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Sample records for 3he-mri study lacunarity

  1. Progression of emphysema in a 12-month hyperpolarized 3He-MRI study: lacunarity analysis provided a more sensitive measure than standard ADC analysis

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva;

    2009-01-01

    results. The lacunarity hypothesis was tested and calculated from the data using a range of 2 x 2 x 2 to 6 x 6 x 6 voxels, and the average was calculated. RESULTS: There was no change in the mean ADC at either lung volume in any subject over the 6- or 12-month period. FRC and residual volume increased...

  2. Hyperpolarised 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    During recent years, magnetic resonance imaging (MRI) using hyperpolarised (HP) 3He gas has emerged as a promising new method for the imaging of lung ventilation. However, systematic comparisons with nuclear medicine techniques have not yet been performed. The aim of this study was to compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed. The three scans were scored visually as percentage of non-ventilated/diseased lung, and a computer-based objective measure of the ventilated volume in HP 3He MRI and 81mKr SPECT and an emphysema index in HRCT were calculated. We found a good correlation between HP 3He MRI and 81mKr SPECT for both visual defect score (r=0.80, p81mKr SPECT (the score on HP 3He MRI was one-third less than that on 81mKr SPECT), but the difference was reduced after normalisation for different breathing depths (HP 3He MRI at total lung capacity; 81mKr SPECT at tidal breathing at functional residual capacity). HP 3He MRI provides detailed ventilation distribution images and defect scores are comparable on HP 3He MRI and 81mKr SPECT. Additionally, new insights into the regional pulmonary microstructure via the apparent diffusion coefficient measurements are provided by HP 3He MRI. HP 3He MRI is a promising new diagnostic tool for the assessment of ventilation distribution. (orig.)

  3. 3He-MRI of pulmonary ventilation: First clinical applications

    Purpose of the study is the visualisation of normal pulmonary ventilation in healthy volunteers and the evaluation of abnormalities in patients with different lung diseases using 3He magnetic resonance imaging (3He-MRI). Material und methods: Hyperpolarised 3He gas (V=300 ml, p=3x105 Pa, polarised to 35-45% by optical pumping, provided in special glass cells) was inhaled by eight healthy volunteers and ten patients with different lung diseases. A 3 D FLASH sequence (TR=11.8 ms; TE=5 ms; matrix 144x256, FOV 350 mm, section thickness 7-10 mm, coronal orientation) was performed in a single breath-hold (22-42 s). Clinical and radiological examinations were available for correlation. Results: The studies were successfully carried out in 8/8 volunteers and in 8/10 patients. The central airways were constantly visualised with intermediate to high signal instensity. The lung parenchyma of volunteers with normal ventilatory function showed rather homogeneous intermediate to high signal, whereas patients with chronic abstructive lung disease and/or pneumonia presented severe signal inhomogeneitises. Space-occupying lesions and pleural effusion caused large areas with little or no signal. The represented the lesion and adjacent ventilatory disturbances whose extent had not been presumed from chest X-ray or CT. The spatial resolution was higher than in ventilation scintigraphy. Conclusion: 3He MRI is a promising new modality for the assessment of pulmonary ventilation and its anormalies. (orig.)

  4. Oxygen-sensitive {sup 3}He-MRI in bronchiolitis obliterans after lung transplantation

    Gast, Klaus K. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, Mainz (Germany); Biedermann, Alexander [Klinikum der Johannes Gutenberg-Universitaet, 3. Medizinische Klinik, Pulmonologie, Mainz (Germany); Herweling, Annette [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Anaesthesiologie, Mainz (Germany); Schreiber, Wolfgang G. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, MR-Physik, Mainz (Germany); Schmiedeskamp, Joerg [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Mayer, Eckhard [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Mainz (Germany); Heussel, Claus P. [Abteilung fuer Radiologie, Thoraxklinik Heidelberg, Heidelberg (Germany); Markstaller, Klaus; Eberle, Balthasar [Inselspital/Universitaetsspital, Klinik fuer Anaesthesiologie, Bern (Switzerland); Kauczor, Hans-Ulrich [Radiologie, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2008-03-15

    Oxygen-sensitive {sup 3}He-MRI was studied for the detection of differences in intrapulmonary oxygen partial pressure (pO{sub 2}) between patients with normal lung transplants and those with bronchiolitis obliterans syndrome (BOS). Using software developed in-house, oxygen-sensitive {sup 3}He-MRI datasets from patients with normal lung grafts (n = 8) and with BOS (n = 6) were evaluated quantitatively. Datasets were acquired on a 1.5-T system using a spoiled gradient echo pulse sequence. Underlying diseases were pulmonary emphysema (n = 10 datasets) and fibrosis (n = 4). BOS status was verified by pulmonary function tests. Additionally, {sup 3}He-MRI was assessed blindedly for ventilation defects. Median intrapulmonary pO{sub 2} in patients with normal lung grafts was 146 mbar compared with 108 mbar in patients with BOS. Homogeneity of pO2 distribution was greater in normal grafts (standard deviation pO2 34 versus 43 mbar). Median oxygen decrease rate during breath hold was higher in unaffected patients (-1.75 mbar/s versus -0.38 mbar/s). Normal grafts showed fewer ventilation defects (5% versus 28%, medians). Oxygen-sensitive {sup 3}He-MRI appears capable of demonstrating differences of intrapulmonary pO2 between normal lung grafts and grafts affected by BOS. Oxygen-sensitive {sup 3}He-MRI may add helpful regional information to other diagnostic techniques for the assessment and follow-up of lung transplant recipients. (orig.)

  5. Longitudinal assessment of treatment effects on pulmonary ventilation using 1H/3He MRI multivariate templates

    Tustison, Nicholas J.; Contrella, Benjamin; Altes, Talissa A.; Avants, Brian B.; de Lange, Eduard E.; Mugler, John P.

    2013-03-01

    The utitlity of pulmonary functional imaging techniques, such as hyperpolarized 3He MRI, has encouraged their inclusion in research studies for longitudinal assessment of disease progression and the study of treatment effects. We present methodology for performing voxelwise statistical analysis of ventilation maps derived from hyper­ polarized 3He MRI which incorporates multivariate template construction using simultaneous acquisition of IH and 3He images. Additional processing steps include intensity normalization, bias correction, 4-D longitudinal segmentation, and generation of expected ventilation maps prior to voxelwise regression analysis. Analysis is demonstrated on a cohort of eight individuals with diagnosed cystic fibrosis (CF) undergoing treatment imaged five times every two weeks with a prescribed treatment schedule.

  6. Hyperpolarised {sup 3}He MRI and {sup 81m}Kr SPECT in chronic obstructive pulmonary disease

    Stavngaard, Trine [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet (Denmark); Copenhagen University Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark); Soegaard, Lise Vejby; Hanson, Lars G. [Copenhagen University Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark); Mortensen, Jann; Berthelsen, Anne Kiil [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet (Denmark); Schmiedeskamp, Joerg [Johannes Gutenberg Universitaet, Institut fuer Physik, Mainz (Germany); Dirksen, Asger [Gentofte University Hospital, Department of Respiratory Medicine, Hellerup (Denmark)

    2005-04-01

    During recent years, magnetic resonance imaging (MRI) using hyperpolarised (HP) {sup 3}He gas has emerged as a promising new method for the imaging of lung ventilation. However, systematic comparisons with nuclear medicine techniques have not yet been performed. The aim of this study was to compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. HP {sup 3}He MRI, {sup 81m}Kr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed. The three scans were scored visually as percentage of non-ventilated/diseased lung, and a computer-based objective measure of the ventilated volume in HP {sup 3}He MRI and {sup 81m}Kr SPECT and an emphysema index in HRCT were calculated. We found a good correlation between HP {sup 3}He MRI and {sup 81m}Kr SPECT for both visual defect score (r=0.80, p<0.0001) and objective estimate of ventilation (r=0.45, p=0.0157). In addition, both scans were well correlated with reference methods for the diagnosis of emphysema (pulmonary function test and HRCT). The defect scores were largest on {sup 81m}Kr SPECT (the score on HP {sup 3}He MRI was one-third less than that on {sup 81m}Kr SPECT), but the difference was reduced after normalisation for different breathing depths (HP {sup 3}He MRI at total lung capacity; {sup 81m}Kr SPECT at tidal breathing at functional residual capacity). HP {sup 3}He MRI provides detailed ventilation distribution images and defect scores are comparable on HP {sup 3}He MRI and {sup 81m}Kr SPECT. Additionally, new insights into the regional pulmonary microstructure via the apparent diffusion coefficient measurements are provided by HP {sup 3}He MRI. HP {sup 3}He MRI is a promising new diagnostic tool for the assessment of ventilation distribution. (orig.)

  7. Two-dimensional and three-dimensional oxygen mapping by 3He-MRI validation in a lung phantom

    The aim of this study was to validate oxygen-sensitive 3He-MRI in noninvasive determination of the regional, two- and three-dimensional distribution of oxygen partial pressure. In a gas-filled elastic silicon ventilation bag used as a lung phantom, oxygen sensitive two- and three-dimensional 3He-MRI measurements were performed at different oxygen concentrations which had been equilibrated in a range of normal and pathologic values. The oxygen partial pressure distribution was determined from 3He-MRI using newly developed software allowing for mapping of oxygen partial pressure. The reference bulk oxygen partial pressure inside the phantom was measured by conventional respiratory gas analysis. In two-dimensional measurements, image-based and gas-analysis results correlated with r=0.98; in three-dimensional measurements the between-methods correlation coefficient was r=0.89. The signal-to-noise ratio of three-dimensional measurements was about half of that of two-dimensional measurements and became critical (below 3) in some data sets. Oxygen-sensitive 3He-MRI allows for noninvasive determination of the two- and three-dimensional distribution of oxygen partial pressure in gas-filled airspaces. (orig.)

  8. Hyperpolarized 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    Stavngaard, Trine; Søgaard, Lise; Mortensen, J;

    2005-01-01

    compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. METHODS: HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed. The...... visual defect score (r=0.80, p<0.0001) and objective estimate of ventilation (r=0.45, p=0.0157). In addition, both scanswere well correlated with reference methods for the diagnosis of emphysema (pulmonary function test and HRCT). The defect scores were largest on 81mKr SPECT (the score on HP 3He MRI was...... defect scores are comparable on HP 3He MRI and 81mKr SPECT. Additionally, new insights into the regional pulmonary microstructure via the apparent diffusion coefficient measurements are provided by HP 3He MRI. HP 3He MRI is a promising new diagnostic tool for the assessment of ventilation distribution...

  9. Improved Technique for Measurement of Regional Fractional Ventilation by Hyperpolarized 3He MRI

    Emami, Kiarash; Kadlecek, Stephen J.; Woodburn, John M.; Zhu, Jianliang; Yu, Jiangsheng; Vahdat, Vahid; Pickup, Stephen; Ishii, Masaru; Rizi, Rahim R.

    2010-01-01

    Quantitative measurement of regional lung ventilation is of great significance in assessment of lung function in many obstructive and restrictive pulmonary diseases. A new technique for regional measurement of fractional ventilation using hyperpolarized 3He MRI is proposed, addressing the shortcomings of an earlier approach that limited its use to small animals. The new approach allows for the acquisition of similar quantitative maps over a shortened period and requires substantially less 3He...

  10. Lacunar versus non-lacunar syndromes.

    Micheli, Sara; Corea, Francesco

    2012-01-01

    Small-vessel disease is the accepted most frequent cause of lacunar stroke. The main clinical features seen with lacunar infarcts are motor and/or sensitive deficit, ataxic sign, without cortical involvement. A lacunar syndrome is generally the result of a small deep infarct within the territory of a single perforating artery with the maximum diameter on imaging of 15 mm. Recent studies have demonstrated alternative causes of lacunar stroke other than small-vessel disease (e.g. cardio embolism, atherosclerosis or other causes), especially in large lacunae, with a potential relevance on functional outcome. These findings suggest that lacunar stroke is not always a benign disease. Moreover, clinical features may be significant in terms of disability in lacunae in close proximity to crucial anatomical site. The following chapter reports the classical lacunar syndrome and discusses the debated etiology of lacunar stroke. PMID:22377873

  11. Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI

    Yu, Jiangsheng; Law, Michelle; Kadlecek, Stephen; Emami, Kiarash; Ishii, Masaru; Stephen, Michael; Woodburn, John M.; Vahdat, Vahid; Rizi, Rahim R.

    2009-01-01

    Hyperpolarized 3He (HP 3He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional and non-invasive way. Structural HP 3He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP 3He pulmonary partial pressure of oxygen (pO2) imaging measures the oxygen transfer efficiency between the lung and blood stream. Although both parameters are affected in chroni...

  12. Clinical predictors of lacunar syndrome not due to lacunar infarction

    Comes Emili

    2010-05-01

    Full Text Available Background Lacunar syndrome not due to lacunar infarct is poorly characterised. This single centre, retrospective study was conducted to describe the clinical characteristics of patients with lacunar syndrome not due to lacunar infarct and to identify clinical predictors of this variant of lacunar stroke. Methods A total of 146 patients with lacunar syndrome not due to lacunar infarction were included in the "Sagrat Cor Hospital of Barcelona Stroke Registry" during a period of 19 years (1986-2004. Data from stroke patients are entered in the stroke registry following a standardized protocol with 161 items regarding demographics, risk factors, clinical features, laboratory and neuroimaging data, complications and outcome. The characteristics of these 146 patients with lacunar syndrome not due to lacunar infarct were compared with those of the 733 patients with lacunar infarction. Results Lacunar syndrome not due to lacunar infarct accounted for 16.6% (146/879 of all cases of lacunar stroke. Subtypes of lacunar syndromes included pure motor stroke in 63 patients, sensorimotor stroke in 51, pure sensory stroke in 14, atypical lacunar syndrome in 9, ataxic hemiparesis in 5 and dysarthria-clumsy hand in 4. Valvular heart disease, atrial fibrillation, sudden onset, limb weakness and sensory symptoms were significantly more frequent among patients with lacunar syndrome not due to lacunar infarct than in those with lacunar infarction, whereas diabetes was less frequent. In the multivariate analysis, atrial fibrillation (OR = 4.62, sensorimotor stroke (OR = 4.05, limb weakness (OR = 2.09, sudden onset (OR = 2.06 and age (OR = 0.96 were independent predictors of lacunar syndrome not due to lacunar infarct. Conclusions Although lacunar syndromes are highly suggestive of small deep cerebral infarctions, lacunar syndromes not due to lacunar infarcts are found in 16.6% of cases. The presence of sensorimotor stroke, limb weakness and sudden onset in a patient

  13. A software tool for analysis and quantification of regional pulmonary ventilation using dynamic hyperpolarised-3He-MRI

    Purpose: 3He-MRI is able to visualize the regional distribution of lung ventilation with a temporal and spatial resolution so far unmatched by any other technique. The main of the study was the development of a new software tool for quantification of dynamic ventilation parameters in absolute physical units. Materials and Methods: During continuous breathing, a bolus of hyperpolarized 3He (300 ml) was applied at inspiration and a series of 168 coronal projection images simultaneously acquired using a 2D FLASH-sequence. Postprocessing software was developed to analyze the 3He distribution in the lung. After correction for lung motion, several ventilation parameters (rise time, delay time, 3He amount and 3He peak flow) were calculated. Due to normalization of signal intensities, these parameters are presented in absolute physical units. The data sets were analyzed on a ROI basis as well as on a pixel-by-pixel basis. Results: Using the developed software, the measurements were analyzed in 6 lung-healthy volunteers, in one patient after lung transplantation, and in one patient with lung emphysema. The volunteers' parameter maps of the pixel-based analysis showed an almost homogeneous distribution of the ventilation parameters within the lung. In the parameter maps of both patients, regions with poor ventilation were observed. Conclusion: The developed software permits an objective and quantitative analysis of regional lung ventilation in absolute physical units. The clinical significance of the parameters, however, has to be determined in larger clinical studies. The software may become valuable in grading and following pulmonary function as well as in monitoring any therapy. (orig.)

  14. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva;

    2008-01-01

    -seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP (3)He-MRI and MSCT. Mean age was 55 (+/-12) years, 18 female and 9 male. Mean ADC from (3)He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0....... Correlations between mean ADC and EI and 15th percentile were both r=0.90 and for MLD r=0.59. There was higher correlation between mean ADC and %predicted DLCO (r=0.90) than between EI and %predicted DLCO (r=0.76). CONCLUSION: HP (3)He-MRI correlates well with density measurements from MSCT and agrees better...

  15. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    Purpose: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium (3He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). Materials and methods: Twenty-seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP 3He-MRI and MSCT. Mean age was 55 (±12) years, 18 female and 9 male. Mean ADC from 3He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. Results: Mean ADC and standard deviation values were 0.392 ± 0.119 cm2/s for the established emphysema group and 0.216 ± 0.046 for the pre-clinical emphysema group. MSCT values for the established emphysema group and pre-clinical emphysema group were: EI (%) 11 ± 12 and 0.4 ± 0.6, respectively; 15th percentile (Hounsfield Units (HU)), -956 ± 25 and -933 ± 13, respectively and MLD (HU) -877 ± 20 and -863 ± 15, respectively. Correlations between mean ADC and EI and 15th percentile were both r = 0.90 and for MLD r = 0.59. There was higher correlation between mean ADC and %predicted DLCO (r = 0.90) than between EI and %predicted DLCO (r = 0.76). Conclusion: HP 3He-MRI correlates well with density measurements from MSCT and agrees better than MSCT with %predicted DLCO which is the PFT most related to emphysema.

  16. Differentiating lacunar stroke from Virchow-Robin space: a preliminary study of FLAIR sequence

    Objective: It is a study of the feasibility of FLAIR sequence in differentiating lacunar stroke from Virchow-Robin space. Method: Brain MRI were retrospectively studied in 50 cases of lacunar stroke and 30 normal people as the control group. MRI examination included SET1WI and FLAIR sequence at transverse section and TSE T2WI at transverse and sagittal section. Result: In all lacunar stroke cases multiple spot lesions at ganglion basilar areas were demonstrated hypointense on T1WI and hyperintense on T2WI. On FLAIR images hyperintense spot lesions were revealed in 30 cases with onset within one month, hypointense areas surrounded by hyper-intense ring or semi-ring were observed in another 9 cases with onset over 1 month, and the above two types of the lesions were demonstrated in 11 cases with repeatedly onset during one year. In comparative group multiple spots at ganglion basilar were revealed hypo-intense on SET1WI and FLAIR sequence, and hyper-intense on TSE T2WI. Conclusion: Differentiating lacunar stroke from Virchow-Robin space is available on FLAIR sequence

  17. Depression in silent lacunar infarction: a cross-sectional study of its association with location of silent lacunar infarction and vascular risk factors

    Wu, Ri-Han; LI Qiang; Tan, Yan; Liu, Xue-Yuan; Huang, Jing

    2014-01-01

    Most previous studies reported a close link between fresh infarcts and post-stroke depression. However, studies on the relation of depression and silent lacunar infarction (SLI) are limited. This study aims to analyze the effects of SLI and the vascular risk factors on depression. A total of 243 patients with SLI were divided into depression and non-depression groups. The presence and location of SLI were evaluated with magnetic resonance imaging. Depression was assessed with the Patient Heal...

  18. Functional {sup 3}He-MRI of the lungs; Funktionelle {sup 3}He-MRT der Lunge

    Gast, K.K.; Wolf, U. [Universitaetsmedizin der Johannes-Gutenberg-Universitaet Mainz, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Mainz (Germany)

    2009-08-15

    Pulmonary diseases have a high health-related and economic significance. {sup 3}He-MRI is an alternative imaging method which can detect ventilatory disturbances with a high sensitivity. The application of different pulse sequences allows static and dynamic assessment of ventilation and bronchial gas flow, non-invasive measurement of intrapulmonary oxygen partial pressure and quantification of pulmonary parenchyma destruction and overinflation. Generally, the method is applicable for obstructive and restrictive ventilatory disturbances but initial approaches also exist for vascular pulmonary diseases. Specific clinical applications remain to be determined but {sup 3}He-MRI is an excellent instrument for the assessment of physiologic and pathophysiologic interrelations in the distribution of ventilation. (orig.) [German] Lungenerkrankungen haben einen hohen gesundheitlichen und volkswirtschaftlichen Stellenwert. Die {sup 3}He-MRT ist eine alternative bildgebende Methode, die sensitiv Ventilationsstoerungen nachweisen kann. Ueber unterschiedliche Pulssequenzen koennen Ventilation und Gasfluesse statisch und dynamisch dargestellt, der intrapulmonale Sauerstoffpartialdruck nichtinvasiv gemessen und die Destruktion und Ueberblaehung des Lungenparenchyms quantifiziert werden. Prinzipiell ist die Methode fuer die Untersuchung obstruktiver und restriktiver Ventilationsstoerungen anwendbar, Ansaetze existieren jedoch auch fuer vaskulaere Lungenerkrankungen. Spezifische klinische Anwendungen fuer die {sup 3}He-MRT muessen noch erarbeitet werden, sie ist jedoch ein hervorragendes Instrument zur Untersuchung physiologischer und pathophysiologischer Zusammenhaenge bei der Ventilationsverteilung. (orig.)

  19. Hyperpolarised 3He MRI versus HRCT in COPD and normal volunteers: PHIL trial

    van Beek, E J R; Dahmen, A M; Stavngaard, T;

    2009-01-01

    ) and age-matched never-smokers. All diagnostic studies were completed in 94 subjects (52 with COPD; 13 with alpha(1)-ATD; 29 healthy subjects; 63 males; and 31 females; median age 62 yrs). The consensus assessment of radiologists, blinded for other test results, estimated nonventilated lung volume (HP...

  20. Emphysematous changes and normal variation in smokers and COPD patients using diffusion 3He MRI

    Introduction: This study aims to quantify global and regional changes of diffusive motion of 3He gas within the lung, as determined by hyperpolarized 3He MR apparent diffusion coefficient (ADC) measurement, in non-smokers, smokers and chronic obstructive pulmonary disease (COPD) patients. Methods: Age-matched groups of six healthy non-smokers, five healthy smokers and five patients with COPD. The experiments were performed with approval from the local Research Ethics Committee. Diffusion imaging was performed following hyperpolarized 3He gas inhalation, producing ADC maps. Mean and standard deviation of the ADCs were used to compare the subject groups and assess regional variations within individuals. Results: The intra-individual standard deviation of ADC in the healthy smokers was significantly larger than that of the non-smoking group (P < 0.02). Compared to the non-smoking group, COPD patients had significantly higher mean and standard deviation of ADC (P < 0.01). The mean ADC in the anterior half of the chest was systematically higher than in the posterior half in the healthy non-smoking subject group. Discussion: This study suggests that there are regional trends in the ADC values of healthy volunteers that may have implications for the clinical interpretation of ADC values. Less homogeneous ADC values have been detected in asymptomatic smokers, indicative of damage to the distal air spaces

  1. Analysis of acute ischemic stroke presenting classic lacunar syndrome. A study by diffusion-weighted MRI

    We retrospectively assessed the pathophysiological features of acute ischemic stroke presenting ''classic'' lacunar syndrome by using diffusion-weighted imaging (DWI). Subjects were 16 patients who were admitted to our hospital within 24 hours of stroke onset and underwent DWI examination on admission. These were divided into three categorical groups; pure motor hemiplegia (PMH) in 8, sensorimotor stroke (SMS) in 7, and dysarthria-clumsy hand syndrome (DCHS) in 1. The fresh responsible lesions were identified by DWI in the perforating territory in 7 patients with PMH and 7 with SMS. Four (one had two possible response lesions; pons and corona radiata) and five patients in the respective groups were diagnosed as lacunar infarction on admission (the largest dimension of the lesion measuring smaller than 15 mm). On the contralateral side to the neurological symptoms, DWI revealed high intensities in cortex, subcortical white matter, and anterior and posterior border zones in the remaining one patient with PMH and in the precentral arterial region in one with DCHS. They were diagnosed as atherothrombotic infarction resulting from the occlusion of the internal carotid artery and cerebral embolism due to atrial fibrillation, respectively. Three patients with PMH showed progressive deterioration after admission and follow-up DWI study in an acute stage revealed enlargement of heir ischemic lesions. The present study suggests that DWI is a useful imaging technique for diagnosis of clinical categories and observation for pathophsiological alteration in the acute ischemic stroke patients with ''classic'' lacunar syndrome. Our results also indicate a necessity to be aware that various types of fresh ischemic lesions other than a single lacune might possibly be developing in cases with this syndrome. (author)

  2. Analysis of acute ischemic stroke presenting classic lacunar syndrome. A study by diffusion-weighted MRI

    Terai, Satoshi; Ota, Kazuki; Tamaki, Kinya [Hakujyuji Hospital, Fukuoka (Japan)

    2002-03-01

    We retrospectively assessed the pathophysiological features of acute ischemic stroke presenting ''classic'' lacunar syndrome by using diffusion-weighted imaging (DWI). Subjects were 16 patients who were admitted to our hospital within 24 hours of stroke onset and underwent DWI examination on admission. These were divided into three categorical groups; pure motor hemiplegia (PMH) in 8, sensorimotor stroke (SMS) in 7, and dysarthria-clumsy hand syndrome (DCHS) in 1. The fresh responsible lesions were identified by DWI in the perforating territory in 7 patients with PMH and 7 with SMS. Four (one had two possible response lesions; pons and corona radiata) and five patients in the respective groups were diagnosed as lacunar infarction on admission (the largest dimension of the lesion measuring smaller than 15 mm). On the contralateral side to the neurological symptoms, DWI revealed high intensities in cortex, subcortical white matter, and anterior and posterior border zones in the remaining one patient with PMH and in the precentral arterial region in one with DCHS. They were diagnosed as atherothrombotic infarction resulting from the occlusion of the internal carotid artery and cerebral embolism due to atrial fibrillation, respectively. Three patients with PMH showed progressive deterioration after admission and follow-up DWI study in an acute stage revealed enlargement of heir ischemic lesions. The present study suggests that DWI is a useful imaging technique for diagnosis of clinical categories and observation for pathophsiological alteration in the acute ischemic stroke patients with ''classic'' lacunar syndrome. Our results also indicate a necessity to be aware that various types of fresh ischemic lesions other than a single lacune might possibly be developing in cases with this syndrome. (author)

  3. A comparative study of symptoms in multiple lacunar state and MRI findings

    A multiple lacunar state is considered to cause gait disturbance, pseudobulbar palsy, or silent stroke. In the present study, these symptoms is multiple lacunar state and the incidences of abnormal findings on magnetic resonance imaging (MRI) were investigated comparatively. Thirty-eight patients (23 males and 15 females; average age 73.6 y.o.) with ischemic cerebral lesions on T2 weighted images of MRI were studied. In the group with gait disturbance only, the incidences of widening of the ventricular system and periventricular hyperintensity (PVH) around the frontal horn were significantly high compared with the group with silent stroke (p<0.01, p<0.005; respectively), and hyperintensity area of the semioval center were demonstrated prominently in the regions perfused by anterior cerebral artery. In the group with pseudobulbar palsy only, the incidences of PVH around the posterior part of the lateral ventricle and hyperintensity area of the basal ganglion region were significantly high as compared with the group with silent stroke (p<0.01, p<0.05; respectively), and hyperintensity area of the semioval center were demonstrated prominently in the regions perfused by middle cerebral artery. (author)

  4. Clinical study on magnetic resonance imaging of lacunar infarcts and cerebrovascular high-risk group

    Hironaka, Masatoshi (Hiroshima Univ. (Japan). School of Medicine)

    1990-04-01

    Magnetic resonance imaging (MRI) study was performed in 32 patients with recent lacunar stroke. T2-weighted images showed ischemic lesions more clearly than T1-weighted images. Sixty-six percent of 32 patients had periventricular lesions. Eighty-four percent had subcortical white matter lesions. Sixty-nine percent had lesions in basal ganglia. Twenty-eight percent had lesions in brainstem. Periventricular lesions were revealed symmetrically. On the other hand, lesions in other areas were not detected symmetrically. Severe periventricular lesions on MRI were similar to those of Binswanger's disease. Patients with severe periventricular lesions had often hypertension. Moreover, two of them had dementia. Twenty-three patients with transient ischemic attack had less remarkable lesions than patients with lacunar stroke. Thirty-seven patients with a history of cerebrovascular risk factors (hypertension, diabetes mellitus) had severer lesions compared with normal controls. Sixty-one percent of controls, who had no cerebrovascular symptoms and signs, had MRI lesions. These results suggest that MRI is useful for detection of cerebral ischemic lesions with no associated clinical symptoms or signs. (author).

  5. Clinical study on magnetic resonance imaging of lacunar infarcts and cerebrovascular high-risk group

    Magnetic resonance imaging (MRI) study was performed in 32 patients with recent lacunar stroke. T2-weighted images showed ischemic lesions more clearly than T1-weighted images. Sixty-six percent of 32 patients had periventricular lesions. Eighty-four percent had subcortical white matter lesions. Sixty-nine percent had lesions in basal ganglia. Twenty-eight percent had lesions in brainstem. Periventricular lesions were revealed symmetrically. On the other hand, lesions in other areas were not detected symmetrically. Severe periventricular lesions on MRI were similar to those of Binswanger's disease. Patients with severe periventricular lesions had often hypertension. Moreover, two of them had dementia. Twenty-three patients with transient ischemic attack had less remarkable lesions than patients with lacunar stroke. Thirty-seven patients with a history of cerebrovascular risk factors (hypertension, diabetes mellitus) had severer lesions compared with normal controls. Sixty-one percent of controls, who had no cerebrovascular symptoms and signs, had MRI lesions. These results suggest that MRI is useful for detection of cerebral ischemic lesions with no associated clinical symptoms or signs. (author)

  6. Multifractal modelling and 3D lacunarity analysis

    This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

  7. Dynamic cerebral autoregulation and cerebrovascular reactivity: a comparative study in lacunar infarct patients

    The major purpose of this study was to simultaneously evaluate dCA before and shortly after cerebral vasodilatation evoked by infusion of acetazolamide (ACZ). It was questioned if and to what degree dCA was changed after ACZ infusion. Using 15 mg kg−1 ACZ infusion cerebrovascular reactivity (CVR) was assessed in 29 first ever lacunar stroke patients (19 M/10 F). During the CVR-test, the electrocardiogram, non-invasive finger arterial blood pressure (ABP) and middle cerebral artery blood flow velocity (CBFV) were recorded. DCA based on spontaneous blood pressure variations was evaluated in 24 subjects by linear transfer function analysis. Squared coherence, gain and phase angle in the frequency range of autoregulation (0.04–0.16 Hz) were compared before and after ACZ infusion. After ACZ infusion, median phase angle decreased significantly (p < 0.005 Wilcoxon) to 0.77 rad compared to a pre-test baseline value of 1.05 rad, indicating less efficient dCA due to ACZ. However, post-test phase values are still mostly within the normal range. Poor and statistically non-significant correlations were found between CVR and absolute dCA phase angle. It can be concluded that CVR testing with body weight adjusted infusion of ACZ lowers dCA performance but by no means exhausts dCA, suggesting that in this way maximal CVR is not determined. Characterizing dCA based on transfer function analysis of ABP to CBFV needs no provocation and adverse patient effects are minimal. The poor correlation between CVR and dCA phase angle supports an interpretation that CVR and dCA study different mechanisms of cerebrovascular control

  8. Multifractal modelling and 3D lacunarity analysis

    Hanen, Akkari, E-mail: bettaieb.hanen@topnet.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Imen, Bhouri, E-mail: bhouri_imen@yahoo.f [Unite de recherche ondelettes et multifractals, Faculte des sciences (Tunisia); Asma, Ben Abdallah, E-mail: asma.babdallah@cristal.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia); Patrick, Dubois, E-mail: pdubois@chru-lille.f [INSERM, U 703, Lille (France); Hedi, Bedoui Mohamed, E-mail: medhedi.bedoui@fmm.rnu.t [Laboratoire de biophysique, TIM, Faculte de Medecine (Tunisia)

    2009-09-28

    This study presents a comparative evaluation of lacunarity of 3D grey level models with different types of inhomogeneity. A new method based on the 'Relative Differential Box Counting' was developed to estimate the lacunarity features of grey level volumes. To validate our method, we generated a set of 3D grey level multifractal models with random, anisotropic and hierarchical properties. Our method gives a lacunarity measurement correlated with the theoretical one and allows a better model classification compared with a classical approach.

  9. Vitamin B12 and Progression of White Matter Lesions. A 2-Year Follow-Up Study in First-Ever Lacunar Stroke Patients

    van Overbeek, Ellen C.; Staals, Julie; van Oostenbrugge, Robert J.

    2013-01-01

    In cross-sectional studies periventricular white matter lesions (WML) were related to low plasma levels of vitamin B12. Whether low vitamin B12 levels are also related to progression of WML is still unknown. We studied baseline vitamin B12 levels and its association with progression of WML over 2 years of follow-up in first-ever lacunar stroke patients. In 107 first-ever lacunar stroke patients in whom baseline brain MRI and vitamin B12 status were available, we obtained a follow-up brain MRI...

  10. Models and Applications of in Vivo Lung Morphometry with Hyperpolarized 3He MRI in a Mild COPD Population

    Quirk, James D.; Sukstanskii, Alexander L.; Gierada, David S.; Woods, Jason C.; Conradi, Mark S.; Yablonskiy, Dmitriy A.

    2008-12-01

    Hyperpolarized 3He diffusion MRI is increasingly used to non-invasively quantify local alveolar structure changes, such as those from Chronic Obstructive Pulmonary Disease (COPD). Previously, we described an in vivo lung morphometry technique that decouples the helium apparent diffusion coefficient (ADC) into components oriented along the longitudinal (DL) and transverse (DT) axes of the acinar airways. Herein, we discuss our recent expansion of this theory, which relates the anisotropy of the MRI diffusion signal to the geometrical parameters of the acinar airways. We demonstrate the utility of this model in human studies and compare the measured airway radii with prior ex vivo experiments.

  11. Lacunar fractal photon sieves

    Gimenez, Fernando; Furlan, Walter D.; Monsoriu, Juan A.

    2007-01-01

    We present a new family of diffractive lenses whose structure is based on the combination of two concepts: photon sieve and fractal zone plates with variable lacunarity. The focusing properties of different members of this family are examined. It is shown that the sieves provide a smoothing effect on the higher order foci of a conventional lacunar fractal zone plate. However, the characteristic self-similar axial response of the fractal zone plates is always preserved.

  12. Physical and structural studies of chemical Vapor deposited lacunar neodymium manganite thin films

    Oumezzine M.

    2012-06-01

    Full Text Available Lacunar Nd1-xMnO3-δ thin films were successfully deposited by a liquid source metal-organic MOCVD technique on (001 SrTiO3 (STO, LaAlO3 (LAO and Si substrates. Optimal growth conditions are reported. TEM and X-ray diffraction characterisations reveal that the thin films grown on STO and LAO substrates are single crystalline layers epitaxially grown on the top of the substrates. The relationship between the crystallographic orientation of the films and those of the substrates were determined. Magnetic transition temperatures (Tc of the as-grown STO films, deduced from Squid Magnetometer measurements, are compared to the corresponding bulk values (typically 100K. Our magnetic measurements also suggest a complicated magnetic behavior close to the one observed in bulk samples: magnetization curves obtained under different applied magnetic fields indicate a possible reverse of the magnetization sign at low temperatures.

  13. Development and application of methods to quantify spatial and temporal hyperpolarized 3He MRI ventilation dynamics: preliminary results in chronic obstructive pulmonary disease

    Kirby, Miranda; Wheatley, Andrew; McCormack, David G.; Parraga, Grace

    2010-03-01

    Hyperpolarized helium-3 (3He) magnetic resonance imaging (MRI) has emerged as a non-invasive research method for quantifying lung structural and functional changes, enabling direct visualization in vivo at high spatial and temporal resolution. Here we described the development of methods for quantifying ventilation dynamics in response to salbutamol in Chronic Obstructive Pulmonary Disease (COPD). Whole body 3.0 Tesla Excite 12.0 MRI system was used to obtain multi-slice coronal images acquired immediately after subjects inhaled hyperpolarized 3He gas. Ventilated volume (VV), ventilation defect volume (VDV) and thoracic cavity volume (TCV) were recorded following segmentation of 3He and 1H images respectively, and used to calculate percent ventilated volume (PVV) and ventilation defect percent (VDP). Manual segmentation and Otsu thresholding were significantly correlated for VV (r=.82, p=.001), VDV (r=.87 p=.0002), PVV (r=.85, p=.0005), and VDP (r=.85, p=.0005). The level of agreement between these segmentation methods was also evaluated using Bland-Altman analysis and this showed that manual segmentation was consistently higher for VV (Mean=.22 L, SD=.05) and consistently lower for VDV (Mean=-.13, SD=.05) measurements than Otsu thresholding. To automate the quantification of newly ventilated pixels (NVp) post-bronchodilator, we used translation, rotation, and scaling transformations to register pre-and post-salbutamol images. There was a significant correlation between NVp and VDV (r=-.94 p=.005) and between percent newly ventilated pixels (PNVp) and VDP (r=- .89, p=.02), but not for VV or PVV. Evaluation of 3He MRI ventilation dynamics using Otsu thresholding and landmark-based image registration provides a way to regionally quantify functional changes in COPD subjects after treatment with beta-agonist bronchodilators, a common COPD and asthma therapy.

  14. A software program for quantitative analysis of alveolar oxygen partial pressure (pAO2) with oxygen-sensitive 3He-MRI

    Purpose: To develop a software tool for quantitative analysis of alveolar oxygen partial pressure (pAO2) as well as its time course during apnea. Material and Methods: T1-relaxation times of hyperpolarized 3He are reduced by paramagnetic oxygen rendering 3He-MRI sensitive to oxygen and thus allowing the assessment of the local oxygen partial pressure in the pulmonary airspaces. Oxygen-related relaxation and loss of polarization by RF-excitation can be discriminated by acquiring two image series with varying interscan delay and/or flip angles. Software was developed to calculate the pAO2 and the decay rate in user-defined regions of interest (ROIs) automatically. Moreover, parameter maps can be calculated. In addition to the analysis of 2-dimensional data sets, the software allows the evaluation of 3-dimensional measurements for the first time. Artifacts due to lung motion were reduced by implementing a motion correction algorithm. Results: The software was successfully applied to data sets from healthy volunteers and from patients with various lung diseases. The parameter maps demonstrated a more homogeneous distribution of pAO2 for the volunteers than for the patients. A regional increase in pAO2 was found in a few patients. Conclusion: the described software allows the absolute quantification of pAO2 as well as its variation over time. In the future therefore, the software may gain importance for detecting mis-matches between ventilation and perfusion, e.g., in patients with pulmonary embolism or chronic obstructive lung diseases. (orig.)

  15. Little association between intracranial arterial stenosis and lacunar stroke

    Wardlaw, Joanna M.; Doubal, Fergus N; Eadie, Elizabeth; Chappell, Francesca; Shuler, Kirsten; Cvoro, Vera

    2011-01-01

    Atheromatous middle cerebral artery (MCA) stenosis could cause lacunar stroke by occluding lenticulostriate artery origins, but atheroma is common, and previous studies lacked suitable controls. We aimed to determine if intracranial atheroma was more common in lacunar than in cortical ischaemic stroke. We recruited patients with lacunar stroke and controls with mild cortical stroke, confirmed the stroke subtype with magnetic resonance imaging and used transcranial Doppler ultrasound imaging t...

  16. Lacunarity as a texture measure for a tropical forest landscape

    Su, Haiping; Krummel, J.

    1996-01-01

    Fragmentation and loss of tropical forest cover alters terrestrial plant and animal population dynamics, reduces biodiversity and carbon storage capacity, and, as a global phenomenon could affect regional and global climate patterns. Lacunarity as a texture measure can offer a simple solution to characterize the texture of tropical forest landscape and determine spatial patterns associated with ecological processes. Lacunarity quantifies the deviation from translational invariance by describing the distribution of gaps within a binary image at multiple scales. As lacunarity increases, the spatial arrangement of tropical forest gaps will also increase. In this study, we used the Spatial Modeler in Imagine as a graphic programming tool to calculate lacunarity indices for a tropical forest landscape in Southern Mexico and Northern Guatemala. Lacunarity indices were derived from classified Landsat MSS images acquired in 1974 and 1984. Random-generated binary images were also used to derive lacunarity indices and compared with the lacunarity of forest patterns derived from the classified MSS images. Tropical forest area declined about 17%, with most of the forest areas converted into pasture/grassland for grazing. During this period, lacunarity increased about 25%. Results of this study suggest that tropical forest fragmentation could be quantified with lacunarity measures. The study also demonstrated that the Spatial Modeler can be useful as a programming tool to quantify spatial patterns of tropical forest landscape by using remotely sensed data.

  17. Visual assessment of functional lungs parenchyma on HRCT and {sup 3}He-MRI in patients after single lung transplantation: comparison with quantitative volumetric results; Visuelle Abschaetzung der funktionellen Lungenanteile in der HRCT und {sup 3}He-MRT bei Patienten nach Einzel-Lungentransplantation: Vergleich mit der absoluten Volumetrie

    Zaporozhan, J.; Ley, S. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); DKFZ, E010 - Radiologie, Heidelberg (Germany); Gast, K.K.; Heussel, C.P.; Thelen, M. [Klinik und Poliklinik fuer Radiologie, Johannes Gutenberg-Univ. Mainz (Germany); Biedermann, A. [III. Medizinische Klinik und Poliklinik, Johannes Gutenberg-Univ. Mainz (Germany); Eberle, B. [Klinik und Poliklinik fuer Anaesthesiologie, Univ. und Inselspital Bern (Switzerland); Mayer, E. [Klinik und Poliklinik fuer Herz-, Thorax- und Gefaesschirurgie, Johannes Gutenberg-Univ. Mainz (Germany); Kauczor, H.U. [DKFZ, E010 - Radiologie, Heidelberg (Germany)

    2005-04-01

    Purpose: Visual assessment of the ventilation using HRCT and {sup 3}He-MRI in patients after single lung transplantation (SLTX). Analysis of specific ventilation defects found with {sup 3}He-MRI and morphological changes found with HRCT. Materials and Methods: We evaluated 8 male patients (54{+-}6 years) suffering from emphysema and six patients (3 males and 3 females, 58{+-}9.5 years) suffering from idiopathic pulmonary fibrosis (IPF) after SLTX. The morphological changes at HRCT were classified and localized. In {sup 3}He-MRI (2D FLASH), 10 to 14 slices (slice thickness 10 mm, gap 5 mm) were acquired in coronal orientation to cover the whole lung. Ventilation defects were localized and characterized. The visually estimated ventilation was recorded on a 5-point scoring system. A double threshold technique was applied to volumetric quantification in {sup 3}He-MRI to serve as internal reference. Results: We found no correlation between morphological changes in HRCT and ventilation defects in {sup 3}He-MRI. The visual assessment of ventilation in {sup 3}He-MRI was sufficient in patients with emphysema, but this was not confirmed in patients with IPF. The visual assessment in HRCT did not correlate with the volumetric evaluation in both conditions. Conclusion: The various ventilation defects were not linked to specific morphological changes. For the visually assessed ventilation in patients with emphysema, {sup 3}He-MRI is superior to HRCT. (orig.)

  18. Clinical evaluation of β-TCP in the treatment of lacunar bone defects: A prospective, randomized controlled study

    The aim of this study was to investigate the potential wide application of beta tricalcium phosphate (β-TCP) only for bone defects as compared to allograft. 95 patients with a solitary bone cyst were randomly assigned to the treatment. A new radiographic scoring system was employed to calculate the biodegradation of bone graft and to evaluate the influence of multiple factors. At an average of 28.43 months after surgery, a radiographic semi-quantitative analysis revealed that the degradation rates of β-TCP and the allograft were comparable (p > 0.05). Age, complication, packing methods and granule diameters have a significant influence on β-TCP degradation. The loose packing method and 3–5 mm granule size should be employed in clinical practice. A histological analysis of biopsy showed that β-TCP supported the growth of fibrous tissue, vascular tissue, as well as bone tissue into the implants. The results proved that single β-TCP is an advantageous alternative to allografts for lacunar bone defect repair and would well guide the design and clinical application of the β-TCP. - Highlights: ► Single beta-TCP was used only for bone defect as compared to allograft. ► Beta-TCP shows similar performance as allografts in degradation rates. ► Age, complication, packing methods and granules diameters influence beta-TCP degradation. ► Loose packing method should be employed in clinical practice. ► The degradation of the beta-TCP tends to be better in young patients

  19. MRI findings on lacunar infarction with no clinical symptoms

    The purpose of this study was to examine how lacunar infarction developed and what its characteristics were. As this disease had little noticeable clinical symptoms and is likely to draw less attention than other types of cerebrovascular diseases like panhemispheric infarction, it's difficult to make an early diagnosis of it or treat it successfully. The subjects in this study were 196 people who showed no clinical symptoms and took a MRI test. When the MRI test data were analyzed, signal intensity and the part where that disease was detected were primarily taken into account. As a result, it's found that 116 people had no lacunar infarction and 80 people suffered from that disease, including 13 with very mild lacunar infarction, 41 with mild lacunar infarction and 26 with lacunar infarction. However, very mild and mild lacunar infarction could not be viewed as clinically significant cases, and only 26 people, which accounted for 13 percent of the subjects, should be considered to be diagnosed with lacunar infarction. The most common part where that disease was found was white matter and basal ganglia, regardless of gender. Accordingly, those who are exposed to health hazards such as hypertension or diabetes should take a MRI test to prevent cerebrovascular diseases that might be caused by those illnesses

  20. MRI findings on lacunar infarction with no clinical symptoms

    Kim, Ham Gyum [Ansan College, Ansan (Korea, Republic of)

    2003-12-15

    The purpose of this study was to examine how lacunar infarction developed and what its characteristics were. As this disease had little noticeable clinical symptoms and is likely to draw less attention than other types of cerebrovascular diseases like panhemispheric infarction, it's difficult to make an early diagnosis of it or treat it successfully. The subjects in this study were 196 people who showed no clinical symptoms and took a MRI test. When the MRI test data were analyzed, signal intensity and the part where that disease was detected were primarily taken into account. As a result, it's found that 116 people had no lacunar infarction and 80 people suffered from that disease, including 13 with very mild lacunar infarction, 41 with mild lacunar infarction and 26 with lacunar infarction. However, very mild and mild lacunar infarction could not be viewed as clinically significant cases, and only 26 people, which accounted for 13 percent of the subjects, should be considered to be diagnosed with lacunar infarction. The most common part where that disease was found was white matter and basal ganglia, regardless of gender. Accordingly, those who are exposed to health hazards such as hypertension or diabetes should take a MRI test to prevent cerebrovascular diseases that might be caused by those illnesses.

  1. Correlative factors of cognitive impairment in patients with lacunar infarcts

    Zhang Qiujuan; Yao Xiaoxin; Guo Youmin; Zhang Gejuan; Yang Junle

    2007-01-01

    Objective To study the relationships between cognitive impairment in patients with lacunar infarcts and quantitative CT measures and to determine the independent correlative factors of cognitive impairment. Methods Neuropsychological examination was conducted for 128 patients with acute lacunar infarct. Number, location, and volume of infarcts, cerebral atrophy index and severity of white matter lesions (WMLs) were measured and recorded. Results The number of lacunar infarcts in cognitive impairment (CI) group was significantly larger than that in cognitive normal (CN) group. Mean width of sulcus and sylvian fissure, index of frontal horn and ventricular-brain ratio (VBR) were significantly different in both groups. There were more patients with 3 grades or 4 grades WMLs in CI group (62%) than those in CN group (22%). The total volume of lacunar infarcts showed no statistically significant difference. Logistic regression analysis indicated that the number of lacunar infarcts in frontal subcortex and thalamus, the volume of infarcts in anterior periventricular white matter, width of cerebral sulcus and sylvian fissure were correlated with cognitive impairment respectively. Additionally, age and education were correlative factors of cognitive impairment in patients with lacunar infarct. Conclusion Correlative factors of cognitive impairment in patients with lacunar infarct are not merely one feature, but a combination of infarct features (number, location, and volume), cortical atrophy and host factors (age and education).

  2. 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.

    Marjolein Huijts

    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.

  3. Comparison of carotid artery intima - media thickness and risk factors of atherosclerosis in lacunar versus non-lacunar cerebral infarcts

    Seyed Ali Mousavi

    2007-07-01

    Full Text Available

    BACKGROUND: Increases in the thickness of the intima-media of the carotid artery have been associated with an increased risk of myocardial infarction and stroke in subjects without a history of cardiovascular disease. Lacunar infarcts, one of the most common subtypes of ischemic stroke, show unique pathological and clinicoradiological characteristics. The present study examined the relationship between the vascular risk factors, including carotid artery intimamedia thickness (IMT, and lacunar versus non-lacunar infarcts.
    METHODS: We collected data from patients admitted to hospital with acute ischemic stroke. 195 Patients and 96 control subjects underwent B-mode ultrasonographic measurements of IMT of the common carotid artery. We examined the association of lacunar and non-lacunar infarcts with age, sex, and potential vascular risk factors.
    RESULTS: Of 195 adult patients with acute ischemic stroke, 87 were considered lacunar and 108 were considered nonlacunar strokes. Between these two groups of patients, we did not find a significantly different percentage of diabetes,
    smoking, hypertension, dyslipidemia, myocardial infarction, or previous history of ischemic stroke, alcohol, obesity,
    atherogen diet, exercise, and IMT. However, patients with lacunar infarct, diabetes mellitus (P = 0.02, and hypertension
    (P = 0.02 had a significantly higher percentage of history of prior CVA (P = 0.03 and a significantly higher percentage
    of non-lacunar infarct.
    CONCLUSIONS: The present results indicated that diabetes mellitus and hypertension are more common in patients with lacunar infarcts, and history of CVA is more common in patients with non–lacunar infarcts. We further concluded that IMT cannot differentiate subtypes of ischemic stroke. Because risk factors and clinical presentation of ischemic stroke differ among races, more national studies

  4. Lacunar infarcts in childhood

    Nine cases, ranging in age from 6 months to 9 years, were diagnosed as lacunar infarcts on computed tomography (CT). Hemiplegia developed rapidly or gradually in 8 cases. Three of 8 cases had transient ischemic attacks of hemiplegia. Other neurological deficits were dysarthria, aphasia, confusion and coarse tremor. One case was asymptomatic. Each of 8 cases had single lacuna and one case two lacunae on CT. These lacunae were localized in the internal capsule, the putamen or the caudate nucleus. Lacunae involving the internal capsule were associated with contralateral hemiplegia, whereas asymptomatic lacunae did not iovolve it. Severity of hemiplegia in the acute stage did not correlate with localization or size of lacunae. Moderate neurological sequelae were noticed in 3 cases, mild sequelae in two and none in three. The sequelae were related to the lacunae which involved the lateral lenticulostriate branch zone of the middle cerebral artery or larger areas. Prognosis did not correlate with the mode of onset or the severity of neurological signs in the acute stage. There were 2 cases with the occlusion of the left internal carotid artery or congenital heart disease, but the etiology of lacunae was unknown in the other cases. (author)

  5. Lacunar infarcts: no black holes in the brain are benign.

    Norrving, Bo

    2008-08-01

    Lacunar infarcts--small subcortical infarcts that result from occlusion of a single penetrating artery--account for about one quarter of all ischaemic strokes. However, there are many diagnostic pitfalls, and causes other than penetrating small vessel disease in up to one third of cases. Recent studies have shown that the prognosis after lacunar infarcts is not benign; the risk of recurrent stroke is no lower than for other ischaemic stroke subtypes, and there is an increased risk for cognitive decline, dementia and death in the long term. Furthermore, silent small vessel disease in the brain at the time of an index stroke has significant prognostic implications. In the acute phase, response to intravenous thrombolysis appears to be similar to other subtypes of ischaemic strokes. Antiplatelet drugs, careful blood pressure control, statins and modification of lifestyle risk factors are key elements in secondary prevention after lacunar infarcts. PMID:18644908

  6. Lacunar strokes: a single institutional experience

    Osama Shukir Muhammed Amin

    2013-08-01

    Full Text Available Abstract: Objective: Lacunar ischemic strokes comprise approximately 25% of all ischemic strokes. We compared the risk factors and clinical pattern of this type of stroke between males and females. Methods: This observational study involved 50 consecutive patients with their first-ever lacunar stroke and was conducted at the department of neurology of Sulaimaniya general teaching hospital, Iraq from December 1, 2010 to March 1, 2013. Patients’ risk factors, clinical presentation, and strokes’ patterns were noted and a comparison was made between males and females. Results: Males (64% outnumbered females (36% with a male to female ration of 1.7. The mean age of males was 63 years while it was 61 years in females. Although hypertension was more common in females than in males, diabetes and smoking were more common in the latter group; however, there were no statistically significant differences between the 2 genders in terms of hypertension (P-value <0.3 and diabetes (P-value < 0.07 while smoking was strongly associated with male gender (P-value<0.0001. Pure motor hemiparesis, ataxic hemiparesis, pure sensory stroke, and dysarthria-clumsy hand syndrome were more common in males; only senori-motor stroke revealed a statistically significant difference in favor males (P-value<0.0001; 95% CI -1.7 to 19.2. There was no statistically significant difference in terms of which side of the brain was infarcted between males and females (P-value<0.4. Conclusion: Males around the age of 63 years were the main target for these lacunar strokes. Cigarette smoking and sensorimotor strokes were significantly associated with male gender. [Cukurova Med J 2013; 38(4.000: 659-666

  7. Risk Factors for Silent Lacunar Infarction in Patients with Transient Ischemic Attack.

    Li, Ying; Liu, Nan; Huang, Yonghua; Wei, Wei; Chen, Fei; Zhang, Weiwei

    2016-01-01

    BACKGROUND Lacunar infarctions represent 25% of ischemic strokes. Lacunar stroke and transient ischemic attack (TIA) share a number of symptoms. This study aimed to assess the potential risk factors for lacunar infarction in patients with TIA. MATERIAL AND METHODS This was a retrospective study performed at the Beijing Military General Hospital in patients with TIA admitted between March 2010 and December 2011. Patients were grouped according to lacunar vs. no lacunar infarction. All patients were diagnosed using diffusion-weighted imaging (DWI) on brain magnetic resonance imaging (MRI). Brain angiography (computed tomography and MRI) was used to measure intracranial stenosis. Carotid artery stenosis was measured by ultrasound. RESULTS Patients with TIA and lacunar infarction (n=298) were older than those without lacunar infarction (n=157) (69.4±10.0 vs. 58.9±9.0 years, Pdiabetes (32.6% vs. 21.0%, P=0.010), hyperlipidemia (53.4% vs. 29.3%, P<0.001), carotid stenosis (73.2% vs. 40.1%, P<0.001), and intracranial stenosis (55.6% vs. 31.9%, P<0.001), but a lower frequency of alcohol drinking (8.1% vs. 14.0%, P=0.045). Lacunar infarction mostly involved the anterior circulation (62.8%). Multivariate analysis showed that age (odds ratio (OR)=1.085, 95% confidence interval (95%CI): 1.054-1.117, P<0.001), hypertension (OR=1.738, 95%CI: 1.041-2.903, P=0.035), hyperlipidemia (OR=2.169, 95%CI: 1.307-3.601, P=0.003), and carotid stenosis (OR=1.878, 95%CI: 1.099-3.206, P=0.021) were independently associated with lacunar infarction. CONCLUSIONS Age, hypertension, hyperlipidemia, and carotid stenosis were independently associated with silent lacunar infarction in patients with TIA. PMID:26864634

  8. The correlation between cognitive function and cerebral white matter lesions/insulin resistance in patients with lacunar infarction:a clinical study of 184 cases

    张琼予

    2013-01-01

    Objective To investigate the correlation between cognitive function and cerebral white matter lesions(WML)/insulin resistance(IR) in patients with stroke.Methods Between May 2011 and October 2011,the clin-ical data of 184 in-patients with lacunar infarction were

  9. Alterations of Mass Density and 3D Osteocyte Lacunar Properties in Bisphosphonate-Related Osteonecrotic Human Jaw Bone, a Synchrotron µCT Study

    Hesse, Bernhard; Langer, Max; Varga, Peter; Pacureanu, Alexandra; Dong, Pei; Schrof, Susanne; Männicke, Nils; Suhonen, Heikki; Olivier, Cecile; Maurer, Peter; Kazakia, Galateia J.

    2014-01-01

    Osteonecrosis of the jaw, in association with bisphosphonates (BRONJ) used for treating osteoporosis or cancer, is a severe and most often irreversible side effect whose underlying pathophysiological mechanisms remain largely unknown. Osteocytes are involved in bone remodeling and mineralization where they orchestrate the delicate equilibrium between osteoclast and osteoblast activity and through the active process called osteocytic osteolysis. Here, we hypothesized that (i) changes of the mineralized tissue matrix play a substantial role in the pathogenesis of BRONJ, and (ii) the osteocyte lacunar morphology is altered in BRONJ. Synchrotron µCT with phase contrast is an appropriate tool for assessing both the 3D morphology of the osteocyte lacunae and the bone matrix mass density. Here, we used this technique to investigate the mass density distribution and 3D osteocyte lacunar properties at the sub-micrometer scale in human bone samples from the jaw, femur and tibia. First, we compared healthy human jaw bone to human tibia and femur in order to assess the specific differences and address potential explanations of why the jaw bone is exclusively targeted by the necrosis as a side effect of BP treatment. Second, we investigated the differences between BRONJ and control jaw bone samples to detect potential differences which could aid an improved understanding of the course of BRONJ. We found that the apparent mass density of jaw bone was significantly smaller compared to that of tibia, consistent with a higher bone turnover in the jaw bone. The variance of the lacunar volume distribution was significantly different depending on the anatomical site. The comparison between BRONJ and control jaw specimens revealed no significant increase in mineralization after BP. We found a significant decrease in osteocyte-lacunar density in the BRONJ group compared to the control jaw. Interestingly, the osteocyte-lacunar volume distribution was not altered after BP treatment. PMID

  10. Changing patterns of residential segregation in a prismatic metropolis: a lacunarity-based study in Houston, 1980 – 2000

    Sui, Daniel Z.; X Ben Wu

    2006-01-01

    The role of race versus class in shaping residential segregation patterns has been a contentious issue in segregation studies for decades. Despite the voluminous, interdisciplinary literature, scholars have reported conflicting evidence on the role of race versus class in residential segregations. We attribute the current inconclusive literature partially to the failure to consider scale explicitly in residential segregation measures, and partially to the growing complexity of a multiethnic m...

  11. Development of an automated method for the detection of chronic lacunar infarct regions in brain MR images

    The purpose of our study is to develop an algorithm that would enable the automated detection of lacunar infarct on T1- and T2-weighted magnetic resonance (MR) images. Automated identification of the lacunar infarct regions is not only useful in assisting radiologists to detect lacunar infarcts as a computer-aided detection (CAD) system but is also beneficial in preventing the occurrence of cerebral apoplexy in high-risk patients. The lacunar infarct regions are classified into the following two types for detection: ''isolated lacunar infarct regions'' and ''lacunar infarct regions adjacent to hyperintensive structures.'' The detection of isolated lacunar infarct regions was based on the multiple-phase binarization (MPB) method. Moreover, to detect lacunar infarct regions adjacent to hyperintensive structures, we used a morphological opening processing and a subtraction technique between images produced using two types of circular structuring elements. Thereafter, candidate regions were selected based on three features -area, circularity, and gravity center. Two methods were applied to the detected candidates for eliminating false positives (FPs). The first method involved eliminating FPs that occurred along the periphery of the brain using the region-growing technique. The second method, the multi-circular regions difference method (MCRDM), was based on the comparison between the mean pixel values in a series of double circles on a T1-weighted image. A training dataset comprising 20 lacunar infarct cases was used to adjust the parameters. In addition, 673 MR images from 80 cases were used for testing the performance of our method; the sensitivity and specificity were 90.1% and 30.0% with 1.7 FPs per image, respectively. The results indicated that our CAD system for the automatic detection of lacunar infarct on MR images was effective. (author)

  12. Fractal analysis: fractal dimension and lacunarity from MR images for differentiating the grades of glioma

    Glioma, the heterogeneous tumors originating from glial cells, generally exhibit varied grades and are difficult to differentiate using conventional MR imaging techniques. When this differentiation is crucial in the disease prognosis and treatment, even the advanced MR imaging techniques fail to provide a higher discriminative power for the differentiation of malignant tumor from benign ones. A powerful image processing technique applied to the imaging techniques is expected to provide a better differentiation. The present study focuses on the fractal analysis of fluid attenuation inversion recovery MR images, for the differentiation of glioma. For this, we have considered the most important parameters of fractal analysis, fractal dimension and lacunarity. While fractal analysis assesses the malignancy and complexity of a fractal object, lacunarity gives an indication on the empty space and the degree of inhomogeneity in the fractal objects. Box counting method with the preprocessing steps namely binarization, dilation and outlining was used to obtain the fractal dimension and lacunarity in glioma. Statistical analysis such as one-way analysis of variance and receiver operating characteristic (ROC) curve analysis helped to compare the mean and to find discriminative sensitivity of the results. It was found that the lacunarity of low and high grade gliomas vary significantly. ROC curve analysis between low and high grade glioma for fractal dimension and lacunarity yielded 70.3% sensitivity and 66.7% specificity and 70.3% sensitivity and 88.9% specificity, respectively. The study observes that fractal dimension and lacunarity increases with an increase in the grade of glioma and lacunarity is helpful in identifying most malignant grades. (paper)

  13. Tunneling in quantum superlattices with variable lacunarity

    Villatoro, Francisco R. [Departamento de Lenguajes y Ciencias de la Computacion, Universidad de Malaga, E-29071 Malaga (Spain); Monsoriu, Juan A. [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, E-46022 Valencia (Spain)], E-mail: jmonsori@fis.upv.es

    2008-05-19

    Fractal superlattices are composite, aperiodic structures comprised of alternating layers of two semiconductors following the rules of a fractal set. The scattering properties of polyadic Cantor fractal superlattices with variable lacunarity are determined. The reflection coefficient as a function of the particle energy and the lacunarity parameter present tunneling curves, which may be classified as vertical, arc, and striation nulls. Approximate analytical formulae for such curves are derived using the transfer matrix method. Comparison with numerical results shows good accuracy. The new results may be useful in the development of band-pass energy filters for electrons, semiconductor solar cells, and solid-state radiation sources up to THz frequencies.

  14. An interactive mapping tool for visualizing lacunarity of laser scanned point clouds

    Kania, Adam; Székely, Balázs

    2016-04-01

    Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery, including, among others, geology, dentistry, neurology. Its application in ecology was suggested more than 20 years ago. The main problem of its application was the lack of appropriate high resolution data. Nowadays, full-waveform laser scanning, also known as FWF LiDAR, provides the tool for mapping the vegetation in unprecedented details and accuracy. Consequently, the lacunarity concept can be revitalized, in order to study the structure of the vegetation in this sense as well. Calculation of lacunarity, even if it is done in two dimensions (2D), is still has its problems: on one hand it is a number-crunching procedure, on the other hand, it produces 4D results: at each 3D point it returns a set of data that are function of scale. These data sets are difficult to visualize, to evaluate, and to compare. In order to solve this problem, an interactive mapping tool has been conceptualized that is designed to manipulate and visualize the data, lets the user set parameters for best visualization or comparison results. The system is able to load large amounts of data, visualize them as lacunarity curves, or map view as horizontal slices or in 3D point clouds coloured according to the user's choice. Lacunarity maps are presented as a series of (usually) horizontal profiles, e.g. rasters, which cells contain color-mapped values of selected lacunarity of the point cloud. As lacunarity is usually analysed in a series of successive windows sizes, the tool can show a series of rasters with sequentially animated lacunarity maps calculated for various window sizes. A very fast switching of colour schemes is possible to facilitate rapid visual feedback to better understand underlying data patterns exposed by lacunarity functions. In the comparison mode, two sites (or two areas

  15. The Influence of Acute Hyperglycemia in an Animal Model of Lacunar Stroke That Is Induced by Artificial Particle Embolization

    Tsai, Ming-Jun; Lin, Ming-Wei; Huang, Yaw-Bin; Kuo, Yu-Min; Tsai, Yi-Hung

    2016-01-01

    Animal and clinical studies have revealed that hyperglycemia during ischemic stroke increases the stroke's severity and the infarct size in clinical and animal studies. However, no conclusive evidence demonstrates that acute hyperglycemia worsens post-stroke outcomes and increases infarct size in lacunar stroke. In this study, we developed a rat model of lacunar stroke that was induced via the injection of artificial embolic particles during full consciousness. We then used this model to compare the acute influence of hyperglycemia in lacunar stroke and diffuse infarction, by evaluating neurologic behavior and the rate, size, and location of the infarction. The time course of the neurologic deficits was clearly recorded from immediately after induction to 24 h post-stroke in both types of stroke. We found that acute hyperglycemia aggravated the neurologic deficit in diffuse infarction at 24 h after stroke, and also aggravated the cerebral infarct. Furthermore, the infarct volumes of the basal ganglion, thalamus, hippocampus, and cerebellum but not the cortex were positively correlated with serum glucose levels. In contrast, acute hyperglycemia reduced the infarct volume and neurologic symptoms in lacunar stroke within 4 min after stroke induction, and this effect persisted for up to 24 h post-stroke. In conclusion, acute hyperglycemia aggravated the neurologic outcomes in diffuse infarction, although it significantly reduced the size of the cerebral infarct and improved the neurologic deficits in lacunar stroke.

  16. Occlusive lesions of carotid and intracranial arteries in patients with symptomatic lacunar infarction. Evaluation by MR angiography

    The purpose of this study is to elucidate the prevalence and degree of occlusive lesions of carotid and intracranial arteries in patients with symptomatic lacunar infarction. We performed carotid and intracranial MR angiography, and T2-weighted MRI on 65 patients with symptomatic lacunar infarction. Stenosis of more than 25% narrowing of the diameter was found in 12 patients (18.5%) in the extracranial carotid arteries and in 14 patients (21.5%) in the intracranial arteries. Most of the stenotic lesions were mild. Multiple logistic regression analysis showed that age was significant and independent predictor for carotid artery stenosis, and that diabetes mellitus was predictor for intracranial artery stenosis. The incidence of intracranial artery stenosis was statistically higher in patients with a symptomatic lacunar infarctions in subcortical white matter area on T2-weighted MRI than in patients without such lesions. Coexistence of carotid artery stenosis should be suspected in aged patients with symptomatic lacunar infarction, and the possibility of intracranial artery stenosis should be considered in patients with diabetes mellitus or asymptomatic lacunar infarctions in subcortical white matter area. (author)

  17. Fractal Dimension and Lacunarity analysis of mammographic patterns in assessing breast cancer risk related to HRT treated population

    Karemore, Gopal Raghunath; Nielsen, Mads

    2009-01-01

      Structural texture measures are used to address the aspect of breast cancer risk assessment in screening mammograms. The current study investigates whether texture properties characterized by local Fractal Dimension (FD) and Lacunarity contribute to asses breast cancer risk. FD represents the....... It was found that there were no differences between cancer and control group for FD (P=0.8) and Lacunarity (P=0.8) in cross-sectional study whereas earlier published heterogeneity examination of radiographs (BC-HER) breast cancer risk score separated groups (p=0.002). In the longitudinal study, FD...... cancer population but marginally varying in HRT treated population. This study yields no evidence that lacunarity or FD are suitable surrogate markers of mammographic heterogeneity as they neither pick up breast cancer risk, nor show good sensitivity to HRT....

  18. Correlative factors of cognitive impairment in patients with lacunar infarcts

    2007-01-01

    Patients with lacunar infarcts are thought tohave an increased risk of cognitive i mpair ment anddementia[1].Cognitive i mpair ment is a predictor ofpoor functional outcome in stroke survivors[2].However,in patients with lacunar infarcts,thepathway leading to cognitive i mpair ment is notclear.According to the lacunar hypothesis,cogni-tive i mpair ment results fromincreased number andvolume of lacunes,especially whenlocated strategi-cally within frontal subcortical loops[3];while Feinet al[4]found that cogn...

  19. A lacunarity-based approach to evaluate Martian surfaces

    Székely, Balázs; Kania, Adam; Magyar, Zoltán

    2016-04-01

    Terrestrial planets show great variety in terms of geomorphological patterns: the surface is shaped on one hand by the various phases of asteroid bombardment, on the other hand internal and external processes create or have created landform elements at various scales. This richness in forms have already been considered in terms of fractal or multifractal analyses, resulting in various considerations. However, so far the counterpart of the fractal analysis, the lacunarity analysis has been seldom carried out. Lacunarity, a measure of the spatial distribution of the empty space in a certain model or real space over large spatial scales, is found to be a useful descriptive quantity in many fields using imagery. Lacunarity can be calculated in various dimensions; in most of the cases 2D calculation is performed. Our project also aims at calculating 2D lacunarity curves, however, we also use digital terrain models (DTMs) of the planet Mars, introducing partly the third dimension into the calculation. DTMs are converted to horizontal slices of the topography and these slices are then treated as images. The lacunarity analysis is performed on these stacks of images resulting in large amount of lacunarity curves. These curves can be compared locally or regionally, and the set of curves can be used for more global comparisons. Our preliminary results show that characteristic differences can be detected between various Martian surface types, i.e. the lacunarity results, similar to fractal dimensions, have a certain descriptive power. As this type of lacunarity analysis provide larger amount of descriptors (multiple lacunarity functions) than the fractal dimension values and the scale of analysis (area of interest taken into account in the computing) can be selected according to the needs, it seems to be possible to create lacunarity libraries for general use. In this preliminary phase of the project tools and techniques are tested to compare effectively the resulting

  20. A software program for quantitative analysis of alveolar oxygen partial pressure (p{sub A}O{sub 2}) with oxygen-sensitive {sup 3}He-MRI; Ein Auswerteprogramm zur quantitativen Analyse von Messungen des alveolaeren Sauerstoffpartialdrucks (p{sub A}O{sub 2}) mit der sauerstoffsensitiven {sup 3}He-MR-Tomographie

    Lehmann, F.; Gast, K.K.; Schreiber, W.G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Eberle, B.; Markstaller, K. [Universitaet Mainz (Germany). Klinik fuer Anaesthesiologie; Schmiedeskamp, J. [Mainz Univ. (Germany). Inst. fuer Physik; Bluemler, P. [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Kauczor, H.-U. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Deutsches Krebsforschungszentrum, Heidelberg (Germany)

    2004-10-01

    Purpose: To develop a software tool for quantitative analysis of alveolar oxygen partial pressure (p{sub A}O{sub 2}) as well as its time course during apnea. Material and Methods: T{sub 1}-relaxation times of hyperpolarized {sup 3}He are reduced by paramagnetic oxygen rendering {sup 3}He-MRI sensitive to oxygen and thus allowing the assessment of the local oxygen partial pressure in the pulmonary airspaces. Oxygen-related relaxation and loss of polarization by RF-excitation can be discriminated by acquiring two image series with varying interscan delay and/or flip angles. Software was developed to calculate the p{sub A}O{sub 2} and the decay rate in user-defined regions of interest (ROIs) automatically. Moreover, parameter maps can be calculated. In addition to the analysis of 2-dimensional data sets, the software allows the evaluation of 3-dimensional measurements for the first time. Artifacts due to lung motion were reduced by implementing a motion correction algorithm. Results: The software was successfully applied to data sets from healthy volunteers and from patients with various lung diseases. The parameter maps demonstrated a more homogeneous distribution of p{sub A}O{sub 2} for the volunteers than for the patients. A regional increase in p{sub A}O{sub 2} was found in a few patients. Conclusion: the described software allows the absolute quantification of p{sub A}O{sub 2} as well as its variation over time. In the future therefore, the software may gain importance for detecting mis-matches between ventilation and perfusion, e.g., in patients with pulmonary embolism or chronic obstructive lung diseases. (orig.)

  1. Prospective study of disturbance of intelligence of patients with lacunar stroke%腔隙性脑梗死患者智能障碍的前瞻性研究

    陈湛愔; 陈逢俭; 梁秀竹

    2003-01-01

    Aim To find the regularity of disturbance of intelligence through prospective study of patients with lacunar stroke.Methods 186 patients with lacunar stroke recruited in Department of Neurology of Affiliated Central Hospital of Guangdong Medical College entered this study,51 cases were combined with slight aphemia and most of them achieved obvious improvement within one week after hopitalization,and aphasis was not seen in others.The symptoms of limb paralysis of all the patients were slight and the muscular strengths were all above grade IV,which were improved obviously within one week.Then all the 186 cases were measured with adult intelligence table and multiple correlation analysis was done according to sex,age,job and education extent of patients and image characteristics.Results The intelligence of 130 patients with lacunar stroke was lower than normal and accounted for 70% of 186 cases.51 cases belonged to severe disturbance of intelligence(VIQ< 69) and accounted for 27.4% .The relationship between education extent and disturbance of intelligence presented significant negative correlation(r=-0.6307,P=0.001).The cerebral infarction in left - side basal ganglion,area of corona radiata and left - side temporal lobe could easily cause disturbance of intelligence(r=-0.217,P=0.003) than right side.Binswanger syndrome was the important reason leading to disturbance of intelligence(r=-0.2677,P< 0.001).Conclusion Different lesion locus often leads to obviously different extent of disturbance of intelligence.Left hemisphere lesion could easily cause disturbance of intelligence,especially left basal ganglion and temporal lobe.The disturbance of intelligence of patients with multiple locus is severer than that with single locus.In addition,single infracortical cava stroke can cause obvious disturbance of intelligence.The disturbance of intelligence caused by sex,age and job has no correlation with that caused by infracortical cava stroke,but it presents negative

  2. Fractal and Lacunarity Analyses: Quantitative Characterization of Hierarchical Surface Topographies.

    Ling, Edwin J Y; Servio, Phillip; Kietzig, Anne-Marie

    2016-02-01

    Biomimetic hierarchical surface structures that exhibit features having multiple length scales have been used in many technological and engineering applications. Their surface topographies are most commonly analyzed using scanning electron microscopy (SEM), which only allows for qualitative visual assessments. Here we introduce fractal and lacunarity analyses as a method of characterizing the SEM images of hierarchical surface structures in a quantitative manner. Taking femtosecond laser-irradiated metals as an example, our results illustrate that, while the fractal dimension is a poor descriptor of surface complexity, lacunarity analysis can successfully quantify the spatial texture of an SEM image; this, in turn, provides a convenient means of reporting changes in surface topography with respect to changes in processing parameters. Furthermore, lacunarity plots are shown to be sensitive to the different length scales present within a hierarchical structure due to the reversal of lacunarity trends at specific magnifications where new features become resolvable. Finally, we have established a consistent method of detecting pattern sizes in an image from the oscillation of lacunarity plots. Therefore, we promote the adoption of lacunarity analysis as a powerful tool for quantitative characterization of, but not limited to, multi-scale hierarchical surface topographies. PMID:26758776

  3. MRI findings in patients with multiple lacunar infarcts manifesting hyperactive-type delirium

    Arahata, Yutaka; Motegi, Yoshimasa; Furuse, Masahiro (Nakatsugawa Municipal General Hospital, Gifu (Japan)); Watanabe, Masaki; Takahashi, Akira

    1994-04-01

    MRI studies were carried out on 69 patients with multiple lacunar infarcts: 32 had hyperactive-type delirium and the other 37 were non-delirious controls. Between the two groups, there were no statistically significant differences in mean age and sex distribution. In the corona radiata and basal ganglia, the number of infarcts did not differ between the two groups. However, the extent of thalamic infarcts and periventricular hyperintensity (PVH), the maximal width of the third ventricle and Evans' ratio among the delirious patients were significantly larger than those in the controls. In conclusion, thalamic lesions and diffuse advanced PVH may have an intimate correlation in the development of hyperactive-type delirium in patients with multiple lacunar infarcts. (author).

  4. Biomaterial porosity determined by fractal dimensions, succolarity and lacunarity on microcomputed tomographic images

    N' Diaye, Mambaye [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); Degeratu, Cristinel [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France); University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Department of Bioresources and Polymer Science, Calea Victoriei 149, 010072, Sector 1, Bucharest (Romania); Bouler, Jean-Michel [Inserm UMR 791, LIOAD, University of Nantes, 44000 Nantes (France); Chappard, Daniel, E-mail: daniel.chappard@univ-angers.fr [LUNAM Université, GEROM Groupe Etudes Remodelage Osseux et bioMatériaux-LHEA, IRIS-IBS Institut de Biologie en Santé, CHU d' Angers, 49933 ANGERS Cedex (France)

    2013-05-01

    Porous structures are becoming more and more important in biology and material science because they help in reducing the density of the grafted material. For biomaterials, porosity also increases the accessibility of cells and vessels inside the grafted area. However, descriptors of porosity are scanty. We have used a series of biomaterials with different types of porosity (created by various porogens: fibers, beads …). Blocks were studied by microcomputed tomography for the measurement of 3D porosity. 2D sections were re-sliced to analyze the microarchitecture of the pores and were transferred to image analysis programs: star volumes, interconnectivity index, Minkowski–Bouligand and Kolmogorov fractal dimensions were determined. Lacunarity and succolarity, two recently described fractal dimensions, were also computed. These parameters provided a precise description of porosity and pores' characteristics. Non-linear relationships were found between several descriptors e.g. succolarity and star volume of the material. A linear correlation was found between lacunarity and succolarity. These techniques appear suitable in the study of biomaterials usable as bone substitutes. Highlights: ► Interconnected porosity is important in the development of bone substitutes. ► Porosity was evaluated by 2D and 3D morphometry on microCT images. ► Euclidean and fractal descriptors measure interconnectivity on 2D microCT images. ► Lacunarity and succolarity were evaluated on a series of porous biomaterials.

  5. 维生素B12与腔隙性梗死后抑郁的相关性分析%Study on the association of Vitamin B12 and depression secondary to lacunar cerebral infarction

    唐劭年; 任兰振; 胡宗继; 刘立雄

    2014-01-01

    目的:对维生素B12与腔隙性梗死后抑郁存在的相关性进行探讨。方法将我院2011-01-2013-01收治的腔隙性梗死患者798例分为对照组708例与观察组90例,对照组无抑郁症,观察组存在抑郁症(根据汉密尔顿抑郁量表判定),对比并分析2组患者的维生素B12水平。结果对照组血清维生素B12平均浓度为(178.6±20.7)pmol/L ,维生素B12缺乏197例(27.9%),观察组,血清维生素 B12平均浓度(141.7±19.7)pmol/L ,维生素 B12缺乏60例(66.7%),2组比较差异均有统计学意义( P<0.05)。结论维生素B12缺乏与腔隙性梗死后抑郁存在着相关性,腔隙性梗死并抑郁患者的维生素B12水平较普通腔隙性梗死患者更低,维生素B12缺乏情况较为明显,在治疗过程中适当补充维生素B12可以让患者的抑郁症状得到缓解,并可提升腔隙性梗死的治疗效果,促进患者恢复。%Objective To investigate the relevance between vitamin B12 and depression after lacunar cerebral infarc-tion.Methods Seventy hundred and ninety-eight patients with lacunar cerebral infarction admitted to our hospital from January 2011 to January 2011 were divided into control group(708 cases) and observation group (90 cases) ,no depression in control group patients ,the observation group patients had depression (judged according to the Hamilton depression rating scale ) ,vita-min B12 levels of patients in the two groups were analyzed and compared.Results The mean concentration of serum vitamin B12 of the control group was(178.6 ± 20.7)pmol/L ,the number of patients with vitamin B12 deficiency was 197 ,the ratio of which was 27.9% ;In the observation group ,the mean concentration of serum vitamin B12 was(141.7 ± 19.7)pmol/L ,the number of patients with vitamin B12 deficiency was 60 ,the ratio of which was 66.7%.The difference between the two groups had statisti-cal significance (P<0.05). Conclusion There is

  6. Preliminary analysis of osteocyte lacunar density in long bones of tetrapods: all measures are bigger in sauropod dinosaurs.

    Koen W H Stein

    Full Text Available Osteocytes harbour much potential for paleobiological studies. Synchrotron radiation and spectroscopic analyses are providing fascinating data on osteocyte density, size and orientation in fossil taxa. However, such studies may be costly and time consuming. Here we describe an uncomplicated and inexpensive method to measure osteocyte lacunar densities in bone thin sections. We report on cell lacunar densities in the long bones of various extant and extinct tetrapods, with a focus on sauropodomorph dinosaurs, and how lacunar densities can help us understand bone formation rates in the iconic sauropod dinosaurs. Ordinary least square and phylogenetic generalized least square regressions suggest that sauropodomorphs have lacunar densities higher than scaled up or comparably sized mammals. We also found normal mammalian-like osteocyte densities for the extinct bovid Myotragus, questioning its crocodilian-like physiology. When accounting for body mass effects and phylogeny, growth rates are a main factor determining the density of the lacunocanalicular network. However, functional aspects most likely play an important role as well. Observed differences in cell strategies between mammals and dinosaurs likely illustrate the convergent nature of fast growing bone tissues in these groups.

  7. Poromicromechanics reveals that physiological bone strains induce osteocyte-stimulating lacunar pressure.

    Scheiner, Stefan; Pivonka, Peter; Hellmich, Christian

    2016-02-01

    Mechanical loads which are macroscopically acting onto bony organs, are known to influence the activities of biological cells located in the pore spaces of bone, in particular so the signaling and production processes mediated by osteocytes. The exact mechanisms by which osteocytes are actually able to "feel" the mechanical loading and changes thereof, has been the subject of numerous studies, and, while several hypotheses have been brought forth over time, this topic has remained a matter of debate. Relaxation times reported in a recent experimental study of Gardinier et al. (Bone 46(4):1075-1081, 2010) strongly suggest that the lacunar pores are likely to experience, during typical physiological load cycles, not only fluid transport, but also undrained conditions. The latter entail the buildup of lacunar pore pressures, which we here quantify by means of a thorough multiscale modeling approach. In particular, the proposed model is based on classical poroelasticity theory, and able to account for multiple pore spaces. First, the model reveals distinct nonlinear dependencies of the resulting lacunar (and vascular) pore pressures on the underlying bone composition, highlighting the importance of a rigorous multiscale approach for appropriate computation of the aforementioned pore pressures. Then, the derived equations are evaluated for macroscopic (uniaxial as well as hydrostatic) mechanical loading of physiological magnitude. The resulting model-predicted pore pressures agree very well with the pressures that have been revealed, by means of in vitro studies, to be of adequate magnitude for modulating the responses of biological cells, including osteocytes. This underlines that osteocytes may respond to many types of loading stimuli at the same time, in particular so to fluid flow and hydrostatic pressure. PMID:26220453

  8. Lacunarity of geophysical well logs in the Cantarell oil field, Gulf of Mexico

    Arizabalo, Ruben Dario [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Oleschko, Klavdia [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Juriquilla, Queretaro (Mexico); Korvin, Gabor [King Fahd University, Dhahran (Saudi Arabia); Lozada, Manuel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Castrejon, Ricardo [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Ronquillo, Gerardo [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2006-04-15

    Lacunarity and fractal variations in geophysical well logs are associated with stratigraphic and petrophysical properties of the naturally fractured Cantarell field in the Gulf of Mexico. Neutron porosity (NPHI), density (RHOB, DRHO, PEF), resistivity (LLD, LLS, MSFL), natural radioactivity (GR, CGR, URAN, POTA, THOR) and caliper (CALI) logs are studied. The resistivity logs yielded remarkably high lacunarity values, especially in the hydrocarbon source- and reservoir rocks. Lacunarity {delta} was found to depend on the resolution and radial depth of penetration of the logging method. It systematically increased in the following order: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD). [Spanish] En este trabajo fueron analizadas las variaciones fractales y de lagunaridad de los registros geofisicos de pozo, con el fin de asociarlos con las propiedades estratigraficas y petrofisicas del yacimiento naturalmente fracturado de Cantarell, en el Golfo de Mexico. Los registros considerados fueron: porosidad neutron (NPHI), densidad (RHOB, DRHO, PEF), resistividad (LLD, LLS, MSFL), radiactividad natural (GR, CGR, URAN, POTA, THOR) y caliper (CALI). Los registros de resistividad produjeron valores de lagunaridad notablemente altos, especialmente en las rocas generadoras y almacenadoras, a diferencia de los demas registros, cuya homogeneidad de traza implico una baja lagunaridad. Los resultados indican que la lagunaridad observada depende de la resolucion y profundidad radial de penetracion del metodo geofisico estudiado y aumenta sistematicamente en el siguiente orden: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD).

  9. Late Onset Bipolar Disorder due to a Lacunar State

    Elena Antelmi; Margherita Fabbri; Lucia Cretella; Maria Guarino; Andrea Stracciari

    2014-01-01

    Objective. To describe a patient with a new onset bipolar disorder (BD) type II, secondary to a lacunar state. Background. Poststroke BD is rare and mainly associated with lesion in the prefrontal-striatal-thalamic circuit. Materials and Methods. A 51-year-old woman came to our attention for a mood disorder of recent onset. At 49, she had suffered acute left-sided limb weakness that improved spontaneously four days later. Arterial hypertension was subsequently diagnosed. After 6 months, she b...

  10. The Association Between Specific Substances of Abuse and Subcortical Intracerebral Hemorrhage versus Ischemic Lacunar Infarction

    Emma H Kaplan

    2014-09-01

    Full Text Available Background: Hypertension damages small vessels, resulting in both lacunar infarction and subcortical intracerebral hemorrhage (ICH. Substance abuse has also been linked to small vessel pathology. This study explores whether the use of specific substances (eg., cocaine, tobacco is associated with subcortical ICH over ischemia in hypertensive individuals.Methods: Patients with hypertension, admitted with lacunar infarcts (measuring 1 drink per day (women, >2 drinks per day (men. Logistic regression was performed with ICH as the dependent variable comparing those presenting with ICH to those presenting with ischemia.Results: Of the 580 patients included in analysis, 217 (37% presented with ICH. The average age was similar between the two groups (64.7 versus 66.3 years. Illicit/controlled drug use was associated with a significantly increased risk of ICH over stroke in unadjusted models (25% versus 15%, p=0.02, with the largest effect seen in users ≥65 years old (not statistically significant. Smoking was associated with ischemia over ICH in a dose-dependent manner: any history of smoking OR 1.84, CI 1.19-2.84; current use OR 2.23, CI 1.37-3.62; heavy use OR 2.48, CI 1.50-4.13. Alcohol use was not preferentially associated with either outcome (p=0.29.Conclusions: In hypertensive patients, tobacco use is associated with an increased risk of subcortical ischemia compared to ICH; while use of illicit/controlled substances appears to be predictive of hemorrhage.

  11. Late Onset Bipolar Disorder due to a Lacunar State

    Elena Antelmi

    2014-01-01

    Full Text Available Objective. To describe a patient with a new onset bipolar disorder (BD type II, secondary to a lacunar state. Background. Poststroke BD is rare and mainly associated with lesion in the prefrontal-striatal-thalamic circuit. Materials and Methods. A 51-year-old woman came to our attention for a mood disorder of recent onset. At 49, she had suffered acute left-sided limb weakness that improved spontaneously four days later. Arterial hypertension was subsequently diagnosed. After 6 months, she began to suffer from alternating brief periods of expansive and elevated mood with longer periods of depressed mood, with a suicide attempt. We performed extensive laboratory and instrumental investigations, as well as, psychiatric consultation, and a cognitive assessment, which was repeated 9 months later. Results. Brain magnetic resonance disclosed leukoaraiosis and a lacunar state of the basal ganglia. Transcranial Doppler showed a patent foramen ovale. A psychiatric consultation led to the diagnosis of BP type II. Neuropsychological evaluation detected deficits in attention/executive functions, verbal fluency, and memory. Nine months later, after specific psychiatric therapy, the psychiatric symptoms were remarkably improved. Conclusion. Our case sheds light on the role of the basal ganglia in mood disorders and the importance of ruling out brain injury in late onset BP.

  12. Airborne pollutants and lacunar stroke: a case cross-over analysis on stroke unit admissions.

    Corea, Francesco; Silvestrelli, Giorgio; Baccarelli, Andrea; Giua, Alessandra; Previdi, Paolo; Siliprandi, Giorgio; Murgia, Nicola

    2012-06-14

    Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD) has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua, Italy. We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006-08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter <10 µm (PM(10)), carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a case-crossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM(10) [odds ratio (OR) 1.01, 95%; confidence interval (CI) 1.00-1.02; P<0.05]. According to the clinical classification, lacunar anterior circulation syndrome stroke type was related to PM(10) level registered on the day of admission for both genders (OR: 1.01, 95%; CI: 1.00-1.02; P<0.05) while for total anterior circulation syndrome stroke only in men (OR: 1.04, 95%; CI 1.01-1.07; P<0.05).In conclusion, our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke. PMID:23139849

  13. Airborne pollutants and lacunar stroke: a case cross-over analysis on stroke unit admissions

    Francesco Corea

    2012-08-01

    Full Text Available Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua, Italy. We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006-08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter <10 mm (PM10, carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a case-crossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM10 [odds ratio (OR 1.01, 95%; confidence interval (CI 1.00-1.02; P<0.05]. According to the clinical classification, lacunar anterior circulation syndrome stroke type was related to PM10 level registered on the day of admission for both genders (OR: 1.01, 95%; CI: 1.00-1.02; P<0.05 while for total anterior circulation syndrome stroke only in men (OR: 1.04, 95%; CI 1.01-1.07; P<0.05. In conclusion, our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke.

  14. EVALUATION OF VERTICAL LACUNARITY PROFILES IN FORESTED AREAS USING AIRBORNE LASER SCANNING POINT CLOUDS

    B. Székely

    2016-06-01

    Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

  15. Millennium Simulation Dark Matter Haloes: Multi-fractal and Lacunarity Analysis with Homogeneity Transition

    Chacón-Cardona, César A

    2012-01-01

    We investigate from the fractal viewpoint the way in which the dark matter is grouped at z = 0 in the Millennium dark matter cosmological simulation. The determination of the cross to homogeneity in the Millennium Simulation data is described from the behaviour of the fractal dimension and the lacunarity. We use the sliding window technique to calculate the fractal mass-radius dimension, the pre-factor F and the lacunarity of this fractal relation. Besides, we determinate the multi-fractal dimension and the lacunarity spectrum, including their dependence with radial distance. This calculations show a radial distance dependency of all the fractal quantities, with heterogeneity clustering of dark matter haloes up to depths of 100 Mpc/h. The dark matter haloes clustering in the Millennium Simulation shows a radial distance dependency, with two regions clearly defined. The lacunarity spectrum for values of the structure parameter q >= 1 shows regions with relative maxima, revealing the formation of clusters and v...

  16. Multimodal magnetic resonance imaging for assessing lacunar infarction after proximal middle cerebral artery occlusion in a canine model

    LU Shan-shan; LIU Sheng; ZU Qing-quan; XU Xiao-quan; WANG Jian-wei; YU Jing; SUN Lei; SHI Hai-bin

    2013-01-01

    Background A new lacunar infarction model was recently established in beagle dogs through proximal middle cerebral artery (MCA) occlusion by thrombus.This study aimed to characterize the model by multimodal magnetic resonance imaging (MRI) and to investigate its potential role for the future stroke research.Methods The left proximal MCA was embolized with an autologous thrombus in six beagles.Diffusion-weighted imaging (DWl) and T2-weighted imaging (T2Wl) were performed every half hour during the first six hours after occlusion,followed by three time points at 12 hours,24 hours,and one week.Perfusion-weighted imaging (PWl) and magnetic resonance angiography (MRA) were carried out at six hours,24 hours and one week.The PWI-DWl mismatch ratio was defined as (PWI-DWI)/DWI ischemic volume.Results Lacunar infarcts induced by MCA occlusion were located in the left caudate nucleus and internal capsule.All the lesions could be detected within two hours by DWI.Lesion volume on DWI increased in a time dependent manner,from (87.19±67.16) mm3 at one hour up to (368.98±217.05) mm3 at 24 hours (P=-0.009),while that on PWI gradually decreased from (7315.00±2054.38) mm3 at six hours to (4900.33±1319.71) mm3 at 24 hours and (3334.33±1195.11) mm3 at one week (P=0.002).The mismatch ratio was 41.93±22.75 at six hours after ischemia,showing "extensive mismatch",and decreased to 18.10+13.74 at 24 hours (P=0.002).No MCA recanalization was observed within 24 hours after MCA occlusion.Conclusions Lacunar infarction induced by proximal MCA occlusion could be detected early by DWI and was characterized by extensive PWI-DWI mismatch.Multimodal MRI is useful to demonstrate the natural evolution of PWI-DWI mismatch.This ischemic model could be further used for investigating early thrombolysis in lacunar stroke showing extensive mismatch.

  17. The relation between prognosis and nocturnal blood pressure variation in hypertensive patients with lacunar infarct%夜间血液变化与高血压腔隙性脑梗死发后及预后的相关性分析

    张微微; 黄勇华; 李娟; 冯军

    2001-01-01

    Objective We conducted a study using MRI and ambulatory blood pressure monitoring(ABPM) to determine whether an inapporpriately low nocturnal blood pressure,or an excess fall in nocturnal blood pressure,might be responsible for lacunar infarct.Method ABPM and Casul blood pressure(CBP) were examined in 35 hypertentives with lacunar infarct( LI) and 33 hypertentives without lacunar infarct as control group.Results There is no significant difference of CBP between two groups.But the mean nighttime systolic blood pressure(nSBP) and diastolic blood pressure(nDBP) in patients with lacunar infarct were significantly smaller than in patients without lacunar infarct.The ratio of nSBP/dSBP and nDBP/dDBP in SI were smaller than in control group respectively.Conclusions The results indicate that an inappropriately low nocturnal blood pressure,or an excessive fall in nocturnal blood pressure,is associated with lacunar infarct.It is necessary not only to controlhigh blood pressure but also to pay attention to circadian changes of blood pressure during the course of anti-hypertensive treatment.

  18. Identifying mangrove species and their surrounding land use and land cover classes using object-oriented approach with a lacunarity spatial measure

    Myint, S.W.; Giri, C.P.; Wang, L.; Zhu, Z.; Gillete, S.C.

    2008-01-01

    Accurate and reliable information on the spatial distribution of mangrove species is needed for a wide variety of applications, including sustainable management of mangrove forests, conservation and reserve planning, ecological and biogeographical studies, and invasive species management. Remotely sensed data have been used for such purposes with mixed results. Our study employed an object-oriented approach with the use of a lacunarity technique to identify different mangrove species and their surrounding land use and land cover classes in a tsunami-affected area of Thailand using Landsat satellite data. Our results showed that the object-oriented approach with lacunarity-transformed bands is more accurate (over-all accuracy 94.2%; kappa coefficient = 0.91) than traditional per-pixel classifiers (overall accuracy 62.8%; and kappa coefficient = 0.57). Copyright ?? 2008 by Bellwether Publishing, Ltd. All rights reserved.

  19. The usefulness of diffusion-weighted/fluid-attenuated inversion recovery imaging in the diagnostics and timing of lacunar and nonlacunar stroke

    Witkowski, Grzegorz; Sienkiewicz-Jarosz, Halina [Institute of Psychiatry and Neurology, 1st Department of Neurology, Warsaw (Poland); Piliszek, Agnieszka; Ryglewicz, Danuta [Central Clinical Hospital of the Ministry of Interior, Department of Radiology, Warsaw (Poland); Skierczynska, Agnieszka; Poniatowska, Renata [Institute of Psychiatry and Neurology, Department of Radiology, Warsaw (Poland); Dorobek, Malgorzata; Filipek-Gliszczynska, Anna [Central Clinical Hospital of the Ministry of Interior, Department of Neurology, Warsaw (Poland); Walecki, Jerzy [Polish Academy of Science, Mossakowski Medical Research Centre, Warsaw (Poland)

    2014-10-15

    The DWI/FLAIR mismatch is a potential radiological marker for the timing of stroke onset. The aim of the study was to assess if the DWI/FLAIR mismatch can help to identify patients with both lacunar and nonlacunar acute ischemic stroke within 4.5 h of onset. A retrospective study was performed in which the authors analysed data from 86 ischemic lacunar and nonlacunar stroke patients with a known time of symptom onset, imaged within the first 24 h from stroke onset (36 patients <4.5 h, 14 patients 4.5-6 h, 15 patients 6-12 h, and 21 patients 12-24 h). Patients underwent the admission CT and MR scan. The presence of lesions was assessed in correlation with the duration of the stroke. The time from stroke onset to neuroimaging was significantly shorter in patients with an ischemic lesion visible only in the DWI (mean 2.78 h, n = 24) as compared to patients with signs of ischemia also in other modalities (mean 8.6 h, n = 62) (p = 0.0001, Kruskal-Wallis ANOVA). The DWI/FLAIR mismatch was characterised by a global sensitivity of 58 %, specificity 94 %, PPV 87.5 %, and NPV 76 % in identifying patients in the 4.5 h thrombolysis time window. For lacunar strokes (n = 20), these parameters were as follows: sensitivity 50 %, specificity 92.8 %, PPV 75 %, and NPV 81.2 %. The presence of acute ischemic lesions only in DWI can help to identify both lacunar and nonlacunar stroke patients who are in the 4.5 h time window for intravenous thrombolysis with high specificity. (orig.)

  20. The usefulness of diffusion-weighted/fluid-attenuated inversion recovery imaging in the diagnostics and timing of lacunar and nonlacunar stroke

    The DWI/FLAIR mismatch is a potential radiological marker for the timing of stroke onset. The aim of the study was to assess if the DWI/FLAIR mismatch can help to identify patients with both lacunar and nonlacunar acute ischemic stroke within 4.5 h of onset. A retrospective study was performed in which the authors analysed data from 86 ischemic lacunar and nonlacunar stroke patients with a known time of symptom onset, imaged within the first 24 h from stroke onset (36 patients <4.5 h, 14 patients 4.5-6 h, 15 patients 6-12 h, and 21 patients 12-24 h). Patients underwent the admission CT and MR scan. The presence of lesions was assessed in correlation with the duration of the stroke. The time from stroke onset to neuroimaging was significantly shorter in patients with an ischemic lesion visible only in the DWI (mean 2.78 h, n = 24) as compared to patients with signs of ischemia also in other modalities (mean 8.6 h, n = 62) (p = 0.0001, Kruskal-Wallis ANOVA). The DWI/FLAIR mismatch was characterised by a global sensitivity of 58 %, specificity 94 %, PPV 87.5 %, and NPV 76 % in identifying patients in the 4.5 h thrombolysis time window. For lacunar strokes (n = 20), these parameters were as follows: sensitivity 50 %, specificity 92.8 %, PPV 75 %, and NPV 81.2 %. The presence of acute ischemic lesions only in DWI can help to identify both lacunar and nonlacunar stroke patients who are in the 4.5 h time window for intravenous thrombolysis with high specificity. (orig.)

  1. Recurrence of lacunar stroke and blood pressure control. Kanagawa REALITY

    Information on the background and status of recurrence realities of lacunar infarction (LI) is still limited. We investigated 856 patients started to treat from 1997 to 2000, in whom a diagnosis of first-ever symptomatic LI was detected by MRI were enrolled, excluding possible cardiogenic embolic stroke or branch atheromatous disease using medical records in 14 institutions in Kanagawa, retrospectively. Recurrent cerebrovascular events (CVEs) occurred in 96 patients (11%) and the annual incidence was 4.8%. The mean systolic blood pressure (SBP) just before recurrence of CVEs was significantly higher than the mean SBP at final follow-up in recurrence-free patients (P<0.001). As the result of multivariate analysis performed after adjusting for following risk factors, antiplatelet therapy, a high SBP just before the end of follow-up, the presence of diabetes mellitus, and a modified Rankin scale≥5 were independent prognostic factors related to recurrence of CVEs. The recurrence rates of CVEs or LI were decreased by lowering of the SBP and diastolic blood pressure (DBP) just before the end of follow-up. Our analyses provide no evidence of a J-curve relationship between BP level and a recurrence after first-ever symptomatic LI. (author)

  2. Detection of lacunar infarction in brain CT-scans: No evidence of bias from accompanying patient information

    Interobserver agreement in assessing brain CT-scans is, in general, high. The extent, however, to which such agreement is caused by bias through knowledge of other clinical details remains uncertain. The hypothesis that observers are somehow prejudiced before assessing ambiguous, CT-scans in this particular situation was tested. Sixteen neurologists and 16 radiologists volunteered to interpret two ambiguous brain CT-scans, with regard to the presence or absence of a lacunar infarct in the region of the internal capsule. The scans were accompanied by 'patient' information that was or was not suggestive of a stroke. These scans were camouflaged by a variety of other scans, to be assessed in the same way, to mask the purpose of the study. I was assumed that the observers, in their assessments of the scans, would somehow let their ratings of the likelihood of a lacunar infarction in or near the internal capsule be subject to the accompanying information. Results showed lower ratings produced by neurologists (i.e., less likelihood of an infarction) than by radiologists in the majority of all assessments, but no bias by the accompanying information. (orig.)

  3. Lacunar Infarction Associated with Anabolic Steroids and Polycythemia: A Case Report

    George W.J. Harston

    2014-02-01

    Full Text Available Lacunar infarction is traditionally ascribed to lipohyalinosis or microatheroma. We report the case of 40-year-old man, without traditional risk factors for ischemic stroke, who presented to the Emergency Department with recurrent episodes of transient right-sided weakness and paresthesia. Lacunar infarction was confirmed on diffusion-weighted MRI and blood tests showed a marked polycythemia. Quantitative magnetic resonance perfusion imaging demonstrated dramatically abnormal perfusion throughout both cerebral hemispheres, and transcranial Doppler revealed reduced cerebral artery velocities, both consistent with the proposed mechanism of hyperviscosity. His symptoms settled with treatment of the polycythemia and workup did not find another cause of ischemic stroke. We propose that hyperviscosity secondary to steroid-induced polycythemia caused ischemia in this case and not lipohyalinosis or microatheroma, to which lacunar disease is commonly attributed.

  4. Magnetic resonance imaging of lacunar infarcts in the basal ganglionic area

    During the previous 2 years, 88 patients have been diagnosed as having lacunar infarcts in the basal ganglioa ( a total of 157 lesions) on magnetic resonance imaging (MRI):42 patients had a single lesion and 46 patients had multiple lesions (2 lesions in 25 patients, 3 lesions in 14, and 4 or more lesions in 7). Seventy-seven lesions (49%) were smaller than 5 mm in diameter, and the others ranged from 5 mm to 15 mm. According to the regional relations to the internal capsule, the lesions were classified as lateral (57 lesions), anterior (36), superior (34), posterior (26), and inferior (4). Lesions of posterior, anterior, superior, and inferior types were associated with severer hemisparetic state, an abnormally slow gait, a sensory disturbance of numbness, and a depressive state, respectively. Forty five lesions (28%) were asymptomatic. Cat scanning failed to deliniate 47 lesions (30%) that were detected on MRI. Twenty three lesions were both asymptomatic and undistinguished on CT, which consisted of the superior type (10), anteior type (7), lateral type (5), and posterior type (one). Twenty four lesions were symptomatic, but were undistinguished on CT, suggesting that MRI is superior to CT in detecting the lacunar infarcts in the basal ganglionic area. Lacunar infarcts in both acute and chronic stages tended to be larger on T2-weighted images than T1-weighted images. In 7 patients who had neither history of hypertension, diabetes mellitus, or cardiac emboli nor CT evidence, MRI was capable of detecting lacunar infarcts. (N.K.)

  5. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium

    This thesis deals with the neutrons propagation by reflection on the vacuum-matter interfaces of a lacunar medium, to control the direct irradiation risk. The more efficient method to simulate this propagation is the use of reflection coefficients (albedo). The first part of the work deals with the generation of albedo for various materials. The Monte Carlo method has been chosen and a new estimator has been developed and validated in the Monte Carlo transport code TRIPOLI4. This estimator is based on the neutrons transport simulation in the matter, to calculate in each collision point the double differential reflexions probability. The second part deals with the implementing of an interpolation module of the generated albedo in a library. These differential albedo of neutrons allow the study of the neutrons propagation by multi-reflections and the accurate calculation of the equivalent dose rate generated by the neutrons reflections. (A.L.B.)

  6. Evaluation of Vertical Lacunarity Profiles in Forested Areas Using Airborne Laser Scanning Point Clouds

    Székely, B.; Kania, A.; Standovár, T.; Heilmeier, H.

    2016-06-01

    The horizontal variation and vertical layering of the vegetation are important properties of the canopy structure determining the habitat; three-dimensional (3D) distribution of objects (shrub layers, understory vegetation, etc.) is related to the environmental factors (e.g., illumination, visibility). It has been shown that gaps in forests, mosaic-like structures are essential to biodiversity; various methods have been introduced to quantify this property. As the distribution of gaps in the vegetation is a multi-scale phenomenon, in order to capture it in its entirety, scale-independent methods are preferred; one of these is the calculation of lacunarity. We used Airborne Laser Scanning point clouds measured over a forest plantation situated in a former floodplain. The flat topographic relief ensured that the tree growth is independent of the topographic effects. The tree pattern in the plantation crops provided various quasi-regular and irregular patterns, as well as various ages of the stands. The point clouds were voxelized and layers of voxels were considered as images for two-dimensional input. These images calculated for a certain vicinity of reference points were taken as images for the computation of lacunarity curves, providing a stack of lacunarity curves for each reference points. These sets of curves have been compared to reveal spatial changes of this property. As the dynamic range of the lacunarity values is very large, the natural logarithms of the values were considered. Logarithms of lacunarity functions show canopy-related variations, we analysed these variations along transects. The spatial variation can be related to forest properties and ecology-specific aspects.

  7. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    Nina Kølln Wittig

    2016-06-01

    Full Text Available Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes of bone on the organ and tissue level, whereas features on the nano- and micrometer scale are much less explored. We investigated the age-related development of organ and tissue level bone properties such as bone volume, bone mineral density, and load to fracture and correlated these with osteocyte lacunar properties in rat cortical bone. Femora of 14 to 42-week-old female Wistar rats were investigated using multiple complementary techniques including X-ray micro-computed tomography and biomechanical testing. The body weight, femoral length, aBMD, load to fracture, tissue volume, bone volume, and tissue density were found to increase rapidly with age at 14–30 weeks. At the age of 30–42 weeks, the growth rate appeared to decrease. However, no accompanying changes were found in osteocyte lacunar properties such as lacunar volume, ellipsoidal radii, lacunar stretch, lacunar oblateness, or lacunar orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties of the osteocyte lacunar network are main determinants of the properties of the bone on larger length scales.

  8. Impaired anticipatory control of fingertip forces in patients with a pure motor or sensorimotor lacunar syndrome

    Raghavan, Preeti; Krakauer, John W.; Gordon, Andrew M.

    2006-01-01

    We examined planning and execution of precision grasp in eight right-handed patients with a right pure motor or sensorimotor lacunar syndrome after a subcortical stroke, and eight age-matched controls, as they grasped and lifted an instrumented object whose weight could be varied without altering its visual appearance. Grip (normal) and load (tangential) forces at the fingertip-object interface were measured and the grip force rate (GFR) and load force rate (LFR) were derived. Planning of pre...

  9. Synchrotron X-ray phase nano-tomography-based analysis of the lacunar-canalicular network morphology and its relation to the strains experienced by osteocytes in situ as predicted by case-specific finite element analysis.

    Varga, Peter; Hesse, Bernhard; Langer, Max; Schrof, Susanne; Männicke, Nils; Suhonen, Heikki; Pacureanu, Alexandra; Pahr, Dieter; Peyrin, Françoise; Raum, Kay

    2015-04-01

    Osteocytes are hypothesized to regulate bone remodeling guided by both biological and mechanical stimuli. Morphology of the lacunar-canalicular network of osteocytes has been hypothesized to be strongly related to the level of mechanical loading and to various bone diseases. Finite element modeling could help to better understand the mechanosensation process by predicting the physiological strain environment. The aims of this study were to (i) quantify the lacunar-canalicular morphology in the cortex of the human femur; (ii) predict the in situ local deformations around and in osteocytes by means of case-specific finite element models; and (iii) investigate the potential relationship between morphology and deformations. Human femoral cortical bone samples were imaged using synchrotron X-ray phase nano-tomography with 50 nm voxel size. Rectangular volumes of interest were selected to contain single osteocyte lacunae and the surrounding matrix. Lacunar-canalicular morphology was quantified and the cell geometry was artificially reconstructed based on a priori assumptions. Finite element models of the volumes of interest were generated, containing the extracellular matrix, osteocyte and peri-cellular matrix, and subjected to uniaxial compression. The morphological analysis revealed that canalicular number was dictated by lacunar size, that the spacing of canaliculi fell within a narrow range, suggesting that these pores are well distributed throughout the bone matrix and indicated the trend that lacunae at the outer osteon boundary were less elongated than others. No apparent relationship was found between the morphological parameters and the predicted strains. The globally applied strain was amplified locally by factors up to 10 and up to 70 in the extracellular matrix and the in cells, respectively. Cell deformations were localized mainly at the body-dendrite junctions, with magnitudes reaching the in vitro stimulatory threshold reported for osteocytes. PMID

  10. Lacunarity, predictability and predictive instability of the daily pluviometric regime in the Iberian Peninsula

    M. D. Martínez

    2007-01-01

    Full Text Available The complexity of the daily pluviometric regime of the Iberian Peninsula is analysed from the point of view of its lacunarity, predictability and predictive instability. The database consists of daily pluviometric records obtained from 43 rain gauges in Spain and Portugal for the period 1950–1990. Five different series are generated for every rain gauge. The first series is constituted by the consecutive daily amounts. The other four consist of dry spell lengths with respect to daily amount thresholds of 0.1, 1.0, 5.0 and 10.0 mm/day. A dry spell length is defined as the number of consecutive days with rainfall amounts below one of these thresholds. The empirical lacunarity for every rain gauge is well reproduced by two power laws, the exponents varying notably from one gauge to another. The spatial distribution of the lacunarity is characterised by a north to south or southeast gradient, thus suggesting that this parameter can be a useful tool to distinguish between different pluviometric regimes. The predictability of the five series is quantified by means of the rescaled analysis and the interpretation of the Hurst exponent. Its patterns reveal that most part of the Iberian Peninsula shows signs of persistence for the daily rainfall and the dry spell series, although persistence is only clearly manifested in some small domains. The instability of possible predictive algorithms is analysed through the Lyapunov exponents. They are only computed for the series of daily amounts and for dry lengths respect to the threshold level of 0.1 mm/day due to the short number of dry spells for larger threshold levels. The series of daily amounts depict the highest instability along the Mediterranean coast. The series of dry spells show an increasing instability from NE to SW Spain, with a relevant nucleus of high Lyapunov values in the south-western Atlantic coast. As a summary, lacunarity and Hurst and Lyapunov exponents depict a relevant spatial

  11. Clinical Study on the Treatment of Lacunar Infarction of Qi Deficiency and Collateral Stasis Type by Quyu Buqi Decoction%祛瘀补气汤治疗气虚络瘀型腔隙性脑梗死临床研究

    王志理

    2012-01-01

    目的:探讨祛瘀补气汤治疗气虚络瘀型腔隙性脑梗死的临床疗效.方法:腔隙性脑梗死(气虚络瘀型)患者165例,采用随机数字表法,依据就诊先后顺序分为治疗组105例,对照组60例.所有患者治疗期间均给予基础治疗.对照组采用血塞通注射液400 mg加入体积分数5%葡萄糖注射液250 mL中(高血糖患者使用体积分数0.9%生理盐水250 mL)缓慢静脉滴注,每日1次.治疗组采用祛瘀补气汤(方药组成:黄芪60 g,当归15 g,赤芍15 g,川芎10 g,桃仁10 g,红花15 g,水蛭10 g,地龙10 g,石菖蒲15 g,鸡血藤30 g,杜仲15 g,牛膝15 g)治疗,每日1剂,水煎服.两组均14 d为1个疗程,2个疗程后统计疗效.结果:对照组60例,痊愈24例,显效15例,有效14例,无效7例,有效率为88.33%;治疗组105例,痊愈67例,显效25例,有效10例,无效3例,有效率为97.14%.两组有效率比较,x2=5.205,P=0.023<0.05,差异有统计学意义.结论:祛瘀补气汤治疗气虚络瘀型腔隙性脑梗死临床疗效显著.%Objective:To discuss the clinical effects of Quyu Buqi Decoction on the treatment of lacunar infarction of qi deficiency and collateral stasis type. Methods: 165 patients of lacunar infarction (with the type of qi deficiency and collateral stasis) were divided into the treatment group(105 cases) and the control group(60 cases) by the method of random number table according to the sequence of treatment. All patients were given basic treatment during treatment. Patients in the control group were treated by slow intravenous drip of Xueshuantong injection plus 250 mL of 5% of GS(replaced by 250 mL of NS for patients of hyperglycemia) ,once a day. Patients in the treatment group were treated by Quyu Buqi Decoction( Recipe components: Astragalus 60 g, Angelica 15 g.red peony root 15 g,hemlock parsley 10 g, walnuts 10 g,safflower 15g,the leech 10 g,earthworm 10 g,the iris 15 g,the Millettia 30 g,the eucommia 15 g,Achyran-thes 15 g) for resolving stasis

  12. Correlation study between cerebral microbleeds and early neurological deterioration in patients with first-onset acute lacunar stroke%首发急性腔隙性脑梗死患者脑微出血与早期神经功能恶化的关联研究

    韩忠奎; 任明山; 夏元亮; 锁六军

    2015-01-01

    Objective The predictive indexes which affect early neurological deterioration ( END) of patients with acute la-cunar stroke still remain unclear .The purpose of the article was to investigate the correlation between the location and numbers of cere -bral microbleeds (CMBs) and END in patients with first-onset lacunar stroke. Methods 217 patients with acute lacunar stroke hos-pitalized in Anhui Provincial Hospital within 24 hours after occurrence from Mar 2009 to May 2012 were prospectively enrolled .All pa-tients underwent susceptibility-weighted imaging MRI right after admission , followed by the investigation on the relationship of the loca-tion and numbers of CMBs and END . Results END occurred in 76 (35.0%) patients.Among these patients, there were 33 positive cases with CMBs (43.3%).There were no significant difference in END incidence between positive group and negative group (P=0.173).In the comparison of the numbers of CMBs foci , patients with more than 5 foci were more prone to END (P=0.005).Logistic regression analysis showed there was relation between CMBs foci numbers>5 and END (OR=3.14, 95% CI: 1.22 ~8.13), and there was no relation between CMBs foci numbers≤5 and END ( OR=1.12, 95%CI:0.53~2.37)as to CMBs negative patients.No signifi-cant relationship was found in CMBs location and END occurrence ( P>0.05). Conclusion The distribution of CMBs foci has nothing to do with early neurological fluctuation .However , more than 5 CMBs foci might be the independent prediction cause of END .%目的:急性腔隙性脑梗死患者早期神经功能恶化( early neurological deterioration , END)的影响预测指标目前尚不明确。文中拟探讨首发急性腔隙性脑梗死患者脑微出血病灶的位置、数量与END的联系。方法选取2009年3月至2012年5月发病24 h内收治于安徽省立医院神经内科的急性腔隙性脑梗死患者217例。所有患者完成磁共振磁敏感成像检查,探讨微出血病灶的位置

  13. Multifractal analysis and lacunarity spectrum of the galaxies of the ninth Sloan Digital Sky Survey (SDSS) data release

    Chacón-Cardona, César A

    2012-01-01

    In this work, we develop a statistical analysis of the large-scale clustering of matter in the Universe from the fractal point of view using galaxies from the Ninth Sloan Digital Sky Survey (SDSS) Data Release (DR9). From the total set of galaxies, a magnitude-limited sample of galaxies with redshifts in the range 0 < z < 0.15 was created. The sample covers the largest completely connected area of the celestial sphere within the catalogue, with limits in right ascension from 120 to 240 degrees and declination from 0 to 60 degrees, which is a region that includes the largest galactic samples that have been studied from the fractal viewpoint to date. The sample contains 164,168 galaxies. Using the sliding-window technique, the multifractal dimension spectrum and its dependence on radial distance are determined. This generalisation of the concept of fractal dimension is used to analyse large-scale clustering of matter in complex systems. Likewise, the lacunarity spectrum, which is a quantity that complemen...

  14. Experimental determination of the permeability in the lacunar-canalicular porosity of bone.

    Gailani, Gaffar; Benalla, Mohammed; Mahamud, Rashal; Cowin, Stephen C; Cardoso, Luis

    2009-10-01

    Permeability of the mineralized bone tissue is a critical element in understanding fluid flow occurring in the lacunar-canalicular porosity (PLC) compartment of bone and its role in bone nutrition and mechanotransduction. However, the estimation of bone permeability at the tissue level is affected by the influence of the vascular porosity in macroscopic samples containing several osteons. In this communication, both analytical and experimental approaches are proposed to estimate the lacunar-canalicular permeability in a single osteon. Data from an experimental stress-relaxation test in a single osteon are used to derive the PLC permeability by curve fitting to theoretical results from a compressible transverse isotropic poroelastic model of a porous annular disk under a ramp loading history (2007, "Compressible and Incompressible Constituents in Anisotropic Poroelasticity: The Problem of Unconfined Compression of a Disk," J. Mech. Phys. Solids, 55, pp. 161-193; 2008, "The Unconfined Compression of a Poroelastic Annular Cylindrical Disk," Mech. Mater., 40(6), pp. 507-523). The PLC tissue intrinsic permeability in the radial direction of the osteon was found to be dependent on the strain rate used and within the range of O(10(-24))-O(10(-25)). The reported values of PLC permeability are in reasonable agreement with previously reported values derived using finite element analysis (FEA) and nanoindentation approaches. PMID:19831477

  15. Clinically unsuspected intracranial hemorrhage as revealed by MR imaging in patients with multiple lacunar infarcts

    Between April 1987 and March 1989, high-field MR imaging was performed in 33 consecutive patients with multiple lacunar infarctions. Although they had no history of hemorrhagic stroke, 17 patients had low-signal intensity areas on T2-weighted images. The low-signal intensity areas were divided into two types: (I) areas more than 1 cm in the maximum diameter (9 patients) and (II) areas measuring as small as 2-3 mm in diameter (8 patients). Three patients had both types of low-signal intensity. For type I, the putamen, thalamus, and right temporal white matter were shown as low-signal intensities in 6, 2, and one patient, respectively. Low-signal intensity for type II was restricted to areas in or near the infarct lesions. Lesions of the putamen or thalamus, as shown in the group of type I, were considered to represent chronic hematoma probably due to previously undiagnosed cerebral hemorrhage. The group of type II seemed to have hemorrhagic infarction. A mean age of the onset of initial symptoms was 55.9 years in the group of type I and 58.6 years in the group of type II. Regarding blood pressure, there was no significant difference between the groups. T2-weighted imaging showed a tendency for low-signal intensity areas in younger patients with hypertension. Thus, MRI imaging may be useful in clinically diagnosing unsuspected intracranial hemorrhage in patients with multiple lacunar infarctions. (N.K.)

  16. Clinically unsuspected intracranial hemorrhage as revealed by MR imaging in patients with multiple lacunar infarcts

    Hashimoto, Shuji; Kawamura, Junichiro; Nakamura, Michikazu; Yamamoto, Toru; Miki, Yukio (Tenri Hospital, Nara (Japan))

    1990-07-01

    Between April 1987 and March 1989, high-field MR imaging was performed in 33 consecutive patients with multiple lacunar infarctions. Although they had no history of hemorrhagic stroke, 17 patients had low-signal intensity areas on T2-weighted images. The low-signal intensity areas were divided into two types: (I) areas more than 1 cm in the maximum diameter (9 patients) and (II) areas measuring as small as 2-3 mm in diameter (8 patients). Three patients had both types of low-signal intensity. For type I, the putamen, thalamus, and right temporal white matter were shown as low-signal intensities in 6, 2, and one patient, respectively. Low-signal intensity for type II was restricted to areas in or near the infarct lesions. Lesions of the putamen or thalamus, as shown in the group of type I, were considered to represent chronic hematoma probably due to previously undiagnosed cerebral hemorrhage. The group of type II seemed to have hemorrhagic infarction. A mean age of the onset of initial symptoms was 55.9 years in the group of type I and 58.6 years in the group of type II. Regarding blood pressure, there was no significant difference between the groups. T2-weighted imaging showed a tendency for low-signal intensity areas in younger patients with hypertension. Thus, MRI imaging may be useful in clinically diagnosing unsuspected intracranial hemorrhage in patients with multiple lacunar infarctions. (N.K.).

  17. Evaluation of 3D tensor tractography of pyramidal tract depicted by 3T MRI in patients with lacunar infarcts. For prediction of motor function outcome

    3D tensor tractography (DTT) has been applied to central nervous system (CNS) diseases to depict neuronal fibers. In this study with 3 tesla MRI, we have evaluated DTT to predict outcome of motor function in patients with lacunar infarcts. Fifteen patients with New lacunar infarcts, underwent DTTs with at least one in the acute (mean 1.4 days) and another in the subacute phase (mean 18.7 days). Patients were separated to 2 groups, recovery and non-recovery. Patients in former group had almost complete recovery in motor function 3 month later, while those to latter had a residual hemiparesis. Motor function was assessed with MMT score, which was uniquely stratefied into 12 levels by a modified MMT (manual muscle testing) protocol. DTT was implemented with 3 tesla MRI (Signa Excite; GE) and analyzed with dTV. IISR which was produced by the Department of Radiology, Tokyo University. The pyramidal tract was delineated by setting each region of interest (ROI), with the cerebral peduncle as the seed point and the motor cortex as the target point. The number of pyramidal fibers was identified as drawn lines obtained from a result display. The ratio of the number of fibers (RF) was calculated based on the number of fibers in the injured side relative to the number of fibers in the intact side x 100. In acute phase mean RFs the recovery (70.8±21.6%) and non-recovery (63.5±23.4%) groups were not significantly different. RF of recovery group in subacute phase was 100.5±28.3%, which was significantly higher with that in acute phase, meanwhile there was no significance difference between RFs of non-recovery group in two phases. In addition there was a significant correlation (R2=0.89) between MMT score 3 month later and RF in subacute phase in all patients group. There seems to be a correlation between long-term recovery of motor function and increased numbers in pyramidal fibers defected by DTT. Therefore, DTT may have a potential use in predicting the outcome of patients

  18. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva;

    2008-01-01

    PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twenty...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0...

  19. Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

    Weaver, C.I.

    1979-01-01

    Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individual morphologies of the plants and the environments in which they occurred.

  20. Immobilization and long-term recovery results in large changes in bone structure and strength but no corresponding alterations of osteocyte lacunar properties

    Bach-Gansmo, Fiona Linnea; Wittig, Nina Kølln; Brüel, Annemarie;

    2016-01-01

    whether osteocyte lacunar properties change during immobilization and subsequent recovery. A rat cortical bone model with negligible Haversian remodeling effects was used, with temporary immobilization of one hindlimb induced by botulinum toxin. Several complementary techniques covering multiple length...

  1. Maximum entropy, fractal dimension and lacunarity in quantification of cellular rejection in myocardial biopsy of patients submitted to heart transplantation

    This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

  2. LACUNARITY OF THE PHRASEOLOGICAL UNITS WITH THE COLOUR COMPONENTS IN THE RUSSIAN, ENGLISH, SPANISH AND PORTUGUESE LANGUAGES

    Khovanskaya E. S.

    2014-05-01

    Full Text Available The article presents a comparative analysis of the factors that influence the appearance of the lacunas with the colour component in the Russian, English, Spanish and Portuguese languages. Lacunar units are the most contrastive in the comparing languages. The article also reveals the phraseological lacunas of some language towards all other comparing languages (concerning phraseo-thematic groups and individual phraseological units

  3. Maximum entropy, fractal dimension and lacunarity in quantification of cellular rejection in myocardial biopsy of patients submitted to heart transplantation

    Neves, L. A.; Oliveira, F. R.; Peres, F. A.; Moreira, R. D.; Moriel, A. R.; de Godoy, M. F.; Murta Junior, L. O.

    2011-03-01

    This paper presents a method for the quantification of cellular rejection in endomyocardial biopsies of patients submitted to heart transplant. The model is based on automatic multilevel thresholding, which employs histogram quantification techniques, histogram slope percentage analysis and the calculation of maximum entropy. The structures were quantified with the aid of the multi-scale fractal dimension and lacunarity for the identification of behavior patterns in myocardial cellular rejection in order to determine the most adequate treatment for each case.

  4. Spatial dispersion and clustering of soil structure through lacunarity of X-ray CT images of soil macropore volumes

    San José Martínez, Fernando; Caniego, Javier; García-Gutiérrez, Carlos

    2016-04-01

    Lacunarity can be seen as a scale dependent measure of heterogeneity or texture ―in terms of image analysis― that was first introduced to quantify different patterns of dispersion and clustering that display geometrical objects with the same fractal dimension. Notwithstanding, lacunarity functions have been revealed as means to measure the deviation of object's geometrical structure from translational invariance beyond self-similarity and fractal geometry. In this work, we will explore how lacunarity quantifies different patterns of dispersion and clustering of different geometrical structures of soil macropore volumes imaged by X-ray computed tomography. Samples extracted from columns were collected at the experimental farm "Finca La Grajera" in La Rioja (Spain), property of La Rioja Regional Government (northern Spain). The vineyard selected was established in 1996. During the 1996 to 2004 period, the soil management was conventional tillage. Before the vineyard was established in 1996, a pasture-legume-cereal rotation was used. In 2004 an experiment was established with different types of soil cover management in between. On December 2010 columns were extracted vertically by percussion drilling between rows of the vineyard.

  5. Assessment of diffusional anisotropy of the corpus callosum in patients with multiple lacunar infarcts. Relationship between the apparent diffusion coefficient ratio and global cognitive impairment

    Ishihara, Makiko; Hayashi, Hiromitsu; Amano, Yasuo; Takagi, Ryo; Nakahara, Madoka; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan); Cho, Keiichi; Okada, Susumu

    1998-06-01

    The purpose of the present study is to evaluate diffusional anisotropy of white matter in patients with multiple lacunar infarcts using diffusion-weighted echo-planar imaging (DW-EPI), and to examine the relationship between diffusional anisotropy and global cognitive ability as assessed by the mini-mental status examination (MMSE). In particular, we focused on the parameter changes for the corpus callosum as a marker for disconnection of the associative cortices. Twenty-nine patients divided into 2 cognitive level groups (low MMSE, n=16; high MMSE, n=13) and 8 normal controls were examined with a GE 1.5 T Horizon system. Three series of DW-EPI images were obtained using the following epidw{sub g}{center_dot}psd{sup TM} sequence: TR/TE=6500/120 ms, single shot, 6.5 mm slice thickness and 1.5 mm gap transaxial sections of the whole brain, with b-factors of 0 and 710 along each x- and y-axial direction. The parametric maps for apparent diffusion coefficient (ADC) in each direction, ADC(x) and ADC(y), and their rate map (ADC rate=ADC(x)/ADC(y)) were created on a pixel-by-pixel basis. ROI data were extracted from images of the corpus callosum and bilateral optic radiata. As a result, the ADC(x) was markedly larger for corpus callosum than that for optic radiata, whereas the ADC(y) showed an inverse trend, attributable to regional differences of diffusional anisotropy. In corpus callosum, however, the ADC(y) values were observed to increase with the level of disease severity, resulting in a decrease of the ADC rate. Notably, there was a significant difference between the three groups for callosal genu, with a slight positive correlation between the ADC rate and the MMSE scores. Our study suggests that a relationship exists between the reduction of diffusional anisotropy in callosal genu and the global cognitive impairment seen in patients with multiple lacunar infarcts. (K.H.)

  6. Assessment of diffusional anisotropy of the corpus callosum in patients with multiple lacunar infarcts. Relationship between the apparent diffusion coefficient ratio and global cognitive impairment

    The purpose of the present study is to evaluate diffusional anisotropy of white matter in patients with multiple lacunar infarcts using diffusion-weighted echo-planar imaging (DW-EPI), and to examine the relationship between diffusional anisotropy and global cognitive ability as assessed by the mini-mental status examination (MMSE). In particular, we focused on the parameter changes for the corpus callosum as a marker for disconnection of the associative cortices. Twenty-nine patients divided into 2 cognitive level groups (low MMSE, n=16; high MMSE, n=13) and 8 normal controls were examined with a GE 1.5 T Horizon system. Three series of DW-EPI images were obtained using the following epidwg·psdTM sequence: TR/TE=6500/120 ms, single shot, 6.5 mm slice thickness and 1.5 mm gap transaxial sections of the whole brain, with b-factors of 0 and 710 along each x- and y-axial direction. The parametric maps for apparent diffusion coefficient (ADC) in each direction, ADC(x) and ADC(y), and their rate map (ADC rate=ADC(x)/ADC(y)) were created on a pixel-by-pixel basis. ROI data were extracted from images of the corpus callosum and bilateral optic radiata. As a result, the ADC(x) was markedly larger for corpus callosum than that for optic radiata, whereas the ADC(y) showed an inverse trend, attributable to regional differences of diffusional anisotropy. In corpus callosum, however, the ADC(y) values were observed to increase with the level of disease severity, resulting in a decrease of the ADC rate. Notably, there was a significant difference between the three groups for callosal genu, with a slight positive correlation between the ADC rate and the MMSE scores. Our study suggests that a relationship exists between the reduction of diffusional anisotropy in callosal genu and the global cognitive impairment seen in patients with multiple lacunar infarcts. (K.H.)

  7. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm;

    2016-01-01

    Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes...... orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties...

  8. Modeling fluorescence recovery after photobleaching in loaded bone: potential applications in measuring fluid and solute transport in the osteocytic lacunar-canalicular system.

    Zhou, Xiaozhou; Novotny, John E; Wang, Liyun

    2008-12-01

    Solute transport through the bone lacunar-canalicular system is essential for osteocyte viability and function, and it can be measured using fluorescence recovery after photobleaching (FRAP). The mathematical model developed here aims to analyze solute transport during FRAP in mechanically loaded bone. Combining both whole bone-level poroelasticity and cellular-level solute transport, we found that load-induced solute transport during FRAP is characterized by an exponential recovery rate, which is determined by the dimensionless Strouhal (St) number that characterizes the oscillation effects over the mean flows, and that significant transport occurs only for St values below a threshold, when the solute stroke displacement exceeds the distance between the source and sink (the canalicular length). This threshold mechanism explains the general flow behaviors such as increasing transport with increasing magnitude and decreasing frequency. Mechanical loading is predicted to enhance transport of all tracers relative to diffusion, with the greatest enhancement for medium-sized tracers and less enhancement for small and large tracers. This study provides guidelines for future FRAP experiments, based on which the model can be used to quantify bone permeability, solute-matrix interaction, and flow velocities. These studies should provide insights into bone adaptation and metabolism, and help to treat various bone diseases and conditions. PMID:18810639

  9. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    Nabatame, Hidehiko; Nakamura, Kazuo; Matsuda, Minoru; Fujimoto, Naoki [Shiga Medical Center, Moriyama (Japan); Fukuyama, Hidenao

    1995-07-01

    We performed MRI and measured cerebral blood flow (CBF) using {sup 123}I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author).

  10. The correlation of the thalamic lesions on MRI with cerebral cortical blood flow in patients with lacunar infarction

    We performed MRI and measured cerebral blood flow (CBF) using 123I-IMP SPECT microsphere model in twenty three right-handed patients with lacunar infarction. Twelve of 23 patients showed chronic deterioration of dysarthria and gait disturbance. The mental function of the patients was evaluated by the Mini-Mental State (MMS) examination. The area of high intensity on T2-weighted images was quantitatively analyzed in the cerebral white matter (WM), lenticular nucleus (LN) and thalamus (THA). The score of MMS was positively correlated with the local CBF in the bilateral frontal, parietal, temporal and occipital cortices (p<0.05). Also, the area of high intensity in the left THA showed a significant negative correlation with local CBF of the bilateral frontal, parietal, temporal and occipital cortices (p<0.001). The high intensity areas of the bilateral LN, right WM and right THA had a significant but weaker negative correlation with local CBF of some cortices. These findings suggest that thalamic lesions on the dominant side play an important role in the reduction of cortical blood flow and the deterioration of mental functions in patients with lacunar infarction. (author)

  11. Hyperpolarized 3helium magnetic resonance ventilation imaging of the lung in cystic fibrosis: comparison with high resolution CT and spirometry

    The purpose of this study was to compare hyperpolarized 3helium magnetic resonance imaging (3He MRI) of the lungs in adults with cystic fibrosis (CF) with high-resolution computed tomography (HRCT) and spirometry. Eight patients with stable CF prospectively underwent 3He MRI, HRCT, and spirometry within 1 week. Three-dimensional (3D) gradient-echo sequence was used during an 18-s breath-hold following inhalation of hyperpolarized 3He. Each lung was divided into six zones; 3He MRI was scored as percentage ventilation per lung zone. HRCT was scored using a modified Bhalla scoring system. Univariate (Spearman rank) and multivariate correlations were performed between 3He MRI, HRCT, and spirometry. Results are expressed as mean±SD (range). Spirometry is expressed as percent predicted. There were four men and four women, mean age=31.9±9 (20-46). Mean forced expiratory volume in 1 s (FEV)1=52%±29 (27-93). Mean 3He MRI score=74%±25 (55-100). Mean HRCT score=48.8±24 (13.5-83). The correlation between 3He MRI and HRCT was strong (R=±0.89, p3He MRI; 3He MRI correlated better with FEV1 and forced vital capacity (FVC) (R=0.86 and 0.93, p3He MRI correlates strongly with structural HRCT abnormalities and is a stronger correlate of spirometry than HRCT in CF. (orig.)

  12. Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells.

    Pandey, R.; Quinn, J.; Joyner, C.; Murray, D W; Triffitt, J T; N. A. Athanasou

    1996-01-01

    OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously i...

  13. Correlation between MRI findings, blood pressure and mental ability in patients with multiple lacunar infarcts

    We studied the association between mental ability as rated by Hasegawa's scale, the severity of hypertension, the severity of brain atrophy, and the severity of lesions in the cerebral white matter on magnetic resonance imaging in 34 patients with multiple cerebral infarcts but without obvious cortical lesions. Data were analyzed using multiple regression analysis. The patients having both marked brain atrophy and severe white matter lesions showed an impairment of mental ability. Brain atrophy was correlated with aging and the severity of white matter lesions. There was a significant positive correlation between the diastolic blood pressure and the severity of white matter lesions. These findings suggest that the white matter lesions in patients with multiple cerebral infarcts are correlated with brain atrophy and mental deterioration, and that uncontrolled hypertension is an important risk factor in exacerbating the lesions in the cerebral white matter. (author)

  14. Effect of observational holes and borders on lacunarity and fractality measurements in a galaxy catalogue

    García-Farieta, Jorge E

    2016-01-01

    Cosmological observations reveal that the Universe contains a hierarchy of galaxy clustering with a transition to homogeneity on large scales according to the $\\Lambda$CDM model. Some observational estimates suggest that the Universe behaves as a multifractal object, where galactic clustering is based on generalisation of the dimension in metric spaces. From this point of view, we study the spatial distribution of points by simulating galaxies on large scales in the Universe with samples from the Sloan Digital Sky Survey (SDSS), including observational holes in the masks. We build homogeneous samples following the radial selection function using the "shuffle" method for a main sample of $3,273,548$ points limited to the redshift range $0.0020$ and percentages of holes near $40\\%$, $r_H$ is displaced on scales on the order of $120~Mpc/h$. Hole percentages between $10\\%$ and $30\\%$ show an $r_H$ of $70-90~Mpc/h$, and for percentages below $10\\%$, $r_H$ decreases to become equal to the $r_H$ value of the SDSS-BO...

  15. Correlation analysis between the carotid artery ather osclerosis severity of patients with lacunar infarct and the level of serum uric acid, high-sensitivity C-reactive protein

    WANG Shu

    2013-01-01

    Full Text Available Background Nowadays, clinical practice shows that the number of patients with cerebral infarction increases year by year in young and middle-aged adults with unclear causes. This paper aims to investigate the correlation between the level of serum uric acid (UA, high-sensitivity C-reactive protein (hsCRP and the degree of carotid atherosclerosis by detecting the level of UA, hsCRP and carotid intima-media thickness (IMT in young and middle-aged patients with lacunar infarct. Methods By using Holland Philips HT-11 color Doppler ultrasonic diagnostic apparatus with linear type probe and 7.50MHz frequency, IMT of end-diastolic distal and bifurcation of arteria carotis communis and proximal internal carotid artery were measured respectively on 186 patients with definitely diagnosed lacunar infarct. As a result, average values were taken as the IMT values. IMT < 1.00 mm was regarded as negative result and 1.00 mm ≤IMT < 1.20 mm was thickening of carotid artery intima. Carotid artery plaque formation was regarded with echo structure existing in the lumen or abnormal blood flow deficits into the lumen, or local IMT ≥1.20 mm at vertical and horizontal scan. At the same time, the levels of UA and hsCRP were detected, and correlation analysis was made between them and IMT. Results The values of UA, hsCRP and IMT in the case group were higher than that in the control group (P = 0.000. The differences among the case subgroups including IMT thickening group, plaque formation group and IMT normal group were statistically significant (P < 0.01, for all. There was linear correlation between the levels of UA, hsCRP and IMT ( r = 0.923, P = 0.000; r = 0.955, P = 0.008. Conclusion UA and hsCRP involve in the formation of atherosclerosis plaque and play an important role in the first-onset lacunar infarct patients without hypertension and other risk factors.

  16. Mapas Lacunares Activación cartográfi ca del espacio vacío

    Roger Pàez i Blanch

    2015-05-01

    Full Text Available ResumenEl mapa se ha venido utilizado habitualmente como documento que  representa la realidad de manera objetiva y pretendidamente neutra. Sin embargo, el mapa no sólo representa, sino que construye la realidad de manera concreta, a partir de una selección limitada de parámetros que hacen posible orientar una cierta mirada sobre el mundo. Esta orientación específi ca de la realidad que el mapa lleva a cabo, abre posibilidades de transformación de la misma sobre las que la arquitectura, entre otrasdisciplinas, puede trabajar. Llamamos cartografía operativa la producción y el uso de mapas para ampliar la concepción de la realidad y promover su transformación. El presente artículo trata de la activación cartográfica del espacio vacío. A través de una serie de ejemplos, acota algunas de las maneras en las cuales las prácticas cartográficas informan nuestra comprensión del espacio vacío. Los ejemplos, que están presentados bajo cinco tipologías de mapas lacunares, representan distintos modos de  cartografiar el vacío que articulan una actitud crítica respecto los propios procesos cartográfi cos y los usos a los cuales pueden ser sometidos. Estos mapas pretenden mostrar como ciertas cartografías construyen la realidad de manera concreta e orientada a partir de la activación del vacío, enriqueciendo el diálogo permanente entre realidad y representación, en aras de abrir nuevos campos de transformación de lo real.AbstractMaps have generally been used as documents that represent reality in an objective and allegedly neutral way. Maps do not just represent reality, however, they also construct it in a specific way. They activate a limited selection of parameters which allow for orienting a particular perspective on the world. This orientation of reality that is characteristic of maps opens up possibilities for the transformation of reality, which can be brought into play by architecture or other disciplines. We use the

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

    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 m2. 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 m2 (OR, 2.9; P-1 per 1.73 m2 (OR, 23.8; P75 years (OR, 4.1; P-1 per 1.73 m2 (OR, 3.7; P-1 per 1.73 m2 (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)

  18. Hyperpolarized {sup 3}helium magnetic resonance ventilation imaging of the lung in cystic fibrosis: comparison with high resolution CT and spirometry

    McMahon, Colm J.; Dodd, Jonathan D.; Skehan, Stephen J.; Masterson, James B. [St. Vincent' s University Hospital, Department of Radiology, Dublin (Ireland); Hill, Catherine; Woodhouse, Neil; Wild, Jim M.; Fichele, Stan [Royal Hallamshire Hospital, The Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); Gallagher, Charles G. [St. Vincent' s University Hospital, Department of National Referral Centre for Adult Cystic Fibrosis, Dublin (Ireland); Beek, Edwin J.R. van [Royal Hallamshire Hospital, The Unit of Academic Radiology, University of Sheffield, Sheffield (United Kingdom); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, IA (United States)

    2006-11-15

    The purpose of this study was to compare hyperpolarized {sup 3}helium magnetic resonance imaging ({sup 3}He MRI) of the lungs in adults with cystic fibrosis (CF) with high-resolution computed tomography (HRCT) and spirometry. Eight patients with stable CF prospectively underwent {sup 3}He MRI, HRCT, and spirometry within 1 week. Three-dimensional (3D) gradient-echo sequence was used during an 18-s breath-hold following inhalation of hyperpolarized {sup 3}He. Each lung was divided into six zones; {sup 3}He MRI was scored as percentage ventilation per lung zone. HRCT was scored using a modified Bhalla scoring system. Univariate (Spearman rank) and multivariate correlations were performed between {sup 3}He MRI, HRCT, and spirometry. Results are expressed as mean{+-}SD (range). Spirometry is expressed as percent predicted. There were four men and four women, mean age=31.9{+-}9 (20-46). Mean forced expiratory volume in 1 s (FEV){sub 1}=52%{+-}29 (27-93). Mean {sup 3}He MRI score=74%{+-}25 (55-100). Mean HRCT score=48.8{+-}24 (13.5-83). The correlation between {sup 3}He MRI and HRCT was strong (R={+-}0.89, p<0.001). Bronchiectasis was the only independent predictor of {sup 3}He MRI; {sup 3}He MRI correlated better with FEV{sub 1} and forced vital capacity (FVC) (R=0.86 and 0.93, p<0.01, respectively) than HRCT (R={+-}0.72 and {+-}0.81, p<0.05, respectively). This study showed that {sup 3}He MRI correlates strongly with structural HRCT abnormalities and is a stronger correlate of spirometry than HRCT in CF. (orig.)

  19. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium; Contribution a la determination de l'albedo doublement differentiel en angle et en energie des neutrons. Application a la propagation dans les milieux lacunaires

    Litaize, O

    2000-07-01

    The goal of this thesis is to study the neutron propagation by reflection from lacunar medium interfaces. The most efficient method to calculate this type of propagation is to use the concept of albedo. Actual version of NARCISSE code uses a simple formulation of angular differential albedos and so, can only treat single reflections. Multiple reflections treatment needs the knowledge of neutron spectrum after reflection. This energetic information is contained in double angular and energy differential albedos. The first step of this study consists to generate these albedos for various materials. Several methods have been tested and the Monte Carlo method was retained. A new estimator has been developed and validated in the Mote Carlo transport code TRIPOLI-4. It computes, during the simulation of the neutron history, the angular and energy reflection probability at each collision site. The second step consists to generate an interpolation scheme and albedo libraries for various materials. A new version of NARCISSE was developed to use these libraries and the interpolation module. Spectrum and dose rates comparisons were made between codes to validate these albedos. The neutron propagation by multiple reflections can be studied now, by using this new version of Narcisse. (author)

  20. Iris Feature Extraction Algorithm Using Vertically Expanded Blanket Dimension and Lacunarity%基于毯子维和缺项的虹膜特征提取算法

    刘凯; 周卫东; 王玉

    2011-01-01

    Iris feature extraction is important in iris recognition. An iris feature extraction algorithm is proposed by using combination of blanket dimension and lacunarity. Because Human iris texture is characterized by fractal geometry due to its rich self-similarity and abundant variation, vertically expanded blanket dimension is employed to represent iris texture variation and radial pattern at different resolution levels. Lacunarity is introduced to extract iris features that have different texture and fractal patterns but have same fractal dimension value. The combination of blanket dimension and lacunarity in iris feature extraction can embody the minute change of texture information comprehensively, and improve the capacity of iris classification. The experimental results on the CASIA-IrisV3-Interval iris database show that the combination of blanket dimension and lacunarity can extract iris textural features accurately and effectively, and high performance for iris recognition is achieved by using those features.%虹膜特征提取是虹膜识别的一个关键环节.文中提出一种毯子维和缺项相结合的虹膜特征提取算法.利用虹膜纹理的自相似和丰富的变化细节所具有的分形几何特性,采用纵向扩展毯子维表达不同分辨能力下虹膜纹理的变化及其辐射排列特点.通过引入缺项进一步提取不同纹理和分形表现却具有相同分形维数的虹膜特征.两者的结合能够更加全面地反映虹膜纹理的细腻变化.将归一化虹膜图像灰度值的毯子维及缺项用于虹膜分类,提高对虹膜的分类能力.针对CASIA-IrisV3-Interval数据库的仿真结果表明,纵向扩展毯子维结合缺项能够有效、快速提取虹膜的纹理信息,所获得的特征具有高的虹膜识别性能.

  1. Analysis of the intracranial lesions, cerebrovascular conditions and lacunar infarction in patients with migraine%偏头痛与脑血管发育异常、脑白质变性、脑腔梗关系分析

    赵轶; 席刚明

    2014-01-01

    目的:观察偏头痛患者脑血管情况及颅内病变情况。方法:以住院偏头痛患者为研究对象、同一时期无偏头痛患者为对照,进行神经影像学比较。结果:58例偏头痛患者中,有脑腔梗病灶19例(32.76%),有脑白质变性17例(29.31%),有脑血管异常37例(63.79%)。61例对照组中有脑腔梗病灶9例(14.75%),有脑白质变性5例(8.20%),有脑血管异常13例(21.31%)。2组比较差异均有统计学意义(P<0.05)。结论:偏头痛与脑白质病变、脑腔梗有关,血管因素可能参与偏头痛的发作。%Objective:To obtain the intracranial lesions and cerebrovascular conditions in patients with migraine.Methods:Patient with migraine collected from the hospitalized were compared with patients with non-migraine in their neurimaging findings.Results:Among 58 patients with migraine, 19 had a or more lacunar infarctions;17 had white matter lesions and 37 had cerebrovascular abnormalities, while 61 patients with non-migraine had 9 lacunar infarctions, 5 white matter lesions and 13 cerebrovascular abnormalities. They were all signiifcantly different(P<0.05).Conclusion:Migraine was associated with the white matter lesions and lacunar infarction, while vascular factors may be involved in the migraine.

  2. Location of lacunar infarcts correlates with cognition in a sample of non-disabled subjects with age-related white-matter changes: the LADIS study

    Benisty, S; Gouw, A A; Porcher, R;

    2009-01-01

    evaluation was based on the Mini Mental Status Examination (MMSE), a modified Alzheimer Diseases Assessment Scale for global cognitive functions, and compound Z scores for memory, executive functions, speed and motor control. WMH were rated according to the Fazekas scale; the number of lacunes was assessed....... There was also a significant negative association between the presence of lacunes in putamen/pallidum and the memory compound Z score (beta = -0.13; p = 0.038). By contrast, no significant negative association was found between cognitive parameters and the presence of lacunes in internal capsule, lobar...

  3. 维生素B12与腔隙性脑梗塞后抑郁的关联研究%Association of Vitamin B12 with Depression after Lacunar Stroke

    李中春; 呙登俊; 江霞

    2013-01-01

    OBJECTIVE To explore the association of serum vitamin B12 with depression after lacunar stroke.METHODS Between June 2009 and June 2012,829 patients with lacunar stroke,according to Hamilton depression scale score,were divided into two groups:group with depression and group without depression.The concentration of serum vitamin B 12 and the ratio of vitamin B12 deficiency were compared.The relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression was analyzed by the curve-fitting method.RESULTS The group without depression contained 750 cases and the mean concentration of serum vitamin B12 of this group was (172.5±20.4)pmol·L-1.There were 212 cases in the group without depression which were considered as vitamin B 12 deficiency.The group with depression contained 79 cases and the mean concentration of serum vitamin B12 of this group was (139.1±18.2)pmol·L-1.There were 53 cases in the group with depression which were considered as vitamin B12 deficiency.There were significant differences in the concentration of serum vitamin B 12 and the ratio of vitamin B 12 deficiency(P<0.000 1).Inverse curve reflected the relationship between Hamilton depression scale score and the concentration of serum vitamin B 12 in the group with depression.CONCLUSION Depression after lacunar stroke is related to vitamin B12 deficiency.%目的 探讨血清维生素B12与腔隙性脑梗塞后抑郁之间关系.方法 2009年6月—2012年6月腔隙性脑梗塞患者共829例,使用汉密尔顿抑郁量表将患者分为两组:无抑郁组和抑郁组,比较两组间血清维生素B12浓度和维生素B12缺乏者的比例.在抑郁组内对汉密尔顿抑郁量表评分和血清维生素B12浓度进行曲线拟合.结果 无抑郁组患者750例,血清维生素B12平均浓度为(172.5±20.4)pmol·L-1,其中维生素B12缺乏者212例.抑郁组79例,血清维生素B12平均浓度为(139.1± 18.2)pmol·L-1,

  4. 早期护理干预在腔隙性脑梗死认知功能康复的效果研究%Effect of early nursing intervention on cognitive function rehabilitation in patients with lacunar cerebral infarction

    黄紫霞; 刘剑平; 李辉; 钟京梅; 徐柳

    2015-01-01

    目的 探讨早期护理干预对腔隙性脑梗死患者认知功能障碍康复的效果.方法 选择90例符合纳入标准的腔隙性脑梗死住院患者,使用中文版蒙特利尔认知评估(MoCA)量表进行认知功能障碍评分,将评分< 26分的患者随机分为实验组和对照组,对照组给予常规的认知康复护理,干预组予制定个体化认知功能康复护理以及手指操训练3个月,在15天、1月、2月、3月分别对两组进行认知功能康复测评.结果 实验组MoCA量表得分及视空间与执行功能、注意、抽象等认知功能评分在分组、时间、时间和分组的交互作用上差异均有统计学意义(P<0.05),记忆、定向两项在时间、时间和分组的交互作用上差异有统计学意义(P<0.05),分组与康复时间存在交互效应,随着时间的推进,两组干预效果差异有统计学意义.语言、命名方面两组差异无统计学意义(P>0.05).结论 早期护理干预对腔隙性脑梗死认知功能障碍的患者认知康复有良好的效果,值得推广.%Objective To explore the effect of early nursing intervention on cognitive function rehabilitation in patients with lacunar cerebral infarction.Methods 90 inpatients meeting the inclusion criteria of lacunar cerebral infarction were selected.Chinese version of Montreal cognitive assessment (MoCA) scale were used to evaluate cognitive dysfunction.The patients whose MoCA scores were below 26 were randomly divide into an experimental group and a control group.The control group received conventional cognitive rehabilitation nursing care,and the experimental group individualized rehabilitation nursing care and cognitive function finger exercise training for 3 months.Cognitive function rehabilitation evaluation was carried out in both group 15 days and 1,2,and 3 months from then.Results There were statistical differences in MoCA score and the scores of visual space,executive,attentiona,and abstract functions in

  5. Carotid artery wall stiffness is increased in patients with small vessel disease: A case-control study

    Salihović-Hajdarević Denisa; Pavlović Aleksandra M.; Smajlović Dževdet; Podgorac Ana; Jovanović Zagorka; Švabić-Međedović Tamara; Čovičković-Šternić Nadežda

    2016-01-01

    Introduction. Cerebral ischemic small-vessel disease (SVD), causing lacunar infarcts and white matter hyperintensities on brain magnetic resonance imaging (MRI), is a progressive disease associated with an increased risk of stroke, dementia and death. Increased arterial stiffness has been associated with ischemic stroke and cerebral SVD independently of common vascular risk factors. Objective. The aim of the study was to analyze arterial stiffness in our pa...

  6. 腔隙性脑梗死患者早期认知功能与脑血流动力学的改变%The changes of early cognitive function and cerebral hemodynamics in patients with lacunar cerebral infarction

    李慧英; 郑晓风; 杨淑贞; 甄伟兰; 杨明宇; 梅飞来; 陈湘

    2015-01-01

    Objective Toinvestigatethechangesofcognitiveimpairmentandcerebralhemodynamics inpatientswithacutelacunarcerebralinfarctionwithin2weeksafteronset.Methods Nineteenpatients with lacunar cerebral infarction (a patient group)were consecutive enrolled in the study. Twenty-three sex-and age-matched inpatients without ischemic cerebrovascular disease or healthy volunteers of outpatient department over the same period were used as a control group. The cerebral hemodynamic features were evaluated with transcranial Doppler (TCD)"breath-holding test" and single photon emission computed tomography (SPECT)"resting + adenosine stress imaging". Simultaneously,the neuropsychological tests were performed,the Montreal cognitive assessment (MoCA)was performed including executive capacity, structural capacity,memory (including auditory memory,visual memory,and logic memory ),information processing speed,and visual-spatial ability. Results (1 )There were no significant differences in the years of education,hypertension,diabetes,hyperlipidemia,coronary heart disease,and smoking between the 2 groups (all P>0. 05). Compared with the control group,there were significant differences in the MoCA score,visual memory,executive function,structural capacity,and information processing speed of the patient group (all P<0. 05). (2)19 patients completed the SPECT resting + load test (12 in the control group and 7 in the patient group). There were significant differences in the uptake ratio (UR)in the right basal ganglia (8. 91[-2. 48 - 5. 87]and -6. 21 [-10. 39 - 5. 42 respectively])and left frontal lobe UR (11. 62 [2. 93-16. 87]and 1. 04 [-10. 17- 3. 82]respectively)between the patient group and the control group (P<0. 05). (3)26 patients completed the breath-holding test + head-up tilt table test (n=13 in each group]. The vascular motor reactivities were 13 ± 5 on the left and 21 ± 7 on the right, and the breath-holding indexes were 0. 66 ± 0. 26 on the left and 1. 0 ± 0. 4 on the right in the

  7. 68例腔隙性脑梗死MRI表现与血脂变化的相关性研究%The correlation of magnetic resonance imaging and lipid levels in 68 cases of lacunar infarction

    田力; 赵一蓉; 刘翠芳

    2014-01-01

    目的:探讨腔隙性脑梗死(LI)的MRI表现与血脂变化的相关性。方法回顾性分析68例LI患者的MRI表现及其血脂水平,选取62例同期住院就诊的非心脑血管疾病患者为对照组,应用多元Logistic回归分析LI的M RI表现与血脂变化的相关关系。结果 L I患者M RI共检出299个腔隙性病灶,其中梗死病灶位于左侧大脑半球58个(19.40%),右侧大脑半球26个(8.70%),双侧基底节区73个(24.41%),丘脑27个(9.03%),侧脑室旁放射冠54个(18.06%),脑干39个(13.04%),小脑22个(7.36%)。LI患者的TC、TG、LDL-C和Ox-LDL水平显著增高(P<0.05),而HDL-C的水平明显低于对照组(P<0.05)。多元Logistic回归分析显示TC、TG、LDL-C、HDL-C和Ox-LDL对LI的相对危险度分别为1.56、1.27、1.39、1.46和1.44。结论 LI患者的M RI表现与血脂水平有一定程度的相关性,血脂水平升高可能是L I的重要危险因素。%Objective To explore relationship between magnetic resonance imaging (MRI) performance and lipid levels in pa-tients with lacunar infarction (LI) .Methods 68 patients with LI were retrospectively analyzed ,62 cases patients without heart ce-rebrovascular disease in the same period were choosen as control group ,the multivariate logistic regression was used to analyze the relationship between MRI performance ,the changed level of lipid .Results A total of 299 lacunar lesions were detected by MRI ,in which there were 58(19 .40% )in the left cerebral hemisphere ,26(8 .70% ) in the right hemisphere ,73(24 .41% ) in the bilateral basal ganglia ,27 (9 .03% ) in thalamus ,54 (18 .06% ) in the lateral ventricles corona radiata ,39 (13 .04% ) in brainstem ,and 22 (7 .36% ) in cerebellum .TC ,TG ,LDL-C and Ox-LDL levels in LI patients were significantly higher than the controls (P<0 .05) , while HDL-C levels were significantly lower than the controls (P<0

  8. Relationship between Cerebral Microbleeds and White Matter Lesions and Lacunar ;Infarcts%脑微出血与脑白质病变及腔隙性梗死关系研究

    高中宝; 赵杏丽; 王振福; 杨扬; 管锦群; 王婷; 吴卫平

    2015-01-01

    目的探讨脑微出血(cerebral microbleeds,CMBs)与脑白质病变(white matter lesions,WML)及腔隙性梗死(lacunar infarcts,LI)的关系。  方法连续纳入2010年2月至2012年2月解放军总医院南楼神经内科病房根据病史及头颅影像学检查确诊患有脑血管病或具有高血压、糖尿病、高脂血症等脑血管病危险因素者217例。采用G E公司1.5T磁共振成像行头颅常规序列及T2*血管加权成像(T2 star weighted angiography,SWAN)序列扫描。记录深部及皮层部位CMBs病灶数,按照Fazekas评分和Scheltens改良量表将脑室旁白质高信号(peri-ventricular hyperintensities,PVH)和深部白质高信号(deep white matter hyperintensities,DWMH)分别评分,根据病灶数量评估LI的严重程度分析CMBs与PVH、DWMH及LI的关系。  结果随着PVH和DWMH评分的升高,CMBs的检出率分别由41.8%(PVH=1)及40.8%(DWMH=1)升高至68.8%(PVH=3)及76.9%(DWMH=3);随着LI数量的增加,CMBs的检出率由46.3%升高至75%。深部CMBs与PVH及DWMH的严重程度有较强相关性(rs=0.345,P<0.001;rs=0.346,P<0.001),与LI亦显著相关(rs=0.281,P<0.001);而皮层CMBs与PVH及DWMH严重程度仅呈弱相关(rs=0.219,P=0.001;rs=0.189,P=0.005),与LI无显著相关性。  结论深部CMBs与脑室旁及深部脑白质病变、LI相关。%Objective To investigate the relationship between cerebral microbleeds(CMBs) and white matter lesions(WML) and lacunar infarcts(LI). Methods The identiifed population inculded 217 patients with cerebral vascular disease or related risk factors admitted to the Department of Geriatric Neurology of the PLA General Hospital between February, 2010 and February, 2012. Routine sequence and T2 star weighted angiography sequence of magnetic resonance imaging were performed with 1.5 Tesla machine maded by General Electric company. The number of CMBs in deep and

  9. Detection of radiation-induced lung injury in non-small cell lung cancer patients using hyperpolarized helium-3 magnetic resonance imaging

    Purpose: To compare hyperpolarized helium-3 magnetic resonance imaging (3He-MRI) acquired from non-small cell lung cancer (NSCLC) patients before and after external beam radiotherapy (EBRT). Methods and materials: In an Ethics Committee-approved prospective study, five patients with histologically confirmed NSCLC gave written informed consent to undergo computed tomography (CT) and 3He-MR ventilation imaging 1 week prior to and 3 months after radiotherapy. Images were registered to pre-treatment CT using anatomical landmark-based rigid registration to enable comparison. Emphysema was graded from examination of the CT. MRI-defined ventilation was calculated as the intersection of 3He-MRI and CT lung volume as a percentage of the CT lung volume for the whole lung and regions of CT-defined pneumonitis. Results: On pre-treatment images, there was a significant correlation between the degree of CT-defined emphysema and 3He-MRI whole lung ventilation (Spearman's rho = 0.90, p = 0.04). After radiation therapy, pneumonitis was evident on CT for 3/5 patients. For these cases, 3He-MRI ventilation was significantly reduced within the regions of pneumonitis (pre: 94.1 ± 2.2%, post: 73.7 ± 4.7%; matched pairs Student's t-test, p = 0.02, mean difference = 20.4%, 95% confidence interval 6.3-34.6%). Conclusions: This work demonstrates the feasibility of detecting ventilation changes between pre- and post-treatment using hyperpolarized helium-3 MRI for patients with NSCLC. Pre-treatment, the degree of emphysema and 3He-MRI ventilation were correlated. For three cases of radiation pneumonitis, 3He-MRI ventilation changes between pre- and post-treatment imaging were consistent with CT evidence of radiation-induced lung injury.

  10. Numerical simulation of osteocyte cell in response to directional mechanical loadings and mechanotransduction analysis: Considering lacunar-canalicular interstitial fluid flow.

    Joukar, Amin; Niroomand-Oscuii, Hanieh; Ghalichi, Farzan

    2016-09-01

    The osteocyte cell is a bone cell that also functions as a bone mechanosensor. In this work, a three-dimensional (3D) fluid-structure interaction (FSI) model of an osteocyte cell under different mechanical loading conditions was used to obtain a better understanding of osteocyte cell behavior under different physiological conditions. In the current study, both fluid and solid parts of osteocyte cell were considered in order to allow for more accurate results. Five different loading conditions have been applied to the osteocyte cell, and consequently the different interstitial fluid flow velocities and shear stresses have been investigated. Furthermore, using a mathematical model, the change in the stimulus function value with shear stress and NO enzyme was revealed. This work suggests that changes in osteocyte morphology and direction of loadings affect cell stimulation. It was found that cell is mostly stimulated and expanded in the direction experiencing the most shear stress. Finally, the amount of cell stimulation was shown quantitatively and there was strong dependency between stimulus function, shear stress, calcium, and NO concentration. PMID:27393805

  11. Clinical analysis of homocysteine, hypersensitive C-reactive protein and cognitive function in patients with early acute lacunar infarction%腔隙性脑梗死早期患者同型半胱氨酸、高敏C反应蛋白及认知功能的临床分析

    王莹; 李慧英; 甄伟兰; 梅飞来

    2015-01-01

    目的:探讨腔隙性脑梗死早期患者认知功能的特点以及同型半胱氨酸(Hcy)、高敏C反应蛋白(hs-CRP)与认知功能障碍的相关性。方法选取2014年5月~2015年4月在北京航天总医院就诊的患者或体检者共50例,其中26例腔隙性脑梗死患者作为病例组,24例同期住院的无缺血性脑卒中患者或门诊健康志愿者作为对照组,测定两组Hcy和hs-CRP的含量,分析两项指标与腔隙性脑梗死的关系;对受试者进行全面的神经心理学测试,包括蒙特利尔认知评估量表(MoCA)、视空间能力、记忆力(包括听觉记忆、视觉记忆和逻辑记忆)、执行能力、结构能力、信息处理速度检查等,比较两组测试结果有无差别,分析影响腔隙性脑梗死的相关因素,并分析血浆Hcy和hs-CRP水平与受试者MoCA得分的相关性。结果病例组血浆Hcy和hs-CRP水平较对照组显著增高,差异有统计学意义(P<0.05);病例组MoCA评分视觉记忆、听觉记忆(即刻记忆、长延迟回忆)、执行能力、结构能力(积木测试、画钟测试)、视空间能力较对照组显著降低,差异有统计学意义(P<0.05)。影响腔隙性脑梗死的相关因素包括高脂血症、冠心病、高hs-CRP(P<0.05)。血浆Hcy和hs-CRP水平与受试者MoCA得分呈负相关,差异有统计学意义(r=-0.327、-0.117,P=0.021、0.397)。结论血浆Hcy和hs-CRP增高可能是腔隙性脑梗死的危险因素;腔隙性脑梗死患者早期已经存在不同程度的认知功能障碍,且与高Hcy和高hs-CRP存在一定的相关性。%Objective To investigate the features of cognitive function of patients with early acute lacunar infarction and the correlation of homocysteine (Hcy), high-sensitivity C-reactive protein (hs-CRP) and cognitive dysfunction. Methods Fifty cases of patients or physical examinees in the Department of Neurology of Beijing Aerospace General Hospital from May 2014 to April 2015 were

  12. Osteocyte lacunar properties in rat cortical bone

    Bach-Gansmo, Fiona Linnea; Weaver, James C.; Jensen, Mads Hartmann;

    2015-01-01

    Recently, the roles of osteocytes in bone maintenance have gained increasing attention. Osteocytes reside in lacunae that are interconnected by canaliculi resulting in a vast cellular network within the mineralized bone matrix. As the structure of the lacuno-canalicular network is highly connecte...

  13. The cognitive changes in patients with lacunar infarction after antery-intervention therapy%腔隙性脑梗死患者介入治疗术后认知功能变化

    赵秀芹; 赵冰; 夏章勇; 杨华; 张凤娥; 郭存举; 曲怀谦

    2012-01-01

    Objective To explore the characteristics of the cognitive changes in patients with lacunar infarction(LI) after carotid artery stenting(CAS).Methods Neuropsychological tests were conducted in 43 patients with LI and carotid stenosis before and 1 month,6 months,12 months after CAS and the scores were compared with those of 41 healthy cases.Results Compared with control group,MMSE scores ( 26.33 ± 1.94),memory and executive function in therapy group lowered obviously.There was statistical difference (P< 0.05 or P< 0.01 ).Compared with before CAS,MMSE scores of 1 month (27.17±2.15),6 months (27.17 ±2.15),12 months (28.15±1.98) after CAS,memory and executive function in therapy group were all better obviously.There was statistical difference (P<0.05 or P<0.01).Conclusion In acute stage of patients with LI (with in 1 week),most cognitive impairment was severe. Most cognition disorders was improved to normal level 12 months after CAS.The mechanism may be associated with the improvement of chronic cerebral insufficiency.%目的 探讨腔隙性脑梗死患者介入治疗术后认知的功能变化特点.方法 43例伴颈动脉狭窄的腔隙性脑梗死患者分别于术前及术后1个月、6个月、12个月进行神经心理学测验,并与41例正常人比较.结果 与对照组比较,治疗组患者术前简易智能状态检查量表( MMSE)评分[(26.33±1.94)分]、记忆力、执行能力均降低,差异有统计学意义(P<0.05或P<0.01).与术前比较,治疗组患者MMSE评分术后1月[(27.17 ±2.15)分]、术后6月[(27.78±2.12)分]、术后12月[(28.15±1.98)分],及记忆力、执行能力大都明显改善,差异有统计学意义(P<0.05或P<0.01).结论 腔隙性脑梗死患者急性期(发病1周内)大部分认知功能损害较重,介入治疗12月后大都恢复正常,其机制可能与慢性脑供血不足的改善有关.

  14. Clinical study of cerebral infarction in hemodialysis patients

    Stroke is one of the leading causes of death in patients undergoing chronic dialysis. However, few clinical studies have so far examined stroke, especially brain infarction, under such conditions. We retrospectively evaluated the clinical features and risk factors for brain infarction in 33 patients undergoing hemodialysis (hemodialysis, 29 patients; continuous ambulatory peritoneal dialysis, 4 patients; male:female ratio, 25:8) between May 2003 and August 2006. The mean age was 68.5±10.9 (mean±standard deviation (SD)) years. The basal renal diseases were chronic glomerulonephritis (n=16), diabetes mellitus (n=10) and other diseases (n=7). The mean duration of maintenance dialysis before the onset of stroke was 5.6±5.2 years. All 33 patients developed brain infarction, including the atherothrombotic (n=13), lacunar (n=9) and cardioembolic (n=11) types. The complications included a high frequency of hypertension (79%) in all groups, diabetes mellitus (36%) and atrial fibrillation (21%). Four of the patients, 2 with lacunar and 2 with atherothrombotic infarction, developed brain infarction within 3 hours after hemodialysis. Hemodynamic changes might have caused the infarction in these patients. The proportion of patients with a modified Rankin Scale grade of 4-6 at discharge was 42%, and the mortality rate was high (15%). The prognosis of brain infarction was poorer in patients with hemodialysis than in those without. (author)

  15. Asymptomatic ischemic cerebral lesions; MRI study on a high risk group

    Udaka, Fukashi; Fushimi, Hisako; Kishino, Bunichiro; Kameyama, Masakuni (Sumitomo Hospital, Osaka (Japan))

    1988-11-01

    For the purpose of studying the incidence, pathomorphology and etiology of asymptomatic ischemic cerebral lesions, we carried out a brain MRI study on 65 patients with diabetes mellitus accompanied with hypertension who are thought to belong to a high risk group of ischemic cerebrovascular diseases. Excluding the abnormality of tendon reflex due to diabetic neuropathy, sixty percent of the total patients had some mild neurological signs and symptoms, most of them was discrepancy in tendon reflex. The percentage of the patients in whom MRI disclosed some abnormalities was as high as 70%, they were lacunar stroke, multiple lacunar state, cortical infarct, and patchy high signal lesions visible only in the T{sub 2} weighted image. Lacunes or these patchy high signal lesions (considered to be the dilatation of the perivascular space or true lacunes) tended to be found along the border zone or the terminal zone. These results indicate that asymptomatic patients in whom MRI discloses the abnormalities should be considered as candidates for the future onset of multi-infarct. (author).

  16. 载荷强度对受载胫骨中骨陷窝-骨小管系统内溶质输运速率影响%The influence from load strength on solute transport rate of lacunar-canalicular system in loaded tibia

    王玉琨; 樊黎霞

    2015-01-01

    目的 利用有限元法研究载荷强度对受载胫骨中骨陷窝-骨小管系统(lacunar-canalicular system,LCS)内溶质输运速率的影响.方法 基于成年鼠胫骨的micro-CT扫描图像,利用Mimics、Hypermesh、FEBio等软件建立其胫骨有限元模型,且视为均质的两相-溶质材料.通过设置3组不同扩散率(3、15、30μm2/s)的溶质和载荷强度(0.2、2.0、5.0 N),得到输运速率和溶质扩散率以及载荷强度之间的关系.对比光脱色荧光恢复(fluorescence recovery after photobleaching,FRAP)实验数据与有限元法得到的结果,分析载荷刺激对输运增强率的影响.结果 输运速率均随着扩散率和载荷强度的增大而增大.通过与FRAP实验的数据进行比对发现,有限元法得到的结果基本符合溶质运移规律.结论 研究结果可为研究皮质骨深层区域的力响应以及流动性提供一定基础,也为进一步揭示骨再生机制提供借鉴.

  17. Effect of early nursing intervention on cognitive and compliance of cognitive function rehabilitation in patients with lacunar infarction%早期护理干预对腔隙性脑梗死患者认知功能康复认知及依从性的影响

    黄紫霞; 刘剑平

    2013-01-01

    目的 探讨早期护理干预对腔隙性脑梗死患者认知功能障碍康复认知及依从性的影响.方法 选择61例初次发病的腔隙性脑梗死住院患者,使用中文版蒙特利尔认知评估(MoCA)量表进行认知功能障碍评分,将评分<26分的患者随机分为实验组和对照组,对照组(31例)给予常规的认知康复护理,实验组(30例)在常规的康复护理基础上实施早期护理干预3个月,即根据患者情况制定个体化认知功能康复训练以及手指操训练,在干预前、后两组进行认知康复治疗的认知情况比较,在干预1,2,3个月后对两组进行认知功能康复治疗的依从性进行调查.结果 护理干预前,两组的认知功能康复认知状况分别得分(4.8±0.68)和(4.8±0.54),差异无统计学意义(P>0.05),干预后2周实验组和对照组的认知功能康复认知状况得分分别为(15.7±2.65),(11.5 ±1.87)分,差异有统计学意义(t=7.088,P<0.01);经护理干预3个月后,实验组的认知功能康复治疗的依从性在1,2,3个月均显著高于对照组,差异均有统计学意义(P<0.05).结论 对腔隙性脑梗死认知功能障碍的患者进行早期护理干预可以显著提高认知功能康复治疗的依从性.%Objective To investigate the effect of early nursing intervention on cognitive and compliance of cognitive function rehabilitation in patients with lacunar infarction.Methods 61 patients with lacunar infarction were chosen and Montreal cognitive assessment (MoCA) was used to evaluate their cognitive dysfunction.Those who scored less than 26 were randomly divided into the experimental group and the control group.The control group was given conventional cognitive rehabilitation nursing,while the experimental group was given early nursing intervention for 3 months in addition,which included developing individual rehabilitation exercise and finger operation training according to patients' conditions.Two weeks after intervention

  18. Clinical and imaging characteristics of the vascular dementia. Preliminary studies

    A descriptive prospective study was carried out in 41 patients presenting with vascular dementia from Habana Vieja municipality, Havana City, in order to know some of the clinical and imaging characteristics of this disease. The main risk factors observed were the history of cerebrovascular disease and arterial hypertension. Depression, sleeping disorders and focal and pseudo bulbar neurologic signs were the most frequent clinical findings. Folstein neuropsychological test evidenced an important disorder of attention, calculation, the evocation memory and orientation. According to this test, 29 % of the patients had a severe dementia and nearly 50 % showed a severe handicap. The most frequent imaging findings observed in the computerized axial tomography of the cranium were cerebral atrophy, and single or multiple infarctions. Multiple cerebral infarctions, the lacunar status, subcortical encephalopathy of Binswanger, and single infarction located in cerebral areas related to cognition were considered as possible psychopathological mechanisms associated with the disease

  19. Hyperpolarized {sup 3}He magnetic resonance imaging: Preliminary evaluation of phenotyping potential in chronic obstructive pulmonary disease

    Mathew, Lindsay, E-mail: lmathew@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Kirby, Miranda, E-mail: mkirby@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Etemad-Rezai, Roya, E-mail: Roya.EtemadRezai@lhsc.on.ca [Department of Medical Imaging, University of Western Ontario (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); McCormack, David G., E-mail: David.McCormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Division of Respirology, Department of Medicine, University of Western Ontario, London (Canada); Lawson Health Research Institute, London (Canada); Parraga, Grace, E-mail: gep@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Department of Medical Imaging, University of Western Ontario (Canada); Lawson Health Research Institute, London (Canada)

    2011-07-15

    Rationale and objectives: Emphysema and small airway obstruction are the pathological hallmarks of chronic obstructive pulmonary disease (COPD). The aim of this pilot study in a small group of chronic obstructive pulmonary disease (COPD) patients was to quantify hyperpolarized helium-3 ({sup 3}He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for {sup 3}He MRI in detecting the lung structural and functional COPD phenotypes. Materials and methods: We evaluated 20 ex-smokers with stage I (n = 1), stage II (n = 9) and stage III COPD (n = 10). All subjects underwent same-day plethysmography, spirometry, {sup 1}H MRI and hyperpolarized {sup 3}He MRI at 3.0 T. {sup 3}He ventilation defect percent (VDP) was generated from {sup 3}He static ventilation images and {sup 1}H thoracic images and the {sup 3}He apparent diffusion coefficient (ADC) was derived from diffusion-weighted MRI. Results: Based on the relative contribution of normalized ADC and VDP, there was evidence of a predominant {sup 3}He MRI measurement in seven patients (n = 3 mainly ventilation defects or VDP dominant (VD), n = 4 mainly increased ADC or ADC dominant (AD)). Analysis of variance (ANOVA) showed significantly lower ADC for subjects with predominantly elevated VDP (p = 0.02 compared to subjects with predominantly elevated ADC; p = 0.008 compared to mixed group) and significantly decreased VDP for subjects with predominantly elevated ADC (p = 0.003, compared to mixed group). Conclusion: In this small pilot study, a preliminary analysis shows the potential for {sup 3}He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  20. Hyperpolarized 3He magnetic resonance imaging: Preliminary evaluation of phenotyping potential in chronic obstructive pulmonary disease

    Rationale and objectives: Emphysema and small airway obstruction are the pathological hallmarks of chronic obstructive pulmonary disease (COPD). The aim of this pilot study in a small group of chronic obstructive pulmonary disease (COPD) patients was to quantify hyperpolarized helium-3 (3He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for 3He MRI in detecting the lung structural and functional COPD phenotypes. Materials and methods: We evaluated 20 ex-smokers with stage I (n = 1), stage II (n = 9) and stage III COPD (n = 10). All subjects underwent same-day plethysmography, spirometry, 1H MRI and hyperpolarized 3He MRI at 3.0 T. 3He ventilation defect percent (VDP) was generated from 3He static ventilation images and 1H thoracic images and the 3He apparent diffusion coefficient (ADC) was derived from diffusion-weighted MRI. Results: Based on the relative contribution of normalized ADC and VDP, there was evidence of a predominant 3He MRI measurement in seven patients (n = 3 mainly ventilation defects or VDP dominant (VD), n = 4 mainly increased ADC or ADC dominant (AD)). Analysis of variance (ANOVA) showed significantly lower ADC for subjects with predominantly elevated VDP (p = 0.02 compared to subjects with predominantly elevated ADC; p = 0.008 compared to mixed group) and significantly decreased VDP for subjects with predominantly elevated ADC (p = 0.003, compared to mixed group). Conclusion: In this small pilot study, a preliminary analysis shows the potential for 3He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  1. MRI study of periventricular regions in multiple sclerosis and in subcortical arteriosclerotic encephalopathy of Binswanger's type

    Periventricular regions are predominantly involved either in Multiple Sclerosis (MS) or in Subcortical Arteriosclerotic Encephalopathy (SAE) of Bingswanger's type. The presence of focal, as well as diffuse lesions in these areas is well known in both pathologies. While focal lesions are linked to plaques or lacunar softening in MS and SAE respectively, the pathogenesis of the diffuse degenerative change is still unclear, either in MS or in SAE. Previous studies have suggested that periventricular alterations may be related to an abnormal Cerebrospinal Dluid (CSF) dynamics either in MS or in SAE, and to the chronic effect of interstitial edema due to an abnormal transependymal flow. In order to further investigate these mechanisms an MRI study of periventricular regions was performed in patients afflicted by MS or SAE as well as in normal volunteers

  2. Lacunar thalamic stroke with pure cerebellar and proprioceptive deficits.

    Gutrecht, J A; Zamani, A A; D N Pandya

    1992-01-01

    Case reports of two patients with cerebellar ataxia and proprioceptive sensory loss are presented. MRI of the brain revealed lesions of the ventroposterior part of the thalamus. These patients illustrate clinically the anatomical independence of cerebellar and sensory pathways in the thalamus. We suggest that the ataxic deficit is caused by interruption of cerebellar outflow pathways in the thalamus and not secondary to sensory deafferentation.

  3. Reformation as proposed solution for the problem of sectioning different levels with {sup 3}He-MRT and HR-CT of the chest; Reformatierungen als Loesungsansatz fuer die Problematik der unterschiedlichen Schichtfuehrung beim Vergleich von {sup 3}He-MRT und HR-CT der Lunge

    Gast, K.K.; Zaporozhan, J.; Schreiber, W.G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Ley, S.; Kauczor, H.U. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. Onkologische Diagnostik und Therapie; Eberle, B.; Knitz, F. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Anaesthesiologie; Biedermann, A. [Mainz Univ. (DE). 3. Medizinische Klinik und Poliklinik (Pneumologie); Schmiedeskamp, J. [Mainz Univ. (Germany). Inst. fuer Physik; Maier, E. [DB Mainz Univ. (Germany). Klinik und Poliklinik fuer Herz-, Thorax- und Gefaesschirurgie

    2003-06-01

    Purpose: {sup 3}He-MRI of the lung has been shown to be a sensitive method for functional imaging of the lung. A previous study compared {sup 3}He-MRI (coronal planes) with CT (transverse planes) by looking for ventilation defects and their pathomorphologic correlation. Anatomic structures, such as lobar fissures and hilar vessels, were used for orientation, but the reliable assignment of ventilation defects to lung segments is problematic. The present work compares multiplanar reformations of {sup 3}He-MRI and HR-CT, which were generated from planes determined by the respective method, and investigates their suitability as a solution of this problem. Materials and Methods: A total of 16 data sets taken from 15 patients with unilateral lung transplantation and one patient with lung emphysema were retrospectively evaluated. Transverse planes of {sup 3}He-MRI and coronal planes of HR-CT were reformatted on an external workstation and images evaluated by two readers in consensus. The evaluation searched for ventilation defects on {sup 3}He-MRI and their corresponding defects on HR-CT. The defects were related to anatomic structures, with hilar vessels and tracheobronchial tree selected for {sup 3}He-MRI reformations and lobar fissures for HR-CT reformations. Results: All cases were successfully reformatted and all ventilation defects were correctly assigned to anatomic structures. On HR-CT reformations, the lobar fissures were partially visible in 12 of 16 cases and completely visible in the remaining 4 cases. Since reformation compromises the spatial resolution, the reformatted images should be evaluated together with the source images. Conclusion: Looking at HR-CT and {sup 3}He-MRI images and their reformations enables the detection of ventilation defects and their assignment to lung segments, facilitating the correlation of ventilation defects with a pathomorphologic pattern on HR-CT. (orig.) [German] Ziel: Die {sup 3}He-MRT der Lunge ist ein sensitives Verfahren

  4. Acute/subacute cerebral infarction (ASCI in HIV-negative adults with cryptococcal meningoencephalitis (CM: a MRI-based follow-up study and a clinical comparison to HIV-negative CM adults without ASCI

    Chang Chiung-Chih

    2011-01-01

    Full Text Available Abstract Background Acute/subacute cerebral infarction (ASCI in HIV-negative cryptococcal meningoencephalitis (CM adults has rarely been examined by a series of MRI-based follow-up study. We studied a series of MRI follow-up study of CM adults and compared the clinical characters of those with ASCI and those without ASCI. Methods The clinical characteristics and a series of brain MRI findings of seven CM adults with ASCI were enrolled for analysis. The clinical characteristics of another 30 HIV-negative CM adults who did not have ASCI were also included for a comparative analysis. Results The seven HIV-negative CM adults with ASCI were four men and three women, aged 46-78 years. Lacunar infarction was the type of ASCI, and 86% (6/7 of the ACSI were multiple infarctions distributed in both the anterior and posterior cerebrovascular territories. The seven CM patients with ASCI were significantly older and had a higher rate of DM and previous stroke than the other 30 CM adults without ASCI. They also had a higher incidence of consciousness disturbance at presentation and had a poor prognosis. Conclusion ASCI was found in 18.9% (7/37 of HIV-negative CM adults. Serial MRI follow-up studies may allow a better delineation of ASCI in this specific group of infectious disease and multiple lacunar infarctions was the most common type. Older in age and presence of DM and previous stroke were the significant underlying conditions. CM patients with ASCI also had a poor therapeutic outcome.

  5. The contribution of twins to the study of cognitive ageing and dementia: the Older Australian Twins Study.

    Sachdev, Perminder S; Lee, Teresa; Wen, Wei; Ames, David; Batouli, Amir H; Bowden, Jocelyn; Brodaty, Henry; Chong, Elizabeth; Crawford, John; Kang, Kristan; Mather, Karen; Lammel, Andrea; Slavin, Melissa J; Thalamuthu, Anbupalam; Trollor, Julian; Wright, Margie J

    2013-12-01

    The Older Australian Twins Study (OATS) is a major longitudinal study of twins, aged ≥ 65 years, to investigate genetic and environmental factors and their interactions in healthy brain ageing and neurocognitive disorders. The study collects psychiatric, neuropsychological, cardiovascular, metabolic, biochemical, neuroimaging, genomic and proteomic data, with two-yearly assessments, and is currently in its third wave. The initial cohort comprises 623 individuals (161 monozygotic and 124 dizygotic twin pairs; 1 MZ triplets; 27 single twins and 23 non-twin siblings), of whom 426 have had wave 2 assessment. A number of salient findings have emerged thus far which assist in the understanding of genetic contributions to cognitive functions such as processing speed, executive ability and episodic memory, and which support the brain reserve hypothesis. The heritability of brain structures, both cortical and subcortical, brain spectroscopic metabolites and markers of small vessel disease, such as lacunar infarction and white matter hyperintensities, have been examined and can inform future genetic investigations. Work on amyloid imaging and functional magnetic resonance imaging is proceeding and epigenetic studies are progressing. This internationally important study has the potential to inform research into cognitive ageing in the future, and offers an excellent resource for collaborative work. PMID:24423226

  6. Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation

    Cereda, Maurizio; Emami, Kiarash; Kadlecek, Stephen; Xin, Yi; Mongkolwisetwara, Puttisarn; Profka, Harrilla; Barulic, Amy; Pickup, Stephen; Månsson, Sven; Wollmer, Per; Ishii, Masaru; Deutschman, Clifford S.; Rizi, Rahim R.

    2010-01-01

    The aim of this study was to assess the utility of 3He MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats (n = 13) were anesthetized, intubated, and ventilated in the supine position (4He-to-O2 ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase o...

  7. [Descriptive study of cerebrovascular accidents in Douala, Cameroon].

    Chiasseu, Mbeumi M T; Mbahe, S

    2011-10-01

    A cerebrovascular accident or stroke is a sudden-onset cerebral deficit of vascular origin lasting more than 24 hours. These events represent the second leading cause of death in the world and take a particularly heavy toll in third world countries. The purpose of this study was to describe cerebrovascular lesions (type, location, size) as well as patient age and gender in Cameroon. Brain CT-scan and MRI findings from 50 stroke patients admitted to two health centers in Douala were reviewed. Data showed that 74% of patients were over 50 years of age, the 51-60 year group being the most affected. Patients were male in 64% of cases. Ischemic stroke accounted for 60% of cases versus 40% for hemorrhagic stroke. The most affected sites were the sylvian territory site in ischemic stroke and the temporal lobe in hemorrhagic stroke, acconting for 43.3% and 35% of cases respectively. The median size of ischemic and hemorrhagic lesions were 2.81 cm3, and 26.98 cm3 respectively. Hemorrhagic stroke and lacunar infarcts were more common in this sample. Discrepancies between results at the two hospitals may be due to the use of different imaging techniques. Indeed, MRI is known to be more sensitive than CT-scan for acute detection of stroke lesions. PMID:22235625

  8. An exploratory intervention study suggests clinical benefits of training in chronic stroke to be paralleled by changes in brain activity using repeated fMRI

    Landsmann B

    2016-01-01

    Full Text Available Barbara Landsmann,1,2 Daniela Pinter,2 Eva Pirker,1,2 Gerald Pichler,3 Walter Schippinger,3 Elisabeth M Weiss,1 Gabriel Mathie,2 Thomas Gattringer,2 Franz Fazekas,2 Christian Enzinger2,4 1Institute of Psychology, University of Graz, Graz, Austria; 2Department of Neurology, Medical University of Graz, Graz, Austria; 3Albert Schweitzer Clinic Graz, Graz, Austria; 4Division of Neuroradiology, Department of Radiology, Medical University of Graz, Graz, Austria Purpose: Previous studies demonstrated changes in sensorimotor network activation over time after stroke that have been interpreted as partly compensatory. Locomotor and balance trainings may improve both mobility and cognition even in chronic stroke and thereby impact on cerebral activation patterns. We here aimed at testing these assumptions in an exploratory study to inform subsequent larger intervention studies. Patients and methods: Eight patients (73.3±4.4 years with a chronic lacunar stroke (mean interval 3.7 years after the acute event with a range from 2 to 4 years and residual leg paresis leading to gait disturbance received a guided 5-week training focusing on mobility, endurance, and coordination. Before and afterward, they underwent clinical, neuropsychological, and gait assessments and brain MRI at 3 T including a functional ankle movement paradigm. Sixteen healthy controls (HCs; 68.8±5.4 years followed the same protocol without intervention. Results: After training, patients had improved in mobility, memory, and delayed recall of memory. While cerebral activations in HC remained completely unaltered, patients showed increased activations in the right precentral gyrus, the right and left superior frontal gyri, and the right frontal lobe, with bipedal ankle movements after training. Conclusion: In this exploratory study of chronic stroke, we found not only significant effects of physical training on mobility but also distinct aspects of cognition already with a small number of

  9. In-hospital cerebrovascular complications following orthotopic liver transplantation: A retrospective study

    Liang Zhijian

    2008-12-01

    Full Text Available Abstract Background Cerebrovascular complications are severe events following orthotopic liver transplantation (OLT. This study aimed to observe the clinical and neuroimaging features and possible risk factors of in-hospital cerebrovascular complications in the patients who underwent OLT. Patients and methods We retrospectively reviewed 337 consecutive patients who underwent 358 OLTs. Cerebrovascular complications were determined by clinical and neuroimaging manifestations, and the possible risk factors were analyzed in the patients with intracranial hemorrhage. Results Ten of 337 (3.0% patients developed in-hospital cerebrovascular complications (8 cases experienced intracranial hemorrhage and 2 cases had cerebral infarction, and 6 of them died. The clinical presentations were similar to common stroke, but with rapid deterioration at early stage. The hematomas on brain CT scan were massive, irregular, multifocal and diffuse, and most of them were located at brain lobes and might enlarge or rebleed. Infarcts presented lacunar and multifocal lesions in basal gangliar but with possible hemorrhagic transformation. The patients with intracranial hemorrhage had older age and a more frequency of systemic infection than non-intracranial hemorrhage patients. (P = 0.011 and 0.029, respectively. Conclusion Posttransplant cerebrovascular complications have severe impact on outcome of the patients who received OLT. Older age and systemic infection may be the possible risk factors of in-hospital intracranial hemorrhage following OLT.

  10. Risk and Determinants of Dementia in Patients with Mild Cognitive Impairment and Brain Subcortical Vascular Changes: A Study of Clinical, Neuroimaging, and Biological Markers—The VMCI-Tuscany Study: Rationale, Design, and Methodology

    Anna Poggesi

    2012-01-01

    Full Text Available Dementia is one of the most disabling conditions. Alzheimer’s disease and vascular dementia (VaD are the most frequent causes. Subcortical VaD is consequent to deep-brain small vessel disease (SVD and is the most frequent form of VaD. Its pathological hallmarks are ischemic white matter changes and lacunar infarcts. Degenerative and vascular changes often coexist, but mechanisms of interaction are incompletely understood. The term mild cognitive impairment defines a transitional state between normal ageing and dementia. Pre-dementia stages of VaD are also acknowledged (vascular mild cognitive impairment, VMCI. Progression relates mostly to the subcortical VaD type, but determinants of such transition are unknown. Variability of phenotypic expression is not fully explained by severity grade of lesions, as depicted by conventional MRI that is not sensitive to microstructural and metabolic alterations. Advanced neuroimaging techniques seem able to achieve this. Beside hypoperfusion, blood-brain-barrier dysfunction has been also demonstrated in subcortical VaD. The aim of the Vascular Mild Cognitive Impairment Tuscany Study is to expand knowledge about determinants of transition from mild cognitive impairment to dementia in patients with cerebral SVD. This paper summarizes the main aims and methodological aspects of this multicenter, ongoing, observational study enrolling patients affected by VMCI with SVD.

  11. Application of Diffusion Tensor Imaging Parameters to Detect Change in Longitudinal Studies in Cerebral Small Vessel Disease.

    Zeestraten, Eva Anna; Benjamin, Philip; Lambert, Christian; Lawrence, Andrew John; Williams, Owen Alan; Morris, Robin Guy; Barrick, Thomas Richard; Markus, Hugh Stephen

    2016-01-01

    Cerebral small vessel disease (SVD) is the major cause of vascular cognitive impairment, resulting in significant disability and reduced quality of life. Cognitive tests have been shown to be insensitive to change in longitudinal studies and, therefore, sensitive surrogate markers are needed to monitor disease progression and assess treatment effects in clinical trials. Diffusion tensor imaging (DTI) is thought to offer great potential in this regard. Sensitivity of the various parameters that can be derived from DTI is however unknown. We aimed to evaluate the differential sensitivity of DTI markers to detect SVD progression, and to estimate sample sizes required to assess therapeutic interventions aimed at halting decline based on DTI data. We investigated 99 patients with symptomatic SVD, defined as clinical lacunar syndrome with MRI confirmation of a corresponding infarct as well as confluent white matter hyperintensities over a 3 year follow-up period. We evaluated change in DTI histogram parameters using linear mixed effect models and calculated sample size estimates. Over a three-year follow-up period we observed a decline in fractional anisotropy and increase in diffusivity in white matter tissue and most parameters changed significantly. Mean diffusivity peak height was the most sensitive marker for SVD progression as it had the smallest sample size estimate. This suggests disease progression can be monitored sensitively using DTI histogram analysis and confirms DTI's potential as surrogate marker for SVD. PMID:26808982

  12. Quantification of Osteocyte Lacunar Density and Anisotropy of Vascular Canals in Compact Bone

    Maštálková, K.; Tonar, Z.; Fiala, P.; Janáček, Jiří

    2007-01-01

    Roč. 29, č. 6 (2007), s. 445-445. ISSN 1279-8517. [Congress of European Association of Clinical Anatomy /9./. 05.09.2007-08.09.2007, Prague] R&D Projects: GA AV ČR(CZ) IAA100110502 Institutional research plan: CEZ:AV0Z50110509 Keywords : cpr1 * osteocyt * bone * stereology Subject RIV: EA - Cell Biology

  13. Quantification of Osteocyte Lacunar Density and Anisotropy of Vascular Canals in Compact Bone

    Maštálková, K.; Tonar, Z.; Fiala, P.; Janáček, Jiří

    Praha: Mediamond, 2008 - (Kachlík, D.), s. 45-48 ISBN 978-88-7587-425-4. [Congress of the European Association of Clinical Anatomy /9./. Praha (CZ), 05.09.2007-08.09.2007] R&D Projects: GA AV ČR(CZ) IAA100110502 Institutional research plan: CEZ:AV0Z50110509 Keywords : osteocyte * disector Subject RIV: EA - Cell Biology

  14. Diabetes and hypertension markedly increased the risk of ischemic stroke associated with high serum resistin concentration in a general Japanese population: the Hisayama Study

    Kawamura Ryoichi

    2009-11-01

    Full Text Available Abstract Background Resistin, secreted from adipocytes, causes insulin resistance in mice. The relationship between resistin and coronary artery disease is highly controversial, and the information regarding resistin and ischemic stroke is limited. In the present study, the association between serum resistin concentration and cardiovascular disease (CVD was investigated in a general Japanese population. Methods A total of 3,201 community-dwelling individuals aged 40 years or older (1,382 men and 1,819 women were divided into quintiles of serum resistin, and the association between resistin and CVD was examined cross-sectionally. The combined effect of either diabetes or hypertension and high serum resistin was also assessed. Serum resistin was measured using ELISA. Results Compared to those without CVD, age- and sex-adjusted mean serum resistin concentrations were greater in subjects with CVD (p = 0.002 or ischemic stroke (p Conclusion Elevated serum resistin concentration appears to be an independent risk factor for ischemic stroke, especially lacunar and atherothrombotic infarction in the general Japanese population. The combination of high resistin and the presence of either diabetes or hypertension increased the risk of ischemic stroke.

  15. A CLINICAL STUDY OF STROKE IN YOUNG

    Kumbha Thulasi Ram

    2015-02-01

    Full Text Available NTRIDUCTION : Stroke is one of the important causes of morbidity and mortality all over the world. Incidence of stroke steadily increases with age. Experts are concerned of the emerging stroke epidemic in India. Stroke affecting the young has potentially devastating consequence son the individual and his family. Certain risk factors are unique to the young. I t needs more studies for identification and modification of risk factors. The study aims to evaluate clinical features, risk factors, etiology and mortality of stroke in young patients. METHODS : 74 young patients satisfying the inclusion criteria were included in this study. A detailed history was taken from young stroke patients, systemic examination and required investigations were done. Data was collected in standardized proforma and analysed. RESULTS: Stroke in young accounts for 7.95% of stroke cases of all age groups. The mean age of the patients was 34.66 ± 7.48 years. Among 74 patients, 47(63.51% were male and 27(36.49% were female. Seizures, decreased consciousness, speech involvement and motor deficit were observed in 33.78%, 44.59%, 22.97% and 100% of cases respectively. 82.43% patients had ischemic and 17.57% patients had hemorrhagic stroke. Among ischemic stroke, large artery atherosclerosis was 16.21%, tuberculous meningoencephalitis with vasculitis was 16.21%, lacunar stroke was 10.81%, CVT was 10.81% and cardio embolic stroke was 6.76%. Smoking (59.45%, alcoholism (58.10%, hypertension (43.24%, coronary artery disease (8.10%, diabetes mellitus (10.81%, elevated total cholesterol (25.67%, elevated low density lipo proteins (22.97%, elevated triglycerides (27.02% and low HDL (22.97% were important risk factors. Carotid doppler was abnormal in 9.45% of patients. 6.76% patients had mitral stenosis in echocardiogram. Low protein C and protein S were found in 1.35% of patients. Eight (10.81% patients died during the hospital stay. INTERPRETATION AND CONCLUSIONS: The major risk

  16. A study of low-density areas, clinical findings, and angiographic findings in patients with cerebral infarction

    55 out of 62 patients with cerebral infarction were investigated in terms of CT scan findings, angiographic findings, and clinical symptoms. The results obtained were as follows: 1) The low-density areas of the CT scan findings were classified into the following four types: large hemispheric or lobular --Type I; wedge-shaped --Type II; small --Type III; and lacunar low-density area. --Type IV. 2) Almost all patients with angiographically occlusive findings showed low-density areas of Type I; however, one patient with ICA occlusion revealed only a lacunar low-density area. 3) The patients with lacunar low-density areas showed an angiographically delayed filling of the angular artery and posterior parietal artery of the middle cerebral artery. 4) The relationship between the types of low-density areas and the clinical conscious disorders was not clear. On the other hand, the patients with Type I low-density areas almost all had motor disturbances, while patients with other types of low-density areas showed only 60 - 70% motor disturbances. 5) In patients with speech disorders, total aphasia cases were found in patients with large hemispheric low-density areas on the left side. Although, motor aphasia cases were seen in patients with various low-density areas on the left inferior frontal and precentral gyri, dysarthria cases were found in the patients with several low-density areas on both sides. 6) The localization of lacunar low-density areas seemed to be near the caudate nucleus on the right side and in the putaminal regions on the left side. The mean and the standard deviation of CT numbers in the lacunar low-density areas showed higher values on the right side than on the left side. (author)

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

    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.

  18. A clinical study in elderly patients with Parkinson's disease using MRI and SPECT

    Parkinson's disease (PD) is often associated with dementia in elderly patients, and sometimes PD coexists with senile dementia of the Alzheimer type (SDAT) or cerebrovascular disease (CVD) in the elderly. However, since there are few previous clinical studies on the coincidence of, or relationship between PD and CVD, the authors evaluated these aspects in 34 elderly patients with PD using MRI and SPECT. All the patients were over 70 years old. The diagnosis of PD was based on the presence of three symptons (resting tremor, cogwheel rigidity and bradikinesia) which are characteristic of PD, and the effectiveness of L-DOPA therapy. We therefore believe that patients with vascular Parkinsonism were excluded from our study. In 34 cases, 24 (71%) had MRI evidence of CVD (mainly the lacunar state). In the 10 cases who had no CVD, 2 (20%) had severe dementia and the decrease of regional cerebral blood flow (rCBF) in the temporal and parietal lobes bilaterally correlated with the SPECT findings commonly found in SDAT. A comparison of the rCBF and the results of Hasegawa's dementia score (HDS) (verbal intelligence score) was made between the patients with PD associated with CVD and the patients with PD who had no CVD and no SPECT findings which correlated with SDAT. The rCBF in the frontal lobes and the results of the HDS of the former group were significantly lower than those of the latter. As mentioned above, elderly patients with PD often had CVD, leading to dementia. We also pointed out the difficulty in making a differential diagnosis between PD with CVD and vascular Parkinsonism, and the necessity of whether or not the concept of 'mixed type Parkinsonism' should be considered. (author)

  19. Achieved Blood Pressures in the Secondary Prevention of Small Subcortical Strokes (SPS3) Study: Challenges and Lessons Learned

    Pergola, Pablo E.; Szychowski, Jeff M.; Talbert, Robert; del Brutto, Oscar; Castellanos, Mar; Graves, John W.; Matamala, Gonzalo; Pretell, Edwin Javier; Yee, Jerry; Rebello, Rosario; Zhang, Yu; Benavente, Oscar R.

    2014-01-01

    BACKGROUND Lowering blood pressure (BP) after stroke remains a challenge, even in the context of clinical trials. The Secondary Prevention of Small Subcortical Strokes (SPS3) BP protocol, BP management during the study, and achieved BPs are described here. METHODS Patients with recent symptomatic lacunar stroke were randomized to 1 of 2 levels of systolic BP (SBP) targets: lower: <130mm Hg, or higher: 130–149mm Hg. SBP management over the course of the trial was examined by race/ethnicity and other baseline conditions. RESULTS Mean SBP decreased for both groups from baseline to the last follow-up, from 142.4 to 126.7mm Hg for the lower SBP target group and from 143.6 to 137.4mm Hg for the higher SBP target group. At baseline, participants in both groups used an average of 1.7±1.2 antihypertensive medications, which increased to a mean of 2.4±1.4 (lower group) and 1.8±1.4 (higher group) by the end-study visit. It took an average of 6 months for patients to reach their SBP target, sustained to the last follow-up. Black participants had the highest proportion of SBP ≥150mm Hg at both study entry (40%) and end-study visit (17%), as compared with whites (9%) and Hispanics (11%). CONCLUSIONS These results show that it is possible to safely lower BP even to a SBP goal <130mm Hg in a variety of patients and settings, including private and academic centers in multiple countries. This provides further support for protocol-driven care in lowering BP and consequently reducing the burden of stroke. PMID:24610884

  20. Study on the Prevalence and Corelation of Carotid Atherosclerosis in Stroke Patients

    Wei Hua; Wang Yongjun; Yah Zhenying

    2000-01-01

    Objective To assess the prevalence and severity of carotid atherosclerosis in stroke patients and the risk factors of carotid atherosclerosis. Methods Two hundred fifty-one ischemic stroke patients,46 ccrcbral hemorrhagc patients and 96 control subjects were entercd into this study. Sonographic assessment of the extracranial carotid arteries was performed in all patients. Diametcr. IMT, plaques and percentage ratio of lumen stenosis were observcd. Results (1)The prevalence of carotid plaqucs was prominent in stroke patients than the control subjects(63.0%vs 36.5%). (2)The prevalencc of lumen stenosis>50% in ischemic stroke patients was higher than the cerebral hemorrhage patients and control subjects (15.6% vs 4.3%. 2.1%).(3) The prevalence of severe carotid artery stcnosis(>75%) was promincnt in aged 61~70 years old patients.(4)Our data revealed 30% of the cortical infarction subgroup, 17.5%of the subcortical infarction subgroup, 17% of the lacunar infarction subgroup,8% of the vcrtibral-basilar artery infarction subgroup.2.8% of thc CT normal subgroup possessed carotid stcnosis >50%. (5)Age, diabetes mellitus and ApoAl(inversely) were independent predictors of the extracranial carotid atherosclcrosis. Discusssion (Ⅰ)There is close relation between extracraniai carotid atherosclerosis and ischemic cerebrovascular disease.(2)The extent of serious carotid artery stcnosis in aged patients was lower.(3)Thc severity of extracranial carotid artery atherosclerosis was prominent in patients with conical infarction. Conclusion There is a high prevalence of extracranial carotid atherosclerosis in Chinese stroke patients.

  1. Regional cerebral blood flow in pure dysarthria. A 3D-SSP study

    Pure dysarthria from brain infarction is a rare condition, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated the lesion sites and regional cerebral blood flow in patients with pure dysarthria. We examined 18 consecutive patients with pure dysarthria (9 men and 9 women; mean age, 71 years) who underwent MRI and cerebral blood flow studies. To visualize the regional cerebral blood flow, we generated Z score images using the three-dimensional stereotactic surface projection (3D-SSP) method with single-photon emission computed tomography (SPECT) and N-isopropyl-p [123I]iodoamphetamine. Data on the brain surface perfusion extracted by the 3D-SSP analysis were compared between the pure dysarthria (PD) patients and 9 control subjects. MRI revealed multiple lacunar infarctions involving the internal capsule and/or corona radiata in 11 patients, left internal capsule-corona radiata infarction in 4 patients, and pontine infarction in 3 patients. SPECT with 3D-SSP demonstrated bilateral frontal cortical hypoperfusion in all patients, particularly in the anterior opercular region. Based on intergroup comparisons, the PD group exhibited pronounced cortical hypoperfusion in the opercular and medial frontal regions, left more than right. In conclusion, pure dysarthria is considered to originate from frontal cortical hypoperfusion, mainly in the anterior opercular and medial frontal regions, which is probably due to interruption of the corticosubcortical neural networks relevant to speech expression and articulation. In addition, it is suggested that left hemispheric lesions may make a greater contribution to the development of pure dysarthria than do right ones. (author)

  2. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  3. Progression of Emphysema Evaluated by MRI Using Hyperpolarized 3He (HP 3He) Measurements in Patients with Alpha-1-Antitrypsin (A1AT) Deficiency Compared with CT and Lung Function Tests

    Stavngaard, T.; Vejby Soegaard, L. (Danish Research Center for Magnetic Resonance, Copenhagen Univ. Hospital Hvidovre, Hvidovre (Denmark)); Batz, M. (Inst. of Physics, Johannes Gutenberg Univ., Mainz (Germany)); Schreiber, L.M. (Dept. of Interventional and Diagnostic Radiology, Johannes Gutenberg Univ. Medical School, Mainz (Germany)); Dirksen, A. (Dept. of Respiratory Medicine, Gentofte Hospital, Univ. of Copenhagen, Copenhagen (Denmark))

    2009-11-15

    Background: The progression of emphysema is traditionally measured by pulmonary function test, with forced expiratory volume in 1 s (FEV1) being the most accepted and used measurement. However, FEV1 is insensitive in detecting mild/slow progression of emphysema because of low reproducibility as compared to yearly decline. Purpose: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) 3He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. Material and Methods: Nine patients with severe A1AT deficiency were studied over a period of 2 years (baseline, year 1, and year 2) with HP 3He MRI using apparent diffusion coefficient (ADC), lung function tests (FEV1 and carbon monoxide lung diffusion capacity [DL,CO]), and computed tomography (CT) using densitometric parameters (15th percentile density [CT-PD15] and relative area of emphysema below -910 HU [CT-RA-910]). Results: Seven patients were scanned three times, one patient two times, and one patient only at baseline. The mean increase in ADC values from first to last HP 3He MR scanning was 3.8% (0.014 cm2/s [SD 0.024 cm2/s]; not significant). The time trends for FEV1, DL,CO, CT-PD15, and CT-RA-910 were all statistically significant. We found a high correlation between ADC and DL,CO (P<0.001). Conclusion: This pilot study indicates the possible use of nonionizing HP 3He MRI for monitoring the progression of emphysema. However, in the future, larger studies are needed to confirm these preliminary results

  4. Cerebral Small Vessel Disease and Risk of Death, Ischemic Stroke, and Cardiac Complications in Patients With Atherosclerotic Disease The Second Manifestations of ARTerial disease-Magnetic Resonance (SMART-MR) Study

    M.M.A. Conijn; R.P. Kloppenborg; A. Algra; W.P.T.M. Mali; L.J. Kappelle; K.L. Vincken; Y. van der Graaf; M.I. Geerlings

    2011-01-01

    Background and Purpose-Cerebral small vessel disease may be related to vascular and nonvascular pathology. We assessed whether lacunar infarcts and white matter lesions on MRI increased the risk of vascular and nonvascular death and future vascular events in patients with atherosclerotic disease. Me

  5. Assessment of lung disease in children with cystic fibrosis using hyperpolarized 3-Helium MRI: comparison with Shwachman score, Chrispin-Norman score and spirometry

    Beek, Edwin J.R. van [University of Sheffield, Unit of Academic Radiology, Sheffield (United Kingdom); University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City (United States); University of Iowa, Department of Radiology, Iowa City, IA (United States); Hill, Catherine; Woodhouse, Neil; Fichele, Stanislao; Fleming, Sally; Wild, Jim M. [University of Sheffield, Unit of Academic Radiology, Sheffield (United Kingdom); Howe, Bridget; Bott, Sandra; Taylor, Christopher J. [University of Sheffield, Academic Unit of Child Health, Sheffield (United Kingdom)

    2007-04-15

    This study assesses the feasibility of hyperpolarized 3-Helium MRI in children with cystic fibrosis (CF) and correlates the findings with standard clinical parameters based on chest radiograph (CXR) and pulmonary function tests (PFT). An uncontrolled, observational study in eighteen children with cystic fibrosis aged 5 - 17 years (median 12.1 years), with different severity of disease was carried out. All subjects underwent routine clinical assessment including PFT and standard auxology; CXR was obtained and Shwachman and Chrispin-Norman scores calculated. Hyperpolarized 3-He magnetic resonance imaging (MRI) was carried out using a spin-exchange polarizer and a whole body 1.5 T scanner. Ventilation distribution images were obtained during a 21-second breath-hold and scored according to previously defined criteria. Spearman's non-parametric correlations test was performed to assess for statistical significance at the p<0.05 level. The children tolerated the procedure well. No desaturation events were observed during 3-He MRI. A significant, albeit moderate, correlation was found between MRI score and FEV1% predicted (r=-0.41; p=0.047) and FVC% predicted (r=-0.42; p=0.04), while there were trends of correlations between Shwachman score and MRI score (r=-0.38; p=0.06) and Shwachman score and FEV1% predicted (r=0.39; p=0.055). The feasibility of hyperpolarized 3-He MRI in children with CF was demonstrated. MRI appears to be able to demonstrate functional lung changes, although correlations with routine clinical tests are only moderate to poor. This non-ionising radiation technique could be useful for monitoring lung disease and assessing therapy in this patient population. (orig.)

  6. Assessment of lung disease in children with cystic fibrosis using hyperpolarized 3-Helium MRI: comparison with Shwachman score, Chrispin-Norman score and spirometry

    This study assesses the feasibility of hyperpolarized 3-Helium MRI in children with cystic fibrosis (CF) and correlates the findings with standard clinical parameters based on chest radiograph (CXR) and pulmonary function tests (PFT). An uncontrolled, observational study in eighteen children with cystic fibrosis aged 5 - 17 years (median 12.1 years), with different severity of disease was carried out. All subjects underwent routine clinical assessment including PFT and standard auxology; CXR was obtained and Shwachman and Chrispin-Norman scores calculated. Hyperpolarized 3-He magnetic resonance imaging (MRI) was carried out using a spin-exchange polarizer and a whole body 1.5 T scanner. Ventilation distribution images were obtained during a 21-second breath-hold and scored according to previously defined criteria. Spearman's non-parametric correlations test was performed to assess for statistical significance at the p<0.05 level. The children tolerated the procedure well. No desaturation events were observed during 3-He MRI. A significant, albeit moderate, correlation was found between MRI score and FEV1% predicted (r=-0.41; p=0.047) and FVC% predicted (r=-0.42; p=0.04), while there were trends of correlations between Shwachman score and MRI score (r=-0.38; p=0.06) and Shwachman score and FEV1% predicted (r=0.39; p=0.055). The feasibility of hyperpolarized 3-He MRI in children with CF was demonstrated. MRI appears to be able to demonstrate functional lung changes, although correlations with routine clinical tests are only moderate to poor. This non-ionising radiation technique could be useful for monitoring lung disease and assessing therapy in this patient population. (orig.)

  7. Progression of Emphysema Evaluated by MRI Using Hyperpolarized 3He (HP 3He Measurements in Patients with Alpha-1-Antitrypsin (A1AT) Deficiency Compared with CT and Lung Function Tests

    Background: The progression of emphysema is traditionally measured by pulmonary function test, with forced expiratory volume in 1 s (FEV1) being the most accepted and used measurement. However, FEV1 is insensitive in detecting mild/slow progression of emphysema because of low reproducibility as compared to yearly decline. Purpose: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) 3He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. Material and Methods: Nine patients with severe A1AT deficiency were studied over a period of 2 years (baseline, year 1, and year 2) with HP 3He MRI using apparent diffusion coefficient (ADC), lung function tests (FEV1 and carbon monoxide lung diffusion capacity [DL,CO]), and computed tomography (CT) using densitometric parameters (15th percentile density [CT-PD15] and relative area of emphysema below -910 HU [CT-RA-910]). Results: Seven patients were scanned three times, one patient two times, and one patient only at baseline. The mean increase in ADC values from first to last HP 3He MR scanning was 3.8% (0.014 cm2/s [SD 0.024 cm2/s]; not significant). The time trends for FEV1, DL,CO, CT-PD15, and CT-RA-910 were all statistically significant. We found a high correlation between ADC and DL,CO (P3He MRI for monitoring the progression of emphysema. However, in the future, larger studies are needed to confirm these preliminary results

  8. Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

    Shu-qing ZHOU

    2011-06-01

    Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

  9. Quantitative {sup 1}H and hyperpolarized {sup 3}He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Owrangi, Amir M., E-mail: aowrangi@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Wang, Jian X., E-mail: jxwang@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Applied Science Laboratories, General Electric Healthcare (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); McCormack, David G., E-mail: David.Mccormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Division of Respirology, Department of Medicine, The University of Western Ontario, London (Canada); Parraga, Grace, E-mail: gparraga@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Department of Medical Imaging, The University of Western Ontario, London (Canada); Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2014-01-15

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary {sup 1}H magnetic resonance imaging (MRI) signal intensity (SI) and {sup 3}He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) {sup 1}H and diffusion-weighted hyperpolarized {sup 3}He MRI (b = 1.6 s/cm{sup 2}) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean {sup 1}H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The {sup 1}H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R{sup 2} = 0.94) compared to COPD subjects (0.29 AU/cm, R{sup 2} = 0.968, p = 0.05). There was a significant correlation between {sup 1}H SI and {sup 3}He ADC (r = −0.58, p = 0.008) and significant correlations between {sup 1}H MR SI and CT measurements of emphysema (RA{sub 950}, r = −0.69, p = 0.02 and HU{sub 15}, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between {sup 1}H SI and {sup 3}He ADC, as well as between {sup 1}H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary {sup 1}H SI may be used to monitor emphysema as a complement to CT and noble gas MRI.

  10. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary 1H magnetic resonance imaging (MRI) signal intensity (SI) and 3He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) 1H and diffusion-weighted hyperpolarized 3He MRI (b = 1.6 s/cm2) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean 1H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The 1H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R2 = 0.94) compared to COPD subjects (0.29 AU/cm, R2 = 0.968, p = 0.05). There was a significant correlation between 1H SI and 3He ADC (r = −0.58, p = 0.008) and significant correlations between 1H MR SI and CT measurements of emphysema (RA950, r = −0.69, p = 0.02 and HU15, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between 1H SI and 3He ADC, as well as between 1H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary 1H SI may be used to monitor emphysema as a complement to CT and noble gas MRI

  11. Changes in the management of acute ischemic stroke after publication of Japanese Guidelines for the Management of Stroke (2004). A multicenter cooperative study in Toyama prefecture

    It is unclear whether the management of stroke has been improved since the Japanese Guidelines for the Management of Stroke (2004) was published. The aim of the present study was to clarify changes in the management for acute ischemic stroke after publication of the Japanese Guidelines. We investigated the management of patients with acute ischemic stroke in nine hospitals belonging to the committee of Toyama Acute Ischemic Stroke Study, before and after publication of the Japanese Guidelines for the Management of Stroke (2004). Two-hundred and ninety-three acute ischemic stroke patients were registered in 2003 and 237 in 2006, respectively. The percentage of lacunar stroke was 39%, 37%, atherothrombotic infarction; 28%, 30%, cardioembolic stroke (CE); 21%, 22%, and others; 12%, 11%, respectively. The ratio of CE patients who were admitted within 3 hours of onset was significantly increased from 34% in 2003 to 57% in 2006. Although 74 patients (31%) with any clinical type were admitted within 3 hours of onset, thrombolytic therapy with tissue plasminogen activator (rt-PA) was administered to only 5 patients (2.1%) in 2006. Diffusion weighted images became available in all hospitals, and were more frequently used for diagnosis of acute ischemic stroke in 92% of patients in 2006 as compared to 59% in 2003. Ischemic lesions were more frequently detected before the start of treatment in 52% of patients in 2006 as compared to 43% in 2003. After the Japanese Guidelines for the Management of Stroke (2004) was published, the treatment of acute ischemic stroke patients appeared to follow this guideline in many patients. Thrombolytic therapy with rt-PA, however, was performed in very few patients. (author)

  12. Statistics and geometry of cosmic voids

    We introduce new statistical methods for the study of cosmic voids, focusing on the statistics of largest size voids. We distinguish three different types of distributions of voids, namely, Poisson-like, lognormal-like and Pareto-like distributions. The last two distributions are connected with two types of fractal geometry of the matter distribution. Scaling voids with Pareto distribution appear in fractal distributions with box-counting dimension smaller than three (its maximum value), whereas the lognormal void distribution corresponds to multifractals with box-counting dimension equal to three. Moreover, voids of the former type persist in the continuum limit, namely, as the number density of observable objects grows, giving rise to lacunar fractals, whereas voids of the latter type disappear in the continuum limit, giving rise to non-lacunar (multi)fractals. We propose both lacunar and non-lacunar multifractal models of the cosmic web structure of the Universe. A non-lacunar multifractal model is supported by current galaxy surveys as well as cosmological N-body simulations. This model suggests, in particular, that small dark matter halos and, arguably, faint galaxies are present in cosmic voids

  13. Blood-brain barrier permeability is increased in normal appearing white matter in patients with lacunar stroke and leukoaraiosis

    Topakian, R; Barrick, T R; Howe, F. A.; Markus, H. S.

    2010-01-01

    Abstract Background and purpose: The pathogenesis of cerebral small vessel disease (SVD) is incompletely understood. Endothelial dysfunction has been implicated and may result in increased blood-brain barrier (BBB) permeability with leakage of blood constituents into the vessel wall and white matter. We used contrast enhanced magnetic resonance imaging (MRI) to determine whether there was evidence for BBB permeability in the white matter of patients with SVD, and whether this was p...

  14. Brain MRI findings of carbon disulfide poisoning

    To evaluate the findings of brain MRI in patients with carbon disulfide poisoning. Ninety-one patients who had suffered carbon disulfide poisoning [male:female=87:4; age, 32-74 (mean 53.3) years] were included in this study. To determine the extent of white matter hyperintensity (Grade 0-V) and lacunar infarction, T2-weighted MR imaging of the brain was performed. T2-weighted images depicted white matter hyperintensity in 70 patients (76.9%) and lacunar infarcts in 27 (29.7%). In these patients, the prevalent findings at T2-weighted MR imaging of the brain were white matter hyperintensity and lacunar infarcts. Disturbance of the cardiovascular system by carbon disulfide might account for these results

  15. The poro-viscoelastic properties of trabecular bone: a micro computed tomography-based finite element study.

    Sandino, Clara; McErlain, David D; Schipilow, John; Boyd, Steven K

    2015-04-01

    Bone is a porous structure with a solid phase that contains hydroxyapatite and collagen. Due to its composition, bone is often represented either as a poroelastic or as a viscoelastic material; however, the poro-viscoelastic formulation that allows integrating the effect of both the fluid flow and the collagen on the mechanical response of the tissue, has not been applied yet. The objective of this study was to develop a micro computed tomography (µCT)-based finite element (FE) model of trabecular bone that includes both the poroelastic and the viscoelastic nature of the tissue. Cubes of trabecular bone (N=25) from human distal tibia were scanned with µCT and stress relaxation experiments were conducted. The µCT images were the basis for sample specific FE models, and the stress relaxation experiments were simulated applying a poro-viscoelastic formulation. The model considers two scales of the tissue: the intertrabecular pore and the lacunar-canalicular pore scales. Independent viscoelastic and poroelastic models were also developed to determine their contribution to the poro-viscoelastic model. All the experiments exhibited a similar relaxation trend. The average reaction force before relaxation was 9.28 × 10(2)N (SD ± 5.11 × 10(2)N), and after relaxation was 4.69 × 10(2)N (SD ± 2.88 × 10(2)N). The slope of the regression line between the force before and after relaxation was 1.92 (R(2)=0.96). The poro-viscoelastic models captured 49% of the variability of the experimental data before relaxation and 33% after relaxation. The relaxation predicted with viscoelastic models was similar to the poro-viscoelastic ones; however, the poroelastic formulation underestimated the reaction force before relaxation. These data suggest that the contribution of viscoelasticity (fluid flow-independent mechanism) to the mechanical response of the tissue is significantly greater than the contribution of the poroelasticity (fluid flow-dependent mechanism). PMID:25591049

  16. Change over time in brain computed tomographic and magnetic resonance imaging findings in healthy elderly persons. A 10 year prospective study

    Early detection, treatment and prevention of dementia have become increasingly important as the population ages. I have performed a follow-up study of changes in the brains of healthy elderly persons with computed tomography (CT) and magnetic resonance imaging (MRI) since 1982. One hundred thirty-three healthy elderly volunteers were first examined in 1982 with CT or MRI, electroencephalography, the Benton Visual Retention Test (BVRT), blood pressure measurement, and interview. Subsequent examinations were done in 1986, 1989, and 1992. On CT, microinfarctions were found in 15.0% of subjects in 1982 and in 13.0% in 1986, and periventricular lucency (PVL) was found in 6.0% and 8.3%. The most frequent findings were vascular changes, which were observed in six persons (5.6%), followed by PVL, which was found in four persons (3.7%). Thus, vascular changes became more pronounced during the follow-up period. Lesions with high signal intensity on T2-weighted images (T2HSI) were found in 69.5% of subjects and increased in prevalence with age in the 1989 study. Such T2HSI lesions were found most frequently in the basal ganglia (61.9%), followed by the thalamus (39.0%), parietal lobe (37.0%), temporal lobe (12.7%), and the pons (8.5%). Of these lesions, lacunar infarctions showed low signal intensity on T1-weighted images and were found in 24.6% of subjects; their prevalence also increased with age. Results of BVRT were closely correlated with T2HSI lesions, suggesting that T2HSIs lesions may affect cognitive function. By 1992, 10 years after the start of the study, 34 (25.6%) of subjects had died and 19 (14.3%) had become demented. Subjects were divided into surviving and dead groups and dementia and non-dementia groups. Findings on CT and BVRT in this study have provided clear clinical indices of death and dementia, especially maximal width of third ventricule in impairment of the diagnosis of dementia. (author)

  17. Cerebral Microbleeds and White Matter Hyperintensities in Cognitively Healthy Elderly: A Cross-Sectional Cohort Study Evaluating the Effect of Arterial Stiffness

    Anna-Märta Gustavsson

    2015-05-01

    Full Text Available Background: Arterial stiffness reflects the ageing processes in the vascular system, and studies have shown an association between reduced cognitive function and cerebral small vessel disease. Small vessel disease can be visualized as white matter hyperintensities (WMH and lacunar infarcts but also as cerebral microbleeds on brain magnetic resonance imaging (MRI. We aimed to investigate if arterial stiffness influences the presence of microbleeds, WMH and cognitive function in a population of cognitively healthy elderly. Methods: The study population is part of the Swedish BioFinder study and consisted of 208 individuals without any symptoms of cognitive impairment, who scored >27 points on the Mini-Mental State Examination. The participants (mean age, 72 years; 59% women underwent MRI of the brain with visual rating of microbleeds and WMH. Arterial stiffness was measured with carotid-femoral pulse wave velocity (cfPWV. Eight cognitive tests covering different cognitive domains were performed. Results: Microbleeds were detected in 12% and WMH in 31% of the participants. Mean (±standard deviation, SD cfPWV was 10.0 (±2.0 m/s. There was no association between the presence of microbleeds and arterial stiffness. There was a positive association between arterial stiffness and WMH independent of age or sex (odds ratio, 1.58; 95% confidence interval, 1.04-2.40, p 0.05. Cognitive performance was not associated with microbleeds, but individuals with WMH performed slightly worse than those without WMH on the Symbol Digit Modalities Test (mean ± SD, 35 ± 7.8 vs. 39 ± 8.1, p Conclusions: Arterial stiffness was not associated with the presence of cerebral microbleeds or cognitive function in cognitively healthy elderly. However, arterial stiffness was related to the presence of WMH, but the association was attenuated when multiple adjustments were made. There was a weak negative association between WMH and performance in one specific test of attention

  18. Land-Use and Land-Cover Mapping Using a Gradable Classification Method

    Keigo Kitada

    2012-05-01

    Full Text Available Conventional spectral-based classification methods have significant limitations in the digital classification of urban land-use and land-cover classes from high-resolution remotely sensed data because of the lack of consideration given to the spatial properties of images. To recognize the complex distribution of urban features in high-resolution image data, texture information consisting of a group of pixels should be considered. Lacunarity is an index used to characterize different texture appearances. It is often reported that the land-use and land-cover in urban areas can be effectively classified using the lacunarity index with high-resolution images. However, the applicability of the maximum-likelihood approach for hybrid analysis has not been reported. A more effective approach that employs the original spectral data and lacunarity index can be expected to improve the accuracy of the classification. A new classification procedure referred to as “gradable classification method” is proposed in this study. This method improves the classification accuracy in incremental steps. The proposed classification approach integrates several classification maps created from original images and lacunarity maps, which consist of lacnarity values, to create a new classification map. The results of this study confirm the suitability of the gradable classification approach, which produced a higher overall accuracy (68% and kappa coefficient (0.64 than those (65% and 0.60, respectively obtained with the maximum-likelihood approach.

  19. Impact of Non-Invasively Induced Motor Deficits on Tibial Cortical Properties in Mutant Lurcher Mice.

    Alena Jindrová

    Full Text Available It has been shown that Lurcher mutant mice have significantly altered motor abilities, regarding their motor coordination and muscular strength because of olivorecebellar degeneration. We assessed the response of the cross-sectional geometry and lacuno-canalicular network properties of the tibial mid-diaphyseal cortical bone to motor differences between Lurcher and wild-type (WT male mice from the B6CBA strain. The first data set used in the cross-sectional geometry analysis consists of 16 mice of 4 months of age and 32 mice of 9 months of age. The second data set used in the lacunar-canalicular network analysis consists of 10 mice of 4 months of age. We compared two cross-sectional geometry and four lacunar-canalicular properties by I-region using the maximum and minimum second moment of area and anatomical orientation as well as H-regions using histological differences within a cross section. We identified inconsistent differences in the studied cross-sectional geometry properties between Lurcher and WT mice. The biggest significant difference between Lurcher and WT mice is found in the number of canaliculi, whereas in the other studied properties are only limited. Lurcher mice exhibit an increased number of canaliculi (p < 0.01 in all studied regions compared with the WT controls. The number of canaliculi is also negatively correlated with the distance from the centroid in the Lurcher and positively correlated in the WT mice. When the Lurcher and WT sample is pooled, the number of canaliculi and lacunar volume is increased in the posterior Imax region, and in addition, midcortical H-region exhibit lower number of canaliculi, lacuna to lacuna distance and increased lacunar volume. Our results indicate, that the importance of precise sample selection within cross sections in future studies is highlighted because of the histological heterogeneity of lacunar-canalicular network properties within the I-region and H-region in the mouse cortical

  20. Evolving Concept of Small Vessel Disease through Advanced Brain Imaging.

    Norrving, Bo

    2015-01-01

    Imaging plays a crucial role in studying and understanding cerebral small vessel disease. Several important findings have emerged from recent applications of advanced brain imaging methods. In patients with acute lacunar syndromes, diffusionweighted MRI studies have shown that the diagnostic precision of using clinical features alone or combined with CT scan findings to diagnose small vessel disease as the underlying cause is poor. Followup imaging studies on patients with acute infarcts rela...

  1. Leaf anatomy of Gaillardia cabrerae (Asteraceae: Basic plan and comparative study of two contrasting habitat populations Anatomía foliar de Gaillardia cabrerae (Asteraceae: plan básico y estudio comparativo de dos poblaciones de hábitats contrastantes

    Laura Beinticinco

    2011-06-01

    Full Text Available This study evaluates the leaf anatomy pattern of Gaillardia cabrerae Covas, an exclusive endemic camephyte from the Lihué Calel National Park, province of La Pampa, Argentina. Leaf cross sections and peelings of plants growing in two different populations were used to determine the basic leaf anatomy patterns and to estimate the influence of growth conditions in the two microhabitats. The analysis showed differences in epidermal cells area, stomata density and main diameter, lacunar parenchyma cells and central vascular bundle diameter and palisade parenchyma cells dimensions. These aspects might be reflecting environmental conditions of the populations, especially sun exposure and soil moisture. The results provide information on the relationship of the species to its environment, which could be used in the establishment of conservation policies.Gaillardia cabrerae Covas es un caméfito endémico del Parque Nacional Lihué Calel. En este estudio se evalúan características anatómicas de individuos de dos poblaciones provenientes de diferentes microhábitats de las Sierras de Lihué Calel. La información proporcionada es importante para entender las condiciones de vida de la especie y provee información inherente para establecer planes de conservación. Mediante cortes transversales y la técnica de peeling fue posible determinar el plan básico de la anatomía foliar y también verificar diferencias significativas en el área de células epidérmicas, densidad estomática, diámetro mayor de los estomas, diámetro de células del parénquima lagunar y del haz vascular central y en las dimensiones de las células del parénquima en empalizada. Las condiciones ambientales a las cuales estas poblaciones están sometidas, especialmente la exposición solar y la humedad del suelo son posibles factores que podrían explicar las diferencias detectadas en la anatomía foliar para ambas poblaciones.

  2. Marked pericardial inhomogeneity of specific ventilation at total lung capacity and beyond

    Sun, Yanping; Butler, James P; Lindholm, Peter;

    2009-01-01

    We measured regional ventilation at 1l above functional residual capacity (FRC+1L) and total lung capacity (TLC) in three normal subjects and four elite breath-hold divers, and above TLC after glossopharyngeal insufflation (TLC+GI) in the divers. Hyperpolarized (3)He MRI was used to map the local...

  3. Two and three-dimensional segmentation of hyperpolarized 3He magnetic resonance imaging of pulmonary gas distribution

    Heydarian, Mohammadreza; Kirby, Miranda; Wheatley, Andrew; Fenster, Aaron; Parraga, Grace

    2012-03-01

    A semi-automated method for generating hyperpolarized helium-3 (3He) measurements of individual slice (2D) or whole lung (3D) gas distribution was developed. 3He MRI functional images were segmented using two-dimensional (2D) and three-dimensional (3D) hierarchical K-means clustering of the 3He MRI signal and in addition a seeded region-growing algorithm was employed for segmentation of the 1H MRI thoracic cavity volume. 3He MRI pulmonary function measurements were generated following two-dimensional landmark-based non-rigid registration of the 3He and 1H pulmonary images. We applied this method to MRI of healthy subjects and subjects with chronic obstructive lung disease (COPD). The results of hierarchical K-means 2D and 3D segmentation were compared to an expert observer's manual segmentation results using linear regression, Pearson correlations and the Dice similarity coefficient. 2D hierarchical K-means segmentation of ventilation volume (VV) and ventilation defect volume (VDV) was strongly and significantly correlated with manual measurements (VV: r=0.98, phierarchical K-means segmentation of VV and VDV was also strongly and significantly correlated with manual measurements (VV: r=0.98, psemi-automated segmentation of 3He MRI gas distribution provides a way to generate novel pulmonary function measurements.

  4. Micro- and nano-CT for the study of bone ultrastructure.

    Peyrin, Françoise; Dong, Pei; Pacureanu, Alexandra; Langer, Max

    2014-12-01

    Micro-computed tomography (micro-CT)-a version of X-ray CT operating at high spatial resolution-has had a considerable success for the investigation of trabecular bone micro-architecture. Currently, there is a lot of interest in exploiting CT techniques at even higher spatial resolutions to assess bone tissue at the cellular scale. After recalling the basic principles of micro-CT, we review the different existing system, based on either standard X-ray tubes or synchrotron sources. Then, we present recent applications of micro- and nano-CT for the analysis of osteocyte lacunae and the lacunar-canalicular network. We also address the question of the quantification of bone ultrastructure to go beyond the sole visualization. PMID:25292366

  5. Clinical study of the relationship between arteriosclerosis obliterans (ASO) and cerebral infarction

    To clarify the relationship between arteriosclerosis obliterans (ASO) and cerebral infarction (CI), brain CT was performed and the risk factors for atherosclerosis were assessed. Thirty-five male and 5 female patients with intermittent claudication and/or leg ulceration were angiographically diagnosed as having ASO. According to CT findings, these patients were divided into three groups [no low-density areas (NLDA), hemorrhage, and infarction (CI)]. CI was subdivided as lacunar, cortical, and watershed infarction. Thirteen patients were in the NLDA group and 26 in the CI group (17 lacunar, 3 cortical and 6 mixed infarcts), indicating a CI incidence of 65%. Comparing the risk factors of the CI group with those of the NLDA group, hypertension (53.8%), diabetes (34.6%), and cigarette smoking (69.2%) was often seen in the CI group, although hypercholesterolemia (53.8%) and ischemic heart disease (42.3%) was the same in both groups. Multivariate analysis revealed that smoking had the strongest effect on the occurrence of CI in ASO patients. Furthermore, the number of combined risk factors (hypertension, diabetes, smoking, hypercholesterolemia) had a significant positive correlation with cortical infarction. As to the chronological relationship between the onset of ASO and CI, CI was present in 14 of 27 ASO patients on CT when the ischemic leg symptoms appeared, while symptomatic cortical infarction preceded ASO in 5 patients. CI patients increased gradually over a decade to 26 out of 40, among whom 16 patients with lacunae had silent infarcts. These findings suggested that ASO is frequently associated with CI, not only due to atherosclerosis of the main trunks of the cerebral vessels, but also due to arteriolosclerosis of the perforating arteries. (author)

  6. Calcium Response in Osteocytic Networks under Steady and Oscillatory Fluid Flow

    Lu, X. Lucas; Huo, Bo; Park, Miri; Guo, X. Edward

    2012-01-01

    The fluid flow in the lacunar-canalicular system of bone is an essential mechanical stimulation on the osteocyte networks. Due to the complexity of human physical activities, the fluid shear stress on osteocyte bodies and processes consists of both steady and oscillatory components. In this study, we investigated and compared the intracellular calcium ([Ca2+]i) responses of osteocytic networks under steady and oscillatory fluid flows. An in vitro osteocytic network was built with MLO-Y4 osteo...

  7. Matrix-dependent adhesion mediates network responses to physiological stimulation of the osteocyte cell process

    Wu, Danielle; Schaffler, Mitchell B.; Weinbaum, Sheldon; SPRAY, DAVID C.

    2013-01-01

    Osteocytes are bone cells that form cellular networks that sense mechanical loads distributed throughout the bone tissue. Interstitial fluid flow in the lacunar canalicular system produces focal strains at localized attachment sites around the osteocyte cell process. These regions of periodic attachment between the osteocyte cell membrane and its canalicular wall are sites where pN-level fluid-flow induced forces are generated in vivo. In this study, we show that focally applied forces of thi...

  8. Forgetting in Dementia With and Without Subcortical Lacunes

    Kramer, Joel H.; Mungas, Dan; Reed, Bruce R.; Schuff, Norbert; Weiner, Michael W.; Miller, Bruce L.; Chui, Helena C.

    2004-01-01

    Alzheimer’s disease (AD) and subcortical ischemic vascular disease (SIVD) are common causes of dementia, often co-occur, and can present quite similarly, making differential diagnosis clinically challenging. This study tested the hypothesis that patients with SIVD retain information better than AD patients. Participants were 35 dementia patients with subcortical lacunes (SIVD group), 27 dementia patients without lacunar infarction (AD group), and 56 normal controls. Results indicated that des...

  9. Relationships between personality traits, medial temporal lobe atrophy and white matter lesion in subjects suffering from mild cognitive impairment

    Emmanuelle eDuron

    2014-07-01

    Full Text Available Mild Cognitive Impairment (MCI is a heterogeneous cognitive status that can be a prodromal stage of Alzheimer‘s disease (AD. It is particularly relevant to focus on prodromal stages of AD such as MCI, because pathophysiological abnormalities of AD start years before the dementia stage. Medial temporal lobe atrophy (MTL resulting from AD lesions and cerebrovascular lesions (i.e. white matter lesions (WML, lacunar strokes and strokes are often revealed concurrently on Magnetic Resonance Imaging (MRI in MCI subjects. Personality changes have been reported to be associated with MCI status and early AD. More specifically, an increase in neuroticism and a decrease in conscientiousness have been reported, suggesting that higher and lower scores, respectively in neuroticism and conscientiousness are associated with an increased risk of developing the disease. However, personality changes have not been studied concomitantly with pathological structural brain alterations detected on MRI in patients suffering from MCI. Therefore, the objective of the present study was to assess the relationship between MTL atrophy, WML, lacunar strokes and personality traits in such patients. The severity of WML was strongly associated with lower levels of conscientiousness and higher levels of neuroticism. Conversely, no association was detected between personality traits and the presence of lacunar strokes or MTL atrophy. Altogether, these results strongly suggest that personality changes occurring in a MCI population, at high risk of AD, are associated with WML, which can induce executive dysfunctions, rather than with MTL atrophy.

  10. Cerebral blood flow single-photon emission tomography with 123I-IMP in vascular dementia

    Cerebral blood flow differences between patients with vascular dementia, patients with multiple lacunar infarction without cognitive dysfunction, and age-matched controls were examined. Thirty four patients with vascular dementia (VD) were selected from consecutive referrals to the Memory Clinic at Narita Memorial Hospital. All the patients had routine assessment including history, physical and neurological examinations, neuropsychological assessment, blood tests, EEG, head MRI, and single photon emission computed tomography (SPECT). All of them fulfilled the NINDS-AIREN diagnostic criteria for vascular dementia. Thirty nine patients with multiple lacunar infarction without cognitive dysfunction and 110 age-matched controls were included in this study. Mean cerebral blood flow (mCBF) and regional cerebral blood flow (rCBF) were measured using N-isopropyl-P-123I-iodoamphetamine (123I-IMP) and SPECT imager. The mCBF in VD was 27.6±5.3 ml/100 g/min, while those in the control group and multiple lacunar infarction without cognitive dysfunction were 36.6±6.1 ml/100 g/min and 32.5±5.5 ml/100 g/min, respectively. The patients with VD demonstrated significantly reduced mCBF and rCBF in twenty regions including both cerebellar hemispheres as compared with those of the control group. Although there was no significant rCBF differences in bilateral inferior occipital regions and the right cerebellar hemisphere between patients with VD and multiple lacunar infarction without cognitive dysfunction, we could find significant lower rCBF in the remaining brain areas. In spite of the severity of VD, the diffuse decrease of cerebral blood flow was recognized in all patients with VD. (author)

  11. 手掌侧单孔入路微创治疗腕管综合征的解剖学研究%Anatomic study of the volar single-aperture approach of endoscopic carpal tunnel release

    魏瑞鸿; 庄永青; 叶凤清; 姜浩力; 熊洪涛; 方锡池; 张轩

    2015-01-01

    Objective To report the palmar approach and surgical method for the view to provide anatomical data for the volar single-aperture approach of endoscopic carpal tunnel release(ECTR). Methods 16 specimens of fresh adult upper limb were used to observe and measure the anatomical structures in the carpal tunnel and palm. 6 specimens of fresh adult upper limb were used randomly to simulate the operation that divided the flexor retinaculum and released the median nerve of ECTR by one-point technique in palm. Results The best entrance point in palm of ECTR: Draw a parallel line along the thumb in the maximal abduction position to the ulnar side, and draw a axis between the middle finger and the ring finger;Mark the intersection of the lines, and then take an incision in the ulnar aspect about 1cm away from the intersection. Surgical plane was the lacunar space between the superficial fascia and palmar aponeursis. Conclusion Our study confirms that ECTR by one-point technique in palm is safe and feasible. It’s practical for surgeons to adopt the surgical approach of ECTR and avoid damage during severance offlexor retinaculum and relief of the median nerve under endoscope.%目的:报道手掌侧单孔入路微创治疗腕管综合征的解剖入路及手术方法,为手掌侧入路微创治疗腕管综合征手术提供解剖学基础。方法选取16例新鲜成人上肢标本,解剖观测腕管及手掌的相关解剖结构。选取6例新鲜成人上肢标本进行模拟手术,镜视下切开屈肌支持带并进行神经外膜松解。结果手术入路点为拇指呈最大外展位,沿掌指关节尺侧取一平行线,与中、环指间的长轴线交叉点处向尺侧1cm处,操作层面为浅筋膜层与掌腱膜间的腔隙。结论手掌侧单孔入路微创治疗腕管综合征是安全可行的,在镜视下可彻底切开屈肌支持带并进行神经外膜松解,有利于术者进行操作及减轻术中损伤。

  12. Pulmonary studies

    Radionuclide studies of the lung are described, as regards perfusion studies, ventilation studies and physiological considerations. The four principal applications for radionuclide studies of the lungs are outlined and the uses of these discussed in relation to particular entities including pulmonary embolic disease, congestive heart failure, asthma, acute, nonasthmatic, bronchial obstruction, chronic pulmonary disease and cancer. (Auth./C.F.)

  13. Cystometric study

    ... page: //medlineplus.gov/ency/article/003904.htm Cystometric study To use the sharing features on this page, please enable JavaScript. Cystometric study measures the amount of fluid in the bladder ...

  14. Initial Study

    Torp, Kristian

    2009-01-01

    increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes to...

  15. Feasibility of image registration and intensity-modulated radiotherapy planning with hyperpolarized helium-3 magnetic resonance imaging for non-small-cell lung cancer

    Ireland, Rob H.; Bragg, Chris M; McJury, Mark; Woodhouse, Neil; Fichele, Stan; van Beek, Edwin J. R.; Wild, Jim M.; Hatton, Matthew Q.

    2007-01-01

    PURPOSE: To demonstrate the feasibility of registering hyperpolarized helium-3 magnetic resonance images ((3)He-MRI) to X-ray computed tomography (CT) for functionally weighted intensity-modulated radiotherapy (IMRT) planning.METHODS AND MATERIALS: Six patients with non-small-cell lung cancer underwent (3)He ventilation MRI, which was fused with radiotherapy planning CT using rigid registration. Registration accuracy was assessed using an overlap coefficient, calculated as the proportion of t...

  16. Case Studies

    Proven options available to Sri Lanka for large scale electricity generation in the future are coal-fired thermal, oil-fired thermal and Nuclear. Four case studies for groups participated are indicated. Case study for group 1 is comparison of the three options by taking into consideration the capital and recurrent expenditure involved. Environmental effects of the three options are also given. Case study for group 2 is economic comparison of three renewable energy based power generation system. Case study for group 3 is based on energy conservation, efficiency, improvement and demand management. Assuming that a continuous saving of 20 MW of demand from 1996 onwards is effective two projects are suggested to achieve this result. Case study for group 4 is a feasibility study for hydro power development of the Kukule Ganga (river) in Sri Lanka. Participants are required to evaluate one of the three optional development concepts which are technically feasible

  17. Security studies

    The so called 'Security Studies' constitute one of the major tools for evaluating the provisions implemented at facilities to protect and control nuclear material (NM) against unauthorized removal. Operators use security studies to demonstrate that they are complying with objectives set by the Competent Authority to counter internal or external acts aimed at unauthorized removal of nuclear material. The paper presents the context of security studies carried out in France. (author)

  18. Absorption studies

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  19. Study on the diagnostic value of emergency-electroencephalogram and hypnogram to acute cerebral infarction

    Objective: To investigate the diagnostic value of emergency-EEG (EmEEG) and sleep electroencephalogram to acute cerebral infarction. Methods: Forty-two patients with acute cerebral infarction were collected. The first 30 minutes artifact-free segment of CEEG was selected as EmEEG, and its diagnostic value was compared with CT. Results: The EmEEG revealed that acute cerebral infarction abnormal accounted for 71.4%, while the number was 59.5% for the first CT scanning. Among those suffering from subcortical and cortical infarct, the EmEEG was more valuable in showing the ill lateral or site than those suffering from lacunar infarct. Along with the time elapsing, the positive rate of CT increased, while EmEEG's advantage of diagnostic value weakened. The abnormal rate of hypnogram was 79.31. Conclusion: The diagnostic value of EmEEG is higher in the patient who is excluded hemorrhage and found no ischemia focus by CT scanning in the earlier stage of acute cerebral infarction. (authors)

  20. Comparative study of SPECT and X-CT in examining elderly patients with acute cerebral infarction

    Objective: To investigate the differences of brain 99Tcm-ECD SPECT and X-CT in examining elderly patients with acute cerebral infarction thus to guide clinical diagnosis and treatment. Methods: 100 elderly patients with acute cerebral infarction underwent 99Tcm-ECD SPECT and X-CT between 1996 and 1997. On each patient, the two procedures were performed sequentially within three days. Results: The positive rate of X-CT was 54%, while the positive rate of SPECT was 92%. The results of X-CT correlated with the results of SPECT (x2 = 0.953, P>0.1), and the positive rate of SPECT was higher (x2 = 30.422, P99Tcm-ECD SPECT is better at predictive diagnosis of elderly acute cerebral infarction and gain valuable time for in-time treating, and it is more sensitive for detecting and localizing the lesions and makes the interpretation of clinical symptoms and signs easier. X-CT is more sensitive to detect basal ganglionic lacunar infarction and to distinguish cerebral infarction from cerebral hemorrhage. SPECT and X-CT can not be used in place of each other

  1. Study of nanosensor systems for hypertension associated cerebrovascular and cardiovascular disorders

    Ramasamy, Mouli; Varadan, Vijay K.

    2015-04-01

    Hypertension and hypertension associated cerebrovascular and cardiovascular diseases are on a rise. At-least 970 million people in the world and Seventy percent of the American adults are affected by high blood pressure, also known as hypertension. Even though blood pressure monitoring systems are readily available, the number of people being affected has been increasing. Most of the blood pressure monitoring systems require cumbersome approaches. Even the noninvasive techniques have not lowered the number of people affected nor did at-least increase the user base of these systems. Uncontrolled or untreated hypertension may lead to various cerebrovascular disorders including stroke, hypertensive crisis, lacunar infarcts intracerebral damage, microaneurysm, and cardiovascular disorders including heart failure, myocardial infraction, and ischemic heart disease. Hypertension is rated as the one of the most important causes of premature death in spite of the technical advances in biomedical technology. This paper briefs a review of the widely adopted blood pressure monitoring methods, research techniques, and finally, proposes a concept of implementing nanosensors and wireless communication for real time non-invasive blood pressure monitoring.

  2. Studying Sideways

    Plesner, Ursula

    2011-01-01

    inequalities in relation to the people we study. This article argues that not all types of social scientific research interviews benefit from an à priori problematization of power and control, ethics and equality, or emancipation. From a constructivist perspective, the article seeks to displace the...... methodological concern with power related to the ideas of studying up or down and introduce another set of concerns in relation to producing good empirical material when we “study sideways.” The argument is based on analyses of interview situations from a concrete research project, where researcher and...... researched share professional background to some degree, where negotiations replace a researcher-imposed dialogue, and where the circulation of shared or common concepts messes up an orderly division between researchers’ vocabulary and interviewees’ vocabularies. It is proposed that when we study sideways...

  3. Floodplain Study

    Montgomery County of Maryland — The purpose of a floodplain study is to establish the 100-year floodplain limits within or near a development in order to preserve the natural resources within the...

  4. Actuarial Studies

    U.S. Department of Health & Human Services — The Office of the Actuary in the Centers for Medicare and Medicaid Services (CMS) from time to time conducts studies on various aspects of the Medicare and Medicaid...

  5. Feasibility study

    The feasibility study itself examines the technical, economic and financial implications of a nuclear power station in depth so as to make sure that nuclear power is the right course to take. This means that it is quite an expensive operation and it is to avoid wasting this money that a pre-feasibility study is carried out. This preliminary study should eliminate cases where the electrical system cannot absorb the capacity of a nuclear station of commercial size, where other sources of power such as hydro-electricity, gas or cheap coal would make nuclear obviously uneconomic or where no suitable sites exist. If this first rather simple survey shows that nuclear power is a credible solution to a utilities need for electricity or heat production plant, then the next stage is a full feasibility study. (orig./TK)

  6. Invisibility Studies

    Invisibility Studies explores current changes in the relationship between what we consider visible and what invisible in different areas of contemporary culture. Contributions trace how these changes make their marks on various cultural fields and investigate the cultural significance of these...... conditioned by physical and social settings that create certain possibilities for visibility and visuality, yet exclude others. The richness and complexity of this cultural framework means that no single discipline or interdisciplinary approach could capture it single-handedly. Invisibility Studies begins...

  7. Treatability studies

    Bennedsen, Lars Rønn; Studds, Phil

    The fundamental information that a well-designed treatability study can provide is essential to the success of all remediation systems. Over the past years several new techniques for in situ and on site remediation of contaminated soil and groundwater have been used with varying degrees of success...... ends up with 3 or 4 applicable techniques.   Drawing up field studies and laboratory data, this paper will discus the importance of conducting screening laboratory and pilot test prior starting up the full scale treatment of a contaminated site with a given technology. For this purpose Rambøll has...... construction of the test unit makes it possible to combine different techniques in order to obtain more aggressive and effective remediation technologies, e.g. UV/ozone or electrochemical/H2O2. Actual case study data is presented to illustrate the benefits of in situ treatability tests prior to full scale...

  8. Security studies

    Full text: Security studies constitute one of the major tools for evaluating the provisions implemented at facilities to protect and control Nuclear Material against unauthorized removal. Operators use security studies to demonstrate that they are complying with objectives set by the Competent Authority to counter internal or external acts aimed at unauthorized removal of NM. The paper presents the context of security studies carried out in France. The philosophy of these studies is based on a postulated unauthorized removal of NM and the study of the behavior of the systems implemented to control and protect NM in a facility. The potential unauthorized removal of NM usually may take place in two stages. The first stage involves the sequence leading to handling of the NM. It occurs inside the physical barriers of a facility and may include action involving the documents corresponding to Material Control and Accounting systems. At this stage it is possible to limit the risk of unauthorized removal of NM by means of detection capabilities of the MC and A systems. The second stage is more specific to theft and involves removing the NM out of the physical barriers of a facility in which they are being held, notably by affecting the Physical Protection System. Operators have to study, from a quantity and time lapse point of view, the ability of the installed systems to detect unauthorized removal, as well as the possibility of tampering with the systems to mask unlawful operations. Operators have also to analyze the sequences during which NM are accessed, removed from their containment and further removed from the facility in which they are stored. At each stage in the process, the probability of detection and the time taken to carry out the above actions have to be estimated. Of course, these two types of studies complement each other. Security studies have begun, in France, for more than fifteen years. Up to now more than fifty security studies are available in the

  9. Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan

    F. Shahzad

    2010-03-01

    Full Text Available We devise a procedure in order to characterize the relative vulnerability of the Earth's surface to tectonic deformation using the geometrical characteristics of drainage systems. The present study focuses on the nonlinear analysis of drainage networks extracted from Digital Elevation Models in order to localize areas strongly influenced by tectonics. We test this approach on the Potwar Plateau in northern Pakistan. This area is regularly affected by damaging earthquakes. Conventional studies cannot pinpoint the zones at risk, as the whole region is characterized by a sparse and diffuse seismicity. Our approach is based on the fact that rivers tend to linearize under tectonic forcing. Thus, the low fractal dimensions of the Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A detailed textural analysis is carried out to investigate the linearization, heterogeneity and connectivity of the drainage patterns. These textural aspects are quantified using the fractal dimension, as well as lacunarity and succolarity analysis. These three methods are complimentary in nature, i.e. objects with similar fractal dimensions can be distinguished further with lacunarity and/or succolarity analysis. We generate maps of fractal dimensions, lacunarity and succolarity values using a sliding window of 2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'. These maps are then interpreted in terms of land surface vulnerability to tectonics. This approach allowed us to localize several zones where the drainage system is highly structurally controlled on the Potwar Plateau. The region located between Muree and Muzaffarabad is found to be prone to destructive events whereas the area westward from the Indus seems relatively unaffected. We conclude that a nonlinear analysis of the drainage system is an efficient additional tool to locate areas likely to be affected by massive destructing events affecting the Earth's surface and therefore threaten human

  10. KALRN Rare and Common Variants and Susceptibility to Ischemic Stroke in Chinese Han Population.

    Dang, Meizheng; Wang, Zhenzhen; Zhang, Ruyou; Li, Xiaoying; Peng, Yanqing; Han, Xuesong; Sun, Litao; Tian, Jiawei

    2015-09-01

    Stroke is the second most common cause of mortality worldwide, and it is a major cause of physical disability. Several genome-wide association studies have yielded numerous common variants which increase the risk of ischemic stroke, including the Kalirin-coding gene, KALRN. KALRN strongly associates with early-onset coronary artery disease and atherosclerosis and plays an important role in stroke in the European population. In this study, we analyzed four KALRN gene SNPs in 503 ischemic stroke patients and 493 control subjects, separating the patients into separate research groups based on comorbidity with hypertension or diabetes and stroke type (atherosis or lacunar and combination type). We found a rare variant of KALRN, rs11712619, that associated with lacunar stroke in the northern Chinese Han population with an average-risk allele frequency 0.009 (OR 2.95, 95 % CI 1.08-8.01, p = 0.028). However, after adjusting for relevant factors, including sex, age, body mass index, dyslipidemia, alcohol consumption, and smoking, this association was not evident. Additionally, the KALRN variant rs6438833 was associated with ischemic stroke, ischemic stroke comorbid with diabetes, and lacunar stroke after adjusting for the relevant factors (p = 0.046, p = 0.019 and p = 0.046, respectively), which remained significant after 10,000 permutation procedure test (p' = 0.047, p' = 0.018 and p' = 0.048, respectively). The association of these rare and common variants of KALRN with ischemic stroke in northern Chinese Han population offers insight for potential therapeutic research. PMID:25917671

  11. Hydrogeological study

    This work shows the hydrogeological study and well drilling carried out in the Teaching Formation Institute San Jose de Mayo Province Uruguay. It was developed a geological review in the National Directorate of Geology and Mining data base as well as field working, geology and hydrogeology recognition and area well drilling inventory.

  12. Reaction of cobalt molybdophosphate with alcoholic solutions of tetraethoxysilane and oxozirconium(IV) chloride

    Interaction of cobalt molybdophosphate with alcohol solutions of tetraethoxysilane and oxozirconium chloride was studied using the methods of IR spectroscopy and thermal analysis with an aim of ascertaining the potentiality of the reagents application for production of thermochrome materials. It was ascertained that as a results of interaction between cobalt molybdophosphate and tetraethoxysilane solution the heteropolyanion [PMo12O40]3- was transformed into lacunar form [HxPMo11O39]7-x. The hydrolysis processes occurring in compositions with oxozirconium chloride does not permit stabilizing the structure of the heteropolycompound responsible for thermochrome transitions

  13. Study protocol

    Thorsteinsson, Troels; Helms, Anne Sofie; Adamsen, Lis;

    2013-01-01

    Background During cancer treatment children have reduced contact with their social network of friends, and have limited participation in education, sports, and leisure activities. During and following cancer treatment, children describe school related problems, reduced physical fitness...... intervention includes an educational program aimed at the child with cancer, the child’s schoolteachers and classmates, and the child’s parents. Children with cancer will each have two ambassadors assigned from their class. The ambassadors visit the child with cancer at the hospital at alternating 2-week......, and one year after the cessation of treatment. The study is powered to quantify the impact of the combined educational, physical, and social intervention programs. Discussion RESPECT is the first population-based study to examine the effect of early rehabilitation for children with cancer, and to use...

  14. Studying Adolescence

    Richter, Linda M.

    2006-01-01

    Young people in their teens constitute the largest age group in the world, in a special stage recognized across the globe as the link in the life cycle between childhood and adulthood. Longitudinal studies in both developed and developing countries and better measurements of adolescent behavior are producing new insights. The physical and psychosocial changes that occur during puberty make manifest generational and early-childhood risks to development, in the form of individual differences in...

  15. Fractal analysis of the structural complexity of the connective tissue in human carotid bodies

    Guidolin, Diego; Porzionato, Andrea; Tortorella, Cinzia; Macchi, Veronica; De Caro, Raffaele

    2014-01-01

    The carotid body (CB) may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of CB, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita's index), gray level co-occurrence matrix (entropy, angular second moment, variance, correlation), and fractal analysis (fractal dimension, lacunarity). Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita's index (p < 0.05), angular second moment (p < 0.05), fractal dimension (p < 0.01), and lacunarity (p < 0.01) permitted to identify significant differences in the disposition of the connective tissue between these two series. A receiver operating characteristic (ROC) curve was also calculated to evaluate the efficiency of each parameter. The fractal dimension and lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy) and 0.8835 (good accuracy), respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the CB, such as different cell populations, vascularization, and innervation

  16. The Relationship between C-Reactive Protein Level and Discharge Outcome in Patients with Acute Ischemic Stroke

    Geng, He-Hong; Wang, Xin-Wang; Fu, Rong-Li; Jing, Meng-Juan; Huang, Ling-Ling; Zhang, Qing; Wang, Xiao-Xiao; Wang, Pei-Xi

    2016-01-01

    Previous studies showed that C-reactive protein (CRP), an inflammatory marker, was associated with stroke severity and long-term outcome. However, the relationship between the acute-phase CRP level and discharge outcome has received little attention. We prospectively studied 301 patients with acute ischemic stroke (over a period of two weeks) from two hospital stroke wards and one rehabilitation department in Henan, China. Patients’ demographic and clinical data were collected and evaluated at admission. Poor discharge outcome was assessed in patients at discharge using the Modified Rankin Scale (MRS > 2). Multivariate logistic regression analysis was performed to determine the risk factors of poor discharge outcome after adjusting for potential confounders. Poor discharge outcome was observed in 78 patients (25.9%). Univariate analyses showed that factors significantly influencing poor discharge outcome were age, residence, recurrent acute ischemic stroke, coronary heart disease, the National Institutes of Health Stroke Scale (NIHSS) score at admission, non-lacunar stroke, time from onset of stroke to admission, CRP, TBIL (total bilirubin), direct bilirubin (DBIL), ALB (albumin), FIB (fibrinogen) and D-dimer (p < 0.05). After adjusting for age, residence, recurrent ischemic stroke, coronary heart disease, NIHSS score at admission, lacunar stroke, time from onset of stroke to admission, CRP, TBIL, DBIL, ALB, FIB and D-dimer, multivariate logistic regression analyses revealed that poor outcome at discharge was associated with recurrent acute ischemic stroke (OR, 2.115; 95% CI, 1.094–4.087), non-lacunar stroke (OR, 2.943; 95% CI, 1.436–6.032), DBIL (OR, 1.795; 95% CI, 1.311–2.458), and CRP (OR, 4.890; 95% CI, 3.063–7.808). In conclusion, the CRP level measured at admission was found to be an independent predictor of poor outcome at discharge. Recurrent acute ischemic stroke, non-lacunar stroke and DBIL were also significantly associated with discharge

  17. Study protocol

    Madsen, Helle Østergaard; Dam, Ole Henrik; Hageman, Ida

    2012-01-01

    yields a Global Seasonal Score and a prevalence of SAD. Outcomes from the two groups will be compared. Moreover, outcomes from subgroups of the visually impaired population will be compared. ETHICS AND DISSEMINATION: The study is approved by the Danish Data Protection Agency. Results will be published in...... persons with severe visual impairments or blindness and to compare the results to a control group without visual impairments. Moreover, the authors wish to investigate whether SAD is correlated to the degree of impairment or to the diagnosis. METHODS AND ANALYSIS: 2781 persons with visual impairments...

  18. Arctic studies

    Idaho National Engineering Laboratory (INEL) conducted a study of contamination of the Arctic Ocean and surrounding areas in order to better understand the severity of the problem and identify possible parallels in the United States. The findings were published in a quarterly report as a part of this technical task plan (TTP). While many radioactive and hazardous material contamination sites in this region have been identified, official Russian statements indicate that contaminant concentrations are within normal limits and are currently confined to specific areas

  19. Conceptual study

    Harty, H.

    1978-09-01

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC.

  20. Conceptual study

    This appendix is a compendium of topical reports prepared for the Hanford Nuclear Energy Center: Status Report: Conceptual Fuel Cycle Studies for the Hanford Nuclear Energy Center; Selection of Heat Disposal Methods for a Hanford Nuclear Energy Center; Station Service Power Supply for a Hanford Nuclear Energy Center (HNEC); Impact of a Hanford Nuclear Energy Center on Ground Level Fog and Humidity; A Review of Potential Technology for the Seismic Characterization of Nuclear Energy Centers; Reliability of Generation at a Hanford Nuclear Energy Center (HNEC); Meteorological Evaluation of Multiple Reactor Contamination Probabilities for a Hanford Nuclear Energy Center; Electric Power Transmission for a Hanford Nuclear Energy Center (HNEC); The Impact of a Hanford Nuclear Energy Center on Cloudiness and Insolation; and A Licensing Review for an HNEC

  1. SOCIOLOGICAL STUDIES

    2012-01-01

    PAPER Post-Sociology: Exploration and Reflection Xie Lizhong Abstract: "Post-Sociology" refers to a new perspective which is different from tradi- tional perspectives of social studies. "Post-Social History" and "Pluralistic Discourse Analysis" could be seen as its two specific examples. "Discourse Constructivism" and "Pluralism" are the two core concepts of "Post-Sociology". That encouraging people to realize that all "social reality" including our experiences, thoughts and speech are just a "discoursive reality" constructed by social actors under the guidance and constraints of certain discourse system, is the major significance of "PostSociology". Some critics on "Post-Sociology" are misunderstandings, while others couldn't stand to strict analysis.

  2. Aerosol studies

    As part of the continuing studies of the effects of very severe reactor accidents, an effort was made to develop, test, and improve simple, effective, and inexpensive methods by which the average citizen, using only materials readily available, could protect his residence, himself, and his family from injury by toxic aerosols. The methods for protection against radioactive aerosols should be equally effective against a clandestine biological attack by terrorists. The results of the tests to date are limited to showing that spores of the harmless bacterium, bacillus globegii (BG), can be used as a simulant for the radioactive aerosols. An aerosol generator of Lauterbach type was developed which will produce an essentially monodisperse aerosol at the rate of 109 spores/min. Analytical techniques have been established which give reproducible results. Preliminary field tests have been conducted to check out the components of the system. Preliminary tests of protective devices, such as ordinary vacuum sweepers, have given protection factors of over 1000

  3. Systems studies

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity, the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the U.S.A. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated Bioenergy Systems (IBS) Activity of IEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the U.S.A. and the U.K. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modelling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from techno-economic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the U.S.A. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review 8 refs, 10 tabs

  4. Systems Studies

    Graham, R.L.

    1998-03-17

    The Systems Studies Activity had two objectives: (1) to investigate nontechnical barriers to the deployment of biomass production and supply systems and (2) to enhance and extend existing systems models of bioenergy supply and use. For the first objective, the Activity focused on existing bioenergy markets. Four projects were undertaken: a comparative analysis of bioenergy in Sweden and Austria; a one-day workshop on nontechnical barriers jointly supported by the Production Systems Activity; the development and testing of a framework for analyzing barriers and drivers to bioenergy markets; and surveys of wood pellet users in Sweden, Austria and the US. For the second objective, two projects were undertaken. First, the Activity worked with the Integrated BioEnergy Systems (TBS) Activity of TEA Bioenergy Task XIII to enhance the BioEnergy Assessment Model (BEAM). This model is documented in the final report of the IBS Activity. The Systems Studies Activity contributed to enhancing the feedstock portion of the model by developing a coherent set of willow, poplar, and switchgrass production modules relevant to both the US and the UK. The Activity also developed a pretreatment module for switchgrass. Second, the Activity sponsored a three-day workshop on modeling bioenergy systems with the objectives of providing an overview of the types of models used to evaluate bioenergy and promoting communication among bioenergy modelers. There were nine guest speakers addressing different types of models used to evaluate different aspects of bioenergy, ranging from technoeconomic models based on the ASPEN software to linear programming models to develop feedstock supply curves for the US. The papers from this workshop have been submitted to Biomass and Bioenergy and are under editorial review.

  5. Mineralogical studies

    The mineralogy of WC-series cores from the project area uranium deposit in the San Juan Basin, New Mexico was studied with respect to the deposit and to the paleohydrologic and present hydrologic gradients. Bulk clay analyses, authigenic clay coatings on detrital grains, sulfur minerals, ferric oxide minerals, carbonate minerals, and detrital magnetite-ilmenite were investigated. Among the clays, chlorite/illite seem to offer some indication of the deposit location. More frequent clay coatings are found in the favorable ore horizon along the paleogradient than along the present gradient. Barite is more abundant in the favorable horizon and near ore than elsewhere. Pyrite and other sulfide minerals are relatively sparse in and near the deposit compared to areas away from the deposit. More than two generations of ferric oxide minerals are present in the area and these are deleted in samples nearest ore down the present gradient. Carbonate minerals aremore abundant in lower parts of the favorable zone. 8 figures, 2 tables

  6. Research and Development of a Chaotic Signal Synchronization Error Dynamics-Based Ball Bearing Fault Diagnostor

    Ying-Che Kuo

    2014-10-01

    Full Text Available This paper describes the fault diagnosis in the operation of industrial ball bearings. In order to cluster the very small differential signals of the four classic fault types of the ball bearing system, the chaos synchronization (CS concept is used in this study as the chaos system is very sensitive to a system’s variation such as initial conditions or system parameters. In this study, the Chen-Lee chaotic system was used to load the normal and fault signals of the bearings into the chaos synchronization error dynamics system. The fractal theory was applied to determine the fractal dimension and lacunarity from the CS error dynamics. Extenics theory was then applied to distinguish the state of the bearing faults. This study also compared the proposed method with discrete Fourier transform and wavelet packet analysis. According to the results, it is shown that the proposed chaos synchronization method combined with extenics theory can separate the characteristics (fractal dimension vs. lacunarity completely. Therefore, it has a better fault diagnosis rate than the two traditional signal processing methods, i.e., Fourier transform and wavelet packet analysis combined with extenics theory.

  7. Age-related reduction of chromatin fractal dimension in toluidine blue - stained hepatocytes.

    Pantic, Igor; Petrovic, Danica; Paunovic, Jovana; Vucevic, Danijela; Radosavljevic, Tatjana; Pantic, Senka

    2016-07-01

    In this study, we proposed a hypothesis that chromatin of mouse hepatocytes exhibits age-related reduction of fractal dimension. This hypothesis was based on previously published works demonstrating that complexity of biological systems such as tissues, decreases during the process of physiological aging. Liver tissue was obtained from 24 male mice divided into 3 age groups: 10-days-old (young, juvenile), 210-days-old (adult) and 390-days-old. The tissue was stained using a modification of toluidine blue (nucleic acid - specific) staining method. A total of 480 chromatin structures (20 for each animal) were analyzed. For each structure, the values of fractal dimension, lacunarity, textural angular second moment and inverse difference moment were calculated using ImageJ software and its plugins. The results indicated the age-related reduction in fractal dimension and increase in lacunarity (p<0.01). Fractal dimension is a potentially good indicator of age associated changes in chromatin structure. To our knowledge, this is the first study to show that fractal complexity of hepatocyte chromatin decreases during the process of physiological aging. Fractal analysis as a method could be useful in detection of small age-related changes in chromatin distribution not otherwise visible with naked eye on conventional tissue micrographs. PMID:27412950

  8. Assessment of intra and extra cranial atherosclerosis in coronary artery disease. Advantage of MRI/MRA

    The incidence of arteriosclerosis has increased in recent years as the aging population has grown. We carried out the present study to investigate the association of internal carotid arteriosclerosis, sclerosis of intracranial main arteries, and cerebral arteriolosclerosis to coronary arteriosclerosis using MRI and MRA in a total of 133 consecutive patients (107 males and 26 females), who visited our hospital with a main complaint of chest pain. We also examined serum lipids and the presence or absence of hypertension and/or diabetes. Coronary arteriosclerosis underlying atherosclerotic lesions was correlated with internal carotid arteriosclerosis, serum cholesterol and low HDL cholesterol level. As characteristic findings of this study, lacunar infarction (LI), which is thought to represent cerebral arteriolosclerosis, was not only significantly correlated with age and hypertension, but increased also lacunar infarcts in number as the number of affected coronary branches increased. Examination of the cases of severe coronary artery disease with MRI/MRA was thought to be able to predict the occurrence of cerebrovascular disorder after CABG and to be useful for the selection of a therapeutic regimen, such as PTCA and MID-CABG. (author)

  9. Assessment of intra and extra cranial atherosclerosis in coronary artery disease. Advantage of MRI/MRA

    Kondo, Hirohide; Oda, Yoshinori; Hirai, Akio; Ibukiyama, Chiharu; Utsugi, Osamu [Tokyo Medical Coll. (Japan)

    1999-02-01

    The incidence of arteriosclerosis has increased in recent years as the aging population has grown. We carried out the present study to investigate the association of internal carotid arteriosclerosis, sclerosis of intracranial main arteries, and cerebral arteriolosclerosis to coronary arteriosclerosis using MRI and MRA in a total of 133 consecutive patients (107 males and 26 females), who visited our hospital with a main complaint of chest pain. We also examined serum lipids and the presence or absence of hypertension and/or diabetes. Coronary arteriosclerosis underlying atherosclerotic lesions was correlated with internal carotid arteriosclerosis, serum cholesterol and low HDL cholesterol level. As characteristic findings of this study, lacunar infarction (LI), which is thought to represent cerebral arteriolosclerosis, was not only significantly correlated with age and hypertension, but increased also lacunar infarcts in number as the number of affected coronary branches increased. Examination of the cases of severe coronary artery disease with MRI/MRA was thought to be able to predict the occurrence of cerebrovascular disorder after CABG and to be useful for the selection of a therapeutic regimen, such as PTCA and MID-CABG. (author)

  10. Asymptomatic ischemic cerebral lesions

    For the purpose of studying the incidence, pathomorphology and etiology of asymptomatic ischemic cerebral lesions, we carried out a brain MRI study on 65 patients with diabetes mellitus accompanied with hypertension who are thought to belong to a high risk group of ischemic cerebrovascular diseases. Excluding the abnormality of tendon reflex due to diabetic neuropathy, sixty percent of the total patients had some mild neurological signs and symptoms, most of them was discrepancy in tendon reflex. The percentage of the patients in whom MRI disclosed some abnormalities was as high as 70%, they were lacunar stroke, multiple lacunar state, cortical infarct, and patchy high signal lesions visible only in the T2 weighted image. Lacunes or these patchy high signal lesions (considered to be the dilatation of the perivascular space or true lacunes) tended to be found along the border zone or the terminal zone. These results indicate that asymptomatic patients in whom MRI discloses the abnormalities should be considered as candidates for the future onset of multi-infarct. (author)

  11. Study on the clinical usefulness of magnetic resonance imaging in cases of multiple cerebral infarction

    The clinical significance of MRI in thrombotic multiple cerebral infarction was examined in 9 patients having recent lacunar stroke. Recent infarct was identified on Gd-enhanced MRI in 4 patients. For patients multiple small infarction, Gd-enhanced MRI made it possible to differentiate recent from other lesions. To clarify the significance of periventricular high intensity lesion (PVH) on T2-weighted MRI, hemodynamic and neuropsychologic examinations were carried out in 41 patients with multiple cerebral infarction. All the patients had PVH, which was classified into three grades as follows: grade I (n=16) showing only a thin high intensity band along the body of lateral ventricles; grade 2 (n=15) showing a definite high intensity area around the lateral ventricles; grade 3 (n=10) showing diffuse thick and irregular foci around the whole ventricle. In these patients, rCBF was measured by 133Xe inhalation methods. Initial slope index was significantly higher in patients with grade 3 than those with grade I. Mini-mental state test score was significantly higher in patients with grade l than those with grade 2 and 3. Progression of PVH may be related with the reduction of the cerebral circulation and mental function in cases of multiple cerebral infarction. Ischemic and hemorrhagic lesions can be distinguished by MRI, because old intracerebral hemorrhage appear as hypointensity areas with or without hyperintensity area on T2w images. In 92 patients with multiple infarction, MRI was used to evaluate the incidence and distribution of coexisting old intracerebral hemorrhage. Old hemorrhage were found in 15 patients (16.3%). locating the site where hypertensive hemorrhage commonly occurred. High-field MRI is useful for assessing the coexistence of hemorrhage in hypertensive patients with multiple cerebral infarction. (N.K.)

  12. Study on the clinical usefulness of magnetic resonance imaging in cases of multiple cerebral infarction

    Miyashita, Kotaro (Niigata Univ. (Japan). Brain Research Inst.)

    1991-09-01

    The clinical significance of MRI in thrombotic multiple cerebral infarction was examined in 9 patients having recent lacunar stroke. Recent infarct was identified on Gd-enhanced MRI in 4 patients. For patients multiple small infarction, Gd-enhanced MRI made it possible to differentiate recent from other lesions. To clarify the significance of periventricular high intensity lesion (PVH) on T2-weighted MRI, hemodynamic and neuropsychologic examinations were carried out in 41 patients with multiple cerebral infarction. All the patients had PVH, which was classified into three grades as follows: grade I (n=16) showing only a thin high intensity band along the body of lateral ventricles; grade 2 (n=15) showing a definite high intensity area around the lateral ventricles; grade 3 (n=10) showing diffuse thick and irregular foci around the whole ventricle. In these patients, rCBF was measured by {sup 133}Xe inhalation methods. Initial slope index was significantly higher in patients with grade 3 than those with grade I. Mini-mental state test score was significantly higher in patients with grade l than those with grade 2 and 3. Progression of PVH may be related with the reduction of the cerebral circulation and mental function in cases of multiple cerebral infarction. Ischemic and hemorrhagic lesions can be distinguished by MRI, because old intracerebral hemorrhage appear as hypointensity areas with or without hyperintensity area on T2w images. In 92 patients with multiple infarction, MRI was used to evaluate the incidence and distribution of coexisting old intracerebral hemorrhage. Old hemorrhage were found in 15 patients (16.3%). locating the site where hypertensive hemorrhage commonly occurred. High-field MRI is useful for assessing the coexistence of hemorrhage in hypertensive patients with multiple cerebral infarction. (N.K.).

  13. Clinicoradiological study on 59 patients with pure motor hemiparesis due to corona radiata infarcts

    To evaluate the clinicoradiological findings of patients with small infarction at the level of the corona radiata, such patients were divided into three groups: Group A (facio-lingual weakness), Group B (arm-dominant weakness) and Group C (leg-dominant weakness). The anteroposterior position and maximum diameter of the radiata infarcts were assessed by axial T2-weighted imaging. In total, 59 consecutive patients (42 men and 17 women) were selected. The frequency of radiata infarct is 9.4% among cerebral infarct patients. The male/female ratio was 1.3. The mean age (SD) was 68.9 (9.5) years. The number of patients was 23 in Group A, 19 in Group B and 17 in Group C. Group B patients needed aid in their daily life, when compared to Group A and Group C. The cerebrovascular risk profiles demonstrated hypertension in 43 patients (72.9%), diabetes mellitus in 15 (25.4%), current smoking in 22 (37.3%), dyslipidemia in 16 (27.1%) and arterial fibrillation in 11 (18.6%). The clinical subtypes revealed 48 patients with lacunar infarct and 11 with cardiogenic emboli. The somatotopical distribution of motor fibers of Groups A to C was arranged in antero-posterior order. There were 24 patients with right lesions and 35 with left lesions. The size of the left infarcts was significantly smaller than that of the right infarcts. The clinical outcome of patients with arm-dominant weakness was relatively poor as compared to that of patients with dysarthria or leg-dominant weakness. The neuroradiological data suggest that left radiata infarct is smaller and more frequent than right infarct. (author)

  14. Fostering Effective Studying and Study Planning with Study Questions

    Wilhelm, Pascal; Pieters, Jules M.

    2007-01-01

    In a course on biological psychology and neuropsychology, study questions were provided that also appeared as test questions in the course exam. This method was introduced to support students in active processing and reproduction of the study texts, and study planning. Data were gathered to test the hypothesis that study question use would be…

  15. MRI and pathological examination of post-mortem brains: the problem of white matter high signal areas

    We examined 21 brains from individuals more than 65 years of age by MRI and neuropathological methods to study the frequency and morphology of white matter changes. There were 16 brains from neurologically normal subjects (Group 1) while the remaining 5 (Group 2) had neurological disturbances. In Group 1 MRI showed high signal areas in the periventricular white matter in 12 brains and in the deep white matter in 9. All had focal areas, with confluent zones in 4; 3 cystic infarcts were also detected. Neuropathology in this Group showed periventricular changes of variable extent in all cases, vacuolated myelin around the perivascular spaces in 14 and degenerate myelin in 4. Macroscopic inspection showed 3 cystic lacunar infarcts, while areas of recent infarction were present on histology in 2. Four of the Group 2 brains had periventricular MRI changes; high signal areas in deep white matter were focal in 2 and confluent in 1. Cystic infarcts were detected in 3 cases. Neuropathology showed periventricular changes in all the brains; in 4 myelin around the perivascular spaces was vacuolated while degenerate myelin was demonstrated in 1. There were also old (1) and recent (2) lacunar infarcts. (orig.)

  16. Racial Differences by Ischemic Stroke Subtype: A Comprehensive Diagnostic Approach

    Sarah Song

    2012-01-01

    Full Text Available Background. Previous studies have suggested that black populations have more small-vessel and fewer cardioembolic strokes. We sought to analyze racial differences in ischemic stroke subtype employing a comprehensive diagnostic workup with magnetic resonance-imaging-(MRI- based evaluation including diffusion-weighted imaging (DWI. Methods. 350 acute ischemic stroke patients admitted to an urban hospital with standardized comprehensive diagnostic evaluations were retrospectively analyzed. Ischemic stroke subtype was determined by three Trial of Org 10172 in Acute Stroke Treatment (TOAST classification systems. Results. We found similar proportions of cardioembolic and lacunar strokes in the black and white cohort. The only subtype category with a significant difference by race was “stroke of other etiology,” more common in whites. Black stroke patients were more likely to have an incomplete evaluation, but this did not reach significance. Conclusions. We found similar proportions by race of cardioembolic and lacunar strokes when employing a full diagnostic evaluation including DWI MRI. The relatively high rate of cardioembolism may have been underappreciated in black stroke patients when employing a CT approach to stroke subtype diagnosis. Further research is required to better understand the racial differences in frequency of “stroke of other etiology” and explore disparities in the extent of diagnostic evaluations.

  17. Spatial heterogeneity analysis of brain activation in fMRI

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  18. Fractal analysis and Gray level co-occurrence matrix method for evaluation of reperfusion injury in kidney medulla.

    Pantic, Igor; Nesic, Zorica; Paunovic Pantic, Jovana; Radojević-Škodrić, Sanja; Cetkovic, Mila; Basta Jovanovic, Gordana

    2016-05-21

    Fractal analysis and Gray level co-occurrence matrix method represent two novel mathematical algorithms commonly used in medical sciences as potential parts of computer-aided diagnostic systems. In this study, we tested the ability of these methods to discriminate the kidney medullar tissue suffering from reperfusion injury, from normal tissue. A total of 320 digital micrographs of Periodic acid-Schiff (PAS) - stained kidney medulla from 16 Wistar albino mice (20 per animal), were analyzed using National Institutes of Health ImageJ software (NIH, Bethesda, MD) and its plugins. 160 micrographs were obtained from the experimental group with induced reperfusion injury, and another 160 were obtained from the controls. For each micrograph we calculated the values of fractal dimension, lacunarity, as well as five GLCM features: angular second moment, entropy, inverse difference moment, GLCM contrast, and GLCM correlation. Discriminatory value of the parameters was tested using receiver operating characteristic (ROC) analysis, by measuring the area below ROC curve. The results indicate that certain features of GLCM algorithm have excellent discriminatory ability in evaluation of damaged kidney tissue. Fractal dimension and lacunarity as parameters of fractal analysis also had a relatively good discriminatory value in differentiation of injured from the normal tissue. Both methods have potentially promising application in future design of novel techniques applicable in cell physiology, histology and pathology. PMID:26964774

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

    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.)

  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

    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. MRI and pathological examination of post-mortem brains: the problem of white matter high signal areas

    Scarpelli, M. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Salvolini, U. (Magnetic Resonance Research Unit, Ancona Univ. (Italy)); Diamanti, L. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Montironi, R. (Inst. of Pathological Anatomy and Histopathology, Ancona Univ. (Italy)); Chiaromoni, L. (Magnetic Resonance Research Unit, Ancona Univ. (Italy)); Maricotti, M. (Magnetic Resonance Research Unit, Ancona Univ. (Italy))

    1994-07-01

    We examined 21 brains from individuals more than 65 years of age by MRI and neuropathological methods to study the frequency and morphology of white matter changes. There were 16 brains from neurologically normal subjects (Group 1) while the remaining 5 (Group 2) had neurological disturbances. In Group 1 MRI showed high signal areas in the periventricular white matter in 12 brains and in the deep white matter in 9. All had focal areas, with confluent zones in 4; 3 cystic infarcts were also detected. Neuropathology in this Group showed periventricular changes of variable extent in all cases, vacuolated myelin around the perivascular spaces in 14 and degenerate myelin in 4. Macroscopic inspection showed 3 cystic lacunar infarcts, while areas of recent infarction were present on histology in 2. Four of the Group 2 brains had periventricular MRI changes; high signal areas in deep white matter were focal in 2 and confluent in 1. Cystic infarcts were detected in 3 cases. Neuropathology showed periventricular changes in all the brains; in 4 myelin around the perivascular spaces was vacuolated while degenerate myelin was demonstrated in 1. There were also old (1) and recent (2) lacunar infarcts. (orig.)

  2. Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation.

    Cereda, Maurizio; Emami, Kiarash; Kadlecek, Stephen; Xin, Yi; Mongkolwisetwara, Puttisarn; Profka, Harrilla; Barulic, Amy; Pickup, Stephen; Månsson, Sven; Wollmer, Per; Ishii, Masaru; Deutschman, Clifford S; Rizi, Rahim R

    2011-02-01

    The aim of this study was to assess the utility of (3)He MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats (n = 13) were anesthetized, intubated, and ventilated in the supine position ((4)He-to-O(2) ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase of PEEP to 9 cmH(2)O and back to zero end-expiratory pressure or alternating between these two PEEP levels. Diffusion MRI was performed to image (3)He apparent diffusion coefficient (ADC) maps in the middle coronal slices of lungs (n = 10). ADC was measured immediately before and after two recruitment maneuvers, which were separated from each other with a wait period (8-44 min). We detected a statistically significant decrease in mean ADC after each recruitment maneuver. The relative ADC change was -21.2 ± 4.1 % after the first maneuver and -9.7 ± 5.8 % after the second maneuver. A significant relative increase in mean ADC was observed over the wait period between the two recruitment maneuvers. The extent of this ADC buildup was time dependent, as it was significantly related to the duration of the wait period. The two postrecruitment ADC measurements were similar, suggesting that the lungs returned to the same state after the recruitment maneuvers were applied. No significant intrasubject differences in ADC were observed between the corresponding PEEP levels in two rats that underwent three repeat maneuvers. Airway pressure tracings were recorded in separate rats undergoing one PEEP maneuver (n = 3) and showed a significant relative difference in peak inspiratory pressure between pre- and poststates. These observations support the hypothesis of redistribution of alveolar gas due to recruitment of collapsed alveoli in presence of atelectasis, which was also supported by

  3. Review: The evolving placenta: Different developmental paths to a hemochorial relationship

    Enders, A C; Carter, A M

    2012-01-01

    syncytial, often leading to a similar relationship in the spongy zone and labyrinth. Old World monkeys, apes and humans have a lacunar stage prior to establishing a villous hemochorial condition. New World monkeys lack a true lacunar stage, retaining portions of maternal vessels for some time and initially...

  4. Case Study: Writing a Journal Case Study

    Prud'homme-Genereux, Annie

    2016-01-01

    This column provides original articles on innovations in case study teaching, assessment of the method, as well as case studies with teaching notes. This month's issue describes incorporating a journal article into the classroom by first converting it into a case study.

  5. Ecological baseline studies

    Vickers, D.

    1980-01-01

    Environmental studies of Merritt Island are discussed. Five areas of the island's ecology are examined. They include: a terrestrial community analyses, a plant community study, a small mammal population study, a rainfall study, and an ichthyological analyses.

  6. Building Transdisciplinary Environmental Studies

    Holm, Jesper

    Conceptual analytical-methodological conceptualization of crossdisciplinary sustainability studies......Conceptual analytical-methodological conceptualization of crossdisciplinary sustainability studies...

  7. German Studies in America. German Studies Notes.

    Sander, Volkmar; Osterle, Heinz D.

    This volume contains two papers, "German Studies in America," by Volkmar Sander, and "Historicism, Marxism, Structuralism: Ideas for German Culture Courses," by Heinz D. Osterle. The first paper discusses the position of German studies in the United States today. The greatest challenge comes from low enrollments; therefore, German departments must…

  8. Mechanisms of osteocyte stimulation in osteoporosis.

    Verbruggen, Stefaan W; Vaughan, Ted J; McNamara, Laoise M

    2016-09-01

    Experimental studies have shown that primary osteoporosis caused by oestrogen-deficiency results in localised alterations in bone tissue properties and mineral composition. Additionally, changes to the lacunar-canalicular architecture surrounding the mechanosensitive osteocyte have been observed in animal models of the disease. Recently, it has also been demonstrated that the mechanical stimulation sensed by osteocytes changes significantly during osteoporosis. Specifically, it was shown that osteoporotic bone cells experience higher maximum strains than healthy bone cells after short durations of oestrogen deficiency. However, in long-term oestrogen deficiency there was no significant difference between bone cells in healthy and normal bone. The mechanisms by which these changes arise are unknown. In this study, we test the hypothesis that complex changes in tissue composition and lacunar-canalicular architecture during osteoporosis alter the mechanical stimulation of the osteocyte. The objective of this research is to employ computational methods to investigate the relationship between changes in bone tissue composition and microstructure and the mechanical stimulation of osteocytes during osteoporosis. By simulating physiological loading, it was observed that an initial decrease in tissue stiffness (of 0.425GPa) and mineral content (of 0.66wt% Ca) relative to controls could explain the mechanical stimulation observed at the early stages of oestrogen deficiency (5 weeks post-OVX) during in situ bone cell loading in an oestrogen-deficient rat model of post-menopausal osteoporosis (Verbruggen et al., 2015). Moreover, it was found that a later increase in stiffness (of 1.175GPa) and mineral content (of 1.64wt% Ca) during long-term osteoporosis (34 weeks post-OVX), could explain the mechanical stimuli previously observed at a later time point due to the progression of osteoporosis. Furthermore, changes in canalicular tortuosity arising during osteoporosis were shown

  9. A study of whole brain perfusion CT and CT angiography in hyperacute and acute cerebral infarction

    Objective: To evaluate the diagnostic value of whole-brain perfusion blood volume-weighted CT imaging (PWCT) and simultaneous CT angiography (CTA) on early stage of cerebral ischemic infarction. Methods: Non-contrast CT (NCCT), CT perfusion-weighted imaging (PWCT) and delayed CT (DCT) were conducted on 20 cases of early ischemic infarction of whose onset time ranged from 2 to 24 hours. All cases were reexamined with CT or MRI one week to one month later. CT values and perfusion blood volume (PBV) of central and peripheral low perfusion areas as well as those of collateral side were measured. CTA was reconstructed with PWCT as source images to evaluate occlusion or stenosis of blood vessel, and DCT was used to detect the collateral circulation. Results: Of the 20 cases, NCCT, PWCT and CTA were negative in 10 cases in which 6 were confirmed as Transient Ischemic Attack (TIA) on reexamined CT and clinical features, and the other 4 were confirmed as lacunar infarction. For the remaining 10 cases, a comparison was made with ANOVA between low perfusion area (central, peripheral inside and outside) and collateral side. The difference was significant (P<0.01). However, no significant difference was revealed in the central, peripheral inside and outside areas. PBV values were significant in low perfusion area and collateral side (P<0.05). The area of the final infarction was larger than that of the low perfusion area, and the percentage of enlargement exhibited medium negative correlation to the time of ischemia. CTA indicated that 2 cases suffered from left middle cerebral artery occlusion, meanwhile anterior and middle branches of MCA in the other 3 cases were not identified. The sensitivity of NCCT, PWCT and CTA were 28.5%, 71.4% and 35.7% respectively. DCT indicated that 5 cases had asymmetrical blood vessels. Conclusion: The whole-brain perfusion-weighted CT imaging and simultaneous CT angiography (CTA) is p roved to be a simple, timesaving and effective method for the

  10. Case Study Teaching

    Herreid, Clyde Freeman

    2011-01-01

    This chapter describes the history of case study teaching, types of cases, and experimental data supporting their effectiveness. It also describes a model for comparing the efficacy of the various case study methods. (Contains 1 figure.)

  11. Chemical Industry Bandwidth Study

    none,

    2006-12-01

    The Chemical Bandwidth Study provides a snapshot of potentially recoverable energy losses during chemical manufacturing. The advantage of this study is the use of "exergy" analysis as a tool for pinpointing inefficiencies.

  12. Esophagram (Barium Swallow Study)

    ... esophagram is a study that is completed in radiology. The test evaluates the esophagus. The esophagus is ... to wear. The study is completed in a radiology (x-ray/fluoroscopy) room. If a child is ...

  13. Tailored Barium Swallow Study

    ... View Denver Pollen Count You are here: Programs & Services > Tests We Offer > Imaging Tests Tailored Barium Swallow Study The TBS is a special study that is completed in radiology. The test evaluates the mouth and the throat ...

  14. The Study of Algae

    Rushforth, Samuel R.

    1977-01-01

    Included in this introduction to the study of algae are drawings of commonly encountered freshwater algae, a summary of the importance of algae, descriptions of the seven major groups of algae, and techniques for collection and study of algae. (CS)

  15. Current Research Studies

    ... Home > Explore CCFA Research > Current Research Studies Current Research Studies Email Print + Share The Crohn’s & Colitis Foundation ... online. Learn more about CCFA Partners. CCFA Clinical Research Alliance The Clinical Research Alliance is a network ...

  16. Future Circular Collider Study

    Benedikt, Michael

    2014-01-01

    This presentation has been given during the 1st EuCARD-2 annual meeting. It contains: • Motivation & scope • Parameters & design challenges • Study organization, study time line • Preparing global FCC collaboration • Summary

  17. Excellence in Social Studies.

    Durfee, David A.

    1986-01-01

    Discusses a strategy for unifying and improving the social studies curriculum through an "outcomes sought" approach. Outlines eight measurable qualities students completing social studies should have achieved. Discusses implications of this approach. (LP)

  18. FEMA DFIRM Study Info

    Minnesota Department of Natural Resources — This table contains details about the study such as the study name, datum, projection, etc. There is normally only one record in this table for each Flood Insurance...

  19. 522 Postmarket Surveillance Studies

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  20. Post-Approval Studies

    U.S. Department of Health & Human Services — The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a...

  1. Satellite servicing economic study

    1990-01-01

    Previous studies have shown that satellite servicing is cost effective; however, all of these studies were of different formats, dollar year, learning rates, availability, etc. Therefore, it was difficult to correlate any useful trends from these studies. The reviewed study was initiated to correlate the economic data into a common data base, using a common set of assumptions. A selected set of existed funded programs was then analyzed to provide an independent analysis of the servicing options and potential economic benefits.

  2. CISSP study guide

    Conrad, Eric; Feldman, Joshua; Riggins, Kevin

    2011-01-01

    "The Eleventh Hour CISSP Study Guide" is keyed to the latest CISSP exam. This book is streamlined to include only core certification information and is presented for ease of last-minute studying. Main objectives of the exam are covered concisely with key concepts highlighted. This is the only guide you need for last-minute studying. This title answers the toughest questions and highlights core topics. This title can be paired with any other study guide so you are completely prepared.

  3. Medicinsk forbedring: study drugs

    Holm Sørensen, Camilla; Juul Asmussen, Melanie; Constantin, Liv; Haugtved, Claire Rigmor

    2015-01-01

    This study investigates medical optimization regarding cognitive enhancement. Study drugs are performance-enhancing drugs that people use in terms of optimizing cognitive skills. The use of study drugs has turned out to have a beneficial effect when it comes to perform in stressful situations for example an examination. The purpose of our project is to analyze central arguments for and against the use of study drugs. We analyze two arguments for and three arguments that express a statem...

  4. Social Psychoanalytic Disability Studies

    Goodley, Dan

    2011-01-01

    This paper explores connections and tensions between psychoanalysis and disability studies. The first part of the paper considers contemporaneous engagements with the psyche by a number of disability studies writers. These scholars have remained accountable to a politicised disability studies but have pushed for critical encounters with the…

  5. Defining (Conceptualizing) Social Studies.

    Shaver, James P.

    1990-01-01

    Critiques James Barth, Robert Barr, and Sam Shermis' three social studies traditions theory and National Commission on Social Studies task force report. Argues first falsely splits essential social studies components; second creates a curricular hodgepodge. Highlights need to consider values as both affective and cognitive and to create…

  6. System studies and applications

    Extensive information is given for each of the following topics: (1) fusion reactor studies, (2) reactor concepts, (3) first wall studies, (4) laser system studies, (5) fusion-fission hybrids, (6) National security applications, and (7) long-range planning for inertial confinement fusion

  7. Studying Engineering Practice

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However,...

  8. Fusion reactor studies

    A review is given of fusion reactor systems studies, the objectives of these studies are outlined and some recent conceptual reactor designs are described. The need for further studies in greater depth is indicated so that progress towards a commercial fusion reactor may be consolidated. (U.K.)

  9. Studying to Learn.

    Air Univ., Maxwell AFB, AL.

    This booklet was prepared in response to a demand from Air Force Officers returning to academic study after being out of school for several years. Its main purpose is to help returning veterans learn how to study. The guide is divided into three sections: (1) the "Reconnaissance-Read-Recall" (RRR) system of study, (2) concepts in "How We Learn,"…

  10. Study deep geothermal energy; Studie dypgeotermisk energi

    Havellen, Vidar; Eri, Lars Sigurd; Andersen, Andreas; Tuttle, Kevin J.; Ruden, Dorottya Bartucz; Ruden, Fridtjof; Rigler, Balazs; Pascal, Christophe; Larsen, Bjoern Tore

    2012-07-01

    The study aims to analyze the potential energy with current technology, challenges, issues and opportunities for deep geothermal energy using quantitative analysis. It should especially be made to identify and investigate critical connections between geothermal potential, the size of the heating requirements and technical solutions. Examples of critical relationships may be acceptable cost of technology in relation to heating, local geothermal gradient / drilling depth / temperature levels and profitability. (eb)

  11. Mysore study: A study of suicide notes

    Namratha, P.; Kishor, M.; Sathyanarayana Rao, T. S.; Raman, Rajesh

    2015-01-01

    Background: Suicide is one of the leading causes of preventable deaths. Recent data suggest South India as one of the regions with highest suicide rates in the world. In 2013, 134,799 people committed suicide in India according to the statistics released by the National Crime Records Bureau. Suicide note is one of the most important sources to understand suicide, which may be beneficial in suicide prevention. Studies on suicidal notes from this part of the world are sparse. Objective: The aim...

  12. Advanced Clothing Studies

    Orndoff, Evelyne; Poritz, Darwin

    2014-01-01

    All human space missions require significant logistical mass and volume that add an unprecedented burden on longduration missions beyond low-Earth orbit. For these missions with limited cleaning resources, a new wardrobe must be developed to reduce this logistical burden by reducing clothing mass and extending clothing wear. The present studies have been undertaken, for the first time, to measure length of wear and to assess the acceptance of such extended wear. Garments in these studies are commercially available exercise T-shirts and shorts, routine-wear T-shirts, and longsleeved pullover shirts. Fabric composition (cotton, polyester, light-weight, superfine Merino wool, modacrylic, cotton/rayon, polyester/Cocona, modacrylic/Xstatic, modacrylic/rayon, modacrylic/lyocell/aramid), construction (open knit, tight knit, open weave, tight weave), and finishing treatment (none, quaternary ammonium salt) are the independent variables. Eleven studies are reported here: five studies of exercise T-shirts, three of exercise shorts, two of routine wear Tshirts, and one of shirts used as sleep-wear. All studies are conducted in a climate-controlled environment, similar to a space vehicle's. For exercise clothing, study participants wear the garments during aerobic exercise. For routine wear clothing, study participants wear the T-shirts daily in an office or laboratory. Daily questionnaires collected data on ordinal preferences of nine sensory elements and on reason for retiring a used garment. Study 1 compares knitted cotton, polyester, and Merino exercise T-shirts (61 participants), study 2, knitted polyester, modacrylic, and polyester/Cocona exercise T-shirts (40 participants), study 3, cotton and polyester exercise shorts, knitted and woven (70 participants), all three using factorial experimental designs with and without a finishing treatment, conducted at the Johnson Space Center, sharing study participants. Study 4 compares knitted polyester and ZQ Merino exercise T

  13. CT diagnosis and clinical findings of subcortical arteriosclerotic encephalopathy

    Objective: A study of the pathology, clinical characteristics and major CT manifestations, in order to obtain a better understanding of the SAE. Methods: In total 94 cases of SAE were enrolled in the study in Jun-an hospital, included 58 males and 36 females, aged from 62-92 years (averagely 77 years). The clinical presentations of SAE included hyper- tension, diabetics, arteriosclerotisc eyeground, and stupor, characterized by progressive decline of intellectual function, different-level of paralysis, aphasia, swirl, dazzle, naupathia, extremity numbness. Results: A predominance was found in the patients aged more than 60 years. CT scan showed symmetrical hypodense shadows with poorly-defined border, complicated with the sign of lacunar infarction, cerebral atrophy, parenchymal hemorrhage and/or subarachnoid hemorrhage in some cases. Conclusion: A good understanding of the clinical and CT features of subcortical arteriosclerotic encephalopathy is valuable for CT diagnosis and differentiated diagnosis. (authors)

  14. Usefulness of the second derivative of the finger photoplethysmogram for assessment of end-organ damage: the J-SHIPP study.

    Tabara, Yasuharu; Igase, Michiya; Okada, Yoko; Nagai, Tokihisa; Miki, Tetsuro; Ohyagi, Yasumasa; Matsuda, Fumihiko; Kohara, Katsuhiko

    2016-07-01

    Early detection of pathological changes in the vasculature is required to identify individuals at risk of cardiovascular diseases. Noninvasive measurement of the second derivative of photoplethysmogram (SDPTG) might aid in evaluating vascular aging. Here we clarified the diagnostic significance of four SDPTG indices for end-organ damage. A total of 1613 community residents (65±10 years) were enrolled. Changes in blood flow volume at the forefinger were measured by photoplethysmography. SDPTG was computationally calculated from the plethysmogram, and the height of five peaks (a-e) on the SDPTG was measured. Carotid intima-media thickness (IMT), brachial-to-ankle pulse wave velocity (baPWV) and silent cerebral lesions were used as indices of end-organ damage. Multivariate analysis identified age, sex, systolic blood pressure and heart rate as strong determinants for the evaluated SDPTG indices, namely b/a, d/a and aging index ([b-d-c-e]/a). In addition, poor glycemic control and carotid IMT were also weakly associated with the SDPTG indices. Compared with other established risk factors, however, the association between the SDPTG indices and carotid IMT was weak or insignificant (b/a: β=0.069, P=0.002; d/a: β=-0.009, P=0.669; and aging index: β=0.047, P=0.037). Further, no significant association was noted between the SDPTG indices and silent lacunar infarction (b/a: P=0.111; d/a: P=0.263; and aging index: P=0.167) and periventricular hyperintensity (b/a: P=0.587; d/a: P=0.254; and aging index: P=0.429). Although the SDPTG indices evaluated here might represent structural and functional changes in arteries, they exhibited limited diagnostic significance for pathophysiological changes in large arteries, as well as small vessel diseases of the brain. PMID:26911232

  15. Cross-cultural studies using a modified mini mental test for healthy subjects and patients with various forms of vascular dementia.

    Thajeb, Peterus; Thajeb, Teguh; Dai, Daofu

    2007-03-01

    Existing neuropsychological tests are often complex and time-consuming. We designed a modified Mini Mental Test (MMT) battery for clinical assessment of the global and regional higher cortical functions of the brain. We tested its applicability in healthy subjects with different ethnic, cultural and educational backgrounds. The usefulness of our MMT as a tool for the clinical evaluation of patients with various forms of vascular dementia was determined. The MMT comprises five subtests, including clinical evaluations of: (A) orientation (6 points); (B) attention, right-left discrimination, speech, and calculation (20); (C) immediate recall, and recent and remote memory retrieval (10); (D) praxis (10); and (E) visuospatial orientation, agnosia, hemianopsia, and visual hemineglect (14). The MMT was administered to 100 healthy subjects from two different ethnic backgrounds (Indonesian and Chinese/Taiwanese) and diverse cultural and educational backgrounds, and to 61 patients with various forms of vascular dementia. MMT scores were significantly lower in healthy subjects with a low level of education regardless of their ethnic background (p<0.001). Patients with vascular dementia had much lower MMT scores than did the comparable age-adjusted normal controls (p<0.001). Of the patients with vascular dementia, those with Binswanger's disease had the lowest MMT scores (25.5+/-28.9), followed by those with large cerebral infarcts (48.0+/-7.1), cerebral haemorrhage (49.0+/-8.5), and multiple lacunar infarctions (55.0+/-0.5) (P<0.001). With a cut-off point of 33/55 (partial score/total score), the sensitivity and positive predictive value of the MMT were 0.98 and 0.94, respectively. The MMT is a simple and useful tool for clinical assessment of the cognitive functions of healthy subjects and patients with or without vascular dementia. It can be used for individuals with different ethnic, cultural and educational backgrounds. PMID:17258132

  16. American Studies in Turkey

    Gülriz Buken

    2006-01-01

    In the discipline of American Studies in Turkey, the major contribution emanates, on the one hand, from the American Culture and Literature Departments instituted in various Universities in Turkey and, on the other, from the American Studies Association of Turkey. Up till now, unfortunately, no Research and Performance Institute or Center for the Study of America has yet been established to secure the necessary contacts with other similar institutions in Europe and in the United States, to fa...

  17. Standardization Study of Ghritas

    D. Shaila; M. K. Santosh; Chandrakumar, T.; I. Sanjeeva Rao

    2004-01-01

    The standardization of ghritas such as amritaprasa ghrita, brahmi ghrita, chagalyadi ghrita and phala ghrita has been studied. These ghritas are the important Ayurvedic formulations used for peri-natal care of mother and child health. Standardization of ghritas were achieved by organoleptic study, physico-chemical analysis, qualitative analysis, thin layer chromatography (TLC), UV - visible spectrophotometry and high performance liquid chromatographic (HPLC) fingerprint studies. Qualitative a...

  18. Single Policy Study

    Kronsell, Annica; Manners, Ian James

    Single policy studies are the most common form of European Union (EU) research. Single policy studies are widely used to understand the role of the EU in a wide variety of sectors, together with their development over time, and often offer public policy prescriptions. This chapter discusses the...... relevance of single policy studies in EU research and give examples of how such research can be designed and carried out. The chapter reviews three examples of single policy studies using different methods based on EU environmental policy, the EU biofuels directive, and the EU Common Security and Defence...

  19. School library user studies

    Zdenka Verlič

    2002-01-01

    Full Text Available The analysis of the results of a questionnaire answered by Slovene primary and secondary school librarians is presented in the article. The purpose of the study was to determine if library user studies were being performed in our school libraries. It was confirmed that more studies had been conducted by school librarians with a completed higher level of education, by librarians with adequate (library and information sciences education and also by the librarians participating in life-long learning in their professional field than by other librarians. An important factor influencing increased user studies was also librarians’ membership in the Slovene librarian professional organization.

  20. Why Study in Australia?

    丁丽丽

    2014-01-01

    Going overseas to pursue further studies is even more generalized in recent years. Students are open to a variety of op-tions to decide which country to go and which university to choose. Why wouldn’t you want to study with some of the best minds in the world? Australia is a leading global education power, with world’s best educators and facilities. It also provides both local and international students with a variety of quality study options. This essay presents some of the important reasons why in-ternational students should study in Australia in regard to education quality, affordable fees, government support, multiple cultures and immigration policies.

  1. Studies on seismic waves

    张海明; 陈晓非

    2003-01-01

    The development of seismic wave study in China in the past four years is reviewed. The discussion is divided into several aspects, including seismic wave propagation in laterally homogeneous media, laterally heterogeneous media, anisotropic and porous media, surface wave and seismic wave inversion, and seismic wave study in prospecting and logging problems. Important projects in the current studies on seismic wave is suggested as the development of high efficient numerical methods, and applying them to the studies of excitation and propagation of seismic waves in complex media and strong ground motion, which will form a foundation for refined earthquake hazard analysis and prediction.

  2. Contemporary American Chinese Studies

    Qiu Huafei

    2008-01-01

    The rise of modern American scholarship on China was largely attributed to the establishment of the American Joint Committee on Contemporary China (JCCC) in 1959 which sponsored all kinds of activities to promote Chinese studies, ranging from institutional support and financial resources to training courses. Since then, American study of China has entered into a period of sustainability that features academic and group-oriented research. It has become a mainstream discipline in American social science studies.1 There are some distinctive differences between early sinology and modern Chinese Studies: the latter is much more concentrated on the study of issues, comparative historical studies, and contemporary Chinese society. American Chinese studies stresses empirical research, textual data, and the application of theory to practice.Shanghai. He was a Fulbright visiting professor at State University of New York at Geneseo from 2006-2007. This treatise is one of a series of studies for China's National Research Foundation of Philosophy and Social Science (05BGJ012), "American Chinese Studies."

  3. Study Groups in Denmark

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions.......Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  4. Human exploration mission studies

    Cataldo, Robert L.

    1989-01-01

    The Office of Exploration has established a process whereby all NASA field centers and other NASA Headquarters offices participate in the formulation and analysis of a wide range of mission strategies. These strategies were manifested into specific scenarios or candidate case studies. The case studies provided a systematic approach into analyzing each mission element. First, each case study must address several major themes and rationale including: national pride and international prestige, advancement of scientific knowledge, a catalyst for technology, economic benefits, space enterprise, international cooperation, and education and excellence. Second, the set of candidate case studies are formulated to encompass the technology requirement limits in the life sciences, launch capabilities, space transfer, automation, and robotics in space operations, power, and propulsion. The first set of reference case studies identify three major strategies: human expeditions, science outposts, and evolutionary expansion. During the past year, four case studies were examined to explore these strategies. The expeditionary missions include the Human Expedition to Phobos and Human Expedition to Mars case studies. The Lunar Observatory and Lunar Outpost to Early Mars Evolution case studies examined the later two strategies. This set of case studies established the framework to perform detailed mission analysis and system engineering to define a host of concepts and requirements for various space systems and advanced technologies. The details of each mission are described and, specifically, the results affecting the advanced technologies required to accomplish each mission scenario are presented.

  5. Information society studies

    Duff, Alistair S

    2013-01-01

    We are often told that we are ""living in an information society"" or that we are ""information workers."" But what exactly do these claims mean, and how might they be verified? In this important methodological study, Alistair S. Duff cuts through the rhetoric to get to the bottom of the ""information society thesis."" Wide-ranging in coverage, this study will be of interest to scholars in information science, communication and media studies and social theory. It is a key text for the newly-unified specialism of information society studies, and an indispensable guide to the future of this disc

  6. Project management case studies

    Kerzner, Harold R

    2013-01-01

    A new edition of the most popular book of project management case studies, expanded to include more than 100 cases plus a ""super case"" on the Iridium Project Case studies are an important part of project management education and training. This Fourth Edition of Harold Kerzner''s Project Management Case Studies features a number of new cases covering value measurement in project management. Also included is the well-received ""super case,"" which covers all aspects of project management and may be used as a capstone for a course. This new edition:Contains 100-plus case studies drawn from re

  7. Research Studies & Networks

    These epidemiological studies may assist in evaluating associations between certain pharmaceuticals and disease risk and contain detailed information on pharmaceutical use and disease risk, including cancer.

  8. 4-D segmentation and normalization of 3He MR images for intrasubject assessment of ventilated lung volumes

    Contrella, Benjamin; Tustison, Nicholas J.; Altes, Talissa A.; Avants, Brian B.; Mugler, John P., III; de Lange, Eduard E.

    2012-03-01

    Although 3He MRI permits compelling visualization of the pulmonary air spaces, quantitation of absolute ventilation is difficult due to confounds such as field inhomogeneity and relative intensity differences between image acquisition; the latter complicating longitudinal investigations of ventilation variation with respiratory alterations. To address these potential difficulties, we present a 4-D segmentation and normalization approach for intra-subject quantitative analysis of lung hyperpolarized 3He MRI. After normalization, which combines bias correction and relative intensity scaling between longitudinal data, partitioning of the lung volume time series is performed by iterating between modeling of the combined intensity histogram as a Gaussian mixture model and modulating the spatial heterogeneity tissue class assignments through Markov random field modeling. Evaluation of the algorithm was retrospectively applied to a cohort of 10 asthmatics between 19-25 years old in which spirometry and 3He MR ventilation images were acquired both before and after respiratory exacerbation by a bronchoconstricting agent (methacholine). Acquisition was repeated under the same conditions from 7 to 467 days (mean +/- standard deviation: 185 +/- 37.2) later. Several techniques were evaluated for matching intensities between the pre and post-methacholine images with the 95th percentile value histogram matching demonstrating superior correlations with spirometry measures. Subsequent analysis evaluated segmentation parameters for assessing ventilation change in this cohort. Current findings also support previous research that areas of poor ventilation in response to bronchoconstriction are relatively consistent over time.

  9. Frequency and pathogenesis of silent subcortical brain infarction in acute first-ever ischemic stroke

    We have often observed silent subcortical brain lesions on CT or MRI in first-ever ischemic stroke, but there is little published information on the relationship of these lesions to stroke subtypes. Here, we describe the incidence of MRI-detected silent subcortical brain lesions, including infarctions and white matter lesions, in a series of patients with first-ever ischemic stroke classified according to stroke subtypes. We also discuss the pathogenesis of these silent subcortical lesions. We evaluated 171 patients with acute first-ever ischemic stroke. The subjects were divided into three groups: lacunar, atherothrombotic and cardioembolic infarction groups. We evaluated silent subcortical brain infarction (SSBI), enlargement of perivascular space (EPS), and other white-matter lesions using MRI. Hypertension was observed in 67.6% of lacunar infarction, 57.1% of atherosclerotic infarction, and 54.1% of cardioembolic infarction. SSBI was more frequently observed in lacunar infarction than the others (lacunar vs. atherothrombotic vs. cardiogenic infarction, 81.5% vs. 44.4% vs. 42.1%, p=0.006). High-grade EPS (grade 2 or higher) was also observed more frequently in lacunar infarction than in the others (lacunar vs. atherothrombotic vs. cardiogenic infarction, 63.3% vs. 24.2% vs. 0%, p<0.001). Scheltens' score of silent subcortical lesions was significantly higher in lacunar infarction than in the others. The frequency of silent subcortical ischemic brain lesions was significantly higher in lacunar infarction than in atherosclerotic or cardioembolic infarction. We suggest that the pathogenesis of silent subcortical ischemic brain lesions is common to that of lacunar infarction, that is, small-vessel vasculopathy. (author)

  10. Prolactinomas : clinical studies

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An

  11. Independent Human Studies.

    Kaplan, Suzanne; Wilson, Gordon

    1978-01-01

    The Independent Human Studies program at Schoolcraft College offers an alternative method of earning academic credits. Students delineate an area of study, pose research questions, gather resources, synthesize the information, state the thesis, choose the method of presentation, set schedules, and take responsibility for meeting deadlines. (MB)

  12. Fusion energy studies

    Current experimental efforts are aimed toward developing cryosorption vacuum pumps for removing unburned fuel and impurities from the plasma, studying deep-bed sorption pumps for roughing and transfer operations, investigating methods for recovery of tritium bred in blankets of lithium or lithium alloys, and studying containment of tritium that permeates metal walls

  13. CDC's Cervical Cancer Study

    ... in Cancer Moonshot Stay Informed CDC’s Cervical Cancer Study Language: English Español (Spanish) Recommend on Facebook Tweet ... year. As part of CDC’s Cervical Cancer (Cx3) Study, we surveyed a sample of both health care ...

  14. Simulation in International Studies

    Boyer, Mark A.

    2011-01-01

    Social scientists have long worked to replicate real-world phenomena in their research and teaching environments. Unlike our biophysical science colleagues, we are faced with an area of study that is not governed by the laws of physics and other more predictable relationships. As a result, social scientists, and international studies scholars more…

  15. Home Study Advertising Handbook.

    Lambert, Michael P., Ed.; Welch, Sally R., Ed.

    This handbook contains a collections of nine articles on the subject of direct-response advertising. The handbook gives advice on how to create effective advertisements for home study courses. The nine articles are the following: "Overview of Home Study Advertising in the 1990s" (Michael P. Lambert); "Ad Features that Sell" (Nancie E. Robertson);…

  16. EAL studying texts

    Napthin, Melanie

    2013-01-01

    EAL: Studying texts has been developed out of Insight's best-selling ESL English for Year 12, which has helped thousands of ESL/ EAL students to achieve top marks. Offering comprehensive coverage of Area of Study 1: Reading and responding in VCE English, the book takes a highly practical approach that builds students' skills progressively.

  17. A Social Studies Imperative.

    Engle, Shirley H.

    1985-01-01

    Despite all the technology at educators' disposal, the field of social studies is more uncertain of its goals and more intellectually confused than ever before. The failure to deal in a rigorous and uncluttered way with current social problems is one of the most unconscionable defects in the social studies today. (RM)

  18. Entrepreneurship and Process Studies

    Hjorth, Daniel; Holt, Robin; Steyaert, Chris

    2015-01-01

    variable as just that, a variable. The resonance with entrepreneurship studies is obvious. If any field is alive to, and fully resonant with, a processual understanding of, for example, the creation of firms, it is entrepreneurship studies. This special issue is an attempt to consider the promise and...

  19. What Are Sleep Studies?

    ... Events Spokespeople Email Alerts E-Newsletters About NHLBI Organization NHLBI Director Budget, Planning, & Legislative Advisory Committees Contact Us FAQs Home » Health Information for the Public » Health Topics » Sleep Studies Explore Sleep Studies What Are... Types Who Needs ...

  20. Spacing Studies in Peppers

    Higher plant stand densities usually result in greater pepper fruit yields. While the impact of stand density on yield has been studied for bell and non-bell peppers, but very little information exists regarding implications on pesticide efficacy. The objective of these studies was to determine th...

  1. English Intonation Studies.

    Lewis, Jack Windsor

    This paper is a critical survey of the work of various linguists in the field of English intonation studies. Crystal's work is cited as being particularly influential in the author's work. It is argued that there is a lack of progress in this field because of a preoccupation on the part of scholars with their own studies and their application and…

  2. Theorizing Iberian Studies

    Newcomb, Robert Patrick

    2015-01-01

    A growing number of scholars invested in Iberian Studies are asking how peninsular literary and cultural studies might be reimagined, and reinvigorated, by placing the Spanish and Portuguese canons into critical dialogue with each other, and with Galician, Catalan, Basque/Euskadi, and Latin American and North African immigrant writers, cultural…

  3. Building Transdisciplinary Environmental Studies

    Holm, Jesper

    department (Dept. of Environment, Technology and Social Studies, Roskilde University), and has originally in another version been presented in the book “Miljøregulering - tværvidenskabelige studier (Environmental Regulation. Interdisciplinary Studies)” (Holm, Kjærgård & Pedersen eds. 1997, in Danish) written...

  4. The CAIRO4 study

    de Wilt, Johannes H W; Verhoef, Cornelis; Punt, Cornelis J A;

    2016-01-01

    stages of the disease. We here propose a randomized trial in order to demonstrate that resection of the primary tumour improves overall survival. METHODS/DESIGN: The CAIRO4 study is a multicentre, randomized, phase III study of the Dutch Colorectal Cancer Group (DCCG). Patients with synchronous...

  5. The CAIRO4 study

    't Lam-Boer, Jorine; Mol, Linda; Verhoef, Cornelis;

    2015-01-01

    stages of the disease. We here propose a randomized trial in order to demonstrate that resection of the primary tumour improves overall survival. METHODS/DESIGN: The CAIRO4 study is a multicentre, randomized, phase III study of the Dutch Colorectal Cancer Group (DCCG). Patients with synchronous...

  6. Managerial Accounting. Study Guide.

    Plachta, Leonard E.

    This self-instructional study guide is part of the materials for a college-level programmed course in managerial accounting. The study guide is intended for use by students in conjuction with a separate textbook, Horngren's "Accounting for Management Control: An Introduction," and a workbook, Curry's "Student Guide to Accounting for Management…

  7. Luminescence study of spodumene

    A comparative study is made of the luminescence of five kinds of spodumene from Minas Gerais, Brazil, studied previously by optical absorption spectroscopy. Natural gemstones are used which, in the course of the experiments, were irradiated with X-rays. (L.C.)

  8. Studies of Personality Disorders

    Ronningstam, Elsa; Simonsen, Erik; Oldham, John M; Maffei, Cesare; Gunderson, John; Chanen, Andrew M; Millon, Theodore

    2014-01-01

    The past 25 years have shown major advances in the studies of personality disorders. This collaborative article by the presidents, past and present, of ISSPD reflects on the progress within several significant areas of studies, i.e., assessment, neuroscience, treatment, prevention, advocacy, and...

  9. Study Groups in Denmark

    Hjorth, Poul G.

    2007-01-01

    Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

  10. MY ENGLISH STUDY

    孙岩; Roxanne; Lees

    2003-01-01

    I am a student of Yanshan University, majoring in English. I have studied English for a long time, which is full of (and have encountered some) special experiences (in my studies). After graduation from (a) junior (middle) school, I did not go to senior (middle) school for

  11. Soil organic matter studies

    The use of isotopes in soil organic matter studies is reviewed. Such studies include measuring the input of organic carbon into soils, the decomposition of isotope-labelled materials such as organic compounds and microbial and plant material in soils, the characterization of soil organic matter and the availability of nutrients released from organic residues. (U.K.)

  12. Danish Rural Eye Study

    Høeg, Tracy Beth; Ellervik, Christina; Buch, Helena;

    2016-01-01

    PURPOSE: To examine the frequency and causes of visual impairment (VI) in a select population of Danish adults. METHODS: A total of 3843 adults aged 20-94 years from the Danish General Suburban Population Study (GESUS) were included in the population-based, cross-sectional ophthalmological study,...

  13. Critical Digital Tourism Studies

    Gyimóthy, Szilvia; Munar, Ana María

    2013-01-01

    This paper advocates the need for a critical and cross-disciplinary research agenda on the field of digital technologies and tourism. The changing virtual landscape of tourism has received increased attention by tourism scholars. However, contemporary studies on information technologies (IT) are...... studying digital socio-technical systems and virtual mediation in tourism. Critical Digital Tourism Studies opens a new cross-disciplinary field where the sociality of virtual tourism interactions is examined (entailing the study of structures, social rules, ideologies, power relations, sustainability...... approached mostly from a business administration perspective and informed by conceptual frameworks developed in management and marketing. IT studies in tourism are still at a stage similar to the first advocacy phase of tourism research in general (Jafari, 1990) and are seldom inspired by relevant...

  14. Subsurface geochemical studies

    Subsurface geochemical studies are composed of spectral radiometric studies and core geochemistry. These studies are aimed at identifying both secondary and remnant primary halos pertinent to the known mineralization. Genetically, any geochemical signatures delineated in the altered rocks are classified as epigenetic dispersion patterns that are formed during post primary-mineralization processes. However, a few remnant hypogene geochemical dispersion patterns, typical of immobile elements, are also manifested in the area. The above-mentioned studies are also oriented towards understanding the genesis of uranium deposits in granitic rocks. Thus these geochemical studies form an essential link in the exploration systems approach to the identification of halos and contribute to drilling plans and the ultimate discovery of blind uranium deposits in granitic rocks. 61 figures, 5 tables

  15. Obtaining the borders of urban areas

    Comin, Cesar Henrique; Costa, Luciano da Fontoura

    2015-01-01

    The access to an ever increasing amount of information in the modern world gave rise to the development of many quantitative indicators about urban regions in the globe. Therefore, there is a growing need for a precise definition of how to delimit urban regions, so as to allow proper respective characterization and modeling. Here we present a straightforward methodology to automatically detect urban region borders. The method is based on the density of street crossings around a single seed point associated to the urban area of interest. We exemplify the potential of the methodology by characterizing the geometry and topology of 21 urban regions obtained from 8 distinct countries. The geometry is studied by employing the lacunarity measurement, which is associated to the regularity of holes contained in a pattern. The topology is analyzed by associating the betweenness centrality of the streets with their respective class, such as motorway or residential, obtained from a database.

  16. A diffusion-based approach to obtaining the borders of urban areas

    Henrique Comin, Cesar; Nascimento Silva, Filipi; da Fontoura Costa, Luciano

    2016-05-01

    The access to an ever increasing amount of information in the modern world gave rise to the development of many quantitative indicators about urban regions in the globe. Therefore, there is a growing need for a precise definition of how to delimit urban regions, so as to allow proper respective characterization and modeling. Here we present a straightforward methodology to automatically detect urban region borders around a single seed point. The method is based on a diffusion process having street crossings and terminations as source points. We exemplify the potential of the methodology by characterizing the geometry and topology of 21 urban regions obtained from 8 distinct countries. The geometry is studied by employing the lacunarity measurement, which is associated to the regularity of holes contained in a pattern. The topology is analyzed by associating the betweenness centrality of the streets with their respective class, such as motorway or residential, obtained from a database.

  17. Electronic teaching materials for inter-professional education in a college of medical professionals.

    Toyama, Hinako; Inoue, Rie; Ito, Yumi; Sakamoto, Chieko; Ishikawa, Toru; Eda, Tetsuya; Saito, Keiichi

    2013-01-01

    In order to promote the utilization of digital clinical information among medical professionals, an education program and electronic teaching materials involving fictitious model patients were developed for students in a health and welfare college. The purposes of this program were for students to learn the role of each medical professional and to understand the medical records written by each medical staff member in interdisciplinary medicine (a collaborative approach to medicine). The materials for fictitious patients, including medical records, study results, medical images and the associated documents, were stored in a database on a virtual private network. The electronic medical records were easily modified according to the specialty of the students in each class. Fictional medical records of patients with lacunar infarction, fracture of the distal radius, fracture of the femur, diabetes mellitus and breast cancer were generated and evaluated in inter-professional education classes. PMID:23920893

  18. Cerebral infarction following intracranial hemorrhage in pediatric Moyamoya disease - A case report and brief review of literature

    Soumya Patra

    2012-01-01

    Full Text Available Moyamoya disease is a clinical entity characterized by progressive cerebrovascular occlusion with spontaneous development of a collateral vascular network called Moyamoya vessels. This disease mainly manifests as cerebral ischemia. Intracranial bleeding is another major presentation of patients with Moyamoya disease. We report here a 12-year-old male child who presented with severe headache, vomiting and meningismus. Initial neuroimaging study with noncontrast computed tomography scan revealed fresh intraventricular hemorrhage in right-sided lateral ventricle. Magnetic resonance imaging with angiography of brain was done 5 days later when the child developed right-sided hemiparesis, and the diagnosis of Moyamoya disease was confirmed along with lacunar infarction of right posterior peri and paraventricular area and in the left paraventricular area and centrum semiovale. Simultaneous presence of cerebral infarction along with intraventricular hemorrhage in adult with bleeding-type Moyamoya disease is reported in literature, but it is a rare entity in a child.

  19. Transient detection of early wallerian degeneration on diffusion-weighted MRI after an acute cerebrovascular accident

    Uchino, A.; Sawada, A.; Takase, Y.; Egashira, R.; Kudo, S. [Department of Radiology, Saga Medical School, 5-1-1 Nabeshima, Saga, 849-8501 (Japan)

    2004-03-01

    We report three patients with a cerebrovascular accident studied serially by MRI, including diffusion-weighted imaging (DWI). In case 1, DWI 1 day after the onset of left frontoparietal cortical infarcts showed no abnormal signal in the left corticospinal tract. DWI 12 days after onset showed high signal in the corticospinal tract, interpreted as early wallerian degeneration. This had disappeared by 22 days after onset. In case 2, DWI obtained 7 days after the onset of a right internal capsule lacunar infarct showed high signal from the right corticospinal tract in the brainstem, which was less marked 15 days after onset. In case 3, MRI on postnatal day 7 showed a cerebral haemorrhage in the right corona radiata and high signal from the right corticospinal tract on DWI. The latter disappeared by day 23. DWI shows early wallerian degeneration; transient signal abnormalities within 2 weeks of stroke should not be mistaken for new ischaemic lesions. (orig.)

  20. Transient detection of early wallerian degeneration on diffusion-weighted MRI after an acute cerebrovascular accident

    We report three patients with a cerebrovascular accident studied serially by MRI, including diffusion-weighted imaging (DWI). In case 1, DWI 1 day after the onset of left frontoparietal cortical infarcts showed no abnormal signal in the left corticospinal tract. DWI 12 days after onset showed high signal in the corticospinal tract, interpreted as early wallerian degeneration. This had disappeared by 22 days after onset. In case 2, DWI obtained 7 days after the onset of a right internal capsule lacunar infarct showed high signal from the right corticospinal tract in the brainstem, which was less marked 15 days after onset. In case 3, MRI on postnatal day 7 showed a cerebral haemorrhage in the right corona radiata and high signal from the right corticospinal tract on DWI. The latter disappeared by day 23. DWI shows early wallerian degeneration; transient signal abnormalities within 2 weeks of stroke should not be mistaken for new ischaemic lesions. (orig.)

  1. Magnetic resonance in neuroborreliosis

    Magnetic resonance (MR) is commonly used in diagnosing infections of the central nervous system. The aim of the study is to evaluate central nervous system changes in neuroborreliosis patients. MR examinations were performed in 44 patients with clinical symptoms, epidemiology and laboratory tests results of neuroborreliosis. Abnormalities were detected in 22 patients. Most of them presented cortico-subcortical atrophy (86%). In 9 cases foci of increased signal in T2-weighted and FLAIR images were observed in white matter. They were single or multiple, located subcorticaly and paraventriculary. In 2 subjects areas of increased signal were found in the brain stem. Central nervous system abnormalities detected with MR are not specific for Lyme disease. They can suggest demyelinating lesions and/or gliosis observed in many nervous system disorders (SM, ADEM, lacunar infarcts). (author)

  2. White matter changes in stroke patients. Relationship with stroke subtype and outcome

    Leys, D; Englund, E; Del Ser, T;

    1999-01-01

    vascular dementia. WMC are more frequent in patients with lacunar infarcts, deep intracerebral hemorrhages, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and cerebral amyloid angiopathy. After an acute ischemic stroke, WMC are associated with a higher risk of...... death or dependency, recurrent stroke of any type, cerebral bleeding under anticoagulation, myocardial infarction, and poststroke dementia. WMC in stroke patients are often associated with small-vessel disease and lead to a higher risk of death, and poor cardiac and neurological outcome. However......White matter changes (WMC), detected by imaging techniques, are frequent in stroke patients. The aim of the study was to determine how WMC relate to stroke subtypes and to stroke outcome. We made a systematic Medline search for articles appearing with two of the following key words: either 'WMC or...

  3. Using Fractal and Local Binary Pattern Features for Classification of ECOG Motor Imagery Tasks Obtained from the Right Brain Hemisphere.

    Xu, Fangzhou; Zhou, Weidong; Zhen, Yilin; Yuan, Qi; Wu, Qi

    2016-09-01

    The feature extraction and classification of brain signal is very significant in brain-computer interface (BCI). In this study, we describe an algorithm for motor imagery (MI) classification of electrocorticogram (ECoG)-based BCI. The proposed approach employs multi-resolution fractal measures and local binary pattern (LBP) operators to form a combined feature for characterizing an ECoG epoch recording from the right hemisphere of the brain. A classifier is trained by using the gradient boosting in conjunction with ordinary least squares (OLS) method. The fractal intercept, lacunarity and LBP features are extracted to classify imagined movements of either the left small finger or the tongue. Experimental results on dataset I of BCI competition III demonstrate the superior performance of our method. The cross-validation accuracy and accuracy is 90.6% and 95%, respectively. Furthermore, the low computational burden of this method makes it a promising candidate for real-time BCI systems. PMID:27255798

  4. China's India Studies

    Liu Qian

    2008-01-01

    Over the past 50 years, with the improvement of relationship between India and China, the scope of India studies in China's IR research has been broadened and the new areas of studies are being explored. The research agenda of India studies has already extended to the areas like economy, society, culture, security, national strategy and their impact on both bilateral and international relations. In this situation, the focuses of India studies in China's IR research can be mainly identified as follows: reviews on India's social, political and economic systems; analysis on the national strategy and foreign policy; Sino-Indian relations; India's relations with some international organizations. However, even though many fresh progresses have been made in India studies, the India studies in China's IR research still lag far behind the study of other important countries like the U.S., UK, Russia and Japan, and more problems and challenges will face in the coming future. The paper believes that a fuller understanding of India probably will not make China and India close friends, but it definitely will help to prevent them from becoming fierce enemies.

  5. STUDY ON CHRONIC LYMPHEDEMA

    Aromal Chekavar

    2014-03-01

    Full Text Available INTRODUCTION: Little attention has been given to the impact of long standing lymphedema and its complications. AIM: The aim of the study was to prepare a profile of long standing lymphedema complications PATIENTS AND METHODS: A total of 88 patients with lymphedema were included in this hospital based descriptive study. The study was designed to include age, sex, etiology, duration, prophylaxis and complications observed in each patient and entered into a proforma separately. RESULTS: A total of 88 cases studied, 74 cases are lower limb and 14 cases are upper limb lymphedema. Among 74 cases of lower limb lymphedema 4 cases occurred after inguinal lymphadenectomy and upper limb lypmhedema are secondary to postmodified radical mastectomy. A total of 40 cases in 88 patients had complications of lymphedema, among 88 cases studied 54 male and 34 were female patients 29 patients had cellulitis 3 patients had infected ulcer with maggots and 1 patient had lymphoma, among 88 patients 50 patients was on regular benzathine pencillin prophylaxis. Incidence of complications is 37.5 percent and incidence of complication in patient on penicillin prophylaxis 28.4 percent. Our study does not show no significant statistical correlation between benzathine prophylaxis and occurrence of complications. (pvalue0.727. CONCLUSION: The study provided relevant information about complications of lymphoedema, Pencillin prophylaxis is not found effective in reducing recurrent cellulitis episodes in chronic lymphedema. In our series we found one case of lymphoma (Diffuse large cell lymphoma developing in lymphedematous tissue of lower limb.

  6. Effective Physics Study Habits

    Zettili, Nouredine

    2011-04-01

    We discuss the methods of efficient study habits and how they can be used by students to help them improve learning physics. In particular, we deal with ideas pertaining to the most effective techniques needed to help students improve their physics study skills. These ideas were developed as part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), an outreach grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. In the presentation, focus on topics such as the skills of how to develop long term memory, how to improve concentration power, how to take class notes, how to prepare for and take exams, how to study scientific subjects such as physics. We argue that the student who conscientiously uses the methods of efficient study habits will be able to achieve higher results than the student who does not; moreover, a student equipped with the proper study skills will spend much less time to learn a subject than a student who has no good study habits. The underlying issue here is not the quantity of time allocated to the study efforts by the student, but the efficiency and quality of actions. This work is supported by the Alabama Commission on Higher Education as part of IMPACTSEED grant.

  7. Study of copper fluorination

    This report deals with the action of fluorine on copper. Comprehensive descriptions are given of the particular technological methods and of the preparation of the reactants. This fluorination reaction has been studied at medium and low fluorine pressures. A nucleation and growth phenomenon is described. The influence of a pollution of the gas phase on the fluorination process is described. The solid-state reaction between cupric fluoride and cooper has also been studied. A special study has been made of the growth of copper deposits by thermal decomposition of gaseous fluorides. (author)

  8. Studying Voltage Transformer Ferroresonance

    Hamid Radmanesh

    2012-09-01

    Full Text Available This study studies the effect of Circuit Breaker Shunt Resistance (CBSR, Metal Oxide Vaistor (MOV and Neutral earth Resistance (NR on the control of ferroresonance in the voltage transformer. It is expected that NR can controlled ferroresonance better than MOV and CBSR. Study has been done on a one phase voltage transformer rated 100 VA, 275 kV. The simulation results reveal that considering the CBSR and MOV exhibits a great mitigating effect on ferroresonance overvoltages, but these resistances cannot control these phenomena for all range of parameters. By applying NR to the system structure, ferroresonance has been controlled and its amplitude has been damped for all parameters values.

  9. Motivations of parametric studies

    The paper concerns the motivations of parametric studies in connection with the Programme for the Inspection of Steel Components PISC II. The objective of the PISC II exercise is to evaluate the effectiveness of current and advanced NDT techniques for inspection of reactor pressure vessel components. The parametric studies were initiated to determine the influence of some parameters on defect detection and dimensioning, and to increase the technical bases of the Round Robin Tests. A description is given of the content of the parametric studies including:- the effect of the defects' characteristics, the effect of equipment characteristics, the effect of cladding, and possible use of electromagnetic techniques. (U.K.)

  10. American Studies in Romania

    Ioana Luca

    2006-01-01

    Full Text Available American Studies at the University of BucharestThe idea of teaching American Studies and founding a program in American Studies was first voiced in the long meetings of faculty and students held at the University of Bucharest soon after the collapse of the communist regime. The proposal was one of many that reflected the spirit of reform and hope for radical changes at the outset of Romania’s transition to democracy. The absence of institutional structures other than English departments and t...

  11. Thyroid function study

    A short revision of thyroid physiology is done. The radioisotopes of common use in thyroid investigation and the choice of the most appropriated ones are discussed. A table showing radioisotopes frequently used in this study, with their main characteristics is presented. Among several isotopic assays in thyroid propaedeutics, those that refer to the function study, topographic studies and tests 'in vitro' are pointed out. Exploration methods 'in vivo' are treated, such as: thyroid uptake; urinary excretion; thyroid scintigraphy, with scintigraphic imagings; stimulation test by TSH; suppression test; pbi; clearance test with perchlorate; iodine deficiency test and thyroid study with technetium. 'In vitro' proofs like triiodothyronine (T3) and thyroxine (T4) assays, as well as free thyroxine index, are treated. At last, the therapeutics by Iodine 131 is commented and emphasis is given to its application on the treatment of hyperthyroidism and thyroid carcinoma

  12. Pavement Subgrade Performance Study

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  13. PPB | Study Team

    The Pleuropulmonary Blastoma (PPB) DICER1 Syndrome Study team is made up of researchers from the National Cancer Institute, Children¹s National Medical Center, the International Pleuropulmonary Blastoma Registry, and Washington University in St. Louis.

  14. The Black Studies Boondoggle

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  15. The Study of Matter.

    Campbell, Peter

    2000-01-01

    Reviews the booklet "The Study of Matter" produced by the Institute of Physics as part of their Shaping the Future series. This booklet is designed for teachers of chemistry, physics, design and technology, and biology. (Author/CCM)

  16. Czech Studies. Language

    Papcunová, Jana

    Leeds: Maney Publ, 2008 - ( Parkinson , S.; Barber, L.), s. 869-882 ISBN 978-1-905981-82-3 Institutional research plan: CEZ:AV0Z90610518 Keywords : linguistics * bibliography * Czech studies Subject RIV: AI - Linguistics

  17. Czech studies : language

    Nováková, Marie; Papcunová, Jana

    Vol. 66. Leeds: Maney Publ., 2006 - ( Parkinson , S.; Barber, L.), s. 761-773 ISBN 978-1-904350-26-2 Institutional research plan: CEZ:AV0Z90610518 Keywords : linguistics * bibliography * Czech studies Subject RIV: AI - Linguistics

  18. Czech Studies. Language

    Nováková, Marie; Papcunová, Jana

    London: Maney Publishing, 2005 - ( Parkinson , S.; Barber, L.), s. 789-799 ISBN 0-901286-94-X Institutional research plan: CEZ:AV0Z90610518 Keywords : linguistics * bibliography * Czech studies Subject RIV: AI - Linguistics

  19. Czech Studies. Language

    Nováková, Marie; Papcunová, Jana

    London: Maney Publishing, 2001 - ( Parkinson , S.), s. 867-878 ISBN 0-901286-94-X R&D Projects: GA AV ČR KSK8002119 Keywords : bibliography * Czech linguistics Subject RIV: AF - Documentation, Librarianship, Information Studies

  20. Czech studies : language

    Nováková, Marie; Papcunová, Jana

    Vol. 67. Leeds: Maney Publ., 2007 - ( Parkinson , S.; Barber, L.), s. 813-825 ISBN 978-1-904350-95-8 Institutional research plan: CEZ:AV0Z90610518 Keywords : linguistics * bibliography * Czech studies Subject RIV: AI - Linguistics

  1. Geomembrane special study

    The objective of the Geomembrane Special Study was to asses the suitability of geomembranes in Uranium Mill Tailings Remedial Action (UMTRA) Project pile designs. Geomembranes, also called flexible membrane liners, are made of polymer resins and are thermoplastic materials. Part of the special study was to evaluate regulatory compliance and acceptability issues. This study was proposed because of the extensive use of geomembranes in hazardous waste site remedial actions and their accepted use in Resource Conservation and Recovery Act (RCRA) cells as both covers and liners to limit infiltration, or as part of leachate collection systems. This study has reviewed the recent geomembrane literature focusing on: (1) longevity; (2) performance; (3) constructibility; and (4) quality control/quality assurance considerations. In addition to these technical considerations, regulatory compliance and acceptability concerns were also evaluated. This report describes the results of the literature review, including correspondence with manufacturers, resin producers, experts in the field, and long-term major users. 12 refs., 2 tabs

  2. Mobile OS Comparative Study

    Joseph, Jyothy; K, Shinto Kurian

    2013-01-01

    In the fast growing mobile revolutionary era, many operating systems are playing vital role in present market. This study is intending to identify the apt and secure mobile based on mobile operating systems capability and user requirements.

  3. Applied Research Study

    Leach, Ronald J.

    1997-01-01

    The purpose of this project was to study the feasibility of reusing major components of a software system that had been used to control the operations of a spacecraft launched in the 1980s. The study was done in the context of a ground data processing system that was to be rehosted from a large mainframe to an inexpensive workstation. The study concluded that a systematic approach using inexpensive tools could aid in the reengineering process by identifying a set of certified reusable components. The study also developed procedures for determining duplicate versions of software, which were created because of inadequate naming conventions. Such procedures reduced reengineering costs by approximately 19.4 percent.

  4. Progress in Aridification Studies

    2005-01-01

    @@ A national key project entitled "Predictive study of aridification in northern China in association with life-supporting environment changes" has recently passed the appraisal of a panel organized by the Ministry of Science & Technology in Beijing.

  5. Videofluoroscopic Swallowing Study (VFSS)

    ... have already had a swallowing test with a speech-language pathologist, also called an SLP. During this test you ... Other resources ASHA documents about VFSS Guidelines for Speech-Language Pathologists Performing Videofluoroscopic Swallowing Studies Knowledge and Skills Needed ...

  6. HYDROGEOLOGIC CASE STUDIES

    Hydrogeology is the foundation of subsurface site characterization for evaluations of monitored natural attenuation (MNA). Three case studies are presented. Examples of the potentially detrimental effects of drilling additives on ground-water samples from monitoring wells are d...

  7. Accelerator research studies

    This progress report for the Accelerator Research Studies program at the University of Maryland covers the second year (June 1, 1989 to May 31, 1990) of the current three-year contract period from June 1, 1988 to May 31, 1991, funded by the Department of Energy under Contract No. AC05-85ER40216. The research program is divided into three separate tasks, as follows: the study of Transport and Longitudinal Compression of Intense, High-Brightness Beams; the study of Collective Ion Acceleration by Intense Electron Beams and Pulse-Powered Plasma Focus; the study of Microwave Sources and Parameter Scaling for High-Frequency Linacs. This report consists of three sections in which the progress for each task is documented separately. An introduction and synopsis is presented at the beginning of the progress report for each task

  8. Techno-economic Study

    Sigurdsson, Halldór Matthias; Point, J.C.; Million, P.

    A techno-economic model for analysing and comparing broadband deployment strategies has been established. The resulting simulation model can compare Capital Expenditure (CAPEX) of dominating broadband technologies in different types of demographic areas. The study reveals the competitiveness and...

  9. The Hi Five study

    Johansen, Anette; Denbæk, Anne Maj; Bonnesen, Camilla Thørring;

    2015-01-01

    BACKGROUND: Infectious illnesses such as influenza and diarrhea are leading causes of absenteeism among Danish school children. Interventions in school settings addressing hand hygiene have shown to reduce the number of infectious illnesses. However, most of these studies include small populations...... and almost none of them are conducted as randomized controlled trials. The overall aim of the Hi Five study was to develop, implement and evaluate a multi-component school-based intervention to improve hand hygiene and well-being and to reduce the prevalence of infections among school children...... randomized multi-component school-based hand hygiene intervention is the first to include education on healthy and appropriate toilet behavior as part of the curriculum. No previous studies have involved supplementary cleaning at the school toilets as an intervention component. The study will have the added...

  10. Comparative Packaging Study

    Perchonok, Michele; Antonini, David

    2008-01-01

    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  11. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under contract number AC05-85ER40216-8, is currently in the third year of its three-year funding cycle. This Renewal Proposal requests DOE support for the next three-year period from June 1, 1991 to May 31, 1994. It documents the progress made during the past year and outlines the proposed research program for the next three years. The program consisted of the following three tasks: Task A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' Task B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' Task C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders.'' These tasks will be discussed in this paper

  12. Exploratory studies, 1988

    This report discusses the following topics: accelerator physics for the ALS; SSC support; machine investigations; mathematical techniques in particle dynamics; APIARY: B-factory studies; and two-beam accelerators and bright electron sources

  13. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks

  14. Upper Kenai Corridor Study

    US Fish and Wildlife Service, Department of the Interior — The Upper Kenai Corridor study describes and evaluates the Upper Kenai River and the land which embraces it. It also places the river corridor in its regional...

  15. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks

  16. Mingo Wilderness study

    US Fish and Wildlife Service, Department of the Interior — This document is a summary of a wilderness study done of the Mingo National Wildlife Refuge pursuant to the Wilderness Act of 1964. It provides information as to...

  17. Prolactinomas: clinical studies

    Kars, Marleen

    2008-01-01

    Prolactinoma are treated with dopamine agonists, which are effective in reducing prolactin and tumor size. Studies reporting clinical and radiological outcome are scarce. The study described in chapter 2, assesses long-term outcome in patients treated with dopamine agonists for macroprolactinoma. An increased risk of cardiac valve disease has been reported in patients treated with cabergoline for Parkinson’s disease. Stimulation of serotonin receptors on cardiac valves by dopamine agonists re...

  18. Thermoluminescence studies in geology

    Even though the phenomenon of thermoluminescence is well studied, particularly over last 3 decades, its potentialities in the field of geology have not been adequately evaluated. In this report several useful applications of TL in mineralogy, petrogenesis, stratigraphy, tectonics, ore-prospecting and other branches have been identified with particular emphasis to the Indian scene. Important areas in the country that may provide the basic material for such studies are indicated at the end along with brief geological or mineralogical accounts. (auth.)

  19. Workshop I: Gender Studies

    Hennessey, Eden; Kurup, Anitha; Meza-Montes, Lilia; Shastri, Prajval; Ghose, Shohini

    2015-12-01

    Participants in the Gender Studies workshop of the 5th IUPAP International Conference on Women in Physics discussed the gender question in science practice from a policy perspective, informed by investigations from the social science disciplines. The workshop's three sessions—"Equity and Education: Examining Gender Stigma in Science," "A Comparative Study of Women Scientists and Engineers: Experiences in India and the US," and "Toward Gender Equity Through Policy: Characterizing the Social Impact of Interventions—are summarized, and the resulting recommendations presented.

  20. Construction 'Work Study'

    Kumaraswamy, Mohan

    2002-01-01

    One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data relating to approaches to 'Construction Work Study'. This is defined as 'A management service based on those techniques, particularly Method Study and Work Measurement, which are used in examining human work in all its contexts, and which lead to systematic investigation of all the resources and factors affecting the efficiency and economy of the situation being reviewed, in order ...

  1. University related studies

    Over the years, opportunities for terrestrial ecology studies have attracted student researchers associated with Pacific Northwest colleges and universities. During the past year, four students have been involved with undergraduate or graduate thesis projects. Brief descriptions of these studies are included in this section. It is expected that university participation will be enhanced by designating parts of the Hanford Reservation as a National Environmental Research Park (NERP)

  2. Tanzania country study

    An objective of this study is to analyse the role of the land use sectors of Tanzania (especially forestry) on mitigation of greenhouse gases. Specific emphasis is placed on the relationship between forestry and energy supply from biomass. This is a follow up study on an earlier effort which worked on mitigation options in the country without an in-depth analysis of the forestry and land use sectors. (au)

  3. Vitrification melter study

    This report presents the results of a study performed to identify the most promising vitrification melter technologies that the Department of Energy (EM-50) might pursue with available funding. The primary focus was on plasma arc systems and graphite arc melters. The study was also intended to assist EM-50 in evaluating competing technologies, formulating effective technology strategy, developing focused technology development projects, and directing the work of contractors involved in vitrification melter development

  4. Cerebral perfution studies

    For detecting in precocious form a coronary disease is necessary to aply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images, proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases

  5. Area studies after poststructuralism

    J K Gibson-Graham

    2004-01-01

    In this paper we address the question of 'what next after poststructuralism' through a reassessment of area studies. In a narrative of our own involvement with place-oriented research and institutions, we examine the traditional position of area studies in geography and anthropology and its reevaluation by poststructuralist scholars in a number of disciplines. We argue that both prestructuralist and poststructuralist treatments of areas are oriented by a narrative of capitalist development; a...

  6. Constellation Commodities Studies Summary

    Dirschka, Eric

    2011-01-01

    Constellation program was NASA's long-term program for space exploration. The goal of the commodities studies was to solicit industry expertise in production, storage, and transportation required for future use and to improve efficiency and life cycle cost over legacy methods. Objectives were to consolidate KSC, CCAFS and other requirements; extract available industry expertise; identify commercial opportunities; and establish synergy with State of Florida partnerships. Study results are reviewed.

  7. Kickstarter - A Case Study

    Willumsen, Ea Christina; Byg-Fabritius, Edith Ursula Tvede

    2013-01-01

    This paper is an investigation of the online crowdfunding platform Kickstarter, and discusses what makes a Kickstarter campaign successful. Two previous Kickstarter campaigns have been debated in focus groups interviews, as the basis of the study is a reception analysis of two focus group interviews. Ee apply theories from Schrøder (2000) and Batey (2008) to our analysis to study how the campaigns appeal to their backers. By drawing on ideas from Rogers (2003) and Pine & Gilmore (1998), we fu...

  8. DOE's Yucca Mountain studies

    This booklet is about the disposal of high-level nuclear waste in the United States. It is for readers who have a general rather than a technical background. It discusses why scientists and engineers thinkhigh-level nuclear waste may be disposed of safely underground. It also describes why Yucca Mountain, Nevada, is being studied as a potential repository site and provides basic information about those studies

  9. Ship accident studies

    This paper summarizes ship accident studies performed by George G. Sharp, Inc. for the U.S. Maritime Administration in connection with the Nuclear Ship Project. Casualties studied include fires/explosions, groundings and collisions for which a method for calculating probability on a specific route was developed jointly with the Babcock and Wilcox Co. Casualty data source was the Liverpool's Underwriters Association Casualty Returns

  10. Zambia country study

    1999-09-01

    The Zambia Country Study, which was part of the Danida-funded project Climate Change Mitigation in Southern Africa: Phase 2, aimed at methodological development, national mitigation analysis and institutional capacity building in Zambia. The study comprised the following five elements: Comprehensive evaluation of national social and economic development framework for climate change; Baseline scenario(s) projection(s); Mitigation scenario(s) projection(s); Macro-economic assessment; Implementation Issues. (au) 17 refs.

  11. Waarom Jesus-studies?

    P.A. Geyser

    2000-01-01

    Why Jesus studies? Present-day historical Jesus studies are the epistemological product of what has become known as the New Historicism. The aim of the article is to emphasize two aspects of the New Historicism as epistemological approach. The one aspect focuses on the profitability of this endeavour and the other on the historical nature of the New Historicism. As far as profitability is concerned, the social standing and identity of the researcher are emphasized. Among otherthings, the soci...

  12. Tanzania country study

    Meena, H.E. [Centre for Energy, Environment, Science and Technology, Dar es Salaam (Tanzania, United Republic of)

    1998-10-01

    An objective of this study is to analyse the role of the land use sectors of Tanzania (especially forestry) on mitigation of greenhouse gases. Specific emphasis is placed on the relationship between forestry and energy supply from biomass. This is a follow up study on an earlier effort which worked on mitigation options in the country without an in-depth analysis of the forestry and land use sectors. (au)

  13. Intrapreneurship - An international study

    Niels Bosma; Sander Wennekers; F. Stam

    2010-01-01

    This paper presents the results of a novel international study of intrapreneurship ( i.e., employees developing new business activities for their employer), carried out in eleven countries in the framework of the Global Entrepreneurship Monitor. At the individual level, it is found that intrapreneurs are much more likely to have intentions to start a new independent business than other employees. However, at the macro level the study finds a negative correlation between intrapreneurship and i...

  14. Rotordynamic Stability Case Studies

    Choudhury Pranabesh

    2004-01-01

    In this article case studies are presented involving rotordynamic instability of modern high-speed turbomachinery relating the field data to analytical methods. The studies include oil seal related field problems, instability caused by aerodynamic cross-coupling in high-pressure, high-speed compressors, and hydrodynamic bearing instability resulting in subsynchronous vibration of a high-speed turbocharger. It has been shown that the analytical tools not only help in problem diagnostics, bu...

  15. Scoping studies for NET

    Scoping studies for NET using the SUPERCOIL system code are described. Capital cost optimized devices satisfying constraints imposed on stresses/strains, fields, access, etc. are compared. The main objectives are to determine what impact the main design characteristics, performance objectives and underlying plasma physics assumptions have on the parameters and cost of NET. A complete picture for choosing the main parameters of NET is developed and illustrated by the main NET study points used during the conceptual design phase. (orig.)

  16. American Studies in Finland

    Jopi Nyman

    2005-01-01

    Since its establishment in 1996, the Finnish American Studies Association has sought to promote the field of American Studies in Finland by organizing conferences, events and by increasing networking amongst its scattered membership (ca. 35) working at various universities and other higher education institutions. The current President of the Association is Dr Jopi Nyman (University of Joensuu) and its Secretary is Dr Ari Helo (University of Helsinki). While currently only the University of He...

  17. Prague Case Study Report

    Kostelecký, Tomáš; Patočková, Věra; Illner, Michal; Vobecká, Jana; Čermák, Daniel

    Aarau: Centre for Democracy Studies Aarau (ZDA), 2014 - (Widmer, C.; Kübler, D.), s. 131-177 ISBN 978-3-9524228-2-3 R&D Projects: GA AV ČR IAA700280802 Institutional support: RVO:68378025 Keywords : urban neighbourhods * regeneration * Prague Subject RIV: AD - Politology ; Political Sciences http://www.zdaarau.ch/dokumente/en/ZDA_Working-Papers/No3_RUN_case-studies_2014.pdf

  18. The correlation between lacunes and microbleeds on magnetic resonance imaging in consecutive 180 patients

    Microbleeds on T2*-weighted magnetic resonance imaging (MRI) represent a hemorrhagic type of small vessel disease. Small vessel disease causes both intracerebral hemorrhages and lacunar infarctions. We studied clinical background and MRI findings of the patients to clarify the correlation between microbleeds and lacunes. This study consisted of 180 consecutive patients who underwent brain MRI using 1.5T system in our hospital for a year. We obtained T2*-weighted gradient-echo imaging as well as T1 and T2-weighted images. We statistically identified the factors related to the presence of microbleeds in all patients. The distribution of lacunes and microbleeds on MRI was compared to clarify the correlation of the lesions in the patients who had both lesions. The overall prevalence of microbleeds was 41.1% (74 of 180 patients). Logistic regression analysis indicated that previous stroke, leukoaraiosis and lacunes were significantly correlated with microbleeds. In the patients who have both microbleeds and lacunes, lesions are tended to locate in thalamus and basal ganglia, especially incidence of lacunes are significantly greater compared with other regions. Thirty-six of 398 lesions (9.05%) diagnosed as lacunes with T1- and T2-weighted imaging were demonstrated as microbleeds with T2*-weighted gradient-echo imaging. Lacunes, leukoaraiosis as a hypertensive change on MRI had statistically significant correlation with the presence of microbleeds. T2*-weighted gradient-echo imaging should be included in the imaging protocol for cerebrovascular disease, because T1- and T2-weighted imaging recognizing some of the microbleeds as lacunar infarction. (author)

  19. Impact studies at Winfrith

    Analytical and experimental studies of subsonic impacts on nuclear reactor plant structures have been in progress at Winfrith since 1977. These studies have examined the behaviour of concrete and metal structures under the impact of missiles typifying those derived either from the plant itself or from external sources, such as crashing aircraft. During 1986 the Winfrith programme was expanded to include studies of the behaviour of radioactive materials transport containers under impact conditions. This report initially describes the experimental facilities available for impact studies at Winfrith. These include both compressed air guns, capable of delivering payloads of up to 65 kg at sonic velocity or payloads up to 2 tonnes at speeds up to 45 ms-1, and drop test facilities for impact testing of models, up to full-scale radioactive materials transport flasks, at relatively low speeds. Supporting facilities include a small concrete manufacturing laboratory to produce concrete targets. Assessments of the resistance of concrete or metal structures to impact damage are performed using empirical or semi-empirical correlations, derived from data obtained in well-characterised experiments, or using structural dynamics finite element codes. The codes used by the analysts and the computing facilities available for impact analysis work are described. Finally the current programme of impact studies is reviewed, recent progress is summarised and future plans outlined. (author)

  20. Laboratory microfusion capability study

    The purpose of this study is to elucidate the issues involved in developing a Laboratory Microfusion Capability (LMC) which is the major objective of the Inertial Confinement Fusion (ICF) program within the purview of the Department of Energy's Defense Programs. The study was initiated to support a number of DOE management needs: to provide insight for the evolution of the ICF program; to afford guidance to the ICF laboratories in planning their research and development programs; to inform Congress and others of the details and implications of the LMC; to identify criteria for selection of a concept for the Laboratory Microfusion Facility and to develop a coordinated plan for the realization of an LMC. As originally proposed, the LMC study was divided into two phases. The first phase identifies the purpose and potential utility of the LMC, the regime of its performance parameters, driver independent design issues and requirements, its development goals and requirements, and associated technical, management, staffing, environmental, and other developmental and operational issues. The second phase addresses driver-dependent issues such as specific design, range of performance capabilities, and cost. The study includes four driver options; the neodymium-glass solid state laser, the krypton fluoride excimer gas laser, the light-ion accelerator, and the heavy-ion induction linear accelerator. The results of the Phase II study are described in the present report

  1. [The DIAN study].

    Shimada, Hiroyuki

    2013-10-01

    The DIAN study compared the pathophysiological markers between carriers and non-carriers of mutation for autosomal dominant Alzheimer's disease (AD). They used the participant's age at baseline assessment and the parent's age at the onset of symptoms of AD to calculate the estimated delay in symptom onset. The study revealed that the biomarker change, which is the reduction of Aβ42 in the CSF of the carrier's brain, started approximately 15-20 years prior to the onset of symptoms. Subsequently, a chronological series of events took place: deposition of fibrillar Aβ as measured by positron emission tomography with the use of Pittsburgh compound B, increase in tau protein in the CSF, hippocampal atrophy and hypometabolism of FDG-PET, and cognitive and clinical changes. The researchers planned to start the prevention trial with 2 monoclonal antibodies and a BACE inhibitor. In contrast, the API study is the clinical trial of the anti-amyloid monoclonal antibody therapy associated with the early-onset familial AD (EOAD), which carries the PSEN1 E280A mutation. This study also showed changes in the same biomarker as reported in the DIAN study. Anti-amyloid treatment in asymptomatic AD (A4) is a prevention trial aimed at treating older individuals with normal cognition but at risk of developing AD dementia on the basis of having biomarker evidence of amyloid (preclinical AD). They selected solanezumab for the anti-amyloid treatment for A4. PMID:24101429

  2. Photovoltaics information user study

    Belew, W.W.; Wood, B.L.; Marie, T.L.; Reinhardt, C.L.

    1980-10-01

    The results of a series of telephone interviews with groups of users of information on photovoltaics (PV) are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The report is 1 of 10 discussing study results. The overall study provides baseline data about information needs in the solar community. It covers these technological areas: photovoltaics, passive solar heating and cooling, active solar heating and cooling, biomass energy, solar thermal electric power, solar industrial and agricultural process heat, wind energy, ocean energy, and advanced energy storage. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven PV groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Researchers Working for Manufacturers, Representatives of Other Manufacturers, Representatives of Utilities, Electric Power Engineers, and Educators.

  3. Cosmos-1989 immunology studies

    Sonnenfeld, Gerald

    1991-01-01

    Evidence from both human and rodent studies has indicated that alterations in immunological parameters occur after space flight. The number of flight experiments has been small, and the full breadth of immunological alterations occurring after space flight remains to be established. Among the major effects on immune responses after space flight that have been reported are: alterations in lymphocyte blastogenesis and natural killer cell activity, alterations in production of cytokines, changes in leukocyte sub-population distribution, and decreases in the ability in the ability of bone marrow cells to respond to colony stimulating factors. Changes have been reported in immunological parameters of both humans and rodents. The significance of these alterations in relation to resistance to infection remains to be established. The current study involved a determination of the effects of flight on Cosmos mission 2044 on leukocyte subset distribution and the sensitivity of bone marrow cells to colony stimulating factor-GM. A parallel study with antiorthostatic suspension was also carried out. The study involved repetition and expansion of studies carried out on Cosmos 1887.

  4. Underground layout tradeoff study

    This report presents the results of a technical and economic comparative study of four alternative underground layouts for a nuclear waste geologic repository in salt. The four alternatives considered in this study are (1) separate areas for spent fuel (SF) and commercial high-level waste (CHLW); (2) panel alternation, in which SF and CHLW are emplaced in adjacent panels of rooms; (3) room alternation, in which SF and CHLW are emplaced in adjacent rooms within each panel; and (4) intimate mixture, in which SF and CHLW are emplaced in random order within each storage room. The study concludes that (1) cost is not an important factor; (2) the separate-areas and intimate-mixture alternatives appear, technically, to be more desirable than the other alternatives; and (3) the selection between the separate-areas and intimate mixture alternatives depends upon future resolution of site-specific and reprocessing questions. 5 refs., 6 figs., 12 tabs

  5. Seal design alternatives study

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  6. Study of iron fluorination

    This report deals with the action of fluorine on iron. Comprehensive descriptions are given of the particular technological methods and of the preparation of the reactants. This fluorination reaction has been investigated over a very broad range of temperature and pressure. A nucleation and growth phenomenon is described. The influence of a pollution of the gas phase by oxygen on the fluorination process is reported. The solid-state reaction between ferric fluoride and iron has been studied by calorimetry and hydrated fluorides βFeF3, 3 H2O and FeF3, H2O have been studied by Moessbauer effect. A special study has been made of the growth of iron deposits by thermal decomposition of gaseous iron fluorides. (author)

  7. Seal design alternatives study

    Van Sambeek, L.L. [RE/SPEC Inc., Rapid City, SD (US); Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D. [Parsons Brinckerhoff Quade & Douglas, Inc., San Francisco, CA (US)

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information.

  8. Epidemiological studies on syncope

    Ruwald, Martin Huth

    2013-01-01

    The epidemiology and prognosis of ''fainting'' or syncope has puzzled physicians over the years. Is fainting dangerous? This is a question often asked by the patient--and the answer is ''it depends on a lot of things''. The diverse pathophysiology of syncope and the underlying comorbidites of the...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate...... thesis demonstrated that the ICD-10 discharge diagnosis could reliably identify a cohort of patients admitted for syncope and that the discharge code carried a high number of unexplained cases despite use of numerous tests. The last studies showed that syncope is a common cause for hospital contact in...

  9. Operation and machine studies

    This annual report describes the GANIL (Grand accelerateur national d'ions lourds, Caen, France) operation and the machine studies realized in 1992. Metallic ions have been accelerated during 36 pc of the time; some were produced for the first time at GANIL: 125Te, 52Cr with ECR3, 181Ta with ECR4. The various machine studies are: comparison of lifetimes of carbon sheets, charge exchange of very heavy ions in carbon foils and in the residual gas of the Ganil cyclotrons, commissioning of the new high intensity axial injection system for Ganil, tantalum acceleration with the new injector, a cyclotron as a mass spectrometer; other studies concerned: implementing the new control system, gettering flux measurement, energy deposited by neutrons and gamma rays in the cryogenic system of SISSI; latest developments on multicharged ECR ion sources, and an on-line isotopic separator test bench at Ganil

  10. Waarom Jesus-studies?

    P. A. Geyser

    2000-01-01

    Full Text Available Why Jesus studies? Present-day historical Jesus studies are the epistemological product of what has become known as the New Historicism. The aim of the article is to emphasize two aspects of the New Historicism as epistemological approach. The one aspect focuses on the profitability of this endeavour and the other on the historical nature of the New Historicism. As far as profitability is concerned, the social standing and identity of the researcher are emphasized. Among otherthings, the social interests of the researcher are taken into account. Concerning the historical nature of this kind of research, a distinction is drawn between the Jesus of history and the Jesus of faith. The aim of the article is to gain clarity on the relationship between the Jesus of history (pre-Easter and the Jesus of faith (post-Easter. J D Crossan's exposition of the reasons for Jesus studies is followed. He distinguishes three reasons: historical, ethical and theological.

  11. Dynamic lung transmission studies

    The aim of this study was to develop a non-invasive method for determining regional lungvolumes, which could replace bronchospirometry in routine clinical use. Transmission through the thorax of sup(99m)Tc-gammarays is measured by means of a gamma camera on line with a computer. The technique of measurement and data analysis is described and tested in several series of phantom studies. The results proved to be good: the mean difference with the real volumes was -4%. The error varied between -10% and +1. Transmission studies and bronchospirometry are compared in a group of 11 patients and there proved to be a good correspondence between the results of these methods. It is concluded that transmission experiments can determine the vital capacity of both lungs as a whole as accurately as spirometry and allows the measurement of vital capacity for each lung separately with the same accuracy as bronchospirometry. (Auth.)

  12. Study of electroweak interactions

    The experimental study of electroweak interactions at Virginia Tech is multifaceted and consists of three parts. The first consists of analysis of the final states of matter produced in electron-positron annihilations at center-of-mass energies √s = 60 GeV at the TRISTAN collider in Japan (AMY). The second is a sensitive search for rare electroweak processes through a study of μ+ → e+γ at the LAMPF facility at Los Alamos (MEGA). It also includes a precise measurement of the Michel ρ parameter (RHO). The third activity is a R ampersand D detector development and is a precursor to anticipated experiments at proposed Bo meson factories in this country and/or abroad. The physics goals are the study of CP violation in the Bo system and the determination of the values for Kobayashi-Maskawa matrix

  13. Studie-Units

    Koustrup, Pia

    2004-01-01

    Denne artikel sætter fokus på tilrettelæggelse af klinisk undervisning og læring, hvor et nyere begreb - studie-units er opstået inden for de sidste par år. Studie-unit er en organisationsform, som sygeplejen helt sikkert vil se en del mere til de næste par år frem i tiden. Artiklen inddrager den...... tyske didaktiker og filosof Wolfgang Klafki i diskussionen om indføring af studie-units. Klafki er valgt, fordi han indgående forholder sig til social læring, og finder læring i fællesskab med ligestillede nødvendigt for at dannelsen i et fag skal kunne lykkes...

  14. International user studies

    Nielsen, Lene; Madsen, Sabine; Jensen, Iben;

    countries/regions they operate in. Instead, they focus on a few strategic markets. International user studies tend to be large-scale studies that involve the effort of many both internal and external/local human resources. The studies typically cover 2-4 countries/regions and many end users in each country......, so far, no best practice for incorporating both national cultural differences and cross-cultural similarities into persona descriptions, segmentations, etc. has been found. Based on the empirical findings, we outline a maturity model. The empirical maturity model consists of two separate dimensions...... end users across nationalities and (2) that it often is more important to focus on and take differences in market conditions into account than national culture per se. Companies are in the process of finding out how best to present the insights about international end users to their employees. However...

  15. Structure study with AMD

    Structure study by the use of AMD in stable and unstable nuclei is reviewed. We put some emphasis on the characteristic features of AMD approach which include variation after parity projection, variation after angular momentum projection, superposition of parity-spin projected AMD Slater determinants. Since AMD is an ab initio theory of nuclear structure, we can study cluster structure without assuming the existence of any clusters and can describe the coexistence of meanfield-type structure and cluster structure. Some examples of calculated results are shown by comparing with the experimental data. They are the studies on neutron-rich Li, BeCB isotopes, on the island of inversion around N=20, and on the excited bands with many-particle many-hole structure in 44Ti. (author)

  16. Parylene C Aging Studies.

    Achyuthan, Komandoor; Sawyer, Patricia Sue.; Mata, Guillermo Adrian; White II, Gregory Von; Bernstein, Robert

    2014-09-01

    Parylene C is used in a device because of its conformable deposition and other advantages. Techniques to study Parylene C aging were developed, and %22lessons learned%22 that could be utilized for future studies are the result of this initial study. Differential Scanning Calorimetry yielded temperature ranges for Parylene C aging as well as post-deposition treatment. Post-deposition techniques are suggested to improve Parylene C performance. Sample preparation was critical to aging regimen. Short-term (~40 days) aging experiments with free standing and ceramic-supported Parylene C films highlighted %22lessons learned%22 which stressed further investigations in order to refine sample preparation (film thickness, single sided uniform coating, machine versus laser cutting, annealing time, temperature) and testing issues (%22necking%22) for robust accelerated aging of Parylene C.

  17. Epidemiological studies on syncope

    Ruwald, Martin Huth

    2013-01-01

    The epidemiology and prognosis of ''fainting'' or syncope has puzzled physicians over the years. Is fainting dangerous? This is a question often asked by the patient--and the answer is ''it depends on a lot of things''. The diverse pathophysiology of syncope and the underlying comorbidites...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate...... thesis demonstrated that the ICD-10 discharge diagnosis could reliably identify a cohort of patients admitted for syncope and that the discharge code carried a high number of unexplained cases despite use of numerous tests. The last studies showed that syncope is a common cause for hospital contact...

  18. Cosmos: 1989 immunology studies

    Sonnenfeld, Gerald

    1991-01-01

    The effects of flight on Cosmos mission 2044 on leukocyte subset distribution and the sensitivity of bone marrow cells to colony stimulating factor-GM were determined. A parallel study with antiorthostatic suspension was also carried out. The study involved repetition and expansion of studies performed on Cosmos 1887. Spleen and bone marrow cells were obtained from flown, vivarium control, synchronous control, and suspended rats. The cells were stained with a series of monoclonal antibodies directed against rat leukocyte cell surface antigens. Control cells were stained with a monoclonal antibody directed against an irrelevant species or were unstained. Cells were then analyzed for fluorescence using a FACSCAN flow cytometer. Bone marrow cells were placed in culture with GM-CSF in McCoy's 5a medium and incubated for 5 days. Cultures were then evaluated for the number of colonies of 50 cells or greater.

  19. a multimodal mapping study

    Barbara Tomasino

    2015-10-01

    Full Text Available Our environment is full of auditory events such as warnings or hazards, and their correct recognition is essential. We explored environmental sound (ES recognition in a series of studies. In study 1 we performed an Activation Likelihood Estimation (ALE meta-Analysis of neuroimaging studies addressing ES processing to delineate the network of areas consistently involved in ES processing. In study 2 we reported a series of 7 neurosurgical patients with lesions involving the areas found consistently activated by the ALE meta-analysis and tested their ES recognition abilities. In study 3 we investigated how the areas involved in ES might be functionally deregulated as an effect of lesion by performing an fMRI study on patients (in comparison to healthy controls. Areas found to be consistently activated in the ALE quantitative meta-analysis involved the STG/MTG, insula/rolandic operculum, parahippocampal gyrus and inferior frontal gyrus complex bilaterally. Some of these areas were found modulated by design choices, e.g., type of task, type of control condition, type of stimuli. Patients with lesions in these areas of the left and the right hemisphere had an impaired ES recognition. The most frequently lesioned area corresponded to the hippocampus/insula/superior temporal gyrus. For the most part, the patients’ responses were unrelated to the target sounds or were semantically related to the target sounds. The other type of responses were: auditorily related, semantically and auditorily related, and "I don't Know" answers. The fMRI evidenced deregulations of the activation reported in the right IFG and in the STG bilaterally and in the left insula. We showed that some of these clusters of activation truly reflect ES processing, whereas others are related to design choices. Our results allowed a parcelization of the activation found along the MTG/STG area

  20. CCNA Wireless Study Guide

    Lammle, Todd

    2010-01-01

    A complete guide to the CCNA Wireless exam by leading networking authority Todd Lammle. The CCNA Wireless certification is the most respected entry-level certification in this rapidly growing field. Todd Lammle is the undisputed authority on networking, and this book focuses exclusively on the skills covered in this Cisco certification exam. The CCNA Wireless Study Guide joins the popular Sybex study guide family and helps network administrators advance their careers with a highly desirable certification.: The CCNA Wireless certification is the most respected entry-level wireless certification

  1. Rockwell support studies

    The Rockwell Hanford Operations (RHO) supported ecological studies are designed to clarify ecosystem structure and functioning as pertaining to the management of radioactive waste control areas. To date, emphasis has been placed on characterizing the abiotic and biotic components of these areas, resulting in publication of over 20 PNL documents and several scientific articles pertinent to the 200 Area Waste Management Program. Results are reported from studies on the food habits of ground-dwelling beetles, mule deer, and American Coots inhabiting the areas, and the radiation dose received by rodents inhabiting waste management areas

  2. Whiteness Studies I

    Kolchin, Peter

    2014-01-01

    Whiteness Studies. Over the past two decades, scholars in the social sciences and humanities have increasingly focused on « whiteness » as a new way of exploring race and racism in America. These two articles evaluate the way historians have approached the subject. The first article, originally published in the Journal of American History in 2002, examines the development of whiteness studies in the 1990s, and the second, which appears here for the first time, provides an update on more recen...

  3. Whiteness Studies II

    Kolchin, Peter

    2014-01-01

    Whiteness Studies. Over the past two decades, scholars in the social sciences and humanities have increasingly focused on « whiteness » as a new way of exploring race and racism in America. These two articles evaluate the way historians have approached the subject. The first article, originally published in the Journal of American History in 2002, examines the development of whiteness studies in the 1990s, and the second, which appears here for the first time, provides an update on more recen...

  4. Biological study in schizophrenia

    Schizophrenia is associated with enormous morbidity, mortality, personal disability, and social cost. Although considerable research on schizophrenia has been performed, the etiology of this disease has not been fully elucidated. In recent years, imaging and genetic technologies have been developed dramatically. Disturbances in glutamate and gamma-aminobutyric acid (GABA)ergic neurotransmission may underlie the pathophysiology of schizophrenia. We attempted an integrative review, of studies pertaining to recent advances of schizophrenia research with a focus on neuroimaging and genetic studies. Additionally, we present the preliminary findings of the clinical research in our outpatient unit, specialized for early intervention, at the University of Tokyo Hospital. (author)

  5. DWPF Welder Parametric Study

    Plodinec, M.J.

    1998-11-20

    After being filled with glass, DWPF canistered waste forms will be welded closed using an upset resistance welding process. This final closure weld must be leaktight, and must remain so during extended storage at SRS. As part of the DWPF Startup Test Program, a parametric study (DWPF-WP-24) has been performed to determine a range of welder operating parameters which will produce acceptable welds. The parametric window of acceptable welds defined by this study is 90,000 + 15,000 lb of force, 248,000 + 22,000 amps of current, and 95 + 15 cycles* for the time of application of the current.

  6. Morphing Terminology Study

    Rose, Stuart J.; Brockman, Fred J.; Hart, Michelle L.; Engel, David W.; Valentine, Nancy B.; Calapristi, Augustin J.

    2010-06-28

    This study investigates methods of automatically identifying and characterizing significant transitions in term usage over time. Within scientific literature, the occurrence of terms reflects the use of technologies and techniques as well as the study of specific species and materials. Transitions in terminology usage may be a result of vocabulary standardization or specialization in which terms are replaced with their shorter form. They may also be a result of new applications, combinations, alternatives, or interests that result in the appearance of new or existing terminology in unexpected contexts.

  7. Critical cyberculture studies

    Silver, David; Jones, Steve

    2006-01-01

    Starting in the early 1990s, journalists and scholars began responding to and trying to take account of new technologies and their impact on our lives. By the end of the decade, the full-fledged study of cyberculture had arrived. Today, there exists a large body of critical work on the subject, with cutting-edge studies probing beyond the mere existence of virtual communities and online identities to examine the social, cultural, and economic relationships that take place online. Taking stock of the exciting work that is being done and positing what cyberculture's future might look like, Criti

  8. Case study - Argentina

    Antecedents and experience of nuclear activities in Argentina; the Atomic Energy Commission (CNEA). First development and research activities. Research reactors and radioisotopes plants. Health physics and safety regulations. - Feasibility studies for the first nuclear power plant. Awarding the first plant CNA I (Atucha I). Relevant data related to the different project stages. Plant performance. - Feasibility study for the second nuclear power plant. Awarding the second plant CNE (Central Nuclear Embalse). Relevant data related to established targets. Differences compared with the first station targets. Local participation. Plant performance. (orig./GL)

  9. Study of estuarine dynamics

    A case study of a shallow, well mixed fjord illustrates the use of radioactive and an activable tracer. An instantaneous injection of the rare earth lanthanum was used as an activable tracer to determine residence-time and internal recirculation in the fjord system. An instantaneous injection of bromine-82 was used to investigate tae bypass of water from a harbour area through a power plant cooling water system to a partly enclosed basin of the fjord. Instantaneous releases of bromine-82 were further used for short time studies of the primary spread and transport of river water discharged to the inner section of the fjord system. (Author)

  10. NMR studies of metabolism

    In this paper, the authors present applications of NMR to the study of different aspects of metabolism. The authors begin with a brief outline of localization methods that are commonly used to obtain in vivo NMR spectra. The authors then describe in more detail metabolic information recently obtained by NMR of perfused organs, intact animals, and humans. Previous reviews have already covered the applications of NMR to the study of metabolism in microorganisms, isolated or cultivated cells, and tumors. NMR spectroscopy of the brain, and human in vivo NMR spectroscopy have also been reviewed

  11. Studies in neuroendocrine pharmacology

    Maickel, R. P.

    1976-01-01

    The expertise and facilities available within the Medical Sciences Program section on Pharmacology were used along with informational input from various NASA sources to study areas relevant to the manned space effort. Topics discussed include effects of drugs on deprivation-induced fluid consumption, brain biogenic amines, biochemical responses to stressful stimuli, biochemical and behavioral pharmacology of amphetamines, biochemical and pharmacological studies of analogues to biologically active indole compounds, chemical pharmacology: drug metabolism and disposition, toxicology, and chemical methodology. Appendices include a bibliography, and papers submitted for publication or already published.

  12. Study of genital lesions

    Anand Kumar B

    2003-03-01

    Full Text Available A total of one hundred patients (75 males and 25 females age ranged from 17-65 years with genital lesions attending the STD clinic of Bowring and LC Hospitals Bangalore constituted the study group. Based on clinical features, the study groups were classified as syphilis (39, chancroid (30, herpes genitolis (13, condylomato lato (9, LGV (7t condylomata acuminata (5, genital scabies (3, granuloma inguinole (2 and genital candidiasis (1. In 68% microbiological findings confirmed the clinical diagnosis. Of the 100 cases 13% and 2% were positive for HIV antibodies and HbsAg respectively.

  13. DWPF Welder Parametric Study

    After being filled with glass, DWPF canistered waste forms will be welded closed using an upset resistance welding process. This final closure weld must be leaktight, and must remain so during extended storage at SRS. As part of the DWPF Startup Test Program, a parametric study (DWPF-WP-24) has been performed to determine a range of welder operating parameters which will produce acceptable welds. The parametric window of acceptable welds defined by this study is 90,000 + 15,000 lb of force, 248,000 + 22,000 amps of current, and 95 + 15 cycles* for the time of application of the current

  14. Stand for studying microcontrollers

    Гринчак, Николай Васильевич; Кузьмичева, Екатерина Владимировна

    2013-01-01

    The problems of studying the basics of microprocessor technology and microcontrollers in technical high schools are considered in the paper. The version of the educational stand -Control computer LMakPic24-64 is proposed. Due to the thought-up design, the computer has a low cost and is suitable for replication in high school conditions. The computer is also suitable for the development of applications, based on the Microchip 16-bit PIC24 family.The main purpose of the study is to solve the fo...

  15. Philippines: Ingestion study

    In addition to the dietary intake of trace elements of radiological and nutritional importance, ten samples each of human liver and lung tissues were also analysed for Th, U and Cs for the adult subjects from the Philippines. The study of the elements of importance in nutrition assumed greater significance in the Philippines in view of the reported malnutrition in all the 13 regions in the country, including the National Capital Region. The Food and Nutrition Research Institute (FNRI), the agency responsible for monitoring the nutrition status of the Philippines, is currently refocusing its studies on the mineral and elemental content of food

  16. Studies in Rheoencephalography (REG

    Michael Bodo

    2010-01-01

    Full Text Available This article presents an overview of rheoencephalography (REG – electrical impedance measurements of the brain – and summarizes past and ongoing research to develop medical applications of REG for neuro-critical care and for primary prevention of stroke and cardiovascular disease. The availability of advanced electronics and computation has opened up the potential for use of REG technology as a noninvasive, continuous and inexpensive brain monitor for military and civilian applications. The clinical background information presented here introduces physiological and clinical environments where REG has potential for use in research and clinical settings. REG studies over the past three decades have involved in vitro and in vivo groups (animal and human, including more than 1500 measurements and related electronic and computational results and practical applications. In vitro studies helped researchers understand the flow/volume relationship between Doppler ultrasound and electrical impedance signals and supported development of REG data processing methods. In animal studies, REG was used to monitor the lower limit of cerebral blood flow (CBF autoregulation (AR using a newly developed algorithm. These animal studies also confirmed correlations between REG and measurements of carotid flow (CF and intracranial pressure (ICP. Human studies confirmed the applicability of REG for detecting cerebrovascular alteration, demonstrating the usefulness of REG in the field of stroke/cardio-vascular disease prevention. In these studies, REG was compared to known stroke risk factors and to results obtained using carotid ultrasound measurements. An intelligent REG system (Cerberus has been developed for primary stroke prevention. In these studies, the biologically relevant variables of the REG signal were pulse amplitude (minimum – maximum distance and duration of the anacrotic (rising portion of the REG pulse wave. The principal limitation of REG for

  17. Regional Studies Program

    Progress is reported on methodology studies with regard to hydrologic analysis; atmospheric transport; forest growth models; distribution of sensitive species; agricultural analysis; and environmental objectives in energy facility siting. National coal utilization assessment studies are reported with regard to technology characterization; air quality impacts; water resources; regional characterization; forest impacts; coal extraction impacts on sensitive animal species; and health impacts. The following special projects were carried out: water resource aspects of inexhaustible technology deployment; ecological constraints on the rapidly expanded use of coal; and U.S. coal and the global carbon problem

  18. Diversity and abundance of invertebrate epifaunal assemblages associated with gorgonians are driven by colony attributes

    Cúrdia, João; Carvalho, Susana; Pereira, Fábio; Guerra-García, José Manuel; Santos, Miguel N.; Cunha, Marina R.

    2015-06-01

    The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple regression analysis, we tested the contribution of several attributes (colony height, width, and area, fractal dimension as a measure of colony complexity, lacunarity as a measure of the heterogeneity, and "colonial" epibiont cover) to abundance and taxonomic richness of associated assemblages. The results highlight the variation in the response of epifaunal assemblages to the gorgonian colony characteristics. The nature and intensity of the relationships were gorgonian species-dependent and varied from one taxonomic group to another. For both gorgonian species analyzed, the strongest predictor of species richness and abundance of the epifaunal assemblages was "colonial" epibiont cover, possibly due to a trophic effect (direct or indirect enhancement of food availability) combined with the surface available for colonization (species-area effect). Although structural complexity is usually indicated as the main driver for rich and abundant coral-associated assemblages, no significant relationship was observed between fractal dimension and the community descriptors; lacunarity, which reflects the sizes of the inter-branch spaces, was only linked to taxonomic richness in the assemblages associated with Leptogorgia lusitanica. The validity of the paradigm that structural complexity enhances biodiversity may be scale-dependent. In the case of gorgonians, the effect of complexity at the "garden" level may be more relevant than at the individual colony level. This reinforces the need for the conservation of gorgonian aggregation areas as a whole in order to preserve host diversity and size structure.

  19. A quantitative evaluation of regional cerebral blood flow in the patients with cerebral vascular accident

    We studied the validity of a new method using 99mTc-HMPAO for quantitative evaluation of regional cerebral blood flow (rCBF) with single-photon emission computed tomography (SPECT). Subjects consisted of 20 patients with various categories of cerebral vascular accident. There were 14 males and six females. Age ranged from 33 to 88 years old with a mean of 67.9. Each category included two cerebral hemorrhages, six atherothrombotic, nine lacunar, and three cardioembolic strokes. By using the method reported by Matsuda et al., rCBF measurements were carried out at least three weeks after the insults. A total of 18 ROIs was set symmetrically on both affected and unaffected hemispheres. Data collected from the frontal, the temporal, and the occipital ROI of the unaffected hemisphere showed 50.5±10.1, 50.4±12.7, and 48.6±8.4ml/100g/min (mean±SD) respectively. Since these values were similar to those measured by other methods including PET, an average of these values was used as a control to evaluate the values of the affected regions. In the affected regions of cerebral hemorrhages, atherothrombotic, and cardioembolic stroke, rCBF showed a significant reduction. No significant decrease in rCBF was revealed in the lesions of lacunar stroke presumably because of relative small lesions. These results suggest that this simple and minimally invasive method is reliable as a quantitative measurement of rCBF and is applicable for clinical uses. (author)

  20. Microarchitectural changes in the aging skeleton.

    Gabet, Yankel; Bab, Itai

    2011-12-01

    The age-related reduction in bone mass is disproportionally related to skeletal weakening, suggesting that microarchitectural changes are also important determinants of bone quality. The study of cortical and trabecular microstructure, which for many years was mainly based on two-dimensional histologic and scanning electron microscopy imaging, gained a tremendous momentum in the last decade and a half, due to the introduction of microcomputed tomography (μCT). This technology provides highly accurate qualitative and quantitative analyses based on three-dimensional images at micrometer resolution, which combined with finite elemental analysis predicts the biomechanical implications of microstructural changes. Global μCT analyses of trabecular bone have repeatedly suggested that the main age-related change in this compartment is a decrease in trabecular number with unaltered, or even increased, trabecular thickness. However, we show here that this may result from a bias whereby thick trabeculae near the cortex and the early clearance of thin struts mask authentic trabecular thinning. The main cortical age-related change is increased porosity due to negatively balanced osteonal remodeling and expansion of Haversian canals, which occasionally merge with endosteal and periosteal resorption bays, thus leading to rapid cortical thinning and cortical weakening. The recent emergence of CT systems with submicrometer resolution provides novel information on the age-related decrease in osteocyte lacunar density and related micropetrosis, the result of lacunar hypermineralization. Last but not least, the use of the submicrometer CT systems confirmed the occurrence of microcracks in the skeletal mineralized matrix and vastly advanced their morphologic characterization and mode of initiation and propagation. PMID:21901426

  1. Canalicular network morphology is the major determinant of the spatial distribution of mass density in human bone tissue: evidence by means of synchrotron radiation phase-contrast nano-CT.

    Hesse, Bernhard; Varga, Peter; Langer, Max; Pacureanu, Alexandra; Schrof, Susanne; Männicke, Nils; Suhonen, Heikki; Maurer, Peter; Cloetens, Peter; Peyrin, Francoise; Raum, Kay

    2015-02-01

    In bone remodeling, maturation of the newly formed osteonal tissue is associated with a rapid primary increase followed by a slower secondary increase of mineralization. This requires supply and precipitation of mineral into the bone matrix. Mineral delivery can occur only from the extracellular fluid via interfaces such as the Haversian system and the osteocyte pore network. We hypothesized that in mineralization, mineral exchange is achieved by the diffusion of mineral from the lacunar-canalicular network (LCN) to the bone matrix, resulting in a gradual change in tissue mineralization with respect to the distance from the pore-matrix interface. We expected to observe alterations in the mass density distribution with tissue age. We further hypothesized that mineral exchange occurs not only at the lacunar but also at the canalicular boundaries. The aim of this study was, therefore, to investigate the spatial distribution of mass density in the perilacunar and pericanalicular bone matrix and to explore how these densities are influenced by tissue aging. This is achieved by analyzing human jawbone specimens originating from four healthy donors and four treated with high-dosage bisphosphonate using synchrotron radiation phase-contrast nano-CT with a 50-nm voxel size. Our results provide the first experimental evidence that mass density in the direct vicinity of both lacunae (p < 0.001) and canaliculi (p < 0.001) is different from the mean matrix mass density, resulting in gradients with respect to the distance from both pore-matrix interfaces, which diminish with increasing tissue age. Though limited by the sample size, these findings support our hypotheses. Moreover, the density gradients are more pronounced around the lacunae than around the canaliculi, which are explained by geometrical considerations in the LCN morphology. In addition, we speculate that mineral exchange occurs at all interfaces of the LCN, not only in mineralization but also in mineral

  2. The Effects of Stroke Type, Locus, and Extent on Long-Term Outcome of Gait Rehabilitation: The LEAPS Experience.

    Nadeau, Stephen E; Dobkin, Bruce; Wu, Samuel S; Pei, Qinglin; Duncan, Pamela W

    2016-08-01

    Background Paresis in stroke is largely a result of damage to descending corticospinal and corticobulbar pathways. Recovery of paresis predominantly reflects the impact on the neural consequences of this white matter lesion by reactive neuroplasticity (mechanisms involved in spontaneous recovery) and experience-dependent neuroplasticity, driven by therapy and daily experience. However, both theoretical considerations and empirical data suggest that type of stroke (large vessel distribution/lacunar infarction, hemorrhage), locus and extent of infarction (basal ganglia, right-hemisphere cerebral cortex), and the presence of leukoaraiosis or prior stroke might influence long-term recovery of walking ability. In this secondary analysis based on the 408 participants in the Locomotor Experience Applied Post-Stroke (LEAPS) study database, we seek to address these possibilities. Methods Lesion type, locus, and extent were characterized by the 2 neurologists in the LEAPS trial on the basis of clinical computed tomography and magnetic resonance imaging scans. A series of regression models was used to test our hypotheses regarding the effects of lesion type, locus, extent, and laterality on 2- to 12-month change in gait speed, controlling for baseline gait speed, age, and Berg Balance Scale score. Results Gait speed change at 1 year was significantly reduced in participants with basal ganglia involvement and prior stroke. There was a trend toward reduction of gait speed change in participants with lacunar infarctions. The presence of right-hemisphere cortical involvement had no significant impact on outcome. Conclusions Type, locus, and extent of lesion, and the loss of substrate for neuroplastic effect as a result of prior stroke may affect long-term outcome of rehabilitation of hemiparetic gait. PMID:26498434

  3. Changes to the cell, tissue and architecture levels in cranial suture synostosis reveal a problem of timing in bone development

    J Regelsberger

    2012-11-01

    Full Text Available Premature fusion of cranial sutures is a common problem with an incidence of 3-5 per 10,000 live births. Despite progress in understanding molecular/genetic factors affecting suture function, the complex process of premature fusion is still poorly understood. In the present study, corresponding excised segments of nine patent and nine prematurely fused sagittal sutures from infants (age range 3-7 months with a special emphasis on their hierarchical structural configuration were compared. Cell, tissue and architecture characteristics were analysed by transmitted and polarised light microscopy, 2D-histomorphometry, backscattered electron microscopy and energy-dispersive-x-ray analyses. Apart from wider sutural gaps, patent sutures showed histologically increased new bone formation compared to reduced new bone formation and osseous edges with a more mature structure in the fused portions of the sutures. This pattern was accompanied by a lower osteocyte lacunar density and a higher number of evenly mineralised osteons, reflecting pronounced lamellar bone characteristics along the prematurely fused sutures. In contrast, increases in osteocyte lacunar number and size accompanied by mineralisation heterogeneity and randomly oriented collagen fibres predominantly signified woven bone characteristics in patent, still growing suture segments. The already established woven-to-lamellar bone transition provides evidence of advanced bone development in synostotic sutures. Since structural and compositional features of prematurely fused sutures did not show signs of pathological/defective ossification processes, this supports the theory of a normal ossification process in suture synostosis – just locally commencing too early. These histomorphological findings may provide the basis for a better understanding of the pathomechanism of craniosynostosis, and for future strategies to predict suture fusion and to determine surgical intervention.

  4. Diversity and abundance of invertebrate epifaunal assemblages associated with gorgonians are driven by colony attributes

    Curdia, Joao

    2015-03-20

    The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple regression analysis, we tested the contribution of several attributes (colony height, width, and area, fractal dimension as a measure of colony complexity, lacunarity as a measure of the heterogeneity, and “colonial” epibiont cover) to abundance and taxonomic richness of associated assemblages. The results highlight the variation in the response of epifaunal assemblages to the gorgonian colony characteristics. The nature and intensity of the relationships were gorgonian species-dependent and varied from one taxonomic group to another. For both gorgonian species analyzed, the strongest predictor of species richness and abundance of the epifaunal assemblages was “colonial” epibiont cover, possibly due to a trophic effect (direct or indirect enhancement of food availability) combined with the surface available for colonization (species–area effect). Although structural complexity is usually indicated as the main driver for rich and abundant coral-associated assemblages, no significant relationship was observed between fractal dimension and the community descriptors; lacunarity, which reflects the sizes of the inter-branch spaces, was only linked to taxonomic richness in the assemblages associated with Leptogorgia lusitanica. The validity of the paradigm that structural complexity enhances biodiversity may be scale-dependent. In the case of gorgonians, the effect of complexity at the “garden” level may be more relevant than at the individual colony level. This reinforces the need for the conservation of gorgonian aggregation areas as a whole in order to preserve host diversity and size structure. © 2015 Springer-Verlag Berlin Heidelberg

  5. Analysis on risk factors of short-term poor outcome among different subtypes of acute cerebral infarction

    Objective: to investigate the risk factors of short-term poor outcome among patients suffering from acute cerebral infarction who had different subtypes of cerebral infarction. Methods: A total of 3231 acute cerebral infarction patients were included in the present study. Data on demographic characteristics, life style, risk factors, history of cardiovascular disease, admission blood pressure, and clinical outcome at discharge were collected for all participants. Poor outcome was defined as NIHSS ≥10 at discharge or death occurring during hospitalization. The association between poor outcome of cerebral infarction and risk factors was analyzed by using multiple logistic models. Results: Incidence rate of poor outcome is the highest in the patients with cerebral embolism, next in patients with cerebral thrombosis and the lowest in patients with lacunar infarction. Cerebral thrombosis was positively associated with smoking (OR: 1.228; 95% CI: 1.013∼1.637), dyslipidemia (OR: 1.264; 95% CI: 1.081∼1.478), and a history of diabetes mellitus (OR: 1.371; 95% CI: 1.075∼1.747); cerebral embolism was positively associated with a history of atrial fibrillation (OR: 3.131; 95% CI: 1.206∼8.128) and a history of rheumatic heart disease (OR: 5.601; 95% CI: 1.561∼20.091); lacunar infarction is positively associated with alcohol consumption, (OR: 1.428; 95% CI: 1.063∼1.919). Conclusion: The incidence rate of poor outcome is the highest in the patients with cerebral embolism among three subtypes of cerebral infarction, there are different risk factors of poor outcome for three subtypes of cerebral infarction. (authors)

  6. Soil washing treatability study

    Krstich, M.

    1995-12-01

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS.

  7. Acid Rain Study Guide.

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  8. Solid waste study

    The purpose of this document is to study the solid waste issues brought about by a Type C Investigation; ''Disposal of Inappropriate Material in the Los Alamos County Landfill'' (May 28, 1993). The study was completed in August 1995 by Coleman Research Corporation, under subcontract number 405810005-Y for Los Alamos National Laboratory (LANL). The study confirmed the issues identified in the Type C investigation, and also ascertained further issues or problems. During the course of this study two incidents involving hazardous waste resulted in the inappropriate disposal of the waste. An accidental spill, on June 8, 1995, at one of Laboratory buildings was not handled correctly, and ended up in the LAC Landfill. Hazardous waste was disposed of in a solid waste container and sent to the Los Alamos County Landfill. An attempt to locate the hazardous waste at the LAC Landfill was not successful. The second incident involving hazardous waste was discovered by the FSS-8, during a random dumpster surveillance. An interim dumpster program managed by FSS-8 discovered hazardous waste and copper chips in the solid waste, on August 9, 1995. The hazardous waste and copper chips would have been transported to the LAC Landfill if the audit team had not brought the problem to the awareness of the facility waste management personnel

  9. Accelerator research studies

    1993-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks.

  10. Fusion energy studies

    The following topics are considered: (1) cryosorption vacuum pumping for fusion reactors, (2) TNS support studies, (3) tritium recovery from irradiated Li-Al and SAP, (4) actinide oxides, nitrides, and carbides, and (5) transition metal-actinide-C phase equilibria

  11. Nuclear fuel cycle studies

    For the metal-matrix encapsulation of radioactive waste, brittle-fracture, leach-rate, and migration studies are being conducted. For fuel reprocessing, annular and centrifugal contactors are being tested and modeled. For the LWBR proof-of-breeding project, the full-scale shear and the prototype dissolver were procured and tested. 5 figures

  12. Steam explosion studies review

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  13. Eastern Frequency Response Study

    Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

    2013-05-01

    This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

  14. Rockwell support studies

    Studies performed for the Rockwell Hanford Operations (RHO) were designed to either identify the role of biota in the uptake and transport of radionuclides from low-level waste management areas or design and/or evaluate methods for reducing biological transport of radionuclides away from waste management areas

  15. NGLW RCRA Storage Study

    The Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory contains radioactive liquid waste in underground storage tanks at the INTEC Tank Farm Facility (TFF). INTEC is currently treating the waste by evaporation to reduce the liquid volume for continued storage, and by calcination to reduce and convert the liquid to a dry waste form for long-term storage in calcine bins. Both treatment methods and activities in support of those treatment operations result in Newly Generated Liquid Waste (NGLW) being sent to TFF. The storage tanks in the TFF are underground, contained in concrete vaults with instrumentation, piping, transfer jets, and managed sumps in case of any liquid accumulation in the vault. The configuration of these tanks is such that Resource Conservation and Recovery Act (RCRA) regulations apply. The TFF tanks were assessed several years ago with respect to the RCRA regulations and they were found to be deficient. This study considers the configuration of the current tanks and the RCRA deficiencies identified for each. The study identifies four potential methods and proposes a means of correcting the deficiencies. The cost estimates included in the study account for construction cost; construction methods to minimize work exposure to chemical hazards, radioactive contamination, and ionizing radiation hazards; project logistics; and project schedule. The study also estimates the tank volumes benefit associated with each corrective action to support TFF liquid waste management planning

  16. A Study in Frusteration

    Hou Weili

    2012-01-01

    FOR the past few months. Du Wenhu, a consultant working in a vocational training center in Beijing, has been vexed by a problem that he can't solve. Du wonders whether he should send his daughter back to his hometown in east China's Shandong Province to attend high school there on her own, or let her continue her study in Beijing.

  17. Why Study Classical Languages?

    Lieberman, Samuel

    This speech emphasizes the significance of living literatures and living cultures which owe a direct debt to the Romans and the Greeks from whom they can trace their origins. After commenting on typical rejoinders to the question "Why study classical languages?" and poking fun at those who advance jaded, esoteric responses, the author dispels the…

  18. Digital communications study

    Boorstyn, R. R.

    1973-01-01

    Research is reported dealing with problems of digital data transmission and computer communications networks. The results of four individual studies are presented which include: (1) signal processing with finite state machines, (2) signal parameter estimation from discrete-time observations, (3) digital filtering for radar signal processing applications, and (4) multiple server queues where all servers are not identical.

  19. Shuttle Communications Blackout Study

    Haben, R. L.; Budica, R. J.

    1983-01-01

    Space Shuttle Orbiter Entry Communications Blackout Study computer program models, investigates, and predicts communication blackout envelopes based on mission entry trajectory and associated data from tracking stations. Of interest to those designing and using communications systems susceptible to blackout. Program is readily adapted to predict entry communications blackout for any nonablative entry vehicle.

  20. Repository seals requirements study

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing

  1. Soil washing treatability study

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS

  2. Innovation and Entrepreneurship Studies

    Landström, Hans; Åström, Fredrik; Harirchi, Gouya

    2015-01-01

    innovation research. The study shows that we are talking about two more or less separate fields of research. Despite common roots in Schumpeter and some interrelated works, the two fields seem to have drifted apart over the last decades. However, there seems to be some elements of overlaps, for example, in...

  3. Nesidioblastosis: a case study.

    Starbuck, A L

    1997-09-01

    Hypoglycemia is a common problem among neonates. Transient in nature, it usually resolves with an increase in glucose intake. However, as clinicians, we must recognize that prolonged hypoglycemia may be caused by increased insulin production. Nesidioblastosis is one cause of persistent hyperinsulinism of the newborn. This case study reviews fetal physiology, neonatal presentation, and treatment. PMID:9325879

  4. Study on clearance system

    The clearance system is a legal word to define as 'the waste not requiring treatment as radioactive waste' on the regulatory control. JNES supports NISA on the approval and the confirmation of clearance measurement by the operator. The objective of this study is to establish technical base of the validation method of the clearance measurement for various objects. In reactor facilities, the statistical sampling measurement technique may be applied to large scale objects. In this study, the criteria of the techniques were examined, and the strategy for setting of radioactivity concentration evaluation level was prepared. In uranium processing facilities, simulation sources to apply to a validity confirmation examination of the measuring equipment were made, and these applicability and problem were studied. The method of the validity evaluation of the performance confirmation of the measuring equipment was devised by measurement experiment using this source. The manual for unexpected incidents which maintained in FY2011 was reviced by reflection of the experience of the radioactivity concentration measurement of disaster waste contaminated by the accident of Fukushima Dai-ichi NPS. JNES also supports NISA technically for the issue on influence of fall out from Fukushima Dai-ichi NPS on clearance system and NR system. In addition, the latest situation of a clearance system operated in Europe was studied. (author)

  5. Studying Aid: Some Methods

    D.R. Gasper (Des)

    2003-01-01

    textabstractINVESTIGATING IDEAS, IDEOLOGIES AND PRACTICES This paper presents some methods for trying to make sense of international aid and of its study.1 Some of the methods may be deemed ethnographic; the others are important partners to them, but rather different. In the course of discussing q

  6. Social Studies: Grade 8.

    Manitoba Dept. of Education, Winnipeg.

    This Manitoba (Canada) curriculum guide for eighth grade social studies students contains suggested teaching strategies and learning activities in four units covering: (1) life during prehistoric and early historic times; (2) ancient civilizations; (3) life in early modern Europe; and (4) life in the modern world. Each unit includes an overview,…

  7. Why Indigenous Nations Studies?

    Porter, Robert; Yellow Bird, Michael

    2000-01-01

    The development of a new Indigenous Nations Studies program at the University of Kansas is described. Success depended on a critical mass of Indigenous and non-Indigenous faculty and students that had a sense of political and social justice and understood the need for institutional change. The biggest challenge was countering the entrenched…

  8. Studying Variation in Tunes

    Janssen, B.; van Kranenburg, P.

    2014-01-01

    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  9. : Case studies: France

    Bonerandi, Emmanuelle; Santamaria, Frédéric

    2005-01-01

    Case studies on territorial governance : urban region of Lyon (France) and the "Pays" policy (France) in the framework of the ESPON 2.3.2 project Études de cas sur la gouvernance territoriale : région urbaine de Lyon et politique des pays

  10. COPEWORK - COPESTRESS Workplace Study

    Ladegaard, Yun Katrine; Netterstrøm, Bo; Langer, Roy

    2012-01-01

    "COPEWORK – COPESTRESS Workplace Study" er en undersøgelse af hvad der sker på arbejdspladser, når en medarbejder sygemeldes med stress. I undersøgelsen indgik 64 ledere og arbejdsmiljørepræsentanter fra fra 38 danske arbejdspladser. Alle arbejdspladser havde haft minimum én stresssygemeldt...

  11. Resources for Women's Studies.

    Ridinger, Robert B.

    Over 120 bibliographies and other reference sources relevant to women's studies are identified in this annotated listing. Subjects include feminist scholarship, women in management, popular culture, autobiographies, other cultures and countries, history, lesbian women, women's education, the arts, politics, and rape. In addition to author, title,…

  12. Environmental Modification: A Study

    Grinnell, Richard M., Jr.; Kyte, Nancy S.

    1975-01-01

    This study shows that environmental modification is a surprisingly intricate technique. This may account for its relatively low use and also for its more frequent use by MSW than non-MSW caseworkers. The findings indicate the need for further research on environmental modification. (Author)

  13. Steam explosion studies review

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  14. Designing satisfaction studies

    Kristensen, Kai; Eskildsen, Jacob Kjær

    In the effect sampling method, presentation of researcher, the intro text, the order of questions in the questionnaire along with the number of categories in the rating scale is tested in relation to the design of satisfaction studies. Based on the analyses specific recommendations for designing...

  15. Studying Ancient History.

    Barrow, Robin

    1982-01-01

    Defends the value and relevance of the study of ancient history and classics in history curricula. The unique homogeneity of the classical period contributes to its instructional manageability. A year-long, secondary-level course on fifth-century Greece and Rome is described to illustrate effective approaches to teaching ancient history. (AM)

  16. Repository seals requirements study

    NONE

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. This report presents the results of a repository sealing requirements study. Sealing is defined as the permanent closure of the shafts, ramps, and exploratory boreholes. Sealing includes those components that would reduce potential inflows above the repository, or that would divert flow near the repository horizon to allow vertical infiltration to below the repository. Sealing of such features as emplacement drifts was not done in this study because the current capability to calculate fracture flow into the drifts is not sufficiently mature. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  17. SOFC interface studies

    Jacobsen, Torben; Bay, Lasse; West, Keld;

    performance and inductive hysteresis phenomena often observed in SOFC kinetic studies (\\ref{TJ01}). Fig.\\,\\ref{cath_laser} shows the YSZ surface developed below a Pt point electrode polarised at -0.10\\, V at $1000^\\circ$C for a period of 85 days. The structural as well as the compositional changes in this and...

  18. Rockwell support studies

    Studies performed for the Rockwell Hanford Operations (RHO) were designed to either (1) identify the role of biota in the uptake and transport of radionuclides from low-level waste managemnt areas or (2) design and/or evaluate methods for reducing biological transport of radionuclides away from waste management areas. The completion and publication of documents reporting the results of previous studies was also emphasized this fiscal year. Field studies were designed to characterize insect and plant communities occupying low-level waste management areas and to evaluate pond ecosystem response to herbicide application. Laboratory studies involved the examination of (1) germination response in plant species proposed for surface stabilization on burial grounds, (2) a synthetic polymer matrix as a carrier and delivery system for phytotoxins to act as a barrier to plant root penetration of shallow-land low-level waste burial sites, and (3) factors responsible for differences in radionuclide availability to plants resulting from the chemical equilibration of radionuclides occurring under field conditions

  19. Plant Study Guide.

    Brynildson, Inga

    Appropriate for secondary school botany instruction, this study guide focuses on the important roles of plants in human lives. Following a rationale for learning the basic skills of a botanist, separate sections discuss the process sunlight undergoes during photosynthesis, the flow of energy in the food chain, alternative plant lifestyles, plant…

  20. Female Studies: No. 1.

    Tobias, Sheila

    This document presents an anthology of syllabi of courses taught or proposed during 1969-70 in the field of Womens Studies. The courses originated in a variety of manners. In some colleges, students pressed for courses based on the insights and challenges of women's liberation material. In other institutions, faculty offered interdisciplinary…

  1. Everglades Environmental Study Units.

    Florida State Dept. of Education, Tallahassee. Office of Environment Education.

    These environmental study units consist of four modules and a tape-slide presentation on the Everglades National Park. Although not required for completion of the modules, the slide-tape presentation provides a resource for orientation of teachers and parents to camping experience for school children in an environmental education program. The four…

  2. HIM Correlational Study

    Powell, Evan R.

    1977-01-01

    This study uses two methods of analysis to examine the degree to which items within the cells of the Hill Interaction Matrix correlate. It is found that the table of specifications does not hold up. But the author recommends caution in interpreting this finding. (Author/BP)

  3. Ethiopia : Regionalization Study

    World Bank

    2000-01-01

    The study outlines the development strategy Ethiopia will need to pursue to achieve a balanced regional progress, and indicates some policy areas for attention, as the strategy develops. It examines the recent constitutional structure, government spending, and fiscal imbalances, including the capacity constraints the country faces, and governance issues. In addition, the role of municipali...

  4. WELL PURGING STUDY

    Purging of wells with bailers has been a standard practice in the underground storage tank program as well as other groundwater regulatory programs for many years. Several studies in the Northeast and the West have shown that, under certain circumstances, samples collected witho...

  5. Translator Studies in Retrospect

    郭勤

    2009-01-01

    The concern about translator has run for thousands of years on which many translators and translation scholars have made comments.A rough examination of the translator within translation studies at home and abroad is expounded in a loosely chronological way as follows.

  6. NGLW RCRA Storage Study

    R. J. Waters; R. Ochoa; K. D. Fritz; D. W. Craig

    2000-06-01

    The Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory contains radioactive liquid waste in underground storage tanks at the INTEC Tank Farm Facility (TFF). INTEC is currently treating the waste by evaporation to reduce the liquid volume for continued storage, and by calcination to reduce and convert the liquid to a dry waste form for long-term storage in calcine bins. Both treatment methods and activities in support of those treatment operations result in Newly Generated Liquid Waste (NGLW) being sent to TFF. The storage tanks in the TFF are underground, contained in concrete vaults with instrumentation, piping, transfer jets, and managed sumps in case of any liquid accumulation in the vault. The configuration of these tanks is such that Resource Conservation and Recovery Act (RCRA) regulations apply. The TFF tanks were assessed several years ago with respect to the RCRA regulations and they were found to be deficient. This study considers the configuration of the current tanks and the RCRA deficiencies identified for each. The study identifies four potential methods and proposes a means of correcting the deficiencies. The cost estimates included in the study account for construction cost; construction methods to minimize work exposure to chemical hazards, radioactive contamination, and ionizing radiation hazards; project logistics; and project schedule. The study also estimates the tank volumes benefit associated with each corrective action to support TFF liquid waste management planning.

  7. ADVANCED CUTTINGS TRANSPORT STUDY

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  8. ADVANCED CUTTINGS TRANSPORT STUDY

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira

    2000-10-30

    This is the first quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between July 14, 2000 and September 30, 2000. This report presents information on the following specific tasks: (a) Progress in Advanced Cuttings Transport Facility design and development (Task 2), (b) Progress on research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress on research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress on research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress on research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Initiate research on project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Progress on instrumentation tasks to measure: Cuttings concentration and distribution (Tasks 11), and Foam properties (Task 12), (h) Initiate a comprehensive safety review of all flow-loop components and operational procedures. Since the previous Task 1 has been completed, we will now designate this new task as: (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  9. Photovoltaic evaluation study

    Johnson, G.; Heikkilae, M.; Melasuo, T.; Spanner, S.

    Realizing the value and potential of PV-power as well as the growing need for increased cooperation and sharing of knowledge in the field of photovoltaics, FINNIDA and UNICEF decided to undertake a study of selected PV-projects. There were two main objectives for the study: To gather, compile, evaluate and share information on the photovoltaic technology appropriate to developing countries, and to promote the interest and competence of Finnish research institutes, consultants and manufacturers in photovoltaic development. For this purpose a joint evaluation of significant, primarily UN-supported projects providing for the basic needs of rural communities was undertaken. The Gambia and Kenya offered a variety of such projects, and were chosen as target countries for the study. The projects were chosen to be both comparable and complimentary. In the Gambia, the main subject was a partially integrated health and telecommunications project, but a long-operating drinking water pumping system was also studied. In Kenya, a health project in the Turkana area was examined, and also a large scale water pumping installation for fish farming. Field visits were made in order to verify and supplement the data gathered through document research and earlier investigations. Individual data gathering sheets for the project form the core of this study and are intended to give the necessary information in an organized and accessible format. The findings could practically be condensed into one sentence: PV-systems work very well, if properly designed and installed, but the resources and requirements of the recipients must be considered to a higher degree.

  10. Tire footprint studies

    Chawla, Mangal; Medzorian, John

    1995-08-01

    This presentation covers the results of tire footprint studies conducted in the Landing Gear Development Facility of the USAF Wright Laboratory at the Wright Patterson Air force Base, OH. Tire footprint studies are essential in understanding tire wear mechanisms and computing tire tread wear rates. The power input into the tread is the driving force for tread wear. Variables needed for power input calculations include the footprint pressure and slip velocity distributions. Studies were performed on the effects of power input distributions due to vertical load, camber, yaw, inflation pressure, and tire construction. For the present study, two tire constructions, one radial and the other bias, were selected. These tires were for the F-16 Block 30 fighter aircraft, both of which were previously worn. The present study was limited to steady straight roll with a 14,000 lb vertical load, a 310 psi inflation pressure, and zero yaw and camber. All tests were conducted on the Tire Force Machine (TFM) with a specialized sensor plate with embedded pressure sensors (X, Y, and Z) and slip sensors (X and Y). All tests were conducted for a table speed of 1 in/s. Tests on the TFM show that the power intensity distributions and total power for both tire constructions are quite similar for straight roll. Later on, tests were also conducted on a modified dynamometer which was overlaid with a grit wear surface. The tire speed was maintained at 40 miles per hour and yaw was set to four degrees. Dynamometer tests showed that radial tires have more tread wear than the bias tire; however, in the field, radial tires have longer life.

  11. Children and Clinical Studies: Why Clinical Studies Are Important

    Full Text Available ... Children & Clinical Studies NHLBI Trials Clinical Trial Websites Children and Clinical Studies Learn more about Children and Clinical Studies Importance of Children in Clinical Studies Children have often had to ...

  12. Radiation studies in Canada

    Public demand to know the delayed risks associated with various working and living environments has led private industry, the health and research communities, labour unions, and government to intensify their efforts to obtain quantitative human data. For example, the long-term health effects of radiation, pesticides and sprays, asbestos, glass fiber and chemicals are of interest. These studies seek to relate prior exposure or circumstances in the lives of people to subsequent harm such as deaths from various causes or cancer among those who are living. Specific files and studies are described and used to illustrate how this information is extremely important in assessing and controlling workplace hazards, for labour negotiations and relations, for the setting of regulatory standards for substances, for developing compensation criteria, and for the evaluation of the efficiency of preventive, control and treatment measures for improving the quality of health care for Canadians

  13. E85 Dispenser Study

    Moriarty, K.; Johnson, C.; Sears, T.; Bergeron, P.

    2009-12-01

    This study reviews E85 dispensing infrastructure advances and issues and evaluates the geographic concentration of flexible fuel vehicles (FFVs), E85 stations, ethanol production facilities, and E85 suppliers. Costs, space, financial incentives, and barriers to adding E85 fueling equipment at existing stations are also assessed. This study found that E85 is increasingly available in the U.S. in half of the states; however, the other half have minimal or no E85 fueling options. Despite these gains, E85 is only available at 1% of U.S. gasoline stations. Ethanol production reached 9.5 billion gallons in 2008, but less than 1% is consumed as E85. FFVs have not reached a significant concentration in any county, metropolitan area, or state.

  14. Studying bacterial multispecies biofilms

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the...... benefits and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial...

  15. The New Modernist Studies

    Douglas Mao

    2014-01-01

    Full Text Available The main task of this article is to describe the new situation of modernist studies at the turn of the 20th century and an attempt to position this description in a broader history of criticism of modernism in art. The transformations in the studies into modernist literature have been characterized here in three aspects: expanding the time frame (going beyond the basic period of modernism from the end of the 19th c. until 1930s, spatial dimension (abandonment of a privileged position of research into West European and American modernism in favour of a transnational perspective and vertical dimension (connected with the necessity to rethink the relationship high art-low art, and also the influence of mass media upon modernist literature.

  16. Remote connector development study

    Plutonium-uranium extraction (PUREX) connectors, the most common connectors used at the Hanford site, offer a certain level of flexibility in pipe routing, process system configuration, and remote equipment/instrument replacement. However, these desirable features have inherent shortcomings like leakage, high pressure drop through the right angle bends, and a limited range of available pipe diameters that can be connect by them. Costs for construction, maintenance, and operation of PUREX connectors seem to be very high. The PUREX connector designs include a 90 degree bend in each connector. This increases the pressure drop and erosion effects. Thus, each jumper requires at least two 90 degree bends. PUREX connectors have not been practically used beyond 100 (4 in.) inner diameter. This study represents the results of a survey on the use of remote pipe-connection systems in US and foreign plants. This study also describes the interdependence between connectors, remote handling equipment, and the necessary skills of the operators

  17. Studies on Aspergillus flavus

    In vitro studies were conducted on conidia of Aspergillus flavus Link (aflatoxin producing) and Aspergillus flavus oryzae (non-toxigenic) strains isolated and identified in this laboratory. These strains differed in resistance to heat and gamma radiation, the toxigenic strain being more resistant to both treatments. Results of tests on dose-modifying factors indicated that composition, temperature and pH of suspending media affected radiation resistance. On the other hand, the size of the initial population and the age of the conidia did not influence the radiation resistance of either strain. Studies on thermal inactivation of the conidia suggested that the temperature employed was more important than the time of heat treatment. Conidia of both strains showed a synergistic effect of combined heat and radiation treatments, although a heat-radiation sequence was more effective than a radiation-heat sequence. (author)

  18. Confinement studies on ASDEX

    This report deals with investigations of plasma confinement carried out on the ASDEX divertor tokamak. It is comprised of two sections: The first section deals with the study of the condinement degradation in auxiliary heated sicharges; in the second section a regime will be described where the severe deterioration of the confinement quality at high heating power is avoided. This regime is called the H-mode because of the high confinement characteristics in contrast to the low confinement L-mode. There is evidence that the L-mode characteristics will not lead to sufficient confinement quality for successful plasma burning. The H-mode was observed for the first time on ASDEX. At present it is considered as the confinement regime with the best prospects for future tokamak operation. But both the study of L- and H-mode confinement physics have increased our understanding on energy transport in tokamaks. (orig./GG)

  19. NASA study grants

    To expand human exploration of the Solar System, the Office of Exploration of the National Aeronautics and Space Administration has awarded 20 contracts for ideas, concepts, devices, systems, and trajectory, operation and implementation plans. Winning proposals came from five industry-related firms, two organizations in the space-support business, and thirteen universities; they were chosen from 115 entries.Geophysical studies to be supported include site characterization of the Oregon moonbase (Oregon L-5 Society, Inc., Oregon City), evolution of design alternatives for exploration of Mars by balloon (Titan Systems, Inc., San Diego, Calif.), design considerations of a lunar production plant (Boston University, Chestnut Hill, Mass.), planetary materials and resource utilization (Michigan Technological University, Houghton), Mars tethered sample return study (University of Colorado, Boulder), Teleprospector, a teleoperated robotic field geologist (University of New Mexico, Albuquerque), and the International Lunar Polar Orbiter (International Space University, Boston, Mass.).

  20. Options Study - Phase II

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  1. Studying bilingual students’ literacy

    Laursen, Helle Pia

    2012-01-01

    contribute to lift the basic understanding of bilinguals’ literacy out of a disqualifying political discourse. Drawing on the ongoing study Sign of Language (Laursen, 2011), I reflect on how a social semiotic framework might help open new research perspectives on bilingual children’s literacy acquisition by...... recognizing as well the child's agency and the micro-stories embedded in the creation of signs as the discursive macro-stories surrounding the meaning making processes. The longitudinal study Signs of Language (2008-2014) involves five multilingual classrooms and aims at getting insight into the children......’s complex uses of the linguistic and semiotic resources available to them by paying close attention to the perspective of the children - as users and interpreters of literacy. Methodologically we adopt an ethnographic approach which also leads us to focus attention to the local use of sociolinguistic and...

  2. Fra studie til arbejdsliv

    Andersen, Line Palle

    2015-01-01

    Universitet (2009) som den første beskæftiget sig med udfordringerne ved overgangen fra studie til arbejdsliv. Undertegnede har i samarbejde med PhD-studerende Helle Bach Riis udført 25 kvalitative interviews blandt danske akademikere, der har været på arbejdsmarkedet ml ½-5 år. Vores undersøgelser bekræfter...... indenfor sit eget felt. Efter 3-4 år på arbejdsmarkedet er ens viden fra uddannelsen bearbejdet og integreret og en naturlig basis ved løsning af arbejdsopgaver. Både uddannelser, aftagerfeltet og kandidaten kan gøre en aktiv indsats, der gør overgangen fra studie til arbejdsliv nemmere. For uddannelsernes...

  3. Remote connector development study

    Parazin, R.J.

    1995-05-01

    Plutonium-uranium extraction (PUREX) connectors, the most common connectors used at the Hanford site, offer a certain level of flexibility in pipe routing, process system configuration, and remote equipment/instrument replacement. However, these desirable features have inherent shortcomings like leakage, high pressure drop through the right angle bends, and a limited range of available pipe diameters that can be connect by them. Costs for construction, maintenance, and operation of PUREX connectors seem to be very high. The PUREX connector designs include a 90{degree} bend in each connector. This increases the pressure drop and erosion effects. Thus, each jumper requires at least two 90{degree} bends. PUREX connectors have not been practically used beyond 100 (4 in.) inner diameter. This study represents the results of a survey on the use of remote pipe-connection systems in US and foreign plants. This study also describes the interdependence between connectors, remote handling equipment, and the necessary skills of the operators.

  4. World Biofuels Study

    Alfstad,T.

    2008-10-01

    This report forms part of a project entitled 'World Biofuels Study'. The objective is to study world biofuel markets and to examine the possible contribution that biofuel imports could make to help meet the Renewable Fuel Standard (RFS) of the Energy Independence and Security Act of 2007 (EISA). The study was sponsored by the Biomass Program of the Assistant Secretary for Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy. It is a collaborative effort among the Office of Policy and International Affairs (PI), Department of Energy and Oak Ridge National Laboratory (ORNL), National Renewable Energy Laboratory (NREL) and Brookhaven National Laboratory (BNL). The project consisted of three main components: (1) Assessment of the resource potential for biofuel feedstocks such as sugarcane, grains, soybean, palm oil and lignocellulosic crops and development of supply curves (ORNL). (2) Assessment of the cost and performance of biofuel production technologies (NREL). (3) Scenario-based analysis of world biofuel markets using the ETP global energy model with data developed in the first parts of the study (BNL). This report covers the modeling and analysis part of the project conducted by BNL in cooperation with PI. The Energy Technology Perspectives (ETP) energy system model was used as the analytical tool for this study. ETP is a 15 region global model designed using the MARKAL framework. MARKAL-based models are partial equilibrium models that incorporate a description of the physical energy system and provide a bottom-up approach to study the entire energy system. ETP was updated for this study with biomass resource data and biofuel production technology cost and performance data developed by ORNL and NREL under Tasks 1 and 2 of this project. Many countries around the world are embarking on ambitious biofuel policies through renewable fuel standards and economic incentives. As a result, the global biofuel demand is expected to grow very

  5. Objectivist case study research

    Ridder, Hanne Mette Ochsner; Fachner, Jörg

    2016-01-01

    In order to comprehend the impact of music therapy or music therapy processes, a researcher might look for an approach where the topic under investigation can be understood within a broader context. This calls for a rich inclusion of data and consequently a limited number of participants and may be...... achieved through the use of objectivist case study research. The strength of the case study design is that it allows for uncovering or suggesting causal relationships in real-life settings through an intensive and rich collection of data. According to Hilliard (1993), the opposite applies for extensive...... designs, in which a small amount of data is gathered on a large number of subjects. With the richness of data, the intensive design is ―the primary pragmatic reason for engaging in single-case or small N research‖ (p. 374) and for working from an idiographic rather than a nomothetic perspective....

  6. Botswana country study

    1999-09-01

    This study was carried out in Botswana, Tanzania and Zambia as part of the project `Climate Change Mitigation in Southern Africa` funded by the Danish International Development Agency (Danida). The project was conducted parallel to the UNEP/GEF project `Economics of Greenhouse Gas Limitations` which involved 8 other developing countries and 2 regional projects in Latin America and the SADC region. The limitation of greenhouse gas (GHG) emissions is a complex issue, intimately connected with economic development at local, national, regional and global levels. Key economic sectors such as energy, agriculture, industry and forestry all produce GHGs, and are likely to be affected directly and indirectly by any mitigation policy. The UNEP Greenhouse Gas Abatement Costing Studies, initiated in 1991, attempted to address these complex issues, developing a methodological framework and testing it through practical application in ten countries. (EHS) 28 refs.

  7. Studies on provoked asthma

    A group of adult patients with perennial bronchial asthma has been studied as to lung perfusion and alveolar ventilation (81m-Kr) at rest and after provocation of an acute attack. Asthma was provoked by exercise and by histamine inhalation. After provocation the peak expiratory flow values were reduced to less than 80% of the base line values. Perfusion was often deranged. Regional ventilation changed rapidly after provocation and not always in the same fashion after exercise and histamine. During attacks lung volume increased. The expansion decreased (in parallel with increased peak expiratory flow) after inhalator of a #betta#-2 agonist (terbutaline). 81m-Kr offers unique opportunities for studying acute regional changes in alveolar ventilation. (Author)

  8. Heliostat cost optimization study

    von Reeken, Finn; Weinrebe, Gerhard; Keck, Thomas; Balz, Markus

    2016-05-01

    This paper presents a methodology for a heliostat cost optimization study. First different variants of small, medium sized and large heliostats are designed. Then the respective costs, tracking and optical quality are determined. For the calculation of optical quality a structural model of the heliostat is programmed and analyzed using finite element software. The costs are determined based on inquiries and from experience with similar structures. Eventually the levelised electricity costs for a reference power tower plant are calculated. Before each annual simulation run the heliostat field is optimized. Calculated LCOEs are then used to identify the most suitable option(s). Finally, the conclusions and findings of this extensive cost study are used to define the concept of a new cost-efficient heliostat called `Stellio'.

  9. Repository seals requirement study

    NONE

    1997-11-03

    The Yucca Mountain Site Characterization Project, managed by the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) is conducting investigations to support the Viability Assessment and the License Application for a high-level nuclear waste repository at Yucca Mountain, Nevada. The sealing subsystem is part of the Yucca Mountain Waste Isolation System. The Yucca Mountain Site Characterization Project is currently evaluating the role of the sealing subsystem (shaft, ramp and exploratory borehole seals) in achieving the overall performance objectives for the Waste Isolation System. This report documents the results of those evaluations. The objective of the study is to provide water or air flow performance based requirements for shafts, ramps, and exploratory boreholes located near the repository. Recommendations, as appropriate, are provided for developing plans, seals component testing, and other studies relating to sealing.

  10. Southeast continental shelf studies

    Menzel, D.W.

    1979-02-12

    Research efforts on the southeast continental shelf currently describe the manner in which fluctuations in Gulf Stream motion influence biological and chemical processes. Current meter arrays are maintained in the Georgia Bight and in Onslow Bay to describe general circulation patterns and to identify forcing functions. biological studies describe processes affecting temporal and spatial variations on the shelf and have attempted to track the biological history of intruded Gulf Stream water masses. Chemical studies examine the influence of both physical and biological variables on the distribution and fate of trace elements. The current state of knowledge is reviewed, the hypotheses developed and are described, a rationale for testing these hypotheses is given. 1 figure, 1 table.

  11. Study on market policy

    In April 2007 the Dutch Minister of Economic Affairs promised the Lower House a study of the development of the public interests of quality, accessibility and efficiency after the introduction of market liberalization. In the debate on market liberalization in May 2007 the Minister complied with the Lower House?s request to include the consequences of the market liberalization operations on sectoral employment and labor conditions. This study addresses two questions: (1) Which developments occurred in the field of public interests quality, accessibility and efficiency and labor conditions since the introduction of market liberalization? and (2) What general findings and conclusions can be drawn from the implemented market liberalization policy in various sectors? What lessons can be learned for the future? Several sectors have been examined, including large energy users; renewable energy; energy market for medium users; energy (gas and electricity)

  12. Lesson study, deel 1

    Verhoef, Nellie

    2011-01-01

    Nellie Verhoef schreef in het Nieuw Archief voor Wiskunde al over de Lesson Study. Een handreiking om denkactiviteiten te ontwerpen in een samenwerkingsverband. Het onderwerp is echter zo veelzijdig dat ze er in Euclides ook aandacht aan besteedt, we publiceren haar artikel in twee delen. Dit eerste deel geeft een overzicht van de methode en een voorbeeld van denkactiviteiten. Het tweede deel gaat concreet in op het samenwerkingsverband en de resultaten daarvan

  13. Journal of Development Studies

    Hou, X.H.

    2010-01-01

    This study uses cross-sectional time-series data to examine the relationship between wealth and child labour and schooling in Pakistan and finds that wealth is crucial in determining a child's activities, but is far from being a sufficient condition to enrol a child in school. This is particularly the case for rural girls. Nonparametric analysis shows a universal increase in school enrolment for rural girls from 1998-2006 and this increase is independent of wealth. Multinomial logit regressio...

  14. American Studies in Hungary

    Éva Federmayer

    2006-01-01

    Full Text Available The beginning of American Studies as an academic discipline at Hungarian colleges and universities is basically coterminous with the watershed years of 1989-1990 when the country made a radical shift from state socialism toward parliamentary democracy and a free economy. This political and economic about-face, which came hand in hand with the undermining of foundationalist certainties and the generation of new anxieties coincided, more or less, with the radical transformation that American St...

  15. Lighting Retrofit Study

    Kromer, S.; Morse, O.; Siminovitch, M.

    1991-09-01

    The Lighting Retrofit Study was an effort to determine the most cost-effective methods of retrofitting several configurations of lighting systems at Lawrence Berkeley Laboratory (LBL) and Lawrence Livermore National Laboratory (LLNL). We developed a test protocol to compare a variety of lighting technologies for their applicability in labs and offices and designed and constructed a novel lighting contrast potential meter to allow for comparison of lighting quality as well as quantity.

  16. Speech Alarms Pilot Study

    Sandor, Aniko; Moses, Haifa

    2016-01-01

    Speech alarms have been used extensively in aviation and included in International Building Codes (IBC) and National Fire Protection Association's (NFPA) Life Safety Code. However, they have not been implemented on space vehicles. Previous studies conducted at NASA JSC showed that speech alarms lead to faster identification and higher accuracy. This research evaluated updated speech and tone alerts in a laboratory environment and in the Human Exploration Research Analog (HERA) in a realistic setup.

  17. Moessbauer studies of malaria

    Moessbauer studies of rat and human erythrocytes infected by malarial parasites have been carried out. Different parameters of the pigment iron were obtained in human and rat infected red blood cells. No difference was found between the parameters obtained in rat erythrocytes infected by drug sensitive and drug resistant strains of P. berghei, both before and after the treatment with chloroquine. The pigment was shown to contain a trivalent, high spin iron compound, which is different from hematin. (Auth.)

  18. Electroweak studies at TRISTAN

    The TRISTAN experiments have each accumulated about 60 pb-1 of data. Systematic analyses have been carried out on most of the available processes, including leptonic pair and multihadronic production as well as higher order processes. Here recent results on electroweak studies are reviewed by emphasizing those which seem to be in disagreement with the standard model. Although all the results are consistent with the theory, some show slight deviations from the theoretical expectations. (author)

  19. Laser Initiated Actuator study

    Watson, B.

    1991-06-27

    The program task was to design and study a laser initiated actuator. The design of the actuator is described, it being comprised of the fiber and body subassemblies. The energy source for all experiments was a Spectra Diode 2200-H2 laser diode. The diode is directly coupled to a 100 micron core, 0.3 numerical aperture fiber optic terminated with an SMA connector. The successful testing results are described and recommendations are made.

  20. Family studies in glaucoma.

    Rosenthal, A R; Perkins, E S

    1985-01-01

    Two groups of patients with a family history of chronic open-angle glaucoma were compared with a normal population of 5919 individuals studied during the Bedford Glaucoma Survey. The mean screening intraocular pressure was significantly raised in both groups with a family history of chronic open-angle glaucoma. The prevalence rate of a raised intraocular pressure was 3.81 times that found in the normal population. This relationship was maintained when age-dependent prevalence rates were evalu...