitalization within 8 weeks of primary PCI (n = 98). Results: Baseline characteristics, presentation of STEMI, and procedural characteristics were similar in both groups. Contrast amount was higher in the separate hospitalization group for both index (175 vs. 153 ml, p = 0.011) and staged (144 vs. 120 ml, p = 0.004) procedures. More staged left main PCI was performed in the separate hospitalization group (3.9 vs. 0.3%, p = 0.008). Angiographic success of staged PCI was similar in both groups, with similar rates of vascular complications and major bleeding. Following staged PCI, in-hospital major adverse cardiac events (3.3 vs. 1.0%, p = 0.43) and mortality (2.7 vs. 0%, p = 0.17) were similar in both groups. Conclusions: Our study supports the safety and feasibility of staged PCI within the same hospitalization as primary PCI, achieving similar procedural success and in-hospital outcomes as staged PCI at a separate hospitalization. Higher contrast amount used during primary PCI and presence of left main lesion in non-culprit vessels may influence the decision to stage the PCI at a separate hospitalization

  17. Comparing treatment outcomes of fractional flow reserve-guided and angiography-guided percutaneous coronary intervention in patients with multi-vessel coronary artery diseases: a systematic review and meta-analysis.

    Science.gov (United States)

    Xiu, Jiancheng; Chen, Gangbin; Zheng, Hua; Wang, Yuegang; Chen, Haibin; Liu, Xuewei; Wu, Juefei; Bin, Jianping

    2016-02-01

    Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is used to assess the need for angioplasty in vessels with intermediate blockages. The treatment outcomes of FFR-guided vs. conventional angiography-guided PCI were evaluated in patients with multi-vessel coronary artery disease (CAD). Prospective and retrospective studies comparing FFR-guided vs. angiography-guided PCI in patients with multi-vessel CAD were identified from medical databases by two independent reviewers using the terms "percutaneous coronary intervention, fractional flow reserve, angiography, coronary heart disease, major adverse cardiac events (MACE) and myocardial infarction". The primary outcome was the number of stents placed, and the secondary outcomes were procedure time, mortality, myocardial infarction (MI) and MACE rates. Seven studies (three retrospective and four prospective), which included 49,517 patients, were included in this review. A total of 4,755 patients underwent FFR, while 44,697 received angiography-guided PCI. The mean patient age ranged from 58 to 71.7 years. The average number of stents used in FFR patients ranged from 0.3-1.9, and in angiography-guided PCI patients ranged from 0.7-2.7. Analysis indicated there was a greater number of stents placed in the angiography-guided group compared with the FFR group (pooled difference in means: -0.64, 95% confidence interval [CI]: -0.81 to -0.47, P < 0.001). There were no differences in the secondary outcomes between the two groups. Both procedures produce similar clinical outcomes, but the fewer number of stents used with FFR may have clinical as was as cost implications.

  18. Diffusion tensor imaging of the hippocampus and verbal memory performance: The RUN DMC Study

    NARCIS (Netherlands)

    van Norden, Anouk G.W.; de Laat, Karlijn F.; Fick, Ilma; van Uden, Inge W.M.; van Oudheusden, Lucas J.B.; Gons, Rob A.R.; Norris, David Gordon; Zwiers, Marcel P.; Kessels, Roy P.C.; de Leeuw, Frank-Erik

    2012-01-01

    Background: Cerebral small vessel disease (SVD) and hippocampal atrophy are related to verbal memory failures and may ultimately result in Alzheimer's disease. However, verbal memory failures are often present before structural changes on conventional MRI appear. Changes in microstructural integrity

  19. Observed Influence of Nitroglycerine on Myocardial Perfusion Scintigraphy in Patients with Multiple Vessel Coronary Artery Disease and Well-Developed Collaterals

    International Nuclear Information System (INIS)

    Rasulova, Nigora; Nazirova, Lyudmila; Akhmedov, Khasan; Akhmedova, Dilyafruz; Djalalov, Farrukh; Seydaliev, Amet; Iskandarov, Farkhod; Kok, T. Y.

    2012-01-01

    0.3. However, these changes were not statistically significant (P = 0.3, P = 0.4, and P = 0.2, respectively). There was also statistically significant improvement of perfusion in the recipient territories from mean severity score at rest of 2.67 ± 0.08 to 1.6 ± 0.09 with nitroglycerine (P < 0.0001), in territories of poorly collateralized arteries from mean severity score at rest of 1.5 ± 0.14 to 0.8 ± 0.12 with nitroglycerine (P < 0.0008), as well as significant deterioration of myocardial perfusion in donor artery territories from mean severity score at rest of 1.7 ± 0.06 to 2.4 ± 0.06 with nitroglycerine (P < 0.0001). Based on the results of the study, we concluded that nitroglycerine administration in patients with multiple vessel coronary artery disease and well-developed collaterals can reduce myocardial perfusion to the areas supplied by donor arteries, even resulting in apparent absent perfusion, probably due to “steal syndrome,” although these arteries were less stenosed angiographically and deemed viable on MPS at rest. It appears that MPS in patients on nitroglycerine medication may result in an inappropriate decision by interventionists and surgeons to forgo revascularization. Hence, in cases where large and severe perfusion abnormalities are noted, MPS should be repeated after omitting nitrates

  20. NCSX Vacuum Vessel Fabrication

    International Nuclear Information System (INIS)

    Viola ME; Brown T; Heitzenroeder P; Malinowski F; Reiersen W; Sutton L; Goranson P; Nelson B; Cole M; Manuel M; McCorkle D.

    2005-01-01

    The National Compact Stellarator Experiment (NCSX) is being constructed at the Princeton Plasma Physics Laboratory (PPPL) in conjunction with the Oak Ridge National Laboratory (ORNL). The goal of this experiment is to develop a device which has the steady state properties of a traditional stellarator along with the high performance characteristics of a tokamak. A key element of this device is its highly shaped Inconel 625 vacuum vessel. This paper describes the manufacturing of the vessel. The vessel is being fabricated by Major Tool and Machine, Inc. (MTM) in three identical 120 o vessel segments, corresponding to the three NCSX field periods, in order to accommodate assembly of the device. The port extensions are welded on, leak checked, cut off within 1-inch of the vessel surface at MTM and then reattached at PPPL, to accommodate assembly of the close-fitting modular coils that surround the vessel. The 120 o vessel segments are formed by welding two 60 o segments together. Each 60 o segment is fabricated by welding ten press-formed panels together over a collapsible welding fixture which is needed to precisely position the panels. The vessel is joined at assembly by welding via custom machined 8-inch (20.3 cm) wide spacer ''spool pieces''. The vessel must have a total leak rate less than 5 X 10 -6 t-l/s, magnetic permeability less than 1.02(micro), and its contours must be within 0.188-inch (4.76 mm). It is scheduled for completion in January 2006

  1. Radioactive waste processing vessel

    International Nuclear Information System (INIS)

    Hayashi, Masaru; Suzuki, Osamu; Ishizaki, Kanjiro.

    1987-01-01

    Purpose: To obtain a vessel of a reduced weight and with no external leaching of radioactive materials. Constitution: The vessel main body is constituted, for example, with light weight concretes or foamed concretes, particularly, foamed concretes containing fine closed bubbles in the inside. Then, layers having dense texture made of synthetic resin such as polystylene, vinylchloride resin, etc. or metal plate such as stainless plate are integrally disposed to the inner surface of the vessel main body. The cover member also has the same structure. (Sekiya, K.)

  2. Tempest in a vessel

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2015-01-01

    As the ASN made some statements about anomalies of carbon content in the EPR vessel bottom and top, the author recalls and comments some technical issues to better understand the information published on this topic. He notably addresses the role of the vessel, briefly indicates its operating conditions, shape and structure, and mechanical components for the top, its material and mechanical properties, and test samples used to assess mechanical properties. He also comments the phenomenon of radio-induced embrittlement, the vessel manufacturing process, and evokes the applicable regulations. He quotes and comments statements made by the ASN and Areva which evoke further assessments of the concerned components

  3. LumenRECON Guidewire: Pilot Study of a Novel, Nonimaging Technology for Accurate Vessel Sizing and Delivery of Therapy in Femoropopliteal Disease.

    Science.gov (United States)

    Nair, Pradeep K; Carr, Jeffrey G; Bigelow, Brian; Bhatt, Deepak L; Berwick, Zachary C; Adams, George

    2018-01-01

    Proper vessel sizing during endovascular interventions is crucial to avoid adverse procedural and clinical outcomes. LumenRECON (LR) is a novel, nonimaging, 0.035-inch wire-based technology that uses the physics-based principle of Ohm's law to provide a simple, real-time luminal size while also providing a platform for therapy delivery. This study evaluated the accuracy, reliability, and safety of the LR system in patients presenting for a femoropopliteal artery intervention. This multicenter, prospective pilot study of 24 patients presenting for peripheral intervention compared LR measurements of femoropopliteal artery size to angiographic visual estimation, duplex ultrasound, quantitative angiography, and intravascular ultrasound. The primary effectiveness and safety end point was comparison against core laboratory adjudicated intravascular ultrasound values and major adverse events, respectively. Additional preclinical studies were also performed in vitro and in vivo in swine to determine the accuracy of the LR guidewire system. No intra- or postprocedure device-related adverse events occurred. A balloon or stent was successfully delivered in 12 patients (50%) over the LR wire. Differences in repeatability between successive LR measurements was 2.5±0.40% ( R 2 =0.96) with no significant bias. Differences in measurements of LR to other modalities were 0.5±1.7%, 5.0±1.8%, -1.5±2.0%, and 6.8±3.4% for intravascular ultrasound core laboratory, quantitative angiography, angiographic, and duplex ultrasound, respectively. This study demonstrates that through a physics-based principle, LR provides a real-time, safe, reproducible, and accurate vessel size of the femoropopliteal artery during intervention and can additionally serve as a conduit for therapy delivery over its wire-based platform. © 2018 American Heart Association, Inc.

  4. Cheboygan Vessel Base

    Data.gov (United States)

    Federal Laboratory Consortium — Cheboygan Vessel Base (CVB), located in Cheboygan, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). CVB was established by congressional...

  5. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  6. 2011 Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  7. 2011 Fishing Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  8. Pressurized Vessel Slurry Pumping

    International Nuclear Information System (INIS)

    Pound, C.R.

    2001-01-01

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air

  9. 2013 Tanker Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  10. Maury Journals - US Vessels

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — U.S. vessels observations, after the 1853 Brussels Conference that set International Maritime Standards, modeled after Maury Marine Standard Observations.

  11. Coastal Logbook Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch (landed catch) and effort for fishing trips made by vessels that have been issued a Federal permit for the Gulf of Mexico reef fish,...

  12. In-vessel tritium

    International Nuclear Information System (INIS)

    Ueda, Yoshio; Ohya, Kaoru; Ashikawa, Naoko; Ito, Atsushi M.; Kato, Daiji; Kawamura, Gakushi; Takayama, Arimichi; Tomita, Yukihiro; Nakamura, Hiroaki; Ono, Tadayoshi; Kawashima, Hisato; Shimizu, Katsuhiro; Takizuka, Tomonori; Nakano, Tomohide; Nakamura, Makoto; Hoshino, Kazuo; Kenmotsu, Takahiro; Wada, Motoi; Saito, Seiki; Takagi, Ikuji; Tanaka, Yasunori; Tanabe, Tetsuo; Yoshida, Masafumi; Toma, Mitsunori; Hatayama, Akiyoshi; Homma, Yuki; Tolstikhina, Inga Yu.

    2012-01-01

    The in-vessel tritium research is closely related to the plasma-materials interaction. It deals with the edge-plasma-wall interaction, the wall erosion, transport and re-deposition of neutral particles and the effect of neutral particles on the fuel recycling. Since the in-vessel tritium shows a complex nonlinear behavior, there remain many unsolved problems. So far, behaviors of in-vessel tritium have been investigated by two groups A01 and A02. The A01 group performed experiments on accumulation and recovery of tritium in thermonuclear fusion reactors and the A02 group studied theory and simulation on the in-vessel tritium behavior. In the present article, outcomes of the research are reviewed. (author)

  13. Reactor pressure vessel support

    International Nuclear Information System (INIS)

    Butti, J.P.

    1977-01-01

    A link and pin support system provides the primary vertical and lateral support for a nuclear reactor pressure vessel without restricting thermally induced radial and vertical expansion and contraction. (Auth.)

  14. 2013 Cargo Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  15. 2013 Fishing Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  16. 2013 Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  17. Ocean Station Vessel

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean Station Vessels (OSV) or Weather Ships captured atmospheric conditions while being stationed continuously in a single location. While While most of the...

  18. Vessel Sewage Discharges

    Science.gov (United States)

    Vessel sewage discharges are regulated under Section 312 of the Clean Water Act, which is jointly implemented by the EPA and Coast Guard. This homepage links to information on marine sanitation devices and no discharge zones.

  19. Impact of valvular heart disease on oral anticoagulant therapy in non-valvular atrial fibrillation: results from the RAMSES study.

    Science.gov (United States)

    Başaran, Özcan; Dogan, Volkan; Beton, Osman; Tekinalp, Mehmet; Aykan, Ahmet Çağrı; Kalaycıoğlu, Ezgi; Bolat, Ismail; Taşar, Onur; Şafak, Özgen; Kalçık, Macit; Yaman, Mehmet; İnci, Sinan; Altıntaş, Bernas; Kalkan, Sedat; Kırma, Cevat; Biteker, Murat

    2017-02-01

    The definition of non-valvular atrial fibrillation (NVAF) is controversial. We aimed to assess the impact of valvular heart disease on stroke prevention strategies in NVAF patients. The RAMSES study was a multicenter and cross-sectional study conducted on NVAF patients (ClinicalTrials.gov identifier NCT02344901). The study population was divided into patients with significant valvular disease (SVD) and non-significant valvular disease (NSVD), whether they had at least one moderate valvular disease or not. Patients with a mechanical prosthetic valve and mitral stenosis were excluded. Baseline characteristics and oral anticoagulant (OAC) therapies were compared. In 5987 patients with NVAF, there were 3929 (66%) NSVD and 2058 (34%) SVD patients. The predominant valvular disease was mitral regurgitation (58.1%), followed by aortic regurgitation (24.1%) and aortic stenosis (17.8%). Patients with SVD had higher CHA 2 DS 2 VASc [3.0 (2.0; 4.0) vs. 4.0 (2.0; 5.0), p valvular heart disease with the predominance of mitral regurgitation. Patients with SVD were at greater risk of stroke and bleeding compared to patients with NSVD. Although patients with mitral regurgitation should be given more aggressive anticoagulant therapy due to their higher risk of stroke, they are undertreated compared to patients with aortic valve diseases.

  20. Reactor pressure vessel design

    International Nuclear Information System (INIS)

    Foehl, J.

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. In chapter 2, the general principles of reactor pressure vessel design are elaborated. Crack and fracture initiation and propagation are treated in some detail

  1. Graywater Discharges from Vessels

    Science.gov (United States)

    2011-11-01

    metals (e.g., cadmium, chromium, lead, copper , zinc, silver, nickel, and mercury), solids, and nutrients (USEPA, 2008b; USEPA 2010). Wastewater from... flotation ), and disinfection (using ultraviolet light) as compared to traditional Type II MSDs that use either simple maceration and chlorination, or...Coliform Naval Vessels Oceanographic Vessels Small Cruise Ships 25a Vendor 2 Hamann AG Biological Treatment with Dissolved Air Flotation and

  2. LANL Robotic Vessel Scanning

    Energy Technology Data Exchange (ETDEWEB)

    Webber, Nels W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-25

    Los Alamos National Laboratory in J-1 DARHT Operations Group uses 6ft spherical vessels to contain hazardous materials produced in a hydrodynamic experiment. These contaminated vessels must be analyzed by means of a worker entering the vessel to locate, measure, and document every penetration mark on the vessel. If the worker can be replaced by a highly automated robotic system with a high precision scanner, it will eliminate the risks to the worker and provide management with an accurate 3D model of the vessel presenting the existing damage with the flexibility to manipulate the model for better and more in-depth assessment.The project was successful in meeting the primary goal of installing an automated system which scanned a 6ft vessel with an elapsed time of 45 minutes. This robotic system reduces the total time for the original scope of work by 75 minutes and results in excellent data accumulation and transmission to the 3D model imaging program.

  3. FFTF and CRBRP reactor vessels

    International Nuclear Information System (INIS)

    Morgan, R.E.

    1977-01-01

    The Fast Flux Test Facility (FFTF) reactor vessel and the Clinch River Breeder Reactor Plant (CRBRP) reactor vessel each serve to enclose a fast spectrum reactor core, contain the sodium coolant, and provide support and positioning for the closure head and internal structure. Each vessel is located in its reactor cavity and is protected by a guard vessel which would ensure continued decay heat removal capability should a major system leak develop. Although the two plants have significantly different thermal power ratings, 400 megawatts for FFTF and 975 megawatts for CRBRP, the two reactor vessels are comparable in size, the CRBRP vessel being approximately 28% longer than the FFTF vessel. The FFTF vessel diameter was controlled by the space required for the three individual In-Vessel Handling Machines and Instrument Trees. Utilization of the triple rotating plug scheme for CRBRP refueling enables packaging of the larger CRBRP core in a vessel the same diameter as the FFTF vessel

  4. [Clinical features of 32 patients with cutaneous small vessel vasculitis].

    Science.gov (United States)

    López de Maturana, Donaldo; Amaro, Patricio; Segovia, Laura; Balestrini, Claudia

    2004-02-01

    The skin is a common target of small vessel vasculitis, with a wide assortment of pathological changes. This condition is usually associated to systemic diseases. To report the clinical and pathological features of patients with cutaneous small vessel vasculitis. A retrospective review of 32 patients with a pathological diagnosis of cutaneous vasculitis. Seventy two percent of patients were women. Cutaneous lesions were mainly located in the lower limbs (94%). The most common lesion was palpable purpura (62%). Connective tissue diseases and systemic vasculitis were the most commonly associated systemic diseases. Palpable purpura is the most common manifestation of cutaneous small vessel vasculitis, that is usually associated to connective tissue diseases or systemic vasculitis.

  5. Singular value decomposition (SVD for extraction of gravity anomaly associated with gold mineralization in Tongshi gold field, Western Shandong Uplifted Block, Eastern China

    Directory of Open Access Journals (Sweden)

    B. B. Zhao

    2011-02-01

    Full Text Available A singular value decomposition (SVD program on MATLAB platform was effectively used to handle gravity signals for the Tongshi gold field. Firstly, the gravity signals were decomposed into different eigenimages with the help of singular value decomposition method (SVD. Secondly, the thresholds between the eigenvalues reflecting different layers of ore-controlling factors were established by multi-fractal method. Finally images reflecting different layers of ore-controlling factors were rebuilt. This yielded two layers of two-dimensional singular value images that depict regional and local ore-controlling factors, respectively.

    1. The regional ore-controlling factor is a saddle valley with the gravity anomaly values varying from −55 to 51 μm s−2 on the NW trending swell with the gravity anomaly values varying from −55 to 567 μm s−2 on the SW side of the Mesozoic volcanic sedimentary basin with the gravity anomaly values varying from −56 to −974 μm s−2. The saddle valley might be tectonically an extensional area where the Tongshi complex pluton and all gold deposits are located and thus this area is favorable for gold deposits.


    2. The local ore-controlling factor is the Tongshi complex pluton with a negative circular gravity anomaly varying from −339 to −11 μm s−2 and the ring contact metasomatic mineralization zone around the Tongshi complex with the positive gravity anomaly varying from 37 to 345 μm s−2. The skarn and porphyry types of gold deposits are located within the complex pluton and the Carlin and cryptobreccia types of gold deposits are located within the contact metasomatic mineralization zone. Thus both of them are potential areas for gold deposits.


    3. The Tongshi gold field exhibits a typical complexity with multi-layers of ore-controlling factors.

  6. Margination of Stiffened Red Blood Cells Regulated By Vessel Geometry.

    Science.gov (United States)

    Chen, Yuanyuan; Li, Donghai; Li, Yongjian; Wan, Jiandi; Li, Jiang; Chen, Haosheng

    2017-11-10

    Margination of stiffened red blood cells has been implicated in many vascular diseases. Here, we report the margination of stiffened RBCs in vivo, and reveal the crucial role of the vessel geometry in the margination by calculations when the blood is seen as viscoelastic fluid. The vessel-geometry-regulated margination is then confirmed by in vitro experiments in microfluidic devices, and it establishes new insights to cell sorting technology and artificial blood vessel fabrication.

  7. Acrylic vessel cleaning tests

    International Nuclear Information System (INIS)

    Earle, D.; Hahn, R.L.; Boger, J.; Bonvin, E.

    1997-01-01

    The acrylic vessel as constructed is dirty. The dirt includes blue tape, Al tape, grease pencil, gemak, the glue or residue form these tapes, finger prints and dust of an unknown composition but probably mostly acrylic dust. This dirt has to be removed and once removed, the vessel has to be kept clean or at least to be easily cleanable at some future stage when access becomes much more difficult. The authors report on the results of a series of tests designed: (a) to prepare typical dirty samples of acrylic; (b) to remove dirt stuck to the acrylic surface; and (c) to measure the optical quality and Th concentration after cleaning. Specifications of the vessel call for very low levels of Th which could come from tape residues, the grease pencil, or other sources of dirt. This report does not address the concerns of how to keep the vessel clean after an initial cleaning and during the removal of the scaffolding. Alconox is recommended as the cleaner of choice. This acrylic vessel will be used in the Sudbury Neutrino Observatory

  8. Radioactive liquid containing vessel

    International Nuclear Information System (INIS)

    Sakurada, Tetsuo; Kawamura, Hironobu.

    1993-01-01

    Cooling jackets are coiled around the outer circumference of a container vessel, and the outer circumference thereof is covered with a surrounding plate. A liquid of good conductivity (for example, water) is filled between the cooling jackets and the surrounding plate. A radioactive liquid is supplied to the container vessel passing through a supply pipe and discharged passing through a discharge pipe. Cooling water at high pressure is passed through the cooling water jackets in order to remove the heat generated from the radioactive liquid. Since cooling water at high pressure is thus passed through the coiled pipes, the wall thickness of the container vessel and the cooling water jackets can be reduced, thereby enabling to reduce the cost. Further, even if the radioactive liquid is leaked, there is no worry of contaminating cooling water, to prevent contamination. (I.N.)

  9. Trends in Tissue Engineering for Blood Vessels

    Directory of Open Access Journals (Sweden)

    Judee Grace Nemeno-Guanzon

    2012-01-01

    Full Text Available Over the years, cardiovascular diseases continue to increase and affect not only human health but also the economic stability worldwide. The advancement in tissue engineering is contributing a lot in dealing with this immediate need of alleviating human health. Blood vessel diseases are considered as major cardiovascular health problems. Although blood vessel transplantation is the most convenient treatment, it has been delimited due to scarcity of donors and the patient’s conditions. However, tissue-engineered blood vessels are promising alternatives as mode of treatment for blood vessel defects. The purpose of this paper is to show the importance of the advancement on biofabrication technology for treatment of soft tissue defects particularly for vascular tissues. This will also provide an overview and update on the current status of tissue reconstruction especially from autologous stem cells, scaffolds, and scaffold-free cellular transplantable constructs. The discussion of this paper will be focused on the historical view of cardiovascular tissue engineering and stem cell biology. The representative studies featured in this paper are limited within the last decade in order to trace the trend and evolution of techniques for blood vessel tissue engineering.

  10. Intracranial vessel wall imaging at 7.0 tesla MRI

    NARCIS (Netherlands)

    van der Kolk, A.G.

    2014-01-01

    Intracranial atherosclerosis is one of the main causes of ischemic stroke. Current conventional imaging techniques assessing intracranial arterial disease in vivo only visualize the vessel wall lumen instead of the pathological vessel wall itself. Therefore, not much is known about the imaging

  11. Pressure vessel integrity 1991

    International Nuclear Information System (INIS)

    Bhandari, S.; Doney, R.O.; McDonald, M.S.; Jones, D.P.; Wilson, W.K.; Pennell, W.E.

    1991-01-01

    This volume contains papers relating to the structural integrity assessment of pressure vessels and piping, with special emphasis on nuclear industry applications. The papers were prepared for technical sessions developed under the sponsorship of the ASME Pressure Vessels and Piping Division Committees for Codes and Standards, Computer Technology, Design and Analysis, and Materials Fabrication. They were presented at the 1991 Pressure Vessels and Piping Division Conference in San Diego, California, June 23-27. The primary objective of the sponsoring organization is to provide a forum for the dissemination and discussion of information on development and application of technology for the structural integrity assessment of pressure vessels and piping. This publication includes contributions from authors from Australia, France, Japan, Sweden, Switzerland, the United Kingdom, and the United States. The papers here are organized in six sections, each with a particular emphasis as indicated in the following section titles: Fracture Technology Status and Application Experience; Crack Initiation, Propagation and Arrest; Ductile Tearing; Constraint, Stress State, and Local-Brittle-Zones Effects; Computational Techniques for Fracture and Corrosion Fatigue; and Codes and Standards for Fatigue, Fracture and Erosion/Corrosion

  12. The reactor vessel steels

    International Nuclear Information System (INIS)

    Bilous, W.; Hajewska, E.; Szteke, W.; Przyborska, M.; Wasiak, J.; Wieczorkowski, M.

    2005-01-01

    In the paper the fundamental steels using in the construction of pressure vessel water reactor are discussed. The properties of these steels as well as the influence of neutron irradiation on its degradation in the time of exploitation are also done. (authors)

  13. Vacuum distilling vessel

    Energy Technology Data Exchange (ETDEWEB)

    Reik, H

    1928-12-27

    Vacuum distilling vessel for mineral oil and the like, characterized by the ring-form or polyconal stiffeners arranged inside, suitably eccentric to the casing, being held at a distance from the casing by connecting members of such a height that in the resulting space if necessary can be arranged vapor-distributing pipes and a complete removal of the residue is possible.

  14. Visualization of vessel traffic

    NARCIS (Netherlands)

    Willems, C.M.E.

    2011-01-01

    Moving objects are captured in multivariate trajectories, often large data with multiple attributes. We focus on vessel traffic as a source of such data. Patterns appearing from visually analyzing attributes are used to explain why certain movements have occurred. In this research, we have developed

  15. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  16. Reactor vessel stud tensioner

    International Nuclear Information System (INIS)

    Malandra, L.J.; Beer, R.W.; Salton, R.B.; Spiegelman, S.R.; Cognevich, M.L.

    1982-01-01

    A quick-acting stud tensioner, for facilitating the loosening or tightening of a stud nut on a reactor vessel stud, has gripper jaws which when the tensioner is lowered into engagement with the upper end of the stud are moved inwards to grip the upper end and which when the tensioner is lifted move outward to release the upper end. (author)

  17. Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

    Science.gov (United States)

    Xiao, Di; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

  18. PDX vacuum vessel stress analysis

    International Nuclear Information System (INIS)

    Nikodem, Z.D.

    1975-01-01

    A stress analysis of PDX vacuum vessel is described and the summary of results is presented. The vacuum vessel is treated as a toroidal shell of revolution subjected to an internal vacuum. The critical buckling pressure is calculated. The effects of the geometrical discontinuity at the juncture of toroidal shell head and cylindrical outside wall, and the concavity of the cylindrical wall are examined. An effect of the poloidal field coil supports and the vessel outside supports on the stress distribution in the vacuum vessel is determined. A method evaluating the influence of circular ports in the vessel wall on the stress level in the vessel is outlined

  19. Long-Term Effectiveness of the Zilver PTX Drug-Eluting Stent for Femoropopliteal Peripheral Artery Disease in Patients with No Patent Tibial Runoff Vessels-Results from the Zilver PTX Japan Post-Market Surveillance Study.

    Science.gov (United States)

    Cipollari, Stefano; Yokoi, Hiroyoshi; Ohki, Takao; Kichikawa, Kimihiko; Nakamura, Masato; Komori, Kimihiro; Nanto, Shinsuke; O'Leary, Erin E; Lottes, Aaron E; Saunders, Alan T; Dake, Michael D

    2018-01-01

    To evaluate 2-year results of the Zilver PTX (Cook Medical, Bloomington, Indiana) drug-eluting stent (DES) for femoropopliteal peripheral artery disease (PAD) in patients with no continuous patent infrapopliteal runoff arteries compared with patients with ≥ 1 continuous patent runoff vessels. A retrospective analysis of patients with femoropopliteal PAD enrolled in the Zilver PTX Post-Market Surveillance Study in Japan was performed. There were no exclusion criteria. Outcomes, including freedom from target lesion revascularization (TLR), patency, and clinical benefit, for the no-runoff group (n = 54) were compared with the runoff group (n = 846). The 2 groups were similar in terms of demographics, lesion characteristics, and comorbidities (P > .05). There was a higher incidence of critical limb ischemia in the no-runoff group compared with the runoff group (44.8% vs 19.7%; P < .01). There were 3 amputations (5.6%) in the no-runoff group versus 7 amputations (0.8%) in the runoff group (P = .02). At 2 years, freedom from TLR rates were 81.3% versus 83.8% (P = .87), patency rates were 68.4% versus 70.7% (P = .95), and clinical benefit rates were 73.7% versus 80.0% (P = .16) in the no-runoff versus runoff group, respectively. Results in patients with no continuous patent tibial runoff were favorable through 2 years and similar to results for patients with ≥ 1 continuous patent runoff vessels, indicating that the Zilver PTX DES may be a valid treatment option for patients with these difficult-to-treat lesions. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  20. Bone marrow blood vessels: normal and neoplastic niche

    Directory of Open Access Journals (Sweden)

    Saeid Shahrabi

    2016-11-01

    Full Text Available Blood vessels are among the most important factors in the transport of materials such as nutrients and oxygen. This study will review the role of blood vessels in normal bone marrow hematopoiesis as well as pathological conditions like leukemia and metastasis. Relevant literature was identified by a Pubmed search (1992-2016 of English-language papers using the terms bone marrow, leukemia, metastasis, and vessel. Given that blood vessels are conduits for the transfer of nutrients, they create a favorable situation for cancer cells and cause their growth and development. On the other hand, blood vessels protect leukemia cells against chemotherapy drugs. Finally, it may be concluded that the vessels are an important factor in the development of malignant diseases.

  1. Screening for New Biomarkers for Subcortical Vascular Dementia and Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Annika Öhrfelt

    2011-01-01

    Full Text Available Background: Novel biomarkers are important for identifying as well as differentiating subcortical vascular dementia (SVD and Alzheimer’s disease (AD at an early stage in the disease process. Methods: In two independent cohorts, a multiplex immunoassay was utilized to analyze 90 proteins in cerebrospinal fluid (CSF samples from dementia patients and patients at risk of developing dementia (mild cognitive impairment. Results: The levels of several CSF proteins were increased in SVD and its incipient state, and in moderate-to-severe AD compared with the control group. In contrast, some CSF proteins were altered in AD, but not in SVD. The levels of heart-type fatty acid binding protein (H-FABP were consistently increased in all groups with dementia but only in some of their incipient states. Conclusions: In summary, these results support the notion that SVD and AD are driven by different pathophysiological mechanisms reflected in the CSF protein profile and that H-FABP in CSF is a general marker of neurodegeneration.

  2. [Large vessels vasculopathy in systemic sclerosis].

    Science.gov (United States)

    Tejera Segura, Beatriz; Ferraz-Amaro, Iván

    2015-12-07

    Vasculopathy in systemic sclerosis is a severe, in many cases irreversible, manifestation that can lead to amputation. While the classical clinical manifestations of the disease have to do with the involvement of microcirculation, proximal vessels of upper and lower limbs can also be affected. This involvement of large vessels may be related to systemic sclerosis, vasculitis or atherosclerotic, and the differential diagnosis is not easy. To conduct a proper and early diagnosis, it is essential to start prompt appropriate treatment. In this review, we examine the involvement of large vessels in scleroderma, an understudied manifestation with important prognostic and therapeutic implications. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  3. Vessel discoloration detection in malarial retinopathy

    Science.gov (United States)

    Agurto, C.; Nemeth, S.; Barriga, S.; Soliz, P.; MacCormick, I.; Taylor, T.; Harding, S.; Lewallen, S.; Joshi, V.

    2016-03-01

    Cerebral malaria (CM) is a life-threatening clinical syndrome associated with malarial infection. It affects approximately 200 million people, mostly sub-Saharan African children under five years of age. Malarial retinopathy (MR) is a condition in which lesions such as whitening and vessel discoloration that are highly specific to CM appear in the retina. Other unrelated diseases can present with symptoms similar to CM, therefore the exact nature of the clinical symptoms must be ascertained in order to avoid misdiagnosis, which can lead to inappropriate treatment and, potentially, death. In this paper we outline the first system to detect the presence of discolored vessels associated with MR as a means to improve the CM diagnosis. We modified and improved our previous vessel segmentation algorithm by incorporating the `a' channel of the CIELab color space and noise reduction. We then divided the segmented vasculature into vessel segments and extracted features at the wall and in the centerline of the segment. Finally, we used a regression classifier to sort the segments into discolored and not-discolored vessel classes. By counting the abnormal vessel segments in each image, we were able to divide the analyzed images into two groups: normal and presence of vessel discoloration due to MR. We achieved an accuracy of 85% with sensitivity of 94% and specificity of 67%. In clinical practice, this algorithm would be combined with other MR retinal pathology detection algorithms. Therefore, a high specificity can be achieved. By choosing a different operating point in the ROC curve, our system achieved sensitivity of 67% with specificity of 100%.

  4. Triple vessel coronary artery disease presenting as a markedly positive stress electrocardiographic test and a negative SPECT-TL scintigram: a case of balanced Ischemia

    Directory of Open Access Journals (Sweden)

    Eyal Herzog

    2011-09-01

    Full Text Available The presence of false negative nuclear stress test in the settings of positive electrocardiographic changes is a very unusual phenomenon and is usually secondary to balanced ischemia of the myocardial segments evaluated by SPECT-TL. We present a case of an 81- year old post-menopausal female who presented to her primary care physician for evaluation of a 6-week dyspnea on exertion and was referred to our institution for exercise stress test with Thallium SPECT with the objective of ruling out coronary artery disease and identifying possible areas of myocardial ischemia. The resting electrocardiogram was unremarkable and stress test evaluation was made. The patient was admitted to the cardiac care unit and coronary artery bypass grafting was successfully performed. The presence of false negative nuclear stress test in the settings of positive electrocardiographic changes is a very unusual phenomenon and is usually secondary to balanced ischemia of the myocardial segments evaluated by SPECT-TL. Patients undergoing stress tests with these characteristics should undergo careful evaluation and a high level of suspicion should be adopted for further diagnostic assessment of coronary artery disease.

  5. Histopathology of the great vessels in patients with pulmonary arterial hypertension in association with congenital heart disease: large pulmonary arteries matter too.

    Science.gov (United States)

    Prapa, Matina; McCarthy, Karen P; Dimopoulos, Konstantinos; Sheppard, Mary N; Krexi, Dimitra; Swan, Lorna; Wort, S John; Gatzoulis, Michael A; Ho, Siew Yen

    2013-10-03

    Pulmonary arterial hypertension (PAH) is considered primarily a disease of the distal pulmonary arteries whereas little is known on the effect of long-standing pulmonary hypertension on the larger proximal pulmonary arteries. This study aims to investigate the structural changes in the great arteries of adults who developed PAH in association with congenital heart disease (CHD), with severe cases termed Eisenmenger syndrome. We performed macroscopic and light microscopy analyses on the great arteries of 10 formalin-fixed human hearts from patients with PAH/CHD and compared them to age-matched healthy controls. A detailed histology grading score was used to assess the severity of medial wall abnormalities. Severe atherosclerotic lesions were found macroscopically in the elastic pulmonary arteries of 4 PAH/CHD specimens and organised thrombi in 3; none were present in the controls. Significant medial wall abnormalities were present in the pulmonary trunk (PT), including fibrosis (80%), and atypical elastic pattern (80%). Cyst-like formations were present in less than one third of patients and were severe in a single case leading to wall rupture. The cumulative PT histology grading score was significantly higher in PAH/CHD cases compared to controls (parteries. These abnormalities are likely to affect haemodynamics and contribute to morbidity and mortality in this cohort. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Unsupervised Retinal Vessel Segmentation Using Combined Filters.

    Directory of Open Access Journals (Sweden)

    Wendeson S Oliveira

    Full Text Available Image segmentation of retinal blood vessels is a process that can help to predict and diagnose cardiovascular related diseases, such as hypertension and diabetes, which are known to affect the retinal blood vessels' appearance. This work proposes an unsupervised method for the segmentation of retinal vessels images using a combined matched filter, Frangi's filter and Gabor Wavelet filter to enhance the images. The combination of these three filters in order to improve the segmentation is the main motivation of this work. We investigate two approaches to perform the filter combination: weighted mean and median ranking. Segmentation methods are tested after the vessel enhancement. Enhanced images with median ranking are segmented using a simple threshold criterion. Two segmentation procedures are applied when considering enhanced retinal images using the weighted mean approach. The first method is based on deformable models and the second uses fuzzy C-means for the image segmentation. The procedure is evaluated using two public image databases, Drive and Stare. The experimental results demonstrate that the proposed methods perform well for vessel segmentation in comparison with state-of-the-art methods.

  7. Vessels in Transit - Web Tool

    Data.gov (United States)

    Department of Transportation — A web tool that provides real-time information on vessels transiting the Saint Lawrence Seaway. Visitors may sort by order of turn, vessel name, or last location in...

  8. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

    An apparatus is described for sealing a cold leg nozzle of a nuclear reactor pressure vessel from a remote location comprising: at least one sealing plug for mechanically sealing the nozzle from the inside of the reactor pressure vessel. The sealing plug includes a plate and a cone assembly having an end part receptive in the nozzle, the plate being axially moveable relative to the cone assembly. The plate and cone assembly have confronting bevelled edges defining an opening therebetween. A primary O-ring is disposed about the opening and is supported on the bevelled edges, the plate being guidably mounted to the cone assembly for movement toward the cone assembly to radially expand the primary O-ring into sealing engagement with the nozzle. A means is included for providing relative movement between the outer plate and the cone assembly

  9. Mobile nuclear reactor containment vessel

    International Nuclear Information System (INIS)

    Thompson, R.E.; Spurrier, F.R.; Jones, A.R.

    1978-01-01

    A containment vessel for use in mobile nuclear reactor installations is described. The containment vessel completely surrounds the entire primary system, and is located as close to the reactor primary system components as is possible in order to minimize weight. In addition to being designed to withstand a specified internal pressure, the containment vessel is also designed to maintain integrity as a containment vessel in case of a possible collision accident

  10. Nuclear reactor vessel inspection apparatus

    International Nuclear Information System (INIS)

    Blackstone, E.G.; Lofy, R.A.; Williams, L.P.

    1979-01-01

    Apparatus for the in situ inspection of a nuclear reactor vessel to detect the location and character of flaws in the walls of the vessel, in the welds joining the various sections of the vessel, in the welds joining attachments such as nozzles, elbows and the like to the reactor vessel and in such attachments wherein an inspection head carrying one or more ultrasonic transducers follows predetermined paths in scanning the various reactor sections, welds and attachments

  11. Reactor vessel stud closure system

    International Nuclear Information System (INIS)

    Spiegelman, S.R.; Salton, R.B.; Beer, R.W.; Malandra, L.J.; Cognevich, M.L.

    1982-01-01

    A quick-acting stud tensioner apparatus for enabling the loosening or tightening of a stud nut on a reactor vessel stud. The apparatus is adapted to engage the vessel stud by closing a gripper around an upper end of the vessel stud when the apparatus is seated on the stud. Upon lifting the apparatus, the gripper releases the vessel stud so that the apparatus can be removed

  12. Reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Van De Velde, J.; Fabry, A.; Van Walle, E.; Chaouuadi, R.

    1998-01-01

    Research and development activities related to reactor pressure vessel steels during 1997 are reported. The objectives of activities of the Belgian Nuclear Research Centre SCK/CEN in this domain are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate a methodology on a broad database; (3) to achieve regulatory acceptance and industrial use

  13. Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Van de Velde, J.; Fabry, A.; Van Walle, E.; Chaoudi, R

    1998-07-01

    SCK-CEN's R and D programme on Reactor Pressure Vessel (RPV) Steels in performed in support of the RVP integrity assessment. Its main objectives are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate the applied methodology on a broad database; (3) to achieve regulatory acceptance and industrial use. Progress and achievements in 1999 are reported.

  14. Phenomenological vessel burst investigations

    International Nuclear Information System (INIS)

    Hippelein, K.W.; Julisch, P.; Muz, J.; Schiedermaier, J.

    1985-07-01

    Fourteen burst experiments have been carried out using vessels with circumferential and longitudinal flaws, for investigation of the fracture behaviour, i.e. the time-related fracture opening. The vessels had dimensions (outer diameter x wall thickness = 800 x 47 mm) which correspond to the dimensions of the main coolant piping of a 1300 MW e PWR. The test specimens had been made of the base-safe material 20 MnMoNi 55 and of a special, 22 NiMoCr 37 base alloy. The experimental conditions with regard to pressure and temperature have been chosen so as to correspond to normal operating conditions of a PWR (p∝17.5 MPa, T∝300 0 C), i.e. the flaws have been so dimensioned that failure was to be expected at a pressure of p∝17.5 MPa. As a rule, water has been used as the pressure medium, or in some cases air, in order to influence the time-dependent pressure decrease. Fluid and structural dynamics calculations have also been made. In order to determine the impact of a fast propagating crack on the leak-to-fracture curve, which normally is defined by quasistationary experiments, suitable tests have been made with large-volume, cylindrical vessels (outer diameter x wall thickness x length = 3000 x 21 x 14000 mm) made of the material WSt E 43. The leak-before-fracture criterion has been confirmed. (orig./HP) [de

  15. Blood Vessels in Allotransplantation.

    Science.gov (United States)

    Abrahimi, P; Liu, R; Pober, J S

    2015-07-01

    Human vascularized allografts are perfused through blood vessels composed of cells (endothelium, pericytes, and smooth muscle cells) that remain largely of graft origin and are thus subject to host alloimmune responses. Graft vessels must be healthy to maintain homeostatic functions including control of perfusion, maintenance of permselectivity, prevention of thrombosis, and participation in immune surveillance. Vascular cell injury can cause dysfunction that interferes with these processes. Graft vascular cells can be activated by mediators of innate and adaptive immunity to participate in graft inflammation contributing to both ischemia/reperfusion injury and allograft rejection. Different forms of rejection may affect graft vessels in different ways, ranging from thrombosis and neutrophilic inflammation in hyperacute rejection, to endothelialitis/intimal arteritis and fibrinoid necrosis in acute cell-mediated or antibody-mediated rejection, respectively, and to diffuse luminal stenosis in chronic rejection. While some current therapies targeting the host immune system do affect graft vascular cells, direct targeting of the graft vasculature may create new opportunities for preventing allograft injury and loss. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  16. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomenology of radiation-induced changes in blood vessels are systematized and authors' experience is generalized. Modern concepts about processes leading to vessel structure injury after irradiation is critically analyzed. Special attention is paid to reparation and compensation of X-ray vessel injury, consideration of which is not yet sufficiently elucidated in literature

  17. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

    Vorob'ev, E.I.; Stepanov, R.P.

    1985-01-01

    Data on phenomeology of radiation changes of blood vessels are systemized and the authors' experience is generalyzed. A critical analysis of modern conceptions on processes resulting in vessel structure damage after irradiation, is given. Special attention is paid to reparation and compensation of radiation injury of vessels

  18. Is right coronary artery chronic total vessel occlusion impacting the surgical revascularization results of patients with multivessel disease? A retrospective study

    Directory of Open Access Journals (Sweden)

    Janusz Konstanty-Kalandyk

    2018-06-01

    Full Text Available Introduction Chronic total occlusion (CTO is common in the presence of other significantly narrowed coronary arteries. The impact of total occlusion and its association with completeness of revascularization on patients with multivessel disease undergoing coronary artery bypass graft (CABG remains largely unknown. Aim The aim of our study was to compare CABG operation characteristics, as well as 30-day mortality, incidence of post-operative major adverse cardiac and cerebrovascular events (MACCE between patients with and without CTO in right coronary artery (RCA. Materials and Methods A total of 156 consecutive patients were included in the analysis. CTO of RCA or right posterior descending artery (RPD was diagnosed in 57 patients (CTO-RCA group. Coronary stenosis without CTO in RCA was diagnosed in 99 patients (nonCTO-RCA group. Baseline characteristics were comparable in both groups. Results The majority of patients had class II (49.1% vs. 46%, p = 0.86 or class III (42.1% vs. 43%, p = 1.0 Canadian Cardiovascular Society grading system symptoms. Patients in the CTO-RCA group had in average 2.2 grafts implanted, as opposed to 2.4 grafts in patients in the nonCTO-RCA group (p = 0.003. Graft to the RCA was performed in 40.3% patients in the CTO-RCA group and in 81% patients in the nonCTO-RCA group (p = 0.001. The 30-day mortality from any cause or cardiac cause did not differ between groups (7% vs. 2%, p = 0.14 and 3.5% vs. 2%, p = 0.57 respectively. In a multivariate analysis CTO in RCA or RPD and peripheral artery disease were independent predictors of post-operative MACCE (7.9 (1.434–43.045 p = 0.02; 18.8 (3.451–101.833 p < 0.01, respectively. Conclusions Chronic total occlusion of RCA was found to be associated with smaller number of grafts performed during the CABG procedure. Although mortality between patients in the CTO-RCA and nonCTO-RCA groups did not differ, patients in the CTO-RCA group had higher incidence of post-operative MACCE.

  19. Application of morphological bit planes in retinal blood vessel extraction.

    Science.gov (United States)

    Fraz, M M; Basit, A; Barman, S A

    2013-04-01

    The appearance of the retinal blood vessels is an important diagnostic indicator of various clinical disorders of the eye and the body. Retinal blood vessels have been shown to provide evidence in terms of change in diameter, branching angles, or tortuosity, as a result of ophthalmic disease. This paper reports the development for an automated method for segmentation of blood vessels in retinal images. A unique combination of methods for retinal blood vessel skeleton detection and multidirectional morphological bit plane slicing is presented to extract the blood vessels from the color retinal images. The skeleton of main vessels is extracted by the application of directional differential operators and then evaluation of combination of derivative signs and average derivative values. Mathematical morphology has been materialized as a proficient technique for quantifying the retinal vasculature in ocular fundus images. A multidirectional top-hat operator with rotating structuring elements is used to emphasize the vessels in a particular direction, and information is extracted using bit plane slicing. An iterative region growing method is applied to integrate the main skeleton and the images resulting from bit plane slicing of vessel direction-dependent morphological filters. The approach is tested on two publicly available databases DRIVE and STARE. Average accuracy achieved by the proposed method is 0.9423 for both the databases with significant values of sensitivity and specificity also; the algorithm outperforms the second human observer in terms of precision of segmented vessel tree.

  20. Improvement of retinal blood vessel detection using morphological component analysis.

    Science.gov (United States)

    Imani, Elaheh; Javidi, Malihe; Pourreza, Hamid-Reza

    2015-03-01

    Detection and quantitative measurement of variations in the retinal blood vessels can help diagnose several diseases including diabetic retinopathy. Intrinsic characteristics of abnormal retinal images make blood vessel detection difficult. The major problem with traditional vessel segmentation algorithms is producing false positive vessels in the presence of diabetic retinopathy lesions. To overcome this problem, a novel scheme for extracting retinal blood vessels based on morphological component analysis (MCA) algorithm is presented in this paper. MCA was developed based on sparse representation of signals. This algorithm assumes that each signal is a linear combination of several morphologically distinct components. In the proposed method, the MCA algorithm with appropriate transforms is adopted to separate vessels and lesions from each other. Afterwards, the Morlet Wavelet Transform is applied to enhance the retinal vessels. The final vessel map is obtained by adaptive thresholding. The performance of the proposed method is measured on the publicly available DRIVE and STARE datasets and compared with several state-of-the-art methods. An accuracy of 0.9523 and 0.9590 has been respectively achieved on the DRIVE and STARE datasets, which are not only greater than most methods, but are also superior to the second human observer's performance. The results show that the proposed method can achieve improved detection in abnormal retinal images and decrease false positive vessels in pathological regions compared to other methods. Also, the robustness of the method in the presence of noise is shown via experimental result. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Estimation of center line and diameter of brain blood vessel using three-dimensional blood vessel matching method with head three-dimensional CTA image

    International Nuclear Information System (INIS)

    Maekawa, Masashi; Shinohara, Toshihiro; Nakayama, Masato; Nakasako, Noboru

    2010-01-01

    To support and automate the brain blood vessel disease diagnosis, a novel method to obtain the center line and the diameter of a blood vessel is proposed with a three-dimensional head computed tomographic angiography (CTA) image. Although the line thinning processing with distance transform or gray information is generally used to obtain the blood vessel center line, this method is not essentially one to obtain the center line and tends to yield extra lines depending on CTA images. In this study, the center line of the blood vessel is obtained by tracing the vessel. The blood vessel is traced by sequentially estimating the center point and direction of the blood vessel. The center point and direction of the blood vessel are estimated by taking the correlation between the blood vessel and a solid model of the blood vessel that is designed by considering noise influence. In addition, the vessel diameter is also estimated by correlating the blood vessel and the blood vessel model of which the diameter is variable. The validity of the proposed method is confirmed by experimentally applied the proposed method to an actual three-dimensional head CTA image. (author)

  2. Pressure vessel lid

    International Nuclear Information System (INIS)

    Schoening, J.; Elter, C.; Becker, G.; Pertiller, S.

    1986-01-01

    The invention concerns a lid for closing openings in reactor pressure vessels containing helium, which is made as a circular casting with hollow spaces and a flat floor and is set on the opening and kept down. It consists of helium-tight metal cast material with sufficient temperature resistance. There are at least two concentric heat resistant seals let into the bottom of the lid. The bottom is in immediate contact with the container atmosphere and has hollow spaces in its inside in the area opposite to the opening. (orig./HP) [de

  3. CT of the heart and great vessels

    International Nuclear Information System (INIS)

    Masuda, Yoshiaki; Inagaki, Yoshiaki

    1982-01-01

    Diseases of the heart and great vessels were diagnosed by CT through comparison of the pictures with that of control. Indications for CT included pericardiac diseases such as pericardial effusion, pericardiac cyst, pericardiac defect, pericardiac fat pad, and dilated or hypertrophic ventriculus. Of coronary artery diseases, myocardial infarction is the best indication for CT; and coronary artery calcification and coronary artery bypass graft for checking up the patency were also indications for this method. CT was useful for diagnosis of valvular diseases, especially mitral valve diseases, congenital heart diseases with structural abnormalities, abnormalities of the aorta and great veins, and of the pulmonary arteries and veins, and for follow-up of pulmonary congestion. (Ueda, J.)

  4. Role of arginase in vessel wall remodeling

    Directory of Open Access Journals (Sweden)

    William eDurante

    2013-05-01

    Full Text Available Arginase metabolizes the semi-essential amino acid L-arginine to L-ornithine and urea. There are two distinct isoforms of arginase, arginase I and II, which are encoded by separate genes and display differences in tissue distribution, subcellular localization, and molecular regulation. Blood vessels express both arginase I and II but their distribution appears to be cell-, vessel-, and species-specific. Both isoforms of arginase are induced by numerous pathologic stimuli and contribute to vascular cell dysfunction and vessel wall remodeling in several diseases. Clinical and experimental studies have documented increases in the expression and/or activity of arginase I or II in blood vessels following arterial injury and in pulmonary and arterial hypertension, aging, and atherosclerosis. Significantly, pharmacological inhibition or genetic ablation of arginase in animals ameliorates abnormalities in vascular cells and normalizes blood vessel architecture and function in all of these pathological states. The detrimental effect of arginase in vascular remodeling is attributable to its ability to stimulate vascular smooth muscle cell and endothelial cell proliferation, and collagen deposition by promoting the synthesis of polyamines and L-proline, respectively. In addition, arginase adversely impacts arterial remodeling by directing macrophages towards an inflammatory phenotype. Moreover, the proliferative, fibrotic, and inflammatory actions of arginase in the vasculature are further amplified by its capacity to inhibit nitric oxide synthesis by competing with nitric oxide synthase for substrate, L-arginine. Pharmacologic or molecular approaches targeting specific isoforms of arginase represent a promising strategy in treating obstructive fibroproliferative vascular disease.

  5. Targeting Therapy Resistant Tumor Vessels

    Science.gov (United States)

    2008-08-01

    Morris LS. Hysterectomy vs. resectoscopic endometrial ablation for the control of abnormal uterine bleeding . A cost-comparative study. J Reprod Med 1994;39...after the antibody treatment contain a pericyte coat, vessel architecture is normal, the diameter of the vessels is smaller (dilated, abnormal vessels...involvement of proteases from inflammatory mast cells and functionally abnormal (Carmeliet and Jain, 2000; Pasqualini (Coussens et al., 1999) and other bone

  6. The vessel fluence; Fluence cuve

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This book presents the proceedings of the technical meeting on the reactors vessels fluence. They are grouped in eight sessions: the industrial context and the stakes of the vessels control; the organization and the methodology for the fluence computation; the concerned physical properties; the reference computation methods; the fluence monitoring in an industrial context; vessels monitoring under irradiation; others methods in the world; the research and development programs. (A.L.B.)

  7. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

    Legarda, F.; Herranz, M.; Idoeta, R.; Abelairas, A.

    2010-01-01

    The adsorption of 241 Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241 Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241 Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  8. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  9. Americium behaviour in plastic vessels.

    Science.gov (United States)

    Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

    2010-01-01

    The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. [Large vessel vasculitides].

    Science.gov (United States)

    Morović-Vergles, Jadranka; Puksić, Silva; Gracanin, Ana Gudelj

    2013-01-01

    Large vessel vasculitis includes Giant cell arteritis and Takayasu arteritis. Giant cell arteritis is the most common form of vasculitis affect patients aged 50 years or over. The diagnosis should be considered in older patients who present with new onset of headache, visual disturbance, polymyalgia rheumatica and/or fever unknown cause. Glucocorticoides remain the cornerstone of therapy. Takayasu arteritis is a chronic panarteritis of the aorta ant its major branches presenting commonly in young ages. Although all large arteries can be affected, the aorta, subclavian and carotid arteries are most commonly involved. The most common symptoms included upper extremity claudication, hypertension, pain over the carotid arteries (carotidynia), dizziness and visual disturbances. Early diagnosis and treatment has improved the outcome in patients with TA.

  11. Reactor pressure vessel embrittlement

    International Nuclear Information System (INIS)

    1992-07-01

    Within the framework of the IAEA extrabudgetary programme on the Safety of WWER-440/230 NPPs, a list of safety issues requiring broad studies of generic interest have been agreed upon by an Advisory Group who met in Vienna in September 1990. The list was later revised in the light of the programme findings. The information on the status of the issues, and on the amount of work already completed and under way in the various countries, needs to be compiled. Moreover, an evaluation of what further work is required to resolve each one of the issues is also necessary. In view of this, the IAEA has started the preparation of a series of status reports on the various issues. This report on the generic safety issue ''Reactor Pressure Vessel Embrittlement'' presents a comprehensive survey of technical information available in the field and identifies those aspects which require further investigation. 39 refs, 21 figs, 4 tabs

  12. Reactor containment vessel

    International Nuclear Information System (INIS)

    Ochiai, Kanehiro; Hayagumo, Sunao; Morikawa, Matsuo.

    1981-01-01

    Purpose: To safety and simplify the structure in a reactor containment vessel. Constitution: Steam flow channels with steam jetting ports communicating to coolants are provided between a communication channel and coolants in a pressure suppression chamber. Upon loss of coolant accidents, pressure in a dry well will increase, then force downwards water in an annulus portion and further flow out the water through steam jetting ports into a suppression pool. Thus, the steam flow channel is filled with steams or airs present in the dry well, which are released through the steam jetting ports into the pressure suppression chamber. Even though water is violently vibrated owing to the upward movement of air bubbles and condensation of steam bubbles, the annular portion and the steam jetting ports are filled with steams or the like, direct dynamic loads onto the structures such as communication channels can be avoided. (J.P.N.)

  13. B-type natriuretic peptide as predictor of heart failure in patients with acute ST elevation myocardial infarction, single-vessel disease, and complete revascularization: follow-up study.

    LENUS (Irish Health Repository)

    Manola, Sime

    2012-01-31

    AIM: To assess the concentration of B-type natriuretic peptide (BNP) as a predictor of heart failure in patients with acute ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) with successful and complete revascularization. METHODS: Out of a total of 220 patients with acute STEMI admitted to the Sisters of Mercy University Hospital in the period January 1 to December 31, 2007, only patients with acute STEMI undergoing primary PCI who had single vessel disease and were successfully revascularized were included in the study. Selected patients had no history of myocardial infarction or heart failure and a normal or near-normal left ventricular ejection fraction (> or =50%) assessed by left ventriculography at admission. Only 58 patients met the inclusion criteria for the study. Out of those, 6 patients refused to participate in the study, and another 5 could not be followed up, so a total of 47 patients were evaluated. Blood samples were taken for measurement of BNP levels at admission, 24 hours later, and 7 days later. Patients were followed up for 1 year. The primary outcome was reduction in left ventricular ejection fraction (LVEF) to <50% after 1 year. RESULTS: Patients who developed echocardiographic signs of reduced systolic function defined as LVEF<50% had significantly higher values of BNP (> or =80 pg\\/mL) at 24 hours (P=0.001) and 7 days (P=0.020) after STEMI and successful reperfusion. Patients who had BNP levels > or =80 pg\\/mL after 7 days were 21 times more likely to develop LVEF<50 (odds ratio, 20.8; 95% confidence interval, 2.2-195.2; P=0.008). CONCLUSION: BNP can be used as a predictor of reduced systolic function in patients with STEMI who underwent successful reperfusion and had normal ejection fraction at admission.

  14. Comparison of Five-Year Outcome of Percutaneous Coronary Intervention With Coronary Artery Bypass Grafting in Triple-Vessel Coronary Artery Disease (from the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2).

    Science.gov (United States)

    Shiomi, Hiroki; Morimoto, Takeshi; Furukawa, Yutaka; Nakagawa, Yoshihisa; Tazaki, Junichi; Sakata, Ryuzo; Okabayashi, Hitoshi; Hanyu, Michiya; Shimamoto, Mitsuomi; Nishiwaki, Noboru; Komiya, Tatsuhiko; Kimura, Takeshi

    2015-07-01

    Studies evaluating long-term (≥5 years) outcomes of percutaneous coronary intervention (PCI) using drug-eluting stents compared with coronary artery bypass grafting (CABG) in patients with triple-vessel coronary artery disease (TVD) are still limited. We identified 2,978 patients with TVD (PCI: n = 1,824, CABG: n = 1,154) of 15,939 patients with first coronary revascularization enrolled in the Coronary Revascularization Demonstrating Outcome Study in Kyoto PCI/CABG Registry Cohort-2. The primary outcome measure in the present analysis was a composite of death, myocardial infarction (MI), and stroke. Median follow-up duration for the surviving patients was 1,973 days (interquartile range 1,700 to 2,244). The cumulative 5-year incidence of death/MI/stroke was significantly higher in the PCI group than in the CABG group (28.2% vs 24.0%, log-rank p = 0.006). After adjusting for confounders, the excess risk of PCI relative to CABG for death/MI/stroke remained significant (hazard ratio [HR] 1.38, 95% confidence interval [CI] 1.13 to 1.68, p = 0.002). The excess risks of PCI relative to CABG for all-cause death, MI, and any coronary revascularization were also significant (HR 1.38, 95% CI 1.10 to 1.74, p = 0.006; HR 2.81, 95% CI 1.69 to 4.66, p PCI and CABG groups (HR 0.88, 95% CI 0.61 to 1.26, p = 0.48). There were no interactions for the primary outcome measure between the mode of revascularization (PCI or CABG) and the subgroup factors such as age, diabetes, and Synergy Between PCI With Taxus and Cardiac Surgery score. In conclusion, CABG compared with PCI was associated with better long-term outcome in patients with TVD. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Imaging Blood Vessel Morphology in Skin

    DEFF Research Database (Denmark)

    Schuh, Sandra; Holmes, Jon; Ulrich, Martina

    2017-01-01

    Conventional optical coherence tomography (OCT) enables the visualization of morphological changes of skin cancer. The use of OCT in the diagnostic investigation and in the therapy decision of non-melanoma skin cancer and other skin changes is already established, and has found its way into routine...... practice. With the development of speckle-variance OCT, also named dynamic OCT (D-OCT), the vascular architecture and the blood flow of the skin can be displayed in vivo and in 3D. This novel angiographic variant of OCT offers the ability to visualize and measure vessel morphology providing a new insight...... into healthy, inflammatory and neoplastic skin lesions such as malignant melanoma. This review focuses on the possibilities of using D-OCT on healthy and diseased skin. We suggest and illustrate key diagnostic characteristics by analyzing the initial publications and preliminary unpublished data on vessel...

  16. Pressure vessel for nuclear reactors

    International Nuclear Information System (INIS)

    1975-01-01

    The invention applies to a pressure vessel for nuclear reactors whose shell, made of cast metal segments, has a steel liner. This liner must be constructed to withstand all operational stresses and to be easily repairable. The invention solves this problem by installing the liner at a certain distance from the inner wall of the pressure vessel shell and by filling this clearance with supporting concrete. Both the concrete and the steel liner must have a lower prestress than the pressure vessel shell. In order to avoid damage to the liner when prestressing the pressure vessel shell, special connecting elements are provided which consist of welded-on fastening elements projecting into recesses in the cast metal segments of the pressure vessel. Their design is described in detail. (TK) [de

  17. Containment vessel stability analysis

    International Nuclear Information System (INIS)

    Harstead, G.A.; Morris, N.F.; Unsal, A.I.

    1983-01-01

    The stability analysis for a steel containment shell is presented herein. The containment is a freestanding shell consisting of a vertical cylinder with a hemispherical dome. It is stiffened by large ring stiffeners and relatively small longitudinal stiffeners. The containment vessel is subjected to both static and dynamic loads which can cause buckling. These loads must be combined prior to their use in a stability analysis. The buckling loads were computed with the aid of the ASME Code case N-284 used in conjunction with general purpose computer codes and in-house programs. The equations contained in the Code case were used to compute the knockdown factors due to shell imperfections. After these knockdown factors were applied to the critical stress states determined by freezing the maximum dynamic stresses and combining them with other static stresses, a linear bifurcation analysis was carried out with the aid of the BOSOR4 program. Since the containment shell contained large penetrations, the Code case had to be supplemented by a local buckling analysis of the shell area surrounding the largest penetration. This analysis was carried out with the aid of the NASTRAN program. Although the factor of safety against buckling obtained in this analysis was satisfactory, it is claimed that the use of the Code case knockdown factors are unduly conservative when applied to the analysis of buckling around penetrations. (orig.)

  18. Pressure vessel design

    International Nuclear Information System (INIS)

    Annaratone, D.

    2007-01-01

    This book guides through general and fundamental problems of pressure vessel design. It moreover considers problems which seem to be of lower importance but which turn out to be crucial in the design phase. The basic approach is rigorously scientific with a complete theoretical development of the topics treated, but the analysis is always pushed so far as to offer concrete and precise calculation criteria that can be immediately applied to actual designs. This is accomplished through appropriate algorithms that lead to final equations or to characteristic parameters defined through mathematical equations. The first chapter describes how to achieve verification criteria, the second analyzes a few general problems, such as stresses of the membrane in revolution solids and edge effects. The third chapter deals with cylinders under pressure from the inside, while the fourth focuses on cylinders under pressure from the outside. The fifth chapter covers spheres, and the sixth is about all types of heads. Chapter seven discusses different components of particular shape as well as pipes, with special attention to flanges. The eighth chapter discusses the influence of holes, while the ninth is devoted to the influence of supports. Finally, chapter ten illustrates the fundamental criteria regarding fatigue analysis. Besides the unique approach to the entire work, original contributions can be found in most chapters, thanks to the author's numerous publications on the topic and to studies performed ad hoc for this book. (orig.)

  19. PWR vessel flaw distribution development

    International Nuclear Information System (INIS)

    Rosinski, S.T.; Kennedy, E.L.; Foulds, J.R.; Kinsman, K.M.

    1990-01-01

    This paper reports on PWR pressure vessels which operate under NRC rules and regulatory guides intended to prevent failure of the vessels. Plants failing to meet the operating criteria specified under these rules and regulations are required to analytically demonstrate fitness for service in order to continue operation. The initial flaw size or distribution of initial vessel flaws is a key input to the required vessel integrity analyses. However, the flaw distribution assumed in the development of the NRC Regulations and recommended for the plant specific analyses is potentially over-conservative. This is because the distribution is based on the limited amount of vessel inspection data available at the time the criteria were being developed and does not take full advantage of the more recent and reliable domestic vessel inspection results. The U.S. Department of Energy is funding an effort through Sandia National Laboratories to investigate the possibility of developing a new flaw distribution based on the increased amount and improved reliability of domestic vessel inspection data. Results of Phase I of the program indicate that state-of-the-art NDE systems' capabilities are sufficient for development of a new flaw distribution that could ultimately provide life extension benefits over the presently required operating practice

  20. Nuclear reactor vessel decontamination systems

    International Nuclear Information System (INIS)

    McGuire, P. J.

    1985-01-01

    There is disclosed in the present application, a decontamination system for reactor vessels. The system is operatable without entry by personnel into the contaminated vessel before the decontamination operation is carried out and comprises an assembly which is introduced into the vertical cylindrical vessel of the typical boiling water reactor through the open top. The assembly includes a circular track which is centered by guideways permanently installed in the reactor vessel and the track guides opposed pairs of nozzles through which water under very high pressure is directed at the wall for progressively cutting and sweeping a tenacious radioactive coating as the nozzles are driven around the track in close proximity to the vessel wall. The whole assembly is hoisted to a level above the top of the vessel by a crane, outboard slides on the assembly brought into engagement with the permanent guideways and the assembly progressively lowered in the vessel as the decontamination operation progresses. The assembly also includes a low pressure nozzle which forms a spray umbrella above the high pressure nozzles to contain radioactive particles dislodged during the decontamination

  1. Gammatography of thick lead vessels

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Sundaram, V.M.

    1979-01-01

    Radiography, scintillation and GM counting and dose measurements using ionisation chamber equipment are commonly used for detecting flaws/voids in materials. The first method is mostly used for steel vessels and to a lesser extent thin lead vessels also and is essentially qualitative. Dose measuring techniques are used for very thick and large lead vessels for which high strength radioactive sources are required, with its inherent handling problems. For vessels of intermediate thicknesses, it is ideal to use a small strength source and a GM or scintillation counter assembly. At the Reactor Research Centre, Kalpakkam, such a system was used for checking three lead vessels of thicknesses varying from 38mm to 65mm. The tolerances specified were +- 4% variation in lead thickness. The measurements also revealed the non concentricity of one vessel which had a thickness varying from 38mm to 44mm. The second vessel was patently non-concentric and the dimensional variation was truly reproduced in the measurements. A third vessel was fabricated with careful control of dimensions and the measurements exhibited good concentricity. Small deviations were observed, attributable to imperfect bondings between steel and lead. This technique has the following advantages: (a) weaker sources used result in less handling problems reducing the personnel exposures considerably; (b) the sensitivity of the instrument is quite good because of better statistics; (c) the time required for scanning a small vessel is more, but a judicious use of a scintillometer for initial fast scan will help in reducing the total scanning time; (d) this method can take advantage of the dimensional variations themselves to get the calibration and to estimate the deviations from specified tolerances. (auth.)

  2. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Cheon, Sang Myung; Kim, Jong Kuk; Kim, Jae Woo

    2004-01-01

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0±7.0 years, educational period; 6.3±5.6 years, CDR; 0.80±0.26). 46 AD (mean age; 69.9±7.4 years, educational period; 5.4±4.7 years, CDR; 0.86±0.23) and 12 normal control subjects (mean age; 67.1±7.7 years, educational period; 6.2±4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness

  3. BY FRUSTUM CONFINING VESSEL

    Directory of Open Access Journals (Sweden)

    Javad Khazaei

    2016-09-01

    Full Text Available Helical piles are environmentally friendly and economical deep foundations that, due to environmental considerations, are excellent additions to a variety of deep foundation alternatives available to the practitioner. Helical piles performance depends on soil properties, the pile geometry and soil-pile interaction. Helical piles can be a proper alternative in sensitive environmental sites if their bearing capacity is sufficient to support applied loads. The failure capacity of helical piles in this study was measured via an experimental research program that was carried out by Frustum Confining Vessel (FCV. FCV is a frustum chamber by approximately linear increase in vertical and lateral stresses along depth from top to bottom. Due to special geometry and applied bottom pressure, this apparatus is a proper choice to test small model piles which can simulate field stress conditions. Small scale helical piles are made with either single helix or more helixes and installed in fine grained sand with three various densities. Axial loading tests including compression and tension tests were performed to achieve pile ultimate capacity. The results indicate the helical piles behavior depends essentially on pile geometric characteristics, i.e. helix configuration and soil properties. According to the achievements, axial uplift capacity of helical model piles is about equal to usual steel model piles that have the helixes diameter. Helical pile compression bearing capacity is too sufficient to act as a medium pile, thus it can be substituted other piles in special geoenvironmental conditions. The bearing capacity also depends on spacing ratio, S/D, and helixes diameter.

  4. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Hagiwara, Koji; Imura, Yasuya.

    1979-01-01

    Purpose: To provide constituted method for easily performing baking of vacuum vessel, using short-circuiting segments. Constitution: At the time of baking, one turn circuit is formed by the vacuum vessel and short-circuiting segments, and current transformer converting the one turn circuit into a secondary circuit by the primary coil and iron core is formed, and the vacuum vessel is Joule heated by an induction current from the primary coil. After completion of baking, the short-circuiting segments are removed. (Kamimura, M.)

  5. PWR vessel inspection performance improvements

    International Nuclear Information System (INIS)

    Blair Fairbrother, D.; Bodson, Francis

    1998-01-01

    A compact robot for ultrasonic inspection of reactor vessels has been developed that reduces setup logistics and schedule time for mandatory code inspections. Rather than installing a large structure to access the entire weld inspection area from its flange attachment, the compact robot examines welds in overlapping patches from a suction cup anchor to the shell wall. The compact robot size allows two robots to be operated in the vessel simultaneously. This significantly reduces the time required to complete the inspection. Experience to date indicates that time for vessel examinations can be reduced to fewer than four days. (author)

  6. A relationship between the integrated assessment of magnetic resonance imaging markers for cerebral small vessel disease and the clinical and functional status in the acute period of ischemic stroke

    Directory of Open Access Journals (Sweden)

    A. A. Kulesh

    2018-01-01

    Full Text Available Cerebral small vessel disease (CSVD is the most common neurological pathological process and contributes to the process of aging and to the development of dementia and stroke. At the same time, the role of CSVD as a factor influencing the course of acute ischemic stroke (IS has been little studied. There is no generally accepted magnetic resonance imaging (MRI scale for the integrated assessment of CSVD markers.Objective: to carry out an integrated assessment of the MRI manifestations of CSVD in acute ischemic stroke and to analyze a correlation of both individual markers and the final indicator with the clinical and functional status of patients.Patients and methods. 100 patients with acute IS were examined. All patients underwent standard clinical, laboratory and instrumental examinations, as well as brain MRI estimating the number of lacunae, visible perivascular spaces (PVSs and leukoaraiosis. The number of cerebral microbleeds (CMBs was additionally calculated in 57 patients. Integral scale scores were calculated by gradation and summation of four MRI markers of CSVD.Results. The patients with acute IS showed the high representativeness of individual markers for CSVD. The values of MRI markers for CSVD correlated with age, education level, and cardiovascular parameters in patients. An integrated CSVD severity assessment scale was developed. The overall manifestations of CSVD, which were assessed using this scale, were associated with the severity of a stenotic process in the brachycephalic arteries, with BP levels at admission, ejection fraction, hyperglycemia, and atherogenic index of blood lipids. The high CSVD score was also correlated with low mobility and more severe disability in patients being discharged from hospital. The high severity of CSVD was associated with lower neurological deficit regression during inpatient treatment. Subgroup analysis showed the greatest negative impact of CSVD on the severity of stroke in female patients

  7. Special enclosure for a pressure vessel

    International Nuclear Information System (INIS)

    Wedellsborg, B.W.; Wedellsborg, U.W.

    1993-01-01

    A pressure vessel enclosure is described comprising a primary pressure vessel, a first pressure vessel containment assembly adapted to enclose said primary pressure vessel and be spaced apart therefrom, a first upper pressure vessel jacket adapted to enclose the upper half of said first pressure vessel containment assembly and be spaced apart therefrom, said upper pressure vessel jacket having an upper rim and a lower rim, each of said rims connected in a slidable relationship to the outer surface of said first pressure vessel containment assembly, mean for connecting in a sealable relationship said upper rim of said first upper pressure vessel jacket to the outer surface of said first pressure vessel containment assembly, means for connecting in a sealable relationship said lower rim of said first upper pressure vessel jacket to the outer surface of said first pressure vessel containment assembly, a first lower pressure vessel jacket adapted to enclose the lower half of said first pressure vessel containment assembly and be spaced apart therefrom, said lower pressure vessel jacket having an upper rim connected in a slidable relationship to the outer surface of said first pressure vessel containment assembly, and means for connecting in a sealable relationship said upper rim of said first lower pressure vessel jacket to the outer surface of said first pressure vessel containment assembly, a second upper pressure vessel jacket adapted to enclose said first upper pressure vessel jacket and be spaced apart therefrom, said second upper pressure vessel jacket having an upper rim and a lower rim, each of said rims adapted to slidably engage the outer surface of said first upper pressure vessel jacket, means for sealing said rims, a second lower pressure vessel jacket adapted to enclose said first lower pressure vessel jacket and be spaced apart therefrom

  8. Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

    Science.gov (United States)

    Prisby, Rhonda D

    2014-07-01

    Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (pnecrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. 2013 West Coast Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  10. 2011 West Coast Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  11. 2013 Great Lakes Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  12. 2011 Great Lakes Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  13. 2011 East Coast Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  14. Coastal Discard Logbook Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data on the type and amount of marine resources that are discarded or interacted with by vessels that are selected to report to the Southeast...

  15. SC/OQ Vessel Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data tables holding information for the Surf Clam/Ocean Quahog vessel and dealer/processor logbooks (negative and positive), as well as individual tag information...

  16. Vessel Permit System Data Set

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GARFO issues federal fishing permits annually to owners of fishing vessels who fish in the Greater Atlantic region, as required by federal regulation. These permits...

  17. Reactor pressure vessel status report

    International Nuclear Information System (INIS)

    Strosnider, J.; Wichman, K.; Elliot, B.

    1994-12-01

    This report gives a brief description of the reactor pressure vessel (RPV), followed by a discussion of the radiation embrittlement of RPV beltline materials and the two indicators for measuring embrittlement, the end-of-license (EOL) reference temperature and the EOL upper-shelf energy. It also summarizes the GL 92-01 effort and presents, for all 37 boiling water reactor plants and 74 pressurized water reactor plants in the United States, the current status of compliance with regulatory requirements related to ensuring RPV integrity. The staff has evaluated the material data needed to predict neutron embrittlement of the reactor vessel beltline materials. These data will be stored in a computer database entitled the reactor vessel integrity database (RVID). This database will be updated annually to reflect the changes made by the licensees in future submittals and will be used by the NRC staff to assess the issues related to vessel structural integrity

  18. Reactor-vessel-sectioning demonstration

    International Nuclear Information System (INIS)

    Lundgren, R.A.

    1981-07-01

    A successful technical demonstration of simulated reactor vessel sectioning was completed using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1/4-in layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques were considered to section the simulated reactor vessel: an air arc gouger was chosen to penetrate the stainless steel, and flame cutting was selected to sever the carbon steel. After the simulated vessel was successfully cut from the SS side, another cut was made, starting from the carbon steel side. This cut was also successful. Cutting from the carbon steel side has the advantages of cost reduction since the air arc gouging step is eliminated and contamination controlled because the molten metal is blown inward

  19. Power reactor pressure vessel benchmarks

    International Nuclear Information System (INIS)

    Rahn, F.J.

    1978-01-01

    A review is given of the current status of experimental and calculational benchmarks for use in understanding the radiation embrittlement effects in the pressure vessels of operating light water power reactors. The requirements of such benchmarks for application to pressure vessel dosimetry are stated. Recent developments in active and passive neutron detectors sensitive in the ranges of importance to embrittlement studies are summarized and recommendations for improvements in the benchmark are made. (author)

  20. Prosopomorphic vessels from Moesia Superior

    Directory of Open Access Journals (Sweden)

    Nikolić Snežana

    2008-01-01

    Full Text Available The prosopomorphic vessels from Moesia Superior had the form of beakers varying in outline but similar in size. They were wheel-thrown, mould-made or manufactured by using a combination of wheel-throwing and mould-made appliqués. Given that face vessels are considerably scarcer than other kinds of pottery, more than fifty finds from Moesia Superior make an enviable collection. In this and other provinces face vessels have been recovered from military camps, civilian settlements and necropolises, which suggests that they served more than one purpose. It is generally accepted that the faces-masks gave a protective role to the vessels, be it to protect the deceased or the family, their house and possessions. More than forty of all known finds from Moesia Superior come from Viminacium, a half of that number from necropolises. Although tangible evidence is lacking, there must have been several local workshops producing face vessels. The number and technological characteristics of the discovered vessels suggest that one of the workshops is likely to have been at Viminacium, an important pottery-making centre in the second and third centuries.

  1. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Kikuchi, Mitsuru; Kurita, Gen-ichi; Onozuka, Masaki; Suzuki, Masaru.

    1997-01-01

    Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and γ rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

  2. Vacuum vessel for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Mitsuru; Kurita, Gen-ichi [Japan Atomic Energy Research Inst., Tokyo (Japan); Onozuka, Masaki; Suzuki, Masaru

    1997-07-31

    Heat of inner walls of a vacuum vessel that receive radiation heat from plasmas by way of first walls is removed by a cooling medium flowing in channels for cooling the inner walls. Nuclear heat generation of constitutional materials of the vacuum vessel caused by fast neutrons and {gamma} rays is removed by a cooling medium flowing in cooling channels disposed in the vacuum vessel. Since the heat from plasmas and the nuclear heat generation are removed separately, the amount of the cooling medium flowing in the channels for cooling inner walls is increased for cooling a great amount of heat from plasmas while the amount of the cooling medium flowing in the channels for cooling the inside of the vacuum vessel is reduced for cooling the small amount of nuclear heat generation. Since the amount of the cooling medium can thus be optimized, the capacity of the facilities for circulating the cooling medium can be reduced. In addition, since the channels for cooling the inner walls and the channels of cooling medium formed in the vacuum vessel are disposed to the inner walls of the vacuum vessel on the side opposite to plasmas, integrity of the channels relative to leakage of the cooling medium can be ensured. (N.H.)

  3. At Risk for Kidney Disease?

    Science.gov (United States)

    ... Heart Disease Mineral & Bone Disorder Causes of Chronic Kidney Disease Diabetes and high blood pressure are the most ... blood vessels in your kidneys. Other causes of kidney disease Other causes of kidney disease include a genetic ...

  4. Native valve disease in patients with non-valvular atrial fibrillation on warfarin or rivaroxaban

    Science.gov (United States)

    Breithardt, Günter; Baumgartner, Helmut; Berkowitz, Scott D; Hellkamp, Anne S; Piccini, Jonathan P; Lokhnygina, Yuliya; Halperin, Jonathan L; Singer, Daniel E; Hankey, Graeme J; Hacke, Werner; Becker, Richard C; Nessel, Christopher C; Mahaffey, Kenneth W; Califf, Robert M; Fox, Keith A A; Patel, Manesh R

    2016-01-01

    Objective To compare the characteristics and outcomes of patients with atrial fibrillation (AF) and aortic stenosis (AS) with patients with AF with mitral regurgitation (MR) or aortic regurgitation (AR) and patients without significant valve disease (no SVD). Methods Using Rivaroxaban Once-Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) data, we analysed efficacy and safety outcomes, adjusting hazard ratios (HRs) for potential confounders using Cox regression analysis. Results Among 14 119 intention-to-treat ROCKET AF trial patients, a trial that excluded patients with mitral stenosis or artificial valve prosthesis, 214 had AS with or without other valve abnormalities, 1726 had MR or AR and 12 179 had no SVD. After adjusting for prognostic factors, the composite of stroke, systemic embolism or vascular death increased approximately twofold in patients with AS (AS 10.84, MR or AR 4.54 and no SVD 4.31 events per 100 patient-years, p=0.0001). All-cause death also significantly increased (AS 11.22, MR or AR 4.90 and no SVD 4.39 events per 100 patient-years, p=0.0003). Major bleeding occurred more frequently in AS (adjusted HR 1.61, confidence intervals (CI) 1.03 to 2.49, p<0.05) and MR or AR (HR 1.30, 1.07 to 1.57, p<0.01) than in no SVD, but there was no difference between AS and MR or AR (HR 1.24, 0.78 to 1.97). The relative efficacy of rivaroxaban versus warfarin was consistent among patients with and without valvular disease. Rivaroxaban was associated with higher rates of major bleeding than warfarin in patients with MR or AR (HR 1.63, 1.15 to 2.31). Conclusions We found that patients with AF and AS on oral anticoagulants may have distinctly different efficacy and safety outcomes than patients with MR or AR or no SVD. Trial registration number NCT00403767; Post-results. PMID:26888572

  5. Relation of time to complete redistribution and the severity of coronary artery disease

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Uehara, Toshiisa; Hayashida, Kohei; Kozuka, Takahiro; Saito, Muneyasu; Sumiyoshi, Tetsuya

    1985-01-01

    The relation between the severity of coronary artery disease and the time to complete redistribution (RD) was investigated in 66 patients with angina pectoris (AP) (28 SVD, 18 DVD and 20 TVD) and 104 patients with myocardial infarction (MI) (45 SVD, 36 DVD and 23 TVD). Stress thallium scan was performed immediately, 30 minutes (early) and 4 hours (delayed) after exercise. RD was classified into three groups (complete, incomplete and no RD). Early complete RD was observed in 15 (23 %) of AP and 3 (3 %) of MI cases. In both cases, the incidence of early RD was higher in SVD compared to DVD and TVD. And diffuse slow washout calculated from exercise and RD study disturbed the incidence of early RD in DVD and TVD. In the early RD cases of AP, coronary stenosis showed mild and collateral was not correlated, however, in the complete or incomplete RD of MI, coronary stenosis showed severe (> 90 %) and the frequency of collateral was higher compared to no RD cases. In MI cases, complete, incomplete and no RD were observed in 22 %, 25 % and 53 %, respectively. In the latter, a- or dys-kinesis at infarct zone was often observed which showed myocardial viability. In conclusion, early RD was observed about 20 % of coronary artery disease and the time to complete RD was closely related to the severity of coronary artery disease. In addition, the sensitivity for detecting transient thallium defect was influenced by the delay in beginning imaging. (author)

  6. Automated method for identification and artery-venous classification of vessel trees in retinal vessel networks.

    Science.gov (United States)

    Joshi, Vinayak S; Reinhardt, Joseph M; Garvin, Mona K; Abramoff, Michael D

    2014-01-01

    The separation of the retinal vessel network into distinct arterial and venous vessel trees is of high interest. We propose an automated method for identification and separation of retinal vessel trees in a retinal color image by converting a vessel segmentation image into a vessel segment map and identifying the individual vessel trees by graph search. Orientation, width, and intensity of each vessel segment are utilized to find the optimal graph of vessel segments. The separated vessel trees are labeled as primary vessel or branches. We utilize the separated vessel trees for arterial-venous (AV) classification, based on the color properties of the vessels in each tree graph. We applied our approach to a dataset of 50 fundus images from 50 subjects. The proposed method resulted in an accuracy of 91.44% correctly classified vessel pixels as either artery or vein. The accuracy of correctly classified major vessel segments was 96.42%.

  7. The TPX vacuum vessel and in-vessel components

    International Nuclear Information System (INIS)

    Heitzenroeder, P.; Bialek, J.; Ellis, R.; Kessel, C.; Liew, S.

    1994-01-01

    The Tokamak Physics Experiment (TPX) is a superconducting tokamak with double-null diverters. TPX is designed for 1,000-second discharges with the capability of being upgraded to steady state operation. High neutron yields resulting from the long duration discharges require that special consideration be given to materials and maintainability. A unique feature of the TPX is the use of a low activation, titanium alloy vacuum vessel. Double-wall vessel construction is used since it offers an efficient solution for shielding, bakeout and cooling. Contained within the vacuum vessel are the passive coil system, Plasma Facing Components (PFCs), magnetic diagnostics, and the internal control coils. All PFCs utilize carbon-carbon composites for exposed surfaces

  8. Clay Corner: Recreating Chinese Bronze Vessels.

    Science.gov (United States)

    Gamble, Harriet

    1998-01-01

    Presents a lesson where students make faux Chinese bronze vessels through slab or coil clay construction after they learn about the history, function, and design of these vessels. Utilizes a variety of glaze finishes in order to give the vessels an aged look. Gives detailed guidelines for creating the vessels. (CMK)

  9. Superior long term outcome associated with native vessel versus graft vessel PCI following secondary PCI in patients with prior CABG.

    Science.gov (United States)

    Mavroudis, Chrysostomos A; Kotecha, Tushar; Chehab, Omar; Hudson, Jonathan; Rakhit, Roby D

    2017-02-01

    Secondary percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass graft surgery is increasingly common. Graft vessel PCI has higher rates of adverse events compared with native coronary vessel PCI. To investigate the clinical outcomes of patients with prior CABG who underwent secondary PCI of either a graft vessel (GV), a native coronary vessel (NV) or both graft and native (NG) vessels. 220 patients (84% male) who underwent PCI in our institution to either GV (n=89), NV (n=103) or both GV and NV (NG group) (n=28) were studied. The study population underwent 378 procedures (GV group; n=126, NV group; n=164 and NG group; n=88). Median follow up was for 36months [range 2-75months]. Target vessel revascularisation (TVR) occurred in 12.5% of the GV group and 3.6% in the NV group [p=0.0004], and was predominantly due to in-stent restenosis. Patients who had PCI due to TVR were more likely to suffer from diabetes and peripheral vascular disease. History of chronic renal failure was associated with higher risk (HR 2.21, p=0.005) whereas preserved left ventricular ejection fraction (LVEF) with lower risk (HR 0.17, p=0.0007) of death. The median survival (interval between CABG and end of follow-up period) was lower in the GV compared with the NV group (315 vs 372months p=0.005). This registry demonstrates inferior long term outcome for patients undergoing secondary PCI of GV versus NV. Where possible, a strategy of NV rather than GV target PCI should be considered in patients with prior CABG. Secondary PCI in patients with prior CABG surgery is increasingly common. Graft vessel PCI has inferior outcomes with high rates of restenosis and occlusion compared with native coronary vessel PCI. We studied the clinical outcomes of 220 patients with prior CABG who underwent secondary PCI to either a graft vessel (GV), a native coronary vessel (NV) or both graft and native (NG) vessels. Target vessel revascularisation was 5 times higher in the GV

  10. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Kikuchi, Mitsuru; Nagashima, Keisuke; Suzuki, Masaru; Onozuka, Masaki.

    1997-01-01

    A vacuum vessel main body and structural members at the inside and the outside of the vacuum vessel main body are constituted by structural materials activated by irradiation of neutrons from plasmas such as stainless steels. Shielding members comprising tungsten or molybdenum are disposed on the surface of the vacuum vessel main body and the structural members of the inside and the outside of the main body. The shielding members have a function also as first walls or a seat member for the first walls. Armor tiles may be disposed to the shielding members. The shielding members and the armor tiles are secured to a securing seat member disposed, for example, to an inner plate of the vacuum vessel main body by bolts. Since the shielding members are disposed, it is not necessary to constitute the vacuum vessel main body and the structural members at the inside and the outside thereof by using a low activation material which is less activated, such as a titanium alloy. (I.N.)

  11. Vacuum vessel for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Mitsuru; Nagashima, Keisuke [Japan Atomic Energy Research Inst., Tokyo (Japan); Suzuki, Masaru; Onozuka, Masaki

    1997-07-11

    A vacuum vessel main body and structural members at the inside and the outside of the vacuum vessel main body are constituted by structural materials activated by irradiation of neutrons from plasmas such as stainless steels. Shielding members comprising tungsten or molybdenum are disposed on the surface of the vacuum vessel main body and the structural members of the inside and the outside of the main body. The shielding members have a function also as first walls or a seat member for the first walls. Armor tiles may be disposed to the shielding members. The shielding members and the armor tiles are secured to a securing seat member disposed, for example, to an inner plate of the vacuum vessel main body by bolts. Since the shielding members are disposed, it is not necessary to constitute the vacuum vessel main body and the structural members at the inside and the outside thereof by using a low activation material which is less activated, such as a titanium alloy. (I.N.)

  12. Molten material-containing vessel

    International Nuclear Information System (INIS)

    Akagawa, Katsuhiko

    1998-01-01

    The molten material-containing vessel of the present invention comprises a vessel main body having an entrance opened at the upper end, a lid for closing the entrance, an outer tube having an upper end disposed at the lower surface of the lid, extended downwardly and having an closed lower end and an inner tube disposed coaxially with the outer tube. When a molten material is charged from the entrance to the inside of the vessel main body of the molten material-containing vessel and the entrance is closed by the lid, the outer tube and the inner tube are buried in the molten material in the vessel main body, accordingly, a fluid having its temperature elevated by absorption of the heat of the molten material rises along the inner circumferential surface of the outer tube, abuts against the lower surface of the lid and cooled by exchanging heat with the lid and forms a circulating flow. Since the heat in the molten material is continuously absorbed by the fluid, transferred to the lid and released from the lid to the atmospheric air, heat releasing efficiency can be improved compared with conventional cases. (N.H.)

  13. Determinants of Vessel Targeting in Vasculitis

    Directory of Open Access Journals (Sweden)

    Gary S. Hoffman

    2004-01-01

    Full Text Available Studies of autoimmune diseases have not yet elucidated why certain organs or vessels become the objects of injury while others are spared. This paper will explore the hypothesis that important differences exist in regions of the aorta that determine vulnerability to diseases, such as atherosclerosis, aortitis, giant cell arteritis and Takayasu's disease. The reader is invited to reassess; (1 whether the aorta is indeed a single homogeneous structure, and (2 whether the initial stage of aortitis (and indeed other diseases considered “autoimmune” may be primarily due to acquired alterations of substrate, that influence unique immune profiles, which by themselves may not be pathogenic. Disease susceptibility and patterns are influenced by many factors that are inborn and acquired. Examples include genetic background, gender, ethnicity, aging, prior and concomitant illnesses, habits, diet, toxin and environmental exposures. Studies of vascular diseases must assess how such variables may affect regional differences in endothelial cells, subendothelial matrix, vascular smooth muscle and the response of each to a variety of stimuli.

  14. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Cheon, Sang Myung; Kim, Jong Kuk; Kim, Jae Woo [Dong-A University School of Medicine, Busan (Korea, Republic of)

    2004-07-01

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0{+-}7.0 years, educational period; 6.3{+-}5.6 years, CDR; 0.80{+-}0.26). 46 AD (mean age; 69.9{+-}7.4 years, educational period; 5.4{+-}4.7 years, CDR; 0.86{+-}0.23) and 12 normal control subjects (mean age; 67.1{+-}7.7 years, educational period; 6.2{+-}4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the

  15. Emergency venting of pressure vessels

    International Nuclear Information System (INIS)

    Steinkamp, H.

    1995-01-01

    With the numerical codes developed for safety analysis the venting of steam vessel can be simulated. ATHLET especially is able to predict the void fraction depending on the vessel height. Although these codes contain a one-dimensional model they allow the description of complex geometries due to the detailed nodalization of the considered apparatus. In chemical reactors, however, the venting process is not only influenced by the flashing behaviour but additionally by the running chemical reaction in the vessel. Therefore the codes used for modelling have to consider the kinetics of the chemical reaction. Further multi-component systems and dissolving processes have to be regarded. In order to preduct the fluid- and thermodynamic process it could be helpful to use 3-dimensional codes in combination with the one-dimensional codes as used in nuclear industry to get a more detailed describtion of the running processes. (orig./HP)

  16. Development of Catamaran Fishing Vessel

    Directory of Open Access Journals (Sweden)

    A. Jamaluddin

    2010-11-01

    Full Text Available Multihull due to a couple of advantages has been the topic of extensive research work in naval architecture. In this study, a series of investigation of fishing vessel to save fuel energy was carried out at ITS. Two types of ship models, monohull (round bilge and hard chine and catamaran, a boat with two hulls (symmetrical and asymmetrical were developed. Four models were produced physically and numerically, tested (towing tank and simulated numerically (CFD code. The results of the two approaches indicated that the catamaran mode might have drag (resistance smaller than those of monohull at the same displacement. A layout of catamaran fishing vessel, proposed here, indicates the freedom of setting the deck equipments for fishing vessel.

  17. Customizable engineered blood vessels using 3D printed inserts.

    Science.gov (United States)

    Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

    2016-04-15

    Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INLAND NAVIGATION RULES INLAND RULES: INTERPRETATIVE RULES § 90.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and...

  19. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES 72 COLREGS: INTERPRETATIVE RULES § 82.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a...

  20. Automated retinal vessel type classification in color fundus images

    Science.gov (United States)

    Yu, H.; Barriga, S.; Agurto, C.; Nemeth, S.; Bauman, W.; Soliz, P.

    2013-02-01

    Automated retinal vessel type classification is an essential first step toward machine-based quantitative measurement of various vessel topological parameters and identifying vessel abnormalities and alternations in cardiovascular disease risk analysis. This paper presents a new and accurate automatic artery and vein classification method developed for arteriolar-to-venular width ratio (AVR) and artery and vein tortuosity measurements in regions of interest (ROI) of 1.5 and 2.5 optic disc diameters from the disc center, respectively. This method includes illumination normalization, automatic optic disc detection and retinal vessel segmentation, feature extraction, and a partial least squares (PLS) classification. Normalized multi-color information, color variation, and multi-scale morphological features are extracted on each vessel segment. We trained the algorithm on a set of 51 color fundus images using manually marked arteries and veins. We tested the proposed method in a previously unseen test data set consisting of 42 images. We obtained an area under the ROC curve (AUC) of 93.7% in the ROI of AVR measurement and 91.5% of AUC in the ROI of tortuosity measurement. The proposed AV classification method has the potential to assist automatic cardiovascular disease early detection and risk analysis.

  1. Spontaneous low-frequency oscillations in cerebral vessels

    DEFF Research Database (Denmark)

    Schytz, Henrik W; Hansson, Andreas; Phillip, Dorte

    2010-01-01

    ). Analysis of CA by measurement of spontaneous oscillations in the low-frequency spectrum in cerebral vessels might be a useful tool for assessing risk and investigating different treatment strategies in carotid artery disease (CAD) and stroke. We reviewed studies exploring spontaneous oscillations...

  2. Containment vessel design and practice

    International Nuclear Information System (INIS)

    Bangash, Y.

    1983-01-01

    The state of the art of analysis and design of the concrete containment vessels required for BWR and PWR is reviewed. A step-by-step critical appraisal of the existing work is given. Elastic, inelastic and cracking conditions under extreme loads are fully discussed. Problems associated with these structures are highlighted. A three-dimensional finite element analysis is included to cater for service, overload and dynamic cracking of such structures. Missile impact and seismic effects are included in this work. The second analysis is known as the limit state analysis, which is given to design such vessels for any kind of load. (U.K.)

  3. Stress analysis of pressure vessels

    International Nuclear Information System (INIS)

    Kim, B.K.; Song, D.H.; Son, K.H.; Kim, K.S.; Park, K.B.; Song, H.K.; So, J.Y.

    1979-01-01

    This interim report contains the results of the effort to establish the stress report preparation capability under the research project ''Stress analysis of pressure vessels.'' 1978 was the first year in this effort to lay the foundation through the acquisition of SAP V structural analysis code and a graphic terminal system for improved efficiency of using such code. Software programming work was developed in pre- and post processing, such as graphic presentation of input FEM mesh geometry and output deformation or mode shope patterns, which was proven to be useful when using the FEM computer code. Also, a scheme to apply fracture mechanics concept was developed in fatigue analysis of pressure vessels. (author)

  4. New vessel formation and aberrant VEGF/VEGFR signaling in acute leukemia : Does it matter?

    NARCIS (Netherlands)

    De Bont, ESJM; Neefjes, VME; Rosati, S; Vellenga, E; Kamps, WA

    2002-01-01

    Although many patients with acute leukemia achieve a hematological complete remission with aggressive intensive therapy protocols, a large proportion shows reoccurrence of disease. Novel strategies are warranted. In acute leukemia new vessel formation is observed. New vessel formation is the result

  5. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current regula...

  6. PLANNING VESSEL BODY SECTION PRODUCTION

    Directory of Open Access Journals (Sweden)

    A. G. Grivachevsky

    2015-01-01

    Full Text Available A problem of planning production of a vessel body section is considered. The problem is reduced to the classic Johnson’s tree-machine flow-shop scheduling problem. A genetic algorithm and computer experiment to compare efficiency of this algorithm and the algorithm of full enumeration are described.

  7. Pressure vessel and method therefor

    Science.gov (United States)

    Saunders, Timothy

    2017-09-05

    A pressure vessel includes a pump having a passage that extends between an inlet and an outlet. A duct at the pump outlet includes at least one dimension that is adjustable to facilitate forming a dynamic seal that limits backflow of gas through the passage.

  8. Commercial Passenger Fishing Vessel Fishery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the logbook data from U.S.A. Commercial Passenger Fishing Vessels (CPFV) fishing in the U.S.A. EEZ and in waters off of Baja California, from...

  9. Development of PWR pressure vessel steels

    International Nuclear Information System (INIS)

    Druce, S.; Edwards, B.

    1982-01-01

    Requirements to be met by vessel steels for pressurized water reactors are analyzed. Chemicat composition of low-alloyed steels, mechanical properties of sheets and forgings made of these steels and changes in the composition and properties over the wall thickness of the reactor vessel are presented. Problems of the vessel manufacturing including welding and heat treatment processes of sheets and forgings are considered. Special attention is paid to steel embrittlement during vessel fabrication and operation (radiation embrittlement, thermal embrittlement). The role of non-metal inclusions and their effect on anisotropy of fracture toughness is discussed. Possible developments of vessel steels and procedures for producing reactor vessels are reviewed

  10. Development of PWR pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Druce, S.; Edwards, B.

    1982-01-01

    Requirements to be met by vessel steels for pressurized water reactors are analyzed. Chemicat composition of low-alloyed steels, mechanical properties of sheets and forgings made of these steels and changes in the composition and properties over the wall thickness of the reactor vessel are presented. Problems of the vessel manufacturing including welding and heat treatment processes of sheets and forgings are considered. Special attention is paid to steel embrittlement during vessel fabrication and operation (radiation embrittlement, thermal embrittlement). The role of non-metal inclusions and their effect on anisotropy of fracture toughness is discussed. Possible developments of vessel steels and procedures for producing reactor vessels are reviewed.

  11. Cerebral vessels segmentation for light-sheet microscopy image using convolutional neural networks

    Science.gov (United States)

    Hu, Chaoen; Hui, Hui; Wang, Shuo; Dong, Di; Liu, Xia; Yang, Xin; Tian, Jie

    2017-03-01

    Cerebral vessel segmentation is an important step in image analysis for brain function and brain disease studies. To extract all the cerebrovascular patterns, including arteries and capillaries, some filter-based methods are used to segment vessels. However, the design of accurate and robust vessel segmentation algorithms is still challenging, due to the variety and complexity of images, especially in cerebral blood vessel segmentation. In this work, we addressed a problem of automatic and robust segmentation of cerebral micro-vessels structures in cerebrovascular images acquired by light-sheet microscope for mouse. To segment micro-vessels in large-scale image data, we proposed a convolutional neural networks (CNNs) architecture trained by 1.58 million pixels with manual label. Three convolutional layers and one fully connected layer were used in the CNNs model. We extracted a patch of size 32x32 pixels in each acquired brain vessel image as training data set to feed into CNNs for classification. This network was trained to output the probability that the center pixel of input patch belongs to vessel structures. To build the CNNs architecture, a series of mouse brain vascular images acquired from a commercial light sheet fluorescence microscopy (LSFM) system were used for training the model. The experimental results demonstrated that our approach is a promising method for effectively segmenting micro-vessels structures in cerebrovascular images with vessel-dense, nonuniform gray-level and long-scale contrast regions.

  12. Blood vessel classification into arteries and veins in retinal images

    Science.gov (United States)

    Kondermann, Claudia; Kondermann, Daniel; Yan, Michelle

    2007-03-01

    The prevalence of diabetes is expected to increase dramatically in coming years; already today it accounts for a major proportion of the health care budget in many countries. Diabetic Retinopathy (DR), a micro vascular complication very often seen in diabetes patients, is the most common cause of visual loss in working age population of developed countries today. Since the possibility of slowing or even stopping the progress of this disease depends on the early detection of DR, an automatic analysis of fundus images would be of great help to the ophthalmologist due to the small size of the symptoms and the large number of patients. An important symptom for DR are abnormally wide veins leading to an unusually low ratio of the average diameter of arteries to veins (AVR). There are also other diseases like high blood pressure or diseases of the pancreas with one symptom being an abnormal AVR value. To determine it, a classification of vessels as arteries or veins is indispensable. As to our knowledge despite the importance there have only been two approaches to vessel classification yet. Therefore we propose an improved method. We compare two feature extraction methods and two classification methods based on support vector machines and neural networks. Given a hand-segmentation of vessels our approach achieves 95.32% correctly classified vessel pixels. This value decreases by 10% on average, if the result of a segmentation algorithm is used as basis for the classification.

  13. Pressure vessel for nuclear reactor plant consisting of several pre-stressed cast pressure vessels

    International Nuclear Information System (INIS)

    Bodmann, E.

    1984-01-01

    Several cylindrical pressure vessel components made of pressure castings are arranged on a sector of a circle around the cylindrical cast pressure vessel for accommodating the helium cooled HTR. Each component pressure vessel is connected to the reactor vessel by a horizontal gas duct. The contact surfaces between reactor and component pressure vessel are in one plane. In the spaces between the individual component pressure vessels, there are supporting blocks made of cast iron, which are hollow and also have flat surfaces. With the reactor vessel and the component pressure vessels they form a disc-shaped connecting part below and above the gas ducts. (orig./PW)

  14. [Hemodynamic phenomena in retrobulhar and eyeball vessels].

    Science.gov (United States)

    Modrzejewska, Monika

    2011-01-01

    The purpose of this review was to evaluate factors connected with blood flow and indices regulating vascular diameter and some parameters influencing retrobulbar circulation such as type of vascular resistance, anatomical structure of vascular wall and vessel lumen. Neurogenic and angiogenic factors, rheological blood composition, presence of anatomical and pathological obstructions on blood flow pathway as well as degree of development of collateral circulation pathways--have influence on the volume and blood flow velocity in eyeball. There were discussed bulbar circulation hemodynamics, emphasizing the importance of perfusion pressure. The role of risk factors was underlined for pathological lesions in vessels supplying blood to eyeball and in ophthalmic artery (OA) and its collaterals, in central retinal artery (CRA) as well as posterior ciliary arteries (PCAs), and in venous system carrying away blood from eye. IN CONCLUSION--the results of many studies of retrobulbar blood flow in different types of ophthalmic diseases of the vascular etiopathogenesis indicate that registry of the mean values of blood flow parameters and vascular resistance indices parallel to measurement of blood flow spectrum in OA, CRA, PCAs arteries, might contribute much information to explain or to evaluate nature of pathological changes in retinal and choroidal circulation.

  15. Novel algorithm by low complexity filter on retinal vessel segmentation

    Science.gov (United States)

    Rostampour, Samad

    2011-10-01

    This article shows a new method to detect blood vessels in the retina by digital images. Retinal vessel segmentation is important for detection of side effect of diabetic disease, because diabetes can form new capillaries which are very brittle. The research has been done in two phases: preprocessing and processing. Preprocessing phase consists to apply a new filter that produces a suitable output. It shows vessels in dark color on white background and make a good difference between vessels and background. The complexity is very low and extra images are eliminated. The second phase is processing and used the method is called Bayesian. It is a built-in in supervision classification method. This method uses of mean and variance of intensity of pixels for calculate of probability. Finally Pixels of image are divided into two classes: vessels and background. Used images are related to the DRIVE database. After performing this operation, the calculation gives 95 percent of efficiency average. The method also was performed from an external sample DRIVE database which has retinopathy, and perfect result was obtained

  16. Dichotomy in Hedgehog Signaling between Human Healthy Vessel and Atherosclerotic Plaques

    NARCIS (Netherlands)

    Queiroz, Karla C. S.; Bijlsma, Maarten F.; Tio, René A.; Zeebregts, Clark J.; Dunaeva, Marina; Ferreira, Carmen V.; Fuhler, Gwenny M.; Kuipers, Ernst J.; Alves, Maria M.; Rezaee, Farhad; Spek, C. Arnold; Peppelenbosch, Maikel P.

    2012-01-01

    The major cause for plaque instability in atherosclerotic disease is neoangiogenic revascularization, but the factors controlling this process remain only partly understood. Hedgehog (HH) is a morphogen with important functions in revascularization, but its function in human healthy vessel biology

  17. AFSC/FMA/Vessel Assessment Logging

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vessels fishing trawl gear, vessels fishing hook-and-line and pot gear that are also greater than 57.5 feet overall, and shoreside and floating processing facilities...

  18. 2013 EPA Vessels General Permit (VGP)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information for any vessel that submitted a Notice of Intent (NOI), Notice of Termination (NOT), or annual report under EPA's 2013 Vessel General Permit (VGP)....

  19. Interstitial Cells of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Vladimír Pucovský

    2010-01-01

    Full Text Available Blood vessels are made up of several distinct cell types. Although it was originally thought that the tunica media of blood vessels was composed of a homogeneous population of fully differentiated smooth muscle cells, more recent data suggest the existence of multiple smooth muscle cell subpopulations in the vascular wall. One of the cell types contributing to this heterogeneity is the novel, irregularly shaped, noncontractile cell with thin processes, termed interstitial cell, found in the tunica media of both veins and arteries. While the principal role of interstitial cells in veins seems to be pacemaking, the role of arterial interstitial cells is less clear. This review summarises the knowledge of the functional and structural properties of vascular interstitial cells accumulated so far, offers hypotheses on their physiological role, and proposes directions for future research.

  20. The Vessel Schedule Recovery Problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Plum, Christian Edinger Munk; Vaaben, Bo

    Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker cons...... consumption and the impact on the remaining network and the customer service level. The model is applied to 4 real cases from Maersk Line. Solutions are comparable or superior to those chosen by operations managers. Cost savings of up to 58% may be achieved.......Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker...

  1. Nuclear power plant pressure vessels. Inservice inspections

    International Nuclear Information System (INIS)

    1995-01-01

    The requirements for the planning and reporting of inservice inspections of nuclear power plant pressure vessels are presented. The guide specifically applies to inservice inspections of Safety class 1 and 2 nuclear power plant pressure vessels, piping, pumps and valves plus their supports and reactor pressure vessel internals by non- destructive examination methods (NDE). Inservice inspections according to the Pressure Vessel Degree (549/73) are discussed separately in the guide YVL 3.0. (4 refs.)

  2. Expanded Fermilab pressure vessel directory program

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, A.

    1983-01-01

    Several procedures have been written to manage the information pertaining to the vacuum tanks and pressure vessels for which the laboratory is responsible. These procedures have been named TANK1 for the vessels belonging to the Accelerator Division, TANK2 and TANK3 for the vessels belonging to the Research Division and to Technical Support respectively, and TANK4 for the vessels belonging to the Business Division. The operating procedures are otherwise identical in every respect.

  3. Expanded Fermilab pressure vessel directory program

    International Nuclear Information System (INIS)

    Tanner, A.

    1983-01-01

    Several procedures have been written to manage the information pertaining to the vacuum tanks and pressure vessels for which the laboratory is responsible. These procedures have been named TANK1 for the vessels belonging to the Accelerator Division, TANK2 and TANK3 for the vessels belonging to the Research Division and to Technical Support respectively, and TANK4 for the vessels belonging to the Business Division. The operating procedures are otherwise identical in every respect

  4. Vacuum vessel for plasma devices

    International Nuclear Information System (INIS)

    Yamada, Masao; Taguchi, Masami.

    1975-01-01

    Object: To permit effective utility of the space in the inner and outer sides of the container wall and also permit repeated assembly for use. Structure: Vacuum vessel wall sections are sealed together by means of welding bellows, and also flange portions formed at the end of the wall sections are coupled together by bolts and are sealed together with a seal ring and a seal cap secured by welding. (Nakamura, S.)

  5. Reactor vessel head permanent shield

    International Nuclear Information System (INIS)

    Hankinson, M.F.; Leduc, R.J.; Richard, J.W.; Malandra, L.J.

    1989-01-01

    A nuclear reactor is described comprising: a nuclear reactor pressure vessel closure head; control rod drive mechanisms (CRDMs) disposed within the closure head so as to project vertically above the closure head; cooling air baffle means surrounding the control rod drive mechanisms for defining cooling air paths relative to the control rod drive mechanisms; means defined within the periphery of the closure head for accommodating fastening means for securing the closure head to its associated pressure vessel; lifting lugs fixedly secured to the closure head for facilitating lifting and lowering movements of the closure head relative to the pressure vessel; lift rods respectively operatively associated with the plurality of lifting lugs for transmitting load forces, developed during the lifting and lowering movements of the closure head, to the lifting lugs; upstanding radiation shield means interposed between the cooling air baffle means and the periphery of the enclosure head of shielding maintenance personnel operatively working upon the closure head fastening means from the effects of radiation which may emanate from the control rod drive mechanisms and the cooling air baffle means; and connecting systems respectively associated with each one of the lifting lugs and each one of the lifting rods for connecting each one of the lifting rods to a respective one of each one of the lifting lugs, and for simultaneously connecting a lower end portion of the upstanding radiation shield means to each one of the respective lifting lugs

  6. Reactor-vessel-sectioning demonstration

    International Nuclear Information System (INIS)

    Lundgren, R.A.

    1981-09-01

    A technical demonstration was successfully completed of simulated reactor vessel sectioning using the combined techniques of air arc gouging and flame cutting. A 4-ft x 3-ft x 9-in. thick sample was fabricated of A36 carbon steel to simulate a reactor vessel wall. A 1/4-in. layer of stainless steel (SS) was tungsten inert gas (TIG)-welded to the carbon steel. Several techniques were considered to section the simulated reactor vessel; air arc gouging was selected to penetrate the stainless steel, and flame cutting was selected to sever the carbon steel. Three sectioning operations were demonstrated. For all three, the operating parameters were the same; but the position of the sample was varied. For the first cut, the sample was placed in a horizontal position, and it was successfully severed from the SS side. For the second cut, the sample was turned over and cut from the carbon steel side. Cutting from the carbon steel side has the advantages of cost reduction

  7. 33 CFR 151.1512 - Vessel safety.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vessel safety. 151.1512 Section... River § 151.1512 Vessel safety. Nothing in this subpart relieves the master of the responsibility for ensuring the safety and stability of the vessel or the safety of the crew and passengers, or any other...

  8. Reactor vessel supported by flexure member

    International Nuclear Information System (INIS)

    Crawford, J.D.; Pankow, B.

    1975-01-01

    A description is given of a reactor pressure vessel which is provided with vertical support means in the form of circumferentially spaced columns upon which the vessel is mounted. The columns are adapted to undergo flexure in order to accommodate the thermally induced displacements experienced by the vessel during operational transients

  9. 19 CFR 4.97 - Salvage vessels.

    Science.gov (United States)

    2010-04-01

    ... United States and Great Britain ‘concerning reciprocal rights for United States and Canada in the... meaning of this statute. (e) A Mexican vessel may engage in a salvage operation on a Mexican vessel in any territorial waters of the United States in which Mexican vessels are permitted to conduct such operations by...

  10. Model tests for prestressed concrete pressure vessels

    International Nuclear Information System (INIS)

    Stoever, R.

    1975-01-01

    Investigations with models of reactor pressure vessels are used to check results of three dimensional calculation methods and to predict the behaviour of the prototype. Model tests with 1:50 elastic pressure vessel models and with a 1:5 prestressed concrete pressure vessel are described and experimental results are presented. (orig.) [de

  11. 50 CFR 648.4 - Vessel permits.

    Science.gov (United States)

    2010-10-01

    ... carrying passengers for hire. (8) Atlantic bluefish vessels. (i) Commercial. Any vessel of the United... lands Atlantic bluefish in or from the EEZ in excess of the recreational possession limit specified at § 648.164 must have been issued and carry on board a valid commercial bluefish vessel permit. (ii) Party...

  12. Segmentation of retinal blood vessels using artificial neural networks for early detection of diabetic retinopathy

    Science.gov (United States)

    Mann, Kulwinder S.; Kaur, Sukhpreet

    2017-06-01

    There are various eye diseases in the patients suffering from the diabetes which includes Diabetic Retinopathy, Glaucoma, Hypertension etc. These all are the most common sight threatening eye diseases due to the changes in the blood vessel structure. The proposed method using supervised methods concluded that the segmentation of the retinal blood vessels can be performed accurately using neural networks training. It uses features which include Gray level features; Moment Invariant based features, Gabor filtering, Intensity feature, Vesselness feature for feature vector computation. Then the feature vector is calculated using only the prominent features.

  13. Bone Marrow Blood Vessel Ossification and “Microvascular Dead Space” in Rat and Human Long Bone

    Science.gov (United States)

    Prisby, Rhonda D.

    2014-01-01

    Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4–6 mon; n=8) and old (22–24 mon; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner’s Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via µCT to quantify microvascular ossification. Bone marrow blood vessels from rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and “normal” vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p necrosis. The progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the difficulties treating bone disease in the elderly. PMID:24680721

  14. Integrating Multiple Autonomous Underwater Vessels, Surface Vessels and Aircraft into Oceanographic Research Vessel Operations

    Science.gov (United States)

    McGillivary, P. A.; Borges de Sousa, J.; Martins, R.; Rajan, K.

    2012-12-01

    Autonomous platforms are increasingly used as components of Integrated Ocean Observing Systems and oceanographic research cruises. Systems deployed can include gliders or propeller-driven autonomous underwater vessels (AUVs), autonomous surface vessels (ASVs), and unmanned aircraft systems (UAS). Prior field campaigns have demonstrated successful communication, sensor data fusion and visualization for studies using gliders and AUVs. However, additional requirements exist for incorporating ASVs and UASs into ship operations. For these systems to be optimally integrated into research vessel data management and operational planning systems involves addressing three key issues: real-time field data availability, platform coordination, and data archiving for later analysis. A fleet of AUVs, ASVs and UAS deployed from a research vessel is best operated as a system integrated with the ship, provided communications among them can be sustained. For this purpose, Disruptive Tolerant Networking (DTN) software protocols for operation in communication-challenged environments help ensure reliable high-bandwidth communications. Additionally, system components need to have considerable onboard autonomy, namely adaptive sampling capabilities using their own onboard sensor data stream analysis. We discuss Oceanographic Decision Support System (ODSS) software currently used for situational awareness and planning onshore, and in the near future event detection and response will be coordinated among multiple vehicles. Results from recent field studies from oceanographic research vessels using AUVs, ASVs and UAS, including the Rapid Environmental Picture (REP-12) cruise, are presented describing methods and results for use of multi-vehicle communication and deliberative control networks, adaptive sampling with single and multiple platforms, issues relating to data management and archiving, and finally challenges that remain in addressing these technological issues. Significantly, the

  15. Flaw distribution development from vessel ISI data

    International Nuclear Information System (INIS)

    Foulds, J.R.; Kennedy, E.L.; Basin, S.L.; Rosinski, S.T.

    1991-01-01

    Previous attempts to develop flaw distributions for use in the structural integrity evaluation of pressurized water reactor (PWR) vessels have aimed at the estimation of a ''generic'' distribution applicable to all vessels. In contrast, this paper describes the analysis of vessel-specific in-service inspection (ISI) data for the development of a flaw distribution reliably representative of the condition of the particular vessel inspected. The application of the methodology may be extended to other vessels, but has been primarily developed for PWR reactor vessels. For this study, the flaw data analyzed included data obtained from three recently performed PWR vessel ISIs and from laboratory inspection of selected weldment sections of the Midland reactor vessel. The variability in both the character of the reviewed data (size range of flaws, number of flaws) and the UT (ultrasonic test) inspection system performance identified a need for analyzing the inspection results on a vessel-, or data set-specific basis. For this purpose, traditional histogram-based methods were inadequate, and a new methodology that can accept a very small number of flaws (typical of vessel-specific ISI results) and that includes consideration of inspection system flaw detection reliability, flaw sizing accuracy and flaw detection threshold, was developed. Results of the application of the methodology to each of the four PWR reactor vessel cases studied are presented and discussed

  16. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    International Nuclear Information System (INIS)

    Spiegel, M; Hornegger, J; Redel, T; Struffert, T; Doerfler, A

    2011-01-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  17. Vitamin D Status in Small Vessel and Large Vessel Ischemic Stroke Patients: A Case–control Study

    Directory of Open Access Journals (Sweden)

    Navid Manouchehri

    2017-01-01

    Full Text Available Background: Vitamin D insufficiency is a globally widespread issue. Recent studies have reported a high prevalence of Vitamin D deficiency in Middle-East countries. Studies have shown negative effects of Vitamin D deficiency on endothelium and related diseases such as ischemic brain stroke. Here, we assessed Vitamin D status in patients with different types of ischemic brain stroke and control group. Materials and Methods: Seventy-five patients (49.3% small vessel, 50.7% large vessel and 75 controls, matched for age (68.01 ± 10.94 vs. 67.64 ± 10.24 and sex (42 male and 33 female were recruited. 25(OH D levels were measured by Chemiluminescence immunoassay. 25(OH D status was considered as severely, moderately, or mildly deficient and normal with 25(OH D levels of less than 5, 5-10, 10-16, and> 16 ng/ml, respectively. Results: Mean ± standard error concentration of 25(OH D in cases and controls were 17.7 ± 1.5 and 26.9 ± 1.6 (P = 0.0001, respectively. Mild, moderate, and severe Vitamin D deficiency were observed in 10.8%, 32.4%, 8.1% vs. 34.3%, 31.5%, 9.5% of small vessel and large vessel group, respectively. 21.7% of the controls were Vitamin D deficient. Vitamin D deficiency was significantly associated with higher risk for ischemic stroke, (P = 0.000, OR = 7.17, 95% confidence interval: 3.36–15.29. 25(OH D levels were significantly higher in control group comparing to small vessel (26.9 ± 1.6 vs. 20.59 ± 2.6 P < 0.05 and large vessel (26.9 ± 1.6 vs. 13.4 ± 1.3 P < 0.001 stroke patients. Small vessel group had significantly higher levels of Vitamin D than large vessel (P < 0.05. Conclusion: Vitamin D deficiency significantly increases the risk of ischemic stroke, favoring the types with the pathogenesis of large vessel strokes.

  18. Primo vessel inside a lymph vessel emerging from a cancer tissue.

    Science.gov (United States)

    Lee, Sungwoo; Ryu, Yeonhee; Cha, Jinmyung; Lee, Jin-Kyu; Soh, Kwang-Sup; Kim, Sungchul; Lim, Jaekwan

    2012-10-01

    Primo vessels were observed inside the lymph vessels near the caudal vena cava of a rabbit and a rat and in the thoracic lymph duct of a mouse. In the current work we found a primo vessel inside the lymph vessel that came out from the tumor tissue of a mouse. A cancer model of a nude mouse was made with human lung cancer cell line NCI-H460. We injected fluorescent nanoparticles into the xenografted tumor tissue and studied their flow in blood, lymph, and primo vessels. Fluorescent nanoparticles flowed through the blood vessels quickly in few minutes, and but slowly in the lymph vessels. The bright fluorescent signals of nanoparticles disappeared within one hour in the blood vessels but remained much longer up to several hours in the case of lymph vessels. We found an exceptional case of lymph vessels that remained bright with fluorescence up to 24 hours. After detailed examination we found that the bright fluorescence was due to a putative primo vessel inside the lymph vessel. This rare observation is consistent with Bong-Han Kim's claim on the presence of a primo vascular system in lymph vessels. It provides a significant suggestion on the cancer metastasis through primo vessels and lymph vessels. Copyright © 2012. Published by Elsevier B.V.

  19. 46 CFR 4.03-40 - Public vessels.

    Science.gov (United States)

    2010-10-01

    ... INVESTIGATIONS Definitions § 4.03-40 Public vessels. Public vessel means a vessel that— (a) Is owned, or demise... Department (except a vessel operated by the Coast Guard or Saint Lawrence Seaway Development Corporation...

  20. DISEASES

    DEFF Research Database (Denmark)

    Pletscher-Frankild, Sune; Pallejà, Albert; Tsafou, Kalliopi

    2015-01-01

    Text mining is a flexible technology that can be applied to numerous different tasks in biology and medicine. We present a system for extracting disease-gene associations from biomedical abstracts. The system consists of a highly efficient dictionary-based tagger for named entity recognition...... of human genes and diseases, which we combine with a scoring scheme that takes into account co-occurrences both within and between sentences. We show that this approach is able to extract half of all manually curated associations with a false positive rate of only 0.16%. Nonetheless, text mining should...... not stand alone, but be combined with other types of evidence. For this reason, we have developed the DISEASES resource, which integrates the results from text mining with manually curated disease-gene associations, cancer mutation data, and genome-wide association studies from existing databases...

  1. Multi-level deep supervised networks for retinal vessel segmentation.

    Science.gov (United States)

    Mo, Juan; Zhang, Lei

    2017-12-01

    Changes in the appearance of retinal blood vessels are an important indicator for various ophthalmologic and cardiovascular diseases, including diabetes, hypertension, arteriosclerosis, and choroidal neovascularization. Vessel segmentation from retinal images is very challenging because of low blood vessel contrast, intricate vessel topology, and the presence of pathologies such as microaneurysms and hemorrhages. To overcome these challenges, we propose a neural network-based method for vessel segmentation. A deep supervised fully convolutional network is developed by leveraging multi-level hierarchical features of the deep networks. To improve the discriminative capability of features in lower layers of the deep network and guide the gradient back propagation to overcome gradient vanishing, deep supervision with auxiliary classifiers is incorporated in some intermediate layers of the network. Moreover, the transferred knowledge learned from other domains is used to alleviate the issue of insufficient medical training data. The proposed approach does not rely on hand-crafted features and needs no problem-specific preprocessing or postprocessing, which reduces the impact of subjective factors. We evaluate the proposed method on three publicly available databases, the DRIVE, STARE, and CHASE_DB1 databases. Extensive experiments demonstrate that our approach achieves better or comparable performance to state-of-the-art methods with a much faster processing speed, making it suitable for real-world clinical applications. The results of cross-training experiments demonstrate its robustness with respect to the training set. The proposed approach segments retinal vessels accurately with a much faster processing speed and can be easily applied to other biomedical segmentation tasks.

  2. Progress of ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Ioki, K., E-mail: Kimihiro.Ioki@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Bayon, A. [F4E, c/ Josep Pla, No. 2, Torres Diagonal Litoral, Edificio B3, E-08019 Barcelona (Spain); Choi, C.H.; Daly, E.; Dani, S.; Davis, J.; Giraud, B.; Gribov, Y.; Hamlyn-Harris, C.; Jun, C.; Levesy, B. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Kim, B.C. [NFRI, 52 Yeoeundong Yuseonggu, Daejeon 305-333 (Korea, Republic of); Kuzmin, E. [NTC “Sintez”, Efremov Inst., 189631 Metallostroy, St. Petersburg (Russian Federation); Le Barbier, R.; Martinez, J.-M. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Pathak, H. [ITER-India, A-29, GIDC Electronic Estate, Sector 25, Gandhinagar 382025 (India); Preble, J. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Sa, J.W. [NFRI, 52 Yeoeundong Yuseonggu, Daejeon 305-333 (Korea, Republic of); Terasawa, A.; Utin, Yu. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); and others

    2013-10-15

    Highlights: ► This covers the overall status and progress of the ITER vacuum vessel activities. ► It includes design, R and D, manufacturing and approval process of the regulators. ► The baseline design was completed and now manufacturing designs are on-going. ► R and D includes ISI, dynamic test of keys and lip-seal welding/cutting technology. ► The VV suppliers produced full-scale mock-ups and started VV manufacturing. -- Abstract: Design modifications were implemented in the vacuum vessel (VV) baseline design in 2011–2012 for finalization. The modifications are mostly due to interface components, such as support rails and feedthroughs for the in-vessel coils (IVC). Manufacturing designs are being developed at the domestic agencies (DAs) based on the baseline design. The VV support design was also finalized and tests on scale mock-ups are under preparation. Design of the in-wall shielding (IWS) has progressed, considering the assembly methods and the required tolerances. Further modifications are required to be consistent with the DAs’ manufacturing designs. Dynamic tests on the inter-modular and stub keys to support the blanket modules are being performed to measure the dynamic amplification factor (DAF). An in-service inspection (ISI) plan has been developed and R and D was launched for ISI. Conceptual design of the VV instrumentation has been developed. The VV baseline design was approved by the agreed notified body (ANB) in accordance with the French Nuclear Pressure Equipment Order procedure.

  3. Progress of ITER vacuum vessel

    International Nuclear Information System (INIS)

    Ioki, K.; Bayon, A.; Choi, C.H.; Daly, E.; Dani, S.; Davis, J.; Giraud, B.; Gribov, Y.; Hamlyn-Harris, C.; Jun, C.; Levesy, B.; Kim, B.C.; Kuzmin, E.; Le Barbier, R.; Martinez, J.-M.; Pathak, H.; Preble, J.; Sa, J.W.; Terasawa, A.; Utin, Yu.

    2013-01-01

    Highlights: ► This covers the overall status and progress of the ITER vacuum vessel activities. ► It includes design, R and D, manufacturing and approval process of the regulators. ► The baseline design was completed and now manufacturing designs are on-going. ► R and D includes ISI, dynamic test of keys and lip-seal welding/cutting technology. ► The VV suppliers produced full-scale mock-ups and started VV manufacturing. -- Abstract: Design modifications were implemented in the vacuum vessel (VV) baseline design in 2011–2012 for finalization. The modifications are mostly due to interface components, such as support rails and feedthroughs for the in-vessel coils (IVC). Manufacturing designs are being developed at the domestic agencies (DAs) based on the baseline design. The VV support design was also finalized and tests on scale mock-ups are under preparation. Design of the in-wall shielding (IWS) has progressed, considering the assembly methods and the required tolerances. Further modifications are required to be consistent with the DAs’ manufacturing designs. Dynamic tests on the inter-modular and stub keys to support the blanket modules are being performed to measure the dynamic amplification factor (DAF). An in-service inspection (ISI) plan has been developed and R and D was launched for ISI. Conceptual design of the VV instrumentation has been developed. The VV baseline design was approved by the agreed notified body (ANB) in accordance with the French Nuclear Pressure Equipment Order procedure

  4. Oxidized Lipoprotein as a Major Vessel Cell Proliferator in Oxidized Human Serum.

    Directory of Open Access Journals (Sweden)

    Yoshiro Saito

    Full Text Available Oxidative stress is correlated with the incidence of several diseases such as atherosclerosis and cancer, and oxidized biomolecules have been determined as biomarkers of oxidative stress; however, the detailed molecular relationship between generated oxidation products and the promotion of diseases has not been fully elucidated. In the present study, to clarify the role of serum oxidation products in vessel cell proliferation, which is related to the incidence of atherosclerosis and cancer, the major vessel cell proliferator in oxidized human serum was investigated. Oxidized human serum was prepared by free radical exposure, separated using gel chromatography, and then each fraction was added to several kinds of vessel cells including endothelial cells and smooth muscle cells. It was found that a high molecular weight fraction in oxidized human serum specifically induced vessel cell proliferation. Oxidized lipids were contained in this high molecular weight fraction, while cell proliferation activity was not observed in oxidized lipoprotein-deficient serum. Oxidized low-density lipoproteins induced vessel cell proliferation in a concentration-dependent manner. Taken together, these results indicate that oxidized lipoproteins containing lipid oxidation products function as a major vessel cell proliferator in oxidized human serum. These findings strongly indicate the relevance of determination of oxidized lipoproteins and lipid oxidation products in the diagnosis of vessel cell proliferation-related diseases such as atherosclerosis and cancer.

  5. Mortality of German travellers on passenger vessels.

    Science.gov (United States)

    Oldenburg, Marcus; Herzog, Jan; Püschel, Klaus; Harth, Volker

    2016-01-01

    In the past two decades, more and more Germans decided to spend their holidays on a passenger vessel. This study examined the frequencies and causes of deaths of German travellers aboard passenger vessels of all flags. The shipboard deaths of all German travellers within the time period from 1998 to 2008 were counted using the German civil central register in Berlin. The available documentation in this register provides information on frequencies, circumstances and causes of deaths on ships. In the above-mentioned period of time, the total cohort of German travellers on cruise ships is estimated to be 5.97 million persons. During the 11-year examination period, 135 shipboard deaths of German passengers [102 males (75.6%) and 33 females (24.4%)] were recorded. Out of these travellers, 110 died on cruise ships. When considering only the passengers on cruise ships (without those on ferries) an average crude mortality rate of 1.8 per 100,000 German passengers was calculated. The crude mortality rate of shipboard death for males and females was 2.5 and 0.8 per 100,000 German passengers with a mean age of 71.2 years [standard deviation (SD) 16.0 years] and 73.3 years (SD 16.0 years), respectively. Significantly, more deceased travellers older than 70 years were observed on traditional cruise ships and resort vessels than on passenger ferries (P = 0.001). The causes of death were documented in 85 cases (63.0%). Out of these documented deaths, 82 (96.5%) cases were regarded to be natural causes (particularly circulatory diseases) and 3 (3.5%) as unnatural causes (twice drowning and once an accidental fall). In spite of the large proportion of unknown causes of death, this study argues for a high significance of internal causes of deaths among German passengers. Thus, ship's doctors-particularly those on traditional cruise ships-should be well experienced in internal and geriatric medicines. © The Author 2016. Published by Oxford University Press on behalf of

  6. Peripheral Vascular Disease

    Science.gov (United States)

    ... smokers aged 20 to 40. Smoking causes the blood vessels to tighten in everyone who smokes. But in people with Buerger’s disease, there is so much tightening in the vessels that a lack of oxygen to the cells (ischemia) or tissue death (necrosis) may result. The symptoms may be different for ...

  7. Intracranial arterial aneurysm vasculopathies: targeting the outer vessel wall

    International Nuclear Information System (INIS)

    Krings, Timo; Piske, Ronie L.; Lasjaunias, Pierre L.

    2005-01-01

    The pathogenesis of intracranial arterial aneurysms (AA) remains unclear, despite their clinical importance. An improved understanding of this disease is important in choosing therapeutic options. In addition to the ''classical'' berry-type aneurysm, there are various other types of intracranial AA such as infectious, dissecting or giant, partially-thrombosed aneurysms. From the clinician's perspective, the hypothesis that some of these intracranial AA might be due to abluminal factors has been proposed for several years. Indeed, this hypothesis and the empirical use of anti-inflammatory drugs in giant intracranial aneurysms have been confirmed by recent studies reporting that an enzyme involved in the inflammatory cascade (5-lipoxygenase or 5-LO) promotes the pathogenesis of specific aneurysms in humans. 5-LO generates different forms of leukotrienes which are potent mediators of inflammation. Adventitial inflammation leads to a weakening of the media from the abluminal part of the vessel wall due to the release of proinflammatory factors that invade the media, thereby degrading the extracellular matrix, the elastic lamina of the vascular wall, and, finally, the integrity of the vessel lumen. This in turn results in a dilation of the vessel and aneurysm formation. Moreover, neoangiogenesis of vasa vasorum is found in close proximity to 5-LO activated macrophages. In addition to this biological cascade, we argue that repeated subadventitial haemorrhages from the new vasa vasorum play an important role in aneurysm pathogenesis, due to a progressive increase in size mediated by the apposition of new layers of intramural haematoma within the vessel wall. Intracranial giant AA can therefore be regarded as a proliferative disease of the vessel wall induced by extravascular activity. (orig.)

  8. Nuclear reactor pressure vessel flaw distribution development

    International Nuclear Information System (INIS)

    Kennedy, E.L.; Foulds, J.R.; Basin, S.L.

    1991-12-01

    Previous attempts to develop flaw distributions for probabilistic fracture mechanics analyses of pressurized water reactor (PWR) vessels have aimed at the estimation of a ''generic'' distribution applicable to all PWR vessels. In contrast, this report describes (1) a new flaw distribution development analytic methodology that can be applied to the analysis of vessel-specific inservice inspection (ISI) data, and (2) results of the application of the methodology to the analysis of flaw data for each vessel case (ISI data on three PWR vessels and laboratory inspection data on sections of the Midland reactor vessel). Results of this study show significant variation among the flaw distributions derived from the various data sets analyzed, strongly suggesting than a vessel-specific flaw distribution (for vessel integrity prediction under pressurized thermal shock) is preferred over a ''generic'' distribution. In addition, quantitative inspection system flaw sizing accuracy requirements have been identified for developing a flaw distribution from vessel ISI data. The new flaw data analysis methodology also permits quantifying the reliability of the flaw distribution estimate. Included in the report are identified needs for further development of several aspects of ISI data acquisition and vessel integrity prediction practice

  9. Engineering Vessels as Good as New?

    Directory of Open Access Journals (Sweden)

    Rebecca D.Levit, MD

    2018-02-01

    Full Text Available Blood vessels convey essential nutrients to end organs, and when diseased, they must be replaced or bypassed. Traditionally plastic and synthetic materials have been used but are susceptible to thrombosis, stenosis, and poor patency rates. A recent report in Science Translational Medicine describes a decellularized matrix grown in vitro from commercially sourced fibroblasts that can be used as a vascular graft. Fibroblasts are grown for several weeks on a fibrin scaffold, laying down a collagen layer. After decellularization and transplantation as an arteriovenous fistula, this group showed that grafts remained patent for several weeks. The lack of cellular material in this graft at the time of transplantation reduced the risk of immune rejection. The matrix laid down by the fibroblasts can serve as a scaffold for recipient cells to colonize after implantation, but also provides structural support for arterial blood flow. Other tissue-engineered grafts of decellularized matrices have recently been tested in clinical trial. For these strategies, the cell type, scaffold material, and culture conditions are key components that dictate not only the type and quality of the end product, but also allow standardization and quality control necessary for widespread translation into clinical use. These off-the-shelf decellularized products may be the first in a new generation of therapies for patients with cardiovascular disease.

  10. Novel Computerized Method for Measurement of Retinal Vessel Diameters

    Directory of Open Access Journals (Sweden)

    Hichem Guedri

    2017-03-01

    Full Text Available Several clinical studies reveal the relationship between alterations in the topologies of the human retinal blood vessel, the outcrop and the disease evolution, such as diabetic retinopathy, hypertensive retinopathy, and macular degeneration. Indeed, the detection of these vascular changes always has gaps. In addition, the manual steps are slow, which may be subjected to a bias of the perceiver. However, we can overcome these troubles using computer algorithms that are quicker and more accurate. This paper presents and investigates a novel method for measuring the blood vessel diameter in the retinal image. The proposed method is based on a thresholding segmentation and thinning step, followed by the characteristic point determination step by the Douglas-Peucker algorithm. Thereafter, it uses the active contours to detect vessel contour. Finally, Heron’s Formula is applied to assure the calculation of vessel diameter. The obtained results for six sample images showed that the proposed method generated less errors compared to other techniques, which confirms the high performance of the proposed method.

  11. Hydrogen storage in insulated pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S.M.; Garcia-Villazana, O. [Lawrence Livermore National Lab., CA (United States)

    1998-08-01

    Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current analysis and experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

  12. Neutron Assay System for Confinement Vessel Disposition

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the CVs. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of special nuclear material (SNM) in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le)100-g 239 Pu equivalent in a vessel for safeguards termination. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements.

  13. Electrical discharge machining for vessel sample removal

    International Nuclear Information System (INIS)

    Litka, T.J.

    1993-01-01

    Due to aging-related problems or essential metallurgy information (plant-life extension or decommissioning) of nuclear plants, sample removal from vessels may be required as part of an examination. Vessel or cladding samples with cracks may be removed to determine the cause of cracking. Vessel weld samples may be removed to determine the weld metallurgy. In all cases, an engineering analysis must be done prior to sample removal to determine the vessel's integrity upon sample removal. Electrical discharge machining (EDM) is being used for in-vessel nuclear power plant vessel sampling. Machining operations in reactor coolant system (RCS) components must be accomplished while collecting machining chips that could cause damage if they become part of the flow stream. The debris from EDM is a fine talclike particulate (no chips), which can be collected by flushing and filtration

  14. Coronary magnetic resonance imaging: visualization of the vessel lumen and the vessel wall and molecular imaging of arteriothrombosis

    International Nuclear Information System (INIS)

    Spuentrup, Elmar; Botnar, Rene M.

    2006-01-01

    Coronary magnetic resonance (MR) imaging has dramatically emerged over the last decade. Technical improvements have enabled reliable visualization of the proximal and midportion of the coronary artery tree for exclusion of significant coronary artery disease. However, current technical developments focus also on direct visualization of the diseased coronary vessel wall and imaging of coronary plaque because plaques without stenoses are typically more vulnerable with higher risk of plaque rupture. Plaque rupture with subsequent thrombosis and vessel occlusion is the main cause of myocardial infarction. Very recently, the first success of molecular imaging in the coronary arteries has been demonstrated using a fibrin-specific contrast agent for selective visualization of coronary thrombosis. This demonstrates in general the high potential of molecular MR imaging in the field of coronary artery disease. In this review, we will address recent technical advances in coronary MR imaging, including visualization of the lumen and the vessel wall and molecular imaging of coronary arteriothrombosis. First results of these new approaches will be discussed. (orig.)

  15. Exponential Stabilization of an Underactuated Surface Vessel

    Directory of Open Access Journals (Sweden)

    Kristin Y. Pettersen

    1997-07-01

    Full Text Available The paper shows that a large class of underactuated vehicles cannot be asymptotically stabilized by either continuous or discontinuous state feedback. Furthermore, stabilization of an underactuated surface vessel is considered. Controllability properties of the surface vessels is presented, and a continuous periodic time-varying feedback law is proposed. It is shown that this feedback law exponentially stabilizes the surface vessel to the origin, and this is illustrated by simulations.

  16. Computerized reactor pressure vessel materials information system

    International Nuclear Information System (INIS)

    Strosnider, J.; Monserrate, C.; Kenworthy, L.D.; Tether, C.D.

    1980-10-01

    A computerized information system for storage and retrieval of reactor pressure vessel materials data was established, as part of Task Action Plan A-11, Reactor Vessel Materials Toughness. Data stored in the system are necessary for evaluating the resistance of reactor pressure vessels to flaw-induced fracture. This report includes (1) a description of the information system; (2) guidance on accessing the system; and (3) a user's manual for the system

  17. How to replace a reactor pressure vessel

    International Nuclear Information System (INIS)

    Huber, R.

    1996-01-01

    A potential life extending procedure for a nuclear reactor after, say, 40 years of service life, might in some circumstances be the replacement of the reactor pressure vessel. Neutron induced degradation of the vessel might make replacement by one of a different material composition desirable, for example. Although the replacement of heavy components, such as steam generators, has been possible for many years, the pressure vessel presents a much more demanding task if only because it is highly irradiated. Some preliminary feasibility studies by Siemens are reported for the two removal strategies that might be considered. These are removal of the entire pressure vessel in one piece and dismantling it into sections. (UK)

  18. Prestressed reactor vessel for nuclear power plants

    International Nuclear Information System (INIS)

    Schoening, J.; Schwiers, H.G.

    1982-01-01

    With usual pressure vessels for nuclear reactor plants, especially for gas-cooled nuclear reactors, the load occurring due to the inner overpressure, especially the tensile load affecting the vessel top and/or bottom, their axis of inertia being horizontal, shall be compensated without a supplementary modification in design of the top and/or the bottom. This is attained by choosing an appropriate prestressing system of the vessel wall in the field the top and/or the bottom, so that the top and/or the bottom form a tension vault directed towards the interior of the vessel. (orig.) [de

  19. Reactor vessel decommissioning project. Final report

    International Nuclear Information System (INIS)

    Schoonen, D.H.

    1984-09-01

    This report describes a reactor vessel decommissioning project; it documents and explains the project objectives, scope, performance results, and sodium removal process. The project was successfully completed in FY-1983, within budget and without significant problems or adverse impact on the environment. Waste generated by the operation included the reactor vessel, drained sodium, and liquid, solid, and gaseous wastes which were significantly less than project estimates. Personnel radiation exposures were minimized, such that the project total was one-half the predicted exposure level. Except for the sodium removed, the material remaining in the reactor vessel is essentially the same as when the vessel arrived for processing

  20. Safety vessels for explosive fusion reactor

    International Nuclear Information System (INIS)

    Mineev, V.

    1994-01-01

    The failure of several types of geometrically similar cylindrical and spherical steel and glass fibers vessels filled with water or air was investigated when an explosive charge of TNT was detonated in the center. Vessels had radius 50-1000 mm, thickness of walls 2-20%. The detonation on TNT imitated energy release. The parameter: K = M/mf is a measure of the strength of the vessel where M is the mass of the vessel, and mf is the mass of TNT for which the vessel fails. This demanded 2-4 destroyed and nondestroyed shots. It may be showed that: K=A/σ f where σ f is the fracture stress of the material vessel, and A = const = F(energy TNT, characteristic of elasticity of vessel material). The chief results are the following: (1) A similar increase in the geometrical dimensions of steel vessels by a factor of 10 leads to the increase of parameter K in about 5 times and to decrease of failure deformation in 7 times (scale effect). (2) For glass fibers, scale effect is absent. (3) This problem is solved in terms of theory energetic scale effect. (4) The concept of TNT equivalent explosive makes it possible to use these investigations to evaluate the response of safety vessels for explosive fusion reactor

  1. Determinants of injuries in passenger vessel accidents.

    Science.gov (United States)

    Yip, Tsz Leung; Jin, Di; Talley, Wayne K

    2015-09-01

    This paper investigates determinants of crew and passenger injuries in passenger vessel accidents. Crew and passenger injury equations are estimated for ferry, ocean cruise, and river cruise vessel accidents, utilizing detailed data of individual vessel accidents that were investigated by the U.S. Coast Guard during the time period 2001-2008. The estimation results provide empirical evidence (for the first time in the literature) that crew injuries are determinants of passenger injuries in passenger vessel accidents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Increase of cyclic durability of pressure vessels

    International Nuclear Information System (INIS)

    Vorona, V.A.; Zvezdin, Yu.I.

    1980-01-01

    The durability of multilayer pressure vessels under cyclic loading is compared with single-layer vessels. The relative conditional durability is calculated taking into account the assumption on the consequent destruction of layers and viewing a vessel wall as an indefinite plate. It is established that the durability is mainly determined by the number of layers and to a lesser degree depends on the relative size of the defect for the given layer thickness. The advantage of the multilayer vessels is the possibility of selecting layer materials so that to exclude the effect of agressive corrosion media on the strength [ru

  3. Vessel size measurements in angiograms: Manual measurements

    International Nuclear Information System (INIS)

    Hoffmann, Kenneth R.; Dmochowski, Jacek; Nazareth, Daryl P.; Miskolczi, Laszlo; Nemes, Balazs; Gopal, Anant; Wang Zhou; Rudin, Stephen; Bednarek, Daniel R.

    2003-01-01

    Vessel size measurement is perhaps the most often performed quantitative analysis in diagnostic and interventional angiography. Although automated vessel sizing techniques are generally considered to have good accuracy and precision, we have observed that clinicians rarely use these techniques in standard clinical practice, choosing to indicate the edges of vessels and catheters to determine sizes and calibrate magnifications, i.e., manual measurements. Thus, we undertook an investigation of the accuracy and precision of vessel sizes calculated from manually indicated edges of vessels. Manual measurements were performed by three neuroradiologists and three physicists. Vessel sizes ranged from 0.1-3.0 mm in simulation studies and 0.3-6.4 mm in phantom studies. Simulation resolution functions had full-widths-at-half-maximum (FWHM) ranging from 0.0 to 0.5 mm. Phantom studies were performed with 4.5 in., 6 in., 9 in., and 12 in. image intensifier modes, magnification factor = 1, with and without zooming. The accuracy and reproducibility of the measurements ranged from 0.1 to 0.2 mm, depending on vessel size, resolution, and pixel size, and zoom. These results indicate that manual measurements may have accuracies comparable to automated techniques for vessels with sizes greater than 1 mm, but that automated techniques which take into account the resolution function should be used for vessels with sizes smaller than 1 mm

  4. Vessels for elevated temperature service

    International Nuclear Information System (INIS)

    O'Donnell, W.J.; Porowski, J.S.

    1983-01-01

    The subject is covered in chapters, entitled: introduction (background; elevated temperature concerns; design tools); design of pressure vessels for elevated temperature per ASME code; basic elevated temperature failure modes; allowable stresses and strains per ASME code (basic allowable stress limits; ASME code limits for bending; time-fraction summations; strain limits; buckling and instability; negligible creep and stress-rupture effects); combined membrane and bending stresses in creep regime; thermal stress cycles; bounding methods based on elastic core concept (bounds on accumulated strains; more accurate bounds; strain ranges; maximum stresses; strains at discontinuities); elastic follow-up; creep strain concentrations; time-dependent fatigue (combined creep rupture and fatigue damage; limits for inelastic design analyses; limits for elastic design analyses); flaw evaluation techniques; type 316 stainless steel; type 304 stainless steel; steel 2 1/4Cr1Mo; Inconel 718; Incolloy 800; Hastelloy X; detailed inelastic design analyses. (U.K.)

  5. Milestones in pressure vessel technology

    International Nuclear Information System (INIS)

    Spence, J.; Nash, D.H.

    2004-01-01

    The progress of pressure vessel technology over the years has been influenced by many important events. This paper identifies a number of 'milestones' which have provided a stimulus to analysis methods, manufacturing, operational processes and new pressure equipment. The formation of a milestone itself along with its subsequent development is often critically dependent on the work of many individuals. It is postulated that such developments takes place in cycles, namely, an initial idea, followed sometimes by unexpected failures, which in turn stimulate analysis or investigation, and when confidence is established, followed finally by the emergence of codes ad standards. Starting from the industrial revolution, key milestones are traced through to the present day and beyond

  6. Reactor pressure vessel thermal annealing

    International Nuclear Information System (INIS)

    Lee, A.D.

    1997-01-01

    The steel plates and/or forgings and welds in the beltline region of a reactor pressure vessel (RPV) are subject to embrittlement from neutron irradiation. This embrittlement causes the fracture toughness of the beltline materials to be less than the fracture toughness of the unirradiated material. Material properties of RPVs that have been irradiated and embrittled are recoverable through thermal annealing of the vessel. The amount of recovery primarily depends on the level of the irradiation embrittlement, the chemical composition of the steel, and the annealing temperature and time. Since annealing is an option for extending the service lives of RPVs or establishing less restrictive pressure-temperature (P-T) limits; the industry, the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC) have assisted in efforts to determine the viability of thermal annealing for embrittlement recovery. General guidance for in-service annealing is provided in American Society for Testing and Materials (ASTM) Standard E 509-86. In addition, the American Society of Mechanical Engineers (ASME) Code Case N-557 addresses annealing conditions (temperature and duration), temperature monitoring, evaluation of loadings, and non-destructive examination techniques. The NRC thermal annealing rule (10 CFR 50.66) was approved by the Commission and published in the Federal Register on December 19, 1995. The Regulatory Guide on thermal annealing (RG 1.162) was processed in parallel with the rule package and was published on February 15, 1996. RG 1.162 contains a listing of issues that need to be addressed for thermal annealing of an RPV. The RG also provides alternatives for predicting re-embrittlement trends after the thermal anneal has been completed. This paper gives an overview of methodology and recent technical references that are associated with thermal annealing. Results from the DOE annealing prototype demonstration project, as well as NRC activities related to the

  7. A robust technique based on VLM and Frangi filter for retinal vessel extraction and denoising.

    Directory of Open Access Journals (Sweden)

    Khan Bahadar Khan

    Full Text Available The exploration of retinal vessel structure is colossally important on account of numerous diseases including stroke, Diabetic Retinopathy (DR and coronary heart diseases, which can damage the retinal vessel structure. The retinal vascular network is very hard to be extracted due to its spreading and diminishing geometry and contrast variation in an image. The proposed technique consists of unique parallel processes for denoising and extraction of blood vessels in retinal images. In the preprocessing section, an adaptive histogram equalization enhances dissimilarity between the vessels and the background and morphological top-hat filters are employed to eliminate macula and optic disc, etc. To remove local noise, the difference of images is computed from the top-hat filtered image and the high-boost filtered image. Frangi filter is applied at multi scale for the enhancement of vessels possessing diverse widths. Segmentation is performed by using improved Otsu thresholding on the high-boost filtered image and Frangi's enhanced image, separately. In the postprocessing steps, a Vessel Location Map (VLM is extracted by using raster to vector transformation. Postprocessing steps are employed in a novel way to reject misclassified vessel pixels. The final segmented image is obtained by using pixel-by-pixel AND operation between VLM and Frangi output image. The method has been rigorously analyzed on the STARE, DRIVE and HRF datasets.

  8. Structural analysis of the KSTAR vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    In, Sang Ryul; Yoon, Byeong Joo [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-10-01

    Structure analysis of the vacuum vessel for the KSTAR tokamak which, is in the end phase of the conceptual design have been performed. Mechanical stresses and deformations of the vessel produced by constant forces due to atmospheric pressure, dead weight, fluid pressure, etc and various transient electromagnetic forces induced during tokamak operations were calculated as well as modal characteristics and buckling properties were investigated. Influences of the temperature gradient and the constraint condition of the support on the thermal stress and deformation of the vessel were analyzed. The thermal stress due to the temperature distribution on the vessel as supplying the N{sub 2} gas of 400 deg C through poloidal channels according to the recent baking concept were calculated. No severe problem in the robustness of the vessel was found when applying the constant pressures on the vessel. However the mechanical stress due to the EM force induced by halo currents flowing on the vessel and the plasma facing components (PFCs) far exceeded the allowable limit. Some reinforcing components should be added on the boundary of the PFC support and the vessel, and that of the vessel support and the vessel. A steep temperature gradient in the vicinity of the inlet and oulet of the heating gas produced a thermal stress much higher than allowable. It is necessary to make the temperature of the vessel as uniform as possible and to develop a new support concept which is flexible enough to accommodate a thermal expansion of a few cm while sufficiently strong to resist mechanical impacts. (author). 5 refs., 41 figs., 9 tabs.

  9. A computational algorithm addressing how vessel length might depend on vessel diameter

    Science.gov (United States)

    Jing Cai; Shuoxin Zhang; Melvin T. Tyree

    2010-01-01

    The objective of this method paper was to examine a computational algorithm that may reveal how vessel length might depend on vessel diameter within any given stem or species. The computational method requires the assumption that vessels remain approximately constant in diameter over their entire length. When this method is applied to three species or hybrids in the...

  10. Vessel classification method based on vessel behavior in the port of Rotterdam

    NARCIS (Netherlands)

    Zhou, Y.; Daamen, W.; Vellinga, T.; Hoogendoorn, S.P.

    2015-01-01

    AIS (Automatic Identification System) data have proven to be a valuable source to investigate vessel behavior. The analysis of AIS data provides a possibility to recognize vessel behavior patterns in a waterway area. Furthermore, AIS data can be used to classify vessel behavior into several

  11. Nuclear reactor with a suspended vessel

    International Nuclear Information System (INIS)

    Lemercier, Guy.

    1977-01-01

    This invention relates to a nuclear reactor with a suspended vessel and applies in particular when this is a fast reactor, the core or active part of the reactor being inside the vessel and immersed under a suitable volume of flowing liquid metal to cool it by extracting the calories released by the nuclear fission in the fuel assemblies forming this core [fr

  12. Fabrication of Separator Demonstration Facility process vessel

    International Nuclear Information System (INIS)

    Oberst, E.F.

    1985-01-01

    The process vessel system is the central element in the Separator Development Facility (SDF). It houses the two major process components, i.e., the laser-beam folding optics and the separators pods. This major subsystem is the critical-path procurement for the SDF project. Details of the vaious parts of the process vessel are given

  13. Irradiation embrittlement of reactor vessel steels

    International Nuclear Information System (INIS)

    Bros, J.

    2000-01-01

    From the historical decision of closing the Yankee Rowe NPP because of the uncertainties on the level of reactor pressure vessel neutron embrittlement, this paper reviews the technical-scientist bases of the degradation phenomena, and refers to the evolution of reactor pressure vessel radiation surveillance programs. (Author)

  14. Ultrasound periodic inspections of reactor pressure vessels

    International Nuclear Information System (INIS)

    Haniger, L.

    1980-01-01

    Two versions are described of ultrasonic equipment for periodic inspections of reactor pressure vessels. One uses the principle of exchangeable programmators with solid-state logic while the other uses programmable logic with semiconductor memories. The equipment is to be used for inspections of welded joints on the upper part of the V-1 reactor pressure vessel. (L.O.)

  15. Elastic plastic buckling of elliptical vessel heads

    International Nuclear Information System (INIS)

    Alix, M.; Roche, R.L.

    1981-08-01

    The risks of buckling of dished vessel head increase when the vessel is thin walled. This paper gives the last results on experimental tests of 3 elliptical heads and compares all the results with some empirical formula dealing with elastic and plastic buckling

  16. Analyzing Vessel Behavior Using Process Mining

    NARCIS (Netherlands)

    Maggi, F.M.; Mooij, A.J.; Aalst, W.M.P. van der

    2013-01-01

    In the maritime domain, electronic sensors such as AIS receivers and radars collect large amounts of data about the vessels in a certain geographical area. We investigate the use of process mining techniques for analyzing the behavior of the vessels based on these data. In the context of maritime

  17. A SVD Based Image Complexity Measure

    DEFF Research Database (Denmark)

    Gustafsson, David Karl John; Pedersen, Kim Steenstrup; Nielsen, Mads

    2009-01-01

    Images are composed of geometric structures and texture, and different image processing tools - such as denoising, segmentation and registration - are suitable for different types of image contents. Characterization of the image content in terms of geometric structure and texture is an important...... problem that one is often faced with. We propose a patch based complexity measure, based on how well the patch can be approximated using singular value decomposition. As such the image complexity is determined by the complexity of the patches. The concept is demonstrated on sequences from the newly...... collected DIKU Multi-Scale image database....

  18. Fluid Dynamics of Magnetic Nanoparticles in Simulated Blood Vessels

    Science.gov (United States)

    Blue, Lauren; Sewell, Mary Kathryn; Brazel, Christopher S.

    2008-11-01

    Magnetic nanoparticles (MNPs) can be used to locally target therapies and offer the benefit of using an AC magnetic field to combine hyperthermia treatment with the triggered release of therapeutic agents. Here, we investigate localization of MNPs in a simulated environment to understand the relationship between magnetic field intensity and bulk fluid dynamics to determine MNP retention in a simulated blood vessel. As MNPs travel through blood vessels, they can be slowed or trapped in a specific area by applying a magnetic field. Magnetic cobalt ferrite nanoparticles were synthesized and labeled with a fluorescent rhodamine tag to visualize patterns in a flow cell, as monitored by a fluorescence microscope. Particle retention was determined as a function of flow rate, concentration, and magnetic field strength. Understanding the relationship between magnetic field intensity, flow behavior and nanoparticle characteristics will aid in the development of therapeutic systems specifically targeted to diseased tissue.

  19. Regulation of blood vessels by prolactin and vasoinhibins.

    Science.gov (United States)

    Clapp, Carmen; Thebault, Stéphanie; Macotela, Yazmín; Moreno-Carranza, Bibiana; Triebel, Jakob; Martínez de la Escalera, Gonzalo

    2015-01-01

    Prolactin (PRL) stimulates the growth of new blood vessels (angiogenesis) either directly through actions on endothelial cells or indirectly by upregulating proangiogenic factors like vascular endothelial growth factor (VEGF). Moreover, PRL acquires antiangiogenic properties after undergoing proteolytic cleavage to vasoinhibins, a family of PRL fragments (including 16 kDa PRL) with potent antiangiogenic, vasoconstrictive, and antivasopermeability effects. In view of the opposing actions of PRL and vasoinhibins, the regulation of the proteases responsible for specific PRL cleavage represents an efficient mechanism for controlling blood vessel growth and function. This review briefly describes the vascular actions of PRL and vasoinhibins, and addresses how their interplay could help drive biological effects of PRL in the context of health and disease.

  20. Metallurgy of steels for PWR pressure vessels

    International Nuclear Information System (INIS)

    Kepka, M.; Mocek, J.; Barackova, L.

    1980-01-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure. (B.S.)

  1. Metallurgy of steels for PWR pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Kepka, M; Mocek, J; Barackova, L [Skoda, Plzen (Czechoslovakia)

    1980-09-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure.

  2. Nuclear reactor vessel fuel thermal insulating barrier

    Science.gov (United States)

    Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

    2013-03-19

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

  3. Method of burying vessel containing radioactive waste

    International Nuclear Information System (INIS)

    Koga, Yoshihito.

    1989-01-01

    A float having an inert gas sealed therein is attached to a tightly closed vessel containing radioactive wastes. The vessel is inserted and kept in a small hole for burying the tightly closed vessel in an excavated shaft in rocks such as of granite or rock salts, while filling bentonite as shielding material therearound. In this case, the float is so adjusted that the apparent specific gravity is made equal or nearer between the tightly closed vessel and the bentonite, so that the rightly closed vessel does not sink and cause direct contact with the rocks even if bentonite flows due to earthquakes, etc. This can prevent radioactivity contamination through water in the rocks. (S.K.)

  4. An experimental study on feasibility of ex-vessel cooling through the external guide vessel

    International Nuclear Information System (INIS)

    Kang, Kyoung-Ho; Kim, Jong-Hwan; Park, Rae-Jun; Kim, Sang-Baik

    2000-01-01

    This paper presents the results of a series of experiments for assessing the efficacy of ex-vessel cooling through the external guide vessel during a severe accident. Four tests were performed in the LAVA test facility at KAERI, varying the boundary conditions at the outer surface of the vessel. The first test was a dry condition test conducted without cooling the outside of the vessel. On the other hand, in the second test, the cooling of the vessel surface was produced by gravity-driven forced injection of water along the annular gap of 25 mm between the vessel and the external guide vessel. Water flow rate was about 0.85 kg/s and total mass of available water was 300 kg. For the evaluation of the water flow rate effect, the third test was performed with a pool type cooling in the annulus without any circulation of water. These two external cooling tests were performed under elevated pressure of about 1.6 MPa. Finally, the fourth test was conducted under atmospheric pressure to evaluate the effect of system pressure on boiling heat transfer characteristics. In the dry test and the pool type ex-vessel cooling test performed under atmospheric pressure, the vessel was failed by a melt penetration at about 40 degree upper position from the vessel bottom, which is coincident with the boundary of the Al 2 O 3 /Fe melt separated layers. On the other hand, in both of the ex-vessel cooling tests conducted under elevated pressure of about 1.6 MPa, the vessel didn't fail. Compared with the pool boiling test, the vessel experienced effective cooling due to the inlet flow in the forced flow test. Synthesized the results of the tests, it was shown that the heat removal with ex-vessel cooling through the guide vessel is feasible, but the additional evaluations should be performed to guarantee enough thermal margin. (author)

  5. Retinal blood vessel extraction using tunable bandpass filter and fuzzy conditional entropy.

    Science.gov (United States)

    Sil Kar, Sudeshna; Maity, Santi P

    2016-09-01

    Extraction of blood vessels on retinal images plays a significant role for screening of different opthalmologic diseases. However, accurate extraction of the entire and individual type of vessel silhouette from the noisy images with poorly illuminated background is a complicated task. To this aim, an integrated system design platform is suggested in this work for vessel extraction using a sequential bandpass filter followed by fuzzy conditional entropy maximization on matched filter response. At first noise is eliminated from the image under consideration through curvelet based denoising. To include the fine details and the relatively less thick vessel structures, the image is passed through a bank of sequential bandpass filter structure optimized for contrast enhancement. Fuzzy conditional entropy on matched filter response is then maximized to find the set of multiple optimal thresholds to extract the different types of vessel silhouettes from the background. Differential Evolution algorithm is used to determine the optimal gain in bandpass filter and the combination of the fuzzy parameters. Using the multiple thresholds, retinal image is classified as the thick, the medium and the thin vessels including neovascularization. Performance evaluated on different publicly available retinal image databases shows that the proposed method is very efficient in identifying the diverse types of vessels. Proposed method is also efficient in extracting the abnormal and the thin blood vessels in pathological retinal images. The average values of true positive rate, false positive rate and accuracy offered by the method is 76.32%, 1.99% and 96.28%, respectively for the DRIVE database and 72.82%, 2.6% and 96.16%, respectively for the STARE database. Simulation results demonstrate that the proposed method outperforms the existing methods in detecting the various types of vessels and the neovascularization structures. The combination of curvelet transform and tunable bandpass

  6. Radiation embrittlement of PWR vessel supports

    International Nuclear Information System (INIS)

    Cheverton, R.D.; Robinson, G.C.; Pennell, W.E.; Nanstad, R.K.

    1989-01-01

    Several studies pertaining to radiation damage of PWR vessel supports were conducted between 1978 and 1987. During this period, apparently there was no reason to believe that low-temperature (<100 degree C) MTR embrittlement data were not appropriate for evaluating embrittlement of PWR vessel supports. However, late in 1986, data from the High Flux Isotope Reactor (HFIR) vessel surveillance program indicated that the embrittlement rates of the several HFIR vessel materials (A212-B, A350-LF3, A105-II) were substantially greater than anticipated on the basis of MTR data. Further evaluation of the HFIR data suggested that a fluence-rate effect was responsible for the apparent discrepancy, and shortly thereafter it became apparent that this rate effect was applicable to the evaluation of LWR vessel supports. As a result, the Nuclear Regulatory Commission (NRC) requested that the Oak Ridge National Laboratory (ORNL) evaluate the impact of the apparent embrittlement rate effect on the integrity of light-water-reactor (LWR) vessel supports. The purpose of the study was to provide an indication of whether the integrity of reactor vessel supports is likely to be challenged by radiation-induced embrittlement. The scope of the evaluation included correlation of the HFIR data for application to the evaluation of LWR vessel supports; a survey and cursory evaluation of all US LWR vessel support designs, selection of two plants for specific-plant evaluation, and a specific-plant evaluation of both plants to determine critical flaw sizes for their vessel supports. 19 refs., 8 figs., 2 tabs

  7. ITER vacuum vessel, in vessel components and plasma facing materials

    International Nuclear Information System (INIS)

    Ioki, Kimihiro; Enoeda, M.; Federici, G.

    2007-01-01

    Design of the NB ports including duct liners under heat loads of the neutral beams has been developed. Design of the in-wall shielding has been developed in more details considering the supporting structure and the assembly method. The ferromagnetic inserts have previously not been installed in the outboard midplane region due to irregularity caused by the tangential ports for NB injection. Due to this configuration, the maximum ripple is relatively large (∝1 %) in a limited region of the plasma and the toroidal field flux lines fluctuate ∝10 mm in the FW region. To avoid these problems, additional ferromagnetic inserts are to be installed in the equatorial port region. Detailed studies were carried out on the ITER vacuum vessel to define appropriate codes and standards in the context of the ITER licensing in France. A set of draft documents regarding the ITER vacuum vessel structural code were prepared including an RCC-MR Addendum for the ITER VV with justified exceptions or modifications. The main deviation from the base Code is the extensive use of UT in lieu of radiography for the volumetric examination of all one-side access welds of the outer shell and field joint. The procurement allocation of blanket modules among 6 parties was fixed and the blanket module design has progressed in cooperation with parties. Fabrication of mock-ups for prequalification testing is under way and the tests will be performed in 2007-2008. Development of new beryllium materials is progressing in China and Russia. The ITER limiters will be installed in equatorial ports at two toroidal locations. The limiter plasma-facing surface protrudes ∝8 cm from the FW during the start-up and shutdown phase. In the new limiter concept, the limiters are retracted by ∝8 cm during the plasma flat top phase. This concept gives important advantages; (i) mitigation of the particle and heat loads due to disruptions, ELMs and blobs, (ii) improvement of the power coupling with the ICRH antenna

  8. Reactor pressure vessel. Status report

    International Nuclear Information System (INIS)

    Elliot, B.J.; Hackett, E.M.; Lee, A.D.

    1996-10-01

    This report describes the issues raised as a result of the staffs review of Generic Letter (GL) 92-01, Revision 1, responses and plant-specific reactor pressure vessel (RPV) assessments and the actions taken or work in progress to address these issues. In addition, the report describes actions taken by the staff and the nuclear industry to develop a thermal annealing process for use at U.S. commercial nuclear power plants. This process is intended to be used as a means of mitigating the effects of neutron radiation on the fracture toughness of RPV materials. The Nuclear Regulatory Commission (NRC) issued GL 92-01, Revision 1, Supplement 1, to obtain information needed to assess compliance with regulatory requirements and licensee commitments regarding RPV integrity. GL 92-01, Revision 1, Supplement 1, was issued as a result of generic issues that were raised in the NRC staff's reviews of licensee responses to GL 92-01, Revision 1, and plant-specific RPV evaluations. In particular, an integrated review of all data submitted in response to GL 92-01, Revision 1, indicated that licensees may not have considered all relevant data in their RPV assessments. This report is representative of submittals to and evaluations by the staff as of September 30, 1996. An update of this report will be issued at a later date

  9. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  10. Heart Disease in Women

    Science.gov (United States)

    ... United States, 1 in 4 women dies from heart disease. The most common cause of heart disease in both men and women is narrowing ... the blood vessels that supply blood to the heart itself. This is called coronary artery disease, and ...

  11. Fractal analysis reveals reduced complexity of retinal vessels in CADASIL.

    Directory of Open Access Journals (Sweden)

    Michele Cavallari

    2011-04-01

    Full Text Available The Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL affects mainly small cerebral arteries and leads to disability and dementia. The relationship between clinical expression of the disease and progression of the microvessel pathology is, however, uncertain as we lack tools for imaging brain vessels in vivo. Ophthalmoscopy is regarded as a window into the cerebral microcirculation. In this study we carried out an ophthalmoscopic examination in subjects with CADASIL. Specifically, we performed fractal analysis of digital retinal photographs. Data are expressed as mean fractal dimension (mean-D, a parameter that reflects complexity of the retinal vessel branching. Ten subjects with genetically confirmed diagnosis of CADASIL and 10 sex and age-matched control subjects were enrolled. Fractal analysis of retinal digital images was performed by means of a computer-based program, and the data expressed as mean-D. Brain MRI lesion volume in FLAIR and T1-weighted images was assessed using MIPAV software. Paired t-test was used to disclose differences in mean-D between CADASIL and control groups. Spearman rank analysis was performed to evaluate potential associations between mean-D values and both disease duration and disease severity, the latter expressed as brain MRI lesion volumes, in the subjects with CADASIL. The results showed that mean-D value of patients (1.42±0.05; mean±SD was lower than control (1.50±0.04; p = 0.002. Mean-D did not correlate with disease duration nor with MRI lesion volumes of the subjects with CADASIL. The findings suggest that fractal analysis is a sensitive tool to assess changes of retinal vessel branching, likely reflecting early brain microvessel alterations, in CADASIL patients.

  12. 78 FR 40891 - Revisions to the Export Administration Regulations: Military Vehicles; Vessels of War...

    Science.gov (United States)

    2013-07-08

    ... Vehicles; Vessels of War; Submersible Vessels, Oceanographic Equipment; Related Items; and Auxiliary and... Regulations: Military Vehicles; Vessels of War; Submersible Vessels, Oceanographic Equipment; Related Items... military vehicles and related items; vessels of war and related items; submersible vessels, oceanographic...

  13. Design of the ITER vacuum vessel

    International Nuclear Information System (INIS)

    Ioki, K.; Johnson, G.; Shimizu, K.; Williamson, D.

    1995-01-01

    The ITER vacuum vessel is a major safety barrier and must support electromagnetic loads during plasma disruptions and vertical displacement events (VDE) and withstand plausible accidents without losing confinement.The vacuum vessel has a double wall structure to provide structural and electrical continuity in the toroidal direction. The inner and outer shells and poloidal stiffening ribs between them are joined by welding, which gives the vessel the required mechanical strength. The space between the shells will be filled with steel balls and plate inserts to provide additional nuclear shielding. Water flowing in this space is required to remove nuclear heat deposition, which is 0.2-2.5% of the total fusion power. The minor and major radii of the tokamak are 3.9 m and 13 m respectively, and the overall height is 15 m. The total thickness of the vessel wall structure is 0.4-0.7 m.The inboard and outboard blanket segments are supported from the vacuum vessel. The support structure is required to withstand a large total vertical force of 200-300 MN due to VDE and to allow for differential thermal expansion.The first candidate for the vacuum vessel material is Inconel 625, due to its higher electric resistivity and higher yield strength, even at high temperatures. Type 316 stainless steel is also considered a vacuum vessel material candidate, owing to its large database and because it is supported by more conventional fabrication technology. (orig.)

  14. Assessment of reactor vessel integrity (ARVI)

    Energy Technology Data Exchange (ETDEWEB)

    Sehgal, B.R. E-mail: sehgal@ne.kth.se; Theerthan, A.; Giri, A.; Karbojian, A.; Willschuetz, H.G.; Kymaelaeinen, O.; Vandroux, S.; Bonnet, J.M.; Seiler, J.M.; Ikkonen, K.; Sairanen, R.; Bhandari, S.; Buerger, M.; Buck, M.; Widmann, W.; Dienstbier, J.; Techy, Z.; Kostka, P.; Taubner, R.; Theofanous, T.; Dinh, T.N

    2003-04-01

    The cost-shared project ARVI (assessment of reactor vessel integrity) involves a total of nine organisations from Europe and USA. The objective of the ARVI Project is to resolve the safety issues that remain unresolved for the melt vessel interaction phase of the in-vessel progression of a severe accident. The work consists of experiments and analysis development. Four tests were performed in the EC-FOREVER Programme, in which failure was achieved in-vessels employing the French pressure vessel steel. The tests were analysed with the commercial code ANSYS-Multiphysics, and the codes SYSTUS+ and PASULA, and quite good agreement was achieved for the failure location. Natural convection experiments in stratified pools have been performed in the SIMECO and the COPO facilities, which showed that much greater heat is transferred downwards for immiscible layers or before layers mix. A model for gap cooling and a set of simplified models for the system codes have been developed. MVITA code calculations have been performed for the Czech and Hungarian VVERs, towards evaluation of the in-vessel melt retention accident management scheme. Tests have been performed at the ULPU facility with organised flow for vessel external cooling. Considerable enhancement of the critical heat flux (CHF) was obtained. The ARVI Project has reached the halfway stage. This paper presents the results obtained thus far from the project.

  15. Flexible Composite-Material Pressure Vessel

    Science.gov (United States)

    Brown, Glen; Haggard, Roy; Harris, Paul A.

    2003-01-01

    A proposed lightweight pressure vessel would be made of a composite of high-tenacity continuous fibers and a flexible matrix material. The flexibility of this pressure vessel would render it (1) compactly stowable for transport and (2) more able to withstand impacts, relative to lightweight pressure vessels made of rigid composite materials. The vessel would be designed as a structural shell wherein the fibers would be predominantly bias-oriented, the orientations being optimized to make the fibers bear the tensile loads in the structure. Such efficient use of tension-bearing fibers would minimize or eliminate the need for stitching and fill (weft) fibers for strength. The vessel could be fabricated by techniques adapted from filament winding of prior composite-material vessels, perhaps in conjunction with the use of dry film adhesives. In addition to the high-bias main-body substructure described above, the vessel would include a low-bias end substructure to complete coverage and react peak loads. Axial elements would be overlaid to contain damage and to control fiber orientation around side openings. Fiber ring structures would be used as interfaces for connection to ancillary hardware.

  16. Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels

    Energy Technology Data Exchange (ETDEWEB)

    Wu Wei [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Gastaldi, Dario, E-mail: dario.gastaldi@polimi.it [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy); Yang Ke; Tan Lili [Division of Specialized Materials and Devices, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); Petrini, Lorenza; Migliavacca, Francesco [Laboratory of Biological Structure Mechanics, Structural Engineering Department, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan (Italy)

    2011-12-15

    Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents.

  17. Finite element analyses for design evaluation of biodegradable magnesium alloy stents in arterial vessels

    International Nuclear Information System (INIS)

    Wu Wei; Gastaldi, Dario; Yang Ke; Tan Lili; Petrini, Lorenza; Migliavacca, Francesco

    2011-01-01

    Biodegradable magnesium alloy stents (MAS) can provide a great benefit for diseased vessels and avoid the long-term incompatible interactions between vessels and permanent stent platforms. However, the existing MAS showed insufficient scaffolding to the target vessels due to short degradation time. In this study, a three dimensional finite element model combined with a degradable material model of AZ31 (Al 0.03, Zn 0.01, Mn 0.002 and Mg balance, mass percentage) was applied to three different MAS designs including an already implanted stent (Stent A), an optimized design (Stent B) and a patented stent design (Stent C). One ring of each design was implanted through a simulation in a vessel model then degraded with the changing interaction between outer stent surface and the vessel. Results showed that a proper stent design (Stent B) can lead to an increase of nearly 120% in half normalized recoil time of the vessel compared to the Stent A; moreover, the expectation that the MAS design, with more mass and optimized mechanical properties, can increase scaffolding time was verified numerically. The Stent C has more materials than Stent B; however, it only increased the half normalized recoil time of the vessel by nearly 50% compared to the Stent A because of much higher stress concentration than that of Stent B. The 3D model can provide a convenient design and testing tool for novel magnesium alloy stents.

  18. Offshore wind transport and installation vessel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The initial objective of the project was to complete a feasibility study to determine the viability of an innovative transportation vessel to be deployed in the installation of offshore wind farms. This included the feasibility of providing a stable-working platform that can be used in harsh offshore environments. A study of current installation contractors and their installation equipment was used to provide a preliminary specification for the installation vessel. A typical barge was selected and a number of hydrodynamic analyses were carried out in order to establish it's on course and operational stability. The analysis proved the stability of the vessel during operation was critical and that in order to utilise the crane's full potential a stabilisation system must be employed. The main aim of the work to date was to establish whether it was feasible to use a stabilisation system on the installation vessel. The spud leg FEED study established that it was feasible to use spud legs to stabilise the vessel. In order to achieve the degree of stability required it is necessary to lift the vessel completely out of the water. This was not the original aim of the study but due to the external loads on the hull it was the only viable option. Lifting the vessel out of the water results in the legs and leg casings becoming very large. This has a number of consequences for the final design. Due to large loads on the legs spud cans must be used to avoid bottom penetration, the spud cans increase the draft of the vessel by 2m. The large loads require larger winches and more reeving to be used, this results in larger pumps and motors, all of which have to be housed. The stabilisation system has been proved to be feasible for a large installation vessel, the cost and physical size are however more excessive than first anticipated. (Author)

  19. Reactor vessel using metal oxide ceramic membranes

    Science.gov (United States)

    Anderson, Marc A.; Zeltner, Walter A.

    1992-08-11

    A reaction vessel for use in photoelectrochemical reactions includes as its reactive surface a metal oxide porous ceramic membrane of a catalytic metal such as titanium. The reaction vessel includes a light source and a counter electrode. A provision for applying an electrical bias between the membrane and the counter electrode permits the Fermi levels of potential reaction to be favored so that certain reactions may be favored in the vessel. The electrical biasing is also useful for the cleaning of the catalytic membrane.

  20. A study of reactor vessel integrity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Hoon [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Kim, Jong Kyung; Shin, Chang Ho; Seo, Bo Kyun [Hanyang Univ., Seoul (Korea, Republic of)

    1999-02-15

    The fast neutron fluence at the Reactor Pressure Vessel(RPV) of KNGR designed for 60 years lifetime was calculated by full-scope Monte Carlo simulation for reactor vessel integrity assessment. KNGR core geometry was modeled on a three-dimensional representation of the one-sixteenth of the reactor in-vessel component. Each fuel assemblies were modeled explicitly, and each fuel pins were axially divided into 5 segments. The maximum flux of 4.3 x 10{sup 10} neutrons/cm{sup 2}. sec at the RPV was obtained by tallying neutrons crossing the beltline of inner surface of the RPV.

  1. Structural Analysis of the NCSX Vacuum Vessel

    International Nuclear Information System (INIS)

    Fred Dahlgren; Art Brooks; Paul Goranson; Mike Cole; Peter Titus

    2004-01-01

    The NCSX (National Compact Stellarator Experiment) vacuum vessel has a rather unique shape being very closely coupled topologically to the three-fold stellarator symmetry of the plasma it contains. This shape does not permit the use of the common forms of pressure vessel analysis and necessitates the reliance on finite element analysis. The current paper describes the NCSX vacuum vessel stress analysis including external pressure, thermal, and electro-magnetic loading from internal plasma disruptions and bakeout temperatures of up to 400 degrees centigrade. Buckling and dynamic loading conditions are also considered

  2. Vessel Sewage Discharges: Statutes, Regulations, and Related Laws and Treaties

    Science.gov (United States)

    Vessel sewage discharges can be regulated under multiple statutes, regulations, and laws/treaties, including the Clean Water Act, Title XIV, MARPOL Annex IV and the Vessel General Permit. This page describes how these are applied to vessel sewage.

  3. Evaluation for In-Vessel Retention Capabilities with In-Vessel Injection and External Reactor Vessel Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Seong; Ryu, In Chul; Moon, Young Tae [KEPCO Engineering and Construction Co. Ltd., Deajeon (Korea, Republic of)

    2016-10-15

    If the accident has not progressed to the point of substantial changes in the core geometry, establishing adequate cooling is as straightforward as re-establishing flow through the reactor core. However, if the accident has progressed to the point where the core geometry is substantially altered as a result of material melting and relocation, as was the case in the TMI-2 accident, the means of cooling the debris are not as straightforward. From this time on, the reactor core was either completely or nearly covered by water, with high pressure injection flow initiated shortly after three hours into the accident. However, the core debris was not coolable in this configuration and a substantial quantity of molten core material drained into the bypass region, with approximately twenty metric tons of molten debris draining into the reactor pressure vessel (RPV) lower head. Hence, the core configuration developed at approximately three hours into the accident was not coolable, even submerged in water. The purpose of this paper is to evaluate in-vessel retention capabilities with in-vessel injection (IVI) and external reactor vessel cooling (ERVC) available in a reactor application by using the integrated severe accident analysis code. The MAAP5 models were improved to facilitate evaluation of the in-vessel retention capability of APR1400. In-vessel retention capabilities have been analyzed for the APR1400 using the MAAP5.03 code. The results show that in-vessel retention is feasible when in-vessel injection is initiated within a relatively short time frame under the simulation condition used in the present study.

  4. Evaluation for In-Vessel Retention Capabilities with In-Vessel Injection and External Reactor Vessel Cooling

    International Nuclear Information System (INIS)

    Lee, Jeong Seong; Ryu, In Chul; Moon, Young Tae

    2016-01-01

    If the accident has not progressed to the point of substantial changes in the core geometry, establishing adequate cooling is as straightforward as re-establishing flow through the reactor core. However, if the accident has progressed to the point where the core geometry is substantially altered as a result of material melting and relocation, as was the case in the TMI-2 accident, the means of cooling the debris are not as straightforward. From this time on, the reactor core was either completely or nearly covered by water, with high pressure injection flow initiated shortly after three hours into the accident. However, the core debris was not coolable in this configuration and a substantial quantity of molten core material drained into the bypass region, with approximately twenty metric tons of molten debris draining into the reactor pressure vessel (RPV) lower head. Hence, the core configuration developed at approximately three hours into the accident was not coolable, even submerged in water. The purpose of this paper is to evaluate in-vessel retention capabilities with in-vessel injection (IVI) and external reactor vessel cooling (ERVC) available in a reactor application by using the integrated severe accident analysis code. The MAAP5 models were improved to facilitate evaluation of the in-vessel retention capability of APR1400. In-vessel retention capabilities have been analyzed for the APR1400 using the MAAP5.03 code. The results show that in-vessel retention is feasible when in-vessel injection is initiated within a relatively short time frame under the simulation condition used in the present study

  5. Simulation of In-Vessel Corium Retention through External Reactor Vessel Cooling for SMART using SIMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin-Sung; Son, Donggun; Park, Rae-Joon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Thermal load analysis from the corium pool to the outer reactor vessel in the lower plenum of the reactor vessel is necessary to evaluate the effect of the IVR-ERVC during a severe accident for SMART. A computational code called SIMPLE (Sever Invessel Melt Progression in Lower plenum Environment) has been developed for analyze transient behavior of molten corium in the lower plenum, interaction between corium and coolant, and heat-up and ablation of reactor vessel wall. In this study, heat load analysis of the reactor vessel for SMART has been conducted using the SIMPLE. Transient behavior of the molten corium in the lower plenum and IVR-ERVC for SMART has been simulated using SIMPLE. Heat flux from the corium pool to the outer reactor vessel is concentrated in metallic layer by the focusing effect. As a result, metallic layer shows higher temperature than the oxidic layer. Also, vessel wall of metallic layer has been ablated by the high in-vessel temperature. Ex-vessel temperature of the metallic layer was maintained 390 K and vessel thickness was maintained 14 cm. It means that the reactor vessel integrity is maintained by the IVR-ERVC.

  6. Small vessel vasculitis History, classification, etiology, histopathology, clinic, diagnosis and treatment

    International Nuclear Information System (INIS)

    Iglesias Gamarra, Antonio; Matteson, Eric L; Restrepo, Jose Felix

    2007-01-01

    Small-vessel vasculitis is a convenient descriptor for a wide range of diseases characterized by vascular inflammation of the venules, capillaries, and/or arterioles with pleomorphic clinical manifestations. The classical clinical phenotype is leucocytoclastic vasculitis with palpable purpura, but manifestations vary widely depending upon the organs involved. Histopathologic examination in leucocytoclastic vasculitis reveals angiocentric segmental inflammation, fibrinoid necrosis, and a neutrophilic infiltrate around the blood vessel walls with erythrocyte extravasation. The etiology of small-vessel vasculitis is unknown in many cases, but in others, drugs, post viral syndromes, malignancy, primary vasculitis such as microscopic polyarteritis, and connective tissue disorders are associated, The diagnosis of small- vessel vasculitis relies on a thorough history and physical examination, as well as relevant antibody testing including antinuclear antibody and anti neutrophil cytoplasmic antibody, hepatitis B and C serologies, assessment of complement, immunoglobulins, blood count, serum creatinine liver function tests, urinalysis, radiographic imaging and biopsy. The treatment is based primarily on corticosteroid and immunosuppressive agents

  7. Melanopsin mediates light-dependent relaxation in blood vessels.

    Science.gov (United States)

    Sikka, Gautam; Hussmann, G Patrick; Pandey, Deepesh; Cao, Suyi; Hori, Daijiro; Park, Jong Taek; Steppan, Jochen; Kim, Jae Hyung; Barodka, Viachaslau; Myers, Allen C; Santhanam, Lakshmi; Nyhan, Daniel; Halushka, Marc K; Koehler, Raymond C; Snyder, Solomon H; Shimoda, Larissa A; Berkowitz, Dan E

    2014-12-16

    Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4(-/-) mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ∼430-460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase- and phosphodiesterase 6-dependent but protein kinase G-independent. β-Adrenergic receptor kinase 1 (βARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, light-activated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor.

  8. Device of supporting a vacuum plasma vessel

    International Nuclear Information System (INIS)

    Kanoi, Minoru; Hori, Yasuro.

    1980-01-01

    Purpose: To improve the earthquake-resistance of a vacuum plasma vessel by equalizing the natural vibrations of a vibrating system formed by supporting mechanisms of the respective sectors of the vessel. Constitution: The vacuum plasma vessel is constructed of bellows interposed among a plurality of thick sector-like rings and the rings, which are respectively supported by supporting mechanisms. Thus, the vibrating systems are divided into the rings interposed with the bellows, arms as the supporting mechanisms, and posts. The natural vibrations of these vibrating systems are equalized to each other by suitably adjusting the configurations and the sized of the arms and the posts or the weight or the like of the rings. Therefore, the respective rings become vibrated at the natural vibrations equal to each other so as to largely reduce the stresses produced at both ends of the bellows. Accordingly, it can remarkably improve the earthquake-resistance of the entire plasma vessel. (Sekiya, K.)

  9. 2013 Gulf of Mexico Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  10. 2011 Gulf of Mexico Vessel Tracklines

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  11. Pressure vessel for a BWR type reactor

    International Nuclear Information System (INIS)

    Shimamoto, Yoshiharu.

    1980-01-01

    Purpose: To prevent the retention of low temperature water and also prevent the thermal fatigue of the pressure vessel by making large the curvature radius of a pressure vessel of a feed water sparger fitting portion and accelerating the mixing of low-temperature water at the feed water sparger base and in-pile hot water. Constitution: The curvature radius of the corner of the feed water sparger fitting portion in a pressure vessel is formed largely. In-pile circulating water infiltrates up to the base portion of the feed water sparger to carry outside low-temperature water at the base part, which is mixed with in-pile hot water. Accordingly, low temperature water does not stay at the base portion of the feed water sparger and generation of thermal fatigue in the pressure vessel can be prevented and the safety of the BWR type reactor can be improved. (Yoshino, Y.)

  12. 2013 Pleasure Craft and Sailing Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  13. Large Pelagic Logbook Set Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch and effort for fishing trips that are taken by vessels with a Federal permit issued for the swordfish and sharks under the Highly...

  14. Large Pelagic Logbook Trip Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch and effort for fishing trips that are taken by vessels with a Federal permit issued for the swordfish and sharks under the Highly...

  15. Initial conditioning of the TFTR vacuum vessel

    International Nuclear Information System (INIS)

    Dylla, H.F.; Blanchard, W.R.; Krawchuk, R.B.; Hawryluk, R.J.; Owens, D.K.

    1984-01-01

    We report on the initial conditioning of the Tokamak Fusion Test Reactor (TFTR) vacuum vessel prior to the initiation of first plasma discharges, and during subsequent operation with high power ohmically-heated plasmas. Following evacuation of the 86 m 3 vessel with the 10 4 1/s high vacuum pumping system, the vessel was conditioned by a 15 A dc glow discharge in H 2 at a pressure of 5 mTorr. Rapid-pulse discharge cleaning was used subsequently to preferentially condition the graphite plasma limiters. The effectiveness of the discharge cleaning was monitored by measuring the exhaust rates of the primary discharge products (CO/C 2 H 4 , CH 4 , and H 2 O). After 175 hours of glow discharge treatment, the equivalent of 50 monolayers of C and O was removed from the vessel, and the partial pressures of impurity gases were reduced to the range of 10 -9 -10 -10 Torr

  16. 75 FR 56015 - Vessel Inspection Alternatives

    Science.gov (United States)

    2010-09-15

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 46 CFR Part 8 Vessel Inspection Alternatives CFR... Certificate; (ii) International Tonnage Certificate; (iii) Cargo Ship Safety Construction Certificate; (iv) Cargo Ship Safety Equipment Certificate; and (v) International Oil Pollution Prevention Certificate; and...

  17. Qualification of anticorrosive coatings in nuclear vessels

    International Nuclear Information System (INIS)

    Perez Flores, C.

    1985-01-01

    Test qualifications of the behavior of anticorrosive coating systems used in nuclear vessels in service and under the accident conditions of radiation decontamination, steam chemical resistance, thermal conductivity, weathering accelerated aging are presented and discussed. (author)

  18. Sealing analysis for nuclear vessels of PWR

    International Nuclear Information System (INIS)

    Qu Jiadi; Dou Yikang

    1988-01-01

    The fundamental equations of sealing analysis for vessels are given and a computer program named SMEC, which considers the change of stud loading, the elastic contact between flange mating surfaces and the transient thermal effects, is developed accordingly. The SMEC is verified by several test. On the basis of analysis, a new concept of classifying vessels into three types according to increasing or decreasing of bolt loading with increasing pressure is suggested. Type-A vessel is that in which the bolt loading increases monotonically with increasing pressure, while in type-B, the bolt loading decreases monotonically, and in type-C, the bolt loading changes nonmonotonically. It is important for vessel design to distinguish the types through analysis. The sealing mechanism is also discussed

  19. Swarm Manipulation of Large Surface Vessels

    National Research Council Canada - National Science Library

    Smith, Erik T

    2007-01-01

    The goal of this Trident project was to develop an independent control scheme to allow a team of autonomous tugboats to move a large disabled vessel, such as a barge, to a desired position and orientation...

  20. Some aspects of reactor pressure vessel integrity

    International Nuclear Information System (INIS)

    Korosec, D.; Vojvodic, G.J.

    1996-01-01

    Reactor pressure vessel of the pressurized water reactor nuclear power plant is the subject of extreme interest due to the fact that presents the pressure boundary of the reactor coolant system, which is under extreme thermal, mechanical and irradiation effects. Reactor pressure vessel by itself prevents the release of fission products to the environment. Design, construction and in-service inspection of such component is governed by strict ASME rules and other forms of administrative control. The reactor pressure vessel in nuclear power plant Kriko is designed and constructed in accordance with related ASME rules. The in-service inspection program includes all requests presented in ASME Code section XI. In the present article all major requests for the periodic inspections of reactor pressure vessel and fracture mechanics analysis are discussed. Detailed and strict fulfillment of all prescribed provisions guarantee the appropriate level of nuclear safety. (author)

  1. Atlantic Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in South Atlantic (Florida to Maryland) waters from 1994 to the...

  2. Method to moor an offshore operating vessel

    Energy Technology Data Exchange (ETDEWEB)

    Flory, J.F.

    1983-01-24

    A vessel such as a storage vessel is permanently moored, by means such as a yoke pivoted on the forecastle of the vessel, to a mooring leg, e.g. a riser or anchor chain, which is attached to a base located on the ocean floor. Mounted on the vessel is tension exsisting means, for example, counterweights, springs, winches, or the like, operably connected with the mooring leg for applying tension thereto such as by lifting the yoke. The top of the mooring leg is connected to the end of the yoke through a mooring swivel and a gimbaled mooring table or a universal joint. A fluid swivel may be located above the mooring table or about a load-carrying shaft connected to the mooring leg. 8 drawings.

  3. Caribbean Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in Caribbean waters conducted during 2000-2001. These surveys were...

  4. Advanced toroidal facility vaccuum vessel stress analyses

    International Nuclear Information System (INIS)

    Hammonds, C.J.; Mayhall, J.A.

    1987-01-01

    The complex geometry of the Advance Toroidal Facility (ATF) vacuum vessel required special analysis techniques in investigating the structural behavior of the design. The response of a large-scale finite element model was found for transportation and operational loading. Several computer codes and systems, including the National Magnetic Fusion Energy Computer Center Cray machines, were implemented in accomplishing these analyses. The work combined complex methods that taxed the limits of both the codes and the computer systems involved. Using MSC/NASTRAN cyclic-symmetry solutions permitted using only 1/12 of the vessel geometry to mathematically analyze the entire vessel. This allowed the greater detail and accuracy demanded by the complex geometry of the vessel. Critical buckling-pressure analyses were performed with the same model. The development, results, and problems encountered in performing these analyses are described. 5 refs., 3 figs

  5. Caribbean ST Thomas trap Logbook Survey (Vessels)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains catch (landed catch) and effort for fishing trips made by vessels fishing in St. Thomas. The catch and effort data for the entire trip are...

  6. 2011 Pleasure Craft Sailing Vessel Density

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and...

  7. Final processing vessel for radioactive waste

    International Nuclear Information System (INIS)

    Tejima, Takaya; Hiraki, Akimitsu.

    1989-01-01

    An inorganic inner layer comprising dense inorganic material such as organic polymer-impregnated concretes is formed to about 10 - 50 mm in average thickness at the inside of a metal vessel. Further, the surface of the vessel is formed as a flat surface with no or only small reinforcing protrusions. Thus, if the final processing vessel should be dropped during transportation or handling by mistake, since impact shocks do not concentrate to protrusions as usual, no local stress concentration occurs to the inorganic inner liner layer. Accordingly, the risk of rapture can be reduced greatly. Further, since impact shock resistance layer put between the metal vessel and the inorganic inner liner layer absorbs shocks, a further sufficient strength can be obtained against dropping accident. (T.M.)

  8. Fatigue evaluation in reactor vessel components

    International Nuclear Information System (INIS)

    Mattar Neto, Miguel; Miranda, Carlos A. de J.

    1994-01-01

    This paper presents a sequence of increasing complexity forms of evaluating fatigue damage of nuclear pressure vessel components caused by cycling loadings. Examples are included in order to illustrate such procedures. (author)

  9. MRA of fibromuscular dysplasia in cervical vessels

    International Nuclear Information System (INIS)

    Link, J.; Steffens, J.C.; Mueller-Huelsbeck, S.; Brossmann, J.; Heller, M.

    1996-01-01

    In 386 selective angiograms of cervical vessels fibromuscular dysplasia was revealed in 4 female patients in the age of 30-54 years. FMD was located in the carotid artery (n=5) and in the vertebral artery (n=2) with a total of 8 lesions. 6/8 of the lesions of the seven cervical vessels were located typically in the mid cervical portion of the vessels and 2/6 lesions were located in the atlas loop of the vertebral artery. 4 lesions showed moderate stenosis and 4 vessels showed only mild stenosis. These patterns which demonstrated the typical morphology of fibromuscular dysplasia with alternating irregular zones of widening and narrowing were evaluated well with MR angiography, the others were missed. (orig./MG) [de

  10. A case of small vessel vasculitis

    Directory of Open Access Journals (Sweden)

    Madhulika Mahashabde

    2014-01-01

    We are reporting a case of un-specified small vessel vasculitis, which was diagnosed on the basis of positive perinuclear anti neutrophil cytoplasmic antibodies (ANCA P MPO done by Enzyme Linked Immunosorbent Assay (ELISA.

  11. Subconjunctival Hemorrhage (Broken Blood Vessel in Eye)

    Science.gov (United States)

    Subconjunctival hemorrhage (broken blood vessel in eye) Overview A subconjunctival hemorrhage (sub-kun-JUNK-tih-vul HEM-uh-ruj) ... may not even realize you have a subconjunctival hemorrhage until you look in the mirror and notice ...

  12. TMI-2 Vessel Investigation Project integration report

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, J. R.; Rempe, J. L.; Stickler, L. A.; Korth, G. E.; Diercks, D. R.; Neimark, L. A.; Akers, D W; Schuetz, B. K.; Shearer, T L; Chavez, S. A.; Thinnes, G. L.; Witt, R. J.; Corradini, M L; Kos, J. A. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

    1994-03-01

    The Three Mile Island Unit 2 (TMI-2) Vessel Investigation Project (VIP) was an international effort that was sponsored by the Nuclear Energy Agency of the Organization for Economic Cooperation and Development. The primary objectives of the VIP were to extract and examine samples from the lower head and to evaluate the potential modes of failure and the margin of structural integrity that remained in the TMI-2 reactor vessel during the accident. This report presents a summary of the major findings and conclusions that were developed from research during the VIP. Results from the various elements of the project are integrated to form a cohesive understanding of the vessel`s condition after the accident.

  13. Wine vessels (Vasa vinaria in roman law

    Directory of Open Access Journals (Sweden)

    Aličić Samir

    2017-01-01

    Full Text Available The notion of 'wine vessels' in Roman law comprises all the winecontaining recipients. There is no legal standardization of wine vessels by means of volume, and although the terms amphora, urna and culleus are used to designate both the vessels and the units of measure, these are two different meanings of the terms. In regard of the question, whether the vessels make appurtenance of the wine, jurisprudents of proculean school divided them in two categories. In the first category are those that follow legal status of wine, usually amphoras and other jars (cadi which are used for 'packaging', i. e. 'bottling' of the wine. The second category make mostly vats (cuppae and ceramic cisterns (dolia, which don't follow legal status of wine, making instead part of farming equipment of a landed property (instrumentum fundi and it's appurtenance. But, the roman jurists are not consistent regarding criteria for distinguishing these two categories.

  14. Conjugate heat transfer analysis for in-vessel retention with external reactor vessel cooling

    International Nuclear Information System (INIS)

    Park, Jong-Woon; Bae, Jae-ho; Song, Hyuk-Jin

    2016-01-01

    Highlights: • A conjugate heat transfer analysis method is applied for in-vessel corium retention. • 3D heat diffusion has a formidable effect in alleviating focusing heat load from metallic layer. • The focusing heat load is decreased by about 2.5 times on the external surface. - Abstract: A conjugate heat transfer analysis method for the thermal integrity of a reactor vessel under external reactor vessel cooling conditions is developed to resolve light metal layer focusing effect issue for in-vessel retention. The method calculates steady-state three-dimensional temperature distribution of a reactor vessel using coupled conjugate heat transfer between in-vessel three-layered stratified corium (metallic pool, oxide pool and heavy metal and polar-angle dependent boiling heat transfer at the outer surface of a reactor vessel). The three-layer corium heat transfer model is utilizing lumped-parameter thermal-resistance circuit method. For the ex-vessel boiling boundary conditions, nucleate, transition and film boiling are considered. The thermal integrity of a reactor vessel is addressed in terms of heat flux at the outer-most nodes of the vessel and remaining thickness profile. The vessel three-dimensional heat conduction is validated against a commercial code. It is found that even though the internal heat flux from the metal layer goes far beyond critical heat flux (CHF) the heat flux from the outermost nodes of the vessel may be maintained below CHF due to massive vessel heat diffusion. The heat diffusion throughout the vessel is more pronounced for relatively low heat generation rate in an oxide pool. Parametric calculations are performed considering thermal conditions such as peak heat flux from a light metal layer, heat generation in an oxide pool and external boiling conditions. The major finding is that the most crucial factor for success of in-vessel retention is not the mass of the molten light metal above the oxide pool but the heat generation rate

  15. Results of reactor pressure vessels ISI

    International Nuclear Information System (INIS)

    Cepcek, S.

    1994-01-01

    To find out the possible influence of the annealing process to reactor pressure vessel integrity, a large in-service inspection programme has been implemented as an associated activity to reactor pressure vessel annealing. In this paper the approach to the RPV in-service inspection is shown. Also, the main results and conclusions following in-service inspection are presented. (author). 3 refs, 1 fig

  16. Analysis of nuclear reactor pressure vessel flanges

    International Nuclear Information System (INIS)

    Oliveira, C.A.N. de; Augusto, O.B.

    1985-01-01

    This work proposes a methodology for the structural analysis of high diameter nuclear reactor pressure vessel flanges. In the analysis the vessel is divided into shell-of-revolution elements, the flanges are represented by rigid rings, and the bolts are treated as beams. The flexibility method is used for solving the problem, and the results are compared with results obtained by the finite element method. (Author) [pt

  17. Reactor vessel nozzle cracks: a photoelastic study

    International Nuclear Information System (INIS)

    Smith, C.W.

    1979-01-01

    A method consisting of a marriage between the ''frozen stress'' photoelastic approach and the local stress field equations of linear elastic fracture mechanics for estimating stress intensity factor distributions in three dimensional, finite cracked body problems is reviewed and extensions of the method are indicated. The method is then applied to the nuclear reactor vessel nozzle corner crack problem for both Intermediate Test Vessel and Boiling Water Reactor geometries. Results are compared with those of other investigators. 35 refs

  18. Proof testing of an explosion containment vessel

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, E.D. [Esparza (Edward D.), San Antonio, TX (United States); Stacy, H.; Wackerle, J. [Los Alamos National Lab., NM (United States)

    1996-10-01

    A steel containment vessel was fabricated and proof tested for use by the Los Alamos National Laboratory at their M-9 facility. The HY-100 steel vessel was designed to provide total containment for high explosives tests up to 22 lb (10 kg) of TNT equivalent. The vessel was fabricated from an 11.5-ft diameter cylindrical shell, 1.5 in thick, and 2:1 elliptical ends, 2 in thick. Prior to delivery and acceptance, three types of tests were required for proof testing the vessel: a hydrostatic pressure test, air leak tests, and two full design charge explosion tests. The hydrostatic pressure test provided an initial static check on the capacity of the vessel and functioning of the strain instrumentation. The pneumatic air leak tests were performed before, in between, and after the explosion tests. After three smaller preliminary charge tests, the full design charge weight explosion tests demonstrated that no yielding occurred in the vessel at its rated capacity. The blast pressures generated by the explosions and the dynamic response of the vessel were measured and recorded with 33 strain channels, 4 blast pressure channels, 2 gas pressure channels, and 3 displacement channels. This paper presents an overview of the test program, a short summary of the methodology used to predict the design blast loads, a brief description of the transducer locations and measurement systems, some of the hydrostatic test strain and stress results, examples of the explosion pressure and dynamic strain data, and some comparisons of the measured data with the design loads and stresses on the vessel.

  19. Design concept for vessels and heat exchangers

    International Nuclear Information System (INIS)

    Elfmann, W.; Ferrari, L.D.B.

    1981-01-01

    A design concept for vessels and heat exchangers against internal and external loads resulting from normal operation and accident is shown. A definition and explanation of the operating conditions and stress levels are given. A description of the type of analysis (stress, fatigue, deformation, stability, earthquake and vibration) is presented in detail, also including technical guidelines which are used for the vessels and heat exchangers and their individual structure parts. (Author) [pt

  20. Magnetic resonance imaging of the heart and great vessels

    International Nuclear Information System (INIS)

    Naitoh, Hiroaki; Nishimura, Tsunehiko; Takamiya, Makoto; Kozuka, Takahiro.

    1985-01-01

    About sixty subjects with normal heart or various cardiovascular diseases were examined with 0.35 or 1.5 T superconductive magnetic resonance imaging (MRI) system, and ECG-gated spin-echo multislice technique was used to evaluate cardiovascular anatomy. MRI accurately demonstrated ventricular wall thinning caused by myocardial infarction and asymmetric ventricular hypertrophy owing to cardiomyopathy. Rheumatic valvular thickening, congenital cardiac malformations, aortic aneurysm and dissection were also clearly demonstrated by gated MRI without the use of any contrast media. MRI was shown to be an excellent non-invasive imaging modality for evaluation of pathoanatomy of the heart and great vessels. (author)