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Sample records for abdominal wall thickness

  1. Semiautomatic vessel wall detection and quantification of wall thickness in computed tomography images of human abdominal aortic aneurysms

    SciTech Connect

    Shum, Judy; DiMartino, Elena S.; Goldhammer, Adam; Goldman, Daniel H.; Acker, Leah C.; Patel, Gopal; Ng, Julie H.; Martufi, Giampaolo; Finol, Ender A.

    2010-02-15

    Purpose: Quantitative measurements of wall thickness in human abdominal aortic aneurysms (AAAs) may lead to more accurate methods for the evaluation of their biomechanical environment. Methods: The authors describe an algorithm for estimating wall thickness in AAAs based on intensity histograms and neural networks involving segmentation of contrast enhanced abdominal computed tomography images. The algorithm was applied to ten ruptured and ten unruptured AAA image data sets. Two vascular surgeons manually segmented the lumen, inner wall, and outer wall of each data set and a reference standard was defined as the average of their segmentations. Reproducibility was determined by comparing the reference standard to lumen contours generated automatically by the algorithm and a commercially available software package. Repeatability was assessed by comparing the lumen, outer wall, and inner wall contours, as well as wall thickness, made by the two surgeons using the algorithm. Results: There was high correspondence between automatic and manual measurements for the lumen area (r=0.978 and r=0.996 for ruptured and unruptured aneurysms, respectively) and between vascular surgeons (r=0.987 and r=0.992 for ruptured and unruptured aneurysms, respectively). The authors' automatic algorithm showed better results when compared to the reference with an average lumen error of 3.69%, which is less than half the error between the commercially available application Simpleware and the reference (7.53%). Wall thickness measurements also showed good agreement between vascular surgeons with average coefficients of variation of 10.59% (ruptured aneurysms) and 13.02% (unruptured aneurysms). Ruptured aneurysms exhibit significantly thicker walls (1.78{+-}0.39 mm) than unruptured ones (1.48{+-}0.22 mm), p=0.044. Conclusions: While further refinement is needed to fully automate the outer wall segmentation algorithm, these preliminary results demonstrate the method's adequate reproducibility and low interobserver variability.

  2. Abdominal wall endometriosis.

    PubMed

    Upadhyaya, P; Karak, A K; Sinha, A K; Kumar, B; Karki, S; Agarwal, C S

    2010-01-01

    Endometriosis of abdominal wall scar following operation on uterus and tubes is extremely rare. The late onset of symptoms after surgery is the usual cause of misdiagnosis. Scar endometriosis is a rare disease which is difficult to diagnose and should always be considered as a differential diagnosis of painful abdominal masses in women. The diagnosis is made only after excision and histopathology of the lesion. Preoperative differentials include hernia, lipoma, suture granuloma or abscess. Hence an awareness of the entity avoids delay in diagnosis, helps clinicians to a more tailored treatment and also avoids unnecessary referrals. We report a case of abdominal endometriosis. The definitive diagnosis of which was established by histopathological studies. PMID:21485605

  3. Behaviour of a New Composite Mesh for the Repair of Full-Thickness Abdominal Wall Defects in a Rabbit Model

    PubMed Central

    Pascual, Gemma; Sotomayor, Sandra; Rodríguez, Marta; Bayon, Yves; Bellón, Juan M.

    2013-01-01

    Introduction Composite biomaterials designed for the repair of abdominal wall defects are composed of a mesh component and a laminar barrier in contact with the visceral peritoneum. This study assesses the behaviour of a new composite mesh by comparing it with two latest-generation composites currently used in clinical practice. Methods Defects (7x5cm) created in the anterior abdominal wall of New Zealand White rabbits were repaired using a polypropylene mesh and the composites: PhysiomeshTM; VentralightTM and a new composite mesh with a three-dimensional macroporous polyester structure and an oxidized collagen/chitosan barrier. Animals were sacrificed on days 14 and 90 postimplant. Specimens were processed to determine host tissue incorporation, gene/protein expression of neo-collagens (RT-PCR/immunofluorescence), macrophage response (RAM-11-immunolabelling) and biomechanical resistance. On postoperative days 7/14, each animal was examined laparoscopically to quantify adhesions between the visceral peritoneum and implant. Results The new composite mesh showed the lowest incidence of seroma in the short term. At each time point, the mesh surface covered with adhesions was greater in controls than composites. By day 14, the implants were fully infiltrated by a loose connective tissue that became denser over time. At 90 days, the peritoneal mesh surface was lined with a stable mesothelium. The new composite mesh induced more rapid tissue maturation than PhysiomeshTM, giving rise to a neoformed tissue containing more type I collagen. In VentralightTM the macrophage reaction was intense and significantly greater than the other composites at both follow-up times. Tensile strengths were similar for each biomaterial. Conclusions All composites showed optimal peritoneal behaviour, inducing good peritoneal regeneration and scarce postoperative adhesion formation. A greater foreign body reaction was observed for VentralightTM. All composites induced good collagen deposition accompanied by optimal tensile strength. The three-dimensional macroporous structure of the new composite mesh may promote rapid tissue regeneration within the mesh. PMID:24236192

  4. Abdominal wall endometriosis: case report.

    PubMed

    Eljuga, Damir; Klari?, Petar; Bolanca, Ivan; Grbavac, Ivan; Kuna, Krunoslav

    2012-06-01

    Abdominal wall endometriosis, also known as scar endometrioma, is a rare condition, in most cases occurring after previous cesarean section or pelvic surgery. The incidence of scar endometrioma is estimated to 0.03%-1.5% of all women with previous cesarean delivery. The predominant clinical picture is cyclic pain. Due to a wide range of mimicking conditions and a relative rarity, a significant delay is often observed from the onset of symptoms to proper treatment. We report on a case of a 36-year-old patient with scar endometrioma after two previous cesarean deliveries. The possible diagnostic pitfalls and treatment options are discussed. PMID:23115952

  5. Genetics Home Reference: Abdominal wall defect

    MedlinePLUS

    ... size and can usually be diagnosed early in fetal development, typically between the tenth and fourteenth weeks of ... organs at the abdominal wall opening late in fetal development may also contribute to organ injury. Intestinal damage ...

  6. Management of Postoperative Abdominal Wall Pain.

    PubMed

    Sharp, Howard T

    2015-12-01

    Postoperative incisional pain is expected after surgery. However, when a patient is complaining of pain months after surgery, this can be a source of frustration and confusion to the patient and the surgeon. Whether the pain is a result of myofascial pain, incisional hernia, or nerve injury, understanding potential sources of abdominal wall pain can simplify this diagnostic dilemma. This chapter will focus on the diagnosis, treatment, and prevention of postsurgical abdominal wall pain. PMID:26512441

  7. Abdominal wall reconstruction using biological tissue grafts.

    PubMed

    Brown, Patricia

    2009-10-01

    Synthetic mesh products have been used to repair abdominal wall defects (eg, hernias) for many years. Biological mesh products are now available as an option when synthetic mesh products are not appropriate. To correctly prepare biological tissue grafts for use in the OR, perioperative nurses must understand the types of grafts available. Biological tissue grafts may be harvested from human, porcine, bovine, or equine hosts and from skin, pericardium, or small intestine submucosa. PMID:19860033

  8. Turbine airfoil with outer wall thickness indicators

    DOEpatents

    Marra, John J; James, Allister W; Merrill, Gary B

    2013-08-06

    A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

  9. Tensor fascia lata musculocutaneous flap for abdominal wall reconstruction

    SciTech Connect

    Peled, I.J.; Kaplan, H.Y.; Herson, M.; Wexler, M.R.

    1983-08-01

    We report a case of abdominal wall reconstruction following excision of irradiated skin and a ventral hernia. A very large tensor fascia lata musculocutaneous flap was used with good results. The anatomical features of this flap make it an excellent method of abdominal wall reconstruction.

  10. Simulation of ultrasonic pulse propagation through the abdominal wall

    E-print Network

    Mast, T. Douglas

    Simulation of ultrasonic pulse propagation through the abdominal wall T. Douglas Mast,a) Laura M 1997 Ultrasonic pulse propagation through the human abdominal wall has been simulated using a model characteristics of ultrasonic wavefront distortion in vivo. However, quantitative agreement was limited by the two

  11. Abdominal wall necrotising fasciitis secondary to fish bone ingestion.

    PubMed

    Lo, Samuel T W; Leung, Siu Lan; Tang, Chung Ngai

    2015-01-01

    Abdominal wall necrotising fasciitis secondary to fish bone ingestion is extremely rare. We present a case of ingested fish bone complicated with self-sealing small bowel perforation and abdominal wall necrotising fasciitis. Following principles of necrotising fasciitis, a high index of suspicion led to early diagnosis and early treatment. The patient enjoyed a good recovery. PMID:26163558

  12. Suture granuloma of the abdominal wall with intra-abdominal extension 12 years after open appendectomy

    PubMed Central

    Augustin, Goran; Korolija, Dragan; Skegro, Mate; Jakic-Razumovic, Jasminka

    2009-01-01

    Most complications after appendectomy occur within ten days; however, we report the unusual case of a suture granuloma 12 years after open appendectomy. The afebrile 75-year-old woman presented with a slightly painful palpable mass in the right lower abdomen. There was no nausea or vomiting and bowel movements were normal. She lost 10 kg during the 3 mo before presentation. The patient had undergone an appendectomy 12 years previously. Physical examination revealed a tender mass, 10 cm in diameter, under the appendectomy scar. The preoperative laboratory findings, tumor markers and plain abdominal radiographs were normal. Multi-slice computed tomography scanning showed an inhomogenous abdominal mass with minimal vascularization in the right lower abdomen 8.6 cm × 8 cm × 9 cm in size which communicated with the abdominal wall. The abdominal wall was thickened, weak and bulging. The abdominal wall mass did not communicate with the cecum or the ascending colon. Complete excision of the abdominal wall mass was performed via median laparotomy. Histopathological examination revealed a granuloma with a central abscess. This case report demonstrates that a preoperative diagnosis of abdominal wall mass after open appendectomy warrants the use of a wide spectrum of diagnostic modalities and consequently different treatment options. PMID:19705509

  13. Living donor liver transplantation with abdominal wall reconstruction for hepatocellular carcinoma with needle track seeding.

    PubMed

    Yang, Horng-Ren; Thorat, Ashok; Gesakis, Kanellos; Li, Ping-Chun; Kiranantawat, Kidakorn; Chen, Hung Chi; Jeng, Long-Bin

    2015-12-24

    Malignant cell seeding in subcutaneous tissues along the needle track and/or percutaneous biliary drainage catheters is rare complication, but pose various technical issues in planning surgical treatment of such patients. If underlying primary hepatic malignancy can be treated, an aggressive resection of subcutaneous tissue bearing cancer cell with subsequent abdominal wall reconstruction has been sporadically reported. But, when hepatic resection is not possible due to underlying advanced cirrhosis, liver transplantation along with abdominal wall resection and subsequent reconstruction remains only feasible option. Herein, we describe our successful experience of living donor liver transplantation for hepatocellular carcinoma with full-thickness abdominal wall resection bearing the tumor seeding followed by reconstruction in single stage surgery. PMID:26722665

  14. Living donor liver transplantation with abdominal wall reconstruction for hepatocellular carcinoma with needle track seeding

    PubMed Central

    Yang, Horng-Ren; Thorat, Ashok; Gesakis, Kanellos; Li, Ping-Chun; Kiranantawat, Kidakorn; Chen, Hung Chi; Jeng, Long-Bin

    2015-01-01

    Malignant cell seeding in subcutaneous tissues along the needle track and/or percutaneous biliary drainage catheters is rare complication, but pose various technical issues in planning surgical treatment of such patients. If underlying primary hepatic malignancy can be treated, an aggressive resection of subcutaneous tissue bearing cancer cell with subsequent abdominal wall reconstruction has been sporadically reported. But, when hepatic resection is not possible due to underlying advanced cirrhosis, liver transplantation along with abdominal wall resection and subsequent reconstruction remains only feasible option. Herein, we describe our successful experience of living donor liver transplantation for hepatocellular carcinoma with full-thickness abdominal wall resection bearing the tumor seeding followed by reconstruction in single stage surgery. PMID:26722665

  15. Delayed dynamic abdominal wall closure following multi-visceral transplantation

    PubMed Central

    Iype, Satheesh; Butler, Andrew; Jamieson, Neville; Middleton, Stephen; Jah, Asif

    2014-01-01

    INTRODUCTION Primary closure of the abdominal wall following intestinal transplantation or multivisceral transplantation could become a challenging problem in a significant number of patients. PRESENTATION OF CASE A 38-year-old woman with familial adenomatous polyposis (FAP) underwent a multi-visceral transplantation for short gut syndrome. She subsequently developed acute graft rejection that proved resistant to conventional treatment. She was relisted and underwent re-transplantation along with kidney transplantation. Abdominal wall closure could not be achieved because of the large size of the graft and bowel oedema. The wound was initially managed with laparostomy followed by insertion of the delayed dynamic abdominal closure (DDAC) device (Abdominal Retraction Anchor – ABRA® system). Continuous dynamic traction to the wound edges resulted in gradual approximation and complete closure of the abdominal wound was achieved within 3 weeks. DISCUSSION Successful abdominal closure after multivisceral transplantation or isolated intestinal transplantation often requires biological mesh, vascularised flaps or abdominal wall transplantation. DDAC eliminated the need for a prosthetic mesh or skin graft and provided an excellent cosmetic result. Adjustment of the dynamic traction at the bedside minimised the need for multiple returns to the operating theatre. It resulted in a well-healed linear scar without a hernia. CONCLUSION Dynamic traction allows delayed closure of laparotomy resulting in strong and cosmetically sound wound healing with native tissue. PMID:25460454

  16. Delayed repair for traumatic abdominal wall hernia: is it safe?

    PubMed

    Sall, I; El Kaoui, H; Bouchentouf, S M; Ait Ali, A; Bounaim, A; Hajjouji, A; Baba, H; Fahssi, M; Alhyane, A; Zentar, A; Sair, K

    2009-08-01

    Abdominal wall hernias after trauma have been recognized for more than a century, with the first case reported as occurring after a fall. Traumatic abdominal wall hernias (TAWHs) after blunt trauma are uncommon. The timing of definitive repair, early or delayed, is not clear. We report a case on TAWH and mesenteric avulsion, highlighting the reasons for immediate or delayed repair. A single case study can hardly be considered as a basis for profound changes in the management of post traumatic hernias. However, damage to all layers of the abdominal wall indicates high-energy trauma. In such cases, the damage is not, in all probability, limited to the integumentary system. For the moment, the timing of surgery in any TAWH should be considered differently according to the trauma, the wall defect, clinical and radiological findings, associated injuries, and the clinical status of the patient. PMID:19153644

  17. Prediction of Regulatory Networks in Mouse Abdominal Wall

    PubMed Central

    Eng, Diana; Campbell, Adam; Hilton, Traci; Leid, Mark; Gross, Michael K.; Kioussi, Chrissa

    2010-01-01

    Sequence specific transcription factors are essential for pattern formation and cell differentiation processes in mammals. The formation of the abdominal wall depends on a flawless merge of several developmental fields in time and space. Absence of Pitx2 leads to open abdominal wall in mice, while mutations in humans result in umbilical defects, suggesting that a single homeobox transcription factor coordinates the formation and patterning of this anatomical structure. Gene expression analysis from abdominal tissue including the abdominal wall after removal of the major organs, of wild type, Pitx2 heterozygote and mutant mice, at embryonic day 10.5, identified 275 genes with altered expression levels. Pitx2 target genes were clustered using the “David Bioinformatics Functional Annotation Tool” web application, which bins genes according to gene ontology (GO) key word enrichment. This provided a way to both narrow the target gene list and to start identifying potential gene families regulated by Pitx2. Target genes in the most enriched bins were further analyzed for the presence and the evolutionary conservation of Pitx2 consensus binding sequence, TAATCY, on the ?20kb, intronic and coding gene sequences. Twenty Pitx2 target genes that passed all the above criteria were classified as genes involved in cell transport and growth. Data from these studies suggest that Pitx2 acts as an inhibitor of protein transport and cell apoptosis contributing to the open body wall phenotype. This work provides the framework to which the developmental network leading to abdominal wall syndromes can be built. PMID:20797427

  18. Abdominal wall closure after a stomal reversal procedure.

    PubMed

    López-Cano, Manuel; Pereira, José Antonio; Villanueva, Borja; Vallribera, Francesc; Espin, Eloy; Armengol Carrasco, Manuel; Arbós Vía, María Antonia; Feliu, Xavier; Morales-Conde, Salvador

    2014-01-01

    The closure of a temporary stoma involves 2 different surgical procedures: the stoma reversal procedure and the abdominal wall reconstruction of the stoma site. The management of the abdominal wall has different areas that should be analyzed such us how to avoid surgical site infection (SSI), the technique to be used in case of a concomitant hernia at the stoma site or to prevent an incisional hernia in the future, how to deal with the incision when the stoma reversal procedure is performed by laparoscopy and how to close the skin at the stoma site. The aim of this paper is to analyze these aspects in relation to abdominal wall reconstruction during a stoma reversal procedure. PMID:24581880

  19. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, L.J.; Bergren, D.A.

    1987-10-06

    An apparatus for measuring the wall thickness of a nonmagnetic article having a housing supporting a magnet and a contiguous supporting surface. The tubular article and the housing are releasably secured to the supporting surface and a support member of an optical comparator, respectively. To determine the wall thickness of the article at a selected point, a magnetically responsive ball is positioned within the tubular article over said point and retained therein by means of a magnetic field produced by the magnet. Thereafter, an optical comparator is employed to project a magnified image of the ball on a screen and the wall thickness at the selected point is calculated by using a ball surface measurement taken with the comparator in conjunction with a previously determined base line measurement.

  20. Simulation of ultrasonic pulse propagation through the abdominal wall.

    PubMed

    Mast, T D; Hinkelman, L M; Orr, M J; Sparrow, V W; Waag, R C

    1997-08-01

    Ultrasonic pulse propagation through the abdominal wall has been simulated using a model for two-dimensional propagation through anatomically realistic tissue cross sections. The time-domain equations for wave propagation in a medium of variable sound speed and density were discretized to obtain a set of coupled finite-difference equations. These difference equations were solved numerically using a two-step MacCormack scheme that is fourth-order accurate in space and second-order accurate in time. The inhomogeneous tissue of the abdominal wall was represented by two-dimensional matrices of sound speed and density values. These values were determined by processing scanned images of abdominal wall cross sections stained to identify connective tissue, muscle, and fat, each of which was assumed to have a constant sound speed and density. The computational configuration was chosen to simulate that of wavefront distortion measurements performed on the same specimens. Qualitative agreement was found between those measurements and the results of the present computations, indicating that the computational model correctly depicts the salient characteristics of ultrasonic wavefront distortion in vivo. However, quantitative agreement was limited by the two-dimensionality of the computation and the absence of detailed tissue microstructure. Calculations performed using an asymptotic straight-ray approximation showed good agreement with time-shift aberrations predicted by the full-wave method, but did not explain the amplitude fluctuations and waveform distortion found in the experiments and the full-wave calculations. Visualization of computed wave propagation within tissue cross sections suggests that amplitude fluctuations and waveform distortion observed in ultrasonic propagation through the abdominal wall are associated with scattering from internal inhomogeneities such as septa within the subcutaneous fat. These observations, as well as statistical analysis of computed and observed amplitude fluctuations, suggest that weak fluctuation models do not fully describe ultrasonic wavefront distortion caused by the abdominal wall. PMID:9265762

  1. Reproducibility of airway wall thickness measurements

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael; Kuhnigk, Jan-Martin; Krass, Stefan; Owsijewitsch, Michael; de Hoop, Bartjan; Peitgen, Heinz-Otto

    2010-03-01

    Airway remodeling and accompanying changes in wall thickness are known to be a major symptom of chronic obstructive pulmonary disease (COPD), associated with reduced lung function in diseased individuals. Further investigation of this disease as well as monitoring of disease progression and treatment effect demand for accurate and reproducible assessment of airway wall thickness in CT datasets. With wall thicknesses in the sub-millimeter range, this task remains challenging even with today's high resolution CT datasets. To provide accurate measurements, taking partial volume effects into account is mandatory. The Full-Width-at-Half-Maximum (FWHM) method has been shown to be inappropriate for small airways1,2 and several improved algorithms for objective quantification of airway wall thickness have been proposed.1-8 In this paper, we describe an algorithm based on a closed form solution proposed by Weinheimer et al.7 We locally estimate the lung density parameter required for the closed form solution to account for possible variations of parenchyma density between different lung regions, inspiration states and contrast agent concentrations. The general accuracy of the algorithm is evaluated using basic tubular software and hardware phantoms. Furthermore, we present results on the reproducibility of the algorithm with respect to clinical CT scans, varying reconstruction kernels, and repeated acquisitions, which is crucial for longitudinal observations.

  2. [Clostridial myonecrosis of the abdominal wall - case report].

    PubMed

    Látrová, S; Cáp, R; Subrt, Z

    2014-06-01

    The authors present a case report of a forty-five-year-old patient operated on for acute appendicitis who developed gas gangrene of the abdominal wall within 48 hours after an appendectomy and subsequently also clostridial sepsis. Due to early diagnosis and intensive care, the patient survived. Clostridial myonecrosis is a rare complication after abdominal surgery and may be fatal in many cases. In our literature, there are only a few publications describing cases of patients who survived this rare postoperative complication. PMID:25047974

  3. On thick domain walls in general relativity

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    Planar scalar field configurations in general relativity differ considerably from those in flat space. It is shown that static domain walls of finite thickness in curved space-time do not possess a reflection symmetry. At infinity, the space-time tends to the Taub vacuum on one side of the wall and to the Minkowski vacuum (Rindler space-time) on the other. Massive test particles are always accelerated towards the Minkowski side, i.e., domain walls are attractive on the Taub side, but repulsive on the Minkowski side (Taub-vacuum cleaner). It is also proved that the pressure in all directions is always negative. Finally, a brief comment is made concerning the possibility of infinite, i.e., bigger than horizon size, domain walls in our universe. All of the results are independent of the form of the potential V(phi) greater than or equal to 0 of the scalar field phi.

  4. Gas turbine bucket wall thickness control

    DOEpatents

    Stathopoulos, Dimitrios (Glenmont, NY); Xu, Liming (Greenville, SC); Lewis, Doyle C. (Greer, SC)

    2002-01-01

    A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

  5. Automated Delineation of Vessel Wall and Thrombus Boundaries of Abdominal Aortic Aneurysms Using Multispectral MR Images

    PubMed Central

    Rodriguez-Vila, B.; Tarjuelo-Gutierrez, J.; Sánchez-González, P.; Verbrugghe, P.; Fourneau, I.; Maleux, G.; Herijgers, P.; Gomez, E. J.

    2015-01-01

    A correct patient-specific identification of the abdominal aortic aneurysm is useful for both diagnosis and treatment stages, as it locates the disease and represents its geometry. The actual thickness and shape of the arterial wall and the intraluminal thrombus are of great importance when predicting the rupture of the abdominal aortic aneurysms. The authors describe a novel method for delineating both the internal and external contours of the aortic wall, which allows distinguishing between vessel wall and intraluminal thrombus. The method is based on active shape model and texture statistical information. The method was validated with eight MR patient studies. There was high correspondence between automatic and manual measurements for the vessel wall area. Resulting segmented images presented a mean Dice coefficient with respect to manual segmentations of 0.88 and a mean modified Hausdorff distance of 1.14?mm for the internal face and 0.86 and 1.33?mm for the external face of the arterial wall. Preliminary results of the segmentation show high correspondence between automatic and manual measurements for the vessel wall and thrombus areas. However, since the dataset is small the conclusions cannot be generalized. PMID:26236390

  6. Distribution of Wall Stress in Abdominal Aortic Aneurysm (AAA)

    NASA Astrophysics Data System (ADS)

    Lasheras, Juan

    2005-11-01

    Abdominal aortic aneurysm (AAA) rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue. Therefore, knowledge of the AAA wall stress distribution could be useful in assessing its risk of rupture. In our research, a finite element analysis was used to determine the wall stresses both in idealized models and in a real clinical model in which the aorta was considered isotropic with nonlinear material properties and was loaded with a given pressure. In the idealized models, both maximum diameter and asymmetry were found to have substantial influence on the distribution of the wall stress. The thrombus inside the AAA was also found to help protecting the walls from high stresses. Using CT scans of the AAA, the actual geometry of the aneurysm was reconstructed and we found that wall tension increases on the flatter surface (typically corresponds to the posterior surface) and at the inflection points of the bulge. In addition to the static analysis, we also performed simulations of the effect of unsteady pressure wave propagation inside the aneurysm.

  7. Acute acalculous cholecystitis after abdominal wall repair (Rives-Stoppa).

    PubMed

    Reurings, Jurrian C; Diaz, Ruben P D; Penninga, Luit; Nellensteijn, David R

    2014-01-01

    Acute acalculous cholecystitis (AAC) is a rare condition normally occurring in critically ill patients. Compared to acute calculous cholecystitis, AAC is associated with complications and has a worse outcome. Hence, knowledge of this condition is very important. We describe a case of a 31-year-old man who developed AAC after abdominal wall repair with mesh (Rives-Stoppa procedure) 1 day after discharge from the hospital. To the best of our knowledge, this is the first paper to report AAC after abdominal incisional hernia repair. Although it is known to be more common in critically ill patients, AAC can also occur postoperatively in outpatients. Early recognition and treatment of AAC may improve outcome. PMID:24739656

  8. The Role of Geometric Parameters in the Prediction of Abdominal Aortic Aneurysm Wall Stress

    E-print Network

    Papaharilaou, Yannis

    The Role of Geometric Parameters in the Prediction of Abdominal Aortic Aneurysm Wall Stress E wall stress (PWS) and abdominal aorta aneurysm (AAA) geometric parameters in the presence rights reserved. Introduction It has been postulated that aneurysm peak wall stress (PWS) may be superior

  9. Necrotizing Fasciitis of the Abdominal Wall Caused by Serratia Marcescens

    PubMed Central

    Lakhani, Naheed A.; Narsinghani, Umesh; Kumar, Ritu

    2015-01-01

    In this article, we present the first case of necrotizing fasciitis affecting the abdominal wall caused by Serratia marcescens and share results of a focused review of S. marcescens induced necrotizing fasciitis. Our patient underwent aorto-femoral bypass grafting for advanced peripheral vascular disease and presented 3 weeks postoperatively with pain, erythema and discharge from the incision site in the left lower abdominal wall and underwent multiple debridement of the affected area. Pathology of debrided tissue indicated extensive necrosis involving the adipose tissue, fascia and skeletal muscle. Wound cultures were positive for Serratia marcescens. She was successfully treated with antibiotics and multiple surgical debridements. Since necrotizing fasciitis is a medical and surgical emergency, it is critical to examine infectivity trends, clinical characteristics in its causative spectrum. Using PubMed we found 17 published cases of necrotizing fasciitis caused by Serratia marcescens, and then analyzed patterns among those cases. Serratia marcescens is prominent in the community and hospital settings, and information on infection presentations, risk factors, characteristics, treatment, course, and complications as provided through this study can help identify cases earlier and mitigate poor outcomes. Patients with positive blood cultures and those patients where surgical intervention was not provided or delayed had a higher mortality. Surgical intervention is a definite way to establish the diagnosis of necrotizing infection and differentiate it from other entities. PMID:26294949

  10. Evaluation of cutaneous abdominal wall sensibility after abdominoplasty.

    PubMed

    Fels, Klaus Werner; Cunha, Marcelo Sacramento; Sturtz, Gustavo Pinó; Gemperli, Rolf; Ferreira, Marcus Castro

    2005-01-01

    Changes in cutaneous sensibility are common after diverse plastic surgical procedures. Although prior studies examined aesthetic results, combined procedures, and new abdominoplasty techniques, few examined the effect of undermining on cutaneous sensibility. This study aimed to analyze and quantify cutaneous sensibility after classic abdominoplasty. Two groups of patients were studied: a control group of 10 patients without surgery and another group of 25 patients who had undergone classic abdominoplasty. The abdominal wall surface was divided into nine regions. Pain sensibility was evaluated by tests with needles, and thermal sensibility by test tubes containing hot and cold water. Superficial tactile sensibility was tested using the Pressure-Specified Sensory Device (PSSD), which is capable of determining the cutaneous pressure threshold. Statistical analysis was conducted using Student's 't-test'. The results showed a decrease in the three types of sensibility. Statistical analysis showed a significant difference (p < 0.05) between the groups for all regions tested. The centermost regions of the abdominal wall presented the highest index of analgesia and thermal anesthesia, as well as higher cutaneous pressure thresholds. PMID:15759089

  11. Athletic injuries of the lateral abdominal wall: review of anatomy and MR imaging appearance.

    PubMed

    Stensby, J Derek; Baker, Jonathan C; Fox, Michael G

    2016-02-01

    The lateral abdominal wall is comprised of three muscles, each with a different function and orientation. The transversus abdominus, internal oblique, and external oblique muscles span the abdominal cavity between the iliocostalis lumborum and quadratus lumborum posteriorly and the rectus abdominis anteriorly. The lateral abdominal wall is bound superiorly by the lower ribs and costal cartilages and inferiorly by the iliac crest and inguinal ligament. The lateral abdominal wall may be acutely or chronically injured in a variety of athletic endeavors, with occasional acute injuries in the setting of high-energy trauma such as motor vehicle collisions. Injuries to the lateral abdominal wall may result in lumbar hernia formation, unique for its high incarceration rate, and also Spigelian hernias. This article will review the anatomy, the magnetic resonance (MR) imaging approach, and the features and complications of lateral abdominal wall injuries. PMID:26450606

  12. Novel Technique for Innervated Abdominal Wall Vascularized Composite Allotransplantation: A Separation of Components Approach

    PubMed Central

    Mavrophilipos, Vasilios D.; Zapora, Jeffrey A.; Berli, Jens; Broyles, Justin; Chopra, Karan; Sabino, Jennifer; Matthews, Jamil; Buckingham, E. Bryan; Maddox, John S.; Bluebond-Langner, Rachel; Silverman, Ronald P.

    2014-01-01

    Objective: Applications for Abdominal Wall Vascularized Composite Allotransplantation may expand if a functional graft with decreased immunosuppressive requirements can be designed. We hypothesize that it is anatomically feasible to prepare a functional, innervated, and vascularized abdominal composite graft using a multilayered component separation technique. Including vascularized bone in the graft design may decrease the immunosuppressive requirements by inducing immunologic chimerism. Methods: Two cadaver torsos were used. Adipocutaneous flaps were elevated from the midaxillary lines, preserving deep inferior epigastric artery perforators. A 2-layered component separation through the external and internal oblique fasciae was carried out, exposing segmental intercostal thoracolumbar nerves. Superiorly directed muscle release over the subcostal margin provided for a 3-rib segment with attached rectus abdominis muscle. The remainder of the full-thickness allograft was harvested with its vasculature. Flap inset into the recipient cadaver abdomen, with osteosynthesis fixation between donor and recipient ribs, was achieved. Results: The harvested grafts had an average size of 845 ± 205 cm2 with a total procurement time of 110 minutes. On one cadaver, 4 thoracolumbar nerves were isolated bilaterally, while the other cadaver yielded 3 nerves. The nerves were transected with an average length of 5.7 ± 1.2 cm. The graft vasculature was transected with a length of 4.40 ± 0.10 cm. Conclusion: Using the principles of component separation technique, we demonstrated a novel approach to harvest and transfer a neurotized osteomyofasciocutaneous abdominal wall allotransplant as a multipedicled, single functional unit. PMID:25328567

  13. The effect of abdominal wall morphology on ultrasonic pulse distortion. Part I. Measurements

    E-print Network

    Mast, T. Douglas

    , a hemispheric transducer transmitted a 3.75-MHz ultrasonic pulse through a tissue section. The receivedThe effect of abdominal wall morphology on ultrasonic pulse distortion. Part I. Measurements Laura abdominal wall in producing ultrasonic wavefront distortion was assessed by means of direct measurements

  14. An Abdominal Aorta Wall Extraction for Liver Cirrhosis Classification Using Ultrasonic Images

    NASA Astrophysics Data System (ADS)

    Hayashi, Takaya; Fujita, Yusuke; Mitani, Yoshihiro; Hamamoto, Yoshihiko; Segawa, Makoto; Terai, Shuji; Sakaida, Isao

    2011-06-01

    We propose a method to extract an abdominal aorta wall from an M-mode image. Furthermore, we propose the use of a Gaussian filter in order to improve image quality. The experimental results show that the Gaussian filter is effective in the abdominal aorta wall extraction.

  15. Abdominal Subcutaneous Fat Thickness Measured by Ultrasonography Correlates with Hyperlipidemia and Steatohepatitis in Obese Children

    PubMed Central

    Lee, Sung Hyun; Kim, Dongwan; Baek, Min Young; Kim, Yeon Sun; Ryoo, Eell; Kim, Yun Mi

    2015-01-01

    Purpose The aim of this study is to evaluate the relationship between abdominal subcutaneous fat thickness measured by ultrasonography (US) and serum lipid profile and liver transaminases in obese children. Methods One hundred and sixty-six children diagnosed with obesity from May 2001 to December 2013 were included in this study. Data on serum lipid profile and liver transaminases were collected from clinical records. Abdominal subcutaneous fat thickness and grade of hepatic steatosis were evaluated by US. Results Of the 166 children, 107 were diagnosed with hepatic steatosis by US, 46 with grade I, 56 with grade II, and five children with grade III. According to the grade of hepatic steasosis, the average values of midline abdominal subcutaneous fat thickness and right flank abdominal subcutaneous fat thickness measured 2.9±0.8 cm and 1.9±0.7 cm in the normal group, 3.3±0.8 cm and 2.0±0.7 cm in grade I, 3.8±0.8 cm and 2.3±0.8 cm in grade II, and 4.1±0.8 cm and 2.8±1.4 cm in grade III, respectively. Abdominal subcutaneous fat thickness correlated with grade of hepatic steatosis (p<0.01). In addition, abdominal subcutaneous fat thickness correlated with concentration of serum lipids and liver transaminases in the age group of 12-14 years (p<0.01). Conclusion Abdominal subcutaneous fat thickness measured by US can be used as a reliable predictor of possible hyperlipidemia and steatohepatitis in children, especially during the adolescent stage. PMID:26157696

  16. Measuring and modeling patient-specific distributions of material properties in abdominal aortic aneurysm wall.

    PubMed

    Reeps, C; Maier, A; Pelisek, J; Härtl, F; Grabher-Meier, V; Wall, W A; Essler, M; Eckstein, H-H; Gee, M W

    2013-08-01

    Both the clinically established diameter criterion and novel approaches of computational finite element (FE) analyses for rupture risk stratification of abdominal aortic aneurysms (AAA) are based on assumptions of population-averaged, uniform material properties for the AAA wall. The presence of inter-patient and intra-patient variations in material properties is known, but has so far not been addressed sufficiently. In order to enable the preoperative estimation of patient-specific AAA wall properties in the future, we investigated the relationship between non-invasively assessable clinical parameters and experimentally measured AAA wall properties. We harvested n = 163 AAA wall specimens (n = 50 patients) during open surgery and recorded the exact excision sites. Specimens were tested for their thickness, elastic properties, and failure loads using uniaxial tensile tests. In addition, 43 non-invasively assessable patient-specific or specimen-specific parameters were obtained from recordings made during surgery and patient charts. Experimental results were correlated with the non-invasively assessable parameters and simple regression models were created to mathematically describe the relationships. Wall thickness was most significantly correlated with the metabolic activity at the excision site assessed by PET/CT (? = 0.499, P = 4 × 10(-7)) and to thrombocyte counts from laboratory blood analyses (? = 0.445, P = 3 × 10(-9)). Wall thickness was increased in patients suffering from diabetes mellitus, while it was significantly thinner in patients suffering from chronic kidney disease (CKD). Elastic AAA wall properties had significant correlations with the metabolic activity at the excision site (PET/CT), with existent calcifications, and with the diameter of the non-dilated aorta proximal to the AAA. Failure properties (wall strength and failure tension) had correlations with the patient's medical history and with results from laboratory blood analyses. Interestingly, AAA wall failure tension was significantly reduced for patients with CKD and elevated blood levels of potassium and urea, respectively, both of which are associated with kidney disease. This study is a first step to a future preoperative estimation of AAA wall properties. Results can be conveyed to both the diameter criterion and FE analyses to refine rupture risk prediction. The fact that AAA wall from patients suffering from CKD featured reduced failure tension implies an increased AAA rupture risk for this patient group at comparably smaller AAA diameters. PMID:22955570

  17. [Mutual influence and development between Gastrointestinal surgery and hernia and abdominal wall surgery].

    PubMed

    Chen, Shuang

    2015-11-25

    The aim of this article is to expound on the crossing and influence each other of gastrointestinal surgery and abdominal wall hernia surgery. Although these two departments are independent respectively, but due to the existence of association among anatomy, physiology and pathology, so they are also overlapping. First of all, the abdominal wall and digestive tract are interdependent, and the abdominal wall provides "protection" for gut. In case of large abdominal wall defect, intra-abdominal viscera, breathing, circulation system and spine will change accordingly. In addition, when intra-abdominal pressure increases due to various reasons, laparotomy is an effective way. But laparotomy is not an easy case, but a crisis. One of the most difficult problems is "enteroatmospheric fistulae". Therefore, to avoid serious complications after laparotomy, the concept of planned ventral hernia is proposed. When life safety is threatened by inter-abdominal hypertension, planned abdominal wall hernia is the style to save life. This is a kind of concept of innovation, and is the concrete practice of the theory of damage control surgery. For a planned abdominal wall hernia patient, it is better to wait and watch, and after making a comprehensive assessment, multidisciplinary collaboration mode should be applied to ensure the safety of surgery. PMID:26616795

  18. Noninvasive monitoring of intra-abdominal pressure by measuring abdominal wall tension

    PubMed Central

    Chen, Yuan-zhuo; Yan, Shu-ying; Chen, Yan-qing; Zhuang, Yu-gang; Wei, Zhao; Zhou, Shu-qin; Peng, Hu

    2015-01-01

    BACKGROUND: Noninvasive monitoring of intra-abdominal pressure (IAP) by measuring abdominal wall tension (AWT) was effective and feasible in previous postmortem and animal studies. This study aimed to investigate the feasibility of the AWT method for noninvasively monitoring IAP in the intensive care unit (ICU). METHODS: In this prospective study, we observed patients with detained urethral catheters in the ICU of Shanghai Tenth People’s Hospital between April 2011 and March 2013. The correlation between AWT and urinary bladder pressure (UBP) was analyzed by linear regression analysis. The effects of respiratory and body position on AWT were evaluated using the paired samples t test, whereas the effects of gender and body mass index (BMI) on baseline AWT (IAP<12 mmHg) were assessed using one-way analysis of variance. RESULTS: A total of 51 patients were studied. A significant linear correlation was observed between AWT and UBP (R=0.986, P<0.01); the regression equation was Y=–1.369+9.57X (P<0.01). There were significant differences among the different respiratory phases and body positions (P<0.01). However, gender and BMI had no significant effects on baseline AWT (P=0.457 and 0.313, respectively). CONCLUSIONS: There was a significant linear correlation between AWT and UBP and respiratory phase, whereas body position had significant effects on AWT but gender and BMI did not. Therefore, AWT could serve as a simple, rapid, accurate, and important method to monitor IAP in critically ill patients. PMID:26056545

  19. The effects of dynamic exercise utilizing PNF patterns on abdominal muscle thickness in healthy adults.

    PubMed

    Gong, Wontae

    2015-06-01

    [Purpose] The purpose of this study is to examine the effects of dynamic exercise utilizing the PNF (proprioceptor neuromuscular facilitation) patterns accompanied by abdominal drawing-in exercises on abdominal muscle thickness in healthy adults. [Subjects] The total number of subjects was 30;15 were randomly placed in the training group (TG), and the remaining 15 made up the control group (CG). [Methods] The subjects in the TG conducted 3-5 sets of dynamic exercises utilizing the PNF patterns each day, 3 times a week for 6 weeks. The thickness of the abdominal muscles was measured by ultrasonography. [Results] When the TG's abdominal muscle thickness pre-test and post-test were compared in this study, there was a statistical significance in all of the external obliquus abdominis (Eo), the internal obliquus abdominis (Io), and the transversus abdominis (Tra). [Conclusion] Dynamic exercise utilizing the PNF patterns increased the thickness of the abdominal muscles that are the basis of trunk stabilization. PMID:26180351

  20. The effects of dynamic exercise utilizing PNF patterns on abdominal muscle thickness in healthy adults

    PubMed Central

    Gong, Wontae

    2015-01-01

    [Purpose] The purpose of this study is to examine the effects of dynamic exercise utilizing the PNF (proprioceptor neuromuscular facilitation) patterns accompanied by abdominal drawing-in exercises on abdominal muscle thickness in healthy adults. [Subjects] The total number of subjects was 30;15 were randomly placed in the training group (TG), and the remaining 15 made up the control group (CG). [Methods] The subjects in the TG conducted 3–5 sets of dynamic exercises utilizing the PNF patterns each day, 3 times a week for 6 weeks. The thickness of the abdominal muscles was measured by ultrasonography. [Results] When the TG’s abdominal muscle thickness pre-test and post-test were compared in this study, there was a statistical significance in all of the external obliquus abdominis (Eo), the internal obliquus abdominis (Io), and the transversus abdominis (Tra). [Conclusion] Dynamic exercise utilizing the PNF patterns increased the thickness of the abdominal muscles that are the basis of trunk stabilization. PMID:26180351

  1. Thick domain walls in a polynomial approximation

    E-print Network

    H. Arodz

    1995-01-18

    Relativistic domain walls are studied in the framework of a polynomial approximation to the field interpolating between different vacua and forming the domain wall. In this approach we can calculate evolution of a core and of a width of the domain wall. In the single, cubic polynomial approximation used in this paper, the core obeys Nambu-Goto equation for a relativistic membrane. The width of the domain wall obeys a nonlinear equation which is solved perturbatively. There are two types of corrections to the constant zeroth order width: the ones oscillating in time, and the corrections directly related to curvature of the core. We find that curving a static domain wall is associated with an increase of its width. As an example, evolution of a toroidal domain wall is investigated.

  2. Reconstruction of Abdominal Wall Musculofascial Defects with Small Intestinal Submucosa Scaffolds Seeded with Tenocytes in Rats

    PubMed Central

    Song, Zhicheng; Peng, Zhiyou; Liu, Zhengni; Yang, Jianjun; Tang, Rui

    2013-01-01

    The repair of abdominal wall defects following surgery remains a difficult challenge. Although multiple methods have been described to restore the integrity of the abdominal wall, there is no clear consensus on the ideal material for reconstruction. This study explored the feasibility of in vivo reconstruction of a rat model of an abdominal wall defect with a composite scaffold of tenocytes and porcine small intestinal submucosa (SIS). In the current study, we created a 2×1.5?cm abdominal wall defect in the anterolateral abdominal wall of Sprague-Dawley rats, which were assigned into three groups: the cell-SIS construct group, the cell-free SIS scaffold group, and the abdominal wall defect group. Tenocytes were obtained from the tendons of rat limbs. After isolation and expansion, cells (2×107/mL) were seeded onto the three-layer SIS scaffolds and cultured in vitro for 5 days. Cell-SIS constructs or cell-free constructs were implanted to repair the abdominal wall defects. The results showed that the tenocytes could grow on the SIS scaffold and secreted corresponding matrices. In addition, both scaffolds could repair the abdominal wall defects with no hernia recurrence. In comparison to the cell-free SIS scaffold, the composite scaffold exhibited increased vascular regeneration and mechanical strength. Furthermore, following increased time in vivo, the mechanical strength of the composite scaffold became stronger. The results indicate that the composite scaffold can provide increased mechanical strength that may be suitable for repairing abdominal wall defects. PMID:23402600

  3. Sonography of Abdominal Wall Masses and Masslike Lesions: Correlation With Computed Tomography and Magnetic Resonance Imaging.

    PubMed

    Ahn, Sung Eun; Park, Seong Jin; Moon, Sung Kyoung; Lee, Dong Ho; Lim, Joo Won

    2016-01-01

    Sonography is usually regarded as a first-line imaging modality for masses and masslike lesions in the abdominal wall. A dynamic study focusing on a painful area or palpable mass and the possibility of ultrasound-guided aspiration or biopsy are the major advantages of sonography. On the other hand, cross-sectional imaging clearly shows anatomy of the abdominal wall; thereby, it is valuable for diagnosing and evaluating the extent of diseases. Cross-sectional imaging can help differentiate neoplastic lesions from non-neoplastic lesions. This pictorial essay focuses on sonographic findings of abdominal wall lesions compared with computed tomographic and magnetic resonance imaging findings. PMID:26657747

  4. The use of a biological graft for the closure of large abdominal wall defects following excision of soft tissue tumours

    PubMed Central

    Illingworth, Emma; Rooney, Paul S.; Heath, Richard; Chandrasekar, Coonoor R.

    2015-01-01

    Primary soft tissue tumours arising from the abdominal wall are uncommon and surgical excision of such tumours can result in large abdominal wall defects. There are many techniques available for abdominal wall repair following tumour excision, each having its own advantages and disadvantages. The options range from direct closure to the use of tissue flap reconstructions and/or prosthetic meshes. Currently, synthetic material such as polypropylene mesh is a common choice for closure of abdominal wall defects after tumour excision. Biological meshes are an alternative option for repair, and this report outlines two cases of abdominal wall repair using the porcine intestinal submucosa biological graft following excision of abdominal wall tumours. There was no evidence of infection, recurrence, seroma or hernias at 2-year follow-up. Following excision of soft tissue tumours of the abdominal wall, biological reconstructions can be successfully used to bridge the defect with minimal morbidity. PMID:26109681

  5. The Effect of Abdominal Bracing in Combination with Low Extremity Movements on Changes in Thickness of Abdominal Muscles and Lumbar Strength for Low Back Pain

    PubMed Central

    Lee, So Hee; Kim, Tae Hoon; Lee, Byoung Hee

    2014-01-01

    [Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO. PMID:24567697

  6. The effect of abdominal bracing in combination with low extremity movements on changes in thickness of abdominal muscles and lumbar strength for low back pain.

    PubMed

    Lee, So Hee; Kim, Tae Hoon; Lee, Byoung Hee

    2014-01-01

    [Purpose] The purpose of this study was to investigate the effects of abdominal bracing with low extremity movement on changes in thickness of abdominal muscles and lumbar strength. [Subjects] Sixteen patients with chronic low back pain were randomly assigned to two groups: an abdominal bracing with active straight leg raise (ABSLR) group and abdominal bracing with ankle dorsiflexion (ABDF) group. [Methods] All subjects were evaluated for their abdominal muscle strength using a MedX Lumbar Extension Machine and thickness of external oblique (EO), internal oblique (IO), and transverse abdominis (TrA) muscles using rehabilitative ultrasound imaging. Subjects in both groups were instructed to perform Abdominal bracing (AB). Simultaneously, those in the ABSLR group performed active SLR, and those in the ABDF group performed ankle dorsiflexion. [Results] In comparison between the ABSLR and ABDF groups, significant differences in the thickness of the IO and TrA muscles were observed after the intervention in the ABSLR group. Also, lumbar strength was showed a significant increase in both groups after interventions. [Conclusion] The results of this study demonstrated that ABSLR is a more effective method than ABDF for improvement of abdominal stabilization by increasing the thicknesses of the TrA and IO. PMID:24567697

  7. Bladder wall thickness mapping for magnetic resonance cystography

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Liang, Zhengrong; Zhu, Hongbin; Han, Hao; Duan, Chaijie; Yan, Zengmin; Lu, Hongbing; Gu, Xianfeng

    2013-08-01

    Clinical studies have shown evidence that the bladder wall thickness is an effective biomarker for bladder abnormalities. Clinical optical cystoscopy, the current gold standard, cannot show the wall thickness. The use of ultrasound by experts may generate some local thickness information, but the information is limited in field-of-view and is user dependent. Recent advances in magnetic resonance (MR) imaging technologies lead MR-based virtual cystoscopy or MR cystography toward a potential alternative to map the wall thickness for the entire bladder. From a high-resolution structural MR volumetric image of the abdomen, a reasonable segmentation of the inner and outer borders of the bladder wall can be achievable. Starting from here, this paper reviews the limitation of a previous distance field-based approach of measuring the thickness between the two borders and then provides a solution to overcome the limitation by an electric field-based strategy. In addition, this paper further investigates a surface-fitting strategy to minimize the discretization errors on the voxel-like borders and facilitate the thickness mapping on the three-dimensional patient-specific bladder model. The presented thickness calculation and mapping were tested on both phantom and human subject datasets. The results are preliminary but very promising with a noticeable improvement over the previous distance field-based approach.

  8. Mechanical behaviour of synthetic surgical meshes: finite element simulation of the herniated abdominal wall.

    PubMed

    Hernández-Gascón, B; Peña, E; Melero, H; Pascual, G; Doblaré, M; Ginebra, M P; Bellón, J M; Calvo, B

    2011-11-01

    The material properties of meshes used in hernia surgery contribute to the overall mechanical behaviour of the repaired abdominal wall. The mechanical response of a surgical mesh has to be defined since the haphazard orientation of an anisotropic mesh can lead to inconsistent surgical outcomes. This study was designed to characterize the mechanical behaviour of three surgical meshes (Surgipro®, Optilene® and Infinit®) and to describe a mechanical constitutive law that accurately reproduces the experimental results. Finally, through finite element simulation, the behaviour of the abdominal wall was modelled before and after surgical mesh implant. Uniaxial loading of mesh samples in two perpendicular directions revealed the isotropic response of Surgipro® and the anisotropic behaviour of Optilene® and Infinit®. A phenomenological constitutive law was used to reproduce the measured experimental curves. To analyze the mechanical effect of the meshes once implanted in the abdomen, finite element simulation of the healthy and partially herniated repaired rabbit abdominal wall served to reproduce wall behaviour before and after mesh implant. In all cases, maximal displacements were lower and maximal principal stresses higher in the implanted abdomen than the intact wall model. Despite the fact that no mesh showed a behaviour that perfectly matched that of abdominal muscle, the Infinit® mesh was able to best comply with the biomechanics of the abdominal wall. PMID:21763794

  9. Occlusion-free Blood Flow Animation with Wall Thickness Visualization.

    PubMed

    Lawonn, Kai; Glaber, Sylvia; Vilanova, Anna; Preim, Bernhard; Isenberg, Tobias

    2016-01-01

    We present the first visualization tool that combines pathlines from blood flow and wall thickness information. Our method uses illustrative techniques to provide occlusion-free visualization of the flow. We thus offer medical researchers an effective visual analysis tool for aneurysm treatment risk assessment. Such aneurysms bear a high risk of rupture and significant treatment-related risks. Therefore, to get a fully informed decision it is essential to both investigate the vessel morphology and the hemodynamic data. Ongoing research emphasizes the importance of analyzing the wall thickness in risk assessment. Our combination of blood flow visualization and wall thickness representation is a significant improvement for the exploration and analysis of aneurysms. As all presented information is spatially intertwined, occlusion problems occur. We solve these occlusion problems by dynamic cutaway surfaces. We combine this approach with a glyph-based blood flow representation and a visual mapping of wall thickness onto the vessel surface. We developed a GPU-based implementation of our visualizations which facilitates wall thickness analysis through real-time rendering and flexible interactive data exploration mechanisms. We designed our techniques in collaboration with domain experts, and we provide details about the evaluation of the technique and tool. PMID:26529724

  10. Gear-shift lever having variable thickness walls

    SciTech Connect

    Tanaka, T.

    1988-01-03

    A one-piece elongated tubular transmission gear shift lever, is described comprising a tubular connector part at a first end of the gear shift lever, whereby the tubular connector part is adapted to be secured to a pivot means; a spherical part extending from the connector part, the connector part and the spherical part having a first wall thickness; a cylindrical part extending from the spherical part in a direction opposite the tubular connector part, the cylindrical part having a second wall thickness less than the first wall thickness; a tapered part extending from the cylindrical part; and a threaded part extending from the tapered part, the threaded part formed at a second end of the gear shift lever opposite the first end, whereby a gear shift knob may be attached.

  11. Fluid wall shear stress measurements in a model of the human abdominal aorta: oscillatory behavior and relationship to atherosclerosis.

    PubMed

    Moore, J E; Xu, C; Glagov, S; Zarins, C K; Ku, D N

    1994-10-01

    Clinically significant atherosclerosis in the human aorta is most common in the infrarenal segment. This study was initiated to test the hypothesis that flowfield properties are closely related to the localization of plaques in this segment of the arterial system. Wall shear stress was calculated from magnetic resonance velocity measurements of pulsatile flow in an anatomically accurate model of the human abdominal aorta. The wall shear stress values were compared with intimal thickening from 15 post-mortem aortas measured by quantitative morphometry of histological cross sections obtained at standard locations. Wall shear stress oscillated in direction throughout most of the infrarenal aorta, most prominently in the distal region. The time-averaged mean wall shear stress (-1.7 to 1.4 dyn/cm2) was lowest near the posterior wall in this region. These hemodynamic parameters coincided with the locations of maximal intimal thickening. Statistical correlation between oscillatory shear and intimal thickness yielded r = 0.79, P < 0.00001. Low mean shear stresses correlated nearly as well (r = -0.75, P < 0.00005). Comparison of our data with surface maps of Sudan Red staining and early lesions as reported by others revealed similar conclusions. In contrast, pulse and maximum shear stresses did not correlate with plaque localization as has been shown for other sites of selective involvement by atherosclerosis (r < 0.345). Simulated exercise conditions markedly changed the magnitude and pattern of wall shear stress in the distal abdominal aorta. These results demonstrate that in the infrarenal aorta, regions of low mean and oscillating wall shear stresses are predisposed to the development of plaque while regions of relatively high wall shear stress tend to be spared. PMID:7848371

  12. Reduction of adhesions with composite AlloDerm/polypropylene mesh implants for abdominal wall reconstruction.

    PubMed

    Butler, Charles E; Prieto, Victor G

    2004-08-01

    Ventral hernia repair often includes the use of structural prosthetic materials, such as polypropylene mesh, that can induce dense abdominal adhesions to peritoneal structures. AlloDerm (LifeCell Corp., Branchburg, N.J.), a commercially available decellularized human dermal analogue with its native basement membrane components intact, is gradually revascularized and replaced with autologous tissue after implantation. The authors hypothesized that AlloDerm integrated with polypropylene mesh would reduce adhesions and provide a biodegradable scaffold to generate an autologous vascularized tissue layer separating the abdominal viscera from the mesh. Ventral hernia defects (3 x 1 cm) in 19 guinea pigs were repaired using an inlay technique with polypropylene mesh alone (n = 6) or with composite implants constructed by integrating polypropylene mesh and AlloDerm with its basement membrane surface oriented toward (polypropylene/AlloIn, n = 7) or away from (polypropylene/ AlloOut, n = 6) the peritoneal cavity. At 4 weeks, the authors determined the amount of mesh implant surface area covered by adhesions, the strength of the adhesions [graded from 0 (none) to 3], and the incidence of bowel adhesions. Histologic analyses were performed on full-thickness tissue sections from the repair sites. The mean surface areas affected by adhesions and mean adhesion strength were significantly lower in the polypropylene/AlloIn (area, 12.4 percent; mean grade, 1.0) and polypropylene/AlloOut (area, 9.5 percent; mean grade, 0.5) groups than in the polypropylene group (area, 79.5 percent; mean grade, 2.9); there were no such differences between the polypropylene/AlloIn and polypropylene/AlloOut groups. The bowel was adherent to 67 percent of polypropylene repairs and 0 percent of the composite mesh repairs. The AlloDerm was remodeled to form a vascularized tissue layer beneath the mesh in composite repairs, unlike the significantly thinner, dense scar layer that formed in the polypropylene repairs. Immunohistochemical labeling for factor VIII showed neovascularization throughout the AlloDerm. The AlloDerm thus functioned as a biodegradable tissue scaffold, guiding the formation of a thick, well-vascularized tissue layer separating the polypropylene mesh from intraperitoneal structures. This significantly reduced both the amount of surface area covered by adhesions and adhesion strength. Basement membrane orientation had no effect. Composite mesh implants composed of structural prosthetic materials integrated with AlloDerm may have useful clinical applications for abdominal wall reconstruction by reducing adhesions and providing a vascularized tissue layer to separate and protect the peritoneal structures from polypropylene mesh fibers. PMID:15277815

  13. Evaluation of scoring accuracy for airway wall thickness

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Ko, Jane P.; Godoy, Myrna C. B.

    2009-02-01

    Bronchial wall thickening is commonly observed in airway diseases. One method often used to quantitatively evaluate wall thickening in CT images is to estimate the ratio of the bronchial wall to the accompanying artery, or BWA ratio, and then assign a severity score based on the ratio. Assessment by visual inspection is unfortunately limited to airways perpendicular or parallel to the scanning plane. With high-resolution images from multi-detector CT scanners, it becomes possible to assess airways in any orientation. We selected CT scans from 20 patients with mild to severe COPD. A computer system automatically segmented each bronchial tree and measured the bronchial wall thicknesses. Next, neighboring arteries were detected and measured to determine BWA ratios. A score characterizing the extent and severity of wall thickening within each lobe was computed according to recommendations by Sheehan et al [1]. Two experienced radiologists independently scored wall thickening using visual assessment. Spearman's rank correlation showed a non-significant negative correlation (r=-0.1) between the computer and the reader average (p=0.4), while the correlation between readers was significant at r=0.65 (p=0.001). We subsequently identified 24 lobes with high discrepancies between visual and automated scoring. The readers re-examined those lobes and measured wall thickness using electronic calipers on perpendicular cross sections, rather than visual assessment. Using this more objective standard of wall thickness, the reader estimates of wall thickening increased to reach a significant positive correlation with automated scoring of r=0.65 (p=0.001). These results indicate that subjectivity is an important problem with visual evaluation, and that visual inspection may frequently underestimate disease extent and severity. Given that a manual evaluation of all airways is infeasible in routine clinical practice, we argue that automated methods should be developed and utilized.

  14. Texture analysis improves level set segmentation of the anterior abdominal wall

    SciTech Connect

    Xu, Zhoubing; Allen, Wade M.; Baucom, Rebeccah B.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-12-15

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention.Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall.Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture.Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture analysis can improve the level set segmentation around the abdominal region.

  15. Paediatric abdominal wall hernia following handlebar injury: should we diagnose more and operate less?

    PubMed Central

    Upasani, Anand; Bouhadiba, Nordeen

    2013-01-01

    Traumatic abdominal wall hernia following handlebar injury can be easily missed and is thus underreported. A 12-year-old boy presented with handlebar injury to the left upper quadrant of his abdomen. Except for a localised swelling, thought to be related to a haematoma, he was haemodynamically stable. CT revealed an abdominal wall defect with herniating fat that was not evident clinically and was also missed on immediate ultrasound examination. As there were no associated injuries and the abdominal wall defect was small without any herniating bowel loops, masterly inactivity was observed. After 6?weeks, the swelling has disappeared completely and there is progressive reduction in the size of the defect. PMID:23606382

  16. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation...PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.109 Nominal wall thickness (t ) for steel pipe. (a) If the nominal wall...

  17. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation...PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Pipe Design § 192.109 Nominal wall thickness (t ) for steel pipe. (a) If the nominal wall...

  18. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Thickness of wall. 179.500-4 Section 179.500-4 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank...

  19. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Thickness of wall. 179.500-4 Section 179.500-4 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for...

  20. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Thickness of wall. 179.500-4 Section 179.500-4 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for...

  1. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Thickness of wall. 179.500-4 Section 179.500-4 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for...

  2. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Thickness of wall. 179.500-4 Section 179.500-4 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for...

  3. Abdominal wall non-clostridian gas cellulitis: a rare complication of a colostoma.

    PubMed

    Maier, A; Boieriu, L

    2014-01-01

    The authors report the case of a 69 year-old patient, with obesity, having a left colostomy that has been made for rectal cancer (12 years ago) and who developed a non-clostridian gascellulitis of the abdominal wall as a result of intraparietal traumatic tract perforation of the colostomy. The presence of the peristomal hernia favoured the posttraumatic injury of the colostomy. Repeated surgical inteventions and the antibiotic treatment determined a favourable evolution. Despite the wound contamination with excrement, transit stoma relocation was not necessary. Some clinical and therapeutic aspects of abdominal wall infections are presented. PMID:25375062

  4. Abdominal wall ischemic fasciitis associated with a torso brace in a young girl.

    PubMed

    Naimer, Sody A

    2012-11-01

    We describe a rare case of ischemic fasciitis of the abdominal wall in a child with scoliosis. The fasciitis was apparently caused by the constant pressure exerted by her torso brace. Clinicians should be alert to the possibility of mechanical factors in the etiology of ischemic fasciitis. PMID:23217950

  5. Primary synovial sarcoma of the abdominal wall: a case report and literature review

    PubMed Central

    Kritsaneepaiboon, Supika; Sangkhathat, Surasak; Mitarnun, Winyou

    2015-01-01

    Synovial sarcoma (SS) is the fourth most common type of soft tissue sarcoma, following malignant fibrous histiocytoma, liposarcoma, and rhabdomyosarcoma. It usually occurs in the extremities near the large joints of middle-aged patients. We describe a case of synovial sarcoma of the anterior abdominal wall (SSAW) in an adolescent girl and undertake a review of the literature. PMID:26629297

  6. Thick domain walls in AdS black hole spacetimes

    SciTech Connect

    Moderski, Rafal; Rogatko, Marek

    2006-08-15

    Equations of motion for a real self-gravitating scalar field in the background of a black hole with negative cosmological constant were solved numerically. We obtain a sequence of static axisymmetric solutions representing thick domain wall cosmological black hole systems, depending on the mass of black hole, cosmological parameter and the parameter binding black hole mass with the width of the domain wall. For the case of extremal cosmological black hole the expulsion of scalar field from the black hole strongly depends on it.

  7. Functional and morphological evaluation of different polypropylene-mesh modifications for abdominal wall repair.

    PubMed

    Klosterhalfen, B; Klinge, U; Schumpelick, V

    1998-12-01

    Modern surgical hernia repair depends increasingly on synthetic meshes for the reconstruction of the abdominal wall. Despite the undisputed advantages of the polypropylene (PP) meshes currently available (Marlex, Prolene), reports of complications after implantation are increasing. Although, serious complications such as perforation and fistula formation are rare, minor and local complaints such as seromas, misfeelings and a decreased abdominal wall mobility are observed in about one-half of the patients. In regard to the exaggerated strength of the currently available mesh modifications a reduction of the material should improve the integration of the meshes into the artificial abdominal wall. In the present study, the commercially available basic mesh Prolene has been compared to two newly constructed PP-mesh modifications with reduced amounts of PP. The modifications have gradually been adopted to the physiological requirements of abdominal wall stability and mobility by reducing the amount of PP to 64% (E-BLUE) and 24% (variant A) of the Prolene mesh (developed by ETHICON, Norderstedt, Germany). All PP-mesh variants have been implanted in a rat model and studied by 3D-photogrammetry, tensiometry, light- and electron microscopy, as well as morphometry over implantation intervals of 3, 7, 14, 21 and 90 days. The data show that current constructions of PP-meshes are oversized and definitely restrict abdominal wall mobility in the present model. Sufficient stability of the artificial abdominal wall is even guaranteed by PP-mesh modifications with a reduction of PP-quantity to about 25% of the Prolene mesh. The degree of fibrosis directly correlated with abdominal wall restriction, whereas the formation of connective tissue in the interface PP-fibre/host-issue depends on the amount and activity of the inflammatory reaction. The quantity and quality of inflammation, again, directly relies to the amount of PP and to the surface area in contact with the recipient tissues. Altogether, the present study suggests that a modification of the PP-meshes could be helpful to prevent major and minor complications of surgical PP-meshes. PMID:9884036

  8. Effects of bridge exercises with a sling and vibrations on abdominal muscle thickness in healthy adults.

    PubMed

    Gong, Won-Tae

    2015-12-01

    In the present study, we aimed to examine the changes in the thickness of the transversus abdominis (TrA) and internal oblique (Io) muscles using ultrasonography in adults who performed bridge exercises with the abdominal drawing-in maneuver and a sling and received micro vibrations. In total, 32 subjects were divided into a therapy (n= 16) and control (n= 16) groups. The therapy group completed nine sets, with four repetitions, of bridge exercises with the sling and received vibrations. The control group completed nine sets, with four repetitions, of bridge exercises with the sling and did not receive vibrations. The thicknesses of the TrA and Io muscles were measured in both groups using ultrasonography before and after therapy. According to the pressure applied to the biofeedback unit, both groups showed significant changes in the thicknesses of the TrA and Io muscles after therapy (P< 0.05). The change in the thickness of the TrA muscle after therapy was significantly different between the 2 groups when the pressures applied at 38, 42, and 46 mmHg (P< 0.05). Moreover, the change in the thickness of the Io muscle did not significantly different between the 2 groups at any of the pressures applied (P> 0.05). These findings indicate that approximately 15 minutes of vibrations during bridge exercises on unstable surfaces with a sling facilitates the activation of the deep trunk muscles and further enhances the activation of the TrA. PMID:25391324

  9. The effects of abdominal draw-in maneuver and core exercise on abdominal muscle thickness and Oswestry disability index in subjects with chronic low back pain

    PubMed Central

    Park, Seong-Doo; Yu, Seong-Hun

    2013-01-01

    The purpose of this study was to effects of abdominal draw-in maneuver and core exercise with 4 weeks using the musculoskeletal ultrasonography on muscle thickness and disability in subjects with low back pain. Twenty patients with nonspecific back pain (abdominal draw-in maneuver group: n= 10, core exercise group: n= 10) were recruited in the study. Both group received exercise intervention 3 times a week for 4weeks. The test were based on muscle thickness (transversus abdominis; Tra, internal oblique; IO and external oblique; EO), disability (Oswestry disability index; ODI) measured immediately before and after intervention. The data was measured by SPSS program 12.0 version and analyzed by Paired t-test and Independent t-test. The following results were obtained. The thickness of IO, EO for both group significantly improved except for muscle thickness of Tra. The ODI were significant difference for both groups. As the results of this study, we suggest that it may be effective method to apply to increase for the thickness of Tra, EO using abdominal draw-in maneuver and thickness of IO using core exercise. PMID:24278873

  10. The effects of abdominal draw-in maneuver and core exercise on abdominal muscle thickness and Oswestry disability index in subjects with chronic low back pain.

    PubMed

    Park, Seong-Doo; Yu, Seong-Hun

    2013-04-01

    The purpose of this study was to effects of abdominal draw-in maneuver and core exercise with 4 weeks using the musculoskeletal ultrasonography on muscle thickness and disability in subjects with low back pain. Twenty patients with nonspecific back pain (abdominal draw-in maneuver group: n= 10, core exercise group: n= 10) were recruited in the study. Both group received exercise intervention 3 times a week for 4weeks. The test were based on muscle thickness (transversus abdominis; Tra, internal oblique; IO and external oblique; EO), disability (Oswestry disability index; ODI) measured immediately before and after intervention. The data was measured by SPSS program 12.0 version and analyzed by Paired t-test and Independent t-test. The following results were obtained. The thickness of IO, EO for both group significantly improved except for muscle thickness of Tra. The ODI were significant difference for both groups. As the results of this study, we suggest that it may be effective method to apply to increase for the thickness of Tra, EO using abdominal draw-in maneuver and thickness of IO using core exercise. PMID:24278873

  11. Evaluation of UT Wall Thickness Measurements and Measurement Methodology

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2007-10-01

    CH2M HILL has requested that PNNL examine the ultrasonic methodology utilized in the inspection of the Hanford double shell waste tanks. Specifically, PNNL is to evaluate the UT process variability and capability to detect changes in wall thickness and to document the UT operator's techniques and methodology in the determination of the reported minimum and average UT data and how it compares to the raw (unanalyzed) UT data.

  12. Free tensor fasciae latae flap for abdominal wall reconstruction: overview and new innovation.

    PubMed

    Chalfoun, Charbel T; McConnell, Michael P; Wirth, Garrett A; Brenner, Kevin A; Evans, Gregory R D; Kobayashi, Mark

    2012-03-01

    Extensive abdominal wall defects may result from tumor extirpation, traumatic injury, or soft tissue infections. Extensive traumatic injuries can often disrupt the soft tissue content of the abdomen as well as the bony support provided by the pelvis. Reconstruction of the lower abdomen should aim to recreate dynamic stability. Five patients with extensive lower abdominal wall disruption following traumatic injuries or infection were treated using a novel flap for functional reconstruction. We devised a free neurotized osteomyocutaneous tensor fasciae latae (TFL) flap that would restore bony continuity by providing a vascularized bone graft and simultaneously maintain the integrity of the attachment of the tensor fascia latae muscle to the iliac crest, reestablishing musculofascial continuity. A branch of the superior gluteal nerve was harvested with this composite flap and coapted to an intercostal nerve for reinnervation, thereby creating a dynamic muscle in these patients. All patients underwent successful free tissue reconstruction with 100% flap survival. The lower abdominal wall and bony integrity of the pelvis were successfully reconstructed. Reinnervation has shown clinical signs of maintained dynamic stability. The innervated TFL osteomyocutaneous flap is an ideal option for lower abdominal reconstruction in patients with complex abdominoperineal defects with loss of bony integrity. PMID:22399254

  13. Thick-wall effects in the theory of resistive wall modes

    SciTech Connect

    Pustovitov, V. D.

    2012-06-15

    Magnetic interaction of the plasma perturbations with the nearby resistive wall is considered as a resistive wall mode (RWM) problem, but with two essential differences from the traditional thin-wall approach. First, the wall is treated as magnetically thick, which means that the skin depth is not assumed larger than the wall thickness. Second, the plasma is allowed to enter the region where the RWM must be deeply unstable without rotation. The latter corresponds to the plasma operation above the no-wall stability limit demonstrated in the DIII-D tokamak [E. J. Strait et al., Phys. Plasmas 11, 2505 (2004)]. It is shown that the rotational stabilization observed in these experiments can be reproduced in this model if the mode is forced to rotate with a frequency above a critical level. The analytical estimates show that this effect (absent in the model based on the thin-wall approximation) is strong at realistic parameters. The model also predicts that the locking of the rotationally stabilized mode gives rise to instability with a growth rate much larger than its thin-wall estimate.

  14. Histological characteristics of the abdominal aortic wall in patients with vascular chronic Q fever.

    PubMed

    Hagenaars, Julia C J P; Koning, Olivier H J; van den Haak, Ronald F F; Verhoeven, Bart A N; Renders, Nicole H M; Hermans, Mirjam H A; Wever, Peter C; van Suylen, Robert Jan

    2014-08-01

    The aim of this study was to describe specific histological findings of the Coxiella burnetii-infected aneurysmal abdominal aortic wall. Tissue samples of the aneurysmal abdominal aortic wall from seven patients with chronic Q fever and 15 patients without evidence of Q fever infection were analysed and compared. Chronic Q fever was diagnosed using serology and tissue PCR analysis. Histological sections were stained using haematoxylin and eosin staining, Elastica van Gieson staining and immunohistochemical staining for macrophages (CD68), T lymphocytes (CD3), T lymphocyte subsets (CD4 and CD8) and B lymphocytes (CD20). Samples were scored by one pathologist, blinded for Q fever status, using a standard score form. Seven tissue samples from patients with chronic Q fever and 15 tissue samples from patients without Q fever were collected. Four of seven chronic Q fever samples showed a necrotizing granulomatous response of the vascular wall, which was characterized by necrotic core of the arteriosclerotic plaque (P = 0.005) and a presence of high numbers of macrophages in the adventitia (P = 0.007) distributed in typical palisading formation (P = 0.005) and surrounded by the presence of high numbers of T lymphocytes located diffusely in media and adventitia. Necrotizing granulomas are a histological finding in the C. burnetii-infected aneurysmal abdominal aortic wall. Chronic Q fever should be included in the list of infectious diseases with necrotizing granulomatous response, such as tuberculosis, cat scratch disease and syphilis. PMID:24953727

  15. Abdominal Wall Endometriosis on the Right Port Site After Laparoscopy: Case Report and Literature Review

    PubMed Central

    Cozzolino, Mauro; Magnolfi, Stefania; Corioni, Serena; Moncini, Daniela; Mattei, Alberto

    2015-01-01

    Background Endometriosis can be intrapelvic or, rarely, extrapelvic. Endometriosis involving the rectus abdominis muscle on the trocar port site is a rare event; until now, only 16 cases have been reported in the literature. The majority of cases were associated with previous abdominal surgery such as diagnostic laparoscopy, cyst excision, appendectomy, myomectomy, or cholecystectomy. We review all the reported cases of this unusual form of extrapelvic endometriosis. Case Report We report a new case of abdominal wall endometriosis at the trocar port site in the rectus abdominis muscle in a woman who had undergone 2 laparoscopies for endometriosis in the 3 years before coming to our attention. The diagnosis was made by sonography. We performed a surgical resection of the lesion with a free macroscopic margin of 5-10 mm. Conclusion Endometriosis should be considered in the differential diagnosis of any abdominal swelling. In our experience, surgery is the treatment of choice. PMID:26412997

  16. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  17. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  18. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  19. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  20. 49 CFR 192.109 - Nominal wall thickness (t) for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Nominal wall thickness (t) for steel pipe. 192.109 Section 192.109 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Nominal wall thickness (t) for steel pipe. (a) If the nominal wall thickness for steel pipe is not...

  1. Desmoid Tumor of the Anterior Abdominal Wall in Female Patients: Comparison with Endometriosis

    PubMed Central

    Krentel, H.; Tchartchian, G.; De Wilde, R. L.

    2012-01-01

    In female patients presenting a tumor of the lower abdominal wall especially after cesarian section, an endometriotic tumor as well as an aggressive desmoid tumor should be considered. Symptoms in correlation with the monthly period can facilitate the presurgical differentiation between endometriosis and fibromatosis. Ultrasound reveals the typical location of both tumors and its remarkable sonographic appearance. In the clinical practice, the desmoid fibromatosis of the lower abdominal wall is a very rare disease. We present a case of a 25-year-old pregnant and discuss diagnostic and therapeutic options by a PubMed literature review. With the knowledge of the prognosis of the desmoid fibromatosis and the respective treatment options including wait and see, complete surgical resection with macroscopically free margins and adjuvant approaches is essential to avoid further interventions and progression of the locally destructive tumor. PMID:22778752

  2. Desmoid tumor of the anterior abdominal wall in female patients: comparison with endometriosis.

    PubMed

    Krentel, H; Tchartchian, G; De Wilde, R L

    2012-01-01

    In female patients presenting a tumor of the lower abdominal wall especially after cesarian section, an endometriotic tumor as well as an aggressive desmoid tumor should be considered. Symptoms in correlation with the monthly period can facilitate the presurgical differentiation between endometriosis and fibromatosis. Ultrasound reveals the typical location of both tumors and its remarkable sonographic appearance. In the clinical practice, the desmoid fibromatosis of the lower abdominal wall is a very rare disease. We present a case of a 25-year-old pregnant and discuss diagnostic and therapeutic options by a PubMed literature review. With the knowledge of the prognosis of the desmoid fibromatosis and the respective treatment options including wait and see, complete surgical resection with macroscopically free margins and adjuvant approaches is essential to avoid further interventions and progression of the locally destructive tumor. PMID:22778752

  3. Emerging Trends in Abdominal Wall Reinforcement: Bringing Bio-Functionality to Meshes.

    PubMed

    Guillaume, Olivier; Teuschl, Andreas Herbert; Gruber-Blum, Simone; Fortelny, René Hartmann; Redl, Heinz; Petter-Puchner, Alexander

    2015-08-26

    Abdominal wall hernia is a recurrent issue world-wide and requires the implantation of over 1 million meshes per year. Because permanent meshes such as polypropylene and polyester are not free of complications after implantation, many mesh modifications and new functionalities have been investigated over the last decade. Indeed, mesh optimization is the focus of intense development and the biomaterials utilized are now envisioned as being bioactive substrates that trigger various physiological processes in order to prevent complications and to promote tissue integration. In this context, it is of paramount interest to review the most relevant bio-functionalities being brought to new meshes and to open new avenues for the innovative development of the next generation of meshes with enhanced properties for functional abdominal wall hernia repair. PMID:26111309

  4. Laparoscopic drainage of abdominal wall abscess from spilled stones post-cholecystectomy

    PubMed Central

    Chong, Vincent; Ram, Rishi

    2015-01-01

    We present a case on abdominal wall abscess from spilled stones post-cholecystectomy and describe laparoscopic drainage as our choice of management. Mr M is a 75-year-old male who presented on multiple occasions to the hospital with right upper quadrant pain and fever post-laparoscopic cholecystectomy. He also required multiple courses of antibiotics. Subsequent computed tomography and magnetic resonance imaging scan confirmed a number of retained stone with signs of chronic inflammation. Hence, 6 months after his initial laparoscopic cholecystectomy, he proceeded to an exploratory laparoscopy. We found an abscess cavity measuring 3 × 4 cm over the anterior abdominal wall. The cavity was de-roofed, drained and washed out. The tissue culture grew Klebsiella pneumoniae. Laparoscopic approach is optimal as the abscess cavity can be clearly identified, stones visualized and removed under direct vision. Patient does not require a laparotomy. PMID:26183574

  5. Fetal abdominal wall defects: six years experience at a tertiary center.

    PubMed

    Ekin, A; Gezer, C; Taner, C E; Ozeren, M; Avci, M E; Ciftci, S; Dogan, A; Gezer, N S

    2015-01-01

    The authors' aim was to detect the associated anomalies and their effect on the management of the fetuses with omphalocele and gastroschisis. Between the period of 2007-2013, the data of fetuses with abdominal wall defects were analyzed. Chromosomal abnormalities and associated morphologic anomalies diagnosed by ultrasonography and autopsy were evaluated. Of the. 61 fetuses, ten (20.4%) omphalocele cases and nine (75%) gastroschisis cases were isolated. Chromosomal abnormalities were found in seven fetuses with omphalocele cases. All fetuses with abnormal karyotypes had multiple additional anomalies. Termination rate was 65.3% for omphalocele group versus none in the gastroschisis group. To give better counseling about the prognosis and outcome of the fetuses with abdominal wall defects, detection of additional anomalies as well as type of the defect are essential tools even if the karyotype is normal. PMID:26152003

  6. Terahertz inline wall thickness monitoring system for plastic pipe extrusion

    SciTech Connect

    Hauck, J. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Stich, D. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Heidemeyer, P. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Bastian, M. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de Hochrein, T. E-mail: d.stich@skz.de E-mail: m.bastian@skz.de

    2014-05-15

    Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

  7. Lateral Abdominal Wall Defects: The Importance of Anatomy and Technique for a Successful Repair

    PubMed Central

    Pulikkottil, Benson J.; Pezeshk, Ronnie A.; Daniali, Lily N.; Bailey, Steven H.; Mapula, Steven

    2015-01-01

    Summary: Flank and lateral abdominal wall defects can be an extremely challenging phenomenon for surgeons to undertake. Their rarity and specific idiosyncrasies in regard to embryologic and anatomical characteristics must be taken into consideration when formulating an operative plan. We will discuss these cardinal points including technical recommendations by notable experts in the field to gain a better understanding in the diagnosis and treatment of this infrequent but morbid occurrence. PMID:26495194

  8. Laparoscopic Cholecystectomy: Incidental Carcinoma of the Gallbladder with Abdominal Wall and Axillary Node Metastasis

    PubMed Central

    Fligelstone, Louis J.; Wheeler, Malcolm H.; Horgan, Kieran; Maughan, Timothy S.

    1997-01-01

    A case report is presented of intra-mural gallbladder carcinoma discovered incidentally after laparoscopic cholecystectomy who subsequently developed abdominal wall recurrence at the epigastric exit port, and axillary lymph node metastases. Possible preventative steps for tumour dissemination and a management plan if incidental carcinoma is diagnosed is discussed. The use of a non-porous retrieval bag, early recognition of the carcinoma and excision of the exit wound are advocated. PMID:9174863

  9. Thick-wall Kevlar 49/Epoxy pressure vessels

    SciTech Connect

    Guess, T.R.

    1984-01-01

    The feasibility of thick-wall composite vessels for very high pressure applications is demonstrated. Prototype vessels, in both spherical and cylindrical geometries, were designed, fabricated and burst tested. It is shown that experimental burst pressures are in excellent agreement with predicted values for burst pressures up to 60 ksi. Each unit consisted of a thin, seamless, copper liner with stainless steel fill stems and a filament-wound Kevlar 49/epoxy outer shell. Analysis of vessel performance accounted for liner thickness and yield strengths, composite thickness, mechanical properties and fiber volume fraction, and stress concentrations caused by the fill stem. Spherical vessels of three different sizes (inside diameters of 2.15 inches, 4.0 inches and 5.3 inches) with either 30 ksi or 60 ksi design burst pressure are discussed. Also, cylindrical vessels with identical liners but of two different composite thicknesses are described. These vessels achieved 50 ksi and 57 ksi burst pressures, respectively. In addition to the design considerations alluded to throughout the paper, the stress state in a thin metal liner during cyclic loading and the life prediction of composite vessels under sustained loading are discussed.

  10. The use of preserved human dura for closure of abdominal wall and diaphragmatic defects.

    PubMed Central

    Rodgers, B M; Maher, J W; Talbert, J L

    1981-01-01

    The surgical management of large body wall defects presents special challenges. The prosthetic materials employed for these defects, although readily available, have the disadvantage of susceptibility to infection. Autologous tissue is frequently not available in sufficient quantity. The long-term functional and histologic results of the use of preserved human dura for closure of abdominal wall and diaphragmatic defects have been evaluated. Dural patches were sutured into abdominal wall and diaphragmatic defects of six dogs, using interrupted sutures of Dexon and Prolene. The animals were killed eight, 16 and 24 weeks after patch placement. The strength of the material was tested with a pneumoperitoneum prior to death and in all animals it appeared firmly incorporated into the host tissue. Histologically there was a mononuclear inflammatory response seen at eight weeks, with resolution by 24 weeks. Ingrowth of surrounding collagen and muscular tissue produced a firm union between the homologous material and the host tissue. The results of this study indicate that preserved human dura is an excellent material for closure of body wall defects. It appears to be well tolerated by host tissue and maintains its strength over prolonged periods of time. Images Fig. 1. Fig. 2. Fig. 3. PMID:6453563

  11. Intensity modulated radiation-therapy for preoperative posterior abdominal wall irradiation of retroperitoneal liposarcomas

    SciTech Connect

    Bossi, Alberto . E-mail: alberto.bossi@uz.kuleuven.ac.be; De Wever, Ivo; Van Limbergen, Erik; Vanstraelen, Bianca

    2007-01-01

    Purpose: Preoperative external-beam radiation therapy (preop RT) in the management of Retroperitoneal Liposarcomas (RPLS) typically involves the delivery of radiation to the entire tumor mass: yet this may not be necessary. The purpose of this study is to evaluate a new strategy of preop RT for RPLS in which the target volume is limited to the contact area between the tumoral mass and the posterior abdominal wall. Methods and Materials: Between June 2000 and Jan 2005, 18 patients with the diagnosis of RPLS have been treated following a pilot protocol of pre-op RT, 50 Gy in 25 fractions of 2 Gy/day. The Clinical Target Volume (CTV) has been limited to the posterior abdominal wall, region at higher risk for local relapse. A Three-Dimensional conformal (3D-CRT) and an Intensity Modulated (IMRT) plan were generated and compared; toxicity was reported following the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events v3.0. Results: All patients completed the planned treatment and the acute toxicity was tolerable: 2 patients experienced Grade 3 and 1 Grade 2 anorexia while 2 patients developed Grade 2 nausea. IMRT allows a better sparing of the ipsilateral and the contralateral kidney. All tumors were successfully resected without major complications. At a median follow-up of 27 months 2 patients developed a local relapse and 1 lung metastasis. Conclusions: Our strategy of preop RT is feasible and well tolerated: the rate of resectability is not compromised by limiting the preop CTV to the posterior abdominal wall and a better critical-structures sparing is obtained with IMRT.

  12. Traumatic abdominal wall hernia associated with small bowel injury-case report.

    PubMed

    Constantin, Vlad; Carâp, Alexandru; Bobic, Simona; Albu, M?d?lina; Nica, Elvira; Socea, Bogdan

    2015-04-01

    Traumatic abdominal wall hernias (TAWHs) are rare. Their diagnosis is mostly clinical and can be overlooked in the setting of trauma and distracting injuries or they can be misinterpreted as parietal hematomas. Associated lesions can influence decision making regarding time of operation and surgical technique. Our case highlights the management of a high-energy TAWH that associates a small bowel traumatic lesion. Surgical repair of TAWHs should follow general hernia repair principles. Further exploration of surgical options is necessary for a consensus to be reached. PMID:25972687

  13. Synovial sarcoma of the abdominal wall: Imaging findings and review of the literature

    PubMed Central

    de Haas, Robbert J.; Bonenkamp, Johannes J.; Flucke, Uta E.; de Rooy, Jacky W.J.

    2015-01-01

    Synovial sarcoma is the fourth most common type of soft-tissue sarcoma (following undifferentiated pleomorphic sarcoma, liposarcoma, and rhabdomyosarcoma), and should be considered a high-grade neoplasm with a high number of local recurrences and late metastases. Synovial sarcoma predominantly occurs in adolescents and young adults, and typically arises near the joints of the lower extremity. However, this tumor can also occur at uncommon sites such as the abdominal wall, which is illustrated in this article. Furthermore, we reviewed the available literatures on the clinical, pathological and radiological appearances, as well as the current knowledge concerning treatment options and prognosis. PMID:25926925

  14. An Abdominal Wall Desmoid Tumour Mimicking Cesarean Scar Endometriomas: A Case Report and Review of the Literature

    PubMed Central

    Vural, Fisun; Müezzinoglu, Bahar

    2015-01-01

    Abdominal wall desmoid tumours (DT) are rare, slow-growing benign muscular-aponeurotic fibrous tumours with the tendency to locally invade and recur. They constitute 0.03% of all neoplasms and high infiltration and recurrence rate, but there is no metastatic potential. Although surgery is the primary treatment modality, the optimal treatment remains unclear. Abdominal wall endometriosis is also an unusual disease, and preoperative clinical diagnosis is not always easy. The preoperative radiologic imaging modalities may not aid all the time. Herein, we report an abdominal mass presenting as cyclic pain. Forty-two years old woman who gave birth by cesarean section admitted the complaints of painful abdominal mass (78x45 mm in size) under her cesarean incision scar. She had severe pain, particularly during menstruation. The clinical and radiological imaging findings mimicking endometrioma. We performed wide surgical excision of mass with a 1 cm tumor-free margin with the diagnosis of a benign mesenchymal tumor in the frozen section. The postoperative course was uneventful and recovered without any complication and recurrence three years after surgery. This report presents a case of abdominal wall desmoid tumor mimicking endometrioma. In this paper, shortcomings in diagnosis, abdominal wall endometriomas, and DTs were discussed in the view of literature. PMID:26500967

  15. Mechanically relevant consequences of the composite laminate-like design of the abdominal wall muscles and connective tissues.

    PubMed

    Brown, Stephen H M

    2012-05-01

    Together, three abdominal wall muscles (external oblique, internal oblique and transversus abdominis) form a tightly bound muscular sheet that has been likened to a composite-laminate structure. Previous work has demonstrated the ability of force generated by these three muscles to be passed between one another through connective tissue linkages. Muscle fibres in each muscle are obliquely oriented with respect to its neighbouring muscles. It is proposed here is that this unique morphology of the abdominal wall muscles functions, through the application of constraining forces amongst the muscles, to increase force- and stiffness-generating capabilities. This paper presents a mathematical formulation of the stress-strain relationship for a transversely isotropic fibrous composite, and establishes a strengthening and stiffening effect when stress can be transferred between the fibrous layers. Application of empirical mechanical properties to this formulation demonstrates this effect for the abdominal wall muscles and, in greater proportion, for the anterior aponeurosis of the abdominal wall. This has implications for increasing the stiffness and passive load bearing ability of the abdominal wall muscles, and has the potential to modulate the whole muscle force-length and force-velocity relationships during contraction. PMID:22137674

  16. Architectural Analysis of Human Abdominal Wall Muscles: Implications for Mechanical Function

    PubMed Central

    Brown, Stephen H. M.; Ward, Samuel R.; Cook, Mark S.; Lieber, Richard L.

    2010-01-01

    Study Design Cadaveric analysis of human abdominal muscle architecture. Objective To quantify the architectural properties of rectus abdominis (RA), external oblique (EO), internal oblique (IO) and transverse abdominis (TrA), and model mechanical function in light of these new data. Summary of Background Data Knowledge of muscle architecture provides the structural basis for predicting muscle function. Abdominal muscles greatly affect spine loading, stability, injury prevention and rehabilitation; however, their architectural properties are unknown. Methods Abdominal muscles from eleven elderly human cadavers were removed intact, separated into regions and micro-dissected for quantification of physiological cross-sectional area (PCSA), fascicle length and sarcomere length. From these data, sarcomere operating length ranges were calculated. Results IO had the largest PCSA and RA the smallest, and would thus generate the largest and smallest isometric forces, respectively. RA had the longest fascicle length, followed by EO, and would thus be capable of generating force over the widest range of lengths. Measured sarcomere lengths, in the post-mortem neutral spine posture, were significantly longer in RA and EO (3.29±0.07 and 3.18±0.11 ?m) compared to IO and TrA (2.61±0.06 and 2.58±0.05 ?m) (p < 0.0001). Biomechanical modeling predicted that RA, EO and TrA act at optimal force-generating length in the mid-range of lumbar spine flexion, where IO can generate approximately 90% of its maximum force. Conclusions These data provide clinically relevant insights into the ability of the abdominal wall muscles to generate force and change length throughout the lumbar spine range of motion. This will impact the understanding of potential postures in which the force-generating and spine stabilizing ability of these muscles become compromised, which can guide exercise/rehabilitation development and prescription. Future work should explore the mechanical interactions among these muscles and their relationship to spine health and function. PMID:21325932

  17. Efficacy and safety of hyaluronate membrane in the rabbit cecum-abdominal wall adhesion model

    PubMed Central

    Kim, Jae Young; Cho, Wan Jin; Kim, Jun Ho; Lim, Sae Hwan; Kim, Hyun Jung; Lee, Young Woo

    2013-01-01

    Purpose Tissue adhesion is a well-known postsurgical phenomenon, causing pain, functional obstruction, and difficult reoperative surgery. To overcome these problems, various synthetic and natural polymer membranes have been developed as postoperative tissue adhesion barriers. However, limitation in their use has hindered its actual application. We prepared a hyaluronate membrane (HM) to evaluate its efficacy and safety as an adhesion barrier compared to a commercialized product (Interceed, Ethicon). Methods To evaluate the antiadhesion effect, a cecum-abdominal wall abrasion model was adopted in a rabbit. The denuded cecum was covered by Interceed or HM or neither and apposed to the abdominal wall (each, n = 10). Four weeks after surgery, the level of adhesion was graded. Acute and chronic toxicity of the three groups were also evaluated. Results Blood samples drawn to evaluate acute toxicity at postoperative day 3 and 7 showed no significant difference among the three groups. The grade and area of adhesion were significantly lower in the HM compared to those of the control and Interceed at four weeks after surgery. Histologic evaluations, which was carried out to estimate tissue reactions at the site of application, as well as to assess chronic toxicity for the major organs, were not significantly different in the three groups. Conclusion This study showed that the antiadhesion efficacy of HM was superior to commercialized antiadhesion membrane, Interceed. Low inflammatory response and nontoxicity were also demonstrated. From these results, we suggest that the HM is a good candidate as a tissue adhesion barrier. PMID:23908960

  18. [Endometriosis of the abdominal wall. Clinical case and review of literature].

    PubMed

    Calabrese, L; Delmonte, O; Mari, R

    1997-01-01

    The authors report a clinical case of endometriosis the abdomen rectum muscle, in woman 28 years old, after a cesarean section delivery. On the basis of literature on the topic, the following are taken into consideration, the incidence, the pathogenesis, the clinical characteristics of this kind of pathology and the aspects which might facilitate the diagnostic approach and correct therapeutic to be given or follow. Parietal endometriosis is an extremely rare disease with incidence in feminine population of 0.03-1%. The pathogenesis is still ill-known. Lack of the classical symptoms and the unusual site can make diagnosis difficult. Pathognomonics but not always present are the presence of tumescence palpable of the abdominal wall near or proximity of preceding surgical scar, the cyclic character of painful symptomatology, the augmentation of volume and the bleeding in period menstrual or premenstrual. The ultrasonography, the computerized axial tomography, the nuclear magnetic resonance can facilitate the preoperative diagnosis but they do not always furnish reports of certainty. The aspirate-needle in ultrasonography control can furnish one of orientation diagnosis. The diagnosis of certainty is founded on the histologic examination after biopsy or excision. The treatment of the abdominal wall endometriosis is surgically essential. The excision of tumescence, easy usually, it is the only means to obtain the definitive recovery. The medical therapy postoperative is adjuvant in the treatment of unrecognized pelvic centres of endometriosis. PMID:9478256

  19. A pilot study on bladder wall thickness at different filling stages

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; Liu, Yang; Li, Baojuan; Zhang, Guopeng; Liang, Zhengrong; Lu, Hongbing

    2015-03-01

    The ever-growing death rate and the high recurrence of bladder cancer make the early detection and appropriate followup procedure of bladder cancer attract more attention. Compare to optical cystoscopy, image-based studies have revealed its potentials in non-invasive observations of the abnormities of bladder recently, in which MR imaging turns out to be a better choice for bladder evaluation due to its non-ionizing and high contrast between urine and wall tissue. Recent studies indicate that bladder wall thickness tends to be a good indicator for detecting bladder wall abnormalities. However, it is difficult to quantitatively compare wall thickness of the same subject at different filling stages or among different subjects. In order to explore thickness variations at different bladder filling stages, in this study, we preliminarily investigate the relationship between bladder wall thickness and bladder volume based on a MRI database composed of 40 datasets acquired from 10 subjects at different filling stages, using a pipeline for thickness measurement and analysis proposed in our previous work. The Student's t-test indicated that there was no significant different on wall thickness between the male group and the female group. The Pearson correlation analysis result indicated that negative correlation with a correlation coefficient of -0.8517 existed between the wall thickness and bladder volume, and the correlation was significant(p <0.01). The corresponding linear regression equation was then estimated by the unary linear regression. Compared to the absolute value of wall thickness, the z-score of wall thickness would be more appropriate to reflect the thickness variations. For possible abnormality detection of a bladder based on wall thickness, the intra-subject and inter-subject thickness variation should be considered.

  20. THICK LIQUID-WALLED, FIELD-REVERSED CONFIGURATION* R. W. Moira

    E-print Network

    California at Los Angeles, University of

    1 THICK LIQUID-WALLED, FIELD-REVERSED CONFIGURATION* R. W. Moira , R. H. Bulmera , K. Gulecb , P 207, Argonne, IL 60439 Abstract A thick flowing layer of liquid (e.g., flibe--a molten salt, or Sn80Li20--a liquid metal) protects the structural walls of the field-reversed configuration (FRC) so

  1. Trocar-related abdominal wall bleeding in 200 patients after laparoscopic cholecistectomy: Personal experience

    PubMed Central

    Geraci, Girolamo; Sciumè, Carmelo; Pisello, Franco; Volsi, Francesco Li; Facella, Tiziana; Modica, Giuseppe

    2006-01-01

    AIM: To determine the complications and incidence of the first and second access-related vascular injuries induced by videolaparoscopic cholecistectomy. METHODS: We retrospectively reviewed vascular injuries in 200 consecutive patients who underwent videolaparoscopic cholecistectomy from 2003 to 2005. One hundred and one patients with placement of radial expanding trocars were assigned into group A and 99 patients with placement of pyramidal tipped trocars into group B. All the patients were submitted to open access according to Hasson for the first trocar. RESULTS: Bleeding did not occur at the intraoperative cannula-site in group A. However, it occurred at the intraoperative cannula-site of 7 patients (7.1%) in group B, with a statistically significant difference (P < 0.01). No mortality was registered. More vascular lesions were found in group B. CONCLUSION: The advantage of Hasson technique is that peritoneal cavity access is gained under direct vision, preventing most severe injuries. The open technique with radial expanding trocars is recommended for secure access to the abdominal cavity in videolaparoscopy. Great care should be taken to avoid major complications and understanding the abdominal wall anatomy is important for reducing bleeding during or after s placement of trocars. PMID:17131480

  2. Subcostal transversus abdominis plane phenol injection for abdominal wall cancer pain.

    PubMed

    Restrepo-Garces, Carlos Eduardo; Asenjo, Juan Francisco; Gomez, Carlos Mario; Jaramillo, Santiago; Acosta, Nathalia; Ramirez, Lizeth Jazmin; Lopera, Luz Maria; Vargas, Juan Felipe

    2014-03-01

    A subcostal transversus abdominis plane (TAP) phenol injection was performed on a patient with refractory cancer pain due a metastatic involvement of the abdominal wall. A diagnostic block with local anesthetic was performed under ultrasound guidance (USG), resulting in a decrease of 80% and 100% in dynamic and static visual analog scale (VAS) for pain, respectively, for 20 hours. A phenol injection was then performed under USG. The patient reported 70% and 100% reduction in the dynamic and static VAS for pain and had a 50% decrease in the opioid requirement that was maintained for 2 months. TAP blocks offer an interesting tool for either diagnosis or therapeutic purpose in chronic pain management. USG provides an optimal approach to soft-tissue lesions where fluoroscopy techniques are not useful. PMID:23560547

  3. Repair of Abdominal Wall Defects with Biodegradable Laminar Prostheses: Polymeric or Biological?

    PubMed Central

    Pascual, Gemma; Sotomayor, Sandra; Rodríguez, Marta; Pérez-Köhler, Bárbara; Bellón, Juan M.

    2012-01-01

    Introduction Biological and synthetic laminar absorbable prostheses are available for the repair of hernia defects in the abdominal wall. They share the important feature of being gradually degraded in the host, resulting in place the formation of a neotissue. This study was designed to assess the host tissue’s incorporation of collagen bioprostheses and a synthetic absorbable prosthesis. Methods Partial defects were created in the abdominal walls of 72 New Zealand rabbits and repaired using collagen bioprostheses Tutomesh® and Strattice® or a synthetic prosthesis Bio-A®. Specimens were collected for light microscopy, collagens gene and protein expression, macrophage response and biomechanical resistance at 14, 30, 90 and 180 days post-implantation. Results Tutomesh® and Bio-A® were gradually infiltrated by the host tissue and almost completely degraded by 180 days post-implantation. In contrast, Strattice® exhibited material encapsulation, no prosthetic degradation and low cell infiltration at earlier timepoints, whereas at later study time, collagen deposition could be observed within the mesh. In the short term, Bio-A® exhibited higher level of collagen 1 and 3 mRNA expression compared with the two other biological prostheses, which exhibited two peaks of higher expression at 14 and 90 days. The expression of collagen III was homogeneous throughout the study and collagen I deposition was more evident in Strattice®. Macrophage response decreased over time in biomeshes. However, in the synthetic mesh remained high and homogeneous until 90 days. The biomechanical analysis demonstrated the progressively increasing tensile strength of all biomaterials. Conclusions The tissue infiltration of laminar absorbable prostheses is affected by the structure and composition of the mesh. The synthetic prosthesis exhibited a distinct pattern of tissue incorporation and a greater macrophage response than did the biological prostheses. Of all of the laminar, absorbable biomaterials that were tested in this study, Strattice® demonstrated the optimal levels of integration and degradation. PMID:23285119

  4. Wall "Thickness" Effects on Raman Spectrum Shift, Thermal Conductivity, and Young's Modulus of Single-Walled Nanotubes

    E-print Network

    Li, Baowen

    Wall "Thickness" Effects on Raman Spectrum Shift, Thermal Conductivity, and Young's Modulus. It can influence the Young's modulus and thermal conductivity, two typical physical quanti- ties of Raman spectrum shift. The introduction of the dynamic thickness changes some conclusions about Young

  5. [A case of fixing an anastomotic site to the abdominal wall out of the abdominal cavity for a small intestinal perforation during chemotherapy].

    PubMed

    Takahashi, Kazutaka; Harano, Masao; Kato, Takuya; Yoshida, Kazuhiro; Sato, Daisuke; Choda, Yasuhiro; Tokumoto, Noriaki; Kanazawa, Takashi; Matsukawa, Hiroyoshi; Ojima, Yasutomo; Idani, Hitoshi; Shiozaki, Shigehiro; Okajima, Masazumi; Ninomiya, Motoki

    2014-11-01

    A 53-year-old man presented with a continuous high fever and was diagnosed with diffuse large B-cell lymphoma with metastasis to the lung, spleen, and mesenterium. He was treated with cyclophosphamide and prednisolone followed by administration of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) chemotherapy 20 days later. Two days after initiation of CHOP therapy, the patient complained of severe abdominal pain. Perforative peritonitis was diagnosed using abdominal computed tomography. A perforation of the small intestine approximately 160 cm distal to the Treitz ligament was uncovered during emergency laparotomy. The risk of leakage was considered too high for anastomosis of the small intestine to be performed. Further, construction of an intestinal stoma could result in a high-output syndrome that could lead to difficulty in resuming chemotherapy. Based on these considerations, we fixed the anastomotic region to the abdominal wall using a technique similar to construction of an intestinal stoma. Post-operative anastomotic leakage did not occur. Nine days later, a perineal hernia was noted near the anastomotic site and a second operation was performed. The anastomotic site was placed back into the abdominal cavity during this operation. CHOP therapy was resumed 16 days after the first operation. PMID:25731554

  6. Thermal stresses and deformations in composite thin-walled and thick-walled tubes and shells

    SciTech Connect

    Tutuncu, Naki.

    1991-01-01

    First, thermal twist of thin-walled tubes made of hybrid laminates and maximization of the thermal twist rate are considered. The twist rate involved both material and geometric parameters. The coefficient of thermal shear, which is a material property, and the cross-sectional geometry of the tube, which is a geometric property, are both optimized keeping the hygrothermal degradation of the material and the change in the torsional stiffness of the tube to a minimum. Next, stresses and deformations due to combined and thermal loads in thick-walled composite cylinders are examined. An elasticity solution is used to calculated radial stresses and deformations. Finally, stresses and deformations in spherical composite shells subject to internal pressure, and thermal loads are studied in two sections: in the first, spherical shells made of balanced laminates are considered, and membrane stresses and deformations are calculated. In the second, a bending theory for composite spherical shells made of antisymmetric laminates with infinitely many plies is developed, and stresses due to edge loads are calculated.

  7. Patient-specific left atrial wall-thickness measurement and visualization for radiofrequency ablation

    NASA Astrophysics Data System (ADS)

    Inoue, Jiro; Skanes, Allan C.; White, James A.; Rajchl, Martin; Drangova, Maria

    2014-03-01

    INTRODUCTION: For radiofrequency (RF) catheter ablation of the left atrium, safe and effective dosing of RF energy requires transmural left atrium ablation without injury to extra-cardiac structures. The thickness of the left atrial wall may be a key parameter in determining the appropriate amount of energy to deliver. While left atrial wall-thickness is known to exhibit inter- and intra-patient variation, this is not taken into account in the current clinical workflow. Our goal is to develop a tool for presenting patient-specific left atrial thickness information to the clinician in order to assist in the determination of the proper RF energy dose. METHODS: We use an interactive segmentation method with manual correction to segment the left atrial blood pool and heart wall from contrast-enhanced cardiac CT images. We then create a mesh from the segmented blood pool and determine the wall thickness, on a per-vertex basis, orthogonal to the mesh surface. The thickness measurement is visualized by assigning colors to the vertices of the blood pool mesh. We applied our method to 5 contrast-enhanced cardiac CT images. RESULTS: Left atrial wall-thickness measurements were generally consistent with published thickness ranges. Variations were found to exist between patients, and between regions within each patient. CONCLUSION: It is possible to visually determine areas of thick vs. thin heart wall with high resolution in a patient-specific manner.

  8. The Bulging Behavior of Thick-Walled 6063 Aluminum Alloy Tubes Under Double-Sided Pressures

    NASA Astrophysics Data System (ADS)

    Cui, Xiao-Lei; Wang, Xiao-Song; Yuan, Shi-Jian

    2015-05-01

    To make further exploration on the deformation behavior of tube under double-sided pressures, the thick-walled 6063 aluminum alloy tubes with an outer diameter of 65 mm and an average thickness of 7.86 mm have been used to be bulged under the combined action of internal and external pressures. In the experiment, two ends of the thick-walled tubes were fixed using the tooth and groove match. Three levels of external pressure (0 MPa, 40 MPa, and 80 MPa), in conjunction with the internal pressure, were applied on the tube outside and inside simultaneously. The effect of external pressure on the bulging behavior of the thick-walled tubes, such as the limiting expansion ratio, the bulging zone profile, and the thickness distribution, has been investigated. It is shown that the limiting expansion ratio, the bulging zone profile, and the thickness distribution in the homogeneous bulging area are all insensitive to the external pressure. However, the external pressure can make the thick-walled tube achieve a thinner wall at the fracture area. It reveals that the external pressure can only improve the fracture limit of the thick-walled 6063 tubes, but it has very little effect on their homogeneous bulging behavior. It might be because the external pressure can only increase the magnitude of the hydrostatic pressure for the tube but has no effect on the Lode parameter.

  9. Method of controlling the side wall thickness of a turbine nozzle segment for improved cooling

    DOEpatents

    Burdgick, Steven Sebastian (Schenectady, NY)

    2002-01-01

    A gas turbine nozzle segment has outer and inner bands and a vane extending therebetween. Each band has a side wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures of the impingement plate to cool the nozzle wall. The side wall of the band has an inturned flange defining with the nozzle wall an undercut region. The outer surface of the side wall is provided with a step prior to welding the cover to the side wall. A thermal barrier coating is applied in the step and, after the cover is welded to the side wall, the side wall is finally machined to a controlled thickness removing all, some or none of the coating.

  10. Developing a new methodology to characterize in vivo the passive mechanical behavior of abdominal wall on an animal model.

    PubMed

    Simón-Allué, R; Montiel, J M M; Bellón, J M; Calvo, B

    2015-11-01

    The most common surgical repair of abdominal wall hernia goes through implanting a mesh that substitutes the abdominal muscle/fascia while it is healing. To reduce the risk of relapse or possible complications, this mesh needs to mimic the mechanical behavior of the muscle/fascia, which nowadays is not fully determined. The aim of this work is to develop a methodology to characterize in vivo the passive mechanical behavior of the abdominal wall. For that, New Zealand rabbits were subjected to pneumoperitoneum tests, taking the inner pressure from 0 mmHg to 12 mmHg, values similar to those used in human laparoscopies. Animals treated were divided into two groups: healthy and herniated animals with a surgical mesh (polypropylene Surgipro(TM) Covidien) previously implanted. All experiments were recorded by a stereo rig composed of two synchronized cameras. During the postprocessing of the images, several points over the abdominal surface were tracked and their coordinates extracted for different levels of internal pressure. Starting from that, a three dimensional model of the abdominal wall was reconstructed. Pressure-displacement curves, radii of curvature and strain fields were also analysed. During the experiments, animals tissue mostly deformed during the first levels of pressure, showing the noticeable hyperelastic passive behavior of abdominal muscles. Comparison between healthy and herniated specimen displayed a strong stiffening for herniated animals in the zone where the high density mesh was situated. Cameras were able to discern this change, so this method can be used to measure the possible effect of other meshes. PMID:26209832

  11. A randomized controlled experimental study comparing chitosan coated polypropylene mesh and Proceed™ mesh for abdominal wall defect closure

    PubMed Central

    Jayanth, S.T.; Pulimood, Anna; Abraham, Deepak; Rajaram, A.; Paul, M.J.; Nair, Aravindan

    2015-01-01

    Background Abdominal wall defects and hernias are commonly repaired with synthetic or biological materials. Adhesions and recurrences are a common problem. A study was conducted to compare Chitosan coated polypropylene mesh and a polypropylene–polydioxanone composite with oxidized cellulose coating mesh (Proceed™) in repair of abdominal wall defect in a Rabbit hernia model. Methods A randomized controlled experimental study was done on twelve New Zealand white rabbits. A ventral abdominal defect was created in each of the rabbits. The rabbits were divided into two groups. In one group the defect was repaired with Chitosan coated polypropylene mesh and Proceed mesh™ in the other. The rabbits were operated in two phases. They were followed up at four weeks and twelve weeks respectively after which the rabbits were sacrificed. They were evaluated by open exploration and histopathological examination. Their efficacy in reducing adhesion and ability of remodeling and tissue integration were studied. Results There was no statistical significance in the area of adhesion, the force required to remove the adhesions, tissue integration and remodeling between Chitosan and Proceed™ group. Histological analysis revealed that the inflammatory response, fibrosis, material degradation and remodeling were similar in both the groups. There were no hernias, wound infection or dehiscence in any of the studied animals. Conclusion Chitosan coated polypropylene mesh was found to have similar efficacy to Proceed™ mesh. Chitosan coated polypropylene mesh, can act as an anti adhesive barrier when used in the repair of incisional hernias and abdominal wall defects. PMID:26594357

  12. Gravity trapping on a finite thickness domain wall: An analytic study

    SciTech Connect

    Cvetic, Mirjam; Robnik, Marko

    2008-06-15

    We construct an explicit model of the gravity trapping domain-wall potential, where for the first time we can study explicitly the graviton wave function fluctuations for any thickness of domain wall. A concrete form of the potential depends on one parameter 0{<=}x{<=}({pi}/2), which effectively parameterizes the thickness of the domain wall with specific limits x{yields}0 and x{yields}({pi}/2) corresponding to the thin and the thick wall, respectively. The analysis of continuum Kaluza-Klein fluctuations yields explicit expressions for both small and large Kaluza-Klein energy. We also derive specific explicit conditions in the regime x>1, for which the fluctuation modes exhibit a resonance behavior, and which could sizably affect the modifications of the four-dimensional Newton's law at distances that typically are by 4 orders of magnitude larger than those relevant for Newton's law modifications of thin walls.

  13. Suprailiac or abdominal skinfold thickness measured with a skinfold caliper as a predictor of body density in Japanese adults.

    PubMed

    Demura, Shin-ichi; Sato, Susumu

    2007-09-01

    Measurement of subcutaneous fat thickness with a skinfold caliper is a simple and inexpensive technique for assessment of body composition, but is influenced by the skin site or the obesity level. The resulting measurement errors may influence the prediction accuracy of body density. We therefore aimed to clarify the characteristics of measurement errors with a skinfold caliper and to determine useful measurement sites for the prediction of body density in Japanese adults of wide-ranging age and obesity levels. The present study included 126 Japanese male and 77 female subjects ranging from 21 to 81 years old. They were divided into a "non-obese group" and an "obese group", based on the Japanese criteria of obesity (BMI > or = 25 kg/m(2)). Subcutaneous fat thickness was measured at 14 sites with a skinfold caliper and ultrasound. Percent body fat was measured by dual-energy x-ray absorptiometry, and body density was calculated using Brozek's formula. Sex and obesity level differences in the measurement error of skinfolds (ultrasound minus skinfold caliper measurements) were examined by 2 x 2 ANOVA (sex and obesity groups) for each site. The relationship between body density and the systematic error was examined. We developed an accurate prediction equation for body density with smaller measurement and systematic errors. Although measurement errors in skinfold thickness tended to increase with increasing obesity levels, the influence was smaller for the abdominal and suprailiac skinfolds compared with other sites. Measurement of suprailiac or abdominal skinfold thickness is useful to accurately estimate body density in Japanese adults. PMID:17785953

  14. Effects of thickness, insulation, and surface color on the net heat loss through an adobe wall

    SciTech Connect

    Herman, R.W.

    1980-01-01

    A finite difference computer program was written and run to study the net thermal losses through a large variety of adobe walls. Fifty-four different combinations of surface color, wall thickness, and insulation position and R value were modeled over a typical two week winter period for locations similar to Albuquerque, New Mexico. A transient analysis of the heat loss from the room to the interior wall surface was compared to both conventional U value and steady-state calculations.

  15. Metastatic breast carcinoma of the abdominal wall muscle: a case report.

    PubMed

    Ogiya, Akiko; Takahashi, Kaoru; Sato, Mutsumi; Kubo, Yoshiko; Nishikawa, Noriko; Kikutani, Mariko; Tadokoro, Yukiko; Tanaka, Kumiko; Uematsu, Takayoshi; Watanabe, Junichiro; Kasami, Masako; Yamasaki, Seiji

    2015-03-01

    Metastasis from breast carcinoma is an uncommon occurrence in skeletal muscle, compared to local invasion into muscle from direct tumor spread. A 49-year-old woman was referred to our hospital with an 8.5-cm mass in the right breast. Core needle biopsy revealed metaplastic carcinoma with squamous metaplasia. The mass was rapidly growing and metaplastic, so mastectomy with dissection of axillary lymph nodes was performed. Pathological examination showed metaplastic carcinoma, histological grade 3, triple negative, and a MIB-1 labeling index of 80%. Six months postoperatively, during adjuvant chemotherapy treatment, she reported numbness and pain in the right lateral thigh and a mass in the right lower abdomen. Computed tomography revealed multiple lined masses in the abdominal wall and iliac muscle. Core needle biopsy showed metastatic breast carcinoma. Radio- and chemotherapy were administered, but the mass in the muscle became enlarged. To control her pain, a combined treatment with morphine, fentanyl, ketamine, antiepilepsy drug, and NSAIDs was administered. Liver metastasis appeared 9 months (15 months postoperatively) after recognition of muscle metastasis, and the patient died 16 months postoperatively. Skeletal muscle metastasis is uncommon, and therapeutic intervention is mainly palliative. The most common symptom of skeletal muscle metastasis is pain; thus, pain control is a pivotal goal of treatment. PMID:22382812

  16. Long-term anisotropic mechanical response of surgical meshes used to repair abdominal wall defects.

    PubMed

    Hernández-Gascón, B; Peña, E; Pascual, G; Rodríguez, M; Bellón, J M; Calvo, B

    2012-01-01

    Routine hernia repair surgery involves the implant of synthetic mesh. However, this type of procedure may give rise to pain and bowel incarceration and strangulation, causing considerable patient disability. The purpose of this study was to compare the long-term behaviour of three commercial meshes used to repair the partially herniated abdomen in New Zealand White rabbits: the heavyweight (HW) mesh, Surgipro(®) and lightweight (LW) mesh, Optilene(®), both made of polypropylene (PP), and a mediumweight (MW) mesh, Infinit(®), made of polytetrafluoroethylene (PTFE). The implanted meshes were mechanical and histological assessed at 14, 90 and 180 days post-implant. This behaviour was compared to the anisotropic mechanical behaviour of the unrepaired abdominal wall in control non-operated rabbits. Both uniaxial mechanical tests conducted in craneo-caudal and perpendicular directions and histological findings revealed substantial collagen growth over the repaired hernial defects causing stiffness in the repair zone, and thus a change in the original properties of the meshes. The mechanical behaviour of the healthy tissue in the craneo-caudal direction was not reproduced by any of the implanted meshes after 14 days or 90 days of implant, whereas in the perpendicular direction, SUR and OPT achieved similar behaviour. From a mechanical standpoint, the anisotropic PP-lightweight meshes may be considered a good choice in the long run, which correlates with the structure of the regenerated tissue. PMID:22100101

  17. Simultaneous Prosthetic Mesh Abdominal Wall Reconstruction with Abdominoplasty for Ventral Hernia and Severe Rectus Diastasis Repairs

    PubMed Central

    Cheesborough, Jennifer E.

    2015-01-01

    Background: Standard abdominoplasty rectus plication techniques may not suffice for severe cases of rectus diastasis. In the authors’ experience, prosthetic mesh facilitates the repair of severe rectus diastasis with or without concomitant ventral hernias. Methods: A retrospective review of all abdominal wall surgery patients treated in the past 8 years by the senior author (G.A.D.) was performed. Patients with abdominoplasty and either rectus diastasis repair with mesh or a combined ventral hernia repair were analyzed. Results: Thirty-two patients, 29 women and three men, underwent mesh-reinforced midline repair with horizontal or vertical abdominoplasty. Patient characteristics included the following: mean age, 53 years; mean body mass index, 26 kg/m2; average width of diastasis or hernia, 6.7 cm; and average surgery time, 151 minutes. There were no surgical-site infections and two surgical-site occurrences—two seromas treated with drainage in the office. After an average of 471 days’ follow-up, none of the patients had recurrence of a bulge or a hernia. Conclusions: For patients with significant rectus diastasis, with or without concomitant hernias, the described mesh repair is both safe and durable. Although this operation requires additional dissection and placement of prosthetic mesh in the retrorectus plane, it may be safely combined with standard horizontal or vertical abdominoplasty skin excision techniques to provide an aesthetically pleasing overall result. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV. PMID:25539311

  18. An Elastomeric Patch Electrospun from a Blended Solution of Dermal Extracellular Matrix and Biodegradable Polyurethane for Rat Abdominal Wall Repair

    PubMed Central

    Hong, Yi; Takanari, Keisuke; Amoroso, Nicholas J.; Hashizume, Ryotaro; Brennan-Pierce, Ellen P.; Freund, John M.; Badylak, Stephen F.

    2012-01-01

    A biodegradable elastomeric scaffold was created by electrospinning a mixed solution of poly(ester urethane)urea (PEUU) and porcine dermal extracellular matrix (dECM) digest, with PEUU included to provide elasticity, flexibility, and mechanical support and dECM used to enhance bioactivity and biocompatibility. Micrographs and differential scanning calorimetry demonstrated partial miscibility between PEUU and dECM. With greater dECM content, scaffolds were found to possess lower breaking strains and suture retention strength, although initial modulus was greater with higher dECM concentrations. The hybrid scaffolds containing 0% to 50% dECM had tensile strengths of 5 to 7?MPa, breaking strains of 138% to 611%, initial moduli of 3 to 11 Mpa, and suture retention strengths of 35 to 59?MPa. When hydrated, scaffolds were found to contract markedly with 50% dECM content. When used in a rat full-thickness abdominal wall replacement model, no herniation, infection, or tissue adhesion was observed after 4 and 8 weeks with a scaffold containing 25% dECM or a control 100% PEUU scaffold. Scaffolds incorporating dECM were significantly thicker at the time of explant, with greater numbers of associated smooth muscle actin–positive staining cells than in the control, but minimal cellular infiltration and remodeling of the scaffold were detected regardless of dECM addition. The processing of dECM and PEUU from a mixed solution thus provided a scaffold with evidence of better bioactivity and with mechanical properties not achievable with digested dECM alone. PMID:21933017

  19. An elastomeric patch electrospun from a blended solution of dermal extracellular matrix and biodegradable polyurethane for rat abdominal wall repair.

    PubMed

    Hong, Yi; Takanari, Keisuke; Amoroso, Nicholas J; Hashizume, Ryotaro; Brennan-Pierce, Ellen P; Freund, John M; Badylak, Stephen F; Wagner, William R

    2012-02-01

    A biodegradable elastomeric scaffold was created by electrospinning a mixed solution of poly(ester urethane)urea (PEUU) and porcine dermal extracellular matrix (dECM) digest, with PEUU included to provide elasticity, flexibility, and mechanical support and dECM used to enhance bioactivity and biocompatibility. Micrographs and differential scanning calorimetry demonstrated partial miscibility between PEUU and dECM. With greater dECM content, scaffolds were found to possess lower breaking strains and suture retention strength, although initial modulus was greater with higher dECM concentrations. The hybrid scaffolds containing 0% to 50% dECM had tensile strengths of 5 to 7 MPa, breaking strains of 138% to 611%, initial moduli of 3 to 11 Mpa, and suture retention strengths of 35 to 59 MPa. When hydrated, scaffolds were found to contract markedly with 50% dECM content. When used in a rat full-thickness abdominal wall replacement model, no herniation, infection, or tissue adhesion was observed after 4 and 8 weeks with a scaffold containing 25% dECM or a control 100% PEUU scaffold. Scaffolds incorporating dECM were significantly thicker at the time of explant, with greater numbers of associated smooth muscle actin-positive staining cells than in the control, but minimal cellular infiltration and remodeling of the scaffold were detected regardless of dECM addition. The processing of dECM and PEUU from a mixed solution thus provided a scaffold with evidence of better bioactivity and with mechanical properties not achievable with digested dECM alone. PMID:21933017

  20. [Colonic localization of Crohn's disease following a recurrent pseudotumor of the abdominal wall (problems of pathogenesis and therapy)].

    PubMed

    Stoica, T; Laky, D; Stadnicov, O; Sorescu, I; Stoica, D T

    1980-01-01

    A pseudo-tumours of the abdominal wall is described, in the left hypochondrum and the left flank, that, recidivating after 5 years, invaded the splenic angle of the colon. The common histological characteristics were very clear and strongly suggested the presence of Crohn disease. The cellular elements found at the first intervention performed for the extirpation of the tumour in the abdominal wall, as well as at reintervention--consisting in the block resection of the recidivating tumour and of the segment of the colon involved (segmental colectomy)--represented by abundant plasmocytic infiltrates suggest the presence of an immune process. The problem raised is the possibility that the Crohn disease could be incriminated in both instances, since the immunological disturbances can be considered as clearly manifest. PMID:6445578

  1. Reconstruction of carotid bifurcation hemodynamics and wall thickness using computational fluid dynamics and MRI.

    PubMed

    Steinman, David A; Thomas, Jonathan B; Ladak, Hanif M; Milner, Jaques S; Rutt, Brian K; Spence, J David

    2002-01-01

    A thorough understanding of the relationship between local hemodynamics and plaque progression has been hindered by an inability to prospectively monitor these factors in vivo in humans. In this study a novel approach for noninvasively reconstructing artery wall thickness and local hemodynamics at the human carotid bifurcation is presented. Three-dimensional (3D) models of the lumen and wall boundaries, from which wall thickness can be measured, were reconstructed from black-blood magnetic resonance imaging (MRI). Along with time-varying inlet/outlet flow rates measured via phase contrast (PC) MRI, the lumen boundary was used as input for computational fluid dynamic (CFD) simulation of the subject-specific flow patterns and wall shear stresses (WSSs). Results from a 59-year-old subject with early, asymptomatic carotid artery disease show good agreement between simulated and measured velocities, and demonstrate a correspondence between wall thickening and low and oscillating shear at the carotid bulb. High shear at the distal internal carotid artery (ICA) was also colocalized with higher WSS; however, a quantitative general relationship between WSS and wall thickness was not found. Similar results were obtained from a 23-year-old normal subject. These findings represent the first direct comparison of hemodynamic variables and wall thickness at the carotid bifurcation of human subjects. The noninvasive nature of this image-based modeling approach makes it ideal for carrying out future prospective studies of hemodynamics and plaque development or progression in otherwise healthy subjects. PMID:11754454

  2. Successful Treatment of Mesenteric Varices After Living Donor Liver Transplantation with Retrograde Transvenous Obliteration Via an Abdominal Wall Vein

    SciTech Connect

    Ikeda, Osamu Tamura, Yoshitaka; Nakasone, Yutaka; Yamashita, Yasuyuki; Okajima, Hideaki; Asonuma, Katsuhiro; Inomata, Yukihiro

    2010-06-15

    Balloon-occluded retrograde transvenous obliteration is an established treatment for gastric varices; it has been used more rarely to treat mesenteric varices. We report a 12-year-old girl who had received a living donor liver transplant and suffered melena due to ruptured mesenteric varices. We addressed treatment of the mesenteric varices by retrograde transvenous obliteration of an abdominal wall collateral vein detected by superior mesenteric arteriography.

  3. Laser Ultrasonic Thickness Measurements of Very Thick Walls at High Temperatures

    SciTech Connect

    Kruger, S. E.; Lord, M.; Monchalin, J.-P.

    2006-03-06

    Laser-ultrasonics presents many advantages compared to conventional ultrasonics, but is, generally, considered as less sensitive. As a consequence, laser-ultrasonics should not be adequate for ultrasonic measurements in coarse microstructure materials or measurements of large thicknesses. However, since the generated waves extend to very low frequencies, measurements in such conditions can be successfully performed if a photorefractive interferometer sensitive also to these low frequencies and properly balanced is used for detection. This is demonstrated by measurements of thicknesses up to 100 mm (4'') for various steel grades and at temperatures up to 1250 deg. C.

  4. Abdominal hollowing and lateral abdominal wall muscles' activity in both healthy men & women: An ultrasonic assessment in supine and standing positions.

    PubMed

    Manshadi, Farideh Dehghan; Parnianpour, Mohamad; Sarrafzadeh, Javad; Azghani, Mahmood Reza; Kazemnejad, Anooshirvan

    2011-01-01

    The objective of this study was to investigate the effects of Abdominal Hollowing (AH) maneuver on External Oblique (EO), Internal Oblique (IO) and Transversus Abdominis (TrA) muscles in both healthy men and women during the two postures of supine and upright standing. The study was conducted on 43 asymptomatic volunteers (22 males and 21 females) aged 19-44 (27.8±6.4) years. Rehabilitative Ultrasonic Imaging (RUSI) was simultaneously performed to measure muscle thickness in both rest and during AH maneuvers while activation of the TrA during AH was controlled by Pressure Biofeedback (PBF) device. Mixed-model ANOVA with repeated measures design, and Pearson correlation tests were used to analyze the data. Muscle thickness of all muscles was significantly higher for male subjects (F>6.2, p<0.017). The interaction effect of gender and muscle status was significant only for IO (F=7.458, p=0.009) indicating that AH maneuver increased the thickness of IO in men. Interaction effect of posture and muscle status on muscular thickness indicated that changing position only affects the resting thickness of TrA (F=5.617, p=0.023). Standing posture significantly affected the TrA contraction ratio (t=3.122, p=0.003) and TrA preferential activation ratio (t=2.76, p=0.008). There was no relationship between age and muscle thickness (r=0.262, p=0.09). The PBF has been introduced as a clinical and available device for monitoring TrA activity, while RUSI showed that both TrA and IO muscles had activated after AH maneuver. We recommend performing further investigations using electromyography and RUSI simultaneously at more functional postures such as upright standing. PMID:21147426

  5. Colonic wall thickness using level sets for CT virtual colonoscopy visual assessment and polyp detection

    NASA Astrophysics Data System (ADS)

    Van Uitert, Robert L.; Summers, Ronald M.

    2007-03-01

    The detection of polyps in virtual colonoscopy is an active area of research. One of the critical elements in detecting cancerous polyps using virtual colonoscopy, especially in conjunction with computer-aided detection, is the accurate segmentation of the colon wall. The large CT attenuation difference between the lumen and inner, mucosal layer of the colon wall makes the segmentation of the lumen easily performed by traditional threshold segmentation techniques. However, determining the location of the colon outer wall is often difficult due to the low contrast difference between the colon wall's outer serosal layer and the fat surrounding the colon. We have developed an automatic, level set based method to determine from a CT colonography scan the location of the colon inner boundary and the colon outer wall boundary. From the location of the inner and outer colon wall boundaries, the wall thickness throughout the colon can be computed. Color mapping of the wall thickness on the colon surface allows for easy visual determination of potential regions of interest. Since the colon wall tends to be thicker at polyp locations, potential polyps also can be detected automatically at sites of increased colon wall thickness. This method was validated on several CT colonography scans containing optical colonoscopy-proven polyps. The method accurately determined thicker colonic wall regions in areas where polyps are present in the ground truth datasets and detected the polyps at a false positive rate between 44.4% and 82.8% lower than a state-of-the-art curvature-based method for initial polyp detection.

  6. Delayed primary closure of contaminated abdominal wall defects with non-crosslinked porcine acellular dermal matrix compared with conventional staged repair: a retrospective study

    PubMed Central

    2014-01-01

    Introduction Synthetic mesh has been used traditionally to repair abdominal wall defects, but its use is limited in the case of bacterial contamination. New biological materials are now being used successfully for delayed primary closure of contaminated abdominal wall defects. The costs of biological materials may prevent surgeons from using them. We compared the conventional staged repair of contaminated abdominal wall defects with a single-stage procedure using a non-crosslinked porcine acellular dermal matrix. Methods A total of 14 cases with Grade 3 contaminated abdominal wall defects underwent delayed primary closure of the abdomen using a non-crosslinked porcine acellular dermal matrix (Strattice™ Reconstructive Tissue Matrix, LifeCell Corp., Branchburg, NJ, USA). The results were compared with a group of 14 patients who had received conventional treatment for the repair of contaminated abdominal wall defects comprising a staged repair during two separate hospital admissions employing synthetic mesh. Treatment modalities, outcomes, and costs were compared. Results In all cases treated with delayed primary closure employing non-crosslinked porcine acellular dermal matrix, there were no complications related to its use. Two patients died due to unrelated events. Although treatment costs were estimated to be similar in the two groups, the patients treated with porcine acellular dermal matrix spent less time as an inpatient than those receiving conventional two-stage repair. Conclusions Delayed primary closure of contaminated abdominal wall defects using a non-crosslinked porcine acellular dermal matrix may be a suitable alternative to conventional staged repair. In our patients, it resulted in early restoration of abdominal wall function and shorter hospitalization. The costs for treating contaminated abdominal wall defects using porcine acellular dermal matrix during a single hospital admission were not higher than costs for conventional two-stage repair. Further randomized studies are needed to expand upon these findings. PMID:25015374

  7. Surface plasmon and photonic mode propagation in gold nanotubes with varying wall thickness

    SciTech Connect

    Kohl, Jesse; Fireman, Micha; O'Carroll, Deirdre M.

    2011-12-15

    Gold nanotube arrays are synthesized with a range of wall thicknesses (15 to >140 nm) and inner diameters of {approx}200 nm using a hard-template method. A red spectral shift (>0.39 eV) with decreasing wall thickness is observed in dark-field spectra of nanotube arrays and single nanowire/nanotube heterostructures. Finite-difference-time-domain simulations show that nanotubes in this size regime support propagating surface plasmon modes as well as surface plasmon ring resonances at visible wavelengths (the latter is observed only for excitation directions normal to the nanotube long axis with transverse polarization). The energy of the surface plasmon modes decreases with decreasing wall thickness and is attributed to an increase in mode coupling between propagating modes in the nanotube core and outer surface and the circumference dependence of ring resonances. Surface plasmon mode propagation lengths for thicker-walled tubes increase by a factor of {approx}2 at longer wavelengths (>700 nm), where ohmic losses in the metal are low, but thinner-walled tubes (30 nm) exhibit a more significant increase in surface plasmon propagation length (by a factor of more than four) at longer wavelengths. Additionally, nanotubes in this size regime support a photonic mode in their core, which does not change in energy with changing wall thickness. However, photonic mode propagation length is found to decrease for optically thin walls. Finally, correlations are made between the experimentally observed changes in dark-field spectra and the changes in surface plasmon mode properties observed in simulations for the various gold nanotube wall thicknesses and excitation conditions.

  8. Multimodal optical measurement in vitro of surface deformations and wall thickness of the pressurized aortic arch

    NASA Astrophysics Data System (ADS)

    Genovese, Katia; Humphrey, Jay D.

    2015-04-01

    Computational modeling of arterial mechanics continues to progress, even to the point of allowing the study of complex regions such as the aortic arch. Nevertheless, most prior studies assign homogeneous and isotropic material properties and constant wall thickness even when implementing patient-specific luminal geometries obtained from medical imaging. These assumptions are not due to computational limitations, but rather to the lack of spatially dense sets of experimental data that describe regional variations in mechanical properties and wall thickness in such complex arterial regions. In this work, we addressed technical challenges associated with in vitro measurement of overall geometry, full-field surface deformations, and regional wall thickness of the porcine aortic arch in its native anatomical configuration. Specifically, we combined two digital image correlation-based approaches, standard and panoramic, to track surface geometry and finite deformations during pressurization, with a 360-deg fringe projection system to contour the outer and inner geometry. The latter provided, for the first time, information on heterogeneous distributions of wall thickness of the arch and associated branches in the unloaded state. Results showed that mechanical responses vary significantly with orientation and location (e.g., less extensible in the circumferential direction and with increasing distance from the heart) and that the arch exhibits a nearly linear increase in pressure-induced strain up to 40%, consistent with other findings on proximal porcine aortas. Thickness measurements revealed strong regional differences, thus emphasizing the need to include nonuniform thicknesses in theoretical and computational studies of complex arterial geometries.

  9. Use of intraoperative indocyanin-green angiography to minimize wound healing complications in abdominal wall reconstruction.

    PubMed

    Patel, Ketan M; Bhanot, Parag; Franklin, Brenton; Albino, Frank; Nahabedian, Maurice Y

    2013-12-01

    Complication rates following abdominal wall reconstruction (AWR) remain high. Early complications are related to skin necrosis and delayed healing, whereas late complications are related to recurrence. When concomitant body contouring procedures are performed, complication rates can be further increased. It is hypothesised that fluorescent angiography using indocyanin green (ICG) can identify poorly perfused tissues and thus reduce the incidence of delayed healing. A retrospective review was conducted of all patients who underwent AWR with concomitant panniculectomy from 2007-2012. Intraoperative ICG angiography with the SPY system (LifeCell Corp.) was used to determine the amount of resection for body contouring in patients who underwent reconstruction in a cohort of patients. SPY-Q was used to assess relative perfusion of analysed areas. Preoperative, postoperative, and operative details were analyzed. Seventeen patients met inclusion criteria, 12 patients were included in the non-ICG cohort, while five patients were included in the ICG cohorts. Wound-healing complications occurred in 5/12 (42%) patients in the non-ICG cohort vs 1/5 (20%) of the ICG cohorts. A description of the sole patient with complications in the ICG cohort is illustrated. Operative debridement and wound infection development occurred more frequently in the non-ICG cohort compared with the ICG cohort (17%, 17% vs 0%, 0%, respectively). Average time to wound healing was 41.1 days. Intraoperative ICG angiography can accurately detect perfusion abnormalities and can decrease wound healing related complications in complex hernia repair with concomitant panniculectomy. Assessing and ensuring skin viability can decrease the need for operative debridement. PMID:23596988

  10. Measurement of Fetal Abdominal and Subscapular Subcutaneous Tissue Thickness during Pregnancy to Predict Macrosomia: A Pilot Study

    PubMed Central

    Chen, Xiao-Hui; Cao, Li; Wu, Yun; Zhu, Li-Jun; Lv, Kang-Tai; Ji, Chen-Bo; Guo, Xi-Rong

    2014-01-01

    This study assessed the growth trends and reference ranges of the ultrasound parameters, fetal abdominal subcutaneous tissue thickness (ASTT) and subscapular subcutaneous tissue thickness (SSTT), in the last two trimesters of normal pregnancy in a Chinese population. We recruited 744 healthy women with singleton pregnancies. The ASTT and SSTT were evaluated at different times between 21 and 36 weeks of gestation. The correlations between these parameters and fetal gestational weeks were assessed using linear regression analysis. Both ASTT and SSTT increased with gestation, and both parameters showed a strong correlation with gestation (ASTT vs. GA, R2?=?0.792; P<0.0001; SSTT vs. GA, R2?=?0.302; P<0.0001). Time-specific reference ranges, including 5th, 50th and 95th percentiles and means ± SD, were constructed for ASTT and SSTT. These results provide a preliminary reference range to evaluate whether fetal development and maternal metabolic health is normal or not in a Chinese population. PMID:24675769

  11. An exact solution for a thick domain wall in general relativity

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1989-01-01

    An exact solution of the Einstein equations for a static, planar domain wall with finite thickness is presented. At infinity, density and pressure vanish and the space-time tends to the Minkowski vacuum on one side of the wall and to the Taub vacuum on the other side. A surprising feature of this solution is that the density and pressure distribution are symmetric about the central plane of the wall whereas the space-time metric and therefore also the gravitational field experienced by a test particle is asymmetric.

  12. Fatigue life improvement of an autofrettage thick-walled pressure vessel with an external groove

    NASA Astrophysics Data System (ADS)

    Koh, Seung K.; Stephens, Ralph I.

    1992-01-01

    This report presents an investigation into a fatigue life improvement of an autofrettaged thick-walled pressure vessel with an external groove subjected to pulsating internal pressure, along with mean strain and mean stress effects on strain-controlled low cycle fatigue behavior. Linear elastic stress analysis of an autofrettaged thick-walled pressure vessel with an external groove is done using a finite element method. Autofrettage loading is performed using a thermal loading analogy. Change of external groove geometry is made using a quasi-optimization technique and finite element method to achieve longer fatigue life by relieving the stress concentration at the groove root. Surface treatment using shot peening is employed to produce compressive residual stresses at the vulnerable surface of the groove root to counteract the high tensile stresses. An evaluation of the fatigue life of an autofrettaged thick-walled pressure vessel with an external groove is done through a series of simulation fatigue tests using C-shaped specimens taken from the thick-walled pressure vessel.

  13. Boll wall thickness in four cotton species and susceptibility to stink bug feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), adults can introduce pathogens into cotton bolls while feeding. Stylet penetration estimates of southern green stink bugs are known, and knowledge of boll wall thickness in cotton species may aid in determining susceptibility...

  14. Millimeter-Thick Single-Walled Carbon Nanotube Forests: Hidden Role of Catalyst Support

    E-print Network

    Maruyama, Shigeo

    the realizations of the vertically-aligned single-walled carbon nanotube (VA-SWNT) forests1) by alcohol chemical conditions.3-6) Among these methods, the water-assisted method, the so-called "super growth" method,3 structure with a diameter and areal density that depended on the initial Fe thickness.8) After the heat

  15. Magnet Fall inside a Conductive Pipe: Motion and the Role of the Pipe Wall Thickness

    ERIC Educational Resources Information Center

    Donoso, G.; Ladera, C. L.; Martin, P.

    2009-01-01

    Theoretical models and experimental results are presented for the retarded fall of a strong magnet inside a vertical conductive non-magnetic tube. Predictions and experimental results are in good agreement modelling the magnet as a simple magnetic dipole. The effect of varying the pipe wall thickness on the retarding magnetic drag is studied for…

  16. Quantification of esophageal wall thickness in CT using atlas-based segmentation technique

    NASA Astrophysics Data System (ADS)

    Wang, Jiahui; Kang, Min Kyu; Kligerman, Seth; Lu, Wei

    2015-03-01

    Esophageal wall thickness is an important predictor of esophageal cancer response to therapy. In this study, we developed a computerized pipeline for quantification of esophageal wall thickness using computerized tomography (CT). We first segmented the esophagus using a multi-atlas-based segmentation scheme. The esophagus in each atlas CT was manually segmented to create a label map. Using image registration, all of the atlases were aligned to the imaging space of the target CT. The deformation field from the registration was applied to the label maps to warp them to the target space. A weighted majority-voting label fusion was employed to create the segmentation of esophagus. Finally, we excluded the lumen from the esophagus using a threshold of -600 HU and measured the esophageal wall thickness. The developed method was tested on a dataset of 30 CT scans, including 15 esophageal cancer patients and 15 normal controls. The mean Dice similarity coefficient (DSC) and mean absolute distance (MAD) between the segmented esophagus and the reference standard were employed to evaluate the segmentation results. Our method achieved a mean Dice coefficient of 65.55 ± 10.48% and mean MAD of 1.40 ± 1.31 mm for all the cases. The mean esophageal wall thickness of cancer patients and normal controls was 6.35 ± 1.19 mm and 6.03 ± 0.51 mm, respectively. We conclude that the proposed method can perform quantitative analysis of esophageal wall thickness and would be useful for tumor detection and tumor response evaluation of esophageal cancer.

  17. Physical modeling of friction conditions on the wall thickness variation during sheet hydroforming

    NASA Astrophysics Data System (ADS)

    Li, Feng; Xu, Peng; Zhang, Xinlong; Liu, Qiang

    2015-05-01

    In order to research the influence of friction conditions on the sheet metal deformation behavior under the fluid pressure, the experimental method that can test the relationship between fluid pressure and wall thickness was proposed in this paper. The theoretical model about the quantitative variation relationship between fluid pressure and wall thickness together with the theoretical model about the quantitative variation relationship between friction coefficient and wall thickness, was obtained by theoretical derivation. At the same time, it could be concluded that friction contact region close to the tensile end was easier to satisfy the plastic yield criterion. Therefore, the plastic deformation initially occurred at this area and fracture emerged on account of excessive reduction of the sheet thickness. Simulation analysis with 304 stainless steel was carried out. The result indicated that the capacity of sheet uniform deformation decreased with the increasing of the friction coefficient. When the friction coefficient increased from 0.08 to 0.20, the uniform elongation decreased by 32%. But when other conditions were kept unchanged, the greater the fluid pressure was, the thinner the sheet would be. Experiments indicated that the necking and fracture appeared in the gauge length near the tensile end with different lubricants. And these provided a theoretical basis for the process and device design of sheet metal hydroforming.

  18. The intricate role of mast cell proteases and the annexin A1-FPR1 system in abdominal wall endometriosis.

    PubMed

    Paula, Rubens; Oliani, Antonio H; Vaz-Oliani, Denise C M; D'Ávila, Solange C G P; Oliani, Sonia M; Gil, Cristiane D

    2015-02-01

    Endometriosis is a continuous and progressive disease with a poorly understood aetiology, pathophysiology and natural history. This study evaluated the histological differences between eutopic and ectopic endometria (abdominal wall endometriosis) and the expression of mast cell proteases (tryptase and chymase), annexin A1 (ANXA1) and formyl peptide receptor 1 (FPR1). Ectopic endometrium from 18 women with abdominal wall endometriosis and eutopic endometrium from 10 women without endometriosis were obtained. The endometrial samples were analysed by histopathology, immunohistochemistry and ultrastructural immunogold labeling to determine mast cell heterogeneity (tryptase and chymase positive cells) and the expression levels of ANXA1 and FPR1. Histopathological analysis of the endometriotic lesions showed a glandular pattern of mixed differentiation and an undifferentiated morphology with a significant influx of inflammatory cells and a change in mast cell heterogeneity, as evidenced by a significant increase in the number of chymase-positive cells and endogenous chymase expression. The undifferentiated glandular pattern of endometriotic lesions was positively associated with a marked increase and co-localization of ANXA1 and FPR1 in the epithelial cells. In conclusion, the co-upregulated expression of mast cell chymase and ANXA1-FPR1 system in ectopic endometrium suggests their involvement in the development of endometriotic lesions. PMID:25201101

  19. Blood Vessel Matrix Seeded with Cells: A Better Alternative for Abdominal Wall Reconstruction—A Long-Term Study

    PubMed Central

    Jundzi??, Arkadiusz; Nazarewski, ?ukasz; Kotela, Andrzej; Kloskowski, Tomasz; Skopi?ska-Wisniewska, Joanna; ?ukasiewicz, Aleksander; Nazarewski, S?awomir; Kotela, Ireneusz; Pokrywczy?ska, Marta; Marsza?ek, Andrzej; Drewa, Tomasz

    2015-01-01

    Purpose. The aim of this study was to present abdominal wall reconstruction using a porcine vascular graft seeded with MSC (mesenchymal stem cells) on rat model. Material and Methods. Abdominal wall defect was prepared in 21 Wistar rats. Acellular porcine-vascular grafts taken from aorta and prepared with Triton X were used. 14 aortic grafts were implanted in place, of which 7 grafts were seeded with rat MSC cells (Group I), and 7 were acellular grafts (Group II). As a control, 7 standard polypropylene meshes were used for defect augmentation (Group III). The assessment method was performed by HE and CD31 staining after 6 months. The mechanical properties have been investigated by Zwick&Roell Z0.5. Results. The strongest angiogenesis and lowest inflammatory response were observed in Group I. Average capillaries density was 2.75, 0.75, and 1.53 and inflammatory effect was 0.29, 1.39, and 2.72 for Groups I, II, and III, respectively. The means of mechanical properties were 12.74 ± 1.48, 7.27 ± 1.56, and 14.4 ± 3.7?N/cm in Groups I and II and control, respectively. Conclusions. Cell-seeded grafts have better mechanical properties than acellular grafts but worse than polypropylene mesh. Cells improved mechanical and physiological properties of decellularized natural scaffolds. PMID:25705696

  20. Short- and long-term biomechanical and morphological study of new suture types in abdominal wall closure.

    PubMed

    Simón-Allué, R; Pérez-López, P; Sotomayor, S; Peña, E; Pascual, G; Bellón, J M; Calvo, B

    2014-09-01

    To perform an abdominal-wall closure, a continuous suture is the preferred method. The suture materials that are most commonly employed in abdominal surgery are polypropylene and polydioxanone. However, in recent times, new products have been marketed, such as non-absorbable polyurethane with elastic properties (Assuplus(®), Assut Europe, Italy) and absorbable barbed polydioxanone (Filbloc(®), Assut Europe, Italy). The purpose of this study was to compare the ability of those against the standard polypropylene (Surgipro(TM), Covidien, USA) and polydioxanone (Assufil(®), Assut Europe, Italy) to mimic the biomechanical behavior of the abdominal wall closure. Comparison of the sutures was made first with the materials alone and later in a laparotomy closure of a rabbit abdomen, used as an animal model. The biomechanical analysis consisted of uniaxial tensile tests of threads and sutured samples of the animal abdomen. In the latter case, results were analyzed at short- (21days) and long- (180days) term intervals after the surgery. The morphology studies and collagen expression of the samples were also investigated. The results determined that polydioxanone and polypropylene sutures showed a linear elastic behavior, with barbed polydioxanone as the most compliant suture and polyurethane as the stiffest. The sutured samples showed a statistically significant loss of resistance, measured as the load needed to perform a certain stretch, when compared with the corresponding control tissue. Analysis of the stress-stretch curves showed that elastic polyurethane was the only suture able to reproduce the mechanical behavior of healthy tissue in the short term, while the rest of the sutures remained less stiff. This coincides with the expression of type I collagen observed in this group at this point in the study. In the long term, there was no difference among the sutures, and none was able to mimic control behavior. PMID:24859461

  1. The effect of fig wall thickness in Ficus erecta var. beecheyana on parasitism

    NASA Astrophysics Data System (ADS)

    Tzeng, Hsy-Yu; Ou, Chern-Hsiung; Lu, Fu-Yuan; Bain, Anthony; Chou, Lien-Siang; Kjellberg, Finn

    2014-05-01

    Fig wasp communities constitute a model system to analyse determinants of community complexity and to investigate how biological interaction networks are maintained. It has been suggested for monoecious figs, that fig pollinating wasps avoid ovipositing in flowers located close to the fig wall because of strong parasitic pressure by wasps ovipositing through the fig wall. This behaviour could help explain why mainly seeds are produced in flowers located close to the fig wall, thus stabilizing the fig-pollinating wasp mutualism. In this contribution we explore, for dioecious figs, whether ovipositor length of parasitic species may really be limiting. In dioecious figs, functionally male figs produce pollinating wasps and pollen while female figs produce only seeds, facilitating selection of traits favouring pollinator reproduction in male figs. We show in Ficus erecta that fig walls are thicker in male figs than in female figs. Male figs presenting thick walls, thicker than the length of the parasites' ovipositors, went unparasitized while male figs presenting thinner walls were systematically parasitized. Hence, in F. erecta, ovipositor length of the parasites is limiting access to some figs. However, we also show that in another dioecious species, Ficus formosana, presenting thin walled male figs, no fig is protected against oviposition by its two parasites. Hence in dioecious as well as in monoecious figs, in some Ficus species, ovipositors of the parasites are limiting access to ovules, while in other Ficus species all ovules are exposed to parasitism.

  2. Sensitivity of dual-wall structures under hypervelocity impact to multi-layer thermal insulation thickness and placement

    NASA Technical Reports Server (NTRS)

    Schonberg, William P.

    1993-01-01

    Results are presented from an experimental study in which Al dual-wall structures were tested, under various high-speed impact conditions, with a view to the effect of multilayer insulation thickness and location on perforation resistance. Attention is given to comparisons of the damage sustained by dual-wall systems with multilayer insulation blankets of various thicknesses and at various locations within the dual-wall system, under comparable impact loading conditions. The placement of the insulation has a significant effect on the ballistic limit of the dual-wall structures considered, while reducing insulation thickness by as much as a third did not.

  3. Modelling the solidification of ductile cast iron parts with varying wall thicknesses

    NASA Astrophysics Data System (ADS)

    Bjerre, M.; Tiedje, N. S.; Thorborg, J.; Hattel, J. H.

    2015-06-01

    In the present paper modelling the solidification of cast iron parts is considered. Common for previous efforts in this field is that they have mainly considered thin walled to medium thickness castings. Hence, a numerical model combining the solidification model presented by Lesoultet al. [1] with a 2D FE solution of the heat conduction equation is developed in an in-house code and model parameters are calibrated using experimental data from representative castings made of ductile cast iron. The main focus is on the influence of casting thickness and resulting local cooling conditions on the solidification pattern and the relation to formation of degenerate graphite.

  4. Standard guide for mutual inductance bridge applications for wall thickness determinations in boiler tubing

    E-print Network

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide describes a procedure for obtaining relative wall thickness indications in ferromagnetic and non-ferromagnetic steels using the mutual inductance bridge method. The procedure is intended for use with instruments capable of inducing two substantially identical magnetic fields and noting the change in inductance resulting from differing amounts of steel. It is used to distinguish acceptable wall thickness conditions from those which could place tubular vessels or piping at risk of bursting under high temperature and pressure conditions. 1.2 This guide is intended to satisfy two general needs for users of industrial Mutual Inductance Bridge (MIB) equipment: (1) the need for a tutorial guide addressing the general principles of Mutual Inductance Bridges as they apply to industrial piping; and (2) the need for a consistent set of MIB performance parameter definitions, including how these performance parameters relate to MIB system specifications. Potential users and buyers, as well as experienced M...

  5. Influence of surrounding wall thickness on the fatigue resistance of molars restored with ceramic inlay.

    PubMed

    Shibata, Shizuma; Gondo, Renata; Araújo, Élito; Mello Roesler, Carlos Rodrigo de; Baratieri, Luiz Narciso

    2014-01-01

    The purpose of this study was to evaluate the influence of buccal and lingual wall thickness on the fatigue resistance of molars restored with CAD/CAM ceramic inlays. Forty human third molars were selected and divided into 4 groups, according to the remaining surrounding wall thickness chosen for inlay preparation (n=10): G1, 2.0 mm; G2, 1.5 mm; G3, 1.0 mm; G4, 0.5 mm. All inlays were made from feldspathic ceramic blocks by a CAD/CAM system, and cemented adhesively. After 1 week stored in distilled water at 37 °C, the specimens were subjected to fatigue testing under the following protocol: 5Hz; pre-load of 200 N for 5,000 cycles, followed by increasing loads of 400, 600, 800, 1000, 1200 and 1400 N for 30,000 cycles each. The specimens were cycled until failure or completion of 185,000 cycles. The survival rate of the groups was compared using the Kaplan-Meier survival curves (p>0.05). All specimens withstood the fatigue protocol (185,000 cycles), representing a 100% survival rate. The Kaplan-Meier survival curves showed no difference between groups. It can be concluded that the remaining tooth wall thickness did not influence the fatigue resistance of molars restored with CAD/CAM ceramic inlays. PMID:24918366

  6. Dynamic film thickness between bubbles and wall in a narrow channel

    NASA Astrophysics Data System (ADS)

    Ito, Daisuke; Damsohn, Manuel; Prasser, Horst-Michael; Aritomi, Masanori

    2011-09-01

    The present paper describes a novel technique to characterize the behavior of the liquid film between gas bubbles and the wall in a narrow channel. The method is based on the electrical conductance. Two liquid film sensors are installed on both opposite walls in a narrow rectangular channel. The liquid film thickness underneath the gas bubbles is recorded by the first sensor, while the void fraction information is obtained by measuring the conductance between the pair of opposite sensors. Both measurements are taken on a large two-dimensional domain and with a high speed. This makes it possible to obtain the two-dimensional distribution of the dynamic liquid film between the bubbles and the wall. In this study, this method was applied to an air-water flow ranging from bubbly to churn regimes in the narrow channel with a gap width of 1.5 mm.

  7. Radical cystectomy and pelvic lymphadenectomy with ileal conduit urinary diversion and abdominal wall reconstruction: an interesting case of multidisciplinary management

    PubMed Central

    Sofos, Stratos S; Walsh, Ciaran J; Parr, Nigel J; Hancock, Kevin

    2015-01-01

    The ileal conduit for urinary diversion after radical cystectomy is a well-described procedure. Furthermore, parastomal hernias, prolapse, stenosis, and retraction of the stoma have been reported as some of the more common complications of this procedure. The subsequent repair of parastomal hernias with a biological mesh and the potential of the conduit to “tunnel” through it has also been described. In this case report, we present a combined repair of a large incisional hernia with a cystectomy and a pelvic lymphadenectomy for invasive bladder cancer, with the use of a biological mesh for posterior component abdominal wall primary repair as well as for support to the ileal conduit used for urinary diversion. PMID:25653561

  8. Radical cystectomy and pelvic lymphadenectomy with ileal conduit urinary diversion and abdominal wall reconstruction: an interesting case of multidisciplinary management.

    PubMed

    Sofos, Stratos S; Walsh, Ciaran J; Parr, Nigel J; Hancock, Kevin

    2015-01-01

    The ileal conduit for urinary diversion after radical cystectomy is a well-described procedure. Furthermore, parastomal hernias, prolapse, stenosis, and retraction of the stoma have been reported as some of the more common complications of this procedure. The subsequent repair of parastomal hernias with a biological mesh and the potential of the conduit to "tunnel" through it has also been described. In this case report, we present a combined repair of a large incisional hernia with a cystectomy and a pelvic lymphadenectomy for invasive bladder cancer, with the use of a biological mesh for posterior component abdominal wall primary repair as well as for support to the ileal conduit used for urinary diversion. PMID:25653561

  9. Lateral abdominal muscle size at rest and during abdominal drawing-in manoeuvre in healthy adolescents.

    PubMed

    Linek, Pawel; Saulicz, Edward; Wolny, Tomasz; My?liwiec, Andrzej; Kokosz, Miros?aw

    2015-02-01

    Lateral abdominal wall muscles in children and adolescents have not been characterised to date. In the present report, we examined the reliability of the ultrasound measurement and thickness of the oblique external muscle (OE), oblique internal muscle (OI) and transverse abdominal muscle (TrA) at rest and during abdominal drawing-in manoeuvre (ADIM) on both sides of the body in healthy adolescents. We also determined possible differences between boys and girls and defined any factors-such as body mass, height and BMI-that may affect the thickness of the abdominal muscles. B-mode ultrasound was used to assess OE, OI and TrA on both sides of the body in the supine position. Ultrasound measurements at rest and during ADIM were reliable in this age group (ICC3,3 > 0.92). OI was always the thickest and TrA the thinnest muscle on both sides of the body. In this group, an identical pattern of the contribution of the individual muscles to the structure of the lateral abdominal wall (OI > OE > TrA) was observed. At rest and during ADIM, no statistically significant side-to-side differences were demonstrated in either gender. The body mass constitutes between 30% and <50% of the thickness differences in all muscles under examination at rest and during ADIM. The structure of lateral abdominal wall in adolescents is similar to that of adults. During ADIM, the abdominal muscles in adolescents react similarly to those in adults. This study provided extensive information regarding the structure of the lateral abdominal wall in healthy adolescents. PMID:25088309

  10. Inverse Transient Analysis for Classification of Wall Thickness Variations in Pipelines

    PubMed Central

    Tuck, Jeffrey; Lee, Pedro

    2013-01-01

    Analysis of transient fluid pressure signals has been investigated as an alternative method of fault detection in pipeline systems and has shown promise in both laboratory and field trials. The advantage of the method is that it can potentially provide a fast and cost effective means of locating faults such as leaks, blockages and pipeline wall degradation within a pipeline while the system remains fully operational. The only requirement is that high speed pressure sensors are placed in contact with the fluid. Further development of the method requires detailed numerical models and enhanced understanding of transient flow within a pipeline where variations in pipeline condition and geometry occur. One such variation commonly encountered is the degradation or thinning of pipe walls, which can increase the susceptible of a pipeline to leak development. This paper aims to improve transient-based fault detection methods by investigating how changes in pipe wall thickness will affect the transient behaviour of a system; this is done through the analysis of laboratory experiments. The laboratory experiments are carried out on a stainless steel pipeline of constant outside diameter, into which a pipe section of variable wall thickness is inserted. In order to detect the location and severity of these changes in wall conditions within the laboratory system an inverse transient analysis procedure is employed which considers independent variations in wavespeed and diameter. Inverse transient analyses are carried out using a genetic algorithm optimisation routine to match the response from a one-dimensional method of characteristics transient model to the experimental time domain pressure responses. The accuracy of the detection technique is evaluated and benefits associated with various simplifying assumptions and simulation run times are investigated. It is found that for the case investigated, changes in the wavespeed and nominal diameter of the pipeline are both important to the accuracy of the inverse analysis procedure and can be used to differentiate the observed transient behaviour caused by changes in wall thickness from that caused by other known faults such as leaks. Further application of the method to real pipelines is discussed.

  11. Design and current status of CONTINT: continuous versus interrupted abdominal wall closure after emergency midline laparotomy - a randomized controlled multicenter trial [NCT00544583

    PubMed Central

    2012-01-01

    Background The optimal strategy for abdominal wall closure has been an issue of ongoing debate. Available studies do not specifically enroll patients who undergo emergency laparotomy and thus do not consider the distinct biological characteristics of these patients. The present randomized controlled trial evaluates the efficacy and safety of two commonly applied abdominal wall closure strategies in patients undergoing primary emergency midline laparotomy. Methods/design The CONTINT trial is a multicenter, open label, randomized controlled trial with a two-group parallel design. Patients undergoing a primary emergency midline laparotomy are enrolled in the trial. The two most commonly applied strategies of abdominal wall closure after midline laparotomy are compared: the continuous, all-layer suture technique using slowly absorbable monofilament material (two Monoplus® loops) and the interrupted suture technique using rapidly absorbable braided material (Vicryl® sutures). The primary endpoint within the CONTINT trial is an incisional hernia within 12 months or a burst abdomen within 30 days after surgery. As reliable data on this primary endpoint is not available for patients undergoing emergency surgery, an adaptive interim analysis will be conducted after the inclusion of 80 patients, allowing early termination of the trial if necessary or modification of design characteristics such as recalculation of sample size. Discussion This is a randomized controlled multicenter trial with a two-group parallel design to assess the efficacy and safety of two commonly applied abdominal wall closure strategies in patients undergoing primary emergency midline laparotomy. Trial registration NCT00544583 PMID:22647387

  12. [The treatment of inguinal lymphocele and of a meta-inflammatory cyst of the abdominal wall with an injection of fibrin glue].

    PubMed

    Viviani, D; Mari, R; Delmonte, O; Bronzoni, S

    1999-01-01

    The authors report two cases of inguinal lymphocele and phlogistic cysts of the abdominal wall treated with fibrin glue. The complete resolution of both cases after one injection, the simplicity of the technique and the low cost suggest a wider experimentation. PMID:10390929

  13. A thick-walled cylinder with an axisymmetric internal or edge crack

    NASA Technical Reports Server (NTRS)

    Erdol, R.; Erdogan, F.

    1978-01-01

    The paper considers the elastostatic axisymmetric problem for a long thick-walled cylinder containing a ring-shaped internal or edge crack. Using the standard transform technique the problem is formulated in terms of an integral equation which has a simple Cauchy kernel for the internal crack and a generalized Cauchy kernel for the edge crack as the dominant part. As examples the uniform axial load and the steady-state thermal stress problems have been solved and the related stress-intensity factors have been calculated. Among other findings the results show that in the cylinder under uniform axial stress containing an internal crack the stress-intensity factor at the inner tip is always greater than that at the outer tip for equal net ligament thicknesses and in the cylinder with an edge crack which is under a state of thermal stress the stress-intensity factor is a decreasing function of the crack depth, tending to zero as the crack depth approaches the wall thickness.

  14. Controlled protein release from monodisperse biodegradable double-wall microspheres of controllable shell thickness

    PubMed Central

    Xia, Yujie; Ribeiro, Pedro F.; Pack, Daniel W.

    2013-01-01

    Biodegradable polymer microparticles are promising delivery depots for protein therapeutics due to their relatively simple fabrication and facile administration. Double-wall microspheres (DWMS) comprising a core and shell made of two distinct polymers may provide enhanced control of the drug release profiles. Using precision particle fabrication (PPF) technology, monodisperse DWMS were fabricated with model protein bovine serum albumin (BSA)-loaded poly(lactide-co-glycolide) (PLG) core and drug-free poly(d,l-lactic acid) (PDLL) shell of uniform thickness. Monolithic single-wall microspheres were also fabricated to mimic the BSA-loaded PLG core. Using ethyl acetate and dichloromethane as shell- and core-phase solvents, respectively, BSA was encapsulated selectively in the core region within DWMS with higher loading and encapsulation efficiency compared to using dichloromethane as core and shell solvents. BSA in vitro release rates were retarded by the presence of the drug-free PDLL shell. Moreover, increasing PDLL shell thickness resulted in decreasing BSA release rate. With a 14-µm thick PDLL shell, an extended period of constant-rate release was achieved. PMID:23954731

  15. Continued research on the strain to failure of thick-walled cylinders subjected to internal pressure

    SciTech Connect

    Roach, D.P.; Priddy, T.G.

    1990-01-01

    The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design. In-house experience in weapon development, new aerospace applications and autofrettage operations all require in-depth knowledge of the strength of high pressure containment structures. This paper presents additional results to support the strain-to-failure analysis of thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through thickness yielding characteristics were determined for these specimens. The critical effective plastic strain depends on the level of tensile stress triaxiality which varies through the wall thickness. It is shown that the proposed strain-to-failure criterion is based on this triaxiality of stress in the critical region and can be used to predict the complete pressure versus strain relations and maximum pressure for the test cylinders. 17 refs., 12 figs.

  16. Relationship between intra-abdominal pressure and vaginal wall movements during Valsalva in women with and without pelvic organ prolapse: technique development and early observations

    PubMed Central

    Spahlinger, D. M.; Newcomb, L.; Ashton-Miller, J. A.; DeLancey, J. O. L.; Chen, Luyun

    2014-01-01

    Objectives To develop and test a method for measuring the relationship between the rise in intra-abdominal pressure and sagittal plane movements of the anterior and posterior vaginal walls during Valsalva in a pilot sample of women with and without prolapse. Methods Mid-sagittal MRI images were obtained during Valsalva while changes in intra-abdominal pressure were measured via a bladder catheter in 5 women with cystocele, 5 women with rectocele, and 5 controls. The regional compliance of the anterior and posterior vagina wall support systems were estimated from the ratio of displacement (mm) of equidistant points along the anterior and posterior vaginal walls to intra-abdominal pressure rise (mmHg). Results The compliance of both anterior and posterior vaginal wall support systems varied along different regions of vaginal wall for all three groups, with the highest compliance found near the vaginal apex and the lowest near the introitus. Women with cystocele had more compliant anterior and posterior vaginal wall support systems than women with rectocele. The movement direction differs between cystocele and rectocele. In cystocele, the anterior vaginal wall moves mostly toward the vaginal orifice in the upper vagina, but in a ventral direction in the lower vagina. In rectocele, the direction of the posterior vaginal wall movement is generally toward the vaginal orifice. Conclusions Movement of the vaginal wall and compliance of its support is quantifiable and was found to vary along the length of the vagina. Compliance was greatest in the upper vagina of all groups. Women with cystocele demonstrated the most compliant vaginal wall support. PMID:24474605

  17. A Multi-Step Algorithm for Measuring Airway Luminal Diameter and Wall Thickness in Lung CT Images.

    PubMed

    Heydarian, Mohammadreza; Noseworthy, Michael D; Kamath, Markad V; Boylan, Colm; Poehlman, W F S

    2014-01-01

    Accurate measurements of airway diameter and wall thickness are important parameters in understanding numerous pulmonary diseases. Here, we describe an automated method of measuring small airway luminal diameter and wall thickness over numerous contiguous computed tomography (CT) images. Using CT lung images from 22 patients and an airway phantom, a seeded region-growing algorithm was first applied to identify the lumen of the airway. The result was applied as an initial region for boundary determination using the level set method. Once found, subsequent algorithmic expansion of the luminal border was used to calculate airway wall thickness. This algorithm automatically evaluates neighboring slices of the airway and measures the airway luminal diameter and wall thickness. This approach also detects airway bifurcations. Our new procedure provides rapid, automated, accurate, and clinically important lung airway measurements that would be useful to radiologists who use CT images for pulmonary disease assessment. PMID:25745801

  18. Numerical study of turbulent natural convection in a cube having finite thickness heat-conducting walls

    NASA Astrophysics Data System (ADS)

    Sheremet, Mikhail A.; Miroshnichenko, Igor V.

    2015-11-01

    Three-dimensional transient natural convection in a cubic enclosure having finite thickness solid walls subject to opposing and horizontal temperature gradient has been investigated by a finite volume method. The turbulent flow considered into the volume is described mathematically by the 3D Reynolds averaged Navier-Stokes equations using the standard k-? model with wall functions, including the energy equation. The velocity and temperature distributions were calculated at fixed Prandtl number, Pr = 0.7 and different values of the Rayleigh number, thermal conductivity ratio and dimensionless time. Three-dimensional velocity and temperature fields, temperature profiles at middle cross-sections and average Nusselt numbers have been presented. It has been found that an insertion of the third coordinate for the conjugate problem leads to a decrease in the average Nusselt number by 5.8 % in conditions of a stationary heat transfer mode.

  19. IFE thick liquid wall chamber dynamics: Governing mechanisms andmodeling and experimental capabilities

    SciTech Connect

    Raffray, A.R.; Meier, W.; Abdel-Khalik, S.; Bonazza, R.; Calderoni, P.; Debonnel, C.S.; Dragojlovic, Z.; El-Guebaly, L.; Haynes,D.; Latkowski, J.; Olson, C.; Peterson, P.F.; Reyes, S.; Sharpe, P.; Tillack, M.S.; Zaghloul, M.

    2005-01-24

    For thick liquid wall concepts, it is important to understand the different mechanisms affecting the chamber dynamics and the state of the chamber prior to each shot a compared with requirements from the driver and target. These include ablation mechanisms, vapor transport and control, possible aerosol formation, as well as protective jet behavior. This paper was motivated by a town meeting on this subject which helped identify the major issues, assess the latest results, review the capabilities of existing modeling and experimental facilities with respect to addressing remaining issues, and helping guide future analysis and R&D efforts; the paper covers these exact points.

  20. Effect of bladder wall thickness on miniature pneumatic artificial muscle performance.

    PubMed

    Pillsbury, Thomas E; Kothera, Curt S; Wereley, Norman M

    2015-10-01

    Pneumatic artificial muscles (PAMs) are actuators known for their high power to weight ratio, natural compliance and light weight. Due to these advantages, PAMs have been used for orthotic devices and robotic limbs. Small scale PAMs have the same advantages, as well as requiring greatly reduced volumes with potential application to prostheses and small scale robotics. The bladder of a PAM affects common actuator performance metrics, specifically: blocked force, free contraction, hysteresis, and dead-band pressure. This paper investigates the effect that bladder thickness has on static actuation performance of small scale PAMs. Miniature PAMs were fabricated with a range of bladder thicknesses to quantify the change in common actuator performance metrics specifically: blocked force, free contraction, and dead-band pressure. These PAMs were then experimentally characterized in quasi-static conditions, where results showed that increasing bladder wall thickness decreases blocked force and free contraction, while dead-band pressure increases. A nonlinear model was then applied to determine the structure of the stress-strain relationship that enables accurate modeling and the minimum number of terms. Two nonlinear models are compared and the identified parameters are analyzed to study the effect of the bladder thickness on the model. PMID:26414160

  1. Crack growth in the through-thickness direction of hydrided thin-wall Zircaloy Patrick A. Raynaud a,

    E-print Network

    Motta, Arthur T.

    Crack growth in the through-thickness direction of hydrided thin-wall Zircaloy sheet Patrick A occur by crack initiation within a defect such as a hydride rim or blister and subsequent crack resistance to crack propagation in the through-thick- ness direction is crucial to predicting cladding

  2. Superthin Abdominal Wall Glove-Like Flap Combined With Vacuum-Assisted Closure Therapy for Soft Tissue Reconstruction in Severely Burned Hands or With Infection.

    PubMed

    Wang, Fei; Liu, Sheng; Qiu, Le; Ma, Ben; Wang, Jian; Wang, Yong-Jie; Peszel, April; Chen, Xu-Lin

    2015-12-01

    Severe burn and infection to hands always involves the deep structures, such as tendons, joints, and bones. These wounds cannot be closed immediately and therefore creates a high risk for complication. We presented 9 cases with deep dermal burns to the dorsal of the hand (6 electrical burns and 3 thermal crush injuries) with wound infections in 2 cases. The vacuum-assisted closure system was used continuously until the flap reconstruction was performed. A random pattern and superthin abdominal wall skin flap-like glove was designed. The flap was transferred to the defected portion of the dorsum of the hand and resected from the abdominal wall about 3 weeks later. The flaps in 8 of the patients treated by this technique survived completely and partial necrosis of the distal flap occurred in 1 patient. The defect resolved after operative treatment and the function of the hands and fingers were successfully salvaged. All patients resulted in having a satisfactory aesthetic outcome with no or minor discomfort at the abdominal donor area. Integration of the vacuum-assisted closure system and the superthin abdominal wall glove-like flap reconstruction appeared to be successful and should be considered in patients with severely burned hands. PMID:26418768

  3. Effects of Chitosan Coatings on Polypropylene Mesh for Implantation in a Rat Abdominal Wall Model

    PubMed Central

    Udpa, Natasha; Iyer, Shama R.; Rajoria, Rohit; Breyer, Kate E.; Valentine, Helen; Singh, Bhupinder; McDonough, Sean P.; Brown, Bryan N.; Bonassar, Lawrence J.

    2013-01-01

    Hernia repair and pelvic floor reconstruction are usually accompanied with the implantation of a surgical mesh, which frequently results in a foreign body response with associated complications. An ideal surgical mesh that allows force generation of muscle tissues without significant granulation tissue and/or fibrosis is of significant clinical interest. The objective of the present study was to evaluate the in vitro and in vivo responses of a chitosan coating on polypropylene mesh (Ch-PPM) in comparison with commercially available meshes. We found that application of a 0.5% (w/v) Ch-PPM elicited preferential attachment of myoblasts over fibroblast attachment in vitro. Therefore, we test the hypothesis that 0.5% Ch-PPM will encourage skeletal muscle tissue ingrowth and decrease fibrosis formation in vivo. We implanted 0.5% Ch-PPM, collagen-coated polypropylene mesh (Pelvitex™; C.R. Bard), and polypropylene (Avaulta Solo®; C.R. Bard) alone using a rat abdominal defect model. Force generation capacity and inflammatory response of each mesh were evaluated 2, 4, and 12 weeks postimplantation. We found that chitosan coating is associated with the restoration of functional skeletal muscle with histomorphologic characteristics that resemble native muscle and an early macrophage phenotypic response that has previously been shown to lead to more functional outcomes. PMID:23859182

  4. New scale to assess breathing movements of the chest and abdominal wall: preliminary reliability testing

    PubMed Central

    Kaneko, Hideo; Horie, Jun; Ishikawa, Akira

    2015-01-01

    [Purpose] Physical examinations for chest movements by inspection and palpation are poorly reproducible. This study aimed to investigate the inter-rater reliability of a new breathing movement scale for patients with respiratory diseases, in clinical practice. [Subjects and Methods] Twenty-six patients with respiratory diseases were enrolled. BMS measurements were obtained during quiet breathing for 13 patients and during deep breathing for the other 13 patients. The BMS used to assess QB and DB movements of the upper chest, lower chest, and abdomen was based on a scale of ?1 to 8. Scale values were measured while in the supine position using a pen-sized breathing movement-measuring device used by two raters during the same session. Scale values at five observation points and total values were recorded. A weighted Kappa coefficient and percentage agreement were used to assess inter-rater reliability with this BMS. [Results] The weighted Kappa coefficients during quiet and deep breathing had substantial to excellent strength of agreement (0.63–1.00) with percentage agreements of 31–100%. [Conclusion] Our results provide preliminary evidence to support the reliability of breathing movement scale measurements to assess breathing movements and chest and abdominal mobility for patients with respiratory diseases. PMID:26180364

  5. On what controls the spacing of spontaneous adiabatic shear bands in collapsing thick-walled cylinders

    NASA Astrophysics Data System (ADS)

    Lovinger, Zev; Rosenberg, Zvi; Rittel, Daniel

    2015-09-01

    Shear bands formation in collapsing thick walled cylinders occurs in a spontaneous manner. The advantage of examining spontaneous, as opposed to forced shear localization, is that it highlights the inherent susceptibility of the material to adiabatic shear banding without prescribed geometrical constraints. The Thick-Walled Cylinder technique (TWC) provides a controllable and repeatable technique to create and study multiple adiabatic shear bands. The technique, reported in the literature uses an explosive cylinder to create the driving force, collapsing the cylindrical sample. Recently, we developed an electro-magnetic set-up using a pulsed current generator to provide the collapsing force, replacing the use of explosives. Using this platform we examined the shear band evolution at different stages of formation in 7 metallic alloys, spanning a wide range of strength and failure properties. We examined the number of shear bands and spacing between them for the different materials to try and figure out what controls these parameters. The examination of the different materials enabled us to better comprehend the mechanisms which control the spatial distribution of multiple shear bands in this geometry. The results of these tests are discussed and compared to explosively driven collapsing TWC results in the literature and to existing analytical models for spontaneous adiabatic shear localization.

  6. Rolled-up optical microcavities with subwavelength wall thicknesses for enhanced liquid sensing applications.

    PubMed

    Huang, Gaoshan; Bolaños Quiñones, Vladimir A; Ding, Fei; Kiravittaya, Suwit; Mei, Yongfeng; Schmidt, Oliver G

    2010-06-22

    Microtubular optical microcavities from rolled-up ring resonators with subwavelength wall thicknesses have been fabricated by releasing prestressed SiO/SiO(2) bilayer nanomembranes from photoresist sacrificial layers. Whispering gallery modes are observed in the photoluminescence spectra from the rolled-up nanomembranes, and their spectral peak positions shift significantly when measurements are carried out in different surrounding liquids, thus indicating excellent sensing functionality of these optofluidic microcavities. Analytical calculations as well as finite-difference time-domain simulations are performed to investigate the light confinement in the optical microcavities numerically and to describe the experimental mode shifts very well. A maximum sensitivity of 425 nm/refractive index unit is achieved for the microtube ring resonators, which is caused by the pronounced propagation of the evanescent field in the surrounding media due to the subwavelength wall thickness design of the microcavity. Our optofluidic sensors show high potential for lab-on-a-chip applications, such as real-time bioanalytic systems. PMID:20527797

  7. On the Opening of Thick Walled Elastic Tubes: A Fluid-Structure Model for Acid Reflux

    NASA Astrophysics Data System (ADS)

    Ghosh, Sudip; Kahrilas, Peter

    2005-11-01

    A coupled fluid-structure mathematical model was developed to quantify rapid opening of thick-walled elastic tubes, a phenomenon underlying biological flows such as gastroesophageal reflux disease (GERD). The wall was modeled using non-linear finite deformation theory to predict space-time radial distention of an axisymmetric tube with luminal fluid flow. Anisotropic azimuthal and longitudinal muscle-induced stresses were incorporated, and interstitial material properties were assumed isotropic and linearly elastic. Fluid flow was modeled using lubrication theory with inertial correction. Opening and flow were driven by a specified inflow pressure and zero pressure gradient was specified at outflow. No-slip and surface force balance were applied at the fluid-wall interface. Viscoelasticity was modeled with ad hoc damping and the evolution of the tube geometry was predicted at mid-layer. A potentially important discovery was made when applied to studies of initiation of opening with GERD: while material stiffness is of minor consequence, small changes in resting lumen distension (˜2 mm diameter) may be a sensitive distinguishing feature of the disease.

  8. Airway wall thickness is increased in COPD patients with bronchodilator responsiveness

    PubMed Central

    2014-01-01

    Rationale Bronchodilator responsiveness (BDR) is a common but variable phenomenon in COPD. The CT characteristics of airway dimensions that differentiate COPD subjects with BDR from those without BDR have not been well described. We aimed to assess airway dimensions in COPD subjects with and without BDR. Methods We analyzed subjects with GOLD 1–4 disease in the COPDGene® study who had CT airway analysis. We divided patients into two groups: BDR?+?(post bronchodilator ?FEV1???10%) and BDR-(post bronchodilator ?FEV1?wall area percent (WA%) of six segmental bronchi in each subject was quantified using VIDA. Using 3D SLICER, airway wall thickness was also expressed as the square root wall area of an airway of 10 mm (Pi10) and 15 mm (Pi15) diameter. %Emphysema and %gas trapping were also calculated. Results 2355 subjects in the BDR-group and 1306 in the BDR?+?group formed our analysis. The BDR?+?group had a greater Pi10, Pi15, and mean segmental WA% compared to the BDR-group. In multivariate logistic regression using gender, race, current smoking, history of asthma, %emphysema, %gas trapping, %predicted FEV1, and %predicted FVC, airway wall measures remained independent predictors of BDR. Using a threshold change in FEV1???15% and FEV1???12% and 200 mL to divide patients into groups, the results were similar. Conclusion BDR in COPD is independently associated with CT evidence of airway pathology. This study provides us with greater evidence of changes in lung structure that correlate with physiologic manifestations of airflow obstruction in COPD. PMID:25248436

  9. A method of computing the transient temperature of thick walls from arbitrary variation of adiabatic-wall temperature and heat-transfer coefficient

    NASA Technical Reports Server (NTRS)

    Hill, P R

    1958-01-01

    A method of calculating the temperature of thick walls has been developed in which the time series and the response to a unit triangle variation of surface temperature concepts are used, together with essentially standard formulas for transient temperature and heat flow into thick walls. The method can be used without knowledge of the mathematical tools of its development. The method is particularly suitable for determining the wall temperature in one-dimensional thermal problems in aeronautics where there is a continuous variation of the heat-transfer coefficient and adiabatic-wall temperature. The method also offers a convenient means for solving the inverse problem of determining the heat-flow history when temperature history is known.

  10. Residual stress analysis in forming process of filament wound thick-walled CFRP pipes

    SciTech Connect

    Kondo, Toshimi; Sekine, Hideki; Nakano, Kunio

    1995-11-01

    Residual stress analysis for the cracking phenomenon of filament would thick-walled CFRP pipes, which frequently occurs in the forming process of curing and thermal cycling through the course of the wet filament winding, was made from both the experimental and theoretical points of view. A simple analytical model to study the cracking in the CFRP pipes was proposed. The pipes are multilayered and reinforced in the axial and circumferential directions alternatively by carbon fibers. Taking account of the anisotropy of mechanical and thermal properties including the shrinkage strain, which depend considerably on the temperature, the residual stresses in the CFRP pipes were elucidated in the forming process, particularly, in cooling of the cure process.

  11. Left Ventricular Relative Wall Thickness Versus Left Ventricular Mass Index in Non-Cardioembolic Stroke Patients

    PubMed Central

    Hashem, M-Sherif; Kalashyan, Hayrapet; Choy, Jonathan; Chiew, Soon K.; Shawki, Abdel-Hakim; Dawood, Ahmed H.; Becher, Harald

    2015-01-01

    Abstract In non-cardioembolic stroke patients, the cardiac manifestations of high blood pressure are of particular interest. Emerging data suggest that echocardiographically determined left ventricular hypertrophy is independently associated with risk of ischemic stroke. The primary objective of this study was to evaluate the frequency of different patterns of left ventricular (LV) remodeling and hypertrophy in a group of consecutive patients admitted with non-cardioembolic stroke or transient ischemic attack (TIA). In particular, we were interested in how often the relative wall thickness (RWT) was abnormal in patients with normal LV mass index (LVMI). As both abnormal RWT and LVMI indicate altered LV remodeling, the secondary objective of this research was to study whether a significant number of patients would be missing the diagnosis of LV remodeling if the RWT is not measured. All patients were referred within 48?hours after a stroke or a TIA for a clinically indicated transthoracic echocardiogram. The echocardiographic findings of consecutive patients with non-cardioembolic stroke or TIA were analyzed. All necessary measurements were performed in 368 patients, who were enrolled in the study. Mean age was 63.7?±?12.5 years, 64.4% men. Concentric remodeling carried the highest frequency, 49.2%, followed by concentric hypertrophy, 30.7%, normal pattern, 15.5%, and eccentric hypertrophy, 4.1%. The frequency of abnormal left ventricular RWT (80.4%) was significantly higher than that of abnormal LVMI (35.3%), (McNemar P?wall thickness is very frequent. As RWT was often found without increased LV mass, the abnormal left ventricular geometry may be missed if RWT is not measured or reported. PMID:25997067

  12. Successful treatment of mesenteric varices by retrograde transvenous obliteration by the delivery of N-butyl-2-cyanoacrylate via an abdominal wall vein.

    PubMed

    Ikeda, Osamu; Nakasone, Yutaka; Yokoyama, Koichi; Inoue, Seijiro; Takamori, Hiroshi; Baba, Hideo; Yamashita, Yasuyuki

    2014-04-01

    Bleeding from mesenteric varices associated with portal hypertension is occasionally life-threatening. A 53-year-old man who had undergone esophageal transection for esophageal varices and balloon-occluded retrograde transvenous obliteration for gastric varices presented with melena due to ruptured mesenteric varices. He was treated by injecting N-butyl-2-cyanoacrylate via an abdominal wall vein to obtain retrograde transvenous obliteration. PMID:23716126

  13. SMAD3 deficiency promotes vessel wall remodeling, collagen fiber reorganization and leukocyte infiltration in an inflammatory abdominal aortic aneurysm mouse model

    PubMed Central

    Dai, Xiaohua; Shen, Jianbin; Priyanka Annam, Neeraja; Jiang, Hong; Levi, Edi; Schworer, Charles M.; Tromp, Gerard; Arora, Anandita; Higgins, Mary; Wang, Xiao-Fan; Yang, Maozhou; Li, Hui J.; Zhang, Kezhong; Kuivaniemi, Helena; Li, Li

    2015-01-01

    TGF-? signaling plays critical roles in the pathogenesis of aneurysms; however, it is still unclear whether its role is protective or destructive. In this study, we investigate the role of SMAD3 in the pathogenesis of calcium chloride (CaCl2)-induced abdominal aortic aneurysms (AAA) in Smad3?/?, Smad3+/? and Smad3+/+ mice. We find that loss of SMAD3 drastically increases wall thickening of the abdominal aorta. Histological analyses show significant vessel wall remodeling with elastic fiber fragmentation. Remarkably, under polarized light, collagen fibers in the hyperplastic adventitia of Smad3?/? mice show extensive reorganization accompanied by loosely packed thin and radial collagen fibers. The expressions of matrix metalloproteinases including MMP2, MMP9, and MMP12 and infiltration of macrophage/T cells are drastically enhanced in the vascular wall of Smad3?/? mice. We also observe marked increase of NF-?B and ERK1/2 signaling as well as the expression of nuclear Smad2, Smad4 and TGF-?1 in the vessel wall of Smad3?/? mice. In addition, we find that SMAD3 expression is reduced in the dedifferentiated medial smooth muscle-like cells of human AAA patients. These findings provide direct in vivo evidence to support the essential roles of SMAD3 in protecting vessel wall integrity and suppressing inflammation in the pathogenesis of AAAs. PMID:25985281

  14. Reconstruction of full-thickness chest wall defects using rectus abdominis musculocutaneous flap: A report of fifteen cases

    SciTech Connect

    Miyamoto, Y.; Hattori, T.; Niimoto, M.; Toge, T. )

    1986-02-01

    In 15 patients chest walls were excised because of recurrent breast cancer, radiation ulcer, or rib tumor. In most cases the full-thickness defect of the chest wall was about 10 x 10 cm. Reconstruction was performed using only a rectus abdominis musculocutaneous flap. No patient developed circulation problems in the flap or severe flail chest, and we had successful results in all our cases. These results show that the rectus abdominis musculocutaneous flap is quite effective and safe to use in the reconstruction of chest wall defects.

  15. Evaluation of a canine small intestinal submucosal xenograft and polypropylene mesh as bioscaffolds in an abdominal full-thickness resection model of growing rats

    PubMed Central

    Lee, A-Jin; Lee, Sung-Ho; Chung, Wook-Hun; Kim, Dae-Hyun; Chung, Dai-Jung; Do, Sun Hee

    2013-01-01

    We evaluated the biological scaffold properties of canine small intestinal submucosa (SIS) compared to a those of polypropylene mesh in growing rats with full-thickness abdominal defects. SIS is used to repair musculoskeletal tissue while promoting cell migration and supporting tissue regeneration. Polypropylene mesh is a non-resorbable synthetic material that can endure mechanical tension. Canine SIS was obtained from donor German shepherds, and its porous collagen fiber structure was identified using scanning electron microscopy (SEM). A 2.50-cm2 section of canine SIS (SIS group) or mesh (mesh group) was implanted in Sprague-Dawley rats. At 1, 2, 4, 12, and 24 weeks after surgery, the implants were histopathologically examined and tensile load was tested. One month after surgery, CD68+ macrophage numbers in the SIS group were increased, but the number of CD8+ T cells in this group declined more rapidly than that in rats treated with the mesh. In the SIS group, few adhesions and well-developed autologous abdominal muscle infiltration into the SIS collagen fibers were observed. No significant differences in the tensile load test results were found between the SIS and mesh groups at 24 weeks. Canine SIS may therefore be a suitable replacement for artificial biological scaffolds in small animals. PMID:23628657

  16. Evaluation of side effects of radiofrequency capacitive hyperthermia with magnetite on the blood vessel walls of tumor metastatic lesion surrounding the abdominal large vessels: an agar phantom study

    PubMed Central

    2014-01-01

    Background Magnetite used in an 8-MHz radiofrequency (RF) capacitive heating device can increase the temperature of a specific site up to 45°C. When treating a metastatic lesion around large abdominal vessels via hyperthermia with magnetite, heating-induced adverse effects on these vessels need to be considered. Therefore, this study examined hyperthermia-induced damage to blood vessel walls in vitro. Methods A large agar phantom with a circulatory system consisting of a swine artery and vein connected to a peristaltic pump was prepared. The blood vessels were placed on the magnetite-containing agar piece. Heating was continued for 30 min at 45°C. After heating, a histological study for injury to the blood vessels was performed. Results The inner membrane temperature did not reach 45°C due to the cooling effect of the blood flow. In the heated vessels, vascular wall collagen degenerated and smooth muscle cells were narrowed; however, no serious changes were noted in the vascular endothelial cells or vascular wall elastic fibers. The heated vessel wall was not severely damaged; this was attributed to cooling by the blood flow. Conclusions Our findings indicate that RF capacitive heating therapy with magnetite may be used for metastatic lesions without injuring the surrounding large abdominal vessels. PMID:25114787

  17. Squamous cell carcinoma of unknown primary site presenting with an abdominal wall lesion as the primary symptom: A case report and review of the literature

    PubMed Central

    ZHANG, YINGLI; CHEN, BO; ZHU, JIANQING; CHEN, LU

    2015-01-01

    Squamous cell carcinoma of unknown primary site (SC CUP) is a rare malignant tumor, and its histogenesis and appropriate treatment are unclear. To the best of our knowledge, this type of carcinoma with abdominal wall lesions as the primary presenting symptom 3 months after laparoscopic surgery, has not been previously described in the literature. In the present study, a postmenopausal 54-year-old female patient was diagnosed with pain from the right abdominal puncture site 3 months after laparoscopic unilateral left salpingo-oophorectomy at a local hospital, at which time the left ovary and Fallopian tube were free of malignant tumor. Computed tomography (CT) imaging showed a subcutaneous nodule with a size of 6.2×3.3 cm. A wide excision of the lesion with safety margins and repair of the abdominal wall was performed, and the histopathological results and various investigations lead to the diagnosis of metastatic well-differentiated SC CUP. The patient underwent three surgeries and eight cycles of Taxol and cisplatin/carboplatin chemotherapy, and received a total of 10.8 Gy palliative radiation. However, the patient succumbed to intestinal bleeding, thrombocytopenia and multiple organ failure with pelvic recurrence and liver metastases at 10 months post-diagnosis. The prognosis of SC CUP, particularly with multiple metastases, is extremely poor. Although chemotherapy, surgery and radiotherapy have a certain role in the treatment, no regimen has been established as a standard therapy and palliative care could be recommended.

  18. Bobbin-Tool Friction-Stir Welding of Thick-Walled Aluminum Alloy Pressure Vessels

    SciTech Connect

    Dalder, E C; Pastrnak, J W; Engel, J; Forrest, R S; Kokko, E; Ternan, K M; Waldron, D

    2007-06-06

    It was desired to assemble thick-walled Al alloy 2219 pressure vessels by bobbin-tool friction-stir welding. To develop the welding-process, mechanical-property, and fitness-for-service information to support this effort, extensive friction-stir welding-parameter studies were conducted on 2.5 cm. and 3.8 cm. thick 2219 Al alloy plate. Starting conditions of the plate were the fully-heat-treated (-T62) and in the annealed (-O) conditions. The former condition was chosen with the intent of using the welds in either the 'as welded' condition or after a simple low-temperature aging treatment. Since preliminary stress-analyses showed that stresses in and near the welds would probably exceed the yield-strength of both 'as welded' and welded and aged weld-joints, a post-weld solution-treatment, quenching, and aging treatment was also examined. Once a suitable set of welding and post-weld heat-treatment parameters was established, the project divided into two parts. The first part concentrated on developing the necessary process information to be able to make defect-free friction-stir welds in 3.8 cm. thick Al alloy 2219 in the form of circumferential welds that would join two hemispherical forgings with a 102 cm. inside diameter. This necessitated going to a bobbin-tool welding-technique to simplify the tooling needed to react the large forces generated in friction-stir welding. The bobbin-tool technique was demonstrated on both flat-plates and plates that were bent to the curvature of the actual vessel. An additional issue was termination of the weld, i.e. closing out the hole left at the end of the weld by withdrawal of the friction-stir welding tool. This was accomplished by friction-plug welding a slightly-oversized Al alloy 2219 plug into the termination-hole, followed by machining the plug flush with both the inside and outside surfaces of the vessel. The second part of the project involved demonstrating that the welds were fit for the intended service. This involved determining the room-temperature tensile and elastic-plastic fracture-toughness properties of the bobbin-tool friction-stir welds after a post-weld solution-treatment, quenching, and aging heat-treatment. These mechanical properties were used to conduct fracture-mechanics analyses to determine critical flaw sizes. Phased-array and conventional ultrasonic non-destructive examination was used to demonstrate that no flaws that match or exceed the calculated critical flaw-sizes exist in or near the friction-stir welds.

  19. Complex Abdominal Wall Repair

    MedlinePLUS

    ... bowel and underwent placement of Veritas in an inlay. And as we talked about during the case, ... repair either utilizing an underlay technique or an inlay technique. I would not recommend placing this in ...

  20. Dynamic Response of a Pulse-Heated, Thick-Walled, Hollow Sphere: Validation of Code Numerics

    SciTech Connect

    Canaan, R.E.

    2000-01-19

    Volumetric pulse heating of a thick-walled hollow sphere is numerically investigated. The primary objective is to validate a variety of LLNL 30 hydrocodes for modeling the dynamic behavior of fissile/fissionable metals subject to rapid ''fission-heating'' transients. The 30 codes tested include both DYNA3D and NIKE3D, as well as the ''ASCI'' code, ALE3D. The codes are compared ''head-to-head'' and are benchmarked against a 1D finite difference solution to the problem that is derived from basic principles. Three pulse-heating transients are examined with full-width-half-maximum pulse durations of 41{micro}s, 85{micro}s, and 140{micro}s, respectively. These three transients produce a significant range of dynamic responses in the thermo-elastic regime. We present results for dynamic radial displacements and stresses for each pulse, and also discuss which code features/options worked best for these types of calculations. In general, the code results are in excellent agreement for the simple system considered. Validation of code numerics in simple systems is a key first step toward future application of the codes in more complicated geometries (U).

  1. Application of the distributed point source method to rough surface scattering and ultrasonic wall thickness measurement.

    PubMed

    Jarvis, A J C; Cegla, F B

    2012-09-01

    The distributed point source method is commonly used to predict the complex acoustic field emitted by ultrasonic transducers. In this paper, it is presented as an alternative to conventional approaches often used when solving rough surface scattering problems. Surface shadowing and multiple scattering effects are inherently included in the mesh-free semi-analytical simulation method through matrix manipulation making it very efficient and simple to implement. Results are presented which illustrate the improvement in accuracy gained over the Kirchhoff approximation and the decrease in computational load over the finite element method, culminating in greater than an order of magnitude decrease in required simulation time. The method is applied to the practical problem of online wall thickness monitoring within corrosive environments, illustrating the variability in reflected pulse shape that could be expected from rough surfaces with similar statistics. Three commonly implemented time-of-flight algorithms are used to analyze a large number of simulated signals from which it is concluded that those based on first arrival time are more stable under increasing roughness conditions than those which are based on reflected pulse shape. PMID:22978861

  2. The interaction of moderately strong shock waves with thick perforated walls of low porosity

    NASA Technical Reports Server (NTRS)

    Grant, D. J.

    1972-01-01

    A theoretical prediction is given of the flow through thick perforated walls of low porosity resulting from the impingement of a moderately strong traveling shock wave. The model was a flat plate positioned normal to the direction of the flow. Holes bored in the plate parallel to the direction of the flow provided nominal hole length-to-diameter ratios of 10:1 and an axial porosity of 25 percent of the flow channel cross section. The flow field behind the reflected shock wave was assumed to behave as a reservoir producing a quasi-steady duct flow through the model. Rayleigh and Fanno duct flow theoretical computations for each of three possible auxiliary wave patterns that can be associated with the transmitted shock (to satisfy contact surface compatibility) were used to provide bounding solutions as an alternative to the more complex influence coefficients method. Qualitative and quantitative behavior was verified in a 1.5- by 2.0-in. helium shock tube. High speed Schlieren photography, piezoelectric pressure-time histories, and electronic-counter wave speed measurements were used to assess the extent of correlation with the theoretical flow models. Reduced data indicated the adequacy of the bounding theory approach to predict wave phenomena and quantitative response.

  3. Abdominal Adhesions

    MedlinePLUS

    ... tissues and organs. [ Top ] What is the abdominal cavity? The abdominal cavity is the internal area of the body between ... adhesions cause tissues and organs in the abdominal cavity to stick together. Abdominal surgery is the most ...

  4. Biometric estimation of chest wall thickness of female radiation workers as an aid in in-vivo detection of the actinides

    SciTech Connect

    Lane, B.H.; Berger, C.D.

    1983-01-01

    An equation was derived to estimate female chest wall thickness from a series of biometric measurements. This technique will result in improved performance for actinide detection in females by accounting for variations in chest wall thickness in derivation of calibration factors.

  5. Ultrasound-Derived Abdominal Muscle Thickness Better Detects Metabolic Syndrome Risk in Obese Patients than Skeletal Muscle Index Measured by Dual-Energy X-Ray Absorptiometry

    PubMed Central

    Ido, Ayumi; Nakayama, Yuki; Ishii, Kojiro; Iemitsu, Motoyuki; Sato, Koji; Fujimoto, Masahiro; Kurihara, Toshiyuki; Hamaoka, Takafumi; Satoh-Asahara, Noriko; Sanada, Kiyoshi

    2015-01-01

    Sarcopenia has never been diagnosed based on site-specific muscle loss, and little is known about the relationship between site-specific muscle loss and metabolic syndrome (MetS) risk factors. To this end, this cross-sectional study aimed to investigate the relationship between site-specific muscle size and MetS risk factors. Subjects were 38 obese men and women aged 40–82 years. Total body fat and lean body mass were assessed by whole-body dual-energy X-ray absorptiometry (DXA) scan. Muscle thickness (MTH) was measured using B-mode ultrasound scanning in six body regions. Subjects were classified into general obesity (GO) and sarcopenic obesity (SO) groups using the threshold values of one standard deviation below the sex-specific means of either MTH or skeletal muscle index (SMI) measured by DXA. MetS risk score was acquired by standardizing and summing the following continuously distributed variables: visceral fat area, mean blood pressure, HbA1c, and serum triglyceride / high density lipoprotein cholesterol, to obtain the Z-score. Multiple regression analysis revealed that the MetS risk score was independently associated with abdominal MTH in all subjects, but not with MTH in other muscle regions, including the thigh. Although HbA1c and the number of MetS risk factors in the SO group were significantly higher than those in the GO group, there were no significant differences between GO and SO groups as defined by SMI. Ultrasound-derived abdominal MTH would allow a better assessment of sarcopenia in obese patients and can be used as an alternative to the conventionally-used SMI measured by DXA. PMID:26700167

  6. Pressure-induced wall thickness variations in multi-layered wall of a pollen tube and Fourier decomposition of growth oscillations.

    PubMed

    Pietruszka, Mariusz; Haduch-Sendecka, Aleksandra

    2015-04-01

    The augmented growth equation introduced by Ortega is solved for the apical portion of the pollen tube as an oscillating volume, which we approach in the framework of a two-fluid model in which the two fluids represent the constant pressure and the fluctuating features of the system. Based on routine Fourier analysis, we calculate the energy spectrum of the oscillating pollen tube, and discuss the resonant frequency problem of growth rate oscillations. We also outline a descriptive model for cell wall thickness fluctuations associated with small, yet regular variations (~ 0.01 MPa) observed in turgor pressure. We propose that pressure changes must lead to the sliding of wall layers, indirectly resulting in a wave of polarization of interlayer bonds. We conclude that pollen tube wall thickness may oscillate due to local variations in cell wall properties and relaxation processes. These oscillations become evident because of low amplitude/high frequency pressure fluctuations ?P being superimposed on turgor pressure P. We also show that experimentally determined turgor pressure oscillates in a strict periodical manner. A solitary frequency f0 ? 0.066 Hz of these (~ 0.01 MPa in magnitude) oscillations for lily pollen tubes was established by the discrete Fourier transform and Lorentz fit. PMID:25675387

  7. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part II. Thick-walled tube with cross-bore

    NASA Astrophysics Data System (ADS)

    Feng, H.; Donth, B.; Mughrabi, H.

    1998-01-01

    In part I, the autofrettage of a smooth thick-walled tube of the austenitic stainless steel AISI 304 L was studied by finite-element (FE) modelling. It was shown that low- temperature autofrettage is more efficient than autofrettage at room temperature, since it produces a larger beneficial compressive residual tangential (hoop) stress at the inner bore of the tube and hence permits a more significant enhancement of the fatigue resistance against pulsating internal pressure. The objective of the present study (part II) was to investigate the technically more relevant case of a thick-walled tube with a cross-bore made of the same steel. For this purpose, three-dimensional FE calculations were performed in order to characterize the influences of the autofrettage pressure and temperature on the stress and strain changes, in particular at the site of the cross-bore, also taking into account the effects of work hardening and reverse yielding. The results indicate that low-temperature autofrettage can also be applied advantageously in the case of thick-walled tubes with a cross-bore by virtue of the significantly larger residual compressive stresses, compared to room temperature autofrettage. From the quantitative FE calculations, the optimal combination of autofrettage temperature and pressure were concluded to lie in the range of 0965-0393/6/1/007/img1 to 0965-0393/6/1/007/img2, respectively. The calculated results were found to be in fair agreement with the measured values.

  8. A synthesis and sensing application of hollow ZnO nanofibers with uniform wall thicknesses grown using polymer templates.

    PubMed

    Park, Jae Young; Choi, Sun-Woo; Kim, Sang Sub

    2010-11-26

    A novel approach is applied to fabricating hollow ZnO nanofibers (ZNFs) with uniform wall thicknesses. In this approach, polymers synthesized by electrospinning are used as sacrificial templates and ZnO is subsequently deposited on these templates using atomic layer deposition, which makes ZnO uniformly cover the round surface of the polymer nanofibers. Heat treatments result in the selective removal of the polymer templates and the formation of hollow ZNFs with very uniform wall thicknesses. To test a potential use of hollow ZNFs in chemical gas sensors, their sensing properties with regard to O(2), NO(2), and CO are investigated in a comparative manner with those of normal ZnO nanofibers. The excellent sensing properties observed in the hollow ZNF sensor are ascribed to (1) the more pronounced change in resistance due to the presence of nanograins and (2) the doubling of the surface-to-volume ratio due to the generation of inner surfaces. PMID:21030772

  9. Recommendations for protecting against failure by brittle fracture: Category II and III ferritic steel shipping containers with wall thickness greater than four inches

    SciTech Connect

    Schwartz, M.W.; Fischer, L.E.

    1996-08-01

    This report provides criteria for selecting ferritic steels that would prevent brittle fracture in Category II and III shipping containers with wall thickness greater than 4 inches. These methods are extensions of those previously used for Category II and III containers less than 4 inches thick and Category I containers more than 4 inches thick.

  10. Residual strain effects on the stress field in a thick wall finite element model of the human carotid bifurcation.

    PubMed

    Delfino, A; Stergiopulos, N; Moore, J E; Meister, J J

    1997-08-01

    A three-dimensional finite element model of the carotid artery bifurcation was constructed in order to determine the stress field and assess the modification of the stress field when residual strain is taken into account. Residual strain in the carotid bifurcation was characterized by experimental observations. According to these observations, a geometrical model of the carotid artery was constructed to exhibit a state free of strain. Appropriate boundary conditions were applied to yield the correct geometry in the unloaded state, and physiological levels of pressure and axial stretching were applied. The model took into account the varying thickness of the arterial wall along the bifurcation. For modeling purposes, the material was considered to be hyperelastic, incompressible, homogenous and isotropic. For comparison, a similar model of the carotid artery which does not include the effects of residual strain was also created. The results demonstrate that in the model of the carotid artery bifurcation with residual strain, the distribution of maximum principal stress along the inner wall and the circumferential stress throughout the wall is much more uniform than in the model without residual strain. The ratio between the stress at the inner and the outer walls is highest at the lateral wall of the carotid sinus; this is the same location known to be a site of low and oscillatory fluid wall shear stress, and the principal location of early intimal thickening. These results suggest that the localization of atherosclerosis in the carotid artery may be due to local variations in both fluid wall shear stress and solid wall stress. PMID:9239562

  11. Riser Difference Evaluation from Ultrasonic Wall Thickness Inspection of Thirteen Double-Shell Tanks

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2010-03-15

    PNNL has performed an analysis of ultrasonic thickness measurements taken on Hanford's double-shell tanks (DSTs) approximately eight years apart. The analysis was performed to determine whether significant differences exist between ultrasonic thickness measurements made in two opposite risers in Hanford DSTs that have been examined twice.

  12. A Review of Thermal Conductivity of Polymer Matrix Syntactic Foams—Effect of Hollow Particle Wall Thickness and Volume Fraction

    NASA Astrophysics Data System (ADS)

    Gupta, Nikhil; Pinisetty, Dinesh

    2013-02-01

    Hollow-particle-filled composites called syntactic foams are lightweight particulate composites that are useful in weight-sensitive applications such as aerospace and marine structures. Extensive literature is now available on the mechanical properties of syntactic foams. The upcoming applications for syntactic foams in aerospace structures require understanding of their thermal properties, such as the thermal conductivity. The present review article summarizes the available experimental results and theoretical models related to the thermal conductivity of syntactic foams. Experimental results are available for only a few compositions of syntactic foams. Basic understating of the relationship between thermal conductivity of syntactic foams and the material parameters, such as hollow particle volume fraction and wall thickness, is not available through experimental results at this point. Four theoretical models are tested with the experimental data and found to provide close predictions. These models are used to conduct parametric studies. It is observed that the thermal conductivity of syntactic foams decreases as the volume fraction of thin-walled particles is increased. An inverse relationship is observed for thick-walled, hollow-particle-filled syntactic foams. These models can help in designing syntactic foams with required thermal conductivity.

  13. Measure Guideline. Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    SciTech Connect

    Lstiburek, Joseph; Baker, Peter

    2015-04-09

    This measure guideline, written by the U.S. Department of Energy’s Building America team Building Science Corporation, provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ in. and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: (1) fundamental building science principles relating to the use of exterior insulation on wall assemblies; (2) design principles for tailoring this use to the specific project goals and requirements; and (3) construction detailing to increase understanding about implementing the various design elements.

  14. Measure Guideline: Incorporating Thick Layers of Exterior Rigid Insulation on Walls

    SciTech Connect

    Lstiburek, Joseph; Baker, Peter

    2015-04-01

    This measure guideline provides information about the design and construction of wall assemblies that use layers of rigid exterior insulation thicker than 1-½ inches and that require a secondary cladding attachment location exterior to the insulation. The guideline is separated into several distinct sections that cover: fundamental building science principles relating to the use of exterior insulation on wall assemblies; design principles for tailoring this use to the specific project goals and requirements; and construction detailing to increase understanding about implementing the various design elements.

  15. [Replacement continent bladder in dogs by opening an antro-pyloric graft onto the abdominal wall (seven cases between 1980 and 1983)].

    PubMed

    Bourdelat, D; Vrsansky, P; Gruel, Y; Babut, J M

    1996-01-01

    To determine the usefulness of antral bladder controlled by the pyloric sphincter denervated for urological applications, bladder replacement was performed in 17 dogs using the antral segment with its own sphincter, initially with the pylorus supplied by the left gastro-epiploic artery, and later by the right gastro-epiploic artery. The smooth pyloric muscle was denervated to obtain permanent spasm and pulled through the striated anterior abdominal muscle. Both ureters were anastomosed by a Cohen's procedure. The best results were obtained with a gastric pouch supplied by the right gastro-epiploic artery; dissection and reimplantation of the ureters in the gastric wall are difficult. IVP and cystography indicated good function of the antral pouch, with no reflux. The antral bladder controlled by the denervated pyloric sphincter could be a possible alternative in the surgical management of neurogenic or exstrophic bladder. PMID:8767812

  16. Safety Analysis Using Lebesgue Strain Measure of Thick-Walled Cylinder for Functionally Graded Material under Internal and External Pressure

    PubMed Central

    Aggarwal, A. K.; Sharma, Richa; Sharma, Sanjeev

    2013-01-01

    Safety analysis has been done for thick-walled circular cylinder under internal and external pressure using transition theory which is based on the concept of generalized principal Lebesgue strain measure. Results have been analyzed theoretically and discussed numerically. From the analysis, it can be concluded that circular cylinder made of functionally graded material is on the safer side of the design as compared to homogeneous cylinder with internal and external pressure, which leads to the idea of “stress saving” that minimizes the possibility of fracture of cylinder. PMID:24089605

  17. A temperature correlation for the radiation resistance of a thick-walled circular duct exhausting a hot gas

    NASA Astrophysics Data System (ADS)

    Mahan, J. R.; Cline, J. G.; Jones, J. D.

    1984-01-01

    It is often useful to know the radiation impedance of an unflanged but thick-walled circular duct exhausting a hot gas into relatively cold surroundings. The reactive component is shown to be insensitive to temperature, but the resistive component is shown to be temperature dependent. A temperature correlation is developed permitting prediction of the radiation resistance from a knowledge of the temperature difference between the ambient air and the gas flowing from the duct, and a physical basis for this correlation is presented.

  18. A comparative assessment of the wall thickness margin taking into account the initial flaws in steam line elements

    NASA Astrophysics Data System (ADS)

    Gladshtein, V. I.

    2011-02-01

    A procedure for estimating the wall thickness margin for operation during a specified design service life under creep conditions if the metal of articles contains initial flaws is presented. The analysis is carried out taking as an example parts of steam lines made of two different grades of steel: a cast elbow with the size d = 426 × 30 mm made of 15Kh1M1FL low-alloy steel and a pipe bend with the size d = 219 × 32 mm made of EI-756 12% chromium steel. The calculated assessments are compared with the results obtained from long-term operation.

  19. Airway wall thickness in patients with near fatal asthma and control groups: assessment with high resolution computed tomographic scanning

    PubMed Central

    Awadh, N.; Muller, N.; Park, C.; Abboud, R.; FitzGerald, J

    1998-01-01

    BACKGROUND—Airway wall thickening has been observed in post mortem studies of patients with asthma. Assessment of airway wall thickening by high resolution computed tomographic (HRCT) scanning has been reported in experimental studies. We have used HRCT scanning to measure airway wall thickness at the segmental and subsegmental levels in 40 patients with asthma and 14 normal controls.?METHODS—The subjects were prospectively divided into four age and sex matched groups: 14 patients with a history of near fatal attack of asthma (NFA; group 1), 12 patients with moderate asthma (group 2), 13 patients with mild asthma (group 3), and 14 normal controls (group 4). All subjects were non-smokers. High resolution (1 mm collimation) CT scans of the chest were done at five different levels.?RESULTS—The mean (SD) forced expiratory volume in one second (FEV1) was 68 (20)% of predicted for group 1, 73 (12)% for group 2, 102(12)% for group 3, and 103 (12)% for group 4. The ratio of airway wall thickness to outer diameter (T/D) and the percentage wall area (WA%) defined as (wall area/total airway area) × 100 were used to compare airway wall thickness between the groups. The mean (SD) T/D and WA% were 0.27 (0.05) and 78.0 (9.2)% for group 1, 0.27 (0.05) and 78.8 (9.2)% for group 2, 0.25 (0.04) and 74.2(7.5)% for group 3, and 0.23 (0.04) and 70.9 (8.2)% for group 4. T/D and WA% were not significantly different between groups 1 and 2. However, both groups 1 and 2 had higher T/D and WA% than either group 3 or 4 (p < 0.001) and group 3 had a higher T/D and WA% than group 4 (p < 0.03).The differences (95% CI) between the groups in WA% were 7.1% (0 to 14.4) for groups 1 and 4, 3.8% (-3.4 to 10) for groups 1 and 3, and 3.3% (-4.4 to 10) for groups 3and 4. The differences between the groups in T/D and WA% were noted both for those with airways with a luminal diameter of >2 mm and those with a luminal diameter of ?2 mm.?CONCLUSIONS—All the patient groups had greater airway wall thickening than the normal subjects as assessed by HRCT scanning, but patients with more severe asthma had greater airway wall thickening than those with mild asthma. The methodology described in this study may be useful in assessing airway calibre in early intervention studies with anti-inflammatory therapy.?? PMID:9741365

  20. Effect of surface roughness on magnetic domain wall thickness, domain size, and coercivity

    E-print Network

    Wang, Gwo-Ching

    is constant. However, in many cases e.g., in NiFe films6 such a law appeared to be invalid, in agreement, composition, and surface/interface roughness. Spe- cifically, surface/interface roughness influences magnetic and straight6 domain walls. Ne´el,7 based on the same concept, derived the well known ``4/3'' law

  1. Abdominal integument atrophy after operative procedures

    PubMed Central

    Ko?aczyk, Katarzyna; Lubi?ski, Jan; Bojko, Stefania; Ga?dy?ska, Maria; Bernatowicz, El?bieta

    2012-01-01

    The aim of the study was to analyze clinical material concerning postoperative atrophy of abdominal integument. Material and methods The evaluated group consisted of 29 patients with sonographically revealed atrophy of the abdominal wall. Those changes were observed after various surgical procedures: mainly after long, anterolateral laparotomies or several classical operations. Ultrasound examinations up to the year 2000 were performed with analog apparatus, in the latter years only with digital apparatus with linear transducers (7–12 MHz) and sometimes convex type conducers (3–5 MHz). The location, size and intestine stratified wall structure were evaluated. In each case the integument thickness was measured in millimeters in the site of the greatest atrophy and it was compared with the integument thickness from the side that had not been operated which enabled the calculation of the percentage reduction of integument in the area of the scar. Results In 3 patients who underwent several laparotomies there was a total reduction of muscular mass in the operated area. In these cases we stated only skin and slightly echogenic subcutaneous strand; probably corresponding to fibrous tissue – the thickness of integument in this area was in the range from 3 to 8 mm. In the remaining 26 patients the integument atrophy on the scar level included muscles in a greater extent and covered an extensive area after classical urological procedures on the upper urinary tract: after nephrectomy and even ureter stone evacuation or kidney cyst excision by means of classical anterolateral approach with the integument incision on the length of almost 20 cm. Reduction in the integument thickness was observed on the smaller area after classical cholecystectomies, appendectomies and other surgical procedures with the incision across the integument. The integument atrophy in the operated sites expressed in absolute numbers was in the range of 7–20 mm (average 14 mm). These values are markedly lower than the comparative integument thickness on the not operated side: 17–52 mm (average 25.4 mm). The percentage value of the integument thickness reduction oscillated in the range of 32–67% (average 44.2%). In most cases the atrophy involved all layers of the abdominal wall, what demonstrated as regional prominence of the integument, mimicking the presence of hernia. Conclusions Ultrasonography allows precise evaluation of the size and extent of atrophy as well as depiction of other lesions simulating that effect. Establishing the correct diagnosis should prevent the unnecessary reconstructions of the abdominal integument. PMID:26675040

  2. Collapse Pressure Analysis of Transversely Isotropic Thick-Walled Cylinder Using Lebesgue Strain Measure and Transition Theory

    PubMed Central

    Aggarwal, A. K.; Sharma, Richa; Sharma, Sanjeev

    2014-01-01

    The objective of this paper is to provide guidance for the design of the thick-walled cylinder made up of transversely isotropic material so that collapse of cylinder due to influence of internal and external pressure can be avoided. The concept of transition theory based on Lebesgue strain measure has been used to simplify the constitutive equations. Results have been analyzed theoretically and discussed numerically. From this analysis, it has been concluded that, under the influence of internal and external pressure, circular cylinder made up of transversely isotropic material (beryl) is on the safer side of the design as compared to the cylinders made up of isotropic material (steel). This is because of the reason that percentage increase in effective pressure required for initial yielding to become fully plastic is high for beryl as compared to steel which leads to the idea of “stress saving” that reduces the possibility of collapse of thick-walled cylinder due to internal and external pressure. PMID:24523632

  3. Thermoelastic Analysis of a Functionally Graded Rotating Thick-Walled Tube Subjected to Mechanical and Thermal Loads

    NASA Astrophysics Data System (ADS)

    Xin, Libiao; Yang, Shengyou; Ma, Baoyu; Dui, Guansuo

    2015-10-01

    A thermoelastic solution for the functionally graded rotating thick-walled tube subjected to axisymmetric mechanical and thermal loads is given in terms of volume fractions of constituents. We assume that the tube consists of two linear elastic constituents and the volume fraction of one phase is a power function varied in the radial direction. By using the assumption of a uniform strain field within the representative volume element, the theoretical solutions of the displacement and the stresses are presented. Based on the relation of the volume average stresses of constituents and the macroscopic stresses of the composite material in micromechanics, the present method can avoid the assumption of the distribution regularities of unknown overall material parameters appeared in existing papers, such as Young's modulus, thermal expansion coefficient, thermal conductivity, and density. The effects of the angular velocity, the volume fraction, the ratio of two thermal expansion coefficients, the ratio of two thermal conductivities, and the ratio of two densities on the displacement and stresses are systematically studied, which should help structural engineers and material scientists optimally design thick-walled tube comprised inhomogeneous materials.

  4. FRAM isotopic analysis of uranium in thick-walled containers using high energy gamma rays and planar HPGe detectors.

    SciTech Connect

    Sampson, Thomas E.; Hypes, P. A.; Vo, Duc T.

    2002-01-01

    We describe the use of the Los Alamos FRAM isotopic analysis software to make the first reported measurements on thick-walled UF{sub 6} cylinders using small planar HPGe detectors of the type in common use at the IAEA. Heretofore, planar detector isotopic analysis measurements on uranium have used the 100-keV region and can be defeated by 10 mm of steel absorber. The analysis of planar detector measurements through 13-16 mm of steel shows that FRAM can successfully carry out these measurements and analysis in the 120-1024 keV energy range, a range previously thought to be the sole province of more efficient coaxial detectors. This paper describes the measurement conditions and results and also compares the results to other FRAM measurements with coaxial HPGe detectors. The technique of gamma-ray isotopic analysis of arbitrary samples is desirable for measuring the isotopic composition of uranium in UF{sub 6} cylinders because it does not require calibration with standards or knowledge of the cylinder wall thickness. The International Atomic Energy Agency (IAEA) uses the MGAU (Multi Group Analysis Uranium) uranium isotopic analysis software with planar high purity germanium (HPGe) detectors to measure the isotopic composition of uranium. Measurements on UF{sub 6} cylinders with 13-16-mm thick steel walls are usually unsuccessful because of the strong absorption of the 89-100 keV gamma rays and x-rays that MGAU requires for the measurement. This paper describes the use of the Los Alamos FRAM isotopic analysis software to make these measurements on UF{sub 6} cylinders. Uranium measurements with FRAM typically cover the energy range from 120-1001 keV and can easily be made through the walls of UF{sub 6} cylinders. While these measurements are usually performed with efficient coaxial HPGe detectors, this paper reports the first successful measurements using small planar HPGe detectors of the type in common use at the IAEA.

  5. Abdominal mass

    MedlinePLUS

    Several conditions can cause an abdominal mass: Abdominal aortic aneurysm can cause a pulsating mass around the navel. ... This could be a sign of a ruptured aortic aneurysm, which is an emergency condition. Contact your health ...

  6. Strength-toughness requirements for thick-walled high pressure vessels

    NASA Astrophysics Data System (ADS)

    Kapp, Joseph A.

    1992-05-01

    The strength and toughness requirements of materials used in high pressure vessels has been the subject of some discussion in the meetings of the Materials Task Group of the Special Working Group - High Pressure Vessels. A fracture mechanics analysis has been performed to theoretically establish the required toughness for a high pressure vessel. The analysis is based on the validity requirement for plane-strain fracture of fracture toughness test specimens. This means that at fracture, the crack length, uncracked ligament, and vessel length must each be greater than fifty times the crack tip plastic zone since for brittle fracture to occur. For high pressure piping applications, the limiting physical dimension is the uncracked ligament, since it can be assumed that the other dimensions are always greater than fifty times the crack tip plastic zone. To perform the fracture mechanics analysis, several parameters must be known, including vessel dimensions, material strength, degree of autofrettage, and design pressure. Remarkably, the results of the analysis show that the effects of radius ratio, pressure, and degree of autofrettage can be ignored when establishing strength and toughness requirements for design code purposes. The only parameters that enter into the calculation are yield strength, toughness and vessel thickness. The final results can easily be represented as a graph of yield strength against toughness on which several curves, one for each vessel thickness, are plotted.

  7. Transversus Abdominal Plane (TAP) block

    E-print Network

    Peak, Derek

    !" Transversus Abdominal Plane (TAP) block Presentation developed by Dr. Ashley Meister Presented by Dr. Kevin Wong April 25, 2015 #12;Objectives ! Goals of the TAP block & effects ! Anatomy-sparing ! Good for abdominal wall pain (incisional pain) ! Does not cover visceral pain ! Field block in fascial

  8. Magnetic seed field generation from electroweak bubble collisions with bubble walls of finite thickness

    SciTech Connect

    Stevens, Trevor; Johnson, Mikkel B.

    2009-10-15

    Building on earlier work, we develop an equation-of-motion method for calculating magnetic seed fields generated from currents arising from charged W{sup {+-}} fields in bubble collisions during a first-order primordial electroweak phase transition allowed in some proposed extensions of the standard model. The novel feature of our work is that it takes into account, for the first time, the dynamics of the bubble walls in such collisions. We conclude that for bubbles with sufficiently thin surfaces the magnetic seed fields may be comparable to, or larger than, those found in earlier work. Thus, our results strengthen the conclusions of previous studies that cosmic magnetic fields observed today may originate from seeds created during the electroweak phase transition, and consequently that these fields may offer a clue relevant to extensions of the standard model.

  9. Uncertainty induced by chest wall thickness assessment methods on lung activity estimation for plutonium and americium: a large population-based study.

    PubMed

    Broggio, D; Lechaftois, X; Franck, D

    2015-03-01

    In vivo lung counting aims at assessing the retained activity in the lungs. The calibration factor relating the measured counts to the worker's specific retained lung activity can be obtained by several means and strongly depends on the chest wall thickness. Here we compare, for 374 male nuclear workers, the activity assessed with a reference protocol, where the material equivalent chest wall thickness is known from ultrasound measurements, with two other protocols. The counting system is an array of four germanium detectors.It is found that non site-specific equations for the assessment of the chest wall thickness induce large biases in the assessment of activity. For plutonium isotopes or (241)Am the proportion of workers for whom the retained activity is within ± 10% of the reference one is smaller than 10%.The use of site-specific equations raises this proportion to 20% and 58% for plutonium and (241)Am, respectively.Finally, for the studied population, when site-specific equations are used for the chest wall thickness, the standard uncertainties for the lung activity are 42% and 12.5%, for plutonium and (241)Am, respectively. Due to the relatively large size of the studied population, these values are a relatively robust estimate of the uncertainties due to the assessment of the chest wall thickness for the current practice at this site. PMID:25517347

  10. Prior Distributions of Material Parameters for Bayesian Calibration of Growth and Remodeling Computational Model of Abdominal Aortic Wall.

    PubMed

    Seyedsalehi, Sajjad; Zhang, Liangliang; Choi, Jongeun; Baek, Seungik

    2015-10-01

    For the accurate prediction of the vascular disease progression, there is a crucial need for developing a systematic tool aimed toward patient-specific modeling. Considering the interpatient variations, a prior distribution of model parameters has a strong influence on computational results for arterial mechanics. One crucial step toward patient-specific computational modeling is to identify parameters of prior distributions that reflect existing knowledge. In this paper, we present a new systematic method to estimate the prior distribution for the parameters of a constrained mixture model using previous biaxial tests of healthy abdominal aortas (AAs). We investigate the correlation between the estimated parameters for each constituent and the patient's age and gender; however, the results indicate that the parameters are correlated with age only. The parameters are classified into two groups: Group-I in which the parameters ce, ck1, ck2, cm2,Ghc,?and??e are correlated with age, and Group-II in which the parameters cm1, Ghm, G1e, G2e,?and?? are not correlated with age. For the parameters in Group-I, we used regression associated with age via linear or inverse relations, in which their prior distributions provide conditional distributions with confidence intervals. For Group-II, the parameter estimated values were subjected to multiple transformations and chosen if the transformed data had a better fit to the normal distribution than the original. This information improves the prior distribution of a subject-specific model by specifying parameters that are correlated with age and their transformed distributions. Therefore, this study is a necessary first step in our group's approach toward a Bayesian calibration of an aortic model. The results from this study will be used as the prior information necessary for the initialization of Bayesian calibration of a computational model for future applications. PMID:26201289

  11. The use of thick-walled hollow cylinder creep tests for evaluating flow criteria for rock salt

    SciTech Connect

    Morgan, H.S.; Wawersik, W.R.

    1990-01-01

    Finite element simulations of two laboratory creep tests on thick-walled hollow cylinders of rock salt are evaluated to determine if such bench-scale experiments can be used to establish applicability of either von Mises or Tresca stress measures and associated flow conditions. In the tests, the cylinders were loaded axially and pressurized both internally and externally to produce stress fields similar to those found around underground excavations in rock salt. Several different loading stages were used in each test. The simulations show that for each of two creep models studied, quite different deformations of the cylinders are predicted with the Mises and Tresca flow criteria, especially if friction between the cylinders and axial loading platens is ignored. When friction is included in the simulations, the differences in deformation are changed but are sill clearly distinguishable. 10 refs., 10 figs.

  12. Quantum confinement effect in Bi anti-dot thin films with tailored pore wall widths and thicknesses

    SciTech Connect

    Park, Y.; Hirose, Y.; Fukumura, T.; Hasegawa, T.; Nakao, S.; Xu, J.

    2014-01-13

    We investigated quantum confinement effects in Bi anti-dot thin films grown on anodized aluminium oxide templates. The pore wall widths (w{sub Bi}) and thickness (t) of the films were tailored to have values longer or shorter than Fermi wavelength of Bi (?{sub F}?=??40?nm). Magnetoresistance measurements revealed a well-defined weak antilocalization effect below 10?K. Coherence lengths (L{sub ?}) as functions of temperature were derived from the magnetoresistance vs field curves by assuming the Hikami-Larkin-Nagaoka model. The anti-dot thin film with w{sub Bi} and t smaller than ?{sub F} showed low dimensional electronic behavior at low temperatures where L{sub ?}(T) exceed w{sub Bi} or t.

  13. Accuracy Evaluation in the Measurement of a Small Change in the Thickness of Arterial Walls and the Measurement of Elasticity of the Human Carotid Artery

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hideyuki; Kanai, Hiroshi; Hoshimiya, Nozomu; Chubachi, Noriyoshi; Koiwa, Yoshiro

    1998-05-01

    For the diagnosis of the early stages of atherosclerosis, it isimportant to evaluate the local acoustic characteristics of thearterial wall. For this purpose, it is necessary to increase thespatial resolution in the axial direction to several millimeters,which corresponds to the size of the macular lesion on the surface ofthe wall. We have proposed a method for measuring small velocitysignals on the intima and adventitia of the arterial wall from theskin surface using pulsive ultrasonic waves. The small change inthickness of the arterial wall is obtained by integrating thedifference between the two velocity signals on the intima andadventitia. The elastic property of the arterial wall is noninvasivelyevaluated from the change in thickness and the arterial innerpressure. In this paper, we evaluate the accuracy of the proposedmethod for measuring the small displacement. Moreover, we applied thismethod to evaluate the elastic property of the arterial wall of 50patients and 8 healthy subjects.

  14. Photovoltaic response of carbon nanotube-silicon heterojunctions: effect of nanotube film thickness and number of walls.

    PubMed

    Castrucci, P; Del Gobbo, S; Camilli, L; Scarselli, M; Casciardi, S; Tombolini, F; Convertino, A; Fortunato, G; De Crescenzi, M

    2011-10-01

    We report on the multiwall carbon nanotube application as energy conversion material to fabricate thin film solar cells, with nanotubes acting as photogeneration sites as well as charge separators, collectors and carrier transporters. The device consists of a semitransparent thin film of nanotubes coating a n-type crystalline silicon substrate. Under illumination electron-hole (e-h) pairs, generated in the nanotubes and in the silicon substrate underneath, are split and charges are transported through the nanotubes (electrons) and the n-Si (holes). We found that a suitable thickness of the nanotube thin film, high density of Schottky junctions between nanotubes and n-Si and lowest number of nanotube walls are all fundamental parameters to improve the device incident photon to electron conversion efficiency. Multiwall carbon nanotubes have been synthesized by chemical vapour deposition in an ultra high vacuum chamber by evaporating a given amount of iron at room temperature and then exposing the substrate kept at 800 degrees C at acetylene gas. The amount of deposited iron is found to directly affect the nanotube size distribution (inner and outer diameter) and therefore the number of walls of the nanotubes. PMID:22400324

  15. Ceramic inlays and partial ceramic crowns: influence of remaining cusp wall thickness on the marginal integrity and enamel crack formation in vitro.

    PubMed

    Krifka, Stephanie; Anthofer, Thomas; Fritzsch, Marcus; Hiller, Karl-Anton; Schmalz, Gottfried; Federlin, Marianne

    2009-01-01

    No information is currently available about what the critical cavity wall thickness is and its influence upon 1) the marginal integrity of ceramic inlays (CI) and partial ceramic crowns (PCC) and 2) the crack formation of dental tissues. This in vitro study of CI and PCC tested the effects of different remaining cusp wall thicknesses on marginal integrity and enamel crack formation. CI (n = 25) and PCC (n = 26) preparations were performed in extracted human molars. Functional cusps of CI and PCC were adjusted to a 2.5 mm thickness; for PCC, the functional cusps were reduced to a thickness of 2.0 mm. Non-functional cusps were adjusted to wall thicknesses of 1) 1.0 mm and 2) 2.0 mm. Ceramic restorations (Vita Mark II, Cerec3 System) were fabricated and adhesively luted to the cavities with Excite/Variolink II. The specimens were exposed to thermocycling and central mechanical loading (TCML: 5000 x 5 degrees C-55 degrees C; 30 seconds/cycle; 500000 x 72.5N, 1.6Hz). Marginal integrity was assessed by evaluating a) dye penetration (fuchsin) on multiple sections after TCML and by using b) quantitative margin analysis in the scanning electron microscope (SEM) before and after TCML. Ceramic- and tooth-luting agent interfaces (LA) were evaluated separately. Enamel cracks were documented under a reflective light microscope. The data were statistically analyzed with the Mann Whitney U-test (alpha = 0.05) and the Error Rates Method (ERM). Crack formation was analyzed with the Chi-Square-test (alpha = 0.05) and ERM. In general, the remaining cusp wall thickness, interface, cavity design and TCML had no statistically significant influence on marginal integrity for both CI and PCC (ERM). Single pairwise comparisons showed that the CI and PCC of Group 2 had a tendency towards less microleakage along the dentin/LA interface than Group 1. Cavity design and location had no statistically significant influence on crack formation, but the specimens with 1.0 mm of remaining wall thickness had statistically significantly more crack formation after TCML than the group with 2.0 mm of remaining cusp wall thickness for CI. The remaining cusp wall thickness of non-functional cusps of adhesively bonded restorations (especially for CI) should have a thickness of at least 2.0 mm to avoid cracks and marginal deficiency at the dentin/LA interface. PMID:19192835

  16. Effect of material properties on the strain to failure of thick-walled cylinders subjected to internal pressure

    SciTech Connect

    Roach, D.P.; Priddy, T.G. )

    1994-05-01

    The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design, especially in autofrettage considerations. This paper presents the results of an experimental study which measured the maximum internal pressure which can be applied to thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through-thickness yielding characteristics were determined for these specimens. It is shown that a strain-to-failure criterion, based on the triaxiality of stress in the critical region, can be used to predict the complete pressure versus strain relations and maximum pressure for these cylinders. A simple tension-true stress-strain relation of the material is employed to analytically predict the response of the cylinder into the plastic regime. Finally, simplified theoretical and empirical formulas for bursting pressures are checked against the experimental results.

  17. Finite-element modelling of low-temperature autofrettage of thick-walled tubes of the austenitic stainless steel AISI 304 L: Part I. Smooth thick-walled tubes

    NASA Astrophysics Data System (ADS)

    Feng, H.; Mughrabi, H.; Donth, B.

    1998-01-01

    The stresses and strains introduced by low-temperature autofrettage of smooth thick-walled tubes made of the austenitic stainless steel AISI 304 L were modelled by the finite-element (FE) method. The objective was to show that low-temperature autofrettage is much more efficient than autofrettage at room temperature in enhancing the fatigue resistance by introducing a higher beneficial tangential (hoop) residual compressive stress at the inner part of the tube. Attention was paid to the influences of the autofrettage temperature and pressure, the work hardening and the reverse yielding on the residual stress components and on the total strain components of the tube. The FE calculations confirmed that more beneficial residual stress patterns can be attained by autofrettage at low rather than at room temperature. From the quantitative calculations, the optimal autofrettage temperature and pressure of the tube were concluded to be about 0965-0393/6/1/006/img1 and 4000 bar, respectively. The results of the calculations were shown to be in good agreement with recently measured data.

  18. Analysis of the Effect of Osteon Diameter on the Potential Relationship of Osteocyte Lacuna Density and Osteon Wall Thickness

    PubMed Central

    Skedros, John G.; Clark, Gunnar C.; Sorenson, Scott M.; Taylor, Kevin W.; Qiu, Shijing

    2011-01-01

    An important hypothesis is that the degree of infilling of secondary osteons (Haversian systems) is controlled by the inhibitory effect of osteocytes on osteoblasts, which might be mediated by sclerostin (a glycoprotein produced by osteocytes). Consequently, this inhibition could be proportional to cell number: relatively greater repression is exerted by progressively greater osteocyte density (increased osteocytes correlate with thinner osteon walls). This hypothesis has been examined, but only weakly supported, in sheep ulnae. We looked for this inverse relationship between osteon wall thickness (On.W.Th) and osteocyte lacuna density (Ot.Lc.N/B.Ar) in small and large osteons in human ribs, calcanei of sheep, deer, elk, and horses, and radii and third metacarpals of horses. Analyses involved: (1) all osteons, (2) smaller osteons, either ?150?m diameter or ? the mean diameter, and (3) larger osteons (>mean diameter). Significant, but weak, correlations between Ot.Lc.N/B.Ar and On.W.Th/On.Dm (On.Dm = osteon diameter) were found when considering all osteons in limb bones (r values ?0.16 to ?0.40, p<0.01; resembling previous results in sheep ulnae: r= ?0.39, p<0.0001). In larger osteons, these relationships were either not significant (five/seven bone types) or very weak (two/seven bone types). In ribs, a negative relationship was only found in smaller osteons (r= ?0.228, p<0.01); this inverse relationship in smaller osteons did not occur in elk calcanei. These results do not provide clear or consistent support for the hypothesized inverse relationship. However, correlation analyses may fail to detect osteocyte-based repression of infilling if the signal is spatially non-uniform (e.g., increased near the central canal). PMID:21809466

  19. Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds

    SciTech Connect

    Wagner, Sabine; Dugan, Sandra; Barth, Martin; Schubert, Frank; Köhler, Bernd

    2014-02-18

    Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

  20. Influence of thick-walled cylinders length on the residual stresses generated during the single-cycle mandrelling

    NASA Astrophysics Data System (ADS)

    Skvortsov, V. F.; Boznak, A. O.; Kim, A. B.; Arlyapov, A. Yu

    2015-09-01

    The paper presents methodology and results of experimental study by Sachs method the effect of length of mandrelled thick-walled cylinders made of steel grade 50 (0.5% C) with 5 mm diameter hole, outer diameter of 15 and 25 mm on residual stresses. Based on the review of studies, it was noted that this effect may be both due to uneven process of mandrelling along the cylinder length and due to zero axial residual stresses on its faces. It was found that the length of cylinders has the strongest influence on axial residual stresses. With allowances between 0.9 and 7.1% and length reduction from 40 to 10 mm, the largest absolute value of axial residual stresses decreases from 210 to 50 MPa. It was noted that when the outer diameter of cylinders is 15 mm their length significantly influence on both hoop and radial residual stresses. With the above-mentioned decrease in cylinders length, absolute values of hoop and radial residual stresses in the region adjacent to the hole, depending on the mandrelling allowance, increase (from -135 to -205 MPa and from -45 to 55 MPa respectively, when allowance is 7.1%), decrease (from -315 to -235 MPa and from -135 to -95 MPa respectively, when allowance is 0.9%) and remain almost unchanged (when allowance is 3.4%). Impact of length on these stresses is weak when the outer diameter of cylinders is 25 mm.

  1. Welding for testability: An approach aimed at improving the ultrasonic testing of thick-walled austenitic and dissimilar metal welds

    NASA Astrophysics Data System (ADS)

    Wagner, Sabine; Dugan, Sandra; Barth, Martin; Schubert, Frank; Köhler, Bernd

    2014-02-01

    Austenitic and dissimilar welds in thick walled components show a coarse grained, dendritic microstructure. Therefore, ultrasonic testing has to deal with beam refraction, scattering and mode conversion effects. As a result, the testing techniques typically applied for isotropic materials yield dissatisfying results. Most approaches for improvement of ultrasonic testing have been based on modeling and improved knowledge of the complex wave propagation phenomena. In this paper, we discuss an alternative approach: is it possible to use a modified welding technology which eliminates the cause of the UT complications, i.e. the large-grained structure of the weld seams? Various modification parameters were tested, including: TIG current pulsing, additional DC and AC magnetic fields, and also additional external vibrations during welding. For all welds produced under different conditions, the grain structure of the weld seam was characterized by optical and GIUM microstructure visualizations on cross sections, wave field propagation measurements, and ultrasonic tests of correct detectability of flaws. The mechanical properties of the welds were also tested.

  2. Mechanical Performance and Failure Mechanism of Thick-walled Composite Connecting Rods Fabricated by Resin Transfer Molding Technique

    NASA Astrophysics Data System (ADS)

    Liu, Gang; Luo, Chuyang; Zhang, Daijun; Li, Xueqin; Qu, Peng; Sun, Xiaochen; Jia, Yuxi; Yi, Xiaosu

    2015-08-01

    A resin transfer molding technique was used to fabricate thick-walled composite connecting rods, and then the mechanical performance of the connecting rod was studied experimentally, at the same time the stress and failure index distributions were simulated numerically. The experimental results show that under a tensile load, the connecting rod first cracks near the vertex of the triangle areas at the two ends, and then the damage propagates along the interface between the main bearing beam and the triangle area as well as along the round angle of the triangle area. Whereas under a compressive load, the delamination primarily occurs at the corner of the U-shaped flange, and the final destruction is caused by the fracture of fibers in the main bearing beam. The simulated results reveal that the tensile failure is originated from the delamination at the round angle transition areas of the T-joints, and the failure strength is determined by the interlaminar strength. Whereas the compressive failure is caused by the fracture of fibers in the main bearing beam, and the failure strength of the structure is determined by the longitudinal compressive strength of the composite material. The simulated results are basically consistent with the experimental results. Hence the mechanical performance and failure mechanism of the complicated composite structure are revealed in great detail through the coupling of the two kinds of research methods, which is helpful for the optimal design of composite structures.

  3. Fluid-structure interaction in abdominal aortic aneurysms: Structural and geometrical considerations

    NASA Astrophysics Data System (ADS)

    Mesri, Yaser; Niazmand, Hamid; Deyranlou, Amin; Sadeghi, Mahmood Reza

    2015-08-01

    Rupture of the abdominal aortic aneurysm (AAA) is the result of the relatively complex interaction of blood hemodynamics and material behavior of arterial walls. In the present study, the cumulative effects of physiological parameters such as the directional growth, arterial wall properties (isotropy and anisotropy), iliac bifurcation and arterial wall thickness on prediction of wall stress in fully coupled fluid-structure interaction (FSI) analysis of five idealized AAA models have been investigated. In particular, the numerical model considers the heterogeneity of arterial wall and the iliac bifurcation, which allows the study of the geometric asymmetry due to the growth of the aneurysm into different directions. Results demonstrate that the blood pulsatile nature is responsible for emerging a time-dependent recirculation zone inside the aneurysm, which directly affects the stress distribution in aneurismal wall. Therefore, aneurysm deviation from the arterial axis, especially, in the lateral direction increases the wall stress in a relatively nonlinear fashion. Among the models analyzed in this investigation, the anisotropic material model that considers the wall thickness variations, greatly affects the wall stress values, while the stress distributions are less affected as compared to the uniform wall thickness models. In this regard, it is confirmed that wall stress predictions are more influenced by the appropriate structural model than the geometrical considerations such as the level of asymmetry and its curvature, growth direction and its extent.

  4. Method and apparatus to produce and maintain a thick, flowing, liquid lithium first wall for toroidal magnetic confinement DT fusion reactors

    DOEpatents

    Woolley, Robert D. (Hillsborough, NJ)

    2002-01-01

    A system for forming a thick flowing liquid metal, in this case lithium, layer on the inside wall of a toroid containing the plasma of a deuterium-tritium fusion reactor. The presence of the liquid metal layer or first wall serves to prevent neutron damage to the walls of the toroid. A poloidal current in the liquid metal layer is oriented so that it flows in the same direction as the current in a series of external magnets used to confine the plasma. This current alignment results in the liquid metal being forced against the wall of the toroid. After the liquid metal exits the toroid it is pumped to a heat extraction and power conversion device prior to being reentering the toroid.

  5. Fracture resistance of welded thick-walled high-pressure vessels in power plants. Report No. 2. Approach to evaluating static strength

    SciTech Connect

    Gorynin, I.V.; Filatov, V.M.; Ignatov, V.A.; Timofeev, B.T.; Zvezdin, Yu. I.

    1986-07-01

    The authors examine data on the effect of defects on the fracture resistance of high-pressure vessels and their models obtained within the framework of the HSST program. Results of internal-pressure tests of two types of vessels with a wall thickness of 152 mm made from forgings of steels SA508 and SA533, as well as small vessels with a wall thickness of 11.5 and 23mm made of steel SA533 are shown. The authors state that testing thick-walled welded high-pressure vessels and thin-walled vessels with surface defects of different sizes has demonstrated that there are substantial static-strength reserves in structures designed by existing domestic and foreign standards on the strength of power-plant equipment. A correction was proposed for the presently used method of calculating the resistance of highpressure vessels to brittle fracture that allows for the dimensions of the defects in relation to the type of vessel, the manufacturing technology, and the method of inspection.

  6. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    PubMed Central

    Gomez-Cardona, Daniel; Nagle, Scott K.; Li, Ke; Robinson, Terry E.; Chen, Guang-Hong

    2015-01-01

    Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (VeoTM, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose levels. For FBP, the relative bias and the angular standard deviation of the measured WT increased steeply with decreasing radiation dose. Except for the smallest airway, MBIR enabled significant reduction in both the relative bias and angular standard deviation of the WT, particularly at low radiation dose levels; the SSQ was reduced by 50%–96% by using MBIR. The optimal reconstruction algorithm was found to be MBIR for the seven airways being assessed, and the combined use of MBIR and optimal kV–mAs selection resulted in a radiation dose reduction of 37%–83% compared with a reference scan protocol with a dose level of 1 mGy. Conclusions: The quantification accuracy of airway WT is strongly influenced by radiation dose and reconstruction algorithm. The MBIR algorithm potentially allows the desired WT quantification accuracy to be achieved with reduced radiation dose, which may enable a wider clinical use of MDCT for the assessment of airway WT, particularly for younger patients who may be more sensitive to exposures with ionizing radiation. PMID:26429266

  7. Abdominal pain

    MedlinePLUS

    Stomach pain; Pain - abdomen; Belly ache; Abdominal cramps; Bellyache; Stomachache ... Almost everyone has pain in the abdomen at some point. Most of the time, it is not serious. How bad your pain is does not always reflect the seriousness ...

  8. Abdominal thrusts

    MedlinePLUS

    ... done on someone who is choking and also conscious . Most experts do not recommend abdominal thrusts for ... the airway, call 911 . If the person loses consciousness, start CPR . If you are not comfortable performing ...

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

    PubMed Central

    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. PMID:26305893

  10. In the femoral artery bifurcation, differences in mean wall shear stress within subjects are associated with different intima-media thicknesses.

    PubMed

    Kornet, L; Hoeks, A P; Lambregts, J; Reneman, R S

    1999-12-01

    In elastic arteries, intima-media thickening is more pronounced in areas with low than with high mean and peak wall shear stress. These findings in elastic arteries are not necessarily representative of the situation in muscular arteries. The former arteries have to store volume energy, whereas the latter are mainly conductive vessels. It was the aim of the present study to investigate noninvasively whether differences in wall shear stress within a muscular artery bifurcation, if any, were associated with different intima-media thicknesses (IMTs). The effect of age on the possible differences was assessed as well. We determined IMT and mean, peak systolic, and the maximum cyclic change in shear stress near the posterior wall in the common (FC) and the superficial (FS) femoral artery 20 to 30 mm from the flow divider in 54 presumed healthy subjects between 21 and 74 years of age. Results were considered in terms of intrasubject differences. Before the study, the reliability of the ultrasonic system to assess wall shear rate and IMT was determined in terms of intrasubject variability. IMT at the posterior wall was significantly larger in the FC than in the FS, probably owing to the significantly lower mean wall shear stress at this site in the FC. The relative differences in IMT and mean wall shear stress between FC and FS were independent of age. The difference in wall shear stress between both arteries can likely be explained by a different influence of reflections. In both the FC and FS, mean, peak systolic, and maximum cyclic change in shear stress near the posterior wall did not change significantly with age, whereas IMT did increase significantly with age. PMID:10591672

  11. Fibrolipomas masquerading as abdominal hernias

    PubMed Central

    Watson, Hannah Isabella; Saunders, Andrew John

    2013-01-01

    A 15-year-old Caucasian girl presented to her general practitioner with a tender, irreducible mass in the paraumbilical region. On examination, two small masses could be felt. She was referred to general surgery. Ultrasound imaging and MRI were unremarkable. However, clinical suspicion suggested multiple areas of abdominal wall herniation. The patient was admitted for elective surgery to exclude herniation. At operation, three subcutaneous masses were found but with no evidence of abdominal wall herniation. Histopathology results from the specimens showed mature adipose tissue mixed with fibrous deposits. There was no evidence of malignancy. A diagnosis of fibrolipoma was given. PMID:24343803

  12. An experimental investigation of lead zirconate titanate--epoxy-multi-walled carbon nanotube bulk and flexible thick film composites

    NASA Astrophysics Data System (ADS)

    Banerjee, Sankha

    Piezoelectric sensors and actuators are needed for a wide range of applications from physiological measurement to industrial monitoring systems. Sensors that can be easily integrated with the host, while maintaining high sensitivity and reliability over a wide range of frequencies are not readily feasible and economical with homogenous piezoelectric materials. It is well known that two-phase piezoelectric-epoxy composites offer several benefits over their single phase counterparts, as the properties of the constituent phases combine to improve the range of applicability. However, the piezoelectric properties of these materials suffer from the electrically insulating properties of the epoxy matrix. The electrical properties of the matrix may be enhanced by including electrically conducting inclusions however, less is known about the mechanisms that drive the changes in these properties. Hence, this experimental investigation of sensor materials builds on the previous work in two-phase piezoelectric composites, where the aims are to understand the roles that specific fabrication parameters and inclusion composition play in determining the piezoelectric and dielectric performance the aforementioned composites. The materials under investigation will be comprised of Lead Zirconate Titanate, Epofix Cold-Setting Embedding Resin and multi-walled carbon nanotubes, i.e. the piezoelectric, epoxy and electrical inclusions respectively. Our work suggests that inclusion of MWCNTs enhances the piezoelectric and dielectric properties with increasing volume fraction below the percolation threshold. This work seeks to understand how the processing parameters: poling temperature, poling type and particle distribution influence the contact resistance, space charge double layer at the piezoelectric and conductor interfaces and electric field intensity at the piezoelectric boundary, which all ultimately dictate the piezoelectric and dielectric performance of the composite materials. Conventional solid oxide mixing, spin coating and deposition techniques will be used to fabricate the bulk and thick films. The piezoelectric and dielectric performance will be determined from the measurement of the piezoelectric strain coefficients, d33 and d31, dielectric constant, impedance and dielectric spectrum, dielectric loss tangent, and capacitance. These measurements will be correlated with inclusion size, shape, distribution, and surface morphology observations obtained from the scanning electron microscope (SEM) and transmission electron microscope (TEM).

  13. Dynamics of thin planar viscous liquid sheets in the presence of viscous gas coflows behind thick-wall injectors.

    NASA Astrophysics Data System (ADS)

    Dopazo, C.; Fueyo, N.; López, E.

    1999-11-01

    The dynamics of a thin 2-D viscous liquid sheet flowing between two viscous gas streams near the injection point is numerically investigated. The liquid and gas coflows are separated by plates with thick trailing edges. A volume of fluid (VOF) method is adopted; a transport equation for a non- diffusive scalar phase-indicator function is treated. Surface tension is taken into account. A finite volume fluid dynamics solver third order accurate in time and second in space is used; fractional step techniques are implemented. Boundary conditions are imposed upstream of the thick trailing edge, giving a chance for Blasins type boundary layer velocity profiles to develop. The dimensionless groups entering the problem are the liquid and gas Reynolds numbers, the air / liquid momentum flux ratio, the air / liquid characteristic velocity ratio, the gas boundary layer momentum thickness to the liquid sheet thickness ratio, the plate to sheet thickness ratio and the Weber number. A systematic analysis of the influence of the various dimensionless parameters on triggering the sheet instability and deformation near the injection nozzle is performed. Steady closed gas recirculation patterns for low Reynolds numbers are predicted. For large gas Reynolds numbers the vortex shedding is numerically predicted with no need for external initial disturbances. Flow time-dependent structures are visualized and characterized by means of pressure fields, streamlines, vorticity isocontours and pressure profiles. The pressure fields induced in the gas by the vorticity patterns forces the liquid sheet motion. Gas vortex shedding frequecies and liquid sheet flapping frequencies are determined.

  14. Development of a Versatile Laser-Ultrasonic System and Application to the Online Measurement for Process Control of Wall Thickness and Eccentricity of Seamless Tubes

    SciTech Connect

    Robert V. Kolarik II

    2002-10-23

    A system for the online, non-contact measurement of wall thickness in steel seamless mechanical tubing has been developed and demonstrated at a tubing production line at the Timken Company in Canton, Ohio. The system utilizes laser-generation of ultrasound and laser-detection of time of flight with interferometry, laser-doppler velocimetry and pyrometry, all with fiber coupling. Accuracy (<1% error) and precision (1.5%) are at targeted levels. Cost and energy savings have exceeded estimates. The system has shown good reliability in measuring over 200,000 tubes in its first six months of deployment.

  15. Abdominal trauma by ostrich

    PubMed Central

    Usurelu, Sergiu; Bettencourt, Vanessa; Melo, Gina

    2015-01-01

    Introduction Ostriches typically avoid humans in the wild, since they correctly assess humans as potential predators, and, if approached, often run away. However, ostriches may turn aggressive rather than run when threatened, especially when cornered, and may also attack when they feel the need to defend their offspring or territories. Presentation of case A 71-year-old male patient presented with intra abdominal injury sustained from being kicked in the abdominal wall by an ostrich. During laparotomy, were found free peritoneal effusion and perforation of the small intestine. Discussion The clinical history and physical examination are extremely important for diagnostic and therapeutic decision making. CT-scan is the most accurate exam for making diagnosis. Surgery is the treatment of choice, and is always indicated when there is injury to the hollow viscera. In general it is possible to suture the defect. Conclusion In cases of blunt abdominal trauma by animals is necessary to have a low threshold of suspicion for acute abdomen. PMID:25685344

  16. Analysis of transient heat flow to thick-walled plates and cylinders. [to determine gas heat transfer coefficient

    NASA Technical Reports Server (NTRS)

    Powell, W. B.

    1973-01-01

    A methodology is described for the analysis of a transient temperature measurement made in a flat or curved plate subjected to convective heat transfer, such that the surface heat flux, the hot-gas temperture, and the gas heat transfer coefficient can be determined. It is shown that if the transient temperature measurement is made at a particular point located nearly midway in the thickness of the plate there is an important simplification in the data analysis process, in that the factor relating the surface heat flux to the measured rate of rise of temperature becomes invariant for a Fourier Number above 0.60 and for all values of the Biot Number. Parameters are derived, tabulated, and plotted which enable straightforward determination of the surface heat flux, the hot-gas temperature, of the plate, the rate of rise of temperature, the plate thickness and curvature, and the mean thermal properties of the plate material at the test temperature.

  17. Analysis of thermal residual stress in a thick-walled ring of Duralcan-base Al-SiC functionally graded material

    SciTech Connect

    Fukui, Yasuyoshi; Watanabe, Yoshimi

    1996-12-01

    A ring-cutting test and an elastic theory were applied to evaluate the macroscopic residual stress in a thick-walled ring made of Al-SiC functionally graded material (FGM). The FGM ring specimens, with outer diameter 90 mm, radial thickness approximately 8.4 to 10 mm, and width 30 mm, were fabricated by the centrifugal casting method from an ingot of Duralcan F3D.20S of Al-20 vol pct SiC master composite. Because of a difference in centrifugal forces of SiC particles and of molten aluminum alloy, the rings had a graded composition of SiC particles in the radial direction. The volume fractions of SiC particles in each ring specimen varied in the range of 0 to 43 vol pct from the inner to the outer surface of the ring, depending on the applied mold spin speed. A ring diametral compression test was performed to validate an analytical formula based on the curved beam theory that can account for the graded properties of the material. Excellent agreement between the theory that can account for the graded properties of the material. Excellent agreement between the theory and the experiment was found. The residual stress was found to be generated by a cooling of {Delta}T = 140 K, which was from half the melting point corresponding stress-free condition to the ambient temperature. The hoop residual stresses in the FGM ring varied in the range of {minus}50 to +35 MPa and from tension at the inner surface to compression at the outer space because of the graded composition. With an increase in wall thickness and/or composition gradation, the residual stresses were found to increase.

  18. Comparative study of the microvascular blood flow in the intestinal wall, wound contraction and fluid evacuation during negative pressure wound therapy in laparostomy using the V.A.C. abdominal dressing and the ABThera open abdomen negative pressure therapy system.

    PubMed

    Lindstedt, Sandra; Malmsjö, Malin; Hlebowicz, Joanna; Ingemansson, Richard

    2015-02-01

    This study aimed to compare the changes in microvascular blood flow in the small intestinal wall, wound contraction and fluid evacuation, using the established V.A.C. abdominal dressing (VAC dressing) and a new abdominal dressing, the ABThera open abdomen negative pressure therapy system (ABThera dressing), in negative pressure wound therapy (NPWT). Midline incisions were made in 12 pigs that were subjected to treatment with NPWT using the VAC or ABThera dressing. The microvascular blood flow in the intestinal wall was measured before and after the application of topical negative pressures of ?50, ?75 and ?125mmHg using laser Doppler velocimetry. Wound contraction and fluid evacuation were also measured. Baseline blood flow was defined as 100% in all settings. The blood flow was significantly reduced to 64·6±6·7% (P <0·05) after the application of ?50mmHg using the VAC dressing, and to 65·3±9·6% (P <0·05) after the application of ?50mmHg using the ABThera dressing. The blood flow was significantly reduced to 39·6±6·7% (P <0·05) after the application of ?125mmHg using VAC and to 40·5±6·2% (P <0·05) after the application of ?125mmHg using ABThera. No significant difference in reduction in blood flow could be observed between the two groups. The ABThera system afforded significantly better fluid evacuation from the wound, better drainage of the abdomen and better wound contraction than the VAC dressing. PMID:23517436

  19. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  20. Estimation of PSD Shifts for High-Resolution Metrology of Thickness Micro-Changes with Possible Applications in Vessel Walls and Biological Membrane Characterization

    PubMed Central

    Ramos, Antonio; Bazán, Ivonne; Negreira, Carlos; Brum, Javier; Gómez, Tomás; Calás, Héctor; Ruiz, Abelardo; de la Rosa, José Manuel

    2012-01-01

    Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura) and thin biological walls (e.g., blood vessels) from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system), is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms). The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD) are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced measurement spectral tool are found to improve the performance of typical cross-correlation methods and provide reliable and high-resolution estimations. PMID:23202216

  1. Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2006-03-01

    Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

  2. Novel synthesis of thick wall coatings of titania supported Bi poisoned Pd catalysts and application in selective hydrogenation of acetylene alcohols in capillary microreactors.

    PubMed

    Cherkasov, Nikolay; Ibhadon, Alex O; Rebrov, Evgeny V

    2015-04-21

    Catalysis in microreactors allows reactions to be performed in a very small volume, reducing the environmental problems and greatly intensifying the processes through easy pressure control and the elimination of heat- and mass-transfer limitations. In this study, we report a novel method for the controlled synthesis of micrometre-thick mesoporous TiO2 catalytic coatings on the walls of long channels (>1 m) of capillary microreactors in a single deposition step. The method uses elevated temperature and introduces a convenient control parameter of the deposition rate (displacement speed controlled by a stepper motor), which allows deposition from concentrated and viscous sols without channel clogging. A capillary microreactor wall-coated with titania supported Bi-poisoned Pd catalyst was obtained using the method and used for the semihydrogenation of 2-methyl-3-butyn-2-ol providing 93 ± 1.5% alkene yield for 100 h without deactivation. Although the coating method was applied only for TiO2 deposition, it is nonetheless suitable for the deposition of volatile sols. PMID:25749619

  3. Differences in near-wall shear rate in the carotid artery within subjects are associated with different intima-media thicknesses.

    PubMed

    Kornet, L; Lambregts, J; Hoeks, A P; Reneman, R S

    1998-12-01

    In the common carotid artery, reflections originating from the periphery and the flow divider may affect the shape of the flow velocity profile and, hence, near-wall shear rate (WSR) differently just before the bifurcation (location B) than 20 to 30 mm farther upstream (location A). Recent developments in ultrasound technology allow the assessment of WSR and intima-media thickness (IMT) at the same site in the carotid artery in vivo. We therefore determined WSR at locations A and B and investigated whether the differences between both sites, if any, were associated with different IMTs and different mechanical properties of the arterial wall. The effect of age on the possible differences was assessed as well. The study was performed on presumably healthy volunteers (n=53). In all individuals, IMT was larger at location B than at location A. The relative difference in IMT between both locations was not affected by age. No significant differences in diameter and distension were found between locations. Near peak systolic and near mean WSR at the posterior wall (PWSRp and MWSRp, respectively) were significantly lower at location B than at location A. The relative differences in PWSRp and MWSRp between both locations within subjects were independent of age. The velocity profiles were more blunted at location A than at location B. PWSRp and MWSRp significantly decreased and IMT significantly increased with age at both locations. IMT was negatively correlated with PWSRP and MWSRP at location B, but this correlation was not significant at location A. In summary, in the common carotid artery, the lower WSR near the bifurcation, as compared with 20 to 30 mm upstream, is associated with a larger IMT than at the more proximal site. The relative difference between both locations within subjects is independent of age. PMID:9848879

  4. Extremal states of energy of a double-layered thick-walled tube - application to residually stressed arteries.

    PubMed

    Waffenschmidt, Tobias; Menzel, Andreas

    2014-01-01

    Various biological tissues are designed to optimally support external loads for complex geometries and mechanobiological structures. This results in complex microstructures of such materials. The design of, for instance, (healthy) arteries, which are in the focus of this work, is characterised by a residually stressed fibre-reinforced multi-layered composite with highly non-linear elastic response. The complex interaction of material properties with the geometry and residual stress effects enables the optimal support under different blood pressures, respectively blood flow, within the vessel. The fibres reinforcing the arterial wall, as well as residual stresses present in the vessel, strongly influence its overall behaviour and performance. Turn-over and remodelling processes of the collagenous fibres occurring in the respective layers - either resulting from natural growth phenomena or from artificially induced changes in loading condition such as stent deployment - support the optimisation of the multi-layered composite structure of arteries for the particular loading conditions present in the artery. Within this contribution, the overall energetic properties of an artery are discussed by means of the inflation, bending and extension of a double-layered cylindrical tube. Different states of residual stresses and different fibre orientations are considered so that, for instance, representative fibre angles that result in extremal states of the total potential energy can be identified. In view of turn-over and remodelling processes, these orientations are considered to constitute preferred directions of fibre alignment. In summary, the main goal of this work is to calculate optimal material, structural and loading parameters by concepts of energy-minimisation. Several numerical studies show that the obtained values - such as the fibre orientations, the residual axial stretch and the opening angle - are in good agreement with respective physiological parameters reported in the literature. PMID:23845915

  5. [The abdominal drop flap].

    PubMed

    Bodin, F; Liverneaux, P; Seigle-Murandi, F; Facca, S; Bruant-Rodier, C; Dissaux, C; Chaput, B

    2015-08-01

    The skin between the mastectomy scar and the future infra-mammary fold may be managed in different ways in delayed breast reconstruction using a DIEP (deep inferior epigastric perforator). Conserving this skin and positioning the flap skin paddle in the middle of the breast usually highlights skin color disparity because of two visible transition zones. Resection of the entire skin under the scar may be more aesthetic but limits direct closure possibility in case of flap failure. In order to benefit from both aesthetic result and safe surgical method, we propose the abdominal drop flap. The inferior thoracic skin flap is detached from the thoracic wall beyond the future infra-mammary fold, preserved and pushed under the breast. PMID:25896871

  6. The biomechanical behavior and host response to porcine-derived small intestine submucosa, pericardium and dermal matrix acellular grafts in a rat abdominal defect model.

    PubMed

    Zhang, Jian; Wang, Guan Yu; Xiao, Yi Pin; Fan, Lie Ying; Wang, Qiang

    2011-10-01

    Several porcine-derived acellular biologic grafts are increasingly used in abdominal wall reconstruction due to the limitations of synthetic meshes in many clinical situations. However, relatively little is known so far about their comparative mechanical characteristics and performance after defect repair. We therefore investigated three most commonly used porcine-derived acellular biomaterials, small intestine submucosa (P-SIS), pericardium (P-PC) and acellular dermal matrix (P-ADM) immediately after prepared, and their effectiveness, biomechanical and histological characteristics in repairing full-thickness abdominal defect in a rat model. P-PC had the best native performance in the burst strength, tensile strength and ball burst among the three porcine-derived scaffolds. P-SIS showed a significantly higher water vapor transmission in comparison with P-PC or P-ADM. Abdominal wall defects in rats were all satisfied repaired with P-SIS, P-PC or P-ADM. No laxity or fistula was observed in the repaired abdominal wall in the P-SIS group up to 8 weeks after surgery. However, there was a tendency for high postoperative abdominal eventration in the P-ADM and P-PC groups as compared with the P-SIS group. With regard to overall aspects of the postoperative laxity, intra-abdominal adhesion formation, tensile stress, stretchability, and degree of tissue ingrowth in terms of collagen deposition and neovascularization, P-SIS exhibits clear advantages over P-PC as well as P-ADM after large abdominal wall defect reconstruction. PMID:21741703

  7. Echo features used by human listeners to discriminate among objects that vary in material or wall thickness: implications for echolocating dolphins.

    PubMed

    DeLong, Caroline M; Au, Whitlow W L; Stamper, Sarah A

    2007-01-01

    Echolocating dolphins extract object feature information from the acoustic parameters of echoes. To gain insight into which acoustic parameters are important for object discrimination, human listeners were presented with echoes from objects used in two discrimination tasks performed by dolphins: Hollow cylinders with varying wall thicknesses (+/-0.2, 0.3, 0.4, and 0.8 mm), and spheres made of different materials (steel, aluminum, brass, nylon, and glass). The human listeners performed as well or better than the dolphins at the task of discriminating between the standard object and the comparison objects on both the cylinders (humans=97.1%; dolphin=82.3%) and the spheres (humans= 86.6%; dolphin= 88.7%). The human listeners reported using primarily pitch and duration to discriminate among the cylinders, and pitch and timbre to discriminate among the spheres. Dolphins may use some of the same echo features as the humans to discriminate among objects varying in material or structure. Human listening studies can be used to quickly identify salient combinations of echo features that permit object discrimination, which can then be used to generate hypotheses that can be tested using dolphins as subjects. PMID:17297814

  8. Abdominal Aortic Aneurysm

    MedlinePLUS

    MENU Return to Web version Abdominal Aortic Aneurysm Overview What is an abdominal aortic aneurysm (AAA)? The main blood vessel in your body ... educational materials I could read? Are there any web sites you recommend where I can learn more ...

  9. Post trauma abdominal cocoon

    PubMed Central

    Kaur, Supreet; Doley, Rudra Prasad; Chabbhra, Mohinish; Kapoor, Rajeev; Wig, Jaidev

    2014-01-01

    Abdominal cocoon or sclerosing peritonitis refers to a rare cause of intestinal obstruction due to formation of a membrane encasing the bowel. We report a case of abdominal cocoon post blunt trauma abdomen. The patient presented with a history of subacute intestinal obstruction and a mobile abdomen lump. Abdominal cocoon was diagnosed on computed tomography. He underwent adhesiolysis with excision of membrane. PMID:25590647

  10. Development of a Versatile Laser Ultrasonic System and Application to On-Line Measurement for Process Control of Wall Thickness and Eccentrictiy of Steel Seamless Mechanical Tubing

    SciTech Connect

    Kisner, R.A.; Kercel, S.W.; Damiano, B.; Bingham, P.R.; Gee, T.F.; Tucker, R.W.; Moore, M.R.; Hileman, M.; Emery, M.; Lenarduzzi, R.; Hardy, J.E.; Weaver, K.; Crutcher, R.; Kolarik, R.V., II; Vandervaart, R.H.

    2002-04-24

    Researchers at the Timken Company conceived a project to develop an on-line instrument for wall thickness measurement of steel seamless mechanical tubing based on laser ultrasonic technology. The instrument, which has been installed and tested at a piercing mill, provides data on tube eccentricity and concentricity. Such measurements permit fine-tuning of manufacturing processes to eliminate excess material in the tube wall and therefore provide a more precisely dimensioned product for their customers. The resulting process energy savings are substantial, as is lowered environmental burden. The expected savings are $85.8 million per year in seamless mechanical tube piercing alone. Applied across the industry, this measurement has a potential of reducing energy consumption by 6 x 10{sup 12} BTU per year, greenhouse gas emissions by 0.3 million metric tons carbon equivalent per year, and toxic waste by 0.255 million pounds per year. The principal technical contributors to the project were the Timken Company, Industrial Materials Institute (IMI, a contractor to Timken), and Oak Ridge National Laboratory (ORNL). Timken provided mill access as well as process and metallurgical understanding. Timken researchers had previously developed fundamental ultrasonic analysis methods on which this project is based. IMI developed and fabricated the laser ultrasonic generation and receiver systems. ORNL developed Bayesian and wavelet based real-time signal processing, spread-spectrum wireless communication, and explored feature extraction and pattern recognition methods. The resulting instrument has successfully measured production tubes at one of Timken's piercing mills. This report concentrates on ORNL's contribution through the CRADA mechanism. The three components of ORNL's contribution were met with mixed success. The real-time signal-processing task accomplished its goal of improvement in detecting time of flight information with a minimum of false data. The signal processing algorithm development resulted in a combination of processing steps that can be set to generate no spoofs from noise, while simultaneously missing fewer than 10% of good trials. The algorithm leads to a 95% probability that the estimate of time of flight is good to within 4 time bins or fewer for laser excitations above 30 mJ for the first two echoes of the signal. Receiver Operating Characteristic (ROC) curves for the algorithm indicate that the algorithm is very robust against errors for excitations above at 35 mJ and above, tolerable at 30 mJ and unacceptable below 30 mJ.

  11. Individuals, grasses, and forests of single-and multi-walled carbon nanotubes grown by supported Co catalysts of different nominal thicknesses

    E-print Network

    Maruyama, Shigeo

    1 Individuals, grasses, and forests of single- and multi-walled carbon nanotubes grown by supported (`grasses'), and vertically-aligned forests of single- and multi-walled carbon nanotubes were grown by only in CNT morphologies from individuals to grasses and grasses to forests. Keywords: single-walled carbon

  12. Fermion localization on thick branes

    SciTech Connect

    Melfo, Alejandra; Pantoja, Nelson; Tempo, Jose David

    2006-02-15

    We consider chiral fermion confinement in scalar thick branes, which are known to localize gravity, coupled through a Yukawa term. The conditions for the confinement and their behavior in the thin-wall limit are found for various different BPS branes, including double walls and branes interpolating between different AdS{sub 5} spacetimes. We show that only one massless chiral mode is localized in all these walls, whenever the wall thickness is keep finite. We also show that, independently of wall's thickness, chiral fermionic modes cannot be localized in dS{sub 4} walls embedded in a M{sub 5} spacetime. Finally, massive fermions in double wall spacetimes are also investigated. We find that, besides the massless chiral mode localization, these double walls support quasilocalized massive modes of both chiralities.

  13. Component Separation for Complex Abdominal Wall Reconstruction

    MedlinePLUS

    ... edges along the midline and also when we onlay the Veritas, as you'll see Dr. Chao ... experience doing the component separation procedure with Veritas onlay or any of the other techniques that we ...

  14. Component Separation for Complex Abdominal Wall Reconstruction

    MedlinePLUS

    ... good tissue to good tissue, and you do see some areas where the fascia is apart, and that's what the Veritas is going to help us with. What we theorize and what some animal studies have shown is that these replacement matrices, ...

  15. Abdominal aortic aneurysm in giant cell arteritis

    PubMed Central

    Kwon, Hyunwook; Han, Youngjin; Son, Da Hye; Cho, Yong-Pil

    2015-01-01

    Aortic complications of giant cell arteritis are a rare cause of abdominal aortic aneurysm. Here, we describe a case of a ruptured aortic aneurysm in a patient with giant call arteritis (GCA) who was preoperatively suspected of having an infectious aortic aneurysm. Intraoperative inspection revealed infectious granulation tissue on the anterior wall of the abdominal aorta. GCA was finally confirmed by pathological diagnosis. Our findings suggest that the surgical and postoperative treatment of nonatheromatous aortic aneurysm should be based on accurate diagnosis. PMID:26448922

  16. Abdominal vacuum lift as an aid to diagnosing abdominal adhesions

    E-print Network

    Strauss, Julius (Julius Y.)

    2006-01-01

    The internal organs are designed to move freely and slide over one another during normal body movement. The abdominal organs, however, have a tendency to adhere to the abdominal cavity (peritoneum) and other abdominal ...

  17. Recurrent Abdominal Pain

    ERIC Educational Resources Information Center

    Banez, Gerard A.; Gallagher, Heather M.

    2006-01-01

    The purpose of this article is to provide an empirically informed but clinically oriented overview of behavioral treatment of recurrent abdominal pain. The epidemiology and scope of recurrent abdominal pain are presented. Referral process and procedures are discussed, and standardized approaches to assessment are summarized. Treatment protocols…

  18. Functional Abdominal Pain in Children

    MedlinePLUS

    ... pain, including recurrent abdominal pain, functional dyspepsia, and irritable bowel syndrome. Recurrent abdominal pain (RAP) was originally defined ... or constipation alternating with diarrhea) is the classic irritable bowel syndrome (IBS). Causes The trigger for functional abdominal ...

  19. Management of the tense abdomen or difficult abdominal closure after operation for ruptured abdominal aortic aneurysms.

    PubMed

    Björck, Martin

    2012-03-01

    Increased intra-abdominal pressure (IAP) and abdominal compartment syndrome (ACS) are important clinical problems after repair of ruptured abdominal aortic aneurysms and are reviewed here. IAP >20 mm Hg occurs in approximately 50% of patients treated with open abdominal aortic aneurysm repair after rupture, and approximately 20% develop organ failure or dysfunction, fulfilling the criteria for ACS. Patients selected for endovascular aneurysm repair are often more hemodynamically stable, perhaps related to not handling the viscera or more favorable anatomy, resulting in less bleeding and, consequently, decreased risk of developing ACS. Centers that treat most patients with endovascular aneurysm repair tend to have the same proportion of ACS as after open repair. There are no randomized data on these aspects. Early nonsurgical therapy can prevent development of ACS. Medical therapy includes neuromuscular blockade and the combination of positive end-expiratory pressure, albumin, and furosemide. This proactive strategy can reduce the number of decompressive laparotomies, an important detail because treatment of ACS with open abdomen is a morbid procedure. When treatment with an open abdomen is necessary, it is important to choose a temporary abdominal closure that maintains sterile conditions during often prolonged treatment. In addition, it should prevent lateralization of the bowel wall and adhesions between the intestines and the bowel wall. Enteroatmospheric fistulae must be prevented. Many alternative methods have been suggested, but we prefer the combination of vacuum-assisted wound closure with mesh-mediated traction, which will be described. PMID:22595480

  20. Gradient Echo MRI Characterization of Development of Atherosclerosis in the Abdominal Aorta in Watanabe Heritable Hyperlipidemic Rabbits

    SciTech Connect

    Wang, Yi-Xiang J. Kuribayashi, Hideto; Wagberg, Maria; Holmes, Andrew P.; Tessier, Jean J.; Waterton, John C.

    2006-08-15

    Purpose. The Watanabe Heritable Hyperlipidemic (WHHL) rabbit provides an important model of spontaneous atherosclerosis. With a strain of WHHL rabbits which do not develop abdominal aorta lumen stenosis even with advanced atherosclerosis, we studied the MRI-histology correlation, and the natural progression of atherosclerosis in the abdominal aorta. In addition, intra-reader segmentation repeatability and scan-rescan reproducibility were assessed. Methods. Two batches of female WHHL rabbits were used. The first batch of 6 rabbits was scanned at 20 weeks old. A second batch of 17 rabbits was scanned at 50 weeks old and then randomly divided into two subgroups: 8 were killed for histologic investigation; 9 were kept alive for follow-up, with repeat scanning a week later to assess scan-rescan reproducibility, and again at 73 weeks old to assess disease progression. MR images were acquired at 4.7 T using a chemical shift selective fat suppression gradient echo with a saturation band suppressing blood signal within the aortic lumen. Five slices per animal were acquired, centered around the renal artery region of the abdominal aorta, with in-plane resolution of 0.195 mm and slice thickness of 3 mm. Results. The coefficient of variation for intra-reader reproducibility for aortic wall thickness measurements was 2.5% for repeat segmentations of the same scans on the same day, but segmentations of these same scans made 8 months later showed a systematic change, suggesting that intra-reader bias as well as increased variability could compromise assessments made over time. Comparative analyses were therefore performed in one postprocessing session. The coefficient of variation for scan-rescan reproducibility for aortic wall thickness was 5.5% for nine pairs of scans acquired a week apart and segmented on the same day. Good MRI-histology correlation was obtained. The MRI-measured mean aortic wall thickness of animals at 20 weeks of age was 76% that of animals at 50 weeks of age (p < 0.001). There was a small increase in aortic wall thickness between 50 and 73 weeks of age, but this was not significant (p > 0.05). The corresponding differences in lumen cross-sectional areas at 20, 50, and 73 weeks of age were not significant. These results were consistent with in-house historical histology data on this strain of rabbits. Conclusions. High-resolution gradient echo MRI can follow disease progression in the WHHL rabbit spontaneous atherosclerosis disease model.

  1. Abdominal compartment syndrome (ACS) in a severely burned patient

    PubMed Central

    kollias, S.; Stampolidis, N.; kourakos, P.; Mantzari, E.; Koupidis, S.; Tsaousi, S.; Dimitrouli, A.; Atiyeh, B.; Castana, O.

    2015-01-01

    Summary Abdominal compartment syndrome (ACS) occurs when increasing intra abdominal-pressure (IAP) reduces blood flow to abdominal organs. This results in impairment of pulmonary, cardiovascular, renal, hepatic, central nervous system and gastro-intestinal (gi) function, causing multiple organ dysfunction syndrome and death. The significant prognostic value of elevated intra-abdominal pressure has prompted many intensive care units to adopt measurement of this physiologic parameter as a routine vital sign in patients at risk. ACS generally occurs in patients who are critically ill due to any of a wide variety of medical and surgical conditions. it has been recently described as a rare complication of burn injury. it is fundamental to: 1) recognize IAP and ACS; 2) resuscitate effectively; and 3) prevent the development IAP-induced end-organ dysfunction and failure. We present our recent experience with one patient suffering from ACS secondary to burn injury and the physiologic results of abdominal wall escharotomy. PMID:26668555

  2. Abdominal compartment syndrome (ACS) in a severely burned patient.

    PubMed

    Kollias, S; Stampolidis, N; Kourakos, P; Mantzari, E; Koupidis, S; Tsaousi, S; Dimitrouli, A; Atiyeh, B; Castana, O

    2015-03-31

    Abdominal compartment syndrome (ACS) occurs when increasing intra abdominal-pressure (IAP) reduces blood flow to abdominal organs. This results in impairment of pulmonary, cardiovascular, renal, hepatic, central nervous system and gastro-intestinal (gi) function, causing multiple organ dysfunction syndrome and death. The significant prognostic value of elevated intra-abdominal pressure has prompted many intensive care units to adopt measurement of this physiologic parameter as a routine vital sign in patients at risk. ACS generally occurs in patients who are critically ill due to any of a wide variety of medical and surgical conditions. it has been recently described as a rare complication of burn injury. it is fundamental to: 1) recognize IAP and ACS; 2) resuscitate effectively; and 3) prevent the development IAP-induced end-organ dysfunction and failure. We present our recent experience with one patient suffering from ACS secondary to burn injury and the physiologic results of abdominal wall escharotomy. PMID:26668555

  3. Abdominal aortic aneurysm

    MedlinePLUS

    ... main blood vessel that supplies blood to the abdomen, pelvis, and legs. An abdominal aortic aneurysm occurs ... dissection). Symptoms of rupture include: Pain in the abdomen or back. The pain may be severe, sudden, ...

  4. Abdominal ultrasound (image)

    MedlinePLUS

    Abdominal ultrasound is a scanning technique used to image the interior of the abdomen. Like the X- ... use high frequency sound waves to produce an image and do not expose the individual to radiation. ...

  5. Interactive segmentation of abdominal aortic aneurysms in Marleen de Bruijne, Bram van Ginneken, Max A. Viergever, and Wiro J. Niessen

    E-print Network

    Utrecht, Universiteit

    Interactive segmentation of abdominal aortic aneurysms in CTA images Marleen de Bruijne, Bram van of thrombus in abdominal aortic aneurysms from CTA data is presented. After manual segmentation of the first aneurysm (AAA) is an enlargement of the infrarenal abdominal aorta, resulting from weakened arterial walls

  6. Parallel-plate capacitor measurements of the superfluid wall-film thickness in a 3He/4He mixture of 3He mole fraction x = 0.75

    NASA Astrophysics Data System (ADS)

    Deng, Weimin; Zimmermann, W., Jr.

    2009-02-01

    A thin 4He-rich superfluid film coats solid surfaces in contact with bulk normal liquid 3He/4He mixtures in a narrow region of the mixture phase diagram at saturated vapor pressure that adjoins the lambda line, the tricritical point, and the 3He-rich branch of the phase-separation curve. Recent arguments suggest that near the tricritical point, the thickness of the film is governed not only by van der Waals forces and gravity but also by Casimir and Helfrich forces that limit the thickness as the phase-separation curve is approached. Experimental evidence has been presented both showing and failing to show this phenomenon. In the present work, parallel-plate capacitor measurements of a mixture having a 3He mole fraction x = 0.75 show a film thickness of from ~ 14 to ~ 22 nm as the phase-separation curve is first reached from higher temperature, depending on choice of background subtraction, whereas van der Waals forces limited only by gravity would be expected in our cell to yield a thickness of ~ 31 nm, rising in the first few mK below the phase-separation temperature to ~ 43 nm. Despite various uncertainties and anomalies, the results suggest that additional forces may be at work.

  7. Wall surveyor project report

    SciTech Connect

    Mullenhoff, D.J.; Johnston, B.C.; Azevedo, S.G.

    1996-02-22

    A report is made on the demonstration of a first-generation Wall Surveyor that is capable of surveying the interior and thickness of a stone, brick, or cement wall. LLNL`s Micropower Impulse Radar is used, based on emitting and detecting very low amplitude and short microwave impulses (MIR rangefinder). Six test walls were used. While the demonstrator MIR Wall Surveyor is not fieldable yet, it has successfully scanned the test walls and produced real-time images identifying the walls. It is planned to optimize and package the evaluation wall surveyor into a hand held unit.

  8. Abdominal cocoon: an unusual cause of subacute intestinal obstruction.

    PubMed

    Shah, Md Yunus S; Gedam, B S; Sonarkar, R; Gopinath, K S S

    2013-06-01

    We report an unusual cause of subacute intestinal obstruction in a young adolescent girl, which is a nontubercular abdominal cocoon. Barium meal follow-through revealed "cauliflower"-like appearance of small bowel. The patient underwent an exploratory laparotomy showing thick fibrous-like coverings which were encasing the small bowel loops to form an abdominal cocoon. Fibrocollagenous membrane was excised after adhesiolysis. Histopathological examination of membrane revealed fibrocollagenous membrane with hyaline deposition of nontubercular origin. PMID:24426626

  9. Liquid Wall Chambers

    SciTech Connect

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  10. Thick Toenails

    MedlinePLUS

    The official consumer website of: Visit ACFAS.org | About ACFAS | Información en Español Advanced Search Home » Foot & Ankle Conditions » Thick Toenails Text Size Print Bookmark Thick Toenails Toenails will often become thick as an individual grows older. Thickening may also occur as ...

  11. Evaluation of Clinical Outcomes after Abdominal Rectopexy and Delorme’s Procedure for Rectal Prolapse: A Prospective Study

    PubMed Central

    Makineni, Hemanth; Rai, B.K. Shivprasad

    2014-01-01

    Background: Complete rectal prolapse is characterized by protrusion of full thickness rectal wall through the anal orifice. Despite its rarity more than 100 surgical procedures have been described and there are no good evidence based recommendations for selection of a surgical procedure. This study was conducted to evaluate the clinical outcomes of commonly used procedures for rectal prolapse at our hospital. Materials and Methods: Twenty seven patients presenting with complete rectal prolapse between May 2011 to May 2013 were included in this prospective study. Patients underwent either Abdominal rectopexy or Delorme’s procedure after evaluation, based on clinical judgment of experienced surgeons. Patient characteristics, complications, post-operative length of hospitalization and clinical outcomes were assessed. Patients were followed up for a mean duration of 14 months. Results: Seventeen patients underwent Abdominal rectopexy (Posterior mesh rectopexy), ten patients underwent Delorme’s procedure. No postoperative mortalities or major complications were noted. Post operative morbidity (minor) was 17% in Abdominal rectopexy group and 10% in Delormes group 0%. Incontinence improved in all six patients (100%) in rectopexy group, four patients (80%) in Delorme’s procedure group. Two patients (11%) in rectopexy group reported increase in constipation post operatively. There was one recurrence in Delorme’s procedure group with no recurrences in Abdominal rectopexy group. Conclusion: The treatment of rectal prolapse should be individualized to achieve best results. Abdominal rectopexy can be safely applied in most of patients with minimal post operative increase in constipation and recurrence by using posterior mesh rectopexy technique. Delorme’s procedure can be performed with minimal morbidity and shorter hospital stay and good functional results with acceptable recurrence rate. Delorme’s can be considered as an alternative to rectopexy not only in patients unfit for laparotomy but also in individuals with a short prolpase, avoiding a laparotomy. PMID:24995208

  12. Measuring Thicknesses of Wastewater Films

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Davenport, R. J.

    1987-01-01

    Sensor determines when thickness of film of electrically conductive wastewater on rotating evaporator drum exceeds preset value. Sensor simple electrical probe that makes contact with liquid surface. Made of materials resistant to chemicals in liquid. Mounted on shaft in rotating cylinder, liquid-thickness sensor extends toward cylinder wall so tip almost touches. Sensor body accommodates probe measuring temperature of evaporated water in cylinder.

  13. DIEP breast reconstruction following multiple abdominal liposuction procedures

    PubMed Central

    Nicholson, Simon; Kotwal, Ashutosh; Akali, Augustine

    2014-01-01

    Objective: Previous abdominal wall surgery is viewed as a contraindication to abdominal free tissue transfer. We present two patients who underwent multiple abdominal liposuction procedures, followed by successful free deep inferior epigastric artery perforator flap. We review the literature pertaining to reliability of abdominal free flaps in those with previous abdominal surgery. Methods: Review of case notes and radiological investigations of two patients, and a PubMed search using the terms “DIEP”, “deep inferior epigastric”, “TRAM”, “transverse rectus abdominis”, “perforator” and “laparotomy”, “abdominal wall”, “liposuction”, “liposculpture”, “fat graft”, “pfannenstiel”, with subsequent appraisal of relevant papers by the first and second authors. Results: Patient 1 had 3 episodes of liposuction from the abdomen for fat grafting to a reconstructed breast. Subsequent revision reconstruction of the same breast with DIEP flap was preceded by CT angiography, which demonstrated normal perforator anatomy. The reconstruction healed well with no ischaemic complications. Patient 2 had 5 liposuction procedures from the abdomen to graft fat to a wide local excision defect. Recurrence of cancer led to mastectomy and immediate reconstruction with free DIEP flap. Preoperative MR angiography demonstrated a large perforator right of the umbilicus, with which the intraoperative findings were consistent. The patient had an uneventful recovery and good healing with no fat necrosis or wound dehiscence. Conclusions: We demonstrate that DIEP flaps can safely be raised without perfusion-related complications following multiple liposuction procedures to the abdomen. The safe interval between procedures is difficult to quantify, but we demonstrate successful free flap after 16 months. PMID:25671046

  14. Screening for Abdominal Aortic Aneurysm

    MedlinePLUS

    Understanding Task Force Recommendations Screening for Abdominal Aortic Aneurysm The U.S. Preventive Services Task Force (Task Force) has issued a final recommendation statement on Screening for Abdominal Aortic Aneurysm. This final recommendation ...

  15. Abdominal Aortic Aneurysm (AAA) Screening

    MedlinePLUS

    ... covered? Search Medicare.gov for covered items Abdominal aortic aneurysm screening How often is it covered? Medicare Part B (Medical Insurance) covers a one-time abdominal aortic aneurysm ultrasound. You must get a referral for it ...

  16. Idiopathic sclerosing encapsulating peritonitis: abdominal cocoon.

    PubMed

    Tannoury, Jenny N; Abboud, Bassam N

    2012-05-01

    Abdominal cocoon, the idiopathic form of sclerosing encapsulating peritonitis, is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel by a fibrocollagenous membrane. Preoperative diagnosis requires a high index of clinical suspicion. The early clinical features are nonspecific, are often not recognized and it is difficult to make a definite pre-operative diagnosis. Clinical suspicion may be generated by the recurrent episodes of small intestinal obstruction combined with relevant imaging findings and lack of other plausible etiologies. The radiological diagnosis of abdominal cocoon may now be confidently made on computed tomography scan. Surgery is important in the management of this disease. Careful dissection and excision of the thick sac with the release of the small intestine leads to complete recovery in the vast majority of cases. PMID:22563185

  17. Prediction of Residual Stress Distributions in Welded Sections of P92 Pipes with Small Diameter and Thick Wall based on 3D Finite Element Simulation

    NASA Astrophysics Data System (ADS)

    Wang, Xiaowei; Gong, Jianming; Zhao, Yanping; Wang, Yanfei

    2015-05-01

    This study used ABAQUS finite element (FE) software to investigate the residual stress distributions of P92 welded pipes in both the as-weld and post weld heat treated (PWHT) condition. Sequential coupling quasi-static thermo-mechanical in conjunction with moving double ellipsoidal heat source and an element add/remove technique to simulate deposition of new weld material, are combined in the 3D FE analysis. To validate the simulation results, the residual stresses in axial direction at the surface of pipe were measured by X-ray diffraction technique and compared with the results of FE analysis. Detailed characteristic distributions of the residual stresses are discussed. Results show that the FE model can predict the residual stress distributions satisfactorily. Highest residual stresses on the outer surface are found in the last weld bead to be deposited. And the highest tensile residual stress for the full welded section take place in heat affected zone (HAZ) near the middle thickness. Larger residual sstress can be found around the welding start point along the pipe circumference. Comparison of heat treated specimen and untreated specimen illustrates that PWHT has a strong effect on the residual stress field.

  18. Abdominal emergencies during pregnancy.

    PubMed

    Bouyou, J; Gaujoux, S; Marcellin, L; Leconte, M; Goffinet, F; Chapron, C; Dousset, B

    2015-12-01

    Abdominal emergencies during pregnancy (excluding obstetrical emergencies) occur in one out of 500-700 pregnancies and may involve gastrointestinal, gynecologic, urologic, vascular and traumatic etiologies; surgery is necessary in 0.2-2% of cases. Since these emergencies are relatively rare, patients should be referred to specialized centers where surgical, obstetrical and neonatal cares are available, particularly because surgical intervention increases the risk of premature labor. Clinical presentations may be atypical and misleading because of pregnancy-associated anatomical and physiologic alterations, which often result in diagnostic uncertainty and therapeutic delay with increased risks of maternal and infant morbidity. The most common abdominal emergencies are acute appendicitis (best treated by laparoscopic appendectomy), acute calculous cholecystitis (best treated by laparoscopic cholecystectomy from the first trimester through the early part of the third trimester) and intestinal obstruction (where medical treatment is the first-line approach, just as in the non-pregnant patient). Acute pancreatitis is rare, usually resulting from trans-ampullary passage of gallstones; it usually resolves with medical treatment but an elevated risk of recurrent episodes justifies laparoscopic cholecystectomy in the 2nd trimester and endoscopic sphincterotomy in the 3rd trimester. The aim of the present work is to review pregnancy-induced anatomical and physiological modifications, to describe the main abdominal emergencies during pregnancy, their specific features and their diagnostic and therapeutic management. PMID:26527261

  19. Abdominal pregnancy - Case presentation

    PubMed Central

    Bohiltea, R; Radoi, V; Tufan, C; Horhoianu, IA; Bohiltea, C

    2015-01-01

    Introduction. Abdominal pregnancy, a rare diagnosis, belongs to the ectopic pregnancy group, the leading cause of pregnancy related exitus. The positive diagnosis is very difficult to establish most often in an acute setting, leading to a staggering percent of feto-maternal morbidity and mortality. Case report. We present the case of 26-weeks-old abdominal pregnancy with partial feto-placental detachment in a patient, after hysteroscopy and in vitro fertilization, which until the acute symptoms that led to emergency laparotomy went unrecognized. The patient recovered completely and satisfactorily after surgery and, due to the high risk of uterine rupture with regard to a second pregnancy, opted for a surrogate mother. Conclusion. Abdominal pregnancy can be regarded as a difficult to establish diagnosis, with a greater chance in case of increased awareness. It is compulsory to be well informed in order not to be surprised by the diagnosis and to apply the correct treatment immediately as the morbidity and mortality rate is elevated. PMID:25914739

  20. Localizing gravity on exotic thick 3-branes

    SciTech Connect

    Castillo-Felisola, Oscar; Melfo, Alejandra; Pantoja, Nelson; Ramirez, Alba

    2004-11-15

    We consider localization of gravity on thick branes with a nontrivial structure. Double walls that generalize the thick Randall-Sundrum solution, and asymmetric walls that arise from a Z{sub 2} symmetric scalar potential, are considered. We present a new asymmetric solution: a thick brane interpolating between two AdS{sub 5} spacetimes with different cosmological constants, which can be derived from a 'fake supergravity' superpotential, and show that it is possible to confine gravity on such branes.

  1. Abdominal aortic aneurysms and diabetes mellitus.

    PubMed

    Pafili, Kalliopi; Gouni-Berthold, Ioanna; Papanas, Nikolaos; Mikhailidis, Dimitri P

    2015-01-01

    There is accumulating evidence that risk profiles differ between coronary artery disease and abdominal aortic aneurysms (AAAs). However, diabetes mellitus (DM) appears to be negatively associated with AAA formation. The underlying mechanisms for this negative relationship are far from defined, but may include: increased arterial wall matrix formation via advanced glycation end products; suppression of plasmin and reduction of levels and activity of matrix metalloproteinases (MMP)-2 and 9; diminished aortic wall macrophage infiltration, elastolysis and neovascularization. In addition, the effect of pharmacological agents used for the treatment of patients with DM on AAA formation has been studied with rather controversial results. Statins, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, fenofibrate, antibiotics and some hypoglycemic agents are beginning to be appreciated for a potential modest protection from AAAs, but further studies are needed. PMID:26440573

  2. Thin Wall Iron Castings

    SciTech Connect

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  3. Domain wall phase diagram and wall widths

    NASA Astrophysics Data System (ADS)

    Klaui, M.; Laufenberg, M.; Backes, D.; Rudiger, U.; Vaz, C. A. F.; Bland, J. A. C.; Heyderman, L. J.; Nolting, F.

    2006-03-01

    The details of the spin structure of domain walls have recently become the focus of intense research due to the fundamental physical questions associated with domain walls (wall width, magnetoresistance, current-induced domain wall propagation). Using photoemission electron microscopy (XMCDPEEM) we have obtained high-resolution images of the spin structure of the domain walls, which allows us to determine the wall type and the wall width for different Co [1] and NiFe wire and ring geometries. We determine the phase transition between the different domain wall types as a function of the geometrical parameters (width, thickness) [1]. Comparison with theoretical calculations [2] and micromagnetic simulations reveals the importance of local energy minima and the geometry-dependent height of the energy barriers separating the two wall types can be derived. The energy barrier height is then directly measured by high-temperature (up to 600 K) imaging of thermally activated transitions from transverse to vortex walls. By varying the spacing between domain walls, we determine the coupling strength that leads to a shift in the phase boundary. [1] M. Klaui et al., APL 85, 5637 (2004); [2] R.D. McMichael and M.J. Donahue, IEEE Trans. Magn. 33, 4167 (1997);

  4. Abdominal perfusion computed tomography.

    PubMed

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-02-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis. PMID:25610249

  5. Abdominal Perfusion Computed Tomography

    PubMed Central

    Ogul, Hayri; Bayraktutan, Ummugulsum; Kizrak, Yesim; Pirimoglu, Berhan; Yuceler, Zeynep; Sagsoz, M. Erdem; Yilmaz, Omer; Aydinli, Bulent; Ozturk, Gurkan; Kantarci, Mecit

    2013-01-01

    The purpose of this article is to provide an up to date review on the spectrum of applications of perfusion computed tomography (CT) in the abdomen. New imaging techniques have been developed with the objective of obtaining a structural and functional analysis of different organs. Recently, perfusion CT has aroused the interest of many researchers who are studying the applicability of imaging modalities in the evaluation of abdominal organs and diseases. Per-fusion CT enables fast, non-invasive imaging of the tumor vascular physiology. Moreover, it can act as an in vivo biomarker of tumor-related angiogenesis. PMID:25610249

  6. Estimation of prenatal aorta intima-media thickness from ultrasound examination.

    PubMed

    Veronese, E; Tarroni, G; Visentin, S; Cosmi, E; Linguraru, M G; Grisan, E

    2014-11-01

    Prenatal events such as intrauterine growth restriction and increased cardiovascular risk in later life have been shown to be associated with an increased intima-media thickness (aIMT) of the abdominal aorta in the fetus. In order to assess and manage atherosclerosis and cardiovascular disease risk in adults and children, in recent years the measurement of abdominal and carotid artery thickness has gained a growing appeal. Nevertheless, no computer aided method has been proposed for the analysis of prenatal vessels from ultrasound data, yet. To date, these measurements are being performed manually on ultrasound fetal images by skilled practitioners. The aim of the presented study is to introduce an automatic algorithm that identifies abdominal aorta and estimates its diameter and aIMT from routine third trimester ultrasonographic fetal data.The algorithm locates the aorta, then segments it and, by modeling the arterial wall longitudinal sections by means of a gaussian mixture, derives a set of measures of the aorta diameter (aDiam) and of the intima-media thickness (aIMT). After estimating the cardiac cycle, the mean diameter and the aIMT at the end-diastole phase are computed.Considering the aIMT value for each subject, the correlation between automatic and manual end-diastolic aIMT measurements is 0.91 in a range of values 0.44-1.10 mm, corresponding to both normal and pathological conditions. The automatic system yields a mean relative error of 19%, that is similar to the intra-observer variability (14%) and much lower that the inter-observer variability (42%).The correlation between manual and automatic measurements and the small error confirm the ability of the proposed system to reliably estimate aIMT values in prenatal ultrasound sequences, reducing measurement variability and suggesting that it can be used for an automatic assessment of aIMT. PMID:25295390

  7. Abdominal cocoon: a potential pitfall in patients with ovarian carcinoma.

    PubMed

    Isacson, Rut; Segal, Amiel; Alberton, Joseph; Reinus, Constantin; Schwarz, Alon; Grenader, Tal

    2012-11-01

    Background. Abdominal cocoon, or sclerosing encapsulating peritonitis, is a rare condition characterized by partial or total encasement of small bowel and mesentery by a thick fibrocollagenous sack that looks like a cocoon. Within the sack, bowel loops are drawn together causing intestinal obstruction.Case presentation. We report on a 57-year-old female patient who developed a very unusual complication of ovarian cancer: abdominal cocoon formation.Conclusions. This report highlights the need for a timely diagnosis of sclerosing encapsulating peritonitis in cancer patients. PMID:23389380

  8. How I Manage Abdominal Injuries.

    ERIC Educational Resources Information Center

    Haycock, Christine E.

    1986-01-01

    In sports, abdominal injuries occur most frequently in cycling, horseback riding, and skiing. Most involve children, not adults. Any athlete sustaining a severe blow to the abdomen should be examined. Guidelines are provided for recognizing and treating injuries to the abdominal muscles, kidneys, spleen, and liver. (Author/MT)

  9. 49 CFR 179.400-8 - Thickness of plates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-8 Thickness of plates. (a) The minimum wall thickness, after forming, of the inner shell and any 2:1...; P = minimum required bursting pressure in psig; L = main inside radius of dished head, in inches; r... the outer jacket shell may not be less than 7/16 inch. The minimum wall thickness, after forming,...

  10. Single vessel abdominal arterial disease.

    PubMed

    van Noord, Désirée; Kuipers, Ernst J; Mensink, Peter B F

    2009-01-01

    The long-standing discussion concerning the mere existence of single vessel abdominal artery disease can be closed: chronic gastrointestinal ischaemia (CGI) due to single vessel abdominal artery stenosis exists, can be treated successfully and in a safe manner. The most common causes of single vessel CGI are the coeliac artery compression syndrome (CACS) in younger patients, and atherosclerotic disease in elderly patients. The clinical symptoms of single vessel CGI patients are postprandial and exercise-related pain, weight loss, and an abdominal bruit. The current diagnostic approach in patients suspected of single vessel CGI is gastrointestinal tonometry combined with radiological visualisation of the abdominal arteries to define possible arterial stenosis. Especially in single vessel abdominal artery stenosis, gastrointestinal tonometry plays a pivotal role in establishing the diagnosis CGI. First-choice treatment of single vessel CGI remains surgical revascularisation, especially in CACS. In elderly or selected patients endovascular stent placement therapy is an acceptable option. PMID:19258186

  11. Novel 3D ultrasound image-based biomarkers based on a feature selection from a 2D standardized vessel wall thickness map: a tool for sensitive assessment of therapies for carotid atherosclerosis

    NASA Astrophysics Data System (ADS)

    Chiu, Bernard; Li, Bing; Chow, Tommy W. S.

    2013-09-01

    With the advent of new therapies and management strategies for carotid atherosclerosis, there is a parallel need for measurement tools or biomarkers to evaluate the efficacy of these new strategies. 3D ultrasound has been shown to provide reproducible measurements of plaque area/volume and vessel wall volume. However, since carotid atherosclerosis is a focal disease that predominantly occurs at bifurcations, biomarkers based on local plaque change may be more sensitive than global volumetric measurements in demonstrating efficacy of new therapies. The ultimate goal of this paper is to develop a biomarker that is based on the local distribution of vessel-wall-plus-plaque thickness change (VWT-Change) that has occurred during the course of a clinical study. To allow comparison between different treatment groups, the VWT-Change distribution of each subject must first be mapped to a standardized domain. In this study, we developed a technique to map the 3D VWT-Change distribution to a 2D standardized template. We then applied a feature selection technique to identify regions on the 2D standardized map on which subjects in different treatment groups exhibit greater difference in VWT-Change. The proposed algorithm was applied to analyse the VWT-Change of 20 subjects in a placebo-controlled study of the effect of atorvastatin (Lipitor). The average VWT-Change for each subject was computed (i) over all points in the 2D map and (ii) over feature points only. For the average computed over all points, 97 subjects per group would be required to detect an effect size of 25% that of atorvastatin in a six-month study. The sample size is reduced to 25 subjects if the average were computed over feature points only. The introduction of this sensitive quantification technique for carotid atherosclerosis progression/regression would allow many proof-of-principle studies to be performed before a more costly and longer study involving a larger population is held to confirm the treatment efficacy.

  12. Superconducting magnetoresistance effect observed in Co/Nb/Co trilayers under a parallel magnetic field: The importance of matching the width of magnetic domain walls of the Co layers with the thickness of the Nb interlayer

    NASA Astrophysics Data System (ADS)

    Aristomenopoulou, E.; Stamopoulos, D.

    2015-08-01

    Magnetoresistance effects observed in ferromagnet/superconductor (FM/SC) hybrids, FM/SC bilayers (BLs) and FM/SC/FM trilayers (TLs), have attracted much interest. Here, we focus on the stray-fields-based superconducting magnetoresistance effect (sMRE) observed in Co(dCo)/Nb(dNb)/Co(dCo) TLs with sufficiently thick Co outer layers so that out-of-plane magnetic domains (MDs) and MDs walls (MDWs) emerge all over their surface when subjected to a parallel external magnetic field, Hex, equal to the coercive field, Hc. To explore the conditions necessary for maximization of the sMRE, we focus on the different kinds of the stray dipolar fields, Hdip, that emerge at the interior of the out-of-plane MDs and at the boundaries of MDWs; these have a different inherent tendency to create straight and semi-loop vortices, respectively. In the recent literature, the creation of straight and semi-loop vortices has been addressed at some extent both theoretically [Laiho et al., Phys. Rev. B 67, 144522 (2003)] and experimentally [Bobba et al., Phys. Rev. B 89, 214502 (2014)] for the case of FM/SC BLs. Here, we address these issues in FM/SC/FM TLs in connection to the sMRE. Specifically, we focus on an experimental finding reported recently [D. Stamopoulos and E. Aristomenopoulou, J. Appl. Phys. 116, 233908 (2014)]; strong magnetostatic coupling of the FM outer layers is accompanied by an intense sMRE in TLs in which the thickness of the SC interlayer, dSC, matches the width of MDWs, DMDWs. To investigate this finding, we employ simulations-modeling and energy-considerations and propose two quantitative criteria that facilitate the creation of straight vortices over semi-loop ones. The first focuses on the maximization of the stray Hdip that occur at the interior of the out-of-plane MDs. The second enables the estimation of a crossover between the preferable creation of one kind of vortices over the other. Both criteria respond well, when tested against experimental results. These generic criteria on the interference between dSC and DMDWs can assist the design of cryogenic devices based on FM/SC/FM TLs.

  13. Tissue Responses to Stent Grafts with Endo-Exo-Skeleton for Saccular Abdominal Aortic Aneurysms in a Canine Model

    PubMed Central

    Kim, Young Il; Chung, Jin Wook; Kim, Hyo-Cheol; So, Young Ho; Kim, Hyun Beom; Min, Seung-Kee; Park, Jae Hyung

    2014-01-01

    Objective We evaluated the effect of close contact between the stent and the graft on the induction of endothelial covering on the stent graft placed over an aneurysm. Materials and Methods Saccular abdominal aortic aneurysms were made with Dacron patch in eight dogs. The stent graft consisted of an inner stent, a expanded polytetrafluoroethylene graft, and an outer stent. After sacrificing the animals, the aortas with an embedded stent graft were excised. The aortas were inspected grossly and evaluated microscopically. Results The animals were sacrificed at two (n = 3), six (n = 3), and eight months (n = 2) after endovascular repair. In two dogs, the aortic lumen was occluded at two months after the placement. On gross inspection of specimens from the other six dogs with a patent aortic lumen, stent grafts placed over the normal aortic wall were covered by glossy white neointima, whereas, stent grafts placed over the aneurysmal aortic wall were covered by brownish neointima. On microscopic inspection, stent grafts placed over the normal aortic wall were covered by thin neointima (0.27 ± 0.05 mm, mean ± standard deviation) with an endothelial layer, and stent grafts placed over the aneurysmal aortic wall were covered by thick neointima (0.62 ± 0.17 mm) without any endothelial lining. Transgraft cell migration at the normal aortic wall was more active than that at the aneurysmal aortic wall. Conclusion Close contact between the stent and the graft, which was achieved with stent grafts with endo-exo-skeleton, could not enhance endothelial covering on the stent graft placed over the aneurysms. PMID:25246823

  14. Unexpectedly ease surgery for a worrisome abdominal mass: Pedunculated GISTs?

    PubMed Central

    Baskiran, Adil; Otan, Emrah; Aydin, Cemalettin; Kayaalp, Cuneyt

    2013-01-01

    INTRODUCTION Discovery of abdominal masses often poses significant diagnostic difficulties. GISTs are mesenchymal masses, with specific histological features. Dimensions may vary from millimeters to giant tumours. We would like to present our case, which had an unexpectedly easy operative course which was easily handled with a simple surgical excision with a short operative duration. PRESENTATION OF CASE A 38 years old female patient was diagnosed to have an abdominal heterogen mass of 15 cm × 12 cm × 10 cm in dimension. Abdominal computed tomography revealed the solid mass between the stomach and pancreas corpus and tail, possibly orginating from the pancreas. With the preoperative diagnosis of locally invasive distal pancreas cancer the patient underwent laparotomy, following the dissection, the mass was observed to be originating from the posterior gastric Wall, extending exophytically with a peduncle of 5 cm in width, without any visual evidence for peritoneal invasion and metastasis. The tumour and the peduncle was resected with stapler device. Total operation time was 30 min. Postoperative course was uneventful. Pathologic diagnosis was gastrointestinal stromal tumour (GIST). DISCUSSION Pedunculated large GISTs are not frequent and they can enlarge as 15 cm in diameter and compress the neighbouring organs. When they were huge, it is difficult to differentiate the origin of the masses. GISTs should be considered in differential diagnosis of giant abdominal masses. CONCLUSION When GISTs are huge and pedunculated, it can be difficult to differentiate the origin of the masses. This case report presents unexpectedly ease surgery for a worrysome abdominal mass. PMID:23999120

  15. Modeling Lesion Growth in Atherosclerosis Kyle Thicke

    E-print Network

    Rowell, Eric C.

    Modeling Lesion Growth in Atherosclerosis Kyle Thicke July 19, 2013 #12;Definitions Atherosclerosis cells (foam cells) in the artery wall Atherogensis The start of atherosclerosis A lesion starts growing

  16. Moisture Research - Optimizing Wall Assemblies

    SciTech Connect

    Arena, Lois; Mantha, Pallavi

    2013-05-01

    In this project, the Consortium for Advanced Residential Buildings (CARB) team evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls. Wall assemblies evaluated included code minimum walls using spray foam insulation and fiberglass batts, high R-value walls at least 12 in. thick (R-40 and R-60 assemblies), and brick walls with interior insulation.

  17. Functional Abdominal Pain in Children

    MedlinePLUS

    ... functional pain. Your doctor will also follow your child to see if any changes take place which would suggest a different problem. Functional Abdominal Pain in Children NASPGHAN • PO Box 6 • Flourtown, PA 19031 • 215-233-0808 • ...

  18. Corrections to the thin wall approximation in general relativity

    NASA Technical Reports Server (NTRS)

    Garfinkle, David; Gregory, Ruth

    1989-01-01

    The question is considered whether the thin wall formalism of Israel applies to the gravitating domain walls of a lambda phi(exp 4) theory. The coupled Einstein-scalar equations that describe the thick gravitating wall are expanded in powers of the thickness of the wall. The solutions of the zeroth order equations reproduce the results of the usual Israel thin wall approximation for domain walls. The solutions of the first order equations provide corrections to the expressions for the stress-energy of the wall and to the Israel thin wall equations. The modified thin wall equations are then used to treat the motion of spherical and planar domain walls.

  19. Abdominal aortic aneurysms: an autoimmune disease?

    PubMed

    Jagadesham, Vamshi P; Scott, D Julian A; Carding, Simon R

    2008-12-01

    Abdominal aortic aneurysms (AAAs) are a multifactorial degenerative vascular disorder. One of the defining features of the pathophysiology of aneurysmal disease is inflammation. Recent developments in vascular and molecular cell biology have increased our knowledge on the role of the adaptive and innate immune systems in the initiation and propagation of the inflammatory response in aortic tissue. AAAs share many features of autoimmune disease, including genetic predisposition, organ specificity and chronic inflammation. Here, this evidence is used to propose that the chronic inflammation observed in AAAs is a consequence of a dysregulated autoimmune response against autologous components of the aortic wall that persists inappropriately. Identification of the molecular and cellular targets involved in AAA formation will allow the development of therapeutic agents for the treatment of AAA. PMID:18980864

  20. Estimation of prenatal aorta intima-media thickness in ultrasound examination

    NASA Astrophysics Data System (ADS)

    Veronese, Elisa; Poletti, Enea; Cosmi, Erich; Grisan, Enrico

    2012-03-01

    Prenatal events such as intrauterine growth restriction have been shown to be associated with an increased thickness of abdominal aorta in the fetus. Therefore the measurement of abdominal aortic intima-media thickness (aIMT) has been recently considered a sensitive marker of artherosclerosis risk. To date measure of aortic diameter and of aIMT has been performed manually on US fetal images, thus being susceptible to intra- and inter- operator variability. This work introduces an automatic algorithm that identifies abdominal aorta and estimates its diameter and aIMT from videos recorded during routine third trimester ultrasonographic fetal biometry. Firstly, in each frame, the algorithm locates and segments the region corresponding to aorta by means of an active contour driven by two different external forces: a static vector field convolution force and a dynamic pressure force. Then, in each frame, the mean diameter of the vessel is computed, to reconstruct the cardiac cycle: in fact, we expect the diameter to have a sinusoidal trend, according to the heart rate. From the obtained sinusoid, we identify the frames corresponding to the end diastole and to the end systole. Finally, in these frames we assess the aIMT. According to its definition, we consider as aIMT the distance between the leading edge of the blood-intima interface, and the leading edge of the media-adventitia interface on the far wall of the vessel. The correlation between end-diastole and end-systole aIMT automatic and manual measures is 0.90 and 0.84 respectively.

  1. [Autophagic flux of cardiomyocytes from 20-week transverse abdominal aortic constriction rats].

    PubMed

    Cui, Long-Biao; Sheng, Juan-Juan; Wang, Yun-Ying; Yu, Zhi-Bin

    2013-06-25

    Cardiac autophagy dramatically increases in heart failure induced by sustained pressure overload. However, it has not yet been addressed if enhanced autophagy plays a role in protecting myocardium or mediating progression from compensative hypertrophy to heart failure. The aim of the present study was to detect autophagic flux of cardiomyocytes from 20-week transverse abdominal aortic constriction (TAC) rats. Fasting rats were used as the positive control for detecting cardiac autophagy. Echocardiography was applied to find the changes of cardiac structure and function. Immunofluorescent histochemistry and Western blot were used to analyze the related biomolecular indexes reflecting cardiac autophagic flux. After the previous methods for detecting cardiac autophagy were confirmed, the autophagic flux in cardiomyocytes of rats subjected to 20-week TAC was examined. The results showed that fasting had no obvious influence on parameters of cardiac structure in rats, including interventricular septal wall thickness and left ventricle posterior wall thickness, but heart rate, diastolic left ventricle internal dimension, fractional shortening of left ventricle dimension, ejection fraction and mitral inflow velocity decreased in rats after fasting for 3 d. Meanwhile, positively stained particles of LC3 and cathepsin D, but not ubiquitin and complement 9, distributed within cardiomyocytes of 3-day fasting rats, indicating augmented autophagic flux. Compared with sham rats, 20-week TAC rats did not show any changes of LC3, cathepsin D, ubiquitin and complement 9 in myocardium detected by immunofluorescent histochemistry. In addition, protein levels of LC3, cathepsin D and p62 in myocardium of TAC rats did not changed. These results reveal the unchanged autophagic flux in cardiomyocytes at middle or late phase of cardiac hypertrophy in TAC rats, implying a balance between inhibition of hypertrophy and activation of pressure load stress on autophagy. PMID:23788187

  2. Thick brane solutions

    NASA Astrophysics Data System (ADS)

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Minamitsuji, Masato

    2010-06-01

    This paper gives a comprehensive review on thick brane solutions and related topics. Such models have attracted much attention from many aspects since the birth of the brane world scenario. In many works, it has been usually assumed that a brane is an infinitely thin object; however, in more general situations, one can no longer assume this. It is also widely considered that more fundamental theories such as string theory would have a minimal length scale. Many multidimensional field theories coupled to gravitation have exact solutions of gravitating topological defects, which can represent our brane world. The inclusion of brane thickness can realize a variety of possible brane world models. Given our understanding, the known solutions can be classified into topologically non-trivial solutions and trivial ones. The former class contains solutions of a single scalar (domain walls), multi-scalar, gauge-Higgs (vortices), Weyl gravity and so on. As an example of the latter class, we consider solutions of two interacting scalar fields. Approaches to obtain cosmological equations in the thick brane world are reviewed. Solutions with spatially extended branes (S-branes) and those with an extra time-like direction are also discussed.

  3. Abdominal Aortic Aneurysm

    PubMed Central

    Moore, Wesley S.; Kashyap, Vikram S.; Vescera, Candace L.; Quiñones-Baldrich, William J.

    1999-01-01

    Objective To test the hypothesis that endovascular repair of abdominal aortic aneurysm (AAA) will result in a significant reduction in mortality and morbidity rates and cost when compared with open transabdominal repair. Summary Background Data Since the introduction of endovascular repair of AAA this decade, multiple groups have evaluated different endovascular grafts. Despite the excellent results reported initially, there has been a paucity of well-controlled, comparative studies looking at long-term outcome. Methods From 1992 to 1998, the first 100 consecutive patients undergoing endovascular AAA repair (mean age 74.7, AAA size 5.6 cm) were compared to 100 patients undergoing transabdominal repair (mean age 72.9, AAA size 5.9 cm). All patients undergoing endovascular repair received a device manufactured by Endovascular Technologies, Inc. (Menlo Park, CA) and were prospectively followed with periodic examination, contrast-enhanced computed tomography, and duplex scanning. Of the 200 patients, 198 have been available for long-term follow-up. Results The two groups had similar preoperative risk factors. Surgical time (211 vs. 256 minutes, p < 0.005), blood loss (326 vs. 1010 ml, p < 0.005), and blood replacement (0.4 vs. 1.6 units, p < 0.005) were all decreased in the endovascular group. Median intensive care unit stay (0 vs. 2 days) and hospital stay (2 vs. 7 days) were significantly reduced in the endovascular group. Insignificant trends in lower morbidity rates (myocardial infarction 1% vs. 5%, respiratory failure 1% vs. 5%, colon ischemia 0% vs. 2%) were present in patients undergoing endovascular repair. This led to decreased hospital cost and increased hospital profit. The surgical mortality rate (2% vs. 3%) and 5-year survival rate (65% vs. 72%) have been equivalent between the two groups. Conclusions The surgical mortality rate is low for both groups and not statistically different. Endovascular repair significantly reduces resource utilization (surgical time, blood replacement, intensive care unit and hospital stay) and cost when compared to transabdominal aneurysm repair. Long-term survival is equivalent in patients undergoing AAA repair regardless of technique. Although endovascular repair appears durable for up to 6 years, longer follow-up studies are warranted. PMID:10493477

  4. Self-gravitating domain walls and the thin-wall limit

    E-print Network

    Rommel Guerrero; Alejandra Melfo; Nelson Pantoja

    2002-02-05

    We analyse the distributional thin wall limit of self gravitating scalar field configurations representing thick domain wall geometries. We show that thick wall solutions can be generated by appropiate scaling of the thin wall ones, and obtain an exact solution for a domain wall that interpolates between AdS_4 asymptotic vacua and has a well-defined thin wall limit.Solutions representing scalar field configurations obtained via the same scaling but that do not have a thin wall limit are also presented.

  5. Abdominal radiation causes bacterial translocation

    SciTech Connect

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  6. Abdominal aortic aneurysms: case report

    PubMed Central

    Hadida, Camille; Rajwani, Moez

    1998-01-01

    A 71-year-old male presented to a chiropractic clinic with subacute low back pain. While the pain appeared to be mechanical in nature, radiographic evaluation revealed an abdominal aortic aneurysm, which required the patient to have vascular surgery. This case report illustrates the importance of the history and physical examination in addition to a thorough knowledge of the features of abdominal aortic aneurysms. The application of spinal manipulative therapy in patients with (AAA) is also discussed. ImagesFigure 1Figure 2Figure 3

  7. Functional abdominal bloating with distention.

    PubMed

    Sullivan, Stephen Norman

    2012-01-01

    Ten to 25% of healthy persons experience bloating. It is particularly common in persons with the irritable bowel syndrome and constipation. While the cause of bloating remains unknown old explanations such as a excessive intestinal gas, exaggerated lumbar lordosis and psychiatric problems have been disproved. New suggestions include recent weight gain, weak or inappropriately relaxed abdominal muscles, an inappropriately contracted diaphragm and retained fluid in loops of distal small bowel. No treatment is of unequivocal benefit but a low FODMAPs diet, probiotics and the non-absorbable antibiotic rifaximin offer some hope. Treatment by weight loss, abdominal exercise, prokinetics and girdles need more study. PMID:22778978

  8. Microwave background distortions from domain walls

    NASA Technical Reports Server (NTRS)

    Goetz, Guenter; Noetzold, Dirk

    1990-01-01

    Domain walls arising in a cosmic phase transition after decoupling were recently proposed as seeds for the formation of large scale structure. The distortion induced in the microwave background radiation is calculated in dependence of the wall thickness, surface density, scalar field potential, cosmic redshift and the velocity of the wall. It was found that the maximal redshift distortion for both spherical and planar walls is of the order pi G sigma H(sup -1)(sub 0), where sigma is the surface energy density and H(sup -1)(sub 0) the Hubble parameter. It was also found that, for a wall thickness smaller than the horizon, walls can be treated as infinitely thin, i.e., the redshift distortion is independent of the wall thickness and the specific form of the scalar potential. For planar walls moving with a Lorentz-factor gamma the redshift distortion is enhanced by gamma cubed.

  9. Rare etiology of mechanical intestinal obstruction: Abdominal cocoon syndrome

    PubMed Central

    Uzunoglu, Yener; Altintoprak, Fatih; Yalkin, Omer; Gunduz, Yasemin; Cakmak, Guner; Ozkan, Orhan V; Celebi, Fehmi

    2014-01-01

    Abdominal cocoon syndrome is a rare cause of intestinal obstruction with unknown etiology. Diagnosis of this syndrome, which can be summarized as the small intestine being surrounded by a fibrous capsule not containing the mesothelium, is difficult in the preoperative period. A 47-year-old male patient was referred to the emergency department with complaints of abdominal pain, nausea, and vomiting for two days. The abdominal computed tomography examination detected dilated small intestinal loops containing air-fluid levels clustered in the left upper quadrant of the abdomen and surrounded by a thick, saclike, contrast-enhanced membrane. During exploratory surgery, a capsular structure was identified in the upper left quadrant with a regular surface that was solid-fibrous in nature. Abdominal cocoon syndrome is a rarely seen condition, for which the preoperative diagnosis is difficult. The combination of physical examination and radiological signs, and the knowledge of “recurrent characteristics of the complaints” that can be learned by a careful history, may be helpful in diagnosis. PMID:25405199

  10. Estimation of prenatal aorta intima-media thickness from ultrasound examination

    NASA Astrophysics Data System (ADS)

    Veronese, E.; Tarroni, G.; Visentin, S.; Cosmi, E.; Linguraru, M. G.; Grisan, E.

    2014-10-01

    Prenatal events such as intrauterine growth restriction and increased cardiovascular risk in later life have been shown to be associated with an increased intima-media thickness (aIMT) of the abdominal aorta in the fetus. In order to assess and manage atherosclerosis and cardiovascular disease risk in adults and children, in recent years the measurement of abdominal and carotid artery thickness has gained a growing appeal. Nevertheless, no computer aided method has been proposed for the analysis of prenatal vessels from ultrasound data, yet. To date, these measurements are being performed manually on ultrasound fetal images by skilled practitioners. The aim of the presented study is to introduce an automatic algorithm that identifies abdominal aorta and estimates its diameter and aIMT from routine third trimester ultrasonographic fetal data. The algorithm locates the aorta, then segments it and, by modeling the arterial wall longitudinal sections by means of a gaussian mixture, derives a set of measures of the aorta diameter (aDiam) and of the intima-media thickness (aIMT). After estimating the cardiac cycle, the mean diameter and the aIMT at the end-diastole phase are computed. Considering the aIMT value for each subject, the correlation between automatic and manual end-diastolic aIMT measurements is 0.91 in a range of values 0.44-1.10 mm, corresponding to both normal and pathological conditions. The automatic system yields a mean relative error of 19%, that is similar to the intra-observer variability (14%) and much lower that the inter-observer variability (42%). The correlation between manual and automatic measurements and the small error confirm the ability of the proposed system to reliably estimate aIMT values in prenatal ultrasound sequences, reducing measurement variability and suggesting that it can be used for an automatic assessment of aIMT. Preliminary results have been presented in E Veronese, E Cosmi, S Visentin, E Grisan: 'Semiautomatic estimation of fetal aorta intima-media thickness from ultrasound examination', MICCAI Workshop on Perinatal and Paediatric Imaging: PaPI 2012.

  11. Abdominal pain - children under age 12

    MedlinePLUS

    Stomach pain in children; Pain - abdomen - children; Abdominal cramps in children; Belly ache in children ... When your child complains of abdominal pain, see if they can describe it to you. Here are different kinds of pain: ...

  12. Abdominal pregnancy: Methods of hemorrhage control

    PubMed Central

    Kunwar, Shipra; Khan, Tamkin; Srivastava, Kumkumrani

    2015-01-01

    Summary Abdominal pregnancy is an extremely rare form of ectopic pregnancy, mostly occurring secondarily after tubal rupture or abortion with secondary implantation anywhere in the peritoneal cavity. Massive intra-abdominal hemorrhage is a life threatening complication associated with secondary abdominal pregnancy. Various methods and techniques have been reported in the literature for controlling hemorrhage. Here, we report a case of massive intraperitoneal haemorrhage following placental removal controlled by abdominal packing and review the literature for diagnostic and management challenges. PMID:25984430

  13. Intra-abdominal adhesions in ultrasound. Part II: The morphology of changes

    PubMed Central

    Starzy?ska, Teresa; Ko?aczyk, Katarzyna; Bojko, Stefania; Ga?dy?ska, Maria; Bernatowicz, El?bieta; Walecka, Anna

    2013-01-01

    Despite their frequent appearance, intra-abdominal adhesions are rarely the subject of clinical studies and academic discussions. For many years the operators have been trying to reduce such unfavourable consequences of interventions in the abdominal structures. The aim of this article is to present the possibilities of intra-abdominal adhesion diagnostics by means of ultrasound imaging based on authors’ own experience and information included in pertinent literature. The anatomy and examination technique of the abdominal wall were discussed in Part I of the article. In order to evaluate intraperitoneal adhesions, one should use a convex transducer with the frequency of 3.5–6 MHz. The article provides numerous examples of US images presenting intra-abdominal adhesions, particularly those which appeared after surgical procedures. The significance of determining their localisation and extensiveness prior to a planned surgical treatment is emphasized. Four types of morphological changes in the ultrasound caused by intra-abdominal adhesions are distinguished and described: visceroperitoneal adhesions, intraperitoneal adhesions, adhesive obstructions as well as adhesions between the liver and abdominal wall with a special form of such changes, i.e. hepatic pseudotumour. Its ultrasound features are as follows:The lesion is localised below the scar in the abdominal wall after their incision.The lesion is localised in the abdominal part of the liver segments III, IV and V.With the US beam focus precisely set, the lack of fascia – peritoneum complex may be noticed. An uneven liver outline or its ventral displacement appears.A hepatic adhesion-related pseudotumour usually has indistinct margins, especially the posterior one, and, gradually, from top to bottom, loses its hypoechogenic nature.In a respiration test, this liver fragment does not present the sliding movement – a neoplastic tumour rarely shows such an effect. The immobility of the liver is a permanent symptom of subdiaphragmatic abscess which needs to be included in the differentiation process.In case of doubts, the suspicious liver area may be examined without the consideration of the scar in the abdominal wall. In the differentiation of visceroperitoneal adhesions, firstly, one needs to exclude the peritoneum infiltration in the course of inflammation and neoplastic spreading, which may be very difficult in patients who have undergone a surgery. Pseudomyxoma peritonei constitutes a source of errors much more rarely. PMID:26675524

  14. Abdominal cocoon secondary to disseminated tuberculosis.

    PubMed

    Puppala, Radha; Sripathi, Smiti; Kadavigere, Rajagopal; Koteshwar, Prakashini; Singh, Jyoti

    2014-01-01

    Abdominal cocoon, also known as sclerosing encapsulating peritonitis, represents a rare entity where a variable length of the small bowel is enveloped by a fibrocollagenous membrane giving the appearance of a cocoon. It may be asymptomatic and is often diagnosed incidentally at laparotomy. We present a rare case of abdominal cocoon due to abdominal tuberculosis. PMID:25239980

  15. 4. STONE CABIN II CLOSEUP VIEW OF DOUBLE THICK FEATURE ...

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

    4. STONE CABIN II CLOSEUP VIEW OF DOUBLE THICK FEATURE OF THE ROCK WALL. WALL PHOTOGRAPHED IS THE NORTHERNMOST WALL TAKEN FROM THE INTERIOR OF STRUCTURE. CAMERA POINTED NORTHWEST. - Florida Mountain Mining Sites, Stone Cabin II, West slope Florida Mountain, East of Empire State Mine below summit, Silver City, Owyhee County, ID

  16. Implanting intra-abdominal radiotransmitters with external whip antennas in ducks

    USGS Publications Warehouse

    Korschgen, C.E.; Kenow, K.P.; Gendron-Fitzpatrick, A.; Green, W.L.; Dein, F.J.

    1996-01-01

    We developed and evaluated a surgical procedure for implanting intra-abdominal radiotransmitters with external whip antennas in captive mallards (Anas platyrhynchos). Transmitters were implanted in the abdominal cavity and the antennas exited through the caudal abdominal wall and skin. Birds with implanted transmitters developed mild to moderate localized air sac reactions. These reactions involved adhesions of the right anterior abdominal air sac to the liver with contractions around the transmitters and antenna catheters. The adhesions were reinforced by a proliferation of connective tissue and lined by multinucleated giant cells (foreign body reaction). Casual observation indicated that neither behavior nor activity of the birds was altered by the histological reaction to the transmitter implant. No increase in systemic lesions (particularly liver or kidney) could be correlated with the histological reactions. Our evaluations indicate that the procedure is a reliable method for radiomarking ducks and the technique has been successfully used in 2 field studies.

  17. Is closure of the peritoneal layer necessary in the repair of midline surgical abdominal wounds?

    PubMed

    Hugh, T B; Nankivell, C; Meagher, A P; Li, B

    1990-01-01

    This study describes a prospective randomized controlled trial to evaluate whether suture of the peritoneal layer is necessary as a separate step in the closure of midline abdominal surgical wounds. Consecutive patients undergoing abdominal operation--elective and emergency surgery--through a midline abdominal wound were randomized to have the peritoneal layer closed with continuous catgut, or to have this step omitted. The linea alba was closed with interrupted stainless steel sutures, and the skin approximated with staples. Patients were evaluated for wound sepsis, wound dehiscence, and subsequent incisional hernia development. Postoperative pain was assessed by a self-administered visual analogue score, and by measuring narcotic requirements. There was no significant difference in narcotic requirements, pain scores, or wound complications between the 2 groups. Single-layer closure of the abdominal wall is quicker, less costly, and theoretically safer than layered closure, and it is recommended that separate suture of the peritoneum be abandoned. PMID:2139269

  18. A case report of abdominal splenosis - a practical mini-review for a gastroenterologist.

    PubMed

    Ksi?dzyna, Dorota

    2011-09-01

    Splenosis is a benign condition caused by ectopic autotransplantation of splenic tissues after splenic trauma or surgery. It is usually diagnosed accidentally. However, occasionally splenosis poses a significant diagnostic dilemma, especially when this condition presents as a metastatic malignant disease on abdominal imaging. This is the case report of a 54-year-old woman, who underwent post-traumatic splenectomy at the age of 12 years. The physical examination of this patient complaining of epigastric and low back pain, except for postoperative abdominal scar, as well as laboratory tests were normal. Esophagogastroduodenoscopy showed chronic gastritis. Abdominal ultrasound revealed no spleen, enlarged lymph nodes in the right retroperitoneum and a focal lesion in the uterus. In addition, the CT scan disclosed enlarged left hepatic lobe, numerous oval tumors between intestinal loops, in the caecal region, under the diaphragm and abdominal wall, periaortic enlarged lymph nodes and an osteolytic lesion in the first lumbar vertebra, suggesting disseminated malignant disease. The exploratory laparotomy showed multiple abdominal nodules, a tumor of the ileum, the greater omentum and the uterus. Except for the last one (leiomyoma), all excised tumors proved to have histological structure typical for the spleen and, finally, abdominal splenosis was diagnosed. Splenosis should be considered when a differential diagnosis of tumor-like lesions disclosed on abdominal imaging occurs in a patient with a splenic injury in the past. PMID:21961104

  19. Intra-abdominal adhesions in ultrasound. Part I: The visceroperitoneal bordeline, anatomy and the method of examination

    PubMed Central

    Starzy?ska, Teresa; Ko?aczyk, Katarzyna; Bojko, Stefania; Ga?dy?ska, Maria; Bernatowicz, El?bieta; Walecka, Anna

    2012-01-01

    It needs to be emphasized that ultrasonography is a primary test performed in order to evaluate the abdominal wall and structures located in their vicinity. It allows for the determination of the anatomy and lesions in this localization. Thorough knowledge concerning the ultrasound anatomy of the tested structures constitutes a basis of all diagnostic successes. Therefore, this part of the article is devoted to this subject matter. The possibility to diagnose intra-abdominal adhesions with ultrasound is underestimated and rarely used. The aim of this paper is to discuss and document the ultrasound anatomy of the posterior surface of the abdominal wall as well as to present techniques directed at the detection of adhesions, in particular the visceroperitoneal ones. The posterior surface of the abdominal wall constitutes an extensive tissue area of complex structure, with folds and ligaments surrounded by various amounts of the epiperitoneal fat. In some places, this tissue separates the components of the fascia and peritoneum complex. The ultrasound manifestation of this complex is two hyperechogenic lines placed parallelly to each other in the places where they are not separated by the accumulated adipose tissue. Another factor which separates the peritoneum from the viscera is of dynamic character. It is a so-called visceral slide induced by easy or deep breathing. Its size should not be lower than 1 cm and the deflections gradually and symmetrically diminish from the epigastric to hypogastric region. Last but not least, the evaluation of the reciprocal relation of the abdominal wall with viscera may be aided by rhythmical manual compressions on the abdominal wall (ballottement sign) performed below the applied ultrasound transducer. During this test, the size of the visceral slide in relation to the abdominal wall is observed. The maneuver is usually performed in uncooperative patients or those with shallow breath. The authors’ own experiences indicate that the effectiveness of the test is increased when lower extremities are moderately bent. This relaxes the muscle tension in the anterior wall of the abdomen. To assess the condition of these structures, linear transducers with the frequency of 5–9 MHz prove the most appropriate. In obese patients, a convex transducer with the frequency of 3.5–5 MHz also may be used. The acoustic focus should be set on the borderline of the abdominal wall and viscera and in order to visualize the changes it might be helpful to use harmonic, compound and XRes imaging. When examining the abdominal wall, the cross and longitudinal sections should be made. The complete evaluation of the visceroperitoneal borderline includes nine segments – three in the epigastrium, three in the mid-abdomen and three in the hypogastrium. PMID:26674107

  20. Improvement of distension and mural visualization of bowel loops using neutral oral contrasts in abdominal computed tomography

    PubMed Central

    Hashemi, Jahanbakhsh; Davoudi, Yasmin; Taghavi, Mina; Pezeshki Rad, Masoud; Moghadam, Amien Mahajeri

    2014-01-01

    AIM: To assess and compare the image quality of 4% sorbitol and diluted iodine 2% (positive oral contrast agent) in abdomino-pelvic multi-detector computed tomography. METHODS: Two-hundred patients, referred to the Radiology Department of a central educational hospital for multi-detector row abdominal-pelvic computed tomography, were randomly divided into two groups: the first group received 1500 mL of 4% sorbitol solution as a neutral contrast agent, while in the second group 1500 mL of meglumin solution as a positive contrast agent was administered in a one-way randomized prospective study. The results were independently reviewed by two radiologists. Luminal distension and mural thickness and mucosal enhancement were compared between the two groups. Statistical analysis of the results was performed by Statistical Package for the Social Sciences software version 16 and the Mann-Whitney test at a confidence level of 95%. RESULTS: Use of neutral oral contrast agent significantly improved visualization of the small bowel wall thickness and mural appearance in comparison with administration of positive contrast agent (P < 0.01). In patients who received sorbitol, the small bowel showed better distention compared with those who received iodine solution as a positive contrast agent (P < 0.05). CONCLUSION: The results of the study demonstrated that oral administration of sorbitol solution allows better luminal distention and visualization of mural features than iodine solution as a positive contrast agent. PMID:25550995

  1. Investigation of the Hemodynamic Effect of Stent Wires on Renal Arteries in Patients with Abdominal Aortic Aneurysms Treated with Suprarenal Stent-Grafts

    SciTech Connect

    Sun Zhonghua; Chaichana, Thanapong

    2009-07-15

    The purpose of the study was to investigate the hemodynamic effect of stent struts (wires) on renal arteries in patients with abdominal aortic aneurysms (AAAs) treated with suprarenal stent-grafts. Two sample patients with AAA undergoing multislice CT angiography pre- and postsuprarenal fixation of stent-grafts were selected for inclusion in the study. Eight juxtarenal models focusing on the renal arteries were generated from the multislice CT datasets. Four types of configurations of stent wires crossing the renal artery ostium were simulated in the segmented aorta models: a single wire crossing centrally, a single wire crossing peripherally, a V-shaped wire crossing centrally, and multiple wires crossing peripherally. The blood flow pattern, flow velocity, wall pressure, and wall shear stress at the renal arteries pre- and post-stent-grafting were analyzed and compared using a two-way fluid structure interaction analysis. The stent wire thickness was simulated with a diameter of 0.4, 1.0, and 2.0 mm, and hemodynamic analysis was performed at different cardiac cycles. The interference of stent wires with renal blood flow was mainly determined by the thickness of stent wires and the type of configuration of stent wires crossing the renal ostium. The flow velocity was reduced by 20-30% in most of the situations when the stent wire thickness increased to 1.0 and 2.0 mm. Of the four types of configuration, the single wire crossing centrally resulted in the highest reduction of flow velocity, ranging from 21% to 28.9% among three different wire thicknesses. Wall shear stress was also dependent on the wire thickness, which decreased significantly when the wire thickness reached 1.0 and 2.0 mm. In conclusion, our preliminary study showed that the hemodynamic effect of suprarenal stent wires in patients with AAA treated with suprarenal stent-grafts was determined by the thickness of suprarenal stent wires. Research findings in our study are useful for follow-up of patients treated with suprarenal stent-grafts to ensure long-term safety of the suprarenal fixation.

  2. De Sitter and double irregular domain walls

    E-print Network

    Rommel Guerrero; R. Omar Rodriguez; R. Ortiz; Rafael Torrealba

    2007-03-15

    A new method to obtain thick domain wall solutions to the coupled Einstein scalar field system is presented. The procedure allows the construction of irregular walls from well known ones, such that the spacetime associated to them are physically different. As consequence of the approach, we obtain two irregular geometries corresponding to thick domain walls with $dS$ expansion and topological double kink embedded in $AdS$ spacetime. In particular, the double brane can be derived from a fake superpotential.

  3. Computed tomographic characteristics of presumed normal canine abdominal lymph nodes.

    PubMed

    Beukers, Martijn; Grosso, Federico Vilaplana; Voorhout, George

    2013-01-01

    Though identification of lymph nodes is essential in staging cancer patients, little has been reported about the CT features of canine abdominal lymph nodes. The purpose of this retrospective study was to describe the visibility, location, and characteristics of abdominal lymph nodes in abdominal CT studies of dogs considered unlikely to have lymphadenopathy. The relationship between the number of identified lymph nodes and intraabdominal fat ranking, body weight, and slice thickness was also investigated. A total of 19 dogs were included. At least two jejunal lymph nodes and both left and right medial iliac lymph nodes were identified in all dogs. Colic lymph nodes were not identified in any of the dogs. Visualization of all other lymph nodes varied. There were significantly more lymph nodes visible in dogs with more intraabdominal fat (P < 0.0001). No correlation between the number of identified lymph nodes and body weight (P = 0.64) or slice thickness (P = 0.76) was found. Though most of all identified lymph nodes had an elongated shape, a rounded shape was most common in splenic, pancreaticoduodenal, renal, ileocolic and caudal mesenteric lymph nodes. Most lymph nodes had a homogeneous structure before and following the intravenous administration of contrast medium. Some lymph nodes had a slightly irregular structure or were relatively more hyper attenuating in the periphery than centrally before and/or after contrast administration. Mean attenuation before contrast was 37 Hounsfield Units (HU) (range 20-52 HU), and 109 HU after contrast (range 36-223 HU). Findings indicated that the CT visibility, characteristics of different abdominal lymph nodes may be variable in dogs. PMID:23815078

  4. 49 CFR 179.200-6 - Thickness of plates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... thickness after forming of the tank shell, dome shell, and of 2:1 ellipsoidal heads must be not less than... bursting pressure in psig; S = Minimum tensile strength of plate material in p.s.i. as prescribed in § 179.200-7; t = Minimum thickness of plate in inches after forming. (b) The wall thickness after forming...

  5. Abdominal and pelvic hydatid cyst obstructing the labor.

    PubMed

    Zulfikaroglu, Ebru; Islimye, Mine; Zulfikaroglu, Baris; Danisman, Nuri

    2010-01-01

    Hydatid cystic disease is a parasitic disease primarily infesting the sheep and cattle. It is a rare condition in pregnancy with an incidence of 1/20000 pregnancies. An eighteen-year-old primigravida was evaluated due to obstructed labor. Multiple abdominal and pelvic hydatid cysts were diagnosed by ultasonography and a healthy infant with birthweight of 3330 g was delivered by cesarean section. While the cysts situated on the posterior uterine wall, paraovarian region and omentum were removed totally, the hepatic cysts were only partially removed and then drained. The hydatid disease should be considered in differential diagnosis of adnexal masses obstructing the labor in pregnancy (Fig. 3, Ref. 9). PMID:21033629

  6. Laparoscopy in Pediatric Abdominal Trauma

    PubMed Central

    Gandhi, Rajesh R.

    1997-01-01

    Background: The use and indications for laparoscopy have been increasing. As part of this trend, a new algorithm may emerge for pediatric trauma in which laparoscopic techniques are used in hemodynamically stable patients with suspected hollow viscus perforation. Case Report: We present a case in which laparoscopy was successfully used in a pediatric trauma patient as a diagnostic and therapeutic modality. A 4-year-old boy was a back-seat passenger in a head-on collision motor vehicle accident. He was restrained by a lap seat belt. He sustained a concussion, a large forehead laceration and a seat belt abdominal injury. On admission, he complained of abdominal pain. Physical examination revealed a soft, nondistended abdomen with moderate diffuse tenderness. He was hemodynamically stable. Computerized tomography of the abdomen revealed free fluid in the pelvis. No abnormalities were detected in the liver or spleen. Because of clinical deterioration and suspected intestinal perforation, diagnostic laparoscopy was utilized instead of proceeding directly to celiotomy. At laparoscopy a jejunal perforation was found and successfully repaired laparoscopically. Large hematomas were seen in the mesentery, as well as an unsuspected splenic laceration. No active bleeding was found. The patient recovered uneventfully and was discharged 5 days following the surgical procedure. Conclusion: This case illustrates the efficacy of using early laparoscopy in children with abdominal trauma when diagnosis is difficult and hollow viscus injury is suspected. PMID:9876702

  7. Collagen Degradation in the Abdominal Aneurysm

    PubMed Central

    Abdul-Hussien, Hazem; Soekhoe, Ratna G.V.; Weber, Ekkehard; von der Thüsen, Jan H.; Kleemann, Robert; Mulder, Adri; van Bockel, J. Hajo; Hanemaaijer, Roeland; Lindeman, Jan H.N.

    2007-01-01

    Growth and rupture of abdominal aortic aneurysms (AAAs) result from increased collagen turnover. Collagen turnover critically depends on specific collagenases that cleave the triple helical region of fibrillar collagen. As yet, the collagenases responsible for collagen degradation in AAAs have not been identified. Increased type I collagen degradation products confirmed collagen turnover in AAAs (median values: <1, 43, and 108 ng/mg protein in control, growing, and ruptured AAAs, respectively). mRNA and protein analysis identified neutrophil collagenase [matrix metalloproteinase (MMP)-8] and cysteine collagenases cathepsin K, L, and S as the principle collagenases in growing and ruptured AAAs. Except for modestly increased MMP-14 mRNA levels, collagenase expression was similar in growing and ruptured AAAs (anterior-lateral wall). Evaluation of posttranslational regulation of protease activity showed a threefold increase in MMP-8, a fivefold increase in cathepsins K and L, and a 30-fold increase in cathepsin S activation in growing and ruptured AAAs. The presence of the osteoclastic proton pump indicated optimal conditions for extracellular cysteine protease activity. Protease inhibitor mRNA expression was similar in AAAs and controls, but AAA protein levels of cystatin C, the principle cysteine protease inhibitor, were profoundly reduced (>80%). We found indications that this secondary deficiency relates to cystatin C degradation by (neutrophil-derived) proteases. PMID:17322367

  8. Cannulation needle-induced anterior wall tenting of internal jugular vein causing posterior wall penetration.

    PubMed

    Yoshida, Hitoshi; Yaguchi, Shinya; Itaya, Hiroyuki; Ito, Kazuo; Hatanaka, Ryo; Nakai, Kishiko; Hirota, Kazuyoshi

    2015-06-01

    Unintentional posterior venous wall penetration during internal jugular vein (IJV) cannulation may cause critical arterial injuries in spite of ultrasound guidance. We aimed to evaluate whether small venous diameter and anterior venous wall tenting by a needle would be associated with posterior venous wall penetration, and to seek factors related to the venous wall tenting. We conducted a retrospective review in patients who underwent IJV cannulation. Using an ultrasound view obtained when puncturing, venous diameter, venous wall thickness, anterior venous wall tenting length, and needle angle were measured, and posterior venous wall penetration was determined. Eleven cannulations in 56 patients were assigned to posterior venous wall penetration. Small venous diameter (p = 0.004), and long anterior venous wall tenting (p = 0.007) were associated with posterior venous wall penetration. The longer anterior venous tenting would be expected with reducing needle angle (p = 0.004) or increasing anterior venous wall thickness (p = 0.006). In conclusion, small IJV and anterior venous wall tenting lead to posterior venous wall penetration. Anterior venous wall tenting is longer with reducing needle angle, or increasing the anterior venous wall thickness. PMID:25365942

  9. CT features in abdominal tuberculosis: 20 years experience.

    PubMed Central

    Sinan, Tariq; Sheikh, Mehraj; Ramadan, Salwa; Sahwney, Sukhpal; Behbehani, Abdulla

    2002-01-01

    Background Abdominal tuberculosis (TB) is endemic in the developing world and is reemerging in the West. Since computed tomography (CT) has the ability to demonstrate changes in the peritonium, mesentry, lymphnodes, bowel and solid organs and is being increasingly used for primary evaluation of abdominal conditions, it is important to be familiar with the CT features of the disease. Methods CT findings were retrospectively analysed in 49 patients with proved abdominal TB. Patients with genitourinary TB and with AIDS/HIV were not included in the study. Results Peritoneal involvement was the most common feature (77.5%) with ascites (wet peritonitis) seen in more than half the cases (55.2%). The rest showed peritoneal, mesenteric or omental thickening or mass formation but no ascites (dry peritonitis). Other findings included lymphadenopathy (46.9% mainly of diffuse nature, bowel wall thickening (38%) and solid organ involvement (20.4%). Conclusions CT reliably demonstrates the entire range of findings which need interpretation in the light of clinical and laboratory data. PMID:12427257

  10. Elastic Coupling between Nonferroelastic Domain Walls

    NASA Astrophysics Data System (ADS)

    Shapovalov, K.; Yudin, P. V.; Tagantsev, A. K.; Eliseev, E. A.; Morozovska, A. N.; Setter, N.

    2014-11-01

    We reveal a strong elastic interaction between nonferroelastic domain walls in ferroelectric thin films. This interaction, having no analogue in bulk materials, is governed by elastic fields that are associated with the domain walls and extends to distances comparable to the film thickness. Such elastic widening of the nonferroelastic domain walls is shown to be particularly strong in common ferroelectric perovskites. The results are especially relevant for the control of domain wall propagation and the understanding of polarization dynamics.

  11. Great Walls.

    ERIC Educational Resources Information Center

    Blackburn, Steve; Moore, Tim

    1996-01-01

    Explains why installing a well-designed indoor climbing wall can draw new users to an athletic facility. Climbing-wall design elements and gear are discussed and a checklist for working with contractors is provided.(GR)

  12. Ultrasound presentation of abdominal non-Hodgkin lymphomas in pediatric patients

    PubMed Central

    Wo?niak, Magdalena Maria; Dudkiewicz, Ewa; Grabowski, Dominik; Stefaniak, Jolanta; Wieczorek, Andrzej Pawe?; Kowalczyk, Jerzy

    2013-01-01

    Introduction Burkitt's lymphoma accounts for approximately 25% of lymphomas diagnosed in children of developmental age. The tumor is localized mainly in the intestine (usually in the ileocecal region), mesenteric lymph nodes and extraperitoneal space. The clinical symptoms are non-specific and include: abdominal pain, vomiting, gastrointestinal bleeding, and acute abdomen suggesting appendicitis or intestinal intussusception. On ultrasound examination, Burkitt's lymphoma may manifest itself in various ways, depending on the origin of the lesion. Aim The aim of this paper was to review the ultrasound manifestation of abdominal Burkitt's lymphoma in children. Material and methods The analysis included 15 pediatric patients with Burkitt's non-Hodgkin lymphoma in the abdominal cavity. The mean age of the patients was 9.5. Abdominal and gastrointestinal ultrasound examinations were conducted using a Siemens scanner with a convex transducer of 3.5–5 MHz and linear array transducer of L4 – 7.5 MHz. Results Ultrasound examinations conducted in the group of 15 patients revealed pathological masses localized in the gastric wall in 3 patients (20%), in the ileocecal region in 10 patients (67%) and a disseminated process in 2 patients (13%). In 12 patients with a diagnosed Burkitt's non-Hodgkin lymphoma in an extragastric localization, differences in the morphology of the lesions were observed. Conclusions The clinical and ultrasound picture of abdominal Burkitt's lymphoma in children is variable. A careful ultrasound assessment of all abdominal organs conducted with the use of convex and linear probes increases the chances of establishing an adequate diagnosis. PMID:26672593

  13. [Abdominal vascular structural and functional features in patients with connective tissue dysplasia].

    PubMed

    Lialiukova, E A; Orlova, N I; Aksenov, S I

    2012-01-01

    Doppler ultrasound study records decreased volume blood flow in patients with connective tissue dysplasia. Their hemodynamic features are more marked during food testing. Dysplasia-dependent structural changes in the vascular system, such as vascular hypoplasia, wall-occluding lesions, different types of deformities, are one of the causes of lower volumetric blood flow in the abdominal vessels. The found abdominal vascular structural and functional features in patients with connective tissue dysplasia can serve as the basis for blood flow disproportion in different stages of digestion. PMID:23214026

  14. Shapes of hydrophobic thick membranes

    E-print Network

    Trinh X. Hoang; Jayanth R. Banavar; Amos Maritan

    2012-06-05

    We introduce and study the behavior of a tethered membrane of non-zero thickness embedded in three dimensions subject to an effective self-attraction induced by hydrophobicity arising from the tendency to minimize the area exposed to a solvent. The phase behavior and the nature of the folded conformations are found to be quite distinct in the small and large solvent size regimes. We demonstrate spontaneous symmetry-breaking with the membrane folding along a preferential axis, when the solvent molecules are small compared to the membrane thickness. For large solvent molecule size, a local crinkling mechanism effectively shields the membrane from the solvent, even in relatively flat conformations. We discuss the binding/unbinding transition of a membrane to a wall that serves to shield the membrane from the solvent.

  15. Pavement Thickness Design Parameter

    E-print Network

    Pavement Thickness Design Parameter Impacts 2012 Municipal Streets Seminar November 14, 2012 Paul D. Wiegand, P.E. #12;Pavement Thickness Design · How do cities decide how thick to build their pavements;Pavement Thickness Design · Correct answer ­ A data-based analysis! · Doesn't have to be difficult and time

  16. Abdominal fibromatosis in a young child: a case study and review of the literature.

    PubMed

    Chu, Hyun Hee; Hwang, Pyoung Han; Jeong, Yeon Jun; Chung, Myoung Ja

    2013-10-01

    Fibromatoses comprise many different entities of well-differentiated fibroblastic proliferation with variable collagen production and form a firm nodular mass. Abdominal fibromatosis is distinguishable from other forms of fibromatosis because of its location and its tendency to occur in women of childbearing age during or following pregnancy. Abdominal fibromatosis in children is an extremely rare condition. A 15-month-old boy presented with an abdominal wall mass that had recently increased in size. Mass excision was perfomed. The tumor was 4.3×4.1 cm and partly circumscribed. Histologically, the tumor was composed of parallel long fascicles of spindle-cells with a uniform appearance. The edges of the resected mass were infiltrative, and the surgical margins were positive. Mitotic figures were <1/10 high power fields. No cellular atypia or necrosis was present. The tumor cells were positive for vimentin and nuclear ?-catenin staining. PMID:24255636

  17. [The advantages of combined US-fluoroscopic guidance in the drainage of abdominal abscesses].

    PubMed

    Lemmi, A; Lupattelli, L; Barzi, F; Malaspina, C; Rizzo, F

    1992-01-01

    The authors report their experience with 19 percutaneous drainages of abdominal abscesses in 19 patients. Six collections were in the subphrenic spaces, 6 in the liver, 1 in the infracolic space, 2 in the psoas muscle, 3 within the abdominal wall, and 1 in the pararenal space. Their etiology was abdominal surgery in 10 patients, biliary obstruction in 1, and trauma in 2; in the extant patients a hematogenous infection was supposed. The procedures were performed under combined US and fluoroscopic guidance, following Seldinger technique in all but two cases. Van Sonnenberg double-lumen sump catheter was successfully employed in all cases. After a review of the technique the authors discuss the advantages of US-fluoroscopic over CT guidance. The latter is preferred if the collection is not well demonstrated by US and in the cases where a posterior approach is needed. The economic advantages of US-fluoroscopic over CT guidance are also stressed. PMID:1557550

  18. Breakup of finite thickness viscous shell microbubbles by ultrasound: A simplified zero-thickness shell model

    PubMed Central

    Hsiao, Chao-Tsung; Chahine, Georges L.

    2013-01-01

    A simplified three-dimensional (3-D) zero-thickness shell model was developed to recover the non-spherical response of thick-shelled encapsulated microbubbles subjected to ultrasound excitation. The model was validated by comparison with previously developed models and was then used to study the mechanism of bubble break-up during non-spherical deformations resulting from the presence of a nearby rigid boundary. The effects of the shell thickness and the bubble standoff distance from the solid wall on the bubble break-up were studied parametrically for a fixed insonification frequency and amplitude. A diagram of bubble shapes versus the normalized shell thickness and wall standoff was derived, and the potential bubble shapes at break-up from reentrant jets were categorized resulting in four distinct zones. PMID:23556560

  19. Management of intra-abdominal hypertension and abdominal compartment syndrome: a review

    PubMed Central

    2014-01-01

    Patients in the intensive care unit (ICU) are at risk of developing of intra abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Aim: This review seeks to define IAH and ACS, identify the aetiology and presentation of IAH and ACS, identify IAP measurement techniques, identify current management and discuss the implications of IAH and ACS for nursing practice. A search of the electronic databases was supervised by a health librarian. The electronic data bases Cumulative Index of Nursing and Allied Health Literature (CINAHL); Medline, EMBASE, and the World Wide Web was undertaken from 1996- January 2011 using MeSH and key words which included but not limited to: abdominal compartment syndrome, intra -abdominal hypertension, intra-abdominal pressure in adult populations met the search criteria and were reviewed by three authors using a critical appraisal tool. Data derived from the retrieved material are discussed under the following themes: (1) etiology of intra-abdominal hypertension; (2) strategies for measuring intra-abdominal pressure (3) the manifestation of abdominal compartment syndrome; and (4) the importance of nursing assessment, observation and interventions. Intra-abdominal pressure (IAP) and abdominal compartment syndrome (ACS) have the potential to alter organ perfusion and compromise organ function. PMID:24499574

  20. Adventitial Tertiary Lymphoid Organs as Potential Source of MicroRNA Biomarkers for Abdominal Aortic Aneurysm

    PubMed Central

    Spear, Rafaelle; Boytard, Ludovic; Blervaque, Renaud; Chwastyniak, Maggy; Hot, David; Vanhoutte, Jonathan; Staels, Bart; Lemoine, Yves; Lamblin, Nicolas; Pruvot, François-René; Haulon, Stephan; Amouyel, Philippe; Pinet, Florence

    2015-01-01

    Abdominal aortic aneurysm (AAA) is an inflammatory disease associated with marked changes in the cellular composition of the aortic wall. This study aims to identify microRNA (miRNA) expression in aneurysmal inflammatory cells isolated by laser microdissection from human tissue samples. The distribution of inflammatory cells (neutrophils, B and T lymphocytes, mast cells) was evaluated in human AAA biopsies. We observed in half of the samples that adventitial tertiary lymphoid organs (ATLOs) with a thickness from 0.5 to 2 mm were located exclusively in the adventitia. Out of the 850 miRNA that were screened by microarray in isolated ATLOs (n = 2), 164 miRNAs were detected in ATLOs. The three miRNAs (miR-15a-3p, miR-30a-5p and miR-489-3p) with the highest expression levels were chosen and their expression quantified by RT-PCR in isolated ATLOs (n = 4), M1 (n = 2) and M2 macrophages (n = 2) and entire aneurysmal biopsies (n = 3). Except for the miR-30a-5p, a similar modulation was found in ATLOs and the two subtypes of macrophages. The modulated miRNAs were then evaluated in the plasma of AAA patients for their potential as AAA biomarkers. Our data emphasize the potential of miR-15a-3p and miR-30a-5p as biomarkers of AAA but also as triggers of ATLO evolution. Further investigations will be required to evaluate their targets in order to better understand AAA pathophysiology. PMID:25993295

  1. [Complicated intra-abdominal infections: pathogens, resistance. Recommendations of the Infectliga on antbiotic therapy].

    PubMed

    Bodmann, K-F

    2010-01-01

    Intra-abdominal infections are generally the result of invasion and multiplication of enteric bacteria in the wall of a hollow viscus within the abdomen to produce peritonitis or abscess. When the infection extends into the peritoneal cavity or another normally sterile region of the abdominal cavity, the infection is described as a "complicated" intra-abdominal infection. Treatment of patients with complicated intra-abdominal infections involves antimicrobial therapy, generally in conjunction with an appropriate and timely surgical source control. Nearly all intra-abdominal infections are caused by multiple microorganisms that constitute the intestinal flora (aerobes and facultative and obligate anaerobes, with Enterobacteriaceae, enterococci and Bacteroides fragilis isolated most frequently). The emergence of drug resistance (e.g. ESBL-producing Enterobacteriaceae or resistant enterococci and staphylococci) poses a substantial threat to patients with surgical infections. Especially in patients with nosocomially acquired infections inadequate empiric antibiotic treatment is associated with treatment failure and death. In patients at risk broader spectrum antibiotic regimens with coverage of resistant Gram-negative bacilli and anaerobes and Gram-positive bacteria such as enterococci (including VRE) and staphylococci should be considered. PMID:20020092

  2. 49 CFR 179.400-8 - Thickness of plates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... (a) The minimum wall thickness, after forming, of the inner shell and any 2:1 ellipsoidal head for..., whichever is greater: t = Pd / 2SE Where: t = minimum thickness of plate, after forming, in inches; P... of the plate material, as prescribed in AAR Specifications for Tank Cars, appendix M, Table M1...

  3. ABDOMINAL PREGNANCY IN A SERVAL (LEPTAILURUS SERVAL) SECONDARY TO UTERINE RUPTURE.

    PubMed

    Bryan, Laura K; Blue-McLendon, Alice; Hoffmann, Aline Rodrigues

    2015-06-01

    A 14-yr-old female serval (Leptailurus serval) died unexpectedly after 2 wk of inappetence and lethargy. Necropsy revealed a pyoabdomen with a full-term, well-developed fetus in the caudal abdomen covered by a mesenteric sac. The mesenteric sac communicated with a tear in the wall of the right uterine horn, supporting a diagnosis of secondary abdominal pregnancy. The uterine wall had evidence of adenomyosis at the rupture site with no evidence of pyometra. The fetus, supporting mesentery, and peritoneum were coated with mixed bacteria, which may have ascended through an open cervix to the site of uterine rupture. This is the first case of abdominal pregnancy related to uterine rupture reported in a large felid species. PMID:26056905

  4. An unusual and difficult diagnosis of intestinal obstruction: The abdominal cocoon. Case report and review of the literature

    PubMed Central

    Devay, Ali O; Gomceli, Ismail; Korukluoglu, Birol; Kusdemir, Ahmet

    2006-01-01

    Abdominal cocoon is a rare cause of intestinal obstruction. The abdominal cocoon is probably a developmental abnormality, largely asymptomatic, and is found incidentally at laparotomy or autopsy. Pre-operative diagnosis cannot be often made correctly. This rare entity of intestinal obstruction has been described in the whole literature as a thick fibrotic sac covering the small bowel partially or completely. The etiology of abdominal cocoon is unknown and most often it is found in adolescent girls from tropical or subtropical countries. Complete recovery is generally expected after the removal of the membrane surgically. This paper reports a male patient who has had intestinal obstruction symptoms and has per-operatively been diagnosed as abdominal cocoon. PMID:16759404

  5. The biaxial biomechanical behavior of abdominal aortic aneurysm tissue.

    PubMed

    O'Leary, Siobhan A; Healey, Donagh A; Kavanagh, Eamon G; Walsh, Michael T; McGloughlin, Tim M; Doyle, Barry J

    2014-12-01

    Rupture of the abdominal aortic aneurysm (AAA) occurs when the local wall stress exceeds the local wall strength. Knowledge of AAA wall mechanics plays a fundamental role in the development and advancement of AAA rupture risk assessment tools. Therefore, the aim of this study is to evaluate the biaxial mechanical properties of AAA tissue. Multiple biaxial test protocols were performed on AAA samples harvested from 28 patients undergoing open surgical repair. Both the Tangential Modulus (TM) and stretch ratio (?) were recorded and compared in both the circumferential (?) and longitudinal (L) directions at physiologically relevant stress levels, the influence of patient specific factors such as sex, age AAA diameter and status were examined. The biomechanical response was also fit to a hyperplastic material model. The AAA tissue was found to be anisotropic with a greater tendency to stiffen in the circumferential direction compared to the longitudinal direction. An anisotropic hyperelastic constitutive model represented the data well and the properties were not influenced by the investigated patient specific factors however, a future study utilizing a larger cohort of patients is warranted to confirm these findings. This work provides further insights on the biomechanical behavior of AAA and may be useful in the development of more reliable rupture risk assessment tools. PMID:25201606

  6. Epithelioid Angiosarcoma With Metastatic Disease After Endovascular Therapy of Abdominal Aortic Aneurysm

    SciTech Connect

    Schmehl, Joerg; Scharpf, Marcus; Brechtel, Klaus; Kalender, Guenay; Heller, Stephan; Claussen, Claus D.; Lescan, Mario

    2012-02-15

    Malignancies of the aortic wall represent a rare condition, and only a few reports have covered cases of sarcomas arising at the site of a prosthesis made of Dacron. A coincidence with endovascular repair has only been reported in one case to date. We report a patient with epithelioid angiosarcoma and metastatic disease, which was found in an aneurysmal sac after endovascular aortic repair for abdominal aortic aneurysm.

  7. The Tribolium homeotic gene Abdominal is homologous to abdominal-A of the Drosophila bithorax complex

    NASA Technical Reports Server (NTRS)

    Stuart, J. J.; Brown, S. J.; Beeman, R. W.; Denell, R. E.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    The Abdominal gene is a member of the single homeotic complex of the beetle, Tribolium castaneum. An integrated developmental genetic and molecular analysis shows that Abdominal is homologous to the abdominal-A gene of the bithorax complex of Drosophila. abdominal-A mutant embryos display strong homeotic transformations of the anterior abdomen (parasegments 7-9) to PS6, whereas developmental commitments in the posterior abdomen depend primarily on Abdominal-B. In beetle embryos lacking Abdominal function, parasegments throughout the abdomen are transformed to PS6. This observation demonstrates the general functional significance of parasegmental expression among insects and shows that the control of determinative decisions in the posterior abdomen by homeotic selector genes has undergone considerable evolutionary modification.

  8. Abdominal surgery. [Radiology, screening techniques

    SciTech Connect

    Welch, C.E.; Malt, R.A.

    1983-03-31

    A new art of ''interventional radiology'' has been developed in the past few years. Major applications include postoperative instrumentation of the biliary tract, percutaneous biliary drainage, tumor biopsy, abscess drainage, and intestinal-intubation procedures. Intervention by angiography encompasses injection of such substances as Pitressin (vasopressin), and embolization. These procedures have been of immense value. Fortunately, complications, such as sepsis and bleeding, have been infrequent. Computerized body tomography has also proved extremely important, particularly in the diagnosis of subphrenic abscess and pancreatic and pelvic pathology. /sup 99m/Tc-labeled-erythrocyte scans can be used to detect gastrointestinal bleeding sites. Scans can also identify hepatobiliary disease and splenic injury or differentiate the cause of jaundice. /sup 111/Indium-labeled autologous leukocytes may be useful in differentiating a pancreatic abscess from a pseudocyst. The advantage of indium scans over /sup 67/Ga scans is that a shorter time is required for maximum resolution: gallium requires 48 hours, indium 4. Another advantage is that indium is cleared through the liver and spleen and is not secreted into the bowel. /sup 67/Ga is absorbed by lymphomas and hepatocarcinomas. Nuclear magnetic resonance has many possible uses in abdominal surgery, but so far little information is available. This technique has been used to detect an empyema of the gallbladder that was not diagnosed by ultrasound. Among hepatic lesions, it can easily differentiate tumors from cysts and in that regard is superior to both ultrasound and scan. (JMT)

  9. Abdominal Tumor in a 14-Year-Old Adolescent: Imperforate Hymen, Resulting in Hematocolpos—A Case Report and Review of the Literature

    PubMed Central

    Makris, George Marios; Macchiella, Doris; Vaidakis, Dennis; Chrelias, Charalampos; Battista, Marco Johannes; Siristatidis, Charalampos

    2015-01-01

    Background. Abdominal masses in female adolescents are uncommon. A rare cause of this condition is hematocolpos due to imperforate hymen. Case. We present a case of an unusually massive asymptomatic abdominal bulk in a 14-year-old female patient, who sought for medical advice after unusual abdominal pain lasting for few weeks. The patient was otherwise asymptomatic, apart from an unusual dramatic expansion of her abdominal wall during the last month. We describe the surgical management and the follow-up of the patient. Summary and Conclusion. Clinicians should keep in mind that an imperforate hymen can cause abdominal growth due to hematocolpos and include it in the differential diagnosis of such a clinical entity in female adolescents. 2D ultrasound is usually efficient for the confirmation of the diagnosis of hematocolpos, but 3D ultrasound is more accurate. Wide excision should be undertaken, as an initial approach, to avoid recurrence. PMID:25737786

  10. Abdominal tumor in a 14-year-old adolescent: imperforate hymen, resulting in hematocolpos-a case report and review of the literature.

    PubMed

    Makris, George Marios; Macchiella, Doris; Vaidakis, Dennis; Chrelias, Charalampos; Battista, Marco Johannes; Siristatidis, Charalampos

    2015-01-01

    Background. Abdominal masses in female adolescents are uncommon. A rare cause of this condition is hematocolpos due to imperforate hymen. Case. We present a case of an unusually massive asymptomatic abdominal bulk in a 14-year-old female patient, who sought for medical advice after unusual abdominal pain lasting for few weeks. The patient was otherwise asymptomatic, apart from an unusual dramatic expansion of her abdominal wall during the last month. We describe the surgical management and the follow-up of the patient. Summary and Conclusion. Clinicians should keep in mind that an imperforate hymen can cause abdominal growth due to hematocolpos and include it in the differential diagnosis of such a clinical entity in female adolescents. 2D ultrasound is usually efficient for the confirmation of the diagnosis of hematocolpos, but 3D ultrasound is more accurate. Wide excision should be undertaken, as an initial approach, to avoid recurrence. PMID:25737786

  11. Intravenous dihydroergotamine therapy for pediatric abdominal migraines.

    PubMed

    Raina, Madiha; Chelimsky, Gisela; Chelimsky, Thomas

    2013-10-01

    Abdominal migraines present with debilitating symptoms in adolescence. At our institution, the gastroenterology, neurology, and autonomic departments collaborated in treating patients with such presentations. This case series describes 6 patients who were given intravenous dihydroergotamine (DHE) for presumed abdominal migraines. DHE was only used when other agents like amitriptyline, verapamil, topiramate, or depakote had proved ineffective. DHE was started at 0.5 mg dose and on average 7 to 9 mg were given on each hospitalization. Patient ages ranged from 13 to 19 years with the majority being female. One patient did not respond to treatment. One patient was admitted 4 times for symptoms of abdominal migraines resolving with DHE. The average time between symptom relapse was about 5 to 12 months. Five of our 6 patients responded to the infusion without significant side effects. Based on these case series, DHE may be a treatment option in children with intractable abdominal migraine. PMID:23820001

  12. An Unusual Case of Abdominal Pain

    PubMed Central

    Desai, Bobby; De Portu, Giuliano

    2012-01-01

    Renal calyceal rupture is a usual etiology of abdominal pain in the emergency department. We present a case of unexpected renal calyx rupture in a patient with symptomatology of renal colic. A discussion and review are provided. PMID:23326726

  13. Atypical abdominal pain: post-traumatic transverse colon stricture.

    PubMed

    Rotar, Raluca; Uwechue, Raphael; Sasapu, Kishore Kumar

    2013-01-01

    A driver presented to the emergency department 1 day after an accident driving his excavator with abdominal pain and vomiting. He was admitted to the surgical ward 2 days later, after reattending. A CT scan revealed wall thickening and oedema in the transverse colon. This was supported by a subsequent CT virtual colonoscopy which raised the suspicion of neoplasia. A follow-up colonoscopy was not carried further than the transverse colon due to an indurated, tight stricture. Biopsies from that area showed ulceration and inflammatory changes non-specific for ischaemia, drug-induced changes or inflammatory bowel disease. As a consequence of the subocclusive symptoms and the possibility of a neoplastic diagnosis, a laparoscopic-assisted transverse colectomy was performed. The histology of the resected segment revealed post-traumatic inflammation and fibrosis with no evidence of neoplasia. PMID:23975915

  14. A focus on intra-abdominal infections

    PubMed Central

    2010-01-01

    Complicated intra-abdominal infections are an important cause of morbidity and are frequently associated with poor prognosis, particularly in higher risk patients. Well defined evidence-based recommendations for intra-abdominal infections treatment are partially lacking because of the limited number of randomized-controlled trials. Factors consistently associated with poor outcomes in patients with intra-abdominal infections include increased illness severity, failed source control, inadequate empiric antimicrobial therapy and healthcare-acquired infection. Early prognostic evaluation of complicated intra-abdominal infections is important to select high-risk patients for more aggressive therapeutic procedures. The cornerstones in the management of complicated intra-abdominal infections are both source control and antibiotic therapy. The timing and the adequacy of source control are the most important issues in the management of intra-abdominal infections, because inadequate and late control of septic source may have a negative effect on the outcomes. Recent advances in interventional and more aggressive techniques could significantly decrease the morbidity and mortality of physiologically severe complicated intra-abdominal infections, even if these are still being debated and are yet not validated by limited prospective trials. Empiric antimicrobial therapy is nevertheless important in the overall management of intra-abdominal infections. Inappropriate antibiotic therapy may result in poor patient outcomes and in the appearance of bacterial resistance. Antimicrobial management is generally standardised and many regimens, either with monotherapy or combination therapy, have proven their efficacy. Routine coverage especially against Enterococci and candida spp is not always recommended, but can be useful in particular clinical conditions. A de escalation approach may be recommended in patients with specific risk factors for multidrug resistant infections such as immunodeficiency and prolonged antibacterial exposure. Therapy should focus on the obtainment of adequate source control and adequate use of antimicrobial therapy dictated by individual patient risk factors. Other critical issues remain debated and more controversies are still open mainly because of the limited number of randomized controlled trials. PMID:20302628

  15. Computed tomography of the postoperative abdominal aorta

    SciTech Connect

    Hilton, S.; Megibow, A.J.; Naidich, D.P.; Bosniak, M.A.

    1982-11-01

    Computed tomography (CT) of the abdomen was performed on 46 patients who had undergone graft replacement of abdominal aortic aneurysms. Twelve post-operative complications were found in nine patients. They included hemorrhage, infection, anastomotic pseudoaneurysms, major vessel occlusion, postoperative pancreatitis, and others. The varied apperance of the normal postoperative graft is also presented. It is concluded that CT is a rapid, sensitive, and noninvasive method for detecting or excluding postoperative complications of abdominal aortic surgery.

  16. Cave Walls

    USGS Multimedia Gallery

    A cave wall showing several cave formations, or speleothems. The larger formations at the bottom formed submerged in water, whereas the smaller formations at the top were exposed to air when they formed....

  17. Factors associated with abdominal obesity in children

    PubMed Central

    Melzer, Matheus Ribeiro Theodósio Fernandes; Magrini, Isabella Mastrangi; Domene, Semíramis Martins Álvares; Martins, Paula Andrea

    2015-01-01

    Objective: To identify the association of dietary, socioeconomic factors, sedentary behaviors and maternal nutritional status with abdominal obesity in children. Methods: A cross-sectional study with household-based survey, in 36 randomly selected census tracts in the city of Santos, SP. 357 families were interviewed and questionnaires and anthropometric measurements were applied in mothers and their 3-10 years-old children. Assessment of abdominal obesity was made by maternal and child's waist circumference measurement; for classification used cut-off points proposed by World Health Organization (1998) and Taylor et al. (2000) were applied. The association between variables was performed by multiple logistic regression analysis. Results: 30.5% of children had abdominal obesity. Associations with children's and maternal nutritional status and high socioeconomic status were shown in the univariate analysis. In the regression model, children's body mass index for age (OR=93.7; 95%CI 39.3-223.3), female gender (OR=4.1; 95%CI 1.8-9.3) and maternal abdominal obesity (OR=2.7; 95%CI 1.2-6.0) were significantly associated with children's abdominal obesity, regardless of the socioeconomic status. Conclusions: Abdominal obesity in children seems to be associated with maternal nutritional status, other indicators of their own nutritional status and female gender. Intervention programs for control of childhood obesity and prevention of metabolic syndrome should consider the interaction of the nutritional status of mothers and their children. PMID:26298655

  18. Influence of surrounding tissues on biomechanics of aortic wall.

    PubMed

    Kim, Jungsil; Peruski, Brooke; Hunley, Chris; Kwon, Sebastian; Baek, Seungik

    2013-09-01

    The present study investigates effects of surrounding tissues and non-uniform wall thickness on the biomechanics of the thoracic aorta. We construct two idealised computational models exemplifying the importance of surrounding tissues and non-uniform wall thickness, namely the uniform-thickness model and the histology image-based model. While the former neglects a connective tissue layer surrounding the aorta, the latter takes it into account with non-uniform wall thickness. Using plane strain finite element analysis, stress distributions in the aortic media between the two models are compared. The histology image-based model substantially enhances the uniformity of stress throughout the aortic media. Furthermore, the altered mechanical properties of surrounding tissues change the stress distribution. These results suggest that surrounding tissues and non-uniform wall thickness should be included in biomechanical analysis to better understand regional adaptation of the aortic wall during normal physiological conditions or pathological conditions such as aortic aneurysms and dissections. PMID:25031610

  19. Body mass normalisation for ultrasound measurements of lumbar multifidus and abdominal muscle size.

    PubMed

    Nuzzo, James L; Mayer, John M

    2013-06-01

    The purpose of this study was to determine if ratio scaling or allometric scaling is the more appropriate method for normalising ultrasound measurements of lumbar multifidus and abdominal muscle size to body mass. In a convenience sample of 62 male career firefighters, cross-sectional area and thickness of the lumbar multifidus, as well as, thicknesses of the external oblique, internal oblique, and transverse abdominal muscles were assessed with ultrasonography. Ratio scaling entailed dividing muscle size by body mass, while allometric scaling entailed dividing muscle size by body mass raised to a power. Significant positive correlations (r = 0.25 to 0.49, p < 0.05) existed between body mass and all muscle size measurements, except for transverse abdominal thickness (r = 0.21, p = 0.100). Ratio scaling was deemed inappropriate for normalising the muscle size measurements, because it merely reversed the direction of the correlations between body mass and the muscle size measurements (r = -0.31 to -0.50, p < 0.05), with external oblique abdominal thickness representing the only exception (r = -0.17, p = 0.192). Allometric scaling with derived allometric parameters was deemed appropriate for normalising muscle size measurements, because it caused the correlations between body mass and muscle size to become insignificant and near to zero (r = -0.06 to 0.00, p > 0.05). The current study provides allometric parameters that can be used to normalise muscle size measurements to body mass in male firefighters. Future research is needed to establish reference databases of population-specific allometric parameters in other groups. PMID:23149061

  20. Ultrasound evaluation of the symmetry of abdominal muscles in mild adolescent idiopathic scoliosis

    PubMed Central

    Linek, Pawe?; Saulicz, Edward; Wolny, Tomasz; My?liwiec, Andrzej; Gogola, Anna

    2015-01-01

    [Purpose] The objective of the study was to evaluate the symmetry of the thickness of the abdominal muscles at rest and while standing in patients with adolescent idiopathic scoliosis. [Subjects and Methods] An ultrasound assessment was performed of the side-to-side differences of the external oblique (EO), internal oblique (IO), and transversus abdominalis (TrA) muscles in the supine and standing positions in adolescent idiopathic scoliosis (AIS) and control groups. [Results] In the AIS group, 64.3% of the patients had left scoliosis with a mean Cobb angle of 10.7°, and 35.7% of the patients had right scoliosis with a mean Cobb angle of 10°. In the supine position, the thickness asymmetry of the TrA was greater in the AIS compared with the control group by an average of 14% (95% CI 3.9–24.2). [Conclusion] Among the abdominal muscles examined, patients with AIS exhibited more asymmetry only for the TrA. In the standing position, the TrA was as symmetric in the patients as in the control group. Mild scoliosis has no impact on the symmetry of the thickness of the OE and OI in the supine and standing positions. The direction of curvature had no effect on the symmetry of the abdominal muscles studied. PMID:25729192

  1. Nondestructive testing of welds on thin-walled tubing

    NASA Technical Reports Server (NTRS)

    Hagemaier, D. J.; Posakony, G. J.

    1969-01-01

    Special ultrasonic search unit, or transducer assembly, reliably inspects the quality of melt-through welds of fusion welded tubing couplers for hydraulic lines. This instrumentation can also be used to detect faulty braze bonds in thin-walled, small diameter joints and wall thickness of thin-walled metal tubing.

  2. Thick film hydrogen sensor

    DOEpatents

    Hoffheins, B.S.; Lauf, R.J.

    1995-09-19

    A thick film hydrogen sensor element includes an essentially inert, electrically-insulating substrate having deposited thereon a thick film metallization forming at least two resistors. The metallization is a sintered composition of Pd and a sinterable binder such as glass frit. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors. 8 figs.

  3. Education and "Thick" Epistemology

    ERIC Educational Resources Information Center

    Kotzee, Ben

    2011-01-01

    In this essay Ben Kotzee addresses the implications of Bernard Williams's distinction between "thick" and "thin" concepts in ethics for epistemology and for education. Kotzee holds that, as in the case of ethics, one may distinguish between "thick" and "thin" concepts of epistemology and, further, that this distinction points to the importance of…

  4. Ballistic Limit Equation for Single Wall Titanium

    NASA Technical Reports Server (NTRS)

    Ratliff, J. M.; Christiansen, Eric L.; Bryant, C.

    2009-01-01

    Hypervelocity impact tests and hydrocode simulations were used to determine the ballistic limit equation (BLE) for perforation of a titanium wall, as a function of wall thickness. Two titanium alloys were considered, and separate BLEs were derived for each. Tested wall thicknesses ranged from 0.5mm to 2.0mm. The single-wall damage equation of Cour-Palais [ref. 1] was used to analyze the Ti wall's shielding effectiveness. It was concluded that the Cour-Palais single-wall equation produced a non-conservative prediction of the ballistic limit for the Ti shield. The inaccurate prediction was not a particularly surprising result; the Cour-Palais single-wall BLE contains shield material properties as parameters, but it was formulated only from tests of different aluminum alloys. Single-wall Ti shield tests were run (thicknesses of 2.0 mm, 1.5 mm, 1.0 mm, and 0.5 mm) on Ti 15-3-3-3 material custom cut from rod stock. Hypervelocity impact (HVI) tests were used to establish the failure threshold empirically, using the additional constraint that the damage scales with impact energy, as was indicated by hydrocode simulations. The criterion for shield failure was defined as no detached spall from the shield back surface during HVI. Based on the test results, which confirmed an approximately energy-dependent shield effectiveness, the Cour-Palais equation was modified.

  5. 'Stucco' Walls

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This projected mosaic image, taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity 's instrument deployment device, or 'arm,' shows the partial clotting or cement-like properties of the sand-sized grains within the trench wall. The area in this image measures approximately 3 centimeters (1.2 inches) wide and 5 centimeters (2 inches) tall.(This image also appears as an inset on a separate image from the rover's navigation camera, showing the location of this particular spot within the trench wall.)

  6. Abdominal sarcoidosis: cross-sectional imaging findings.

    PubMed

    Gezer, Naciye Sinem; Ba?ara, I??l; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%-70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  7. Segmentation of images of abdominal organs.

    PubMed

    Wu, Jie; Kamath, Markad V; Noseworthy, Michael D; Boylan, Colm; Poehlman, Skip

    2008-01-01

    Abdominal organ segmentation, which is, the delineation of organ areas in the abdomen, plays an important role in the process of radiological evaluation. Attempts to automate segmentation of abdominal organs will aid radiologists who are required to view thousands of images daily. This review outlines the current state-of-the-art semi-automated and automated methods used to segment abdominal organ regions from computed tomography (CT), magnetic resonance imaging (MEI), and ultrasound images. Segmentation methods generally fall into three categories: pixel based, region based and boundary tracing. While pixel-based methods classify each individual pixel, region-based methods identify regions with similar properties. Boundary tracing is accomplished by a model of the image boundary. This paper evaluates the effectiveness of the above algorithms with an emphasis on their advantages and disadvantages for abdominal organ segmentation. Several evaluation metrics that compare machine-based segmentation with that of an expert (radiologist) are identified and examined. Finally, features based on intensity as well as the texture of a small region around a pixel are explored. This review concludes with a discussion of possible future trends for abdominal organ segmentation. PMID:20092428

  8. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Ba?ara, I??l; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  9. Possible Dual Role of Decorin in Abdominal Aortic Aneurysm

    PubMed Central

    Ueda, Koshiro; Yoshimura, Koichi; Yamashita, Osamu; Harada, Takasuke; Morikage, Noriyasu; Hamano, Kimikazu

    2015-01-01

    Abdominal aortic aneurysm (AAA) is characterized by chronic inflammation, which leads to pathological remodeling of the extracellular matrix. Decorin, a small leucine-rich repeat proteoglycan, has been suggested to regulate inflammation and stabilize the extracellular matrix. Therefore, the present study investigated the role of decorin in the pathogenesis of AAA. Decorin was localized in the aortic adventitia under normal conditions in both mice and humans. AAA was induced in mice using CaCl2 treatment. Initially, decorin protein levels decreased, but as AAA progressed decorin levels increased in all layers. Local administration of exogenous decorin prevented the development of CaCl2-induced AAA. However, decorin was highly expressed in the degenerative lesions of human AAA walls, and this expression positively correlated with matrix metalloproteinase (MMP)-9 expression. In cell culture experiments, the addition of decorin inhibited secretion of MMP-9 in vascular smooth muscle cells, but had the opposite effect in macrophages. The results suggest that decorin plays a dual role in AAA. Adventitial decorin in normal aorta may protect against the development of AAA, but macrophages expressing decorin in AAA walls may facilitate the progression of AAA by up-regulating MMP-9 secretion. PMID:25781946

  10. Mechanical platelet activation potential in abdominal aortic aneurysms.

    PubMed

    Hansen, Kirk B; Arzani, Amirhossein; Shadden, Shawn C

    2015-04-01

    Intraluminal thrombus (ILT) in abdominal aortic aneurysms (AAA) has potential implications to aneurysm growth and rupture risk; yet, the mechanisms underlying its development remain poorly understood. Some researchers have proposed that ILT development may be driven by biomechanical platelet activation within the AAA, followed by adhesion in regions of low wall shear stress. Studies have investigated wall shear stress levels within AAA, but platelet activation potential (AP) has not been quantified. In this study, patient-specific computational fluid dynamic (CFD) models were used to analyze stress-induced AP within AAA under rest and exercise flow conditions. The analysis was conducted using Lagrangian particle-based and Eulerian continuum-based approaches, and the results were compared. Results indicated that biomechanical platelet activation is unlikely to play a significant role for the conditions considered. No consistent trend was observed in comparing rest and exercise conditions, but the functional dependence of AP on stress magnitude and exposure time can have a large impact on absolute levels of anticipated platelet AP. The Lagrangian method obtained higher peak AP values, although this difference was limited to a small percentage of particles that falls below reported levels of physiologic background platelet activation. PMID:25588057

  11. Wall Art

    ERIC Educational Resources Information Center

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  12. Abdominal Sarcoidosis May Mimic Peritoneal Carcinomatosis

    PubMed Central

    Gorkem, Umit; Gungor, Tayfun; Bas, Y?lmaz; Togrul, Cihan

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disorder of unknown etiology. It shows a great variety of clinical presentation, organ involvement, and disease progression. Lungs and lymphoid system are the most common sites involved with a frequency of 90% and 30%, respectively. Extrapulmonary involvement of sarcoidosis is reported in 30% of patients and abdomen is the most frequent site. Furthermore, peritoneal involvement is extremely rare in sarcoidosis. The case presented here described peritoneal manifestations of sarcoidosis without involvement of lungs. A 78-year-old woman possessing signs of malignancy on blood test and abdominal magnetic resonance imaging underwent laparatomy with a suspicion of ovarian malignancy. The macroscopic interpretation during surgery was peritoneal carcinomatosis. Total abdominal hysterectomy, bilateral salpingo-oophorectomy, peritoneal biopsies, total omentectomy, and appendectomy were performed. Final histopathological result revealed the diagnosis of sarcoidosis. Clinicians must keep in mind that peritoneal sarcoidosis can mimic intra-abdominal malignancies. PMID:26558122

  13. An animal-specific FSI model of the abdominal aorta in anesthetized mice.

    PubMed

    Trachet, Bram; Bols, Joris; Degroote, Joris; Verhegghe, Benedict; Stergiopulos, Nikolaos; Vierendeels, Jan; Segers, Patrick

    2015-06-01

    Recent research has revealed that angiotensin II-induced abdominal aortic aneurysm in mice can be related to medial ruptures occurring in the vicinity of abdominal side branches. Nevertheless a thorough understanding of the biomechanics near abdominal side branches in mice is lacking. In the current work we present a mouse-specific fluid-structure interaction (FSI) model of the abdominal aorta in ApoE(-/-) mice that incorporates in vivo stresses. The aortic geometry was based on contrast-enhanced in vivo micro-CT images, while aortic flow boundary conditions and material model parameters were based on in vivo high-frequency ultrasound. Flow waveforms predicted by FSI simulations corresponded better to in vivo measurements than those from CFD simulations. Peak-systolic principal stresses at the inner and outer aortic wall were locally increased caudal to the celiac and left lateral to the celiac and mesenteric arteries. Interestingly, these were also the locations at which a tear in the tunica media had been observed in previous work on angiotensin II-infused mice. Our preliminary results therefore suggest that local biomechanics play an important role in the pathophysiology of branch-related ruptures in angiotensin-II infused mice. More elaborate follow-up research is needed to demonstrate the role of biomechanics and mechanobiology in a longitudinal setting. PMID:25824368

  14. Development of the ventral body wall in the human embryo.

    PubMed

    Mekonen, Hayelom K; Hikspoors, Jill P J M; Mommen, Greet; Köhler, S Eleonore; Lamers, Wouter H

    2015-11-01

    Migratory failure of somitic cells is the commonest explanation for ventral body wall defects. However, the embryo increases ~ 25-fold in volume in the period that the ventral body wall forms, so that differential growth may, instead, account for the observed changes in topography. Human embryos between 4 and 10 weeks of development were studied, using amira(®) reconstruction and cinema 4D(®) remodeling software for visualization. Initially, vertebrae and ribs had formed medially, and primordia of sternum and hypaxial flank muscle primordium laterally in the body wall at Carnegie Stage (CS)15 (5.5 weeks). The next week, ribs and muscle primordium expanded in ventrolateral direction only. At CS18 (6.5 weeks), separate intercostal and abdominal wall muscles differentiated, and ribs, sterna, and muscles began to expand ventromedially and caudally, with the bilateral sternal bars fusing in the midline after CS20 (7 weeks) and the rectus muscles reaching the umbilicus at CS23 (8 weeks). The near-constant absolute distance between both rectus muscles and approximately fivefold decline of this distance relative to body circumference between 6 and 10 weeks identified dorsoventral growth in the dorsal body wall as determinant of the 'closure' of the ventral body wall. Concomitant with the straightening of the embryonic body axis after the 6th week, the abdominal muscles expanded ventrally and caudally to form the infraumbilical body wall. Our data, therefore, show that the ventral body wall is formed by differential dorsoventral growth in the dorsal part of the body. PMID:26467243

  15. Fillability of Thin-Wall Steel Castings

    SciTech Connect

    Robert C. Voigt; Joseph Bertoletti; Andrew Kaley; Sandi Ricotta; Travis Sunday

    2002-07-30

    The use of steel components is being challenged by lighter nonferrous or cast iron components. The development of techniques for enhancing and ensuring the filability of thin-wall mold cavities is most critical for thinner wall cast steel production. The purpose of this research was to develop thin-wall casting techniques that can be used to reliably produce thin-wall castings from traditional gravity poured sand casting processes. The focus of the research was to enhance the filling behavior to prevent misrunds. Experiments were conducted to investigate the influence of various foundry variables on the filling of thin section steel castings. These variables include casting design, heat transfer, gating design, and metal fluidity. Wall thickness and pouring temperature have the greatest effect on casting fill. As wall thickness increases the volume to surface area of the casting increases, which increases the solidification time, allowing the metal to flow further in thicker sect ions. Pouring time is another significant variable affecting casting fill. Increases or decreases of 20% in the pouring time were found to have a significant effect on the filling of thin-wall production castings. Gating variables, including venting, pouring head height, and mold tilting also significantly affected thin-wall casting fill. Filters offer less turbulent, steadier flow, which is appropriate for thicker castings, but they do not enhance thin-wall casting fill.

  16. Imaging for chronic abdominal pain in adults

    PubMed Central

    Mendelson, Richard

    2015-01-01

    Summary Diagnostic imaging is often not indicated in chronic abdominal pain. In particular, undifferentiated abdominal pain is rarely an indication for a CT scan. CT scanning is overused even when imaging is required. Other modalities may be preferable. A normal CT scan does not rule out cancer. Alarm symptoms, including anaemia, blood in the stool, waking at night with gastrointestinal symptoms, and weight loss, should be investigated. The most appropriate modality depends on the symptoms. Clinical information on request forms for CT scans should be specific and include the suspected condition as this helps the radiologist to determine an appropriate imaging protocol. PMID:26648616

  17. Origami of thick panels

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-01

    Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures.

  18. Automated anatomical labeling method for abdominal arteries extracted from 3D abdominal CT images

    NASA Astrophysics Data System (ADS)

    Oda, Masahiro; Hoang, Bui Huy; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Mori, Kensaku

    2012-02-01

    This paper presents an automated anatomical labeling method of abdominal arteries. In abdominal surgery, understanding of blood vessel structure concerning with a target organ is very important. Branching pattern of blood vessels differs among individuals. It is required to develop a system that can assist understanding of a blood vessel structure and anatomical names of blood vessels of a patient. Previous anatomical labbeling methods for abdominal arteries deal with either of the upper or lower abdominal arteries. In this paper, we present an automated anatomical labeling method of both of the upper and lower abdominal arteries extracted from CT images. We obtain a tree structure of artery regions and calculate feature values for each branch. These feature values include the diameter, curvature, direction, and running vectors of a branch. Target arteries of this method are grouped based on branching conditions. The following processes are separately applied for each group. We compute candidate artery names by using classifiers that are trained to output artery names. A correction process of the candidate anatomical names based on the rule of majority is applied to determine final names. We applied the proposed method to 23 cases of 3D abdominal CT images. Experimental results showed that the proposed method is able to perform nomenclature of entire major abdominal arteries. The recall and the precision rates of labeling are 79.01% and 80.41%, respectively.

  19. Fluid, solid and fluid-structure interaction simulations on patient-based abdominal aortic aneurysm models.

    PubMed

    Kelly, Sinead; O'Rourke, Malachy

    2012-04-01

    This article describes the use of fluid, solid and fluid-structure interaction simulations on three patient-based abdominal aortic aneurysm geometries. All simulations were carried out using OpenFOAM, which uses the finite volume method to solve both fluid and solid equations. Initially a fluid-only simulation was carried out on a single patient-based geometry and results from this simulation were compared with experimental results. There was good qualitative and quantitative agreement between the experimental and numerical results, suggesting that OpenFOAM is capable of predicting the main features of unsteady flow through a complex patient-based abdominal aortic aneurysm geometry. The intraluminal thrombus and arterial wall were then included, and solid stress and fluid-structure interaction simulations were performed on this, and two other patient-based abdominal aortic aneurysm geometries. It was found that the solid stress simulations resulted in an under-estimation of the maximum stress by up to 5.9% when compared with the fluid-structure interaction simulations. In the fluid-structure interaction simulations, flow induced pressure within the aneurysm was found to be up to 4.8% higher than the value of peak systolic pressure imposed in the solid stress simulations, which is likely to be the cause of the variation in the stress results. In comparing the results from the initial fluid-only simulation with results from the fluid-structure interaction simulation on the same patient, it was found that wall shear stress values varied by up to 35% between the two simulation methods. It was concluded that solid stress simulations are adequate to predict the maximum stress in an aneurysm wall, while fluid-structure interaction simulations should be performed if accurate prediction of the fluid wall shear stress is necessary. Therefore, the decision to perform fluid-structure interaction simulations should be based on the particular variables of interest in a given study. PMID:22611869

  20. Pulse wave velocity and age- and gender-dependent aortic wall hardening in fowl

    PubMed Central

    Ruiz-Feria, Ciro A.; Yang, Yimu; Thomason, Donald B.; White, Jarred; Su, Guibin; Nishimura, Hiroko

    2009-01-01

    Before sexual maturation, chickens (Gallus gallus) show high blood pressure (BP) and neointimal plaques in the lower abdominal aortae (AbA). We investigated age/sex-related changes in pulse wave velocity (PWV), elastin, collagen, and protein levels in AbA, and cardiac morphology to determine whether PWV increases during incremental increases in BP of maturing fowl, while arterial stiffness becomes dominant with aging. PWV (m/s) was significantly greater in male chicks (6-7 wk, 9.3 ± 0.8; females, 6.1 ± 0.5) and remained high in cockerels (13 wk), young (27-28 wk), and adults (44-66 wk). PWV increased in prepubertal pullets (10.0 ± 0.9), dropped significantly in young hens, and remained low in adults. In contrast, medial thickness, protein levels, and collagen levels increased, while elastin/collagen ratios decreased, with maturation/aging. Males had heavier ventricular mass and thicker ventricular walls than females at all ages; left ventricular thickness decreased with maturation/aging. Thus, sustained high BP may have caused progressive medial hypertrophy, increased aortic rigidity, and enlarged hearts with left ventricular dilation. PWV of AbA was already greater in male chicks at an age when both sexes have similar collagen levels and low protein levels, suggesting that a factor other than structural stiffness may be an important determinant of PWV. PMID:19689927

  1. 49 CFR 179.500-4 - Thickness of wall.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...by direct measurement to an accuracy of 0.001 inch. Take D = d + 2t. Calculate the value of (D 2 ?d2 )/(D 2 + d2 ) (1) Make similar measurements and calculation for a corresponding location at the other end of the...

  2. Thick hollow cylindrical waveguides: A theoretical, numerical and experimental study

    NASA Astrophysics Data System (ADS)

    Ziaja, Aleksandra; Cheng, Li; Su, Zhongqing; Packo, Pawel; Pieczonka, Lukasz; Uhl, Tadeusz; Staszewski, Wieslaw

    2015-08-01

    The paper investigates elastic waves guided by thick-walled, hollow cylindrical structures. Theoretical, numerical and experimental investigations are presented to facilitate understanding of various wave propagation phenomena in thick-walled cylinders for potential damage detection applications. Semi-analytical analysis of dispersion characteristics is performed, revealing a repetitive pattern of coupled pairs of higher-order longitudinal modes. This behaviour is found to be analogue to terrace-like structures formed by interlacing high-frequency symmetric and antisymmetric plate mode curves. A hyperbolic behaviour of curves and modeshape transitions is observed due to mode coupling. The work presented demonstrates analytically how solutions for a thick-walled hollow cylinder correspond to the Lamb wave theory. The relevant pseudo-symmetry relations for mode displacement patterns are obtained using asymptotic approximations of Bessel functions. Theoretical solutions of dispersion characteristics are compared with numerical simulations that are based on the local interaction simulation approach. The results are validated experimentally using laser vibrometry.

  3. OCT assessment of aortic wall degradation for surgical guidance

    NASA Astrophysics Data System (ADS)

    Real, E.; Val-Bernal, J. F.; Pontón, A.; Calvo Díez, M.; Mayorga, M.; Revuelta, J. M.; López-Higuera, J. M.; Conde, O. M.

    2014-05-01

    The degradation of the wall in large cardiovascular vessels, such as the aorta artery, induces weakness in the vessel that can lead to the formation of aneurysms and the rupture of the vessel. Characterization of the wall integrity is assessed by OCT for future intraoperative assistance in aneurysm graft surgery interventions. Optical Coherence Tomography (OCT) provides cross sectional images of the wall of the aortic media layer. Wall degradations appear as spatial anomalies in the reflectivity profile through the wall thickness. Wall degradation assessment is proposed by automatic identification and dimensioning of these anomalies within the homogeneous surrounding tissue.

  4. Immersive virtual reality for visualization of abdominal CT

    NASA Astrophysics Data System (ADS)

    Lin, Qiufeng; Xu, Zhoubing; Li, Bo; Baucom, Rebeccah; Poulose, Benjamin; Landman, Bennett A.; Bodenheimer, Robert E.

    2013-03-01

    Immersive virtual environments use a stereoscopic head-mounted display and data glove to create high fidelity virtual experiences in which users can interact with three-dimensional models and perceive relationships at their true scale. This stands in stark contrast to traditional PACS-based infrastructure in which images are viewed as stacks of two dimensional slices, or, at best, disembodied renderings. Although there has substantial innovation in immersive virtual environments for entertainment and consumer media, these technologies have not been widely applied in clinical applications. Here, we consider potential applications of immersive virtual environments for ventral hernia patients with abdominal computed tomography imaging data. Nearly a half million ventral hernias occur in the United States each year, and hernia repair is the most commonly performed general surgery operation worldwide. A significant problem in these conditions is communicating the urgency, degree of severity, and impact of a hernia (and potential repair) on patient quality of life. Hernias are defined by ruptures in the abdominal wall (i.e., the absence of healthy tissues) rather than a growth (e.g., cancer); therefore, understanding a hernia necessitates understanding the entire abdomen. Our environment allows surgeons and patients to view body scans at scale and interact with these virtual models using a data glove. This visualization and interaction allows users to perceive the relationship between physical structures and medical imaging data. The system provides close integration of PACS-based CT data with immersive virtual environments and creates opportunities to study and optimize interfaces for patient communication, operative planning, and medical education.

  5. ABDOMINAL OBESITY, MUSCLE COMPOSITION, AND INSULIN RESISTANCE IN PREMENOPAUSAL WOMEN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The independent relationships between visceral and abdominal subcutaneous adipose tissue (AT) depots, muscle composition, and insulin sensitivity were examined in 40 abdominally obese, premenopausal women. Measurements included glucose disposal by euglycemic clamp, muscle composition by computed to...

  6. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...abdominal decompression chamber is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

  7. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...abdominal decompression chamber is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

  8. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...abdominal decompression chamber is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

  9. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...abdominal decompression chamber is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

  10. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...abdominal decompression chamber is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

  11. Abdominal cocoon: a unique presentation in an immunodeficient infant.

    PubMed

    Browne, Lorna P; Patel, Jigar; Guillerman, R Paul; Hanson, Imelda C; Cass, Darrell L

    2012-02-01

    Abdominal cocoon is a rare disorder that may pose a diagnostic conundrum in patients presenting with intermittent symptoms of small bowel obstruction. We describe the imaging findings of a unique case of abdominal cocoon that presented in infancy. PMID:21713442

  12. Rehabilitative ultrasound imaging of the abdominal muscles.

    PubMed

    Teyhen, Deydre S; Gill, Norman W; Whittaker, Jackie L; Henry, Sharon M; Hides, Julie A; Hodges, Paul

    2007-08-01

    Rehabilitative ultrasound imaging (RUSI) of the abdominal muscles is increasingly being used in the management of conditions involving musculoskeletal dysfunctions associated with the abdominal muscles, including certain types of low back and pelvic pain. This commentary provides an overview of current concepts and evidence related to RUSI of the abdominal musculature, including issues addressing the potential role of ultrasound imaging in the assessment and training of these muscles. Both quantitative and qualitative aspects associated with clinical and research applications are considered, as are the possible limitations related to the interpretation of measurements made with RUSI. Research to date has utilized a range of methodological approaches, including different transducer placements and imaging techniques. The pros and cons of the various methods are discussed, and guidelines for future investigations are presented. Potential implications and opportunities for clinical use of RUSI to enhance evidence-based practice are outlined, as are suggestions for future research to further clarify the possible role of RUSI in the evaluation and treatment of abdominal muscular morphology and function. PMID:17877281

  13. Association of Abdominal Obesity with Lumbar Disc Degeneration – A Magnetic Resonance Imaging Study

    PubMed Central

    Takatalo, Jani; Karppinen, Jaro; Taimela, Simo; Niinimäki, Jaakko; Laitinen, Jaana; Sequeiros, Roberto Blanco; Samartzis, Dino; Korpelainen, Raija; Näyhä, Simo; Remes, Jouko; Tervonen, Osmo

    2013-01-01

    Purpose To evaluate whether midsagittal (abdominal) obesity in magnetic resonance imaging (MRI), waist circumference (WC) and body fat percentage are associated with lumbar disc degeneration in early adulthood. Methods We obtained the lumbar MRI (1.5-T scanner) of 325 females and 233 males at a mean age of 21 years. Lumbar disc degeneration was evaluated using Pfirrmann classification. We analysed the associations of MRI measures of obesity (abdominal diameter (AD), sagittal diameter (SAD), ventral subcutaneous thickness (VST), and dorsal subcutaneous thickness (DST)), WC and body fat percentage with disc degeneration sum scores using ordinal logistic regression. Results A total of 155 (48%) females and 147 (63%) males had disc degeneration. AD and SAD were associated with a disc degeneration sum score of ?3 compared to disc degeneration sum score of 0–2 (OR 1.67; 95% confidence interval (CI) 1.20–2.33 and OR 1.40; 95% CI 1.12–1.75, respectively) among males, but we found no association among females. WC was also associated with disc degeneration among males (OR 1.03 per one cm; 95% CI 1.00–1.05), but not among females. Conclusion Measures of abdominal obesity in MRI and waist circumference were associated with disc degeneration among 21-year-old males. PMID:23418543

  14. Hypoperfusion of the Adventitial Vasa Vasorum Develops an Abdominal Aortic Aneurysm

    PubMed Central

    Sasaki, Takeshi; Sano, Masaki; Yamamoto, Naoto; Saito, Takaaki; Inuzuka, Kazunori; Hayasaka, Takahiro; Goto-Inoue, Naoko; Sugiura, Yuki; Sato, Kohji; Kugo, Hirona; Moriyama, Tatsuya; Konno, Hiroyuki; Setou, Mitsutoshi; Unno, Naoki

    2015-01-01

    The aortic wall is perfused by the adventitial vasa vasorum (VV). Tissue hypoxia has previously been observed as a manifestation of enlarged abdominal aortic aneurysms (AAAs). We sought to determine whether hypoperfusion of the adventitial VV could develop AAAs. We created a novel animal model of adventitial VV hypoperfusion with a combination of a polyurethane catheter insertion and a suture ligation of the infrarenal abdominal aorta in rats. VV hypoperfusion caused tissue hypoxia and developed infrarenal AAA, which had similar morphological and pathological characteristics to human AAA. In human AAA tissue, the adventitial VV were stenotic in both small AAAs (30–49 mm in diameter) and in large AAAs (> 50 mm in diameter), with the sac tissue in these AAAs being ischemic and hypoxic. These results indicate that hypoperfusion of adventitial VV has critical effects on the development of infrarenal AAA. PMID:26308526

  15. Mycotic Saccular Abdominal Aortic Aneurysm in an Infant after Cardiac Catheterization: A Case Report.

    PubMed

    Benrashid, Ehsan; McCoy, Christopher C; Rice, Henry E; Shortell, Cynthia K; Cox, Mitchell W

    2015-10-01

    Abdominal aortic aneurysms (AAAs) are a rare entity in the pediatric population. Children with mycotic (infectious) AAA in particular are at risk of life-threatening rupture due to their rapid expansion coupled with aortic wall thinning and deterioration. Here, we present the case of a 10-month-old infant with prior 2-staged repair for hypoplastic left heart syndrome that was incidentally discovered to have a mycotic AAA on abdominal ultrasound (US) for evaluation of renovascular hypertension. Before the time of evaluation with US, the infant had developed methicillin-resistant Staphylococcus aureus bacteremia 3 days after cardiac catheterization with percutaneous thoracic aortic balloon angioplasty. She had normal aortic contours on contrasted computed tomography scan of the abdomen approximately 2 weeks before the aforementioned US evaluation. This infant subsequently underwent open aneurysmorrhaphy with cryopreserved vein patch angioplasty with resolution of her aneurysmal segment. PMID:26115611

  16. IVC Filter Perforation through the Duodenum Found after Years of Abdominal Pain

    PubMed Central

    Jehangir, Asad; Rettew, Andrew; Shaikh, Bilal; Bennett, Kyle; Jehangir, Qasim; Qureshi, Anam; Arshad, Sharjeel; Spiegel, Adam

    2015-01-01

    Patient: Female, 67 Final Diagnosis: IVC filter perforation through duodenum Symptoms: Abdominal pain Medication: — Clinical Procedure: Esophagogastroduodenoscopy Specialty: Gastroenterology and Hepatology Objective: Challenging differential diagnosis Background: The number of IVC filter-related complications has increased with their growing utilization; however, IVC filter perforation of the duodenum is rare. It can manifest with nonspecific abdominal pain, gastrointestinal bleeding, cava-duodenal fistula, or small bowel obstruction. Case Report: A 67-year-old female presented with several years of right upper quadrant abdominal pain which was exacerbated by movement and food intake. She had a history of hepatic steatosis, cholecystectomy, and multiple DVTs with inferior vena cava filter placement. Physical exam was unremarkable. Laboratory tests demonstrated elevated alkaline phosphatase and transaminases. Esophagogastroduodenoscopy revealed a thin metallic foreign body embedded in the duodenal wall and protruding into the duodenal lumen with surrounding erythema and edema, but no active hemorrhage. Further evaluation with non-contrast CT scan revealed that one of the prongs of her IVC filter had perforated through the vena cava wall into the adjacent duodenum. Exploratory laparotomy was required for removal of the IVC filter and repair of the vena cava and duodenum. Her post-operative course was uneventful. Conclusions: In patients with history of IVC filter placement with non-specific abdominal pain, a high clinical suspicion of IVC filter perforation of the duodenum should be raised, as diagnosis may be challenging. CT scan and EGD are valuable in the diagnosis. Excellent outcomes have been reported with open surgical filter removal. Low retrieval rates of IVC filters have led to increased complications; hence, early removal should be undertaken as clinically indicated. PMID:25979859

  17. Small bowell perforation and mesentery injury after an unusual blunt abdominal trauma–Case report

    PubMed Central

    Pimenta de Castro, J.; Gomes, G.; Mateus, N.; Escrevente, R.; Pereira, L.; Jácome, P.

    2014-01-01

    Introduction In blunt abdominal trauma, lesions of the small bowell and mesentery are often underdiagnosed; although unusual, they represent the third most injured organ, with increasing morbidity and mortality. Presentation of case The authors present the case of a 68 years old male, admitted to the emergency department after being hit by a bale of straw, weighing around 300 kg, in the abdomen. After successful ressuscitation, a CT scan was performed, suggesting hemoperitoneum because of vascular lesion of the right colon bleeding. An exploratory laparotomy was performed, confirming the presence of blood in the abdominal cavity and identifying jejunal perforation, an apparently innocent hematoma of the small bowel mesentery (beside the bowel wall) distally to the first lesion and a laceration of the sigmoid serosa; a segmental jejunal resection and suture of the colon serosa were performed. In the early post-operative period, an enteric discharge was noticed, mandating surgical reexploration; a previously unnoticed bowel perforation, in the mesenteric border where the hematoma was identified, justified an additional enterectomy, after what the patients recovery progressed uneventfully. Discussion In this case, a sudden increase in abdominal pressure could explain that missed rupture of the mesenteric border of the jejunum, also causing the mesenteric hematoma, or, in spite of that, a state of low perfusion could have lead to total wall ischemia of an already irrigation compromised segment. Only noted after surgical exploration, despite prior evaluation with a computed tomography. Small bowell and mesenteric injuries are potentially missed due to decreased exploratory laparotomies for blunt abdominal trauma. Conclusion Although uncommon, small bowel and mesenteric injuries are associated with high morbidity and mortality. High clinical suspicion is essential for an early diagnosis PMID:25576959

  18. 2013 WSES guidelines for management of intra-abdominal infections

    PubMed Central

    2013-01-01

    Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high. The 2013 update of the World Society of Emergency Surgery (WSES) guidelines for the management of intra-abdominal infections contains evidence-based recommendations for management of patients with intra-abdominal infections. PMID:23294512

  19. Relative Activity of Abdominal Muscles during Commonly Prescribed Strengthening Exercises.

    ERIC Educational Resources Information Center

    Willett, Gilbert M.; Hyde, Jennifer E.; Uhrlaub, Michael B.; Wendel, Cara L.; Karst, Gregory M.

    2001-01-01

    Examined the relative electromyographic (EMG) activity of upper and lower rectus abdominis (LRA) and external oblique (EOA) muscles during five abdominal strengthening exercises. Isometric and dynamic EMG data indicated that abdominal strengthening exercises activated various abdominal muscle groups. For the LRA and EOA muscle groups, there were…

  20. Diagnostic yield of oesophagogastroduodenoscopy in children with abdominal pain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abdominal pain is the most common indication for OGD in children. However, existing studies examining the diagnostic outcomes of OGD in children with abdominal pain are limited. We conducted the current study to examine the diagnostic yield of OGD with biopsy in the evaluation of abdominal pain and ...

  1. Thick DGP braneworlds

    SciTech Connect

    Quiros, Israel; Matos, Tonatiuh

    2008-11-15

    We study Dvali-Gabadadze-Porrati (DGP) braneworlds with finite thickness. In respect to the standard (thin) DGP Friedmann equation, finite thickness of the brane causes a subtle modification of the cosmological equations that can lead to significant physical consequences. The resulting cosmology is governed by two length scales which are associated with the brane thickness and with the crossover length, respectively. In this setup both early inflation and late-time acceleration of the expansion are a consequence of the 5D geometry. At early times, as well as at late times, 5D effects become dominant (gravity leaks into the extra dimension), while, at intermediate times, gravity is effectively 4D due to nontrivial physics occurring in standard (thin) DGP scenarios.

  2. Adaptive sound speed correction for abdominal ultrasonography: preliminary results

    NASA Astrophysics Data System (ADS)

    Jin, Sungmin; Kang, Jeeun; Song, Tai-Kyung; Yoo, Yangmo

    2013-03-01

    Ultrasonography has been conducting a critical role in assessing abdominal disorders due to its noninvasive, real-time, low cost, and deep penetrating capabilities. However, for imaging obese patients with a thick fat layer, it is challenging to achieve appropriate image quality with a conventional beamforming (CON) method due to phase aberration caused by the difference between sound speeds (e.g., 1580 and 1450m/s for liver and fat, respectively). For this, various sound speed correction (SSC) methods that estimate the accumulated sound speed for a region-of interest (ROI) have been previously proposed. However, with the SSC methods, the improvement in image quality was limited only for a specific depth of ROI. In this paper, we present the adaptive sound speed correction (ASSC) method, which can enhance the image quality for whole depths by using estimated sound speeds from two different depths in the lower layer. Since these accumulated sound speeds contain the respective contributions of layers, an optimal sound speed for each depth can be estimated by solving contribution equations. To evaluate the proposed method, the phantom study was conducted with pre-beamformed radio-frequency (RF) data acquired with a SonixTouch research package (Ultrasonix Corp., Canada) with linear and convex probes from the gel pad-stacked tissue mimicking phantom (Parker Lab. Inc., USA and Model539, ATS, USA) whose sound speeds are 1610 and 1450m/s, respectively. From the study, compared to the CON and SSC methods, the ASSC method showed the improved spatial resolution and information entropy contrast (IEC) for convex and linear array transducers, respectively. These results indicate that the ASSC method can be applied for enhancing image quality when imaging obese patients in abdominal ultrasonography.

  3. A diode for ferroelectric domain-wall motion

    PubMed Central

    Whyte, J.R.; Gregg, J.M.

    2015-01-01

    For over a decade, controlling domain-wall injection, motion and annihilation along nanowires has been the preserve of the nanomagnetics research community. Revolutionary technologies have resulted, like racetrack memory and domain-wall logic. Until recently, equivalent research in analogous ferroic materials did not seem important. However, with the discovery of sheet conduction, the control of domain walls in ferroelectrics has become vital for the future of what has been termed ‘domain-wall electronics'. Here we report the creation of a ferroelectric domain-wall diode, which allows a single direction of motion for all domain walls, irrespective of their polarity, under a series of alternating electric field pulses. The diode's sawtooth morphology is central to its function. Domain walls can move readily in the direction in which thickness increases gradually, but are prevented from moving in the other direction by the sudden thickness increase at the sawtooth edge. PMID:26059779

  4. A diode for ferroelectric domain-wall motion.

    PubMed

    Whyte, J R; Gregg, J M

    2015-01-01

    For over a decade, controlling domain-wall injection, motion and annihilation along nanowires has been the preserve of the nanomagnetics research community. Revolutionary technologies have resulted, like racetrack memory and domain-wall logic. Until recently, equivalent research in analogous ferroic materials did not seem important. However, with the discovery of sheet conduction, the control of domain walls in ferroelectrics has become vital for the future of what has been termed 'domain-wall electronics'. Here we report the creation of a ferroelectric domain-wall diode, which allows a single direction of motion for all domain walls, irrespective of their polarity, under a series of alternating electric field pulses. The diode's sawtooth morphology is central to its function. Domain walls can move readily in the direction in which thickness increases gradually, but are prevented from moving in the other direction by the sudden thickness increase at the sawtooth edge. PMID:26059779

  5. Fluid Characteristics in Abdominal Aortic Aneurysms (AAAs) and Its Correlation to Thrombus Formation

    NASA Astrophysics Data System (ADS)

    Tang, Rubing; Bar-Yoseph, Pinhas Z.; Lasheras, Juan

    2008-11-01

    It has been observed that most large Abdominal Aortic Aneurysms (AAAs) develop an intraluminal thrombus as they progressively enlarge. Previous studies have suggested that the build up of the thrombus may be associated with the altered hemodynamic patterns that arise inside the AAA. We have performed a parametrical computational study of the flow patterns inside enlarging AAA to investigate the possible mechanism controlling the thrombus formation. Pulsatile blood flows were simulated in idealized models of fusiform aneurysms with different dilatation ratios and the effects of shear-activated platelet accumulation and platelet/wall interaction were evaluated based on the calculated flow fields. The platelet activation level (PAL) was determined by computing the integral over time of flow shear stresses exerted over the platelets as they are transported throughout the aneurysm. Our results have shown that the values of PAL in AAAs are in fact smaller than the maximum value obtained in a healthy abdominal aorta. However, we show that the transportation of blood cells towards the wall and the formation of stagnation points on the aneurysm's wall play more significant roles in thrombus formation than PAL.

  6. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  7. Abdominal aortic aneurysms. Ultrasonic measurement of the transverse diameter and its prognostic significance in the light of pathological observations.

    PubMed Central

    McGregor, J. C.

    1977-01-01

    The risk of rupture of an abdominal aortic aneurysm is related to size. Pathological observations suggest that there is usually an asymmetric formation of mural thrombus in the aneurysm sac and that rupture occurs more commonly through the lateral walls where there would be less. Ultrasonic estimation of the transverse diameter of an aneurysm offers a useful clinical method of monitoring size and likelihood of rupture. Images Fig. 2 Fig. 3a Fig. 3b Fig. 4 PMID:604987

  8. Sclerosing encapsulating peritonitis (abdominal cocoon) associated with liver cirrhosis and diffuse large B-cell lymphoma: autopsy case.

    PubMed

    Yamada, Sohsuke; Tanimoto, Akihide; Matsuki, Yasumasa; Hisada, Yuji; Sasaguri, Yasuyuki

    2009-09-01

    A case of sclerosing encapsulating peritonitis (SEP) associated with liver cirrhosis (LC) and complicated by diffuse large B-cell lymphoma (DLBCL) is reported herein. A 49-year-old Japanese man had undergone peritoneo-venous shunt against refractory ascites due to hepatitis C virus-positive uncompensated LC for 2 years. After he received a diagnosis of DLBCL of the left neck lymph node 3 months before his death, palliative care was given because of his poor general condition. He developed severe abdominal distention and pain over 1 week and was found to have marked ascites and whole bowel lumped together on abdominal CT. At autopsy, the peritoneum was covered with a thick white membrane and the bowel could not be distinguished, which was macroscopically characterized by a cocoon-like appearance. Histology indicated a proliferation of diffusely thickened or hyalinized fibrocollagenous tissue in the entire peritoneum with a slight chronic inflammatory infiltrate and without remarkable change of mucosa. A diagnosis of SEP, also known as abdominal cocoon, was established based on these features. Additionally, in the abdominal cavity, a large amount of serous ascites and multiple peritoneal nodules or masses involved by DLBCL were recognized. To the authors' knowledge this is the first case report of SEP associated with LC and complicated by the invasion of DLBCL in the abdominal cavity. PMID:19712139

  9. Abdominal compartment syndrome after hip arthroscopy.

    PubMed

    Fowler, Justin; Owens, Brett D

    2010-01-01

    As hip arthroscopy becomes a more common procedure, more complications may occur. We present a case of abdominal compartment syndrome resulting from fluid extravasation in a 42-year-old man who underwent routine hip arthroscopy for femoral acetabular impingement. He had not had previous surgeries to that hip, and arthroscopy was performed in the supine position. After adequate distraction, arthroscopy was performed with an automated pressure- and flow-controlled pump with the pressure maintained between 40 and 60 mm Hg. We performed debridement of a degenerative tear of the anterosuperior labrum, removal of a pincer lesion, and a psoas tenotomy through a capsular window. A distended abdomen was noted on drape removal, and the patient required decompressive laparotomy for abdominal compartment syndrome. Extravasation of arthroscopy fluid is a potentially devastating complication during hip arthroscopy, and there should be careful monitoring by the surgeons, anesthesiologists, and operating room staff. PMID:20117637

  10. ["Arteriosclerotic" aneurysm of the abdominal aorta].

    PubMed

    Stein, S D; Baldi, T; Uthoff, H; Jäger, K A

    2010-09-01

    We present a patient with an aortic aneurysm and the epidemiology, etiology, screening, symptoms and therapeutic options of abdominal aortic aneurysms are discussed. A widening of the abdominal aorta >3 cm is termed aortic aneurysm. As patients with aortic aneurysm are mostly oligosymptomatic until rupture occurs and an estimated 30,000 patients annually die from ruptured aortic aneurysm in the US a screening of the population at greatest risk (smokers, familial predisposition) is recommended. Screening is best done by ultrasound. Noninvasive therapy is limited to antiplatelet therapy and optimal adjustment of risk factors. For definitive treatment endovascular aortic repair (EVAR) is considered an established alternative to open surgery with lower 30 days mortality but higher reintervention rate. PMID:20824610

  11. Color Doppler ultrasonography of the abdominal aorta

    PubMed Central

    Battaglia, S.; Danesino, G.M.; Danesino, V.; Castellani, S.

    2010-01-01

    Alterations of the abdominal aorta are relatively common, particularly in older people. Technological advances in the fields of ultrasonography, computed tomography, angiography, and magnetic resonance imaging have greatly increased the imaging options for the assessment of these lesions. Because it can be done rapidly and is also non-invasive, ultrasonography plays a major role in the exploration of the abdominal aorta, from its emergence from the diaphragm to its bifurcation. It is indicated for the diagnosis and follow-up of various aortic diseases, especially aneurysms. It can be used to define the shape, size, and location of these lesions, the absence or presence of thrombi and their characteristics. It is also useful for monitoring the evolution of the lesion and for postoperative follow-up. However, its value is limited in surgical planning and in emergency situations. PMID:23396814

  12. Non-invasive characterization of polyurethane-based tissue constructs in a rat abdominal repair model using high frequency ultrasound elasticity imaging.

    PubMed

    Yu, Jiao; Takanari, Keisuke; Hong, Yi; Lee, Kee-Won; Amoroso, Nicholas J; Wang, Yadong; Wagner, William R; Kim, Kang

    2013-04-01

    The evaluation of candidate materials and designs for soft tissue scaffolds would benefit from the ability to monitor the mechanical remodeling of the implant site without the need for periodic animal sacrifice and explant analysis. Toward this end, the ability of non-invasive ultrasound elasticity imaging (UEI) to assess temporal mechanical property changes in three different types of porous, biodegradable polyurethane scaffolds was evaluated in a rat abdominal wall repair model. The polymers utilized were salt-leached scaffolds of poly(carbonate urethane) urea, poly(ester urethane) urea and poly(ether ester urethane) urea at 85% porosity. A total of 60 scaffolds (20 each type) were implanted in a full thickness muscle wall replacement in the abdomens of 30 rats. The constructs were ultrasonically scanned every 2 weeks and harvested at weeks 4, 8 and 12 for compression testing or histological analysis. UEI demonstrated different temporal stiffness trends among the different scaffold types, while the stiffness of the surrounding native tissue remained unchanged. The changes in average normalized strains developed in the constructs from UEI compared well with the changes of mean compliance from compression tests and histology. The average normalized strains and the compliance for the same sample exhibited a strong linear relationship. The ability of UEI to identify herniation and to characterize the distribution of local tissue in-growth with high resolution was also investigated. In summary, the reported data indicate that UEI may allow tissue engineers to sequentially evaluate the progress of tissue construct mechanical behavior in vivo and in some cases may reduce the need for interim time point animal sacrifice. PMID:23347836

  13. Non-invasive Characterization of Polyurethane-based Tissue Constructs in a Rat Abdominal Repair Model Using High Frequency Ultrasound Elasticity Imaging

    PubMed Central

    Yu, Jiao; Takanari, Keisuke; Hong, Yi; Lee, Kee-Won; Amoroso, Nicholas J.; Wang, Yadong; Wagner, William R.; Kim, Kang

    2013-01-01

    The evaluation of candidate materials and designs for soft tissue scaffolds would benefit from the ability to monitor the mechanical remodeling of the implant site without the need for periodic animal sacrifice and explant analysis. Toward this end, the ability of non-invasive ultrasound elasticity imaging (UEI) to assess temporal mechanical property changes in three different types of porous, biodegradable polyurethane scaffolds was evaluated in a rat abdominal wall repair model. The polymers utilized were salt-leached scaffolds of poly(carbonate urethane) urea, poly(ester urethane) urea and poly(ether ester urethane) urea at 85% porosity. A total of 60 scaffolds (20 each type) were implanted in a full thickness muscle wall replacement in the abdomens of 30 rats. The constructs were ultrasonically scanned every 2 weeks and harvested at weeks 4, 8 and 12 for compression testing or histological analysis. UEI demonstrated different temporal stiffness trends among the different scaffold types, while the stiffness of the surrounding native tissue remained unchanged. The changes in average normalized strains developed in the constructs from UEI compared well with the changes of mean compliance from compression tests and histology. The average normalized strains and the compliance for the same sample exhibited a strong linear relationship. The ability of UEI to identify herniation and to characterize the distribution of local tissue in-growth with high resolution was also investigated. In summary, the reported data indicate that UEI may allow tissue engineers to sequentially evaluate the progress of tissue construct mechanical behavior in vivo and in some cases may reduce the need for interim time point animal sacrifice. PMID:23347836

  14. Interposed Abdominal Compression CPR for an Out-of-Hospital Cardiac Arrest Victim Failing Traditional CPR

    PubMed Central

    McClung, Christian D.; Anshus, Alexander J.

    2015-01-01

    Interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) is an alternative technique to traditional cardiopulmonary resuscitation (CPR) that can improve perfusion and lead to restoration of circulation in patients with chest wall deformity either acquired through vigorous CPR or co-morbidity such as chronic obstructive pulmonary disease. We report a case of out-of-hospital cardiac arrest where IAC-CPR allowed for restoration of spontaneous circulation and eventual full neurologic recovery when traditional CPR was failing to generate adequate pulses with chest compression alone. PMID:26587092

  15. Endografts, Pressure, and the Abdominal Aortic Aneurysm 

    E-print Network

    Meyer, Clark A.

    2010-07-14

    Quick Head of Department, Gerard Cot? May 2009 Major Subject: Biomedical Engineering iii ABSTRACT Endografts, Pressure, and the Abdominal Aortic Aneurysm. (May 2009) Clark Andrew Meyer, B.S., Texas A&M University Chair.... .......................................................................... 68? Figure 16. Hydraulic diameters (calculated normal to the centerline and normal to axial direction) as functions of axial distance from top of neck. ................ 69? Figure 17. Endograft, with nodes used in hydraulic diameter normal...

  16. Abdominal compartment syndrome from bleeding duodenal diverticulum.

    PubMed

    Tchantchaleishvili, Vakhtang; Groth, Shawn S; Leon, Jorge A; Mohr, William J

    2012-04-01

    Duodenal diverticuli are acquired false diverticuli of unknown etiology. Although mostly asymptomatic, they can occasionally cause upper gastrointestinal hemorrhage, rarely with massive bleeding. In this report, we present (to the best of our knowledge) the first reported case of duodenal diverticular bleeding, causing abdominal compartment syndrome. Albeit a rare event, duodenal diverticular bleeding should be included in the differential diagnosis of upper gastrointestinal bleeding. As with our case, a multidisciplinary approach to managing such patients is crucial. PMID:22787350

  17. Endoscopic full-thickness resection: Current status

    PubMed Central

    Schmidt, Arthur; Meier, Benjamin; Caca, Karel

    2015-01-01

    Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices. PMID:26309354

  18. [An unusual cause of severe abdominal pain].

    PubMed

    Egger, M; Binder, M; Wewalka, F; Dieplinger, B; Kastler, M; Lenz, K

    2008-09-01

    A 33-year-old previously healthy man was admitted to the hospital with a 6-day history of diffuse abdominal pain and constipation. He was afebrile, looked unwell with a pale skin and displayed an elevated blood pressure. He had no peritoneal sign, and bowel sounds were normal. Blood tests were remarkable for a hematocrit of 26 % and mean cell volume of 83 fl, bilirubin levels were slightly elevated. Abdominal radiographs, abdominal ultrasound and computed tomography showed stool throughout the colon with a non-specific bowel gas pattern. Moreover, colonoscopy and gastroscopy provided no information on the underlying cause of the patient's severe pain. He was treated with fluids and spasmolytic drugs until the result of the urinary porphyrin level was received, which showed an elevated concentration of 1608 microg/d. Consequently, the plasma lead concentration was determined showing an elevated level of 92.3 microg/d. The examination of blood slides revealed erythrocytes with basophile stippling. On physical examination, a bluish discoloration could be seen along the gums. After starting the detoxication therapy with DMPS - 1800 mg p. o. for the first two days followed by 600 mg DMPS daily - the complaints disappeared. In spite of an extensive anamnestic exploration the source of the lead intoxication could not be found until now. PMID:18810673

  19. Abdominal tuberculosis--a disease revived.

    PubMed Central

    Addison, N. V.

    1983-01-01

    Abdominal tuberculosis was common in the United Kingdom in the 18th and 19th centuries and in the first half of the 20th century. During the 1950's the recognition of Crohn's disease, the use of streptomycin and other drugs, and the pasteurisation of milk led to the virtual disappearance of abdominal tuberculosis in the western world. During the last two decades a new type, mycobacterium tuberculosis hominis, has appeared mainly in the immigrant population, especially in those from the Indian subcontinent. A retrospective review of 68 patients with abdominal tuberculosis is presented. The pathology, diagnosis and management of these cases is discussed, together with the differential diagnosis of Crohn's disease. It is suggested that the immigrant brings the disease into the United Kingdom in his mesenteric glands and that the disease is reactivated or 'revived' at some later date due to some modification of the immune process. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:6338801

  20. Wall to Wall Optimal Transport

    NASA Astrophysics Data System (ADS)

    Chini, Gregory P.; Hassanzadeh, Pedram; Doering, Charles R.

    2013-11-01

    How much heat can be transported between impermeable fixed-temperature walls by incompressible flows with a given amount of kinetic energy or enstrophy? What do the optimal velocity fields look like? We employ variational calculus to address these questions in the context of steady 2D flows. The resulting nonlinear Euler-Lagrange equations are solved numerically, and in some cases analytically, to find the maximum possible Nusselt number Nu as a function of the Péclect number Pe , a measure of the flow's energy or enstrophy. We find that in the fixed-energy problem Nu ~ Pe , while in the fixed-enstrophy problem Nu ~ Pe 10 / 17 . In both cases, the optimal flow consists of an array of convection cells with aspect ratio ? (Pe) . Interpreting our results in terms of the Rayleigh number Ra for relevant buoyancy-driven problems, we find Nu <= 1 + 0 . 035 Ra and ? ~ Ra - 1 / 2 for porous medium convection (which occurs with fixed energy), and Nu <= 1 + 0 . 115 Ra 5 / 12 and ? ~ Ra - 1 / 4 for Rayleigh-Bénard convection (which occurs with fixed enstrophy and for free-slip walls). This work was supported by NSF awards PHY-0855335, DMS-0927587, and PHY-1205219 (CRD) and DMS-0928098 (GPC). Much of this work was completed at the 2012 Geophysical Fluid Dynamics (GFD) Program at Woods Hole Oceanographic Institution.

  1. Abdominal mucinous cystic neoplasm in a male child.

    PubMed

    Luo, Jean J; Baksh, Fabien K; Pfeifer, John D; Eastman, James T; Beyer, Frederick C; Dehner, Louis P

    2008-01-01

    Mucinous cystic neoplasms (MCNs) make up a morphologic family of similar appearing tumors arising in the ovary and various extraovarian sites, including the pancreas, hepatobiliary tract, paratesticular soft tissues, and mesentery. Other than the uncommon mucinous cystadenoma of the ovary presenting in adolescence, MCNs are rarely seen by the pediatric pathologist. The present case is a 5-year-old boy with an abdominal mass appearing to arise in the mesentery of the small intestine. Because of its unresectability, a generous biopsy was performed and disclosed a MCN with focal complex papillary architecture in the absence of appreciable cytologic atypia or invasion into the wall. Like other MCNs, this tumor had an inhibin-positive, ovarian-like stroma that was nonreactive for estrogen and progesterone receptors. Only 1 other case of a mesenteric MCN has been reported to date in a child and none in a male. The MCN of the mesentery joins other, somewhat more common cystic lesions of the omentum and mesentery presenting in childhood. PMID:18237233

  2. 49 CFR 179.220-6 - Thickness of plates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) The wall thickness, after forming of the inner container shell and 2:1 ellipsoidal heads must be not... seamless heads; L = Main inside radius to which head is dished, measured on concave side in inches; P... cylindrical section and heads of the outer shell must be not less than seven-sixteenths of an inch. (d)...

  3. Full tape thickness feature conductors for EMI structures

    SciTech Connect

    Peterson, Kenneth A.; Knudson, Richard T.; Smith, Frank R.; Barner, Gregory

    2014-06-10

    Generally annular full tape thickness conductors are formed in single or multiple tape layers, and then stacked to produce an annular solid conductive wall for enclosing an electromagnetic isolation cavity. The conductors may be formed using punch and fill operations, or by flowing conductor-containing material onto the tape edge surfaces that define the interior sidewalls of the cavity.

  4. Screening and retardation effect on 180o-domain wall motion in ferroelectrics: wall velocity and non-linear dynamics due to polarization-screening charge interactions

    SciTech Connect

    Eliseev, E. A.; Morozovska, A. N.; Svechnikov, S. V.; Rumyantsev, E; Shishkin, E.; Shur, V.Y.; Kalinin, Sergei V

    2008-01-01

    The effect of the domain wall intrinsic width, relaxation time of the screening charges and the dead layer thickness on the velocity of the planar 180o-domain wall moving under homogeneous external electric field in ferroelectric capacitor is analyzed. The limiting cases of domain wall motion, including (i) the motion induced by the external and local internal field originated at the wall-surface junction for nonzero dead layer thickness; (ii) the motion induced by the effective electric field averaged over the domain wall surface are considered. We demonstrate the crossover between two screening regimes: the first one corresponds to the low domain wall velocity, when the wall drags the sluggish screening charges, while the second regime appears for high domain wall velocity, when the delay of sluggish screening charges are essential and the wall depolarization field is screened by the instant free charges located at the electrode.

  5. Heterogeneous distribution of a diffusional tracer in the aortic wall of normal and atherosclerotic rabbits

    SciTech Connect

    Tsutsui, H.; Tomoike, H.; Nakamura, M. )

    1990-08-01

    Tracer distribution as an index of nutritional support across the thoracic and abdominal aortas in rabbits in the presence or absence of atherosclerotic lesions was evaluated using ({sup 14}C)antipyrine, a metabolically inert, diffusible indicator. Intimal plaques were produced by endothelial balloon denudation of the thoracic aorta and a 1% cholesterol diet. After a steady intravenous infusion of 200 microCi of ({sup 14}C)antipyrine for 60 seconds, thoracic and abdominal aortas and the heart were excised, and autoradiograms of 20-microns-thick sections were quantified, using microcomputer-aided densitometry. Regional radioactivity and regional diffusional support, as an index of nutritional flow estimated from the timed collections of arterial blood, was 367 and 421 nCi.g-1 (82 and 106 ml.min-1.100 g-1) in thoracic aortic media of the normal and atherosclerotic rabbits, respectively. Radioactivity at the thickened intima was 179 nCi.g-1 (p less than 0.01 versus media). The gruel was noted at a deeper site within the thickened intima, and diffusional support here was 110 nCi.g-1 (p less than 0.01 versus an average radioactivity at the thickened intima). After ligating the intercostal arteries, regional tracer distribution in the media beneath the fibrofatty lesion, but not the plaque-free intima, was reduced to 46%. Thus, in the presence of advanced intimal thickening, the heterogeneous distribution of diffusional flow is prominent across the vessel wall, and abluminal routes are crucial to meet the increased demands of nutritional requirements.

  6. Changes in optical density of normal vessel wall and lipid atheromatous plaque after Nd:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Schwarzmaier, Hans-Joachim; Heintzen, Matthias P.; Zumdick, Mathias; Kaufmann, Raimund; Wolbarsht, Myron L.

    1991-06-01

    135 transmission spectra were obtained from 26 autopsy specimens of healthy as well as lipid atheromatous human abdominal aorta. The tissue samples were irradiated using a Nd:YAG laser (1064 nm, continuous wave, 60 W, 1 s) and analyzed by microspectrophotometry (spectral range 250 nm to 800 nm, cryosections 25 micrometers thick, area measured 16 micrometers in diameter). Spectra were recorded from native tissue and from the coagulation zone adjacent to the ablation area. The optical density of the coagulation zone was significantly increased compared to the untreated areas within all tissue samples over the entire spectral range investigated. In the ultraviolet increases were 2 to 6 fold for intima, 1.2 to 3 fold for media, 2 to 4 fold for adventitia and 1.2 to 2.5 fold for lipid atheromatous plaque respectively. In the visible spectral range increases were 7 to 12 fold for intima, 2 to 5 fold for media, 5 to 9 fold for adventitia and up to 3 fold for lipid atheromatous plaque respectively (data p < 0.001). In addition, differences in the optical density between lipid atheromatous plaque and normal vessel wall decreased after laser irradiation. This indicated that due to the changes of optical properties during laser irradiation data obtained from transmission spectra of the native vessel wall may not be sufficient to predict laser-tissue interaction at least with respect to continuous wave lasers.

  7. On constitutive descriptors of the biaxial mechanical behaviour of human abdominal aorta and aneurysms

    PubMed Central

    Ferruzzi, J.; Vorp, D. A.; Humphrey, J. D.

    2011-01-01

    The abdominal aorta (AA) in older individuals can develop an aneurysm, which is of increasing concern in our ageing population. The structural integrity of the ageing aortic wall, and hence aneurysm, depends primarily on effective elastin and multiple families of oriented collagen fibres. In this paper, we show that a structurally motivated phenomenological ‘four-fibre family’ constitutive relation captures the biaxial mechanical behaviour of both the human AA, from ages less than 30 to over 60, and abdominal aortic aneurysms. Moreover, combining the statistical technique known as non-parametric bootstrap with a modal clustering method provides improved confidence intervals for estimated best-fit values of the eight associated constitutive parameters. It is suggested that this constitutive relation captures the well-known loss of structural integrity of elastic fibres owing to ageing and the development of abdominal aneurysms, and that it provides important insight needed to construct growth and remodelling models for aneurysms, which in turn promise to improve our ability to predict disease progression. PMID:20659928

  8. Titan's thick haze layer

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Titan's thick haze layer is shown in this enhanced Voyager 1 image taken Nov. 12, 1980 at a distance of 435,000 kilometers (270,000 miles). Voyager images of Saturn's largest moon show Titan completely enveloped by haze that merges with a darker 'hood' or cloud layer over the north pole. Such a mantle is not present at the south pole. At Voyager's closest approach to Titan on Nov. 11, 1980, spacecraft instruments found that the moon has a substantial atmosphere, far denser than that of Mars and possibly denser than Earth's. The Voyager Project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  9. [Surgery of abdominal aorta with horseshoe kidney].

    PubMed

    Lotina, S L; Davidovi?, L B; Kosti?, D M; Velimirovi?, D V; Petrovi?, P Lj; Perisi?-Savi?, M V; Kovacevi?N S

    1997-01-01

    Seventy one surgical procedures on abdominal aorta in patients with horseshoe kidney have been reported in literature until 1980. Bergan reviewed 30 operations of abdominal aortic aneurysms (AAA) in these patients until 1974. Of them 3 AAA were ruptured. Gutowitz noticed 57 surgically treated AAA in patients with horseshoe kidney until 1984. Over the period from 1991 to 1996 thirty nine new cases were reported , including 2 ruptured AAA. The surgery of the abdominal aorta in patients with horseshoe kidney is associated with the following major problems: -reservation of anomalous (aberrant) renal arteries; reservation of the kidney excretory system; approach to the abdominal aorta (especially in patients with AAA) and graft placement The aim of the paper is the presentation of 5 new patients operated for abdominal aorta with horseshoe kidney. Over the last 12 years (January 1, 1984 to December 31, 1996) at the Centre of Vascular Surgery of the Institute of Cardiovascular Diseases of the Clinical Centre of Serbia, 5 patients with horseshoe kidney underwent surgery of the abdominal aorta. There were 4 male and one female patients whose average age was 57.8 years (50-70). Patient 1. A 50-year-old male patient was admitted to the hospital for disabling claudication discomforts (Fontan stadium IlI) and with significantly decreased Ankle-Brachial indexes (ABI). The translumbal aortography showed aorto-iliac occlusive disease and horseshoe kidney with two normal and one anomalous renal artery originating from infrarenal aorta (Crawford type II). Intravenous pyelography and retrograde urography showed two separated ureters. The aorto-bifemoral (AFF) bypass with Dacron graft was done with end-to-end (TT) proximal anastomosis just under the anomalous renal artery. The graft was placed behind the isthmus. During a 12-year follow-up renal failure, renovascular hypertension and graft occlusion were not observed. Patient 2. A 53-year-old male patient was admitted to the hospital for symptomatic AAA. Two years before admission the patient underwent coronary artery bypass grafting. The Duplex scan ultrasonography and translumbal aortography showed an infrarenal AAA, aneurysm of the right iliac artery and horseshoe kidney with two normal and one anomalous renal artery originating from the left iliac artery (Crawford type III). Intravenous pyelography and retrograde urography showed two separated ureters. After partial aneurysmectomy, the flow was restaured using bifurcated Dacron graft placed behind the isthmus. The right limb of the bifurcated graft was anastomosed with the common femoral artery and the left limb with left iliac artery just above the origin of the anomalous renal artery. The first day after operation thrombosis of the left common femoral artery with leg ischaemia was observed. (That artery was cannulated for ECC during coronary artery bypass grafting 2 years ago). The revascularisation of the left leg was done with femoro-femoral cross over bypass. During a 11-year follow-up period, the graft was patent and renal failure or revascular hypertension were not observed. Patient 3. A 66-year-old male patient was admitted to the hospital for rest pain (Fontan stadium III) and significantly decreased ABI. The patient had diabetes mellitus and myocardial infarction two months before admission. Translumbar aortography showed an aorto-iliac occlusive disease associated with horseshoe kidney with 5 anomalous renal arteries. (Crawford type III). Due to high risk, the axillo-bifemoral (AxFF) extra-anatomic bypass graft was performed. Five years after the operation the patient died due to new myocardial infarction. During the follow-up period the graft was patent and there were no signs of renal failure and renovascular hypertension. Patient 4. A 50-year old male patient was admitted to the hospital for high asymptomatic AAA. The diagnosis was established by Duplex scan and translumbal aortography. The large infrarenal AAA (transverse diameter 7 cm) associated with horseshoe kidney with two normal renal arteries (Crawford type I) were

  10. Comparison of deep and superficial abdominal muscle activity between experienced Pilates and resistance exercise instructors and controls during stabilization exercise

    PubMed Central

    Moon, Ji-Hyun; Hong, Sang-Min; Kim, Chang-Won; Shin, Yun-A

    2015-01-01

    Pilates and resistance exercises are used for lumbar stabilization training. However, it is unclear which exercise is more effective for lumbar stabilization. In our study, we aimed to compare surface muscle activity and deep muscle thickness during relaxation and spinal stabilization exercise in experienced Pilates and resistance exercise instructors. This study is a retrospective case control study set in the Exercise Prescription Laboratory and Sports Medicine Center. The participants included Pilates instructors (mean years of experience, 3.20±1.76; n=10), resistance exercise instructors (mean years of experience, 2.53±0.63; n=10), and controls (n=10). The participants performed 4 different stabilization exercises: abdominal drawing-in maneuver, bridging, roll-up, and one-leg raise. During the stabilization exercises, surface muscle activity was measured with electromyography, whereas deep muscle thickness was measured by ultrasound imaging. During the 4 stabilization exercises, the thickness of the transverse abdominis (TrA) was significantly greater in the Pilates-trained group than the other 2 other groups. The internal oblique (IO) thickness was significantly greater in the Pilates- and resistance-trained group than the control group, during the 4 exercises. However, the surface muscle activities were similar between the groups. Both Pilates and resistance exercise instructors had greater activation of deep muscles, such as the TrA and IO, than the control subjects. Pilates and resistance exercise are both effective for increasing abdominal deep muscle thickness. PMID:26171383

  11. Determination of passive viscoelastic response of the abdominal muscle and related constitutive modeling: stress-relaxation behavior.

    PubMed

    Calvo, B; Sierra, M; Grasa, J; Muñoz, M J; Peña, E

    2014-08-01

    In this paper, the authors investigate the passive viscoelastic properties of rabbit abdominal wall. In vitro strain relaxation tests were performed in the oblique muscle (in two perpendicular directions), the rectus abdominis and the linea alba in the longitudinal direction. Based on experimental data, a model for the viscoelastic mechanical properties of this tissue is presented here. In particular, we used a 3D non-linear viscoelastic model to fit data sets obtained from tissue of the rabbit abdominal wall. Uniaxial relaxation tests were carried out for samples obtained from the abdominal wall. The experimental results clearly demonstrate the anisotropy and nonlinearity of the abdominal tissue. The stress relaxation was higher in the transverse direction (closer to muscle fibers) with an average value of the final stress ratio of 48%, than in the longitudinal direction with around 56% of this ratio for the oblique muscle. These tests, at several stretch levels, presented a different behavior depending on the region where the tissue sample was located. There was no dependence between the stress relaxation ratio and the stretch level for the oblique muscles in their longitudinal or transverse directions (p>0.01). In contrast, for rectus abdominis and linea alba a dependence between the stress relaxation ratio and stretch level was found. Our study revealed an increase in the stress relaxation ratio for the rectus abdominis (p<0.01) and a decrease for the linea alba with higher stretch levels (p<0.01). Overall good predictions ?<0.115 were obtained with the model proposed for the oblique muscle (no dependence on the stretch level) and to reproduce the non-linear viscoelastic response of rectus abdominis and linea alba. PMID:24793173

  12. Abdominal cocoon: idiopathic sclerosing encapsulating peritonitis.

    PubMed

    Frost, Jason H; Price, Elizabeth E

    2015-01-01

    Abdominal cocoon, or idiopathic sclerosing encapsulating peritonitis, is a rare condition characterised by the presence of a dense fibrocollagenous membrane partially or totally encapsulating the small bowel leading to recurrent intestinal obstructions. We present the case of a patient who has presented for the fourth time with a small bowel obstruction. Previous laparoscopy revealed a plaque-like reactive process encapsulating much of the small bowel and the liver. After initial adhesiolysis, the patient's obstructions continued to reoccur. Further laparotomy was performed in order to excise the entirety of the cocoon membrane and free up loops of small bowel encapsulated by the process, hopefully preventing future obstructions. PMID:25612756

  13. Standing diagnostic and therapeutic equine abdominal surgery.

    PubMed

    Graham, Sarah; Freeman, David

    2014-04-01

    The widespread use of laparoscopy in equine surgery has increased interest in the standing approach to a wide range of procedures typically regarded as feasible only through a ventral midline incision. Although a commonly cited benefit of standing surgery relates to avoiding costs of general anesthesia and risks associated with it, some procedures and horses are not suitable candidates for standing abdominal procedures. Some procedures, such as nephrectomy, colostomy, and closure of the nephrosplenic space, are not only suitable for standing surgery but are performed more easily and more safely through this approach than with general anesthesia. PMID:24680210

  14. Large posterior abdominal masses: computed tomographic localization

    SciTech Connect

    Engel, I.A.; Auh, Y.H.; Rubenstein, W.A.; Whalen, J.P.; Kazam, E.

    1983-10-01

    Large posterior abdominal masses, particularly those in the right upper abdomen, may be difficult to localize correctly into the peritoneal or retroperitoneal compartments. The following signs were found to be reliable CT indicators of retroperitoneal location: obliteration of the perinephric fat outlining the psoas muscle; lateral displacement of the fat outlining the posterior right lobe of the liver; rotation of the intrahepatic portal veins to the left; anterior displacement of the inferior vena cava and renal veins; and anterior displacement of the ascending colon, descending duodenum, or pancreatic head.

  15. [An abdominal aortic aneurysm revealing Behçet's disease].

    PubMed

    Naouli, H; Zrihni, Y; Jiber, H; Bouarhroum, A

    2014-12-01

    Behçet's disease is a vasculitis of unknown origin. Vascular lesions predominantly affect veins. Arterial involvement is rare but usually associated with poor prognosis. Aortic syndromes are usually aneurysmal and occasionally reveal Behçet's disease. We report the case of a 46-year-old man whose Behçet's disease was revealed by a sub-renal abdominal aortic aneurysm in pre-rupture state. The diagnosis of this disease was retained based on clinical, biological and radiological criteria. The surgical procedure consisted in the resection of the aneurysmal sac and the interposition of a prosthetic PTFE tube. PMID:25457357

  16. Pleural ascites without abdominal fluid: surgical considerations.

    PubMed

    Hartz, R S; Bomalaski, J; LoCicero, J; Murphy, R L

    1984-01-01

    The presence of ascitic fluid in the pleural cavity in the absence of peritoneal fluid is rare. We have recently encountered two patients who presented with red-sided pleural effusions and no abdominal ascites. Both patients had diaphragmatic defects: One was an old traumatic diaphragmatic tear and the other a pinpoint spontaneous perforation. These cases are unique because the diagnosis of total ascitic fluid movement across the diaphragm was made during life, and the condition was surgically corrected. The literature concerning transdiaphragmatic movement of fluid is reviewed, and an operative approach is outlined. PMID:6690852

  17. Exercise-related transient abdominal pain (ETAP).

    PubMed

    Morton, Darren; Callister, Robin

    2015-01-01

    Exercise-related transient abdominal pain (ETAP), commonly referred to as 'stitch', is an ailment well known in many sporting activities. It is especially prevalent in activities that involve repetitive torso movement with the torso in an extended position, such as running and horse riding. Approximately 70% of runners report experiencing the pain in the past year and in a single running event approximately one in five participants can be expected to suffer the condition. ETAP is a localized pain that is most common in the lateral aspects of the mid abdomen along the costal border, although it may occur in any region of the abdomen. It may also be related to shoulder tip pain, which is the referred site from tissue innervated by the phrenic nerve. ETAP tends to be sharp or stabbing when severe, and cramping, aching, or pulling when less intense. The condition is exacerbated by the postprandial state, with hypertonic beverages being particularly provocative. ETAP is most common in the young but is unrelated to sex or body type. Well trained athletes are not immune from the condition, although they may experience it less frequently. Several theories have been presented to explain the mechanism responsible for the pain, including ischemia of the diaphragm; stress on the supportive visceral ligaments that attach the abdominal organs to the diaphragm; gastrointestinal ischemia or distension; cramping of the abdominal musculature; ischemic pain resulting from compression of the celiac artery by the median arcuate ligament; aggravation of the spinal nerves; and irritation of the parietal peritoneum. Of these theories, irritation of the parietal peritoneum best explains the features of ETAP; however, further investigations are required. Strategies for managing the pain are largely anecdotal, especially given that its etiology remains to be fully elucidated. Commonly purported prevention strategies include avoiding large volumes of food and beverages for at least 2 hours prior to exercise, especially hypertonic compounds; improving posture, especially in the thoracic region; and supporting the abdominal organs by improving core strength or wearing a supportive broad belt. Techniques for gaining relief from the pain during an episode are equivocal. This article presents a contemporary understanding of ETAP, which historically has received little research attention but over the past 15 years has been more carefully studied. PMID:25178498

  18. Intracranial and Abdominal Aortic Aneurysms: Similarities, Differences, and Need for a New Class of Computational Models

    PubMed Central

    Humphrey, J.D.; Taylor, C.A.

    2009-01-01

    Intracranial and abdominal aortic aneurysms result from different underlying disease processes and exhibit different rupture potentials, yet they share many histopathological and biomechanical characteristics. Moreover, as in other vascular diseases, hemodynamics and wall mechanics play important roles in the natural history and possible treatment of these two types of lesions. The goals of this review are twofold: first, to contrast the biology and mechanics of intracranial and abdominal aortic aneurysms to emphasize that separate advances in our understanding of each disease can aid in our understanding of the other disease, and second, to suggest that research on the biomechanics of aneurysms must embrace a new paradigm for analysis. That is, past biomechanical studies have provided tremendous insight but have progressed along separate lines, focusing on either the hemodynamics or the wall mechanics. We submit that that there is a pressing need to couple in a new way the separate advances in vascular biology, medical imaging, and computational biofluid and biosolid mechanics to understand better the mechanobiology, pathophysiology, and treatment of these lesions, which continue to be responsible for significant morbidity and mortality. We shall refer to this needed new class of computational tools as Fluid-Solid-Growth (FSG) Models. PMID:18647115

  19. Serial bedside emergency ultrasound in a case of pediatric blunt abdominal trauma with severe abdominal pain.

    PubMed

    Pershad, J; Gilmore, B

    2000-10-01

    We present a case of a teenager with isolated left renal laceration with perirenal hematoma. The patient had presented with severe left upper quadrant (LUQ) pain following blunt abdominal trauma (BAT) sustained during a sledding accident. A screening bedside focused abdominal sonogram for trauma (FAST) rapidly excluded free fluid on two serial examinations, 30 minutes apart. It provided the pediatric emergency physician with a measure of diagnostic confidence that the patient could be safely transported to the CT suite for detailed delineation of his injury. Moreover, narcotic analgesia was liberally administered early in his illness course, without the fear of unmasking potential hypovolemia when it was known that he did not have gross intra-abdominal bleeding on his bedside ultrasound (US). It also provided a working diagnosis of the primary organ of injury. Our hospital, like many pediatric hospitals around the nation, does not have in-house 24-hour radiology support. We suggest that the use of the bedside US be extended to the stable pediatric patient in severe abdominal pain following BAT. It can serve as a valuable, rapid, noninvasive, bedside, easily repeated, fairly accurate triage tool to evaluate pediatric BAT with severe pain. PMID:11063373

  20. Abdominal Pain Associated with an Intra-Abdominal Gonad in an Adult

    PubMed Central

    Twiss, Christian; Grasso, Michael

    2000-01-01

    Controversy still surrounds management of cryptorchidism in adults. Options include orchiectomy, orchiopexy, and close observation. What about fertility if orchiectomy is chosen? How is the risk of cancer affected when observation is the choice? Follow the reasoning for the management strategy for this adult presenting with abdominal pain. PMID:16985771

  1. Cost and Reimbursement for Three Fibroid Treatments: Abdominal Hysterectomy, Abdominal Myomectomy, and Uterine Fibroid Embolization

    SciTech Connect

    Goldberg, Jay Bussard, Anne; McNeil, Jean; Diamond, James

    2007-02-15

    Purpose. To compare costs and reimbursements for three different treatments for uterine fibroids. Methods. Costs and reimbursements were collected and analyzed from the Thomas Jefferson University Hospital decision support database from 540 women who underwent abdominal hysterectomy (n 299), abdominal myomectomy (n = 105), or uterine fibroid embolization (UFE) (n = 136) for uterine fibroids during 2000-2002. We used the chi-square test and ANOVA, followed by Fisher's Least Significant Difference test, for statistical analysis. Results. The mean total hospital cost (US$) for UFE was $2,707, which was significantly less than for hysterectomy ($5,707) or myomectomy ($5,676) (p < 0.05). The mean hospital net income (hospital net reimbursement minus total hospital cost) for UFE was $57, which was significantly greater than for hysterectomy (-$572) or myomectomy (-$715) (p < 0.05). The mean professional (physician) reimbursements for UFE, hysterectomy, and myomectomy were $1,306, $979, and $1,078, respectively. Conclusion. UFE has lower hospital costs and greater hospital net income than abdominal hysterectomy or abdominal myomectomy for treating uterine fibroids. UFE may be more financially advantageous than hysterectomy or myomectomy for the insurer, hospital, and health care system. Costs and reimbursements may vary amongst different hospitals and regions.

  2. Early Postoperative Pain After Keyless Abdominal Rope-Lifting Surgery

    PubMed Central

    Hüsey?no?lu, Ürfettin; Ç?çek, Melek

    2015-01-01

    Background and Objectives: Keyless abdominal rope-lifting surgery is a novel, gasless, single-incision laparoscopic surgical technique. In this study we aimed to compare the postoperative pain from keyless abdominal rope-lifting surgery with carbon dioxide laparoscopy performed for benign ovarian cysts. Methods: During a 20-month period, 77 women underwent surgery for a benign ovarian cyst. Keyless abdominal rope-lifting surgery and conventional carbon dioxide laparoscopy techniques were used for the operations in 32 women and 45 women, respectively. The 2 operative techniques were compared with regard to demographic characteristics; preoperative, intraoperative, and postoperative data including early postoperative pain scores; and frequency of shoulder pain and analgesic requirements. Results: Data regarding demographic characteristics, preoperative findings, cyst diameters and rupture rates, intra-abdominal adhesions, intraoperative blood loss, and postoperative hospital stay did not differ between groups (P > .05). However, the mean operative and abdominal access times were significantly longer in the keyless abdominal rope-lifting surgery group (P < .05). Visual analog scale pain scores at initially and at the second, fourth, and 24th hours of the postoperative period were significantly lower in the keyless abdominal rope-lifting surgery group (P < .05). Similarly, keyless abdominal rope-lifting surgery caused significantly less shoulder pain and additional analgesic use (P < .05). Conclusion: Keyless abdominal rope-lifting surgery seems to cause less pain in the management of benign ovarian cysts in comparison with conventional carbon dioxide laparoscopy. PMID:25848177

  3. Mouth Dryness or Thick Saliva

    MedlinePLUS

    ... throat pain or sores Mouth dryness or thick saliva Radiation therapy to the head and neck areas, ... other medicines can cause dry mouth or thick saliva. The glands that make saliva can become irritated ...

  4. Ultrasonic Inspection Of Thick Sections

    NASA Technical Reports Server (NTRS)

    Friant, C. L.; Djordjevic, B. B.; O'Keefe, C. V.; Ferrell, W.; Klutz, T.

    1993-01-01

    Ultrasonics used to inspect large, relatively thick vessels for hidden defects. Report based on experiments in through-the-thickness transmission of ultrasonic waves in both steel and filament-wound composite cases of solid-fuel rocket motors.

  5. Critical thickness in silicone thermosets

    E-print Network

    Deopura, Manish, 1975-

    2005-01-01

    Critical thickness effects are utilized to achieve high fracture toughness in brittle polymers. The postulate of critical thickness, which is: "Macroscopically brittle polymers deform in a ductile fashion below a critical ...

  6. Mesenteric calcification following abdominal stab wound

    PubMed Central

    Hicks, Caitlin W.; Velopulos, Catherine G.; Sacks, Justin M.

    2014-01-01

    INTRODUCTION Heterotopic ossification (HO) refers to the formation of bone in non-ossifying tissue. Heterotopic mesenteric ossification is a rare form of HO that is characterized by the formation of an ossifying pseudotumour at the base of the mesentery, usually following abdominal surgery. PRESENTATION OF CASE We describe a case of mesenteric HO in a young male who presented for elective ventral incisional hernia repair following a stab wound to the abdomen requiring exploratory laparotomy 21 months earlier. Preoperative workup was unremarkable, but a hard, bone-like lesion was noted to encircle the base of the mesentery upon entering the abdomen, consistent with HO. The lesion was excised with close margins, and his hernia was repaired without incident. DISCUSSION Traumatic HO describes the ossification of extra-skeletal tissue that specifically follows a traumatic event. It usually occurs adjacent to skeletal tissue, but has been occasionally described in the abdomen as well, usually in patients who suffer abdominal trauma. Overall the prognosis of HO is good, as it is considered a benign lesion with no malignant potential. However, the major morbidity associated with mesenteric HO is bowel obstruction. CONCLUSION The size, location, and symptoms related to our patient's mesenteric HO put him risk for obstruction in the future. As a result, the mass was surgically excised during his ventral hernia repair with good outcomes. PMID:24981165

  7. Abdominal aneurysm and horseshoe kidney: a review.

    PubMed Central

    Bietz, D S; Merendino, K A

    1975-01-01

    Two patients with aortic abdominal aneurysms in association with horseshoe kidney are presented, making a total of 34 cases recorded in the literature. In 29 patients, the aneurysm was resected and five patients were non-resectable. Because of the abnormalities in vascular supply to the abnormal kidney, it is important to diagnose the combination of aneurysm and horseshoe kidney preoperatively. An error in diagnosis should be unusual if an intravenous pyelogram is routinely obtained on all patients. This study may reveal abnormalities which will allow the diagnosis of horseshoe kidney to be made or suspected. If the intravenous pyelogram is abnormal, it should be followed by an aortogram. This may substantiate the diagnosis of aneurysm and horseshoe kidney and provide the necessary detailed information regarding the pattern of blood supply and its relationship to functioning tissue. The amount and disposition of functioning renal parenchyma may be further amplified by renal scan. If this sequence is followed, the unanticipated combination of abdominal aneurysm and horseshoe kidney should be rare. PMID:1130850

  8. Abdominal vascular emergencies: US and CT assessment

    PubMed Central

    2013-01-01

    Acute vascular emergencies can arise from direct traumatic injury to the vessel or be spontaneous (non-traumatic). The vascular injuries can also be divided into two categories: arteial injury and venous injury. Most of them are life-treatening emergencies, sice they may cause an important ipovolemic shock or severe ischemia in their end organ and require prompt diagnosis and treatment. In the different clinical scenarios, the correct diagnostic approach to vascular injuries isn’t firmly established and advantages of one imaging technique over the other are not obvious. Ultrasound (US) is an easy accessible, safe and non-invasive diagnostic modality but Computed Tomography (CT) with multiphasic imaging study is an accurate modality to evaluate the abdominal vascular injuries therefore can be considered the primary imaging modality in vascular emergencies. The aim of this review article is to illustrate the different imaging options for the diagnosis of abdominal vascular emergencies, including traumatic and non traumatic vessel injuries, focusing of US and CT modalities. PMID:23902665

  9. Constipation Risk in Patients Undergoing Abdominal Surgery

    PubMed Central

    Celik, Sevim; Atar, Nurdan Yalcin; Ozturk, Nilgun; Mendes, Guler; Kuytak, Figen; Bakar, Esra; Dalgiran, Duygu; Ergin, Sumeyra

    2015-01-01

    Background: Problems regarding bowel elimination are quite common in patients undergoing abdominal surgery. Objectives: To determine constipation risk before the surgery, bowel elimination during postoperative period, and the factors affecting bowel elimination. Patients and Methods: This is a cross-sectional study. It was conducted in a general surgery ward of a university hospital in Zonguldak, Turkey between January 2013 and May 2013. A total of 107 patients were included in the study, who were selected by convenience sampling. Constipation Risk Assessment Scale (CRAS), patient information form, medical and nursing records were used in the study. Results: The mean age of the patients was found to be 55.97 ± 15.74 (year). Most of the patients have undergone colon (37.4%) and stomach surgeries (21.5%). Open surgical intervention (83.2%) was performed on almost all patients (96.3%) under general anesthesia. Patients were at moderate risk for constipation with average scores of 11.71 before the surgery. A total of 77 patients (72%) did not have bowel elimination problem during postoperative period. The type of the surgery (P < 0.05), starting time for oral feeding after the surgery (P < 0.05), and mobilization (P < 0.05) were effective on postoperative bowel elimination. Conclusions: There is a risk for constipation after abdominal surgery. Postoperative practices are effective on the risk of constipation. PMID:26380107

  10. NOVA 201 ultrasonic thickness gage (NOVA Gage)

    NASA Technical Reports Server (NTRS)

    Garecht, Diane

    1990-01-01

    The measurement integrity of the NOVA 201 digital ultrasonic thickness gage (NOVA gage) was demonstrated by comparing the NOVA gage measurements to the thickness gage measurements, and determining the bias and uncertainty of the NOVA gage when measuring redesigned solid rocket motor (RSRM) hardware per engineering test plans (ETP). The NOVA gage was tested by three different operators on steel and aluminum RSRM hardware for wall thickness. The results show that the measurement bias is not consistent. The uncertainty of the bias is caused by the heterogeneous material properties of the RSRM components that influence the time of flight of ultrasonic waves. The measurement uncertainty inherent to the design and operation of the NOVA gage is less in comparison to the uncertainty of the bias. The total measurement uncertainty cannot be substantially reduced by taking more than one measurement. There is no correlation between bias and the surface finish range of this test unless 3-in-One oil is used as a couplant, in which case there appears to be a slight trend. There is no correlation between uncertainty and the surface finish range. The measurement uncertainty of the NOVA gage can be reduced using 3-in-One oil as a couplant.

  11. Graphical determination of wall temperatures for heat transfers through walls of arbitrary shape

    NASA Technical Reports Server (NTRS)

    Lutz, Otto

    1950-01-01

    A graphical method is given which permits determining of the temperature distribution during heat transfer in arbitrarily shaped walls. Three examples show the application of the method. The further development of heat engines depends to a great extent on the control of the thermal stresses in the walls. The thermal stresses stem from the nonuniform temperature distribution in heat transfer through walls which are, for structural reasons, of various thicknesses and sometimes complicated shape. Thus, it is important to know the temperature distribution in these structural parts. Following, a method is given which permits solution of this problem.

  12. Cell Wall Remodeling Enzymes Modulate Fungal Cell Wall Elasticity and Osmotic Stress Resistance

    PubMed Central

    Ene, Iuliana V.; Walker, Louise A.; Schiavone, Marion; Lee, Keunsook K.; Martin-Yken, Hélène; Dague, Etienne; Gow, Neil A. R.; Munro, Carol A.

    2015-01-01

    ABSTRACT The fungal cell wall confers cell morphology and protection against environmental insults. For fungal pathogens, the cell wall is a key immunological modulator and an ideal therapeutic target. Yeast cell walls possess an inner matrix of interlinked ?-glucan and chitin that is thought to provide tensile strength and rigidity. Yeast cells remodel their walls over time in response to environmental change, a process controlled by evolutionarily conserved stress (Hog1) and cell integrity (Mkc1, Cek1) signaling pathways. These mitogen-activated protein kinase (MAPK) pathways modulate cell wall gene expression, leading to the construction of a new, modified cell wall. We show that the cell wall is not rigid but elastic, displaying rapid structural realignments that impact survival following osmotic shock. Lactate-grown Candida albicans cells are more resistant to hyperosmotic shock than glucose-grown cells. We show that this elevated resistance is not dependent on Hog1 or Mkc1 signaling and that most cell death occurs within 10 min of osmotic shock. Sudden decreases in cell volume drive rapid increases in cell wall thickness. The elevated stress resistance of lactate-grown cells correlates with reduced cell wall elasticity, reflected in slower changes in cell volume following hyperosmotic shock. The cell wall elasticity of lactate-grown cells is increased by a triple mutation that inactivates the Crh family of cell wall cross-linking enzymes, leading to increased sensitivity to hyperosmotic shock. Overexpressing Crh family members in glucose-grown cells reduces cell wall elasticity, providing partial protection against hyperosmotic shock. These changes correlate with structural realignment of the cell wall and with the ability of cells to withstand osmotic shock. PMID:26220968

  13. A Computational Model of Biochemomechanical Effects of Intraluminal Thrombus on the Enlargement of Abdominal Aortic Aneurysms.

    PubMed

    Virag, Lana; Wilson, John S; Humphrey, Jay D; Karšaj, Igor

    2015-12-01

    Abdominal aortic aneurysms (AAAs) typically develop an intraluminal thrombus (ILT), yet most computational models of AAAs have focused on either the mechanics of the wall or the hemodynamics within the lesion, both in the absence of ILT. In the few cases wherein ILT has been modeled directly, as, for example, in static models that focus on the state of stress in the aortic wall and the associated rupture risk, thrombus has been modeled as an inert, homogeneous, load-bearing material. Given the biochemomechanical complexity of an ILT, there is a pressing need to consider its diverse effects on the evolving aneurysmal wall. Herein, we present the first growth and remodeling model that addresses together the biomechanics, mechanobiology, and biochemistry of thrombus-laden AAAs. Whereas it has been shown that aneurysmal enlargement in the absence of ILT depends primarily on the stiffness and turnover of fibrillar collagen, we show that the presence of a thrombus within lesions having otherwise the same initial wall composition and properties can lead to either arrest or rupture depending on the biochemical effects (e.g., release of proteases) and biomechanical properties (e.g., stiffness of fibrin) of the ILT. These computational results suggest that ILT should be accounted for when predicting the potential enlargement or rupture risk of AAAs and highlight specific needs for further experimental and computational research. PMID:26070724

  14. Droplet splashing on a wet moving wall

    NASA Astrophysics Data System (ADS)

    Lou, Jing; Cheng, Ming

    2013-11-01

    The splash of a liquid drop onto a moving solid wall covered with a thin film of the same liquid is simulated numerically for an impact Reynolds number of 1000 and a Weber number of 400. A two-phase flow lattice Boltzmann model is employed for the simulations. The characteristics of drop splashing on the wall are investigated by systematically varying the impact angle and wall speed. The angle of incidence ? ranges from 0 to 60 degrees, while the wall speed to the initial drop velocity ratio Uw varies from 0 to 3. In case of Uw equals to 0 and ?large than 0 degree, the splashing is asymmetric. The increase of the angle leads to the transition from splash to partial splash. The present results indicate the existence of a critical ?c value of about 55 degrees, which is determined by the liquid film thickness, Reynolds and Weber numbers.

  15. The abdominal drawing-in manoeuvre for detecting activity in the deep abdominal muscles: is this clinical tool reliable and valid?

    PubMed Central

    Kaping, Karsten; Äng, Björn O; Rasmussen-Barr, Eva

    2015-01-01

    Objective The abdominal drawing-in manoeuvre (ADIM) is a common clinical tool for manually assessing whether a preferential activation of the deep abdominal muscles in patients with low back pain (LBP) is ‘correct’ or not. The validity and reliability of manual assessment of the ADIM are, however, as yet unknown. This study evaluated the concurrent and discriminative validity and reliability of the manually assessed ADIM. Design Single-blinded cross-sectional study. Settings General population in Stockholm County, Sweden. Participants The study sample comprised 38 participants seeking care for LBP, and 15 healthy subjects. Measures The manual ADIM was assessed as correct or not following a standard procedure. Ultrasound imaging (USI) was used as the concurrent reference (gold standard) for the manually assessed ADIM by calculating a ratio of the change in muscle thickness between the resting and the contracted states: the correlation between manual test and USI was calculated. Discriminative validity was analysed by calculating sensitivity and specificity. A sample of 24 participants was analysed with ? coefficients for interobserver reliability between two raters. Results The concurrent validity between the manual ADIM and the ADIM–USI ratios showed poor correlations (r=0.13–0.40). The discriminative validity of the manually assessed ADIM to predict LBP showed a sensitivity/specificity of 0.30/0.73, while the ADIM–USI ratio to predict LBP showed 0.19/0.87. The interobserver reliability for the manually assessed ADIM revealed substantial agreement: K=0.71, CI (95%) 0.41 to 1.00. Conclusions Although the interobserver reliability of the manually assessed ADIM was high, the concurrent and discriminative validity were both low for examining the preferential activity of the deep abdominal muscles. Neither the manually assessed ADIM nor the ultrasound testing discriminated between participants with LBP and healthy subjects regarding preferential activity of the transversus muscle as this ability/inability was also present in healthy subjects. PMID:26656015

  16. Waterway Ice Thickness Measurements

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The ship on the opposite page is a U. S. Steel Corporation tanker cruising through the ice-covered waters of the Great Lakes in the dead of winter. The ship's crew is able to navigate safely by plotting courses through open water or thin ice, a technique made possible by a multi-agency technology demonstration program in which NASA is a leading participant. Traditionally, the Great Lakes-St. Lawrence Seaway System is closed to shipping for more than three months of winter season because of ice blockage, particularly fluctuations in the thickness and location of ice cover due to storms, wind, currents and variable temperatures. Shippers have long sought a system of navigation that would allow year-round operation on the Lakes and produce enormous economic and fuel conservation benefits. Interrupted operations require that industrial firms stockpile materials to carry them through the impassable months, which is costly. Alternatively, they must haul cargos by more expensive overland transportation. Studies estimate the economic benefits of year-round Great Lakes shipping in the hundreds of millions of dollars annually and fuel consumption savings in the tens of millions of gallons. Under Project Icewarn, NASA, the U.S. Coast Guard and the National Oceanic Atmospheric Administration collaborated in development and demonstration of a system that permits safe year-round operations. It employs airborne radars, satellite communications relay and facsimile transmission to provide shippers and ships' masters up-to-date ice charts. Lewis Research Center contributed an accurate methods of measuring ice thickness by means of a special "short-pulse" type of radar. In a three-year demonstration program, Coast Guard aircraft equipped with Side-Looking Airborne Radar (SLAR) flew over the Great Lakes three or four times a week. The SLAR, which can penetrate clouds, provided large area readings of the type and distribution of ice cover. The information was supplemented by short-pulse radar measurements of ice thickness. The radar data was relayed by a NOAA satellite to a ground station where NOAA analyzed it and created picture maps, such as the one shown at lower left, showing where icebreakers can cut paths easily or where shipping can move through thin ice without the aid of icebreakers. The ice charts were then relayed directly to the wheelhouses of ships operating on the Lakes. Following up the success of the Great Lakes program, the icewarn team applied its system in another demonstration, this one a similarly successful application designed to aid Arctic coast shipping along the Alaskan North Slope. Further improvement of the ice-monitoring system is planned. Although aircraft-mounted radar is effective, satellites could provide more frequent data. After the launch this year of Seasat, an ocean-monitoring satellite, NASA will conduct tests to determine the ice-mapping capability and accuracy of satellite radar images.

  17. Options for assessing and measuring chest wall motion.

    PubMed

    Seddon, Paul

    2015-01-01

    Assessing chest wall motion is a basic and vital component in managing the child with respiratory problems, whether these are due to pathology in the lungs, airways, chest wall or muscles. Since the 1960s, clinical assessment has been supplemented with an ever-growing range of technological options for measuring chest wall motion, each with unique advantages and disadvantages. Measurements of chest wall motion can be used to: (1) Assess respiratory airflow and volume change, as a non-invasive alternative to measurement at the airway opening, (2) Monitor breathing over long periods of time, to identify apnoea and other types of sleep-disordered breathing, (3)Identify and quantify patterns of abnormal chest wall movement, whether between ribcage and abdominal components (thoracoabdominal asynchrony) or between different regions of the ribcage (eg in scoliosis and pectus excavatum). Measuring chest wall motion allows us to do things which simply cannot be done by more mainstream respiratory function techniques measuring flow at the airway opening: it allows respiratory airflow to be measured when it would otherwise be impossible, and it tells us how the different parts of the chest wall (eg ribcage vs abdomen, right vs left) are moving in order to generate that airflow. The basis of the different techniques available to assess and measure chest wall motion will be reviewed and compared, and their relevance to paediatric respiratory practice assessed. PMID:25468220

  18. If walls could talk

    NASA Technical Reports Server (NTRS)

    Braam, J.; McIntire, L. V. (Principal Investigator)

    1999-01-01

    The plant cell wall is very complex, both in structure and function. The wall components and the mechanical properties of the wall have been implicated in conveying information that is important for morphogenesis. Proteoglycans, fragments of polysaccharides and the structural integrity of the wall may relay signals that influence cellular differentiation and growth control. Furthering our knowledge of cell wall structure and function is likely to have a profound impact on our understanding of how plant cells communicate with the extracellular environment.

  19. A study on automated anatomical labeling to arteries concerning with colon from 3D abdominal CT images

    NASA Astrophysics Data System (ADS)

    Hoang, Bui Huy; Oda, Masahiro; Jiang, Zhengang; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Mori, Kensaku

    2011-03-01

    This paper presents an automated anatomical labeling method of arteries extracted from contrasted 3D CT images based on multi-class AdaBoost. In abdominal surgery, understanding of vasculature related to a target organ such as the colon is very important. Therefore, the anatomical structure of blood vessels needs to be understood by computers in a system supporting abdominal surgery. There are several researches on automated anatomical labeling, but there is no research on automated anatomical labeling to arteries concerning with the colon. The proposed method obtains a tree structure of arteries from the artery region and calculates features values of each branch. These feature values are thickness, curvature, direction, and running vectors of branch. Then, candidate arterial names are computed by classifiers that are trained to output artery names. Finally, a global optimization process is applied to the candidate arterial names to determine final names. Target arteries of this paper are nine lower abdominal arteries (AO, LCIA, RCIA, LEIA, REIA, SMA, IMA, LIIA, RIIA). We applied the proposed method to 14 cases of 3D abdominal contrasted CT images, and evaluated the results by leave-one-out scheme. The average precision and recall rates of the proposed method were 87.9% and 93.3%, respectively. The results of this method are applicable for anatomical name display of surgical simulation and computer aided surgery.

  20. Particle Image Velocimetry measurements in an abdominal aortic aneurysm model

    E-print Network

    Papaharilaou, Yannis

    Particle Image Velocimetry measurements in an abdominal aortic aneurysm model Ch. Stamatopoulos1 School, Univ. of Crete, Greece Abdominal aortic aneurysm (AAA) is an abnormal dilatation of the aortic by the flow rate ratio during the cycle. a b c Fig.2 Measured intra-aneurysmal flow patterns with: zero flow

  1. 77 FR 59928 - Draft Guidance for Industry on Complicated Intra-Abdominal Infections: Developing Drugs for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ...Industry on Complicated Intra-Abdominal Infections: Developing Drugs for Treatment; Availability...entitled ``Complicated Intra-Abdominal Infections: Developing Drugs for Treatment...treatment of complicated intra-abdominal infections (cIAIs). Specifically, this...

  2. Endovascular grafts for abdominal aortic aneurysm.

    PubMed

    Steuer, Johnny; Lachat, Mario; Veith, Frank J; Wanhainen, Anders

    2016-01-01

    During the last two decades, endovascular technology has revolutionized the management of patients with abdominal aortic aneurysm (AAA). Today, endovascular aortic repair (EVAR) is the treatment of choice for the majority of patients with an AAA. Randomized controlled trials provide robust evidence for the indication of AAA repair and the rationale for the use of EVAR in selected patients. However, despite that, practice varies and several areas need further elucidation. Important future challenges and areas of research include the role of medical therapy in AAA, whether the indication for repair should be any different in women and in the elderly, and long-term follow-up of patients undergoing complex EVAR with adjuncts, both for elective treatment and for ruptured AAA. Continuous rapid technical and clinical development is to be expected. In this paper, we review the current practice and evidence of stenting in AAA. PMID:26543044

  3. Standardized anatomic space for abdominal fat quantification

    NASA Astrophysics Data System (ADS)

    Tong, Yubing; Udupa, Jayaram K.; Torigian, Drew A.

    2014-03-01

    The ability to accurately measure subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from images is important for improved assessment and management of patients with various conditions such as obesity, diabetes mellitus, obstructive sleep apnea, cardiovascular disease, kidney disease, and degenerative disease. Although imaging and analysis methods to measure the volume of these tissue components have been developed [1, 2], in clinical practice, an estimate of the amount of fat is obtained from just one transverse abdominal CT slice typically acquired at the level of the L4-L5 vertebrae for various reasons including decreased radiation exposure and cost [3-5]. It is generally assumed that such an estimate reliably depicts the burden of fat in the body. This paper sets out to answer two questions related to this issue which have not been addressed in the literature. How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? At what anatomic location do the volumes of SAT and VAT correlate maximally with the corresponding single-slice area measures? To answer these questions, we propose two approaches for slice localization: linear mapping and non-linear mapping which is a novel learning based strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. We then study the volume-to-area correlations and determine where they become maximal. We demonstrate on 50 abdominal CT data sets that this mapping achieves significantly improved consistency of anatomic localization compared to current practice. Our results also indicate that maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized.

  4. Dynamic response of cantilever retaining walls

    SciTech Connect

    Veletsos, A.S.; Younan, A.H.; Bandyopadhyay, K.

    1996-10-01

    A critical evaluation is made of the response to horizontal ground shaking of flexible cantilever retaining walls that are elastically constrained against rotation at their base. The retained medium is idealized as a uniform, linear, viscoelastic stratum of constant thickness and semi-infinite extent in the horizontal direction. The parameters varied include the flexibilities of the wall and its base, the properties of the retained medium, and the characteristics of the ground motion. In addition to long-period, effectively static excitations, both harmonic base motions and an actual earthquake record are considered. The response quantities examined include the displacements of the wall relative to the moving base, the wall pressures, and the associated shears and bending moments. The method of analysis employed is described only briefly, emphasis being placed on the presentation and interpretation of the comprehensive numerical solutions. It is shown that, for realistic wall flexibilities, the maximum wall forces are significantly lower than those obtained for fixed-based rigid walls and potentially of the same order of magnitude as those computed by the Mononobe-Okabe method.

  5. [State of the abdominal organs and vessels on the background of simulated venous plethora in the splanchnic vascular system].

    PubMed

    Afonin, B V; Noskov, V B; Nichiporuk, I A; Sedova, E A; Goncharova, N P

    2007-01-01

    Ultrasonic investigations of the abdominal organs and splanchnic veins were performed in essentially healthy subjects tilted at 12 degrees and 15 degrees for the period of 12 hrs. and 24 hrs. Tilting produced typical redistribution of venous blood and body liquids toward the cranial end. In its turn, blood redistribution caused excessive venous plethora and abdominal stasis. These were succeeded by expansion of large veins in the abdomen, enlargement of parenchymal organs and contraction of their echogenicity, and thickening of the hollow organs walls. Changes in the gastrointestinal functions before meal included elevated gastric, hepatic and pancreatic secretion, and an increased amount of intestinal content. The investigations demonstrated that stasis of the splanchnic veins altered functioning of the digestive organs in tilted human subjects. PMID:18350819

  6. Nanosurgery: Observation of Peptidoglycan Strands in Lactobacillus helveticus Cell Walls

    E-print Network

    Max Firtel; Grant Henderson; Igor Sokolov

    2004-07-05

    The internal cell wall structure of the bacterium Lactobacillus helveticus has been observed in situ in aqueous solution using an atomic force microscope (AFM). The AFM tip was used not only for imaging but presumably to remove mechanically large patches of the outer cell wall after appropriate chemical treatment, which typically leaves the bacteria alive. The surface exposed after such a surgery revealed ca. 26 nm thick twisted strands within the cell wall. The structure and location of the observed strands are consistent with the glycan backbone of peptidoglycan fibers that give strength to the cell wall. The found structural organization of these fibers has not been observed previously.

  7. Long-term Outcomes Following Abdominal Sacrocolpopexy for Pelvic Organ Prolapse

    PubMed Central

    Nygaard, Ingrid; Brubaker, Linda; Zyczynski, Halina M.; Cundiff, Geoffrey; Richter, Holly; Gantz, Marie; Fine, Paul; Menefee, Shawn; Ridgeway, Beri; Visco, Anthony; Warren, Lauren Klein; Zhang, Min; Meikle, Susan

    2013-01-01

    Importance Over 225,000 surgeries are performed annually in the U.S. for pelvic organ prolapse (POP). Abdominal sacrocolpopexy is considered the most durable POP surgery, but little is known about long-term effectiveness and adverse events. Objective To describe anatomic and symptomatic outcomes up to 7 years after abdominal sacrocolpopexy, and to determine whether these are affected by concomitant anti-incontinence surgery (Burch urethropexy). Design, setting, participants Long-term follow-up of the randomized, masked 2-year CARE trial (Colpopexy And urinary Reduction Efforts). Participants were stress continent women undergoing abdominal sacrocolpopexy between 2002–5 for symptomatic POP randomized to concomitant urethropexy or not. 92% (215/233) of eligible 2-year CARE trial completers enrolled into this extended study with 181 (84%) and 126 (59%) completing 5 and 7 years follow-up, respectively. Median follow-up was 7 years. Main Outcome Measures POP: Symptomatic failure: POP retreatment or reporting bulge on Pelvic Floor Distress Inventory (PFDI); Anatomic failure: POP retreatment or Pelvic Organ Prolapse Quantification demonstrating descent of the vaginal apex descend below upper third of the vagina or anterior or posterior vaginal wall prolapse beyond the hymen. Urinary incontinence (UI): Stress UI: more than 1 stress urinary incontinence symptom on PFDI or interval treatment; Overall UI: score ? 3 on Incontinence Severity Index. Results By year 7, the estimated probabilities of failure (POP, SUI, UI) from parametric survival modeling for the urethropexy and no urethropexy groups respectively were were 0.27 and 0.22 for anatomic POP (difference 0.050; 95% CI ?0.161, 0.271), 0.29 and 0.24 for symptomatic POP (0.049; ?0.060, 0.162), 0.48 and 0.34 for composite POP (0.134; ?0.096, 0.322), 0.62 and 0.77 for SUI (?0.153; ?0.268, 0.030) 0.75 and 0.81 for overall UI (?0.064; ?0.161, 0.032). Mesh erosion probability estimated by Kaplan-Meier method was 10.5% (95% CI 6.8, 16.1) at 7 years. Conclusion and Relevance Over seven years, abdominal sacrocolpopexy failure rates increased in both randomized groups. Urethropexy prevented SUI longer than no urethropexy. Abdominal sacrocolpopexy effectiveness must be balanced with long-term risks of mesh and /or suture erosion. PMID:23677313

  8. A kinematic comparison of four abdominal training devices and a traditional abdominal crunch.

    PubMed

    Sands, William A; McNeal, Jeni R

    2002-02-01

    Abdominal exercises are often performed on roller or rocker mechanisms, which have been aggressively promoted through the television and print media. However, justifications are lacking as to why these devices are superior to traditional abdominal exercises such as crunches. This study sought to describe and compare the range of motion (ROM) of several joints during crunches performed on 4 different abdominal conditioning devices (2 roller and 2 pivot types) and a traditional crunch exercise. Ten men (29 +/- 5.87 years, 177.5 +/- 6.46 cm, 80.96 +/- 11.72 kg) and 10 women (33.4 +/- 10.16 years, 162.23 +/- 3.83 cm, 56.99 +/- 7.36 kg) subjects agreed to participate in the study. Subjects were videotaped in the sagittal plane (60 Hz) using standard kinematic methods. Reflective markers were placed on the right temple, auditory meatus, shoulder, hip, knee, ankle, heel, toe, and 2 sternum markers placed on a foam piece strapped to the subject's chest. The videotaped movements were automatically digitized (PEAK5 2-D) and the data smoothed using a Butterworth filter. Relative angular ROMs of the head (temple, auditory meatus, shoulder); neck (auditory meatus, shoulder, hip); trunk (near sternum, shoulder, hip); hip (shoulder, hip, knee); sternum/head (sternum near and sternum far with temple and auditory meatus); sternum/trunk (sternum near and sternum far with shoulder and hip); and a sum of 4 angles (head, neck, trunk, hip) were calculated. Sex by equipment repeated measures analyses of variance (ANOVAs) were calculated on the angles of the 5 exercises. When no main effect for sex was found, the data were collapsed across sex and a one-way ANOVA with repeated measures was calculated on the resulting data. Post hoc analyses of pairwise differences were calculated using Tukey's honestly significant difference statistic. Results showed that crunches performed with the abdominal devices resulted in less ROM in all angles measured when compared with a traditional crunch. The traditional crunch exercise was most closely simulated by the pivot-type devices. The results indicated that prescription of abdominal conditioning exercises via these devices results in training through smaller ROMs compared with a traditional crunch. The specific angle changes may require careful judgment as to appropriate application for exercisers with specific back and neck motion limitations. PMID:11834119

  9. Surgical removal of multiple mesenteric fibroids (Kg 4,500) by abdominal spread of previous laparoscopic uterine myomectomy

    PubMed Central

    LEANZA, V.; GULINO, F.A.; LEANZA, G.; ZARBO, G.

    2015-01-01

    Introduction Huge and multiple mesenteric fibroids (4,500 Kg weight) are very unusual. In many cases they are mistaken for subserosal fibroids of the womb due to the proximity with uterine walls. When they have a rapid growth, the risk of becoming malignant (sarcoma) has not to be underestimated. Surgery is challenging to remove abdominal nodes. Case report A case of a 40-year old woman, admitted to the hospital with abdominal masses occupying the entire cavity was reported. Both computerized tomography (CT) and ultrasounds (US) were not diriment for belonging of tumours. Clinical history of patient reports a laparoscopic removal of uterine fibroids, using the morcellator. Laparoscopy was performed four years before. Open surgery by means of a large transversal suprapubic laparotomy according to Pfannestiel was carried out. Multiple and huge mesenteric, peritoneal and intestinal tumours spread in the whole abdominal cavity were found, removed and examined by frozen section histology; in addition a series of small conglomerated myomas in the site of previous laparoscopic transumbilical route was taken away as well (the largest fibroid weighed Kg 3.500 and the all tumors removed 4,500 Kg); the result was benign (fibroids) and genital apparatus was preserved. Operation was challenging. Postoperative course was uneventful; after five days patient was discharged. Conclusions This case is very interesting for many factors: A) many extra-uterine fibroids spread throughout abdominal cavity; B) considerable weight of the masses C) intraoperative and postoperative danger. Finally, due to involvement of previous laparoscopic transumbilical incision together with other findings, the hypothesis of post laparoscopic dissemination has to be considered. A case of so large extragenital abdominal fibroids following laparoscopic uterine myomectomy has never been published so far. PMID:25827668

  10. Dependence of magnetization process on thickness of Permalloy antidot arrays

    SciTech Connect

    Merazzo, K. J.; Real, R. P. del; Asenjo, A.; Vazquez, M.

    2011-04-01

    Nanohole films or antidot arrays of Permalloy have been prepared by the sputtering of Ni{sub 80}Fe{sub 20} onto anodic alumina membrane templates. The film thickness varies from 5 to 47 nm and the antidot diameters go from 42 to 61 nm, for a hexagonal lattice parameter of 105 nm. For the thinner antidot films (5 and 10 nm thick), magnetic moments locally distribute in a complex manner to reduce the magnetostatic energy, and their mostly reversible magnetization process is ascribed to spin rotations. In the case of the thicker (20 and 47 nm) antidot films, pseudodomain walls appear and the magnetization process is mostly irreversible where hysteresis denotes the effect of nanoholes pinning to wall motion.

  11. Simultaneous axial conduction in the fluid and the pipe wall for forced convective laminar flow with blowing and suction at the wall

    NASA Technical Reports Server (NTRS)

    Faghri, Amir; Chen, Ming-Ming; Mahefkey, E. T.

    1989-01-01

    Numerical solutions are reported for conjugate heat transfer in a porous pipe having an internal flow with blowing or suction at the inner surface of the pipe and constant heat flux at the outer surface. The effect of the simultaneous axial conduction through the wall and the fluid has been studied for the combined hydrodynamic and thermal entry lengths. The results show that the ratio of the thermal conductivities of the pipe wall to the fluid and the thickness of the pipe wall may become significant factors on the heat transfer when the Peclet number is small, especially for the case when fluid is injected into the pipe. It is also shown that the effect of axial wall conduction for the case of constant heat flux at the outer wall surface can be neglected when the wall thickness is small and the ratio of the conductivities of the wall to the fluid approaches unity.

  12. Effect of laparoscopic abdominal surgery on splanchnic circulation: Historical developments

    PubMed Central

    Hatipoglu, Sinan; Akbulut, Sami; Hatipoglu, Filiz; Abdullayev, Ruslan

    2014-01-01

    With the developments in medical technology and increased surgical experience, advanced laparoscopic surgical procedures are performed successfully. Laparoscopic abdominal surgery is one of the best examples of advanced laparoscopic surgery (LS). Today, laparoscopic abdominal surgery in general surgery clinics is the basis of all abdominal surgical interventions. Laparoscopic abdominal surgery is associated with systemic and splanchnic hemodynamic alterations. Inadequate splanchnic perfusion in critically ill patients is associated with increased morbidity and mortality. The underlying pathophysiological mechanisms are still not well understood. With experience and with an increase in the number and diversity of the resulting data, the pathophysiology of laparoscopic abdominal surgery is now better understood. The normal physiology and pathophysiology of local and systemic effects of laparoscopic abdominal surgery is extremely important for safe and effective LS. Future research projects should focus on the interplay between the physiological regulatory mechanisms in the splanchnic circulation (SC), organs, and diseases. In this review, we discuss the effects of laparoscopic abdominal surgery on the SC. PMID:25561784

  13. What is a Suitable Pressure for the Abdominal Drawing-in Maneuver in the Supine Position Using a Pressure Biofeedback Unit?

    PubMed Central

    Park, Du-Jin; Lee, Su-Kyoung

    2013-01-01

    [Purpose] The aim of this study was to determine the appropriate pressure variation for performing a successful abdominal drawing-in maneuver (ADIM). The abdominal muscle thickness variations and contraction ratios were examined in relation to pressure variations using a Pressure Biofeedback Unit (PBU) during an ADIM in the supine position. [Methods] The PBU was placed identically between the lumbar lordosis of 20 healthy subjects (12 males and 8 females) and the pressure of the PBU was maintained at 40 mmHg. Then, while the subjects performed ADIM at four random pressure variations (0, 2, 4, or 6 mmHg), the thicknesses of the transversus abdominis (TrA), the internal oblique abdominal muscle (IO), and the external oblique abdominal muscle (EO) were measured using ultrasonography. [Results] Pressure increases of 0–2 mmHg resulted in significant decreases in IO and EO thicknesses compared to pressure increases of 6 mmHg. Increases of 0–2 mmHg also resulted in significant decreases in IO+EO and EO contraction ratios compared to pressure increases of 6 mmHg, while the preferential activation ratio of the TrA was significantly increased. [Conclusion] Compared to the other pressure increases, an increase of 0–2 mmHg effectively regulated the thicknesses and contraction ratios of superficial muscles such as IO and EO, rather than the thickness and contraction ratio of the TrA, showing high and indirect preferential activation ratios for TrA. Therefore, for successful ADIM, rather than using large PBU pressure increases, exercises that promote slight increases of around 0–2 mmHg from a baseline of 40 mmHg are desirable. PMID:24259794

  14. WASTE HANDLING BUILDING SHIELD WALL ANALYSIS

    SciTech Connect

    D. Padula

    2000-01-13

    The scope of this analysis is to estimate the shielding wall, ceiling or equivalent door thicknesses that will be required in the Waste Handling Building to maintain the radiation doses to personnel within acceptable limits. The shielding thickness calculated is the minimum required to meet administrative limits, and not necessarily what will be recommended for the final design. The preliminary evaluations will identify the areas which have the greatest impact on mechanical and facility design concepts. The objective is to provide the design teams with the necessary information to assure an efficient and effective design.

  15. A Rapid Ultrasonic Method for Nondestructive Thickness Mapping of Bronze Liner in Steel-Backed Bearing Sleeves

    SciTech Connect

    Fei Dong; Rebinsky, Douglas A.

    2004-02-26

    In this paper a nondestructive, automatic, ultrasonic scanning method was developed to permit rapid thickness mapping of the bronze liner in a steel-backed bearing sleeve. Because the sound velocity in bronze was unknown, an indirect two-step approach was used: the first step utilized a simultaneous velocity and thickness mapping method to measure the total wall thickness while the second step measured the thickness of the steel backing. The difference of the two obtained thickness maps yielded the thickness map of the bronze liner. Comparison to destructive examination results showed a measurement accuracy of approximately 20 {mu}m or 2%.

  16. An Animal Model of Abdominal Aortic Aneurysm Created with Peritoneal Patch: Technique and Initial Results

    SciTech Connect

    Maynar, Manuel Hernandez, Javier; Sun Fei; Miguel, Carmen de; Crisostomo, Veronica; Uson, Jesus; Pineda, Luis-Fernando

    2003-04-15

    The purpose of this study was to develop an abdominal aortic aneurysm model that more closely resembles themorphology of human aneurysms with potential for further growth of the sac. An infrarenal abdominal aortic aneurysm (AAA) model was created with a double-layered peritoneal patch in 27 domestic swine. The patch,measuring in average from 6 to 12 cm in length and from 2 to 3 cm in width, was sutured to the edge of an aortotomy. Pre- and postsurgical digital subtraction aortograms (DSA) were obtained to document the appearance and dimensions of the aneurysm. All animals were followed with DSA for up to 5 months. Laparoscopic examination enhanced by the use of laparoscopic ultrasound was also carried out in 2 animals to assess the aneurysm at 30 and 60 days following surgery. Histological examination was performed on 4 animals. All the animals that underwent the surgical creation of the AAA survived the surgical procedure.Postsurgical DSA demonstrated the presence of the AAA in all animals,defined as more than 50% increase in diameter. The aneurysmal mean diameter increased from the baseline of 10.27 {+-} 1.24 to 16.69{+-} 2.29 mm immediately after surgery, to 27.6 {+-} 6.59 mm at 14 days, 32.45 {+-} 8.76 mm at 30 days (p <0.01), and subsequently decreased to 25.98 {+-} 3.75 mm at 60 days. A total of 15 animals died of aneurysmal rupture that occurred more frequently in the long aneurysms ({>=}6 cm in length) than the short aneurysms (<6 cm in length) during the first 2 weeks after surgery(p < 0.05). No rupture occurred beyond 16 days after surgery. Four animals survived and underwent 60-day angiographic follow-up. Laparoscopic follow-up showed strong pulses, a reddish external appearance and undetectable suture lines on the aneurysmal wall. On pathology, the patches were well incorporated into the aortic wall, the luminal wall appeared almost completely endothelialized, and cellular and matrix proliferation were noted in the aneurysmal wall. A reproducible technique for the creation of an infrarenal AAA model was developed using a peritoneal patch in swine. The aneurysm model proved to have potential for further growth of the sac and a tendency to rupture. Because of the growth potential, this might be a better model than those with a noncompliant aneurysmal wall for the preclinical evaluation of stent-graft devices.

  17. In vivo hypertensive arterial wall uptake of radiolabeled liposomes

    SciTech Connect

    Hodis, H.N.; Amartey, J.K.; Crawford, D.W.; Wickham, E.; Blankenhorn, D.H. )

    1990-06-01

    Using five sham-operated and seven aortic coarctation-induced hypertensive New Zealand White rabbits intravenously injected with neutral small unilamellar vesicles loaded with (111In)nitrilotriacetic acid, we demonstrated in vivo that the normal aortic arterial wall participates in liposome uptake and that this uptake is increased in the hypertensive aortic wall by approximately threefold (p less than or equal to 0.0001). Among the three regions examined, aortic arch, thoracic aorta, and lower abdominal aorta, the difference in uptake between the normotensive and hypertensive arterial walls was significantly different, p less than or equal to 0.05, p less than or equal to 0.0001, and p less than 0.05, respectively. The uptake by the different regions of the hypertensive arterial wall is consistent with the pathological changes present in these areas. Furthermore, the extent of liposome uptake by the aortic wall is strongly correlated with the height of the blood pressure (r = 0.85, p = 0.001, n = 11). We conclude that neutral small unilamellar liposomes can be used to carry agents into the arterial wall in vivo in the study of hypertensive vascular disease and could be especially useful for the delivery of pharmacologically or biologically active agents that would otherwise be inactivated within the circulation or are impermeable to the arterial wall.

  18. Cladding Attachment Over Thick Exterior Insulating Sheathing

    SciTech Connect

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1.What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2.Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3.What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  19. Cladding Attachment Over Thick Exterior Insulating Sheathing

    SciTech Connect

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  20. Evaluation of abdominal pain in the AIDS patient.

    PubMed Central

    Potter, D A; Danforth, D N; Macher, A M; Longo, D L; Stewart, L; Masur, H

    1984-01-01

    Acquired immune deficiency syndrome (AIDS) is a recently recognized entity characterized by a deficiency in cell mediated immune response. The syndrome is manifested by the development of otherwise rare malignant neoplasms and severe life-threatening opportunistic infections. Case histories of five AIDS patients evaluated for abdominal pain are presented to demonstrate the unusual spectrum of intra-abdominal pathology that may be encountered in the AIDS patient. As the number of patients with AIDS continues to escalate, surgical evaluation and intervention will be required more frequently. An understanding of this syndrome and its complications is mandatory for the surgeon to adequately evaluate AIDS patients with abdominal pain. PMID:6322708

  1. Application of the Ultrasonic Oil Film Thickness Measurement System in Bearing Chambers

    NASA Astrophysics Data System (ADS)

    Zhong, Chong; Hu, Jian-ping; Liu, Zhen-xia; Lu, Ya-guo; Hao, Yu-ya

    2014-06-01

    The oil film thickness in aero-engine bearing chamber influences the heat transfer capacity of the bearing chamber wall, so measuring oil film thickness accuspeedly is essential to the design and thermal analysis of lubricating oil system. In this paper, software and hardware of an ultrasonic measurement system based on pulse echo technique, which measures the oil film thickness in bearing chamber, are established. The hardware system mainly consists of signal acquisition card, probe, delay block and the corresponding cables. Functions as measurement parameter setup, real-time display of measured waveforms, post-processing and so on are included in the measurement software. Finally, the oil film thickness of the wall is measured with the measurement system developed. Signal quality of the dynamic measurement is analyzed. Comparison and analysis of different oil film thickness under different rotation rates are conducted.

  2. Skyrmion Multi-Walls

    E-print Network

    J. Silva Lobo; R. S. Ward

    2009-10-28

    Skyrmion walls are topologically-nontrivial solutions of the Skyrme system which are periodic in two spatial directions. We report numerical investigations which show that solutions representing parallel multi-walls exist. The most stable configuration is that of the square $N$-wall, which in the $N\\to\\infty$ limit becomes the cubically-symmetric Skyrme crystal. There is also a solution resembling parallel hexagonal walls, but this is less stable.

  3. A Literature Review of the Numerical Analysis of Abdominal Aortic Aneurysms Treated with Endovascular Stent Grafts

    PubMed Central

    Roy, David; Kauffmann, Claude; Delorme, Sébastien; Lerouge, Sophie; Cloutier, Guy; Soulez, Gilles

    2012-01-01

    The purpose of this paper is to present the basic principles and relevant advances in the computational modeling of abdominal aortic aneurysms and endovascular aneurysm repair, providing the community with up-to-date state of the art in terms of numerical analysis and biomechanics. Frameworks describing the mechanical behavior of the aortic wall already exist. However, intraluminal thrombus nonhomogeneous structure and porosity still need to be well characterized. Also, although the morphology and mechanical properties of calcifications have been investigated, their effects on wall stresses remain controversial. Computational fluid dynamics usually assumes a rigid artery wall, whereas fluid-structure interaction accounts for artery compliance but is still challenging since arteries and blood have similar densities. We discuss alternatives to fluid-structure interaction based on dynamic medical images that address patient-specific hemodynamics and geometries. We describe initial stresses, elastic boundary conditions, and statistical strength for rupture risk assessment. Special emphasis is accorded to workflow development, from the conversion of medical images into finite element models, to the simulation of catheter-aorta interactions and stent-graft deployment. Our purpose is also to elaborate the key ingredients leading to virtual stenting and endovascular repair planning that could improve the procedure and stent-grafts. PMID:22997538

  4. Method of non-destructively inspecting a curved wall portion

    DOEpatents

    Fong, James T. (Bethel Park, PA)

    1996-01-01

    A method of non-destructively inspecting a curved wall portion of a large and thick walled vessel for a defect by computed tomography is provided. A collimated source of radiation is placed adjacent one side of the wall portion and an array of detectors for the radiation is placed on the other side adjacent the source. The radiation from the source passing through the wall portion is then detected with the detectors over a limited angle, dependent upon the curvature of the wall of the vessel, to obtain a dataset. The source and array are then coordinately moved relative to the wall portion in steps and a further dataset is obtained at each step. The plurality of datasets obtained over the limited angle is then processed to produce a tomogram of the wall portion to determine the presence of a defect therein. In a preferred embodiment, the curved wall portion has a center of curvature so that the source and the array are positioned at each step along a respective arc curved about the center. If desired, the detector array and source can be reoriented relative to a new wall portion and an inspection of the new wall portion can be easily obtained. Further, the source and detector array can be indexed in a direction perpendicular to a plane including the limited angle in a plurality of steps so that by repeating the detecting and moving steps at each index step, a three dimensional image can be created of the wall portion.

  5. Halogenation of microcapsule walls

    NASA Technical Reports Server (NTRS)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  6. The Lamportian cell wall

    SciTech Connect

    Keiliszewski, M.; Lamport, D. )

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  7. Wall stress and deformation analysis in a numerical model of pulse wave propagation.

    PubMed

    He, Fan; Hua, Lu; Gao, Lijian

    2015-08-17

    To simulate pulse wave propagation, we set up a wave propagation model using blood-wall interaction in previous work. In this paper, our purpose is to investigate wall stress and deformation of the wave propagation model. The finite element method is employed for solving the governing equations of blood and wall. Our results suggest that there are two peaks in the circumferential stress and strain distributions of the normal model. The stress and strain values change with the varieties of different factors, such as wall thickness and vessel diameter. The results indicate that different parameters of fluid and tube wall have remarked impact on wall stress and deformation. PMID:26406044

  8. Possible Genetic Origin of Limb-Body Wall Complex

    PubMed Central

    Gajzer, David C.; Hirzel, Alicia Cristina; Saigal, Gaurav; Rojas, Claudia Patricia; Rodriguez, Maria Matilde

    2015-01-01

    Limb body wall complex (LBWC) is characterized by multiple severe congenital malformations including an abdominal and/or thoracic wall defect covered by amnion, a short or absent umbilical cord with the placenta almost attached to the anterior fetal wall, intestinal malrotation, scoliosis, and lower extremity anomalies. There is no consensus about the etiology of LBWC and many cases with abnormal facial cleft do not meet the requirements for the true complex. We describe a series of four patients with LBWC and other malformations in an attempt to explain their etiology. There are several reports of fetuses with LBWC and absent gallbladder and one of our patients also had polysplenia. Absent gallbladder and polysplenia are associated with laterality genes including HOX, bFGF, transforming growth factor beta/activins/BMP4, WNT 1–8, and SHH. We postulate that this severe malformation may be due to abnormal genes involved in laterality and caudal development. PMID:26111189

  9. Ventilation distribution and chest wall mechanics in microgravity

    NASA Technical Reports Server (NTRS)

    Paiva, M.; Wantier, M.; Verbanck, S.; Engel, L. A.; Prisk, G. K.; Guy, H. J. B.; West, J. B.

    1997-01-01

    The effect of gravity on lung ventilation distribution and the mechanisms of the chest wall were investigated. The following tests were performed with the respiratory monitoring system of the Anthorack, flown onboard Spacelab D2 mission: single breath washout (SBW), multiple breath washout (MBW) and argon rebreathing (ARB). In order to study chest wall mechanisms in microgravity, a respiratory inductive plethysmograph was used. The SBW tests did not reach statistical significance, while the ARB tests showed that gravity independent inhomogeneity of specific ventilation is larger than gravity dependent inhomogeneity. In which concerns the chest wall mechanisms, the analysis on the four astronauts during the normal respirations of the relaxation maneuver showed a 40 percent increase on the abdominal contribution to respiration.

  10. Anal avulsion caused by abdominal crush injury.

    PubMed

    Terrosu, G; Rossetto, A; Kocjancic, E; Rossitti, P; Bresadola, V

    2011-12-01

    We report the case of a pelvic and lower abdomen crushing trauma in 37-year-old male patient. The patient had an open lumbar wound, laceration of the psoas muscle, pelvic fracture, a ruptured urogenital diaphragm, and extensive urogenital lacerations. An emergency laparotomy was performed with debridment, urethral reconstruction, and osteosynthesis of the pubic bone. The mobilization of the patient revealed a deep gap, about 8 × 8 cm, in the perineum, with the anus and rectum displaced from their original site. Anal reimplantation was performed, suturing the median raphe, inserting two pelvic drainage tubes, and fashioning a loop transverse colostomy. Closed rectal traumas account for only 4-11% of all rectal traumas. Crushing of the pelvis causes a sudden reduction in its anteroposterior diameter and a corresponding increase in its latero-lateral diameter, together with an abrupt rise in intra-abdominal pressure. The anus is pushed out of the perineal plane due to the divarication of the levator muscles. As suggested in the literature, the standard treatment is wound debridement with immediate or deferred repair, fashioning a diversion colostomy, and repair of the rectum, wherever possible. PMID:21556880

  11. [Abdominal pain with a microvascular cause].

    PubMed

    Slegers, Claire A D; Bloemsma, Gijsbert C; Horjus, Carmen S; Visser, Henk; Robijn, Rob J; Spillenaar Bilgen, Ernst Jan

    2012-01-01

    A 50-year-old Caucasian man was admitted with unexplained abdominal pain. Based on CT scan results, a perforation resulting from colitis of the transverse colon was suspected. Additional colonoscopy showed ulcerative stenosis of the transverse colon. Initially, the patient recovered on conservative treatment; however, because of persistent stenosis, an elective resection of the transverse colon was performed. A CT scan revealed free gas around the anastomosis on the fourth postoperative day. Relaparotomy revealed leakage and diffuse ischaemic changes around the anastomosis as well as perforations at different sites on the small bowel. Postoperative CT angiography showed stenosis of the proximal celiac trunk, which was successfully stented. Digital subtraction angiography (DSA) revealed luminal irregularities of the superior mesenteric, the middle colic as well as the main hepatic and splenic arteries. Eventually, the clinical presentation and surgical, radiologic and histopathological findings together led to the diagnosis of polyarteritis nodosa (PAN). Aggressive treatment with glucocorticoids and cyclophosphamide resulted in the resolution of symptoms and the disappearance of radiologic abnormalities. PMID:22414672

  12. National Outcomes for Open Ventral Hernia Repair Techniques in Complex Abdominal Wall Reconstruction.

    PubMed

    Ross, Samuel W; Oommen, Bindhu; Huntington, Ciara; Walters, Amanda L; Lincourt, Amy E; Kercher, Kent W; Augenstein, Vedra A; Heniford, B Todd

    2015-08-01

    Modern adjuncts to complex, open ventral hernia repair often include component separation (CS) and/or panniculectomy (PAN). This study examines nationwide data to determine how these techniques impact postoperative complications. The National Surgical Quality Improvement Program database was queried from 2005 to 2013 for inpatient, elective open ventral hernia repairs (OVHR). Cases were grouped by the need for and type of concomitant advancement flaps: OVHR alone (OVHRA), OVHR with CS, OVHR with panniculectomy (PAN), or both CS and PAN (BOTH). Multivariate regression to control for confounding factors was conducted. There were 58,845 OVHR: 51,494 OVHRA, 5,357 CS, 1,617 PAN, and 377 BOTH. Wound complications (OVHRA 8.2%, CS 12.8%, PAN 14.4%, BOTH 17.5%), general complications (15.2%, 24.9%, 25.2%, 31.6%), and major complications (6.9%, 11.4%, 7.2%, 13.5%) were different between groups (P < 0.0001). There was no difference in mortality. Multivariate regression showed CS had higher odds of wound [odds ratio (OR) 1.7, 95% confidence interval (CI) 1.5-2.0], general (OR 1.5, 95% CI: 1.3-1.8), and major complications (OR 2.1, 95%, CI: 1.8-2.4), and longer length of stay by 2.3 days. PAN had higher odds of wound (OR 1.5, 95%, CI: 1.3-1.8) and general complications (OR 1.7, 95%CI: 1.5-2.0). Both CS and PAN had higher odds of wound (OR 2.2, 95%, CI: 1.5-3.2), general (OR 2.5, 95%, CI: 1.8-3.4), and major complications (OR 2.2, 95%CI: 1.4-3.4), and two days longer length of stay. In conclusion, patients undergoing OVHR that require CS or PAN have a higher independent risk of complications, which increases when the procedures are combined. PMID:26215239

  13. Dynamic response of flexible retaining walls

    SciTech Connect

    Younan, A.H.; Veletsos, A.S.; Bandyopadhyay, K.

    1997-01-01

    Making use of an extension of a recently proposed, relatively simple, approximate method of analysis, a critical evaluation is made of the response to horizontal ground shaking of flexible walls retaining a uniform, linear, viscoelastic stratum of constant thickness and semiinfinite extent in the horizontal direction. Both cantilever and top-supported walls are examined. Following a detailed description of the method and of its rate of convergence, comprehensive numerical solutions are presented that elucidate the action of the system and the effects of the various parameters involved. The parameters varied include the flexibility of the wall, the condition of top support, and the characteristics of the ground motion. The effects of both harmonic base motions and an actual earthquake record are examined. Special attention is paid to the effects of long-period, effectively static excitations. A maximum dynamic response is then expressed as the product of the corresponding static response and an appropriate amplification or deamplification factor. The response quantities examined include the displacements of the wall relative to the moving base, the dynamic wall pressures, and the total wall force, base shear and base moment.

  14. ZACH SKINNER Thin-wall Pressure System

    E-print Network

    Clement, Prabhakar

    and Output Input Output Radius (in.) 1.75 Thickness (in.) 0.083 Pressure (psi) 250 E (psi) 28000000 Gage (Microstrain) 91.3 v 0.27 Thin Wall Stress Calculator L Theoretical (psi) 2510.5 H Theoretical (psi) 5021.1 G 11023622.0 X (Microstrain) 33.3 Y (Microstrain) 144.8 XY (Microstrain) 4.0 L Measured (psi) 2186.2 H

  15. Machining Thin-Walled Cylindrical Parts

    NASA Technical Reports Server (NTRS)

    Cimbak, Joe; Spagnolo, Jim; Kraus, Dan

    1988-01-01

    Cylindrical walls only few thousandths of inch thick machined accurately and without tears or punctures with aid of beryllium copper mandrel. Chilled so it contracts, then inserted in cylinder. As comes to room temperature, mandrel expands and fits snugly inside cylinder. Will not allow part to slide and provides solid backup to prevent deflection when part machined by grinding wheel. When machining finished, cylinder-and-mandrel assembly inserted in dry ice, mandrel contracts and removed from part.

  16. On determining wall shear stress in spatially developing two-dimensional wall-bounded flows

    NASA Astrophysics Data System (ADS)

    Mehdi, Faraz; Johansson, T. Gunnar; White, Christopher M.; Naughton, Jonathan W.

    2014-01-01

    A full momentum integral-based method for determining wall shear stress is presented. The method is mathematically exact and has the advantage of having no explicit streamwise gradient terms. It is applicable for flows that change rapidly in the streamwise direction and, in particular, to flows with ill-defined outer boundary conditions or when the measurement grid does not extend over the whole boundary layer thickness. The method is applied to two different experimental plane turbulent wall jet data sets for which independent estimates of wall shear stress were known, and the different results compare favorably. Complications owing to experimental limitations and measurement error in determining wall shear stress from the proposed method are presented, and mitigating strategies are described.

  17. Successful management of abdominal wound dehiscence using a vacuum assisted closure system combined with mesh-mediated medial traction.

    PubMed

    Lord, A C; Hompes, R; Venkatasubramaniam, A; Arnold, S

    2015-01-01

    Management of the open abdomen has advanced significantly in recent years with the increasing use of vacuum assisted closure (VAC) techniques leading to increased rates of fascial closure. We present the case of a patient who suffered two complete abdominal wall dehiscences after an elective laparotomy, meaning primary closure was no longer possible. She was treated successfully with a VAC system combined with continuous medial traction using a Prolene(®) mesh. This technique has not been described before in the management of patients following wound dehiscence. PMID:25519257

  18. Chest wall mechanics in sustained microgravity

    NASA Technical Reports Server (NTRS)

    Wantier, M.; Estenne, M.; Verbanck, S.; Prisk, G. K.; Paiva, M.; West, J. B. (Principal Investigator)

    1998-01-01

    We assessed the effects of sustained weightlessness on chest wall mechanics in five astronauts who were studied before, during, and after the 10-day Spacelab D-2 mission (n = 3) and the 180-day Euromir-95 mission (n = 2). We measured flow and pressure at the mouth and rib cage and abdominal volumes during resting breathing and during a relaxation maneuver from midinspiratory capacity to functional residual capacity. Microgravity produced marked and consistent changes (Delta) in the contribution of the abdomen to tidal volume [DeltaVab/(DeltaVab + DeltaVrc), where Vab is abdominal volume and Vrc is rib cage volume], which increased from 30.7 +/- 3. 5 (SE)% at 1 G head-to-foot acceleration to 58.3 +/- 5.7% at 0 G head-to-foot acceleration (P < 0.005). Values of DeltaVab/(DeltaVab + DeltaVrc) did not change significantly during the 180 days of the Euromir mission, but in the two subjects DeltaVab/(DeltaVab + DeltaVrc) was greater on postflight day 1 than on subsequent postflight days or preflight. In the two subjects who produced satisfactory relaxation maneuvers, the slope of the Konno-Mead plot decreased in microgravity; this decrease was entirely accounted for by an increase in abdominal compliance because rib cage compliance did not change. These alterations are similar to those previously reported during short periods of weightlessness inside aircrafts flying parabolic trajectories. They are also qualitatively similar to those observed on going from upright to supine posture; however, in contrast to microgravity, such postural change reduces rib cage compliance.

  19. Does Lower Limb Exercise Worsen Renal Artery Hemodynamics in Patients with Abdominal Aortic Aneurysm?

    PubMed Central

    Zhang, Nan; Xu, Zaipin; Deng, Xiaoyan; Liu, Ming; Liu, Xiao

    2015-01-01

    Renal artery stenosis (RAS) and renal complications emerge in some patients after endovascular aneurysm repair (EVAR) to treat abdominal aorta aneurysm (AAA). The mechanisms for the causes of these problems are not clear. We hypothesized that for EVAR patients, lower limb exercise could negatively influence the physiology of the renal artery and the renal function, by decreasing the blood flow velocity and changing the hemodynamics in the renal arteries. To evaluate this hypothesis, pre- and post-operative models of the abdominal aorta were reconstructed based on CT images. The hemodynamic environment was numerically simulated under rest and lower limb exercise conditions. The results revealed that in the renal arteries, lower limb exercise decreased the wall shear stress (WSS), increased the oscillatory shear index (OSI) and increased the relative residence time (RRT). EVAR further enhanced these effects. Because these parameters are related to artery stenosis and atherosclerosis, this preliminary study concluded that lower limb exercise may increase the potential risk of inducing renal artery stenosis and renal complications for AAA patients. This finding could help elucidate the mechanism of renal artery stenosis and renal complications after EVAR and warn us to reconsider the management and nursing care of AAA patients. PMID:25946196

  20. Optical design of a robotic TV camera probe for minimally invasive abdominal surgery

    NASA Astrophysics Data System (ADS)

    Todaro, Susanna; He, Weiyi; Killinger, Dennis

    2011-03-01

    Minimally invasive techniques are a promising new field of surgery; however, they limit the surgeon's access points and maneuverability. In order to increase the number of access points in minimally invasive abdominal surgery, a proposed implantable medical probe braces to the abdominal wall and provides illumination and video signal. The probe is cylindrical, about 25 mm long and 10 mm in diameter. A ring of LEDs on the end of the probe illuminates the tissue, and the resulting image is focused onto an HD video detector. It was necessary to apply beam-shaping reflectors to collimate the light onto a small target area, to avoid illuminating areas not picked up by the video. These reflectors were designed and simulated using the optical ray tracing software TracePro. Two LED chip geometries and three types of reflector geometries were analyzed, and the parameters for each geometry were optimized. For the straight-edged reflectors, the intensity patterns and optimization were compared to experimental results. Although parabolic reflectors produced the best collimation, cone reflectors with a 20-degree half-angle produced significant collimation at a much cheaper price. This work was supported by NSF REU program (award No DMR-1004873).