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Sample records for vessel lumen diameter

  1. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography.

    Science.gov (United States)

    van Velsen, Evert F S; Niessen, Wiro J; de Weert, Thomas T; de Monyé, Cécile; van der Lugt, Aad; Meijering, Erik; Stokking, Rik

    2007-07-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results.

  2. Evaluation of an improved technique for lumen path definition and lumen segmentation of atherosclerotic vessels in CT angiography

    International Nuclear Information System (INIS)

    Velsen, Evert F.S. van; Niessen, Wiro J.; Meijering, Erik; Stokking, Rik; Weert, Thomas T. de; Monye, Cecile de; Lugt, Aad van der

    2007-01-01

    Vessel image analysis is crucial when considering therapeutical options for (cardio-) vascular diseases. Our method, VAMPIRE (Vascular Analysis using Multiscale Paths Inferred from Ridges and Edges), involves two parts: a user defines a start- and endpoint upon which a lumen path is automatically defined, and which is used for initialization; the automatic segmentation of the vessel lumen on computed tomographic angiography (CTA) images. Both parts are based on the detection of vessel-like structures by analyzing intensity, edge, and ridge information. A multi-observer evaluation study was performed to compare VAMPIRE with a conventional method on the CTA data of 15 patients with carotid artery stenosis. In addition to the start- and endpoint, the two radiologists required on average 2.5 (SD: 1.9) additional points to define a lumen path when using the conventional method, and 0.1 (SD: 0.3) when using VAMPIRE. The segmentation results were quantitatively evaluated using Similarity Indices, which were slightly lower between VAMPIRE and the two radiologists (respectively 0.90 and 0.88) compared with the Similarity Index between the radiologists (0.92). The evaluation shows that the improved definition of a lumen path requires minimal user interaction, and that using this path as initialization leads to good automatic lumen segmentation results. (orig.)

  3. True-lumen and false-lumen diameter changes in the downstream aorta after frozen elephant trunk implantation.

    Science.gov (United States)

    Berger, Tim; Kreibich, Maximilian; Morlock, Julia; Kondov, Stoyan; Scheumann, Johannes; Kari, Fabian A; Rylski, Bartosz; Siepe, Matthias; Beyersdorf, Friedhelm; Czerny, Martin

    2018-02-19

    To evaluate early and mid-term clinical outcomes and to assess the potential of the frozen elephant trunk technique to induce remodelling of downstream aortic segments in acute and chronic thoracic aortic dissections. Over a 4-year period, 65 patients (48 men, aged 61 ± 12 years) underwent total aortic arch replacement using the frozen elephant trunk technique for acute (n = 31) and chronic (n = 34) thoracic aortic dissections at our institution. We assessed diameter changes at 3 levels: the L1 segment at the stent graft level; the L2 segment at the thoraco-abdominal transition level and the L3 segment at the coeliac trunk level. True-lumen (TL) and false-lumen (FL) diameter changes were assessed at each level. Fifty-six percent of patients had already undergone previous aortic or cardiac surgery. In-hospital mortality was 6%. Symptomatic spinal cord injury was not observed in this series. During a mean follow-up of 12 ± 12 months, late death was observed in 6% of patients. Aortic reinterventions in downstream aortic segments were performed in 28% at a mean of 394 ± 385 days. TL expansion and FL shrinkage were measured in all segments and were observed at each level. This effect was the most pronounced at the level of the stent graft in patients with chronic aortic dissection, TL diameter increased from 15 ± 17 mm before surgery to 28 ± 2 mm (P = 0.001) after 2 years, and the FL diameter decreased from 40 ± 11 mm before surgery to 32 ± 17 mm (P = 0.026). The frozen elephant trunk technique is associated with an excellent clinical outcome in a complex cohort of patients, and also effectively induces remodelling in downstream aortic segments in acute and chronic thoracic aortic dissections. The need for secondary interventions in downstream segments, which mainly depends on the extent of the underlying disease process, remains substantial. Further studies are required to assess the long-term outcome of

  4. Two Automated Techniques for Carotid Lumen Diameter Measurement: Regional versus Boundary Approaches.

    Science.gov (United States)

    Araki, Tadashi; Kumar, P Krishna; Suri, Harman S; Ikeda, Nobutaka; Gupta, Ajay; Saba, Luca; Rajan, Jeny; Lavra, Francesco; Sharma, Aditya M; Shafique, Shoaib; Nicolaides, Andrew; Laird, John R; Suri, Jasjit S

    2016-07-01

    The degree of stenosis in the carotid artery can be predicted using automated carotid lumen diameter (LD) measured from B-mode ultrasound images. Systolic velocity-based methods for measurement of LD are subjective. With the advancement of high resolution imaging, image-based methods have started to emerge. However, they require robust image analysis for accurate LD measurement. This paper presents two different algorithms for automated segmentation of the lumen borders in carotid ultrasound images. Both algorithms are modeled as a two stage process. Stage one consists of a global-based model using scale-space framework for the extraction of the region of interest. This stage is common to both algorithms. Stage two is modeled using a local-based strategy that extracts the lumen interfaces. At this stage, the algorithm-1 is modeled as a region-based strategy using a classification framework, whereas the algorithm-2 is modeled as a boundary-based approach that uses the level set framework. Two sets of databases (DB), Japan DB (JDB) (202 patients, 404 images) and Hong Kong DB (HKDB) (50 patients, 300 images) were used in this study. Two trained neuroradiologists performed manual LD tracings. The mean automated LD measured was 6.35 ± 0.95 mm for JDB and 6.20 ± 1.35 mm for HKDB. The precision-of-merit was: 97.4 % and 98.0 % w.r.t to two manual tracings for JDB and 99.7 % and 97.9 % w.r.t to two manual tracings for HKDB. Statistical tests such as ANOVA, Chi-Squared, T-test, and Mann-Whitney test were conducted to show the stability and reliability of the automated techniques.

  5. A computational algorithm addressing how vessel length might depend on vessel diameter

    Science.gov (United States)

    Jing Cai; Shuoxin Zhang; Melvin T. Tyree

    2010-01-01

    The objective of this method paper was to examine a computational algorithm that may reveal how vessel length might depend on vessel diameter within any given stem or species. The computational method requires the assumption that vessels remain approximately constant in diameter over their entire length. When this method is applied to three species or hybrids in the...

  6. High-resolution computed tomography evaluation of the bronchial lumen to vertebral body diameter and pulmonary artery to vertebral body diameter ratios in anesthetized ventilated normal cats.

    Science.gov (United States)

    Lee-Fowler, Tekla M; Cole, Robert C; Dillon, A Ray; Tillson, D Michael; Garbarino, Rachel; Barney, Sharron

    2017-10-01

    Objectives Bronchial lumen to pulmonary artery diameter (BA) ratio has been utilized to investigate pulmonary pathology on high-resolution CT images. Diseases affecting both the bronchi and pulmonary arteries render the BA ratio less useful. The purpose of the study was to establish bronchial lumen diameter to vertebral body diameter (BV) and pulmonary artery diameter to vertebral body diameter (AV) ratios in normal cats. Methods Using high-resolution CT images, 16 sets of measurements (sixth thoracic vertebral body [mid-body], each lobar bronchi and companion pulmonary artery diameter) were acquired from young adult female cats and 41 sets from pubertal female cats. Results Young adult and pubertal cat BV ratios were not statistically different from each other in any lung lobe. Significant differences between individual lung lobe BV ratios were noted on combined age group analysis. Caudal lung lobe AV ratios were significantly different between young adult and pubertal cats. All other lung lobe AV ratios were not significantly different. Caudal lung lobe AV ratios were significantly different from all other lung lobes but not from each other in both the young adult and pubertal cats. Conclusions and relevance BV ratio reference intervals determined for individual lung lobes could be applied to both young adult and pubertal cats. Separate AV ratios for individual lung lobes would be required for young adult and pubertal cats. These ratios should allow more accurate evaluation of cats with concurrent bronchial and pulmonary arterial disease.

  7. Coronary magnetic resonance imaging: visualization of the vessel lumen and the vessel wall and molecular imaging of arteriothrombosis

    International Nuclear Information System (INIS)

    Spuentrup, Elmar; Botnar, Rene M.

    2006-01-01

    Coronary magnetic resonance (MR) imaging has dramatically emerged over the last decade. Technical improvements have enabled reliable visualization of the proximal and midportion of the coronary artery tree for exclusion of significant coronary artery disease. However, current technical developments focus also on direct visualization of the diseased coronary vessel wall and imaging of coronary plaque because plaques without stenoses are typically more vulnerable with higher risk of plaque rupture. Plaque rupture with subsequent thrombosis and vessel occlusion is the main cause of myocardial infarction. Very recently, the first success of molecular imaging in the coronary arteries has been demonstrated using a fibrin-specific contrast agent for selective visualization of coronary thrombosis. This demonstrates in general the high potential of molecular MR imaging in the field of coronary artery disease. In this review, we will address recent technical advances in coronary MR imaging, including visualization of the lumen and the vessel wall and molecular imaging of coronary arteriothrombosis. First results of these new approaches will be discussed. (orig.)

  8. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit

    2006-01-01

    PURPOSE: To assess the relative influence of genetic and environmental effects on retinal vessel diameters and blood pressure in healthy adults, as well as the possible genetic connection between these two characteristics. METHODS: In 55 monozygotic and 50 dizygotic same-sex healthy twin pairs......%-80%) for CRAE, 83% (95% CI: 73%-89%) for CRVE, and 61% (95% CI: 44%-73%) for mean arterial blood pressure (MABP). Retinal artery diameter decreased with increasing age and increasing arterial blood pressure. Mean vessel diameters in the population were 165.8 +/- 14.9 microm for CRAE, 246.2 +/- 17.7 microm...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...

  9. Visual function and retinal vessel diameters during hyperthermia in man

    DEFF Research Database (Denmark)

    Jensen, Bettina Hagström; Bram, Thue; Kappelgaard, Per

    2017-01-01

    .01), a 10.6-mmHg mean reduction in diastolic blood pressure (p vein...... laser ophthalmoscopy was used to measure retinal trunk vessel diameters. Assessment was made at baseline, during hyperthermia and after cooling. RESULTS: The induction of a mean increase in core body temperature of 1.02°C was associated with a 7.15-mmHg mean reduction in systolic blood pressure (p

  10. Novel Computerized Method for Measurement of Retinal Vessel Diameters

    Directory of Open Access Journals (Sweden)

    Hichem Guedri

    2017-03-01

    Full Text Available Several clinical studies reveal the relationship between alterations in the topologies of the human retinal blood vessel, the outcrop and the disease evolution, such as diabetic retinopathy, hypertensive retinopathy, and macular degeneration. Indeed, the detection of these vascular changes always has gaps. In addition, the manual steps are slow, which may be subjected to a bias of the perceiver. However, we can overcome these troubles using computer algorithms that are quicker and more accurate. This paper presents and investigates a novel method for measuring the blood vessel diameter in the retinal image. The proposed method is based on a thresholding segmentation and thinning step, followed by the characteristic point determination step by the Douglas-Peucker algorithm. Thereafter, it uses the active contours to detect vessel contour. Finally, Heron’s Formula is applied to assure the calculation of vessel diameter. The obtained results for six sample images showed that the proposed method generated less errors compared to other techniques, which confirms the high performance of the proposed method.

  11. Vessel diameter measurements in gadolinium contrast-enhanced three-dimensional MRA of peripheral arteries

    NARCIS (Netherlands)

    Westenberg, J.J.M.; Geest, van der R.J.; Wasser, M.N.J.M.; Linden, van der E.L.; Walsum, van T.; Assen, van H.C.; Roos, de A.; Vanderschoot, J.; Reiber, J.H.C.

    2000-01-01

    In this study, the possibilities for quantification of vessel diameters of peripheral arteries in gadolinium contrast-enhanced magnetic resonance angiography (Gd CE MRA) were evaluated. Absolute vessel diameter measurements were assessed objectively and semi-automatically in maximum intensity

  12. Vessel Sampling and Blood Flow Velocity Distribution With Vessel Diameter for Characterizing the Human Bulbar Conjunctival Microvasculature.

    Science.gov (United States)

    Wang, Liang; Yuan, Jin; Jiang, Hong; Yan, Wentao; Cintrón-Colón, Hector R; Perez, Victor L; DeBuc, Delia C; Feuer, William J; Wang, Jianhua

    2016-03-01

    This study determined (1) how many vessels (i.e., the vessel sampling) are needed to reliably characterize the bulbar conjunctival microvasculature and (2) if characteristic information can be obtained from the distribution histogram of the blood flow velocity and vessel diameter. Functional slitlamp biomicroscope was used to image hundreds of venules per subject. The bulbar conjunctiva in five healthy human subjects was imaged on six different locations in the temporal bulbar conjunctiva. The histograms of the diameter and velocity were plotted to examine whether the distribution was normal. Standard errors were calculated from the standard deviation and vessel sample size. The ratio of the standard error of the mean over the population mean was used to determine the sample size cutoff. The velocity was plotted as a function of the vessel diameter to display the distribution of the diameter and velocity. The results showed that the sampling size was approximately 15 vessels, which generated a standard error equivalent to 15% of the population mean from the total vessel population. The distributions of the diameter and velocity were not only unimodal, but also somewhat positively skewed and not normal. The blood flow velocity was related to the vessel diameter (r=0.23, Psampling size of the vessels and the distribution histogram of the blood flow velocity and vessel diameter, which may lead to a better understanding of the human microvascular system of the bulbar conjunctiva.

  13. Effects of cryopreservation on excretory function, cellular adhesion molecules and vessel lumen formation in human umbilical vein endothelial cells.

    Science.gov (United States)

    Cai, Guoping; Lai, Binbin; Hong, Huaxing; Lin, Peng; Chen, Weifu; Zhu, Zhong; Chen, Haixiao

    2017-07-01

    Cryopreservation is widely used in regenerative medicine for tissue preservation. In the present study, the effects of cryopreservation on excretory function, cellular adhesion molecules and vessel lumen formation in human umbilical vein endothelial cells (HUVECs) were investigated. After 0, 4, 8, 12 or 24 weeks of cryopreservation in liquid nitrogen, the HUVECs were thawed. The excretory functions markers (endothelin‑1, prostaglandin E1, von Willebrand factor and nitric oxide) of HUVECs were measured by ELISA assay. The expression of intercellular adhesion molecule‑1 (ICAM‑1) in HUVECs was analyzed using flow cytometry. An angiogenesis assay was used to determine the angiogeneic capabilities of the thawed HUVECs. The results demonstrated that cryopreserved/thawed and recultivated HUVECs were unsuitable for tissue‑engineered microvascular construction. Specifically, the excretory function of the cells was significantly decreased in the post‑cryopreserved HUVECs at 24 weeks. In addition, the level of ICAM‑1 in HUVECs was significantly upregulated from the fourth week of cryopreservation. Furthermore, the tube‑like structure‑forming potential was weakened with increasing cryopreservation duration, and the numbers of lumen and the length of the pipeline were decreased in the thawed HUVECs, in a time‑dependent manner. In conclusion, the results of the present study revealed that prolonged cryopreservation may lead to HUVEC dysfunction and did not create stable cell lines for tissue‑engineered microvascular construction.

  14. The Precise Determination of Vascular Lumen and Stent Diameters: Correlation Among Calibrated Angiography, Intravascular Ultrasound, and Pressure-Fixed Specimens

    International Nuclear Information System (INIS)

    Froelich, Jens J.; Hoppe, Martin; Nahrstedt, Christoph; Barth, Klemens H.; Wagner, H. Joachim; Klose, Klaus J.

    1997-01-01

    Purpose: Luminal diameters measured in vivo by calibrated-catheter angiography and by intravascular ultrasound were correlated with those obtained from pressure-fixed histologic cross-sections to determine the accuracy of both methods. Methods: Angiographic and endosonographic diameter measurements were performed in the center of stents placed in the iliac arteries of 10 miniature pigs and were compared with luminal and stent diameters in postmortem, pressure-fixed, histologic cross-sections from identical locations. Results: Compared with histologic diameters, magnification-corrected angiographic measurements still magnified vascular luminal diameters by 0.7 ± 0.71 mm (r= 0.41, Pearson; p 0.5, Wilcoxon, matched pairs). Similarly, stent diameters correlated well between endosonographic and histologic measurements (r= 0.91; p= 0.002), and less well between angiographic and histologic diameters (r= 0.62; p= 0.002). Conclusion: Since calibrated angiography still overestimates vascular lumina, endosonography is the preferred technique for accurate in vivo measurements

  15. Relationship of the duke jeopardy score combined with minimal lumen diameter as assessed by computed tomography angiography to the hemodynamic relevance of coronary artery stenosis.

    Science.gov (United States)

    Yu, Mengmeng; Zhao, Yonghong; Li, Wenbin; Lu, Zhigang; Wei, Meng; Zhou, Wenxiao; Zhang, Jiayin

    2018-03-02

    To study the diagnostic performance of the ratio between the Duke jeopardy score (DJS) and the minimal lumen diameter (MLD) (DJS/MLD CT ratio) as assessed by coronary computed tomographic angiography (CTA) for differentiating functionally significant from non-significant coronary artery stenoses, with reference to invasive fractional flow reserve (FFR). Patients who underwent both coronary CTA and FFR measurement during invasive coronary angiography (ICA) within 2 weeks were retrospectively included in the study. Invasive FFR measurement was performed in patients with intermediate to severe coronary stenoseis. DJS/MLD CT ratio and anatomical parameters were recorded. Lesions with FFR ≤0.80 were considered to be functionally significant. One hundred and sixty-one patients with 175 lesions were included into the analysis. Diameter stenosis in CT, area stenosis, plaque burden, lesion length (LL), ICA-based stenosis degree, DJS, LL/MLD 4 ratio, DJS/MLA ratio as well as DJS/MLD ratio were all significantly different between hemodynamically significant and non-significant lesions (pvalue for DJS/MLD CT ratio to be 1.96 (area under curve = 0.863, 95 % confidence interval = 0.803-0.910), yielding a high diagnostic accuracy (86.9%, 152/175). In coronary artery stenoses detected by coronary CTA, the DJS/MLD ratio is able to predict hemodynamic relevance. Copyright © 2018 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  16. The design of lifting attachments for the erection of large diameter and heavy wall pressure vessels

    International Nuclear Information System (INIS)

    Antalffy, Leslie P.; Miller, George A.; Kirkpatrick, Kenneth D.; Rajguru, Anil; Zhu, Yong

    2016-01-01

    Lifting attachments for the erection of large diameter and heavy wall pressure vessels require special consideration to ensure that their attachment to their vessel shells or heads do not overstress the vessel during the erection process when lifting these from grade onto their respective foundations. Today, in refinery and petrochemical services, large diameter vessels with diameters ranging up to 15 m and reactors with lifting weights in the range of 700–1400 tons are not uncommon. In today's fabrication market, these vessels may be purchased and fabricated in shops dispersed globally and will require unique equipment for their safe handling, transportation and subsequent erection. The challenge is to design the lifting attachments in such a manner that the attachments provide a safe, cost effective and effective solution based upon the limitations of the job site lift equipment available for erection. Such equipment for the transportation and subsequent lifting of large diameter and heavy wall pressure equipment is usually scarce and quite expensive. Planning ahead, well in advance of the lift date is almost a mandatory requirement. Usually, the specific parameters of the vessel to be lifted and the lifting equipment available at the site will dictate the type of lifting attachments to be designed for the vessel. Once the type of vessel attachment has been chosen, careful consideration must be given to the design of attachments to the pressure vessel in consideration to ensure that the vessel and lifting components are not overstressed during the lifting process. The paper also discusses different types of lifting attachments that may be attached to each end of the vessel either by bolting or welding and discusses the pros and cons of each. The paper also provides an example of a finite element analysis (FEA) of a top nozzle, a FEA of a pair of lifting trunnions and a FEA of welded on lifting lugs for buried pipe. The purpose of the paper is to outline the

  17. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...

  18. Quantitative measurement of changes in retinal vessel diameter in ocular fundus images

    DEFF Research Database (Denmark)

    Pedersen, Lars; Grunkin, Michael; Ersbøll, Bjarne Kjær

    2000-01-01

    The change in diameter of retinal vessels as a function of increasing distance to the optic disc is believed to be indicative of the risk level of various vascular diseases such as generalised arteriosclerosis and Diabetes Mellitus. In particular, focal arteriolar narrowing (FAN) is considered re...

  19. Automatic evaluation of vessel diameter variation from 2D X-ray angiography.

    Science.gov (United States)

    M'hiri, Faten; Duong, Luc; Desrosiers, Christian; Dahdah, Nagib; Miró, Joaquim; Cheriet, Mohamed

    2017-11-01

    Early detection of blood vessel pathologies can be made through the evaluation of functional and structural abnormalities in the arteries, including the arterial distensibility measure. We propose a feasibility study on computing arterial distensibility automatically from monoplane 2D X-ray sequences for both small arteries (such as coronary arteries) and larger arteries (such as the aorta). To compute the distensibility measure, three steps were developed: First, the segment of an artery is extracted using our graph-based segmentation method. Then, the same segment is tracked in the moving sequence using our spatio-temporal segmentation method: the Temporal Vessel Walker. Finally, the diameter of the artery is measured automatically at each frame of the sequence based on the segmentation results. The method was evaluated using one simulated sequence and 4 patients' angiograms depicting the coronary arteries and three depicting the ascending aorta. Results of the simulated sequence achieved a Dice index of 98%, with a mean squared error in diameter measurement of [Formula: see text] mm. Results obtained from patients' X-ray sequences are consistent with manual assessment of the diameter by experts. The proposed method measures changes in diameter of a specific segment of a blood vessel during the cardiac sequence, automatically based on monoplane 2D X-ray sequence. Such information might become a key to help physicians in the detection of variations of arterial stiffness associated with early stages of various vasculopathies.

  20. Relationship between retinal vessel diameters and retinopathy in the Inter99 Eye Study

    DEFF Research Database (Denmark)

    Drobnjak, Dragana; Munch, Inger Christine; Glümer, Charlotte

    2017-01-01

    PURPOSE: To examine the association between retinal vessel diameters and retinopathy in participants with and without type 2 diabetes in a Danish population-based cohort. METHODS: The study included 878 persons aged 30 to 60 years from the Inter99 Eye Study. Retinopathy was defined as a presence...... was 6.3 µm (CI 95%: 1.0 to 11.6, p = 0.020) wider and CRVE was 7.9 µm (CI 95%: 0.7 to 15.2, p = 0.030) wider in those with retinopathy compared to those without retinopathy, after adjusting for age, gender, HbA1c, blood pressure, smoking, serum total and HDL cholesterol. In all participants, CRAE.......001), and decreased with higher HDL cholesterol (p gender was associated with wider CRVE (p = 0.029). CONCLUSIONS: Wider retinal vessel diameters were associated with the presence of retinopathy in participants with diabetes, but not in participants without diabetes...

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  2. Pulmonary artery pulsatility and effect on vessel diameter assessment in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Shariat, Masoud; Schantz, Daryl; Yoo, Shi-Joon; Wintersperger, Bernd J.; Seed, Mike; Alnafisi, Bahiyah; Chu, Leysia; MacGowan, Christopher K.; Amerom, Joshua van; Grosse-Wortmann, Lars

    2014-01-01

    Background: Information about thoracic vascular sizes can crucially affect clinical decision-making in cardiovascular disease. A variety of imaging techniques such as catheter angiography, contrast enhanced computed tomography (CT) and cardiac magnetic resonance imaging (CMR) are routinely used to measure vascular diameters. Traditionally, CMR black blood sequences were the main anatomical tool for visualization of vascular anatomy and still are in many centers. More recently, the vessel diameters are measured on multiplanar reconstructions derived from static magnetic resonance angiography (MRA). This study was performed to investigate the variation of vessel diameter measurements on different CMR techniques with respect to their data acquisition scheme. Methods: We recruited two groups of patients for this prospective study. One group included patients with repaired tetralogy of Fallot (TOF), with at least moderate pulmonary insufficiency and another group of patients who underwent CMR as part of a diagnostic work-up for arrhythmogenic right ventricular cardiomyopathy (ARVC). Additional images of the right pulmonary artery (RPA) were acquired in the double inversion recovery (DIR) black blood, cine steady state free precession (SSFP) and MRA. All images were reviewed by two CMR trained readers using the electronic caliper provided within the picture archiving and communication system package. The maximum diameter of each artery was recorded in millimeters with up to one decimal point. Paired t-tests and Bland–Altman plots were used for comparison of measurements between different sequences. Results: A total of 52 patients were recruited for this study, 26 patients in the TOF group (15 males, age 12.55 ± 2.9) and 26 patients in the ARVC group (15 males, age 15.6 ± 2.3). In both groups, the RPA sizes were not significantly different between the DIR images and diastolic cine SSFP (p > 0.05). Measurements on DIR were significantly smaller than those made on

  3. Pulmonary artery pulsatility and effect on vessel diameter assessment in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shariat, Masoud, E-mail: masoudshariat@gmail.com [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Schantz, Daryl, E-mail: daryl.schantz@gmail.com [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Yoo, Shi-Joon, E-mail: shi-joon.yoo@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Wintersperger, Bernd J., E-mail: bernd.wintersperger@uhn.ca [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Seed, Mike, E-mail: mike.seed@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Cardiology, Hospital for Sick Children, Toronto, Ontario (Canada); Alnafisi, Bahiyah, E-mail: bahiyah.alnafisi@uhn.ca [Department of Medical Imaging, University Health Network, University of Toronto, Toronto, Ontario (Canada); Chu, Leysia, E-mail: leysia_99@yahoo.com [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); MacGowan, Christopher K., E-mail: christopher.macgowan@sickkids.ca [Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Amerom, Joshua van, E-mail: Joshu.vanamerom@sickkids.ca [Department of Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario (Canada); Grosse-Wortmann, Lars, E-mail: lars.grosse-wortmann@sickkids.ca [Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario (Canada); Department of Cardiology, Hospital for Sick Children, Toronto, Ontario (Canada)

    2014-02-15

    Background: Information about thoracic vascular sizes can crucially affect clinical decision-making in cardiovascular disease. A variety of imaging techniques such as catheter angiography, contrast enhanced computed tomography (CT) and cardiac magnetic resonance imaging (CMR) are routinely used to measure vascular diameters. Traditionally, CMR black blood sequences were the main anatomical tool for visualization of vascular anatomy and still are in many centers. More recently, the vessel diameters are measured on multiplanar reconstructions derived from static magnetic resonance angiography (MRA). This study was performed to investigate the variation of vessel diameter measurements on different CMR techniques with respect to their data acquisition scheme. Methods: We recruited two groups of patients for this prospective study. One group included patients with repaired tetralogy of Fallot (TOF), with at least moderate pulmonary insufficiency and another group of patients who underwent CMR as part of a diagnostic work-up for arrhythmogenic right ventricular cardiomyopathy (ARVC). Additional images of the right pulmonary artery (RPA) were acquired in the double inversion recovery (DIR) black blood, cine steady state free precession (SSFP) and MRA. All images were reviewed by two CMR trained readers using the electronic caliper provided within the picture archiving and communication system package. The maximum diameter of each artery was recorded in millimeters with up to one decimal point. Paired t-tests and Bland–Altman plots were used for comparison of measurements between different sequences. Results: A total of 52 patients were recruited for this study, 26 patients in the TOF group (15 males, age 12.55 ± 2.9) and 26 patients in the ARVC group (15 males, age 15.6 ± 2.3). In both groups, the RPA sizes were not significantly different between the DIR images and diastolic cine SSFP (p > 0.05). Measurements on DIR were significantly smaller than those made on

  4. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... is a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels. Multimodal...

  5. Retinal vessel diameters in relation to hematocrit variation during acclimatization of highlanders to sea level altitude

    DEFF Research Database (Denmark)

    Kofoed, Peter Kristian; Sander, Birgit; Zubieta-Calleja, Gustavo

    2009-01-01

    PURPOSE: To examine variations in retinal vessel diameters during acclimatization of native highlanders to normobaric normoxia at sea level. METHODS: Fifteen healthy residents of the greater La Paz region in Bolivia (3600 m above sea level) were examined thrice over a 72-day period, after having...... traveled by airplane to Copenhagen, Denmark, near sea level. RESULTS: In the study subjects, hematocrit decreased from 49.6% (day 2) to 45.9% (P = 0.0066, day 23) and 41.7% (P ... diameters were indistinguishable from baseline after 72 days. No funduscopic signs of retinopathy were observed. Arterial blood pressure remained stable throughout the study. CONCLUSIONS: Although a 16% reduction in hematocrit occurred between days 2 and 72 after arrival at sea level, the only significant...

  6. Vascular lumen formation.

    Science.gov (United States)

    Lammert, Eckhard; Axnick, Jennifer

    2012-04-01

    The vascular system developed early in evolution. It is required in large multicellular organisms for the transport of nutrients, oxygen, and waste products to and from tissues. The vascular system is composed of hollow tubes, which have a high level of complexity in vertebrates. Vasculogenesis describes the de novo formation of blood vessels, e.g., aorta formation in vertebrate embryogenesis. In contrast, angiogenesis is the formation of blood vessels from preexisting ones, e.g., sprouting of intersomitic blood vessels from the aorta. Importantly, the lumen of all blood vessels in vertebrates is lined and formed by endothelial cells. In both vasculogenesis and angiogenesis, lumen formation takes place in a cord of endothelial cells. It involves a complex molecular mechanism composed of endothelial cell repulsion at the cell-cell contacts within the endothelial cell cords, junctional rearrangement, and endothelial cell shape change. As the vascular system also participates in the course of many diseases, such as cancer, stroke, and myocardial infarction, it is important to understand and make use of the molecular mechanisms of blood vessel formation to better understand and manipulate the pathomechanisms involved.

  7. The dimensional changes of a 24 inch diameter vessel during a campaign of successive glass making runs

    International Nuclear Information System (INIS)

    Chidley, B.E.

    1983-01-01

    Throughout the life of a 24 inch diameter Glass Making Vessel used on the inactive Harvest Vitrification Plant dimensional measurements have been recorded. When glass is present the diameter increases due to thermal stresses. Some permanent longitudinal extension (about 1%) occurred over the 20 runs comprising the glass-making campaign. (author)

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

    Science.gov (United States)

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

    2018-01-01

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

  9. Retinal Oximetry and Vessel Diameter Measurements With a Commercially Available Scanning Laser Ophthalmoscope in Diabetic Retinopathy.

    Science.gov (United States)

    Blair, Norman P; Wanek, Justin; Felder, Anthony E; Joslin, Charlotte E; Kresovich, Jacob K; Lim, Jennifer I; Chau, Felix Y; Leiderman, Yannek; Shahidi, Mahnaz

    2017-10-01

    To test the hypothesis that retinal vascular diameter and hemoglobin oxygen saturation alterations, according to stages of diabetic retinopathy (DR), are discernible with a commercially available scanning laser ophthalmoscope (SLO). One hundred eighty-one subjects with no diabetes (No DM), diabetes with no DR (No DR), nonproliferative DR (NPDR), or proliferative DR (PDR, all had photocoagulation) underwent imaging with an SLO with dual lasers (532 nm and 633 nm). Customized image analysis software determined the diameters of retinal arteries and veins (DA and DV) and central retinal artery and vein equivalents (CRAE and CRVE). Oxygen saturations of hemoglobin in arteries and veins (SO2A and SO2V) were estimated from optical densities of vessels on images at the two wavelengths. Statistical models were generated by adjusting for effects of sex, race, age, eye, and fundus pigmentation. DA, CRAE, and CRVE were reduced in PDR compared to No DM (P ≤ 0.03). DV and CRVE were similar between No DM and No DR, but they were higher in NPDR than No DR (P ≤ 0.01). Effect of stage of disease on SO2A differed by race, being increased relative to No DM in NPDR and PDR in Hispanic participants only (P ≤ 0.02). Relative to No DM, SO2V was increased in NPDR and PDR (P ≤ 0.05). Alterations in retinal vascular diameters and SO2 by diabetic retinopathy stage can be detected with a widely available SLO, and covariates such as race can influence the results.

  10. Dependence of light scattering profile in tissue on blood vessel diameter and distribution: a computer simulation study.

    Science.gov (United States)

    Duadi, Hamootal; Fixler, Dror; Popovtzer, Rachela

    2013-11-01

    Most methods for measuring light-tissue interactions focus on the volume reflectance while very few measure the transmission. We investigate both diffusion reflection and diffuse transmission at all exit angles to receive the full scattering profile. We also investigate the influence of blood vessel diameter on the scattering profile of a circular tissue. The photon propagation path at a wavelength of 850 nm is calculated from the absorption and scattering constants via Monte Carlo simulation. Several simulations are performed where a different vessel diameter and location were chosen but the blood volume was kept constant. The fraction of photons exiting the tissue at several central angles is presented for each vessel diameter. The main result is that there is a central angle that below which the photon transmission decreased for lower vessel diameters while above this angle the opposite occurred. We find this central angle to be 135 deg for a two-dimensional 10-mm diameter circular tissue cross-section containing blood vessels. These findings can be useful for monitoring blood perfusion and oxygen delivery in the ear lobe and pinched tissues. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

  11. A study of magnification effect to precision of computerized diameter measurement of a 3-mm vessel phantom in cineangiograms

    International Nuclear Information System (INIS)

    Yanagihara, Yoshio; Sugahara, Tetsuo; Sugimoto, Naozou; Fukunishi, Yasunobu.

    1994-01-01

    To estimate influence of magnification on digitizing to Precision of computerized measurement of coronary vessel diameter, the two measurement methods, i.e., a combined filter and Entropy filter, were applied to magnified images (x1-x6) of cineangiograms radiographed for a 3-mm vessel phantom. In conclusion, the desirable precision in clinical use, we thought, was obtainable at the magnification of x3 to x4. (author)

  12. Does Physical Fitness Buffer the Relationship between Psychosocial Stress, Retinal Vessel Diameters, and Blood Pressure among Primary Schoolchildren?

    Science.gov (United States)

    Endes, Katharina; Herrmann, Christian; Colledge, Flora; Brand, Serge; Donath, Lars; Faude, Oliver; Pühse, Uwe; Hanssen, Henner; Zahner, Lukas

    2016-01-01

    Background. Strong evidence exists showing that psychosocial stress plays an important part in the development of cardiovascular diseases. Because physical inactivity is associated with less favourable retinal vessel diameter and blood pressure profiles, this study explores whether physical fitness is able to buffer the negative effects of psychosocial stress on retinal vessel diameters and blood pressure in young children. Methods. 325 primary schoolchildren (51% girls, Mage = 7.28 years) took part in this cross-sectional research project. Retinal arteriolar diameters, retinal venular diameters, arteriolar to venular ratio, and systolic and diastolic blood pressure were assessed in all children. Interactions terms between physical fitness (performance in the 20 m shuttle run test) and four indicators of psychosocial stress (parental reports of critical life events, family, peer and school stress) were tested in a series of hierarchical regression analyses. Results. Critical life events and family, peer, and school-related stress were only weakly associated with retinal vessel diameters and blood pressure. No support was found for a stress-buffering effect of physical fitness. Conclusion. More research is needed with different age groups to find out if and from what age physical fitness can protect against arteriolar vessel narrowing and the occurrence of other cardiovascular disease risk factors. PMID:27795958

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

    Science.gov (United States)

    Armstrong, Richard A

    2006-11-01

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

  14. Turbulent flow in a vessel agitated by side entering inclined blade turbine with different diameter using CFD simulation

    Science.gov (United States)

    Fathonah, N. N.; Nurtono, T.; Kusdianto; Winardi, S.

    2018-03-01

    Single phase turbulent flow in a vessel agitated by side entering inclined blade turbine has simulated using CFD. The aim of this work is to identify the hydrodynamic characteristics of a model vessel, which geometrical configuration is adopted at industrial scale. The laboratory scale model vessel is a flat bottomed cylindrical tank agitated by side entering 4-blade inclined blade turbine with impeller rotational speed N=100-400 rpm. The effect of the impeller diameter on fluid flow pattern has been investigated. The fluid flow patterns in a vessel is essentially characterized by the phenomena of macro-instabilities, i.e. the flow patterns change with large scale in space and low frequency. The intensity of fluid flow in the tank increase with the increase of impeller rotational speed from 100, 200, 300, and 400 rpm. It was accompanied by shifting the position of the core of circulation flow away from impeller discharge stream and approached the front of the tank wall. The intensity of fluid flow in the vessel increase with the increase of the impeller diameter from d=3 cm to d=4 cm.

  15. Retinal vessel diameter and estimated cerebrospinal fluid pressure in arterial hypertension: the Beijing Eye Study.

    Science.gov (United States)

    Jonas, Jost B; Wang, Ningli; Wang, Shuang; Wang, Ya Xing; You, Qi Sheng; Yang, Diya; Wei, Wen Bin; Xu, Liang

    2014-09-01

    Hypertensive retinal microvascular abnormalities include an increased retinal vein-to-artery diameter ratio. Because central retinal vein pressure depends on cerebrospinal fluid pressure (CSFP), we examined whether the retinal vein-to-artery diameter ratio and other retinal hypertensive signs are associated with CSFP. Participants of the population-based Beijing Eye Study (n = 1,574 subjects) underwent measurement of the temporal inferior and superior retinal artery and vein diameter. CSFP was calculated as 0.44 × body mass index (kg/m(2)) + 0.16 × diastolic blood pressure (mm Hg) - 0.18 × age (years) - 1.91. Larger retinal vein diameters and higher vein-to-artery diameter ratios were significantly associated with higher estimated CSFP (P = 0.001) in multivariable analysis. In contrast, temporal inferior retinal arterial diameter was marginally associated (P = 0.03) with estimated CSFP, and temporal superior artery diameter was not significantly associated (P = 0.10) with estimated CSFP; other microvascular abnormalities, such as arteriovenous crossing signs, were also not significantly associated with estimated CSFP. In a reverse manner, higher estimated CSFP as a dependent variable in the multivariable analysis was associated with wider retinal veins and higher vein-to-artery diameter ratio. In the same model, estimated CSFP was not significantly correlated with retinal artery diameters or other retinal microvascular abnormalities. Correspondingly, arterial hypertension was associated with retinal microvascular abnormalities such as arteriovenous crossing signs (P = 0.003), thinner temporal retinal arteries (P arterial hypertension, an increased retinal vein-to-artery diameter ratio depends on elevated CSFP, which is correlated with blood pressure. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Automatic Segmentation of Vessels in In-Vivo Ultrasound Scans

    DEFF Research Database (Denmark)

    Tamimi-Sarnikowski, Philip; Brink-Kjær, Andreas; Moshavegh, Ramin

    2017-01-01

    presents a fully automatic segmentation algorithm, for robustly segmenting the vessel lumen in longitudinal B-mode ultrasound images. The automatic segmentation is performed using a combination of B-mode and power Doppler images. The proposed algorithm includes a series of preprocessing steps, and performs......Ultrasound has become highly popular to monitor atherosclerosis, by scanning the carotid artery. The screening involves measuring the thickness of the vessel wall and diameter of the lumen. An automatic segmentation of the vessel lumen, can enable the determination of lumen diameter. This paper...... a vessel segmentation by use of the marker-controlled watershed transform. The ultrasound images used in the study were acquired using the bk3000 ultrasound scanner (BK Ultrasound, Herlev, Denmark) with two transducers ”8L2 Linear” and ”10L2w Wide Linear” (BK Ultrasound, Herlev, Denmark). The algorithm...

  17. Lumen and calcium characteristics within calcified coronary lesions. Comparison of computed tomography coronary angiography versus intravascular ultrasound.

    Science.gov (United States)

    Noll, Dariusz; Kruk, Mariusz; Pręgowski, Jerzy; Kaczmarska, Edyta; Kryczka, Karolina; Pracoń, Radosław; Skwarek, Mirosław; Dzielińska, Zofia; Petryka, Joanna; Spiewak, Mateusz; Lubiszewska, Barbara; Norwa-Otto, Bożena; Opolski, Maksymilian; Witkowski, Adam; Demkow, Marcin; Rużyłło, Witold; Kępka, Cezary

    2013-01-01

    Computed tomography coronary angiography (CTCA) is a diagnostic method used for exclusion of coronary artery disease. However, lower accuracy of CTCA in assessment of calcified lesions is a significant factor impeding applicability of CTCA for assessment of coronary atherosclerosis. To provide insight into lumen and calcium characteristics assessed with CTCA, we compared these parameters to the reference of intravascular ultrasound (IVUS). Two hundred and fifty-two calcified lesions within 97 arteries of 60 patients (19 women, age 63 ±10 years) underwent assessment with both 2 × 64 slice CT (Somatom Definition, Siemens) and IVUS (s5, Volcano Corp.). Coronary lumen and calcium dimensions within calcified lesions were assessed with CTCA and compared to the reference measurements made with IVUS. On average CTCA underestimated mean lumen diameter (2.8 ±0.7 mm vs. 2.9 ±0.8 mm for IVUS), lumen area (6.4 ±3.4 mm(2) vs. 7.0 ±3.7 mm(2) for IVUS, p < 0.001) and total calcium arc (52 ±35° vs. 83 ±54°). However, analysis of tertiles of the examined parameters revealed that the mean lumen diameter, lumen area and calcium arc did not significantly differ between CTCA and IVUS within the smallest lumens (1(st) tertile of mean lumen diameter at 2.1 mm, and 1(st) tertile of lumen area at 3.7 mm(2)) and lowest calcium arc (mean of 40°). Although, on average, CTCA underestimates lumen diameter and area as well as calcium arc within calcified lesions, the differences are not significant within the smallest vessels and calcium arcs. The low diagnostic accuracy of CTCA within calcified lesions may be attributed to high variance and not to systematic error of measurements.

  18. The relationship of flow velocities to vessel diameters differs between extracranial carotid and vertebral arteries of stroke patients.

    Science.gov (United States)

    Owolabi, Mayowa O; Agunloye, Atinuke M; Ogunniyi, Adesola

    2014-01-01

    Chronic changes in flow rate through arteries produce adjustment of arterial diameters. We compared the relationship between flow velocity and diameter in the carotid and in the vertebral arteries of stroke patients. Using triplex ultrasonography, the internal diameter and flow velocities of the common carotid, internal carotid, and vertebral arteries of 176 consecutive stroke patients were measured. Correlations were examined with Pearson's statistics at an alpha level of 0.05. Mean age of the patients was 59.3 ± 12 years, and 66% had cerebral infarcts. Diameter and blood flow velocities showed significant negative correlations (-0.115 ≥ r ≥ -0.382) in the carotid arteries on both sides, but positive correlations (0.211 ≤ r ≤ 0.320) in the vertebral arteries, even after controlling for age, gender, and blood pressure. Our study demonstrated different diameter/flow relationships in the carotid and the vertebral arteries of stroke patients, which may suggest pathologic changes in the adaptive processes governing vessel diameter and growth, especially in the carotid arteries. Copyright © 2013 Wiley Periodicals, Inc.

  19. Automated detection and classification of major retinal vessels for determination of diameter ratio of arteries and veins

    Science.gov (United States)

    Muramatsu, Chisako; Hatanaka, Yuji; Iwase, Tatsuhiko; Hara, Takeshi; Fujita, Hiroshi

    2010-03-01

    Abnormalities of retinal vasculatures can indicate health conditions in the body, such as the high blood pressure and diabetes. Providing automatically determined width ratio of arteries and veins (A/V ratio) on retinal fundus images may help physicians in the diagnosis of hypertensive retinopathy, which may cause blindness. The purpose of this study was to detect major retinal vessels and classify them into arteries and veins for the determination of A/V ratio. Images used in this study were obtained from DRIVE database, which consists of 20 cases each for training and testing vessel detection algorithms. Starting with the reference standard of vasculature segmentation provided in the database, major arteries and veins each in the upper and lower temporal regions were manually selected for establishing the gold standard. We applied the black top-hat transformation and double-ring filter to detect retinal blood vessels. From the extracted vessels, large vessels extending from the optic disc to temporal regions were selected as target vessels for calculation of A/V ratio. Image features were extracted from the vessel segments from quarter-disc to one disc diameter from the edge of optic discs. The target segments in the training cases were classified into arteries and veins by using the linear discriminant analysis, and the selected parameters were applied to those in the test cases. Out of 40 pairs, 30 pairs (75%) of arteries and veins in the 20 test cases were correctly classified. The result can be used for the automated calculation of A/V ratio.

  20. Evaluation of Mechanical Properties and Medical Applications of Polycaprolactone Small Diameter Artificial Blood Vessels

    Directory of Open Access Journals (Sweden)

    Mahnazsadat Mirbagheri

    2017-03-01

    Full Text Available Increasing the cardiovascular diseases and decreasing the possibility of autograft surgery are important factors that cause the choice of artificial vascular graft as an alternative treatment method. In this regard, producing artificial grafts similar to natural vessels is an important purpose that has long been followed as a gold standard by many researchers worldwide. In addition, mechanical properties including strength, long patency, bio-compatibility and hydrophobicity are necessary properties to achieve ideal vascular grafts. Hence there are various factors such as polymer type and preparation methods, which contribute to suitable mechanical properties. The electrospinning as an optimized method on one side and biocompatible, degradable and semicrystalline polycaprolactone (PCL on the other side are used for their acceptable mechanical properties to manufacture synthetic vessels. In this study, PCL vascular grafts have been reviewed and a wide range of parameters affecting the improvement of mechanical properties and their performance have been described along with clinical applications. Therefore, by investigating and comparing single and composite PCL vascular grafts, we achieved acceptable results in the field of cell growth and adhesion as well as implanting grafts in animals such as rat and rabbit. By reviewing other studies, it was revealed that synthetic composite vessels made of PCL and natural polymers such as collagen and chitosan and synthetic polymers such as polyurethane (PU for long patency and acceptable cell adhesion have shown good clinical results.

  1. About a mechanism of the influence of shear stress for viscosity of the blood in vessels of small diameter

    Directory of Open Access Journals (Sweden)

    Лев Николаевич Катюхин

    2014-12-01

    Full Text Available It is proposed a physiological and experimentally confirmed explanation of Fåhraeus-Lindqvist-effect in capillaries using the profile analyses of osmotic deformability of red blood cells. It was shown the dose-dependent change of the erythrocytes deformability in the stage of isotropic spheres after forming artificial water pores (nystatin and occlusion (PbCl2 of available pores. The Sigma-effect reducing of hematocrit and viscosity in a shear flow of blood through the vessels of a small diameter was conditioned by the interchange of liquid phase between the erythrocyte and the plasma.

  2. Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Grønskov, Karen; Larsen, Michael

    2014-01-01

    diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS: Retinal arteries and veins were...... ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION: Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels...

  3. Physics of lumen growth.

    Science.gov (United States)

    Dasgupta, Sabyasachi; Gupta, Kapish; Zhang, Yue; Viasnoff, Virgile; Prost, Jacques

    2018-05-22

    We model the dynamics of formation of intercellular secretory lumens. Using conservation laws, we quantitatively study the balance between paracellular leaks and the build-up of osmotic pressure in the lumen. Our model predicts a critical pumping threshold to expand stable lumens. Consistently with experimental observations in bile canaliculi, the model also describes a transition between a monotonous and oscillatory regime during luminogenesis as a function of ion and water transport parameters. We finally discuss the possible importance of regulation of paracellular leaks in intercellular tubulogenesis.

  4. Porous hybrid structures based on P(DLLA-co-TMC) and collagen for tissue engineering of small-diameter blood vessels

    NARCIS (Netherlands)

    Buttafoco, L.; Boks, Niels P.; Engbers-Buijtenhuijs, P.; Grijpma, Dirk W.; Poot, Andreas A.; Dijkstra, Pieter J.; Vermes, I.; Feijen, Jan

    2006-01-01

    Poly (D,L-lactide)-7co-(1,3-trimethylene carbonate) [P(DLLA-co-TMC)] (83 mol % DLLA) was used to produce matrices suitable for tissue engineering of small-diameter blood vessels. The copolymer was processed into tubular structures with a porosity of 98% by melt spinning and fiber winding, thus

  5. Mechanisms of lumen formation during sprouting angiogenesis in vivo

    OpenAIRE

    Gebala, V. M.

    2016-01-01

    During development, vascular networks expand following a process known as sprouting angiogenesis. New vascular branches arise from pre-existing vessels through the coordinated migration and proliferation of endothelial cells, and eventually connect to form new vascular loops. The functionality of these new vessel segments is dependent on the opening of a central lumen to allow perfusion. While mechanisms of lumen formation during the establishment of the primary vasculature by vasculogenesis ...

  6. Chapter 16 Lumen Modification

    Science.gov (United States)

    Rebecca E. Ibach; Roger M. Rowell

    2012-01-01

    When wood is vacuum impregnated with liquid vinyl monomers that do not swell wood, and then in situ polymerized either by chemical catalyst-heat, or gamma radiation, the polymer is located almost solely in the lumens of the wood. Figure 16.1 is a scanning electron microscopy (SEM) micrograph of unmodified wood showing open cells that are...

  7. Comparison between MDCT and Grayscale IVUS in a Quantitative Analysis of Coronary Lumen in Segments with or without Atherosclerotic Plaques

    Energy Technology Data Exchange (ETDEWEB)

    Falcão, João L. A. A.; Falcão, Breno A. A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil); Gurudevan, Swaminatha V. [Cedars-Sinai Heart Institute, Los Angeles, California, USA (United States); Campos, Carlos M.; Silva, Expedito R.; Kalil-Filho, Roberto; Rochitte, Carlos E.; Shiozaki, Afonso A.; Coelho-Filho, Otavio R.; Lemos, Pedro A. [Heart Institute (InCor), University of São Paulo Medical School (USP), São Paulo, SP (Brazil)

    2015-04-15

    The diagnostic accuracy of 64-slice MDCT in comparison with IVUS has been poorly described and is mainly restricted to reports analyzing segments with documented atherosclerotic plaques. We compared 64-slice multidetector computed tomography (MDCT) with gray scale intravascular ultrasound (IVUS) for the evaluation of coronary lumen dimensions in the context of a comprehensive analysis, including segments with absent or mild disease. The 64-slice MDCT was performed within 72 h before the IVUS imaging, which was obtained for at least one coronary, regardless of the presence of luminal stenosis at angiography. A total of 21 patients were included, with 70 imaged vessels (total length 114.6 ± 38.3 mm per patient). A coronary plaque was diagnosed in segments with plaque burden > 40%. At patient, vessel, and segment levels, average lumen area, minimal lumen area, and minimal lumen diameter were highly correlated between IVUS and 64-slice MDCT (p < 0.01). However, 64-slice MDCT tended to underestimate the lumen size with a relatively wide dispersion of the differences. The comparison between 64-slice MDCT and IVUS lumen measurements was not substantially affected by the presence or absence of an underlying plaque. In addition, 64-slice MDCT showed good global accuracy for the detection of IVUS parameters associated with flow-limiting lesions. In a comprehensive, multi-territory, and whole-artery analysis, the assessment of coronary lumen by 64-slice MDCT compared with coronary IVUS showed a good overall diagnostic ability, regardless of the presence or absence of underlying atherosclerotic plaques.

  8. An agent-based model of the response to angioplasty and bare-metal stent deployment in an atherosclerotic blood vessel.

    Directory of Open Access Journals (Sweden)

    Antonia E Curtin

    Full Text Available PURPOSE: While animal models are widely used to investigate the development of restenosis in blood vessels following an intervention, computational models offer another means for investigating this phenomenon. A computational model of the response of a treated vessel would allow investigators to assess the effects of altering certain vessel- and stent-related variables. The authors aimed to develop a novel computational model of restenosis development following an angioplasty and bare-metal stent implantation in an atherosclerotic vessel using agent-based modeling techniques. The presented model is intended to demonstrate the body's response to the intervention and to explore how different vessel geometries or stent arrangements may affect restenosis development. METHODS: The model was created on a two-dimensional grid space. It utilizes the post-procedural vessel lumen diameter and stent information as its input parameters. The simulation starting point of the model is an atherosclerotic vessel after an angioplasty and stent implantation procedure. The model subsequently generates the final lumen diameter, percent change in lumen cross-sectional area, time to lumen diameter stabilization, and local concentrations of inflammatory cytokines upon simulation completion. Simulation results were directly compared with the results from serial imaging studies and cytokine levels studies in atherosclerotic patients from the relevant literature. RESULTS: The final lumen diameter results were all within one standard deviation of the mean lumen diameters reported in the comparison studies. The overlapping-stent simulations yielded results that matched published trends. The cytokine levels remained within the range of physiological levels throughout the simulations. CONCLUSION: We developed a novel computational model that successfully simulated the development of restenosis in a blood vessel following an angioplasty and bare-metal stent deployment based on

  9. Cerebro-afferent vessel and pupillary basal diameter variation induced by stomatognathic trigeminal proprioception: a case report.

    Science.gov (United States)

    De Cicco, Vincenzo

    2012-09-03

    A patient affected by asymmetric hemodynamics of cerebro-afferent vessels underwent duplex color scanner investigations in occlusal proprioceptive un- and rebalance conditions. Pupillometric video-oculographic examinations were performed in order to spot connected trigeminal proprioceptive motor patterns able to interfere on sympathetic autonomic activity. The aim of this case report is to verify if involuntary jaw closing during swallowing, executed in unbalance and rebalance myoelectric activity, would be able to modify cerebral hemodynamics. A 56-year-old Caucasian Italian woman affected by asymmetric blood flow of cerebro-afferent vessels underwent an electromyographic investigation of her occlusal muscles in order to assess their occlusal functional balance. The extreme asymmetry of myoelectric activity in dental occlusion evidenced by electromyographic values suggested the rebalancing of the functions of occlusal muscles through concurrent transcutaneous stimulation of the trigeminal nerve supra- and submandibular motor branches. The above-mentioned method allowed the detection of a symmetric craniomandibular muscular relation that can be kept constant through the use of a cusp bite modeled on the inferior dental arch: called orthotic-syntropic bite for its peculiar use of electrostimulation. A few days later, the patient underwent a duplex color scanner investigation and pupillometric video-oculographic examinations in occlusal unbalance and rebalance conditions. A comparative data analysis showed that an unbalanced dental occlusal function may represent an interferential pattern on cerebral hemodynamics velocity and pupillometric evaluations have proved useful both in the analysis of locus coeruleus functional modalities and as a diagnostic tool in the assessment of pathologies involving locus coeruleus and autonomic systems. The inclusion of myoelectric masseter examinations can be useful in patients with asymmetric hemodynamics of cerebro

  10. Dependence of diameters and oxygen saturation of retinal vessels on visual field damage and age in primary open-angle glaucoma.

    Science.gov (United States)

    Ramm, Lisa; Jentsch, Susanne; Peters, Sven; Sauer, Lydia; Augsten, Regine; Hammer, Martin

    2016-05-01

    To investigate the interrelationship between the oxygen supply of the retina and its regulation with the severity of primary open-angle glaucoma (POAG). Central retinal artery (CRAE) and vein (CRVE) diameters and oxygen saturation of peripapillary retinal vessels in 41 patients suffering from POAG (64.1 ± 12.9 years) and 40 healthy volunteers (63.6 ± 14.1 years) were measured using the retinal vessel analyzer. All measures were taken before and during flicker light stimulation. The mean retinal nerve fiber layer thickness (RNFLT) was determined by OCT and the visual field mean defect (MD) was identified using perimetry. In glaucoma patients, CRAE (r = -0.48 p = 0.002) and CRVE (r = -0.394 p = 0.014) at baseline were inversely related to MD, while arterial and venous oxygen saturation showed no significant dependence on the severity of the damage. However, the flicker light-induced change in arterio-venous difference in oxygen saturation was correlated with the MD (r = 0.358 p = 0.027). The diameters of arteries and veins at baseline decreased with reduction of the mean RNFLT (arteries: r = 0.718 p field loss, may be explained by a reduction of the retinal metabolic demand with progressive loss of neuronal tissue in glaucoma. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  11. Variations of vessel diameter and δ13C in false rings of Arbutus unedo L. reflect different environmental conditions.

    Science.gov (United States)

    Battipaglia, Giovanna; De Micco, Veronica; Brand, Willi A; Linke, Petra; Aronne, Giovanna; Saurer, Matthias; Cherubini, Paolo

    2010-12-01

    Woody species in Mediterranean ecosystems form intra-annual density fluctuations (IADFs) in tree rings in response to changes in environmental conditions, especially water availability. Dendrochronology, quantitative wood anatomy and high-resolution isotopic analysis (using a laser ablation technique) were used to characterize IADFs in Arbutus unedo shrubs grown on two sites with different water availability on the island of Elba (Italy). Our findings show that IADF characterization can provide information about the relationship between environmental factors and tree growth at the seasonal level. At the more xeric site, IADFs mainly located in the early and middle parts of the annual ring, showed a decrease in vessel size and an increase in δ(13) C as a result of drought deficit. Opposite trends were found at the more mesic site, with IADFs located at the end of the ring and associated with a lower δ(13) C. Moreover, at the first site, IADFs are induced by drought deficit, while at the second site IADFs are linked with the regrowth in the last part of the growing season triggered by favourable wet conditions. This combined approach is a promising way for dating problematic wood samples and interpreting the phenomena that trigger the formation of IADFs in the Mediterranean environment. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  12. Synergy of cell-cell repulsion and vacuolation in a computational model of lumen formation.

    Science.gov (United States)

    Boas, Sonja E M; Merks, Roeland M H

    2014-03-06

    A key step in blood vessel development (angiogenesis) is lumen formation: the hollowing of vessels for blood perfusion. Two alternative lumen formation mechanisms are suggested to function in different types of blood vessels. The vacuolation mechanism is suggested for lumen formation in small vessels by coalescence of intracellular vacuoles, a view that was extended to extracellular lumen formation by exocytosis of vacuoles. The cell-cell repulsion mechanism is suggested to initiate extracellular lumen formation in large vessels by active repulsion of adjacent cells, and active cell shape changes extend the lumen. We used an agent-based computer model, based on the cellular Potts model, to compare and study both mechanisms separately and combined. An extensive sensitivity analysis shows that each of the mechanisms on its own can produce lumens in a narrow region of parameter space. However, combining both mechanisms makes lumen formation much more robust to the values of the parameters, suggesting that the mechanisms may work synergistically and operate in parallel, rather than in different vessel types.

  13. Synergy of cell–cell repulsion and vacuolation in a computational model of lumen formation

    Science.gov (United States)

    Boas, Sonja E. M.; Merks, Roeland M. H.

    2014-01-01

    A key step in blood vessel development (angiogenesis) is lumen formation: the hollowing of vessels for blood perfusion. Two alternative lumen formation mechanisms are suggested to function in different types of blood vessels. The vacuolation mechanism is suggested for lumen formation in small vessels by coalescence of intracellular vacuoles, a view that was extended to extracellular lumen formation by exocytosis of vacuoles. The cell–cell repulsion mechanism is suggested to initiate extracellular lumen formation in large vessels by active repulsion of adjacent cells, and active cell shape changes extend the lumen. We used an agent-based computer model, based on the cellular Potts model, to compare and study both mechanisms separately and combined. An extensive sensitivity analysis shows that each of the mechanisms on its own can produce lumens in a narrow region of parameter space. However, combining both mechanisms makes lumen formation much more robust to the values of the parameters, suggesting that the mechanisms may work synergistically and operate in parallel, rather than in different vessel types. PMID:24430123

  14. MRT of carotid stents: influence of stent properties and sequence parameters on visualization of the carotid artery lumen

    International Nuclear Information System (INIS)

    Straube, T.; Wolf, S.; Alfke, K.; Jansen, O.; Flesser, A.; Deli, M.; Nabavi, A.

    2005-01-01

    Purpose: To evaluate MR artifacts of carotid artery stents and to optimize stent properties and sequence parameters. Material and Methods: Four carotid artery stents - Wallstent (mediloy), Precise (nitinol), ACCULINK (nitinol) and a stent prototype (nitinol) - were investigated in a flow model of the cervical vessels. The model was made of silicon tubing and a flow pump that produces realistic flow curves of the carotid artery. To investigate the effects of magnetic susceptibility and radiofrequency induced shielding artifacts, turbo spin echo and gradient echo sequences as well as CE-MRAs were measured. To improve the visualization of the stent lumen in a CE-MRA, flip angle as well as geometry and covering of the stent prototype were altered. Results: Susceptibility artifacts in stents of the carotid artery only influence the lumen visualization at the proximal and distal end of the braided mediloy stent. A change of stent coverings has no significant influence on radiofrequency artifacts, whereas a reduction in linking elements between stent segments and a change in diameter of stent struts improves visualization of the stent lumen. By increasing the flip angle in a CE-MRA, visualization of the stent lumen is possible in both mediloy and nitinol stents. Conclusion: The choice of stent material and changes in stent geometry as well as the optimization of the flip angle of the CE-MRA may reduce susceptibility and radiofrequency artifacts, rendering feasible the CE-MRA of a stented carotid artery. (orig.)

  15. Drug-eluting stents appear superior to bare metal stents for vein-graft PCI in vessels up to a stent diameter of 4 mm

    Directory of Open Access Journals (Sweden)

    Oliver P. Guttmann

    2016-05-01

    Full Text Available BackgroundResearch trials have shown improved short-term outcome with drug-eluting stents (DES over bare metal stents (BMS in saphenous vein graft (SVG percutaneous coronary intervention (PCI, primarily by reducing target vessel revascularization (TVR for in-stent restenosis. We compared the outcomes in patients undergoing SVG stent implantation treated with DES or BMS. In exploratory analyses we investigated the influence of stent generation and diameter.MethodsData were obtained from a prospective database of 657 patients who underwent PCI for SVG lesions between 2003 and 2011. A total of 344 patients had PCI with BMS and 313 with DES. Propensity scores were developed based on 15 observed baseline covariates in a logistic regression model with stent type as the dependent variable. The nearest-neighbour-matching algorithm with Greedy 5-1 Digit Matching was used to produce two patient cohorts of 313 patients each. We assessed major adverse cardiac events (MACE out to a median of 3.3 years (interquartile range: 2.1-4.1. MACE was defined as all-cause mortality, myocardial infarction (MI, TVR and stroke.ResultsThere was a significant difference in MACE between the two groups in favour of DES (17.9% DES vs. 31.2% BMS group; p = 0.0017 over the 5-year follow-up period. MACE was driven by increased TVR in the BMS group. There was no difference in death, MI or stroke. Adjusted Cox analysis confirmed a decreased risk of MACE for DES compared with BMS 0.75 (95% confidence interval (CI 0.52-0.94, with no difference in the hazard of all-cause mortality (hazard ratio: 1.08; 95% CI: 0.77-1.68. However, when looking at stent diameters greater than 4 mm, no difference was seen in MACE rates between BMS and DES.ConclusionsOverall in our cohort of patients who had PCI for SVG disease, DES use resulted in lower MACE rates compared with BMS over a 5-year follow-up period; however, for stent diameters over 4 mm no difference in MACE rates was seen.

  16. Neurovascular Network Explorer 1.0: a database of 2-photon single-vessel diameter measurements with MATLAB(®) graphical user interface.

    Science.gov (United States)

    Sridhar, Vishnu B; Tian, Peifang; Dale, Anders M; Devor, Anna; Saisan, Payam A

    2014-01-01

    We present a database client software-Neurovascular Network Explorer 1.0 (NNE 1.0)-that uses MATLAB(®) based Graphical User Interface (GUI) for interaction with a database of 2-photon single-vessel diameter measurements from our previous publication (Tian et al., 2010). These data are of particular interest for modeling the hemodynamic response. NNE 1.0 is downloaded by the user and then runs either as a MATLAB script or as a standalone program on a Windows platform. The GUI allows browsing the database according to parameters specified by the user, simple manipulation and visualization of the retrieved records (such as averaging and peak-normalization), and export of the results. Further, we provide NNE 1.0 source code. With this source code, the user can database their own experimental results, given the appropriate data structure and naming conventions, and thus share their data in a user-friendly format with other investigators. NNE 1.0 provides an example of seamless and low-cost solution for sharing of experimental data by a regular size neuroscience laboratory and may serve as a general template, facilitating dissemination of biological results and accelerating data-driven modeling approaches.

  17. Spectral Imaging for Intracranial Stents and Stent Lumen.

    Science.gov (United States)

    Weng, Chi-Lun; Tseng, Ying-Chi; Chen, David Yen-Ting; Chen, Chi-Jen; Hsu, Hui-Ling

    2016-01-01

    Application of computed tomography for monitoring intracranial stents is limited because of stent-related artifacts. Our purpose was to evaluate the effect of gemstone spectral imaging on the intracranial stent and stent lumen. In vitro, we scanned Enterprise stent phantom and a stent-cheese complex using the gemstone spectral imaging protocol. Follow-up gemstone spectral images of 15 consecutive patients with placement of Enterprise from January 2013 to September 2014 were also retrospectively reviewed. We used 70-keV, 140-keV, iodine (water), iodine (calcium), and iodine (hydroxyapatite) images to evaluate their effect on the intracranial stent and stent lumen. Two regions of interest were individually placed in stent lumen and adjacent brain tissue. Contrast-to-noise ratio was measured to determine image quality. The maximal diameter of stent markers was also measured to evaluate stent-related artifact. Two radiologists independently graded the visibility of the lumen at the maker location by using a 4-point scale. The mean of grading score, contrast/noise ratio and maximal diameter of stent markers were compared among all modes. All results were analyzed by SPSS version 20. In vitro, iodine (water) images decreased metallic artifact of stent makers to the greatest degree. The most areas of cheese were observed on iodine (water) images. In vivo, iodine (water) images had the smallest average diameter of stent markers (0.33 ± 0.17mm; P stent lumen (160.03 ±37.79; P stent-related artifacts of Enterprise and enhance contrast of in-stent lumen. Spectral imaging may be considered a noninvasive modality for following-up patients with in-stent stenosis.

  18. Evaluation of an improved technique for automated center lumen line definition in cardiovascular image data

    International Nuclear Information System (INIS)

    Gratama van Andel, Hugo A.F.; Meijering, Erik; Vrooman, Henri A.; Stokking, Rik; Lugt, Aad van der; Monye, Cecile de

    2006-01-01

    The aim of the study was to evaluate a new method for automated definition of a center lumen line in vessels in cardiovascular image data. This method, called VAMPIRE, is based on improved detection of vessel-like structures. A multiobserver evaluation study was conducted involving 40 tracings in clinical CTA data of carotid arteries to compare VAMPIRE with an established technique. This comparison showed that VAMPIRE yields considerably more successful tracings and improved handling of stenosis, calcifications, multiple vessels, and nearby bone structures. We conclude that VAMPIRE is highly suitable for automated definition of center lumen lines in vessels in cardiovascular image data. (orig.)

  19. Regional blood flow analysis and its relationship with arterial branch lengths and lumen volume in the coronary arterial tree

    International Nuclear Information System (INIS)

    Molloi, Sabee; Wong, Jerry T

    2007-01-01

    The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions (30-70% diameter stenosis) where it is difficult to determine whether a particular lesion is the cause of ischaemia. Therefore, a functional measure of stenosis severity is needed. The purpose of this study is to determine whether the expected maximum coronary blood flow in an arterial tree is predictable from its sum of arterial branch lengths or lumen volume. Using a computer model of a porcine coronary artery tree, an analysis of blood flow distribution was conducted through a network of millions of vessels that included the entire coronary artery tree down to the first capillary branch. The flow simulation results show that there is a linear relationship between coronary blood flow and the sum of its arterial branch lengths. This relationship holds over the entire arterial tree. The flow simulation results also indicate that there is a 3/4 er relation between coronary blood flow (Q) and the sum of its arterial lumen volume (V). Moreover, there is a linear relationship between normalized Q and normalized V raised to a power of 3/4 over the entire arterial tree. These results indicate that measured arterial branch lengths or lumen volumes can be used to predict the expected maximum blood flow in an arterial tree. This theoretical maximum blood flow, in conjunction with an angiographically measured blood flow, can potentially be used to calculate fractional flow reserve based entirely on angiographic data

  20. A nonimaging catheter for measurement of coronary artery lumen area: a first in man pilot study.

    Science.gov (United States)

    Hermiller, James; Choy, Jenny S; Svendsen, Mark; Bigelow, Brian; Fouts, Andrew M; Hall, Jack; Parr, Kirk; Ball, Michael; Sinha, Anjan; Bhatt, Deepak L; Kassab, Ghassan S

    2011-08-01

    The objective of this human pilot study was to determine the safety and the level of agreement between a novel nonimaging 2.7 Fr. catheter-based system (LumenRECON, LR) that uses electrical conductance for measurement of lumen cross-sectional area (CSA) with intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA). Based on previous animal studies, we hypothesized the level of agreement between LR and IVUS to be 13%. Accurate and reproducible vessel sizing is essential for optimal percutaneous coronary intervention (PCI). A total of 12 patients were studied to evaluate the safety, accuracy, and reproducibility of the system in comparison with IVUS and QCA. The CSA of coronary arteries was determined by IVUS, QCA, and LR in the distal, proximal, and center of a lesion during standard PCI. A Bland-Altman plot of the LR versus IVUS and QCA show a nonsignificant mean difference between the two measurements of 0.04 and 0.07 mm in diameter, respectively. The root mean square error of LR versus IVUS and QCA was 14.3 and 25.8% of the mean IVUS or QCA diameter, respectively. The mean of the difference between two LR duplicate measurements was nearly zero (0.03 mm) and the repeatability coefficient was within 8.7% of the mean of the two measurements. There were no procedural complications nor were any device-related MACE reported within 30 days of the procedure. This proof of concept pilot study establishes the safety and accuracy of the conductance technology for a pivotal trial of coronary sizing. Copyright © 2011 Wiley-Liss, Inc.

  1. Imaging of pediatric great vessel stents: Computed tomography or magnetic resonance imaging?

    Directory of Open Access Journals (Sweden)

    A M den Harder

    Full Text Available Complications might occur after great vessel stent implantation in children. Therefore follow-up using imaging is warranted.To determine the optimal imaging modality for the assessment of stents used to treat great vessel obstructions in children.Five different large vessel stents were evaluated in an in-vitro setting. All stents were expanded to the maximal vendor recommended diameter (20mm; n = 4 or 10mm; n = 1, placed in an anthropomorphic chest phantom and imaged with a 256-slice CT-scanner. MRI images were acquired at 1.5T using a multi-slice T2-weighted turbo spin echo, an RF-spoiled three-dimensional T1-weighted Fast Field Echo and a balanced turbo field echo 3D sequence. Two blinded observers assessed stent lumen visibility (measured diameter/true diameter *100% in the center and at the outlets of the stent. Reproducibility of diameter measurements was evaluated using the intraclass correlation coefficient for reliability and 95% limits of agreement for agreement analysis.Median stent lumen visibility was 88 (IQR 86-90% with CT for all stents at both the center and outlets. With MRI, the T2-weighted turbo spin echo sequence was preferred which resulted in 82 (78-84% stent lumen visibility. Interobserver reliability and agreement was good for both CT (ICC 0.997, mean difference -0.51 [-1.07-0.05] mm and MRI measurements (ICC 0.951, mean difference -0.05 [-2.52 --2.41] mm.Good in-stent lumen visibility was achievable in this in-vitro study with both CT and MRI in different great vessel stents. Overall reliability was good with clinical acceptable limits of agreement for both CT and MRI. However, common conditions such as in-stent stenosis and associated aneurysms were not tested in this in-vitro study, limiting the value of the in-vitro study.

  2. Imaging of pediatric great vessel stents: Computed tomography or magnetic resonance imaging?

    Science.gov (United States)

    den Harder, A M; Suchá, D; van Hamersvelt, R W; Budde, R P J; de Jong, P A; Schilham, A M R; Bos, C; Breur, J M P J; Leiner, T

    2017-01-01

    Complications might occur after great vessel stent implantation in children. Therefore follow-up using imaging is warranted. To determine the optimal imaging modality for the assessment of stents used to treat great vessel obstructions in children. Five different large vessel stents were evaluated in an in-vitro setting. All stents were expanded to the maximal vendor recommended diameter (20mm; n = 4 or 10mm; n = 1), placed in an anthropomorphic chest phantom and imaged with a 256-slice CT-scanner. MRI images were acquired at 1.5T using a multi-slice T2-weighted turbo spin echo, an RF-spoiled three-dimensional T1-weighted Fast Field Echo and a balanced turbo field echo 3D sequence. Two blinded observers assessed stent lumen visibility (measured diameter/true diameter *100%) in the center and at the outlets of the stent. Reproducibility of diameter measurements was evaluated using the intraclass correlation coefficient for reliability and 95% limits of agreement for agreement analysis. Median stent lumen visibility was 88 (IQR 86-90)% with CT for all stents at both the center and outlets. With MRI, the T2-weighted turbo spin echo sequence was preferred which resulted in 82 (78-84%) stent lumen visibility. Interobserver reliability and agreement was good for both CT (ICC 0.997, mean difference -0.51 [-1.07-0.05] mm) and MRI measurements (ICC 0.951, mean difference -0.05 [-2.52 --2.41] mm). Good in-stent lumen visibility was achievable in this in-vitro study with both CT and MRI in different great vessel stents. Overall reliability was good with clinical acceptable limits of agreement for both CT and MRI. However, common conditions such as in-stent stenosis and associated aneurysms were not tested in this in-vitro study, limiting the value of the in-vitro study.

  3. Hemodynamics in stenotic vessels of small diameter under steady state conditions: Effect of viscoelasticity and migration of red blood cells.

    Science.gov (United States)

    Dimakopoulos, Yannis; Kelesidis, George; Tsouka, Sophia; Georgiou, Georgios C; Tsamopoulos, John

    2015-01-01

    In microcirculation, the non-Newtonian behavior of blood and the complexity of the microvessel network are responsible for the high flow resistance and the large reduction of the blood pressure. Red blood cell aggregation along with inward radial migration are two significant mechanisms determining the former. Yet, their impact on hemodynamics in non-straight vessels is not well understood. In this study, the steady state blood flow in stenotic rigid vessels is examined, employing a sophisticated non-homogeneous constitutive law. The effect of red blood cells migration on the hydrodynamics is quantified and the constitutive model's accuracy is evaluated. A numerical algorithm based on the two-dimensional mixed finite element method and the EVSS/SUPG technique for a stable discretization of the mass and momentum conservation equations in addition to the constitutive model is employed. The numerical simulations show that a cell-depleted layer develops along the vessel wall with an almost constant thickness for slow flow conditions. This causes the reduction of the drag force and the increase of the pressure gradient as the constriction ratio decreases. Viscoelastic effects in blood flow were found to be responsible for steeper decreases of tube and discharge hematocrits as decreasing function of constriction ratio.

  4. Rationale and design of the East-West late lumen loss study: Comparison of late lumen loss between Eastern and Western drug-eluting stent study cohorts.

    Science.gov (United States)

    Harrison, Robert W; Radhakrishnan, Vaishnavi; Lam, Peter S; Allocco, Dominic J; Brar, Sandeep; Fahy, Martin; Fisher, Rebecca; Ikeno, Fumiaki; Généreux, Philippe; Kimura, Takeshi; Liu, Minglei; Lye, Weng Kit; Mintz, Gary S; Nagai, Hirofumi; Suzuki, Yuka; White, Roseann; Allen, John C; Krucoff, Mitchell W

    2016-12-01

    The contemporary evaluation of novel drug-eluting stents (DES) includes mechanistic observations that characterize postdeployment stent behavior. Quantification of late lumen loss due to neointimal hyperplasia 8-13 months after stent implantation, via quantitative coronary angiography (QCA), constitutes such an observation and is required by most regulatory authorities. Late lumen loss, as determined by QCA, has been validated as a surrogate for clinical endpoints such as target vessel revascularization. The mechanistic response to DES has not been directly compared across predominantly Asian or Western populations, whereas understanding their comparability across geographic populations could enhance global DES evaluation. The East-West late lumen loss study is designed to demonstrate whether the residual differences in late lumen loss, as assessed by QCA, is different between Eastern and Western DES recipients from studies with protocol angiography at 8-13 months of follow-up. Data from independent core laboratories that have characterized angiographic late lumen loss in DES clinical trials with protocol follow-up angiography will be compiled and dichotomized into Eastern and Western populations. A prospectively developed propensity score model incorporating clinical and anatomic variables affecting late lumen loss will be used to adjust comparisons of QCA measurements. Documentation of whether there are clinically meaningful differences in mechanistic response to DES implantation across genetically unique geographies could facilitate both the quality and efficiency of global device evaluation requiring invasive follow-up for novel stent designs. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Enlargement of halloysite clay nanotube lumen by selective etching of aluminum oxide.

    Science.gov (United States)

    Abdullayev, Elshad; Joshi, Anupam; Wei, Wenbo; Zhao, Yafei; Lvov, Yuri

    2012-08-28

    Halloysite clay tubes have 50 nm diameter and chemically different inner and outer walls (inner surface of aluminum oxide and outer surface of silica). Due to this different chemistry, the selective etching of alumina from inside the tube was realized, while preserving their external diameter (lumen diameter changed from 15 to 25 nm). This increases 2-3 times the tube lumen capacity for loading and further sustained release of active chemical agents such as metals, corrosion inhibitors, and drugs. In particular, halloysite loading efficiency for the benzotriazole increased 4 times by selective etching of 60% alumina within the tubes' lumens. Specific surface area of the tubes increased over 6 times, from 40 to 250 m(2)/g, upon acid treatment.

  6. In 6- to 8-year-old children, hair cortisol is associated with body mass index and somatic complaints, but not with stress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness.

    Science.gov (United States)

    Gerber, Markus; Endes, Katharina; Brand, Serge; Herrmann, Christian; Colledge, Flora; Donath, Lars; Faude, Oliver; Pühse, Uwe; Hanssen, Henner; Zahner, Lukas

    2017-02-01

    Hair cortisol measurement has become an increasingly accepted approach in endocrinology and biopsychology. However, while in adult research hair cortisol has been proposed as a relevant biomarker for chronic stress (and its adverse consequences), studies with children are scarce. Therefore, the goal of the present exploratory study was to examine the associations between hair cortisol concentrations (HCCs), stress, and a series of health-related outcomes in a sample of Swiss first grade schoolchildren. The sample consisted of 318 children (53% girls, M age =7.26, SD=0.35). Hair strands were taken near the scalp from a posterior vertex position, and HCCs were tested for the first 3-cm hair segment. Parents provided information about their children's age, gender, parental education, children's stress (recent critical life events, daily hassles), health-related quality of life, and psychosomatic complaints. Body composition, blood pressure, retinal vessel diameters, and cardiorespiratory fitness were measured with established methods. In multiple regression analyses, higher HCCs were weakly associated with increased BMI in girls (β=0.22, pstress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness. Although small significant relationships were found between HCCs, BMI and somatic complaints, the findings of this exploratory study challenge the view that HCCs can be used as a reliable biomarker of recent critical life events, daily hassles, health-related quality of life, and cardiovascular health indicators in non-clinical young children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Manufacturing of ultra-large diameter 20 MnMoNi 5 5 steel forgings for reactor pressure vessels and their properties

    International Nuclear Information System (INIS)

    Onodera, S.; Kawaguchi, S.; Tsukada, H.; Moritani, H.; Suzuki, K.; Sato, I.

    1985-01-01

    As the structural material for RPV typical of increased dimensions, as set of ultra-large diameter steel forgings for a PHWR RPV is presented as outlined below. (1) Material designation: 20 MnMoNi 5 5 (similar to SA508, Cl.3) (2) Size of the forgings: flanges, 8.440 mm OD, a weight of 238 tons for shell flange; shells and torus, 7,920 mm OD, with large height, cover dome, 6,800 mm OD in chord and 460 mm thick; blank before formed to dome is ca. 8,000 mm OD. (3) Chemical composition: particular effort was made for minimizing the tramp elements as P, S, As, Sn, Sb, Cu. (4) Manufacturing, key points: steel making - combined refining and degassing in ladle; ingot making - largest size ingots, including 570 ton and 500 ton ingots; forging - special ''outside-the-press'' forging and forming techniques; heat treatment - prevention of H 2 flaking in normalizing and tempering and handling of the extra-large forgings at water quenching. (5) Metallurgical properties: sufficiently uniform carbon distributions in the forgings; a lowest possible content of hydrogen, non-metallic inclusions and oxygen. Mechanical properties: uniformity in tensile and toughness properties; flaws - only limited number of spots of UT indications under 2 mm EFG (EFS). (orig.)

  8. Performance improvements of the BNC tubes from unique double-silicone-tube bioreactors by introducing chitosan and heparin for application as small-diameter artificial blood vessels.

    Science.gov (United States)

    Li, Xue; Tang, Jingyu; Bao, Luhan; Chen, Lin; Hong, Feng F

    2017-12-15

    In order to improve property of bacterial nano-cellulose (BNC) to achieve the requirements of clinical application as small caliber vascular grafts, chitosan (CH) was deposited into the fibril network of the BNC tubes fabricated in unique Double-Silicone-Tube bioreactors. Heparin (Hep) was then chemically grafted into the BNC-based tubes using EDC/NHS crosslinking to improve performance of anticoagulation and endothelialization. Physicochemical and mechanical property, blood compatibility, and cytocompatibility were compared before and after compositing. The results indicated that strength at break was increased but burst pressure decreased slightly after compositing. Performance of the BNC tubes was improved remarkably after introducing chitosan and heparin. The EDC/NHS crosslinking catalyzed both amide bonds and ester bonds formation in the BNC/CH-Hep composites. Three-dimensional surface structure and roughness were firstly obtained and discussed in relation to the hemocompatibility of BNC-based tubes. This work demonstrates the heparinized BNC-based tubes have great potential in application as small-diameter vascular prosthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Technical Note: Measurement of common carotid artery lumen dynamics using black-blood MR cine imaging.

    Science.gov (United States)

    Dai, Erpeng; Dong, Li; Zhang, Zhe; Li, Lyu; Zhang, Hui; Zhao, Xihai; Wang, Jinnan; Yuan, Chun; Guo, Hua

    2017-03-01

    To demonstrate the feasibility of measuring the common carotid artery (CCA) lumen dynamics using a black-blood cine (BB-cine) imaging method. Motion-sensitized driven-equilibrium (MSDE) prepared spoiled gradient sequence was used for the BB-cine imaging. CCAs of eleven healthy volunteers were studied using this method. Lumen dynamics, including lumen area evolution waveforms and distension values, were measured and evaluated by comparing this method with bright-blood cine (BrB-cine) imaging. Compared with the BrB-cine images, flow artifacts were effectively suppressed in the BB-cine images. BrB-cine images generally show larger lumen areas than BB-cine images. The lumen area waveforms and distension measurements from BB-cine imaging showed smaller variances among different subjects than BrB-cine imaging. The proposed BB-cine imaging technique can suppress the flow artifacts effectively and reduce the partial volume effects from the vessel wall. This might allow more accurate lumen dynamics measurements than traditional BrB-cine imaging, which may further be valuable for investigating biomechanical and functional properties of the cardiovascular system. © 2017 American Association of Physicists in Medicine.

  10. ARCOCT: Automatic detection of lumen border in intravascular OCT images.

    Science.gov (United States)

    Cheimariotis, Grigorios-Aris; Chatzizisis, Yiannis S; Koutkias, Vassilis G; Toutouzas, Konstantinos; Giannopoulos, Andreas; Riga, Maria; Chouvarda, Ioanna; Antoniadis, Antonios P; Doulaverakis, Charalambos; Tsamboulatidis, Ioannis; Kompatsiaris, Ioannis; Giannoglou, George D; Maglaveras, Nicos

    2017-11-01

    Intravascular optical coherence tomography (OCT) is an invaluable tool for the detection of pathological features on the arterial wall and the investigation of post-stenting complications. Computational lumen border detection in OCT images is highly advantageous, since it may support rapid morphometric analysis. However, automatic detection is very challenging, since OCT images typically include various artifacts that impact image clarity, including features such as side branches and intraluminal blood presence. This paper presents ARCOCT, a segmentation method for fully-automatic detection of lumen border in OCT images. ARCOCT relies on multiple, consecutive processing steps, accounting for image preparation, contour extraction and refinement. In particular, for contour extraction ARCOCT employs the transformation of OCT images based on physical characteristics such as reflectivity and absorption of the tissue and, for contour refinement, local regression using weighted linear least squares and a 2nd degree polynomial model is employed to achieve artifact and small-branch correction as well as smoothness of the artery mesh. Our major focus was to achieve accurate contour delineation in the various types of OCT images, i.e., even in challenging cases with branches and artifacts. ARCOCT has been assessed in a dataset of 1812 images (308 from stented and 1504 from native segments) obtained from 20 patients. ARCOCT was compared against ground-truth manual segmentation performed by experts on the basis of various geometric features (e.g. area, perimeter, radius, diameter, centroid, etc.) and closed contour matching indicators (the Dice index, the Hausdorff distance and the undirected average distance), using standard statistical analysis methods. The proposed method was proven very efficient and close to the ground-truth, exhibiting non statistically-significant differences for most of the examined metrics. ARCOCT allows accurate and fully-automated lumen border

  11. Effects of irradiation on renal vessels of rabbits

    International Nuclear Information System (INIS)

    Hanayama, Hirotaka

    1982-01-01

    The male rabbits weighing approximately 3 kg were divided into two groups: one group received irradiation to the left kidney through 6 x 4 cm field size with doses of 5 Gy, while the other group was irradiated with 50 Gy. The vessel casts were observed using the injection replica scanning electron microscopic method. In 50 Gy irradiated group, the surface of blood vessel's lumen became irregular with a decrease in the number of glomeruli at 5 days. Partial narrowing was also seen in the cortex and glomerular vessels. The number of glomeruli decreased by 48% one week later and 90% 4 weeks later. The cortex vessels progressively narrowed, and irregularity of the net-like structure was also observed. Similarly, a decrease in the number of glomeruli and partial narrowing of the blood vessels were seen at 5 days on the nonirradiated side, but the damage was considerably less than that on the irradiated side. In the 5 Gy irradiated group, a decrease in the number of glomeruli was seen 5 days later and it became 71% 5 days later and 81% one week later. It returned to 95% 4 weeks later. No changes whatsoever were seen in the non-irradiated side after 4 weeks and changes in the number of glomeruli were not observed. The vasculation of medulla showed no changes in the 50 Gy or the 5 Gy irradiated group. There were seen no significant changes in the blood vessel diameter. (J.P.N.)

  12. Quantification of arterial plaque and lumen density with MDCT

    International Nuclear Information System (INIS)

    Paul, Narinder S.; Blobel, Joerg; Kashani, Hany; Rice, Murray; Ursani, Ali

    2010-01-01

    Purpose: This study aimed to derive a mathematical correction function in order to normalize the CT number measurements for small volume arterial plaque and small vessel mimicking objects, imaged with multidetector CT (MDCT). Methods: A commercially available calcium plaque phantom (QRM GmbH, Moehrendorf, Germany) and a custom built cardiovascular phantom were scanned with 320 and 64 MDCT scanners. The calcium hydroxyapatite plaque phantom contained objects 0.5-5.0 mm in diameter with known CT attenuation nominal values ranging 50-800 HU. The cardiovascular phantom contained vessel mimicking objects 1.0-5.0 mm in diameter with different contrast media. Both phantoms were scanned using clinical protocols for CT angiography and images were reconstructed with different filter kernels. The measured CT number (HU) and diameter of each object were analyzed on three clinical postprocessing workstations. From the resultant data, a mathematical formula was derived based on absorption function exp(-μ * d) to demonstrate the relation between measured CT numbers and object diameters. Results: The percentage reduction in measured CT number (HU) for the group of selected filter kernels, apparent during CT angiography, is dependent only on the object size (plaque or vessel diameter). The derived formula of the form 1-c * exp(-a * d b ) showed reduction in CT number for objects between 0.5 and 5 mm in diameter, with asymptote reaching background noise for small objects with diameters nearing the CT in-plane resolution (0.35 mm). No reduction was observed for the objects with diameters equal or larger than 5 mm. Conclusions: A clear mathematical relationship exists between object diameter and reduction in measured CT number in HU. This function is independent of exposure parameters and inherent attenuation properties of the objects studied. Future developments include the incorporation of this mathematical model function into quantification software in order to automatically

  13. A novel lumen-apposing metal stent for endoscopic ultrasound-guided drainage of pancreatic fluid collections

    DEFF Research Database (Denmark)

    Walter, Daisy; Will, Uwe; Sanchez-Yague, Andres

    2015-01-01

    BACKGROUND AND STUDY AIMS: A novel large-diameter, lumen-apposing, self-expanding metal stent with bilateral flanges was recently developed for endoscopic ultrasound (EUS)-guided transmural drainage of symptomatic pancreatic fluid collections (PFCs). The aim of this study was to evaluate the effi......BACKGROUND AND STUDY AIMS: A novel large-diameter, lumen-apposing, self-expanding metal stent with bilateral flanges was recently developed for endoscopic ultrasound (EUS)-guided transmural drainage of symptomatic pancreatic fluid collections (PFCs). The aim of this study was to evaluate...

  14. FFTF and CRBRP reactor vessels

    International Nuclear Information System (INIS)

    Morgan, R.E.

    1977-01-01

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

  15. Multiple versus single lumen umbilical venous catheters for newborn infants.

    Science.gov (United States)

    Kabra, N S; Kumar, M; Shah, S S

    2005-07-20

    needed to treat (NNT) or number needed to harm (NNH) was calculated. Three studies qualified for inclusion in this review (Khilnani 1991; Loisel 1996; Soupre 1998). There was a decrease in the ML-UVCs group in the number of additional PIVs used in the first week of life [WMD -1.42, (95% CI -1.74, -1.10), pcatheter malfunction in the ML-UVCs group [typical RR 3.69 (95% CI 0.99, 13.81), p=0.05; RD 0.15 (95% CI 0.03, 0.27), p=0.01; NNH was 7, 95% CI 4, 33; n=99]. The following outcomes were not significantly different in the two groups: clinical sepsis, catheter related blood stream infection, catheter-associated thrombosis, complications related to catheter malposition in heart and great vessels, NEC and early neonatal mortality. The use of ML-UVCs in comparison to SL-UVCs in neonates is associated with decrease in the usage of PIVs in first week of life, but an increase in catheter malfunctions. As the quality of included randomized studies is poor and the estimates of clinically important complications are imprecise, no firm recommendations can be made regarding the choice of UVC. Adequately powered, properly randomized and properly blinded controlled trials are needed that address the effectiveness and safety of ML-UVCs (double and triple lumen) in comparison to SL-UVCs. These studies should also address the impact of type of catheter material.

  16. Vascular diameter measurement in CT angiography: comparison of model-based iterative reconstruction and standard filtered back projection algorithms in vitro.

    Science.gov (United States)

    Suzuki, Shigeru; Machida, Haruhiko; Tanaka, Isao; Ueno, Eiko

    2013-03-01

    The purpose of this study was to evaluate the performance of model-based iterative reconstruction (MBIR) in measurement of the inner diameter of models of blood vessels and compare performance between MBIR and a standard filtered back projection (FBP) algorithm. Vascular models with wall thicknesses of 0.5, 1.0, and 1.5 mm were scanned with a 64-MDCT unit and densities of contrast material yielding 275, 396, and 542 HU. Images were reconstructed images by MBIR and FBP, and the mean diameter of each model vessel was measured by software automation. Twenty separate measurements were repeated for each vessel, and variance among the repeated measures was analyzed for determination of measurement error. For all nine model vessels, CT attenuation profiles were compared along a line passing through the luminal center on axial images reconstructed with FBP and MBIR, and the 10-90% edge rise distances at the boundary between the vascular wall and the lumen were evaluated. For images reconstructed with FBP, measurement errors were smallest for models with 1.5-mm wall thickness, except those filled with 275-HU contrast material, and errors grew as the density of the contrast material decreased. Measurement errors with MBIR were comparable to or less than those with FBP. In CT attenuation profiles of images reconstructed with MBIR, the 10-90% edge rise distances at the boundary between the lumen and vascular wall were relatively short for each vascular model compared with those of the profile curves of FBP images. MBIR is better than standard FBP for reducing reconstruction blur and improving the accuracy of diameter measurement at CT angiography.

  17. Maximizing Lumen Gain With Directional Atherectomy.

    Science.gov (United States)

    Stanley, Gregory A; Winscott, John G

    2016-08-01

    To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization. © The Author(s) 2016.

  18. Linear-regression convolutional neural network for fully automated coronary lumen segmentation in intravascular optical coherence tomography

    Science.gov (United States)

    Yong, Yan Ling; Tan, Li Kuo; McLaughlin, Robert A.; Chee, Kok Han; Liew, Yih Miin

    2017-12-01

    Intravascular optical coherence tomography (OCT) is an optical imaging modality commonly used in the assessment of coronary artery diseases during percutaneous coronary intervention. Manual segmentation to assess luminal stenosis from OCT pullback scans is challenging and time consuming. We propose a linear-regression convolutional neural network to automatically perform vessel lumen segmentation, parameterized in terms of radial distances from the catheter centroid in polar space. Benchmarked against gold-standard manual segmentation, our proposed algorithm achieves average locational accuracy of the vessel wall of 22 microns, and 0.985 and 0.970 in Dice coefficient and Jaccard similarity index, respectively. The average absolute error of luminal area estimation is 1.38%. The processing rate is 40.6 ms per image, suggesting the potential to be incorporated into a clinical workflow and to provide quantitative assessment of vessel lumen in an intraoperative time frame.

  19. Linear-regression convolutional neural network for fully automated coronary lumen segmentation in intravascular optical coherence tomography.

    Science.gov (United States)

    Yong, Yan Ling; Tan, Li Kuo; McLaughlin, Robert A; Chee, Kok Han; Liew, Yih Miin

    2017-12-01

    Intravascular optical coherence tomography (OCT) is an optical imaging modality commonly used in the assessment of coronary artery diseases during percutaneous coronary intervention. Manual segmentation to assess luminal stenosis from OCT pullback scans is challenging and time consuming. We propose a linear-regression convolutional neural network to automatically perform vessel lumen segmentation, parameterized in terms of radial distances from the catheter centroid in polar space. Benchmarked against gold-standard manual segmentation, our proposed algorithm achieves average locational accuracy of the vessel wall of 22 microns, and 0.985 and 0.970 in Dice coefficient and Jaccard similarity index, respectively. The average absolute error of luminal area estimation is 1.38%. The processing rate is 40.6 ms per image, suggesting the potential to be incorporated into a clinical workflow and to provide quantitative assessment of vessel lumen in an intraoperative time frame. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

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

    Science.gov (United States)

    Modrzejewska, Monika

    2011-01-01

    The purpose of this review was to evaluate factors connected with blood flow and indices regulating vascular diameter and some parameters influencing retrobulbar circulation such as type of vascular resistance, anatomical structure of vascular wall and vessel lumen. Neurogenic and angiogenic factors, rheological blood composition, presence of anatomical and pathological obstructions on blood flow pathway as well as degree of development of collateral circulation pathways--have influence on the volume and blood flow velocity in eyeball. There were discussed bulbar circulation hemodynamics, emphasizing the importance of perfusion pressure. The role of risk factors was underlined for pathological lesions in vessels supplying blood to eyeball and in ophthalmic artery (OA) and its collaterals, in central retinal artery (CRA) as well as posterior ciliary arteries (PCAs), and in venous system carrying away blood from eye. IN CONCLUSION--the results of many studies of retrobulbar blood flow in different types of ophthalmic diseases of the vascular etiopathogenesis indicate that registry of the mean values of blood flow parameters and vascular resistance indices parallel to measurement of blood flow spectrum in OA, CRA, PCAs arteries, might contribute much information to explain or to evaluate nature of pathological changes in retinal and choroidal circulation.

  1. Polarized protein transport and lumen formation during epithelial tissue morphogenesis.

    Science.gov (United States)

    Blasky, Alex J; Mangan, Anthony; Prekeris, Rytis

    2015-01-01

    One of the major challenges in biology is to explain how complex tissues and organs arise from the collective action of individual polarized cells. The best-studied model of this process is the cross talk between individual epithelial cells during their polarization to form the multicellular epithelial lumen during tissue morphogenesis. Multiple mechanisms of apical lumen formation have been proposed. Some epithelial lumens form from preexisting polarized epithelial structures. However, de novo lumen formation from nonpolarized cells has recently emerged as an important driver of epithelial tissue morphogenesis, especially during the formation of small epithelial tubule networks. In this review, we discuss the latest findings regarding the mechanisms and regulation of de novo lumen formation in vitro and in vivo.

  2. Does the type of renal artery anatomic variant determine the diameter of the main vessel supplying a kidney? A study based on CT data with a particular focus on the presence of multiple renal arteries.

    Science.gov (United States)

    Majos, Marcin; Stefańczyk, Ludomir; Szemraj-Rogucka, Zofia; Elgalal, Marcin; De Caro, Raffaele; Macchi, Veronica; Polguj, Michał

    2018-04-01

    An in-depth knowledge of renal vascular anatomy is essential when planning many surgical procedures; however, a few data exists regarding renal artery diameter. The aim of this study was to assess this morphological feature and to investigate whether a correlation exists between renal artery diameter and the type of arterial supply, with a particular emphasis on variant anatomy and the presence of multiple renal arteries. Computed tomography angiography (CTA) studies of 248 patients, i.e., a total of 496 kidneys, were evaluated. The mean age of the patients was 66.4 ± 15.01 years. Renal artery diameter was measured based on the type of arterial blood supply. The frequency of occurrence of three anatomic variants of renal arterial supply was established: single renal artery (RA) 43.35%, single artery with prehilar branching (pRA) 37.30%, and multiple renal artery (mRA) 19.35%. The diameter of single renal arteries, with either prehilar or hilar branching, was significantly larger than when multiple arteries were present. A detailed analysis of just the mRA variant demonstrated that the diameter of the renal arteries in men was larger (p = 0.012) than those in women and that there was no difference in diameter with regard to the side of the body (p = 0.219). The classification described in our study containing a detailed description of renal artery diameter. It may be helpful in clinical practice, especially for transplantologists, surgeons, and vascular surgeons.

  3. Vessel Operating Units (Vessels)

    Data.gov (United States)

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

  4. Evolution of regular geometrical shapes in fiber lumens

    KAUST Repository

    Le, Ngoc Lieu; Kim, Dooli; Nunes, Suzana Pereira

    2017-01-01

    of the internal channels or lumens of polymeric hollow fibers, leading to polygonal geometries with increasing number of sides. The elasticity of the incipient channel skin and instabilities during fiber formation are affected by the internal coagulant fluid

  5. Spermine oxidase promotes bile canalicular lumen formation through acrolein production.

    Science.gov (United States)

    Uemura, Takeshi; Takasaka, Tomokazu; Igarashi, Kazuei; Ikegaya, Hiroshi

    2017-11-01

    Spermine oxidase (SMOX) catalyzes oxidation of spermine to generate spermidine, hydrogen peroxide (H 2 O 2 ) and 3-aminopropanal, which is spontaneously converted to acrolein. SMOX is induced by a variety of stimuli including bacterial infection, polyamine analogues and acetaldehyde exposure. However, the physiological functions of SMOX are not yet fully understood. We investigated the physiological role of SMOX in liver cells using human hepatocellular carcinoma cell line HepG2. SMOX localized to the bile canalicular lumen, as determined by F-actin staining. Knockdown of SMOX reduced the formation of bile canalicular lumen. We also found that phospho-Akt (phosphorylated protein kinase B) was localized to canalicular lumen. Treatment with Akt inhibitor significantly reduced the formation of bile canalicular lumen. Acrolein scavenger also inhibited the formation of bile canalicular lumen. PTEN, phosphatase and tensin homolog and an inhibitor of Akt, was alkylated in a SMOX-dependent manner. Our results suggest that SMOX plays a central role in the formation of bile canalicular lumen in liver cells by activating Akt pathway through acrolein production.

  6. Intracranial vessel wall imaging at 7.0 tesla MRI

    NARCIS (Netherlands)

    van der Kolk, A.G.

    2014-01-01

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

  7. Mechanism of lumen gain with a novel rotational aspiration atherectomy system for peripheral arterial disease: examination by intravascular ultrasound.

    Science.gov (United States)

    Hassan, Ali H M; Ako, Junya; Waseda, Katsuhisa; Honda, Yasuhiro; Zeller, Thomas; Leon, Martin B; Fitzgerald, Peter J

    2010-01-01

    The purpose of this study was to evaluate the mechanism of luminal gain with a novel atheroablation system (Pathway PV) for the treatment of peripheral artery disease using intravascular ultrasound (IVUS). The atherectomy system is a rotational atherectomy device, which employs expandable rotating blades with ports that allow flushing and aspiration of the plaque material or thrombus. In this first-in-man clinical study, IVUS analysis was available in 6 patients with lower limb ischemia treated with this device. The treatment results were assessed using IVUS at pre and post atherectomy. Lumen beyond burr size (LBB) was defined as lumen gain divided by the estimated burr area determined by the burr-size. IVUS analysis was available in six patients (superficial femoral artery n=3, popliteal artery n=2, posterior tibial artery n=1). Atheroablation achieved a significant increase in lumen area (LA) (preintervention 3.9+/-0.4, postatheroablation 8.0+/-1.7 mm(2), Patherectomy device achieved significant luminal gain by debulking in the absence of vessel stretching. The LA was greater than burr-sized lumen expectancy at cross-sections along the treated segments, suggesting a complimentary role of aspiration in luminal gain in atherosclerotic peripheral artery lesions.

  8. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

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

  9. Failure Diameter Resolution Study

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-12-19

    Previously the SURFplus reactive burn model was calibrated for the TATB based explosive PBX 9502. The calibration was based on fitting Pop plot data, the failure diameter and the limiting detonation speed, and curvature effect data for small curvature. The model failure diameter is determined utilizing 2-D simulations of an unconfined rate stick to find the minimum diameter for which a detonation wave propagates. Here we examine the effect of mesh resolution on an unconfined rate stick with a diameter (10mm) slightly greater than the measured failure diameter (8 to 9 mm).

  10. Automated assessment of aortic and main pulmonary arterial diameters using model-based blood vessel segmentation for predicting chronic thromboembolic pulmonary hypertension in low-dose CT lung screening

    Science.gov (United States)

    Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Sugiura, Toshihiko; Tanabe, Nobuhiro; Kusumoto, Masahiko; Eguchi, Kenji; Kaneko, Masahiro

    2018-02-01

    Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by obstruction of the pulmonary vasculature by residual organized thrombi. A morphological abnormality inside mediastinum of CTEPH patient is enlargement of pulmonary artery. This paper presents an automated assessment of aortic and main pulmonary arterial diameters for predicting CTEPH in low-dose CT lung screening. The distinctive feature of our method is to segment aorta and main pulmonary artery using both of prior probability and vascular direction which were estimated from mediastinal vascular region using principal curvatures of four-dimensional hyper surface. The method was applied to two datasets, 64 lowdose CT scans of lung cancer screening and 19 normal-dose CT scans of CTEPH patients through the training phase with 121 low-dose CT scans. This paper demonstrates effectiveness of our method for predicting CTEPH in low-dose CT screening.

  11. Is quantitative coronary angiography reliable in assessing the late lumen loss of the everolimus-eluting bioresorbable polylactide scaffold in comparison with the cobalt-chromium metallic stent?

    NARCIS (Netherlands)

    Sotomi, Yohei; Onuma, Yoshinobu; Miyazaki, Yosuke; Asano, Taku; Katagiri, Yuki; Tenekecioglu, Erhan; Jonker, Hans; Dijkstra, Jouke; de Winter, Robbert J.; Wykrzykowska, Joanna J.; Stone, Gregg W.; Popma, Jeffrey J.; Kozuma, Ken; Tanabe, Kengo; Serruys, Patrick W.; Kimura, Takeshi

    2017-01-01

    Aims: Immediately after stent/scaffold implantation, quantitative coronary angiography (QCA) in comparison to optical coherence tomography (OCT) more severely underestimates the lumen diameter (LD) in Absorb than in XIENCE. This OCT-QCA discrepancy has not been evaluated at long-term follow-up. The

  12. Bronchial lumen is the safer route for an airway exchange catheter in double-lumen tube replacement: preventable complication in airway management for thoracic surgery.

    Science.gov (United States)

    Wu, Hsiang-Ling; Tai, Ying-Hsuan; Wei, Ling-Fang; Cheng, Hung-Wei; Ho, Chiu-Ming

    2017-10-01

    There is no current consensus on which lumen an airway exchange catheter (AEC) should be passed through in double-lumen endotracheal tube (DLT) to exchange for a single-lumen endotracheal tube (SLT) after thoracic surgery. We report an unusual case to provide possible solution on this issue. A 71-year-old man with lung adenocarcinoma had an event of a broken exchange catheter used during a DLT replacement with a SLT, after a video-assisted thoracic surgery. The exchange catheter was impinged at the distal tracheal lumen and snapped during manipulation. All three segments of the catheter were retrieved without further airway compromises. Placement of airway tube exchanger into the tracheal lumen of double-lumen tube is a potential contributing factor of the unusual complication. We suggest an exchange catheter be inserted into the bronchial lumen in optimal depth with the adjunct of video laryngoscope, as the safe method for double-lumen tube exchange.

  13. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki

    2000-01-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year (ΔD) were significantly greater than in groups R and B (%TFV: 74.1±0.07 vs 15.2±0.03 vs 11.8±0.04, p<0.01; ΔD: 3.62±0.82 vs 0 vs 0.58±0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and ΔD (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  14. Evaluation of flow volume and flow patterns in the patent false lumen of chronic aortic dissections using velocity-encoded cine magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Toshihisa; Watanabe, Shigeru; Sakurada, Hideki; Ono, Katsuhiro; Urano, Miharu; Hijikata, Yasuyoshi; Saito, Isao; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine

    2000-10-01

    In 21 patients with chronic aortic dissections and proven patent false lumens, the flow volume and flow patterns in the patent false lumens was evaluated using velocity-encoded cine magnetic resonance imaging (VENC-MRI) and the relationship between the flow characteristics and aortic enlargement was retrospectively examined. Flow patterns in the false lumen were divided into 3 groups: pattern A with primarily antegrade flow (n=6), pattern R with primarily retrograde flow (n=3), and pattern B with bidirectional flow (n=12). In group A, the rate of flow volume in the false lumen compared to the total flow volume in true and false lumens (%TFV) and the average rate of enlargement of the maximum diameter of the dissected aorta per year ({delta}D) were significantly greater than in groups R and B (%TFV: 74.1{+-}0.07 vs 15.2{+-}0.03 vs 11.8{+-}0.04, p<0.01; {delta}D: 3.62{+-}0.82 vs 0 vs 0.58{+-}0.15 mm/year, p<0.05, respectively). There was a significant correlation between %TFV and {delta}D (r=0.79, p<0.0001). Evaluation of flow volume and flow patterns in the patent false lumen using VENC-MRI may be useful for predicting enlargement of the dissected aorta. (author)

  15. Targeting Therapy Resistant Tumor Vessels

    Science.gov (United States)

    2008-08-01

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

  16. Quantitative coronary CT angiography: absolute lumen sizing rather than %stenosis predicts hemodynamically relevant stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Plank, Fabian [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Innsbruck Medical University, Department of Internal Medicine III - Cardiology, Innsbruck (Austria); Burghard, Philipp; Mayr, Agnes; Klauser, Andrea; Feuchtner, Gudrun [Innsbruck Medical University, Department of Radiology, Innsbruck (Austria); Friedrich, Guy; Dichtl, Wolfgang [Innsbruck Medical University, Department of Internal Medicine III - Cardiology, Innsbruck (Austria); Wolf, Florian [Vienna Medical University, Department of Cardiovascular and Interventional Radiology, Vienna (Austria)

    2016-11-15

    To identify the most accurate quantitative coronary stenosis parameter by CTA for prediction of functional significant coronary stenosis resulting in coronary revascularization. 160 consecutive patients were prospectively examined with CTA. Proximal coronary stenosis was quantified by minimal lumen area (MLA) and minimal lumen diameter (MLD), %area and %diameter stenosis. Lesion length (LL) was measured. The reference standard was invasive coronary angiography (ICA) (>70 % stenosis, FFR <0.8). 210 coronary segments were included (59 % positive). MLA of ≤1.8 mm{sup 2} was identified as the optimal cut-off (c = 0.97, p < 0.001; 95 % CI 0.94-0.99) (sensitivity 90.9 %, specificity 89.3 %) for prediction of functional-relevant stenosis (for MLA >2.1 mm{sup 2} sensitivity was 100 %). The optimal cut-off for MLD was 1.2 mm (c = 0.92; p < 0.001; 95 % CI 0.88-95) (sensitivity 90.9, specificity 85.2) while %area and %diameter stenosis were less accurate (c = 0.89; 95 % CI 0.84-93, c = 0.87; 95 % CI 0.82-92, respectively, with thresholds at 73 % and 61 % stenosis). Accuracy for LL was c = 0.74 (95 % CI 0.67-81), and for LL/MLA and LL/MLD ratio c = 0.90 and c = 0.84. MLA ≤1.8 mm{sup 2} and MLD ≤1.2 mm are the most accurate cut-offs for prediction of haemodynamically significant stenosis by ICA, with a higher accuracy than relative % stenosis. (orig.)

  17. Selective fabrication of iron oxide particles in halloysite lumen

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Pengwu; Du, Yuanyuan [School of Pharmacy, Jiangxi Science and Technology Normal University, Nanchang, Jiangxi 330013 (China); Ma, Xiaofei, E-mail: maxiaofei@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China)

    2015-02-01

    As the adsorbents or the supports of photocatalysts, halloysite nanotubes (HNT) were expected to have intact external surface for adsorption or catalyst immobilization, when Fe{sub 3}O{sub 4} particles was introduced to prepare magnetic HNTs for easy separation. The negatively charged urease was loaded inside positively charged HNT lumen, and urease catalyzed the hydrolysis of urea and resulted in the alkaline environment in HNT lumen. When Fe{sup 3+} and Fe{sup 2+} diffused in, Fe{sub 3}O{sub 4} particles were selectively synthesized in the lumen of HNT. The obtained Fe{sub 3}O{sub 4}@HNT is characterized by transmission electron microscopy and Fourier transform infrared spectroscopy, X-ray diffraction and hysteresis loops. The obtained magnetic Fe{sub 3}O{sub 4}@HNT can be magnetically collected with intact external surface, which can support photocatalysts or remove the pollutants. - Highlights: • Fe{sub 3}O{sub 4}@HNT was prepared. • Fe{sub 3}O{sub 4}@HNT was characterized. • Fe{sub 3}O{sub 4} particles were selectively synthesized in the lumen of HNT.

  18. Selective fabrication of iron oxide particles in halloysite lumen

    International Nuclear Information System (INIS)

    Zheng, Pengwu; Du, Yuanyuan; Ma, Xiaofei

    2015-01-01

    As the adsorbents or the supports of photocatalysts, halloysite nanotubes (HNT) were expected to have intact external surface for adsorption or catalyst immobilization, when Fe 3 O 4 particles was introduced to prepare magnetic HNTs for easy separation. The negatively charged urease was loaded inside positively charged HNT lumen, and urease catalyzed the hydrolysis of urea and resulted in the alkaline environment in HNT lumen. When Fe 3+ and Fe 2+ diffused in, Fe 3 O 4 particles were selectively synthesized in the lumen of HNT. The obtained Fe 3 O 4 @HNT is characterized by transmission electron microscopy and Fourier transform infrared spectroscopy, X-ray diffraction and hysteresis loops. The obtained magnetic Fe 3 O 4 @HNT can be magnetically collected with intact external surface, which can support photocatalysts or remove the pollutants. - Highlights: • Fe 3 O 4 @HNT was prepared. • Fe 3 O 4 @HNT was characterized. • Fe 3 O 4 particles were selectively synthesized in the lumen of HNT

  19. Hollow fiber membrane lumen modified by polyzwitterionic grafting

    KAUST Repository

    Le, Ngoc Lieu

    2016-08-24

    In this study, we demonstrate an effective way to modify the lumen of polyetherimide hollow fibers by grafting zwitterionic poly(sulfobetaine) to increase the membrane resistance to fouling. Surface-selective grafting of the protective hydrogel layers has been achieved in a facile two-step process. The first step is the adsorption of a macromolecular redox co-initiator on the lumen-side surface of the membrane, which in the second step, after flushing the lumen of the membrane with a solution comprising monomers and a complementary redox initiator, triggers the in situ cross-linking copolymerization at room temperature. The success of grafting reaction has been verified by the surface elemental analyses using X-ray photoelectron spectroscopy (XPS) and the surface charge evaluation using zeta potential measurements. The hydrophilicity of the grafted porous substrate is improved as indicated by the change of contact angle value from 44° to 30°, due to the hydration layer on the surface produced by the zwitterionic poly(sulfobetaine). Compared to the pristine polyetherimide (PEI) substrate, the poly(sulfobetaine) grafted substrates exhibit high fouling resistance against bovine serum albumin (BSA) adsorption, E. coli attachment and cell growth on the surface. Fouling minimization in the lumen is important for the use of hollow fibers in different processes. For instance, it is needed to preserve power density of pressure-retarded osmosis (PRO). In high-pressure PRO tests, a control membrane based on PEI with an external polyamide selective layer was seriously fouled by BSA, leading to a high water flux drop of 37%. In comparison, the analogous membrane, whose lumen was modified with poly(sulfobetaine), not only had a less water flux decline but also had better flux recovery, up to 87% after cleaning and hydraulic pressure impulsion. Clearly, grafting PRO hollow fiber membranes with zwitterionic polymeric hydrogels as a protective layer potentially sustains PRO

  20. Research vessels

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.

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

  1. A Novel Device for True Lumen Re-Entry After Subintimal Recanalization of Superficial Femoral Arteries: First-in-Man Experience and Technical Description

    International Nuclear Information System (INIS)

    Airoldi, Flavio; Faglia, Ezio; Losa, Sergio; Tavano, Davide; Latib, Azeem; Mantero, Manuela; Lanza, Gaetano; Clerici, Giacomo

    2011-01-01

    Subintimal angioplasty (SAP) is frequently performed for the treatment of critical limb ischemia (CLI) and has been recognized as an effective technique for these patients. Nevertheless, this approach is limited by the lack of controlled re-entry into the true lumen of the target vessel. We describe a novel device for true lumen re-entry after subintimal recanalization of superficial femoral arteries (SFA). We report our experience with six patients treated between April 2009 and January 2010 with a novel system designed to facilitate true lumen re-entry. The device was advanced by ipsilateral antegrade approach through a 6-French sheath. Successful reaccess into the true lumen was obtained in five of six patients without complications. The patient in whom the reaccess to the true lumen was not possible underwent successful bypass surgery. At 30 days follow-up, the SFA was patent in all patients according to echo-Doppler examination. Our preliminary experience indicates that this novel re-entry device increases the success rate of percutaneous revascularization of chronically occluded SFA.

  2. Normal ureteral diameter in infancy and childhood

    International Nuclear Information System (INIS)

    Hellstroem, M.; Hjaelmaas, K.; Jacobsson, B.; Jodal, U.; Oden, A.; Oestra Sjukhuset, Goeteborg; Oestra Sjukhuset, Goeteborg; Goeteborg Univ.

    1985-01-01

    Ureteral diameters were estimated on films from intravenous urography in 194 children (100 boys and 94 girls) aged 0-16 years. Children with signs of urinary tract infection, calculi, obstruction, duplication or malformation were excluded. Films obtained without abdominal compression were used for measurements, including only ureters visualized over 50 per cent of their lengths. A good correlation was demonstrated between ureteral diameter and age and between ureteral diameter and the length of a segment of the lumbar spine. The widest part of the ureter was most often located just above the crossing of the iliac vessels. The right ureter was slightly wider than the left one. No difference between boys and girls was noted. The results are in good agreement with those of others obtained at autopsy. Bearing in mind the possible physiologic variations, it would seem that measuring the ureteral diameter can be of value for a more objective differentiation between dilated and non-dilated ureters. (orig.)

  3. Laser beam diameter for port wine stain treatment

    NARCIS (Netherlands)

    Keijzer, M.; Pickering, J. W.; van Gemert, M. J.

    1991-01-01

    Optimal port wine stain treatment requires the selective absorption of light by the ectatic blood vessels. We investigated whether deeper blood vessels can be coagulated, without damaging other cutaneous structures, by varying the laser beam diameter. The penetration of the light was simulated with

  4. Diffusive oxygen shunting between vessels in the preglomerular renal vasculature: anatomic observations and computational modeling.

    Science.gov (United States)

    Gardiner, Bruce S; Thompson, Sarah L; Ngo, Jennifer P; Smith, David W; Abdelkader, Amany; Broughton, Brad R S; Bertram, John F; Evans, Roger G

    2012-09-01

    To understand how geometric factors affect arterial-to-venous (AV) oxygen shunting, a mathematical model of diffusive oxygen transport in the renal cortex was developed. Preglomerular vascular geometry was investigated using light microscopy (providing vein shape, AV separation, and capillary density near arteries) and published micro-computed tomography (CT) data (providing vessel size and AV separation; Nordsletten DA, Blackett S, Bentley MD, Ritman EL, Smith NP. IUPS Physiome Project. http://www.physiome.org.nz/publications/nordsletten_blackett_ritman_bentley_smith_2005/folder_contents). A "U-shaped" relationship was observed between the arterial radius and the distance between the arterial and venous lumens. Veins were found to partially wrap around the artery more consistently for larger rather than smaller arteries. Intrarenal arteries were surrounded by an area of fibrous tissue, lacking capillaries, the thickness of which increased from ∼5 μm for the smallest arteries (200-μm diameter). Capillary density was greater near smaller arteries than larger arteries. No capillaries were observed between wrapped AV vessel pairs. The computational model comprised a single AV pair in cross section. Geometric parameters critical in renal oxygen transport were altered according to variations observed by CT and light microscopy. Lumen separation and wrapping of the vein around the artery were found to be the critical geometric factors determining the amount of oxygen shunted between AV pairs. AV oxygen shunting increases both as lumen separation decreases and as the degree of wrapping increases. The model also predicts that capillaries not only deliver oxygen, but can also remove oxygen from the cortical parenchyma close to an AV pair. Thus the presence of oxygen sinks (capillaries or tubules) near arteries would reduce the effectiveness of AV oxygen shunting. Collectively, these data suggest that AV oxygen shunting would be favored in larger vessels common to the

  5. [Telescopic adhesive anastomosis of small blood vessel applied in formation of arteriovenous fistula for hemodialysis].

    Science.gov (United States)

    Shen, G; Leng, Y; Rong, G

    1997-03-01

    The formation of an arteriovenous fistual for dialysis by routine interrupted sutures anastomosing the vein and artery is difficult to perform and time-consuming. A new method, telescopic adhesive anastomosis was studied and applied in 10 hemodialysis patients, who were in need of an arteriovenous fistula. The external diameter of the vessels anastomosed was 2.40 +/- 0.20 mm (radial artery) or 2.40 +/- 0.35 mm (cephalic vein). After thorough debridement of the vascular ends, the arterial end was put in the venous lumen. In order to fix the telescopic vessels, two stitches were applied 180 degrees apart from each other and tied. Each stitch was inserted from vein (penetrating the whole wall) to artery (just through the adventitia and partial thickness of the media vasorum). The distance from the stitch to the edge of the vein was 0.5 mm, and that of the artery was approximated to the external diameter of the vessle. The medical adhesive was then applied for sealing the anastomotic adventitia. Ten seconds were given for the solidification of the adhesive. The patients were followed up for 8 months. The patency rate was 100%, and the rate of blood flow was more than 300 ml/min (measured by ultrasonography). It was shown that this method could be managed easily and quickly, and the so-formed fistula would fulfill the need of hemodialysis.

  6. Public relations ve firmě LUMEN INTERNATIONAL a.s.

    OpenAIRE

    DICHTLOVÁ, Hana

    2012-01-01

    Goal of the thesis was to assess current significance and usage of public relations in LUMEN INTERNATIONAL a.s. company and to create plan of another development. The author analysed development and current situation of public relations in LUMEN holding. There are a few suggestions in this thesis how to improve public relations in whole LUMEN holding.

  7. Stanford type A aortic dissection with closed false lumen: Analysis of prognostic factors at initial CT or MRI

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Yohjiro; Sakamoto, Ichiro; Ogawa, Yohji; Sueyoshi, Eijun; Hayashi, Kuniaki; Takagi, Masatake [Nagasaki Univ. (Japan). School of Medicine; Narimatsu, Motoharu

    1997-08-01

    Nineteen patients with Stanford type A acute aortic dissection with closed false lumen were reviewed. In the follow-up examinations, ulcerlike projection (ULP) in the ascending aorta (AA) or aortic arch (AR) was identified in 8 of 19 patients. In 5 of these 8 patients, acute cardiac tamponade occurred and 3 of them died. In the other 11 patients, there was no mortality, and only one patient underwent elective surgery. The appearance of ULP in the AA/AR is considered an indication for urgent surgery because it is regarded as a precursor of lethal complications such as cardiac tamponade. The purpose of this study was to investigate predictors of the appearance of ULP in the AA/AR with early imagings (CT or MRI) before the appearance of ULP. The patients were divided into two groups: patients with ULP in the AA/AR (8 patients) and others (11 patients). Initial CT or MRI findings of the thoracic aorta were retrospectively statistically analyzed in each group. Three predictive factors were statistically significant for the appearance of ULP in the AA/AR (diameter of the AA{>=}5 cm, thickness of the false lumen of the AA{>=}1 cm, thickness of the false lumen of the AA{>=} that of the descending aorta). Close attention should be paid, if any of these 3 factors is observed at initial CT or MRI. (author)

  8. Stanford type A aortic dissection with closed false lumen: Analysis of prognostic factors at initial CT or MRI

    International Nuclear Information System (INIS)

    Matsuoka, Yohjiro; Sakamoto, Ichiro; Ogawa, Yohji; Sueyoshi, Eijun; Hayashi, Kuniaki; Takagi, Masatake; Narimatsu, Motoharu.

    1997-01-01

    Nineteen patients with Stanford type A acute aortic dissection with closed false lumen were reviewed. In the follow-up examinations, ulcerlike projection (ULP) in the ascending aorta (AA) or aortic arch (AR) was identified in 8 of 19 patients. In 5 of these 8 patients, acute cardiac tamponade occurred and 3 of them died. In the other 11 patients, there was no mortality, and only one patient underwent elective surgery. The appearance of ULP in the AA/AR is considered an indication for urgent surgery because it is regarded as a precursor of lethal complications such as cardiac tamponade. The purpose of this study was to investigate predictors of the appearance of ULP in the AA/AR with early imagings (CT or MRI) before the appearance of ULP. The patients were divided into two groups: patients with ULP in the AA/AR (8 patients) and others (11 patients). Initial CT or MRI findings of the thoracic aorta were retrospectively statistically analyzed in each group. Three predictive factors were statistically significant for the appearance of ULP in the AA/AR (diameter of the AA≥5 cm, thickness of the false lumen of the AA≥1 cm, thickness of the false lumen of the AA≥ that of the descending aorta). Close attention should be paid, if any of these 3 factors is observed at initial CT or MRI. (author)

  9. Vessel-diameter quantification and embolus detection in CTA images

    NARCIS (Netherlands)

    Bouma, H.

    2008-01-01

    Pulmonary embolism (PE) is the sudden obstruction of an artery in the lungs, usually due to a blood clot. There are more than 50 cases of PE per 100,000 persons every year in the USA. Of these cases, 11% die in the first hour and in total, the untreated mortality rate of PE is estimated to be 30%.

  10. Scribble is required for normal epithelial cell–cell contacts and lumen morphogenesis in the mammalian lung

    Science.gov (United States)

    Yates, Laura L.; Schnatwinkel, Carsten; Hazelwood, Lee; Chessum, Lauren; Paudyal, Anju; Hilton, Helen; Romero, M. Rosario; Wilde, Jonathan; Bogani, Debora; Sanderson, Jeremy; Formstone, Caroline; Murdoch, Jennifer N.; Niswander, Lee A.; Greenfield, Andy; Dean, Charlotte H.

    2013-01-01

    During lung development, proper epithelial cell arrangements are critical for the formation of an arborized network of tubes. Each tube requires a lumen, the diameter of which must be tightly regulated to enable optimal lung function. Lung branching and lumen morphogenesis require close epithelial cell–cell contacts that are maintained as a result of adherens junctions, tight junctions and by intact apical–basal (A/B) polarity. However, the molecular mechanisms that maintain epithelial cohesion and lumen diameter in the mammalian lung are unknown. Here we show that Scribble, a protein implicated in planar cell polarity (PCP) signalling, is necessary for normal lung morphogenesis. Lungs of the Scrib mouse mutant Circletail (Crc) are abnormally shaped with fewer airways, and these airways often lack a visible, ‘open’ lumen. Mechanistically we show that Scrib genetically interacts with the core PCP gene Vangl2 in the developing lung and that the distribution of PCP pathway proteins and Rho mediated cytoskeletal modification is perturbed in ScribCrc/Crc lungs. However A/B polarity, which is disrupted in Drosophila Scrib mutants, is largely unaffected. Notably, we find that Scrib mediates functions not attributed to other PCP proteins in the lung. Specifically, Scrib localises to both adherens and tight junctions of lung epithelia and knockdown of Scrib in lung explants and organotypic cultures leads to reduced cohesion of lung epithelial cells. Live imaging of Scrib knockdown lungs shows that Scrib does not affect bud bifurcation, as previously shown for the PCP protein Celsr1, but is required to maintain epithelial cohesion. To understand the mechanism leading to reduced cell–cell association, we show that Scrib associates with β-catenin in embryonic lung and the sub-cellular distribution of adherens and tight junction proteins is perturbed in mutant lung epithelia. Our data reveal that Scrib is required for normal lung epithelial organisation and lumen

  11. Evolution of regular geometrical shapes in fiber lumens

    KAUST Repository

    Le, Ngoc Lieu

    2017-08-17

    The geometry of polymeric hollow fibers for hemodialysis or desalination is a key factor determining their performance. Deformations are frequently observed, but they are rather random. Here we were able to exactly control the shape evolution of the internal channels or lumens of polymeric hollow fibers, leading to polygonal geometries with increasing number of sides. The elasticity of the incipient channel skin and instabilities during fiber formation are affected by the internal coagulant fluid composition and flow rate; and highly influence the polygonal shape. We propose a holistic explanation by analyzing the thermodynamic, kinetic and rheological aspects involved in the skin formation and their synergy.

  12. Phenomenological vessel burst investigations

    International Nuclear Information System (INIS)

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

    1985-07-01

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

  13. Computed Tomographic Window Setting for Bronchial Measurement to Guide Double-Lumen Tube Size.

    Science.gov (United States)

    Seo, Jeong-Hwa; Bae, Jinyoung; Paik, Hyesun; Koo, Chang-Hoon; Bahk, Jae-Hyon

    2018-04-01

    The bronchial diameter measured on computed tomography (CT) can be used to guide double-lumen tube (DLT) sizes objectively. The bronchus is known to be measured most accurately in the so-called bronchial CT window. The authors investigated whether using the bronchial window results in the selection of more appropriately sized DLTs than using the other windows. CT image analysis and prospective randomized study. Tertiary hospital. Adults receiving left-sided DLTs. The authors simulated selection of DLT sizes based on the left bronchial diameters measured in the lung (width 1,500 Hounsfield unit [HU] and level -700 HU), bronchial (1,000 HU and -450 HU), and mediastinal (400 HU and 25 HU) CT windows. Furthermore, patients were randomly assigned to undergo imaging with either the bronchial or mediastinal window to guide DLT sizes. Using the underwater seal technique, the authors assessed whether the DLT was appropriately sized, undersized, or oversized for the patient. On 130 CT images, the bronchial diameter (9.9 ± 1.2 mm v 10.5 ± 1.3 mm v 11.7 ± 1.3 mm) and the selected DLT size were different in the lung, bronchial, and mediastinal windows, respectively (p study, oversized tubes were chosen less frequently in the bronchial window than in the mediastinal window (6/110 v 23/111; risk ratio 0.38; 95% CI 0.19-0.79; p = 0.003). No tubes were undersized after measurements in these two windows. The bronchial measurement in the bronchial window guided more appropriately sized DLTs compared with the lung or mediastinal windows. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The dual-gate lumen model of renal monoamine transport

    Directory of Open Access Journals (Sweden)

    Marty Hinz

    2010-07-01

    Full Text Available Marty Hinz1, Alvin Stein2, Thomas Uncini31Clinical Research, NeuroResearch Clinics, Inc. Cape Coral, Florida, USA; 2Stein Orthopedic Associates, Plantation, Florida, USA; 3DBS Labs, Duluth, Minnesota, USAAbstract: The three-phase response of urinary serotonin and dopamine in subjects ­simultaneously taking amino acid precursors of serotonin and dopamine has been defined.1,2 No model exists regarding the renal etiology of the three-phase response. This writing outlines a model explaining the origin of the three-phase response of urinary serotonin and dopamine. A “dual-gate lumen transporter model” for the basolateral monoamine transporters of the kidneys is proposed as being the etiology of the three-phase urinary serotonin and dopamine responses.Purpose: The purpose of this writing is to document the internal renal function model that has evolved in research during large-scale assay with phase interpretation of urinary serotonin and dopamine.Patients and methods: In excess of 75,000 urinary monoamine assays from more than 7,500 patients were analyzed. The serotonin and the dopamine phase were determined for specimens submitted in the competitive inhibition state. The phase determination findings were then correlated with peer-reviewed literature.Results: The correlation between the three-phase response of urinary serotonin and dopamine with internal renal processes of the bilateral monoamine transporter and the apical monoamine transporter of the proximal convoluted renal tubule cells is defined.Conclusion: The phase of urinary serotonin and dopamine is dependent on the status of the serotonin gate, dopamine gate, and lumen of the basolateral monoamine transporter while in the competitive inhibition state.Keywords: serotonin, dopamine, basolateral, apical, kidney, proximal

  15. Variable impact of CSF flow suppression on quantitative 3.0T intracranial vessel wall measurements.

    Science.gov (United States)

    Cogswell, Petrice M; Siero, Jeroen C W; Lants, Sarah K; Waddle, Spencer; Davis, L Taylor; Gilbert, Guillaume; Hendrikse, Jeroen; Donahue, Manus J

    2018-03-31

    Flow suppression techniques have been developed for intracranial (IC) vessel wall imaging (VWI) and optimized using simulations; however, simulation results may not translate in vivo. To evaluate experimentally how IC vessel wall and lumen measurements change in identical subjects when evaluated using the most commonly available blood and cerebrospinal fluid (CSF) flow suppression modules and VWI sequences. Prospective. Healthy adults (n = 13; age = 37 ± 15 years) were enrolled. A 3.0T 3D T 1 /proton density (PD)-weighted turbo-spin-echo (TSE) acquisition with post-readout anti-driven equilibrium module, with and without Delay-Alternating-with-Nutation-for-Tailored-Excitation (DANTE) was applied. DANTE flip angle (8-12°) and TSE refocusing angle (sweep = 40-120° or 50-120°) were varied. Basilar artery and internal carotid artery (ICA) wall thicknesses, CSF signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and signal ratio (SR) were assessed. Measurements were made by two readers (radiology resident and board-certified neuroradiologist). A Wilcoxon signed-rank test was applied with corrected two-sided P CSF suppression. Addition of the DANTE preparation reduced CSF SNR from 17.4 to 6.7, thereby providing significant (P CSF suppression. The DANTE preparation also resulted in a significant (P CSF CNR improvement (P = 0.87). There was a trend for a difference in blood SNR with vs. without DANTE (P = 0.05). The outer vessel wall diameter and wall thickness values were lower (P CSF suppression and CNR of the approaches evaluated. However, improvements are heterogeneous, likely owing to intersubject vessel pulsatility and CSF flow variations, which can lead to variable flow suppression efficacy in these velocity-dependent modules. 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  16. Evaluation of Esophageal Motility Utilizing the Functional Lumen Imaging Probe.

    Science.gov (United States)

    Carlson, Dustin A; Kahrilas, Peter J; Lin, Zhiyue; Hirano, Ikuo; Gonsalves, Nirmala; Listernick, Zoe; Ritter, Katherine; Tye, Michael; Ponds, Fraukje A; Wong, Ian; Pandolfino, John E

    2016-12-01

    Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia. In all, 145 patients (aged 18-85 years, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered "abnormal". FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered "abnormal" if EGJ-DI was esophageal motility and 29 normal motility. In all, 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI. FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia.

  17. Containment vessel

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  18. Nonvisualization of the gallbladder lumen on sonogram: a sign of acute viral hepatitis

    International Nuclear Information System (INIS)

    Lim, Jae Hoon; Ko, Young Tae

    1986-01-01

    Six cases of nonvisulization of the gallbladder lumen in patients with acute viral hepatitis are presented. Follow-up ultrasonographic examinations done during the convalescent period in 2 patients showed normal gallbladders and this was correlated with improvement in enzyme levels. It is suggested that acute viral hepatitis should be considered in the differential diagnosis of nonvisualization of the gallbladder lumen on sonogram.

  19. Nonvisualization of the gallbladder lumen on sonogram: a sign of acute viral hepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Hoon; Ko, Young Tae [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    1986-04-15

    Six cases of nonvisulization of the gallbladder lumen in patients with acute viral hepatitis are presented. Follow-up ultrasonographic examinations done during the convalescent period in 2 patients showed normal gallbladders and this was correlated with improvement in enzyme levels. It is suggested that acute viral hepatitis should be considered in the differential diagnosis of nonvisualization of the gallbladder lumen on sonogram.

  20. Preparation of lumen-loaded kenaf pulp with magnetite (Fe3O4)

    International Nuclear Information System (INIS)

    Zakaria, S.; Ong, B.H.; Ahmad, S.H.; Abdullah, M.; Yamauchi, T.

    2005-01-01

    Magnetic pulps were prepared from unbleached kenaf (hibiscus cannabinus L.) kraft pulps. Fe 3 O 4 or magnetite powder was used to load into the pulp's lumen and pit. Aluminum sulphate [Al 2 (SO 4 ) 3 ] (alum) and polyethylenimine (PEI), both mainly function as retention aid were used throughout the experiment and found to be beneficial in the preparation of this magnetic pulps. The ash content method was used to determine the amount of magnetite retained in the lumen and pit. The utilization of PEI up to 2% per pulp fibres was found to be the best result on lumen loading. The deposition of magnetite powder in lumen and pit is found decrease as the addition of PEI used is more than 2% per pulp fibres. Scanning electron microscope (SEM) clearly shows the distribution of magnetite deposited in the lumen. Tensile index and folding endurance of the loaded fibre decreased slightly as the percentage of loading pigment increased

  1. Automated quantification of bronchiectasis, airway wall thickening and lumen tapering in chest CT

    DEFF Research Database (Denmark)

    Perez-Rovira, Adria; Kuo, Wieying; Petersen, Jens

    thickness and accompanying artery radius), and inter-branch Lumen-Ratio (LR, ratio between a branch's lumen and its parent branch lumen radius, a tapering measurement) were computed. Because CF-related structural abnormalities only affect a portion of branches, the 75th percentile was used as summarising......Purpose: To automatically quantify airway structural properties visualised on CT in children with cystic fibrosis (CF) and controls, including: bronchiectasis, airway wall thickening, and lumen tapering. Methods and materials: The 3D surface of the airway lumen, outer wall, and bronchial arteries...... were obtained using a fully automatic, in-house developed, segmentation method. Subsequently, for each detected airway branch, the Airway-Artery Ratio (AAR, ratio between airway outer wall and accompanying artery radius, a bronchiectasis measurement), Wall-Artery Ratio (WAR, ratio between airway wall...

  2. Computed tomography airway lumen volumetry in patients with acromegaly: Association with growth hormone levels and lung function.

    Science.gov (United States)

    Camilo, Gustavo Bittencourt; Carvalho, Alysson Roncally Silva; Guimarães, Alan Ranieri Medeiros; Kasuki, Leandro; Gadelha, Mônica Roberto; Mogami, Roberto; de Melo, Pedro Lopes; Lopes, Agnaldo José

    2017-10-01

    The segmentation and skeletonisation of images via computed tomography (CT) airway lumen volumetry provide a new perspective regarding the incorporation of this technique in medical practice. Our aim was to quantify morphological changes in the large airways of patients with acromegaly through CT and, secondarily, to correlate these findings with hormone levels and pulmonary function testing (PFT) parameters. This was a cross-sectional study in which 28 non-smoker patients with acromegaly and 15 control subjects underwent CT analysis of airway lumen volumetry with subsequent image segmentation and skeletonisation. Moreover, all participants were subjected to PFT. Compared with the controls, patients with acromegaly presented higher diameters in the trachea, right main bronchus and left main bronchus. The patients with acromegaly also showed a higher tracheal sinuosity index (the deviation of a line from the shortest path, calculated by dividing total length by shortest possible path) than the controls [1.06 (1.02-1.09) vs. 1.03 (1.02-1.04), P = 0.04], and tracheal stenosis was observed in 25% of these individuals. The tracheal area was correlated with the levels of growth hormone (r s  = 0.45, P = 0.02) and insulin-like growth factor type I (r s  = 0.38, P = 0.04). The ratio between the forced expiratory flow and forced inspiratory flow at 50% of the forced vital capacity was correlated with the tracheal area (r s  = 0.36, P = 0.02) and Δ tracheal diameters (r s  = 0.58, P volumetry, hormone levels and functional parameters of large airway obstruction. © 2017 The Royal Australian and New Zealand College of Radiologists.

  3. Claudin5a is required for proper inflation of Kupffer's vesicle lumen and organ laterality.

    Directory of Open Access Journals (Sweden)

    Jeong-Gyun Kim

    Full Text Available Left-right asymmetric organ development is critical to establish a proper body plan of vertebrates. In zebrafish, the Kupffer's vesicle (KV is a fluid-filled sac which controls asymmetric organ development, and a properly inflated KV lumen by means of fluid influx is a prerequisite for the asymmetric signal transmission. However, little is known about the components that support the paracellular tightness between the KV luminal epithelial cells to sustain hydrostatic pressure during KV lumen expansion. Here, we identified that the claudin5a (cldn5a is highly expressed at the apical surface of KV epithelial cells and tightly seals the KV lumen. Downregulation of cldn5a in zebrafish showed a failure in organ laterality that resulted from malformed KV. In addition, accelerated fluid influx into KV by combined treatment of forskolin and 3-isobutyl-1-methylxanthine failed to expand the partially-formed KV lumen in cldn5a morphants. However, malformed KV lumen and defective heart laterality in cldn5a morphants were significantly rescued by exogenous cldn5a mRNA, suggesting that the tightness between the luminal epithelial cells is important for KV lumen formation. Taken together, these findings suggest that cldn5a is required for KV lumen inflation and left-right asymmetric organ development.

  4. Claudin5a is required for proper inflation of Kupffer's vesicle lumen and organ laterality.

    Science.gov (United States)

    Kim, Jeong-Gyun; Bae, Sung-Jin; Lee, Hye Shin; Park, Ji-Hyeon; Kim, Kyu-Won

    2017-01-01

    Left-right asymmetric organ development is critical to establish a proper body plan of vertebrates. In zebrafish, the Kupffer's vesicle (KV) is a fluid-filled sac which controls asymmetric organ development, and a properly inflated KV lumen by means of fluid influx is a prerequisite for the asymmetric signal transmission. However, little is known about the components that support the paracellular tightness between the KV luminal epithelial cells to sustain hydrostatic pressure during KV lumen expansion. Here, we identified that the claudin5a (cldn5a) is highly expressed at the apical surface of KV epithelial cells and tightly seals the KV lumen. Downregulation of cldn5a in zebrafish showed a failure in organ laterality that resulted from malformed KV. In addition, accelerated fluid influx into KV by combined treatment of forskolin and 3-isobutyl-1-methylxanthine failed to expand the partially-formed KV lumen in cldn5a morphants. However, malformed KV lumen and defective heart laterality in cldn5a morphants were significantly rescued by exogenous cldn5a mRNA, suggesting that the tightness between the luminal epithelial cells is important for KV lumen formation. Taken together, these findings suggest that cldn5a is required for KV lumen inflation and left-right asymmetric organ development.

  5. Accuracy of geometrical modelling of heat transfer from tissue to blood vessels

    NARCIS (Netherlands)

    Leeuwen, van G.M.J.; Kotte, A.N.T.J.; Bree, de J.; Koijk, van der J.F.; Crezee, J.; Lagendijk, J.J.W.

    1997-01-01

    We have developed a thermal model in which blood vessels are described as geometrical objects, 3D curves with associated diameters. Here the behaviour of the model is examined for low resolutions compared with the vessel diameter and for strongly curved vessels. The tests include a single straight

  6. Neutron Assay System for Confinement Vessel Disposition

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the CVs. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of special nuclear material (SNM) in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le)100-g 239 Pu equivalent in a vessel for safeguards termination. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements.

  7. To assess the intimal thickness, flow velocities, and luminal diameter of carotid arteries using high-resolution B-mode ultrasound doppler imaging

    Science.gov (United States)

    Vemuru, Madhuri; Jabbar, Afzal; Chandra, Suman

    2004-04-01

    Carotid imaging is a Gold Standard test that provides useful information about the structure and functions of carotid arteries. Spectral imaging helps to evaluate the vessel and hemodynamic changes. High resolution B-mode imaging has emerged as one of the methods of choice for determining the anatomic extent of atherosclerosis and its progression and for assessing cardiovascular risks. The measurements made with Doppler correlate well with pathologic measurements. Recent prospective studies have clearly demonstrated that these measurements of carotid intimal thickness are potent predictors of Myocardial Infarction and Stroke. This method appears very attractive as it is non-invasive, extremely safe, well accepted by the patient and relatively inexpensive. It can be performed serially and has the advantage of visualizing the arterial wall in contrast to angiographic techniques which provide only an outline of the arterial lumen. Recently, there has been an interest in the clinical use of this technique in making difficult clinical decisions like deciding on preventive therapies. 30 subjects aged 21-60 years and 30 subjects aged 61-85 years of both sexes are selected after doing a baseline study to exclude Hypertension, Diabetes, Obesity and Hyperlipidemia. The carotid arteries were examined for intimal thickening, blood flow velocities and luminal diameter. With aging there is a narrowing of the carotid vessels and significant increase in intimal thickening with a consequent increase in the blood flow velocities. Inter-observer, intra-observer and instrument variations are seen and there is no significant change in the values when the distal flow pattern is considered for measurements. Aging produces major cardiovascular changes including decreased elasticity and compliance of great arteries leading to structural and functional alterations in heart and vessels. With aging there is increased intimal thickness and increased pulse wave velocity which is clearly

  8. Joint segmentation of lumen and outer wall from femoral artery MR images: Towards 3D imaging measurements of peripheral arterial disease.

    Science.gov (United States)

    Ukwatta, Eranga; Yuan, Jing; Qiu, Wu; Rajchl, Martin; Chiu, Bernard; Fenster, Aaron

    2015-12-01

    Three-dimensional (3D) measurements of peripheral arterial disease (PAD) plaque burden extracted from fast black-blood magnetic resonance (MR) images have shown to be more predictive of clinical outcomes than PAD stenosis measurements. To this end, accurate segmentation of the femoral artery lumen and outer wall is required for generating volumetric measurements of PAD plaque burden. Here, we propose a semi-automated algorithm to jointly segment the femoral artery lumen and outer wall surfaces from 3D black-blood MR images, which are reoriented and reconstructed along the medial axis of the femoral artery to obtain improved spatial coherence between slices of the long, thin femoral artery and to reduce computation time. The developed segmentation algorithm enforces two priors in a global optimization manner: the spatial consistency between the adjacent 2D slices and the anatomical region order between the femoral artery lumen and outer wall surfaces. The formulated combinatorial optimization problem for segmentation is solved globally and exactly by means of convex relaxation using a coupled continuous max-flow (CCMF) model, which is a dual formulation to the convex relaxed optimization problem. In addition, the CCMF model directly derives an efficient duality-based algorithm based on the modern multiplier augmented optimization scheme, which has been implemented on a GPU for fast computation. The computed segmentations from the developed algorithm were compared to manual delineations from experts using 20 black-blood MR images. The developed algorithm yielded both high accuracy (Dice similarity coefficients ≥ 87% for both the lumen and outer wall surfaces) and high reproducibility (intra-class correlation coefficient of 0.95 for generating vessel wall area), while outperforming the state-of-the-art method in terms of computational time by a factor of ≈ 20. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The Functional Lumen Imaging Probe Detects Esophageal Contractility not Observed with Manometry in Patients with Achalasia

    Science.gov (United States)

    Carlson, Dustin A.; Lin, Zhiyue; Kahrilas, Peter J.; Sternbach, Joel; Donnan, Erica N.; Friesen, Laurel; Listernick, Zoe; Mogni, Benjamin; Pandolfino, John E.

    2015-01-01

    Background & Aims The functional lumen imaging probe (FLIP) could improve characterization of achalasia subtypes by detecting non-occlusive esophageal contractions not observed with standard manometry. We aimed to evaluate for esophageal contractions during volumetric distention in patients with achalasia using FLIP topography. Methods Fifty one treatment-naïve patients with achalasia, defined and sub-classified by high-resolution esophageal pressure topography, and 10 asymptomatic individuals (controls) were evaluated with the FLIP during endoscopy. During stepwise distension, simultaneous intra-bag pressures and 16 channels of cross-sectional areas were measured; data were exported to software that generated FLIP topography plots. Esophageal contractility was identified by noting periods of reduced luminal diameter. Esophageal contractions were further characterized by propagation direction, repetitiveness, and based on whether they were occluding or non-occluding. Results Esophageal contractility was detected in all 10 controls: 8/10 had repetitive, antegrade, contractions and 9/10 had occluding contractions. Contractility was detected in 27% (4/15) of patients with type I achalasia and 65% (18/26, including 9 with occluding contractions) of patients with type II achalasia. Contractility was detected in all 10 patients with type III achalasia; 8 of these patients had a pattern of contractility not observed in controls (repetitive, retrograde contractions). Conclusions Esophageal contractility not observed with manometry can be detected in patients with achalasia using FLIP topography. The presence and patterns of contractility detected with FLIP topography may represent variations in pathophysiology, such as mechanisms of pan-esophageal pressurization in patients with type II achalasia. These findings could have implications for additional sub-classification to supplement prediction of the achalasia disease course. PMID:26278501

  10. Double-lumen tubes and auto-PEEP during one-lung ventilation.

    Science.gov (United States)

    Spaeth, J; Ott, M; Karzai, W; Grimm, A; Wirth, S; Schumann, S; Loop, T

    2016-01-01

    Double-lumen tubes (DLT) are routinely used to enable one-lung-ventilation (OLV) during thoracic anaesthesia. The flow-dependent resistance of the DLT's bronchial limb may be high as a result of its narrow inner diameter and length, and thus potentially contribute to an unintended increase in positive end-expiratory pressure (auto-PEEP). We therefore studied the impact of adult sized DLTs on the dynamic auto-PEEP during OLV. In this prospective clinical study, dynamic auto-PEEP was determined in 72 patients undergoing thoracic surgery, with right- and left-sided DLTs of various sizes. During OLV, air trapping was provoked by increasing inspiration to expiration ratio from 1:2 to 2:1 (five steps). Based on measured flow rate, airway pressure (Paw) and bronchial pressure (Pbronch), the pressure gradient across the DLT (ΔPDLT) and the total auto-PEEP in the respiratory system (i.e. the lungs, the DLT and the ventilator circuit) were determined. Subsequently the DLT's share in total auto-PEEP was calculated. ΔPDLT was 2.3 (0.7) cm H2O over the entire breathing cycle. At the shortest expiratory time the mean total auto-PEEP was 2.9 (1.5) cm H2O (range 0-5.9 cm H2O). The DLT caused 27 to 31% of the total auto-PEEP. Size and side of the DLT's bronchial limb did not impact auto-PEEP significantly. Although the DLT contributes to the overall auto-PEEP, its contribution is small and independent of size and side of the DLT's bronchial limb. The choice of DLT does not influence the risk of auto-PEEP during OLV to a clinically relevant extent. DRKS00005648. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Segmentation of the lumen and media-adventitia boundaries of the common carotid artery from 3D ultrasound images

    Science.gov (United States)

    Ukwatta, E.; Awad, J.; Ward, A. D.; Samarabandu, J.; Krasinski, A.; Parraga, G.; Fenster, A.

    2011-03-01

    Three-dimensional ultrasound (3D US) vessel wall volume (VWV) measurements provide high measurement sensitivity and reproducibility for the monitoring and assessment of carotid atherosclerosis. In this paper, we describe a semiautomated approach based on the level set method to delineate the media-adventitia and lumen boundaries of the common carotid artery from 3D US images to support the computation of VWV. Due to the presence of plaque and US image artifacts, the carotid arteries are challenging to segment using image information alone. Our segmentation framework combines several image cues with domain knowledge and limited user interaction. Our method was evaluated with respect to manually outlined boundaries on 430 2D US images extracted from 3D US images of 30 patients who have carotid stenosis of 60% or more. The VWV given by our method differed from that given by manual segmentation by 6.7% +/- 5.0%. For the media-adventitia and lumen segmentations, respectively, our method yielded Dice coefficients of 95.2% +/- 1.6%, 94.3% +/- 2.6%, mean absolute distances of 0.3 +/- 0.1 mm, 0.2 +/- 0.1 mm, maximum absolute distances of 0.8 +/- 0.4 mm, 0.6 +/- 0.3 mm, and volume differences of 4.2% +/- 3.1%, 3.4% +/- 2.6%. The realization of a semi-automated segmentation method will accelerate the translation of 3D carotid US to clinical care for the rapid, non-invasive, and economical monitoring of atherosclerotic disease progression and regression during therapy.

  12. Fission tracks diameters in glasses

    International Nuclear Information System (INIS)

    Garzon Ruiperez, L.; Veiguela, J.

    1974-01-01

    Standard glass microscope slides have been irradiated with fission fragments from the uranium. The etching track conditions have been the same for the series, having changed the etching time only for each specimen. For each glass, a minimum of 250 measurements of the tracks diameters have been made, the distributions of which are the bimodal type. Diameters-etching dependence with time is roughly lineal. Energy determinations have been made with the help of the diameters-energy relations. The calculated values agree very well with the know ones. (author) [es

  13. Improved automated lumen contour detection by novel multifrequency processing algorithm with current intravascular ultrasound system.

    Science.gov (United States)

    Kume, Teruyoshi; Kim, Byeong-Keuk; Waseda, Katsuhisa; Sathyanarayana, Shashidhar; Li, Wenguang; Teo, Tat-Jin; Yock, Paul G; Fitzgerald, Peter J; Honda, Yasuhiro

    2013-02-01

    The aim of this study was to evaluate a new fully automated lumen border tracing system based on a novel multifrequency processing algorithm. We developed the multifrequency processing method to enhance arterial lumen detection by exploiting the differential scattering characteristics of blood and arterial tissue. The implementation of the method can be integrated into current intravascular ultrasound (IVUS) hardware. This study was performed in vivo with conventional 40-MHz IVUS catheters (Atlantis SR Pro™, Boston Scientific Corp, Natick, MA) in 43 clinical patients with coronary artery disease. A total of 522 frames were randomly selected, and lumen areas were measured after automatically tracing lumen borders with the new tracing system and a commercially available tracing system (TraceAssist™) referred to as the "conventional tracing system." The data assessed by the two automated systems were compared with the results of manual tracings by experienced IVUS analysts. New automated lumen measurements showed better agreement with manual lumen area tracings compared with those of the conventional tracing system (correlation coefficient: 0.819 vs. 0.509). When compared against manual tracings, the new algorithm also demonstrated improved systematic error (mean difference: 0.13 vs. -1.02 mm(2) ) and random variability (standard deviation of difference: 2.21 vs. 4.02 mm(2) ) compared with the conventional tracing system. This preliminary study showed that the novel fully automated tracing system based on the multifrequency processing algorithm can provide more accurate lumen border detection than current automated tracing systems and thus, offer a more reliable quantitative evaluation of lumen geometry. Copyright © 2011 Wiley Periodicals, Inc.

  14. Analysis of nuclear reactor pressure vessel flanges

    International Nuclear Information System (INIS)

    Oliveira, C.A.N. de; Augusto, O.B.

    1985-01-01

    This work proposes a methodology for the structural analysis of high diameter nuclear reactor pressure vessel flanges. In the analysis the vessel is divided into shell-of-revolution elements, the flanges are represented by rigid rings, and the bolts are treated as beams. The flexibility method is used for solving the problem, and the results are compared with results obtained by the finite element method. (Author) [pt

  15. Diameter 2 properties and convexity

    Czech Academy of Sciences Publication Activity Database

    Abrahamsen, T. A.; Hájek, Petr Pavel; Nygaard, O.; Talponen, J.; Troyanski, S.

    2016-01-01

    Roč. 232, č. 3 (2016), s. 227-242 ISSN 0039-3223 R&D Projects: GA ČR GA16-07378S Institutional support: RVO:67985840 Keywords : diameter 2 property * midpoint locally uniformly rotund * Daugavet property Subject RIV: BA - General Mathematics Impact factor: 0.535, year: 2016 https://www.impan.pl/pl/wydawnictwa/czasopisma-i-serie-wydawnicze/studia- mathematica /all/232/3/91534/diameter-2-properties-and-convexity

  16. Vessel size measurements in angiograms: A comparison of techniques

    International Nuclear Information System (INIS)

    Hoffmann, Kenneth R.; Nazareth, Daryl P.; Miskolczi, Laszlo; Gopal, Anant; Wang Zhou; Rudin, Stephen; Bednarek, Daniel R.

    2002-01-01

    As interventional procedures become more complicated, the need for accurate quantitative vascular information increases. In response to this need, many commercial vendors provide techniques for measurement of vessel sizes, usually based on derivative techniques. In this study, we investigate the accuracy of several techniques used in the measurement of vessel size. Simulated images of vessels having circular cross sections were generated and convolved with various focal spot distributions taking into account the magnification. These vessel images were then convolved with Gaussian image detector line spread functions (LSFs). Additionally, images of a phantom containing vessels with a range of diameters were acquired for the 4.5'', 6'', 9'', and 12'' modes of an image intensifier-TV (II-TV) system. Vessel sizes in the images were determined using a first-derivative technique, a second-derivative technique, a linear combination of these two measured sizes, a thresholding technique, a densitometric technique, and a model-based technique. For the same focal spot size, the shape of the focal spot distribution does not affect measured vessel sizes except at large magnifications. For vessels with diameters larger than the full-width-at-half-maximum (FWHM) of the LSF, accurate vessel sizes (errors ∼0.1 mm) could be obtained by using an average of sizes determined by the first and second derivatives. For vessels with diameters smaller than the FWHM of the LSF, the densitometric and model-based techniques can provide accurate vessel sizes when these techniques are properly calibrated

  17. Vessel Operator System

    Data.gov (United States)

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

  18. Nuclear reactor vessel fuel thermal insulating barrier

    Science.gov (United States)

    Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

    2013-03-19

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

  19. Non-gated vessel wall imaging of the internal carotid artery using radial scanning and fast spin echo sequence. Evaluation of vessel signal intensity by flow rate at 3.0 tesla

    International Nuclear Information System (INIS)

    Nakamura, Manami; Makabe, Takeshi; Ichikawa, Masaki; Hatakeyama, Ryohei; Sugimori, Hiroyuki; Sakata, Motomichi

    2013-01-01

    Vessel wall imaging using radial scanning does not use a blood flow suppression pulse with gated acquisition. It has been proposed that there may not be a flow void effect if the flow rate is slow; however, this has yet to be empirically tested. To clarify the relationship between the signal intensity of the vessel lumen and the blood flow rate in a flow phantom, we investigated the usefulness of vessel wall imaging at 3.0 tesla (T). We measured the signal intensity while changing the flow rate in the flow phantom. Radial scanning at 1.5 T showed sufficient flow voids at above medium flow rates. There was no significant difference in lumen signal intensity at the carotid artery flow rate. The signal intensity of the vessel lumen decreased sufficiently using the radial scan method at 3.0 T. We thus obtained sufficient flow void effects at the carotid artery flow rate. We conclude this technique to be useful for evaluating plaque if high contrast can be maintained for fixed tissue (such as plaque) and the vessel lumen. (author)

  20. Endoscopic Retrograde Cholangiopancreatography Using a Dual-Lumen Endogastroscope for Patients with Billroth II Gastrectomy

    Directory of Open Access Journals (Sweden)

    Wei Yao

    2013-01-01

    Full Text Available Objective. To evaluate the safety and efficacy of a dual-lumen forward-viewing endoscope for ERCP in patients with prior Billroth II gastrectomy. Methods. The records of 46 patients treated with ERCP by a dual-lumen forward-viewing endoscope after Billroth II gastrectomy from 2007 to 2012 were reviewed. Results. The success rate of selective cannulation was 82.6% (38/46. Of the 38 cases with successful selective cannulation, endoscopic sphincterotomy was achieved in 23 cases by placing the needle knife through the 2nd lumen, while endoscopic papillary balloon dilatation was conducted in the other 15 cases. Of the 8 failed cases of selective cannulation, 6 had failed afferent loop intubation, and 3 of these 6 patients had Braun’s anastomosis. The safety and efficacy of catheter-assisted endoscopic sphincterotomy were increased by placing the needle knife through the 2nd lumen without altering the conventional endoscopic sphincterotomy procedure. Conclusions. A dual-lumen forward-viewing endoscope can be safely and effectively used to perform ERCP in patients with a Billroth II gastrectomy, except for patients with additional Braun’s anastomosis.

  1. Age-Related Changes in Pharyngeal Lumen Size: A Retrospective MRI Analysis.

    Science.gov (United States)

    Molfenter, Sonja M; Amin, M R; Branski, R C; Brumm, J D; Hagiwara, M; Roof, S A; Lazarus, C L

    2015-06-01

    Age-related loss of muscle bulk and strength (sarcopenia) is often cited as a potential mechanism underlying age-related changes in swallowing. Our goal was to explore this phenomenon in the pharynx, specifically, by measuring pharyngeal wall thickness and pharyngeal lumen area in a sample of young versus older women. MRI scans of the neck were retrospectively reviewed from 60 women equally stratified into three age groups (20s, 60s, 70+). Four de-identified slices were extracted per scan for randomized, blinded analysis: one mid-sagittal and three axial slices were selected at the anterior inferior border of C2 and C3, and at the pit of the vallecula. Pixel-based measures of pharyngeal wall thickness and pharyngeal lumen area were completed using ImageJ and then converted to metric units. Measures of pharyngeal wall thickness and pharyngeal lumen area were compared between age groups with one-way ANOVAs using Sidak adjustments for post-hoc pairwise comparisons. A significant main effect for age was observed across all variables whereby pharyngeal wall thickness decreased and pharyngeal lumen area increased with advancing age. Pairwise comparisons revealed significant differences between 20s versus 70+ for all variables and 20s versus 60s for all variables except those measured at C2. Effect sizes ranged from 0.54 to 1.34. Consistent with existing sacropenia literature, the pharyngeal muscles appear to atrophy with age and consequently, the size of the pharyngeal lumen increases.

  2. Long-term lumen depreciation behavior and failure modes of multi-die array LEDs

    Science.gov (United States)

    Jayawardena, Asiri; Marcus, Daniel; Prugue, Ximena; Narendran, Nadarajah

    2013-09-01

    One of the main advantages of multi-die array light-emitting diodes (LEDs) is their high flux density. However, a challenge for using such a product in lighting fixture applications is the heat density and the need for thermal management to keep the junction temperatures of all the dies low for long-term reliable performance. Ten multi-die LED array samples for each product from four different manufacturers were subjected to lumen maintenance testing (as described in IES-LM-80-08), and their resulting lumen depreciation and failure modes were studied. The products were tested at the maximum case (or pin) temperature reported by the respective manufacturer by appropriately powering the LEDs. In addition, three samples for each product from two different manufacturers were subjected to rapid thermal cycling, and the resulting lumen depreciation and failure modes were studied. The results showed that the exponential lumen decay model using long-term lumen maintenance data as recommended in IES TM-21 does not fit for all package types. The failure of a string of dies and single die failure in a string were observed in some of the packages.

  3. Heavy wall pressure vessels for energy systems

    International Nuclear Information System (INIS)

    Canonico, D.A.

    Modifications of steels currently accepted in the Code appear to provide improved mechanical properties. These steels may permit the fabrication of larger diameter vessels with thinner section sizes and improved reliability and integrity. Adapting current specifications should expedite Code approval. Finally the challenge of improving welding procedures and adapting processes for field applications will result in higher quality weldments

  4. Fluid-solid contact vessel having fluid distributors therein

    Science.gov (United States)

    Jones, Jr., John B.

    1980-09-09

    Rectangularly-shaped fluid distributors for large diameter, vertical vessels include reinforcers for high heat operation, vertical sides with gas distributing orifices and overhanging, sloped roofs. Devices are provided for cleaning the orifices from a buildup of solid deposits resulting from the reactions in the vessel.

  5. A new evaluation of the upper esophageal sphincter using the functional lumen imaging probe: a preliminary report.

    LENUS (Irish Health Repository)

    Regan, J

    2012-03-06

    Objective and reliable evaluation of upper esophageal sphincter (UES) opening during swallowing based on videofluoroscopy and pharyngeal manometry challenges dysphagia clinicians. The functional lumen imaging probe (FLIP) is a portable tool based on impedance planimetry originally designed to measure esophogastric junction compliance. It is hypothesized that FLIP can evaluate UES distensibility, and can provide UES diameter and pressure measurements at rest, during swallowing, and during voluntary maneuvers. Eleven healthy adult subjects consented to FLIP evaluation. The probe was inserted transorally, and the balloon was positioned across the UES. Two 20-mL ramp distensions were completed. Changes in UES diameter and intraballoon pressure were measured during dry and 5-mL liquid swallows, and during voluntary swallow postures and maneuvers employed in clinical practice. The protocol was completed by 10 of 11 healthy subjects. Mean intraballoon pressure increased throughout 5-mL (5.8 mmHg; -4.5-18.6 mmHg), 10-mL (8.7 mmHg; 2.3-28.5 mmHg), 15-mL (17.3 mmHg; 9.5-34.8 mmHg), and 20-mL (31.2 mmHg; 16-46.3 mmHg) balloon volumes. Mean resting UES diameter (4.9 mm) increased during dry swallows (9.2 mm) and 5-mL liquid swallows (7.7 mm). Mean UES diameter increased during 5-mL liquid swallows with head turn to right (8.1 mm) and left (8.3 mm), chin tuck (8.4 mm), effortful swallow (8.5 mm), Mendelsohn maneuver (8.1 mm), and supraglottic swallow (7.8 mm). FLIP was safely inserted and distended in the UES, and provided useful quantitative data regarding UES distensibility and UES diameter changes during swallowing maneuvers. Further research is being conducted to explore the role of FLIP in UES evaluation.

  6. BY FRUSTUM CONFINING VESSEL

    Directory of Open Access Journals (Sweden)

    Javad Khazaei

    2016-09-01

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

  7. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W. Sr.

    1992-01-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system use relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, Monte Carlo calculations were performed using the code Electron Gamma Shower (EGS4). Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessel sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was or cross fire between blood vessels was assumed. Results are useful in assessing the doses to blood and blood vessel walls for different nuclear medicine procedures

  8. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    International Nuclear Information System (INIS)

    Akabani, G.; Poston, J.W.

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was assumed nor cross fire between vessel was assumed. Results are useful in assessing the dose in blood and blood vessel walls for different nuclear medicine procedures. 6 refs., 6 figs., 5 tabs

  9. Multiple shell pressure vessel

    International Nuclear Information System (INIS)

    Wedellsborg, B.W.

    1988-01-01

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

  10. Neutrophil-Mediated Delivery of Therapeutic Nanoparticles across Blood Vessel Barrier for Treatment of Inflammation and Infection

    OpenAIRE

    Chu, Dafeng; Gao, Jin; Wang, Zhenjia

    2015-01-01

    Endothelial cells form a monolayer in lumen of blood vessels presenting a great barrier for delivery of therapeutic nanoparticles (NPs) into extravascular tissues where most diseases occur, such as inflammation disorders and infection. Here, we report a strategy for delivering therapeutic NPs across this blood vessel barrier by nanoparticle in situ hitchhiking activated neutrophils. Using intravital microscopy of TNF-α-induced inflammation of mouse cremaster venules and a mouse model of acute...

  11. FACTORS AND COMPLICATIONS AFFECTING CATHETER AND TECHNIQUE SURVIVAL WITH PERMANENT SINGLE-LUMEN DIALYSIS CATHETERS

    NARCIS (Netherlands)

    DEMEESTER, J; VANHOLDER, R; DEROOSE, J; RINGOIR, S

    1994-01-01

    This long-term study on the outcome of permanent silicone single-lumen dialysis catheters consisted of 43 surgically inserted catheters in 33 patients. All catheters were attached to a pressure-pressure single-cannula dialysis system. Technique and catheter survival were 80 and 59% at 1 year, and 63

  12. Thrombosis caused by polyurethane double-lumen subclavian superior vena cava catheter and hemodialysis

    DEFF Research Database (Denmark)

    Wanscher, Maria Rørbæk; Frifelt, J J; Smith-Sivertsen, C

    1988-01-01

    During an 18-month period, 82 consecutive patients (37 women and 45 men), with a mean age of 50 yr (range 15 to 74), underwent hemodialysis with 91 polyurethane double-lumen subclavian superior vena cava catheters inserted via the right subclavian vein. Upon catheter removal, venograms were...

  13. Fate of the dissecting lumen by CT study following surgical repair

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Nobuyuki; Ando, Taizo; Kawazoe, Kohei; Tomino, Tetsuo; Fujita, Takeshi; Naito, Hiroaki; Yamaguchi, Toshio

    1983-03-01

    A postoperative follow-up study on the fate of dissecting lumen by means of computer tomography has been evaluated. The materials were 21 patients who underwent surgery for dissection of the aorta, including 8 patients in type 1 of DeBakey classification, 3 in type 11, 8 in type 111 and 2 patients of localized dissection in descending and abdominal aorta. The susceptibility for thrombus formation in dissecting lumen appeared to be related to the background etiology of dissection where poor tendency for thrombus formation was observed in a group of patients with Marfan syndrome and its' incomplete form. On the other hand in the group of patients who had a history of hypertension and atherosclerosis probable, a strong tendency of thrombus formation and eventual occlusion of lumen was obtained. On the basis of above findings, it will be said that the surgical intervention for type 1 of DeBakey classification in Marfan patient is merely creating type 111 dissection, closed observation in the future change of dissecting lumen is of utmost importance especially in those groups of patients.

  14. Fate of the dissecting lumen by CT study following surgical repair

    International Nuclear Information System (INIS)

    Nakajima, Nobuyuki; Ando, Taizo; Kawazoe, Kohei; Tomino, Tetsuo; Fujita, Takeshi; Naito, Hiroaki; Yamaguchi, Toshio.

    1983-01-01

    A postoperative follow-up study on the fate of dissecting lumen by mean of computer tomography has been evaluated. The materials were 21 patients who underwent surgery for dissection of the aorta, including 8 patients in type 1 of DeBakey classification, 3 in type 11, 8 in type 111 and 2 patients of localized dissection in descending and abdominal aorta. The susceptibility for thrombus formation in dissecting lumen appeared to be relating to the background etiology of dissection where poor tendency for thrombus formation was observed in group of patients with Marfan syndrome and its' incomplete form. On the other hand in those group of patients who had a history of hypertension and atherosclerosis probable, a strong tendency of thrombus formation and eventual occlusion of lumen was obtained. On the basis of above findings, it will be said that the surgical intervention for type 1 of DeBakey classification in Marfan patient is merely creating type 111 dissection, closed observation in the future change of dissecting lumen is utmost important especially in those group of patients. (author)

  15. Lumen Formation Is an Intrinsic Property of Isolated Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Kenichiro Taniguchi

    2015-12-01

    Full Text Available We demonstrate that dissociated human pluripotent stem cells (PSCs are intrinsically programmed to form lumens. PSCs form two-cell cysts with a shared apical domain within 20 hr of plating; these cysts collapse to form monolayers after 5 days. Expression of pluripotency markers is maintained throughout this time. In two-cell cysts, an apical domain, marked by EZRIN and atypical PKCζ, is surrounded by apically targeted organelles (early endosomes and Golgi. Molecularly, actin polymerization, regulated by ARP2/3 and mammalian diaphanous-related formin 1 (MDIA, promotes lumen formation, whereas actin contraction, mediated by MYOSIN-II, inhibits this process. Finally, we show that lumenal shape can be manipulated in bioengineered micro-wells. Since lumen formation is an indispensable step in early mammalian development, this system can provide a powerful model for investigation of this process in a controlled environment. Overall, our data establish that lumenogenesis is a fundamental cell biological property of human PSCs.

  16. Analysis of proteome dynamics inside the silk gland lumen of Bombyx mori

    Science.gov (United States)

    Dong, Zhaoming; Zhao, Ping; Zhang, Yan; Song, Qianru; Zhang, Xiaolu; Guo, Pengchao; Wang, Dandan; Xia, Qingyou

    2016-01-01

    The silk gland is the only organ where silk proteins are synthesized and secreted in the silkworm, Bombyx mori. Silk proteins are stored in the lumen of the silk gland for around eight days during the fifth instar. Determining their dynamic changes is helpful for clarifying the secretion mechanism of silk proteins. Here, we identified the proteome in the silk gland lumen using liquid chromatography–tandem mass spectrometry, and demonstrated its changes during two key stages. From day 5 of the fifth instar to day 1 of wandering, the abundances of fibroins, sericins, seroins, and proteins of unknown functions increased significantly in different compartments of the silk gland lumen. As a result, these accumulated proteins constituted the major cocoon components. In contrast, the abundances of enzymes and extracellular matrix proteins decreased in the silk gland lumen, suggesting that they were not the structural constituents of silk. Twenty-five enzymes may be involved in the regulation of hormone metabolism for proper silk gland function. In addition, the metabolism of other non-proteinous components such as chitin and pigment were also discussed in this study. PMID:27102218

  17. An artificial neural network method for lumen and media-adventitia border detection in IVUS.

    Science.gov (United States)

    Su, Shengran; Hu, Zhenghui; Lin, Qiang; Hau, William Kongto; Gao, Zhifan; Zhang, Heye

    2017-04-01

    Intravascular ultrasound (IVUS) has been well recognized as one powerful imaging technique to evaluate the stenosis inside the coronary arteries. The detection of lumen border and media-adventitia (MA) border in IVUS images is the key procedure to determine the plaque burden inside the coronary arteries, but this detection could be burdensome to the doctor because of large volume of the IVUS images. In this paper, we use the artificial neural network (ANN) method as the feature learning algorithm for the detection of the lumen and MA borders in IVUS images. Two types of imaging information including spatial, neighboring features were used as the input data to the ANN method, and then the different vascular layers were distinguished accordingly through two sparse auto-encoders and one softmax classifier. Another ANN was used to optimize the result of the first network. In the end, the active contour model was applied to smooth the lumen and MA borders detected by the ANN method. The performance of our approach was compared with the manual drawing method performed by two IVUS experts on 461 IVUS images from four subjects. Results showed that our approach had a high correlation and good agreement with the manual drawing results. The detection error of the ANN method close to the error between two groups of manual drawing result. All these results indicated that our proposed approach could efficiently and accurately handle the detection of lumen and MA borders in the IVUS images. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Pancreatic Necrosectomy Through a Novel Double-flange Lumen-apposing Covered Metal Stent (Video

    Directory of Open Access Journals (Sweden)

    Andres Sanchez-Yague

    2014-12-01

    A double flange lumen apposing FC-SEMS used as a port for necrosectomy significantly improves management of walled-off pancreatic necrosis. Placement of this stents should be considered when multiple necrosectomy sessions are anticipated. Procedure time can be significantly decreased using a catheter that combines a cautery tip and stent delivery system.

  19. Ezetimibe Promotes Brush Border Membrane-to-Lumen Cholesterol Efflux in the Small Intestine.

    Directory of Open Access Journals (Sweden)

    Takanari Nakano

    Full Text Available Ezetimibe inhibits Niemann-Pick C1-like 1 (NPC1L1, an apical membrane cholesterol transporter of enterocytes, thereby reduces intestinal cholesterol absorption. This treatment also increases extrahepatic reverse cholesterol transport via an undefined mechanism. To explore this, we employed a trans-intestinal cholesterol efflux (TICE assay, which directly detects circulation-to-intestinal lumen 3H-cholesterol transit in a cannulated jejunal segment, and found an increase of TICE by 45%. To examine whether such increase in efflux occurs at the intestinal brush border membrane(BBM-level, we performed luminal perfusion assays, similar to TICE but the jejunal wall was labelled with orally-given 3H-cholesterol, and determined elevated BBM-to-lumen cholesterol efflux by 3.5-fold with ezetimibe. Such increased efflux probably promotes circulation-to-lumen cholesterol transit eventually; thus increases TICE. Next, we wondered how inhibition of NPC1L1, an influx transporter, resulted in increased efflux. When we traced orally-given 3H-cholesterol in mice, we found that lumen-to-BBM 3H-cholesterol transit was rapid and less sensitive to ezetimibe treatment. Comparison of the efflux and fractional cholesterol absorption revealed an inverse correlation, indicating the efflux as an opposite-regulatory factor for cholesterol absorption efficiency and counteracting to the naturally-occurring rapid cholesterol influx to the BBM. These suggest that the ezetimibe-stimulated increased efflux is crucial in reducing cholesterol absorption. Ezetimibe-induced increase in cholesterol efflux was approximately 2.5-fold greater in mice having endogenous ATP-binding cassette G5/G8 heterodimer, the major sterol efflux transporter of enterocytes, than the knockout counterparts, suggesting that the heterodimer confers additional rapid BBM-to-lumen cholesterol efflux in response to NPC1L1 inhibition. The observed framework for intestinal cholesterol fluxes may provide ways to

  20. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

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

  1. Improvement to reactor vessel

    International Nuclear Information System (INIS)

    1974-01-01

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

  2. ALICE HMPID Radiator Vessel

    CERN Document Server

    2003-01-01

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

  3. Quantification of common carotid artery and descending aorta vessel wall thickness from MR vessel wall imaging using a fully automated processing pipeline.

    Science.gov (United States)

    Gao, Shan; van 't Klooster, Ronald; Brandts, Anne; Roes, Stijntje D; Alizadeh Dehnavi, Reza; de Roos, Albert; Westenberg, Jos J M; van der Geest, Rob J

    2017-01-01

    To develop and evaluate a method that can fully automatically identify the vessel wall boundaries and quantify the wall thickness for both common carotid artery (CCA) and descending aorta (DAO) from axial magnetic resonance (MR) images. 3T MRI data acquired with T 1 -weighted gradient-echo black-blood imaging sequence from carotid (39 subjects) and aorta (39 subjects) were used to develop and test the algorithm. The vessel wall segmentation was achieved by respectively fitting a 3D cylindrical B-spline surface to the boundaries of lumen and outer wall. The tube-fitting was based on the edge detection performed on the signal intensity (SI) profile along the surface normal. To achieve a fully automated process, Hough Transform (HT) was developed to estimate the lumen centerline and radii for the target vessel. Using the outputs of HT, a tube model for lumen segmentation was initialized and deformed to fit the image data. Finally, lumen segmentation was dilated to initiate the adaptation procedure of outer wall tube. The algorithm was validated by determining: 1) its performance against manual tracing; 2) its interscan reproducibility in quantifying vessel wall thickness (VWT); 3) its capability of detecting VWT difference in hypertensive patients compared with healthy controls. Statistical analysis including Bland-Altman analysis, t-test, and sample size calculation were performed for the purpose of algorithm evaluation. The mean distance between the manual and automatically detected lumen/outer wall contours was 0.00 ± 0.23/0.09 ± 0.21 mm for CCA and 0.12 ± 0.24/0.14 ± 0.35 mm for DAO. No significant difference was observed between the interscan VWT assessment using automated segmentation for both CCA (P = 0.19) and DAO (P = 0.94). Both manual and automated segmentation detected significantly higher carotid (P = 0.016 and P = 0.005) and aortic (P < 0.001 and P = 0.021) wall thickness in the hypertensive patients. A reliable and reproducible pipeline for fully

  4. Volumetric analysis demonstrates that true and false lumen remodeling persists for 12 months after thoracic endovascular aortic repair

    Directory of Open Access Journals (Sweden)

    Ga-Young Suh, PhD

    2016-09-01

    Full Text Available A 62-year-old man underwent an elephant trunk procedure followed by thoracic endovascular aortic repair (TEVAR. Computed tomography angiography-based models were built to quantify volume of the whole aorta and true and false lumens preoperatively, before TEVAR, after TEVAR, and at follow-up at 3, 6, and 12 months. With TEVAR, descending aortic true lumen volume increased by 54%, then increased additionally by 60% during 12 months. The descending aortic false lumen volume regressed continuously for 12 months following TEVAR, with the most rapid rate from 6 to 12 months at 16 cm3/month. TEVAR immediately increased true lumen volume and continued to remodel the true and false lumens throughout the following 12 months.

  5. Lumen modifications

    Science.gov (United States)

    Rebecca E. Ibach; W. Dale Ellis

    2005-01-01

    Wood is used to produce many products (structural and nonstructural) for applications in which its natural properties are adequate. With the decrease of wood availability and the increase of less durable, younger and faster-growing trees, it is possible to modify wood in various ways to improve the properties, depending on the ultimate application. Wood- polymer...

  6. Nuclear reactor construction with bottom supported reactor vessel

    International Nuclear Information System (INIS)

    Sharbaugh, J.E.

    1987-01-01

    This patent describes an improved liquid metal nuclear reactor construction comprising: (a) a nuclear reactor core having a bottom platform support structure; (b) a reactor vessel for holding a large pool of low pressure liquid metal coolant and housing the core; (c) a containment structure surrounding the reactor vessel and having a sidewall spaced outwardly from the reactor vessel side wall and having a base mat spaced below the reactor vessel bottom end wall; (d) a central small diameter post anchored to the containment structure base mat and extending upwardly to the reactor vessel to axially fix the bottom end wall of the reactor vessel and provide a center column support for the lower end of the reactor core; (e) annular support structure disposed in the reactor vessel on the bottom end wall and extending about the lower end of the core; (f) structural support means disposed between the containment structure base mat and bottom end of the reactor vessel wall and cooperating for supporting the reactor vessel at its bottom end wall on the containment structure base mat to allow the reactor vessel to expand radially but substantially prevent any lateral motions that might be imposed by the occurrence of a seismic event; (g) a bed of insulating material disposed between the containment structure base mat and the bottom end wall of the reactor vessel and uniformly supporting the reactor vessel at its bottom end wall; freely expand radially from the central post as it heats up while providing continuous support thereof; (h) a deck supported upon the wall of the containment vessel above the top open end of the reactor vessel; and (i) extendible and retractable coupling means extending between the deck and the top open end of the reactor vessel and flexibly and sealably interconnecting the reactor vessel at its top end to the deck

  7. Measuring the diameter of rising gas bubbles by means of the ultrasound transit time technique

    Energy Technology Data Exchange (ETDEWEB)

    Richter, T., E-mail: Thomas.Richter6@tu-dresden.de; Eckert, K., E-mail: Kerstin.Eckert@tu-dresden.de; Yang, X.; Odenbach, S.

    2015-09-15

    Highlights: • Ultrasound transit time technique (UTTT) is applied to the zig-zag raise of gas bubble. • Comparison of bubble diameter and tilt, measured by UTTT, with high-speed imaging. • Uncertainty in the determination of the bubble diameter by UTTT is less than 7%. • UTTT is able to measure dynamic changes in bubble size in opaque liquids and vessels. • UTTT can be applied to liquid metal loops. - Abstract: This study presents ultrasound transit time technique (UTTT) measurements of the diameter variations of single argon bubbles rising in a zig-zag trajectory in water. Simultaneous size measurements with a high-speed camera show that UTTT resolves both the apparent diameter and the tilt of the bubble axis with an accuracy of better than 7%. This qualifies UTTT for the measurement of bubble sizes in opaque liquids, such as liquid metals, or vessels.

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  9. Lumen and Chromaticity Maintenance of LED PAR38 Lamps Operated in Steady-State Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    The lumen depreciation and color shift of 38 different lamps (32 LED, 2 CFL, 1 ceramic metal halide [CMH], 3 halogen) were monitored in a specially developed automated long-term test apparatus (ALTA2) for nearly 14,000 hours. Five samples of each lamp model were tested, with measurements recorded on a weekly basis. The lamps were operated continuously at a target ambient temperature between 44°C and 45°C.

  10. Small-Diameter PTFE Portosystemic Shunts: Portocaval vs Mesocaval

    Directory of Open Access Journals (Sweden)

    Robert Shields

    1998-01-01

    Full Text Available Fifty-seven patients with failed sclerotherapy received a mesocaval interposition shunt with an externally supported, ringed polytetrafluoroethylene prosthesis of either 10 or 12 mm diameter. Thirty-one patients had Child-Pugh gradeA disease and 26 grade B; all had a liver volume of 1000– 2500 ml. Follow-up ranged from 16 months to 6 years 3 months. Three patients (5 per cent died in the postoperative period. There were two postoperative recurrences of variceal haemorrhage and one recurrent bleed in the second year after surgery. The cumulative shunt patency rate was 95 per cent and the incidence of encephalopathy 9 per cent; the latter was successfully managed by protein restriction and/or lactulose therapy. The actuarial survival rate for the whole group at 6 years was 78 per cent, for those with Child-Pugh grade A 88 per cent and for grade B 67 per cent. Small-lumen mesocaval interposition shunting achieves portal decompression, preserves hepatopetal flow, has a low incidence of shunt thrombosis, prevents recurrent variceal bleeding and is not associated with significant postoperative encephalopathy.

  11. Selective modification of halloysite lumen with octadecylphosphonic acid: new inorganic tubular micelle.

    Science.gov (United States)

    Yah, Weng On; Takahara, Atsushi; Lvov, Yuri M

    2012-01-25

    Selective fatty acid hydrophobization of the inner surface of tubule halloysite clay is demonstrated. Aqueous phosphonic acid was found to bind to alumina sites at the tube lumen and did not bind the tube's outer siloxane surface. The bonding was characterized with solid-state nuclear magnetic resonance ((29)Si, (13)C, (31)P NMR), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy. NMR and FTIR spectroscopy of selectively modified tubes proved binding of octadecylphosphonic acid within the halloysite lumen through bidentate and tridentate P-O-Al linkage. Selective modification of the halloysite clay lumen creates an inorganic micelle-like architecture with a hydrophobic aliphatic chain core and a hydrophilic silicate shell. An enhanced capacity for adsorption of the modified halloysite toward hydrophobic derivatives of ferrocene was shown. This demonstrates that the different inner and outer surface chemistry of clay nanotubes can be used for selective modification, enabling different applications from water purification to drug immobilization and controlled release. © 2011 American Chemical Society

  12. Microbes vs. chemistry in the origin of the anaerobic gut lumen.

    Science.gov (United States)

    Friedman, Elliot S; Bittinger, Kyle; Esipova, Tatiana V; Hou, Likai; Chau, Lillian; Jiang, Jack; Mesaros, Clementina; Lund, Peder J; Liang, Xue; FitzGerald, Garret A; Goulian, Mark; Lee, Daeyeon; Garcia, Benjamin A; Blair, Ian A; Vinogradov, Sergei A; Wu, Gary D

    2018-04-17

    The succession from aerobic and facultative anaerobic bacteria to obligate anaerobes in the infant gut along with the differences between the compositions of the mucosally adherent vs. luminal microbiota suggests that the gut microbes consume oxygen, which diffuses into the lumen from the intestinal tissue, maintaining the lumen in a deeply anaerobic state. Remarkably, measurements of luminal oxygen levels show nearly identical pO 2 (partial pressure of oxygen) profiles in conventional and germ-free mice, pointing to the existence of oxygen consumption mechanisms other than microbial respiration. In vitro experiments confirmed that the luminal contents of germ-free mice are able to chemically consume oxygen (e.g., via lipid oxidation reactions), although at rates significantly lower than those observed in the case of conventionally housed mice. For conventional mice, we also show that the taxonomic composition of the gut microbiota adherent to the gut mucosa and in the lumen throughout the length of the gut correlates with oxygen levels. At the same time, an increase in the biomass of the gut microbiota provides an explanation for the reduction of luminal oxygen in the distal vs. proximal gut. These results demonstrate how oxygen from the mammalian host is used by the gut microbiota, while both the microbes and the oxidative chemical reactions regulate luminal oxygen levels, shaping the composition of the microbial community throughout different regions of the gut.

  13. Confinement Vessel Assay System: Calibration and Certification Report

    Energy Technology Data Exchange (ETDEWEB)

    Frame, Katherine C. [Los Alamos National Laboratory; Bourne, Mark M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Evans, Louise [Los Alamos National Laboratory; Gomez, Cipriano [Retired CMR-OPS: OPERATIONS; Mayo, Douglas R. [Los Alamos National Laboratory; Miko, David K. [Los Alamos National Laboratory; Salazar, William R. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory

    2012-07-17

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of SNM in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of {le} 100-g {sup 239}Pu equivalent in a vessel for safeguards termination. The system was calibrated in three different mass regions (low, medium, and high) to cover the entire plutonium mass range that will be assayed. The low mass calibration and medium mass calibration were verified for material positioned in the center of an empty vessel. The systematic uncertainty due to position bias was estimated using an MCNPX model to simulate the response of the system to material localized at various points along the inner surface of the vessel. The background component due to cosmic ray spallation was determined by performing measurements of an empty vessel and comparing to measurements in the same location with no vessel present. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements of CVs before and after cleanout.

  14. Confinement Vessel Assay System: Calibration and Certification Report

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Gomez, Cipriano; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels (CVs) remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1 to 2 inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. The Confinement Vessel Assay System (CVAS) was developed to measure the amount of SNM in CVs before and after cleanout. Prior to cleanout, the system will be used to perform a verification measurement of each vessel. After cleanout, the system will be used to perform safeguards-quality assays of (le) 100-g 239 Pu equivalent in a vessel for safeguards termination. The system was calibrated in three different mass regions (low, medium, and high) to cover the entire plutonium mass range that will be assayed. The low mass calibration and medium mass calibration were verified for material positioned in the center of an empty vessel. The systematic uncertainty due to position bias was estimated using an MCNPX model to simulate the response of the system to material localized at various points along the inner surface of the vessel. The background component due to cosmic ray spallation was determined by performing measurements of an empty vessel and comparing to measurements in the same location with no vessel present. The CVAS has been tested and calibrated in preparation for verification and safeguards measurements of CVs before and after cleanout.

  15. Problems in Pressure Vessel Design and Manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Hellstroem, O [Uddeholms AB, Degerfors (Sweden); Nilson, Ragnar [AB Atomenergi, Nykoeping (Sweden)

    1963-05-15

    The general desire by the power reactor process makers to increase power rating and their efforts to involve more advanced thermal behaviour and fuel handling facilities within the reactor vessels are accompanied by an increase in both pressure vessel dimensions and various difficulties in giving practical solutions of design materials and fabrication problems. In any section of this report it is emphasized that difficulties and problems already met with will meet again in the future vessels but then in modified forms and in many cases more pertinent than before. As for the increase in geometrical size it can be postulated that with use of better materials and adjusted fabrication methods the size problems can be taken proper care of. It seems likely that vessels of sufficient large diameter and height for the largest power output, which is judged as interesting in the next ten year period, can be built without developing totally new site fabrication technique. It is, however, supposed that such a fabrication technique will be feasible though at higher specific costs for the same quality requirements as obtained in shop fabrication. By the postulated use of more efficient vessel material with principally the same good features of easy fabrication in different stages such as preparation, welding, heat treatment etc as ordinary or slightly modified carbon steels the increase in wall thickness might be kept low. There exists, however, a development work to be done for low-alloy steels to prove their justified use in large reactor pressure vessels.

  16. Problems in Pressure Vessel Design and Manufacture

    International Nuclear Information System (INIS)

    Hellstroem, O.; Nilson, Ragnar

    1963-05-01

    The general desire by the power reactor process makers to increase power rating and their efforts to involve more advanced thermal behaviour and fuel handling facilities within the reactor vessels are accompanied by an increase in both pressure vessel dimensions and various difficulties in giving practical solutions of design materials and fabrication problems. In any section of this report it is emphasized that difficulties and problems already met with will meet again in the future vessels but then in modified forms and in many cases more pertinent than before. As for the increase in geometrical size it can be postulated that with use of better materials and adjusted fabrication methods the size problems can be taken proper care of. It seems likely that vessels of sufficient large diameter and height for the largest power output, which is judged as interesting in the next ten year period, can be built without developing totally new site fabrication technique. It is, however, supposed that such a fabrication technique will be feasible though at higher specific costs for the same quality requirements as obtained in shop fabrication. By the postulated use of more efficient vessel material with principally the same good features of easy fabrication in different stages such as preparation, welding, heat treatment etc as ordinary or slightly modified carbon steels the increase in wall thickness might be kept low. There exists, however, a development work to be done for low-alloy steels to prove their justified use in large reactor pressure vessels

  17. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

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

  18. Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

    Energy Technology Data Exchange (ETDEWEB)

    Palmucci, S., E-mail: spalmucci@sirm.org; Piccoli, M.; Piana, S.; Foti, P.V.; Siverino, R.O.A.; Mauro, L.A.; Milone, P.; Ettorre, G.C.

    2017-01-15

    Objectives: To compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel. Methods: From January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5 T MRI. Diffusion MRI was obtained using echo-planar imaging with b = 800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis. Results: Border ADC mean value for diffusion MR sequences without endorectal contrast was 1.122 mm{sup 2}/sec, with 95% Confidence Interval (CI) = 1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269 mm{sup 2}/s (95% CI = 1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p < 0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038 mm{sup 2}/s (95% CI = 0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127 mm{sup 2}/s (95% CI = 0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p = 0.13). A very strong positive correlation was observed, with r value of 0.81. Conclusions: ADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to

  19. Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension

    International Nuclear Information System (INIS)

    Palmucci, S.; Piccoli, M.; Piana, S.; Foti, P.V.; Siverino, R.O.A.; Mauro, L.A.; Milone, P.; Ettorre, G.C.

    2017-01-01

    Objectives: To compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel. Methods: From January 2014 to July 2016, 25 patients (average age 63.7, range 41–85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5 T MRI. Diffusion MRI was obtained using echo-planar imaging with b = 800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers − for each type of ADC measurement − were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis. Results: Border ADC mean value for diffusion MR sequences without endorectal contrast was 1.122 mm 2 /sec, with 95% Confidence Interval (CI) = 1.02–1.22; using gel lumen distension, higher border ADC mean value of 1.269 mm 2 /s (95% CI = 1.16–1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p < 0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038 mm 2 /s (95% CI = 0.91–1.16) for diffusion sequences acquired without endorectal distension and 1.127 mm 2 /s (95% CI = 0.98–1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p = 0.13). A very strong positive correlation was observed, with r value of 0.81. Conclusions: ADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to investigate better

  20. Mural cell associated VEGF is required for organotypic vessel formation.

    Directory of Open Access Journals (Sweden)

    Lasse Evensen

    Full Text Available BACKGROUND: Blood vessels comprise endothelial cells, mural cells (pericytes/vascular smooth muscle cells and basement membrane. During angiogenesis, mural cells are recruited to sprouting endothelial cells and define a stabilizing context, comprising cell-cell contacts, secreted growth factors and extracellular matrix components, that drives vessel maturation and resistance to anti-angiogenic therapeutics. METHODS AND FINDINGS: To better understand the basis for mural cell regulation of angiogenesis, we conducted high content imaging analysis on a microtiter plate format in vitro organotypic blood vessel system comprising primary human endothelial cells co-cultured with primary human mural cells. We show that endothelial cells co-cultured with mural cells undergo an extensive series of phenotypic changes reflective of several facets of blood vessel formation and maturation: Loss of cell proliferation, pathfinding-like cell migration, branching morphogenesis, basement membrane extracellular matrix protein deposition, lumen formation, anastamosis and development of a stabilized capillary-like network. This phenotypic sequence required endothelial-mural cell-cell contact, mural cell-derived VEGF and endothelial VEGFR2 signaling. Inhibiting formation of adherens junctions or basement membrane structures abrogated network formation. Notably, inhibition of mural cell VEGF expression could not be rescued by exogenous VEGF. CONCLUSIONS: These results suggest a unique role for mural cell-associated VEGF in driving vessel formation and maturation.

  1. Maury Journals - German Vessels

    Data.gov (United States)

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

  2. Proof testing of an explosion containment vessel

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, E.D. [Esparza (Edward D.), San Antonio, TX (United States); Stacy, H.; Wackerle, J. [Los Alamos National Lab., NM (United States)

    1996-10-01

    A steel containment vessel was fabricated and proof tested for use by the Los Alamos National Laboratory at their M-9 facility. The HY-100 steel vessel was designed to provide total containment for high explosives tests up to 22 lb (10 kg) of TNT equivalent. The vessel was fabricated from an 11.5-ft diameter cylindrical shell, 1.5 in thick, and 2:1 elliptical ends, 2 in thick. Prior to delivery and acceptance, three types of tests were required for proof testing the vessel: a hydrostatic pressure test, air leak tests, and two full design charge explosion tests. The hydrostatic pressure test provided an initial static check on the capacity of the vessel and functioning of the strain instrumentation. The pneumatic air leak tests were performed before, in between, and after the explosion tests. After three smaller preliminary charge tests, the full design charge weight explosion tests demonstrated that no yielding occurred in the vessel at its rated capacity. The blast pressures generated by the explosions and the dynamic response of the vessel were measured and recorded with 33 strain channels, 4 blast pressure channels, 2 gas pressure channels, and 3 displacement channels. This paper presents an overview of the test program, a short summary of the methodology used to predict the design blast loads, a brief description of the transducer locations and measurement systems, some of the hydrostatic test strain and stress results, examples of the explosion pressure and dynamic strain data, and some comparisons of the measured data with the design loads and stresses on the vessel.

  3. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    Directory of Open Access Journals (Sweden)

    Ana Carvalho

    Full Text Available The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

  4. The Functional Lumen Imaging Probe Detects Esophageal Contractility Not Observed With Manometry in Patients With Achalasia.

    Science.gov (United States)

    Carlson, Dustin A; Lin, Zhiyue; Kahrilas, Peter J; Sternbach, Joel; Donnan, Erica N; Friesen, Laurel; Listernick, Zoe; Mogni, Benjamin; Pandolfino, John E

    2015-12-01

    The functional lumen imaging probe (FLIP) could improve the characterization of achalasia subtypes by detecting nonocclusive esophageal contractions not observed with standard manometry. We aimed to evaluate esophageal contractions during volumetric distention in patients with achalasia using FLIP topography. Fifty-one treatment-naive patients with achalasia, defined and subclassified by high-resolution esophageal pressure topography, and 10 asymptomatic individuals (controls) were evaluated with the FLIP during endoscopy. During stepwise distension, simultaneous intrabag pressures and 16 channels of cross-sectional areas were measured; data were exported to software that generated FLIP topography plots. Esophageal contractility was identified by noting periods of reduced luminal diameter. Esophageal contractions were characterized further by propagation direction, repetitiveness, and based on whether they were occluding or nonoccluding. Esophageal contractility was detected in all 10 controls: 8 of 10 had repetitive antegrade contractions and 9 of 10 had occluding contractions. Contractility was detected in 27% (4 of 15) of patients with type I achalasia and in 65% (18 of 26, including 9 with occluding contractions) of patients with type II achalasia. Contractility was detected in all 10 patients with type III achalasia; 8 of these patients had a pattern of contractility that was not observed in controls (repetitive retrograde contractions). Esophageal contractility not observed with manometry can be detected in patients with achalasia using FLIP topography. The presence and patterns of contractility detected with FLIP topography may represent variations in pathophysiology, such as mechanisms of panesophageal pressurization in patients with type II achalasia. These findings could have implications for additional subclassification to supplement prediction of the achalasia disease course. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights

  5. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    Science.gov (United States)

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

  6. Obesity and overweight associated with increased carotid diameter and decreased arterial function in young otherwise healthy men.

    Science.gov (United States)

    Kappus, Rebecca M; Fahs, Christopher A; Smith, Denise; Horn, Gavin P; Agiovlasitis, Stomatis; Rossow, Lindy; Jae, Sae Y; Heffernan, Kevin S; Fernhall, Bo

    2014-04-01

    Obesity is linked to cardiovascular disease, stroke, increased mortality and vascular remodeling. Although increased arterial diameter is associated with multiple cardiovascular risk factors and obesity, it is unknown whether lumen enlargement is accompanied by unfavorable vascular changes in young and otherwise healthy obese individuals. The purpose of this study was to compare carotid and brachial artery diameter, blood pressure, arterial stiffness, and endothelial function in young, apparently healthy, normal-weight, overweight, and obese male subjects. One hundred sixty-five male subjects (27.39±0.59 years) were divided into 3 groups (normal weight, overweight, and obese) according to body mass index. Subjects underwent cardiovascular measurements to determine arterial diameter, function, and stiffness. After adjusting for age, the obese group had significantly greater brachial, carotid, and aortic pressures, brachial pulse wave velocity, carotid intima media thickness, and carotid arterial diameter compared with both the overweight and normal-weight groups. Obesity is associated with a much worse arterial profile, as an increased carotid lumen size was accompanied by higher blood pressure, greater arterial stiffness, and greater carotid intima media thickness in obese compared with overweight or normal-weight individuals. These data suggest that although obesity may be a factor in arterial remodeling, such remodeling is also accompanied by other hemodynamic and arterial changes consistent with reduced arterial function and increased cardiovascular risk.

  7. Defining an adequate sample of earlywood vessels for retrospective injury detection in diffuse-porous species.

    Directory of Open Access Journals (Sweden)

    Estelle Arbellay

    Full Text Available Vessels of broad-leaved trees have been analyzed to study how trees deal with various environmental factors. Cambial injury, in particular, has been reported to induce the formation of narrower conduits. Yet, little or no effort has been devoted to the elaboration of vessel sampling strategies for retrospective injury detection based on vessel lumen size reduction. To fill this methodological gap, four wounded individuals each of grey alder (Alnus incana (L. Moench and downy birch (Betula pubescens Ehrh. were harvested in an avalanche path. Earlywood vessel lumina were measured and compared for each tree between the injury ring built during the growing season following wounding and the control ring laid down the previous year. Measurements were performed along a 10 mm wide radial strip, located directly next to the injury. Specifically, this study aimed at (i investigating the intra-annual duration and local extension of vessel narrowing close to the wound margin and (ii identifying an adequate sample of earlywood vessels (number and intra-ring location of cells attesting to cambial injury. Based on the results of this study, we recommend analyzing at least 30 vessels in each ring. Within the 10 mm wide segment of the injury ring, wound-induced reduction in vessel lumen size did not fade with increasing radial and tangential distances, but we nevertheless advise favoring early earlywood vessels located closest to the injury. These findings, derived from two species widespread across subarctic, mountainous, and temperate regions, will assist retrospective injury detection in Alnus, Betula, and other diffuse-porous species as well as future related research on hydraulic implications after wounding.

  8. High-performance fiber/epoxy composite pressure vessels

    Science.gov (United States)

    Chiao, T. T.; Hamstad, M. A.; Jessop, E. S.; Toland, R. H.

    1978-01-01

    Activities described include: (1) determining the applicability of an ultrahigh-strength graphite fiber to composite pressure vessels; (2) defining the fatigue performance of thin-titanium-lined, high-strength graphite/epoxy pressure vessel; (3) selecting epoxy resin systems suitable for filament winding; (4) studying the fatigue life potential of Kevlar 49/epoxy pressure vessels; and (5) developing polymer liners for composite pressure vessels. Kevlar 49/epoxy and graphite fiber/epoxy pressure vessels, 10.2 cm in diameter, some with aluminum liners and some with alternation layers of rubber and polymer were fabricated. To determine liner performance, vessels were subjected to gas permeation tests, fatigue cycling, and burst tests, measuring composite performance, fatigue life, and leak rates. Both the metal and the rubber/polymer liner performed well. Proportionately larger pressure vessels (20.3 and 38 cm in diameter) were made and subjected to the same tests. In these larger vessels, line leakage problems with both liners developed the causes of the leaks were identified and some solutions to such liner problems are recommended.

  9. Automated registration of multispectral MR vessel wall images of the carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Klooster, R. van ' t; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der, E-mail: rvdgeest@lumc.nl [Department of Radiology, Division of Image Processing, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Klein, S. [Department of Radiology and Department of Medical Informatics, Biomedical Imaging Group Rotterdam, Erasmus MC, Rotterdam 3015 GE (Netherlands); Kwee, R. M.; Kooi, M. E. [Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht 6202 AZ (Netherlands)

    2013-12-15

    Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

  10. Automated registration of multispectral MR vessel wall images of the carotid artery

    International Nuclear Information System (INIS)

    Klooster, R. van 't; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der; Klein, S.; Kwee, R. M.; Kooi, M. E.

    2013-01-01

    Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

  11. A model for ultrasound contrast agent in a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2014-02-01

    A theoretical framework to model the dynamics of Ultrasound Contrast Agent (UCA) inside a phantom vessel is presented. The model is derived from the reduced Navier-Stokes equation and is coupled with the evolving flow field solution inside the vessel by a similarity transformation approach. The results are computed, and compared with experiments available in literature, for the initial UCA radius of Ro=1.5 μm and 2 μm for the vessel diameter of D=12 μm and 200 μm with the acoustic parameters as utilized in the experiments. When compared to other models, better agreement on smaller vessel diameter is obtained with the proposed coupled model. The model also predicts, quite accurately, bubble fragmentation in terms of acoustic and geometric parameters. © 2014 IEEE.

  12. Vertebral Artery Diameter and Flow: Nature or Nurture.

    Science.gov (United States)

    Tarnoki, Adam Domonkos; Fejer, Bence; Tarnoki, David Laszlo; Littvay, Levente; Lucatelli, Pierleone; Cirelli, Carlo; Fanelli, Fabrizio; Sacconi, Beatrice; Fagnani, Corrado; Medda, Emanuela; Farina, Filippo; Meneghetti, Giorgio; Horvath, Tamas; Pucci, Giacomo; Schillaci, Giuseppe; Stazi, Maria Antonietta; Baracchini, Claudio

    2017-09-01

    In contrast with the carotid arteries, the vertebral arteries (VAs) show considerable variation in length, caliber, and vessel course. This study investigated whether the variation in diameter and flow characteristics of the VAs might be inherited. A total of 172 Italian twins from Padua, Perugia, and Terni (54 monozygotic, 32 dizygotic) recruited from the Italian Twin Registry underwent B-mode and pulsed-wave Doppler ultrasound assessment of their VAs. VA diameters, peak systolic velocity (PSV) and end diastolic velocity (EDV) were assessed at the level of a horizontal V2 segment. Univariate quantitative genetic modeling was performed. Fourteen percent of the sample had VA hypoplasia. Within pair correlation in monozygotic twins was higher than in dizygotics (.552 vs. .229) for VA diameter. Age- and sex-adjusted genetic effect, under the most parsimonious model, accounted for 54.7% (95% CI: 42.2-69.1%) of the variance of VA diameter, and unshared environmental effect for 45.3% (95% CI: 30.9-57.8%). No heritability was found for the PSV of VA, but shared (34.1%; 95% CI: 16.7-53.7%) and unshared (65.9%; 95% CI: 45.9-83.1%) environmental factors determined the variance. EDV of VA is moderately genetically influenced (42.4%; 95% CI: 16.1-64.9%) and also determined by the unshared environment (57.6%; 95% CI: 34.7-83.7%). The diameter of the VAs is moderately genetically determined. Different factors influence the PSV and EDV of VAs, which may highlight the complex hemodynamic background of VA flow and help to understand the vertebral flow anomalies found by ultrasound. Copyright © 2017 by the American Society of Neuroimaging.

  13. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

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

  14. Containment vessel drain system

    Science.gov (United States)

    Harris, Scott G.

    2018-01-30

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

  15. Distinct patterns of inflammation in the airway lumen and bronchial mucosa of children with cystic fibrosis.

    Science.gov (United States)

    Regamey, Nicolas; Tsartsali, Lemonia; Hilliard, Tom N; Fuchs, Oliver; Tan, Hui-Leng; Zhu, Jie; Qiu, Yu-Sheng; Alton, Eric W F W; Jeffery, Peter K; Bush, Andrew; Davies, Jane C

    2012-02-01

    Studies in cystic fibrosis (CF) generally focus on inflammation present in the airway lumen. Little is known about inflammation occurring in the airway wall, the site ultimately destroyed in end-stage disease. To test the hypothesis that inflammatory patterns in the lumen do not reflect those in the airway wall of children with CF. Bronchoalveolar lavage (BAL) fluid and endobronchial biopsies were obtained from 46 children with CF and 16 disease-free controls. BAL cell differential was assessed using May-Gruenwald-stained cytospins. Area profile counts of bronchial tissue immunopositive inflammatory cells were determined. BAL fluid from children with CF had a predominance of neutrophils compared with controls (median 810×10(3)/ml vs 1×10(3)/ml, p<0.0001). In contrast, subepithelial bronchial tissue from children with CF was characterised by a predominance of lymphocytes (median 961 vs 717 cells/mm(2), p=0.014), of which 82% were (CD3) T lymphocytes. In chest exacerbations, BAL fluid from children with CF had more inflammatory cells of all types compared with those with stable disease whereas, in biopsies, only the numbers of lymphocytes and macrophages, but not of neutrophils, were higher. A positive culture of Pseudomonas aeruginosa was associated with higher numbers of T lymphocytes in subepithelial bronchial tissue (median 1174 vs 714 cells/mm(2), p=0.029), but no changes were seen in BAL fluid. Cell counts in BAL fluid and biopsies were positively correlated with age but were unrelated to each other. The inflammatory response in the CF airway is compartmentalised. In contrast to the neutrophil-dominated inflammation present in the airway lumen, the bronchial mucosa is characterised by the recruitment and accumulation of lymphocytes.

  16. Contura Multi-Lumen Balloon Breast Brachytherapy Catheter: Comparative Dosimetric Findings of a Phase 4 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Douglas W., E-mail: darthur@mcvh-vcu.edu [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Vicini, Frank A. [Michigan Healthcare Professionals/21st Century Oncology, Farmington Hills, Michigan (United States); Todor, Dorin A. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Julian, Thomas B. [Allegheny General Hospital, Temple University School of Medicine, Pittsburgh, Pennsylvania (United States); Cuttino, Laurie W.; Mukhopadhyay, Nitai D. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States)

    2013-06-01

    Purpose: Final dosimetric findings of a completed, multi-institutional phase 4 registry trial using the Contura Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer are presented. Methods and Materials: Three dosimetric plans with identical target coverage were generated for each patient for comparison: multilumen multidwell (MLMD); central-lumen multidwell (CLMD); and central-lumen single-dwell (CLSD) loading of the Contura catheter. For this study, a successful treatment plan achieved ideal dosimetric goals and included the following: ≥95% of the prescribed dose (PD) covering ≥95% of the target volume (TV); maximum skin dose ≤125% of the PD; maximum rib dose ≤145% of the PD; and V150 ≤50 cc and V200 ≤10 cc. Results: Between January 2008 and February 2011, 23 institutions participated. A total of 318 patients were available for dosimetric review. Using the Contura MLB, all dosimetric criteria were met in 78.93% of cases planned with MLMD versus 55.38% with the CLMD versus 37.66% with the CLSD (P≤.0001). Evaluating all patients with the full range of skin to balloon distance represented, median maximum skin dose was reduced by 12% and median maximum rib dose by 13.9% when using MLMD-based dosimetric plans compared to CLSD. The dosimetric benefit of MLMD was further demonstrated in the subgroup of patients where skin thickness was <5 mm, where MLMD use allowed a 38% reduction in median maximum skin dose over CLSD. For patients with rib distance <5 mm, the median maximum rib dose reduction was 27%. Conclusions: Use of the Contura MLB catheter produced statistically significant improvements in dosimetric capabilities between CLSD and CLMD treatments. This device approach demonstrates the ability not only to overcome the barriers of limited skin thickness and close rib proximity, but to consistently achieve a higher standard of dosimetric planning goals.

  17. Contura Multi-Lumen Balloon breast brachytherapy catheter: comparative dosimetric findings of a phase 4 trial.

    Science.gov (United States)

    Arthur, Douglas W; Vicini, Frank A; Todor, Dorin A; Julian, Thomas B; Cuttino, Laurie W; Mukhopadhyay, Nitai D

    2013-06-01

    Final dosimetric findings of a completed, multi-institutional phase 4 registry trial using the Contura Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer are presented. Three dosimetric plans with identical target coverage were generated for each patient for comparison: multilumen multidwell (MLMD); central-lumen multidwell (CLMD); and central-lumen single-dwell (CLSD) loading of the Contura catheter. For this study, a successful treatment plan achieved ideal dosimetric goals and included the following: ≥ 95% of the prescribed dose (PD) covering ≥ 95% of the target volume (TV); maximum skin dose ≤ 125% of the PD; maximum rib dose ≤ 145% of the PD; and V150 ≤50 cc and V200 ≤ 10 cc. Between January 2008 and February 2011, 23 institutions participated. A total of 318 patients were available for dosimetric review. Using the Contura MLB, all dosimetric criteria were met in 78.93% of cases planned with MLMD versus 55.38% with the CLMD versus 37.66% with the CLSD (P ≤.0001). Evaluating all patients with the full range of skin to balloon distance represented, median maximum skin dose was reduced by 12% and median maximum rib dose by 13.9% when using MLMD-based dosimetric plans compared to CLSD. The dosimetric benefit of MLMD was further demonstrated in the subgroup of patients where skin thickness was <5 mm, where MLMD use allowed a 38% reduction in median maximum skin dose over CLSD. For patients with rib distance <5 mm, the median maximum rib dose reduction was 27%. Use of the Contura MLB catheter produced statistically significant improvements in dosimetric capabilities between CLSD and CLMD treatments. This device approach demonstrates the ability not only to overcome the barriers of limited skin thickness and close rib proximity, but to consistently achieve a higher standard of dosimetric planning goals. Copyright © 2013 Elsevier Inc. All rights

  18. Assessment of lumen degradation and remaining useful life of LEDs using particle filter

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep [Auburn Univ., AL (United States); Zhang, Hao [Auburn Univ., AL (United States); Davis, Lynn [Auburn Univ., AL (United States)

    2013-07-16

    With the development of light-emitting diode (LED) technology, light emitting diodes system is becoming a popular light source in daily life and industry area. It has shown that Led from same factory and work under same working condition, may have significantly different behavior. Therefore, it is very important to learn the fail mechanisms, especially in the case of safety critical and harsh environment application. This paper focus on a prognostic health management (PHM) method based on the measurement of forward voltage and forward current of bare LED under harsh environment. In this paper, experiment has been done with ten samples. Ten pristine bare LEDs have been tested at 85°C while simultaneously being subjected to 85% humid environment. Pulse width modulation (PWM) control method has been employed to drive the bare LED in order to reduce the heat effect caused by forward current and high frequency (300HZ) data acquisition has been used to measure the peak forward voltage and forward current. Test to failure (lumen drops to 70 percent) data has been measured to study the effects of high temperature and humid environment loadings on the bare LED. Also, solid state cooling method with peltier cooler has been used to control the temperature of LED in the integrating sphere when take the measurement of lumen flux. The shift of forward voltage forward current curve and lumen degradation has been recorded to help build the fail model and predicted the remaining useful life. In this method, particle filter has been employed to predict the remaining useful life (RUL) of the bare LED and give us a whole picture how Led system fails. Result shows that predication of remaining useful life of Led, made by the particle filter model works under reasonable limit, and hence this method can be employed to predict the failure of Led caused by thermal and humid stress under harsh environment.

  19. Diameter-speed relation of sprite streamers

    International Nuclear Information System (INIS)

    Kanmae, T; Stenbaek-Nielsen, H C; McHarg, M G; Haaland, R K

    2012-01-01

    Propagation and splitting of sprite streamers has been observed at high temporal and spatial resolution using two intensified high-speed CMOS cameras recording at 10 000 and 16 000 frames per second. Concurrent video recordings from a remote site provided data for triangulation allowing us to determine accurate altitude scales for the sprites. Diameters and speeds of the sprite streamers were measured from the high-speed images, and the diameters were scaled to the reduced diameters based on the triangulated locations. The sprite streamers with larger reduced diameter move faster than those with smaller diameter; the relation between the reduced diameter and speed is roughly linear. The reduced diameters at ≈65-70 km altitude are larger than streamer diameters measured at ground pressure in laboratory discharges indicating a deviation from the similarity law possibly due to the effects of the photoionization and an expansion of the streamer head along its propagation over a long distance. The reduced diameter and speed of the sprite streamers agree well with the diameter-velocity relation proposed by Naidis (2009 Phys. Rev. E 79 057401), and the peak electric field of the sprite streamers is estimated to be approximately 3-5 times the breakdown threshold field. (paper)

  20. Fluoroscopic guidance for placing a double lumen endotracheal tube in adults.

    Science.gov (United States)

    Calenda, Emile; Baste, Jean Marc; Hajjej, Ridha; Rezig, Najiba; Moriceau, Jerome; Diallo, Yaya; Sghaeir, Slim; Danielou, Eric; Peillon, Christophe

    2014-09-01

    The aim of this study was to assess the right placement of the double lumen endotracheal tube with fluoroscopic guidance, which is used in first intention prior to the fiberscope in our institution. This was a prospective observational study. The study was conducted in vascular and thoracic operating rooms. We enrolled 205 patients scheduled for thoracic surgery, with ASA physical statuses of I (n = 37), II (n = 84), III (n = 80), and IV (n = 4). Thoracic procedures were biopsy (n = 20), wedge (n = 34), culminectomy (n = 6), lobectomy (n = 82), pneumonectomy (n = 4), sympathectomy (n = 9), symphysis (n = 47), and thymectomy (n = 3). The intubation with a double lumen tube was performed with the help of a laryngoscope. Tracheal and bronchial balloons were inflated and auscultation was performed after right and left exclusions. One shot was performed to locate the position of the bronchial tube and the hook. Fluoroscopic guidance was used to relocate the tube in case of a wrong position. When the fluoroscopic guidance failed to position the tube, a fiberscope was used. Perioperative collapse of the lung was assessed by the surgeon during the surgery. Correct fluoroscopic image was obtained after the first attempt in 58.5% of patients therefore a misplaced position was encountered in 41.5%. The fluoroscopic guidance allowed an exact repositioning in 99.5% of cases, and the mean duration of the procedure was 8 minutes. A fiberscope was required to move the hook for one patient. We did not notice a moving of the double lumen endotracheal tube during the surgery. The surgeon satisfaction was 100%. The fluoroscopy evidenced the right position of the double lumen tube and allowed a right repositioning in 99.5% of patients with a very simple implementation. Copyright © 2014. Published by Elsevier B.V.

  1. The microbiota mediates pathogen clearance from the gut lumen after non-typhoidal Salmonella diarrhea.

    Directory of Open Access Journals (Sweden)

    Kathrin Endt

    Full Text Available Many enteropathogenic bacteria target the mammalian gut. The mechanisms protecting the host from infection are poorly understood. We have studied the protective functions of secretory antibodies (sIgA and the microbiota, using a mouse model for S. typhimurium diarrhea. This pathogen is a common cause of diarrhea in humans world-wide. S. typhimurium (S. tm(att, sseD causes a self-limiting gut infection in streptomycin-treated mice. After 40 days, all animals had overcome the disease, developed a sIgA response, and most had cleared the pathogen from the gut lumen. sIgA limited pathogen access to the mucosal surface and protected from gut inflammation in challenge infections. This protection was O-antigen specific, as demonstrated with pathogens lacking the S. typhimurium O-antigen (wbaP, S. enteritidis and sIgA-deficient mice (TCRβ(-/-δ(-/-, J(H (-/-, IgA(-/-, pIgR(-/-. Surprisingly, sIgA-deficiency did not affect the kinetics of pathogen clearance from the gut lumen. Instead, this was mediated by the microbiota. This was confirmed using 'L-mice' which harbor a low complexity gut flora, lack colonization resistance and develop a normal sIgA response, but fail to clear S. tm(att from the gut lumen. In these mice, pathogen clearance was achieved by transferring a normal complex microbiota. Thus, besides colonization resistance ( = pathogen blockage by an intact microbiota, the microbiota mediates a second, novel protective function, i.e. pathogen clearance. Here, the normal microbiota re-grows from a state of depletion and disturbed composition and gradually clears even very high pathogen loads from the gut lumen, a site inaccessible to most "classical" immune effector mechanisms. In conclusion, sIgA and microbiota serve complementary protective functions. The microbiota confers colonization resistance and mediates pathogen clearance in primary infections, while sIgA protects from disease if the host re-encounters the same pathogen. This has

  2. Prediction of L70 lumen maintenance and chromaticity for LEDs using extended Kalman filter models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, Lynn

    2013-09-30

    Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying damage using physics-based models. Life

  3. Does bipolar electrocoagulation time affect vessel weld strength?

    Science.gov (United States)

    Harrison, J D; Morris, D L

    1991-01-01

    The value of the bipolar electrocoagulator in the haemostasis of bleeding ulcers is controversial. We have therefore investigated the effect of different coagulation times on vessel weld strength achieved by the bipolar device. Welds were then made in vessels of known diameter using a standard 10F endoscopic haemostatic probe at coagulation times of two and 20 seconds. The intravascular temperature achieved at each time was measured. Vessel weld strength achieved by bipolar electrocoagulation was much greater at 20 seconds (approximately twice that at two seconds) and was highly significantly greater at all vessel diameters. There was a gradual reduction in weld strength with increasing vessel diameter, an effect that was seen for both two and 20 seconds of electrocoagulation. Intravascular temperature was significantly higher at 20 seconds than at two seconds. We conclude that vessel weld strength is related to coagulation time and that any future studies comparing the bipolar electrocoagulator with other haemostatic devices should use longer periods of bipolar electrocoagulation and record the coagulation time in order to optimise the clinical value of the device. PMID:1864540

  4. Characterization of swallow modulation in response to bolus volume in healthy subjects accounting for catheter diameter.

    Science.gov (United States)

    Ferris, Lara; Schar, Mistyka; McCall, Lisa; Doeltgen, Sebastian; Scholten, Ingrid; Rommel, Nathalie; Cock, Charles; Omari, Taher

    2018-06-01

    Characterization of the pharyngeal swallow response to volume challenges is important for swallowing function assessment. The diameter of the pressure-impedance recording catheter may influence these results. In this study, we captured key physiological swallow measures in response to bolus volume utilizing recordings acquired by two catheters of different diameter. Ten healthy adults underwent repeat investigations with 8- and 10-Fr catheters. Liquid bolus swallows of volumes 2.5, 5, 10, 20, and 30 mL were recorded. Measures indicative of distension, contractility, and flow timing were assessed. Pressure-impedance recordings with pressure-flow analysis were used to capture key distension, contractility, and pressure-flow timing parameters. Larger bolus volumes increased upper esophageal sphincter distension diameter (P < .001) and distension pressures within the hypopharynx and upper esophageal sphincter (P < .05). Bolus flow timing measures were longer, particularly latency of bolus propulsion ahead of the pharyngeal stripping wave (P < .001). Use of a larger-diameter catheter produced higher occlusive pressures, namely upper esophageal sphincter basal pressure (P < .005) and upper esophageal sphincter postdeglutitive pressure peak (P < .001). The bolus volume swallowed changed measurements indicative of distension pressure, luminal diameter, and pressure-flow timing; this is physiologically consistent with swallow modulation to accommodate larger, faster-flowing boluses. Additionally, catheter diameter predominantly affects lumen occlusive pressures. Appropriate physiological interpretation of the pressure-impedance recordings of pharyngeal swallowing requires consideration of the effects of volume and catheter diameter. NA. Laryngoscope, 128:1328-1334, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  5. NCSX Vacuum Vessel Fabrication

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  6. Radioactive waste processing vessel

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  7. Tempest in a vessel

    International Nuclear Information System (INIS)

    Barre, Bertrand

    2015-01-01

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

  8. SAS-6 assembly templated by the lumen of cartwheel-less centrioles precedes centriole duplication.

    Science.gov (United States)

    Fong, Chii Shyang; Kim, Minhee; Yang, T Tony; Liao, Jung-Chi; Tsou, Meng-Fu Bryan

    2014-07-28

    Centrioles are 9-fold symmetric structures duplicating once per cell cycle. Duplication involves self-oligomerization of the centriolar protein SAS-6, but how the 9-fold symmetry is invariantly established remains unclear. Here, we found that SAS-6 assembly can be shaped by preexisting (or mother) centrioles. During S phase, SAS-6 molecules are first recruited to the proximal lumen of the mother centriole, adopting a cartwheel-like organization through interactions with the luminal wall, rather than via their self-oligomerization activity. The removal or release of luminal SAS-6 requires Plk4 and the cartwheel protein STIL. Abolishing either the recruitment or the removal of luminal SAS-6 hinders SAS-6 (or centriole) assembly at the outside wall of mother centrioles. After duplication, the lumen of engaged mother centrioles becomes inaccessible to SAS-6, correlating with a block for reduplication. These results lead to a proposed model that centrioles may duplicate via a template-based process to preserve their geometry and copy number. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Utility of dark-lumen MR colonography for the assessment of extra-colonic organs

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Goyen, Mathias; Ruehm, Stefan G.; Ladd, Susanne C.; Gerken, Guido

    2007-01-01

    The aim of the study was to evaluate the utility of dark-lumen MR colonography (MRC) for the assessment of extra-colonic organs. Three hundred seventy-five subjects with suspected colonic disease underwent a complete MRC examination. MRC data were evaluated by two radiologists in a blinded fashion. In addition to the large bowel, the extra-intestinal organs from the lung bases to the pelvis were assessed for the presence of pathologies. All findings were divided into known or unknown findings and therapeutically relevant or irrelevant findings. If deemed necessary, other diagnostic imaging tests to further assess those findings were performed. In total, 510 extra-colonic findings were found in 260 (69%) of the 375 subjects. Known extra-colonic findings were found in 140 subjects (54%) and unknown findings in 120 subjects (46%). Thirty-one (12%) of the 260 subjects had therapeutically relevant findings (45 findings); 229 patients (88%) had irrelevant findings (465 findings). Dark-lumen MRC is a useful tool not only for the assessment of the entire colon, but also for the evaluation of extra-colonic organs. Thus, intra- and extra-colonic pathologies can be diagnosed within the same examination. (orig.)

  10. Proteomics of the chloroplast: systematic identification and targeting analysis of lumenal and peripheral thylakoid proteins

    DEFF Research Database (Denmark)

    Peltier, J B; Friso, G; Kalume, D E

    2000-01-01

    The soluble and peripheral proteins in the thylakoids of pea were systematically analyzed by using two-dimensional electrophoresis, mass spectrometry, and N-terminal Edman sequencing, followed by database searching. After correcting to eliminate possible isoforms and post-translational modificati......The soluble and peripheral proteins in the thylakoids of pea were systematically analyzed by using two-dimensional electrophoresis, mass spectrometry, and N-terminal Edman sequencing, followed by database searching. After correcting to eliminate possible isoforms and post......-translational modifications, we estimated that there are at least 200 to 230 different lumenal and peripheral proteins. Sixty-one proteins were identified; for 33 of these proteins, a clear function or functional domain could be identified, whereas for 10 proteins, no function could be assigned. For 18 proteins, no expressed...... sequence tag or full-length gene could be identified in the databases, despite experimental determination of a significant amount of amino acid sequence. Nine previously unidentified proteins with lumenal transit peptides are presented along with their full-length genes; seven of these proteins possess...

  11. CT arterial portography and CT arteriography with a triple-lumen balloon catheter

    International Nuclear Information System (INIS)

    Murakami, T.; Oi, H.; Hori, M.; Kim, T.; Takahashi, S.; Matsushita, M.; Narumi, Y.; Nakamura, H.

    1997-01-01

    Purpose: To evaluate the usefulness of the triple-lumen balloon catheter in the serial performance of CT arterial portography (CT-AP) and CT arteriography (CT-A). Material and Methods: A combined CT-AP and CT-A examination of 58 patients was carried out in which a cobra-type triple-lumen balloon catheter was used. CT-AP was performed by injecting contrast medium either into the splenic artery through a side-hole in the catheter proximal to the balloon inflated in the common hepatic artery, or into the superior mesentric artery through an end-hole in the catheter. Then CT-A was serially performed by delivering contrast medium either to the common hepatic artery or the proper hepatic artery from the end-hole, or to the accessory right hepatic artery through a side-hole proximal to the inflated balloon. Results: Sufficient CT-APs were obtained in 53 of the 58 patients (91%), CT-A in 42 (72%), and both in 42 (72%). Incomplete CT-AP was due to technical failure or anatomical anomaly, as was incomplete CT-A. No complications were seen. (orig.)

  12. Single- and double- lumen silicone breast implant integrity: prospective evaluation of MR and US criteria.

    Science.gov (United States)

    Berg, W A; Caskey, C I; Hamper, U M; Kuhlman, J E; Anderson, N D; Chang, B W; Sheth, S; Zerhouni, E A

    1995-10-01

    To evaluate the accuracy of magnetic resonance (MR) and ultrasound (US) criteria for breast implant integrity. One hundred twenty-two single-lumen silicone breast implants and 22 bilumen implants were evaluated with surface coil MR imaging and US and surgically removed. MR criteria for implant failure were a collapsed implant shell ("linguine sign"), foci of silicone outside the shell ("noose sign"), and extracapsular gel, US criteria were collapsed shell, low-level echoes within the gel, and "snowstorm" echoes of extracapsular silicone. Among single-lumen implants, MR imaging depicted 39 of 40 ruptures, 14 of 28 with minimal leakage; 49 of 54 intact implants were correctly interpreted. US depicted 26 of 40 ruptured implants, four of 28 with minimal leakage, and 30 of 54 intact implants. Among bilumen implants, MR imaging depicted four of five implants with rupture of both lumina and nine of 10 as intact; US depicted one rupture and helped identify two of 10 as intact. Mammography accurately depicted the status of 29 of 30 bilumen implants with MR imaging correlation. MR imaging depicts implant integrity more accurately than US; neither method reliably depicts minimal leakage with shell collapse. Mammography is useful in screening bilumen implant integrity.

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

    Science.gov (United States)

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

    2013-04-01

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

  14. Cheboygan Vessel Base

    Data.gov (United States)

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

  15. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

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

  16. 2011 Vessel Density

    Data.gov (United States)

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

  17. 2011 Fishing Vessel Density

    Data.gov (United States)

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

  18. Pressurized Vessel Slurry Pumping

    International Nuclear Information System (INIS)

    Pound, C.R.

    2001-01-01

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

  19. 2013 Tanker Vessel Density

    Data.gov (United States)

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

  20. Maury Journals - US Vessels

    Data.gov (United States)

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

  1. Coastal Logbook Survey (Vessels)

    Data.gov (United States)

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

  2. In-vessel tritium

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  3. Reactor pressure vessel support

    International Nuclear Information System (INIS)

    Butti, J.P.

    1977-01-01

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

  4. 2013 Cargo Vessel Density

    Data.gov (United States)

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

  5. 2013 Fishing Vessel Density

    Data.gov (United States)

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

  6. 2013 Vessel Density

    Data.gov (United States)

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

  7. Ocean Station Vessel

    Data.gov (United States)

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

  8. Vessel Sewage Discharges

    Science.gov (United States)

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

  9. Sonographic study about differential diagnosis between acute appendicitis and non-appendicitis in appendices of borderline diameter

    International Nuclear Information System (INIS)

    Chung, Hwan Hoon; Kim, Yun Hwan; Kim, Hong Won; Park, Seung Cheol; Lee, Eun Jeong; Chung, Kyoo Byung; Suh, Won Hyuck

    2000-01-01

    To find out the sonographic criteria which can be effectively used to differentiate acute appendicitis from non-appendicitis in patients with appendices with borderline diameter(5-8 mm). Sixteen patients diagnosed as acute appendicitis, another 16 patients diagnosed as non-appendicitis were included in this study. They complained of RLQ pain and their appendices measured 5-8 mm in diameter on sonogram. Features such as appendiceal wall thickness, presence or absence of air in appendiceal lumen, movability of tip of the appendix, compressibility of the appendix were evaluated on gray-scale sonogram and thereafter, presence or absence of color flow in the wall of the appendix was evaluated on color Doppler sonogram. Thickness of appendiceal wall is 2.98 ± 0.77 mm in acute appendicitis group and 1.73 ± 0.44 mm in non-appendicitis group (p<0.05). When 2.5 mm thickness of appendiceal wall is applied for diagnosis of acute appendicitis, sensitivity is 81.3%, specificity is 87.5% and accuracy is 84.4%. With absence of air in appendiceal lumen, sensitivity is 93.8%, specificity is 68.8% and accuracy is 81.3%. With absence of movability of appendiceal tip, sensitivity is 87.5%, specificity is 50% and accuracy is 68.8%. With absence of compressibility of the appendix, sensitivity is 100%, specificity is 31.3% and accuracy is 65.6%. With color flow in appendiceal wall, sensitivity is 81.3%, specificity is 62.5% and accuracy is 71.9%. The above mentioned criteria show statistically significant difference between acute appendicitis and non-appendicitis groups (p<0.05). When the diameter of the appendix measures 5-8 mm on sonogram, evaluation of thickness of appendiceal wall, air in appendiceal lumen, movability of tip, compressibility and color flow in the wall will be helpful to diagnose the acute appendicitis with confidence.

  10. Reactor pressure vessel design

    International Nuclear Information System (INIS)

    Foehl, J.

    1998-01-01

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

  11. Graywater Discharges from Vessels

    Science.gov (United States)

    2011-11-01

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

  12. 7 CFR 51.320 - Diameter.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Grades of Apples Definitions § 51.320 Diameter. When measuring for minimum size, “diameter...

  13. LANL Robotic Vessel Scanning

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-25

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

  14. Diameter-dependent coloration of silver nanowires

    International Nuclear Information System (INIS)

    Stewart, Mindy S; Qiu Chao; Jiang Chaoyang; Kattumenu, Ramesh; Singamaneni, Srikanth

    2011-01-01

    Silver nanowires were synthesized with a green method and characterized with microscopic and diffractometric methods. The correlation between the colors of the nanowires deposited on a solid substrate and their diameters was explored. Silver nanowires that appear similar in color in the optical micrographs have very similar diameters as determined by atomic force microscopy. We have summarized the diameter-dependent coloration for these silver nanowires. An optical interference model was applied to explain such correlation. In addition, microreflectance spectra were obtained from individual nanowires and the observed spectra can be explained with the optical interference theory. This work provides a cheap, quick and simple screening method for studying the diameter distribution of silver nanowires, as well as the diameter variations of individual silver nanowires, without complicated sample preparation.

  15. Pressure vessels and methods of sealing leaky tubes disposed in pressure vessels

    International Nuclear Information System (INIS)

    Larson, G.C.

    1980-01-01

    This invention relates to pressure vessels and to methods of sealing leaky tubes in them and is especially applicable to pressure vessels in the form of sheet-and-tube type heat exchangers constructed with a large number of relatively small diameter tubes grouped in a bundle. To seal off a leaky tube in such a heat exchanger an explosive activated plug in the form of a hollow metal body is used, inserted at each end of the tube to be sealed. Using the arrangement of pressure vessel and associated tube sheets and the explosive activated plug method of sealing a leaky tube as described in this invention it is claimed that distortion of the adjacent tubes and the tube sheets is reduced when the explosive activated plugs are detonated. (U.K.)

  16. Preparation of lumen-loaded kenaf pulp with magnetite (Fe{sub 3}O{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, S.; Ong, B.H.; Ahmad, S.H.; Abdullah, M.; Yamauchi, T

    2005-02-15

    Magnetic pulps were prepared from unbleached kenaf (hibiscus cannabinus L.) kraft pulps. Fe{sub 3}O{sub 4} or magnetite powder was used to load into the pulp's lumen and pit. Aluminum sulphate [Al{sub 2}(SO{sub 4}){sub 3}] (alum) and polyethylenimine (PEI), both mainly function as retention aid were used throughout the experiment and found to be beneficial in the preparation of this magnetic pulps. The ash content method was used to determine the amount of magnetite retained in the lumen and pit. The utilization of PEI up to 2% per pulp fibres was found to be the best result on lumen loading. The deposition of magnetite powder in lumen and pit is found decrease as the addition of PEI used is more than 2% per pulp fibres. Scanning electron microscope (SEM) clearly shows the distribution of magnetite deposited in the lumen. Tensile index and folding endurance of the loaded fibre decreased slightly as the percentage of loading pigment increased.

  17. Construction of tissue-engineered small-diameter vascular grafts in fibrin scaffolds in 30 days.

    Science.gov (United States)

    Gui, Liqiong; Boyle, Michael J; Kamin, Yishai M; Huang, Angela H; Starcher, Barry C; Miller, Cheryl A; Vishnevetsky, Michael J; Niklason, Laura E

    2014-05-01

    Tissue-engineered small-diameter vascular grafts have been developed as a promising alternative to native veins or arteries for replacement therapy. However, there is still a crucial need to improve the current approaches to render the tissue-engineered blood vessels more favorable for clinical applications. A completely biological blood vessel (3-mm inner diameter) was constructed by culturing a 50:50 mixture of bovine smooth muscle cells (SMCs) with neonatal human dermal fibroblasts in fibrin gels. After 30 days of culture under pulsatile stretching, the engineered blood vessels demonstrated an average burst pressure of 913.3±150.1 mmHg (n=6), a suture retention (53.3±15.4 g) that is suitable for implantation, and a compliance (3.1%±2.5% per 100 mmHg) that is comparable to native vessels. These engineered grafts contained circumferentially aligned collagen fibers, microfibrils and elastic fibers, and differentiated SMCs, mimicking a native artery. These promising mechanical and biochemical properties were achieved in a very short culture time of 30 days, suggesting the potential of co-culturing SMCs with fibroblasts in fibrin gels to generate functional small-diameter vascular grafts for vascular reconstruction surgery.

  18. THE ALGORITHM OF DETERMINATION OF EYE FUNDUS VESSELS BLOOD FLOW CHARACTERISTICS ON VIDEOSEQUENCE

    Directory of Open Access Journals (Sweden)

    O. V. Nedzvedz

    2018-01-01

    Full Text Available The method of determination of the dynamic characteristics like the vessel diameter change, the linear and volume blood velocities in the vessels of the eye fundus is considered. Such characteristics allow to determine blood flow changes in the microvasculature affecting the blood flow in the brain, kidneys and coronary vessels. Developed algorithm includes four stages: the video sequence stabilization, the vessels segmentation with the help of a neural network, the determination of the instantaneous velocity in the vessels based on the optical flow and the analysis of the results.

  19. Dual-Lumen Chest Port Infection Rates in Patients with Head and Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bos, Aaron, E-mail: abos1210@gmail.com; Ahmed, Osman [University of Chicago Medical Center (United States); Jilani, Danial [Wright State University Boonshoft School of Medicine (United States); Giger, Maryellen; Funaki, Brian S.; Zangan, Steven M. [University of Chicago Medical Center (United States)

    2015-06-15

    PurposeThe aim of this study was to investigate dual-lumen chest port infection rates in patients with head and neck cancer (HNC) compared to those with other malignancies (non-HNC).Materials and MethodsAn IRB-approved retrospective study was performed on 1,094 consecutive chest ports placed over a 2-year period. Patients with poor follow-up (n = 53), no oncologic history (n = 13), or single-lumen ports (n = 183) were excluded yielding a study population of 845 patients. The electronic medical records were queried for demographic information, data regarding ports and infections, and imaging review.ResultsHNC patients experienced more infections (42 vs. 30), an increased infection rate per 1,000 catheter days (0.68 vs. 0.21), and more early infections within 30 days compared to non-HNC patients (10 vs. 6) (p < 0.001, p < 0.001, p = 0.02, respectively). An existing tracheostomy at the time of port placement was associated with infection in the HNC group (p = 0.02) but was not an independent risk factor for infection in the study population overall (p = 0.06). There was a significant difference in age, male gender, and right-sided ports between the HNC and non-HNC groups (p < 0.01, p < 0.001, and p = 0.01), although these were not found to be independent risk factors for infection (p = 0.32, p = 0.76, p = 0.16).ConclusionHNC patients are at increased risk for infection of dual-lumen chest ports placed via a jugular approach compared to patients with other malignancies. Tracheostomy is associated with infection in HNC patients but is not an independent risk factor for infection in the oncologic population as a whole.

  20. Dual-Lumen Chest Port Infection Rates in Patients with Head and Neck Cancer

    International Nuclear Information System (INIS)

    Bos, Aaron; Ahmed, Osman; Jilani, Danial; Giger, Maryellen; Funaki, Brian S.; Zangan, Steven M.

    2015-01-01

    PurposeThe aim of this study was to investigate dual-lumen chest port infection rates in patients with head and neck cancer (HNC) compared to those with other malignancies (non-HNC).Materials and MethodsAn IRB-approved retrospective study was performed on 1,094 consecutive chest ports placed over a 2-year period. Patients with poor follow-up (n = 53), no oncologic history (n = 13), or single-lumen ports (n = 183) were excluded yielding a study population of 845 patients. The electronic medical records were queried for demographic information, data regarding ports and infections, and imaging review.ResultsHNC patients experienced more infections (42 vs. 30), an increased infection rate per 1,000 catheter days (0.68 vs. 0.21), and more early infections within 30 days compared to non-HNC patients (10 vs. 6) (p < 0.001, p < 0.001, p = 0.02, respectively). An existing tracheostomy at the time of port placement was associated with infection in the HNC group (p = 0.02) but was not an independent risk factor for infection in the study population overall (p = 0.06). There was a significant difference in age, male gender, and right-sided ports between the HNC and non-HNC groups (p < 0.01, p < 0.001, and p = 0.01), although these were not found to be independent risk factors for infection (p = 0.32, p = 0.76, p = 0.16).ConclusionHNC patients are at increased risk for infection of dual-lumen chest ports placed via a jugular approach compared to patients with other malignancies. Tracheostomy is associated with infection in HNC patients but is not an independent risk factor for infection in the oncologic population as a whole

  1. A complex dissected chronic occlusion: targeted balloon dilatation of false lumen to access true lumen, combined localized subintimal tracking and reentry, parallel wire, contralateral injection and a useful antegrade lumen re-entry technique

    Directory of Open Access Journals (Sweden)

    James W. Tam

    2012-02-01

    Full Text Available Chronic total occlusion (CTO angioplasty is one of the most challenging procedures remaining for the interventional operator. Recanalizing CTOs can improve exercise capacity, symptoms, left ventricular function and possibly reduce mortality. Multiple strategies such as escalating wire, parallel wire, seesaw, contralateral injection, subintimal tracking and re-entry (STAR, retrograde wire techniques (controlled antegrade retrograde subintimal tracking, CART, reverse CART, confluent balloon, rendezvous in coronary, and other techniques have all been described. Selection of the most appropriate approach is based on assessment of vessel course, length of occluded segment, presence of bridging collaterals, presence of bifurcating side branches at the occlusion site, and other variables. Today, with significant operator expertise and the use of available techniques, the literature reports a 50-95% success rate for recanalizing CTOs.

  2. Decellularized ovine arteries as small-diameter vascular grafts

    International Nuclear Information System (INIS)

    Mancuso, L; Cao, G; Gualerzi, A; Boschetti, F; Loy, F

    2014-01-01

    Atherosclerosis and its complications still represent the leading cause of death in the developed countries. While autologous blood vessels may be regarded as the best solution for peripheral and coronary bypass, they are unavailable in most patients. Even though tissue engineering techniques are often applied to the development of small-diameter vascular grafts, limiting factors of this approach are represented by the lack of essential extracellular matrix proteins and/or poor biomechanical properties of the scaffolds used. Along these lines, the aim of this study was to develop a decellularization protocol for ovine carotids to be used as suitable small-diameter vascular grafts. Samples were treated either with sodium dodecyl sulphate (SDS) or with Trypsin and Triton X-100; a final nuclease digestion was performed for both protocols. Morphological analyses demonstrate complete removal of nuclei and cellular components in treated vessels, also confirmed by significant reduction in wall thickness and DNA content. Essential extracellular matrix proteins such as collagen, elastin, and fibronectin are well preserved after decellularization. From a mechanical point of view, Trypsin and Triton X-100 treated arteries show elastic modules and compliance comparable to native carotids, whereas the use of SDS makes samples stiffer, with a significant decrease in the compliance mean value and an increase in longitudinal and circumferential Young’s modules. It is demonstrated that the treatment where Trypsin and Triton X-100 are combined guarantees complete decellularization of carotids, with no significant alteration of biomechanical and structural properties, thus preserving a suitable environment for adhesion, proliferation, and migration of cells. (paper)

  3. High lumenal chloride in the lysosome is critical for lysosome function.

    Science.gov (United States)

    Chakraborty, Kasturi; Leung, KaHo; Krishnan, Yamuna

    2017-07-25

    Lysosomes are organelles responsible for the breakdown and recycling of cellular machinery. Dysfunctional lysosomes give rise to lysosomal storage disorders as well as common neurodegenerative diseases. Here, we use a DNA-based, fluorescent chloride reporter to measure lysosomal chloride in Caenorhabditis elegans as well as murine and human cell culture models of lysosomal diseases. We find that the lysosome is highly enriched in chloride, and that chloride reduction correlates directly with a loss in the degradative function of the lysosome. In nematodes and mammalian cell culture models of diverse lysosomal disorders, where previously only lysosomal pH dysregulation has been described, massive reduction of lumenal chloride is observed that is ~10 3 fold greater than the accompanying pH change. Reducing chloride within the lysosome impacts Ca 2+ release from the lysosome and impedes the activity of specific lysosomal enzymes indicating a broader role for chloride in lysosomal function.

  4. Further understanding of PbWO4 Scintillator characteristics and their optimisation. LUMEN activity in 1998

    CERN Document Server

    Baccaro, Stefania; Borgia, Bruno; Cecilia, Angelica; Dafinei, Ioan; Diemoz, Marcella; Fabeni, P; Festinesi, Armando; Longo, Egidio; Martini, M; Meinardi, F; Mihoková, E; Montecchi, Marco; Nikl, M; Pazzi, G P; Rosa, J; Sulc, Miroslav

    2000-01-01

    The aim of LUMEN collaboration was the investigation on single crystals of PbWO4 ( PWO): the results performed up to now provide the evidence of the possibility to optimise the optical properties of an intrinsic scintillator such as PWO. The control of essential requirements in the crystal preparation ( raw material purity, growing methods and post-growth annealing) as well as the introduction of selected dopants at suitable concentrations ( particularly trivalent and pentavalent ions) were found to be very successful in lowering the concentration of point defects in the lattice which strongly affect scintillation properties and radiation hardness. The systematic investigation effort to better understand the scintillation characteristics and to improve the quality of PWO crystals is due to their use for the CMS electromagnetic calorimeter.

  5. Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.

    Science.gov (United States)

    Sanz-Requena, Roberto; Moratal, David; García-Sánchez, Diego Ramón; Bodí, Vicente; Rieta, José Joaquín; Sanchis, Juan Manuel

    2007-03-01

    Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media-adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove noise from the images without blurring the edges. Segmentation of media-adventitia contour is achieved using active contours (snakes). In particular, we use the gradient vector flow (GVF) as external force for the snakes. The detection of lumen border is obtained taking into account gray-level information of the inner part of the previously detected contours. A knowledge-based approach is used to determine which level of gray corresponds statistically to the different regions of interest: intima, plaque and lumen. The catheter region is automatically discarded. An estimate of plaque type is also given. Finally, 3D reconstruction of all detected regions is made. The suitability of this methodology has been verified for the analysis and visualization of plaque length, stenosis severity, automatic detection of the most problematic regions, calculus of plaque volumes and a preliminary estimation of plaque type obtaining for automatic measures of lumen and vessel area an average error smaller than 1mm(2) (equivalent aproximately to 10% of the average measure), for calculus of plaque and lumen volume errors smaller than 0.5mm(3) (equivalent approximately to 20% of the average measure) and for plaque type estimates a mismatch of less than 8% in the analysed frames.

  6. Acrylic vessel cleaning tests

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  7. Vessel wall reaction after vena cava filter placement

    NARCIS (Netherlands)

    Hoekstra, A; Elstrodt, JM; Nikkels, PGJ; Tiebosch, ATMG

    2002-01-01

    Purpose: To evaluate the interaction between the Cordis Keeper vena caval filter and vessel wall in a porcine model. Methods: Implantation of the filter was performed in five pigs. Radiologic data concerning inferior vena cava (IVC) diameter and filter patency, filter leg span, and stability were

  8. Analysis of the intestinal lumen microbiota in an animal model of colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Qingchao Zhu

    Full Text Available Recent reports have suggested that multiple factors such as host genetics, environment and diet can promote the progression of healthy mucosa towards sporadic colorectal carcinoma. Accumulating evidence has additionally associated intestinal bacteria with disease initiation and progression. In order to examine and analyze the composition of gut microbiota in the absence of confounding influences, we have established an animal model of 1, 2-dimethylhydrazine (DMH-induced colon cancer. Using this model, we have performed pyrosequencing of the V3 region of the 16S rRNA genes in this study to determine the diversity and breadth of the intestinal microbial species. Our findings indicate that the microbial composition of the intestinal lumen differs significantly between control and tumor groups. The abundance of Firmicutes was elevated whereas the abundance of Bacteroidetes and Spirochetes was reduced in the lumen of CRC rats. Fusobacteria was not detected in any of the healthy rats and there was no significant difference in observed Proteobacteria species when comparing the bacterial communities between our two groups. Interestingly, the abundance of Proteobacteria was higher in CRC rats. At the genus level, Bacteroides exhibited a relatively higher abundance in CRC rats compared to controls (14.92% vs. 9.22%, p<0.001. Meanwhile, Prevotella (55.22% vs. 26.19%, Lactobacillus (3.71% vs. 2.32% and Treponema (3.04% vs. 2.43%, were found to be significantly more abundant in healthy rats than CRC rats (p<0.001, respectively. We also demonstrate a significant reduction of butyrate-producing bacteria such as Roseburia and Eubacterium in the gut microbiota of CRC rats. Furthermore, a significant increase in Desulfovibrio, Erysipelotrichaceae and Fusobacterium was also observed in the tumor group. A decrease in probiotic species such as Ruminococcus and Lactobacillus was likewise observed in the tumor group. Collectively, we can conclude that a significant

  9. Heissdampfreaktor (HDR) steel-containment-vessel and floodwater-storage-tank structural-dynamics tests

    International Nuclear Information System (INIS)

    Arendts, J.G.

    1982-01-01

    Inertance (vibration) testing of two significant vessels at the Heissdampfreaktor (HDR) facility, located near Kahl, West Germany, was recently completed. Transfer functions were obtained for determination of the modal properties (frequencies, mode shapes and damping) of the vessels using two different test methods for comparative purposes. One of the vessels tested was the steel containment vessel (SCV). The SCV is approximately 180 feet high and 65 feet in diameter with a 1.2-inch wall thickness. The other vessel, called the floodwater storage tank (FWST), is a vertically standing vessel approximately 40 feet high and 10 feet in diameter with a 1/2-inch wall thickness. The FWST support skirt is square (in plan views) with its corners intersecting the ellipsoidal bottom head near the knuckle region

  10. Enteroclysis in adult celiac disease: assessment of jejuno-ileal diameter and of number of folds

    International Nuclear Information System (INIS)

    La Seta, F.; Bucellato, A.; Cabibbo, L.; Cottone, M.; Salerno, G.; Dardanoni, G.

    1991-01-01

    The authors retrospectively reviewed the radiographic findings (obtained with double-contrast small bowel enema) of 27 patients with adult celiac disease and of 27 healthy control subjects. Two parameters were measurated in two different locations; lumen diameter and number of folds both in proximal jejunum and in the distal ileum. Statistical differences in mean values between cases and controls were calculated, and correlations between the four variables were assessed. Sensitivity, specificity and their 95% confidence limits were calculated for all the variables. The best parameter in discriminating cases from controls seems to be the caliber of distal ileum (>3 cm), with 93% sensitivity and 100% specificity. The value of the obtained results is discussed

  11. Elephant trunk in a small-calibre true lumen for chronic aortic dissection: cause of haemolytic anaemia?

    Science.gov (United States)

    Araki, Haruna; Kitamura, Tadashi; Horai, Tetsuya; Shibata, Ko; Miyaji, Kagami

    2014-12-01

    The elephant trunk technique for aortic dissection is useful for reducing false lumen pressure; however, a folded vascular prosthesis inside the aorta can cause haemolysis. The purpose of this study was to investigate whether an elephant trunk in a small-calibre lumen can cause haemolysis. Inpatient and outpatient records were retrospectively reviewed. Two cases of haemolytic anaemia after aortic surgery using the elephant trunk technique were identified from 2011 to 2013. A 64-year-old man, who underwent graft replacement of the ascending aorta for acute Stanford type A aortic dissection, presented with enlargement of the chronic dissection of the descending aorta and moderate aortic regurgitation. A two-stage surgery was scheduled. Total arch replacement with an elephant trunk in the true lumen and concomitant aortic valve replacement were performed. Postoperatively, he developed severe haemolytic anaemia because of the folded elephant trunk. The anaemia improved after the second surgery, including graft replacement of the descending aorta. Similarly, a 61-year-old man, who underwent total arch replacement for acute Stanford type A aortic dissection, presented with enlargement of the chronic dissection of the descending aorta. Graft replacement of the descending aorta with an elephant trunk inserted into the true lumen was performed. The patient postoperatively developed haemolytic anaemia because of the folded elephant trunk, which improved after additional stent grafting into the elephant trunk. A folded elephant trunk in a small-calibre lumen can cause haemolysis. Therefore, inserting an elephant trunk in a small-calibre true lumen during surgery for chronic aortic dissection should be avoided. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  12. SEX DETERMINATION FROM FEMORAL HEAD DIAMETERS IN ...

    African Journals Online (AJOL)

    hi-tech

    2000-03-01

    Mar 1, 2000 ... In medico-legal cases where sophisticated methods of sex determination is lacking, these ... scientific methods(3). Using the visual method ... between the sexes and the values of the right and left femoral head diameters.

  13. Multiple cell common pressure vessel nickel hydrogen battery

    Science.gov (United States)

    Zagrodnik, Jeffrey P.; Jones, Kenneth R.

    1991-01-01

    A multiple cell common pressure vessel (CPV) nickel hydrogen battery was developed that offers significant weight, volume, cost, and interfacing advantages over the conventional individual pressure vessel (IPV) nickel hydrogen configuration that is currently used for aerospace applications. The baseline CPV design was successfully demonstrated though the testing of a 26 cell prototype, which completed over 7,000 44 percent depth of discharge LEO cycles. Two-cell boilerplate batteries have now exceeded 12,500 LEO cycles in ongoing laboratory tests. CPV batteries using both nominal 5 and 10 inch diameter vessels are currently available. The flexibility of the design allows these diameters to provide a broad capability for a variety of space applications.

  14. Radioactive liquid containing vessel

    International Nuclear Information System (INIS)

    Sakurada, Tetsuo; Kawamura, Hironobu.

    1993-01-01

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

  15. Effective diameters and corresponding states of fluids

    Science.gov (United States)

    Del Río, Fernando

    Effective hard-sphere diameters of fluids with purely repulsive interactions are derived from a generalized corresponding-states principle of Leland, Rowlinson and coworkers. Various alternative definitions are discussed and related. Virial expansions of the effective diameters and their corresponding volumes are obtained and compared with results of perturbation theory. Applications are made to inverse-power potentials, the repulsive part of the Lennard-Jones potential and hard spherocylinders and dumbells.

  16. Appendiceal diameter: CT versus sonographic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Orscheln, Emily S. [University of Cincinnati Medical Center, Department of Radiology, Cincinnati, OH (United States); Trout, Andrew T. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2016-03-15

    Ultrasound and CT are the dominant imaging modalities for assessment of suspected pediatric appendicitis, and the most commonly applied diagnostic criterion for both modalities is appendiceal diameter. The classically described cut-off diameter for the diagnosis of appendicitis is 6 mm when using either imaging modality. To demonstrate the fallacy of using the same cut-off diameter for both CT and US in the diagnosis of appendicitis. We conducted a retrospective review of patients younger than 18 years who underwent both US and CT of the appendix within 24 h. The shortest transverse dimension of the appendix was measured at the level of the proximal, mid and distal appendix on US and CT images. We compared mean absolute difference in appendiceal diameter between US and CT, using the paired t-test. We reviewed exams of 155 children (58.7% female) with a mean age of 11.3 ± 4.2 years; 38 of the children (24.5%) were diagnosed with appendicitis. The average time interval between US and CT was 7.0 ± 5.4 h. Mean appendiceal diameter measured by CT was significantly larger than that measured by US in cases without appendicitis (5.3 ± 1.0 mm vs. 4.7 ± 1.1 mm, P < 0.0001) and in cases with appendicitis (8.3 ± 2.2 mm vs. 7.0 ± 2.0 mm, P < 0.0001). Mean absolute diameter difference at any location along the appendix was 1.3-1.4 mm in normal appendices and 2 mm in cases of appendicitis. Measured appendiceal diameter differs between US and CT by 1-2 mm, calling into question use of the same diameter cut-off (6 mm) for both modalities for the diagnosis of appendicitis. (orig.)

  17. Small Diameter Bomb Increment II (SDB II)

    Science.gov (United States)

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-439 Small Diameter Bomb Increment II (SDB II) As of FY 2017 President’s Budget Defense... Bomb Increment II (SDB II) DoD Component Air Force Joint Participants Department of the Navy Responsible Office References SAR Baseline (Production...Mission and Description Small Diameter Bomb Increment II (SDB II) is a joint interest United States Air Force (USAF) and Department of the Navy

  18. Appendiceal diameter: CT versus sonographic measurements

    International Nuclear Information System (INIS)

    Orscheln, Emily S.; Trout, Andrew T.

    2016-01-01

    Ultrasound and CT are the dominant imaging modalities for assessment of suspected pediatric appendicitis, and the most commonly applied diagnostic criterion for both modalities is appendiceal diameter. The classically described cut-off diameter for the diagnosis of appendicitis is 6 mm when using either imaging modality. To demonstrate the fallacy of using the same cut-off diameter for both CT and US in the diagnosis of appendicitis. We conducted a retrospective review of patients younger than 18 years who underwent both US and CT of the appendix within 24 h. The shortest transverse dimension of the appendix was measured at the level of the proximal, mid and distal appendix on US and CT images. We compared mean absolute difference in appendiceal diameter between US and CT, using the paired t-test. We reviewed exams of 155 children (58.7% female) with a mean age of 11.3 ± 4.2 years; 38 of the children (24.5%) were diagnosed with appendicitis. The average time interval between US and CT was 7.0 ± 5.4 h. Mean appendiceal diameter measured by CT was significantly larger than that measured by US in cases without appendicitis (5.3 ± 1.0 mm vs. 4.7 ± 1.1 mm, P < 0.0001) and in cases with appendicitis (8.3 ± 2.2 mm vs. 7.0 ± 2.0 mm, P < 0.0001). Mean absolute diameter difference at any location along the appendix was 1.3-1.4 mm in normal appendices and 2 mm in cases of appendicitis. Measured appendiceal diameter differs between US and CT by 1-2 mm, calling into question use of the same diameter cut-off (6 mm) for both modalities for the diagnosis of appendicitis. (orig.)

  19. Extravasal occlusion of large vessels with titanic clips: efficiency, indications, and contraindications.

    Science.gov (United States)

    Vasilenko, Yu V; Kim, A I; Kotov, S A

    2002-11-01

    The mechanism of extravasal occlusion of blood vessels with titanic clips "Atrauclip" and "Ligaclip extra" was studied in order to reveal indications and contraindications to their use. Occlusion with the clips of both types was ineffective in vessels with a diameter of >7.0 mm. Arteritis or the presence of an intravascular occlusion facility in the vessel were also the contraindications for clip occlusion. In overcases the procedure of occlusion with titanic clips was efficient and atraumatic.

  20. Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography

    International Nuclear Information System (INIS)

    Lucarelli, Claudio Luiz

    1995-01-01

    The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

  1. Assessment of W7-X plasma vessel pressurisation in case of LOCA taking into account in-vessel components

    Energy Technology Data Exchange (ETDEWEB)

    Urbonavičius, E., E-mail: Egidijus.Urbonavicius@lei.lt; Povilaitis, M., E-mail: Mantas.Povilaitis@lei.lt; Kontautas, A., E-mail: Aurimas.Kontautas@lei.lt

    2015-11-15

    Highlights: • Analysis of the vacuum vessel response to the LOCA in W7-X was performed using lumped-parameter codes COCOSYS and ASTEC. • Benchmarking of the results received with two codes provides more confidence in results and helps in identification of possible important differences in the modelling. • The performed analysis answered the questions set in the installed plasma vessel venting system during overpressure of PV in case of 40 mm diameter LOCA in “baking” mode. • Differences in time until opening the burst disk observed in ASTEC and COCOSYS results are caused by differences in heat transfer modelling. - Abstract: This paper presents the analysis of W7-X vacuum vessel response taking into account in-vessel components. A detailed analysis of the vacuum vessel response to the loss of coolant accident was performed using lumped-parameter codes COCOSYS and ASTEC. The performed analysis showed that the installed plasma vessel venting system prevents overpressure of PV in case of 40 mm diameter LOCA in “baking” mode. The performed analysis revealed differences in heat transfer modelling implemented in ASTEC and COCOSYS computer codes, which require further investigation to justify the correct approach for application to fusion facilities.

  2. Assessment of W7-X plasma vessel pressurisation in case of LOCA taking into account in-vessel components

    International Nuclear Information System (INIS)

    Urbonavičius, E.; Povilaitis, M.; Kontautas, A.

    2015-01-01

    Highlights: • Analysis of the vacuum vessel response to the LOCA in W7-X was performed using lumped-parameter codes COCOSYS and ASTEC. • Benchmarking of the results received with two codes provides more confidence in results and helps in identification of possible important differences in the modelling. • The performed analysis answered the questions set in the installed plasma vessel venting system during overpressure of PV in case of 40 mm diameter LOCA in “baking” mode. • Differences in time until opening the burst disk observed in ASTEC and COCOSYS results are caused by differences in heat transfer modelling. - Abstract: This paper presents the analysis of W7-X vacuum vessel response taking into account in-vessel components. A detailed analysis of the vacuum vessel response to the loss of coolant accident was performed using lumped-parameter codes COCOSYS and ASTEC. The performed analysis showed that the installed plasma vessel venting system prevents overpressure of PV in case of 40 mm diameter LOCA in “baking” mode. The performed analysis revealed differences in heat transfer modelling implemented in ASTEC and COCOSYS computer codes, which require further investigation to justify the correct approach for application to fusion facilities.

  3. Pressure vessel integrity 1991

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  4. The reactor vessel steels

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  5. Vacuum distilling vessel

    Energy Technology Data Exchange (ETDEWEB)

    Reik, H

    1928-12-27

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

  6. Visualization of vessel traffic

    NARCIS (Netherlands)

    Willems, C.M.E.

    2011-01-01

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

  7. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

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

  8. Reactor vessel stud tensioner

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  9. An 810 ft/sec soil impact test of a 2-foot diameter model nuclear reactor containment system

    Science.gov (United States)

    Puthoff, R. L.

    1972-01-01

    A soil impact test was conducted on a 880-pound 2-foot diameter sphere model. The impact area consisted of back filled desert earth and rock. The impact generated a crater 5 feet in diameter by 5 feet deep. It buried itself a total of 15 feet - as measured to the bottom of the model. After impact the containment vessel was pressure checked. No leaks were detected nor cracks observed.

  10. Intracranial arterial aneurysm vasculopathies: targeting the outer vessel wall

    International Nuclear Information System (INIS)

    Krings, Timo; Piske, Ronie L.; Lasjaunias, Pierre L.

    2005-01-01

    The pathogenesis of intracranial arterial aneurysms (AA) remains unclear, despite their clinical importance. An improved understanding of this disease is important in choosing therapeutic options. In addition to the ''classical'' berry-type aneurysm, there are various other types of intracranial AA such as infectious, dissecting or giant, partially-thrombosed aneurysms. From the clinician's perspective, the hypothesis that some of these intracranial AA might be due to abluminal factors has been proposed for several years. Indeed, this hypothesis and the empirical use of anti-inflammatory drugs in giant intracranial aneurysms have been confirmed by recent studies reporting that an enzyme involved in the inflammatory cascade (5-lipoxygenase or 5-LO) promotes the pathogenesis of specific aneurysms in humans. 5-LO generates different forms of leukotrienes which are potent mediators of inflammation. Adventitial inflammation leads to a weakening of the media from the abluminal part of the vessel wall due to the release of proinflammatory factors that invade the media, thereby degrading the extracellular matrix, the elastic lamina of the vascular wall, and, finally, the integrity of the vessel lumen. This in turn results in a dilation of the vessel and aneurysm formation. Moreover, neoangiogenesis of vasa vasorum is found in close proximity to 5-LO activated macrophages. In addition to this biological cascade, we argue that repeated subadventitial haemorrhages from the new vasa vasorum play an important role in aneurysm pathogenesis, due to a progressive increase in size mediated by the apposition of new layers of intramural haematoma within the vessel wall. Intracranial giant AA can therefore be regarded as a proliferative disease of the vessel wall induced by extravascular activity. (orig.)

  11. Diameter effect on critical heat flux

    International Nuclear Information System (INIS)

    Tanase, A.; Cheng, S.C.; Groeneveld, D.C.; Shan, J.Q.

    2009-01-01

    The critical heat flux look-up table (CHF LUT) is widely used to predict CHF for various applications, including design and safety analysis of nuclear reactors. Using the CHF LUT for round tubes having inside diameters different from the reference 8 mm involves conversion of CHF to 8 mm. Different authors [Becker, K.M., 1965. An Analytical and Experimental Study of Burnout Conditions in Vertical Round Ducts, Aktiebolaget Atomenergie Report AE 177, Sweden; Boltenko, E.A., et al., 1989. Effect of tube diameter on CHF at various two phase flow regimes, Report IPE-1989; Biasi, L., Clerici, G.C., Garriba, S., Sala, R., Tozzi, A., 1967. Studies on Burnout, Part 3, Energia Nucleare, vol. 14, pp. 530-536; Groeneveld, D.C., Cheng, S.C., Doan, T., 1986. AECL-UO critical heat flux look-up table. Heat Transfer Eng., 7, 46-62; Groeneveld et al., 1996; Hall, D.D., Mudawar, I., 2000. Critical heat flux for water flow in tubes - II subcooled CHF correlations. Int. J. Heat Mass Transfer, 43, 2605-2640; Wong, W.C., 1996. Effect of tube diameter on critical heat flux, MaSC dissertation, Ottawa Carleton Institute for Mechanical and Aeronautical Engineering, University of Ottawa] have proposed several types of correlations or factors to describe the diameter effect on CHF. The present work describes the derivation of new diameter correction factor and compares it with several existing prediction methods

  12. PDX vacuum vessel stress analysis

    International Nuclear Information System (INIS)

    Nikodem, Z.D.

    1975-01-01

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

  13. PdNP Decoration of Halloysite Lumen via Selective Grafting of Ionic Liquid onto the Aluminol Surfaces and Catalytic Application.

    Science.gov (United States)

    Dedzo, Gustave K; Ngnie, Gaëlle; Detellier, Christian

    2016-02-01

    The synthesis of selectively deposited palladium nanoparticles (PdNPs) inside tubular halloysite lumens is reported. This specific localization was directed by the selective modification of the aluminol surfaces of the clay mineral through stable Al-O-C bonds. An ionic liquid (1-(2-hydroxyethyl)-3-methylimidazolium) was grafted onto halloysite following the guest displacement method (generally used for kaolinite) using halloysite-DMSO preintercalate. The characterization of this clay nanohybrid material (XRD, NMR, TGA) showed characteristics reminiscent of similar materials synthesized from kaolinite. The grafting on halloysite lumens was also effective without using the DMSO preintercalate. The presence of these new functionalities in halloysite directs the synthesis of uniform PdNPs with size ranging between 3 and 6 nm located exclusively in the lumens. This results from the selective adsorption of PdNPs precursors in functionalized lumens through an anion exchange mechanism followed by in situ reduction. In contrast, the unmodified clay mineral displayed nanoparticles both inside and outside the tubes. These catalysts showed significant catalytic activity for the reduction of 4-nitrophenol (4-NP). The most efficient catalysts were recycled up to three times without reducing significantly the catalytic activities.

  14. Low Iodine in the Follicular Lumen Caused by Cytoplasm Mis-localization of Sodium Iodide Symporter may Induce Nodular Goiter.

    Science.gov (United States)

    Huang, Huibin; Shi, Yaxiong; Liang, Bo; Cai, Huiyao; Cai, Qingyan

    2017-10-01

    Iodine is a key ingredient in the synthesis of thyroid hormones and also a major factor in the regulation of thyroid function. A local reduction of iodine content in follicular lumen leads to overexpression of local thyroid-stimulating hormone receptor (TSHr), which in turn excessively stimulates the regional thyroid tissue, and result in the formation of nodular goiter. In this study, we investigated the relationship between iodine content and sodium iodide symporter (NIS) expression by using the clinical specimens from patients with nodular goiter and explored the pathogenesis triggered by iodine deficiency in nodular goiter. In total, 28 patients were clinically histopathologically confirmed to have nodular goiter and the corresponding adjacent normal thyroid specimens were harvested simultaneously. Western blot and immunohistochemistry were performed to assay NIS expression and localization in thyrocytes of both nodular goiter and adjacent normal thyroid tissues. NIS expression mediated by iodine in follicular lumen was confirmed by follicular model in vitro. Meanwhile, radioscan with iodine-131were conducted on both nodular goiter and adjacent normal thyroid. Our data showed that NIS expression in nodular goiter was significantly higher than that in adjacent normal tissues, which was associated with low iodine in the follicular lumen. Abnormal localization of NIS and lower amount of radioactive iodine-131 were also found in nodular goiter. Our data implied that low iodine in the follicular lumen caused by cytoplasm mis-localization of NIS may induce nodular goiter.

  15. Measuring Electrospun Nanofibre Diameter: a Novel Approach

    International Nuclear Information System (INIS)

    Ziabari, M.; Mottaghitalab, V.; Haghi, A. K.; McGovern, S. T.

    2008-01-01

    A new method based on image analysis for electrospun nanofibre diameter measurement is presented. First, the SEM micrograph of the nanofibre web obtained by electrospinning process is converted to binary image using local thresholding method. In the next step, skeleton and distance transformed image are generated. Then, the intersection points which bring about untrue measurements are identified and removed from the skeleton. Finally, the resulting skeleton and distance transformed image are used to determine fibre diameter. The method is evaluated by a simulated image with known characteristics generated by ?-randomness procedure. The results indicate that this approach is successful in making fast, accurate automated measurements of electrospun fibre diameters. (cross-disciplinary physics and related areas of science and technology)

  16. Geometric Deformations of the Thoracic Aorta and Supra-Aortic Arch Branch Vessels Following Thoracic Endovascular Aortic Repair.

    Science.gov (United States)

    Ullery, Brant W; Suh, Ga-Young; Hirotsu, Kelsey; Zhu, David; Lee, Jason T; Dake, Michael D; Fleischmann, Dominik; Cheng, Christopher P

    2018-04-01

    To utilize 3-D modeling techniques to better characterize geometric deformations of the supra-aortic arch branch vessels and descending thoracic aorta after thoracic endovascular aortic repair. Eighteen patients underwent endovascular repair of either type B aortic dissection (n = 10) or thoracic aortic aneurysm (n = 8). Computed tomography angiography was obtained pre- and postprocedure, and 3-D geometric models of the aorta and supra-aortic branch vessels were constructed. Branch angle of the supra-aortic branch vessels and curvature metrics of the ascending aorta, aortic arch, and stented thoracic aortic lumen were calculated both at pre- and postintervention. The left common carotid artery branch angle was lower than the left subclavian artery angles preintervention ( P Supra-aortic branch vessel angulation remains relatively static when proximal landing zones are distal to the left common carotid artery.

  17. Influence of a Double-Lumen Extension Tube on Drug Delivery: Examples of Isosorbide Dinitrate and Diazepam.

    Directory of Open Access Journals (Sweden)

    Aurélie Maiguy-Foinard

    Full Text Available Plastic materials such as polyurethane (PUR, polyethylene (PE, polypropylene (PP and polyvinyl chloride (PVC are widely used in double-lumen extension tubing. The purposes of our study were to 1 compare in vitro drug delivery through the double extension tubes available on the market 2 assess the plastic properties of PUR in infusion devices and their impact on drug delivery.The study compared eight double-lumen extension tubes in PUR, co-extruded (PE/PVC plastic and plasticised PVC from different manufacturers. Isosorbide dinitrate and diazepam were used as model compounds to evaluate their sorption on the internal surface of the infusion device. Control experiments were performed using norepinephrine known not to absorb to plastics. Drug concentrations delivered at the egress of extension tubes were determined over time by an analytical spectrophotometric UV-Vis method. The main characteristics of plastics were also determined.Significant differences in the sorption phenomenon were observed among the eight double-lumen extension tubes and between pairs of extension tubes. Mean concentrations of isosorbide dinitrate delivered at the egress of double-lumen extension tubes after a 150-minute infusion (mean values ± standard deviation in percentage of the initial concentrations in the prepared syringes ranged between 80.53 ± 1.66 (one of the PUR tubes and 92.84 ± 2.73 (PE/PVC tube. The same parameters measured during diazepam infusion ranged between 48.58 ± 2.88 (one of the PUR tubes and 85.06 ± 3.94 (PE/PVC tube. The double-lumen extension tubes in PUR were either thermosetting (resin or thermoplastic according to reference.Clinicians must be aware of potential drug interactions with extension tube materials and so must consider their nature as well as the sterilisation method used before selecting an infusion device.

  18. Moisture monitoring in large diameter boreholes

    International Nuclear Information System (INIS)

    Tyler, S.

    1985-01-01

    The results of both laboratory and field experiments indicate that the neutron moisture gauge traditionally used in soil physics experiments can be extended for use in large diameter (up to 15 cm) steel-cased boreholes with excellent results. This application will permit existing saturated zone monitoring wells to be used for unsaturated zone monitoring of recharge, redistribution and leak detection from waste disposal facilities. Its applicability to large diameter cased wells also gives the soil physicist and ground-water hydrologist and new set of monitoring points in the unsaturated zone to study recharge and aquifer properties. 6 refs., 6 figs., 2 tabs

  19. Subadventitial techniques for chronic total occlusion percutaneous coronary intervention: The concept of "vessel architecture".

    Science.gov (United States)

    Azzalini, Lorenzo; Carlino, Mauro; Brilakis, Emmanouil S; Vo, Minh; Rinfret, Stéphane; Uretsky, Barry F; Karmpaliotis, Dimitri; Colombo, Antonio

    2018-03-01

    Despite improvements in guidewire technologies, the traditional antegrade wire escalation approach to chronic total occlusion (CTO) recanalization is successful in only 60-80% of selected cases. In particular, long, calcified, and tortuous occlusions are less successfully approached with a true-to-true lumen approach. Frequently, the guidewire tracks into the subadventitial space, with no guarantee of distal re-entry into the true lumen. The ability to manage the subadventitial space has been a key step in the tremendous improvement in success rates of contemporary CTO percutaneous coronary intervention (PCI), whether operating antegradely or retrogradely. A modern approach to CTO PCI involves understanding the concept of "vessel architecture," which is based on the distinction between coronary structures (occlusive plaque, comprising the disrupted intima and media, and the outer adventitia) and extravascular space. The vessel architecture represents a safe work environment for guidewire and device manipulation. This review provides an anatomy-based description of the concept of vessel architecture, along with a historical perspective of subadventitial techniques for CTO PCI, and outcome data of CTO PCI utilizing the subadventitial space. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Confinement Vessel Assay System: Design and Implementation Report

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Gomez, Cipriano D.; Miko, David K.; Salazar, William R.; Stange, Sy; Vigil, Georgiana M.

    2012-01-01

    Los Alamos National Laboratory has a number of spherical confinement vessels remaining from tests involving nuclear materials. These vessels have an inner diameter of 6 feet with 1- to 2-inch thick steel walls. The goal of the Confinement Vessel Disposition (CVD) project is to remove debris and reduce contamination inside the vessels. We have developed a neutron assay system for the purposes of Materials Control and Accountability (MC and A) measurements of the vessel prior to and after cleanout. We present our approach to confronting the challenges in designing, building, and testing such a system. The system was designed to meet a set of functional and operational requirements. A Monte Carlo model was developed to aid in optimizing the detector design as well as to predict the systematic uncertainty associated with confinement vessel measurements. Initial testing was performed to optimize and determine various measurement parameters, and then the system was characterized using 252 Cf placed a various locations throughout the measurement system. Measurements were also performed with a 252 Cf source placed inside of small steel and HDPE shells to study the effect of moderation. These measurements compare favorably with their MCNPX model equivalent, making us confident that we can rely on the Monte Carlo simulation to predict the systematic uncertainty due to variations in response to material that may be localized at different points within a vessel.

  1. Vessels in Transit - Web Tool

    Data.gov (United States)

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

  2. Axial vessel widening in arborescent monocots.

    Science.gov (United States)

    Petit, Giai; DeClerck, Fabrice A J; Carrer, Marco; Anfodillo, Tommaso

    2014-02-01

    Dicotyledons have evolved a strategy to compensate for the increase in hydraulic resistance to water transport with height growth by widening xylem conduits downwards. In monocots, the accumulation of hydraulic resistance with height should be similar, but the absence of secondary growth represents a strong limitation for the maintenance of xylem hydraulic efficiency during ontogeny. The hydraulic architecture of monocots has been studied but it is unclear how monocots arrange their axial vascular structure during ontogeny to compensate for increases in height. We measured the vessel lumina and estimated the hydraulic diameter (Dh) at different heights along the stem of two arborescent monocots, Bactris gasipaes (Kunth) and Guadua angustifolia (Kunth). For the former, we also estimated the variation in Dh along the leaf rachis. Hydraulic diameter increased basally from the stem apex to the base with a scaling exponent (b) in the range of those reported for dicot trees (b = 0.22 in B. gasipaes; b = 0.31 and 0.23 in G. angustifolia). In B. gasipaes, vessels decrease in Dh from the stem's centre towards the periphery, an opposite pattern compared with dicot trees. Along the leaf rachis, a pattern of increasing Dh basally was also found (b = 0.13). The hydraulic design of the monocots studied revealed an axial pattern of xylem conduits similar to those evolved by dicots to compensate and minimize the negative effect of root-to-leaf length on hydrodynamic resistance to water flow.

  3. Dark-lumen magnetic resonance colonography in patients with suspected sigmoid diverticulitis: a feasibility study

    International Nuclear Information System (INIS)

    Ajaj, Waleed; Lauenstein, Thomas; Goehde, Susanne; Kuehle, Christiane; Herborn, Christoph U.; Ruehm, Stefan G.; Langhorst, Jost; Zoepf, Thomas; Gerken, Guido; Goyen, Mathias

    2005-01-01

    To assess dark-lumen magnetic resonance colonography (MRC) for the evaluation of patients with suspected sigmoid diverticulitis. Forty patients with suspected sigmoid diverticulitis underwent MRC within 72 h prior to conventional colonoscopy (CC). A three-dimensional T1-weighted volumetric interpolated breath-hold examination sequence was acquired after an aqueous enema and intravenous administration of gadolinium-based contrast agents. All MRC data were evaluated by two radiologists. Based on wall thickness and focal uptake of contrast material and pericolic reaction including mesenteric infiltration on T1-weighted sequence the sigmoid colon was assessed for the presence of diverticulitis. MRC classified 17 of the 40 patients as normal with regard to sigmoid diverticulitis. However, CC confirmed the presence of light inflammatory signs in four patients which were missed in MRC. MRC correctly identified wall thickness and contrast uptake of the sigmoid colon in the other 23 patients. In three of these patients false-positive findings were observed, and MRC classified the inflammation of the sigmoid colon as diverticulitis whereas CC and histopathology confirmed invasive carcinoma. MRC detected additionally relevant pathologies of the entire colon and could be performed in cases where CC was incomplete. MRC may be considered a promising alternative to CC for the detection of sigmoid diverticulitis. (orig.)

  4. "Detachment of the carinal hook following endobronchial intubation with a double lumen tube"

    Directory of Open Access Journals (Sweden)

    Rocha Ana C

    2011-10-01

    Full Text Available Abstract Background Carinal hooks increases difficulty at endotracheal intubation. Amputation of the carinal hook during passage and malpositioning of the tube to the hook are some of the potential problems related with left-sided Carlens double lumen tube (DLT. This article reports an amputation of the hook during a difficult selective intubation and aimed at calling the attention to complications associated with DLTs and the importance of fiberoptic bronchoscopy. Case presentation A 68 year-old woman was scheduled for right-sided thoracotomy in whom blind DLT insertion was performed. Narrowed trachea causes difficulty in rotating the DLT 90° counter-clockwise. After carinal hook was noticed upon visual inspection of the DLT, fiberoptic bronchoscopy was used to remove the missing part (with the use of forceps from the right mainstem bronchus. Conclusion Insertion of DLTs with carinal hook is associated with technical problems and potentially life-threatening hazards have discouraged their use. Fiberoptic evaluation and repositioning solves most of the problems. Although amputation of the carinal hook has not been previously reported, clinicians should be alert. This case report emphasizes the utility of the fiberoptic bronchoscopy in the operating theatre for placement, positioning and inspection of the carinal hook DLT.

  5. Lumen apposing metal stents for pancreatic fluid collections: Recognition and management of complications.

    Science.gov (United States)

    DeSimone, Michael L; Asombang, Akwi W; Berzin, Tyler M

    2017-09-16

    For patients recovering from acute pancreatitis, the development of a pancreatic fluid collection (PFC) predicts a more complex course of recovery, and introduces difficult management decisions with regard to when, whether, and how the collection should be drained. Most PFCs resolve spontaneously and drainage is indicated only in pseudocysts and walled-off pancreatic necrosis when the collections are causing symptoms and/or local complications such as biliary obstruction. Historical approaches to PFC drainage have included surgical (open or laparoscopic cystgastrostomy or pancreatic debridement), and the placement of percutaneous drains. Endoscopic drainage techniques have emerged in the last several years as the preferred approach for most patients, when local expertise is available. Lumen-apposing metal stents (LAMS) have recently been developed as a tool to facilitate potentially safer and easier endoscopic drainage of pancreatic fluid collections, and less commonly, for other indications, such as gallbladder drainage. Physicians considering LAMS placement must be aware of the complications most commonly associated with LAMS including bleeding, migration, buried stent, stent occlusion, and perforation. Because of the patient complexity associated with severe pancreatitis, management of pancreatic fluid collections can be a complex and multidisciplinary endeavor. Successful and safe use of LAMS for patients with pancreatic fluid collections requires that the endoscopist have a full understanding of the potential complications of LAMS techniques, including how to recognize and manage expected complications.

  6. Rap1 integrates tissue polarity, lumen formation, and tumorigenicpotential in human breast epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Masahiko; Nelson, Celeste M.; Myers, Connie A.; Bissell,Mina J.

    2006-09-29

    Maintenance of apico-basal polarity in normal breast epithelial acini requires a balance between cell proliferation, cell death, and proper cell-cell and cell-extracellular matrix signaling. Aberrations in any of these processes can disrupt tissue architecture and initiate tumor formation. Here we show that the small GTPase Rap1 is a crucial element in organizing acinar structure and inducing lumen formation. Rap1 activity in malignant HMT-3522 T4-2 cells is appreciably higher than in S1 cells, their non-malignant counterparts. Expression of dominant-negative Rap1 resulted in phenotypic reversion of T4-2 cells, led to formation of acinar structures with correct apico-basal polarity, and dramatically reduced tumor incidence despite the persistence of genomic abnormalities. The resulting acini contained prominent central lumina not observed when other reverting agents were used. Conversely, expression of dominant-active Rap1 in T4-2 cells inhibited phenotypic reversion and led to increased invasiveness and tumorigenicity. Thus, Rap1 acts as a central regulator of breast architecture, with normal levels of activation instructing apical polarity during acinar morphogenesis, and increased activation inducing tumor formation and progression to malignancy.

  7. Epithelial organization and cyst lumen expansion require efficient Sec13–Sec31-driven secretion

    Science.gov (United States)

    Townley, Anna K.; Schmidt, Katy; Hodgson, Lorna; Stephens, David J.

    2012-01-01

    Epithelial morphogenesis is directed by interactions with the underlying extracellular matrix. Secretion of collagen and other matrix components requires efficient coat complex II (COPII) vesicle formation at the endoplasmic reticulum. Here, we show that suppression of the outer layer COPII component, Sec13, in zebrafish embryos results in a disorganized gut epithelium. In human intestinal epithelial cells (Caco-2), Sec13 depletion causes defective epithelial polarity and organization on permeable supports. Defects are seen in the ability of cells to adhere to the substrate, form a monolayer and form intercellular junctions. When embedded in a three-dimensional matrix, Sec13-depleted Caco-2 cells form cysts but, unlike controls, are defective in lumen expansion. Incorporation of primary fibroblasts within the three-dimensional culture substantially restores normal morphogenesis. We conclude that efficient COPII-dependent secretion, notably assembly of Sec13–Sec31, is required to drive epithelial morphogenesis in both two- and three-dimensional cultures in vitro, as well as in vivo. Our results provide insight into the role of COPII in epithelial morphogenesis and have implications for the interpretation of epithelial polarity and organization assays in cell culture. PMID:22331354

  8. Epithelial organization and cyst lumen expansion require efficient Sec13-Sec31-driven secretion.

    Science.gov (United States)

    Townley, Anna K; Schmidt, Katy; Hodgson, Lorna; Stephens, David J

    2012-02-01

    Epithelial morphogenesis is directed by interactions with the underlying extracellular matrix. Secretion of collagen and other matrix components requires efficient coat complex II (COPII) vesicle formation at the endoplasmic reticulum. Here, we show that suppression of the outer layer COPII component, Sec13, in zebrafish embryos results in a disorganized gut epithelium. In human intestinal epithelial cells (Caco-2), Sec13 depletion causes defective epithelial polarity and organization on permeable supports. Defects are seen in the ability of cells to adhere to the substrate, form a monolayer and form intercellular junctions. When embedded in a three-dimensional matrix, Sec13-depleted Caco-2 cells form cysts but, unlike controls, are defective in lumen expansion. Incorporation of primary fibroblasts within the three-dimensional culture substantially restores normal morphogenesis. We conclude that efficient COPII-dependent secretion, notably assembly of Sec13-Sec31, is required to drive epithelial morphogenesis in both two- and three-dimensional cultures in vitro, as well as in vivo. Our results provide insight into the role of COPII in epithelial morphogenesis and have implications for the interpretation of epithelial polarity and organization assays in cell culture.

  9. Point-of-care ultrasound versus auscultation in determining the position of double-lumen tube.

    Science.gov (United States)

    Hu, Wei-Cai; Xu, Lei; Zhang, Quan; Wei, Li; Zhang, Wei

    2018-03-01

    This study was designed to assess the accuracy of point-of-care ultrasound in determining the position of double-lumen tubes (DLTs).A total of 103 patients who required DLT intubation were enrolled into the study. After DLTs were tracheal intubated in the supine position, an auscultation researcher and ultrasound researcher were sequentially invited in the operating room to conduct their evaluation of the DLT. After the end of their evaluation, fiberscope researchers (FRs) were invited in the operating room to evaluate the position of DLT using a fiberscope. After the patients were changed to the lateral position, the same evaluation process was repeated. These 3 researchers were blind to each other when they made their conclusions. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were obtained by statistical analysis.When left DLTs (LDLTs) were used, the accuracy of ultrasound (84.2% [72.1%, 92.5%]) was higher than the accuracy of auscultation (59.7% [45.8%, 72.4%]) (P auscultation (67.4% [52.0%, 80.5%]) (P auscultation (54.4% [40.7%, 67.6%]) (P auscultation (47.8% [32.9%, 63.1%]) (P auscultation in determining the position of DLTs.

  10. Delivery of CSF-1R to the lumen of macropinosomes promotes its destruction in macrophages

    Science.gov (United States)

    Lou, Jieqiong; Low-Nam, Shalini T.; Kerkvliet, Jason G.; Hoppe, Adam D.

    2014-01-01

    ABSTRACT Activation of the macrophage colony stimulating factor-1 receptor (CSF-1R) by CSF-1 stimulates pronounced macropinocytosis and drives proliferation of macrophages. Although the role of macropinocytosis in CSF-1R signaling remains unknown, we show here that, despite internalizing large quantities of plasma membrane, macropinosomes contribute little to the internalization of the CSF-1–CSF-1R complex. Rather, internalization of the CSF-1R in small endocytic vesicles that are sensitive to clathrin disruption, outcompetes macropinosomes for CSF-1R endocytosis. Following internalization, small vesicles carrying the CSF-1R underwent homotypic fusion and then trafficked to newly formed macropinosomes bearing Rab5. As these macropinosomes matured, acquiring Rab7, the CSF-1R was transported into their lumen and degraded. Inhibition of macropinocytosis delayed receptor degradation despite no disruption to CSF-1R endocytosis. These data indicate that CSF-1-stimulated macropinosomes are sites of multivesicular body formation and accelerate CSF-1R degradation. Furthermore, we demonstrate that macropinocytosis and cell growth have a matching dose dependence on CSF-1, suggesting that macropinosomes might be a central mechanism coupling CSF-1R signaling and macrophage growth. PMID:25335894

  11. Evaluation of esophageal motility utilizing the functional lumen imaging probe (FLIP)

    Science.gov (United States)

    Carlson, Dustin A.; Kahrilas, Peter J.; Lin, Zhiyue; Hirano, Ikuo; Gonsalves, Nirmala; Listernick, Zoe; Ritter, Katherine; Tye, Michael; Ponds, Fraukje A.; Wong, Ian; Pandolfino, John E.

    2016-01-01

    Background Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia. Methods 145 patients (ages 18 – 85, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered ‘abnormal’. FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered ‘abnormal’ if EGJ-DI was esophageal motility and 29 normal motility. 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI. Conclusions FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia. PMID:27725650

  12. Improving lumen maintenance by nanopore array dispersed quantum dots for on-chip light emitting diodes

    Science.gov (United States)

    Chen, Quan; Yang, Fan; Wan, Renzhuo; Fang, Dong

    2017-12-01

    The temperature stability of quantum dots (QDs), which is crucial for integrating into high power light-emitting diodes (LEDs) in the on-chip configuration, needs to be further improved. In this letter, we report warm white LEDs, where CdSe/ZnS nanoparticles were incorporated into a porous anodic alumina (PAA) matrix with a chain structure by the self-assembly method. Experiments demonstrate that the QD concentration range in toluene solvent from 1% mg/μl to 1.2% mg/μl in combination with the PAA matrix shows the best luminous property. To verify the reliability of the as-prepared device, a comparison experiment was conducted. It indicates excellent lumen maintenance of the light source and less chromaticity coordinate shift under accelerated life testing conditions. Experiments also prove that optical depreciation was only up to 4.6% of its initial value after the 1500 h aging test at the junction temperature of 76 °C.

  13. Numerical Investigation of Characteristic of Anisotropic Thermal Conductivity of Natural Fiber Bundle with Numbered Lumens

    Directory of Open Access Journals (Sweden)

    Guan-Yu Zheng

    2014-01-01

    Full Text Available Natural fiber bundle like hemp fiber bundle usually includes many small lumens embedded in solid region; thus, it can present lower thermal conduction than that of conventional fibers. In the paper, characteristic of anisotropic transverse thermal conductivity of unidirectional natural hemp fiber bundle was numerically studied to determine the dependence of overall thermal property of the fiber bundle on that of the solid region phase. In order to efficiently predict its thermal property, the fiber bundle was embedded into an imaginary matrix to form a unit composite cell consisting of the matrix and the fiber bundle. Equally, another unit composite cell including an equivalent solid fiber was established to present the homogenization of the fiber bundle. Next, finite element thermal analysis implemented by ABAQUS was conducted in the two established composite cells by applying proper thermal boundary conditions along the boundary of unit cell, and influences of the solid region phase and the equivalent solid fiber on the composites were investigated, respectively. Subsequently, an optional relationship of thermal conductivities of the natural fiber bundle and the solid region was obtained by curve fitting technique. Finally, numerical results from the obtained fitted curves were compared with the analytic Hasselman-Johnson’s results and others to verify the present numerical model.

  14. High lumenal chloride in the lysosome is critical for lysosome function

    Science.gov (United States)

    Chakraborty, Kasturi; Leung, KaHo; Krishnan, Yamuna

    2017-01-01

    Lysosomes are organelles responsible for the breakdown and recycling of cellular machinery. Dysfunctional lysosomes give rise to lysosomal storage disorders as well as common neurodegenerative diseases. Here, we use a DNA-based, fluorescent chloride reporter to measure lysosomal chloride in Caenorhabditis elegans as well as murine and human cell culture models of lysosomal diseases. We find that the lysosome is highly enriched in chloride, and that chloride reduction correlates directly with a loss in the degradative function of the lysosome. In nematodes and mammalian cell culture models of diverse lysosomal disorders, where previously only lysosomal pH dysregulation has been described, massive reduction of lumenal chloride is observed that is ~103 fold greater than the accompanying pH change. Reducing chloride within the lysosome impacts Ca2+ release from the lysosome and impedes the activity of specific lysosomal enzymes indicating a broader role for chloride in lysosomal function. DOI: http://dx.doi.org/10.7554/eLife.28862.001 PMID:28742019

  15. In-vessel coolability and steam explosion in Nordic BWRs

    Energy Technology Data Exchange (ETDEWEB)

    Ma, W.; Li, L.; Hansson, R.; Villanueva, W.; Kudinov, P.; Manickam, L.; Tran, C.-T. (Royal Institute of Technology (KTH) (Sweden))

    2011-05-15

    The objective of this research is to reduce the uncertainty in quantification of steam explosion risk and in-vessel coolability in the Nordic BWR plants which employ cavity flooding as severe accident management (SAM) strategy. To quantify the coolability of debris bed packed with irregular particles, the friction laws of fluid flow in particulate beds packed with non-spherical particles were investigated on the POMECO-FL test facility, and the experimental data suggest that the Ergun equation is applicable if the effective particle diameter of the particles is represented by the equivalent diameter of the particles, which is the product of Sauter mean diameter and shape factor of the particles. One-way coupling analysis between PECM model for melt pool heat transfer and ANSYS thermo-structural mechanics was performed to analyze the vessel creep, and the results revealed two different modes of vessel failure: a 'ballooning' of the vessel bottom and a 'localized creep' concentrated within the vicinity of the top surface of the melt pool. Single-droplet steam explosion experiments were carried out by using oxidic mixture of WO{sub 3}-CaO, and the results show an apparent difference in steam explosion energetics between the eutectic and non-eutectic melts at low melt superheat (100 deg. C). (Author)

  16. In-vessel coolability and steam explosion in Nordic BWRs

    International Nuclear Information System (INIS)

    Ma, W.; Li, L.; Hansson, R.; Villanueva, W.; Kudinov, P.; Manickam, L.; Tran, C.-T.

    2011-05-01

    The objective of this research is to reduce the uncertainty in quantification of steam explosion risk and in-vessel coolability in the Nordic BWR plants which employ cavity flooding as severe accident management (SAM) strategy. To quantify the coolability of debris bed packed with irregular particles, the friction laws of fluid flow in particulate beds packed with non-spherical particles were investigated on the POMECO-FL test facility, and the experimental data suggest that the Ergun equation is applicable if the effective particle diameter of the particles is represented by the equivalent diameter of the particles, which is the product of Sauter mean diameter and shape factor of the particles. One-way coupling analysis between PECM model for melt pool heat transfer and ANSYS thermo-structural mechanics was performed to analyze the vessel creep, and the results revealed two different modes of vessel failure: a 'ballooning' of the vessel bottom and a 'localized creep' concentrated within the vicinity of the top surface of the melt pool. Single-droplet steam explosion experiments were carried out by using oxidic mixture of WO 3 -CaO, and the results show an apparent difference in steam explosion energetics between the eutectic and non-eutectic melts at low melt superheat (100 deg. C). (Author)

  17. Learning-based automated segmentation of the carotid artery vessel wall in dual-sequence MRI using subdivision surface fitting.

    Science.gov (United States)

    Gao, Shan; van 't Klooster, Ronald; Kitslaar, Pieter H; Coolen, Bram F; van den Berg, Alexandra M; Smits, Loek P; Shahzad, Rahil; Shamonin, Denis P; de Koning, Patrick J H; Nederveen, Aart J; van der Geest, Rob J

    2017-10-01

    The quantification of vessel wall morphology and plaque burden requires vessel segmentation, which is generally performed by manual delineations. The purpose of our work is to develop and evaluate a new 3D model-based approach for carotid artery wall segmentation from dual-sequence MRI. The proposed method segments the lumen and outer wall surfaces including the bifurcation region by fitting a subdivision surface constructed hierarchical-tree model to the image data. In particular, a hybrid segmentation which combines deformable model fitting with boundary classification was applied to extract the lumen surface. The 3D model ensures the correct shape and topology of the carotid artery, while the boundary classification uses combined image information of 3D TOF-MRA and 3D BB-MRI to promote accurate delineation of the lumen boundaries. The proposed algorithm was validated on 25 subjects (48 arteries) including both healthy volunteers and atherosclerotic patients with 30% to 70% carotid stenosis. For both lumen and outer wall border detection, our result shows good agreement between manually and automatically determined contours, with contour-to-contour distance less than 1 pixel as well as Dice overlap greater than 0.87 at all different carotid artery sections. The presented 3D segmentation technique has demonstrated the capability of providing vessel wall delineation for 3D carotid MRI data with high accuracy and limited user interaction. This brings benefits to large-scale patient studies for assessing the effect of pharmacological treatment of atherosclerosis by reducing image analysis time and bias between human observers. © 2017 American Association of Physicists in Medicine.

  18. Reactor vessel sealing plug

    International Nuclear Information System (INIS)

    Dooley, R.A.

    1986-01-01

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

  19. Mobile nuclear reactor containment vessel

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  20. Nuclear reactor vessel inspection apparatus

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  1. Reactor vessel stud closure system

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  2. Refueling system with small diameter rotatable plugs

    International Nuclear Information System (INIS)

    Ritz, W.C.

    1987-01-01

    This patent describes a liquid-metal fastbreeder nuclear reactor comprising a reactor pressure vessel and closure head therefor, a reactor core barrel disposed within the reactor vessel and enclosing a reactor core having therein a large number of closely spaced fuel assemblies, and the reactor core barrel and the reactor core having an approximately concentric circular cross-sectional configuration with a geometric center in predetermined location within the reactor vessel. The improved refueling system described here comprises: a large controllably rotatable plug means comprising the substantial portion of the closure head, a reactor upper internals structure mounted from the large rotatable plug means. The large rotatable plug means has an approximately circular configuration which approximates the cross-sectional configuration of the reactor core barrel with a center of rotation positioned a first predetermined distance from the geometric center of the reactor core barrel so that the large rotatable plug means rotates eccentrically with respect to the reactor core barrel; a small controllably rotatable plug means affixed to the large rotatable plug means and rotatable with respect thereto. The small rotatable plug means has a center of rotation which is offset a second predetermined distance from the rotational center of the large rotatable plug means so that the small rotatable plug means rotates eccentrically with respect to the large rotatable plug means

  3. Reactor pressure vessel steels

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  4. Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-07-01

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

  5. Small diameter symmetric networks from linear groups

    Science.gov (United States)

    Campbell, Lowell; Carlsson, Gunnar E.; Dinneen, Michael J.; Faber, Vance; Fellows, Michael R.; Langston, Michael A.; Moore, James W.; Multihaupt, Andrew P.; Sexton, Harlan B.

    1992-01-01

    In this note is reported a collection of constructions of symmetric networks that provide the largest known values for the number of nodes that can be placed in a network of a given degree and diameter. Some of the constructions are in the range of current potential engineering significance. The constructions are Cayley graphs of linear groups obtained by experimental computation.

  6. Changing the Diameter of a Viewing Tube

    Science.gov (United States)

    Obara, Samuel

    2009-01-01

    This article is about the students' investigation about the relationship between the diameter of the view tubes (x) of constant lengths and the viewable vertical distance (y) on the wall while keeping the perpendicular distance from the eyeball to the wall constant. The students collected data and used and represented it in tabular and graphical…

  7. Height - Diameter predictive equations for Rubber (Hevea ...

    African Journals Online (AJOL)

    BUKOLA

    They proffer logistic data for modeling and futuristic prediction for sustainable forest management. Diameter is one of the most ... in various quantitative estimation following the intricacy of time, availability of modern equipments .... growth functions. This trend is shown in Figure 1 where the prediction equations are plotted.

  8. Blood Vessels in Allotransplantation.

    Science.gov (United States)

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

    2015-07-01

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

  9. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  10. Ionizing radiations and blood vessels

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  11. Automatic design of prestressed concrete vessels

    International Nuclear Information System (INIS)

    Sotomura, Kentaro; Murazumi, Yasuyuki

    1984-01-01

    Prestressed concrete appeared after high strnegth steel had been produced, therefore it has the history of only 40 years even in Europe where it was developed. High compressive force is given to concrete beforehand by high strength steel to resist tensile force. It is superior to ordinary steel in strength, economy, rust prevention, fire protection and workability, and it competes with ordinary steel in the fields of bridges, towers, water tanks, water pipes, barges, LPG and LNG tanks, reactor pressure vessels, reactor containment vessels and so on. The design of prestressed concrete containment vessels (PCCV) being constructed in Japan adopts the form of mounting a semi-spherical dome on a cylindrical wall of 43m inside diameter and about 1.5m thickness, and the steel pipe sheaths for inserting tendons are arranged in the wall. The Taisei Construction Co. has developed the PC-ADE system which enables the optimum design of PCCVs. The outline of the automatic design system, the design of tendon arrangement, the preparation of the data on the load for stress analysis, the stress analysis by axisymmetric finite element method and the calculation of cross sections are explained. Design is a creative activity, and in the design of PCCVs also, the intention of designers should be materialized when this program is utilized. (Kako, I.)

  12. Inservice inspection of Halden BWR pressure vessel

    International Nuclear Information System (INIS)

    Foerli, O.; Hernes, T.

    1978-01-01

    A description is given of how the recertification inspection of the 20 years old Halden Reactor pressure vessel was carried out in accordance with the latest ASME-CODES, despite the fact that inspection accessibility was poor. As no volumetric inspection had been carried out since the preservice radiography in 1957, the ultrasonic inspection included the high flux region of all welds. In total 70% of longitudinal welds and 20% of bottom circumferential welds were inspected as well as the bottom nozzle connection. The vessel was not designed with provisions for inservice inspection, the welds are unaccessible from the outside and removal of the lid is virtually impossible. The ultrasonic probes could only be loaded through 77 mm diameter holes in the top lid and remotely positioned inside the vessel. The inspection was performed using 450C and 60OC 1 MHz angle probes and 2.25 MHz normal probes in immersion technique. In a zone around the welds, small regions with lack of bonding between the stainless steel cladding and the boiler steel were revealed. One root defect known and accepted from the preservice radiographs was examined. The defect was found to be 6x30mm as a maximum and well within acceptable limits according to the fracture mechanics analysis method recommended in ASME X1. The inspection required a period of three weeks' work in the reactor hall. (UK)

  13. Vessel wall and indium-111-labelled platelet response to carotid endarterectomy

    International Nuclear Information System (INIS)

    Lusby, R.J.; Ferrell, L.D.; Englestad, B.L.; Price, D.C.; Lipton, M.J.; Stoney, R.J.

    1983-01-01

    Postendarterectomy platelet deposition and thrombus formation may play an important role not only in vessel wall healing but also in the small incidence of postoperative cerebral ischemia and postoperative stenosis. A study has been performed using a canine model to investigate the healing response to carotid endarterectomy and the validity of an in vivo indium-111 (In-111) radiotracer technique in the assessment of postendarterectomy deposition of autologous labelled platelets. Sixteen endarterectomized carotid arteries showed uptake of autologous In-111 platelets immediately after infusion, reaching a maximum by 1 hour with little increase at 24 or 48 hours. No uptake was seen in ten control vessels following platelet infusion (P less than 0.05). At autopsy, seven vessels were demonstrated to have In-111 platelet deposition immediately prior to sacrifice of the animals. Postmortem scanning confirmed the localization to the vessel lumens, and microscopy revealed thrombus formation with or without partial endothelialization. Complete reendothelialization had occurred in the vessels that failed to show platelet deposition. Delayed healing was associated with continuing platelet deposition, excessive thrombus formation, and luminal stenosis. Arteriotomy closure with a vein patch altered the healing characteristics of the vessel with segmental thrombus formation over the vein patch. A preliminary study of the postendarterectomy in vivo In-111 platelet response in humans demonstrated platelet deposition that was not influenced by the administration of antiplatelet drugs at currently prescribed levels

  14. Endoscopic visualization of luminal organ and great vessels with three dimensional CT scanner

    International Nuclear Information System (INIS)

    Kobayashi, Hisashi; Okumura, Toshiyuki; Amemiya, Ryuta; Hasegawa, Hiroshi

    1992-01-01

    Thirty cases examined by three dimensional CT scanner (3DCT) are reported. The observation of inner view using 3DCT were performed in 12 large vessels with vascular disorder, 10 pulmonary bronchi with lung cancer and 8 common bile ducts involved obstructive disease. In order to visualize interface of the lumen, a new software, which was developed by HITACHI MEDICO Inc., was used. In all cases but one the inner view of the luminal organ was clearly demonstrated as 3D images and it was possible to judge some changes of luminal interface involved by the diseases. The 3DCT endoscopic image might be useful as a new endoscopic technique without fiberscopy. (author)

  15. Tree diameter at breast height in relation to stump diameter by species group

    Science.gov (United States)

    Arthur G. Horn; Richard C. Keller

    1957-01-01

    A stump tally is one method of determining the volume of timber previously removed from an area in a logging operation. To estimate volume of standing timber from stumps, foresters must first know the relationship between stump diameters and tree diameters at breast height (d.b.h.).

  16. SU-F-T-20: Novel Catheter Lumen Recognition Algorithm for Rapid Digitization

    International Nuclear Information System (INIS)

    Dise, J; McDonald, D; Ashenafi, M; Peng, J; Mart, C; Koch, N; Vanek, K

    2016-01-01

    Purpose: Manual catheter recognition remains a time-consuming aspect of high-dose-rate brachytherapy (HDR) treatment planning. In this work, a novel catheter lumen recognition algorithm was created for accurate and rapid digitization. Methods: MatLab v8.5 was used to create the catheter recognition algorithm. Initially, the algorithm searches the patient CT dataset using an intensity based k-means filter designed to locate catheters. Once the catheters have been located, seed points are manually selected to initialize digitization of each catheter. From each seed point, the algorithm searches locally in order to automatically digitize the remaining catheter. This digitization is accomplished by finding pixels with similar image curvature and divergence parameters compared to the seed pixel. Newly digitized pixels are treated as new seed positions, and hessian image analysis is used to direct the algorithm toward neighboring catheter pixels, and to make the algorithm insensitive to adjacent catheters that are unresolvable on CT, air pockets, and high Z artifacts. The algorithm was tested using 11 HDR treatment plans, including the Syed template, tandem and ovoid applicator, and multi-catheter lung brachytherapy. Digitization error was calculated by comparing manually determined catheter positions to those determined by the algorithm. Results: he digitization error was 0.23 mm ± 0.14 mm axially and 0.62 mm ± 0.13 mm longitudinally at the tip. The time of digitization, following initial seed placement was less than 1 second per catheter. The maximum total time required to digitize all tested applicators was 4 minutes (Syed template with 15 needles). Conclusion: This algorithm successfully digitizes HDR catheters for a variety of applicators with or without CT markers. The minimal axial error demonstrates the accuracy of the algorithm, and its insensitivity to image artifacts and challenging catheter positioning. Future work to automatically place initial seed

  17. Photoaffinity labeling of the lumenal K+ site of the gastric (H+ + K+)-ATPase

    International Nuclear Information System (INIS)

    Keeling, D.J.; Fallowfield, C.; Lawrie, K.M.; Saunders, D.; Richardson, S.; Ife, R.J.

    1989-01-01

    A photoaffinity label for the lumenal K+ site of the gastric (H+ + K+)-ATPase has been identified. Seven azido derivatives based upon the reversible K+ site inhibitor SCH 28080 were studied, one of which, m-ATIP (8-(3-azidophenylmethoxy)-1,2,3-trimethylimidazo[1,2-a] pyridinium iodide), was subsequently synthesized in radiolabeled form. In the absence of UV irradiation, m-ATIP inhibited K+ -stimulated ATPase activity in lyophilized gastric vesicles competitively with respect to K+, with a Ki value of 2.4 microM at pH 7.0. Irradiation of lyophilized gastric vesicles at pH 7.0 with [ 14 C]m-ATIP in the presence of 0.2 mM ATP resulted in a time-dependent inactivation of ATPase activity that was associated with an incorporation of radioactivity into a 100-kDa polypeptide representing the catalytic subunit of the (H+ + K+)-ATPase. Both inactivation and incorporation were blocked in the presence of 10 mM KCl but not with 10 mM NaCl, consistent with interaction at the K+ site. The level of incorporation required to produce complete inhibition of ATPase activity was 1.9 +/- 0.2 times the number of catalytic phosphorylation sites in the same preparation. Tryptic digestion of gastric vesicle membranes, labeled with [ 14 C]m-ATIP, failed to release the radioactivity from the membranes suggesting that the site of interaction was close to or within the membrane-spanning sections of this ion pump

  18. Gastric washing by distilled water can reduce free gastric cancer cells exfoliated into the stomach lumen.

    Science.gov (United States)

    Ohki, Atsuko; Abe, Nobutsugu; Yoshimoto, Eri; Hashimoto, Yoshikazu; Takeuchi, Hirohisa; Nagao, Gen; Masaki, Tadahiko; Mori, Toshiyuki; Ohkura, Yasuo; Sugiyama, Masanori

    2018-04-25

    Intragastric free cancer cells in patients with gastric cancer have rarely been studied. The purpose of this study was to investigate the detection rate of intragastric free cancer cells in gastric washes using two types of solutions during endoscopic examination. We further clarified risk factors affecting the presence of exfoliated free cancer cells. A total of 175 patients with gastric cancer were enrolled. Lactated Ringer's solution (N = 89) or distilled water (DW; N = 86) via endoscopic working channel was sprayed onto the tumor surface, and the resultant fluid was collected for cytological examination. We compared the cancer-cell positivity rate between the two (Ringer and DW) groups. We also tested the correlation between cancer-cell positivity and clinicopathological factors in the Ringer group to identify risk factors for the presence of exfoliated cancer cells. The cancer-cell positivity rate was significantly higher in the Ringer group than that in the DW group (58 vs 6%). Cytomorphology in the Ringer group was well maintained, but not in the DW group. The larger tumor size (≥ 20 mm) and positive lymphatic involvement were significant risk factors of exfoliated free cancer cells. Cancer cells can be highly exfoliated from the tumor surface into the gastric lumen by endoscopic irrigation in large gastric cancer with lymphatic involvement. Gastric washing by DW can lead to cytoclasis of free cancer cells; therefore, it may minimize the possibility of cancer-cell seeding in procedures carrying potential risks of tumor-cell seeding upon transluminal communication, such as endoscopic full-thickness resection and laparoscopy-endoscopy cooperative surgery.

  19. Polymeric immunoglobulin receptor in intestinal immune defense against the lumen-dwelling protozoan parasite Giardia.

    Science.gov (United States)

    Davids, Barbara J; Palm, J E Daniel; Housley, Michael P; Smith, Jennifer R; Andersen, Yolanda S; Martin, Martin G; Hendrickson, Barbara A; Johansen, Finn-Eirik; Svärd, Staffan G; Gillin, Frances D; Eckmann, Lars

    2006-11-01

    The polymeric Ig receptor (pIgR) is conserved in mammals and has an avian homologue, suggesting evolutionarily important functions in vertebrates. It transports multimeric IgA and IgM across polarized epithelia and is highly expressed in the intestine, yet little direct evidence exists for its importance in defense against common enteric pathogens. In this study, we demonstrate that pIgR can play a critical role in intestinal defense against the lumen-dwelling protozoan parasite Giardia, a leading cause of diarrheal disease. The receptor was essential for the eradication of Giardia when high luminal IgA levels were required. Clearance of Giardia muris, in which IgA plays a dominant role, was severely compromised in pIgR-deficient mice despite significant fecal IgA output at 10% of normal levels. In contrast, eradication of the human strain Giardia lamblia GS/M, for which adaptive immunity is less IgA dependent in mice, was unaffected by pIgR deficiency, indicating that pIgR had no physiologic role when lower luminal IgA levels were sufficient for parasite elimination. Immune IgA was greatly increased in the serum of pIgR-deficient mice, conferred passive protection against Giardia, and recognized several conserved giardial Ags, including ornithine carbamoyltransferase, arginine deiminase, alpha-enolase, and alpha- and beta-giardins, that are also detected in human giardiasis. Corroborative observations were made in mice lacking the J chain, which is required for pIgR-dependent transepithelial IgA transport. These results, together with prior data on pIgR-mediated immune neutralization of luminal cholera toxin, suggest that pIgR is essential in intestinal defense against pathogenic microbes with high-level and persistent luminal presence.

  20. SU-F-T-20: Novel Catheter Lumen Recognition Algorithm for Rapid Digitization

    Energy Technology Data Exchange (ETDEWEB)

    Dise, J; McDonald, D; Ashenafi, M; Peng, J; Mart, C; Koch, N; Vanek, K [Medical University of South Carolina, Charleston, SC (United States)

    2016-06-15

    Purpose: Manual catheter recognition remains a time-consuming aspect of high-dose-rate brachytherapy (HDR) treatment planning. In this work, a novel catheter lumen recognition algorithm was created for accurate and rapid digitization. Methods: MatLab v8.5 was used to create the catheter recognition algorithm. Initially, the algorithm searches the patient CT dataset using an intensity based k-means filter designed to locate catheters. Once the catheters have been located, seed points are manually selected to initialize digitization of each catheter. From each seed point, the algorithm searches locally in order to automatically digitize the remaining catheter. This digitization is accomplished by finding pixels with similar image curvature and divergence parameters compared to the seed pixel. Newly digitized pixels are treated as new seed positions, and hessian image analysis is used to direct the algorithm toward neighboring catheter pixels, and to make the algorithm insensitive to adjacent catheters that are unresolvable on CT, air pockets, and high Z artifacts. The algorithm was tested using 11 HDR treatment plans, including the Syed template, tandem and ovoid applicator, and multi-catheter lung brachytherapy. Digitization error was calculated by comparing manually determined catheter positions to those determined by the algorithm. Results: he digitization error was 0.23 mm ± 0.14 mm axially and 0.62 mm ± 0.13 mm longitudinally at the tip. The time of digitization, following initial seed placement was less than 1 second per catheter. The maximum total time required to digitize all tested applicators was 4 minutes (Syed template with 15 needles). Conclusion: This algorithm successfully digitizes HDR catheters for a variety of applicators with or without CT markers. The minimal axial error demonstrates the accuracy of the algorithm, and its insensitivity to image artifacts and challenging catheter positioning. Future work to automatically place initial seed

  1. Laparoscopic prototype for optical sealing of renal blood vessels

    Science.gov (United States)

    Hardy, Luke A.; Hutchens, Thomas C.; Larson, Eric R.; Gonzalez, David A.; Chang, Chun-Hung; Nau, William H.; Fried, Nathaniel M.

    2017-02-01

    Energy-based, radiofrequency and ultrasonic devices provide rapid sealing of blood vessels during laparoscopic procedures. We are exploring infrared lasers as an alternative for vessel sealing with less collateral thermal damage. Previous studies demonstrated vessel sealing in an in vivo porcine model using a 1470-nm laser. However, the initial prototype was designed for open surgery and featured tissue clasping and light delivery mechanisms incompatible with laparoscopic surgery. In this study, a laparoscopic prototype similar to devices in surgical use was developed, and tests were conducted on porcine renal blood vessels. The 5-mm-OD prototype featured a traditional Maryland jaw configuration. Laser energy was delivered through a 550-μm-core fiber and side-delivery from the lower jaw, with beam dimensions of 18-mm-length x 1.2-mm-width. The 1470-nm diode laser delivered 68 W with 3 s activation time. A total of 69 porcine renal vessels with mean diameter of 3.3 +/- 1.7 mm were tested, ex vivo. Vessels smaller than 5 mm were consistently sealed (48/51) with burst pressures greater than malignant hypertension blood pressure (180 mmHg), averaging 1038 +/- 474 mmHg. Vessels larger than 5 mm were not consistently sealed (6/18), yielding burst pressures of only 174 +/- 221 mmHg. Seal width, thermal damage zone, and thermal spread averaged 1.7 +/- 0.8, 3.4 +/- 0.7, and 1.0 +/- 0.4 mm. A novel optical laparoscopic prototype with 5-mm- OD shaft integrated within a standard Maryland jaw design consistently sealed vessels less than 5 mm with minimal thermal spread. Further in vivo studies are planned to test performance across a variety of vessels and tissues.

  2. DESIGN OF PARTICULATE MATERIAL COMPACTOR ROLLS DIAMETER

    Directory of Open Access Journals (Sweden)

    Peter Peciar

    2017-09-01

    Full Text Available At present, in a period of an industrial expansion great emphasis is placed on the environment. That means aiming for a reduced energy consumption, and also lessening dustiness from very fine powder material. This category also includes particulate material agglomeration processes. Because this process is very energy-intensive, it is necessary to correctly design these devices. The aim of this paper is to focus on a theoretical design of a production compactor with the rolls diameter for an experimental particulate material, based on Johanson’s theory and experimentally measured material properties. The material used for experimental measurements was an NPK-based industrial fertilizer consisting of several components. The results of this paper is the dependence of the ratio of the maximum compression pressure to the initial compression pressure from the rolls diameter of the proposed compactor.

  3. Device for guiding various diameter size cable

    Energy Technology Data Exchange (ETDEWEB)

    Litvinov, I.M.; Klauzer, L.P.; Yeganov, L.I.; Zaripov, A.M.

    1982-01-30

    A design is submitted for a device to guide cable of various diameters. This device consists of a profiled multiple-pass roller, and clamps for uniting cut cable. This design is simplified by allowing both the rollers and their supports to rotate on the roller axis thus facilitating interaction with the clamps. The working surface of the supports is evolute while the outside surfaces have screw-channels for transfering the cable from one roller pass to the other.

  4. Pressure vessel lid

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  5. [Small vessel cerebrovascular disease].

    Science.gov (United States)

    Cardona Portela, P; Escrig Avellaneda, A

    2018-05-09

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

  6. Percutaneous Selective Embolectomy using a Fogarty Thru-Lumen Catheter for Pancreas Graft Thrombosis: A Case Report

    International Nuclear Information System (INIS)

    Izaki, Kenta; Yamaguchi, Masato; Matsumoto, Ippei; Shinzeki, Makoto; Ku, Yonson; Sugimura, Kazuro; Sugimoto, Koji

    2011-01-01

    A 57-year-old woman with a history of diabetes mellitus underwent simultaneous pancreas–kidney transplantation. The pancreaticoduodenal graft was implanted in the right iliac fossa. The donor’s portal vein was anastomosed to the recipient’s inferior vena cava (IVC). Seven days after the surgery, a thrombus was detected in the graft veins. Percutaneous thrombolysis was immediately performed; however, venous congestion was still present. We therefore attempted selective embolectomy using a Fogarty Thru-Lumen Catheter. Thrombi were directed from the graft veins toward the IVC and captured in the IVC filter with complete elimination of the thrombus without any major complications. We present our technique for the successful treatment of pancreas graft thrombosis within a short time period by percutaneous selective embolectomy using a Fogarty Thru-Lumen Catheter.

  7. Activity of LUMEN (1996-97) Understanding of PbWO4 Scintillator Characteristics and their Optimisation

    CERN Document Server

    Baccaro, Stefania; Borgia, Bruno; Cecilia, Angelica; Croci, S; Dafinei, Ioan; Diemoz, Marcella; Fabeni, P; Festinesi, Armando; Jarolímek, O; Longo, Egidio; Martini, M; Mihoková, E; Montecchi, Marco; Nikl, M; Nitsch, K; Organtini, Giovanni; Pazzi, G P; Spinolo, G; Vedda, A

    1998-01-01

    The aim of the LUMEN co-operation, supported by INFN, is to obtain ful experimental characterisation and deep expertise of heavy scintillator for high energy physics. The advantage of this collaboration was mainly in the complementary character of the experimental techniques available in the partner laboratories and in the availability of highly experienced scientists indifferent fields. Furthermore close feedback to technological laboratories preparing on request PWO samples appeared extremely helpful. The present paper reports on the most important results obtained during the LUMEN activity in 1996-97. The aim of the report is to provide also enough useful information for the PWO application and novel ideas to stimulate further interest for new detectors as well as application in different fields.

  8. Concentration polarization effects on the macromolecular transport in the presence of non-uniform magnetic field: A numerical study using a lumen-wall model

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadpourfard, M., E-mail: Mohammadpour@azaruniv.edu [Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz 53751-71379 (Iran, Islamic Republic of); Aminfar, H., E-mail: hh_aminfar@tabrizu.ac.ir [Faculty of Mechanical Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of); Khajeh, K., E-mail: khajeh.k.2005@gmail.com [Faculty of Mechanical Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2014-04-01

    In this paper, the concentration polarization phenomena in a two dimensional tube under steady state conditions containing ferrofluid (blood and 4 vol% Fe{sub 3}O{sub 4}) is reported in the presence of non-uniform magnetic field. Lumen-wall model has been used for solving the mass transport equation. Hemodynamics parameters such as flow rate, viscosity, wall shear stress (WSS) and the macromolecules surface concentration which accumulate on the blood vessel wall, influenced the formation and progression of atherosclerosis disease. Effective parameters on the low density lipoprotein (LDL) surface concentration (LSC) such as: the wall filtration velocity, inlet Reynolds number and WSS under applied non-uniform magnetic field have been examined. Numerical solution of governing equations of the flow field have been obtained by using the single-phase model and the control volume technique. Magnetic field is generated by an electric current going through a thin and straight wire oriented perpendicular to the tube. Results show WSS in the vicinity of magnetic field source increased and LSC decreased along the wall. - Highlights: • In this paper the concentration polarization phenomena of blood flow is reported in the presence of non-uniform magnetic field. • In presence of non-uniform magnetic field LSC will decrease along the wall due to the increasing the velocity gradients near the magnetic source. • When non-uniform magnetic field intensity increases, LSC along the wall becomes lower. • Non-uniform magnetic field can affects the flow more in low Reynolds numbers.

  9. Lumen and calcium characteristics within calcified coronary lesions. Comparison of computed tomography coronary angiography versus intravascular ultrasound

    OpenAIRE

    Noll, Dariusz; Kruk, Mariusz; Pręgowski, Jerzy; Kaczmarska, Edyta; Kryczka, Karolina; Pracoń, Radosław; Skwarek, Mirosław; Dzielińska, Zofia; Petryka, Joanna; Śpiewak, Mateusz; Lubiszewska, Barbara; Norwa-Otto, Bożena; Opolski, Maksymilian; Witkowski, Adam; Demkow, Marcin

    2013-01-01

    Introduction Computed tomography coronary angiography (CTCA) is a diagnostic method used for exclusion of coronary artery disease. However, lower accuracy of CTCA in assessment of calcified lesions is a significant factor impeding applicability of CTCA for assessment of coronary atherosclerosis. Aim To provide insight into lumen and calcium characteristics assessed with CTCA, we compared these parameters to the reference of intravascular ultrasound (IVUS). Material and methods Two hundred and...

  10. Standardized evaluation framework for evaluating coronary artery stenosis detection, stenosis quantification and lumen segmentation algorithms in computed tomography angiography.

    Science.gov (United States)

    Kirişli, H A; Schaap, M; Metz, C T; Dharampal, A S; Meijboom, W B; Papadopoulou, S L; Dedic, A; Nieman, K; de Graaf, M A; Meijs, M F L; Cramer, M J; Broersen, A; Cetin, S; Eslami, A; Flórez-Valencia, L; Lor, K L; Matuszewski, B; Melki, I; Mohr, B; Oksüz, I; Shahzad, R; Wang, C; Kitslaar, P H; Unal, G; Katouzian, A; Örkisz, M; Chen, C M; Precioso, F; Najman, L; Masood, S; Ünay, D; van Vliet, L; Moreno, R; Goldenberg, R; Vuçini, E; Krestin, G P; Niessen, W J; van Walsum, T

    2013-12-01

    Though conventional coronary angiography (CCA) has been the standard of reference for diagnosing coronary artery disease in the past decades, computed tomography angiography (CTA) has rapidly emerged, and is nowadays widely used in clinical practice. Here, we introduce a standardized evaluation framework to reliably evaluate and compare the performance of the algorithms devised to detect and quantify the coronary artery stenoses, and to segment the coronary artery lumen in CTA data. The objective of this evaluation framework is to demonstrate the feasibility of dedicated algorithms to: (1) (semi-)automatically detect and quantify stenosis on CTA, in comparison with quantitative coronary angiography (QCA) and CTA consensus reading, and (2) (semi-)automatically segment the coronary lumen on CTA, in comparison with expert's manual annotation. A database consisting of 48 multicenter multivendor cardiac CTA datasets with corresponding reference standards are described and made available. The algorithms from 11 research groups were quantitatively evaluated and compared. The results show that (1) some of the current stenosis detection/quantification algorithms may be used for triage or as a second-reader in clinical practice, and that (2) automatic lumen segmentation is possible with a precision similar to that obtained by experts. The framework is open for new submissions through the website, at http://coronary.bigr.nl/stenoses/. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Evaluation of the conformity of assistential practice in the maintenance of the temporary double-lumen dialysis catheter.

    Science.gov (United States)

    Rosetti, Késia Alves Gomes; Tronchin, Daisy Maria Rizatto

    2014-01-01

    to evaluate the conformity of the assistential practice in the maintenance of the temporary double-lumen catheter for hemodialysis, by means of the use of the process indicator, in the University Hospital of the University of São Paulo. a quantitative, exploratory-descriptive and observational study. The sample was made up of 155 observations of persons with temporary double-lumen catheters, in the period March-November 2011, using the Indicator of the Maintenance of the Temporary Double Lumen Catheter for Hemodialysis. the rate of general conformity of the assistential practice corresponded to 65.8%. Of the practice's 13 components, 9 (69.2%) attained 100% conformity. The hygienization of hands by the professionals and the use of a mask by the patients during the disconnection from the hemodialysis had the worst rates (83.9%). although the actions evaluated are implemented in the unit, it is necessary to propose and apply educational strategies with the health team, as well as to institute periodical assessments, so as to raise the conformity rates, ensuring the quality of the hemodialysis services.

  12. Vacuum vessels for the LHC magnets arrive at CERN

    CERN Multimedia

    2001-01-01

    The first batch of pre-series vacuum vessels for the LHC dipole magnets has just been delivered to CERN. The vessels are components of the cryostats and will provide the thermal insulation for the superconducting magnets. The first batch of vacuum vessels for the LHC dipole magnets with the team taking part at CERN in ordering and installing them. Left to right : Claude Hauviller, Monique Dupont, Lloyd Williams, Franck Gavin, Alain Jacob, Christophe Vuitton, Davide Bozzini, Laure Sandri, Mikael Sjoholm and André de Saever. In 2006 all that will be seen of the LHC superconducting dipoles in the LHC tunnel will be a line of over 1230 blue cylindrical vacuum vessels. Ten vessels, each weighing 4 tonnes, are already at CERN. On 6 July the first batch of pre-series vessels reached the Lab-oratory from the firm SIMIC Spa whose works are near Savona in north-western Italy. Despite appearances, these 15-metre long, 1-metre diameter blue tubes are much more sophisticated than sections of a run-of-the-mill...

  13. In vitro stent lumen visualisation of various common and newly developed femoral artery stents using MR angiography at 1.5 and 3 tesla.

    Science.gov (United States)

    Syha, R; Ketelsen, D; Kaempf, M; Mangold, S; Sixt, S; Zeller, T; Springer, F; Schick, F; Claussen, C D; Brechtel, K

    2013-02-01

    To evaluate stent lumen assessment of various commonly used and newly developed stents for the superficial femoral artery (SFA) using MR angiography (MRA) at 1.5 and 3 T. Eleven nitinol stents and one cobalt-chromium stent were compared regarding stent lumen visualisation using a common three-dimensional MRA sequence. Maximum visible stent lumen width and contrast ratio were analysed in three representative slices for each stent type. A scoring system for lumen visualisation was applied. Nitinol stents showed significantly better performance than the cobalt chromium stent (P stent lumen ranged between 43.4 and 95.5 %, contrast ratio between 7.2 and 110.6 %. Regarding both field strengths, seven of the nitinol stents were classified as "suitable". Three nitinol stents were "limited", and one nitinol stent and the cobalt chromium stent were "not suitable". Intraluminal loss of signal and artefacts of most of the SFA stents do not markedly limit assessment of stent lumen by MRA at 1.5 and 3 T. MRA can thus be considered a valid technique for detection of relevant in-stent restenosis. Applied field strength does not strongly influence stent lumen assessment in general, but proper choice of field strength might be helpful.

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  15. Vessel Wall Reaction after Vena Cava Filter Placement

    International Nuclear Information System (INIS)

    Hoekstra, Arend; Elstrodt, Jan M.; Nikkels, Peter G.J.; Tiebosch, Anton T.M.G.

    2002-01-01

    Purpose: To evaluate the interaction between the Cordis Keeper vena caval filter and vessel wall in aporcine model.Methods: Implantation of the filter was performed in five pigs. Radiologic data concerning inferior vena cava(IVC) diameter and filter patency, filter leg span, and stability were collected. At 2 or 6 months post-implantation, histopathologic analysis of the IVC wall was performed.Results: All filters remained patent with no evidence of migration. However, at 6 months follow-up, two legs of one filter penetrated the vessel wall and were adherent to the liver. These preliminary results suggest that with the observed gradual increase in the filter span, the risk of caval wall penetration increases with time, especially in a relatively small IVC(average diameter 16 mm).Conclusion: The Cordis Keeper filter was well tolerated, but seems to be prone to caval wall penetration in the long term

  16. Noninvasive diagnosis of thrombus in the heart and large vessels

    International Nuclear Information System (INIS)

    Masuda, Yoshiaki; Morooka, Nobuhiro; Yoshida, Hideo; Watanabe, Shigeru; Inagaki, Yoshiaki

    1984-01-01

    The usefulness of two dimensional echocardiography (2-D echocardiography) and x-ray computed tomography (CT) for the diagnosis of thrombi in the cardiac cavity and large vessels was studied by comparing them with the findings of invasive methods. Among 56 subjects with mitral stenosis, left atrial thrombi were noted in 12 cases (16 regions) by CT and 8 cases (9 regions) by 2-D echocardiography. In 16 subjects who underwent operations, one false negative case by CT and 3 false negative and one false positive cases by 2-D echocardiography were found. In 80 subjects with myocardial infarction 2-D echocardiography, CT and left ventriculography (LVG) were performed at approximately the same time. Thrombi were detected in 10 subjects (12.5%) by 2-D echocardiography, in 15 (18.8%) by CT and in 14 (17.5%) by LVG. Although mural thrombi in abdominal aortic aneurysm were detected very easily, thin thrombi surrounding the false lumen of the dissecting aneurysm were not detected ultrasonographically. These thrombi were only detected by the enhanced CT. Our results show the usefulness of both methods for detecting thrombi in the heart and large vessels. CT can distinguish the thrombi more clearly than 2-D echocardiography, but 2-D echocardiography is performed more easily, safely and economically than CT. (author)

  17. Multiple Coronary Chamber Microfistulas or Persistent Thebesian Vessels?

    Directory of Open Access Journals (Sweden)

    Cernica Daniel

    2017-09-01

    Full Text Available Coronary fistulas are rare, not gender-specific congenital conditions, consisting of communications between the coronary arteries and either another coronary vessel or a cardiac chamber. In contrast to large fistulas, small fistulas, named “minimae cordis veneae” or the Thebesius venous system, are draining into heart chambers and form a vascular network in the cardiac lumen. In this article, we present the case of a 72-year-old female with a significant history of cardiovascular disease, admitted to our clinic because of rest dyspnea, fatigue, and minimal chest pain. The 12-lead electrocardiogram showed a trifascicular block (a second-degree atrioventricular block Mobitz II, associated with a right bundle branch block and left anterior fascicle block and negative T waves in DII, DIII, aVF, V4–V6 leads. An invasive coronary angiography was performed, which revealed no significant atherosclerotic lesions. However, a persistent capillary blush was present at the apex site of the left ventricular chamber, draining from the distal segments of both the anterior descending coronary artery and the posterior interventricular coronary artery. The intramural vascular network generating a left ventricle angiogram image of this kind was suggestive for persistent Thebesian vessels connecting the two coronaries with the left ventricular chamber.

  18. Diameter-dependent hydrophobicity in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kyakuno, Haruka, E-mail: h-kyakuno@kanagawa-u.ac.jp [Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); Institute of Physics, Faculty of Engineering, Kanagawa University, Yokohama 221-8686 (Japan); Fukasawa, Mamoru; Ichimura, Ryota; Nakai, Yusuke; Maniwa, Yutaka, E-mail: maniwa@phys.se.tmu.ac.jp [Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); Matsuda, Kazuyuki [Institute of Physics, Faculty of Engineering, Kanagawa University, Yokohama 221-8686 (Japan); Miyata, Yasumitsu [Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); PRESTO, JST, Kawaguchi 332-0012 (Japan); Saito, Takeshi [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565 (Japan)

    2016-08-14

    Single-wall carbon nanotubes (SWCNTs) are a good model system that provides atomically smooth nanocavities. It has been reported that water-SWCNTs exhibit hydrophobicity depending on the temperature T and the SWCNT diameter D. SWCNTs adsorb water molecules spontaneously in their cylindrical pores around room temperature, whereas they exhibit a hydrophilic-hydrophobic transition or wet-dry transition (WDT) at a critical temperature T{sub wd} ≈ 220-230 K and above a critical diameter D{sub c} ≈ 1.4-1.6 nm. However, details of the WDT phenomenon and its mechanism remain unknown. Here, we report a systematic experimental study involving X-ray diffraction, optical microscopy, and differential scanning calorimetry. It is found that water molecules inside thick SWCNTs (D > D{sub c}) evaporate and condense into ice Ih outside the SWCNTs at T{sub wd} upon cooling, and the ice Ih evaporates and condenses inside the SWCNTs upon heating. On the other hand, residual water trapped inside the SWCNTs below T{sub wd} freezes. Molecular dynamics simulations indicate that upon lowering T, the hydrophobicity of thick SWCNTs increases without any structural transition, while the water inside thin SWCNTs (D < D{sub c}) exhibits a structural transition, forming an ordered ice. This ice has a well-developed hydrogen bonding network adapting to the cylindrical pores of the SWCNTs. Thus, the unusual diameter dependence of the WDT is attributed to the adaptability of the structure of water to the pore dimension and shape.

  19. Retrobulbar diameter of optic nerve in glaucoma

    Directory of Open Access Journals (Sweden)

    Stefanović Ivan

    2009-01-01

    Full Text Available Introduction. The ultrasound diagnostics of the optic nerve includes the analysis of the optic nerve disc (PNO and measuring of its retrobulbar diameter. With B-scan, by Schraeder's method, it is possible to measure very precisely the optic nerve, the pial diameter, the normal values for the pial diameter being 2.8-4.1 mm. In glaucoma, the disease that is most frequently associated with higher intraocular pressure, there comes the destruction of nerve fibres, which can be visualized as the excavation of the optic nerve disc. Objective. In this paper, we were interested in finding whether in glaucoma, and in what phase of the disease, the optic nerve starts growing thinner. Aware of many forms of this very complex disease, we were interested in knowing if the visualization of excavation on the optic nerve disc is related to diminishing of the pial diameter of the retrobulbar nerve part. Methods. There were treated the patients who had already had the diagnosis of glaucoma and the visualized excavation of the optic disc of various dimensions. Echographically, there was measured the thickness of the retrobulbar part of the optic nerve and the finding compared in relation to the excavation of the optic disc. Results. In all eyes with glaucoma, a normal size of the retrobulbar part of the optic nerve was measured, ranging from 3.01 to 3.91 mm with the median of 3.36 mm. Also, by testing the correlation between the thickness of the optic nerve and the excavation of the PNO, by Pearson test, we found that there was no correlation between these two parameters (r=0.109; p>0.05. Conclusion. In the patients with glaucoma, the retrobulbar part of the optic nerve is not thinner (it has normal values, even not in the cases with a totally excavated optic disc. There is no connection between the size of the PNO excavation and the thickness of the retrobulbar part of the optic nerve.

  20. 29 mm Diameter Target Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Angela Carol [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-10-23

    After numerous delays, the test of the 29 mm diameter target was conducted on 8/18/2017. The complete target design report, dated 8/15/2016, is reproduced below for completeness. This describes in detail the 10 disk target with varying thickness disks. The report presents and discusses the test results. In brief summary, there appears to have been multiple instrumentation errors. Measured temperatures, pressures and IR camera window temperature measurement are all suspect. All tests were done at 35 MeV, with 171 μA current, or 6 kW of beam power.

  1. The vessel fluence; Fluence cuve

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

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

  2. Intravital two-photon microscopy of immune cell dynamics in corneal lymphatic vessels.

    Directory of Open Access Journals (Sweden)

    Philipp Steven

    Full Text Available BACKGROUND: The role of lymphatic vessels in tissue and organ transplantation as well as in tumor growth and metastasis has drawn great attention in recent years. METHODOLOGY/PRINCIPAL FINDINGS: We now developed a novel method using non-invasive two-photon microscopy to simultaneously visualize and track specifically stained lymphatic vessels and autofluorescent adjacent tissues such as collagen fibrils, blood vessels and immune cells in the mouse model of corneal neovascularization in vivo. The mouse cornea serves as an ideal tissue for this technique due to its easy accessibility and its inducible and modifiable state of pathological hem- and lymphvascularization. Neovascularization was induced by suture placement in corneas of Balb/C mice. Two weeks after treatment, lymphatic vessels were stained intravital by intrastromal injection of a fluorescently labeled LYVE-1 antibody and the corneas were evaluated in vivo by two-photon microscopy (TPM. Intravital TPM was performed at 710 nm and 826 nm excitation wavelengths to detect immunofluorescence and tissue autofluorescence using a custom made animal holder. Corneas were then harvested, fixed and analyzed by histology. Time lapse imaging demonstrated the first in vivo evidence of immune cell migration into lymphatic vessels and luminal transport of individual cells. Cells immigrated within 1-5.5 min into the vessel lumen. Mean velocities of intrastromal corneal immune cells were around 9 µm/min and therefore comparable to those of T-cells and macrophages in other mucosal surfaces. CONCLUSIONS: To our knowledge we here demonstrate for the first time the intravital real-time transmigration of immune cells into lymphatic vessels. Overall this study demonstrates the valuable use of intravital autofluorescence two-photon microscopy in the model of suture-induced corneal vascularizations to study interactions of immune and subsequently tumor cells with lymphatic vessels under close as possible

  3. Depiction of blood vessels by x-ray phase contrast

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [School of Engineering, University of Tokyo, Tokyo (Japan); Takeda, Tohoru; Itai, Yuji [Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki (Japan)

    2001-04-01

    Blood vessels in livers of a mouse and a rat were depicted by phase-contrast x-ray imaging with an x-ray interferometer without using contrast agents. X-ray interference patterns were converted to image mapping x-ray phase shift caused by the livers using the technique of phase-shifting x-ray interferometry. The arteries and veins to and from the livers were tied before excision in order to prevent blood from flowing out of the liver. The x-ray phase shift caused by blood was substantially different from that caused by other soft sues, and consequently trees of blood vessels were revealed in the images. Vessels of diameter smaller than 0.1 mm were detected. This result suggests new possibilities for investigating vascular systems. (author)

  4. Ultrasound assessment of the posterior circumflex humeral artery in elite volleyball players: Aneurysm prevalence, anatomy, branching pattern and vessel characteristics

    OpenAIRE

    van de Pol, Daan; Maas, Mario; Terpstra, Aart; Pannekoek-Hekman, Marja; Alaeikhanehshir, Sena; Kuijer, P. Paul F. M.; Planken, R. Nils

    2016-01-01

    Objectives To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players. Methods Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ?150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter. R...

  5. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  6. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-15

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

  7. Americium behaviour in plastic vessels.

    Science.gov (United States)

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

    2010-01-01

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

  8. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    International Nuclear Information System (INIS)

    Spiegel, M; Hornegger, J; Redel, T; Struffert, T; Doerfler, A

    2011-01-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  9. Diaphragmatic lymphatic vessel behavior during local skeletal muscle contraction.

    Science.gov (United States)

    Moriondo, Andrea; Solari, Eleonora; Marcozzi, Cristiana; Negrini, Daniela

    2015-02-01

    The mechanism through which the stresses developed in the diaphragmatic tissue during skeletal muscle contraction sustain local lymphatic function was studied in 10 deeply anesthetized, tracheotomized adult Wistar rats whose diaphragm was exposed after thoracotomy. To evaluate the direct effect of skeletal muscle contraction on the hydraulic intraluminal lymphatic pressures (Plymph) and lymphatic vessel geometry, the maximal contraction of diaphragmatic fibers adjacent to a lymphatic vessel was elicited by injection of 9.2 nl of 1 M KCl solution among diaphragmatic fibers while Plymph was recorded through micropuncture and vessel geometry via stereomicroscopy video recording. In lymphatics oriented perpendicularly to the longitudinal axis of muscle fibers and located at skeletal muscle contraction (Dmc) decreased to 61.3 ± 1.4% of the precontraction value [resting diameter (Drest)]; however, if injection was at >900 μm from the vessel, Dmc enlarged to 131.1 ± 2.3% of Drest. In vessels parallel to muscle fibers, Dmc increased to 122.8 ± 2.9% of Drest. During contraction, Plymph decreased as much as 22.5 ± 2.6 cmH2O in all submesothelial superficial vessels, whereas it increased by 10.7 ± 5.1 cmH2O in deeper vessels running perpendicular to contracting muscle fibers. Hence, the three-dimensional arrangement of the diaphragmatic lymphatic network seems to be finalized to efficiently exploit the stresses exerted by muscle fibers during the contracting inspiratory phase to promote lymph formation in superficial submesothelial lymphatics and its further propulsion in deeper intramuscular vessels. Copyright © 2015 the American Physiological Society.

  10. [Large vessel vasculitides].

    Science.gov (United States)

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

    2013-01-01

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

  11. Reactor pressure vessel embrittlement

    International Nuclear Information System (INIS)

    1992-07-01

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

  12. Reactor containment vessel

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  13. Sagittal Abdominal Diameter: Application in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Thaís Da Silva-Ferreira

    2014-05-01

    Full Text Available Excess visceral fat is associated with cardiovascular risk factors. Sagittal abdominal diameter (SAD has recently been highlighted as an indicator of abdominal obesity, and also may be useful in predicting cardiovascular risk. The purpose of the present study was to review the scientific literature on the use of SAD in adult nutritional assessment. A search was conducted for scientific articles in the following electronic databases: SciELO , MEDLINE (PubMed and Virtual Health Library. SAD is more associated with abdominal fat (especially visceral, and with different cardiovascular risk factors, such as, insulin resistance, blood pressure, and serum lipoproteins than the traditional methods of estimating adiposity, such as body mass index and waist-to-hip ratio. SAD can also be used in association with other anthropometric measures. There are still no cut-off limits established to classify SAD as yet. SAD can be an alternative measure to estimate visceral adiposity. However, the few studies on this diameter, and the lack of consensus on the anatomical site to measure SAD, are obstacles to establish cut-off limits to classify it.

  14. Morphometric analysis of rat femoral vessels under a video magnification system

    Directory of Open Access Journals (Sweden)

    Rui Sergio Monteiro de Barros

    Full Text Available Abstract The right femoral vessels of 80 rats were identified and dissected. External lengths and diameters of femoral arteries and femoral veins were measured using either a microscope or a video magnification system. Findings were correlated to animals’ weights. Mean length was 14.33 mm for both femoral arteries and femoral veins, mean diameter of arteries was 0.65 mm and diameter of veins was 0.81 mm. In our sample, rats’ body weights were only correlated with the diameter of their femoral veins.

  15. Reducing catheter-related thrombosis using a risk reduction tool centered on catheter to vessel ratio.

    Science.gov (United States)

    Spencer, Timothy R; Mahoney, Keegan J

    2017-11-01

    In vascular access practices, the internal vessel size is considered important, and a catheter to vessel ratio (CVR) is recommended to assist clinicians in selecting the most appropriate-sized device for the vessel. In 2016, new practice recommendations stated that the CVR can increase from 33 to 45% of the vessels diameter. There has been evidence on larger diameter catheters and increased thrombosis risk in recent literature, while insufficient information established on what relationship to vessel size is appropriate for any intra-vascular device. Earlier references to clinical standards and guidelines did not clearly address vessel size in relation to the area consumed or external catheter diameter. The aim of this manuscript is to present catheter-related thrombosis evidence and develop a standardized process of ultrasound-guided vessel assessment, integrating CVR, Virchow's triad phenomenon and vessel health and preservation strategies, empowering an evidence-based approach to device placement. Through review, calculation and assessment on the areas of the 33 and 45% rule, a preliminary clinical tool was developed to assist clinicians make cognizant decisions when placing intravascular devices relating to target vessel size, focusing on potential reduction in catheter-related thrombosis. Increasing the understanding and utilization of CVRs will lead to a safer, more consistent approach to device placement, with potential thrombosis reduction strategies. The future of evidence-based data relies on the clinician to capture accurate vessel measurements and device-related outcomes. This will lead to a more dependable data pool, driving the relationship of catheter-related thrombosis and vascular assessment.

  16. Problems in manufacturing and transport of pressure vessels of integral reactors

    International Nuclear Information System (INIS)

    Kralovec, J.

    1997-01-01

    Integral water-cooled reactors are typical with eliminating large-diameter primary pipes and placing primary components, i.e. steam generators and pressurizers in reactor vessels. This arrangement leads to reactor pressure vessels of large dimensions: diameters, heights and thick walls and subsequently to great weights. Thus, even medium power units have pressure vessels which are on the very limit of present manufacturing capabilities. Principal manufacturing and inspection operations as well as pertinent equipment are concerned: welding, cladding, heat treatment, machining, shop-handling, non-destructive testing, hydraulic pressure tests etc. Tile transport of such a large and heavy component makes a problem which effects its design as well as the selection of the plant site. Railway, road and ship are possible ways of transport each of them having its advantages and limitations. Specific features and limits of the manufacture and transport of large pressure vessels are discussed in the paper. (author)

  17. Thirty-centimeter-diameter ion milling source

    International Nuclear Information System (INIS)

    Robinson, R.S.

    1978-01-01

    A 30 cm beam diameter ion source has been designed and fabricated for micromachining and sputtering applications. An argon ion current density of 1 mA/cm 2 at 500 eV ion energy was selected as a design operating condition. The completed ion source met the design criteria at this operating condition with a uniform and well-collimated beam having an average variation in current density of +- 5% over the center of 20 cm of the beam. This ion source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. Langmuir probe surveys of the source plasma support the design concepts of a multipole field and a circumferential cathode to enhance plasma uniformity

  18. CALiPER Retail Lamps Study 3.2: Lumen and Chromaticity Maintenance of LED A Lamps Operated in Steady-State Conditions

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-12-31

    This CALiPER report examines lumen depreciation and color shift of 17 different A lamps in steady-state conditions (15 LED, 1 CFL, 1 halogen). The goal of this investigation was to examine the long-term performance of complete LED lamps relative to benchmark halogen and CFL lamps—in this case, A lamps emitting approximately 800 lumens operated continuously at a relatively high ambient temperature of 45°C.

  19. Percutaneous transluminal angioplasty of supraaortic vessel

    International Nuclear Information System (INIS)

    Belli, L.; Puricelli, G.; Cerasano, A.; Cornalba, P.; Rota, L.; Facchinetti, P.

    1988-01-01

    Sixteen cases are reported of dilatation of supra-aortic vessels; in 14/16 patients the vessel involved was either the subclavian artery or the brachio-cephalich trunk. Special attention is paid to the choice of patients - the ideal one presenting with a single uncalcified lesion, with stenosis more than 50% of diameter; the symptoms have recently appeared, with a significant difference (more than 20 mmHg) in the pressure of the two arms. The technical aspects of the angioplastic procedure are discussed, especially in order to preserve the intracriminal circulation and to limit possible complications. The presence of reversed blood flow in the vertebral artery is extremely important to preserve intracranial circulation from possible embolism; normal flow obtained at the end of the procedure is therefore an useful proof of successful dilatation. The advantages are stressed of dilatation over the surgical technique used in the past. Finally, the importance is emphasized of a correct follow-up and doppler control of supra-aortic circulation

  20. Pressure vessel for nuclear reactors

    International Nuclear Information System (INIS)

    1975-01-01

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

  1. Sugar maple height-diameter and age-diameter relationships in an uneven-aged northern hardwood stand

    Science.gov (United States)

    Laura S. Kenefic; R.D. Nyland

    1999-01-01

    Sugar maple (Acer saccharum Marsh.) height-diameter and age-diameter relationships are explored in a balanced uneven-aged northern hardwood stand in central New York. Results show that although both height and age vary considerably with diameter, these relationships can be described by statistically valid equations. The age-diameter relationship...

  2. The Effects of Distention and Obstruction on the Accumulation of Fluid in the Lumen of Small Bowel of Dogs

    Science.gov (United States)

    Mishra, Nand K.; Appert, Hubert E.; Howard, John M.

    1974-01-01

    Fluid accumulation in either the obstructed upper or lower intestinal segments of the dog was found in most animals to be negligible. Distention pressures of 25 cm of water tended to reduce fluid accumulation within the intestinal lumen. These studies suggest that if the dog is comparable to man, the intraluminal accumulation of fluid in the obstructed small bowel of man might be due to alterations in blood supply to the intestine, rather than to obstruction per se, or the accumulated fluid originates proximal to the jejunum. PMID:4419581

  3. 3D time-lapse analysis of Rab11/FIP5 complex: spatiotemporal dynamics during apical lumen formation.

    Science.gov (United States)

    Mangan, Anthony; Prekeris, Rytis

    2015-01-01

    Fluorescent imaging of fixed cells grown in two-dimensional (2D) cultures is one of the most widely used techniques for observing protein localization and distribution within cells. Although this technique can also be applied to polarized epithelial cells that form three-dimensional (3D) cysts when grown in a Matrigel matrix suspension, there are still significant limitations in imaging cells fixed at a particular point in time. Here, we describe the use of 3D time-lapse imaging of live cells to observe the dynamics of apical membrane initiation site (AMIS) formation and lumen expansion in polarized epithelial cells.

  4. Prediction of Lumen Output and Chromaticity Shift in LEDs Using Kalman Filter and Extended Kalman Filter Based Models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, J Lynn

    2014-06-24

    Abstract— Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. Life prediction of L70 life for the LEDs used in SSL luminaires from KF and EKF based models have

  5. Containment vessel stability analysis

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  6. Pressure vessel design

    International Nuclear Information System (INIS)

    Annaratone, D.

    2007-01-01

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

  7. Structural analysis of the JT-60SA cryostat vessel body

    Energy Technology Data Exchange (ETDEWEB)

    Botija, José, E-mail: jose.botija@ciemat.es [Association EURATOM – CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Alonso, Javier; Fernández, Pilar; Medrano, Mercedes; Ramos, Francisco; Rincon, Esther; Soleto, Alfonso [Association EURATOM – CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain); Davis, Sam; Di Pietro, Enrico; Tomarchio, Valerio [Fusion for Energy, JT-60SA European Home Team, 85748 Garching bei Munchen (Germany); Masaki, Kei; Sakasai, Akira; Shibama, Yusuke [JAEA – Japan Atomic Energy Agency, Naka Fusion Institute, Ibaraki 311-0193 (Japan)

    2013-10-15

    Highlights: ► Structural analysis to validate the JT-60SA cryostat vessel body design. ► Design code ASME 2007 “Boiler and Pressure Vessel Code. Section VIII”. ► First buckling mode: load multiplier of 10.644, higher than the minimum factor 4.7. ► Elastic and elastic–plastic stress analysis meets ASME against plastic collapse. ► Bolted fasteners have been analyzed showing small gaps closed by strong welding. -- Abstract: The JT-60SA cryostat is a stainless steel vacuum vessel (14 m diameter, 16 m height) which encloses the Tokamak providing the vacuum environment (10{sup −3} Pa) necessary to limit the transmission of thermal loads to the components at cryogenic temperature. It must withstand both external atmospheric pressure during normal operation and internal overpressure in case of an accident. The paper summarizes the structural analyses performed in order to validate the JT-60SA cryostat vessel body design. It comprises several analyses: a buckling analysis to demonstrate stability under the external pressure; an elastic and an elastic–plastic stress analysis according to ASME VIII rules, to evaluate resistance to plastic collapse including localized stress concentrations; and, finally, a detailed analysis with bolted fasteners in order to evaluate the behavior of the flanges, assuring the integrity of the vacuum sealing welds of the cryostat vessel body.

  8. Cold source vessel development for the advanced neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Williams, P.T.; Lucas, A.T. [Oak Ridge National Lab., TN (United States)

    1995-09-01

    The Advanced Neutron Source (ANS), in its conceptual design phase at Oak Ridge National Laboratory (ORNL), will be a user-oriented neutron research facility that will produce the most intense flux of neutrons in the world. Among its many scientific applications, the productions of cold neutrons is a significant research mission for the ANS. The cold neutrons come from two independent cold sources positioned near the reactor core. Contained by an aluminum alloy vessel, each cold source is a 410 mm diameter sphere of liquid deuterium that functions both as a neutron moderator and a cryogenic coolant. With nuclear heating of the containment vessel and internal baffling, steady-state operation requires close control of the liquid deuterium flow near the vessel`s inner surface. Preliminary thermal-hydraulic analyses supporting the cold source design are being performed with multi-dimensional computational fluid dynamics simulations of the liquid deuterium flow and heat transfer. This paper presents the starting phase of a challenging program and describes the cold source conceptual design, the thermal-hydraulic feasibility studies of the containment vessel, and the future computational and experimental studies that will be used to verify the final design.

  9. Automated retinal vessel type classification in color fundus images

    Science.gov (United States)

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

    2013-02-01

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

  10. PWR vessel flaw distribution development

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  11. Nuclear reactor vessel decontamination systems

    International Nuclear Information System (INIS)

    McGuire, P. J.

    1985-01-01

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

  12. Investigation of vessel visibility of iterative reconstruction method in coronary computed tomography angiography using simulated vessel phantom

    International Nuclear Information System (INIS)

    Inoue, Takeshi; Uto, Fumiaki; Ichikawa, Katsuhiro; Hara, Takanori; Urikura, Atsushi; Hoshino, Takashi; Miura, Youhei; Terakawa, Syouichi

    2012-01-01

    Iterative reconstruction methods can reduce the noise of computed tomography (CT) images, which are expected to contribute to the reduction of patient dose CT examinations. The purpose of this study was to investigate impact of an iterative reconstruction method (iDose 4 , Philips Healthcare) on vessel visibility in coronary CT angiography (CTA) by using phantom studies. A simulated phantom was scanned by a CT system (iCT, Philips Healthcare), and the axial images were reconstructed by filtered back projection (FBP) and given a level of 1 to 7 (L1-L7) of the iterative reconstruction (IR). The vessel visibility was evaluated by a quantitative analysis using profiles across a 1.5-mm diameter simulated vessel as well as visual evaluation for multi planar reformation (MPR) images and volume rendering (VR) images in terms of the normalized-rank method with analysis of variance. The peak CT value of the profiles decreased with IR level and full width at half maximum of the profile also decreased with the IR level. For normalized-rank method, there was no statistical difference between FBP and L1 (20% dose reduction) for both MPR and VR images. The IR levels higher than L1 sacrificed the spatial resolution for the 1.5-mm simulated vessel, and their visual vessel visibilities were significantly inferior to that of the FBP. (author)

  13. Gammatography of thick lead vessels

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  14. Waste system optimization - can diameter selection

    International Nuclear Information System (INIS)

    Ashline, R.C.

    1983-08-01

    The purpose of the waste system optimization study is to define in terms of cost incentives the preferred waste package for HLW which has been converted to glass at a commercial reprocessing plant. The Waste Management Economic Model (WMEM) was employed to analyze the effect of varying important design parameters on the overall net present cost of waste handling. The parameters found to have the greatest effect on the calculated overall net present cost were can diameter, repository type (salt, basalt/bentonite, or welded tuff), allowable areal heat loading, and the repository availability date. The overall net present of a waste handling option is calculated over a 20-year operating period. It includes the total capital and operating costs associated with high-level and intermediate-level liquid waste storage, liquid waste solidification, hulls storage and compaction, and general process trash handling. It also includes the cask leasing and transportation costs associated with each waste type and the waste repository disposal costs. The waste repository disposal costs used in WMEM for this analysis were obtained from Battelle Pacific Northwest Laboratories and thir RECON model. 2 figures, 2 tables

  15. Packing configuration performance for small stem diameters

    International Nuclear Information System (INIS)

    Aikin, J.A.; Spence, C.G.; Cumming, D.

    1997-01-01

    The extensive use of graphite packing and its excellent track record for large isolating valves in CANDU, Primary Heat Transfer (PHT) systems has resulted in an increased application of graphite packing on the conventional side. Many of these applications are in air operated valves (AOVs) where the packing sets are used on small stem diameters (<1 inch) with frequent short-cycling strokes (± 10% of full stroke). The direct application of the proven packing configurations for large isolated valves to control valve application has generated problems such as stiction, packing wear and, in isolated cases, stem stall. To address this issue, a test program was conducted at AECL, CRL by MED branch. The testing showed that by reconfiguring the packing sets and using PTFE wafers reductions in stem friction of 50% at ambient conditions, a 3 fold at hot conditions are achievable. The test program also demonstrated benefits gained in packing wear with different stem roughness finishes and the potential need to exercise small stems valves that see less than full stroke cycling. The paper describes the tests results and provides field support experience. (author)

  16. Small diameter electrospun silk fibroin vascular grafts: Mechanical properties, in vitro biodegradability, and in vivo biocompatibility.

    Science.gov (United States)

    Catto, Valentina; Farè, Silvia; Cattaneo, Irene; Figliuzzi, Marina; Alessandrino, Antonio; Freddi, Giuliano; Remuzzi, Andrea; Tanzi, Maria Cristina

    2015-09-01

    To overcome the drawbacks of autologous grafts currently used in clinical practice, vascular tissue engineering represents an alternative approach for the replacement of small diameter blood vessels. In the present work, the production and characterization of small diameter tubular matrices (inner diameter (ID)=4.5 and 1.5 mm), obtained by electrospinning (ES) of Bombyx mori silk fibroin (SF), have been considered. ES-SF tubular scaffolds with ID=1.5 mm are original, and can be used as vascular grafts in pediatrics or in hand microsurgery. Axial and circumferential tensile tests on ES-SF tubes showed appropriate properties for the specific application. The burst pressure and the compliance of ES-SF tubes were estimated using the Laplace's law. Specifically, the estimated burst pressure was higher than the physiological pressures and the estimated compliance was similar or higher than that of native rat aorta and Goretex® prosthesis. Enzymatic in vitro degradation tests demonstrated a decrease of order and crystallinity of the SF outer surface as a consequence of the enzyme activity. The in vitro cytocompatibility of the ES-SF tubes was confirmed by the adhesion and growth of primary porcine smooth muscle cells. The in vivo subcutaneous implant into the rat dorsal tissue indicated that ES-SF matrices caused a mild host reaction. Thus, the results of this investigation, in which comprehensive morphological and mechanical aspects, in vitro degradation and in vitro and in vivo biocompatibility were considered, indicate the potential suitability of these ES-SF tubular matrices as scaffolds for the regeneration of small diameter blood vessels. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

    Hagiwara, Koji; Imura, Yasuya.

    1979-01-01

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

  18. PWR vessel inspection performance improvements

    International Nuclear Information System (INIS)

    Blair Fairbrother, D.; Bodson, Francis

    1998-01-01

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

  19. Healthy Lung Vessel Morphology Derived From Thoracic Computed Tomography

    Directory of Open Access Journals (Sweden)

    Michael Pienn

    2018-04-01

    Full Text Available Knowledge of the lung vessel morphology in healthy subjects is necessary to improve our understanding about the functional network of the lung and to recognize pathologic deviations beyond the normal inter-subject variation. Established values of normal lung morphology have been derived from necropsy material of only very few subjects. In order to determine morphologic readouts from a large number of healthy subjects, computed tomography pulmonary angiography (CTPA datasets, negative for pulmonary embolism, and other thoracic pathologies, were analyzed using a fully-automatic, in-house developed artery/vein separation algorithm. The number, volume, and tortuosity of the vessels in a diameter range between 2 and 10 mm were determined. Visual inspection of all datasets was used to exclude subjects with poor image quality or inadequate artery/vein separation from the analysis. Validation of the algorithm was performed manually by a radiologist on randomly selected subjects. In 123 subjects (men/women: 55/68, aged 59 ± 17 years, the median overlap between visual inspection and fully-automatic segmentation was 94.6% (69.2–99.9%. The median number of vessel segments in the ranges of 8–10, 6–8, 4–6, and 2–4 mm diameter was 9, 34, 134, and 797, respectively. Number of vessel segments divided by the subject's lung volume was 206 vessels/L with arteries and veins contributing almost equally. In women this vessel density was about 15% higher than in men. Median arterial and venous volumes were 1.52 and 1.54% of the lung volume, respectively. Tortuosity was best described with the sum-of-angles metric and was 142.1 rad/m (138.3–144.5 rad/m. In conclusion, our fully-automatic artery/vein separation algorithm provided reliable measures of pulmonary arteries and veins with respect to age and gender. There was a large variation between subjects in all readouts. No relevant dependence on age, gender, or vessel type was observed. These data may

  20. Pressure vessels for reactors made from structural steel with limited tensile strength

    International Nuclear Information System (INIS)

    Machatti, H.

    1973-01-01

    The reactor pressure vessel is prestressed in several directions with prestressing elements fabricated of steel with a high yielding point. This design allows a substantial reduction of wall thickness or an increase of the inner diameter at equal wall thickness. The prestress of the prestressing elements is designed to achieve a maximum stress release of the vessel walls at normal operating conditions and to fully utilize the maximum load of the vessel walls. For safety reasons the cross section of the prestressing elements is constructed in a way that strain is always 20 % lower the yield point. (P.K.)

  1. A basic study on the ITER tritium storage vessel design and components

    International Nuclear Information System (INIS)

    Chung, H. S.; Ahn, D. H.; Kim, K. R.; Yim, S. P.; Paek, S. W.; Lee, M. S.; Lee, S. H.; Shim, M. H.

    2006-01-01

    The ZrCo getter beds are built of a primary vessel which contains the ZrCo powder mixed with Cu spheres of less than one mm diameter and of a secondary outer vessel. The purpose of the secondary outer vessel is to capture permeated or leaked tritium and to present a good thermal insulation when properly evacuated. A third volume, a helium filled loop, is installed in the primary volume to remove the decay heat and is used to perform tritium accountancy measurements

  2. High-fidelity simulation of lung isolation with double-lumen endotracheal tubes and bronchial blockers in anesthesiology resident training.

    Science.gov (United States)

    Failor, Erin; Bowdle, Andrew; Jelacic, Srdjan; Togashi, Kei

    2014-08-01

    Demonstrate the feasibility of using the AirSim Bronchi airway simulator to teach residents how to manage lung isolation with double-lumen endotracheal tubes and bronchial blockers and evaluate their performance with a detailed checklist. Prospective observational study. University anesthesiology residency training program. Anesthesiology residents taking a cardiothoracic anesthesiology rotation. Residents were instructed in 7 tasks using the AirSim Bronchi: The use of the fiberoptic bronchoscope, methods for placing left and right double-lumen endotracheal tubes and 3 bronchial blockers (Univent, Arndt, and Cohen), and application of continuous positive airway pressure (CPAP) to the unventilated lung. Two to 3 weeks later, checklists and a detailed scoring system were used to assess performance. Residents rated the curriculum and their own confidence in performing the tasks using a 5-point Likert scale. Thirteen residents completed the curriculum. Their median Likert scale ratings of the curriculum based on a questionnaire with 6 items ranged from 4 to 5 of 5. Resident confidence scores for each lung isolation technique improved after the simulation training, with the median gain ranging from 0.5 to 1.5 Likert levels depending on the task. The largest improvement occurred with the bronchial blockers (psimulator in a novel simulation curriculum to teach lung-isolation techniques to anesthesiology residents and evaluated performance using a detailed checklist scoring system. This curriculum is a promising educational tool. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Incidental extracolonic findings on bright lumen MR colonography in a population at increased risk for colorectal carcinoma

    International Nuclear Information System (INIS)

    Yusuf, Erlangga; Florie, Jasper; Nio, Chung Yung; Jensch, Sebastian; Nievelstein, Rutger A.J.; Baak, Lubbertus; Stoker, Jaap

    2011-01-01

    Purpose: Incidental extracolonic findings affect patient treatment and cost. Therefore, to consider magnetic resonance colonography (MRC) as a tool for colorectal cancer and polyps screening, more knowledge is needed on extracolonic findings. In this study, we sought to determine the prevalence and the spectrum of extracolonic findings in patients with an increased risk colorectal cancer that underwent bright lumen MRC. Materials and methods: MRC examinations were performed in 210 patients. A gadolinium solution was administered rectally for distension of the colon. Extracolonic findings were scored by two radiologists and classified by using C-RADS Reporting System. All findings (with advice regarding work-up) were reported to the patient's physician and followed up for 4.5 years on average. Results: Extracolonic findings were found in 125 (59.5%) patients. Ten (4.8%) had 'potentially important' findings (C-RADS category E4). Twenty-five patients (11.9%) had 'likely unimportant' findings (E3), 90 (42.8%) had 'clinically unimportant' findings (E2) and 85 (40.5%) had a normal exam (E1). In 14 (6.7%) patients additional work-up was performed for their incidentally discovered lesions. In three of them surgery was performed. After work-up, only in two (1.0%) patients a malignancy was found. Conclusion: The number of new relevant extracolonic findings is small and the required additional work-up is limited. This should be considered for implementation of 'bright lumen' MRC as a screening tool.

  4. Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

    International Nuclear Information System (INIS)

    Leberer, E.; Charuk, J.H.M.; MacLennan, D.H.; Green, N.M.

    1989-01-01

    Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1,308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH 2 -terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca 2+ . The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45 C 2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca 2+ with the membrane. The authors propose that this lumenal Ca 2+ binding glycoprotein of the sarcoplasmic reticulum be designated sarcalumenin

  5. Scoping calculations for design and analysis of large reactor vessels for liquid-metal fast breeder reactor (LMFBR) plants

    International Nuclear Information System (INIS)

    Fiala, C.; Kulak, R.F.; Ma, D.C.; Pan, Y.C.; Seidensticker, R.W.; Wang, C.Y.; Zeuch, W.R.

    1982-01-01

    Reactor vessels for commercial-sized LMFBR plants are quite large - ranging 40 to 70 ft in diameter and 50 to 70 ft in overall depth. These stainless steel vessels contain liquid sodium at relatively low pressures, but at high temperatures. The resulting thin-walled vessels present the structural designer and analyst with special problems, particularly in providing a balanced design to accommodate seismic loads, design basis accident loads, and thermal loadings. A comprehensive set of scoping calculations - though preliminary in detail and depth of design - provides substantial guidance to the vessel designer for subsequent design iterations. Emphasis is placed on the analysis of the large-diameter top closure of the vessel - the deck structure

  6. Reactor Pressure Vessel (RPV) Acquisition Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Mizia, Ronald Eugene [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2008-04-01

    The Department of Energy has selected the High Temperature Gas-cooled Reactor design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, TRISO-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. The purpose of this report is to address the acquisition strategy for the NGNP Reactor Pressure Vessel (RPV). This component will be larger than any nuclear reactor pressure vessel presently in service in the United States. The RPV will be taller, larger in diameter, thicker walled, heavier and most likely fabricated at the Idaho National Laboratory (INL) site of multiple subcomponent pieces. The pressure vessel steel can either be a conventional materials already used in the nuclear industry such as listed within ASME A508/A533 specifications or it will be fabricated from newer pressure vessel materials never before used for a nuclear reactor in the US. Each of these characteristics will present a

  7. Special enclosure for a pressure vessel

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  8. Establishment of an animal model of mice with radiation- injured soft tissue blood vessels

    International Nuclear Information System (INIS)

    Wang Daiyou; Yu Dahai; Wu Jiaxiao; Wei Shanliang; Wen Yuming

    2004-01-01

    Objective: The aim of this study was to establish an animal model of mice with radiation-injured soft tissue blood vessels. Methods: Forty male mice were irradiated with 30 Gy on the right leg. After the irradiation was finished each of the 40 male mice was tested with angiography, and its muscle tissues on the bilateral legs were examined with vessel staining assay and electron microscopy. Results: The results showed that the number of vessels on the right leg was less than that on the left leg, the microvessel density, average diameter and average sectional area of the right leg were all lower than those of the left, and the configuration and ultra-structure of vessels were also different between both sides of legs. Conclusion: In the study authors successfully established an animal model of mice with radiation-injured soft tissue blood vessels

  9. A system for the thermal insulation of a pre-stressed concrete vessel

    International Nuclear Information System (INIS)

    Aubert, Gilles; Petit, Guy.

    1975-01-01

    This invention concerns the thermal insulation of a pre-stressed concrete vessel for a pressurised water nuclear reactor, this vessel being fitted internally with a leak-proof metal lining. Two rings are placed at the lower and upper parts of the vessel respectively. The upper ring is closed with a cover. These rings differ in diameter, are fitted with a metal insulating and mark the limits of a chamber between the vaporisable fluid and the internal wall of the vessel. This chamber is filled with a fluid in the liquid phase up to the liquid/vapor interface level of the fluid and with a gas above that level, the covering of the rings forming a cold fluid liquid seal. Each ring is supported by the vessel. Leak-proof components take up the radial expansion of the rings [fr

  10. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  11. Analysis of carotid lumen surface morphology using three-dimensional ultrasound imaging

    International Nuclear Information System (INIS)

    Chiu, Bernard; Beletsky, Vadim; Spence, J David; Parraga, Grace; Fenster, Aaron

    2009-01-01

    Carotid plaque surface irregularity and ulcerations play an important role in the risk of ischemic stroke. Ulcerated or fissured plaque, characterized by irregular surface morphology, exposes thrombogenic materials to the bloodstream, possibly leading to life- or brain-threatening thrombosis and embolization. Therefore, the quantification of plaque surface irregularity is important to identify high-risk plaques that would likely lead to vascular events. Although a number of studies have characterized plaque surface irregularity using subjective classification schemes with two or more categories, only a few have quantified surface irregularity using an objective and continuous quantity, such as Gaussian or mean curvature. In this work, our goal was to use both Gaussian and mean curvatures for identifying ulcers from 3D carotid ultrasound (US) images of human subjects. Before performing experiments using patient data, we verified the numerical accuracy of the surface curvature computation method using discrete spheres and tori with different sampling intervals. We also showed that three ulcers of the vascular phantom with 2 mm, 3 mm and 4 mm diameters were associated with high Gaussian and mean curvatures, and thus, were easily detected. Finally, we demonstrated the application of the proposed method for detecting ulcers on luminal surfaces, which were segmented from the 3D US images acquired for two human subjects.

  12. Analysis of carotid lumen surface morphology using three-dimensional ultrasound imaging

    Science.gov (United States)

    Chiu, Bernard; Beletsky, Vadim; Spence, J. David; Parraga, Grace; Fenster, Aaron

    2009-03-01

    Carotid plaque surface irregularity and ulcerations play an important role in the risk of ischemic stroke. Ulcerated or fissured plaque, characterized by irregular surface morphology, exposes thrombogenic materials to the bloodstream, possibly leading to life- or brain-threatening thrombosis and embolization. Therefore, the quantification of plaque surface irregularity is important to identify high-risk plaques that would likely lead to vascular events. Although a number of studies have characterized plaque surface irregularity using subjective classification schemes with two or more categories, only a few have quantified surface irregularity using an objective and continuous quantity, such as Gaussian or mean curvature. In this work, our goal was to use both Gaussian and mean curvatures for identifying ulcers from 3D carotid ultrasound (US) images of human subjects. Before performing experiments using patient data, we verified the numerical accuracy of the surface curvature computation method using discrete spheres and tori with different sampling intervals. We also showed that three ulcers of the vascular phantom with 2 mm, 3 mm and 4 mm diameters were associated with high Gaussian and mean curvatures, and thus, were easily detected. Finally, we demonstrated the application of the proposed method for detecting ulcers on luminal surfaces, which were segmented from the 3D US images acquired for two human subjects.

  13. 2013 West Coast Vessel Tracklines

    Data.gov (United States)

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

  14. 2011 West Coast Vessel Tracklines

    Data.gov (United States)

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

  15. 2013 Great Lakes Vessel Tracklines

    Data.gov (United States)

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

  16. 2011 Great Lakes Vessel Tracklines

    Data.gov (United States)

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

  17. 2011 East Coast Vessel Tracklines

    Data.gov (United States)

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

  18. Coastal Discard Logbook Survey (Vessels)

    Data.gov (United States)

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

  19. SC/OQ Vessel Database

    Data.gov (United States)

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

  20. Vessel Permit System Data Set

    Data.gov (United States)

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

  1. Reactor pressure vessel status report

    International Nuclear Information System (INIS)

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

    1994-12-01

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

  2. Reactor-vessel-sectioning demonstration

    International Nuclear Information System (INIS)

    Lundgren, R.A.

    1981-07-01

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

  3. Demineralized water flow cancelling experiments with ice plug into high diameter horizontal tube (300 nominal diameter)

    International Nuclear Information System (INIS)

    Gyongyosi, T.; Valeca, S.; Corbescu, B.; Puiu, D.; Panaitescu, V. N.

    2015-01-01

    The isolation with ice plug of a high diameter horizontal pipeline section is a specific technique for repairs activities/ replacements of components owning to thermo-hydraulic installations working with liquid agents. The application of such technique don.t assumes stopping of the entire system. The ice plugging inside of the pipeline assumes using of a special device and of an own specific technology for application. The paper contains a brief description of the experimental technological facilities used, followed by setting off the main moments in evolution of two experimental tests carried out on the test section with 300 mm nominal diameter for demineralized water and, finally, by a brief results analysis and some conclusions. The paper is dedicated to the specialists working in the research and technological engineering. (authors)

  4. Modelling diameter growth, mortality and recruitment of trees in ...

    African Journals Online (AJOL)

    Modelling diameter growth, mortality and recruitment of trees in miombo woodlands of Tanzania. ... Individual tree diameter growth and mortality models, and area-based recruitment models were developed. ... AJOL African Journals Online.

  5. Nineteen-Foot Diameter Explosively Driven Blast Simulator; TOPICAL

    International Nuclear Information System (INIS)

    VIGIL, MANUEL G.

    2001-01-01

    This report describes the 19-foot diameter blast tunnel at Sandia National Laboratories. The blast tunnel configuration consists of a 6 foot diameter by 200 foot long shock tube, a 6 foot diameter to 19 foot diameter conical expansion section that is 40 feet long, and a 19 foot diameter test section that is 65 feet long. Therefore, the total blast tunnel length is 305 feet. The development of this 19-foot diameter blast tunnel is presented. The small scale research test results using 4 inch by 8 inch diameter and 2 foot by 6 foot diameter shock tube facilities are included. Analytically predicted parameters are compared to experimentally measured blast tunnel parameters in this report. The blast tunnel parameters include distance, time, static, overpressure, stagnation pressure, dynamic pressure, reflected pressure, shock Mach number, flow Mach number, shock velocity, flow velocity, impulse, flow duration, etc. Shadowgraphs of the shock wave are included for the three different size blast tunnels

  6. Shiitake mushroom production on small diameter oak logs in Ohio

    Science.gov (United States)

    S.M. Bratkovich

    1991-01-01

    Yields of different strains of shiitake mushrooms (Lentinus edodes) were evaluated when produced on small diameter oak logs in Ohio. Logs averaging between 3-4 inches in diameter were inoculated with four spawn strains in 1985.

  7. Power reactor pressure vessel benchmarks

    International Nuclear Information System (INIS)

    Rahn, F.J.

    1978-01-01

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

  8. Instability of Reference Diameter in the Evaluation of Stenosis After Coronary Angioplasty: Percent Diameter Stenosis Overestimates Dilative Effects Due to Reference Diameter Reduction

    International Nuclear Information System (INIS)

    Hirami, Ryouichi; Iwasaki, Kohichiro; Kusachi, Shozo; Murakami, Takashi; Hina, Kazuyoshi; Matano, Shigeru; Murakami, Masaaki; Kita, Toshimasa; Sakakibara, Noburu; Tsuji, Takao

    2000-01-01

    Purpose: To examine changes in the reference segment luminal diameter after coronary angioplasty.Methods: Sixty-one patients with stable angina pectoris or old myocardial infarction were examined. Coronary angiograms were recorded before coronary angioplasty (pre-angioplasty) and immediately after (post-angioplasty), as well as 3 months after. Artery diameters were measured on cine-film using quantitative coronary angiographic analysis.Results: The diameters of the proximal segment not involved in the balloon inflation and segments in the other artery did not change significantly after angioplasty, but the reference segment diameter significantly decreased (4.7%). More than 10% luminal reduction was observed in seven patients (11%) and more than 5% reduction was observed in 25 patients (41%). More than 5% underestimation of the stenosis was observed in 22 patients (36%) when the post-angioplasty reference diameter was used as the reference diameter, compared with when the pre-angioplasty measurement was used and more than 10% underestimation was observed in five patients (8%).Conclusion: This study indicated that evaluation by percent diameter stenosis, with the reference diameter from immediately after angioplasty, overestimates the dilative effects of coronary angioplasty, and that it is thus better to evaluate the efficacy of angioplasty using the absolute diameter in addition to percent luminal stenosis

  9. Abnormal splenic artery diameter/hepatic artery diameter ratio in cirrhosis-induced portal hypertension

    Science.gov (United States)

    Zeng, Dao-Bing; Dai, Chuan-Zhou; Lu, Shi-Chun; He, Ning; Wang, Wei; Li, Hong-Jun

    2013-01-01

    AIM: To determine an optimal cutoff value for abnormal splenic artery diameter/proper hepatic artery diameter (S/P) ratio in cirrhosis-induced portal hypertension. METHODS: Patients with cirrhosis and portal hypertension (n = 770) and healthy volunteers (n = 31) underwent volumetric computed tomography three-dimensional vascular reconstruction to measure the internal diameters of the splenic artery and proper hepatic artery to calculate the S/P ratio. The cutoff value for abnormal S/P ratio was determined using receiver operating characteristic curve analysis, and the prevalence of abnormal S/P ratio and associations between abnormal S/P ratio and major complications of portal hypertension were studied using logistic regression. RESULTS: The receiver operating characteristic analysis showed that the cutoff points for abnormal splenic artery internal diameter and S/P ratio were > 5.19 mm and > 1.40, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.2%, 45.2%, 97.1%, and 6.6%, respectively. The prevalence of an abnormal S/P ratio in the patients with cirrhosis and portal hypertension was 83.4%. Patients with a higher S/P ratio had a lower risk of developing ascites [odds ratio (OR) = 0.708, 95%CI: 0.508-0.986, P = 0.041] and a higher risk of developing esophageal and gastric varices (OR = 1.483, 95%CI: 1.010-2.175, P = 0.044) and forming collateral circulation (OR = 1.518, 95%CI: 1.033-2.230, P = 0.034). After splenectomy, the portal venous pressure and maximum and mean portal venous flow velocities were reduced, while the flow rate and maximum and minimum flow velocities of the hepatic artery were increased (P portal hypertension, and it can be used as an important marker of splanchnic hemodynamic disturbances. PMID:23483462

  10. Prosopomorphic vessels from Moesia Superior

    Directory of Open Access Journals (Sweden)

    Nikolić Snežana

    2008-01-01

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

  11. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  12. Vacuum vessel for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-31

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

  13. [Successful double-lumen endotracheal tube exchange with a soft-tipped extra firm exchange catheter in a patient with severe subcutaneous emphysema].

    Science.gov (United States)

    Okamoto, Kaori; Komasawa, Nobuyasu; Ishio, Junichi; Nakano, Shoko; Tatsumi, Shinichi; Minami, Toshiaki

    2014-07-01

    We report a case of successful double-lumen endotracheal tube exchange with a soft-tipped extra firm exchange catheter in a patient with severe subcutaneous emphysema. A 70-year-old man underwent right lower lobectomy for primary lung cancer under general anesthesia. He developed pneumothorax on postoperative day (POD) 14, which led to subcutaneous emphysema. An emergent operation was performed on POD20 to close the pulmonary fistula under general anesthesia with a single-lumen endotracheal tube and bronchial blocker. Subcutaneous emphysema became worse and pharyngeal emphysema was also suspected; re-operation to close the pulmonary or bronchial fistula was planned. We decided to place a double-lumen tube to precisely detect the fistula. Under the guide of a Pentax-AWS Airwayscope, the single-lumen endotracheal tube was exchanged uneventfully to a 35 Fr double-lumen endotracheal tube with a 110 cm soft-tipped extra firm exchange catheter. The fistula was detected by a leak test and the operation was performed uneventfully, leading to improvement of subcutaneous emphysema.

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

    Science.gov (United States)

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

    2014-01-01

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

  15. Neutron Assay System for Con?nement Vessel Disposition

    International Nuclear Information System (INIS)

    Frame, Katherine C.; Bourne, Mark M.; Crooks, William J.; Evans, Louise; Mayo, Douglas R.; Miko, David K.; Salazar, William R.; Stange, Sy; Valdez, Jose I.; Vigil, Georgiana M.

    2012-01-01

    Waste will be removed from confinement vessels remaining from 1970s-era experiments. Los Alamos has 9+ spherical confinement vessels remaining from experiments. Each vessel contains ∼ 500 lbs of radioactive debris such as actinide metals and oxides, metals, powdered silica, graphite, and wires and hardware. In order to dispose of the vessels, debris and contamination must be removed. Neutron assay system was designed to assay vessels before and after cleanout. System requirements are: (1) Modular and moveable; (2) Capable of detecting ∼100g 239 Pu equivalent in a 2-inch thick steel sphere with 6 foot diameter; and (3) Capable of safeguards-quality assays. Initial design parameters arethe use of 4-atm 3 He tubes with length of 6 feet, and 3 He tubes embedded in polyethelene for moderation. This paper describes the calibration of the Confinement Vessel Assay System (CVAS) and quantification of its uncertainties. Assay uncertainty depends on five factors: (1) Statistical uncertainty in the assay measurement; (2) Statistical uncertainty in the background measurement; (3) Statistical uncertainty in the isotopics determination - This should be much smaller than the other uncertainties; (4) Systematic uncertainty due to position bias; and (5) Systematic uncertainty due to fluctuations in cosmic ray spallation. This one can be virtually eliminated by performing the background measurement with an empty vessel - but that may not be possible. We used modeling and experiments to quantify the systematic uncertainties. The calibration assumes a uniform distribution of material, but reality will be different. MCNPX modeling was used to quantify the positional bias. The model was benchmarked to build confidence in its results. Material at top of vessel is 44% greater than amount assayed, according to singles. Material near 19-tube detector is 38% less than amount assayed, according to singles. Cosmic ray spallation contributes significantly to the background. Comparing rates

  16. Displacer Diameter Effect in Displacer Pulse Tube Refrigerator

    Science.gov (United States)

    Zhu, Shaowei

    2017-12-01

    Gas driving displacer pulse tube refrigerators are one of the work recovery type of pulse tube refrigerators whose theoretical efficiency is the same as Stirling refrigerators'. Its cooling power is from the displacement of the displacer. Displace diameter, rod diameter and pressure drop of the regenerator influence the displacement, which are investigated by numerical simulation. It is shown that the displacement ratio of the displacer over the piston is almost not affected by the displacer diameter at the same rod diameter ratio, or displacer with different diameters almost has the same performance.

  17. Tissue-Engineered Vascular Graft of Small Diameter Based on Electrospun Polylactide Microfibers

    Directory of Open Access Journals (Sweden)

    P. V. Popryadukhin

    2017-01-01

    Full Text Available Tubular vascular grafts 1.1 mm in diameter based on poly(L-lactide microfibers were obtained by electrospinning. X-ray diffraction and scanning electron microscopy data demonstrated that the samples treated at T=70°C for 1 h in the fixed state on a cylindrical mandrel possessed dense fibrous structure; their degree of crystallinity was approximately 44%. Strength and deformation stability of these samples were higher than those of the native blood vessels; thus, it was possible to use them in tissue engineering as bioresorbable vascular grafts. The experiments on including implantation into rat abdominal aorta demonstrated that the obtained vascular grafts did not cause pathological reactions in the rats; in four weeks, inner side of the grafts became completely covered with endothelial cells, and fibroblasts grew throughout the wall. After exposure for 12 weeks, resorption of PLLA fibers started, and this process was completed in 64 weeks. Resorbed synthetic fibers were replaced by collagen and fibroblasts. At that time, the blood vessel was formed; its neointima and neoadventitia were close to those of the native vessel in structure and composition.

  18. The TPX vacuum vessel and in-vessel components

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  19. Clay Corner: Recreating Chinese Bronze Vessels.

    Science.gov (United States)

    Gamble, Harriet

    1998-01-01

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

  20. Design features of the KSTAR in-vessel control coils

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.K. [National Fusion Research Institute (NFRI), 52 Yeoeun-dong, Yusung-ku, Daejeon, 305-333 (Korea, Republic of)], E-mail: hkkim@nfri.re.kr; Yang, H.L.; Kim, G.H.; Kim, Jin-Yong; Jhang, Hogun; Bak, J.S.; Lee, G.S. [National Fusion Research Institute (NFRI), 52 Yeoeun-dong, Yusung-ku, Daejeon, 305-333 (Korea, Republic of)

    2009-06-15

    In-vessel control coils (IVCCs) are to be used for the fast plasma position control, field error correction (FEC), and resistive wall mode (RWM) stabilization for the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The IVCC system comprises 16 segments to be unified into a single set to achieve following remarkable engineering advantages; (1) enhancement of the coil system reliability with no welding or brazing works inside the vacuum vessel, (2) simplification in fabrication and installation owing to coils being fabricated outside the vacuum vessel and installed after device assembly, and (3) easy repair and maintenance of the coil system. Each segment is designed in 8 turns coil of 32 mm x 15 mm rectangular oxygen free high conductive copper with a 7 mm diameter internal coolant hole. The conductors are enclosed in 2 mm thick Inconel 625 rectangular welded vacuum jacket with epoxy/glass insulation. Structural analyses were implemented to evaluate structural safety against electromagnetic loads acting on the IVCC for the various operation scenarios using finite element analysis. This paper describes the design features and structural analysis results of the KSTAR in-vessel control coils.

  1. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

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

    Science.gov (United States)

    Kondermann, Claudia; Kondermann, Daniel; Yan, Michelle

    2007-03-01

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

  3. Molecular imaging of tumor blood vessels in prostate cancer.

    Science.gov (United States)

    Tilki, Derya; Seitz, Michael; Singer, Bernhard B; Irmak, Ster; Stief, Christian G; Reich, Oliver; Ergün, Süleyman

    2009-05-01

    In the past three decades many efforts have been undertaken to understand the mechanisms of tumor angiogenesis. The introduction of anti-angiogenic drugs in tumor therapy during the last few years necessitates the establishment of new techniques enabling molecular imaging of tumor vascular remodelling. The determination of tumor size as commonly used is not appropriate since the extended necrosis under anti-angiogenic therapy does not necessarily result in the reduction of tumor diameter. The basis for the molecular imaging of tumor blood vessels is the remodelling of the tumor vessels under anti-angiogenic therapy which obviously occurs at an early stage and seems to be a convincing parameter. Beside the enormous progress in this field during the last few years the resolution is still not high enough to evaluate the remodelling of the micro tumor vessels. New imaging approaches combining specific molecular markers for tumor vessels with the different imaging techniques are needed to overcome this issue as exemplarily discussed for prostate cancer in this review. Molecular contrast agents targeting the vasculature will allow clinicians the visualization of vascular remodelling processes taking place under anti-angiogenic therapy and improve tumor diagnosis and follow-up.

  4. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    International Nuclear Information System (INIS)

    Iannicelli, Elsa; Di Renzo, Sara; Ferri, Mario; Pilozzi, Emanuela; Di Girolamo, Marco; Sapori, Alessandra; Ziparo, Vincenzo; David, Vincenzo

    2014-01-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting

  5. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Iannicelli, Elsa; Di Renzo, Sara [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ferri, Mario [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Pilozzi, Emanuela [Department of Clinical and Molecular Sciences, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Di Girolamo, Marco; Sapori, Alessandra [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ziparo, Vincenzo [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); David, Vincenzo [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy)

    2014-07-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

  6. Clinical application of hysterosalpingography with a double-lumen catheter of a contrast media combination consisting iohexol and saline

    International Nuclear Information System (INIS)

    Xi Jiayuan; Jiang Yong; Cao Xinhua; Zhu Ying; Lv Liang; Zhao Xinxiang; Wei Dingying; Shao Jingxuan; Hua Jian

    2005-01-01

    Objective: To evaluate the clinical value of hysteosalpingographic diagnosis in infertile women. Methods: After a catheter with a double-lumen saccule was inserted into the uterine cavity, saline or air of 2.5-3.5 ml was injected to fill the saccule. The filled saccule was inserted at the isthmus of uterus for blocking the internal orifice. The contrast medium was injected through the catheter into the uterine cavity and fallopian tubes to undertake hysterosalpingography and fallopian tube reopening. In case of fallopian tube obstruction, the injection pressure could be increased to obtain recanalization. All operations and selective imagings were carried out under TV supervision. Results: 2698 cases including 806 primary infertile women and 1868 secondary infertile women were examined by this method. Technical success rate was 99.5% with 2198 cases (81.9%) having normal uterus, 249 (9.3%) congenital abnormal uterus and 238 (8.9%) uterus diseases. The number of obstructed fallopian tube was 3028 with 117 serious hydropsy (3.8%). Ninety-eight cases had been examined with lipiodol hysterosalpingography in other hospitals with 35 cases still having lipiodol accumulated within the uterine cavities and fallopian tubes. No serious complications or death occurred except slight pain. Conclusions: Double-lumen cather with a contrast media combination of iohexol and saline for hysterosal pinography is safe, easy and effective, outcoming with excellent quality images. More information can be gained with this method than traditional lipiodol hyterosalpinography, and furthermore could have compression during radiogrophy and avoid the long term stasis of lipiodol. (authors)

  7. Vacuum vessel for thermonuclear device

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  8. Vacuum vessel for thermonuclear device

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-11

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

  9. Molten material-containing vessel

    International Nuclear Information System (INIS)

    Akagawa, Katsuhiko

    1998-01-01

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

  10. Single pressure vessel (SPV) nickel-hydrogen battery design

    Energy Technology Data Exchange (ETDEWEB)

    Coates, D.; Grindstaff, B.; Fox, C. [Eagle-Picher Industries, Inc., Joplin, MO (United States)

    1995-07-01

    Single pressure vessel (SPV) technology combines an entire multi-cell nickel-hydrogen (NiH{sub 2}) space battery within a single pressure vessel. SPV technology has been developed to improve the performance (volume/mass) of the NiH{sub 2} system at the battery level and ultimately to reduce overall battery cost and increase system reliability. Three distinct SPV technologies are currently under development and in production. Eagle-Picher has license to the COMSAT Laboratories technology, as well as internally developed independent SPV technology. A third technology resulted from the acquisition of Johnson Controls NiH{sub 2} battery assets in June, 1994. SPV batteries are currently being produced in 25 ampere-hour (Ah), 35 Ah and 50 Ah configurations. The battery designs have an overall outside diameter of 10 inches (25.4 centimeters).

  11. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi; Bull, Joseph L.

    2013-01-01

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  12. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  13. Microstructural evolution in reactor pressure vessel steel under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Katsumi; Fukuya, Koji [Institute of Nuclear Safety System Inc., Seika, Kyoto (Japan)

    2000-09-01

    Understanding microstructural changes in reactor pressure vessel steels is important in order to evaluate radiation-induced embrittlement, one of the major aging phenomena affecting the extension of plant life. In this study, actual surveillance test specimens and samples of rector vessel low-alloy steel (A533B steel) irradiated in a research reactor were examined using state-of-the-art techniques to clarify the neutron flux effect on the microstructural changes. These techniques included small angle neutron scattering and atom probes. Microstructural changes which are considered to be the main factors affecting embrittlement, including the production of copper-rich precipitates and the segregation of impurity elements, were confirmed by the results of the study. In addition, the mechanical properties were predicted based on the obtained quantitative data such as the diameters of precipitates. Consequently, the hardening due to irradiation was almost simulated. (author)

  14. Large vessel imaging using cosmic-ray muons

    International Nuclear Information System (INIS)

    Jenneson, P.M.

    2004-01-01

    Cosmic-ray muons are assessed for their practical use in the tomographic imaging of the internal composition of large vessels over 2 m in diameter. The technique is based on the attenuation and scattering of cosmic-ray muons passing through a vessel and has advantages over photon-based methods of tomography that it is extendable to object containing high-density materials over many tens of metres. The main disadvantage is the length of time required to produce images of sufficient resolution and hence cosmic ray muon tomography will be most suited to the imaging of large structures whose internal composition is effectively static for the duration of the imaging period. Simulation and theoretical results are presented here which demonstrate the feasibility of cosmic ray muon tomography

  15. ETS transcription factor ELF5 induces lumen formation in a 3D model of mammary morphogenesis and its expression is inhibited by Jak2 inhibitor TG101348.

    Science.gov (United States)

    Chean, Jennifer; Chen, Charng-Jui; Shively, John E

    2017-10-01

    The loss of expression of a single gene can revert normal tissue to a malignant phenotype. For example, while normal breast has high lumenal expression of CEACAM1, the majority of breast cancers exhibit the early loss of this gene with the concurrent loss of their lumenal phenotype. MCF7 cells that lack CEACAM1 expression and fail to form lumena in 3D culture, regain the normal phenotype when transfected with CEACAM1. In order to probe the mechanism of this gain of function, we treated these cells with the clinically relevant Jak2 inhibitor TG101348 (TG), expecting that disruption of the prolactin receptor signaling pathway would interfere with the positive effects of transfection of MCF7 cells with CEACAM1. Indeed, lumen formation was inhibited, resulting in the down regulation of a set of genes, likely involved in the complex process of lumen formation. As expected, inhibition of the expression of many of these genes also inhibited lumen formation, confirming their involvement in a single pathway. Among the genes identified by the inhibition assay, ETS transcription factor ELF5 stood out, since it has been identified as a master regulator of mammary morphogenesis, and is associated with prolactin receptor signaling. When ELF5 was transfected into the parental MCF7 cells that lack CEACAM1, lumen formation was restored, indicating that ELF5 can replace CEACAM1 in this model system of lumenogenesis. We conclude that the event(s) that led to the loss of expression of CEACAM1 is epistatic in that multiple genes associated with a critical pathway were affected, but that restoration of the normal phenotype can be achieved with reactivation of certain genes at various nodal points in tissue morphogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E.; Kang, Yunqing [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Findlay, Michael W. [Department of Plastic and Reconstructive Surgery, Stanford University, Stanford, CA (United States); University of Melbourne Department of Surgery, Royal Melbourne Hospital, Parkville, VIC (Australia); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States)

    2015-04-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10{sup −6} cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts.

  17. Submillimeter Diameter Poly(Vinyl Alcohol) Vascular Graft Patency in Rabbit Model

    Science.gov (United States)

    Cutiongco, Marie F. A.; Kukumberg, Marek; Peneyra, Jonnathan L.; Yeo, Matthew S.; Yao, Jia Y.; Rufaihah, Abdul Jalil; Le Visage, Catherine; Ho, Jackie Pei; Yim, Evelyn K. F.

    2016-01-01

    Microvascular surgery is becoming a prevalent surgical practice. Replantation, hand reconstruction, orthopedic, and free tissue transfer procedures all rely on microvascular surgery for the repair of venous and arterial defects at the millimeter and submillimeter levels. Often, a vascular graft is required for the procedure as a means to bridge the gap between native arteries. While autologous vessels are desired for their bioactivity and non-thrombogenicity, the tedious harvest process, lack of availability, and caliber or mechanical mismatch contribute to graft failure. Thus, there is a need for an off-the-shelf artificial vascular graft that has low thrombogenic properties and mechanical properties matching those of submillimeter vessels. Poly(vinyl alcohol) hydrogel (PVA) has excellent prospects as a vascular graft due to its bioinertness, low thrombogenicity, high water content, and tunable mechanical properties. Here, we fabricated PVA grafts with submillimeter diameter and mechanical properties that closely approximated those of the rabbit femoral artery. In vitro platelet adhesion and microparticle release assay verified the low thrombogenicity of PVA. A stringent proof-of-concept in vivo test was performed by implanting PVA grafts in rabbit femoral artery with multilevel arterial occlusion. Laser Doppler measurements indicated the improved perfusion of the distal limb after implantation with PVA grafts. Moreover, ultrasound Doppler and angiography verified that the submillimeter diameter PVA vascular grafts remained patent for 2 weeks without the aid of anticoagulant or antithrombotics. Endothelial cells were observed in the luminal surface of one patent PVA graft. The advantageous non-thrombogenic and tunable mechanical properties of PVA that are retained even in the submillimeter diameter dimensions support the application of this biomaterial for vascular replacement in microvascular surgery. PMID:27376059

  18. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    International Nuclear Information System (INIS)

    Mercado-Pagán, Ángel E.; Kang, Yunqing; Findlay, Michael W.; Yang, Yunzhi

    2015-01-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10 −6 cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts

  19. Distribution of Different Sized Ocular Surface Vessels in Diabetics and Normal Individuals.

    Science.gov (United States)

    Banaee, Touka; Pourreza, Hamidreza; Doosti, Hassan; Abrishami, Mojtaba; Ehsaei, Asieh; Basiry, Mohsen; Pourreza, Reza

    2017-01-01

    To compare the distribution of different sized vessels using digital photographs of the ocular surface of diabetic and normal individuals. In this cross-sectional study, red-free conjunctival photographs of diabetic and normal individuals, aged 30-60 years, were taken under defined conditions and analyzed using a Radon transform-based algorithm for vascular segmentation. The image areas occupied by vessels (AOV) of different diameters were calculated. The main outcome measure was the distribution curve of mean AOV of different sized vessels. Secondary outcome measures included total AOV and standard deviation (SD) of AOV of different sized vessels. Two hundred and sixty-eight diabetic patients and 297 normal (control) individuals were included, differing in age (45.50 ± 5.19 vs. 40.38 ± 6.19 years, P distribution curves of mean AOV differed between patients and controls (smaller AOV for larger vessels in patients; P distribution curve of vessels compared to controls. Presence of diabetes mellitus is associated with contraction of larger vessels in the conjunctiva. Smaller vessels dilate with diabetic retinopathy. These findings may be useful in the photographic screening of diabetes mellitus and retinopathy.

  20. An approach to localize the retinal blood vessels using bit planes and centerline detection.

    Science.gov (United States)

    Fraz, M M; Barman, S A; Remagnino, P; Hoppe, A; Basit, A; Uyyanonvara, B; Rudnicka, A R; Owen, C G

    2012-11-01

    The change in morphology, diameter, branching pattern or tortuosity of retinal blood vessels is an important indicator of various clinical disorders of the eye and the body. This paper reports an automated method for segmentation of blood vessels in retinal images. A unique combination of techniques for vessel centerlines detection and morphological bit plane slicing is presented to extract the blood vessel tree from the retinal images. The centerlines are extracted by using the first order derivative of a Gaussian filter in four orientations and then evaluation of derivative signs and average derivative values is performed. Mathematical morphology has emerged as a proficient technique for quantifying the blood vessels in the retina. The shape and orientation map of blood vessels is obtained by applying a multidirectional morphological top-hat operator with a linear structuring element followed by bit plane slicing of the vessel enhanced grayscale image. The centerlines are combined with these maps to obtain the segmented vessel tree. The methodology is tested on three publicly available databases DRIVE, STARE and MESSIDOR. The results demonstrate that the performance of the proposed algorithm is comparable with state of the art techniques in terms of accuracy, sensitivity and specificity. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. A novel Hsp70 of the yeast ER lumen is required for the efficient translocation of a number of protein precursors.

    OpenAIRE

    Craven, R A; Egerton, M; Stirling, C J

    1996-01-01

    The yeast genome sequencing project predicts an open reading frame (YKL073) that would encode a novel member of the Hsp70 family of molecular chaperones. We report that this 881 codon reading frame represents a functional gene expressing a 113-119 kDa glycoprotein localized within the lumen of the endoplasmic reticulum (ER). We therefore propose to designate this gene LHS1 (Lumenal Hsp Seventy). Our studies indicate that LHS1 is regulated by the unfolded protein response pathway, as evidenced...

  2. The behaviour of the pulmonary vessels on X-ray films of children with asthma bronchiale

    International Nuclear Information System (INIS)

    Hegenbarth, R.; Toeroek, M.; Medizinische Hochschule Hannover

    1986-01-01

    On X-ray films of 51 children with asthma bronchiale the authors determined the vascular diameter of the right ascending pulmonary artery, the right vein of the upper lobe, and the peripheral vessels in the upper and lower pulmonary fields at an exactly defined distance from the hilus point, and compared these data with those of a control group of 143 healthy children. During the asthma attack the width of the right descending pulmonary artery and of the vein of the upper lobe corresponded to the values of the control group, whereas the vascular diameters in the upper and lower fields were clearly narrowed. Moreover, in most of the asthmatic children the authors found arc-shaped vessels and irregularly occluded vessels in the periphery of the lungs. (orig.) [de

  3. Emergency venting of pressure vessels

    International Nuclear Information System (INIS)

    Steinkamp, H.

    1995-01-01

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

  4. Development of Catamaran Fishing Vessel

    Directory of Open Access Journals (Sweden)

    A. Jamaluddin

    2010-11-01

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

  5. CT and histopathologic characteristics of lung adenocarcinoma with pure ground-glass nodules 10 mm or less in diameter

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Fang [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Capital Medical University, Department of Radiology, Xuanwu Hospital, Beijing (China); Tian, Shu-ping [Navy General Hospital, Department of Radiology, Beijing (China); Jin, Xin; Jing, Rui; Yang, Yue-qing; Jin, Mei; Zhao, Shao-hong [Chinese PLA General Hospital, Department of Radiology, Beijing (China)

    2017-10-15

    To evaluate CT and histopathologic features of lung adenocarcinoma with pure ground-glass nodule (pGGN) ≤10 mm in diameter. CT appearances of 148 patients (150 lesions) who underwent curative resection of lung adenocarcinoma with pGGN ≤10 mm (25 atypical adenomatous hyperplasias, 42 adenocarcinoma in situs, 38 minimally invasive adenocarcinomas, and 45 invasive pulmonary adenocarcinomas) were analyzed for lesion size, density, bubble-like sign, air bronchogram, vessel changes, margin, and tumour-lung interface. CT characteristics were compared among different histopathologic subtypes. Univariate and multivariate analysis were used to assess the relationship between CT characteristics of pGGN and lesion invasiveness, respectively. There were statistically significant differences among histopathologic subtypes in lesion size, vessel changes, and tumour-lung interface (P<0.05). Univariate analysis revealed significant differences of vessel changes, margin and tumour-lung interface between preinvasive and invasive lesions (P<0.05). Logistic regression analysis showed that the vessel changes, unsmooth margin and clear tumour-lung interface were significant predictive factors for lesion invasiveness, with odds ratios (95% CI) of 2.57 (1.17-5.62), 1.83 (1.25-2.68) and 4.25 (1.78-10.14), respectively. Invasive lesions are found in 55.3% of subcentimeter pGGNs in our cohort. Vessel changes, unsmooth margin, and clear lung-tumour interface may indicate the invasiveness of lung adenocarcinoma with subcentimeter pGGN. (orig.)

  6. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

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

  7. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    Science.gov (United States)

    2010-07-01

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

  8. Neutrophil-Mediated Delivery of Therapeutic Nanoparticles across Blood Vessel Barrier for Treatment of Inflammation and Infection.

    Science.gov (United States)

    Chu, Dafeng; Gao, Jin; Wang, Zhenjia

    2015-12-22

    Endothelial cells form a monolayer in lumen of blood vessels presenting a great barrier for delivery of therapeutic nanoparticles (NPs) into extravascular tissues where most diseases occur, such as inflammation disorders and infection. Here, we report a strategy for delivering therapeutic NPs across this blood vessel barrier by nanoparticle in situ hitchhiking activated neutrophils. Using intravital microscopy of TNF-α-induced inflammation of mouse cremaster venules and a mouse model of acute lung inflammation, we demonstrated that intravenously (iv) infused NPs made from denatured bovine serum albumin (BSA) were specifically internalized by activated neutrophils, and subsequently, the neutrophils containing NPs migrated across blood vessels into inflammatory tissues. When neutrophils were depleted using anti-Gr-1 in a mouse, the transport of albumin NPs across blood vessel walls was robustly abolished. Furthermore, it was found that albumin nanoparticle internalization did not affect neutrophil mobility and functions. Administration of drug-loaded albumin NPs markedly mitigated the lung inflammation induced by LPS (lipopolysaccharide) or infection by Pseudomonas aeruginosa. These results demonstrate the use of an albumin nanoparticle platform for in situ targeting of activated neutrophils for delivery of therapeutics across the blood vessel barriers into diseased sites. This study demonstrates our ability to hijack neutrophils to deliver nanoparticles to targeted diseased sites.

  9. Containment vessel design and practice

    International Nuclear Information System (INIS)

    Bangash, Y.

    1983-01-01

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

  10. Stress analysis of pressure vessels

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  11. Vessel dilatation in coronary angiograms

    International Nuclear Information System (INIS)

    Hinterauer, L.; Goebel, N.

    1983-01-01

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

  12. Vessel dilatation in coronary angiograms

    Energy Technology Data Exchange (ETDEWEB)

    Hinterauer, L.; Goebel, N.

    1983-11-01

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

  13. The Clementine Nickel Hydrogen Common Pressure Vessel Battery

    OpenAIRE

    Garner, Christopher

    1994-01-01

    The Clementine spacecraft was launched in January 1994 to demonstrate advanced lightweight technologies for the Ballistic Missile Defense Organization (BMDO). One of the key technologies was the first use of a multi-cell nickel hydrogen (NiH2) common pressure vessel (CPV) battery. The 5.0 inch diameter, 22 cell, 15.0 ampere-hour NiH2 CPV battery was manufactured by Johnson Controls Battery Group Inc., (JCBGI). Battery test and integration was performed by the Naval Research Laboratory (NRL). ...

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Estimation of Scatterer Diameter by Normalized Power Spectrum of High-Frequency Ultrasonic RF Echo for Assessment of Red Blood Cell Aggregation

    Science.gov (United States)

    Fukushima, Taku; Hasegawa, Hideyuki; Kanai, Hiroshi

    2011-07-01

    Red blood cell (RBC) aggregation, as one of the determinants of blood viscosity, plays an important role in blood rheology, including the condition of blood. RBC aggregation is induced by the adhesion of RBCs when the electrostatic repulsion between RBCs weakens owing to increases in protein and saturated fatty acid levels in blood, excessive RBC aggregation leads to various circulatory diseases. This study was conducted to establish a noninvasive quantitative method for assessment of RBC aggregation. The power spectrum of ultrasonic RF echoes from nonaggregating RBCs, which shows the frequency property of scattering, exhibits Rayleigh behavior. On the other hand, ultrasonic RF echoes from aggregating RBCs contain the components of reflection, which have no frequency dependence. By dividing the measured power spectrum of echoes from RBCs in the lumen by that of echoes from a posterior wall of the vein in the dorsum manus, the attenuation property of the propagating medium and the frequency responses of transmitting and receiving transducers are removed from the former spectrum. RBC aggregation was assessed by the diameter of a scatterer, which was estimated by minimizing the square difference between the measured normalized power spectrum and the theoretical power spectrum. In this study, spherical scatterers with diameters of 5, 11, 15, and 30 µm were measured in basic experiments. The estimated scatterer diameters were close to the actual diameters. Furthermore, the transient change of the scatterer diameters were measured in an in vivo experiment with respect to a 24-year-old healthy male during the avascularization using a cuff. The estimated diameters (12-22 µm) of RBCs during avascularization were larger than the diameters (4-8 µm) at rest and after recirculation. These results show the possibility of the use of the proposed method for noninvasive assessment of RBC aggregation.

  16. Brain Arterial Diameters as a Risk Factor for Vascular Events

    OpenAIRE

    Gutierrez, Jose; Cheung, Ken; Bagci, Ahmet; Rundek, Tatjana; Alperin, Noam; Sacco, Ralph L; Wright, Clinton B; Elkind, Mitchell S V

    2015-01-01

    Background Arterial luminal diameters are routinely used to assess for vascular disease. Although small diameters are typically considered pathological, arterial dilatation has also been associated with disease. We hypothesize that extreme arterial diameters are biomarkers of the risk of vascular events. Methods and Results Participants in the Northern Manhattan Study who had a time-of-flight magnetic resonance angiography were included in this analysis (N=1034). A global arterial Z-score, ca...

  17. Retinal Vessel Diameters and Their Relationship with Cardiovascular Risk and All-Cause Mortality in the Inter99 Eye Study

    DEFF Research Database (Denmark)

    Drobnjak, Dragana; Munch, Inger Christine; Glümer, Charlotte

    2016-01-01

    equivalent (CRAE). Multiple linear regression analyses and Cox regression models were used. Results. Multiple linear regression analyses showed that narrower CRAE was associated with higher systolic blood pressure, age, and higher HDL cholesterol, whereas wider CRAE and CRVE were associated with smoking...

  18. Database and prediction model for CANDU pressure tube diameter

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J.Y.; Park, J.H. [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of)

    2014-07-01

    The pressure tube (PT) diameter is basic data in evaluating the CCP (critical channel power) of a CANDU reactor. Since the CCP affects the operational margin directly, an accurate prediction of the PT diameter is important to assess the operational margin. However, the PT diameter increases by creep owing to the effects of irradiation by neutron flux, stress, and reactor operating temperatures during the plant service period. Thus, it has been necessary to collect the measured data of the PT diameter and establish a database (DB) and develop a prediction model of PT diameter. Accordingly, in this study, a DB for the measured PT diameter data was established and a neural network (NN) based diameter prediction model was developed. The established DB included not only the measured diameter data but also operating conditions such as the temperature, pressure, flux, and effective full power date. The currently developed NN based diameter prediction model considers only extrinsic variables such as the operating conditions, and will be enhanced to consider the effect of intrinsic variables such as the micro-structure of the PT material. (author)

  19. Electronic transport behavior of diameter-graded Ag nanowires

    International Nuclear Information System (INIS)

    Wang Xuewei; Yuan Zhihao

    2010-01-01

    Ag nanowires with a graded diameter in anodic aluminum oxide (AAO) membranes were fabricated by the direct-current electrodeposition. The Ag nanowires have a graded-change in diameter from 8 to 32 nm, which is matched with the graded-change of the AAO pore diameter. Electronic transport measurements show that there is a transport behavior similar to that of a metal-semiconductor junction along the axial direction in the diameter-graded Ag nanowires. Such a novel homogeneous nanojunction will be of great fundamental and practical significance.

  20. Electronic transport behavior of diameter-graded Ag nanowires

    Science.gov (United States)

    Wang, Xue Wei; Yuan, Zhi Hao

    2010-05-01

    Ag nanowires with a graded diameter in anodic aluminum oxide (AAO) membranes were fabricated by the direct-current electrodeposition. The Ag nanowires have a graded-change in diameter from 8 to 32 nm, which is matched with the graded-change of the AAO pore diameter. Electronic transport measurements show that there is a transport behavior similar to that of a metal-semiconductor junction along the axial direction in the diameter-graded Ag nanowires. Such a novel homogeneous nanojunction will be of great fundamental and practical significance.

  1. In-vessel coolability and steam explosion in Nordic BWRs

    International Nuclear Information System (INIS)

    Ma, W.; Hansson, R.; Li, L.; Kudinov, P.; Cadinu, F.; Tran, C-.T.

    2010-05-01

    The INCOSE project is to reduce the uncertainty in quantification of steam explosion risk and in-vessel coolability in Nordic BWR plants with the cavity flooding as a severe accident management (SAM) measure. During 2009 substantial advances and new insights into physical mechanisms were gained for studies of: (i) in-vessel corium coolability - development of the methodologies to assess the efficiency of the control rod guide tube (CRGT) cooling as a potential SAM measure; (ii) debris bed coolability - characterization of the effective particle diameter of multi-size particles and qualification of friction law for two-phase flow in the beds packed with multi-size particles; and (iii) steam explosion - investigation of the effect of binary oxides mixtures properties on steam explosion. An approach for coupling of ECM/PECM models with RELAP5 was developed to enhance predictive fidelity for melt pool heat transfer. MELCOR was employed to examine the CRGT cooling efficiency by considering an entire accident scenario, and the simulation results show that the nominal flowrate (∼10kg/s) of CRGT cooling is sufficient to maintain the integrity of the vessel in a BWR of 3900 MWth, if the water injection is activated no later than 1 hour after scram. The POMECO-FL experimental data suggest that for a particulate bed packed with multi-size particles, the effective particle diameter can be represented by the area mean diameter of the particles, while at high velocity (Re>7) the effective particle diameter is closer to the length mean diameter. The pressure drop of two-phase flow through the particulate bed can be predicted by Reed's model. The steam explosion experiments performed at high melt superheat (>200oC) using oxidic mixture of WO3-CaO didn't detect an apparent difference in steam explosion energetics and preconditioning between the eutectic and noneutectic melts. This points out that the next step of MISTEE experiment will be conducted at lower superheat. (author)

  2. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

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

  3. PLANNING VESSEL BODY SECTION PRODUCTION

    Directory of Open Access Journals (Sweden)

    A. G. Grivachevsky

    2015-01-01

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

  4. Pressure vessel and method therefor

    Science.gov (United States)

    Saunders, Timothy

    2017-09-05

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

  5. Commercial Passenger Fishing Vessel Fishery

    Data.gov (United States)

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

  6. Ex-vessel boiling experiments: laboratory- and reactor-scale testing of the flooded cavity concept for in-vessel core retention. Pt. II. Reactor-scale boiling experiments of the flooded cavity concept for in-vessel core retention

    International Nuclear Information System (INIS)

    Chu, T.Y.; Bentz, J.H.; Slezak, S.E.; Pasedag, W.F.

    1997-01-01

    For pt.I see ibid., p.77-88 (1997). This paper summarizes the results of a reactor-scale ex-vessel boiling experiment for assessing the flooded cavity design of the heavy water new production reactor. The simulated reactor vessel has a cylindrical diameter of 3.7 m and a torispherical bottom head. Boiling outside the reactor vessel was found to be subcooled nucleate boiling. The subcooling mainly results from the gravity head, which in turn results from flooding the side of the reactor vessel. The boiling process exhibits a cyclic pattern with four distinct phases: direct liquid-solid contact, bubble nucleation and growth, coalescence, and vapor mass dispersion. The results show that, under prototypic heat load and heat flux distributions, the flooded cavity will be effective for in-vessel core retention in the heavy water new production reactor. The results also demonstrate that the heat dissipation requirement for in-vessel core retention, for the central region of the lower head of an AP-600 advanced light water reactor, can be met with the flooded cavity design. (orig.)

  7. Vasculites dos médios e grandes vasos Medium and large vessel vasculitis

    Directory of Open Access Journals (Sweden)

    Hebert Roberto Clivati Brandt

    2009-02-01

    Full Text Available As vasculites são constituídas por um grande grupo de síndromes caracterizadas por inflamação e necrose da parede dos vasos sangüíneos, resultando em estreitamento ou oclusão do lúmen. A distribuição dos vasos envolvidos varia consideravelmente e serve de base para a classificação das síndromes vasculíticas: grandes vasos (arterite de Takayasu, arterite temporal; pequenos e médios vasos (poliarterite nodosa, síndrome de Churg-Strauss, granulomatose de Wegener, vasculites nas doenças reumáticas; e pequenos vasos (vasculite de hipersensibilidade, púrpura de Henoch-Schonlein, poliangeíte microscópica, crioglobulinemia. Este artigo revisa as vasculites dos médios e grandes vasos e opções terapêuticas atuais; além de oferecer orientação sobre abordagem diagnóstica e tratamento dos pacientes com suspeita de vasculite cutânea.Vasculitis comprises a broad group of syndromes characterized by inflammation and necrosis on the walls of blood vessels, resulting in narrowing or occlusion of the lumen. The distribution of involved blood vessel varies considerably and serves as the basis for one classification of vasculitic syndromes: large vessels (Takayasu arteritis, giant cell arteritis; medium and small muscular arteries (polyarteritis nodosa, Churg-Strauss syndrome, Wegener's granulomatosis, vasculitis in rheumatic diseases; and small vessels ("hypersensitivity" vasculitis, Henoch-Schonlein purpura, microscopic polyangiitis, cryoglobulinemia. This article reviews medium and large vessel vasculitis and current treatment options; it also presents a comprehensive approach to diagnosing and treating patients with suspected cutaneous vasculitis.

  8. Towards cavitation-enhanced permeability in blood vessel on a chip

    Science.gov (United States)

    De Luca, R.; Silvani, G.; Scognamiglio, C.; Sinibaldi, G.; Peruzzi, G.; Chinappi, M.; Kiani, M. F.; Casciola, C. M.

    2017-08-01

    The development of targeted delivery systems releasing pharmaceutical agents directly at the desired site of action may improve their therapeutic efficiency while minimizing damage to healthy tissues, toxicity to the patient and drug waste. In this context, we have developed a bio-inspired microdevice mimicking the tumour microvasculature which represents a valuable tool for assessing the enhancement of blood vessel permeability due to cavitation. This novel system allows us to investigate the effects of ultrasound-driven microbubbles that temporarily open the endothelial intercellular junctions allowing drug to extravasate blood vessels into tumour tissues. The blood vessel on a chip consists of a tissue chamber and two independent vascular channels (width 200 µm, height 100 µm, length 2762 µm) cultured with endothelial cells placed side-by-side and separated by a series of 3 µm pores. Its geometry and dimensions mimic the three-dimensional morphology, size and flow characteristics of microvessels in vivo. The early stage of this project had a twofold objective: 1. To define the protocol for culturing of Human Umbilical Vein Endothelial Cells (HUVECs) within the vascular channel; 2. To develop a fluorescence based microscopy technique for measuring permeability. We have developed a reliable and reproducible protocol to culture endothelial cells within the artificial vessels in a realistic manner: HUVECs show the typical elongated shape in the direction of flow, exhibit tight junction formation and form a continuous layer with a central lumen that completely covers the channels wall. As expected, the permeability of cell-free device is higher than the one cultured with HUVECs in the vascular channels. The proposed blood vessel on a chip and the permeability measurement protocol have a significant potential to allow for the study of cavitation-enhanced permeability of the endothelium and improve efficiency in screening drug delivery systems.

  9. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  10. Follicular thyroid carcinoma invades venous rather than lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Liu Yulin

    2010-01-01

    Full Text Available Abstract Follicular thyroid carcinoma (FTC tends to metastasize to remote organs rather than local lymph nodes. Separation of FTC from follicular thyroid adenoma (FTA relies on detection of vascular and/or capsular invasion. We investigated which vascular markers, CD31, CD34 and D2-40 (lymphatic vessel marker, can best evaluate vascular invasion and why FTC tends to metastasize via blood stream to remote organs. Thirty two FTCs and 34 FTAs were retrieved for evaluation. The average age of patients with FTA was 8 years younger than FTC (p = 0.02. The female to male ratio for follicular neoplasm was 25:8. The average size of FTC was larger than FTA (p = 0.003. Fourteen of 32 (44% FTCs showed venous invasion and none showed lymphatic invasion, with positive CD31 and CD34 staining and negative D2-40 staining of the involved vessels. The average number of involved vessels was 0.88 ± 1.29 with a range from 0 to 5, and the average diameter of involved vessels was 0.068 ± 0.027 mm. None of the 34 FTAs showed vascular invasion. CD31 staining demonstrated more specific staining of vascular endothelial cells than CD34, with less background staining. We recommended using CD31 rather than CD34 and/or D2-40 in confirming/excluding vascular invasion in difficult cases. All identified FTCs with vascular invasions showed involvement of venous channels, rather than lymphatic spaces, suggesting that FTCs prefer to metastasize via veins to distant organs, instead of lymphatic vessels to local lymph nodes, which correlates with previous clinical observations.

  11. CALiPER Report 20.4: Lumen and Chromaticity Maintenance of LED PAR38 Lamps Operated in Steady-State Conditions

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-12-30

    This CALiPER report focuses on lumen maintenance, chromaticity maintenance, and catastrophic failure in 32 of the Series 20 LED PAR38 lamps and 8 benchmark lamps, which were monitored for nearly 14,000 hours at ambient temperatures between 44°C and 45°C.

  12. Intracoronary stent implantation: new approach using a monorail system and new large-lumen 7F catheters from the brachial route.

    Science.gov (United States)

    Jenny, D B; Robert, G P; Fajadet, J C; Cassagneau, B G; Marco, J

    1992-04-01

    In this brief report we describe a case of successful multivessel PTCA with intracoronary stent implantation using a new large-lumen 7F catheter from the left brachial approach. The application of this technique should be considered for intravascular stent implantation when anticoagulation ideally should not be interrupted or in anatomical situations limiting femoral vascular access.

  13. Comparison of coronary arterial lumen dimensions on angiography and plaque characteristics on optical coherence tomography images and their changes induced by statin

    International Nuclear Information System (INIS)

    Dong, Nana; Xie, Zulong; Wang, Wei; Dai, Jiannan; Sun, Meng; Pu, Zhongyue; Tian, Jinwei; Yu, Bo

    2016-01-01

    Coronary angiography (CAG) is widely used to assess lumen dimensions, and optical coherence tomography (OCT) is used to evaluate the characteristics of atherosclerotic plaque. This study was aimed to compare coronary lumen dimensions using CAG and plaque characteristics using OCT and their changes during statin therapy. We identified 97 lipid-rich plaques from 69 statin-naïve patients, who received statin therapy in the following 12 months. CAG and OCT examinations were conducted at baseline and 12-month follow-up period. Lesion length, as measured by CAG, was closely correlated with lipid length by OCT (baseline: r = 0.754, p < 0.001; follow-up: r = 0.639, p < 0.001). However, no significant correlations were found between the other findings on OCT and data on CAG. With 12-month statin therapy, microstructures of lipid-rich plaques were significantly improved, but CAG-derived lumen dimensions were not improved. Moreover, we found no significant relationship between changes in OCT measurements and changes in CAG data over time. Lipid length on OCT and lesion length on CAG were closely correlated. However, plaque microstructural characteristics on OCT showed no significantly statistically correlations with lumen dimensions on CAG, neither did their evolutionary changes induced by statin over time. Clinical trial registry: ClinicalTrial.gov. Registered number: NCT01023607. Registered 1 December 2009

  14. Development of PWR pressure vessel steels

    International Nuclear Information System (INIS)

    Druce, S.; Edwards, B.

    1982-01-01

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

  15. Development of PWR pressure vessel steels

    Energy Technology Data Exchange (ETDEWEB)

    Druce, S.; Edwards, B.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Bodmann, E.

    1984-01-01

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

  17. Protection of thylakoids against combined light and drought by a lumenal substance in the resurrection plant Haberlea rhodopensis

    Science.gov (United States)

    Georgieva, Katya; Sárvári, Éva; Keresztes, Áron

    2010-01-01

    Background and Aims Haberlea rhodopensis is a perennial, herbaceous, saxicolous, poikilohydric flowering plant that is able to survive desiccation to air-dried state under irradiance below 30 µmol m−2 s−1. However, desiccation at irradiance of 350 µmol m−2 s−1 induced irreversible changes in the photosynthetic apparatus, and mature leaves did not recover after rehydration. The aim here was to establish the causes and mechanisms of irreversible damage of the photosynthetic apparatus due to dehydration at high irradiance, and to elucidate the mechanisms determining recovery. Methods Changes in chloroplast structure, CO2 assimilation, chlorophyll fluorescence parameters, fluorescence imaging and the polypeptide patterns during desiccation of Haberlea under medium (100 µmol m−2 s−1; ML) irradiance were compared with those under low (30 µmol m−2 s−1; LL) irradiance. Key Results Well-watered plants (control) at 100 µmol m−2 s−1 were not damaged. Plants desiccated at LL or ML had similar rates of water loss. Dehydration at ML decreased the quantum efficiency of photosystem II photochemistry, and particularly the CO2 assimilation rate, more rapidly than at LL. Dehydration induced accumulation of stress proteins in leaves under both LL and ML. Photosynthetic activity and polypeptide composition were completely restored in LL plants after 1 week of rehydration, but changes persisted under ML conditions. Electron microscopy of structural changes in the chloroplast showed that the thylakoid lumen is filled with an electron-dense substance (dense luminal substance, DLS), while the thylakoid membranes are lightly stained. Upon dehydration and rehydration the DLS thinned and disappeared, the time course largely depending on the illumination: whereas DLS persisted during desiccation and started to disappear during late recovery under LL, it disappeared from the onset of dehydration and later was completely lost under ML. Conclusions Accumulation of DLS

  18. The lumenal loop M672-P707 of the Menkes protein (ATP7A) transfers copper to peptidylglycine monooxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Otoikhian, Adenike [Oregon Health & Sciences University; Barry, Amanda N. [Los Alamos National Laboratory; Mayfield, Mary [Oregon Health & Science University; Nilges, Mark [Illinois EPR Center; Huang, Yiping [Johns Hopkins University; Lutsenko, Svetlana [Johns Hopkins University; Blackburn, Ninian [Oregon Health & Science University

    2012-05-14

    Copper transfer to cuproproteins located in vesicular compartments of the secretory pathway depends on activity of the copper translocating ATPase (ATP7A or ATP7B) but the mechanism of transfer is largely unexplored. Copper-ATPase ATP7A is unique in having a sequence rich in histidine and methionine residues located on the lumenal side of the membrane. The corresponding fragment binds Cu(I) when expressed as a chimera with a scaffold protein, and mutations or deletions of His and/or Met residues in its sequence inhibit dephosphorylation of the ATPase, a catalytic step associated with copper release. Here we present evidence for a potential role of this lumenal region of ATP7A in copper transfer to cuproenzymes. Both Cu(II) and Cu(I) forms were investigated since the form in which copper is transferred to acceptor proteins is currently unknown. Analysis of Cu(II) using EPR demonstrated that at Cu:P ratios below 1:1, 15N-substituted protein had Cu(II) bound by 4 His residues, but this coordination changed as the Cu(II) to protein ratio increased towards 2:1. XAS confirmed this coordination via analysis of the intensity of outer-shell scattering from imidazole residues. The Cu(II) complexes could be reduced to their Cu(I) counterparts by ascorbate, but here again, as shown by EXAFS and XANES spectroscopy, the coordination was dependent on copper loading. At low copper Cu(I) was bound by a mixed ligand set of His + Met while at higher ratios His coordination predominated. The copper-loaded loop was able to transfer either Cu(II) or Cu(I) to peptidylglycine monooxygenase in the presence of chelating resin, generating catalytically active enzyme in a process that appeared to involve direct interaction between the two partners. The variation of coordination with copper loading suggests copper-dependent conformational change which in turn could act as a signal for regulating copper release by the ATPase pump.

  19. Isotachophoresis system having larger-diameter channels flowing into channels with reduced diameter and with selectable counter-flow

    Energy Technology Data Exchange (ETDEWEB)

    Mariella, Jr., Raymond P.

    2018-03-06

    An isotachophoresis system for separating a sample containing particles into discrete packets including a flow channel, the flow channel having a large diameter section and a small diameter section; a negative electrode operably connected to the flow channel; a positive electrode operably connected to the flow channel; a leading carrier fluid in the flow channel; a trailing carrier fluid in the flow channel; and a control for separating the particles in the sample into discrete packets using the leading carrier fluid, the trailing carrier fluid, the large diameter section, and the small diameter section.

  20. Pulsed dye laser treatment of rosacea using a novel 15 mm diameter treatment beam.

    Science.gov (United States)

    Bernstein, Eric F; Schomacker, Kevin; Paranjape, Amit; Jones, Christopher J

    2018-04-10

    The pulsed-dye laser has been used to treat facial redness and rosacea for decades. Recent advances in dye laser technology enable 50% higher output energies supporting 50% larger treatment areas, and beam-diameters up to 15 mm with clinically-relevant fluences. In this study, we investigate this novel pulsed-dye laser using a 15 mm diameter beam for treatment of rosacea. Twenty subjects with erythemato-telangiectatic rosacea were enrolled in the study. A total of 4 monthly treatments were administered, first treating linear vessels with a 3 × 10 mm elliptical beam, then diffuse redness with a 15-mm diameter circular beam. Blinded assessment of digital, cross-polarized photographs taken 2 months following the last treatment was performed using an 11-point clearance scale. Nineteen subjects completed the study. Blinded reviewers correctly identified baseline photos in 55 out of the total of 57 images (96.5%). The blinded reviewers scored 17 of the 19 subjects with an improvement greater than 40%, and 11 of the 19 subjects greater than 50%. The average improvement was 53.9%. Side effects were limited to mild edema, mild to moderate erythema, and mild to moderate bruising. This study demonstrates that a newly designed pulsed-dye laser having a novel 15-mm diameter treatment beam improves the appearance of rosacea with a favorable safety profile. Lasers Surg. Med. 9999:1-5, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

  1. Design of vacuum vessel for Indian Test Facility (INTF) for 100 keV neutral beams

    International Nuclear Information System (INIS)

    Joshi, Jaydeep; Yadav, Ashish; Gangadharan, Roopesh; Prasad, Rambilas; Ulahannan, Shino; Rotti, Chandramouli; Bandyopadhyay, Mainak; Chakraborty, Arun

    2015-01-01

    Highlights: • Thickness calculation and optimization for the main shell, ducts, Dishends and top lid on the main shell. • Nozzle and flange design for the port openings. • Support structure design for the main shell and ducts. • FEA validation of the INTF vessel for operational, seismic and lifting condition. - Abstract: The Indian Test Facility (INTF) vacuum vessel is designed to install a full-scale test set-up of Diagnostic Neutral Beam (DNB) [1] for the qualification of beam parameters and the behavior of beam-line components prior to installation and operation in ITER. Vacuum vessel is designed in cylindrical shape having length of ∼9 m with diameter of ∼4.5 m and has a detachable top-lid for mounting as well as removal of internal components during installation and maintenance phases. The Vessel has hemispherical dish-ends with large openings for high-voltage bushing on one side and duct on another side. Vessel is provided with openings for hydraulic, cryo, gas-feed and diagnostics. Vessel duct is composed of three segments with length ranges from 3 m to 5 m with diameter of ∼1.5 m and one vessel at the end to house the second calorimeter. The objective of this paper is to present the design and analysis of vacuum vessel, with respect to its functional and operational requirements. The design calculations are done as per ASME-BPVC SectionVIII-Div.1 and subsequently Finite Element Analysis (FEM) method has been adopted to verify the design.

  2. Design of vacuum vessel for Indian Test Facility (INTF) for 100 keV neutral beams

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Jaydeep, E-mail: Jaydeep.joshi@iter-india.org [ITER-India, Institute for Plasma Research, A29, GIDC Electronics Estate, Gandhinagar 382016, Gujarat (India); Yadav, Ashish; Gangadharan, Roopesh [ITER-India, Institute for Plasma Research, A29, GIDC Electronics Estate, Gandhinagar 382016, Gujarat (India); Prasad, Rambilas [Madan Mohan Malaviya University of Technology, Gorakhpur, Uttar Pradesh 273001 (India); Ulahannan, Shino [Airframe Aerodesigns Pvt. Ltd., HAL Airport Exit Road, Old Airport Road, Bengaluru 17 (India); Rotti, Chandramouli; Bandyopadhyay, Mainak; Chakraborty, Arun [ITER-India, Institute for Plasma Research, A29, GIDC Electronics Estate, Gandhinagar 382016, Gujarat (India)

    2015-10-15

    Highlights: • Thickness calculation and optimization for the main shell, ducts, Dishends and top lid on the main shell. • Nozzle and flange design for the port openings. • Support structure design for the main shell and ducts. • FEA validation of the INTF vessel for operational, seismic and lifting condition. - Abstract: The Indian Test Facility (INTF) vacuum vessel is designed to install a full-scale test set-up of Diagnostic Neutral Beam (DNB) [1] for the qualification of beam parameters and the behavior of beam-line components prior to installation and operation in ITER. Vacuum vessel is designed in cylindrical shape having length of ∼9 m with diameter of ∼4.5 m and has a detachable top-lid for mounting as well as removal of internal components during installation and maintenance phases. The Vessel has hemispherical dish-ends with large openings for high-voltage bushing on one side and duct on another side. Vessel is provided with openings for hydraulic, cryo, gas-feed and diagnostics. Vessel duct is composed of three segments with length ranges from 3 m to 5 m with diameter of ∼1.5 m and one vessel at the end to house the second calorimeter. The objective of this paper is to present the design and analysis of vacuum vessel, with respect to its functional and operational requirements. The design calculations are done as per ASME-BPVC SectionVIII-Div.1 and subsequently Finite Element Analysis (FEM) method has been adopted to verify the design.

  3. Fast retinal vessel detection and measurement using wavelets and edge location refinement.

    Directory of Open Access Journals (Sweden)

    Peter Bankhead

    Full Text Available The relationship between changes in retinal vessel morphology and the onset and progression of diseases such as diabetes, hypertension and retinopathy of prematurity (ROP has been the subject of several large scale clinical studies. However, the difficulty of quantifying changes in retinal vessels in a sufficiently fast, accurate and repeatable manner has restricted the application of the insights gleaned from these studies to clinical practice. This paper presents a novel algorithm for the efficient detection and measurement of retinal vessels, which is general enough that it can be applied to both low and high resolution fundus photographs and fluorescein angiograms upon the adjustment of only a few intuitive parameters. Firstly, we describe the simple vessel segmentation strategy, formulated in the language of wavelets, that is used for fast vessel detection. When validated using a publicly available database of retinal images, this segmentation achieves a true positive rate of 70.27%, false positive rate of 2.83%, and accuracy score of 0.9371. Vessel edges are then more precisely localised using image profiles computed perpendicularly across a spline fit of each detected vessel centreline, so that both local and global changes in vessel diameter can be readily quantified. Using a second image database, we show that the diameters output by our algorithm display good agreement with the manual measurements made by three independent observers. We conclude that the improved speed and generality offered by our algorithm are achieved without sacrificing accuracy. The algorithm is implemented in MATLAB along with a graphical user interface, and we have made the source code freely available.

  4. Influence of high intensity ultrasound with different probe diameter ...

    African Journals Online (AJOL)

    The main goal of this research is to analyze the influence of ultrasonic probe diameters (7 and 10 mm) of high-intensity ultrasound with constant frequency (30 kHz) on the degree of homogenization (variance) of cow milk. Influence of different probe diameters on the physical properties of cow milk was also tested. Changes ...

  5. Lumbar Vertebral Canal Diameters in Adult Ugandan Skeletons ...

    African Journals Online (AJOL)

    Background: Normal values of lumbar vertebral canal diameters are useful in facilitating diagnosis of lumbar vertebral canal stenosis. Various studies have established variation on values between different populations, gender, age, and ethnic groups. Objectives: To determine the lumbar vertebral canal diameters in adult ...

  6. Relationships between diameter and height of trees in natural ...

    African Journals Online (AJOL)

    Relationships between diameter and height of trees in natural tropical forest in Tanzania. Wilson A Mugasha, Ole M Bollandsås, Tron Eid. Abstract. The relationship between tree height (h) and tree diameter at breast height (dbh) is an important element describing forest stands. In addition, h often is a required variable in ...

  7. Heritability of optic disc diameters: a twin study

    DEFF Research Database (Denmark)

    Drobnjak, Dragana; Taarnhøj, Nina Charlotte; Mitchell, Paul

    2011-01-01

    , additive genetic factors (i.e. heritability) explained 77% (95% CI: 65-85%) of variation of vertical disc diameters, whereas estimated unshared environmental effect was 23% (95% CI: 15-35%). For vertical cup diameters, heritability accounted for 70% (95% CI: 55-80%) and environmental factors 30% (95% CI...

  8. Diameter of the thoracic and abdominal aorta in healthy Japanese

    International Nuclear Information System (INIS)

    Matsunaga, Wakako

    1989-01-01

    In 300 cases, diameter of thoracic and abdominal aorta in healthy Japanese is measured by computed tomography (CT) and the values are analyzed in relation to the age, sex and the level of the aorta on CT scan. Aorta becomes dilated with age. In female diameter of the aorta is correlated with age, on the other hand, diameter of those is not correlated with age in male. Diameter in male is larger than in female. Aorta tapers off and the ratio of tapering of the thoracic aorta is more prominent than that of the abdominal aorta. Therefore the calculations of the landmarks of tapering of the aorta and the ratio of diameter of the aorta to transverse diameter of the vertebral body at the levels of 10th thoracic and 3rd lumber vertebrae on CT scan are useful for judgement of normal range of diameter of the aorta. Calcifications of the wall of the aorta are seen initially at the age of 5th decade in the abdominal aorta and 6th decade in the thoracic aorta in healthy Japanese. They are noted in almost of the persons after the age of seventy years old. The presence of calcification is not correlated with diameter of the aorta at the same level on CT scan. (author)

  9. Generalized height-diameter models for Populus tremula L. stands

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... and stand density) into the base height-diameter models increased the accuracy of prediction for P. tremula. .... parameter estimates compared with those obtained with ... using coefficient of determination for non-linear regression (. 2. R ), ..... stochastic height-diameter model for maritime pine ecoregions in.

  10. Sex Dimorphism of the Heart Diameters and Cardiothoracic Ratios ...

    African Journals Online (AJOL)

    Objective: To determine gender associated differences in the cardiothoracic ratio (CTR) and heart diameters in a normal Nigerian population. Subject and Method: The normal heart diameters and cardiothoracic ratios were measured from posteroanterior (PA) chest radiographs of healthy 510 male and 508 female ...

  11. Lysosome Transport as a Function of Lysosome Diameter

    Science.gov (United States)

    Bandyopadhyay, Debjyoti; Cyphersmith, Austin; Zapata, Jairo A.; Kim, Y. Joseph; Payne, Christine K.

    2014-01-01

    Lysosomes are membrane-bound organelles responsible for the transport and degradation of intracellular and extracellular cargo. The intracellular motion of lysosomes is both diffusive and active, mediated by motor proteins moving lysosomes along microtubules. We sought to determine how lysosome diameter influences lysosome transport. We used osmotic swelling to double the diameter of lysosomes, creating a population of enlarged lysosomes. This allowed us to directly examine the intracellular transport of the same organelle as a function of diameter. Lysosome transport was measured using live cell fluorescence microscopy and single particle tracking. We find, as expected, the diffusive component of intracellular transport is decreased proportional to the increased lysosome diameter. Active transport of the enlarged lysosomes is not affected by the increased lysosome diameter. PMID:24497985

  12. Inner and outer coronary vessel wall segmentation from CCTA using an active contour model with machine learning-based 3D voxel context-aware image force

    Science.gov (United States)

    Sivalingam, Udhayaraj; Wels, Michael; Rempfler, Markus; Grosskopf, Stefan; Suehling, Michael; Menze, Bjoern H.

    2016-03-01

    In this paper, we present a fully automated approach to coronary vessel segmentation, which involves calcification or soft plaque delineation in addition to accurate lumen delineation, from 3D Cardiac Computed Tomography Angiography data. Adequately virtualizing the coronary lumen plays a crucial role for simulating blood ow by means of fluid dynamics while additionally identifying the outer vessel wall in the case of arteriosclerosis is a prerequisite for further plaque compartment analysis. Our method is a hybrid approach complementing Active Contour Model-based segmentation with an external image force that relies on a Random Forest Regression model generated off-line. The regression model provides a strong estimate of the distance to the true vessel surface for every surface candidate point taking into account 3D wavelet-encoded contextual image features, which are aligned with the current surface hypothesis. The associated external image force is integrated in the objective function of the active contour model, such that the overall segmentation approach benefits from the advantages associated with snakes and from the ones associated with machine learning-based regression alike. This yields an integrated approach achieving competitive results on a publicly available benchmark data collection (Rotterdam segmentation challenge).

  13. AFSC/FMA/Vessel Assessment Logging

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vessels fishing trawl gear, vessels fishing hook-and-line and pot gear that are also greater than 57.5 feet overall, and shoreside and floating processing facilities...

  14. 2013 EPA Vessels General Permit (VGP)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information for any vessel that submitted a Notice of Intent (NOI), Notice of Termination (NOT), or annual report under EPA's 2013 Vessel General Permit (VGP)....

  15. A chloroplast thylakoid lumen protein is required for proper photosynthetic acclimation of plants under fluctuating light environments.

    Science.gov (United States)

    Liu, Jun; Last, Robert L

    2017-09-19

    Despite our increasingly sophisticated understanding of mechanisms ensuring efficient photosynthesis under laboratory-controlled light conditions, less is known about the regulation of photosynthesis under fluctuating light. This is important because-in nature-photosynthetic organisms experience rapid and extreme changes in sunlight, potentially causing deleterious effects on photosynthetic efficiency and productivity. Here we report that the chloroplast thylakoid lumenal protein MAINTENANCE OF PHOTOSYSTEM II UNDER HIGH LIGHT 2 (MPH2; encoded by At4g02530 ) is required for growth acclimation of Arabidopsis thaliana plants under controlled photoinhibitory light and fluctuating light environments. Evidence is presented that mph2 mutant light stress susceptibility results from a defect in photosystem II (PSII) repair, and our results are consistent with the hypothesis that MPH2 is involved in disassembling monomeric complexes during regeneration of dimeric functional PSII supercomplexes. Moreover, mph2 -and previously characterized PSII repair-defective mutants-exhibited reduced growth under fluctuating light conditions, while PSII photoprotection-impaired mutants did not. These findings suggest that repair is not only required for PSII maintenance under static high-irradiance light conditions but is also a regulatory mechanism facilitating photosynthetic adaptation under fluctuating light environments. This work has implications for improvement of agricultural plant productivity through engineering PSII repair.

  16. Delivery of Mesenchymal Stem Cells from Gelatin–Alginate Hydrogels to Stomach Lumen for Treatment of Gastroparesis

    Directory of Open Access Journals (Sweden)

    Binata Joddar

    2018-02-01

    Full Text Available Gastroparesis (GP is associated with depletion of interstitial cells of Cajal (ICCs and enteric neurons, which leads to pyloric dysfunction followed by severe nausea, vomiting and delayed gastric emptying. Regenerating these fundamental structures with mesenchymal stem cell (MSC therapy would be helpful to restore gastric function in GP. MSCs have been successfully used in animal models of other gastrointestinal (GI diseases, including colitis. However, no study has been performed with these cells on GP animals. In this study, we explored whether mouse MSCs can be delivered from a hydrogel scaffold to the luminal surfaces of mice stomach explants. Mouse MSCs were seeded atop alginate–gelatin, coated with poly-l-lysine. These cell–gel constructs were placed atop stomach explants facing the luminal side. MSCs grew uniformly all across the gel surface within 48 h. When placed atop the lumen of the stomach, MSCs migrated from the gels to the tissues, as confirmed by positive staining with vimentin and N-cadherin. Thus, the feasibility of transplanting a cell–gel construct to deliver stem cells in the stomach wall was successfully shown in a mice stomach explant model, thereby making a significant advance towards envisioning the transplantation of an entire tissue-engineered ‘gastric patch’ or ‘microgels’ with cells and growth factors.

  17. Blood in the gastric lumen increases splanchnic blood flow and portal pressure in portal-hypertensive rats.

    Science.gov (United States)

    Chen, L; Groszmann, R J

    1996-10-01

    In portal-hypertensive humans, portal blood flow and pressure increase after a meal. These hemodynamic changes may increase variceal rupture risk. The aim of this study was to determine whether blood in the stomach lumen increases splanchnic flow and portal pressure (PP) in portal-hypertensive rats. superior mesenteric artery flow and PP were measured in conscious, unrestrained, fasted partial portal vein-ligated rats with chronically implanted Doppler flow probes or portal vein catheters before and after gavage with heparinized, warmed blood from donor rats, air, standard meal, or empty tube. Percentage of changes in flow and pressure from baseline were significantly greater after gavage with blood (an increase of 22.6% +/- 3.5% and an increase of 16.4% +/- 3.1%, respectively) than empty tube (an increase of 3.4% +/- 0.6% and a decrease of 5.4% +/- 3.5%, respectively) (P empty tube (P calories probably contributes to these hemodynamic changes. In patients with variceal hemorrhage, blood in the stomach may increase the risk of persistent variceal bleeding or rebleeding.

  18. Histomorphometric comparative study of blood vessels and their pattern in follicular cyst, odontogenic keratocyst, and ameloblastoma.

    Science.gov (United States)

    Seifi, Safora; Feizi, Farideh; Khafri, Thoraya; Aram, Mehrdad

    2013-03-01

    The present study aimed at assessment and histomorphometric analysis of intratumoral and peritumoral (cystic) blood vessels in odontogenic lesions and their pattern on their clinical behavior by immunohistochemistry and morphometry. In a descriptive and analytical cross-sectional study, 45 paraffin blocks of ameloblastoma, odontogenic keratocyst, and follicular cyst were selected and stained immunohistochemically for CD34. In each slide, images of 3 microscopic fields with the highest microvessel density in intratumoral and peritumoral (cystic) areas were captured at 40× magnification with attached camera system. Inner vascular diameter (IVD) and outer vascular diameter (OVD), cross-sectional area (CSA), and the wall thickness (WT) of the vessels were measured with Motic Plus 2 software. The vascular pattern in odontogenic lesions was analyzed. Outer vascular diameter, IVD, and CSA of the vessels in peritumoral (cystic) areas were greater in ameloblastoma than keratocyst (P = 0.001) and follicular cyst (P keratocyst and follicular cyst. Morphometric specifications of blood vessels (IVD, OVD, CSA) and their pattern in peritumoral (cystic) areas may influence the aggressive clinical behavior of ameloblastoma in comparison with keratocyst and follicular cyst.

  19. Interstitial Cells of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Vladimír Pucovský

    2010-01-01

    Full Text Available Blood vessels are made up of several distinct cell types. Although it was originally thought that the tunica media of blood vessels was composed of a homogeneous population of fully differentiated smooth muscle cells, more recent data suggest the existence of multiple smooth muscle cell subpopulations in the vascular wall. One of the cell types contributing to this heterogeneity is the novel, irregularly shaped, noncontractile cell with thin processes, termed interstitial cell, found in the tunica media of both veins and arteries. While the principal role of interstitial cells in veins seems to be pacemaking, the role of arterial interstitial cells is less clear. This review summarises the knowledge of the functional and structural properties of vascular interstitial cells accumulated so far, offers hypotheses on their physiological role, and proposes directions for future research.

  20. The Vessel Schedule Recovery Problem

    DEFF Research Database (Denmark)

    Brouer, Berit Dangaard; Plum, Christian Edinger Munk; Vaaben, Bo

    Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker cons...... consumption and the impact on the remaining network and the customer service level. The model is applied to 4 real cases from Maersk Line. Solutions are comparable or superior to those chosen by operations managers. Cost savings of up to 58% may be achieved.......Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker...