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Sample records for abdominal wall thickness

  1. [The cutaneous groin flap for coverage of a full-thickness abdominal wall defect].

    PubMed

    Doebler, O; Spierer, R

    2010-08-01

    A full-thickness defect of the abdominal wall is rare and may occur as a complication of extended abdominal surgery procedures. We report about a 69-year-old patient who was presented to our department with a full-thickness abdominal wall defect and a fully exposed collagen-mesh for reconstructive wound closure. 13 operations with resections of necrotic parts of the abdominal wall were performed following a complicated intraabdominal infection. After debridement and mesh explantation, closure of the remaining defect of the lower abdominal region was achieved by a cutaneous groin flap.

  2. [An example of multi-stage reconstruction of a full-thickness abdominal wall defect].

    PubMed

    Kaczmarzyk, Janusz; Elsaftawy, Ahmed; Jabłecki, Jerzy; Kaczmarzyk, Leszek

    2013-01-01

    Abdominal wall reconstruction is a highly complex procedure that may requires a multiple stages surgical operations. The aim of a such reconstruction is to close the abdominal wall defect and to create a support for the internal organs. It's a challenge for both general and reconstructive surgery. An incomplete thickness defects of the abdominal wall are so much easier to challenge than complete ones. Also the size of the primary defect determines the way and stages of the operation. Such defects can occur in necrotizing fasciitis of the abdominal wall, after abdominal walls tumors removal, in traffic accidents or after "open abdomen" procedures (acute severe pancreatitis). In this paper the authors present a case of 62-yo patient which was operated because of large intestine perforation with various complications of which the most serious was the abdominal wall defect.

  3. Study of Individual Characteristic Abdominal Wall Thickness Based on Magnetic Anchored Surgical Instruments

    PubMed Central

    Dong, Ding-Hui; Liu, Wen-Yan; Feng, Hai-Bo; Fu, Yi-Li; Huang, Shi; Xiang, Jun-Xi; Lyu, Yi

    2015-01-01

    Background: Magnetic anchored surgical instruments (MASI), relying on magnetic force, can break through the limitations of the single port approach in dexterity. Individual characteristic abdominal wall thickness (ICAWT) deeply influences magnetic force that determines the safety of MASI. The purpose of this study was to research the abdominal wall characteristics in MASI applied environment to find ICAWT, and then construct an artful method to predict ICAWT, resulting in better safety and feasibility for MASI. Methods: For MASI, ICAWT is referred to the thickness of thickest point in the applied environment. We determined ICAWT through finding the thickest point in computed tomography scans. We also investigated the traits of abdominal wall thickness to discover the factor that can be used to predict ICAWT. Results: Abdominal wall at C point in the middle third lumbar vertebra plane (L3) is the thickest during chosen points. Fat layer thickness plays a more important role in abdominal wall thickness than muscle layer thickness. “BMI-ICAWT” curve was obtained based on abdominal wall thickness of C point in L3 plane, and the expression was as follow: f(x) = P1 × x2 + P2 × x + P3, where P1 = 0.03916 (0.01776, 0.06056), P2 = 1.098 (0.03197, 2.164), P3 = −18.52 (−31.64, −5.412), R-square: 0.99. Conclusions: Abdominal wall thickness of C point at L3 could be regarded as ICAWT. BMI could be a reliable predictor of ICAWT. In the light of “BMI-ICAWT” curve, we may conveniently predict ICAWT by BMI, resulting a better safety and feasibility for MASI. PMID:26228215

  4. Fluid-structure interaction in abdominal aortic aneurysms: effects of asymmetry and wall thickness

    PubMed Central

    Scotti, Christine M; Shkolnik, Alexander D; Muluk, Satish C; Finol, Ender A

    2005-01-01

    Background Abdominal aortic aneurysm (AAA) is a prevalent disease which is of significant concern because of the morbidity associated with the continuing expansion of the abdominal aorta and its ultimate rupture. The transient interaction between blood flow and the wall contributes to wall stress which, if it exceeds the failure strength of the dilated arterial wall, will lead to aneurysm rupture. Utilizing a computational approach, the biomechanical environment of virtual AAAs can be evaluated to study the affects of asymmetry and wall thickness on this stress, two parameters that contribute to increased risk of aneurysm rupture. Methods Ten virtual aneurysm models were created with five different asymmetry parameters ranging from β = 0.2 to 1.0 and either a uniform or variable wall thickness to study the flow and wall dynamics by means of fully coupled fluid-structure interaction (FSI) analyses. The AAA wall was designed to have a (i) uniform 1.5 mm thickness or (ii) variable thickness ranging from 0.5 – 1.5 mm extruded normally from the boundary surface of the lumen. These models were meshed with linear hexahedral elements, imported into a commercial finite element code and analyzed under transient flow conditions. The method proposed was then compared with traditional computational solid stress techniques on the basis of peak wall stress predictions and cost of computational effort. Results The results provide quantitative predictions of flow patterns and wall mechanics as well as the effects of aneurysm asymmetry and wall thickness heterogeneity on the estimation of peak wall stress. These parameters affect the magnitude and distribution of Von Mises stresses; varying wall thickness increases the maximum Von Mises stress by 4 times its uniform thickness counterpart. A pre-peak systole retrograde flow was observed in the AAA sac for all models, which is due to the elastic energy stored in the compliant arterial wall and the expansion force of the artery

  5. 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

  6. Lateral Abdominal Wall Reconstruction

    PubMed Central

    Baumann, Donald P.; Butler, Charles E.

    2012-01-01

    Lateral abdominal wall (LAW) defects can manifest as a flank hernias, myofascial laxity/bulges, or full-thickness defects. These defects are quite different from those in the anterior abdominal wall defects and the complexity and limited surgical options make repairing the LAW a challenge for the reconstructive surgeon. LAW reconstruction requires an understanding of the anatomy, physiologic forces, and the impact of deinnervation injury to design and perform successful reconstructions of hernia, bulge, and full-thickness defects. Reconstructive strategies must be tailored to address the inguinal ligament, retroperitoneum, chest wall, and diaphragm. Operative technique must focus on stabilization of the LAW to nonyielding points of fixation at the anatomic borders of the LAW far beyond the musculofascial borders of the defect itself. Thus, hernias, bulges, and full-thickness defects are approached in a similar fashion. Mesh reinforcement is uniformly required in lateral abdominal wall reconstruction. Inlay mesh placement with overlying myofascial coverage is preferred as a first-line option as is the case in anterior abdominal wall reconstruction. However, interposition bridging repairs are often performed as the surrounding myofascial tissue precludes a dual layered closure. The decision to place bioprosthetic or prosthetic mesh depends on surgeon preference, patient comorbidities, and clinical factors of the repair. Regardless of mesh type, the overlying soft tissue must provide stable cutaneous coverage and obliteration of dead space. In cases where the fasciocutaneous flaps surrounding the defect are inadequate for closure, regional pedicled flaps or free flaps are recruited to achieve stable soft tissue coverage. PMID:23372458

  7. The effects of modified wall squat exercises on average adults' deep abdominal muscle thickness and lumbar stability.

    PubMed

    Cho, Misuk

    2013-06-01

    [Purpose] The purpose of this study was to compare the effects of bridge exercises applying the abdominal drawing-in method and modified wall squat exercises on deep abdominal muscle thickness and lumbar stability. [Subjects] A total of 30 subjects were equally divided into an experimental group and a control group. [Methods] The experimental group completed modified wall squat exercises, and the control group performed bridge exercises. Both did so for 30 minutes three times per week over a six-week period. Both groups' transversus abdominis (Tra), internal oblique (IO), and multifidus muscle thickness were measured using ultrasonography, while their static lumbar stability and dynamic lumbar stability were measured using a pressure biofeedback unit. [Results] A comparison of the pre-intervention and post-intervention measures of the experimental group and the control group was made; the Tra and IO thicknesses were significantly different in both groups. [Conclusion] The modified wall squat exercise and bridge exercise affected the thicknesses of the Tra and the IO muscles. While the bridge exercise requirs space and a mattress to lie on, the modified wall squat exercise can be conveniently performed anytime.

  8. Dynamic reconstruction of full-thickness abdominal wall defects using free innervated vastus lateralis muscle flap combined with free anterolateral thigh flap.

    PubMed

    Iida, Takuya; Mihara, Makoto; Narushima, Mitsunaga; Todokoro, Takeshi; Hara, Hisako; Yoshimatu, Hidehiko; Koshima, Isao; Kadono, Takafumi

    2013-03-01

    Reconstruction of full-thickness abdominal wall defects remains a difficult surgical challenge. Although various reconstructive methods, including artificial mesh, pedicled and free flaps, have been reported, most reported reconstruction of only the fascia layer, leaving the resected rectus abdominis muscle unreconstructed. However, recent studies suggested the importance of dynamic reconstruction with functional muscle in preventing abdominal hernia in the long-term. According to the principle of reconstructive surgery, "replace lost tissue with similar tissue," a functionally and aesthetically ideal reconstruction is to reconstruct all components of the abdominal wall structure, including skin, subcutaneous fat, fascia, and muscle. We present 2 cases with full-thickness abdominal wall defects in the upper abdominal region, which we reconstructed with a free innervated vastus lateralis muscle flap combined with a free anterolateral thigh flap. The motor nerve of the vastus lateralis muscle was sutured with the intercostal nerve, and reinnervation was confirmed by electromyography. This method allows reconstruction of all components of the abdominal wall with a single flap, and dynamic reconstruction is achieved which will reduce the risk of postoperative hernia. We believe this method can be a good option for reconstruction of full-thickness abdominal wall defects with long-term stability.

  9. Reconstruction of a four-quadrant full-thickness abdominal wall defect after removal and debridement of an infected mesh hernioplasty.

    PubMed

    Schmitz, C; Schramm, S; Hankiss, J

    2011-02-01

    This case-report shows our experience with a patient, who underwent mesh hernioplasty followed by infection of the mesh and full-thickness loss of the abdominal wall after debridement due to necrosis. The anamnesis included generalised arteriosclerosis, chronic nicotine and alcohol abuse and recurring wound-healing disorders after surgical procedures. The initial infection was treated by radical debridement, targeted antibiotics and V.A.C.(®) Therapy. After this, a staged plastic reconstructive procedure with four pedicled flaps was performed. The functional integrity of the abdominal wall was completely re-established. The patient was able to continue her occupation as a facility manager. Although the use of free flaps is very common in modern plastic and reconstructive surgery, procedures such as pedicled flaps still have their significance for special indications. In this case, a full recovery of the abdominal wall with autologous tissue was successful under difficult vascular conditions by using local flaps.

  10. Soft tissue coverage in abdominal wall reconstruction.

    PubMed

    Baumann, Donald P; Butler, Charles E

    2013-10-01

    Abdominal wall defects requiring soft tissue coverage can be either partial-thickness defects or full-thickness composite defects. Soft tissue flap reconstruction offers significant advantages in defects that cannot be closed primarily. Flap reconstruction is performed in a single-stage procedure obviating chronic wound management. If the defect size exceeds the availability of local soft tissue for coverage, regional pedicled flaps can be delivered into the abdominal wall while maintaining blood supply from their donor site. Microsurgical free tissue transfer increases the capacity to provide soft tissue coverage for abdominal wall defects that are not amenable to either local or regional flap coverage.

  11. Pedicled full-thickness abdominal flap combined with skin grafting for the reconstruction of anterior chest wall defect following major electrical burn.

    PubMed

    Zhao, Jing-Chun; Xian, Chun-Jing; Yu, Jia-Ao; Shi, Kai

    2015-02-01

    Successful reconstruction of extensive anterior chest wall defect following major electrical burn represents a very challenging surgery. Herein we report the first case using pedicled full-thickness abdominal flap combined with skin grafting to treat this injury with severe infection and exposure of pericardium and ribs in a Chinese patient. Following the performance of chest debridement to remove necrotic and infected tissues and the injection of broad-spectrum antibiotics to reduce infection, a pedicled full-thickness abdominal flap was used to cover the exposed pericardium and ribs, and skin grafting from the right leg of the patient was done to cover the exposed vital tissues. The patient was followed up for a total of 3·5 years, and satisfactory cosmetic and functional outcomes were obtained without complications. This report provides an effective method for the surgeons who encounter similar cases where reconstruction of extensive anterior chest wall is required.

  12. 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

  13. Economics of abdominal wall reconstruction.

    PubMed

    Bower, Curtis; Roth, J Scott

    2013-10-01

    The economic aspects of abdominal wall reconstruction are frequently overlooked, although understandings of the financial implications are essential in providing cost-efficient health care. Ventral hernia repairs are frequently performed surgical procedures with significant economic ramifications for employers, insurers, providers, and patients because of the volume of procedures, complication rates, the significant rate of recurrence, and escalating costs. Because biological mesh materials add significant expense to the costs of treating complex abdominal wall hernias, the role of such costly materials needs to be better defined to ensure the most cost-efficient and effective treatments for ventral abdominal wall hernias.

  14. Abdominal wall surgery

    MedlinePlus

    ... the results of abdominoplasty. Many feel a new sense of self-confidence. Alternative Names Cosmetic surgery of the abdomen; Tummy tuck; Abdominoplasty Images Abdominoplasty - series Abdominal muscles References McGrath MH, Pomerantz J. Plastic surgery. In: Townsend ...

  15. Recovery after abdominal wall reconstruction.

    PubMed

    Jensen, Kristian Kiim

    2017-03-01

    Incisional hernia is a common long-term complication to abdominal surgery, occurring in more than 20% of all patients. Some of these hernias become giant and affect patients in several ways. This patient group often experiences pain, decreased perceived body image, and loss of physical function, which results in a need for surgical repair of the giant hernia, known as abdominal wall reconstruction. In the current thesis, patients with a giant hernia were examined to achieve a better understanding of their physical and psychological function before and after abdominal wall reconstruction. Study I was a systematic review of the existing standardized methods for assessing quality of life after incisional hernia repair. After a systematic search in the electronic databases Embase and PubMed, a total of 26 studies using standardized measures for assessment of quality of life after incisional hernia repair were found. The most commonly used questionnaire was the generic Short-Form 36, which assesses overall health-related quality of life, addressing both physical and mental health. The second-most common questionnaire was the Carolinas Comfort Scale, which is a disease specific questionnaire addressing pain, movement limitation and mesh sensation in relation to a current or previous hernia. In total, eight different questionnaires were used at varying time points in the 26 studies. In conclusion, standardization of timing and method of quality of life assessment after incisional hernia repair was lacking. Study II was a case-control study of the effects of an enhanced recovery after surgery pathway for patients undergoing abdominal wall reconstruction for a giant hernia. Sixteen consecutive patients were included prospectively after the implementation of a new enhanced recovery after surgery pathway at the Digestive Disease Center, Bispebjerg Hospital, and compared to a control group of 16 patients included retrospectively in the period immediately prior to the

  16. [Hypogastric abdominal wall reconstruction with a pedicled anterolateral thigh flap].

    PubMed

    Moullot, P; Philandrianos, C; Gonnelli, D; Casanova, D

    2014-10-01

    Looking at a full-thickness abdominal wall defect, it is necessary to use reconstructive surgery techniques. The authors present an original case of reconstruction of the abdominal wall, using an anterolateral thigh flap (ALT) harvested with vascularised fascia lata. We describe the advantages of this technique, which has rarely been used for this indication. An 80-year-old woman presenting a full-thickness abdominal wall defect of 15×18cm was reconstructed by a pedicled ALT flap. Skin wound healing was obtained within 15 days, with no complication. There was no donor site sequela. The pedicled ALT flap appears to be a good solution for hypogastric abdominal wall defect in a one step procedure. Vacularised fascia lata bring with the cutaneous flap is useful to reconstruct the abdominal fascia.

  17. Blunt traumatic abdominal wall disruption with evisceration

    PubMed Central

    McDaniel, Ellen; Stawicki, Stanislaw PA; Bahner, David P

    2011-01-01

    Blunt traumatic abdominal wall disruptions associated with evisceration are very rare. The authors describe a case of traumatic abdominal wall disruption with bowel evisceration that occurred after a middle-aged woman sustained direct focal blunt force impact to the lower abdomen. Abdominal exploration and surgical repair of the abdominal wall defect were performed, with good clinical outcome. A brief overview of literature pertinent to this rare trauma scenario is presented. PMID:22229144

  18. Pulmonary complications of abdominal wall defects.

    PubMed

    Panitch, Howard B

    2015-01-01

    The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

  19. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, P.R.

    1985-06-21

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and radius by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  20. Tube wall thickness measurement apparatus

    DOEpatents

    Lagasse, Paul R.

    1987-01-01

    An apparatus for measuring the thickness of a tube's wall for the tube's entire length and circumference by determining the deviation of the tube wall thickness from the known thickness of a selected standard item. The apparatus comprises a base and a first support member having first and second ends. The first end is connected to the base and the second end is connected to a spherical element. A second support member is connected to the base and spaced apart from the first support member. A positioning element is connected to and movable relative to the second support member. An indicator is connected to the positioning element and is movable to a location proximate the spherical element. The indicator includes a contact ball for first contacting the selected standard item and holding it against the spherical element. The contact ball then contacts the tube when the tube is disposed about the spherical element. The indicator includes a dial having a rotatable needle for indicating the deviation of the tube wall thickness from the thickness of the selected standard item.

  1. Reconstruction of complex abdominal wall defects.

    PubMed

    Leppäniemi, A; Tukiainen, E

    2013-01-01

    Complex abdominal wall defects refer to situations where simple ventral hernia repair is not feasible because the defect is very large, there is a concomitant infection or failed previous re-pair attempt, or if there is not enough original skin to cover the repair. Usually a complex abdominal wall repair is preceded by a period of temporary abdominal closure where the short-term aims include closure of the catabolic drain, protection of the viscera and preventing fistula formation, preventing bowel adherence to the abdominal wall, and enabling future fascial and skin closure. Currently the best way to achieve these goals is the vacuum- and mesh-mediated fascial traction method achieving close to 90% fascial closure rates. The long-term aims of an abdominal closure following a planned hernia strategy include intact skin cover, fascial closure at midline (if possible), good functional outcome with innervated abdominal musculature, no pain and good cosmetic result. The main methods of abdominal wall reconstruction include the use of prosthetic (mesh) or autologous material (tissue flaps). In patients with original skin cover over the fascial defect (simple ventral hernia), the most commonly used method is hernia repair with an artificial mesh. For more complex defects, our first choice of reconstruction is the component separation technique, sometimes combined with a mesh. In contaminated fields where component separation alone is not feasible, a combination with a biological mesh can be used. In large defects with grafted skin, a free TFL flap is the best option, sometimes reinforced with a mesh and enhanced with components separation.

  2. [Large abdominal wall reconstruction by free flap after recurrence of a dermatofibrosarcoma protuberans].

    PubMed

    Le Fourn, B; Lejeune, F; Sartre, J Y; Loirat, Y; Pannier, M

    1996-12-01

    Based on a case of recurrence of a dermatofibrosarcoma protuberans of the abdominal wall, the authors discuss the need for initial wide resection of this type of skin tumour and the possibilities of repair of extensive full thickness defects of the abdominal wall by means of a latissimus dorsi myocutaneous free flap.

  3. Genetics Home Reference: abdominal wall defect

    MedlinePlus

    ... Aug;6(4):232-6. Citation on PubMed Islam S. Clinical care outcomes in abdominal wall defects. Curr ... Site Map Customer Support Selection Criteria for Links USA.gov Copyright Privacy Accessibility FOIA Viewers & Players U.S. ...

  4. 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.

  5. Abdominal wall abscess: more than meets the eye.

    PubMed

    Gandhi, Jamish; Gandhi, Natasha

    2010-01-01

    An 83-year-old, mildly demented rest home resident presented to the emergency department with a 2 day history of a right sided abdominal wall mass. He had a mechanical fall 2 days previously and landed on his right side and had attributed the mass to this. He had no symptoms apart from feeling bloated and not being able to pass wind for a day. He had passed a normal bowel motion the day before presentation. On abdominal examination there was an 11 × 4 cm mass in the right lower quadrant. It was firm in consistency, non-fluctuant and non-tender to touch. There was mild erythema over the area but no skin breaks. Chest radiograph was unremarkable. The abdominal film showed dilated small bowel and no large bowel could be seen. A computed tomography (CT) scan showed a thick walled gallbladder with multiple calculi and air present. There was also an extensive air and fluid collection in the layers of the abdominal wall and subcutaneous fat which arose from a perforation of the gallbladder. The patient was not a surgical candidate due to multiple comorbidities. The patient was treated with antibiotics and underwent a CT guided percutaneous cholecystostomy. Despite the radiological intervention and antibiotics the patient progressively deteriorated and died peacefully 5 days after admission.

  6. Mesh Sutured Repairs of Abdominal Wall Defects

    PubMed Central

    Lanier, Steven T.; Jordan, Sumanas W.; Miller, Kyle R.; Ali, Nada A.; Stock, Stuart R.

    2016-01-01

    Background: A new closure technique is introduced, which uses strips of macroporous polypropylene mesh as a suture for closure of abdominal wall defects due to failures of standard sutures and difficulties with planar meshes. Methods: Strips of macroporous polypropylene mesh of 2 cm width were passed through the abdominal wall and tied as simple interrupted sutures. The surgical technique and surgical outcomes are presented. Results: One hundred and seven patients underwent a mesh sutured abdominal wall closure. Seventy-six patients had preoperative hernias, and the mean hernia width by CT scan for those with scans was 9.1 cm. Forty-nine surgical fields were clean-contaminated, contaminated, or dirty. Five patients had infections within the first 30 days. Only one knot was removed as an office procedure. Mean follow-up at 234 days revealed 4 recurrent hernias. Conclusions: Mesh sutured repairs reliably appose tissue under tension using concepts of force distribution and resistance to suture pull-through. The technique reduces the amount of foreign material required in comparison to sheet meshes, and avoids the shortcomings of monofilament sutures. Mesh sutured closures seem to be tolerant of bacterial contamination with low hernia recurrence rates and have replaced our routine use of mesh sheets and bioprosthetic grafts. PMID:27757361

  7. Planned ventral hernia. Staged management for acute abdominal wall defects.

    PubMed Central

    Fabian, T C; Croce, M A; Pritchard, F E; Minard, G; Hickerson, W L; Howell, R L; Schurr, M J; Kudsk, K A

    1994-01-01

    OBJECTIVE: Analysis of a staged management scheme for initial and definitive management of acute abdominal wall defects is provided. METHODS: A four-staged scheme for managing acute abdominal wall defects consists of the following stages: stage I--prosthetic insertion; stage II--2 to 3 weeks after prosthetic insertion and wound granulation, the prosthesis is removed; stage III--2 to 3 days later, planned ventral hernia (split thickness skin graft [STSG] or full-thickness skin and subcutaneous fat); stage IV--6 to 12 months later, definitive reconstruction. Cases were evaluated retrospectively for benefits and risks of the techniques employed. RESULTS: Eighty-eight cases (39 visceral edema, 27 abdominal sepsis, 22 abdominal wall resection) were managed during 8.5 years. Prostheses included polypropylene mesh in 45 cases, polyglactin 910 mesh in 27, polytetrafluorethylene in 10, and plastic in 6. Twenty-four patients died from their initial disease. The fistula rates associated with prosthetic management was 9%; no wound-related mortality occurred. Most wounds had split thickness skin graft applied after prosthetic removal. Definitive reconstruction was undertaken in 21 patients in the authors' institution (prosthetic mesh in 12 and modified components separation in 9). Recurrent hernias developed in 33% of mesh reconstructions and 11% of the components separation technique. CONCLUSIONS: The authors concluded that 1) this staged approach was associated with low morbidity and no technique-related mortality; 2) prostheses placed for edema were removed with fascial approximation accomplished in half of those cases; 3) absorbable mesh provided the advantages of reasonable durability, ease of removal, and relatively low cost--it has become the prosthesis of choice; and 4) the modified components separation technique of reconstruction provided good results in patients with moderate sized defects. Images Figure 2. Figure 3. Figure 4. Figure 5. PMID:8203973

  8. Abdominal Wall Haematoma Complicating Laparoscopic Cholecystectomy

    PubMed Central

    Tate, J. J. T.; Davidson, B. R.; Hobbs, K. E. F.

    1994-01-01

    Of 61 consecutive patients undergoing laparoscopic cholecystectomy, 4 (6.25%) developed abdominal wall haematomas. This complication of laparoscopic cholecystectomy may occur more commonly than existing literature suggests, and manifests in the post-operative period (days 2 to 6) by visible bruising, excessive pain or an asymptomatic drop in haematocrit. It is readily confirmed by ultrasonography. While no specific treatment is necessary apart from replacement of significant blood loss, the patient requires reassurance that this apparently alarming complication will rapidly resolve. PMID:8204548

  9. Isolated Abdominal Wall Metastasis of Endometrial Carcinoma

    PubMed Central

    Simões, Jorge; Gonçalves, Matilde; Matos, Isabel

    2014-01-01

    A woman in her mid-60s presented with a bulky mass on the anterior abdominal wall. She had a previous incidental diagnosis of endometrial adenocarcinoma FIGO stage IB following a vaginal hysterectomy. Physical exam and imaging revealed a well circumscribed bulging tumour at the umbilical region, measuring 10 × 9 × 9 cm, with overlying intact skin and subcutaneous tissue. Surgical resection was undertaken, and histological examination showed features of endometrial carcinoma. She began chemotherapy and is alive with no signs of recurrent disease one year after surgery. This case brings up to light an atypical location of a solitary metastasis of endometrial carcinoma. PMID:25349753

  10. Modern reconstructive techniques for abdominal wall defects after oncologic resection.

    PubMed

    Khansa, Ibrahim; Janis, Jeffrey E

    2015-04-01

    Resection of abdominal wall tumors often leaves patients with debilitating soft tissue defects. Modern reconstructive techniques can be used to restore abdominal wall integrity. In this article, we present an overview of preoperative patient evaluation, analysis of the defect, surgical planning, and the spectrum of available surgical techniques, ranging from simple to complex. The established clinical evidence in the field of abdominal wall reconstruction is summarized and a case example is provided.

  11. Remote revascularization of abdominal wall transplants using the forearm.

    PubMed

    Giele, H; Bendon, C; Reddy, S; Ramcharan, R; Sinha, S; Friend, P; Vaidya, A

    2014-06-01

    Primary abdominal wall closure following small bowel transplantation is frequently impossible due to contraction of the abdominal domain. Although abdominal wall transplantation was reported 10 years ago this, technique has not been widely adopted, partly due to its complexity, but largely because of concerns that storing the abdominal allograft until the end of a prolonged intestinal transplant procedure would cause severe ischemia-reperfusion injury. We report six cases of combined small bowel and abdominal wall transplantation where the ischemic time was minimized by remotely revascularizing the abdominal wall on the forearm vessels, synchronous to the intestinal procedure. When the visceral transplant was complete, the abdominal wall was removed from the forearm and revascularized on the abdomen (n = 4), or used to close the abdomen while still vascularized on the forearm (n = 2). Primary abdominal wall closure was achieved in all. Mean cold ischemia was 305 min (300-330 min), and revascularization on the arm was 50 min (30-60 min). Three patients had proven abdominal wall rejection, all treated successfully. Immediate revascularization of the abdominal wall allograft substantially reduces cold ischemia without imposing constraints on the intestinal transplant. Reducing storage time may also have benefits with respect to ischemia-reperfusion-related graft immunogenicity.

  12. Tube-Wall Thickness Detector

    NASA Technical Reports Server (NTRS)

    Kleint, R. E.; Baily, R. D.

    1985-01-01

    Eddy-current measurements detect wear of thin walls (0.01 in) (0.25 mm) in small diameter (0.19 in) (5 mm) heat exchanger tubing. Flexible durable thin rod inserts eddy-current coil into the heatexchanger tube.

  13. Vertically transmitted hypoplasia of the abdominal wall musculature.

    PubMed

    Chan, Yuin-Chew; Bird, Lynne M

    2004-01-01

    The prune belly syndrome (OMIM 100100) is an association of bladder dilation with hypoplasia of the abdominal wall muscles. This malformation sequence is due to early urethral obstruction. We report a family with abdominal wall muscular hypoplasia as an isolated defect, not associated with the urethral obstruction sequence. The proband is a q3-year-old male who presented with abdominal wall laxity and severe constipation. His mother, maternal grandmother and younger brother had varying degrees of abdominal wall muscular deficiency and constipation. His mother's condition was aggravated by her 2 pregnancies. This family shows vertical transmission (compatible with autosomal dominant or mitochondrial inheritance) of the abdominal phenotype of prune belly sequence without any evidence of urinary tract or renal pathology. The expression in the sons may remain incomplete because abdominal distention due to pregnancy will not occur.

  14. 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.

  15. Niche reconstructive techniques for complex abdominal wall reconstruction: a review.

    PubMed

    Sue, Gloria R; Narayan, Deepak

    2014-04-01

    Abdominal wall defects resulting from recurrent hernias, trauma, and radiation necrosis are difficult and challenging to repair given the high rates of recurrence and surgical morbidity. Complex abdominal wall defects often require the transposition of autologous material to bridge the fascial gap. We present a review of niche reconstructive techniques that have been used in complex abdominal wall repair. The specific techniques reviewed include use of delayed and tunneled pedicled tensor fascia lata myofascial flap, de-epithelialized flap closure, free latissimus dorsi myocutaneous flap with or without innervation, and abdominal wall transplant. These niche surgical techniques have great potential to reduce recurrence rates when used in the proper setting for complex abdominal wall reconstruction. More studies are needed to evaluate the relative use of these techniques with the more widely established surgical methods of reconstruction.

  16. Practical Approaches to Definitive Reconstruction of Complex Abdominal Wall Defects.

    PubMed

    Latifi, Rifat

    2016-04-01

    With advances in abdominal surgery and the management of major trauma, complex abdominal wall defects have become the new surgical disease, and the need for abdominal wall reconstruction has increased dramatically. Subsequently, how to reconstruct these large defects has become a new surgical question. While most surgeons use native abdominal wall whenever possible, evidence suggests that synthetic or biologic mesh needs to be added to large ventral hernia repairs. One particular group of patients who exemplify "complex" are those with contaminated wounds, enterocutaneous fistulas, enteroatmospheric fistulas, and/or stoma(s), where synthetic mesh is to be avoided if at all possible. Most recently, biologic mesh has become the new standard in high-risk patients with contaminated and dirty-infected wounds. While biologic mesh is the most common tissue engineered used in this field of surgery, level I evidence is needed on its indication and long-term outcomes. Various techniques for reconstructing the abdominal wall have been described, however the long-term outcomes for most of these studies, are rarely reported. In this article, I outline current practical approaches to perioperative management and definitive abdominal reconstruction in patients with complex abdominal wall defects, with or without fistulas, as well as those who have lost abdominal domain.

  17. Wall thickness measuring method and apparatus

    DOEpatents

    Salzer, Leander J.; Bergren, Donald A.

    1989-01-01

    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.

  18. Advanced Gastric Cancer Perforation Mimicking Abdominal Wall Abscess

    PubMed Central

    Cho, Jinbeom; Park, Ilyoung; Lee, Dosang; Sung, Kiyoung; Baek, Jongmin

    2015-01-01

    Surgeons occasionally encounter a patient with a gastric cancer invading an adjacent organ, such as the pancreas, liver, or transverse colon. Although there is no established guideline for treatment of invasive gastric cancer, combined resection with radical gastrectomy is conventionally performed for curative purposes. We recently treated a patient with a large gastric cancer invading the abdominal wall, which was initially diagnosed as a simple abdominal wall abscess. Computed tomography showed that an abscess had formed adjacent to the greater curvature of the stomach. During surgery, we made an incision on the abdominal wall to drain the abscess, and performed curative total gastrectomy with partial excision of the involved abdominal wall. The patient received intensive treatment and wound management postoperatively with no surgery-related adverse events. However, the patient could not receive adjuvant chemotherapy and expired on the 82nd postoperative day. PMID:26468420

  19. Prosthetics and Techniques in Repair of Animal's Abdominal Wall

    PubMed Central

    Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled

    2016-01-01

    The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity. PMID:27293982

  20. Prosthetics and Techniques in Repair of Animal's Abdominal Wall.

    PubMed

    Karrouf, Gamal; Zaghloul, Adel; Abou-Alsaud, Mohamed; Barbour, Elie; Abouelnasr, Khaled

    2016-01-01

    The management of abdominal wall repair continues to present a challenging problem, especially in the repair of major defects. Many abdominal wall defects can be repaired by primary closure; however, if the defect is large and there is a tension on the closure of the wound, the use of prosthetic materials becomes indispensable. Many studies have been performed with various materials and implant techniques, without the comparison of their degrees of success, based on sound meta-analysis and/or inclusive epidemiologic studies. This review covered the effectiveness of recent advances in prosthetic materials and implant procedures used in repair of abdominal wall, based on biomechanical properties and economic aspects of reconstructed large abdominal wall defects and hernias in animals. The presented results in this review helped to reach treatment algorithms that could maximize outcomes and minimize morbidity.

  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. Desmoid tumor of the abdominal wall: a case report

    PubMed Central

    2011-01-01

    Introduction Desmoid tumors are rare lesions without any metastatic potential but a strong tendency to invade locally and to recur. These tumors are associated with women of fertile age, especially during and after pregnancy. Case presentation The case of a desmoid tumor of the anterior abdominal wall in a 40-year-old Caucasian man with no relevant family history is presented, describing its appearance on computed tomography and ultrasonography. The patient, who presented with a painless mass in the left anterolateral abdomen, had a history of previous urgent abdominal surgery after a shotgun injury two years earlier. Radical resection of the affected abdominal wall musculature was performed, and the defect was reconstructed with polypropylene mesh. Conclusion The diagnosis of desmoid tumor should be strongly considered even in male patients with an abdominal mass and a history of previous abdominal surgery. The goal of its treatment is complete tumor excision and avoidance of the development of complications such as hernia. PMID:21787413

  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. Wandering Ascaris Coming Out Through the Abdominal Wall

    PubMed Central

    Wani, Mohd L; Rather, Ajaz A.; Parray, Fazl Q.; Ahangar, Abdul G.; Bijli, Akram H.; Irshad, Ifat; Nayeem-Ul-Hassan; Khan, Tahir S.

    2013-01-01

    A rare case of ascaris coming out through the anterior abdominal wall is reported here. A 40-year-old female had undergone dilatation and curettage by a quack. On the second day she presented with presented with features of peritonitis. She was explored. Resection anastomosis of the ileum was done for multiple perforations of the ileum. Patient developed a fistula in the anterior abdominal wall which was draining bile-colored fluid. On the 12th postoperative day a 10-cm-long worm was seen coming out through the fistulous tract which was found to be Ascaris lumbricoids. Ascaris lumbricoids can lead to many complications ranging from worm colic to intestinal obstruction, volvulus, peritonitis, pancreatitis, cholangiohepatitis, liver abscess and many more. Worm has been reported to come out through mouth, nostrils, abdominal drains, T-tubes etc. But ascaris coming out through the anterior abdominal wall is very rare hence reported here. PMID:23930192

  5. Wandering ascaris coming out through the abdominal wall.

    PubMed

    Wani, Mohd L; Rather, Ajaz A; Parray, Fazl Q; Ahangar, Abdul G; Bijli, Akram H; Irshad, Ifat; Nayeem-Ul-Hassan; Khan, Tahir S

    2013-06-01

    A rare case of ascaris coming out through the anterior abdominal wall is reported here. A 40-year-old female had undergone dilatation and curettage by a quack. On the second day she presented with presented with features of peritonitis. She was explored. Resection anastomosis of the ileum was done for multiple perforations of the ileum. Patient developed a fistula in the anterior abdominal wall which was draining bile-colored fluid. On the 12(th) postoperative day a 10-cm-long worm was seen coming out through the fistulous tract which was found to be Ascaris lumbricoids. Ascaris lumbricoids can lead to many complications ranging from worm colic to intestinal obstruction, volvulus, peritonitis, pancreatitis, cholangiohepatitis, liver abscess and many more. Worm has been reported to come out through mouth, nostrils, abdominal drains, T-tubes etc. But ascaris coming out through the anterior abdominal wall is very rare hence reported here.

  6. Abdominal wall abscesses in patients with Crohn's disease: clinical outcome.

    PubMed

    Neufeld, David; Keidar, Andrei; Gutman, Mordechai; Zissin, Rivka

    2006-03-01

    Abdominal wall abscess due to Crohn's Disease used to be one of the definitive indications for operative treatment. The advent of interventional radiology, the accessibility to percutaneous drainage, and the availability of new medications raised the possibility of nonoperative treatment of this condition. The clinical presentation, treatment, and follow-up of 13 patients with abdominal wall abscesses secondary to Crohn's Disease were retrospectively reviewed. During a 10-year period (1993-2003), 13 patients with abdominal wall abscess were treated. Five patients had an anterolateral abdominal wall abscess and eight had a posterior abscess (psoas). In 11 patients, 17 drainage procedures were performed: 12 percutaneous and 5 operative. Despite initial adequate drainage and resolution of the abscess, all 13 patients eventually needed resection of the offending bowel segment, which was undertaken in 12 patients. The mean time between abscess presentation and definitive operation was 2 months. Percutaneous drainage is an attractive option in most cases of abdominal abscesses. However, in Crohn's Disease patients with an abdominal wall abscess, we found a high failure rate despite initial adequate drainage. We suggest that surgical resection of the diseased bowel segment should be the definitive therapy.

  7. Gas turbine bucket wall thickness control

    DOEpatents

    Stathopoulos, Dimitrios; Xu, Liming; Lewis, Doyle C.

    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.

  8. 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

  9. Hot Wall Thickness Variation Measurement System

    DTIC Science & Technology

    1979-06-01

    Subtltia) HOT WALL THICKNESS VARIATION MEASUREMENT SYSTEM 7. AUTHORfa; 3. J. KRUPSKI 9 . PERFORMING ORGANIZATION NAME AND ADDRESS PRODUCT...THE FORGING 3. ULTRASONICS ON A HOT TUBE 4. SYSTEt-l DESCRIPTION 5. TESTING RESULTS 6. CONCLUSIONS 7. HffLEMENTATION PAGE i ii 1 2 4 6 9 ...printed out. The grip procedure was repeated toward the breech end of the forging with good results. The third and 9 breech end prints were at about

  10. Synthetic, biological and composite scaffolds for abdominal wall reconstruction.

    PubMed

    Meintjes, Jennifer; Yan, Sheng; Zhou, Lin; Zheng, Shusen; Zheng, Minghao

    2011-03-01

    The reconstruction of abdominal wall defects remains a huge surgical challenge. Tension-free repair is proven to be superior to suture repair in abdominal wall reconstruction. Scaffolds are essential for tension-free repair. They are used to bridge a defect or reinforce the abdominal wall. A huge variety of scaffolds are now commercially available. Most of the synthetic scaffolds are composed of polypropylene. They provide strong tissue reinforcement, but cause a foreign body reaction, which can result in serious complications. Absorbable synthetic scaffolds, such as Dexon™ (polyglycolic acid) and Vicryl™ (polyglactin 910), are not suitable for abdominal wall reconstruction as they usually require subsequent surgeries to repair recurrent hernias. Composite scaffolds combine the strength of nonabsorbable synthetic scaffolds with the antiadhesive properties of the absorbable scaffold, but require long-term follow-up. Biological scaffolds, such as Permacol™, Surgisis(®) and Alloderm(®), are derived from acellular mammalian tissues. Non-cross-linked biological scaffolds show excellent biocompatibility and degrade slowly over time. However, remnant DNA has been found in several products and the degradation leads to recurrence. Randomized controlled trials with long-term follow-up studies are lacking for all of the available scaffolds, particularly those derived from animal tissue. This article provides an overview of the different types of scaffolds available, and presents the key clinical studies of the commercially available synthetic, composite and biological scaffolds for abdominal wall reconstruction.

  11. Improving the efficiency of abdominal aortic aneurysm wall stress computations.

    PubMed

    Zelaya, Jaime E; Goenezen, Sevan; Dargon, Phong T; Azarbal, Amir-Farzin; Rugonyi, Sandra

    2014-01-01

    An abdominal aortic aneurysm is a pathological dilation of the abdominal aorta, which carries a high mortality rate if ruptured. The most commonly used surrogate marker of rupture risk is the maximal transverse diameter of the aneurysm. More recent studies suggest that wall stress from models of patient-specific aneurysm geometries extracted, for instance, from computed tomography images may be a more accurate predictor of rupture risk and an important factor in AAA size progression. However, quantification of wall stress is typically computationally intensive and time-consuming, mainly due to the nonlinear mechanical behavior of the abdominal aortic aneurysm walls. These difficulties have limited the potential of computational models in clinical practice. To facilitate computation of wall stresses, we propose to use a linear approach that ensures equilibrium of wall stresses in the aneurysms. This proposed linear model approach is easy to implement and eliminates the burden of nonlinear computations. To assess the accuracy of our proposed approach to compute wall stresses, results from idealized and patient-specific model simulations were compared to those obtained using conventional approaches and to those of a hypothetical, reference abdominal aortic aneurysm model. For the reference model, wall mechanical properties and the initial unloaded and unstressed configuration were assumed to be known, and the resulting wall stresses were used as reference for comparison. Our proposed linear approach accurately approximates wall stresses for varying model geometries and wall material properties. Our findings suggest that the proposed linear approach could be used as an effective, efficient, easy-to-use clinical tool to estimate patient-specific wall stresses.

  12. Pedicled fasciocutaneous anterolateral thigh flap for the reconstruction of a large postoncologic abdominal wall resection defect: a case report.

    PubMed

    Nthumba, Peter; Barasa, Jack; Cavadas, Pedro C; Landin, Luis

    2012-02-01

    The anterolateral thigh (ALT) flap has been used to cover defects between the proximal third of the leg and lower abdomen, and with modification, may cover epigastric defects. We used the ALT flap to cover a full-thickness defect of over half the anterior abdominal wall. We conclude that abdominal wall defects of large sizes can be successfully reconstructed using an appropriately designed ALT flap; a simple, single-stage effective reconstruction.

  13. Reduced dermis thickness and AGE accumulation in diabetic abdominal skin.

    PubMed

    Niu, Yiwen; Cao, Xiaozan; Song, Fei; Xie, Ting; Ji, Xiaoyun; Miao, Mingyuan; Dong, Jiaoyun; Tian, Ming; Lin, Yuan; Lu, Shuliang

    2012-09-01

    Dermatological problems in diabetes might play an important role in the spontaneous ulcers and impaired wound healing that are seen in diabetic patients. Investigation of the cause of diabetic skin disorders is critical for identifying effective treatment. The abdominal full-thickness skin tissues of 33 patients (14 nondiabetic and 19 diabetic) were analyzed. The cell viability and malondialdehyde (MDA) production of fibroblasts were measured after advanced glycosylation end product (AGE)-bovine serum albumin (BSA) exposure. Cutaneous histological observation showed reduced thickness of the diabetic abdominal dermis with morphological characteristics of obscured multilayer epithelium and shortened, thinned, and disorganized collagen fibrils with focal chronic inflammatory cell infiltration when compared with controls of the same age. Accumulation of AGEs in diabetic skin was prominent. Less hydroxyproline, higher myeloperoxidase activity, and increased MDA content were detected in diabetic skin. In vitro, the time- and dose-dependent inhibitory effects of AGE-BSA on fibroblast viability as well as the fact that AGE-BSA could promote MDA production of fibroblasts were shown. It is shown that the accumulation of AGEs in diabetic skin tissue induces an oxidative damage of fibroblasts and acts as an important contributor to the thinner diabetic abdominal dermis. The authors believe that diabetic cutaneous properties at baseline may increase the susceptibility to injury, and diabetic wounds possess atypical origin in the repair process.

  14. Emergency abdominal wall reconstruction with polypropylene mesh: short-term benefits versus long-term complications.

    PubMed Central

    Voyles, C R; Richardson, J D; Bland, K I; Tobin, G R; Flint, L M; Polk, H C

    1981-01-01

    The acute replacement of full-thickness abdominal wall has been facilitated by polypropylene mesh (Marlex) (PPM), allowing debridement of nonviable tissue and restoration of abdominal wall integrity without tension. However, no substantial long-term follow-up has been reported on the definitive wound coverage after the use of PPM in open wounds. Since 1976, we have placed PPM in 31 patients; 25 for infectious complication, three for massive bowel distension preventing abdominal closure, and three for shotgun wounds with extensive tissue loss. In 29 of 31 patients, the mesh was placed in heavily contaminated wounds; extensive fasciitis was present in 23 patients and 21 had intra-abdominal abscesses. Following mesh placement, 23 reoperations were required for continuing complications. No patients eviscerated, despite these multiple procedures. Polypropylene mesh was highly effective in restoring abdominal wall continuity. Despite advantages when PPM was used, significant long-term problems developed. Seven patients died from their primary illness in the postoperative period. Nine wounds were closed by granulation and subsequent split-thickness skin grafts. All nine developed mesh extrusion and/or enteric fistulae. Nine wounds healed by secondary intention, six developed enteric fistulae or continuing mesh extrusion. Full-thickness flap coverage after granulation provided the best means of wound closure. Polypropylene mesh had significant early advantages for providing abdominal wall integrity even in the presence of severe infection. However, long-term problems were common when wounds were closed to skin grafts or secondary intention. If the mesh cannot be completely removed, strong consideration should be given to myocutaneous flaps for coverage after the primary illness has resolved. Images Fig. 1. Fig. 2. Fig. 3. PMID:6455099

  15. Tunnelled tensor fascia lata flap for complex abdominal wall reconstruction

    PubMed Central

    Wang, Frederick; Buonocore, Samuel; Narayan, Deepak

    2011-01-01

    This study describes the treatment of two patients with recurrent, infected abdominal wall defects using bilateral delayed and tunnelled pedicled tensor fascia lata (TFL) myofascial flaps. TFL flaps were elevated and delayed for 4 weeks in both cases. In the second case, Parietex Composite mesh was positioned underneath the TFL flap and allowed to incorporate. After a delay of 4 weeks, the flaps were harvested and tunnelled subcutaneously to repair the abdominal wall defect. Both patients have stable repairs but had donor site seromas requiring drainage. Cadaver dissection was also performed to identify structures related to TFL flap harvest. We identified a variant of lateral femoral cutaneous nerve that traversed the TFL flap, necessitating meticulous dissection during surgery. In summary, we describe a new technique of incorporating mesh into the TFL prior to flap harvest for reconstruction of complex abdominal wall. PMID:22707661

  16. 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.

  17. Takedown of enterocutaneous fistula and complex abdominal wall reconstruction.

    PubMed

    Slade, Dominic Alexander James; Carlson, Gordon Lawrence

    2013-10-01

    Key steps in managing patients with enterocutaneous fistulation and an abdominal wall defect include dealing effectively with abdominal sepsis and providing safe and effective nutritional support and skin care, then assessing intestinal and abdominal anatomy, before undertaking reconstructive surgery. The complexity, cost, and morbidity associated with such cases justifies creation of specialized centers in which gastroenterologic, hernia, and plastic surgical expertise, as well as experienced wound and stoma nursing and nutritional and psychological support, can be made available for patients with these challenging problems.

  18. Ultrasonography and computed tomography of inflammatory abdominal wall lesions

    SciTech Connect

    Yeh, H.C.; Rabinowitz, J.G.

    1982-09-01

    Twenty-four patients with inflammatory lesions of the abdominal wall were examined by ultrasonography. Nine of these patients underwent computed tomographic (CT) scanning as well. Both ultrasonography and CT clearly delineated the exact location and extent of abdominal wall abscesses. Abscesses were easily differentiated from cellulitis or phlegmon with ultrasound. The peritoneal line was more clearly delineated on ultrasonograms than on CT scans; abscesses were also more distinct on the ultrasonograms because of their low echogenicity compared with the surrounding structures. Gas bubbles, fat density with specific low attenuation values, and underlying inflamed bowel loops in obese patients with Crohn's disease were better delineated by CT.

  19. [A Case of Abdominal Wall Hernia Rupture during Bevacizumab Treatment].

    PubMed

    Sugimoto, Satoshi; Miyazaki, Yasuaki; Hirose, Sou; Michiura, Toshiya; Fujita, Shigeo; Yamabe, Kazuo; Miyazaki, Satoru; Nagaoka, Makio

    2015-11-01

    A 78 -year-old man with rectal cancer underwent abdominoperineal resection of the rectum. In the postoperative period, the patient experienced wound infection, leading to an abdominal wall hernia. Two years following surgery, a rise in the serum CEA level was seen. A metastatic tumor was detected in the right lung on chest CT. VATS right lung inferior lobe segmental resection was performed. After lobectomy, the serum CEA level continued to increase. Another metastatic tumor was detected in the right lung on chest CT. Chemotherapy with capecitabine, oxaliplatin, and bevacizumab was commenced. The erosive part of the abdominal wall scar hernia extended during the nine weeks of chemotherapy. The chemotherapy was then discontinued. In the follow-up CT scan, a right pleural recurrence, local recurrence in the pelvis, and a liver metastasis were detected. Chemotherapy was re-introduced 3 years after surgery. The erosive part of the abdominal wall hernia again began to spread with chemotherapy recommencement. Four months after restarting chemotherapy, the hernia ruptured, with a loop of the small intestine protruding out of it. The patient covered this with a sheet of vinyl and was taken by the ambulance to our hospital. The erosive part of the abdominal wall hernia had split by 10 cm, and a loop of the small intestine was protruding. As ischemia of the small intestine was not observed, we replaced it into the abdominal cavity, and performed a temporary suture repair of the hernia sac. Following this, bevacizumab was discontinued, and the erosive part reduced. We performed a radical operation for abdominal wall scar hernia repair 11 weeks after the discontinuation of bevacizumab.

  20. Transversus abdominal plane block as a sole anesthetic technique for abdominal wall hematoma drainage.

    PubMed

    Varela, N; Golvano, M; Monedero, P

    2016-10-01

    Transversus abdominal plane (TAP) block is a known and useful technique, widely used for postoperative pain management of abdominal wall incisions. During the past years, and following the expansion of ultrasound guided techniques, its use has even gained more adepts. It is usually used as an adjuvant technique, primarily in order to control postoperative pain and reduce opioids consumption. We report the case of an 82 years old patient admitted for drainage of a postoperative abdominal wall hematoma after correction of a McBurney incisional hernia. The corrective surgery had gone on without incident, under general anesthesia with laryngeal mask. Two weeks later, the patient came back to our emergency department with a clear hematoma of the abdominal wall. Surgery was decided. A sole local anesthetic technique was achieved, using a TAP block. The block was performed under ultrasound guidance, using a subcostal approach. The surgery went on without complications. Therefore, TAP block offers a hemodynamic stability, appropriate intra-operative anesthesia and post-surgical analgesia of the abdominal wall.

  1. Wall thickness effect on the resistive wall mode stability in toroidal plasmas

    SciTech Connect

    Zheng, L.-J.; Kotschenreuther, M.T.

    2005-07-15

    The effect of finite wall thickness on the stability of n=1 resistive wall modes in toroidal plasmas is investigated. A fusion reactor-relevant configuration is examined. The investigation employs a novel ideal-magnetohydrodynamics adaptive shooting code for axisymmetric plasmas, extended to take into account the wall thickness. Although finite wall thickness generally reduces the growth rate of the resistive wall modes, no contribution to stabilization is found to be made by the portion of the wall that is located beyond the critical position for perfectly conducting wall stabilization. Thus, when the inner side of the wall lies near the critical wall position, the scaling of the growth rate versus wall thickness in the realistic thick-wall calculation is significantly different from that of the usual thin-wall theory. The thin-wall estimate is relevant only when the wall is brought very close to the plasma and is not too thick.

  2. Which mesh or graft? Prosthetic devices for abdominal wall reconstruction.

    PubMed

    Abid, Shazia; El-Hayek, Kevin

    2016-03-01

    This article reviews the ever-increasing number of prosthetic devices--both synthetic mesh and biologic grafts--now in use for abdominal wall reconstruction. It also introduces a novel hybrid synthetic/biologic graft (Zenapro) and suture passer device (Novapass).

  3. Extragastrointestinal Stromal Tumour of The Abdominal Wall - A Case Report

    PubMed Central

    Kumar, A. Sathish Selva; Padmini, R; Veena, G; Murugesan, N

    2013-01-01

    Stromal tumours occurring in areas other than the GastroIntestinal Tract (GIT) are known as Extra GastroIntestinal Stromal Tumours (EGISTs). They usually arise in the mesentery, omentum or retroperitoneum, while EGISTs which occur in the abdominal wall are very rare. Both gastrointestinal stromal tumours (GISTs) and EGISTs are histologically and immunophenotypically similar. We are reporting a case of EGIST, which occurred in the anterior abdominal wall in a twenty five-year-old female patient. The tumour was present in the right loin and imaging studies suggested that it was a desmoid tumour. It was surgically excised by doing an abdominal wall mesh repair. The histological examinations revealed a tumour with spindle cell morphology, with <2 mitoses per 50 High Power Field (HPF) and no necrosis, with tumour free margins. Immunohistochemistry was strongly positive for CD117 and Smooth Muscle Actin (SMA), while it was negative for β-catenin and S100. The patient is well post operatively and is on close follow up. EGISTs should be considered in the differential diagnosis of mesenchymal tumours which occur in the abdominal wall, inspite of their rarity, as the high risk patients may need Imatinib chemotherapy. PMID:24551695

  4. Planned hernia repair and late abdominal wall reconstruction.

    PubMed

    Leppäniemi, Ari; Tukiainen, Erkki

    2012-03-01

    Planned ventral hernia is a management strategy in which the abdominal fascial layer has been left unclosed and the viscera are covered only with original or grafted skin. Leaving the fascia open can be deliberate or unavoidable and most commonly results from staged repair of the abdominal wall due to trauma, peritonitis, pancreatitis, abdominal vascular emergencies, or abdominal compartment syndrome. The abdominal wall defects can be categorized as type I or II defects depending on whether there is intact, stable skin coverage. In defects with intact skin coverage, the most commonly used methods are the components separation technique and a prosthetic repair, sometimes used in combination. The advantages of the components separation technique is the ability to close the linea alba at the midline, creating a better functional result than a repair with inert mesh. Although the reherniation risk seems higher after components separation, the risk of infection is considerably lower. With a type II defect, with absent or unstable skin coverage, fascial repair alone is inadequate. Of the more complex reconstruction techniques, the use of a free tensor fasciae latae (TFL) flap utilizing a saphenous vein arteriovenous loop is the most promising. The advantages of the TFL flap include constant anatomy of the pedicle, a strong fascial layer, large-caliber vessels matching the size of the AV loop, and the ability to use large flaps (up to 20 × 35 cm). Whatever technique is used, the repair of complex abdominal wall defects requires close collaboration with plastic and abdominal surgeons, which is best managed in specialized centers.

  5. Reconstruction of extensive abdominal wall defect using an eccentric perforator-based pedicled anterolateral thigh flap: a case report.

    PubMed

    Jang, Joonchul; Jeong, Seong-Ho; Han, Seung-Kyu; Kim, Woo-Kyung

    2013-09-01

    Reconstruction of extensive abdominal wall defects is a challenge for reconstructive surgeons. In this report, a case of reconstruction of a large abdominal wall defect using an eccentric perforator-based pedicled anterolateral thigh (ALT) flap is presented. A 30-year-old man presented with recurrent desmoid-type fibromatosis in the abdominal wall. The recurrent tumor was radically excised, and the en bloc excision resulted in a full-thickness, large abdominal wall defect (25 cm × 20 cm). An eccentric perforator-based pedicled ALT flap, including wide fascial extension, was transferred to the abdominal defect; fascial portions were sutured to the remnant abdominal fascia. Plication of the fascia along the sutured portion was performed to relieve the skin tension between the flap and the marginal skin of the abdominal defect. Eight months after surgery, the reconstructed abdomen had an acceptable esthetic appearance without tumor recurrence or hernia. The use of an eccentric perforator-based pedicled ALT flap may be an alternative method for the reconstruction of extensive abdominal wall defects.

  6. Wall thickness design and corrosion management

    SciTech Connect

    Gestel, W.M. van; Guijt, J.

    1994-12-31

    In 1995, Norske Shell will install two 36-in. sweet wet gas pipe lines in the Norwegian sector of the North Sea. The lines cross the Norwegian trench with water depths up to 350 meter. For the last 3.5 km. of the route the pipelines will be laid in a tunnel which will be flooded after construction. The two lines will transport largely untreated well fluids from the Troll field to an onshore processing plant at Kollsness, North of Bergen. From there sales gas will be transported to the continent via the Furopipe and Zeepipe systems. Gas contracts covering 30 years have been concluded with gas utilities on the continent. The maximum wall thickness that could be installed was limited by the capabilities of the present generation of lay barges and pipe mill capacities. The over-thickness, i.e. beyond that what is required for pressure containment and external collapse, is available as corrosion allowance. The paper discusses a novel probabilistic approach to define the corrosion control measures. The corrosion control system is based on the injection of glycol for corrosion mitigation and inspection by ultrasonic internal smart pigs, which in combination with identified fall back options, ensure a minimum 50 year service life.

  7. Is abdominal wall tenderness a useful sign in the diagnosis of non-specific abdominal pain?

    PubMed Central

    Gray, D. W.; Dixon, J. M.; Seabrook, G.; Collin, J.

    1988-01-01

    Pain arising from the abdominal wall has been implicated as a cause of non-specific abdominal pain (NSAP), and the presence of abdominal wall tenderness (AWT) has been proposed as an accurate diagnostic test for NSAP. One hundred and fifty eight patients admitted to hospital with abdominal pain were tested for the presence of positive AWT. In 53 patients the final diagnosis was appendicitis and positive AWT was found in five. Thirty eight patients were found to have a variety of other recognised pathological diagnoses, none of whom had a positive AWT. In 67 patients a diagnosis of NSAP was made in the absence of other pathological diagnosis, 19 of whom had positive AWT, which was significantly different from the other diagnostic groups. This study confirms the presence of AWT in up to 28% of patients with NSAP, and suggests that testing for AWT is of value in patients with abdominal pain, although a positive AWT is not as accurate a predictor of NSAP as previously reported. PMID:2970820

  8. Towards the mechanical characterization of abdominal wall by inverse analysis.

    PubMed

    Simón-Allué, R; Calvo, B; Oberai, A A; Barbone, P E

    2017-02-01

    The aim of this study is to characterize the passive mechanical behaviour of abdominal wall in vivo in an animal model using only external cameras and numerical analysis. The main objective lies in defining a methodology that provides in vivo information of a specific patient without altering mechanical properties. It is demonstrated in the mechanical study of abdomen for hernia purposes. Mechanical tests consisted on pneumoperitoneum tests performed on New Zealand rabbits, where inner pressure was varied from 0mmHg to 12mmHg. Changes in the external abdominal surface were recorded and several points were tracked. Based on their coordinates we reconstructed a 3D finite element model of the abdominal wall, considering an incompressible hyperelastic material model defined by two parameters. The spatial distributions of these parameters (shear modulus and non linear parameter) were calculated by inverse analysis, using two different types of regularization: Total Variation Diminishing (TVD) and Tikhonov (H(1)). After solving the inverse problem, the distribution of the material parameters were obtained along the abdominal surface. Accuracy of the results was evaluated for the last level of pressure. Results revealed a higher value of the shear modulus in a wide stripe along the craneo-caudal direction, associated with the presence of linea alba in conjunction with fascias and rectus abdominis. Non linear parameter distribution was smoother and the location of higher values varied with the regularization type. Both regularizations proved to yield in an accurate predicted displacement field, but H(1) obtained a smoother material parameter distribution while TVD included some discontinuities. The methodology here presented was able to characterize in vivo the passive non linear mechanical response of the abdominal wall.

  9. Spontaneous abscesses of the abdominal wall, omentum and abdominal cavity caused by group G streptococci: a case report.

    PubMed

    De Brabandere, K; Vanpaemel, G; Verheyen, L

    2008-01-01

    We report the first case, to our knowledge, of spontaneous abscess of the abdominal wall, omentum and abdominal cavity caused by group G streptococci. A 52-year-old diabetic woman presented with abdominal tenderness and weight loss that had persisted for a few weeks. CT scan showed several abscesses of the abdominal wall, omentum and abdominal cavity. The abscesses were drained laparoscopically and antibiotics were given postoperatively. Biopsies and cultures showed group G streptococci. The patient recovered without any complication and left our hospital on the 17th postoperative day.

  10. Quantitative anatomical labeling of the anterior abdominal wall

    NASA Astrophysics Data System (ADS)

    Allen, Wade M.; Xu, Zhoubing; Asman, Andrew J.; Poulose, Benjamin K.; Landman, Bennett A.

    2013-03-01

    Ventral hernias (VHs) are abnormal openings in the anterior abdominal wall that are common side effects of surgical intervention. Repair of VHs is the most commonly performed procedure by general surgeons worldwide, but VH repair outcomes are not particularly encouraging (with recurrence rates up to 43%). A variety of open and laparoscopic techniques are available for hernia repair, and the specific technique used is ultimately driven by surgeon preference and experience. Despite routine acquisition of computed tomography (CT) for VH patients, little quantitative information is available on which to guide selection of a particular approach and/or optimize patient-specific treatment. From anecdotal interviews, the success of VH repair procedures correlates with hernia size, location, and involvement of secondary structures. Herein, we propose an image labeling protocol to segment the anterior abdominal area to provide a geometric basis with which to derive biomarkers and evaluate treatment efficacy. Based on routine clinical CT data, we are able to identify inner and outer surfaces of the abdominal walls and the herniated volume. This is the first formal presentation of a protocol to quantify these structures on abdominal CT. The intra- and inter rater reproducibilities of this protocol are evaluated on 4 patients with suspected VH (3 patients were ultimately diagnosed with VH while 1 was not). Mean surfaces distances of less than 2mm were achieved for all structures.

  11. Abdominal wall endometrioma: Our experience in Vladimir, Russia

    PubMed Central

    Gachabayov, Mahir; Horta, Roman; Afanasyev, Dmitriy; Gilyazov, Timur

    2016-01-01

    Background: Endometriosis is defined as an estrogen-dependent, benign inflammatory disease characterized by the presence of ectopic endometrial implants. Abdominal wall endometrioma (AWE) being a rare entity is a benign tumor defined as ectopic functional, endometrial tissue located in the abdominal wall. Subjects and Methods: A retrospective study of 23 female patients treated with AWE in four departments of three centers in Vladimir city, Russia, from January 2010 to December 2014 was performed. Results: In twenty patients (87%), AWE was symptomatic, and in three patients (13%), AWE was asymptomatic. Esquivel triad presented in 17 patients (74%), and modified Esquivel triad existed in 20 patients (87%). All 23 patients were operated, and AWE excision was performed. Recurrence occurred in 4 cases (17.4%) and was associated with postoperative pain and seroma. Conclusion: Postoperative pain for more than 7 days and seroma (on ultrasonography) seem to be associated with recurrence of AWE. PMID:27942100

  12. Management of Complex Abdominal Wall Defects Associated with Penetrating Abdominal Trauma

    DTIC Science & Technology

    2014-05-09

    management of the abdominal wall was determined by a multidisciplinary team of general and plastic surgeons, intensivists and specialist nurses . The...otomy is performed when the patient’s physiology has normalised, usually at 12–72 h after the damage control procedure. Closure of the midline... nurse specialist, microbiology, intensive care, the hos- pital medical director and the orthopaedic surgeons if there was concomitant bony or extremity

  13. 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.

  14. Effects of the flexibility of the arterial wall on the wall shear stresses and wall tension in Abdominal Aortic Aneurysms.

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Fernandez, Miguel; Chomaz, Jean-Marc

    2005-11-01

    As an abdominal aortic aneurysm develops, large changes occur in the composition and structure of the arterial wall, which result in its stiffening. So far, most studies, whether experimental or numerical, have been conducted assuming the walls to be rigid. A numerical simulation of the fluid structure interactions is performed in different models of aneurysms in order to analyze the effects that the wall compliance might have on the flow topology. Both symmetric and non-symmetric models of aneurysms are considered, all idealistic in shape. The wall mechanical properties are varied in order to simulate the progressive stiffening of the walls. The spatial and temporal distributions of wall tension are calculated for the different values of the wall elasticity and compared to the results for the rigid walls. In the case of rigid walls, the calculation of the wall shear stresses and pressure compare very well with experimental results.

  15. 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

  16. Cytoreductive strategy for multiple intra-abdominal and abdominal wall desmoid tumors in familial adenomatous polyposis: report of three cases.

    PubMed

    Tanaka, Koji; Toiyama, Yuji; Okugawa, Yoshinaga; Hiro, Junichiro; Kawamoto, Aya; Inoue, Yasuhiro; Uchida, Keiichi; Araki, Toshimitsu; Mohri, Yasuhiko; Kusunoki, Masato

    2012-10-01

    Desmoid tumors (DTs) are benign myofibroblastic neoplasms originating from the fascia or muscle aponeurosis, which occur in one-third of patients with familial adenomatous polyposis (FAP). Most FAP-associated DTs occur in the intra-abdominal or abdominal wall region, thus, their infiltrative or expansive growth causes life-threatening organ damage, such as intestinal obstruction, urethral obstruction, and mesenteric infiltration with the involvement of mesenteric vessels. Treatments including surgical resection, cytotoxic chemotherapy, nonsteroidal anti-inflammatory drugs and anti-estrogen therapy have all been tried with variable success. Here, we report on three patients with FAP who developed multiple intra-abdominal and abdominal wall DTs after total proctocolectomy and ileal pouch-anal anastomosis. Two cases underwent surgical resection of uncontrolled abdominal wall DTs after successful control of intra-abdominal DTs by systemic chemotherapy. The remaining case underwent repeated surgical resections of multiple intra-abdominal and abdominal wall DTs, and consequently had recurrent intra-abdominal DTs, with involvement of the small bowel and ureter. Surgical intervention as tumor volume reduction (cytoreduction) may be useful for cases with medical treatment-refractory or symptomatic FAP-associated abdominal DTs.

  17. Abdominal Wall Transplantation: Skin as a Sentinel Marker for Rejection.

    PubMed

    Gerlach, U A; Vrakas, G; Sawitzki, B; Macedo, R; Reddy, S; Friend, P J; Giele, H; Vaidya, A

    2016-06-01

    Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT-AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX-AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8-12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT-AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection.

  18. Bioprosthetic Tissue Matrices in Complex Abdominal Wall Reconstruction

    PubMed Central

    Broyles, Justin M.; Abt, Nicholas B.; Sacks, Justin M.

    2013-01-01

    Background: Complex abdominal defects are difficult problems encountered by surgeons in multiple specialties. Although current evidence supports the primary repair of these defects with mesh reinforcement, it is unclear which mesh is superior for any given clinical scenario. The purpose of this review was to explore the characteristics of and clinical relevance behind bioprosthetic tissue matrices in an effort to better clarify their role in abdominal wall reconstruction. Methods: We reviewed the peer-reviewed literature on the use of bioprosthetic mesh in human subjects. Basic science articles and large retrospective and prospective reviews were included in author’s analysis. The clinical performance and characteristics of 13 bioprosthetic tissue matrices were evaluated. Results: The majority of the products evaluated perform well in contaminated fields, where the risk of wound-healing difficulties is high. Clinical outcomes, which included infection, reherniation, and bulge formation, were variable, and the majority of the studies had a mean follow-up of less than 24 months. Conclusions: Although bioprosthetic matrix has a multitude of indications within the growing field of abdominal wall reconstruction, the functionality, regenerative capacity, and long-term fate of these products have yet to be fully established. Furthermore, the clinical performance, indications, and contraindications for each type of matrix need to be fully evaluated in long-term outcome studies. PMID:25289285

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500-4 Thickness of wall. (a) Minimum thickness of wall of each finished tank shall be such that at a pressure equal to 7/10...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500-4 Thickness of wall. (a) Minimum thickness of wall of each finished tank shall be such that at a pressure equal to 7/10...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500-4 Thickness of wall. (a) Minimum thickness of wall of each finished tank shall be such that at a pressure equal to 7/10...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500-4 Thickness of wall. (a) Minimum thickness of wall of each finished tank shall be such that at a pressure equal to 7/10...

  3. Advances in surgery for abdominal wall defects: gastroschisis and omphalocele.

    PubMed

    Islam, Saleem

    2012-06-01

    Abdominal wall defects (AWDs) are a common congenital surgical problem in fetuses and neonates. The incidence of these defects has steadily increased over the past few decades due to rising numbers of gastroschisis. Most of these anomalies are diagnosed prenatally and then managed at a center with available pediatric surgical, neonatology, and high-risk obstetric support. Omphaloceles and gastroschisis are distinct anomalies that have different management and outcomes. There have been a number of recent advances in the care of patients with AWDs, both in the fetus and the newborn, which will be discussed in this article.

  4. Changes in wall shear stresses in abdominal aortic aneurysms with increasing wall stiffness

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Fernandez, Miguel

    2006-11-01

    During the growth of abdominal aortic aneurysms, local changes occur in the composition and structure of the diseased wall, resulting in its stiffening. A numerical simulation of the fluid structure interactions is performed in idealized models of aneurysms using a finite element method. A full coupling of the equations governing the pulsatile blood flow and the deformation of the compliant wall is undertaken. The effect of the progressive stiffening of the wall is analyzed at various stages in the growth of the aneurysm. Increasing the wall stiffness alters the distribution of wall shear stresses and leads to an increase in their magnitude. The wall compliance is shown to have a more pronounced effect on non-axisymmetric aneurysms, which sustain large displacements. The overall movement of the aneurysm models increases the three-dimensionality of the flow.

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

    PubMed

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

    2015-04-15

    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.

  6. An abdominal wall simulator for testing suprapubic urinary catheters.

    PubMed

    Coveney, V A; Gröver, D

    2001-08-01

    Urinary catheters (drainage tubes) are in widespread use. The most common type of long-term catheter is the Foley, which is made from natural or synthetic rubber. Foley catheters are passed into the bladder via the urethra or the suprapubic puncture channel (through the abdominal wall). A simulator for the abdominal wall has been developed to simulate aspects of the interaction between it and a suprapubic catheter. The simulator is based on a slab of ultrasoft elastomer with tensionable reinforcing polyamide filaments. The behaviour of the simulator has been compared with data published. A soft membrane (contact pressure) transducer (SMT) was used and novel instrumented 'tongs' for lateral indentation of the puncture track giving indentation stiffness. Slab materials were used with shear moduli of 0.1 and 0.021 MPa. Two filament-tensioning methods were used: by clamping to a winding mechanism and by weights. The combination of the softer slab material and tensioning by weights gave good conformity to physiological data; other combinations did not.

  7. Reconstruction of Abdominal Wall Defects Using a Pedicled Anterolateral Thigh Flap including the Vastus Lateralis Muscle: A Report of Two Cases

    PubMed Central

    Fujioka, Masaki; Ishiyama, Satoko

    2016-01-01

    The purpose of abdominal wall reconstruction is to prevent hernias and protect the abdominal viscera. In cases involving full-thickness defects of the rectus abdominis muscle, the muscle layer should be repaired. We present 2 cases in which full-thickness lower rectus abdominis muscle defects were reconstructed using vastus lateralis-anterolateral thigh flaps. The pedicled vastus lateralis-anterolateral thigh flap provides skin, fascia, and muscle tissue. Furthermore, it has a long neurovascular pedicle and can reach up to the periumbilical area and cover large defects. We consider that this muscle flap is a good option for repairing full-thickness lower abdominal defects. PMID:28074168

  8. Management of strangulated abdominal wall hernias with mesh; early results

    PubMed Central

    Ozbagriacik, Mustafa; Bas, Gurhan; Basak, Fatih; Sisik, Abdullah; Acar, Aylin; Kudas, Ilyas; Yucel, Metin; Ozpek, Adnan; Alimoglu, Orhan

    2015-01-01

    OBJECTIVE: Surgery for abdominal wall hernias is a common procedure in general surgery practice. The main causes of delay for the operation are comorbid problems and patient unwillingness, which eventually, means that some patients are admitted to emergency clinics with strangulated hernias. In this report, patients who admitted to the emergency department with strangulated adominal wall hernias are presented together with their clinical management. METHODS: Patients who admitted to our clinic between January 2009 and November 2011 and underwent emergency operation were included in the study retrospectively. Demographic characteristics, hernia type, length of hospital stay, surgical treatment and complications were assessed. RESULTS: A total 81 patients (37 female, 44 male) with a mean age of 52.1±17.64 years were included in the study. Inguinal, femoral, umbilical and incisional hernias were detected in 40, 26, 9 and 6 patients respectively. Polypropylene mesh was used in 75 patients for repair. Primary repair without mesh was used in six patients. Small bowel (n=10; 12.34%), omentum (n=19; 23.45%), appendix (n=1; 1.2%) and Meckel’s diverticulum (n=1; 1.2%) were resected. Median length of hospital stay was 2 (1–7) days. Surgical site infection was detected in five (6.2%) patients. No significant difference was detected for length of hospital stay and surgical site infection in patients who had mesh repair (p=0.232 and 0.326 respectively). CONCLUSION: The need for bowel resection is common in strangulated abdominal wall hernias which undergo emergency operation. In the present study, an increase of morbidity was seen in patients who underwent bowel resection. No morbidity was detected related to the usage of prosthetic materials in repair of hernias. Hence, we believe that prosthetic materials can be used safely in emergency cases. PMID:28058336

  9. 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.

  10. The effect of food consumption on the thickness of abdominal muscles, employing ultrasound measurements.

    PubMed

    Kordi, Ramin; Rostami, Mohsen; Noormohammadpour, Pardis; Mansournia, Mohammad Ali

    2011-08-01

    Recently, the roles of transabdominal muscles particularly TrA (transverse abdominis) muscle in spinal stability leading to treatment of low back pain have been suggested. Both in clinical setting and follow up studies, abdominal muscle thickness measurements need to be repeated at a later point in time to demonstrate efficacy of a therapeutic intervention. Different issues have been suggested as source of error in the repeated measurements of abdominal muscle thickness in different days such as patient position and stability of probe location. The level of stomach fullness has not been investigated as a source of error in ultrasonic measurements of transabdominal muscles thickness. This study was performed to evaluate the effect of food consumption on thickness of lateral abdominal muscles. Lateral abdominal muscles thicknesses of 63 healthy volunteer men were measured before and after food consumption. All the measurements were performed in two transducer positions and both sides. Waist circumference and body weight of participants were also measured before and post-food consumption. The thickness measures of all three muscles layers of lateral abdominal muscles (external oblique, internal oblique and transversus abdominis) in both sides and measured positions were significantly reduced after food consumption. We found no correlation between the increase of waist circumference and reduction of muscle layer thicknesses after food consumption. In case of comparison between the values of transabdominal muscle thicknesses over the time, the effect of food consumption on muscle thickness might be assumed as a potential source of error.

  11. A comparison of prosthetic materials used to repair abdominal wall defects.

    PubMed

    Jenkins, S D; Klamer, T W; Parteka, J J; Condon, R E

    1983-08-01

    A large abdominal wall hernia, not amenable to primary closure, may require insertion of a prosthesis. The ideal prosthesis maintains strength, is incorporated by surrounding tissues, and does not stimulate adhesions. These qualities vary among available synthetic prostheses. We tested tensile strength, bursting strength, and adhesion formation in response to six materials used in repair of abdominal wall hernias. Adult Sprague-Dawley rats (196) were randomly divided into a control group and six experimental groups. A 4 by 4 cm full-thickness resection of abdominal wall was closed with patches of polypropylene mesh (Marlex), polyglactin 910 mesh (Vicryl), expanded polytetrafluoroethylene (Gore-tex), Dacron-reinforced silicone rubber (Silastic), preserved human dura (PHD), or polypropylene mesh overlying gelatin film (Marlex and Gelfilm, respectively). In controls the 4 cm longitudinal full-thickness incisions were closed primarily. Seven rats randomly selected from each group were sacrificed after 1, 2, 4, and 8 weeks; bursting and tensile strength (tensiometer) and adhesion formation were assessed. There were no differences in bursting strength among the experimental groups at each testing period. Although bursting strength increased linearly with time it was significantly weaker than in controls at 1 and 8 weeks (P less than 0.05). Tensiometric data were inconclusive due to wide variability within the experimental groups. Adhesion formation was moderate to maximal at all evaluation periods for Marlex and Gore-tex. Early adhesion formation was minimal to moderate for both PHD and Vicryl, but later increased with PHD and decreased with Vicryl as this prosthesis was absorbed. No adhesions formed with Marlex and Gelfilm until the gelatin dissolved (1 week), after which the adhesion response was similar to that with Marlex alone. No adhesions formed after Silastic implantation, but graft extrusion and evisceration were common (75%). Controls had no adhesions at all

  12. Arnebia euchroma ointment can reduce abdominal fat thickness and abdominal circumference of overweight women: A randomized controlled study

    PubMed Central

    Siavash, Mansour; Naseri, Mohsen; Rahimi, Mojgan

    2016-01-01

    Background: Obesity is a worldwide health problem which is associated with a lot of complications. One of these comorbidities is the metabolic syndrome that is in correlation with abdominal fat thickness and waist circumference. Various methods were used to reduce abdominal fat thickness such as liposuction. A noninvasive method is the topical agent. In this study, we investigated the effectiveness of Arnebia euchroma (AE) ointment on the abdominal fat thickness. Materials and Methods: This study was a double-blind clinical trial which was done at the endocrinology clinic in Khorshid Hospital, Isfahan, Iran, in 2014. After explaining the procedure and obtaining informed consent, the candidates were randomly divided into the case and control groups. The participants of the case and control groups applied AE ointment or placebo for 6 weeks on their abdominal area. Body mass index, waist and buttock circumference, and abdominal fat thickness were measured in both case and control groups at their first visit and then at the next 2, 4, and 6 weeks. We used t-test for comparing parametric variables between groups, paired t-test for changes from baseline to final, and repeated measure ANOVA for changes at different steps. Results: Sixty female candidates participated in this study (thirty in each group). Ten patients left the study and fifty participants finished the trial. At the end of the study, participants had a significant weight loss (2.96 ± 1.6 kg, P < 0.001) that was slightly more in the case group (3.15 ± 1.5 kg vs. 2.75 ± 1.7, P = 0.375). Abdominal circumference also decreased significantly in the participants (11.3 ± 6.7 cm, P < 0.001), but the changes were more significant in the case group (13.9 vs. 6.5 cm, P = 0.004). Similarly, abdominal fat thickness decreased significantly in the participants (2.3 ± 1.1 cm, P < 0.001), although changes were not significantly different between two groups (2.53 vs. 2.04 cm, P = 0.139). Conclusion: Topical AE ointment

  13. Myocardium wall thickness transducer and measuring method

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H. (Inventor)

    1976-01-01

    A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described.

  14. Evaluation of Tube Wall Thickness of Feed Water Heater

    NASA Astrophysics Data System (ADS)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  15. [Postoperative necrotizing fasciitis of the anterior abdominal wall].

    PubMed

    Fichev, G; Poromanski, I; Marina, M

    1995-01-01

    Postoperative necrotizing fasciitis of the anterior abdominal wall is a serious and life-endangering complication of an acute progressive synergistic infective process. There is an absolute increase in its incidence rate attributable to a number of situations in modern life. Morphological and clinical studies are carried out on personal case material of 28 patients, followed up over a 3-year period. The presence of aerobic-anaerobic mixed polyinfection, consisting of average 3.75 bacterial species of which 1.43 aerobes and 2.32 anaerobes, is demonstrated microbiologically. Of the latter non-spore-bearing obligate anaerobes predominate among which B fragillis is the most common. As shown by the study, the process is characterized by slow initial course with ensuring rapid spreading by neighbourhood. The process reveals all signs of a mixed aerobic-anaerobic polyinfection, thereby necessitating subordination of both antibiotic therapy and surgical tactics to the latter.

  16. Components separation for abdominal wall reconstruction: the Memphis modification.

    PubMed

    DiCocco, Jennifer M; Fabian, Timothy C; Emmett, Katrina P; Magnotti, Louis J; Goldberg, Steven P; Croce, Martin A

    2012-01-01

    Since the advent of damage control surgery, more patients are left with an open abdomen. Surgeons are then left with the challenge of how to restore continuity of the abdominal wall. Many different techniques have been utilized for reconstruction with widely variable recurrence rates, mainly depending on the length of follow-up. A modification of the components separation technique was developed in Memphis, Tennessee at the Presley Memorial Trauma Center. This modification greatly increased the length gained in the midline. Additionally, many patients can be reconstructed without the use of prosthetics, reducing the infectious complications. The purpose of this manuscript is to describe in detail how to perform a modification of the components separation technique that has been shown to have one of the lowest recurrence rates in the literature.

  17. Resection and Abdominal Wall Reconstruction of a Desmoid Tumor with Endometrioma Features

    PubMed Central

    Majors, Jaqueline; Stoikes, Nathaniel F.; Nejati, Reza

    2016-01-01

    Desmoid tumors are rare, musculoaponeurotic mesenchymal origin tumors arising from the proliferation of well-differentiated fibroblasts. Desmoid tumors may arise from any location with the abdominal cavity, abdominal wall and extremity locations being most frequent. We present the case of a 35-year-old female with a history of endometriosis who presented palpable abdominal mass and cyclic abdominal pain. Resection was performed for a presumed desmoid soft tissue tumor. Final pathology demonstrated desmoid histology admixed with abdominal wall endometriosis (endometrioma). This unique pathologic finding has only been rarely reported and is discussed with a brief review of the literature. PMID:27247824

  18. Probabilistic noninvasive prediction of wall properties of abdominal aortic aneurysms using Bayesian regression.

    PubMed

    Biehler, Jonas; Kehl, Sebastian; Gee, Michael W; Schmies, Fadwa; Pelisek, Jaroslav; Maier, Andreas; Reeps, Christian; Eckstein, Hans-Henning; Wall, Wolfgang A

    2017-02-01

    Multiple patient-specific parameters, such as wall thickness, wall strength, and constitutive properties, are required for the computational assessment of abdominal aortic aneurysm (AAA) rupture risk. Unfortunately, many of these quantities are not easily accessible and could only be determined by invasive procedures, rendering a computational rupture risk assessment obsolete. This study investigates two different approaches to predict these quantities using regression models in combination with a multitude of noninvasively accessible, explanatory variables. We have gathered a large dataset comprising tensile tests performed with AAA specimens and supplementary patient information based on blood analysis, the patients medical history, and geometric features of the AAAs. Using this unique database, we harness the capability of state-of-the-art Bayesian regression techniques to infer probabilistic models for multiple quantities of interest. After a brief presentation of our experimental results, we show that we can effectively reduce the predictive uncertainty in the assessment of several patient-specific parameters, most importantly in thickness and failure strength of the AAA wall. Thereby, the more elaborate Bayesian regression approach based on Gaussian processes consistently outperforms standard linear regression. Moreover, our study contains a comparison to a previously proposed model for the wall strength.

  19. Measurement the thickness of the transverse abdominal muscle in different tasks

    PubMed Central

    Pang, Ling; Yin, Liquan; Tajiri, Kimiko; Huo, Ming; Maruyama, Hitoshi

    2017-01-01

    [Purpose] This study examined the measurement of the thickness of the transverse abdominal muscle in different tasks. [Subjects and Methods] The subjects were eleven healthy adult females. Thicknesses of transverse abdominal muscle were measured in seven tasks in the supine position. The tasks were: 1) Resting state, 2) Maximal contraction of transverse abdominal muscle, 3) Maximal contraction of levator ani muscle, 4) Maximal simultaneous contraction of both transverse abdominal muscle and levator ani muscle, 5) Maximal simultaneous contraction of both transverse abdominal muscle and levator ani muscle with front side resistance added to both knee, 6) Maximal simultaneous contraction of both transverse abdominal muscle and levator ani muscle with diagonal resistance added to both knees, and 7) Maximal simultaneous contraction of both transverse abdominal muscle and levator ani muscle with lateral resistance added to both knees. [Results] The thicknesses of transverse abdominal muscle during maximal simultaneous contraction and maximal simultaneous contraction with resistance were greater than during the resting state. [Conclusion] The muscle output during simultaneous contraction and resistance movement were larger than that of each individual muscle. PMID:28265140

  20. 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.

  1. 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.

  2. Bladder wall thickness mapping for magnetic resonance cystography.

    PubMed

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

    2013-08-07

    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.

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

    PubMed

    Lawonn, Kai; Glaßer, 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.

  4. 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.

  5. PET/CT detects abdominal wall and port site metastases of colorectal carcinoma.

    PubMed

    Goshen, E; Davidson, T; Aderka, D; Zwas, S T

    2006-07-01

    Abdominal wall metastases from colorectal cancer (CRC) may be resected with curative results. Such lesions, often indicators of additional intra-abdominal lesions, may appear in surgical scars, stomas and port site metastases after laparoscope-assisted surgery (LAS). Post-operative changes, primarily surgical scars, alter local physical findings making early detection of small lesions challenging. The purpose of this study was to retrospectively evaluate the contribution of PET/CT to the diagnosis of recurrent colorectal cancer in the post-operative abdominal wall. 120 patients were referred for PET/CT with suspected recurrent CRC based on clinical, radiological or laboratory findings. All underwent whole body PET/CT imaging. 12 of these 120 (10%), were found to have abdominal wall lesions. A total of 16 abdominal wall lesions were detected, located to surgical scars, stomas, drain and laparoscope ports. Additional findings on PET/CT in this group included liver metastases, intra-abdominal lesions and retroperitoneal lymph node involvement. In general, the patients in this small group were young with high grade tumours presenting in advanced stages. In conclusion, PET/CT appears to be a sensitive tool for the diagnosis of abdominal wall recurrence of CRC. The accuracy of localization afforded by the fused functional and anatomic images makes PET/CT a likely tool for diagnosing abdominal wall lesions, including port site metastases of other aetiologies.

  6. A clinically relevant in vivo model for the assessment of scaffold efficacy in abdominal wall reconstruction

    PubMed Central

    Chan, Jeffrey CY; Burugapalli, Krishna; Huang, Yi-Shiang; Kelly, John L; Pandit, Abhay

    2016-01-01

    An animal model that allows for assessment of the degree of stretching or contraction of the implant area and the in vivo degradation properties of biological meshes is required to evaluate their performance in vivo. Adult New Zealand rabbits underwent full thickness subtotal unilateral rectus abdominis muscle excision and were reconstructed with the non-biodegradable Peri-Guard®, Prolene® or biodegradable Surgisis® meshes. Following 8 weeks of recovery, the anterior abdominal wall tissue samples were collected for measurement of the implant dimensions. The Peri-Guard and Prolene meshes showed a slight and obvious shrinkage, respectively, whereas the Surgisis mesh showed stretching, resulting in hernia formation. Surgisis meshes showed in vivo biodegradation and increased collagen formation. This surgical rabbit model for abdominal wall defects is advantageous for evaluating the in vivo behaviour of surgical meshes. Implant area stretching and shrinkage were detected corresponding to mesh properties, and histological analysis and stereological methods supported these findings. PMID:28228932

  7. 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.

  8. Reconstruction of abdominal wall musculofascial defects with small intestinal submucosa scaffolds seeded with tenocytes in rats.

    PubMed

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

    2013-07-01

    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 (2×10(7)/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.

  9. The effect of resistance exercise direction for hip joint stabilization on lateral abdominal muscle thickness

    PubMed Central

    Jung, Ju-Hyeon; Lee, Sang-Yeol

    2016-01-01

    The aim of this study was to determine the effects of resistance direction in hip joint stabilization exercise on change in lateral abdominal muscle thickness in healthy adults. Twenty-six healthy adults were randomly allocated to either a hip stabilization exercise by hip straight resistance group (n=12) or a hip diagonal resistance group (n=14). The outcome measures included contraction thickness ratio in transversus abdominis (TrA), internal oblique (IO) and external oblique, and TrA lateral slide were assessed during the abdominal drawing-in maneuver by b-mode ultrasound. The researcher measured the abdominal muscle thickness of each participant before the therapist began the intervention and at the moment intervention was applied. There was a significant difference in lateral abdominal muscle thickness between the straight resistance exercise of hip joint group and the diagonal resistance exercise of hip joint group. Significant differences were found between the two groups in the percentage of change of muscle thickness of the TrA (P=0.018) and in the thickness ratio of the TrA (P=0.018). Stability exercise accompanied by diagonal resistance on the hip joint that was applied in this study can induce automatic contraction of the IO and TrA, which provides stability to the lumbar spine. PMID:27807520

  10. Stability of resistive wall modes with plasma rotation and thick wall in ITER scenario

    NASA Astrophysics Data System (ADS)

    Zheng, L. J.; Kotschenreuther, M.; Chu, M.; Chance, M.; Turnbull, A.

    2004-11-01

    The rotation effect on resistive wall modes (RWMs) is examined for realistically shaped, high-beta tokamak equilibria, including reactor relevant cases with low mach number M and realistic thick walls. For low M, Stabilization of RWMs arises from unusually thin inertial layers. The investigation employs the newly developed adaptive eigenvalue code (AEGIS: Adaptive EiGenfunction Independent Solution), which describes both low and high n modes and is in good agreement with GATO in the benchmark studies. AEGIS is unique in using adaptive methods to resolve such inertial layers with low mach number rotation. This feature is even more desirable for transport barrier cases. Additionally, ITER and reactors have thick conducting walls ( ˜.5-1 m) which are not well modeled as a thin shell. Such thick walls are considered here, including semi-analytical approximations to account for the toroidally segmented nature of real walls.

  11. The use of Surgisis for abdominal wall reconstruction in the separation of omphalopagus conjoined twins.

    PubMed

    Dasgupta, Roshni; Wales, Paul W; Zuker, Ronald M; Fisher, David M; Langer, Jacob C

    2007-09-01

    Abdominal wall reconstruction in omphalopagus twins poses a difficult reconstructive challenge, as separation often results in a large abdominal wall defect. A number of options are available for closure, including tissue flaps, expanders and patches made of foreign material. Surgisis is a new biodegradable small intestine scaffolding substrate that permits tissue in-growth and results in a permanent durable scar. We describe its use in abdominal wall reconstruction after separation of a set of conjoined twins. A set of omphalopagus conjoined twins shared liver and abdominal wall. After separation at 6 months of age, Twin A's abdomen could be closed primarily, but Twin B could not. A 4-ply Surgisis mesh was used in the upper abdominal closure, and a skin flap was created, to completely cover the patch. Both twins survived the operation. A small portion of the skin flap over the Surgisis broke down, healing by secondary intention. In follow up of over 18 months post procedure, there have been no wound infections and the abdominal wall is intact with no evidence of a hernia. Surgisis can be successfully used for the reconstruction of complex abdominal wall defects in the pediatric patient, including reconstruction after separation of conjoined twins.

  12. Combined Visualization of Wall Thickness and Wall Shear Stress for the Evaluation of Aneurysms.

    PubMed

    Glaßer, Sylvia; Lawonn, Kai; Hoffmann, Thomas; Skalej, Martin; Preim, Bernhard

    2014-12-01

    For an individual rupture risk assessment of aneurysms, the aneurysm's wall morphology and hemodynamics provide valuable information. Hemodynamic information is usually extracted via computational fluid dynamic (CFD) simulation on a previously extracted 3D aneurysm surface mesh or directly measured with 4D phase-contrast magnetic resonance imaging. In contrast, a noninvasive imaging technique that depicts the aneurysm wall in vivo is still not available. Our approach comprises an experiment, where intravascular ultrasound (IVUS) is employed to probe a dissected saccular aneurysm phantom, which we modeled from a porcine kidney artery. Then, we extracted a 3D surface mesh to gain the vessel wall thickness and hemodynamic information from a CFD simulation. Building on this, we developed a framework that depicts the inner and outer aneurysm wall with dedicated information about local thickness via distance ribbons. For both walls, a shading is adapted such that the inner wall as well as its distance to the outer wall is always perceivable. The exploration of the wall is further improved by combining it with hemodynamic information from the CFD simulation. Hence, the visual analysis comprises a brushing and linking concept for individual highlighting of pathologic areas. Also, a surface clustering is integrated to provide an automatic division of different aneurysm parts combined with a risk score depending on wall thickness and hemodynamic information. In general, our approach can be employed for vessel visualization purposes where an inner and outer wall has to be adequately represented.

  13. Abdominal wall reconstruction by a regionally distinct biocomposite of extracellular matrix digest and a biodegradable elastomer.

    PubMed

    Takanari, Keisuke; Hong, Yi; Hashizume, Ryotaro; Huber, Alexander; Amoroso, Nicholas J; D'Amore, Antonio; Badylak, Stephen F; Wagner, William R

    2016-09-01

    Current extracellular matrix (ECM) derived scaffolds offer promising regenerative responses in many settings, however in some applications there may be a desire for more robust and long lasting mechanical properties. A biohybrid composite material that offers both strength and bioactivity for optimal healing towards native tissue behavior may offer a solution to this problem. A regionally distinct biocomposite scaffold composed of a biodegradable elastomer (poly(ester urethane)urea) and porcine dermal ECM gel was generated to meet this need by a concurrent polymer electrospinning/ECM gel electrospraying technique where the electrosprayed component was varied temporally during the processing. A sandwich structure was achieved with polymer fiber rich upper and lower layers for structural support and an ECM-rich inner layer to encourage cell ingrowth. Increasing the upper and lower layer fiber content predictably increased tensile strength. In a rat full thickness abdominal wall defect model, the sandwich scaffold design maintained its thickness whereas control biohybrid scaffolds lacking the upper and lower fiber-rich regions failed at 8 weeks. Sandwich scaffold implants also showed higher collagen content 4 and 8 weeks after implantation, exhibited an increased M2 macrophage phenotype response at later times and developed biaxial mechanical properties better approximating native tissue. By employing a processing approach that creates a sheet-form scaffold with regionally distinct zones, it was possible to improve biological outcomes in body wall repair and provide the means for further tuning scaffold mechanical parameters when targeting other applications. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Primary Liver Abscess with Anterior Abdominal Wall Extension Caused by Mycobacterium tuberculosis Complex

    PubMed Central

    Kandekar, Rahul Vilas; Tiwari, Ajeet Ramamani; Kadam, Rahul; Adhikari, Devbrata Radhikamohan

    2016-01-01

    Tubercular liver abscess is generally secondary to some other primary foci in the body, most notably pulmonary and gastrointestinal system. To find primary tubercular liver abscess is rare, with prevalence of 0.34% in patients with hepatic tuberculosis. Abscess tracking into abdominal wall from spinal and para spinal tuberculosis is known, however primary liver tuberculosis rupturing into anterior abdominal wall has been reported only twice in literature. We report a case of 43-year-old female with direct invasion of the anterior abdominal wall from an isolated tubercular parenchymal liver abscess, caused by Mycobacterium tuberculosis complex, diagnosed primarily on smear for Acid Fast Bacilli (AFB), imaging and isolated by culture and BACTEC MGIT 960 KIT. We discuss here the diagnostic dilemma, management and outcome of primary tubercular liver parenchymal abscess with direct invasion into anterior abdominal wall. PMID:28050433

  15. Thoraco-abdominal wall reconstruction after surgical debulking of a giant retroperitoneal liposarcoma: a case report.

    PubMed

    Colebunders, B; Colpaert, S D M; Mertens, M; Willemsen, P

    2011-01-01

    A case of a patient with a recurrent dedifferentiated retroperitoneal liposarcoma with extensive invasion of the thoraco-abdominal wall including the skin, requiring reconstructive surgery after debulking of the tumor is reported.

  16. [MORPHOLOGICAL PECULIARITIES OF MUSCULO-APONEUROTIC TISSUES OF ANTERIOR ABDOMINAL WALL IN PATIENTS, SUFFERING MORBID OBESITY].

    PubMed

    Usenko, O Yu; Gomolyako, I V; Kondratenko, B M; Moskalenko, V V

    2015-11-01

    Results of morphological investigation of musculo-aponeurotic structures of anterior abdominal wall were presented in the morbid obesity patients. The role of obesity as a primary cause for morphofunctional insufficience of musculo-aponeurotic structures was established.

  17. Severe cellulitis and abdominal wall emphysema following laparoscopic colonic surgery: A case report.

    PubMed

    Tanaka, Ryo; Kameyama, Hitoshi; Chida, Tadasu; Kanda, Tatsuo; Kano, Yosuke; Ichikawa, Hiroshi; Hanyu, Takaaki; Ishikawa, Takashi; Kosugi, Shin-Ichi; Wakai, Toshifumi

    2015-05-01

    Abdominal wall emphysema is a common complication of laparoscopic surgery. This condition is usually harmless; however, if an infection occurs, it can develop into a serious condition such as necrotizing fasciitis. We report a case of a 51-year-old woman suffering from severe cellulitis that spread from an area of abdominal wall emphysema after laparoscopic surgery for sigmoid colon cancer. Recognizing this complication, early diagnosis, and prompt treatment are cornerstones for successful management of this potentially fatal disease.

  18. 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.

  19. The role of myocardial wall thickness in atrial arrhythmogenesis.

    PubMed

    Whitaker, John; Rajani, Ronak; Chubb, Henry; Gabrawi, Mark; Varela, Marta; Wright, Matthew; Niederer, Steven; O'Neill, Mark D

    2016-12-01

    Changes in the structure and electrical behaviour of the left atrium are known to occur with conditions that predispose to atrial fibrillation (AF) and in response to prolonged periods of AF. We review the evidence that changes in myocardial thickness in the left atrium are an important part of this pathological remodelling process. Autopsy studies have demonstrated changes in the thickness of the atrial wall between patients with different clinical histories. Comparison of the reported tissue dimensions from pathological studies provides an indication of normal ranges for atrial wall thickness. Imaging studies, most commonly done using cardiac computed tomography, have demonstrated that these changes may be identified non-invasively. Experimental evidence using isolated tissue preparations, animal models of AF, and computer simulations proves that the three-dimensional tissue structure will be an important determinant of the electrical behaviour of atrial tissue. Accurately identifying the thickness of the atrial may have an important role in the non-invasive assessment of atrial structure. In combination with atrial tissue characterization, a comprehensive assessment of the atrial dimensions may allow prediction of atrial electrophysiological behaviour and in the future, guide radiofrequency delivery in regions based on their tissue thickness.

  20. Noninvasive Stiffness Sensing of Ventricular Wall Based on a Thick-walled Cylinder Model

    NASA Astrophysics Data System (ADS)

    Higashimori, Mitsuru; Ojio, Takeshi; Takeda, Yasuharu; Sakata, Yasushi; Yamamoto, Kazuhiro; Kaneko, Makoto

    This paper discusses a concept of a noninvasive sensing method that can estimate a left ventricular wall stiffness towards a medical diagnosis. Focusing on not only the strain of ventricular wall but also the displacements of epicardium during diastole of heart beat, we propose an index of ventricular wall stiffness based on a thick-walled cylinder model. Applying the proposed method to the echocardiography, we show statistical results where normal and HFpEF (Heart Failure with preserved Ejection Fraction) can be separated towards a medical diagnosis.

  1. The surface landmarks of the abdominal wall: a plea for standardization

    PubMed Central

    Cirocchi, Roberto; Boselli, Carlo; Renzi, Claudio; Cagini, Lucio; Boccolini, Andrea; Noya, Giuseppe; Fingerhut, Abe

    2014-01-01

    Despite centuries of anatomical studies, controversies and contradictions still exist in the literature regarding the definition, anatomical terminology and the limits of the abdominal wall. We conducted a systematic research of books published from 1901 until December 2012 in Google Books. After the index screening, 16 remaining books were further assessed for eligibility. We decided to exclude journals. The aim of the study was to focus on surface landmarks and borders of the abdominal cavity. After this revision of the literature, we propose that the surface landmarks of the abdominal wall should be standardized. PMID:25097589

  2. Multilayer injection moulding of thick-walled optical plastics parts

    NASA Astrophysics Data System (ADS)

    Hopmann, Ch.; Neuss, A.; Weber, M.; Walach, P.

    2014-05-01

    Optical components are often thick-walled. The cycle time of precise polymer optics with a wall thickness of more than 20 mm exceeds several minutes. The multilayer injection moulding or compression moulding lowers the cycle time and increases the quality of the moulded parts. For the production of multilayer moulded lenses the mould design plays an important role. An innovative mould concept is presented with the possiblity to produce double or triple layer lenses. To ensure the quality and the endurance of multilayer moulded optical components in their applications, the cohesion in the interface is important. Tensile shear tests show the ability of multilayer moulded parts with high cohesion values for optical applications.

  3. Chest wall thickness measurements for enriched uranium: An alternative approach

    SciTech Connect

    Kramer, G.H.; Puscalau, M.

    1994-05-01

    Human Monitoring Laboratory has developed a technique to determine the chest wall thickness of an individual using information from the spectrum produced by internally deposited radionuclides. The technique has been investigated both theoretically and practically using phoswich detectors and the Lawrence Livermore Torso Phantom. The phantom was used with lung sets containing homogeneously distributed 93% enriched uranium, 20% enriched uranium, natural uranium, and {sup 241}Am. It was found that a 3-cm chest wall thickness can be estimated to within 9% when measuring 93% enriched uranium. The technique does not work for the latter two radionuclides because of an insufficient separation in the photon energies and poor resolution of the phoswich detectors. The technique is only of value for activity levels limit. 5 refs., 3 figs., 1 tab.

  4. 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.

  5. Abdominal and scrotal wall emphysema in a patient with severe ulcerative colitis.

    PubMed

    Sharma, Manik; Thandassery, Ragesh Babu; Hilli, Shatha Al; Kaabi, Saad Al

    2014-07-01

    Severe ulcerative colitis can be associated with bowel perforation. Bowel perforation rarely leads on to abdominal wall and scrotal wall emphysema. Bowel perforation in such cases can be spontaneous or iatrogenic (colonoscopy-related). We report a rare scenario where a patient presented with abdominal wall and scrotal emphysema after topical corticosteroid enema-induced traumatic rectal perforation. Topical corticosteroids were stopped immediately after identification of rectal perforation. The patient was managed conservatively with intravenous antibiotics. With this report we intend to sensitise clinicians and topical enema manufacturers regarding this rare complication.

  6. [Approaches to the abdominal cavity and closure of the abdominal wall].

    PubMed

    Dittmar, Y; Rauchfuss, F; Ardelt, M; Settmacher, U

    2011-12-01

    Although minimally invasive approaches to the abdominal cavity are becoming increasingly more important, open surgical techniques are still of essential interest and must be mastered by general and visceral surgeons. The choice of the particular approach depends on the specificity and location of the scheduled procedure. The following article is intended to give an overview on the current literature as well as experiences in the field of open surgical approaches to the abdominal cavity.

  7. Primary closure of the abdominal wall after "open abdomen" situation.

    PubMed

    Kääriäinen, M; Kuokkanen, H

    2013-01-01

    "Open abdomen" is a strategy used to avoid or treat abdominal compartment syndrome. It has reduced mortality both in trauma and non-trauma abdominal catastrophes but also has created a challenging clinical problem. Traditionally, open abdomen is closed in two phases; primarily with a free skin graft and later with a flap reconstruction. A modern trend is to close the abdomen within the initial hospitalization. This requires multi-professional co-operation. Temporary abdominal closure methods, e.g. negative pressure wound therapy alone or combined with mesh-mediated traction, have been developed to facilitate direct fascial closure. Components separation technique, mesh reinforcement or bridging of the fascial defect with mesh and perforator saving skin undermining can be utilized in the final closure if needed. These techniques can be combined. Choice of the treatment depends on the condition of the patient and size of the fascia and skin defect, and the state of the abdominal contents. In this paper we review the literature on the closure of an open abdomen and present the policy used in our institution in the open abdomen situations.

  8. Paragonimiasis mimicking chest cancer and abdominal wall metastaisis: A case report

    PubMed Central

    ZHOU, RONGXING; ZHANG, MINJIA; CHENG, NANSHENG; ZHOU, YONG

    2016-01-01

    Typical human paragonimiasis demonstrates an elevated eosinophil count, positive immunoblot, nodular shadows of the lung and pleural thickening with pleural effusion, and these symptoms may be confused with chest cancer. In the present case, a rare case of human paragonimiasis mimicking chest cancer and abdominal wall metastasis is described, the 39-year-old male patient was admitted in our hospital for cough, weight loss 5 kg and a firm mass in right upper abdominal wall. The laboratory test showed unremarkable hematology and biochemistry results. Chest X-ray, Plain computed tomography of the chest and abdomen showed right pleural effusion, several nodules in right lower lung and a mass in the right upper abdominal wall. The initial diagnosis was lung or chest cancer with abdominal wall metastasis, and the abdominal wall mass was resected for the final diagnosis. The biopsy revealed eosinophilic granuloma with Charcot-Leyden crystal formation infiltrated in the muscular fibers. Subsequent to assessment of the antibodies against parasites, the final diagnosis of paragonimiasis was made. PMID:27313691

  9. The effect of lumbar-pelvic alignment and abdominal muscle thickness on primary dysmenorrhea

    PubMed Central

    Kim, Moon-jeong; Baek, Il-hun; Goo, Bong-oh

    2016-01-01

    [Purpose] The purpose of this study was to identify effects of malalignment of the lumbar pelvis, as a passive element, and the thicknesses of abdominal muscles, as active elements, on primary dysmenorrhea. [Subjects and Methods] The subjects were divided into a primary dysmenorrhea group and normal group according to Visual Analogue Scale, and ultimately there were 28 subjects in the dysmenorrhea group and 22 subjects in the normal group. Alignment of the lumbar pelvis was measured by using a Formetric 4D analysis system, and the thicknesses of abdominal muscles were measured by using ultrasound imaging. [Result] Scoliosis was 6.7 ± 4.3° in the primary dysmenorrhea group and 3.8 ± 2.0° in the normal group, and the lordotic angles of the two groups were 0.6 ± 0.5° and 0.1 ± 0.3°, respectively. The thickness of the internal oblique was 3.8 ± 1.3 mm in the primary dysmenorrhea group and 6.0 ± 1.9 mm in the thicknesses of the transverse abdominis in the two groups were 2.6 ± 6.8 mm and 3.5 ± 6.1 mm, respectively. Furthermore, the thickness of the normal group, and the external oblique was 4.0 ± 0.8 mm in the primary dysmenorrhea group and 5.4 ± 1.4 mm in the normal group. [Conclusion] This study showed significant differences between the primary dysmenorrhea group and the normal group in lumbar-pelvic alignment and thicknesses of abdominal muscles. PMID:27821975

  10. Testicular Ectopia in the Anterior Abdominal Wall of a Neonate: A Rare Site of Ectopic Testis

    PubMed Central

    Siddiqui, Salman Atiq; Marei, Tamer Ibrahim; Al-Makhaita, Ghada

    2016-01-01

    Patient: Male, 3-day Final Diagnosis: Ectopic right testis in anterior abdominal wall Symptoms: — Medication: — Clinical Procedure: Testicular ultrasound and MRI abdomen Specialty: Radiology Objective: Unusual clinical course Background: Abnormal testicular descent can either be undescended or, less commonly, ectopic. Most undescended testes complete the course of descent by the first year of life only if these remain in the normal path of descent. The deviation of the testis may occur to an ectopic location during the transinguinal phase. Of the known ectopic sites, the anterior abdominal wall is the rarest site of testicular ectopia and to our knowledge only 3 cases of this nature have been reported in the available literature to date. Case Report: This rare case of testicular ectopia occurred in a 3-day-old boy in whom the right scrotal sac was empty; on abdominal ultrasound, the right testis was found in the subcutaneous tissues of the right antero-lateral abdominal wall. These findings were confirmed on abdominal MRI, where the right testis was seen beneath the skin between the subcutaneous tissues and external oblique aponeurosis. No aponeurotic or muscular defect was appreciable under the abdominal wall. The neonate underwent orchiopexy at the age of 6 months and remained uneventful postoperatively. Conclusions: Preoperative imaging is recommended to detect and confirm the ectopic site as well as the morphology of testis, thereby increasing the chance of surveillance and preservation of an ectopic testis. Imaging can serve as preoperative road mapping to localize the exact site for surgical exploration of an ectopic testis if there is no apparent or palpable swelling over the anterior abdominal wall. PMID:27411886

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

    PubMed Central

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

    2013-01-01

    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

  12. 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

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

    2014-05-01

    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.

  15. Ectodermal Wnt signaling regulates abdominal myogenesis during ventral body wall development.

    PubMed

    Zhang, Lingling; Li, Hanjun; Yu, Jian; Cao, Jingjing; Chen, Huihui; Zhao, Haixia; Zhao, Jianzhi; Yao, Yiyun; Cheng, Huihui; Wang, Lifang; Zhou, Rujiang; Yao, Zhengju; Guo, Xizhi

    2014-03-01

    Defects of the ventral body wall are prevalent birth anomalies marked by deficiencies in body wall closure, hypoplasia of the abdominal musculature and multiple malformations across a gamut of organs. However, the mechanisms underlying ventral body wall defects remain elusive. Here, we investigated the role of Wnt signaling in ventral body wall development by inactivating Wls or β-catenin in murine abdominal ectoderm. The loss of Wls in the ventral epithelium, which blocks the secretion of Wnt proteins, resulted in dysgenesis of ventral musculature and genito-urinary tract during embryonic development. Molecular analyses revealed that the dermis and myogenic differentiation in the underlying mesenchymal progenitor cells was perturbed by the loss of ectodermal Wls. The activity of the Wnt-Pitx2 axis was impaired in the ventral mesenchyme of the mutant body wall, which partially accounted for the defects in ventral musculature formation. In contrast, epithelial depletion of β-catenin or Wnt5a did not resemble the body wall defects in the ectodermal Wls mutant. These findings indicate that ectodermal Wnt signaling instructs the underlying mesodermal specification and abdominal musculature formation during ventral body wall development, adding evidence to the theory that ectoderm-mesenchyme signaling is a potential unifying mechanism for the origin of ventral body wall defects.

  16. Use of a hand-held Doppler to avoid abdominal wall vessels in laparoscopic surgery.

    PubMed Central

    Whiteley, M. S.; Laws, S. A.; Wise, M. H.

    1994-01-01

    Laparoscopy in general surgery is becoming a wide-spread technique. Substantial anterior abdominal wall haemorrhage is a recognised complication of the laparoscopic technique. Ten patients were examined with an 8 MHz hand-held Doppler and the anterior abdominal wall vessels were marked on the skin. Colour flow duplex was used to confirm the presence of vessels found in this way. All 40 epigastric arteries were marked accurately and confirmed; 75 other intramural arteries were identified, although the majority were too small for duplex confirmation. The preoperative use of hand-held Doppler is a quick and non-invasive way to identify the epigastric and larger intramural arteries. Routine use of this technique to mark abdominal wall vessels in the areas of trocar insertion should reduce this complication of laparoscopic surgery. PMID:7661918

  17. Abdominal Wall Endometriosis: Myofibroblasts as a Possible Evidence of Metaplasia: A Case Report.

    PubMed

    Ibrahim, Mohamed Gamal; Delarue, Eleonore; Abesadze, Elene; Haas, Matthias; Sehouli, Jalid; Chiantera, Vito; Mechsner, Sylvia

    2017-01-01

    In this study, we report about a patient with extra-uterine endometriosis (EM) in the abdominal wall muscle with evident metaplasia based on the abundant alpha smooth muscle actin (ASMA)-expressing myofibroblasts. Laparotomy excision of the abdominal wall EM was done following ultrasonographic evidence of a hypodense swelling in the right rectus abdominis, which was confirmed by MRI. Immunohistochemistry staining for ASMA and collagen I was done, with the results confirming that endometriotic stromal cells expressed both. Anterior abdominal wall endometriosis was suspected because of the patient's history of recurrent EM combined with the cyclic nature of symptoms. MRI is useful in determining the extent of the disease. In case of persisting symptoms even under hormonal treatment, surgical excision is mandatory. The expression of both ASMA and collagen I in and around EM lesions supports the notion of the metaplastic process in the course of disease development.

  18. Congenital defects of the abdominal wall. A review of the experience in New Mexico.

    PubMed

    Klein, M D; Kosloske, A M; Hertzler, J H

    1981-04-24

    Omphalocele, umbilical cord hernia, and gastroschisis are surgically correctable defects of the abdominal wall. Each of these defects has a distinct embryologic basis that results in a characteristic clinical picture. Twenty-five infants with congenital defects of the abdominal wall were treated at the University of New Mexico Hospital in the past four years. Six infants had omphalocele, one had umbilical cord hernia, and 18 had gastroschisis. Survival among infants who underwent a corrective operation was as follows: omphalocele, 50%; umbilical cord hernia, 100%; and gastroschisis, 82%. Long-term survival for the entire group was 72% (18/25). Gastroschisis, which had a lower incidence of major associated anomalies, had a better prognosis than omphalocele. The mortality of congenital abdominal wall defects was related to presence of severe associated anomalies and to poor clinical condition on admission. Prompt and informed initial care may increase the chance of survival.

  19. A More Accurate Solution to the Elastic-Plastic Problem of Pressurized Thick-Walled Cylinders.

    DTIC Science & Technology

    1985-02-01

    PLASTIC PROBLEM OF PRESSURIZED THICK-WALLED CYLINDERS Wt) .0 PETER C. T...34ACT’rowim- -noes Sei Nomee..w snidswitby block numbr) A new method has been developed for solving the partially plastic problems of * thick-walled...34. -.........,..- - -. .. . ..... ,.... . ..... .*...**..*.... ... INTRODUCTION The partially plastic problem of pressurized thick-walled cylinder is of practical importance to pressure vessels and the

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. Abdominal wall reconstruction after extensive abdominal wall necrosis resulting from chevron incision for liver transplant and subsequent Y-shaped incision for re-transplantation--clinical experience and literature review.

    PubMed

    Rieger, Ulrich M; Petschke, Fabian; Djedovic, Gabriel; Engelhardt, Timm O; Biebl, Matthias; Pierer, Gerhard

    2012-03-01

    Extensive Abdominal wall necrosis is a devastating complication. In visceral transplant patients a quick and easy to perform reconstructive technique may be crucial for patient survival. Based on a clinical case a literature review is performed including a thorough analysis of abdominal wall perfusion and surgical options for defect closure are presented and critically appraised.

  6. Aesthetic and functional abdominal wall reconstruction after multiple bowel perforations secondary to liposuction.

    PubMed

    Di Candia, Michele; Malata, Charles M

    2011-04-01

    This report describes a case of aesthetic and functional abdominal wall reconstruction performed to salvage a deformed, scarred, and herniated anterior abdomen after severe peritonitis and partial rectus muscle necrosis secondary to multiple bowel perforations sustained during liposuction performed in a cosmetic clinic. The diagnosis of intestinal perforation was missed intraoperatively and in the immediate postoperative period. The patient was admitted 4 days after the surgery to the intensive therapy unit in septicemic shock. After resuscitation and stabilization, she was treated by debridement of the abdominal wall, bowel resection, and temporary jejunostomy and colostomy (reversed 10 months later). She was referred 18 months after liposuction to the Plastic Surgery Service with a large central midline abdominal incisional hernia presenting with thinned out skin (14 × 11 cm) overlying adherent bowel. A components separation technique was successfully used to reconstruct the abdominal wall, with no recurrent herniation 2 years later. Survivors of bowel perforations sustained during abdominal liposuction may later present with challenging aesthetic and functional problems, as described in this report. These long-term sequelae have not been addressed hitherto in the literature.

  7. Abdominal wall injuries: rectus abdominis strains, oblique strains, rectus sheath hematoma.

    PubMed

    Johnson, Rob

    2006-04-01

    Abdominal wall injuries are reported to be less common than actually perceived by sports medicine practitioners. National Collegiate Athletic Association injury statistics for 2004-2005 cite a high of 0.71 abdominal muscle injuries per 1000 player-hours in wrestling competition to a low of 0.01 injuries per 1000 player-hours in autumn football practices. British professional soccer clubs reported an incidence of "torso" injuries of up to 7% of all injuries over the course of several seasons. Injury definition is most likely the explanation for this discrepancy. The abdominal wall muscles (rectus abdominis, external and internal obliques, and transverse abdominis) are injured by direct blows to the abdomen or by sudden or repetitive trunk movement, either rotation or flexion/extension. With the exception of the rare rectus sheath hematoma that does not self-tamponade, the treatment for these problems is nonoperative with symptoms guiding rehabilitation and return to play decisions.

  8. QUALITY OF LIFE OF IN PATIENTS SUBMITTED TO ANTERIOR ABDOMINAL WALL LAPAROSCOPIC HERNIOPLASTY

    PubMed Central

    ABDALLA, Ricardo Zugaib; GARCIA, Rodrigo Biscuola; SAID, Danniel Frade; ABDALLA, Beatrice Martinez Zugaib

    2014-01-01

    Background The laparoscopic ventral hernia repair technique made possible surgeries with smaller skin incisions and smaller dissection of the soft tissue around the hernia, therefore with a better wound, a quicker postoperative recovery and a lower complication rate. Aim To evaluate the applicability of a quality of life survey based on the molds of the American Hernia Society, European Hernia Society and Carolinas Equation for Quality of Life, through telephone in patients submitted to laparoscopic hernioplasty by IPOM technique. Methods A retrospective cohort study was made to evaluate the quality of life of 21 patients that underwent anterior abdominal wall laparoscopic hernioplasty by intraperitoneal onlay mesh technique. Questionnaire was applied through telephone. Results Of the 21 patients, 19% felt that the hernia recurred. Also 19% passed through another abdominal wall surgery, and among these, 75% was related to the previously hernia correction. Finally, 81% of patients did not undergo any other abdominal wall surgery. Conclusion It was possible to apply the quality of life questionnary by telephone on patients who underwent an anterior abdominal wall. The results, in its turn, were satisfactory and showed that patients, in general, were satisfied with the surgical procedure. PMID:24676295

  9. Urinary bladder herniation through a caudoventral abdominal wall defect in a mature cat.

    PubMed

    Neville-Towle, Jack; Sakals, Sherisse

    2015-09-01

    A 16-year-old spayed female domestic shorthair cat with no history of trauma was presented to the Western College of Veterinary Medicine for assessment of urinary incontinence. Diagnostic investigation revealed herniation of the urinary bladder through a caudoventral abdominal wall defect. Clinical signs resolved after surgical reduction of the bladder.

  10. Stress intensity factors in a reinforced thick-walled cylinder

    NASA Technical Reports Server (NTRS)

    Tang, R.; Erdogan, F.

    1984-01-01

    An elastic thick-walled cylinder containing a radial crack is considered. It is assumed that the cylinder is reinforced by an elastic membrane on its inner surface. The model is intended to simulate pressure vessels with cladding. The formulation of the problem is reduced to a singular integral equation. Various special cases including that of a crack terminating at the cylinder-reinforcement interface are investigated and numerical examples are given. Results indicate that in the case of the crack touching the interface the crack surface displacement derivative is finite and consequently the stress state around the corresponding crack tip is bounded; and generally, for realistic values of the stiffness parameter, the effect of the reinforcement is not very significant.

  11. Rectus abdominis muscle resection and fascial reconstruction for the treatment of uterine leiomyosarcoma invading the abdominal wall: a case report.

    PubMed

    Yoon, B S; Seong, S J; Song, T; Kim, M L; Kim, M K

    2014-01-01

    The authors present a case of intra-abdominal recurrent leiomyosarcoma invading a large area of the abdominal wall. The patient underwent cytoreductive surgery, including resection of the rectus abdominis muscle, followed by reconstruction of the defect using synthetic mesh. The tumor was surgically removed by en bloc resection, including most of the rectus abdominis muscle and ileum. The abdominal wall defect was repaired using synthetic mesh. The patient underwent radiotherapy and chemotherapy after the surgery and was healthy one year later.

  12. The logic behind thick, liquid-walled, fusion concepts

    SciTech Connect

    Moir, R.W.

    1994-04-15

    It may be possible to surround the region where fusion reactions are taking place with a neutronically thick liquid blanket which has penetrations that allow only a few tenths of a percent of the neutrons to leak out. Even these neutrons can be attenuated by adding an accurately placed liquid or solid near the target to shadow-shield the beam ports from line-of-sight neutrons. The logic of such designs are discussed and their evolution is described with examples applied to both magnetic and inertial fusion (HYLIFE-II). These designs with liquid protection are self healing when exposed to pulsed loading and have a number of advantages-over the usual designs with solid first walls. For example, the liquid-protected solid components will last the life of the plant, and therefore the capacity factor is estimated to be approximately 10% higher than for the non-liquid-walled blankets, because no blanket replacement shutdowns are required. The component replacement, operations, and maintenance costs might be half the usual value because no blanket change-out costs or accompanying facilities are required. These combined savings might lower the cost of electricity by 20%. Nuclear-grade construction should not be needed, largely because the liquid attenuates neutrons and results in less activation of materials. Upon decommissioning, the reactor materials should qualify for disposal by shallow burial even when constructed of ordinary 304 stainless steel. The need for a high-intensity 14-MeV neutron test facility to develop first-wall materials is avoided or greatly reduced, saving billions of development dollars. Flowing molten Li, the molten salt Flibe (Li{sub 2}BeF{sub 4}), and molten Li{sub l7}Pb{sub 83} have been considered. An advantage of molten salt is that it will not burn and has a low tritium solubility and therefore low tritium inventory.

  13. Thick Liquid-Walled, Field-Reversed Configuration

    SciTech Connect

    Moir, R W; Bulmer, R H; Gulec, K; Fogarty, P; Nelson, B; Ohnishi, M; Rensink, M; Rognlien, T D; Santarious, J F; Sze, D K

    2000-09-22

    A thick flowing layer of liquid (e.g., flibe--a molten salt, or Sn{sub 80}Li{sub 20}--a liquid metal) protects the structural walls of the field-reversed configuration (FRC) so that they can last the life of the plant even with intense 14 MeV neutron bombardment from the D-T fusion reaction. The surface temperature of the liquid rises as it passes from the inlet nozzles to the exit or receiver nozzles due to absorption of line and bremsstrahlung radiation, and neutrons. The surface temperature can be reduced by enhancement of convection near the surface to transport hot surface liquid into the cooler interior. This surface temperature must be compatible with a practical heat transport and energy recovery system. The evaporative flux from the wall driven by the surface temperature must also result in an acceptable impurity level in the core plasma. The shielding of the core by the edge plasma is modeled with a 2D transport code for the resulting impurity ions; these ions are either swept out to the distant end tanks, or diffuse to the hot plasma core. An auxiliary plasma between the edge plasma and the liquid wall can further attenuate evaporating flux of atoms and molecules by ionization. The current in this auxiliary plasma might serve as the antenna for the current drive method, which produces a rotating magnetic field. Another method of current drive uses small spheromaks injected along the magnetic fields, which additionally provide fueling along with pellet fueling if necessary.

  14. Collagenopathies—Implications for Abdominal Wall Reconstruction: A Systematic Review

    PubMed Central

    Harrison, Bridget; Sanniec, Kyle

    2016-01-01

    Background: The etiology of hernia formation is strongly debated and includes mechanical strain, prior surgical intervention, abnormal embryologic development, and increased intraabdominal pressure. Although the most common inciting cause in ventral hernias is previous abdominal surgery, many other factors contribute. We explore this etiology through an examination of the current literature and existing evidence on patients with collagen vascular diseases, such as Ehlers–Danlos syndrome. Methods: A systematic review of the published literature was performed of all available Spanish and English language PubMed and Cochrane articles containing the key words “collagenopathies,” “collagenopathy,” “Ehlers-Danlos,” “ventral hernia,” and “hernia.” Results: Three hundred fifty-two articles were identified in the preliminary search. After review, 61 articles were included in the final review. Conclusions: Multiple authors suggest a qualitative or quantitative defect in collagen formation as a common factor in hernia formation. High-level clinical data clearly linking collagenopathies and hernia formation are lacking. However, a trend in pathologic studies suggests a link between abnormal collagen production and/or processing that is likely associated with hernia development. PMID:27826465

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

    PubMed

    Gong, Won-tae

    2015-01-01

    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.

  16. 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.

  17. Abdominal wall Type-I complex regional pain syndrome treated effectively with peripheral nerve field stimulation: a case report

    PubMed Central

    Zhou, Linqiu; Chou, Henry; Holder, Eric

    2017-01-01

    Chronic abdominal wall pain is a well-documented complication of abdominal surgery. However, abdominal wall complex regional pain syndrome (CRPS) is a rare medical condition. We present a case of abdominal wall CRPS and its treatment with peripheral nerve field stimulation (PNfS). A 34-year-old female presented with right periumbilical pain for 2 years. She developed burning, sharp and stabbing pain with allodynia (extremely sensitive to wind and light touch) and erythema or pallor 2 weeks after an exploratory appendectomy. The extensive evaluation ruled out the underlining pathology. After she failed conservative therapies, she underwent a 7-day trial of thoracic spinal cord stimulation (SCS) and abdominal wall PNfS. Thoracic SCS failed to provide pain relief; however, PNfS provided significant relief (>90%) of burning sensation. It has now been 5 years since the PNfS was implanted and she continues to demonstrate substantial pain relief. PMID:28044002

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

    PubMed Central

    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

    2014-01-01

    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

  19. Pathological Analysis of the Ruptured Vascular Wall of Hypoperfusion-induced Abdominal Aortic Aneurysm Animal Model.

    PubMed

    Kugo, Hirona; Zaima, Nobuhiro; Tanaka, Hiroki; Hashimoto, Keisuke; Miyamoto, Chie; Sawaragi, Ayaka; Urano, Tetsumei; Unno, Naoki; Moriyama, Tatsuya

    2017-04-04

    Abdominal aortic aneurysm (AAA) is a vascular disease that results in the gradual dilation of the abdominal aorta and has a high rupture-related mortality rate. However, the mechanism of AAA rupture remains unknown. In our previous study, we established a novel AAA animal model (hypoperfusion-induced AAA rat model) with spontaneous AAA rupture. Using the hypoperfusion-induced AAA rat model, we demonstrated that the abnormal appearance of adipocytes in the vascular wall is associated with AAA rupture. However, pathological analysis of the rupture area has not been performed because it is particularly difficult to identify the rupture point. In this study, we succeeded in obtaining samples from the rupture point and performed a histological analysis of the ruptured area in the vascular wall in the hypoperfusion-induced AAA rat model. Adipocytes were observed along the AAA-ruptured area of the vascular wall. In the areas around the adipocytes, macrophage infiltration and protein levels of matrix metalloproteinases 2 and 9 were significantly increased and collagen-positive areas were significantly decreased, as compared with areas without adipocytes. The AAA diameter was correlated with the number of adipocytes in the vascular wall of the hypoperfusion-induced AAA rat model. On the other hand, serum triglyceride levels and serum total cholesterol levels were not correlated with the number of adipocytes in the vascular wall. These results suggest that local adipocyte accumulation in the vascular wall, not serum lipids, has an important role in AAA rupture.

  20. Recurrent tense pneumoperitoneum due to air influx via abdominal wall stoma of a PEG tube.

    PubMed

    Vijayakrishnan, Rajakrishnan; Adhikari, Deep; Anand, Curuchi P

    2010-07-28

    A 70 years old male on ventilatory and circulatory support for sepsis and non ST segment elevation myocardial infarction developed abdominal distension 14 d after placement of a percutaneous endoscopic gastrostomy tube for enteral feeding. Radiography revealed free air in the abdomen and gastrograffin (G) study showed no extravasation into the peritoneum. The G tube was successfully repositioned with mechanical release of air. Imaging showed complete elimination of free air but the patient had a recurrence of pneumoperitoneum. Mechanical release of air with sealing of the abdominal wound was performed. Later, the patient was restarted on tube feeding with no complications. This case demonstrates a late complication of pneumoperitoneum with air leakage from the abdominal wall stoma.

  1. Correlation between the bronchial subepithelial layer and whole airway wall thickness in patients with asthma

    PubMed Central

    Kasahara, K; Shiba, K; Ozawa, T; Okuda, K; Adachi, M

    2002-01-01

    Background: The epithelial reticular basement membrane (Rbm) of the airway wall thickens in patients with asthma. However, whether the thickening parallels whole airway wall thickening, which limits airflow, is unknown. The aim of this study was to examine the correlation between the bronchial Rbm thickening and whole airway wall thickening in asthma. In addition, the association of Rbm and whole wall thickening with airflow obstruction was examined. Methods: Forty nine patients with asthma and 18 healthy control subjects took part in the study. The Rbm thickness was measured in bronchial biopsy specimens and whole airway wall thickness was assessed with high resolution computed tomographic (HRCT) scanning after pretreatment with oral steroids for 2 weeks and inhaled ß2 agonist to minimise reversible changes of the airway walls. The percentage airway wall area (WA%; defined as (wall area/total airway area) x 100) and percentage airway wall thickness (WT%; defined as [(ideal outer diameter – ideal luminal diameter)/ideal outer diameter] x 100) were determined from HRCT scans to assess whole airway wall thickness. Spirometric tests were also performed. Results: WA% and WT% were higher in patients with asthma than in healthy subjects. Both WA% and WT% were strongly correlated with Rbm thickness. Moreover, these three indices of airway wall thickness were inversely correlated with the percentage of predicted forced expiratory volume in 1 second in patients with asthma. Conclusions: These findings indicate that Rbm thickening parallels whole airway wall thickening which can cause irreversible airflow obstruction in patients with asthma. PMID:11867829

  2. 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

  3. Abdominal wall defects: prenatal diagnosis, newborn management, and long-term outcomes.

    PubMed

    Gamba, Piergiorgio; Midrio, Paola

    2014-10-01

    Omphalocele and gastroschisis represent the most frequent congenital abdominal wall defects a pediatric surgeon is called to treat. There has been an increased reported incidence in the past 10 years mainly due to the diffuse use of prenatal ultrasound. The early detection of these malformations, and related associated anomalies, allows a multidisciplinary counseling and planning of delivery in a center equipped with high-risk pregnancy assistance, pediatric surgery, and neonatology. At present times, closure of defects, even in multiple stages, is always possible as well as management of most of cardiac-, urinary-, and gastrointestinal-associated malformations. The progress, herein discussed, in the care of newborns with abdominal wall defects assures most of them survive and reach adulthood. Some aspects of transition of medical care will also be considered, including fertility and cosmesis.

  4. Evidence-Based Abdominal Wall Reconstruction: The Maxi-Mini Approach.

    PubMed

    Janis, Jeffrey E; Khansa, Ibrahim

    2015-12-01

    Complex abdominal wall reconstruction is a high-risk procedure, but it can be performed safely if a systematic approach is followed. In this article, the authors present their evidence-based technique for abdominal wall reconstruction. This approach aims at reducing rates of complications and hernia recurrence, starting with critical patient selection; preoperative patient optimization; adherence to intraoperative principles including preservation of vascular perforators through maintenance of composite tissue with limited undermining; direct supported mesh reinforcement of midline musculofascial reapproximation; use of percutaneous transfascial suture mesh fixation; careful attention to dead space obliteration in any plane; and aggressive soft-tissue resection of marginal, undermined, or tenuous skin and subcutaneous tissue. Postoperative strategies to decrease complications are also used. The authors' surgical technique is described in detail, and pilot data are presented to support the authors' approach.

  5. 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

  6. Clostridial Gas Gangrene of the Abdominal Wall After Laparoscopic Cholecystectomy: A Case Report and Review.

    PubMed

    Harmsen, Annelieke M K; van Tol, Erik; Giannakopoulos, Georgios F; de Brauw, L Maurits

    2016-08-01

    Clostridial gas gangrene is a rare, yet severe, complication after laparoscopic cholecystectomy. We present a case report of a 48-year-old man with obesity, coronary artery disease, and diabetes, who developed clostridial gas gangrene of the abdominal wall after an uncomplicated laparoscopic cholecystectomy. Although the diagnosis was missed initially, successful radical surgical debridement was performed and the patient survived. Pathogenesis, symptoms, prognostic factors, and the best treatment are discussed.

  7. [Clostridial sepsis and gas gangrene of the abdominal wall after cholecystectomy].

    PubMed

    Lochman, P; Kabelác, K; Pospísil, I; Dobes, D; Cáp, R

    2007-01-01

    Clostridial sepsis is a rare complication after intraabdominal operations, mostly fatal. According to our knowledge only two papers describing clostridial sepsis as postoperative complication in 4 patients were published in the Czech literature, only one of them survived. Authors present a case report of patient operated on for cholecystolithiasis and obstructive icterus where within 48 hours after cholecystectomy the clostridial sepsis and gas gangrene of the abdominal wall developed and that were successfuly managed.

  8. Abdominal Wall Reconstruction Using Retrorectus Self-adhering Mesh: A Novel Approach

    PubMed Central

    Khansa, Ibrahim

    2016-01-01

    Background: In abdominal wall reconstruction, the retrorectus plane offers an ideal location for mesh placement. Mesh fixation in this plane is often achieved using transfascial sutures, which risks entrapping intercostal nerves and causing significant pain, and takes time to place. A novel alternative is the use of sutureless self-adhering mesh. Although the use of this mesh in inguinal hernias has been well described, studies on its use in abdominal wall reconstruction are lacking. Methods: Consecutive patients who underwent ventral hernia repair with retrorectus mesh were reviewed. This included patients who received transfascially sutured mesh and those who received sutureless self-adhering mesh. All patients were followed up for at least 12 months. The amount of narcotics required by each patient postoperatively was calculated. Surgical-site occurrences (SSOs) and hernia recurrence and bulge were measured. Results: Twenty-six patients underwent abdominal wall reconstruction with retrorectus mesh. This included 12 patients with transfascially sutured mesh and 14 patients with self-adhering mesh. Mean follow-up was 600 days. Baseline characteristics were similar between the 2 groups. Patients receiving self-adhering mesh required significantly less narcotics than patients with transfascially sutured mesh. There were no significant differences in the rate of SSOs between the 2 groups. No hernia recurrences, bulges, or chronic pain occurred in either group. Conclusions: This is the first study to compare the outcomes of retrorectus self-adhering mesh and transfascially sutured mesh in abdominal wall reconstruction. Our results show low rates of SSO, recurrence, and bulge with both options, with significantly less acute pain with self-adhering mesh. PMID:27975037

  9. Extragastrointestinal Stromal Tumor (EGIST) in the abdominal wall: Case report and literature review

    PubMed Central

    Alkhatib, Loiy; Albtoush, Omar; Bataineh, Nesreen; Gharaibeh, Kamal; Matalka, Ismail; Tokuda, Yasuharu

    2011-01-01

    INTRODUCTION Gastro Intestinal Stromal Tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract (GI). GIST that arises primarily outside the GI tract is termed Extragastrointestinal Stromal Tumor (EGIST). To the best of our knowledge, few cases of EGIST in the abdominal wall were reported. PRESENTATION OF CASE We present a rare case of EGIST in the abdominal wall of a 57 year-old female patient. The asymptomatic tumor was located in the superior aspect of the left rectus abdominis muscle, measured 5.4 × cm 5.3 × cm 6.9 cm and was well circumscribed. Histological examination showed an epithelioid cell morphology. The mitotic count was 7/50 HPFs. Immunohistochemistry showed diffuse strong CD117 positivity, focal positivity for S100. The tumor was excised and the margins were free of malignancy. The patient was doing well postoperatively and was discharged on STI-571 regimen. DISCUSSION Although GIST is the most common mesenchymal tumor of the gastrointestinal tract, a case with EGIST in the abdominal wall is rare. Positive immunohistochemical staining for CD117 is a defining feature of GISTs. A great percentage of EGISTs represent a metastasis from a primary GIST. In our case, the clinical and diagnostic work-up have been proved it to be an EGIST. CONCLUSION The existing data on EGIST is insufficient to make a final conclusion regarding the malignant potential and clinicopathological factors of EGISTs that determine patient prognosis. Thus a follow-up for a long period is required. EGISTs should be kept in mind in the differential diagnosis for patients presenting with solid mass of the abdominal wall. PMID:22096744

  10. Evolution of the wall shear stresses during the progressive enlargement of symmetric abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Salsac, A.-V.; Sparks, S. R.; Chomaz, J.-M.; Lasheras, J. C.

    2006-08-01

    The changes in the evolution of the spatial and temporal distribution of the wall shear stresses (WSS) and gradients of wall shear stresses (GWSS) at different stages of the enlargement of an abdominal aortic aneurysm (AAA) are important in understanding the aetiology and progression of this vascular disease since they affect the wall structural integrity, primarily via the changes induced on the shape, functions and metabolism of the endothelial cells. Particle image velocimetry (PIV) measurements were performed in in vitro aneurysm models, while changing their geometric parameters systematically. It has been shown that, even at the very early stages of the disease, i.e. increase in the diameter ≤ 50%, the flow separates from the wall and a large vortex ring, usually followed by internal shear layers, is created. These lead to the generation of WSS that drastically differ in mean and fluctuating components from the healthy vessel. Inside the AAA, the mean WSS becomes negative along most of the aneurysmal wall and the magnitude of the WSS can be as low as 26% of the value in a healthy abdominal aorta.

  11. Reconstruction of the abdominal wall by using a combination of the human acellular dermal matrix implant and an interpositional omentum flap after extensive tumor resection in patients with abdominal wall neoplasm: A preliminary result

    PubMed Central

    Gu, Yan; Tang, Rui; Gong, Ding-Quan; Qian, Yun-Liang

    2008-01-01

    AIM: To present our trial using a combination of the human acellular dermal matrix (HADM) implant and an interpositional omentum flap to repair giant abdominal wall defects after extensive tumor resection. METHODS: Between February and October of 2007, three patients with giant defects of the abdominal wall after extensive tumor resection underwent reconstruction with a combination of HADM and omentum flap. Postoperative morbidities and signs of herniation were monitored. RESULTS: The abdominal wall reconstruction was successful in these three patients, there was no severe morbidity and no signs of herniation in the follow-up period. CONCLUSION: The combination of HADM and omentum flap offers a new, safe and effective alternative to traditional forms in the repair of giant abdominal wall defects. Further analysis of the long-term outcome and more cases are needed to assess the reliability of this technique. PMID:18205267

  12. Excision of the urachal remnant using the abdominal wall-lift laparoscopy: A case report

    PubMed Central

    Kobayashi, Kosuke; Sasaki, Kazuhito; Iijima, Tatsuo; Yoshimi, Fuyo; Nagai, Hideo

    2016-01-01

    Introduction Here, we report the surgical excision of the urachal remnant using the abdominal wall-lift laparoscopy with a camera port in the umbilicus, combined with a small Pfannenstiel incision to optimally treat the bladder apex. Presentation of case A 21-year-old woman presented with periumbilical discharge and pain on urination. Contrast enhanced CT and MRI showed an abscess in the umbilical region that was connected to the bladder via a long tube-like structure. It was diagnosed as an infected urachal sinus. Partial excision of the umbilical fossa followed by dissection of the urachal remnant was easily performed using the abdominal wall-lift laparoscopy from the umbilicus down to the bladder without pneumoperitoneum or additional trocar placement. A Pfannenstiel incision was made above the pubis to get access to the junction between the urachal remnant and the bladder. Under direct vision, we succeeded in accurately dividing the remnant tract, and we adequately closed the bladder opening with absorbable sutures. This method has the advantage of easily closing peritoneal defects after excision of the urachal remnant with direct sutures under a laparoscopic view from the umbilicus. Cosmetic satisfaction was obtained postoperatively. Discussion and conclusion Urachal sinus excision using the abdominal wall-lift laparoscopy seems to surpass the previously reported methods in term of safety, cosmetics, and adequacy of surgical procedures. PMID:27064744

  13. Value-based Clinical Quality Improvement (CQI) for Patients Undergoing Abdominal Wall Reconstruction.

    PubMed

    Stephan, Bradley; Ramshaw, Bruce; Forman, Brandie

    2015-05-01

    Patients with complex ventral/incisional hernias often undergo an abdominal wall reconstruction (AWR). These operations have a high cost of care and often result in a long hospital stay and high complication rates. Using the principles of clinical quality improvement (CQI), several attempts at process improvement were implemented in one hernia program over a 3-year period. For consecutive cases of patients undergoing abdominal wall reconstruction, process improvement attempts included the use of a long-term resorbable synthetic mesh (TIGR® Resorbable Matrix, Novus Scientific, Uppsala, Sweden) in place of a biologic mesh, the use of the transversus abdominis release approach in place of an open or endoscopic component separation (external oblique release) technique, and the use of a preoperative transversus abdominis plane (TAP) block using a long-acting local anesthetic (Exparel®, Pacira Pharmaceutical, Parsippany, NJ) as a part of perioperative multi-modal pain management and an enhanced recovery program. After over 60 cases, improvement in materials costs and postoperative outcomes were documented. No mesh-related complications occurred and no mesh removal was required. In this real-world, value-based application of CQI, several attempts at process improvement led to decreased costs and improved outcomes for patients who underwent abdominal wall reconstruction for complex ventral/incisional hernias. Value-based CQI could be a tool for improved health care value globally.

  14. [New abdominal wall reconstruction technique with a plastic-rehabilitative intent (back pain improvement)].

    PubMed

    Palmieri, Beniamino; Grappolini, Simone; Blandini, Daniele; De-Anna, Dino; Savio, Stefano; Ferrari, Paolo; Ferrari, Giovanni; William, Pillosu; Campanini, Isabella; Guido, Vezzosi; Tenchini, Paolo; Benuzzi, Giorgia; Palmieri, Lucia

    2004-01-01

    Many abdominal wall reconstruction techniques have generally failed to pay attention to a number of anatomical considerations concerning the continuity of the thoraco-lumboabdominal fascia that envelops the dorsal and ventral muscles. We have introduced a new surgical technique (round mesh) developed to improve the abdominal wall weakness or pathology (hernia, laparocele) with the aim of restoring the muscular synergy between the anterior and posterior trunk compartments, thus improving sacroiliac stability, posture, and standing effort endurance. One hundred patients of both sexes were enrolled in this investigation. All were affected by abdominal wall impairment, frank hernia or laparocele, and had been complaining of lumbar and sciatic pain for long periods without any definite intervertebral disk pathology. They underwent pre- and postoperative subjective and objective evaluation and insertion of a prefascial polypropylene mesh with a posterior martingale that passes across the spine and paravertebral muscles, ending in two wider rectangles that are criss-crossed ventrally and finally sutured to the iliopubic brim. All the patients improved either subjectively or objectively with the round mesh procedure. This new technique is particularly useful in cases of reduction or impairment of the recti abdominis, transverse and oblique muscles, because simple suture and plication of these muscles is no guarantee of long-term functional restoration.

  15. The quasi-static failure properties of the abdominal aortic aneurysm wall estimated by a mixed experimental-numerical approach.

    PubMed

    Forsell, Caroline; Swedenborg, Jesper; Roy, Joy; Gasser, T Christian

    2013-07-01

    Assessing the risk for abdominal aortic aneurysm (AAA) rupture is critical in the management of aneurysm patients and an individual assessment is possible with the biomechanical rupture risk assessment. Such an assessment could potentially be improved by a constitutive AAA wall model that accounts for irreversible damage-related deformations. Because of that the present study estimated the elastic and inelastic properties of the AAA wall through a mixed experimental-numerical approach. Specifically, finite element (FE) models of bone-shaped tensile specimens were used to merge data from failure testing of the AAA wall with their measured collagen orientation distribution. A histo-mechanical constitutive model for collagen fibers was employed, where plastic fibril sliding determined not only remaining deformations but also weakening of the fiber. The developed FE models were able to replicate the experimentally recorded load-displacement property of all 16 AAA wall specimens that were investigated in the study. Tensile testing in longitudinal direction of the AAA defined a Cauchy strength of 569(SD 411) kPa that was reached at a stretch of 1.436(SD 0.118). The stiffness and strength of specimens decreased with the wall thickness and were elevated (p = 0.018; p = 0.030) in patients with chronic obstructive pulmonary disease (COPD). Smoking affected the tissue parameters that were related to the irreversible deformation response, and no correlation with gender and age was found. The observed effects on the biomechanical properties of the AAA wall could have long-term consequences for the management of aneurysm patients, i.e., specifically they might influence future AAA rupture risk assessments. However, in order to design appropriate clinical validation studies our findings should firstly be verified in a larger patient cohort.

  16. 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.

  17. [Indications and results of preventive endoprosthezing of the abdominal wall during operations on organs of the abdominal cavity and retroperitoneal space].

    PubMed

    Sukovatykh, B S; Valuĭskaia, N M; Netiaga, A A; Zhukovskiĭ, V A; Pravednikova, N V; Kas'ianova, M A

    2011-01-01

    Complex examination and treatment of 120 patients with anatomo-functional insufficiency of the abdominal wall was made after operations on organs of the abdominal cavity and retroperitoneal space. In the 1st group (60 patients) the abdominal wall was sutured by traditional methods. In the 2nd group (60 patients) laparotomy was followed by implantation of polypropylene endoprosthesis by over-aponeurotic method, and suturing of the lateral wall--by sub-aponeurotic method. At the long-term postoperative period the postoperative ventral hernias were formed in 21.6% of patients of the 1st group, in the 2nd group of patients hernias were not detected. Physical component of quality of life of the 2nd group was 1.5 times, and mental component 1.7 times higher than in the 1st group.

  18. CLASSICAL AREAS OF PHENOMENOLOGY: Influence of the abdominal wall on the nonlinear propagation of focused therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Liu, Zhen-Bo; Fan, Ting-Bo; Zhang, Dong; Gong, Xiu-Fen

    2009-11-01

    This article theoretically studies the influence of inhomogeneous abdominal walls on focused therapeutic ultrasound based on the phase screen model. An inhomogeneous tissue is considered as a combination of a homogeneous medium and a phase aberration screen. Variations of acoustic parameters such as peak positive pressure, peak negative pressure, and acoustic intensity are discussed with respect to the phase screen statistics of human abdominal walls. Results indicate that the abdominal wall can result in energy loss of the sound in the focal plane. For a typical human abdominal wall with correlation length of 7.9 mm and variance of 0.36, the peak acoustic intensity radiated from a 1 MHz transmitter with a radius of 30 mm can be reduced by about 14% at the focal plane.

  19. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness.

    PubMed

    Voß, S; Glaßer, S; Hoffmann, T; Beuing, O; Weigand, S; Jachau, K; Preim, B; Thévenin, D; Janiga, G; Berg, P

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches-when averaged over the complete aneurysm sac-are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations.

  20. Fluid-Structure Simulations of a Ruptured Intracranial Aneurysm: Constant versus Patient-Specific Wall Thickness

    PubMed Central

    Hoffmann, T.; Beuing, O.; Jachau, K.; Thévenin, D.; Janiga, G.; Berg, P.

    2016-01-01

    Computational Fluid Dynamics is intensively used to deepen the understanding of aneurysm growth and rupture in order to support physicians during therapy planning. However, numerous studies considering only the hemodynamics within the vessel lumen found no satisfactory criteria for rupture risk assessment. To improve available simulation models, the rigid vessel wall assumption has been discarded in this work and patient-specific wall thickness is considered within the simulation. For this purpose, a ruptured intracranial aneurysm was prepared ex vivo, followed by the acquisition of local wall thickness using μCT. The segmented inner and outer vessel surfaces served as solid domain for the fluid-structure interaction (FSI) simulation. To compare wall stress distributions within the aneurysm wall and at the rupture site, FSI computations are repeated in a virtual model using a constant wall thickness approach. Although the wall stresses obtained by the two approaches—when averaged over the complete aneurysm sac—are in very good agreement, strong differences occur in their distribution. Accounting for the real wall thickness distribution, the rupture site exhibits much higher stress values compared to the configuration with constant wall thickness. The study reveals the importance of geometry reconstruction and accurate description of wall thickness in FSI simulations. PMID:27721898

  1. Local influence of calcifications on the wall mechanics of abdominal aortic aneurysm

    NASA Astrophysics Data System (ADS)

    de Putter, Sander; van de Vosse, Frans N.; Breeuwer, Marcel; Gerritsen, Frans A.

    2006-03-01

    Finite element wall stress simulations on patient-specific models of abdominal aortic aneurysm (AAA) may provide a better rupture risk predictor than the currently used maximum transverse diameter. Calcifications in the wall of AAA lead to a higher maximum wall stress and thus may lead to an elevated rupture risk. The reported material properties for calcifications and the material properties actually used for simulations show great variation. Previous studies have focused on simplified modelling of the calcification shapes within a realistic aneurysm shape. In this study we use an accurate representation of the calcification geometry and a simplified model for the AAA. The objective of this approach is to investigate the influence of the calcification geometry, the material properties and the modelling approach for the computed peak wall stress. For four realistic calcification shapes from standard clinical CT images of AAA, we performed simulations with three distinct modelling approaches, at five distinct elasticity settings. The results show how peak wall stress is sensitive to the material properties of the calcifications. For relatively elastic calcifications, the results from the different modelling approaches agree. Also, for relatively elastic calcifications the computed wall stress in the tissue surrounding the calcifications shows to be insensitive to the exact calcification geometry. For stiffer calcifications the different modelling approaches and the different geometries lead to significantly different results. We conclude that an important challenge for future research is accurately estimating the material properties and the rupture potential of the AAA wall including calcifications.

  2. Effects of Antimony and Wall Thickness on Graphite Morphology in Ductile Iron Castings

    NASA Astrophysics Data System (ADS)

    Glavas, Zoran; Strkalj, Anita; Maldini, Kresimir

    2016-08-01

    Effects of Sb additions on the graphite morphology of ductile iron castings in different wall thicknesses (3, 12, 25, 38, 50, 75, and 100 mm) were analyzed in this paper. In the wall thicknesses of 3, 12, and 25 mm, low contents of rare earth (RE) elements showed a beneficial effect on nodule count and nodularity. Nodularity >80 pct and a high nodule count were achieved without the addition of Sb. In the wall thicknesses of 38, 50, 75, and 100 mm, nodularity >80 pct was not achieved without the use of the chill or proper content of Sb. Excess of RE elements was neutralized with the addition of proper amount of Sb to the wall thickness. Addition of 0.01 wt pct Sb (ratio of RE/Sb = 0.34, ratio of RE/SE = 0.105) was sufficient to achieve nodularity >80 pct in the wall thicknesses of 38, 50, 75, and 100 mm.

  3. A More Accurate Solution to the Elastic-Plastic Problem of Pressurized Thick-Walled Cylinders

    DTIC Science & Technology

    1985-02-01

    ACCURATE SOLUTION TO THE ELASTIC- PLASTIC PROBLEM OF PRESSURIZED THICK-WALLED CYLINDERS S. TYPE OF REPORT 4’ PERIOD COVERED Final 8. PERFORMING...o £ ) A MORE ACCURATE SOLUTION TO THE ELASTIC- PLASTIC PROBLEM OF PREr SURIZED THICK-WALLED CYLINDERS < • Peter C. T. Chen U.S. Army Armament...Watervllet, NY 12189 I iJSTRACT. A new method has been developed for solving the partially plastic problems of thlc’ -walled cylinders made of strain

  4. Metastasectomy of Abdominal Wall Lesions due to Prostate Cancer Detected Through PET/CT Gallium 68-PMSA: First Case Report.

    PubMed

    Ochoa, Claudia; Ramirez, Angie; Varela, Rodolfo; Godoy, Fabian; Vargas, Rafael; Forero, Jorge; Rojas, Andres; Roa, Carmen; Céspedes, Carlos; Ramos, Jose; Cabrera, Marino; Calderon, Andres

    2017-05-01

    Introducing the topic of abdominal wall metastasis secondary to prostate cancer with a reminder of the disease's rarity, being the first published case. This article is about a 66 year old patient diagnosed with prostate cancer [cT2aNxMx iPSA: 5,6 ng/ml Gleason 3+3, (Grade 1 Group)], treated with radical prostatectomy as well as accompanied with amplified pelvic lymphadenectomy, who subsequently presented metastatic lesions to the abdominal wall diagnosed with PET/CT Gallium 68-PMSA technique and treated with abdominal metastasectomy with adequate short term results.

  5. A simulation framework for estimating wall stress distribution of abdominal aortic aneurysm.

    PubMed

    Qin, Jing; Zhang, Jing; Chui, Chee-Kong; Huang, Wei-Min; Yang, Tao; Pang, Wai-Man; Sudhakar, Venkatesh; Chang, Stephen

    2011-01-01

    Abdominal aortic aneurysm (AAA) rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue. In endovascular aneurysm repair, a stent-graft in a catheter is released at the aneurysm site to form a new blood vessel and protect the weakened AAA wall from the pulsatile pressure and, hence, possible rupture. In this paper, we propose a framework to estimate the wall stress distribution of non-stented/stented AAA based on fluid-structure interaction, which is utilized in a surgical simulation system (IRAS). The 3D geometric model of AAA is reconstructed from computed tomography angiographic (CTA) images. Based on our experiments, a combined logarithm and polynomial strain energy equation is applied to model the elastic properties of arterial wall. The blood flow is modeled as laminar, incompressible, and non-Newtonian flow by applying Navier-Stokes equation. The obtained pressure of blood flow is applied as load on the AAA meshes with and without stent-graft and the wall stress distribution is calculated by fluid-structure interaction (FSI) solver equipped in ANSYS. Experiments demonstrate that our analytical results are consistent with clinical observations.

  6. Trace elements in the wall of abdominal aortic aneurysms with and without coexisting iliac artery aneurysms.

    PubMed

    Ziaja, Damian; Chudek, Jerzy; Sznapka, Mariola; Kita, Andrzej; Biolik, Grzegorz; Sieroń-Stołtny, Karolina; Pawlicki, Krzysztof; Domalik, Jolanta; Ziaja, Krzysztof

    2015-06-01

    Iliac artery aneurysms (IAA) and abdominal aortic aneurysms (AAA) frequently coexist. It remains unknown whether the content of trace elements in AAA walls depends on the coexistence of IAAs. The aim of this study was to compare the content of selected trace elements in AAA walls depending on the coexistence of IAAs. The content of trace elements was assessed in samples of AAA walls harvested intraoperatively in 19 consecutive patients. In the studied group, coexisting IAAs were diagnosed in 11 out of the 19 patients with AAA. The coexistence of IAAs was associated with a slightly lower content of nickel (0.28 (0.15-0.40) vs. 0.32 (0-0.85) mg/g; p = 0.09) and a significantly higher content of cadmium (0.71 (0.26-1.17) vs. 0.25 (0.20-0.31) mg/g; p = 0.04) in AAA walls. The levels of the remaining studied elements, copper, zinc, manganese, magnesium and calcium, were comparable. The elevated levels of cadmium in the walls of AAA coexisting with IAAs may suggest an impact of the accumulation of this trace element on the greater damage of the iliac artery wall.

  7. Method of manufacturing hollow members having uniform wall thickness through use of ablation

    DOEpatents

    Anderson, Paul R.; Downs, Raymond L.; Henderson, Timothy M.

    1982-01-01

    A method of manufacturing a hollow structure of uniform wall thickness comprising the steps of selecting or forming a precursor having one wall surface of desired geometry, treating a portion of the precursor consisting of the one wall surface and a uniform depth of material beneath the wall surface to increase resistance to ablation, and then removing by ablation and discarding the remaining or untreated portion of the precursor.

  8. The development and structure of thick-walled, multicellular, aerial spores in Diheterospora chlamydosporia (=Verticillium chlamydosporium).

    PubMed

    Cambell, W P; Griffiths, D A

    1975-07-01

    The aerial, thick-walled spores in Diheterospara chlamydosporia arose as terminal swellings on erect hyphae. Repeated septation of the continuously swelling spore resulted in a multicellular structure. Immediately after the onset of septation secondary wall material was laid down between the two-layered primary wall and the plasmalemma. The presence of secondary wall material indicates that the multicellular spore is a dictyochlamydospore and not an aleuriospore. The relationship between chlamydospores and aleuriospores in other fungi is discussed.

  9. Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles

    PubMed Central

    Jung, Sharon Jiyoon; Kim, Min-Suk; Lee, Jin-Kyu; Kim, Young-Jae; Soh, Kwang-Sup

    2016-01-01

    The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson’s trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density. PMID:26937963

  10. Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles.

    PubMed

    Jang, HyunSuk; Yoon, Joohwan; Gil, HyunJi; Jung, Sharon Jiyoon; Kim, Min-Suk; Lee, Jin-Kyu; Kim, Young-Jae; Soh, Kwang-Sup

    2016-01-01

    The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson's trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density.

  11. Energy dependent chest wall thickness equations for male lung monitoring with germanium detectors.

    PubMed

    Broggio, D; Lechaftois, X; Abline, O; Fleury, B; Vial, A; Corrèze, P; Franck, D; Merzoug, V

    2014-03-01

    The thickness and fat fraction of the chest wall are important parameters for in vivo lung monitoring. They have been measured from ultrasonic images on 374 male workers of the French nuclear industry using four measurement locations, as dictated by the size and position of the germanium detectors used for monitoring. The plastic muscle equivalent chest wall thickness (PMECWT) and the plastic 50% muscle-50% adipose equivalent chest wall thickness (X5050) have been calculated for each worker at 17, 59.5, and 185.7 keV, respectively. Multi-linear regression models have been tested to predict PMECWT and X5050 as a function of anthropometric measurements. Finally, it was considered whether the average chest wall thickness could be used instead of the material equivalent chest wall thickness. It was found that the mean chest wall thickness was (27 ± 5) mm and the mean fat fraction was (25 ± 8)%. The best and more convenient model for material equivalent chest wall thickness is a linear function of the body mass index. Depending on the energy, the standard errors of estimate for this model range between 3.2-3.4 mm for PMECWT and between 3.2-3.7 mm for X5050. At 59.5 and 185.7 keV, it was determined, to an excellent approximation, that the fat fraction and consideration of an equivalent material are unnecessary, contrary to the case at 17 keV.

  12. 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.

  13. 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.

  14. 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.

  15. Heavy Metal Bioaccumulation in an Atypical Primitive Neuroectodermal Tumor of the Abdominal Wall.

    PubMed

    Roncati, Luca; Gatti, Antonietta Morena; Capitani, Federico; Barbolini, Giuseppe; Maiorana, Antonio; Palmieri, Beniamino

    2015-01-01

    Heavy metals are able to interfere with the function of vital cellular components. Besides in trace heavy metals, which are essential at low concentration for humans, there are heavy metals with a well-known toxic and oncogenic potential. In this study, for the first time in literature, we report the unique adulthood case of an atypical primitive neuroectodermal tumor of the abdominal wall, diagnosed by histology and immunohistochemistry, with the molecular hybridization support. The neoplasia occurred in a patient chronically exposed to a transdermal delivery of heavy metal salts (aluminum and bismuth), whose intracellular bioaccumulation has been revealed by elemental microanalysis.

  16. Method and apparatus for determining diameter and wall thickness of minute hollow spherical shells

    DOEpatents

    Steinman, D.A.

    1980-05-30

    Method and apparatus for determining diameter and wall thickness of hollow microspheres or shells wherein terminal velocities of shells traveling in fluid-filled conduits of differing diameters are measured. A wall-effect factor is determined as a ratio of the terminal velocities, and shell outside diameter may then be ascertained as a predetermined empirical function of wall-effect factor. For shells of known outside diameter, wall thickness may then be ascertained as a predetermined empirical function of terminal velocity in either conduit.

  17. Method and apparatus for determining diameter and wall thickness of minute hollow spherical shells

    DOEpatents

    Steinman, David A.

    1982-01-01

    Method and apparatus for determining diameter and wall thickness of hollow microspheres or shells wherein terminal velocities of shells traveling in fluid-filled conduits of differing diameters are measured. A wall-effect factor is determined as a ratio of the terminal velocities, and shell outside diameter may then be ascertained as a predetermined empirical function of wall-effect factor. For shells of known outside diameter, wall thickness may then be ascertained as a predetermined empirical function of terminal velocity in either conduit.

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

    DOEpatents

    Burdgick, Steven Sebastian

    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.

  19. [Reconstruction of an abdominal wall defect with a superior epigastric perforator propeller flap: case report].

    PubMed

    Lepivert, J-C; Alet, J-M; Michot, A; Pélissier, P; Pinsolle, V

    2014-10-01

    Perforators flaps take a special place in reconstructive surgery. These flaps can be dissected and turned as a propeller blade on its pedicule axis. We report the case of a 54-year-old man presenting a recurrence of a dermatofibrosarcoma in the right hypochondrium. Tumor resection caused a large abdominal wall defect taking the anterior aponeurosis of the rectus abdominis. An angioscanner was realized in preoperative to locate the perforators of the deep superior epigastric artery. We realized a propeller flap based on a perforator of the left superior epigastric artery who allowed to cover the wall defect. We set up a patch of Vicryl® to reconstruct the aponeurosis plan at the same operative time. We didn't note any necrosis and complete healing occurred in 2 weeks. The margins were healthy. The cosmetic result and the low morbidity make this flap a good therapeutic option. This flap seems reliable, arteries perforators are constant with good diameter.

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS... wall of tank multiplied by 3.0 will not exceed the tensile strength of any specimen taken from the...

  1. Thermal variations of domain wall thickness and number of domains in magnetic rectangular grains

    NASA Astrophysics Data System (ADS)

    Xu, Song; Merrill, Ronald T.

    1990-12-01

    Equilibrium domain wall thickness and number of domains in rectangular magnetic grains are determined by using a modified Amar model. It is shown that domain structure, particularly domain wall thickness, in a magnetized grain depends strongly on grain shape and orientation. These dependencies are attributed to the existence of two competing self-magnetostatic interactions, one from the ends of the grain and the other from the sides. One of the consequences of this is that the thermal variation of domain wall thickness in an elongated grain is greater (smaller) than predicted by classical theory when the grain is magnetized along the shortest (longest) dimension. For magnetite, classical theory provides a good approximation in predicting both domain wall thickness and number of domains in equal-dimensional grains larger than about 4 μm.

  2. A microfluidic device approach to generate hollow alginate microfibers with controlled wall thickness and inner diameter

    NASA Astrophysics Data System (ADS)

    Pham, Uyen H. T.; Hanif, Madiha; Asthana, Amit; Iqbal, Samir M.

    2015-06-01

    Alginate is a natural polymer with inherent biocompatibility. A simple polydimethylsiloxane (PDMS) microfluidic device based self-assembled fabrication of alginate hollow microfibers is presented. The inner diameter as well as wall thickness of the microfibers were controlled effortlessly, by altering core and sheath flow rates in the microfluidic channels. The gelation/cross-linking occured while the solutions were ejected. The microfibers were generated spontaneously, extruding out of the outlet microchannel. It was observed that the outer diameter was independent of the flow rates, while the internal diameter and wall thickness of the hollow fibers were found to be functions of the core and sheath flow rates. At a constant sheath flow, with increasing core flow rates, the internal diameters increased and the wall thicknesses decreased. At a fixed core flow, when sheath flow rate increased, the internal diameters decreased and the wall thickness increased. The immobilization of enzymes in such hollow microfibers can be a potential application as microbioreactors.

  3. 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.

  4. Whole abdominal wall segmentation using augmented active shape models (AASM) with multi-atlas label fusion and level set

    NASA Astrophysics Data System (ADS)

    Xu, Zhoubing; Baucom, Rebeccah B.; Abramson, Richard G.; Poulose, Benjamin K.; Landman, Bennett A.

    2016-03-01

    The abdominal wall is an important structure differentiating subcutaneous and visceral compartments and intimately involved with maintaining abdominal structure. Segmentation of the whole abdominal wall on routinely acquired computed tomography (CT) scans remains challenging due to variations and complexities of the wall and surrounding tissues. In this study, we propose a slice-wise augmented active shape model (AASM) approach to robustly segment both the outer and inner surfaces of the abdominal wall. Multi-atlas label fusion (MALF) and level set (LS) techniques are integrated into the traditional ASM framework. The AASM approach globally optimizes the landmark updates in the presence of complicated underlying local anatomical contexts. The proposed approach was validated on 184 axial slices of 20 CT scans. The Hausdorff distance against the manual segmentation was significantly reduced using proposed approach compared to that using ASM, MALF, and LS individually. Our segmentation of the whole abdominal wall enables the subcutaneous and visceral fat measurement, with high correlation to the measurement derived from manual segmentation. This study presents the first generic algorithm that combines ASM, MALF, and LS, and demonstrates practical application for automatically capturing visceral and subcutaneous fat volumes.

  5. Whole Abdominal Wall Segmentation using Augmented Active Shape Models (AASM) with Multi-Atlas Label Fusion and Level Set

    PubMed Central

    Xu, Zhoubing; Baucom, Rebeccah B.; Abramson, Richard G.; Poulose, Benjamin K.; Landman, Bennett A.

    2016-01-01

    The abdominal wall is an important structure differentiating subcutaneous and visceral compartments and intimately involved with maintaining abdominal structure. Segmentation of the whole abdominal wall on routinely acquired computed tomography (CT) scans remains challenging due to variations and complexities of the wall and surrounding tissues. In this study, we propose a slice-wise augmented active shape model (AASM) approach to robustly segment both the outer and inner surfaces of the abdominal wall. Multi-atlas label fusion (MALF) and level set (LS) techniques are integrated into the traditional ASM framework. The AASM approach globally optimizes the landmark updates in the presence of complicated underlying local anatomical contexts. The proposed approach was validated on 184 axial slices of 20 CT scans. The Hausdorff distance against the manual segmentation was significantly reduced using proposed approach compared to that using ASM, MALF, and LS individually. Our segmentation of the whole abdominal wall enables the subcutaneous and visceral fat measurement, with high correlation to the measurement derived from manual segmentation. This study presents the first generic algorithm that combines ASM, MALF, and LS, and demonstrates practical application for automatically capturing visceral and subcutaneous fat volumes. PMID:27127333

  6. Improved surgical mesh integration into the rat abdominal wall with arginine administration.

    PubMed

    Arbos, M A; Ferrando, J M; Quiles, M T; Vidal, J; López-Cano, M; Gil, J; Manero, J M; Peña, J; Huguet, P; Schwartz-Riera, S; Reventós, J; Armengol, M

    2006-02-01

    Prosthetic meshes are used as the standard of care in abdominal wall hernia repair. However, hernia recurrences and side effects remain unsolved problems. The demand by health care providers for increasingly efficient and cost-effective surgery encourages the development of newer strategies to improve devices and outcomes. Here, we evaluated whether l-arginine administration was able to ameliorate long-term polypropylene prostheses incorporation into the abdominal wall of Sprague-Dawley rats. Meshes were placed on-lay and continuous l-arginine was administered. In vivo biocompatibility was studied at 7, 25 and 30 days post-implantation. Effectively, l-arginine administration in combination with mesh triggered subtle changes in ECM composition that impinged on critical biochemical and structural features. Lastly, tensile strength augmented and stiffness decreased over the control condition. This could help to restructure the mechanical load transfer from the implant to the brittle surrounding tissues, i.e., impact load and fatigue load associated with mechanical tensions could be distributed between the mesh and the restored tissue in a more balanced manner, and ultimately help to reduce the incidence of loosening, recurrences, and local wound complications. Since the newly formed tissue is more mechanically stable, this approach could eventually be introduced to human hernia repair.

  7. Invariant-based anisotropic constitutive models of the healthy and aneurysmal abdominal aortic wall.

    PubMed

    Basciano, C A; Kleinstreuer, C

    2009-02-01

    The arterial wall is a complex fiber-reinforced composite. Pathological conditions, such as aneurysms, significantly alter the mechanical response of the arterial wall, resulting in a loss of elasticity, enhanced anisotropy, and increased chances of mechanical failure. Invariant-based models of the healthy and aneurysmal abdominal aorta were constructed based on first principles and published experimental data with implementations for several numerical cases, as well as comparisons to current healthy and aneurysmal tissue data. Inherent limitations of a traditional invariant-based methodology are also discussed and compared to the models' ability to accurately reproduce experimental trends. The models capture the nonlinear and anisotropic mechanical responses of the two arterial sections and make reasonable predictions regarding the effects of alterations in healthy and diseased tissue histology. Additionally, the new models exhibit convex and anisotropic monotonically increasing energy contours (suggesting numerical stability) but have potentially the inherent limitations of a covariant theoretical framework. Although the traditional invariant framework exhibits significant covariance, the invariant terms utilized in the new models exhibited limited covariance and are able to accurately reproduce experimental trends. A streamlined implementation is also possible for future numerical investigations of fluid-structure interactions in abdominal aortic aneurysms.

  8. Vacuum-assisted abdominal wall lift for minimal-access surgery: a porcine model study.

    PubMed

    Udwadia, T E; Kathrani, B K; Bernie, W; Gadgil, U S; Chariar, V M

    2005-08-01

    Carbon dioxide pneumoperitoneum, although used universally in laparoscopy, has several well-documented complications and disadvantages. The authors describe a simple method of creating vacuum between a rigid shell and the abdominal wall in a porcine model to create adequate operative space for minimal-access surgery, which does not requires carbon dioxide, does not raise intraabdominal pressure, and is safe, cost effective, and feasible. The proposed device and method could be useful wherever basic laparoscopic equipment and a vacuum pump are available, including many parts of the developing world. The study was carried out with three groups using individual porcine models for each study. Group 1 was studied for feasibility of abdominal wall lift, adequacy of intraabdominal space, optimal vacuum levels, and safety and efficacy of the procedure. Group 2 was subjected to laparoscopic cholecystectomy and salpingectomy. Group 3 was studied for 2 days and 8 days after the animals were subjected to prolonged, high-level vacuum and monitored every 24 h to establish long-term effects. In all three groups the safety and efficacy of the proposed method were established, as well as the absence of physiological or histological alterations.

  9. Comparison of Maximal Wall Thickness in Hypertrophic Cardiomyopathy Differs Between Magnetic Resonance Imaging and Transthoracic Echocardiography.

    PubMed

    Bois, John P; Geske, Jeffrey B; Foley, Thomas A; Ommen, Steve R; Pellikka, Patricia A

    2017-02-15

    Left ventricular (LV) wall thickness is a prognostic marker in hypertrophic cardiomyopathy (HC). LV wall thickness ≥30 mm (massive hypertrophy) is independently associated with sudden cardiac death. Presence of massive hypertrophy is used to guide decision making for cardiac defibrillator implantation. We sought to determine whether measurements of maximal LV wall thickness differ between cardiac magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE). Consecutive patients were studied who had HC without previous septal ablation or myectomy and underwent both cardiac MRI and TTE at a single tertiary referral center. Reported maximal LV wall thickness was compared between the imaging techniques. Patients with ≥1 technique reporting massive hypertrophy received subset analysis. In total, 618 patients were evaluated from January 1, 2003, to December 21, 2012 (mean [SD] age, 53 [15] years; 381 men [62%]). In 75 patients (12%), reported maximal LV wall thickness was identical between MRI and TTE. Median difference in reported maximal LV wall thickness between the techniques was 3 mm (maximum difference, 17 mm). Of the 63 patients with ≥1 technique measuring maximal LV wall thickness ≥30 mm, 44 patients (70%) had discrepant classification regarding massive hypertrophy. MRI identified 52 patients (83%) with massive hypertrophy; TTE, 30 patients (48%). Although guidelines recommend MRI or TTE imaging to assess cardiac anatomy in HC, this study shows discrepancy between the techniques for maximal reported LV wall thickness assessment. In conclusion, because this measure clinically affects prognosis and therapeutic decision making, efforts to resolve these discrepancies are critical.

  10. The study on ``load relief`` mechanism of multiple cracks in thick-wall cylinder

    SciTech Connect

    Zhang, Y.H.; Huang, Z.Z.; Tan, Y.; Chen, L.Y.; Pan, B.Z.

    1995-11-01

    In this paper, the stress field on a given cross section in a thick-wall cylinder with single or multiple cracks is analyzed by means of 3-D photoelastic. Based on the study of the effect of crack on stress field, the concept of ``Additional Bending Moment`` is presented and the expression for non-dimensional ABM, M, is derived. The ``load relief`` mechanism of multiple cracks in a thick-wall cylinder is studied.

  11. Influence and Modeling of Residual Stresses in Thick Walled Pressure Vessels with Through Holes

    DTIC Science & Technology

    2012-02-28

    Technical Report ARWSB-TR-12003 INFLUENCE AND MODELING OF RESIDUAL STRESSES IN THICK WALLED PRESSURE VESSELS WITH...DATE (DD-MM-YYYY) 28/02/2012 2. REPORT TYPE Technical Report 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Influence and Modeling of...Residual Stresses in Thick Walled Pressure Vessels with Through Holes 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  12. Post-cast EDM method for reducing the thickness of a turbine nozzle wall

    DOEpatents

    Jones, Raymond Joseph; Bojappa, Parvangada Ganapathy; Kirkpatrick, Francis Lawrence; Schotsch, Margaret Jones; Rajan, Rajiv; Wei, Bin

    2002-01-01

    A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

  13. Effectiveness of laparoscopic gonadectomy using abdominal wall lift method on Turner's syndrome patients with 45, X/46, XY mosaicism.

    PubMed

    Nakano, H; Kawashima, M; Okada, S; Igarashi, T; Nakata, M; Ogino, M

    2001-04-01

    We present a Turner's syndrome patient with a 45, X/46, XY mosaicism who underwent a prophylactic laparoscopic gonadectomy using the abdominal wall lift method. The patient was a 14-year-old phenotypic girl who was referred for an examination of primary amenorrhea. She had already been found to have Turner's syndrome with 45, X/46, XY mosaicism. After an extensive discussion with the patient and her family regarding her high risk for developing a gonadoblastoma, a laparoscopic bilateral salpingo-oophorectomy using the abdominal wall-life method was performed. Laparoscopy using the abdominal wall lift method has an advantage over CO2 pneumoperitoneum method for patients with Turner's syndrome when it is difficult to intubate because of a webbed neck or a shortened trachea.

  14. Assessment of the chest wall thickness of the lawrence livermore torso phantom using a voxel image.

    PubMed

    Ahmed, A S M Sabbir; Capello, Kevin; Kramer, Gary H

    2011-06-01

    This paper describes the methodology of measuring the chest wall thickness using the voxel image of the Lawrence Livermore National Lab (LLNL) torso phantom. The LLNL phantom is used as a standard to calibrate a lung counter consisting of a 2 × 2 array of germanium detectors. In general, an average thickness estimated from four counting positions is used as the chest wall thickness for a given overlay plate. For a given overlay, the outer chest surface differs from that of inner one, and the chest wall thickness varies from one position to other. The LLNL phantom with chest plate and C4 overlay plate installed was scanned with a CT (computed tomography) scanner. The image data, collected in DICOM (Digital Imaging and Communication) format, were converted to the MCNP input file by using the Scan2Mcnp program. The MCNP file was visualized and analyzed with the Moritz visual editor. An analytic expression was formulated and solved to calculate the chest wall thickness by using the point detector responses (F 5 tally of MCNP). To map the chest thickness, the entire chest wall was meshed into virtual grids of 1 cm width. A source and detector pair was moved along the inner and outer surface of the chest wall from right to left at different heights from neck to abdomen. For each height (z(k)), (x(i), y(j)) coordinates for the detector source pair were calculated from the visual editor and were scaled on-screen. For each (x(i), y(j), z(k)) position, a mesh thickness was measured from on-screen measurement and by solving the detector responses. The chest wall thicknesses at different positions on the outer surface of the chest were compared and verified using two methods.

  15. Functional electrical stimulation to the abdominal wall muscles synchronized with the expiratory flow does not induce muscle fatigue

    PubMed Central

    Okuno, Yukako; Takahashi, Ryoichi; Sewa, Yoko; Ohse, Hirotaka; Imura, Shigeyuki; Tomita, Kazuhide

    2017-01-01

    [Purpose] Continuous electrical stimulation of abdominal wall muscles is known to induce mild muscle fatigue. However, it is not clear whether this is also true for functional electrical stimulation delivered only during the expiratory phase of breathing. This study aimed to examine whether or not intermittent electrical stimulation delivered to abdominal wall muscles induces muscle fatigue. [Subjects and Methods] The subjects were nine healthy adults. Abdominal electrical stimulation was applied for 1.5 seconds from the start of expiration and then turned off during inspiration. The electrodes were attached to both sides of the abdomen at the lower margin of the 12th rib. Abdominal electrical stimulation was delivered for 15 minutes with the subject in a seated position. Expiratory flow was measured during stimulus. Trunk flexor torque and electromyography activity were measured to evaluate abdominal muscle fatigue. [Results] The mean stimulation on/off ratio was 1:2.3. The declining rate of abdominal muscle torque was 61.1 ± 19.1% before stimulus and 56.5 ± 20.9% after stimulus, not significantly different. The declining rate of mean power frequency was 47.8 ± 11.7% before stimulus and 47.9 ± 10.2% after stimulus, not significantly different. [Conclusion] It was found that intermittent electrical stimulation to abdominal muscles synchronized with the expiratory would not induce muscle fatigue. PMID:28356636

  16. Functional electrical stimulation to the abdominal wall muscles synchronized with the expiratory flow does not induce muscle fatigue.

    PubMed

    Okuno, Yukako; Takahashi, Ryoichi; Sewa, Yoko; Ohse, Hirotaka; Imura, Shigeyuki; Tomita, Kazuhide

    2017-03-01

    [Purpose] Continuous electrical stimulation of abdominal wall muscles is known to induce mild muscle fatigue. However, it is not clear whether this is also true for functional electrical stimulation delivered only during the expiratory phase of breathing. This study aimed to examine whether or not intermittent electrical stimulation delivered to abdominal wall muscles induces muscle fatigue. [Subjects and Methods] The subjects were nine healthy adults. Abdominal electrical stimulation was applied for 1.5 seconds from the start of expiration and then turned off during inspiration. The electrodes were attached to both sides of the abdomen at the lower margin of the 12th rib. Abdominal electrical stimulation was delivered for 15 minutes with the subject in a seated position. Expiratory flow was measured during stimulus. Trunk flexor torque and electromyography activity were measured to evaluate abdominal muscle fatigue. [Results] The mean stimulation on/off ratio was 1:2.3. The declining rate of abdominal muscle torque was 61.1 ± 19.1% before stimulus and 56.5 ± 20.9% after stimulus, not significantly different. The declining rate of mean power frequency was 47.8 ± 11.7% before stimulus and 47.9 ± 10.2% after stimulus, not significantly different. [Conclusion] It was found that intermittent electrical stimulation to abdominal muscles synchronized with the expiratory would not induce muscle fatigue.

  17. ACUTE TEARING OF THE OBLIQUE ABDOMINAL WALL INSERTION ONTO THE ILIAC CREST IN AN AUSTRALIAN FOOTBALL PLAYER: A CASE REPORT

    PubMed Central

    Stockden, Marshall; Breidahl, Bill

    2016-01-01

    Background Tears of the abdominal obliques have previously been reported in the vicinity of the lower ribs but they have not been reported in the vicinity of the iliac crest. The purpose of this case report is to describe the mechanism of injury and diagnosis of a distal abdominal oblique tear and subsequent rehabilitation programming. Case Description A 21-year-old male Australian football player experienced acute right-sided abdominal pain during a game while performing a commonly executed rotation skill. He was assessed clinically before being further examined with ultrasound and magnetic resonance imaging which revealed a rupture of the abdominal oblique wall at its insertion onto the iliac crest. The player then underwent a structured and graduated rehabilitation program with clear key performance indicators to optimize return to play and prevent recurrence. Outcomes The player was able to return to play at 35 days post injury and had no recurrence or complications at 12 month follow up post injury. Discussion This is the first time an abdominal oblique wall rupture at its insertion onto the iliac crest has been reported. In players with acute abdominal pain following twisting an insertional oblique tear should be considered as a differential diagnosis. A structured rehabilitation program may also help optimize an athlete's return to play after distal abdominal oblique rupture. PMID:27999726

  18. Necrotizing cellulitis of the abdominal wall, caused by Pediococcus sp., due to rupture of a retroperitoneal stromal cell tumor

    PubMed Central

    Michalopoulos, Nick; Arampatzi, Stergiani; Papavramidis, Theodossis S.; Kotidis, Efstathios; Laskou, Styliani; Papavramidis, Spiros T.

    2013-01-01

    INTRODUCTION Soft tissue necrotizing infections are a significant cause of morbidity and mortality. The aim of this study is to present a patient with necrotizing infection of abdominal wall resulting from the rupture of a retroperitoneal stromal tumor. PRESENTATION OF CASE We present a 60-year-old Caucasian male patient with necrotizing infection of abdominal wall secondary to the rupture of a retroperitoneal stromal tumor. The patient was initially treated with debridement and fasciotomy of the anterior abdominal wall. Laparotomy revealed purulent peritonitis caused by infiltration and rupture of the splenic flexure by the tumor. Despite prompt intervention the patient died 19 days later. The isolated microorganism causing the infection was the rarely identified as cause of infections in humans Pediococcus sp., a gram-positive, catalase-negative coccus. DISCUSSION Necrotizing infections of abdominal wall are usually secondary either to perineal or to intra-abdominal infections. Gastrointestinal stromal cell tumors could be rarely complicated with perforation and abscess formation. In our case, the infiltrated by the extra-gastrointestinal stromal cell tumor ruptured colon was the source of the infection. The pediococci are rarely isolated as the cause of severe septicemia. CONCLUSION Ruptured retroperitoneal stromal cell tumors are extremely rare cause of necrotizing fasciitis, and before this case, Pediococcus sp. has never been isolated as the responsible agent. PMID:23357010

  19. The Effects of Horse Riding Simulation Training on Stroke Patients’ Balance Ability and Abdominal Muscle Thickness Changes

    PubMed Central

    Baek, Il-Hun; Kim, Byeong Jo

    2014-01-01

    [Purpose] The purpose of this study was to assess the effects of horse riding simulation training on changes in balance ability and abdominal muscle thicknesses of stroke patients. [Subjects] Thirty stroke patients with hemiplegia were recruited, and they were randomly assigned to a control or experimental group. [Methods] The experimental group performed horse riding simulation training, whereas the control group performed trunk exercises for 8 weeks. Balance ability was measured using a BioRescue system. The thicknesses of subjects’ external oblique, internal oblique, and transversus abdominis muscles were measured by ultrasonic imaging. [Results] In the experimental group, balance ability was significantly improved after training. Similarly, the thickness of the abdominal muscles on the affected side changed after training in the experimental group, whereas the control group showed no statistically significant changes. [Conclusion] We suggest that horse riding simulation training is more effective than trunk exercises at reducing the center of pressure path length and travel speed and improving the asymmetry of the abdominal muscles of stroke patients. PMID:25202200

  20. [Intra-abdominal hypertension as a consequence of plasty in the abdominal wall defects, the methods of its determination and prophylaxis].

    PubMed

    Vorovs'kyĭ, O O

    2013-09-01

    The results of various methods of investigation of intraabdominal hypertension (IAH) in 186 patients were analyzed. In 134 (27.1%) patients IAH was measured via bladder, in 46 (8.9%)--the investigation using nasogastric probe was added and in 8 (1.6%), in whom the abdominal wall defect coincided with adhesive disease, the measurement was performed immediately via drainages. In 44 (8.9%) patients the IAH measurement while abdominal wall defect closure was performed, using Stryker Intra Compartmental Pressure Monitor apparatus. The data obtained using this apparatus were considered the most informative. For the IAH prophylaxis it is mandatory to prognosticate the intraabdominal pressure raising, so on the stage of the hernia gates edges approximation it must not be bigger than a second degree level.

  1. High resolution computed tomographic evaluation of bronchial wall thickness in healthy and clinically asthmatic cats

    PubMed Central

    WON, Sungjun; YUN, Sookyung; LEE, Jeosoon; LEE, Mikyung; CHOI, Mincheol; YOON, Junghee

    2017-01-01

    The objective of study is to determine the thickness of bronchial walls of clinically diagnosed asthmatic cats using high resolution computed tomography (HRCT) compared to that of healthy cats. The bronchial walls and pulmonary arteries were measured in healthy 16 cats and clinically asthmatic 4 cats. The bronchial walls and pulmonary arteries were measured under general anesthesia with positive pressure inspiration using HRCT. In healthy and asthmatic cats, bronchial lumen to the artery ratio (BA ratio), the ratio of bronchial wall thickness to bronchial diameter (TD ratio) and ratio of bronchial wall thickness to pulmonary artery (TA ratio) were measured. The mean BA ratio, TD ratio and TA ratio in healthy cats were 0.86 ± 0.12, 0.18 ± 0.02 and 0.25 ± 0.05, respectively. Under the same condition, the mean BA ratio, TD ratio and TA ratio in asthmatic cats were 0.93 ± 0.21, 0.22 ± 0.24 and 0.37 ± 0.06. The TD ratio and TA ratio in asthmatic cats were significantly higher than healthy cats (P<0.001). BA ratio was not significantly different in both groups (P>0.05). The evaluation of bronchial wall thickness by HRCT could be useful for diagnosis of disease of bronchial wall thickening, such as feline asthma. PMID:28163274

  2. A Multidisciplinary Approach to Medical Weight Loss Prior to Complex Abdominal Wall Reconstruction: Is it Feasible?

    PubMed

    Rosen, Michael J; Aydogdu, Kasim; Grafmiller, Kevin; Petro, Clayton C; Faiman, Gregg H; Prabhu, Ajita

    2015-08-01

    Obesity is a major risk factor for perioperative morbidity, especially for patients undergoing complex incisional hernia repair. The feasibility and effectiveness of medical weight loss programs prior to complex abdominal wall reconstruction have not been well characterized. Here, we report our experience collaborating with a medical weight loss specialist utilizing a protein sparing modified fast in order to optimize weight loss prior to complex abdominal wall reconstruction. Morbidly obese patients (body mass index (BMI) > 35 kg/m(2)) evaluated by our medical weight loss specialist prior to complex ventral hernia repair were identified within our prospective database. Our primary outcome measure was the amount of weight lost prior to surgical intervention. Our secondary outcome measure was to determine the maintenance of weight loss during long-term follow-up after the surgical intervention. A total of 25 patients with a BMI > 35 kg/m(2) were evaluated by our medical weight loss specialist prior to undergoing a planned incisional hernia repair. The mean weight of the patients preoperatively was 128 kg ± 25 (range 96-205 kg) (mean ± standard deviation), and the mean BMI was 49 kg/m(2) ± 10 (range 36-85). After completion of the preoperative modified protein sparing fast, the mean preoperative weight loss of the group was 24 kg ± 21 (range 2-80 kg). The overall change in BMI for the group prior to surgery was 9 kg/m(2) ± 8 (0.6 to 33). The percentage of excess BMI loss and total BMI loss preoperatively was 37 % ± 23 (2 to 83) and 18 % ± 12 (1 to 43), respectively. Of the 24 patients that initially lost weight in the program preoperatively, 22 (88 %) successfully maintained their weight loss for the entire study period for an average of 18 months. Collaboration with a medical weight loss specialist and a surgeon with a structured approach using a modified protein sparing fast can successfully result in meaningful weight

  3. Evaluation of porcine dermal collagen (Permacol) used in abdominal wall reconstruction.

    PubMed

    Hsu, Patrick W; Salgado, Christopher J; Kent, Kathryn; Finnegan, Matthew; Pello, Mark; Simons, Robert; Atabek, Umur; Kann, Brian

    2009-11-01

    Various methods have been employed to reconstruct complex abdominal wall defects. Structural prosthetic materials such as polypropylene mesh and ePTFE (expanded polytetrafluoroethylene) have been widely used to close these large fascial defects, however, complications with infection and adhesions have led to the recent use of more biocompatible implants. Permacol (acellular porcine dermis) is used as a dermal scaffold, which eventually becomes vascularised and remodelled to reconstruct the abdominal wall in these complex patients. A retrospective review was performed of all patients who underwent consecutive abdominal wall reconstruction with Permacol at our institution in the year 2006. Twenty-eight patients were identified and included in our study. Factors evaluated were: body mass index, relevant co-morbidities, aetiology of hernia, hernia defect size based on CT scan and intraoperative measurement, size of Permacol implant, length of hospital stay, and postoperative complications. Surgical technique was standardised among six surgeons and involved a single layer of acellular porcine dermis as a subfascial 'underlay' graft under moderate tension upon maximal hernia reduction. Tissue expanders were not required for skin closure. Out of 28 patients, 12 were male and 16 were female. Mean intraoperative hernia size was 150 cm(2) (range of 10 cm(2) to 600 cm(2)). Mean age was 55 years with an average body mass index (BMI) of 34 (largest BMI of 61.4). Defects were attributed to either a previous laparotomy incision or open abdomen. Mean hospital stay was 9.67 days. At a mean follow-up of sixteen months, there were three recurrent hernias (10.7%) based on physical examination and postoperative CT scan evaluation. One patient developed a superficial wound dehiscence which was successfully treated with local wound care and one patient developed a cellulitis which was successfully treated with antibiotic therapy. Four patients (14.3%) developed a chronic, non

  4. Obesity increases the odds of acquiring and incarcerating noninguinal abdominal wall hernias.

    PubMed

    Lau, Briana; Kim, Hanjoo; Haigh, Philip I; Tejirian, Talar

    2012-10-01

    The current data available describing the relationship of obesity and abdominal wall hernias is sparse. The objective of this study was to investigate the current prevalence of noninguinal abdominal wall hernias and their correlation with body mass index (BMI) and other demographic risk factors. Patients with umbilical, incisional, ventral, epigastric, or Spigelian hernias with or without incarceration were identified using the regional database for 14 hospitals over a 3-year period. Patients were stratified based on their BMI. Univariate and multivariate analyses were performed to distinguish other significant risk factors associated with the hernias. Of 2,807,414 patients, 26,268 (0.9%) had one of the specified diagnoses. Average age of the patients was 52 years and 61 per cent were male. The majority of patients had nonincarcerated umbilical hernias (74%). Average BMI was 32 kg/m2. Compared with patients with a normal BMI, the odds of having a hernia increased with BMI: BMI of 25 to 29.9 kg/m2 odds ratio (OR) 1.63, BMI of 30 to 39.9 kg/m2 OR 2.62, BMI 40 to 49.9 kg/m2 OR 3.91, BMI 50 to 59.9 kg/m2 OR 4.85, and BMI greater than 60 kg/m2 OR 5.17 (P<0.0001). Age older than 50 years was associated with a higher risk for having a hernia (OR, 2.12; 95% [CI], 2.07 to 2.17), whereas female gender was associated with a lower risk (OR, 0.53; 95% CI, 0.52 to 0.55). Those with incarcerated hernias had a higher average BMI (32 kg/m2 vs 35 kg/m2; P<0.0001). Overall, BMI greater than 40 kg/m2 showed an increased chance of incarceration, and a BMI greater than 60 kg/m2 had the highest chance of incarceration, OR 12.7 (P<0.0001). Age older than 50 years and female gender were also associated with a higher risk of incarceration (OR, 1.28; 95% CI, 1.02 to 1.59 and OR, 1.80; CI, 1.45 to 2.24). Increasing BMI and increasing age are associated with a higher prevalence and an increased risk of incarceration of noninguinal abdominal wall hernias.

  5. Chest wall thickness measurements: The alternative approach extended for {sup 241}Am

    SciTech Connect

    Kramer, G.H.; Burns, L.C.

    1997-02-01

    The Human Monitoring Laboratory has extended the technique of determining the chest wall thickness of an individual using information from the spectrum produced by internally deposited radionuclides. The technique has been investigated both theoretically and practically using germanium detectors and the Lawrence Livermore Torso Phantom. The phantom was used with a lung set containing homogeneously distributed {sup 241}Am. Chest wall thicknesses were varied by using a series of muscle equivalent overlay plates that gave a range of 1.6 cm to 3.9 cm thickness. It was found that a 3-cm chest wall thickness can be estimated to within 18%. Using a spectral addition technique 1 kBq was estimated to be the {open_quotes}practical{close_quotes} lower limit of activity for this method. 7 refs., 2 figs., 3 tabs.

  6. A Probabilistic Method for Estimation of Bowel Wall Thickness in MR Colonography

    PubMed Central

    Menys, Alex; Jaffer, Asif; Bhatnagar, Gauraang; Punwani, Shonit; Atkinson, David; Halligan, Steve; Hawkes, David J.; Taylor, Stuart A.

    2017-01-01

    MRI has recently been applied as a tool to quantitatively evaluate the response to therapy in patients with Crohn’s disease, and is the preferred choice for repeated imaging. Bowel wall thickness on MRI is an important biomarker of underlying inflammatory activity, being abnormally increased in the acute phase and reducing in response to successful therapy; however, a poor level of interobserver agreement of measured thickness is reported and therefore a system for accurate, robust and reproducible measurements is desirable. We propose a novel method for estimating bowel wall-thickness to improve the poor interobserver agreement of the manual procedure. We show that the variability of wall thickness measurement between the algorithm and observer measurements (0.25mm ± 0.81mm) has differences which are similar to observer variability (0.16mm ± 0.64mm). PMID:28072831

  7. A Probabilistic Method for Estimation of Bowel Wall Thickness in MR Colonography.

    PubMed

    Hampshire, Thomas; Menys, Alex; Jaffer, Asif; Bhatnagar, Gauraang; Punwani, Shonit; Atkinson, David; Halligan, Steve; Hawkes, David J; Taylor, Stuart A

    2017-01-01

    MRI has recently been applied as a tool to quantitatively evaluate the response to therapy in patients with Crohn's disease, and is the preferred choice for repeated imaging. Bowel wall thickness on MRI is an important biomarker of underlying inflammatory activity, being abnormally increased in the acute phase and reducing in response to successful therapy; however, a poor level of interobserver agreement of measured thickness is reported and therefore a system for accurate, robust and reproducible measurements is desirable. We propose a novel method for estimating bowel wall-thickness to improve the poor interobserver agreement of the manual procedure. We show that the variability of wall thickness measurement between the algorithm and observer measurements (0.25mm ± 0.81mm) has differences which are similar to observer variability (0.16mm ± 0.64mm).

  8. Chest wall thickness measurements of the LLNL and JAERI torso phantoms for germanium detector counting

    SciTech Connect

    Kramer, G.H.; Hauck, B.M.

    1997-11-01

    The Lawrence Livermore National Laboratory and Japanese Atomic Energy Research Institute torso phantoms were developed to calibrate lung counting systems that are used to estimate plutonium and other radionuclides deposited in the lung. Originally, low energy photon counting systems consisted of phoswich detectors. The average chest wall thicknesses and individual measurement points of the Lawrence Livermore National Laboratory phantom and its overlay plates in the regions covered by these detectors were provided by the manufacturer. Germanium detectors are of a different size and are placed in different locations on the phantom so that the manufacturer`s data are no longer applicable for the locations of the germanium detectors on the phantom. The Human Monitoring Laboratory has re-evaluated the chest wall thickness of both the Lawrence Livermore National Laboratory and Japanese Atomic Energy Research Institute phantoms and their overlay plates for its germanium lung counting system. The measurements were made in the upper right, lower right, upper left, and lower left positions on the phantom`s torso plate above the lungs. The effective chest wall thicknesses (17 keV) for the Lawrence Livermore National Laboratory torso plate are 1.46 cm, 1.43 cm, 1.66 cm, 1.48 cm, respectively. The manufacturer`s quoted average effective chest wall thickness for a pair of phoswich detectors is 1.63 cm. The measured effective chest wall thicknesses (17 keV) for the JAERI`s torso plate are 1.76 cm, 2.15 cm, 1.79 cm, 2.15 cm, respectively. The manufacturer`s quoted average chest wall thickness for an unspecified region of the chest is 1.50 cm. This paper presents effective chest wall thickness data for the phantoms with and without their overlay plates at 17 keV, 60 keV, 200 keV and 1,500 keV. 13 refs., 2 figs., 4 tabs.

  9. 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.

  10. Spontaneous extraskeletal osteosarcoma with various histological growth patterns in the abdominal wall of an ICR mouse

    PubMed Central

    Ito, Tsuyoshi; Katoh, Yoshitaka; Shimada, Yuko; Ohnuma-Koyama, Aya; Takahashi, Naofumi; Kuwahara, Maki; Harada, Takanori

    2015-01-01

    Extraskeletal osteosarcoma is extremely rare in mice. This case report demonstrates a spontaneous murine extraskeletal osteosarcoma that exhibited various histological growth patterns in an ICR mouse. At necropsy, the tumor mass was located in the abdominal wall and was 45 × 30 × 25 mm in size. Histopathologically, the tumor showed the following four growth patterns: a solid pattern of polygonal cells embedded in an osteoid eosinophilic matrix with calcification, an irregular sheet pattern of short spindle cells accompanying some eosinophilic multinucleated cells, a fascicular pattern of spindle cells and a cystic pattern lined by short spindle cells. Immunohistochemically, most of the tumor cells were positive for vimentin, proliferating cell nuclear antigen and osterix. The multinucleated cells mentioned above were desmin positive and were regarded as regenerative striated muscles but not tumor cells. Since no clear continuity with normal bone tissues was observed, the tumor was diagnosed as an “extraskeletal osteosarcoma.” PMID:26989300

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

    PubMed

    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.

  12. Exercise-mediated changes in conduit artery wall thickness in humans: role of shear stress.

    PubMed

    Thijssen, Dick H J; Dawson, Ellen A; van den Munckhof, Inge C L; Tinken, Toni M; den Drijver, Evert; Hopkins, Nicola; Cable, N Timothy; Green, Daniel J

    2011-07-01

    Episodic increases in shear stress have been proposed as a mechanism that induces training-induced adaptation in arterial wall remodeling in humans. To address this hypothesis in humans, we examined bilateral brachial artery wall thickness using high-resolution ultrasound in healthy men across an 8-wk period of bilateral handgrip training. Unilaterally, shear rate was attenuated by cuff inflation around the forearm to 60 mmHg. Grip strength, forearm volume, and girth improved similarly between the limbs. Acute bouts of handgrip exercise increased shear rate (P < 0.005) in the noncuffed limb, whereas cuff inflation successfully decreased exercise-induced increases in shear. Brachial blood pressure responses similarly increased during exercise in both the cuffed and noncuffed limbs. Handgrip training had no effect on baseline brachial artery diameter, blood flow, or shear rate but significantly decreased brachial artery wall thickness after 6 and 8 wk (ANOVA, P < 0.001) and wall-to-lumen ratio after week 8 (ANOVA, P = 0.005). The magnitude of decrease in brachial artery wall thickness and wall-to-lumen ratio after exercise training was similar in the noncuffed and cuffed arms. These results suggest that exercise-induced changes in shear rate are not obligatory for arterial wall remodeling during a period of 8 wk of exercise training in healthy humans.

  13. Effects of arterial blood flow on walls of the abdominal aorta: distributions of wall shear stress and oscillatory shear index determined by phase-contrast magnetic resonance imaging.

    PubMed

    Sughimoto, Koichi; Shimamura, Yoshiaki; Tezuka, Chie; Tsubota, Ken'ichi; Liu, Hao; Okumura, Kenichiro; Masuda, Yoshitada; Haneishi, Hideaki

    2016-07-01

    Although abdominal aortic aneurysms (AAAs) occur mostly inferior to the renal artery, the mechanism of the development of AAA in relation to its specific location is not yet clearly understood. The objective of this study was to evaluate the hypothesis that even healthy volunteers may manifest specific flow characteristics of blood flow and alter wall shear or oscillatory shear stress in the areas where AAAs commonly develop. Eight healthy male volunteers were enrolled in this prospective study, aged from 24 to 27. Phase-contrast magnetic resonance imaging (MRI) was performed with electrocardiographic triggering. Flow-sensitive four-dimensional MR imaging of the abdominal aorta, with three-directional velocity encoding, including simple morphological image acquisition, was performed. Information on specific locations on the aortic wall was applied to the flow encodes to calculate wall shear stress (WSS) and oscillatory shear index (OSI). While time-framed WSS showed the highest peak of 1.14 ± 0.25 Pa in the juxtaposition of the renal artery, the WSS plateaued to 0.61 Pa at the anterior wall of the abdominal aorta. The OSI peaked distal to the renal arteries at the posterior wall of the abdominal aorta of 0.249 ± 0.148, and was constantly elevated in the whole abdominal aorta at more than 0.14. All subjects were found to have elevated OSI in regions where AAAs commonly occur. These findings indicate that areas of constant peaked oscillatory shear stress in the infra-renal aorta may be one of the factors that lead to morphological changes over time, even in healthy individuals.

  14. [Case of abdominal wall malignant peripheral nerve sheath tumor which is difficult to distinguish from a urachal disease].

    PubMed

    Tatenuma, Tomoyuki; Sakata, Ryoko; Sugiura, Shinpei; Tajiri, Takehiro; Gondo, Toshikazu; Kitami, Kazuo

    2013-09-01

    Malignant peripheral nerve sheath tumors (MPNST) are highly malignant soft tissue sarcomas. It is very rare for MPNST to arise in the abdominal wall. We report a case of abdominal wall MPNST that was difficult to distinguish from a urachal disease. A 72-year-old woman found a mass of the umbilicus in October 2011. She visited a digestive surgery department in November because it gradually enlarged. Diagnostic imaging suggested a urachal tumor. She was then referred to our clinic. Contrast enhanced CT showed that the 5-cm cystic tumor extended from the umbilicus to abdominal wall. The tumor showed low uptake value in PET-CT. We diagnosed her with a urachal cyst, but could not deny urachal carcinoma. Therefore, we performed surgical resection in January 2012. The pathological diagnosis was MPNST. She has not experienced recurrence for 9 months. MPNST mostly occur in the retroperitoneum close to the spine, extremities, head, and neck. It is very rare for them to occur in the abdominal wall. This is the sixth case including overseas reports. In addition, this is the first case in which it was difficult to distinguish from a urachal disease.

  15. Isotropic 3D Black Blood MRI of Abdominal Aortic Aneurysm Wall and Intraluminal Thrombus

    PubMed Central

    Zhu, Chengcheng; Haraldsson, Henrik; Faraji, Farshid; Owens, Christopher; Gasper, Warren; Ahn, Sinyeob; Liu, Jing; Laub, Gerhard; Hope, Michael D.; Saloner, David

    2015-01-01

    Introduction The aortic wall and intraluminal thrombus (ILT) have been increasingly studied as potential markers of progressive disease with abdominal aortic aneurysms (AAAs). Our goal was to develop a high resolution, 3D black blood MR technique for AAA wall and ILT imaging within a clinically acceptable scan time. Methods Twenty two patients with AAAs (maximal diameter 4.3±1.0cm), along with five healthy volunteers, were imaged at 3T with a 3D T1-weighted fast-spin-echo sequence using variable flip angle trains (SPACE) with a preparation pulse (DANTE) for suppressing blood signal. Volunteers and ten patients were also scanned with SPACE alone for comparison purposes. The signal to noise ratio (SNR) and the aortic wall/ILT to lumen contrast to noise ratio (CNR) were measured. Qualitative image scores (1–4 scale) assessing the inner lumen and outer wall boundaries of AAA were performed by two blinded reviewers. In patients with ILT, the ratio of ILT signal intensity (ILTSI) over psoas muscle SI (MuscleSI) was calculated, and the signal heterogeneity of ILT was quantified as standard deviation (SD) over the mean. Results All subjects were imaged successfully with an average scan time of 7.8±0.7 minutes. The DANTE preparation pulse for blood suppression substantially reduced flow artifacts in SPACE with lower lumen SNR (8.8 vs. 21.4, p<0.001) and improved the wall/ILT to lumen CNR (9.9 vs. 6.3, p<0.001) in patients. Qualitative assessment showed improved visualization of lumen boundaries (73% higher scores on average, p=0.01) and comparable visualization of outer wall boundary (p>0.05). ILT was present in ten patients, with relatively high signal and a wide SD (average ILTSI/MuscleSI 1.42±0.48 (range 0.75–2.11) ) and with SD/mean of 27.7%±6.6% (range 19.6% – 39.4%). Conclusion High resolution, 3D black blood MRI of AAAs can be achieved in a clinical accepted scan time with reduction of flow artifacts using the DANTE preparation pulse. Signal characteristics

  16. Examinations of a new long-term degradable electrospun polycaprolactone scaffold in three rat abdominal wall models.

    PubMed

    Jangö, Hanna; Gräs, Søren; Christensen, Lise; Lose, Gunnar

    2017-02-01

    Alternative approaches to reinforce native tissue in reconstructive surgery for pelvic organ prolapse are warranted. Tissue engineering combines the use of a scaffold with the regenerative potential of stem cells and is a promising new concept in urogynecology. Our objective was to evaluate whether a newly developed long-term degradable polycaprolactone scaffold could provide biomechanical reinforcement and function as a scaffold for autologous muscle fiber fragments. We performed a study with three different rat abdominal wall models where the scaffold with or without muscle fiber fragments was placed (1) subcutaneously (minimal load), (2) in a partial defect (partial load), and (3) in a full-thickness defect (heavy load). After 8 weeks, no animals had developed hernia, and the scaffold provided biomechanical reinforcement, even in the models where it was subjected to heavy load. The scaffold was not yet degraded but showed increased thickness in all groups. Histologically, we found a massive foreign body response with numerous large giant cells intermingled with the fibers of the scaffold. Cells from added muscle fiber fragments could not be traced by PKH26 fluorescence or desmin staining. Taken together, the long-term degradable polycaprolactone scaffold provided biomechanical reinforcement by inducing a marked foreign-body response and attracting numerous inflammatory cells to form a strong neo-tissue construct. However, cells from the muscle fiber fragments did not survive in this milieu. Properties of the new neo-tissue construct must be evaluated at the time of full degradation of the scaffold before its possible clinical value in pelvic organ prolapse surgery can be evaluated.

  17. Combined Use of an Anterolateral Thigh Flap and Superficial Inferior Epigastric Artery Flap for Reconstruction of an Extensive Abdominal Wall Defect

    PubMed Central

    Kagaya, Yu; Arikawa, Masaki; Kobayashi, Eisuke

    2016-01-01

    Summary: Reconstruction of large abdominal wall defects is challenging. We herein report the successful reconstruction of an extensive abdominal wall defect using a novel combination of flaps after sarcoma resection. A 74-year-old man presented with a dedifferentiated liposarcoma on his abdominal wall. He underwent excision of the tumor, which resulted in an extensive abdominal wall defect. The defect was reconstructed with a pedicled anterolateral thigh flap with an iliotibial tract and a pedicled superficial inferior epigastric artery flap. No skin graft was necessary. The wounds healed successfully, and no herniation occurred. The combination of an anterolateral thigh flap and a superficial inferior epigastric artery flap is a versatile option for reconstruction of extensive abdominal wall defects. PMID:27975026

  18. [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.

  19. A Novel Diagnostic Aid for Detection of Intra-Abdominal Adhesions to the Anterior Abdominal Wall Using Dynamic Magnetic Resonance Imaging

    PubMed Central

    Randall, David; Fenner, John; Gillott, Richard; ten Broek, Richard; Strik, Chema; Spencer, Paul; Bardhan, Karna Dev

    2016-01-01

    Introduction. Abdominal adhesions can cause serious morbidity and complicate subsequent operations. Their diagnosis is often one of exclusion due to a lack of a reliable, non-invasive diagnostic technique. Development and testing of a candidate technique are described below. Method. During respiration, smooth visceral sliding motion occurs between the abdominal contents and the walls of the abdominal cavity. We describe a technique involving image segmentation and registration to calculate shear as an analogue for visceral slide based on the tracking of structures throughout the respiratory cycle. The presence of an adhesion is attributed to a resistance to visceral slide resulting in a discernible reduction in shear. The abdominal movement due to respiration is captured in sagittal dynamic MR images. Results. Clinical images were selected for analysis, including a patient with a surgically confirmed adhesion. Discernible reduction in shear was observed at the location of the adhesion while a consistent, gradually changing shear was observed in the healthy volunteers. Conclusion. The technique and its validation show encouraging results for adhesion detection but a larger study is now required to confirm its potential. PMID:26880884

  20. Thickness measuring of electroconductive pipe walls using the dual-frequency eddy-current method

    NASA Astrophysics Data System (ADS)

    Yakimov, Evgeny; Galtseva, Olga; Ustyugov, Daniil

    2017-01-01

    The paper describes a dual-frequency method for reducing the impact of changes in the gap size between the eddy-current transducer and the pipe, as well as the pipe electrical conductivity on the eddy-current thickness gauge readings. A block-diagram of the dual-frequency eddy-current thickness gauge is proposed for light-alloy drill pipes. The amplitude and signal phase dependencies on the wall thickness in the range from 6 to 17 mm and the gap in the range from 0 to 13.5 mm were studied, the results are presented. The digital signal processing algorithms based on the piecewise-linear approximation of low-frequency and high-frequency signal phase dependencies on the wall thickness are proposed. It is shown that the proposed correction algorithms can reduce the error caused by variations of electrical conductivity and the gap between the transducer and the pipe.

  1. Enhancing cell-free layer thickness by bypass channels in a wall.

    PubMed

    Saadatmand, M; Shimogonya, Y; Yamaguchi, T; Ishikawa, T

    2016-07-26

    When blood flows near a wall, red blood cells (RBCs) drift away from the wall and a cell-free layer (CFL) is formed adjacent to the wall. Controlling the CFL thickness is important for preventing adhesion of cells in the design of biomedical devices. In this study, a novel wall configuration with stenoses and bypass channels is proposed to increase the CFL thickness. We found that the presence of bypass channels modified the spatial distribution of cells and substantially increased the CFL downstream of the stenosis. A single-bypass geometry with 5% hematocrit (Hct) blood flow showed a 1.7μm increase in CFL thickness compared to without the bypass. In the case of three bypass channels, a 3μm increase in CFL thickness was observed. The CFL enhancement was observed up to 10% Hct, but no significant enhancement of CFL was indicated for 20% Hct blood flow. The mechanism of the CFL enhancement was investigated using a numerical simulation of the flow field. The results showed that the distance between each streamline and the corner of the stenosis compared with size of RBC was important parameter in regulating CFL thickness. These results show the potential of the proposed mechanism to prevent adhesion of cells to biomedical devices.

  2. Colonic wall thickness, pancreatic enzyme dose and type of preparation in cystic fibrosis

    PubMed Central

    Ramsden, W; Moya, E; Littlewood, J

    1998-01-01

    Increased colonic wall thickness has been reported in patients exposed to large doses of high strength pancreatic enzyme preparations who did not develop fibrosing colonopathy. This has been interpreted as evidence for a spectrum of subclinical disease. The relation between sonographically measured colonic wall thickness and pancreatic enzyme preparation and dose was studied in 86 children with cystic fibrosis (CF). Colonic wall thickness of a control group was also measured. The average thickness in all colonic regions was higher in the CF group (overall average range 0.7-2.5 mm v 0.6-1.4 mm in the control group). There was no significant relation between colonic wall thickness and age, sex, total dose of lipase, or copolymer. Apart from one patient with an early colonic stricture, none of those exposed to high doses of lipase, or the methacrylic acid copolymer Eudragit L30 D55, showed evidence of subclinical damage to the colon. The reproducibility of the sonographic measurements was poor.

 PMID:9875045

  3. Fourier Transform Infrared Spectroscopic Imaging-Derived Collagen Content and Maturity Correlates with Stress in the Aortic Wall of Abdominal Aortic Aneurysm Patients.

    PubMed

    Cheheltani, Rabee; Pichamuthu, Joseph E; Rao, Jayashree; Weinbaum, Justin S; Kiani, Mohammad F; Vorp, David A; Pleshko, Nancy

    2017-03-01

    Abdominal aortic aneurysm (AAA) is a degenerative disease of the aorta characterized by severe disruption of the structural integrity of the aortic wall and its major molecular constituents. From the early stages of disease, elastin in the aorta becomes highly degraded and is replaced by collagen. Questions persist as to the contribution of collagen content, quality and maturity to the potential for rupture. Here, using our recently developed Fourier transform infrared imaging spectroscopy (FT-IRIS) method, we quantified collagen content and maturity in the wall of AAA tissues in pairs of specimens with different wall stresses. CT scans of AAAs from 12 patients were used to create finite element models to estimate stress in different regions of tissue. Each patient underwent elective repair of the AAA, and two segments of the AAA tissues from anatomic regions more proximal or distal with different wall stresses were evaluated by histology and FT-IRIS after excision. For each patient, collagen content was generally greater in the tissue location with lower wall stress, which corresponded to the more distal anatomic regions. The wall stress/collagen ratio was greater in the higher stress region compared to the lower stress region (1.01 ± 1.09 vs. 0.55 ± 0.084, p = 0.02). The higher stress region also corresponded to the location with reduced intraluminal thrombus thickness. Further, collagen maturity tended to decrease with increased collagen content (p = 0.068, R = 0.38). Together, these results suggest that an increase in less mature collagen content in AAA patients does not effectively compensate for the loss of elastin in the aortic wall, and results in a reduced capability to endure wall stresses.

  4. 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.

  5. 3-D segmentation and quantitative analysis of inner and outer walls of thrombotic abdominal aortic aneurysms

    NASA Astrophysics Data System (ADS)

    Lee, Kyungmoo; Yin, Yin; Wahle, Andreas; Olszewski, Mark E.; Sonka, Milan

    2008-03-01

    An abdominal aortic aneurysm (AAA) is an area of a localized widening of the abdominal aorta, with a frequent presence of thrombus. A ruptured aneurysm can cause death due to severe internal bleeding. AAA thrombus segmentation and quantitative analysis are of paramount importance for diagnosis, risk assessment, and determination of treatment options. Until now, only a small number of methods for thrombus segmentation and analysis have been presented in the literature, either requiring substantial user interaction or exhibiting insufficient performance. We report a novel method offering minimal user interaction and high accuracy. Our thrombus segmentation method is composed of an initial automated luminal surface segmentation, followed by a cost function-based optimal segmentation of the inner and outer surfaces of the aortic wall. The approach utilizes the power and flexibility of the optimal triangle mesh-based 3-D graph search method, in which cost functions for thrombus inner and outer surfaces are based on gradient magnitudes. Sometimes local failures caused by image ambiguity occur, in which case several control points are used to guide the computer segmentation without the need to trace borders manually. Our method was tested in 9 MDCT image datasets (951 image slices). With the exception of a case in which the thrombus was highly eccentric, visually acceptable aortic lumen and thrombus segmentation results were achieved. No user interaction was used in 3 out of 8 datasets, and 7.80 +/- 2.71 mouse clicks per case / 0.083 +/- 0.035 mouse clicks per image slice were required in the remaining 5 datasets.

  6. Biomechanical and morphological study of a new elastic mesh (Ciberlastic) to repair abdominal wall defects.

    PubMed

    Calvo, B; Pascual, G; Peña, E; Pérez-Khöler, B; Rodríguez, M; Bellón, J M

    2016-06-01

    The aim of this study was to conduct a preclinical evaluation of the behaviour of a new type of abdominal LW prosthesis (Ciberlastic), which was designed with a non-absorbable elastic polyurethane monofilament (Assuplus, Assut Europe, Italy) to allow greater adaptability to mechanical area requirements and higher bio-mimicking with the newly formed surrounding tissues. Our hypothesis was that an increase in the elasticity of the mesh filament could improve the benefits of LW prostheses. To verify our hypothesis, we compared the short- and long-term behaviour of Ciberlastic and Optilene(®) elastic commercial meshes by repairing the partially herniated abdomen in New Zealand White rabbits. The implanted meshes were mechanically and histologically assessed at 14 and 180 days post-implant. We mechanically characterized the partially herniated repaired muscle tissue and also determined mesh shrinkage at different post-implant times. This was followed by a histological study in which the tissue incorporation process was analysed over time. The new prosthesis designed by our group achieved good behaviour that was similar to that of Optilene(®), one of the most popular LW prostheses on the market, with the added advantage of its elastic property. The mechanical properties are significantly lower than those of the polypropylene Optilene(®) mesh, and the new elastic mesh meets the basic mechanical requirements for positioning in the abdominal wall, which was also demonstrated by the absence of recurrences after implantation in the experimental model. We found that the growth of a connective tissue rich in collagen over the hernial defect and the proper deposit of the collagen fibres in the regenerated tissue substantially modified the original properties of the mesh, thereby increasing its biomechanical strength and making the whole tissue/mesh stiffer.

  7. Delay in diagnosis and lessons learnt from a case of abdominal wall abscess caused by fishbone perforation.

    PubMed

    Hakeem, A; Shanmugam, V; Badrinath, K; Dube, M; Panto, P

    2015-04-01

    Complications following foreign body (FB) ingestion are an uncommon clinical problem. A 59-year-old man presented with a 4-week history of left iliac fossa pain and 1 episode of dark red blood mixed with stools. Inflammatory markers were elevated, and computed tomography (CT) of the abdomen and pelvis showed an ill defined abdominal wall inflammatory collection in close contact with the small bowel loops. He was treated with antibiotics, and follow-up CT, colonoscopy and small bowel enema were mostly unremarkable. The patient presented again ten months later with left iliac fossa cellulitis and fever. Multiplanar CT (the patient's fourth scan) demonstrated a 10cm abdominal wall collection with a linear hyperdense structure in the collection. The radiologists suspected a FB and on close scrutiny of the previous scans, they noted it to have been present on all of them. A targeted incision led to the removal of a 3cm fishbone from the collection. This case highlights the need to consider the possibility of a FB being the underlying cause in any unexplained intra-abdominal or abdominal wall inflammatory process so that the diagnosis is made in a timely manner.

  8. Large antigenic skin load in total abdominal wall transplants permits chimerism induction.

    PubMed

    Nasir, Serdar; Bozkurt, Mehmet; Klimczak, Aleksandra; Siemionow, Maria

    2008-11-01

    The application of composite tissue allograft (CTA) transplants in clinical reconstruction is parallel with extended knowledge of anatomy, microsurgical skills and development of transplantation immunology. CTAs are composed of multiple tissues, some of which such as skin are highly immunogenic and cause strong immunologic responses. Strong antigenic nature of skin may be related to Langerhans cells, which are powerful antigen-presenting cells. They are leukocytes found in the epidermis as members of immunologic cascade. Large skin components of CTA transplant may cause higher antigenic load as a result of increased surface area of transplanted skin correlating with increased load of Langerhans cells. In clinical abdominal wall transplants, increased rejection episodes were reported compared with other CTA transplant. This complication may correlate to large skin component of these transplants. To evaluate correlation between large skin island flaps and immunologic responses, CTA models with large skin components should be tested in experimental studies. Here we propose a total abdominal wall (TAW) transplant model in rat to test the feasibility of TAW transplantation in 2 groups: the anatomic study and experimental transplantation group. In anatomic study, TAW flaps were elevated bilaterally on superficial epigastric vessels and replaced. The entire TAW skin islands of all flaps were viable at postoperative day 21. Dye study confirmed that TAW flap was supplied by 2 vascular pedicles. Data in this group demonstrated that this flap is composed of the largest skin island when compared with other CTA transplant models such as full face, hemiface, limb, and groin flap. In experimental group, isograft transplantations were performed between Lewis rats (RT1(1)) while allograft transplantations were performed Lewis (RT1(1)) donors and LBN (RT(1+n)) recipients. All TAW transplants showed viable islands at posttransplant day 200 under cyclosporine A monotherapy protocol

  9. [Influence of wall thickness on the stress distribution within transtibial monolimb].

    PubMed

    Liu, Zhan; Fan, Yubo; Zhang, Ming; Jiang, Wentao; Pu, Fang; Chen, Junkai

    2004-08-01

    Monolimb is a new type of lower-limb prostheses made of macromolecule polymer, in which the socket and prosthetic shank are integrative. Compared with traditional prosthesis, monolimb is more economical, good-looking and portable, so it indicates a possible direction in the future. Biomechanical research on trans-tibial monolimb is necessary and helpful just like traditional prosthesis. In this article, a 3D FE model based on real geometry shape of an endoskeletal trans-tibial monolimb is established. Keeping the same geometrical shape, three 3D FE models of transtibial monolimbs with different wall thickness are established. The influence of wall thickness on the stress distribution is analyzed under the load corresponding to the subphase of stance of Heel Off. The results indicate that stress within transtibial monolimb and pressure on the surface of soft tissue could be decreased with wall thickness of transtibial monolimb increased. This study will be helpful for the standard of wall thickness in designing transtibial monolimb.

  10. 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...

  11. Wall-Thickness Dependence of Cooling-Induced Deformation of Polystyrene Spherical Shells

    SciTech Connect

    Endo, T.; Kobayashi, N.; Goto, K.; Yasuda, M.; Fujima, Y.

    2003-05-15

    Experiments on the wall-thickness dependence of the cooling-induced deformation (CID) of polystyrene (PS) spherical shells were carried out. For the experiments, the PS shells were fabricated by the density-matched emulsion method using the hand-shaken microencapsulation technique. The number-averaged and weight-averaged molecular weights of the PS were M{sub n} 1.1 x 10{sup 5} and M{sub w} = 4.0 x 10{sup 5}, respectively. The diameter of the PS shells was {approx}400-550 {mu}m. To investigate the wall-thickness dependence of the CID, the wall thickness of the PS shells was varied between 5 and 60 {mu}m. In the experiments, the PS shells were cooled by using liquid nitrogen, and their images were captured at 0 and -190 deg. C. For the investigation of the CID, two shapes of each shell that were measured at 0 and -190 deg. C were compared. The thinner PS shells showed larger CID. The maximum deformation was almost 1% of the outer radius when the shell aspect ratio (outer radius)/(wall thickness) was higher than 20. The repeatability of the CID was studied, and the results implied that residual stress in the PS shells had an influence on the CID.

  12. Automatic Thickness and Volume Estimation of Sprayed Concrete on Anchored Retaining Walls from Terrestrial LIDAR Data

    NASA Astrophysics Data System (ADS)

    Martínez-Sánchez, J.; Puente, I.; GonzálezJorge, H.; Riveiro, B.; Arias, P.

    2016-06-01

    When ground conditions are weak, particularly in free formed tunnel linings or retaining walls, sprayed concrete can be applied on the exposed surfaces immediately after excavation for shotcreting rock outcrops. In these situations, shotcrete is normally applied conjointly with rock bolts and mesh, thereby supporting the loose material that causes many of the small ground falls. On the other hand, contractors want to determine the thickness and volume of sprayed concrete for both technical and economic reasons: to guarantee their structural strength but also, to not deliver excess material that they will not be paid for. In this paper, we first introduce a terrestrial LiDAR-based method for the automatic detection of rock bolts, as typically used in anchored retaining walls. These ground support elements are segmented based on their geometry and they will serve as control points for the co-registration of two successive scans, before and after shotcreting. Then we compare both point clouds to estimate the sprayed concrete thickness and the expending volume on the wall. This novel methodology is demonstrated on repeated scan data from a retaining wall in the city of Vigo (Spain), resulting in a rock bolts detection rate of 91%, that permits to obtain a detailed information of the thickness and calculate a total volume of 3597 litres of concrete. These results have verified the effectiveness of the developed approach by increasing productivity and improving previous empirical proposals for real time thickness estimation.

  13. 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…

  14. A new technique for minimally invasive abdominal wall reconstruction of complex incisional hernias: totally laparoscopic component separation and incisional hernia repair.

    PubMed

    Moazzez, Ashkan; Mason, Rodney J; Katkhouda, Namir

    2010-10-01

    Since Ramirez et al. presented the first case of component separation for abdominal wall hernias in 1990, it has undergone multiple modifications. This technique, which has been mainly used for large hernias where primary closure of the abdominal wall is not feasible, or for staged management of patients with open abdomens, results in multiple wound complications. In 2007, Rosen et al. reported on the laparoscopic approach to component separation that is associated with less subcutaneous dissection and the consequent advantage of a decreased risk of flap necrosis and wound infection. Here we discuss our totally laparoscopic approach to abdominal wall reconstruction. A minimally invasive abdominal wall reconstruction consists of a bilateral component separation, an intra-abdominal adhesiolysis, primary approximation of rectus muscles, and placement of an intraperitoneal mesh for reinforcing the repair, all performed laparoscopically. Patient-selection criteria, detailed operative technique, tips in preventing and managing the potential pitfalls, and postoperative care are discussed.

  15. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition.

    PubMed

    Boehme, Mario; Ionescu, Emanuel; Fu, Ganhua; Ensinger, Wolfgang

    2011-01-01

    Conductive nanotubes consisting of indium tin oxide (ITO) were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs) with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed.

  16. Comparison of the thicknesses of the transversus abdominis and internal abdominal obliques during plank exercises on different support surfaces.

    PubMed

    Do, Yong-Chan; Yoo, Won-Gyu

    2015-01-01

    [Purpose] This study applied variable plank exercises on a stable surface consisting of a mat, on an unstable surface consisting of a dynamic cushion placed under the upper extremities and lower extremities. [Subjects] Forty-three healthy male and female subjects in their 20s voluntarily consented to participate in this study. [Methods] The subjects performed the plank exercises on the three support surfaces. Ultrasound imaging was conducted while they carried out plank exercises. [Results] The changes in the thicknesses of both the transversus abdominis and internal abdominal obliques were statistically more significant for LEDCP than for MatP. In addition, the changes in the thickness of the transversus abdominis were statistically more significant for LEDCP than for UEDCP. [Conclusion] Therefore, applying an unstable condition to the lower limbs using a dynamic cushion is considered more effective during plank exercises.

  17. Effect of wall thickness on measurement of dose for high energy neutrons.

    PubMed

    Perez-Nunez, Delia; Braby, Leslie A

    2010-01-01

    Neutrons produced from the interaction between galactic cosmic rays and spacecraft materials are responsible for a very important portion of the dose received by astronauts. The neutron energy spectrum depends on the incident charged particle spectrum and the scattering environment but generally extends to beyond 100 MeV. Tissue-equivalent proportional counters (TEPC) are used to measure the dose during the space mission, but their weight and size are very important factors for their design and construction. To achieve ideal neutron dosimetry, the wall thickness should be at least the range of a proton having the maximum energy of the neutrons to be monitored. This proton range is 0.1 cm for 10 MeV neutrons and 7.6 cm for 100 MeV neutrons. A 7.6 cm wall thickness TEPC would provide charged particle equilibrium (CPE) for neutrons up to 100 MeV, but for space applications it would not be reasonable in terms of weight and size. In order to estimate the errors in measured dose due to absence of CPE, MCNPX simulations of energy deposited by 10 MeV and 100 MeV neutrons in sites with wall thickness between 0.1 cm and 8.5 cm were performed. The results for 100 MeV neutrons show that energy deposition per incident neutron approaches a plateau as the wall thickness approaches 7.6 cm. For the 10 MeV neutrons, energy deposition per incident neutron decreases as the wall thickness increases above 0.1 cm due to attenuation.

  18. Detection of Cardiac Function Abnormality from MRI Images Using Normalized Wall Thickness Temporal Patterns.

    PubMed

    Wael, Mai; Ibrahim, El-Sayed H; Fahmy, Ahmed S

    2016-01-01

    Purpose. To develop a method for identifying abnormal myocardial function based on studying the normalized wall motion pattern during the cardiac cycle. Methods. The temporal pattern of the normalized myocardial wall thickness is used as a feature vector to assess the cardiac wall motion abnormality. Principal component analysis is used to reduce the feature dimensionality and the maximum likelihood method is used to differentiate between normal and abnormal features. The proposed method was applied on a dataset of 27 cases from normal subjects and patients. Results. The developed method achieved 81.5%, 85%, and 88.5% accuracy for identifying abnormal contractility in the basal, midventricular, and apical slices, respectively. Conclusions. A novel feature vector, namely, the normalized wall thickness, has been introduced for detecting myocardial regional wall motion abnormality. The proposed method provides assessment of the regional myocardial contractility for each cardiac segment and slice; therefore, it could be a valuable tool for automatic and fast determination of regional wall motion abnormality from conventional cine MRI images.

  19. 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.

  20. Urinary Bladder Adenocarcinoma Metastatic to the Abdominal Wall: Report of a Case with Cytohistologic Correlation

    PubMed Central

    Baliga, Mithra

    2016-01-01

    We report a case of adenocarcinoma metastatic to the abdominal wall in a 71-year-old man with a history of primary bladder adenocarcinoma. CT-guided core biopsy was performed; imprints and histologic sections showed malignant glands lined by tumor cells with hyperchromatic nuclei and prominent nucleoli, infiltrating through skeletal muscle. Immunohistochemistry revealed positivity for CK7, membranous/cytoplasmic β-catenin, caudal-type homeobox transcription factor 2 (CDX2), and α-methylacyl coenzyme A racemase and negativity for CK20, p63, prostate-specific antigen (PSA), and prostate-specific acid phosphatase (PSAP). These findings were interpreted as metastatic adenocarcinoma, consistent with bladder primary. Primary bladder adenocarcinoma is a rare malignancy arising within glandular metaplasia and is associated with cystitis cystica and cystitis glandularis. Predisposing factors include bladder exstrophy, schistosomiasis, and other causes of chronic bladder irritation. This tumor is divided into intestinal, clear cell, and signet ring cell subtypes. Treatment involves radical cystectomy with pelvic lymph node dissection, and prognosis is unfavorable. Primary bladder adenocarcinoma should be differentiated from urachal adenocarcinoma, which arises from urachal remnants near the bladder dome, and secondary adenocarcinoma, or vesical involvement by adenocarcinoma from a different primary. CK7, CK20, CDX2, thrombomodulin, and β-catenin can help distinguish primary bladder adenocarcinoma from colonic adenocarcinoma; PSA and PSAP can help distinguish primary bladder adenocarcinoma from prostate adenocarcinoma. PMID:27006847

  1. Case report of traumatic abdominal wall hernia following blunt motorcycle handlebar injury and review of the literature.

    PubMed

    Ogundiran, T O; Obamuyide, H A; Adesina, M A; Ademola, A F

    2012-01-01

    A 25-year-old man, riding a motorcycle, rammed into a moving car at a T junction and sustained a blunt lower-right abdominal injury with the handlebar of his motorbike. He developed a swelling at the point of impact for which he presented in hospital 10 days later. Clinical assessment revealed a healthy young man with a soft, nontender reducible swelling over the lateral half of the right inguinal area. A diagnosis of acute traumatic hernia was made. Abdominal ultrasonography revealed a wide-necked defect in the anterior abdominal wall over the right inguinal area with protruding bowel loops beneath an intact skin. He was planned for herniorrhaphy but has defaulted since then.

  2. Wall energy and wall thickness of exchange-coupled rare-earth transition-metal triple layer stacks

    SciTech Connect

    Raasch, D.; Mathieu, C.

    1997-08-01

    The room-temperature wall energy {sigma}{sub w}=4.0{times}10{sup {minus}3}J/m{sup 2} of an exchange-coupled Tb{sub 19.6}Fe{sub 74.7}Co{sub 5.7}/Dy{sub 28.5}Fe{sub 43.2}Co{sub 28.3} double layer stack can be reduced by introducing a soft magnetic intermediate layer in between both layers exhibiting a significantly smaller anisotropy compared to Tb{endash}FeCo and Dy{endash}FeCo. {sigma}{sub w} will decrease linearly with increasing intermediate layer thickness, d{sub IL}, until the wall is completely located within the intermediate layer for d{sub IL}{ge}d{sub w}, where d{sub w} denotes the wall thickness. Thus, d{sub w} can be obtained from the plot {sigma}{sub w} versus d{sub IL}. We determined {sigma}{sub w} and d{sub w} on Gd{endash}FeCo intermediate layers with different anisotropy behavior (perpendicular and in-plane easy axis) and compared the results with data obtained from Brillouin light-scattering measurements, where exchange stiffness, A, and uniaxial anisotropy, K{sub u}, could be determined. With the knowledge of A and K{sub u}, wall energy and thickness were calculated and showed an excellent agreement with the magnetic measurements. A ten times smaller perpendicular anisotropy of Gd{sub 28.1}Fe{sub 71.9} in comparison to Tb{endash}FeCo and Dy{endash}FeCo resulted in a much smaller {sigma}{sub w}=1.1{times}10{sup {minus}3}J/m{sup 2} and d{sub w}=24nm at 300 K. A Gd{sub 34.1}Fe{sub 61.4}Co{sub 4.5} with in-plane anisotropy at room temperature showed a further reduced {sigma}{sub w}=0.3{times}10{sup {minus}3}J/m{sup 2} and d{sub w}=17nm. The smaller wall energy was a result of a different wall structure compared to perpendicular layers. {copyright} {ital 1997 American Institute of Physics.}

  3. Patient-specific models of wall stress in abdominal aortic aneurysm: a comparison between MR and CT

    NASA Astrophysics Data System (ADS)

    de Putter, Sander; Breeuwer, Marcel; van de Vosse, Frans N.; Kose, Ursula; Gerritsen, Frans A.

    2006-03-01

    Finite element method based patient-specific wall stress in abdominal aortic aneurysm (AAA) may provide a more accurate rupture risk predictor than the currently used maximum transverse diameter. In this study, we have investigated the sensitivity of the wall stress in AAA with respect to geometrical variations. We have acquired MR and CT images for four patients with AAA. Three individual users have delineated the AAA vessel wall contours on the image slices. These contours were used to generate synthetic feature images for a deformable model based segmentation method. We investigated the reproducibility and the influence of the user variability on the wall stress. For sufficiently smooth models of the AAA wall, the peak wall stress is reproducible for three out of the four AAA geometries. The 0.99 percentiles of the wall stress show excellent reproducibility for all four AAAs. The variations induced by user variability are larger than the errors caused by the segmentation variability. The influence of the user variability appears to be similar for MR and CT. We conclude that the peak wall stress in AAA is sensitive to small geometrical variations. To increase reproducibility it appears to be best not to allow too much geometrical detail in the simulations. This could be achieved either by using a sufficiently smooth geometry representation or by using a more robust statistical parameter derived from the wall stress distribution.

  4. 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.

  5. 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.

  6. Gasless laparoscopic surgery plus abdominal wall lifting for giant hiatal hernia-our single-center experience.

    PubMed

    Yu, Jiang-Hong; Wu, Ji-Xiang; Yu, Lei; Li, Jian-Ye

    2016-12-01

    Giant hiatal hernia (GHH) comprises 5% of hiatal hernia and is associated with significant complications. The traditional operative procedure, no matter transthoracic or transabdomen repair of giant hiatal hernia, is characteristic of more invasion and more complications. Although laparoscopic repair as a minimally invasive surgery is accepted, a part of patients can not tolerate pneumoperitoneum because of combination with cardiopulmonary diseases or severe posterior mediastinal and neck emphesema during operation. The aim of this article was to analyze our experience in gasless laparoscopic repair with abdominal wall lifting to treat the giant hiatal hernia. We performed a retrospective review of patients undergoing gasless laparoscopic repair of GHH with abdominal wall lifting from 2012 to 2015 at our institution. The GHH was defined as greater than one-third of the stomach in the chest. Gasless laparoscopic repair of GHH with abdominal wall lifting was attempted in 27 patients. Mean age was 67 years. The results showed that there were no conversions to open surgery and no intraoperative deaths. The mean duration of operation was 100 min (range: 90-130 min). One-side pleura was injured in 4 cases (14.8%). The mean postoperative length of stay was 4 days (range: 3-7 days). Median follow- up was 26 months (range: 6-38 months). Transient dysphagia for solid food occurred in three patients (11.1%), and this symptom disappeared within three months. There was one patient with recurrent hiatal hernia who was reoperated on. Two patients still complained of heartburn three months after surgery. Neither reoperation nor endoscopic treatment due to signs of postoperative esophageal stenosis was required in any patient. Totally, satisfactory outcome was reported in 88.9% patients. It was concluded that the gasless laparoscopic approach with abdominal wall lifting to the repair of GHH is feasible, safe, and effective for the patients who cannot tolerate the pneumoperitoneum.

  7. High Power Laser Beam Welding of Thick-walled Ferromagnetic Steels with Electromagnetic Weld Pool Support

    NASA Astrophysics Data System (ADS)

    Fritzsche, André; Avilov, Vjaceslav; Gumenyuk, Andrey; Hilgenberg, Kai; Rethmeier, Michael

    The development of modern high power laser systems allows single pass welding of thick-walled components with minimal distortion. Besides the high demands on the joint preparation, the hydrostatic pressure in the melt pool increases with higher plate thicknesses. Reaching or exceeding the Laplace pressure, drop-out or melt sagging are caused. A contactless electromagnetic weld support system was used for laser beam welding of thick ferromagnetic steel plates compensating these effects. An oscillating magnetic field induces eddy currents in the weld pool which generate Lorentz forces counteracting the gravity forces. Hysteresis effects of ferromagnetic steels are considered as well as the loss of magnetization in zones exceeding the Curie temperature. These phenomena reduce the effective Lorentz forces within the weld pool. The successful compensation of the hydrostatic pressure was demonstrated on up to 20 mm thick plates of duplex and mild steel by a variation of the electromagnetic power level and the oscillation frequency.

  8. Comparative physical and chemical analyses of cotton fibers from two near isogenic upland lines differing in fiber wall thickness.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The thickness of cotton fiber cell walls is an important property that partially determines the economic value of cotton. To better understand the physical and chemical manifestations of the genetic variations that regulate the degree of fiber wall thickness, we used a comprehensive set of methods t...

  9. Surgically placed abdominal wall catheters on postoperative analgesia and outcomes after living liver donation.

    PubMed

    Khan, James; Katz, Joel; Montbriand, Janice; Ladak, Salima; McCluskey, Stuart; Srinivas, Coimbatore; Ko, Raynauld; Grant, David; Bradbury, Ashleene; LeManach, Yannick; Clarke, Hance

    2015-04-01

    Living donor liver resections are associated with significant postoperative pain. Epidural analgesia is the gold standard for postoperative pain management, although it is often refused or contraindicated. Surgically placed abdominal wall catheters (AWCs) are a novel pain modality that can potentially provide pain relief for those patients who are unable to receive an epidural. A retrospective review was performed at a single center. Patients were categorized according to their postoperative pain modality: intravenous (IV) patient-controlled analgesia (PCA), AWCs with IV PCA, or patient-controlled epidural analgesia (PCEA). Pain scores, opioid consumption, and outcomes were compared for the first 3 postoperative days. Propensity score matches (PSMs) were performed to adjust for covariates and to confirm the primary analysis. The AWC group had significantly lower mean morphine-equivalent consumption on postoperative day 3 [18.1 mg, standard error (SE)=3.1 versus 28.2 mg, SE=3.0; P=0.02] and mean cumulative morphine-equivalent consumption (97.2 mg, SE=7.2 versus 121.0 mg, SE=9.1; P=0.04) in comparison with the IV PCA group; the difference in cumulative-morphine equivalent remained significant in the PSMs. AWC pain scores were higher than those in the PCEA group and were similar to the those in the IV PCA group. The AWC group had a lower incidence of pruritus and a shorter hospital stay in comparison with the PCEA group and had a lower incidence of sedation in comparison with both groups. Time to ambulation, nausea, and vomiting were comparable among all 3 groups. The PSMs confirmed all results except for a decrease in the length of stay in comparison with PCEA. AWCs may be an alternative to epidural analgesia after living donor liver resections. Randomized trials are needed to verify the benefits of AWCs, including the safety and adverse effects.

  10. Sir Ganga Ram Hospital classification of groin and ventral abdominal wall hernias

    PubMed Central

    Chowbey, Pradeep K; Khullar, Rajesh; Mehrotra, Magan; Sharma, Anil; Soni, Vandana; Baijal, Manish

    2006-01-01

    Background: Numerous classifications for groin and ventral hernias have been proposed over the past five to six decades. The old, simple classification of groin hernia in to direct, inguinal and femoral components is no longer adequate to understand the complex pathophysiology and management of these hernias. The most commonly followed classification for ventral hernias divide them into congenital, acquired, incisional and traumatic, which also does not convey any information regarding the predicted level of difficulty. Aim: All the previous classification systems were based on open hernia repairs and have their own fallacies particularly for uncommon hernias that cannot be classified in these systems. With the advent of laparoscopic/ endoscopic approach, surgical access to the hernia as well as the functional anatomy viewed by the surgeon changed. This change in the surgical approach and functional anatomy opened the doors for newer classifications. The authors have thus proposed a classification system based on the expected level of intraoperative difficulty for endoscopic hernia repair. Classification: In the proposed classification higher grades signify increasing levels of expected intraoperative difficulty. This functional classification grades groin hernias according to the: a) Pre -operative predictive level of difficulty of endoscopic surgery, and b) Intraoperative factors that lead to a difficult repair. Pre operative factors include multiple or pantaloon hernias, recurrent hernias, irreducible and incarcerated hernias. Intraoperative factors include reducibility at operation, degree of descent of the hernial sac and previous hernia repairs. Hernial defects greater than 7 cm in diameter are categorized one grade higher. Conclusion: Though there have been several classification systems for groin or inguinal hernias, none have been described for total classification of all ventral hernias of the abdomen. The system proposed by us includes all abdominal wall

  11. The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

    PubMed

    Smerup, Morten; Damkjær, Mads; Brøndum, Emil; Baandrup, Ulrik T; Kristiansen, Steen Buus; Nygaard, Hans; Funder, Jonas; Aalkjær, Christian; Sauer, Cathrine; Buchanan, Rasmus; Bertelsen, Mads Frost; Østergaard, Kristine; Grøndahl, Carsten; Candy, Geoffrey; Hasenkam, J Michael; Secher, Niels H; Bie, Peter; Wang, Tobias

    2016-02-01

    Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

  12. Separation occurring during the drop weight tear test of thick-walled X80 pipeline steels

    NASA Astrophysics Data System (ADS)

    Sha, Qing-yun; Li, Da-hang; Huang, Guo-jian; Guan, Ju

    2013-08-01

    A separation phenomenon occurring during the drop weight tear test of commercial thick-walled API (American Petroleum Institute) X80 strip steel was investigated in this work. Microstructural analysis showed that the band structure of bainite elongated along the rolling direction works as the initiation sites of separation. The propagation of separation can be promoted not only by the occurrence of the band structure of martensite/austenite constituent, prior austenite grain boundaries, and elongated bainite, but also by fine acicular ferrite and bainite. Wide separation formed in the former case, while the narrow one appeared in the latter case. Some methods were proposed to obtain fine and homogeneous acicular ferrite in thick-walled X80 pipeline steel in order to minimize the occurrence of separation.

  13. Simulation on the Effect of Bottle Wall Thickness Distribution using Blow Moulding Technique

    NASA Astrophysics Data System (ADS)

    Suraya, S.; Azman, M. D.; Fatchurrohman, N.; Jaafar, A. A.; Yusoff, A. R.

    2016-02-01

    The aims of this study are to assess the deformation behavior of a polymeric material during a blow moulding process. Transient computations of two dimensional model of a PP bottle were performed using ANSYS Polyflow computer code to predict the wall thickness distribution at four different parison's diameter; 8mm, 10mm, 18mm, and 20mm. Effects on the final wall thickness diameter and time step are studied. The simulated data shows that the inflation performance degrades with increasing parison diameter. It is concluded that the blow moulding process using 10mm parison successfully meet the product processing requirements. Factors that contribute to the variation in deformation behaviour of the plastic during the manufacturing process are discussed.

  14. A thermoelastic transversely isotropic thick walled cylinder/disk application: An analytical solution and study

    NASA Technical Reports Server (NTRS)

    Arnold, S. M.

    1989-01-01

    A continuum theory is utilized to represent the thermoelastic behavior of a thick walled composite cylinder that can be idealized as transversely isotropic. A multiaxial statement of the constitutive theory employed is presented, as well as the out of the plane of isotropy, plane stress, and plane strain reductions. The derived analytical solution presented is valid for a cylindrical tube or thin disk with a concentric hole, subjected to internal and/or external pressure and a general radial temperature distribution. A specific problem examined is that of a thick walled cylinder subjected to an internal and external pressure loading and a linear radial temperature distribution. The results are expressed in nondimensional form and the effects on the response behavior are examined for various material properties, fiber orientation and types of loadings.

  15. A successful early gore-tex reconstruction of an abdominal wall defect in a neonate with Cantrell pentalogy: a case report and literature review

    PubMed Central

    Divkovic, Dalibor; Kvolik, Slavica; Sipl, Mirna; Sego, Krunoslav; Puseljic, Silvija; Rakipovic-Stojanovic, Andreja; Kovacic, Borna

    2015-01-01

    Key Clinical Message A surgical technique, materials used for abdominal wall reconstruction, and postoperative care are important for patient outcomes. We report the first case of neonate with Cantrell's pentalogy surviving early reconstruction of abdominal, diaphragmal and pericardial defects. Several recent investigations suggest that intraabdominal pressure monitoring may improve outcomes in this patient category. PMID:25678967

  16. Experimental evaluation of a new composite mesh with the selective property of incorporation to the abdominal wall without adhering to the intestines.

    PubMed

    Amid, P K; Shulman, A G; Lichtenstein, I L; Sostrin, S; Young, J; Hakakha, M

    1994-03-01

    This preliminary study examined the possibility of preventing intestinal adhesions to biomaterials while preserving their incorporation with the abdominal wall. White New Zealand rabbits received intraperitoneal implants of different biomaterials for repair of defects created on the abdominal wall. The following biomaterials were used: polypropylene, polyester, expanded polytetraflueroethylene, polypropylene mesh/polypropylene sheeting (polypropylene mesh covered with polypropylene sheeting on the peritoneal side), polypropylene/silastic, polypropylene/polyglactin, polypropylene/polyglycolic acid, and polypropylene/fibrin. All biomaterials evaluated caused adhesions to the intestines except for polypropylene mesh/polypropylene sheeting and polypropylene mesh/silastic composites. Because adhesion of the intestine to the biomaterial is the first stage of biomaterial-related intestinal fistula, its prevention is logical for the elimination of this complication. Composites with the selective property of adhering to the abdominal wall, yet sparing the viscera, would facilitate thoracic and abdominal wall surgeries, as well as intraperitoneal laparoscopic hernioplasties.

  17. Remodeling of blood vessels: responses of diameter and wall thickness to hemodynamic and metabolic stimuli.

    PubMed

    Pries, Axel R; Reglin, Bettina; Secomb, Timothy W

    2005-10-01

    Vascular functions, including tissue perfusion and peripheral resistance, reflect continuous structural adaptation (remodeling) of blood vessels in response to several stimuli. Here, a theoretical model is presented that relates the structural and functional properties of microvascular networks to the adaptive responses of individual segments to hemodynamic and metabolic stimuli. All vessels are assumed to respond, according to a common set of adaptation rules, to changes in wall shear stress, circumferential wall stress, and tissue metabolic status (indicated by partial pressure of oxygen). An increase in vessel diameter with increasing wall shear stress and an increase in wall mass with increased circumferential stress are needed to ensure stable vascular adaptation. The model allows quantitative predictions of the effects of changes in systemic hemodynamic conditions or local adaptation characteristics on vessel structure and on peripheral resistance. Predicted effects of driving pressure on the ratio of wall thickness to vessel diameter are consistent with experimental observations. In addition, peripheral resistance increases by approximately 65% for an increase in driving pressure from 50 to 150 mm Hg. Peripheral resistance is predicted to be markedly increased in response to a decrease in vascular sensitivity to wall shear stress, and to be decreased in response to increased tissue metabolic demand. This theoretical approach provides a framework for integrating available information on structural remodeling in the vascular system and predicting responses to changing conditions or altered vascular reactivity, as may occur in hypertension.

  18. COANDA Control of a Thick Wall-Jet in the Static Case

    DTIC Science & Technology

    1982-11-01

    conforming to its shape ( Coanda effect ) and induces upstream air on the upper c surface to follow the jet flow. This phenomenon effectively increases the...downward (and in some cases more than 90 degrees downward, producing thrust reversal) when the CC Coanda jet is activated. Experimental research was...ro.r.d~d trailing edge. r Thikcxtes5 of the Coanda jet, It Entrainnment length--the distance between the exit plane of the thick " wall-jet nozzle and

  19. Stress Intensity Factors for Radial Cracks in a Partially Autofrettaged Thick-Wall Cylinder

    DTIC Science & Technology

    1981-07-01

    P., "Simulation of Partial Autofrettage by Thermal Loads," Journal of Pressure Vessel Technology, Vol. 102, No. 3, 1980, pp. 314-318. ^ Baratta , F...OF LOAD RELIEF FACTOR Baratta ^ extended the coefficient of load relief of Neuber^^ to estimate SIF arising from multiple cracking in a thick-wall...Array Radial Cracks Using Isoparametric Singular Elements," ASTM STP-677, 1979, pp. 685-699. ■^ Baratta , F. I., "Stress Intensity Factors For

  20. The Measurement and Analysis of Fatigue Crack Growth in Thick-Walled Cylinders

    DTIC Science & Technology

    1974-09-01

    NAME AND ADDRESS Benet Weapons laboratory Watervliet Arsenal, Watervliet, N.Y . 12189 SARWV-RDT 11 CONTF>OLLING O FFI CE NA~E AND ADDRESS 5. TYPE...depth in thick-walled cylinders using a straight-beam ultrasonic probe. This technique has proved useful not only under laboratory conditions, but...R. R. FUJCZAK BENET WEAPONS LABORATORY WATERVLIET ARSENAL WATERVLIET. N.Y. 12189 SEPTEMBER 1974 TECHNICAL REPORT AMCMS No. 5596.OM.6350

  1. Clinical anatomy of the inferior epigastric artery with special relevance to invasive procedures of the anterior abdominal wall

    PubMed Central

    Joy, Praisy; Prithishkumar, Ivan James; Isaac, Bina

    2017-01-01

    INTRODUCTION: Injury to the inferior epigastric artery (IEA) has been reported following lower abdominal wall surgical incisions, abdominal peritoneocentesis and trocar placements at laparoscopic port sites, resulting in the formation of abdominal wall haematomas that may expand considerably due to lack of tissue resistance. The aim of this study was to localise its course in relation to standard anatomic landmarks and suggest safe areas for performance of invasive procedures. MATERIALS AND METHODS: Sixty IEAs of 30 adult cadavers (male = 19; female = 11) were dissected and the course of the IEA noted in relation to the mid-inguinal point, anterior superior iliac spine (ASIS) and umbilicus. RESULTS: The mean distance of the IEA from the midline was 4.45 ± 1.42 cm at the level of the mid-inguinal point, 4.10 ± 1.15 cm at the level of ASIS and 4.49 ± 1.15 cm at the level of umbilicus. There was an average of 3.3 branches per IEA with more branches arising from its lateral aspect. The IEA was situated within one-third (32%) of the distance between the midline and the sagittal plane through ASIS at all levels. CONCLUSION: To avoid injury to IEA, trocars can be safely inserted 5.5 cm [mean + 1 standard deviation (SD)] away from the midline (or) slightly more than one-third of the distance between the midline and a sagittal plane running through ASIS. These findings may be useful not only for laparoscopic procedures but also for image-guided biopsy, abdominal paracentesis, and placement of abdominal drains. PMID:27251822

  2. Effects of the Transient Blood Flow-Wall Interaction on the Wall Stress Distribution in Abdominal Aortic Aneurysm (AAA)

    NASA Astrophysics Data System (ADS)

    Tang, Rubing; Geindreau, Christian; Lasheras, Juan

    2006-11-01

    Our static finite element analysis (FEA) of both idealized and real clinical models has shown that the maximum diameter and asymmetry have substantial influence on the AAA wall stress distribution. The thrombus inside the AAA was also found to reduce the magnitude of the wall stresses. To achieve a better understanding of the wall stress distribution in real AAAs, a dynamic FEA was also performed. We considered models, both symmetric and non-symmetric, in which the aorta is assumed isotropic with nonlinear material properties. For the limiting case of rigid walls, the evolution of the flow pattern and the wall shear stresses due to fluid flow at different stages of cardiac cycle predicted by our simulations are compared with experimental results obtained in in-vitro models. A good agreement is found between both results. Finally, we have extended the analysis to the physiologically correct case of deformable walls and characterized the transient effects on the wall stresses.

  3. Gas gangrene of the abdominal wall due to late-onset enteric fistula after polyester mesh repair of an incisional hernia.

    PubMed

    Moussi, A; Daldoul, S; Bourguiba, B; Othmani, D; Zaouche, A

    2012-04-01

    The occurrence of enteric fistulae after wall repair using a prosthetic mesh is a serious but, fortunately, rare complication. We report the case of a 66-year-old diabetic man who presented with gas gangrene of the abdominal wall due to an intra-abdominal abscess caused by intestinal erosion six years after an incisional hernia repair using a polyester mesh. The aim of this case report is to illustrate the seriousness of enteric fistula after parietal repair using a synthetic material.

  4. 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

  5. Carotid wall stress calculated with continuous intima-media thickness assessment using B-mode ultrasound

    NASA Astrophysics Data System (ADS)

    Pascaner, A. F.; Craiem, D.; Casciaro, M. E.; Danielo, R.; Graf, S.; Guevara, E.

    2016-04-01

    Cardiovascular risk is normally assessed using clinical risk factors but it can be refined using non-invasive infra-clinical markers. Intima-Media Thickness (IMT) is recognized as an early indicator of cardiovascular disease. Carotid Wall Stress (CWS) can be calculated using arterial pressure and carotid size (diameter and IMT). Generally, IMT is measured during diastole when it reaches its maximum value. However, it changes during the cardiac cycle and a time-dependant waveform can be obtained using B-mode ultrasound images. In this work we calculated CWS considering three different approaches for IMT assessment: (i) constant IMT (standard diastolic value), (ii) estimated IMT from diameter waveform (assuming a constant cross-sectional wall area) and (iii) continuously measured IMT. Our results showed that maximum wall stress depends on the IMT estimation method. Systolic CWS progressively increased using the three approaches (p<0.024). We conclude that maximum CWS is highly dependent on wall thickness and accurate IMT measures during systole should be encouraged.

  6. Detection of colonic polyp candidates with level set-based thickness mapping over the colon wall

    NASA Astrophysics Data System (ADS)

    Han, Hao; Li, Lihong; Duan, Chaijie; Zhao, Yang; Wang, Huafeng; Liang, Zhengrong

    2015-03-01

    Further improvement of computer-aided detection (CADe) of colonic polyps is vital to advance computed tomographic colonography (CTC) toward a screening modality, where the detection of flat polyps is especially challenging because limited image features can be extracted from flat polyps, and the traditional geometric features-based CADe methods usually fail to detect such polyps. In this paper, we present a novel pipeline to automatically detect initial polyp candidates (IPCs), especially flat polyps, from CTC images. First, the colon wall mucosa was extracted via a partial volume segmentation approach as a volumetric layer, where the inner border of colon wall can be obtained by shrinking the volumetric layer using level set based adaptive convolution. Then the outer border of colon wall (or the colon wall serosa) was segmented via a combined implementation of geodesic active contour and Mumford-Shah functional in a coarse-to-fine manner. Finally, the wall thickness was estimated along a unique path between the segmented inner and outer borders with consideration of the volumetric layers and was mapped onto a patient-specific three-dimensional (3D) colon wall model. The IPC detection results can usually be better visualized in a 2D image flattened from the 3D model, where abnormalities were detected by Z-score transformation of the thickness values. The proposed IPC detection approach was validated on 11 patients with 22 CTC scans, and each scan has at least one flat poly annotation. The above presented novel pipeline was effective to detect some flat polyps that were missed by our CADe system while keeping false detections in a relative low level. This preliminary study indicates that the presented pipeline can be incorporated into an existing CADe system to enhance the polyp detection power, especially for flat polyps.

  7. Expression of matrix metalloproteinases, their tissue inhibitors, and osteopontin in the wall of thoracic and abdominal aortas with dilatative pathology.

    PubMed

    Lesauskaite, Vaiva; Epistolato, Maria Carmela; Castagnini, Marta; Urbonavicius, Sigitas; Tanganelli, Piero

    2006-08-01

    Matrix metalloproteinases (MMPs) degrade extracellular matrix and may play a central role in the pathogenesis of aortic aneurysms. We studied 2 groups of patients: 15 with dilatative pathology of the ascending thoracic aorta and 17 with aneurysm of the abdominal aortic wall (AAA). We compared the expression of MMPs, tissue inhibitors of matrix metalloproteinases (TIMPs), and osteopontin in the wall of thoracic and abdominal aneurysms. In AAA, MMP-9 and TIMP-1 expression in inflammatory cells was higher than in smooth muscle cells (SMCs) (median score: 3.5 versus 1, P < .0001; 2 versus 1, P < .04, respectively), whereas MMP-2 demonstrated higher expression in SMCs than in inflammatory cells (median score: 0 versus 4, P < .0001). In ATA, MMP-2, MMP-9, TIMP-1, TIMP-2, TIMP-3, and osteopontin expression in SMCs was higher than in inflammatory cells (median score: 3 versus 0, P < .0001; 4 versus 1, P < .0005; 2 versus 0, P < .001; 5 versus 2, P < .0001; 2 versus 0, P < .005; and 5 versus 1.5, P < .0001, respectively), when both inflammatory cells of the media and the adventitia were considered together. The cellular expression of MMP-9 and their tissue inhibitors TIMP-1, TIMP-2, and TIMP-3 differs in the dilatative pathology of abdominal and thoracic aortas, so the hypothetical model of morphogenesis of AAA cannot completely explain the formation of dilatative pathology of the ascending thoracic aorta.

  8. Critical analysis of Strattice performance in complex abdominal wall reconstruction: intermediate-risk patients and early complications.

    PubMed

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

    2013-01-01

    The purpose of this study was to analyze the performance of a porcine-derived acellular dermal matrix (Strattice Reconstructive Tissue Matrix) in patients at increased risk for perioperative complications. We reviewed medical records for patients with complex abdominal wall reconstruction (AWR) and Strattice underlay from 2007 to 2010. Intermediate-risk patients were defined as having multiple comorbidities without abdominal infection. Forty-one patients met the inclusion criteria (mean age, 60 years; mean body mass index, 35.5 kg/m(2)). Comorbidities included coronary artery disease (63.4%), diabetes mellitus (36.6%), and chronic obstructive pulmonary disease (17.1%). Fascial closure was achieved in 40 patients (97.6%). Average hospitalization was 6.4 days (range, 1-24 days). Complications included seroma (7.3%), wound dehiscence with Strattice exposure (4.9%), cellulitis (2.4%), and hematoma (2.4%). All patients achieved abdominal wall closure with no recurrent hernias or need for Strattice removal. Patients with multiple comorbidities at intermediate risk of postoperative complications can achieve successful, safe AWR with Strattice.

  9. Increased Expression of Lamin A/C Correlate with Regions of High Wall Stress in Abdominal Aortic Aneurysms

    PubMed Central

    Malkawi, Amir; Pirianov, Grisha; Torsney, Evelyn; Chetter, Ian; Sakalihasan, Natzi; Loftus, Ian M.; Nordon, Ian; Huggins, Christopher; Charolidi, Nicoletta; Thompson, Matt; Xu, Xie Yun; Cockerill, Gillian W.

    2015-01-01

    Background Since aortic diameter is the most ­significant risk factor for rupture, we sought to identify stress-dependent changes in gene expression to illuminate novel molecular processes in aneurysm rupture. Materials and Methods We constructed finite element maps of abdominal computerized tomography scans (CTs) of seven abdominal aortic aneurysm (AAA) patients to map wall stress. Paired biopsies from high- and low-stress areas were collected at surgery using vascular landmarks as coordinates. Differential gene expression was evaluated by Illumina Array analysis, using the whole genome DNA-mediated, annealing, selection, extension, and ligation (DASL) gene chip (n = 3 paired samples). Results The sole significant candidate from this analysis, Lamin A/C, was validated at the protein level, using western blotting. Lamin A/C expression in the inferior mesenteric vein (IMV) of AAA patients was compared to a control group and in aortic smooth muscle cells in culture in response to physiological pulsatile stretch. ­Areas of high wall stress (n = 7) correlate to those ­regions which have the thinnest walls [778 µm (585–1120 µm)] in comparison to areas of lowest wall stress [1620 µm (962–2919 µm)]. Induced expression of Lamin A/C ­correlated with areas of high wall stress from AAAs but was not significantly induced in the IMV from AAA patients compared to controls (n = 16). Stress-induced expression of Lamin A/C was mimicked by exposing aortic smooth muscle cells to prolonged pulsatile stretch. Conclusion Lamin A/C protein is specifically increased in areas of high wall stress in AAA from patients, but is not increased on other vascular beds of aneurysm patients, suggesting that its elevation may be a compensatory response to the pathobiology leading to aneurysms. PMID:27175366

  10. Accurate measurement of respiratory airway wall thickness in CT images using a signal restoration technique

    NASA Astrophysics Data System (ADS)

    Park, Sang Joon; Kim, Tae Jung; Kim, Kwang Gi; Lee, Sang Ho; Goo, Jin Mo; Kim, Jong Hyo

    2008-03-01

    Airway wall thickness (AWT) is an important bio-marker for evaluation of pulmonary diseases such as chronic bronchitis, bronchiectasis. While an image-based analysis of the airway tree can provide precise and valuable airway size information, quantitative measurement of AWT in Multidetector-Row Computed Tomography (MDCT) images involves various sources of error and uncertainty. So we have developed an accurate AWT measurement technique for small airways with three-dimensional (3-D) approach. To evaluate performance of these techniques, we used a set of acryl tube phantom was made to mimic small airways to have three different sizes of wall diameter (4.20, 1.79, 1.24 mm) and wall thickness (1.84, 1.22, 0.67 mm). The phantom was imaged with MDCT using standard reconstruction kernel (Sensation 16, Siemens, Erlangen). The pixel size was 0.488 mm × 0.488 mm × 0.75 mm in x, y, and z direction respectively. The images were magnified in 5 times using cubic B-spline interpolation, and line profiles were obtained for each tube. To recover faithful line profile from the blurred images, the line profiles were deconvolved with a point spread kernel of the MDCT which was estimated using the ideal tube profile and image line profile. The inner diameter, outer diameter, and wall thickness of each tube were obtained with full-width-half-maximum (FWHM) method for the line profiles before and after deconvolution processing. Results show that significant improvement was achieved over the conventional FWHM method in the measurement of AWT.

  11. New research perspectives from a novel approach to quantify tracheid wall thickness.

    PubMed

    Prendin, Angela Luisa; Petit, Giai; Carrer, Marco; Fonti, Patrick; Björklund, Jesper; von Arx, Georg

    2017-04-04

    The analysis of xylem cell anatomical features in dated tree rings provides insights into xylem functional responses and past growth conditions at intra-annual resolution. So far, special focus has been given to the lumen of the water-conducting cells, whereas the equally relevant cell wall thickness (CWT) has been less investigated due to methodological limitations. Here we present a novel approach to measure tracheid CWT in high-resolution images of wood cross-sections that is implemented within the specialized image-analysis tool 'ROXAS'. Compared with the traditional manual line measurements along a selection of few radial files, this novel image-analysis tool can: (i) measure CWT of all tracheids in a tree-ring cross-section, thus increasing the number of individual tracheid measurements by a factor of ~10-20; (ii) measure the tangential and radial walls separately; and (iii) laterally integrate the measurements in a customizable way from only the thinnest central part of the cell walls up to the thickest part of the tracheids at the corners. Cell wall thickness measurements performed with our novel approach and the traditional manual approach showed comparable accuracy for several image resolutions, with an optimal accuracy-efficiency balance at 100× magnification. The configurable settings intended to underscore different cell wall properties indeed changed the absolute levels and intra- and inter-annual patterns of CWT. This versatility, together with the high data production capacity, allows to tailor the measurements of CWT to the specific goal of each study, which opens new research perspectives, e.g., for investigating structure-function relationships, tree stress responses and carbon allocation patterns, and for reconstructing climate based on intra- and inter-annual variability of anatomical wood density.

  12. Abdominal wall reconstruction after resection of an enterocutaneous fistula with an island pedicled anterolateral thigh perforator flap. Case report.

    PubMed

    Ali, F; Safawi, E B; Zakaria, Z; Basiron, N

    2013-01-01

    Entero-cutaneous fistula resulting from a locally invasive large bowel carcinoma is a difficult surgical challenge. En-bloc resection of the involved organs and the entero-cutaneous fistula tract with a healthy tissue margin will result in a composite abdominal wall defect that requires closure. Reconstructive surgical options include primary closure, components separation and the use of local, regional or free flaps with or without prosthetic mesh. We report a case of an abdominal enterocutaneous fistula secondary to a locally invasive sigmoid carcinoma, which was reconstructed with a pedicled antero-lateral thigh perforator (ALT) flap. To our knowledge, this is the first case of a malignant entero-cutaneous fistula, which was reconstructed with an ALT flap.

  13. The effect of wall thickness distribution on mechanical reliability and strength in unidirectional porous ceramics.

    PubMed

    Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J

    2016-01-01

    Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, we performed crush tests on samples with controlled microstructural features with the loading direction parallel to the porosity. The compressive strength data were fitted using two different fitting techniques, ordinary least squares and Bayesian Markov Chain Monte Carlo, to evaluate whether Weibull statistics are an adequate descriptor of the strength distribution. The statistical descriptors indicated that the strength data are well described by the Weibull statistical approach, for both fitting methods used. Furthermore, we assess the effect of different microstructural features (volume, size, densification of the walls, and morphology) on Weibull modulus and strength. We found that the key microstructural parameter controlling reliability is wall thickness. In contrast, pore volume is the main parameter controlling the strength. The highest Weibull modulus ([Formula: see text]) and mean strength (198.2 MPa) were obtained for the samples with the smallest and narrowest wall thickness distribution (3.1 [Formula: see text]m) and lower pore volume (54.5%).

  14. The effect of wall thickness distribution on mechanical reliability and strength in unidirectional porous ceramics

    PubMed Central

    Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J.

    2016-01-01

    Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, we performed crush tests on samples with controlled microstructural features with the loading direction parallel to the porosity. The compressive strength data were fitted using two different fitting techniques, ordinary least squares and Bayesian Markov Chain Monte Carlo, to evaluate whether Weibull statistics are an adequate descriptor of the strength distribution. The statistical descriptors indicated that the strength data are well described by the Weibull statistical approach, for both fitting methods used. Furthermore, we assess the effect of different microstructural features (volume, size, densification of the walls, and morphology) on Weibull modulus and strength. We found that the key microstructural parameter controlling reliability is wall thickness. In contrast, pore volume is the main parameter controlling the strength. The highest Weibull modulus (m=13.2) and mean strength (198.2 MPa) were obtained for the samples with the smallest and narrowest wall thickness distribution (3.1 μm) and lower pore volume (54.5%). PMID:27877864

  15. Growth and Remodeling in a Thick-Walled Artery Model: Effects of Spatial Variations in Wall Constituents

    PubMed Central

    Alford, Patrick W.; Humphrey, Jay D.; Taber, Larry A.

    2008-01-01

    A mathematical model is presented for growth and remodeling of arteries. The model is a thick-walled tube composed of a constrained mixture of smooth muscle cells, elastin and collagen. Material properties and radial and axial distributions of each constituent are prescribed according to previously published data. The analysis includes stress-dependent growth and contractility of the muscle and turnover of collagen fibers. Simulations were conducted for homeostatic conditions and for the temporal response following sudden hypertension. Numerical pressure-radius relations and opening angles (residual stress) show reasonable agreement with published experimental results. In particular, for realistic material and structural properties, the model predicts measured variations in opening angles along the length of the aorta with reasonable accuracy. These results provide a better understanding of the determinants of residual stress in arteries and could lend insight into the importance of constituent distributions in both natural and tissue-engineered blood vessels. PMID:17786493

  16. 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

  17. Injection-moulded models of major and minor arteries: the variability of model wall thickness owing to casting technique.

    PubMed

    O'Brien, T; Morris, L; O'Donnell, M; Walsh, M; McGloughlin, T

    2005-09-01

    Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

  18. Preparation of poly(L-lactic acid)-modified polypropylene mesh and its antiadhesion in experimental abdominal wall defect repair.

    PubMed

    Zhang, Zhigang; Zhang, Tianzhu; Li, Junsheng; Ji, Zhenling; Zhou, Hemei; Zhou, Xuefeng; Gu, Ning

    2014-01-01

    A new type of polypropylene (PP) hernia mesh, modified with poly(L-lactic acid) (PLLA), was developed and used to repair rat abdominal wall defect. The PP mesh was first treated with oxygen plasma and then grafted with PLLA in phosphorus pentachloride (PCl5 ) solution in dichloride methane. The water contact angle changed during the procedure, and the coverage percentage of PLLA on the PP was about 80%. ATR-FTIR spectroscopy measurements showed the existence of carbonyl group absorption peak (1756.9 cm(-1) ), and atomic force microscope and scanning electron microscope morphological observation indicated that the surface of the PP mesh was covered with PLLA graft. X-ray photoelectron spectroscopy spectra was used to probe chemical group changes and confirmed that the PLLA was grafted onto the PP. A total of 36 Sprague-Dawley rats were randomly divided into six groups, and they received either modified meshes (experimental groups) or PP meshes (control groups) to repair abdominal wall defects. All animals survived until the end of the experiment. Rats in each group were dissected after the operation (after 1 week, 2 weeks, and 1 month, respectively), and the adhesion effects were evaluated. Sections of the mesh parietal peritoneum overlap were examined histologically and graded for inflammation reaction. Compared with the control groups, the experimental groups showed a better ability to resist peritoneal cavity adhesions (P < 0.05), and there was no increase in inflammation formation (P > 0.05). This new type of PLLA-modified PP mesh displayed an additional property of antiadhesion in animal abdominal wall defect repair.

  19. A hybrid method for airway segmentation and automated measurement of bronchial wall thickness on CT.

    PubMed

    Xu, Ziyue; Bagci, Ulas; Foster, Brent; Mansoor, Awais; Udupa, Jayaram K; Mollura, Daniel J

    2015-08-01

    Inflammatory and infectious lung diseases commonly involve bronchial airway structures and morphology, and these abnormalities are often analyzed non-invasively through high resolution computed tomography (CT) scans. Assessing airway wall surfaces and the lumen are of great importance for diagnosing pulmonary diseases. However, obtaining high accuracy from a complete 3-D airway tree structure can be quite challenging. The airway tree structure has spiculated shapes with multiple branches and bifurcation points as opposed to solid single organ or tumor segmentation tasks in other applications, hence, it is complex for manual segmentation as compared with other tasks. For computerized methods, a fundamental challenge in airway tree segmentation is the highly variable intensity levels in the lumen area, which often causes a segmentation method to leak into adjacent lung parenchyma through blurred airway walls or soft boundaries. Moreover, outer wall definition can be difficult due to similar intensities of the airway walls and nearby structures such as vessels. In this paper, we propose a computational framework to accurately quantify airways through (i) a novel hybrid approach for precise segmentation of the lumen, and (ii) two novel methods (a spatially constrained Markov random walk method (pseudo 3-D) and a relative fuzzy connectedness method (3-D)) to estimate the airway wall thickness. We evaluate the performance of our proposed methods in comparison with mostly used algorithms using human chest CT images. Our results demonstrate that, on publicly available data sets and using standard evaluation criteria, the proposed airway segmentation method is accurate and efficient as compared with the state-of-the-art methods, and the airway wall estimation algorithms identified the inner and outer airway surfaces more accurately than the most widely applied methods, namely full width at half maximum and phase congruency.

  20. Impaired Gallbladder Motility and Increased Gallbladder Wall Thickness in Patients with Nonalcoholic Fatty Liver Disease

    PubMed Central

    Colak, Yasar; Bozbey, Gulcin; Erim, Tolga; Caklili, Ozge Telci; Ulasoglu, Celal; Senates, Ebubekir; Mutlu, Hasan Huseyin; Mesci, Banu; Doğan, Mehmet Sait; Tasan, Guralp; Enc, Feruze Yilmaz; Tuncer, Ilyas

    2016-01-01

    Background/Aims Nonalcoholic fatty liver disease (NAFLD) is currently the most common chronic liver disease worldwide. Along with the increase in the incidence of NAFLD and associated obesity, an increase in gallbladder disease (GD) has been noted. This has led to the identification of a new disease entity called fatty GD. There is a gap in the literature on the dynamics of gallbladder function in patients with NAFLD. Methods An observational case-control study, a total of 50 patients with biopsy proven NAFLD without gallbladder stone/sludge and 38 healthy comparison subjects were enrolled. Fasting, postprandial gallbladder volumes (PGV), gallbladder ejection fraction (GEF), and fasting gallbladder wall thickness (FGWT) were measured by real-time 2-dimensional ultrasonography. Results Fasting gallbladder wall thickness, fasting gallbladder volumes and PGV were significantly higher in patients with NAFLD than control subjects (P < 0.001, P = 0.006, and P < 0.001, respectively). Gallbladder ejection fraction was significantly lower in the NAFLD group than the controls (P = 0.008). The presence of NAFLD was an independent predictor for GEF, PGV, and FGWT. Also, steatosis grade was an independent predictor for GEF, and GEF was significantly lower in the nonalcoholic steatohepatitis (NASH) subgroup than the controls. Conclusions Gallbladder dysfunction and increase in gallbladder wall thickness exists in asymptomatic (without stone/sludge and related symptoms) patients with NAFLD and are useful in identifying fatty GD. Measurement of these variables in NAFLD patients may be useful in identifying those at higher risk for GD. PMID:26932908

  1. Automatic identification and validation of planar collagen organization in the aorta wall with application to abdominal aortic aneurysm.

    PubMed

    Polzer, Stanislav; Gasser, T Christian; Forsell, Caroline; Druckmüllerova, Hana; Tichy, Michal; Staffa, Robert; Vlachovsky, Robert; Bursa, Jiri

    2013-12-01

    Arterial physiology relies on a delicate three-dimensional (3D) organization of cells and extracellular matrix, which is remarkably altered by vascular diseases like abdominal aortic aneurysms (AAA). The ability to explore the micro-histology of the aorta wall is important in the study of vascular pathologies and in the development of vascular constitutive models, i.e., mathematical descriptions of biomechanical properties of the wall. The present study reports and validates a fast image processing sequence capable of quantifying collagen fiber organization from histological stains. Powering and re-normalizing the histogram of the classical fast Fourier transformation (FFT) is a key step in the proposed analysis sequence. This modification introduces a powering parameter w, which was calibrated to best fit the reference data obtained using classical FFT and polarized light microscopy (PLM) of stained histological slices of AAA wall samples. The values of w = 3 and 7 give the best correlation (Pearson's correlation coefficient larger than 0.7, R 2 about 0.7) with the classical FFT approach and PLM measurements. A fast and operator independent method to identify collagen organization in the arterial wall was developed and validated. This overcomes severe limitations of currently applied methods like PLM to identify collagen organization in the arterial wall.

  2. 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.

  3. A joint thermal and electromagnetic diagnostics approach for the inspection of thick walls

    NASA Astrophysics Data System (ADS)

    Le Touz, Nicolas; Dumoulin, Jean; Gennarelli, Gianluca; Soldovieri, Francesco

    2017-02-01

    In this study, we present an inversion approach to detect and localize inclusions in thick walls under natural solicitations. The approach is based on a preliminary analysis of surface temperature field evolution with time (for instance acquired by infrared thermography); subsequently, this analysis is improved by taking advantage of a priori information provided by ground-penetrating radar reconstruction of the structure under investigation. In this way, it is possible to improve the accuracy of the images achievable with the stand-alone thermal reconstruction method in the case of quasi-periodic natural excitation.

  4. Structure and Properties of Thick-Walled Joints of Alloy 1570s Prepared by Friction Stir Welding

    NASA Astrophysics Data System (ADS)

    Velichko, O. V.; Ivanov, S. Yu.; Karkhin, V. A.; Lopota, V. A.; Makhin, I. D.

    2016-09-01

    The microstructure and mechanical properties of thick-walled joints of Al - Mg - Sc alloy 1570S, prepared by friction stir welding are studied. Joint microstructural and mechanical inhomogeneity are revealed.

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

    PubMed

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

    2015-09-28

    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.

  6. The importance of ultrasonographic measurement of peritoneal wall thickness in pediatric chronic peritoneal dialysis patients.

    PubMed

    Yavaşcan, Önder; Aksu, Nejat; Alparslan, Caner; Sarıtaş, Serdar; Elmas, Cengiz Han; Eraslan, Ali Nihat; Duman, Soner; Mir, Sevgi

    2015-04-01

    Loss of peritoneal function due to peritoneal fibrosing syndrome (PFS) is a major factor leading to treatment failure in chronic peritoneal dialysis (PD) patients. Although the precise biologic mechanisms responsible for these changes have not been defined, the general assumption is that alterations in peritoneal function are related to structural changes in the peritoneal membrane. Studies of the peritoneal membrane by non-invasive ultrasonography (US) in chronic PD patients are limited. The aim of the present study is to assess the relationship between functional parameters of peritoneum and peritoneal thickness measured by US in children treated by chronic PD. We recruited two groups of patients: 23 subjects (13 females, 10 males) on chronic PD (patient group) and 26 (7 females, 19 males) on predialysis out-patient follow-up (creatinine clearance: 20-60 mL/min/1.73 m(2)) (control group). Age, sex, weight, height, body mass index (BMI), chronic PD duration, episodes of peritonitis and the results of peritoneal equilibration test (PET) were recorded. Hemoglobin (Hb), blood pressure (BP), left ventricular mass index (LVMI) and renal osteodystrophy (ROD) parameters were also obtained. The thickness of the parietal peritoneum was measured by trans-abdominal US in all children. Statistical analyses were performed by using Student's t and Pearson's correlation tests. Mean peritoneal thickness in chronic PD patients (1028.26 ± 157.26 μm) was significantly higher than control patients (786.52 ± 132.33). Mean peritoneal thickness was significantly correlated with mean body height (R(2) = 0.93, p < 0.05), BMI (R(2) = 0.25, p < 0.05), chronic PD duration (R(2) = 0.64, p < 0.05), episodes of peritonitis (R(2) = 0.93, p < 0.05), D/Pcreatinine (R(2) = 0.76, p < 0.05) and D4/D0glucose (R(2) = 0.81, p < 0.05). No correlation was found between peritoneal thickness and Hb, BP, LVMI and ROD parameters. In conclusion

  7. Giant Cutaneous Leiomyosarcoma Originating From the Abdominal Wall: A Case Report

    PubMed Central

    Eken, Huseyin; Karagul, Servet; Topgül, Koray; Yoruker, Savaş; Ozen, Necati; Gun, Seda; Balci, Mecdi Gurhan; Somuncu, Erkan; Cimen, Orhan; Soyturk, Mehmet; Karavas, Erdal

    2016-01-01

    Patient: Male, 44 Final Diagnosis: Cutaneous Leiomyosarcoma Symptoms: Abdominal mass Medication: — Clinical Procedure: Surgery Specialty: Surgery Objective: Rare disease Background: Leiomyosarcoma, a rare type of tumor, accounts for 5–10% of all soft tissue tumors. Case Report: A 44-year-old male patient was admitted to the emergency service of our medical faculty with the complaints of fatigue and abdominal mass. Conclusions: The pathology result was leiomyosarcoma. Leiomyosarcoma of the skin is rare and our case is the largest such lesion reported in the literature. PMID:26787636

  8. Effect of subcooling and wall thickness on pool boiling from downward-facing curved surfaces in water

    SciTech Connect

    El-Genk, M.S.; Glebov, A.G.

    1995-09-01

    Quenching experiments were performed to investigate the effects of water subcooling and wall thickness on pool boiling from a downward-facing curved surface. Experiments used three copper sections of the same diameter (50.8 mm) and surface radius (148 mm), but different thickness (12.8, 20 and 30 mm). Local and average pool boiling curves were obtained at saturation and 5 K, 10 K, and 14 K subcooling. Water subcooling increased the maximum heat flux, but decreased the corresponding wall superheat. The minimum film boiling heat flux and the corresponding wall superheat, however, increased with increased subcooling. The maximum and minimum film boiling heat fluxes were independent of wall thickness above 20 mm and Biot Number > 0.8, indicating that boiling curves for the 20 and 30 thick sections were representative of quasi steady-state, but not those for the 12.8 mm thick section. When compared with that for a flat surface section of the same thickness, the data for the 12.8 mm thick section showed significant increases in both the maximum heat flux (from 0.21 to 0.41 MW/m{sup 2}) and the minimum film boiling heat flux (from 2 to 13 kW/m{sup 2}) and about 11.5 K and 60 K increase in the corresponding wall superheats, respectively.

  9. The behavior of different types of polytetrafluoroethylene (PTFE) prostheses in the reparative scarring process of abdominal wall defects.

    PubMed

    Buján, J; Contreras, L A; Carrera-San Martín, A; Bellón, J M

    1997-07-01

    Currently one of the most widely used prosthetic materials in the repair of abdominal wall defects, is expanded polytetrafluoroethylene (ePTFE). It has been suggested that its behavior with respect to the reparative process may depend on its structure. The aim of the present study was to evaluate the effect of the structure of 3 ePTFE prostheses on the scarring process in an abdominal-wall-defect experimental model. The prostheses employed were the Soft Tissue Patch (STP) which is laminar in structure, Mycro Mesh (MM) which is multilaminar with perforations, and the Dual Mesh (DM) prosthesis which has one non-porous surface. Abdominal wall defects (7 x 5 cm) were created in 36 New Zealand rabbits and repaired using fragments of STP, MM and DM. Follow-up periods were 14, 30, 60 and 90 days post-implant. At these times prostheses were macroscopically examined for the presence of infection and/or rejection and the formation of adhesions to abdominal viscera. Specimens were also taken for microscopic analysis (optical and scanning electron) and for immunohistochemical analysis using the rabbit macrophage-specific monoclonal antibody RAM-11. Labelled macrophage counts were performed at each follow-up session. No cases of infection or rejection were found. Loose adhesions between prosthesis and underlying viscera were observed in 2 of the STP, 4 of the MM and 2 of the DM implants. STP and DM implants were progressively encapsulated by organized connective tissue on both peritoneal and subcutaneous surfaces. Cellular colonization was observed on both STP surfaces and on the porous surface of the DM although no more than a third of the biomaterial was penetrated by cells in either case. Colonization was very slight at prosthesis anchorage points. MM implants differed only in the formation of connective tissue bridges in perforated areas, and cellular infiltration in interlaminar spaces. Macrophage response was similar in the 3 prostheses with a reduction in RAM-11 labelled

  10. 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.

  11. Carbon nanotubes as VEGF carriers to improve the early vascularization of porcine small intestinal submucosa in abdominal wall defect repair

    PubMed Central

    Liu, Zhengni; Feng, Xueyi; Wang, Huichun; Ma, Jun; Liu, Wei; Cui, Daxiang; Gu, Yan; Tang, Rui

    2014-01-01

    Insufficient early vascularization in biological meshes, resulting in limited host tissue incorporation, is thought to be the primary cause for the failure of abdominal wall defect repair after implantation. The sustained release of exogenous angiogenic factors from a biocompatible nanomaterial might be a way to overcome this limitation. In the study reported here, multiwalled carbon nanotubes (MWNT) were functionalized by plasma polymerization to deliver vascular endothelial growth factor165 (VEGF165). The novel VEGF165-controlled released system was incorporated into porcine small intestinal submucosa (PSIS) to construct a composite scaffold. Scaffolds incorporating varying amounts of VEGF165-loaded functionalized MWNT were characterized in vitro. At 5 weight percent MWNT, the scaffolds exhibited optimal properties and were implanted in rats to repair abdominal wall defects. PSIS scaffolds incorporating VEGF165-loaded MWNT (VEGF–MWNT–PSIS) contributed to early vascularization from 2–12 weeks postimplantation and obtained more effective collagen deposition and exhibited improved tensile strength at 24 weeks postimplantation compared to PSIS or PSIS scaffolds, incorporating MWNT without VEGF165 loading (MWNT–PSIS). PMID:24648727

  12. Diagnostic Accuracy of Abdominal wall Ultrasonography and Local Wound Exploration in Predicting the Need for Laparotomy following Stab Wound

    PubMed Central

    Vafaei, Ali; Heidari, Kamran; Saboorizadeh, Afshin; shams akhtari, Amin

    2017-01-01

    Introduction: Screening of patients with anterior abdominal penetrating trauma in need for laparotomy is an important issue in management of these cases. This study aimed to compare the accuracy of abdominal wall ultrasonography (AWU) and local wound exploration (LWE) in this regard. Methods: This diagnostic accuracy study was conducted on ≥ 18 year-old patients presenting to emergency department with anterior abdominal stab wound and stable hemodynamics, to compare the characteristics of AWU and LWE in screening of patients in need of laparotomy. Results: 50 cases with the mean age of 28.44 ± 7.14 years were included (80% male). Sensitivity, specificity and area under the receiver operating characteristic (ROC) curve of AWU were 70.58 (95% CI: 44.04 – 88.62), 93.33 (95% CI: 76.49 – 98.83), and 81.96 (95% CI: 69.91 – 94.01), respectively. These measures were 88.23 (62.25 – 97.93), 93.33 (76.49 – 98.83), and 90.78 (95% CI: 81.67 – 99.89) for LWE, respectively. The difference in overall accuracy of the two methods was not statistically significant (p = 0.0641). Conclusion: Based on the findings of the present study, AWU and LWE had the same specificity but different sensitivities in screening of anterior abdominal stab wound patients in need of laparotomy. The overall accuracy of LWE was slightly higher (91.48% versus 85.1%). PMID:28286841

  13. Reproducibility of The Abdominal and Chest Wall Position by Voluntary Breath-Hold Technique Using a Laser-Based Monitoring and Visual Feedback System

    SciTech Connect

    Nakamura, Katsumasa . E-mail: nakam@radiol.med.kyushu-u.ac.jp; Shioyama, Yoshiyuki; Nomoto, Satoru; Ohga, Saiji; Toba, Takashi; Yoshitake, Tadamasa; Anai, Shigeo; Terashima, Hiromi; Honda, Hiroshi

    2007-05-01

    Purpose: The voluntary breath-hold (BH) technique is a simple method to control the respiration-related motion of a tumor during irradiation. However, the abdominal and chest wall position may not be accurately reproduced using the BH technique. The purpose of this study was to examine whether visual feedback can reduce the fluctuation in wall motion during BH using a new respiratory monitoring device. Methods and Materials: We developed a laser-based BH monitoring and visual feedback system. For this study, five healthy volunteers were enrolled. The volunteers, practicing abdominal breathing, performed shallow end-expiration BH (SEBH), shallow end-inspiration BH (SIBH), and deep end-inspiration BH (DIBH) with or without visual feedback. The abdominal and chest wall positions were measured at 80-ms intervals during BHs. Results: The fluctuation in the chest wall position was smaller than that of the abdominal wall position. The reproducibility of the wall position was improved by visual feedback. With a monitoring device, visual feedback reduced the mean deviation of the abdominal wall from 2.1 {+-} 1.3 mm to 1.5 {+-} 0.5 mm, 2.5 {+-} 1.9 mm to 1.1 {+-} 0.4 mm, and 6.6 {+-} 2.4 mm to 2.6 {+-} 1.4 mm in SEBH, SIBH, and DIBH, respectively. Conclusions: Volunteers can perform the BH maneuver in a highly reproducible fashion when informed about the position of the wall, although in the case of DIBH, the deviation in the wall position remained substantial.

  14. Optimization of Cone Wall Thickness to Reduce High Energy Electron Generation for Fast-Ignition Scheme

    NASA Astrophysics Data System (ADS)

    Kojima, Sadaoki; Zhe, Zhang; Sawada, Hiroshi; Firex Team

    2015-11-01

    In Fast Ignition Inertial Confinement Fusion, optimization of relativistic electron beam (REB) accelerated by a high-intensity laser pulse is critical for the efficient core heating. The high-energy tail of the electron spectrum is generated by the laser interaction with a long-scale-length plasma and does not efficiently couple to a fuel core. In the cone-in-shell scheme, long-scale-length plasmas can be produced inside the cone by the pedestal of a high-intensity laser, radiation heating of the inner cone wall and shock wave from an implosion core. We have investigated a relation between the presence of pre-plasma inside the cone and the REB energy distribution using the Gekko XII and 2kJ-PW LFEX laser at the Institute of Laser Engineering. The condition of an inner cone wall was monitored using VISAR and SOP systems on a cone-in-shell implosion. The generation of the REB was measured with an electron energy analyzer and a hard x-ray spectrometer on a separate shot by injecting the LFEX laser in an imploded target. The result shows the strong correlation between the preheat and high-energy tail generation. Optimization of cone-wall thickness for the fast-ignition will be discussed. This work is supported by NIFS, MEXT/JSPS KAKENHI Grant and JSPS Fellows (Grant Number 14J06592).

  15. 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 ΔFEV1 ≥ 10%) and BDR-(post bronchodilator ΔFEV1 < 10%). The mean 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

  16. Extensive Abdominal Wall Incisional Heterotopic Ossification Reconstructed with Component Separation and Strattice Inlay

    PubMed Central

    Suleiman, Nergis Nina

    2016-01-01

    Summary: Symptomatic heterotopic ossification of abdominal surgical incisions is a rare occurrence. We present a 67-year-old man with severe discomfort caused by heterotopic ossification extending from the xiphoid to the umbilicus. The patient underwent an abdominal aortic aneurysm repair 3 years before our treatment. A 13 × 3.5 cm ossified lesion was excised. The resulting midline defect was closed using component separation and inlay Strattice. Tension-free midline adaptation of the recti muscles was achieved. A computed tomography scan of the abdomen 6 months after the surgery showed no recurrence or hernias. Heterotopic ossification in symptomatic patients has previously been treated with excision and primary closure. We believe that tension-free repair is important to prevent recurrence. Acellular dermal matrix may add to this effect and also compartmentalize the process. PMID:27536495

  17. Avoiding Complications in Abdominal Wall Surgery: A Mathematical Model to Predict the Course of the Motor Innervation of the Rectus Abdominis.

    PubMed

    Tessone, Ariel; Nava, Maurizio; Blondeel, Phillip; Spano, Andrea

    2016-02-01

    Ever since its introduction, the transverse rectus abdominis myocutaneous flap has become the mainstay of autologous breast reconstruction. However, concerns regarding donor site morbidity due to the breach of abdominal wall musculature integrity soon followed. Muscle-sparing techniques, eventually eliminating the muscle from the flap all-together with the deep inferior epigastric artery perforator flap, did not eliminate the problem of abdominal wall weakness. This led to the conclusion that motor innervation might be at fault. Studies have shown that even in the presence of an intact rectus abdominis muscle, and an intact anterior rectus sheath, denervation of the rectus abdominis muscle results in significant abdominal wall weakness leading to superior and inferior abdominal bulges, and abdominal herniation. Our aim was to establish a mathematical model to predict the location of the motor innervation to the rectus abdominis muscle, and thus provide surgeons with a tool that will allow them to reduce abdominal morbidity during deep inferior epigastric artery perforator and free muscle-sparing transverse rectus abdominis myocutaneous surgery. We dissected 42 cadaveric hemiabdomens and mapped the course of the thoracolumbar nerves. We then standardized and analyzed our findings and presented them as a relative map which can be adjusted to body type and dimensions. Our dissections show that the motor innervation is closely related to the lateral vascular supply. Thus, when possible, we support the preferred utilization of the medial vascular supply, and the preservation of the lateral supply and motor innervation.

  18. Treatment of a chronic vesicocutaneous fistula and abdominal wall defect after resection of a soft tissue sarcoma using a bipedicled latissimus dorsi and serratus anterior free flap.

    PubMed

    Ludolph, Ingo; Apel, Hendrik; Horch, Raymund E; Beier, Justus P

    2014-11-01

    We present a surgical treatment for bladder reconstruction in a case of chronic vesicocutaneous radiation-induced fistula and reconstruction of the abdominal wall after resection of a liposarcoma in the rectus abdominis muscle. Fistulas are sequelae after radiotherapy. To regain bladder function and reconstitute abdominal wall stability, a microsurgical flap approach should be considered. A male patient underwent resection of a liposarcoma in the rectus abdominis muscle with adjuvant radiotherapy, suffering from a chronic vesicocutaneous fistula. A bipedicled combined latissimus dorsi and serratus anterior flap was carried out after resection of the fistula for reconstruction of the urine bladder and the abdominal wall. Ascending urethrography 4 weeks postoperatively showed no leakage. In the 4-month follow-up period, no signs of recurrence of the fistula or herniation occurred. A bipedicled flap allowed reconstruction of the urine bladder and the abdominal wall. Using non-irradiated, well-perfused intra-abdominal muscle tissue over the urine bladder prevented recurrence of the fistula.

  19. 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.

  20. 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.

  1. Experiments on fracture toughness of thick-wall cylinder for modes I, II, III

    SciTech Connect

    Saegusa, T.; Urabe, N.; Ito, C.; Shirai, K.; Kosaki, A.

    1999-07-01

    There have been few data on fracture toughness for Mode 2 and 3 as compared with those for Mode 1. Experimental data on fracture toughness of plates made of ductile cast iron (ASTM A874-89) and forged steel (ASME SA350 LF5 C1.1) were obtained at a temperature range from 77K to 293K for Mode 1, 2 and 3. The results showed: J{sub IC} < J{sub IIC} < J{sub IIIC}, and K{sub IC} < K{sub IIC} K{sub IIIC}. Integrity of a thick-wall cylinder with artificial flaw was demonstrated against brittle fracture at 233K for Mode 1, 2 and 3, which is one of the design requirements of containers shipping radioactive materials.

  2. Helium ion microscopy based wall thickness and surface roughness analysis of polymer foams obtained from high internal phase emulsion.

    PubMed

    Rodenburg, C; Viswanathan, P; Jepson, M A E; Liu, X; Battaglia, G

    2014-04-01

    Due to their wide range of applications, porous polymers obtained from high internal phase emulsions have been widely studied using scanning electron microscopy. However, due to their lack of electrical conductivity, quantitative information of wall thicknesses and surface roughness, which are of particular interest to tissue engineering, has not been obtained. Here, Helium Ion Microscopy is used to examine uncoated polymer foams and some very strong but unexpected contrast is observed, the origin of which is established here. Based on this analysis, a method for the measurement of wall thickness variations and wall roughness measurements has been developed, based on the modeling of Helium ion transmission. The results presented here indicate that within the walls of the void structure there exist small features with height variations of ~30 nm and wall thickness variations from ~100 nm to larger 340 nm in regions surrounding interconnecting windows within the structure. The suggested imaging method is applicable to other porous carbon based structures with wall thicknesses in the range of 40-340 nm.

  3. Observation of cerebral aneurysm wall thickness using intraoperative microscopy: clinical and morphological analysis of translucent aneurysm.

    PubMed

    Song, Jihye; Park, Jung Eon; Kim, Hyoung Ryoul; Shin, Yong Sam

    2015-06-01

    Intracranial aneurysms suffer various interactions between hemodynamics and pathobiology, and rupture when this balance disrupted. Aneurysm wall morphology is a result of these interactions and reflects the quality of the maturation. However, it is a poorly documented in previous studies. The purpose of this study is to observe aneurysm wall thickness and describe the characteristics of translucent aneurysm by analyzing clinical and morphological parameters. 253 consecutive patients who underwent clipping surgery in a single institute were retrospectively analyzed. Only middle cerebral artery aneurysms (MCA) which exposed most part of the dome during surgery were included. Aneurysms were categorized based on intraoperative video findings. Aneurysms more than 90 % of super-thin dome and any aneurysms with entirely super-thin-walled daughter sac were defined as translucent aneurysm. A total of 110 consecutive patients with 116 unruptured MCA aneurysms were included. Ninety-two aneurysms (79.3 %) were assigned to the not-translucent group and 24 (20.7 %) to the translucent group. The relative proportion of translucent aneurysm in each age group was highest at ages 50-59 years and absent at ages 30-39 and 70-79 years. There was a trend that translucent aneurysms were smaller in size (p = 0.019). Multivariate logistic analysis showed that translucent aneurysm was strongly correlated with height <3 mm (p = 0.003). We demonstrated that the translucent aneurysms were smaller in size and the aneurysm height <3 mm was related. These results may provide information in determining treatment strategies in patients with small size aneurysm.

  4. Development of Thick B4C Coatings for the First Wall of W7-X

    NASA Astrophysics Data System (ADS)

    Kötterl, S.; Bolt, H.; Greuner, H.; Huber, A.; Linke, J.; Mayer, M.; Pospieszczyk, A.; Renner, H.; Roth, J.; Schweer, B.; Sergienko, G.; Valenza, D.

    For the actively cooled first wall panels of the W7-X stellarator under construction at Greifswald, Germany, boron carbide (B4C) coatings with a thickness up to 500 μm are being developed as plasma facing surface on the stainless steel component. Different coating technologies (vacuum plasma spray (VPS), atmospherical plasma spray (APS)) are investigated. Characterisation of the coatings comprises metallo"graphic and SEM investigations, impurity determination and measurement of the thermal conductivity, characterisation of the sputtering behaviour and the behaviour under plasma exposure. First in-pile-tests in the tokamak TEXTOR-94 at the Research Centre Juelich have been performed. 10 poloidal limiter elements and 5 test limiters made of copper with a 170 μm thick B4C VPS coating were exposed to plasma discharges with ohmic and additional heating. By varying the limiter positions and plasma density, different loading conditions were imposed. After exposure, the test limiters were removed for further analyses. First results showed the formation of small craters in the coating, probably due to arcing. Although melting occurred within a limited zone around the craters, the coatings did not detach from the substrate or show severe cracking outside the molten area.

  5. Novel superhydrophilic poly(l-lactic acid-co-ε-caprolactone)/fibrinogen electrospun patch for rat abdominal wall reconstruction.

    PubMed

    Liu, Zhang; Li, Shaojie; Su, Ling; Sun, Kang; Wu, Xujun; Wu, Feng; Huang, Weihong; Yang, Li; Tang, Jianxiong; He, Hongbing

    2015-08-01

    A novel superhydrophilic hybrid scaffold was created by electrospinning a mixture of poly(l-lactic acid-co-ε-caprolactone) and formulated fibrinogen. The hybrid scaffolds possess the combined benefits of each individual component, such as moderate mechanical strength and excellent biocompatibility. In vitro studies also revealed that endothelial cells seeded on the hybrid scaffolds achieved a relatively high level of cell attachment after three days of culture and a significant increase in the proliferation rate after seven days of culture, compared with pure fibrinogen or poly(l-lactic acid-co-ε-caprolactone) scaffolds. A comparative study of hybrid and pure poly(l-lactic acid-co-ε-caprolactone) patches was performed in an abdominal wall defect model in rats. In both groups, implants degraded by six months, but muscle reconstruction was only observed in the hybrid patch group.

  6. [Results of partial splenic resection and transposition to the lateral abdominal wall in portal hypertension in childhood].

    PubMed

    Bennek, J; Tröbs, R B; Mühlig, K; Richter, T

    1996-01-01

    Between 1977 and 1995, 19 children with portal hypertension (nine extrahepatic, ten intrahepatic) were treated by transpositioning the spleen into the left abdominal wall. Among the patients with intrahepatic portal hypertension three died. Two patients underwent secondary diminuition of the transposed spleen due to relapsed hypersplenism. In one of our first patients the transposed spleen atrophied after tangential resection. All surviving patients except one preserved hepatic function. The serum colloid osmotic pressure was stable. Plasma ammonia levels were normal. Serum immunoglobulins (IgG, IgM, IgA and IgG subclasses) and complement components (C3c, C4) were analyzed. After transposition patients had normal or slightly elevated values of these proteins compared with controls.

  7. Changes in the Frequencies of Abdominal Wall Hernias and the Preferences for Their Repair: A Multicenter National Study From Turkey

    PubMed Central

    Şeker, Gaye; Kulacoglu, Hakan; Öztuna, Derya; Topgül, Koray; Akyol, Cihangir; Çakmak, Atıl; Karateke, Faruk; Özdoğan, Mehmet; Ersoy, Eren; Gürer, Ahmet; Zerbaliyev, Elbrus; Seker, Duray; Yorgancı, Kaya; Pergel, Ahmet; Aydın, İbrahim; Ensari, Cemal; Bilecik, Tuna; Kahraman, İzzettin; Reis, Erhan; Kalaycı, Murat; Canda, Aras Emre; Demirağ, Alp; Kesicioğlu, Tuğrul; Malazgirt, Zafer; Gündoğdu, Haldun; Terzi, Cem

    2014-01-01

    Abdominal wall hernias are a common problem in the general population. A Western estimate reveals that the lifetime risk of developing a hernia is about 2%.1–3 As a result, hernia repairs likely comprise the most frequent general surgery operations. More than 20 million hernias are estimated to be repaired every year around the world.4 Numerous repair techniques have been described to date however tension-free mesh repairs are widely used today because of their low hernia recurrence rates. Nevertheless, there are some ongoing debates regarding the ideal approach (open or laparoscopic),5,6 the ideal anesthesia (general, local, or regional),7,8 and the ideal mesh (standard polypropylene or newer meshes).9,10 PMID:25216417

  8. Changes in the wall shear stresses (WSS) during the enlargement of Abdominal Aortic Aneurysms (AAA)

    NASA Astrophysics Data System (ADS)

    Salsac, Anne-Virginie; Sparks, Steven R.; Chomaz, Jean-Marc; Lasheras, Juan C.

    2004-11-01

    The changes in the evolution of the spatial and temporal distribution of the WSS and gradients of WSS at different stages of the enlargement of AAAs are important to understand the etiology and progression of this vascular disease, since they affect the wall structural integrity, primarily via the changes induced on the shape, functions and metabolism of the endothelial cells. PIV measurements were performed in aneurysm models, while changing systematically their geometric parameters. We show that, even at very early stages of the disease (dilatation > 30%), the flow separates from the wall and the formation of a large vortex ring followed by internal shear layers leads to the generation of WSS that drastically differ from the healthy vessel. Inside the AAA, the mean WSS decreases to zero and the magnitude of the WSS can be as low as 26% of the value in a healthy vessel. Two regions with distinct patterns of WSS were identified. The region of flow detachment, with oscillatory WSS of very low mean, and the region of flow reattachment, located distally, where large, negative WSS and sustained gradients of WSS are produced as a result of the impact of the vortex ring on the wall.

  9. 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.

  10. Utilization of a global data grid repository in CAD assessment of carotid wall thickness

    NASA Astrophysics Data System (ADS)

    Gutierrez, Marco A.; Lee, Jasper; Zhou, Zheng; Pilon, Paulo E.; Lage, Silvia G.

    2007-03-01

    A CAD method of calculating wall thickness of carotid vessels addresses the time-consuming issue of using B-mode ultrasound as well as inter- and intra-observer variability in results. Upon selection of a region-of-interest and filtering of a series of ultrasound carotid images, the CAD is able to measure the geometry of the lumen and plaque surfaces using a least-square fitting of the active contours during systole and diastole. To evaluate the approach, ultrasound image sequences from 30 patients were submitted to the procedure. The images were stored on an international data grid repository that consists of three international sites: Image Processing and Informatics (IPI) Laboratory at University of Southern California, USA; InCor (Heart Institute) at Sao Paulo, Brazil, and Hong Kong Polytechnic University, Hong Kong. The three chosen sites are connected with high speed international networks including the Internet2, and the Brazilian National Research and Education Network (RNP2). The Data Grid was used to store, backup, and share the ultrasound images and analysis results, which provided a large-scale and a virtual data system. In order to study the variability between the automatic and manual definition of artery boundaries, the pooled mean and the standard deviation for the difference between measurements of lumen diameter were computed. The coefficient of variation and correlation were also calculated. For the studied population the difference between manual and automatic measurement of the lumen diameter (LD) and intima-media-thickness (IMT) were 0.12 +/-0.10 and 0.09+/- 0.06, respectively.

  11. A new possibility of melt cooling in extrusion dies to prevent sagging-effects in thick-walled pipes

    NASA Astrophysics Data System (ADS)

    te Heesen, O.; Wortberg, J.

    2014-05-01

    One challenge in the extrusion process of thick-walled pipes is the cooling of the product. Besides the output of the extruder, the line speed is also limited by the efficiency of the cooling line. The cooling time increases according to the wall thickness of the pipe under otherwise equal process conditions. State of the art is the cooling of the outer surface in water tanks or spray-cool-tanks. In addition to that, it is possible to cool the inner surface by air that is sucked through the pipe. Despite these technologies it is problematic to cool down thick walled-products with the right speed. Especially thick-walled pipes show problems by cooling the layers in the middle of the wall. On the one hand an intensive cooling of the outer and inner surface of the pipe entail the formation of shrink holes in the middle of the pipe wall. On the other hand without a quick cooling the melt flow in circumferential direction because of the gravity takes place (sagging-effect). Because of this reason in the presented paper new possibilities of melt cooling in extrusion dies to prevent sagging-effects are given. An aimed cooling of the inbound melt layers inside the extrusion die could prevent the effect of melt flow in circumferential direction after the extrusion die, allows the specification of a specific temperature profile over the radius of the pipe wall and helps to reduce the melt temperature for rising mass throughputs and screw driving speeds of the extruder. It is also thinkable to influence the crystallization process and thereby the mechanical properties of the end-product by an aimed cooling of the inner pipe layers.

  12. 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

  13. Antenatal Diagnosis of a Large Immature Abdominal Wall Teratoma by 2D-3D Ultrasound Using HDlive and Magnetic Resonance Imaging.

    PubMed

    Werner, Heron; Mocarzel, Carolina; Sá, Renato Augusto; Tonni, Gabriele; Novoa Y Novoa, Victoria Arruga; Avvad-Portari, Elyzabeth; Bonasoni, Paola; Araujo Júnior, Edward

    2016-01-01

    We describe the first case of prenatally detected teratoma of the fetal abdomen wall using ultrasound and fetal magnetic resonance imaging (MRI). A heterogeneous mass, partly solid and cystic, originating from the anterior abdominal wall of the fetus close to an omphalocele sac was detected by means of 2D/3D ultrasound and MRI. Amniodrainage was performed and due to sign of impending fetal risk, an emergency Cesarean section was performed. A bulky, crumbly and bleeding tumoral mass was confirmed at delivery. Ligation of the supplying artery to the tumor was complicated by uncontrollable hemorrhage and early neonatal death. Pathology identified the tumor as an immature teratoma of the anterior fetal abdominal wall. 2D/3D ultrasound, especially using HDlive application and MRI demonstrated accurate detection and characterization of this congenital tumor.

  14. 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).

  15. 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.

  16. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  17. Optimum heating of thick-walled pressure components assuming a quasi-steady state of temperature distribution

    NASA Astrophysics Data System (ADS)

    Dzierwa, Piotr; Trojan, Marcin; Taler, Dawid; Kamińska, Katarzyna; Taler, Jan

    2016-08-01

    As a result of the development of wind farms, the gas — steam blocks, which shall quickly ensure energy supply in case the wind velocity is too low, are introduced to the energy system. To shorten the start-up time of the gas — steam and conventional blocks, the structure of the basic components of the blocks are changed, e.g. by reducing the diameter of the boiler, the thickness of its wall is also reduced. The attempts were also made to revise the currently binding TRD 301 regulations, replacing them by the EN 12952-3 European Standard, to reduce the allowable heating and cooling rates of thick walled boiler components. The basic assumption, on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based, was the quasi — steady state of the temperature field in the simple shaped component, such as a slab, cylindrical or spherical wall.

  18. Indications and Outcomes of the Components Separation Technique in the Repair of Complex Abdominal Wall Hernias: Experience From the Cambridge Plastic Surgery Department

    PubMed Central

    Adekunle, Shola; Pantelides, Nicholas M.; Hall, Nigel R.; Praseedom, Raaj; Malata, Charles M.

    2013-01-01

    Objectives: The components separation technique (CST) is a widely described abdominal wall reconstructive technique. There have, however, been no UK reports of its use, prompting the present review. Methods: Between 2008 and 2012, 13 patients who underwent this procedure by a single plastic surgeon (C.M.M.) were retrospectively evaluated. The indications, operative details, and clinical outcomes were recorded. Results: There were 7 women and 6 men in the series with a mean age of 53 years (range: 30-80). Patients were referred from a variety of specialties, often as a last resort. The commonest indication for CST was herniation following abdominal surgery. All operations except 1 were jointly performed with general surgeons (for bowel resection, stoma reversal, and hernia dissection). The operations lasted a mean of 5 hours (range: 3-8 hours). There were no major intra- and postoperative problems, except in 1 patient who developed intra-abdominal compartment syndrome, secondary to massive hemorrhage. All patients were satisfied with the cosmetic improvement in their abdominal contours. None of the patients have developed a clinical recurrence after a mean follow-up of 16 months (range: 3-38 months). Conclusions: The components separation technique is an effective method of treating large recalcitrant hernias but appears to be underutilized in the United Kingdom. The management of large abdominal wall defects requires a multidisciplinary approach, with input across a variety of specialities. Liaison with plastic surgery teams should be encouraged at an early stage and the CST should be more widely considered when presented with seemingly intractable abdominal wall defects. PMID:24058718

  19. Initial experience with the use of porcine acellular dermal matrix (Strattice) for abdominal wall reinforcement after transverse rectus abdominis myocutaneous flap breast reconstruction.

    PubMed

    Cicilioni, Orlando; Araujo, Gerson; Mimbs, Nancy; Cox, Matthew D

    2012-03-01

    Reestablishing anterior rectus fascial integrity remains a clinical challenge after transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. The main concerns include herniation and bulging due to abdominal weakness. Mesh-assisted closure of the fascial defect has improved bulging and herniation rates but infection, extrusion, and encapsulation are serious concerns with mesh use. Biologic tissue matrices may overcome some of these mesh-related complications. The initial experience of using Strattice for fascial closure after TRAM flap procedure is described in this article. Strattice was in-lain and sutured between the anterior and posterior layers of the rectus fascia, at the rectus muscle donor site. The abdominal wall was closed with progressive tension sutures. Postoperative complications at the donor site were assessed. A total of 16 unilateral and 9 bilateral reconstructions were performed in 25 patients. Length of hospital stay was 2 to 3 days which is shorter than with mesh repair (typically 4-5 days). During a mean follow-up period of 14.0 months, complications occurred in 7 patients (28%): seroma formation (2), minor skin separation (2), superficial skin infection (2), and superficial wound dehiscence (1). Complications were not directly related to Strattice and all, except one (superficial skin infection), were resolved without surgical intervention. In all patients, routine abdominal functions were restored 4 months postoperatively. Strattice is a safe, alternative option to synthetic mesh for fascial repair following TRAM flap breast reconstruction. When used in conjunction with progressive tension suture closure of the abdominal wall, dynamic reconstruction of the abdominal wall with resumption of abdominal function is possible with Strattice.

  20. 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.

  1. A Multiscale Analysis of the Residual Stresses Occurring During Cooling of Thick-Walled Unidirectionally Filament-Wound Cylinders

    NASA Astrophysics Data System (ADS)

    Memarianfard, H.; Turusov, R. A.

    2016-09-01

    A numerical multiscale analysis to predict the residual thermal stresses occurring during cooling in thick-walled filament-wound cylinders made of a reinforced polymer at macro-and microscales is presented. Two types of contact — bonded and unbonded — between the mandrel and the composite are considered. The fields of microstresses are calculated in three different zones across the thickness of the cylinder by using the multiscale finite-element method. Results of the microscale analysis showed that the microstresses several times exceeded the macrostresses in these areas. The value and position of the maximum microstresses were found to depend on the type of contact between the mandrel and the thick-walled cylinder.

  2. Influence of wall thickness and diameter on arterial shear wave elastography: a phantom and finite element study

    NASA Astrophysics Data System (ADS)

    Maksuti, Elira; Bini, Fabiano; Fiorentini, Stefano; Blasi, Giulia; Urban, Matthew W.; Marinozzi, Franco; Larsson, Matilda

    2017-04-01

    Quantitative, non-invasive and local measurements of arterial mechanical properties could be highly beneficial for early diagnosis of cardiovascular disease and follow up of treatment. Arterial shear wave elastography (SWE) and wave velocity dispersion analysis have previously been applied to measure arterial stiffness. Arterial wall thickness (h) and inner diameter (D) vary with age and pathology and may influence the shear wave propagation. Nevertheless, the effect of arterial geometry in SWE has not yet been systematically investigated. In this study the influence of geometry on the estimated mechanical properties of plates (h  =  0.5–3 mm) and hollow cylinders (h  =  1, 2 and 3 mm, D  =  6 mm) was assessed by experiments in phantoms and by finite element method simulations. In addition, simulations in hollow cylinders with wall thickness difficult to achieve in phantoms were performed (h  =  0.5–1.3 mm, D  =  5–8 mm). The phase velocity curves obtained from experiments and simulations were compared in the frequency range 200–1000 Hz and showed good agreement (R 2  =  0.80  ±  0.07 for plates and R 2  =  0.82  ±  0.04 for hollow cylinders). Wall thickness had a larger effect than diameter on the dispersion curves, which did not have major effects above 400 Hz. An underestimation of 0.1–0.2 mm in wall thickness introduces an error 4–9 kPa in hollow cylinders with shear modulus of 21–26 kPa. Therefore, wall thickness should correctly be measured in arterial SWE applications for accurate mechanical properties estimation.

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

    PubMed

    Linek, Pawel; Saulicz, Edward; Wolny, Tomasz; Myśliwiec, Andrzej; Kokosz, Mirosław

    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.

  4. Comparison of Lateral Abdominal Muscle Thickness and Cross Sectional Area of Multifidus in Adolescent Soccer Players with and without Low Back Pain: A Case Control Study

    PubMed Central

    Noormohammadpour, Pardis; Hosseini Khezri, Alireza; Linek, Paweł; Mansournia, Mohammad Ali; Hassannejad, Alireza; Younesian, Ali; Farahbakhsh, Farzin; Kordi, Ramin

    2016-01-01

    Background Low back pain (LBP) is a common complaint amongst adolescent athletes. While different studies have shown association between LBP and trunk muscle thickness in the general population, few articles have studied it in adolescent athletes. Objectives The aim of this study is to compare lateral abdominal muscle thickness and function, and cross sectional area (CSA) of lumbar multifidus (LM) in adolescent soccer players with and without LBP. Methods In total, 28 adolescent soccer players with and without LBP, from the premier league participated in this study. The thickness of external oblique, internal oblique and transversus abdominis and the CSA of the LM muscles at L4 level on both sides were measured at rest and contraction via ultrasound imaging (USI). In addition, leg length discrepancy, hamstring flexibility, active lumbar forward flexion, and isometric muscle endurance of trunk extensors were measured in both groups. (study design/setting: case control study). Results The mean (SD) age in LBP group and non-LBP group were 14.0 (1.1) and 14.1 (0.9) years, respectively. There was no significant difference in baseline characteristics of participants between groups. Findings showed no significant difference between LBP and non-LBP groups comparing all measured variables. Conclusions The data obtained support that there is not a correlation between abdominal muscle thickness and CSA of the lumbar multifidi and LBP in adolescent soccer players. These findings suggest that other factors rather than the thickness of deep trunk muscles may play a more significant role in the etiology of LBP in adolescent soccer players. PMID:28144414

  5. Free-breathing black-blood CINE fast-spin echo imaging for measuring abdominal aortic wall distensibility: A feasibility study.

    PubMed

    Lin, Jyh-Miin; Patterson, Andrew; Chao, Tzu-Cheng; Zhu, Chengcheng; Chang, Hing-Chiu; Mendes, Jason; Chung, Hsiao-Wen; Gillard, Jonathan; Graves, Martin

    2017-03-22

    The paper reports a free-breathing black-blood CINE fast-spin echo (FSE) technique for measuring abdominal aortic wall motion. The free-breathing CINE FSE includes the following MR techniques: 1) variable-density sampling with fast iterative reconstruction; 2) inner-volume imaging; and 3) a blood-suppression preparation pulse. The proposed technique was evaluated in eight healthy subjects. The inner-volume imaging significantly reduced the intraluminal artifacts of respiratory motion (p = 0.015). The quantitative measurements were a diameter of 16.3 ± 2.8 mm and wall distensibility of 2.0 ± 0.4 mm (12.5 ± 3.4%) and 0.7 ± 0.3 mm (4.1 ± 1.0%) for the anterior and posterior walls, respectively. The cyclic cross-sectional distensibility was 35 ± 15% greater in the systolic phase than in the diastolic phase. In conclusion, we developed a feasible CINE FSE method to measure the motion of the abdominal aortic wall, which will enable clinical scientists to study the elasticity of the abdominal aorta.

  6. Measurement of three-dimensional normal vectors, principal curvatures, and wall thickness of the heart using cine-MRI

    NASA Astrophysics Data System (ADS)

    Coghlan, Leslie; Singleton, H. R.; Dell'Italia, L. J.; Linderholm, C. E.; Pohost, G. M.

    1995-05-01

    We have developed a method for measuring the detailed in vivo three dimensional geometry of the left and right ventricles using cine-magnetic resonance imaging. From data in the form of digitized short axis outlines, the normal vectors, principal curvatures and directions, and wall thickness were computed. The method was evaluated on simulated ellipsoids and on human MRI data. Measurements of normal vectors and of wall thickness were very accurate in simulated data and appeared appropriate in patient data. On simulated data, measurements of the principal curvature k1 (corresponding approximately to the short axis direction of the left ventricle) and of principal directions were quite accurate, but measurements of the other principal curvature (k2) were less accurate. The reasons behind this are considered. We expect improvements in the accuracy with thinner slices and improved representation of the surface data. Gradient echo images were acquired from 8 dogs with a 1.5T system (Philips Gyroscan) at baseline and four months after closed chest experimentally produced mitral regurgitation (MR). The product (k1 + k2) X wall thickness averaged over all slices at end-diastole was significantly lower after surgery (n equals 8, p < 0.005). These geometry changes were consistent with the expected increase in wall stress after MR.

  7. Techniques for Abdominal Wall Closure after Damage Control Laparotomy: From Temporary Abdominal Closure to Early/Delayed Fascial Closure—A Review

    PubMed Central

    Huang, Qian; Li, Jieshou; Lau, Wan-yee

    2016-01-01

    Open abdomen (OA) has been an effective treatment for abdominal catastrophes in traumatic and general surgery. However, management of patients with OA remains a formidable task for surgeons. The central goal of OA is closure of fascial defect as early as is clinically feasible without precipitating abdominal compartment syndrome. Historically, techniques such as packing, mesh, and vacuum-assisted closure have been developed to assist temporary abdominal closure, and techniques such as components separation, mesh-mediated traction, bridging fascial defect with permanent synthetic mesh, or biologic mesh have also been attempted to achieve early primary fascial closure, either alone or in combined use. The objective of this review is to present the challenges of these techniques for OA with a goal of early primary fascial closure, when the patient's physiological condition allows. PMID:26819597

  8. A reduced-order model for wall shear stress in abdominal aortic aneurysms by proper orthogonal decomposition.

    PubMed

    Chang, Gary Han; Schirmer, Clemens M; Modarres-Sadeghi, Yahya

    2017-03-21

    In this paper, we introduce a method to construct a Reduced-Order Model (ROM) to study the physiological flow and the Wall Shear Stress (WSS) conditions in Abdominal Aortic Aneurysms (AAA). We start the process by running a training case using Computational Fluid Dynamics (CFD) simulations with time-varying flow parameters, such that these parameters cover the range of parameters that we would like to consider in our ROM. We use the inflow angle as the variable parameter in the current study. Then we use the snapshot Proper Orthogonal Decomposition (POD) to construct the reduced-order bases, which are subsequently enhanced using a QR-factorization technique to satisfy the relevant fluid boundary conditions. The resulting ROM enables us to study the flow pattern and the WSS distribution over a range of system parameters computationally very efficiently. We have used this method to show how the WSS varies significantly for an AAA with a simplified geometry, over a range of inflow angles usually considered mild in clinical terms. We have validated the ROM results with CFD results. This approach enables comprehensive analysis of the model system across a range of inflow angles and frequencies without the need to re-compute the simulation for small changes.

  9. Reconstruction of large-size abdominal wall defect using biodegradable poly-p-dioxanone mesh: an experimental canine study

    PubMed Central

    2014-01-01

    Background Reconstruction of large-size abdominal wall defect (AWDs) is a huge challenge faced in current surgical practice. In this study, we aimed to evaluate the effectiveness and safety of biodegradable poly-p-dioxanone (PDO) mesh for reconstructing large-size AWDs in an experimental canine model. Methods Eighteen experimental canines were randomly and equally divided into three groups, namely, a PDO group, a Marlex group and a control group (n = 6 each). Following the creation of a 6 cm × 5.5 cm AWD, PDO mesh and Marlex mesh were used to reconstruct the defect in the PDO and Marlex groups, respectively. The defect was closed using relaxation sutures alone in the control group. Animals were killed 24 weeks after surgery, and reconstruction outcomes were evaluated using radiography, histology and biomechanical testing. Results All animals except those in the control group survived the experiment. The PDO group showed no wound dehiscence, herniation or infection, whereas the animals in the Marlex group exhibited marked foreign body reactions. The PDO group had less intraabdominal adhesion than the Marlex group. As shown by radiography, histology and biomechanical testing, PDO mesh exhibited complete degradation and favorable biochemical strength at 24 weeks postsurgery. Conclusions PDO mesh implantation is an effective, safe treatment modality for reconstructing large-size AWDs. PMID:24625138

  10. Risk factors associated with early failure in complex abdominal wall reconstruction: a 5 year single surgeon experience.

    PubMed

    Wink, Jason D; Wes, Ari M; Fischer, John P; Nelson, Jonas A; Stranksy, Carrie; Kovach, Stephen J

    2015-04-01

    Complex abdominal wall reconstruction (AWR) is commonly performed, but with a significant rate of surgical complications and hernia recurrence. The aim of this experiential review is to assess risk factors for hernia recurrence after complex AWR. A retrospective review of AWR patients from 2007-2012 was performed. Rates of hernia recurrence were assessed. Univariate analyses and subsequent multivariate logistic regression analysis was used to assess independent predictors of early hernia recurrence. One hundred and thirty-four consecutive cases of AWR were performed over a 5-year period. Hernia recurrence developed in 14 (10.4%) patients. Hernias derived from trauma (OR = 19.76, p = 0.011) and those who experienced postoperative wound infections (OR = 18.81, p = 0.004) were at increased risk for hernia recurrence. In conclusion, increased vigilance must be paid to patients presenting after trauma with massive loss of domain and those who experience postoperative infection, as these cohorts are at added risk for failed reconstruction.

  11. Charged magnetic domain walls as observed in nanostructured thin films: dependence on both film thickness and anisotropy.

    PubMed

    Favieres, C; Vergara, J; Madurga, V

    2013-02-13

    The magnetic domain configurations of soft magnetic, nanostructured, pulsed laser-deposited Co films were investigated. Their dependence on both the thickness t (20 nm ≤ t ≤ 200 nm) and the anisotropy was studied. Charged zigzag walls, with a characteristic saw-tooth vertex angle θ, were observed. θ changed with t from θ ≈ 17° to ≈25°, presenting an intermediate sharp maximum that has not been described before. The reduced length of the zigzag walls also exhibited a peak at t ≈ 70 nm. The relationship between the total reduced length and the density energy of the magnetic wall allowed us to establish a change from a Néel-type to a Bloch-type core of the zigzag walls at this thickness, t ≈ 70 nm. We also accounted for the magnetic energy arising from the surface roughness of the thinner films after imaging the film surface morphologies. Moreover, this distinctive behaviour of the zigzag walls of these low-anisotropy films was compared to that of high-anisotropy films.

  12. 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.

  13. CRITICAL ANALYSIS OF EXPERIMENTAL MODEL FOR STUDY OF ADHESIONS AFTER INCISIONAL HERNIAS INDUCED IN RATS’ AND REPAIR OF ABDOMINAL WALL WITH DIFFERENT BIOMATERIALS

    PubMed Central

    SERIGIOLLE, Leonardo Carvalho; BARBIERI, Renato Lamounier; GOMES, Helbert Minuncio Pereira; RODRIGUES, Daren Athiê Boy; STUDART, Sarah do Valle; LEME, Pedro Luiz Squilacci

    2015-01-01

    Background: Adhesions induced by biomaterials experimentally implanted in the abdominal cavity are basically studied by primary repair of different abdominal wall defects or by the correction of incisional hernias previously performed with no precise definition of the most appropriate model. Aim: To describe the adhesions which occur after the development of incisional hernias, before the prosthesis implantation, in an experimental model to study the changes induced by different meshes. Methods: Incisional hernias were performed in 10 rats with hernia orifices of standardized dimensions, obtained by the median incision of the abdominal wall and eversion of the defect edges. Ten days after the procedure adhesions of abdominal structures were found when hernias were repaired with different meshes. Results: The results showed hernia sac well defined in all rats ten days after the initial procedure. Adhesions of the greater omentum occurred in five animals of which two also showed adhesions of small bowel loops besides the omentum, and another two showed liver adhesions as well as the greater omentum, numbers with statistical significance by Student's t test (p<0.05). Conclusion: Although it reproduces the real clinical situation, the choice of experimental model of incisional hernia repair previously induced implies important adhesions, with possible repercussions in the evaluation of the second operation, when different implants of synthetic materials are used. PMID:26537141

  14. Reconstruction of the Abdominal Wall in Anatomical Plans. Pre- and Postoperative Keys in Repairing “Cold” Incisional Hernias

    PubMed Central

    POPA, FLORINA; ROSCA, OANA; GEORGESCU, ALEXANDRU; CANNISTRA, CLAUDIO

    2016-01-01

    Background and aims The clinical results of the vertical “vest-over-pants” Mayo repair were evaluated, and the risk factors for incisional hernia recurrence were studied. The purpose of this study is to point out the importance of reducing pre and post operative risk factors in the incisional hernia repair process in order to achieve a physiologically normal abdominal wall. Methods Twenty patients diagnosed with incisional hernia underwent an abdominal reconstruction procedure using the Mayo (Paletot) technique at Bichat Claude Bernard Hospital between 2005 and 2015. All procedures were performed by a single surgeon and all patients were pre-operatively prepared, identifying all coexisting conditions and treating them accordingly before undergoing surgery. Results All patients underwent at least one surgical operation before the hernia repair procedure and a quarter had experienced at least three, prior to this one. Nine patients had a body mass index of >30 kg/m2. Additional risk factors and comorbidities included obesity in 45%, diabetes mellitus in 10%, smoking in 55%, and high blood pressure in 40%. Hernia defect width was from 3 cm (25% F) to 15 cm (5% M) of which nine patients (45%) had a 10 cm defect. Most of the patients had an average hospitalization of 7 days. The patients were carefully monitored and were called on periodic consultations after 3, 6, and 12 months from the moment of the procedure. Patient feedback regarding hernia recurrence and complaints about the scar were noted. Physical examination is essential in determining the hernia recurrence therefore the scar was examined for any abnormalities that may have occurred, which was defined as any palpable or detected fascial defect located within seven centimeters of the hernia repair. Post-operative complications: seroma formation, wound hematoma, superficial and deep wound infection, recurrences and chronic pain were followed and no complications were registered during the follow-up period

  15. [Influence of mydocalm on the degree of intra-abdominal hypertension and local blood circulation in the intestinal wall in experiment].

    PubMed

    Sapegin, V I; Sapegin, I D; Il'chenko, F N

    2014-01-01

    The effect of mydocalm (tolperison, 5 mg/kg single dose) on the dynamics of intra-abdominal hypertension (IAH), blood circulation regulation, and oxygen balance in the tissues of intestinal wall were studied in acute experiments on rabbits. Using a special stand of original design, the initial IAH level was modeled at 200 mm H2O with the subsequent stopping of further receipt of liquid during 3 hours in an elastic container in the abdominal cavity. During 3-h observation without drug administration, no changes in IAH due to the tone of muscles of the frontal abdominal wall takes place, but there is progressive deceleration of local blood flow (-35.33 + 0.99%, p < 0.01), suppressed dilation (-20.02 + 0.54%, p < 0.01) and constriction (-60.45 + 1.17%, p < 0.01) reactivity of vessels, and decreased oxygen tension (-47.18 + 0.75%, p < 0.01) in the intestinal wall at the end of experiment. The introduction of mydocalm reduces the tone of muscles of the frontal abdominal wall, which leads to a decrease in IAH (maximum effect after 1.5 hours, -20.81 + 0.84%, p < 0.01) and prevents decrease in the local blood flow (-26.77 + 0.41%, p < 0.01), suppression of dilation (-16.51 + 0.34%, p < 0.01) and constriction (-37.85 + 0.61%, p < 0.01) reactivity of vessels, and reduction in oxygen tension (-36.60 + 1.18%, p < 0.01) at the end of experiment. The administration of mydocalm can extend the limits of application of a conservative therapy for patients with IAH and to improve the results.

  16. Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy

    PubMed Central

    Xu, Fei; Wang, Tao; Ma, Tianyong; Wang, Ying; Zhu, Shimeng; Li, Fashen

    2016-01-01

    This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50–230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data. PMID:26821614

  17. Collapse pressure analysis of transversely isotropic thick-walled cylinder using Lebesgue strain measure and transition theory.

    PubMed

    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.

  18. Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy.

    PubMed

    Xu, Fei; Wang, Tao; Ma, Tianyong; Wang, Ying; Zhu, Shimeng; Li, Fashen

    2016-01-29

    This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50-230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data.

  19. Enhanced film thickness for Néel wall in soft magnetic film by introducing strong magnetocrystalline anisotropy

    NASA Astrophysics Data System (ADS)

    Xu, Fei; Wang, Tao; Ma, Tianyong; Wang, Ying; Zhu, Shimeng; Li, Fashen

    2016-01-01

    This study investigated the magnetic domain walls in a single-layer soft magnetic film with strong magnetocrystalline anisotropy energy. The soft magnetic film is composed of a highly c-axis-oriented hcp-Co81Ir19 alloy with strong negative magnetocrystalline anisotropy. The domain structure of the soft Co81Ir19 films with thickness ranging from 50-230 nm in a demagnetization state was observed through magnetic force microscopy and Lorentz transmission electron microscopy. Results reveal that the critical transition thickness at which the domain wall changes from Néel type to Bloch type is about 138 nm, which is much larger than the critical value of traditional Fe- and Co-based soft magnetic films with negligible magnetocrystalline anisotropy. Theoretical calculation was also performed and the calculated result agrees well with experimental data.

  20. Chest-wall thickness and percent thoracic fat estimation by B-mode ultrasound: system and procedure review

    SciTech Connect

    Berger, C.D.; Lane, B.H.; Dunsmore, M.R.

    1983-02-01

    Accurate measurement of chest wall thickness is necessary for estimation of lung burden of transuranic elements in humans. To achieve tis capability, the ORNL Whole Body Counter has acquired a B-mode ultrasonic imaging system for defining the structure within the thorax of the body. This report contains a review of the ultrasound system in use at the ORNL Whole Body Counter, including its theory of operation, and te procedure for use of the system. Future developmental plans are also presented.

  1. [Inconsistency between voltage of the electrocardiogram and the left ventricular wall thickness. diagnostic key in cardiac amyloidosis].

    PubMed

    Contreras, A; Beacon, E; Brenna, Eduardo J; Parisi, Gustavo R; Chamale, Roberto A; Gilardi, F; Bürguesser, M V; Salomone, O

    2013-01-01

    Restrictive cardiomyopathy is the least common form of cardiomyopathy, and the disease that most often cause it, is the system amyloidosis. We present a 62-year-old with a history of heart failure, which in its assessment highlights the discrepancy between the low voltage ventricular complexes in the electrocardiogram and the severity of left ventricular wall thickness on echocardiography. This discrepancy was the source of suspicion and subsequent confirmation of systemic amyloidosis with cardiac involvement.

  2. Dimensionless analysis of valveless pumping in a thick-wall elastic tube: Application to the tubular embryonic heart.

    PubMed

    Kozlovsky, Pavel; Rosenfeld, Moshe; Jaffa, Ariel J; Elad, David

    2015-06-25

    The physical mechanism that drives blood flow in the valveless tubular embryonic heart is still debatable whether it is peristaltic flow or valveless dynamic suction. Previous studies of valveless pumping were concerned with either the role of the excitation parameters or the mechanisms that generate the unidirectional outflow. In this study, a dimensionless one-dimensional (1D) analysis of the valveless pumping due to local excitation at an asymmetric longitudinal location was performed for non-uniform thick-wall elastic tubes, including tubes with local bulging and tapering. A general tube law that accounts for wall thicknesses was implemented for describing the physically realistic dynamics of the tube and the two-step MacCormack algorithm was utilized for the numerical analysis. A comprehensive analysis was conducted to explore the affecting roles of the system (e.g., tube geometry) and the working (e.g., Strouhal number and flow friction parameter) parameters on the net outflow of the pump. The maximal positive net outflow in all the tested cases always occurred when the natural Strouhal number was about π. Flow reversals were observed only for relatively low friction parameters. A local bulging at the site of excitation and thick walls contributed to larger outflows, while tube tapering reduced the net outflow.

  3. Stoichiometry, Length, and Wall Thickness Optimization of TiO2 Nanotube Array for Efficient Alcohol Sensing.

    PubMed

    Hazra, A; Bhowmik, B; Dutta, K; Chattopadhyay, P P; Bhattacharyya, P

    2015-05-13

    The present study concerns development of an efficient alcohol sensor by controlling the stoichiometry, length, and wall thickness of electrochemically grown TiO2 nanotube array for its use as the sensing layer. Judicious variation of H2O content (0, 2, 10 and 100% by volume) in the mixed electrolyte comprising ethylene glycol and NH4F resulted into the desired variation of stoichiometry. The sensor study was performed within the temperature range of 27 to 250 °C for detecting the alcohols in the concentration range of 10-1000 ppm. The nanotubes grown with the electrolyte containing 2 vol % H2O offered the maximum response magnitude. For this stoichiometry, variation of corresponding length (1.25-2.4 μm) and wall thickness (19.8-9 nm) of the nanotubes was achieved by varying the anodization time (4-16 h) and temperatures (42-87 °C), respectively. While the variation of length influenced the sensing parameters insignificantly, the best response magnitude was achieved for ∼13 nm wall thickness. The underlying sensing mechanism was correlated with the experimental findings on the basis of structural parameters of the nanotubes.

  4. Image-guided intensity-modulated radiotherapy for refractory bilateral breast cancer in a patient with extensive cutaneous metastasis in the chest and abdominal walls

    PubMed Central

    Lu, Yueh-Feng; Lin, Yu-Chin; Chen, Kuo-Hsin; Shueng, Pei-Wei; Yeh, Hsin-Pei; Hsieh, Chen-Hsi

    2016-01-01

    Treatment for bilateral breast cancer with chest wall and abdominal skin invasion normally involves conventional radiotherapy (RT); however, conventional RT provides inadequate target volume coverage and excessive treatment of large volumes of normal tissue. Helical tomotherapy (HT) has the ability to deliver continuous craniocaudal irradiation that suppresses junction problems and provides good conformity of dose distribution. A 47-year-old female with stage IV bilateral breast cancer with chest wall and pectoralis major muscle invasion, lymphadenopathy, bilateral pleural effusion, and multiple bone metastases received chemotherapy and target therapy beginning in January 2014; 4 months after the initiation of chemotherapy, computed tomography revealed progression of chest and abdominal wall invasion. A total dose of 70.2 Gy was delivered to both breasts, the chest wall, the abdominal wall, and the bilateral supraclavicular nodal areas in 39 fractions via HT. The total planning target volume was 4,533.29 cm3. The percent of lung volume receiving at least 20 Gy (V20) was 28%, 22%, and 25% for the right lung, left lung, and whole lung, respectively. The mean dose to the heart was 8.6 Gy. Follow-up computed tomography revealed complete response after the RT course. Grade 1 dysphagia, weight loss, grade 2 neutropenia, and grade 3 dermatitis were noted during the RT course. Pain score decreased from 6 to 1. No cardiac, pulmonary, liver, or intestinal toxicity developed during treatment or follow-up. Concurrent HT with or without systemic treatment could be a safe salvage therapy for chemorefractory locally advanced breast cancer patients with extensive cutaneous metastasis. PMID:27284253

  5. 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.

  6. Diffusion capacity and CT measures of emphysema and airway wall thickness – relation to arterial oxygen tension in COPD patients

    PubMed Central

    Saure, Eirunn Waatevik; Bakke, Per Sigvald; Eagan, Tomas Mikal Lind; Aanerud, Marianne; Jensen, Robert Leroy; Grydeland, Thomas Blix; Johannessen, Ane; Nilsen, Roy Miodini; Thorsen, Einar; Hardie, Jon Andrew

    2016-01-01

    Background Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased arterial oxygen tension (PaO2), but there are limited data on associations between PaO2 and computed tomography (CT) derived measures of emphysema and airway wall thickness. Objective To examine whether CT measures of emphysema and airway wall thickness are associated with level of arterial oxygen tension beyond that provided by measurements of diffusion capacity and spirometry. Methods The study sample consisted of 271 smoking or ex-smoking COPD patients from the Bergen COPD Cohort Study examined in 2007–2008. Emphysema was assessed as percent of low-attenuation areas<−950 Hounsfield units (%LAA), and airway wall thickness as standardised measure at an internal perimeter of 10 mm (AWT-Pi10). Multiple linear regression models were fitted with PaO2 as the outcome variable, and %LAA, AWT-Pi10, DLCO and carbon monoxide transfer coefficient (KCO) as main explanatory variables. The models were adjusted for sex, age, smoking status, and haemoglobin concentration, as well as forced expiratory volume in one second (FEV1). Results Sixty two per cent of the subjects were men, mean (SD) age was 64 (7) years, mean (SD) FEV1 in percent predicted was 50 (15)%, and mean PaO2 (SD) was 9.3 (1.1) kPa. The adjusted regression coefficient (CI) for PaO2 was –0.32 (−0.04–(−0.019)) per 10% increase in %LAA (p<0.01). When diffusion capacity and FEV1 were added to the model, respectively, the association lost its statistical significance. No relationship between airway wall thickness and PaO2 was found. Conclusion CT assessment of airway wall thickness is not associated with arterial oxygen tension in COPD patients. Emphysema score measured by chest CT, is related to decreased PaO2, but cannot replace measurements of diffusion capacity in the clinical evaluation of hypoxaemia. PMID:27178139

  7. Computer simulation of the precordial QRS complex: effects of simulated changes in ventricular wall thickness and volume.

    PubMed

    Salu, Y; Marcus, M L

    1976-12-01

    The cardiac electric field generated by depolarization of the human ventricle is simulated with a computer model which utilizes 1,500 dipoles. The configuration of the ventricles utilized in the model assumed that the cross-sectional shape of the left ventricle was circular and the right ventricular free wall was a portion of an ellipse. The torso was assumed to be homogeneous and infinite. The activation sequence was based on the measurements of Durrer. The depolarizational wave was simulated by dipole layers. The output of the model is presented as a standard multilead precordial ECG. The ECG complexes generated by the model closely resemble the precordial QRS complexes of normal man. Simulated increases in wall thickness (1 to 2.2 X control) were associated with changes in the calculated precordial QRS complexes which were characteristic of left ventricular hypertrophy. Voltage (R in V5 or V6 and S in V1) and QRS duration increased linearly as a function of calculated left ventricular mass. Increases in ventricular activation time were related nonlinearly to changes in left ventricular mass and did not occur in the absence of a simulated increase in wall thickness. The effects of simulated changes in left ventricular volume (0.6 to 3.0 X control) on the QRS complex were mainly dependent on the resultant increase in left ventricular mass. This model may be useful in simulating the precordial QRS complexes that result from isolated or combined changes in ventricular volume or wall thickness or other disorders of the heart. Furthermore, it may be useful whenever a simulation of a QRS generator is needed.

  8. 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

  9. Automatic airway wall segmentation and thickness measurement for long-range optical coherence tomography images.

    PubMed

    Qi, Li; Huang, Shenghai; Heidari, Andrew E; Dai, Cuixia; Zhu, Jiang; Zhang, Xuping; Chen, Zhongping

    2015-12-28

    We present an automatic segmentation method for the delineation and quantitative thickness measurement of multiple layers in endoscopic airway optical coherence tomography (OCT) images. The boundaries of the mucosa and the sub-mucosa layers are accurately extracted using a graph-theory-based dynamic programming algorithm. The algorithm was tested with sheep airway OCT images. Quantitative thicknesses of the mucosal layers are obtained automatically for smoke inhalation injury experiments.

  10. Large-scale, thick, self-assembled, nacre-mimetic brick-walls as fire barrier coatings on textiles

    PubMed Central

    Das, Paramita; Thomas, Helga; Moeller, Martin; Walther, Andreas

    2017-01-01

    Highly loaded polymer/clay nanocomposites with layered structures are emerging as robust fire retardant surface coatings. However, time-intensive sequential deposition processes, e.g. layer-by-layer strategies, hinders obtaining large coating thicknesses and complicates an implementation into existing technologies. Here, we demonstrate a single-step, water-borne approach to prepare thick, self-assembling, hybrid fire barrier coatings of sodium carboxymethyl cellulose (CMC)/montmorillonite (MTM) with well-defined, bioinspired brick-wall nanostructure, and showcase their application on textile. The coating thickness on the textile is tailored using different concentrations of CMC/MTM (1–5 wt%) in the coating bath. While lower concentrations impart conformal coatings of fibers, thicker continuous coatings are obtained on the textile surface from highest concentration. Comprehensive fire barrier and fire retardancy tests elucidate the increasing fire barrier and retardancy properties with increasing coating thickness. The materials are free of halogen and heavy metal atoms, and are sourced from sustainable and partly even renewable building blocks. We further introduce an amphiphobic surface modification on the coating to impart oil and water repellency, as well as self-cleaning features. Hence, our study presents a generic, environmentally friendly, scalable, and one-pot coating approach that can be introduced into existing technologies to prepare bioinspired, thick, fire barrier nanocomposite coatings on diverse surfaces. PMID:28054589

  11. Large-scale, thick, self-assembled, nacre-mimetic brick-walls as fire barrier coatings on textiles

    NASA Astrophysics Data System (ADS)

    Das, Paramita; Thomas, Helga; Moeller, Martin; Walther, Andreas

    2017-01-01

    Highly loaded polymer/clay nanocomposites with layered structures are emerging as robust fire retardant surface coatings. However, time-intensive sequential deposition processes, e.g. layer-by-layer strategies, hinders obtaining large coating thicknesses and complicates an implementation into existing technologies. Here, we demonstrate a single-step, water-borne approach to prepare thick, self-assembling, hybrid fire barrier coatings of sodium carboxymethyl cellulose (CMC)/montmorillonite (MTM) with well-defined, bioinspired brick-wall nanostructure, and showcase their application on textile. The coating thickness on the textile is tailored using different concentrations of CMC/MTM (1–5 wt%) in the coating bath. While lower concentrations impart conformal coatings of fibers, thicker continuous coatings are obtained on the textile surface from highest concentration. Comprehensive fire barrier and fire retardancy tests elucidate the increasing fire barrier and retardancy properties with increasing coating thickness. The materials are free of halogen and heavy metal atoms, and are sourced from sustainable and partly even renewable building blocks. We further introduce an amphiphobic surface modification on the coating to impart oil and water repellency, as well as self-cleaning features. Hence, our study presents a generic, environmentally friendly, scalable, and one-pot coating approach that can be introduced into existing technologies to prepare bioinspired, thick, fire barrier nanocomposite coatings on diverse surfaces.

  12. Large-scale, thick, self-assembled, nacre-mimetic brick-walls as fire barrier coatings on textiles.

    PubMed

    Das, Paramita; Thomas, Helga; Moeller, Martin; Walther, Andreas

    2017-01-05

    Highly loaded polymer/clay nanocomposites with layered structures are emerging as robust fire retardant surface coatings. However, time-intensive sequential deposition processes, e.g. layer-by-layer strategies, hinders obtaining large coating thicknesses and complicates an implementation into existing technologies. Here, we demonstrate a single-step, water-borne approach to prepare thick, self-assembling, hybrid fire barrier coatings of sodium carboxymethyl cellulose (CMC)/montmorillonite (MTM) with well-defined, bioinspired brick-wall nanostructure, and showcase their application on textile. The coating thickness on the textile is tailored using different concentrations of CMC/MTM (1-5 wt%) in the coating bath. While lower concentrations impart conformal coatings of fibers, thicker continuous coatings are obtained on the textile surface from highest concentration. Comprehensive fire barrier and fire retardancy tests elucidate the increasing fire barrier and retardancy properties with increasing coating thickness. The materials are free of halogen and heavy metal atoms, and are sourced from sustainable and partly even renewable building blocks. We further introduce an amphiphobic surface modification on the coating to impart oil and water repellency, as well as self-cleaning features. Hence, our study presents a generic, environmentally friendly, scalable, and one-pot coating approach that can be introduced into existing technologies to prepare bioinspired, thick, fire barrier nanocomposite coatings on diverse surfaces.

  13. 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. PMID:26622812

  14. 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.

  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. [Inflammatory aneurysms of the abdominal aorta].

    PubMed

    Tovar Martín, E; Acea Nebril, B

    1993-01-01

    Approximately 10 per cent of abdominal aneurysms have an excessively thick wall that sometimes involve duodenum, cava or colon by an inflammatory process. Between February 1986 and December 1992, 147 patients with abdominal aortic aneurysm (AAA) were treated surgically and in 13 (8.8%) the aneurysms were found to be inflammatory. Their mean age was 67.3 years (70.1 years in non inflammatory group) and all were symptomatics initially (abdominal pain in 53%, rupture in 23%, mass in 15%). The operative mortality for elective resection was 37% in patients with inflammatory abdominal aortic aneurysms (IAAA) decreasing to 9% in the AAA group without inflammatory involvement. We conclude that surgery is indicated in these patients to prevent rupture and to hasten the subsidense of inflammatory process ever with postoperative morbi-mortality increased.

  17. 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.

  18. 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.

  19. Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs.

    PubMed

    Roje, Zdravko; Roje, Zeljka; Matić, Dario; Librenjak, Davor; Dokuzović, Stjepan; Varvodić, Josip

    2011-12-23

    Necrotizing fasciitis (NF) is an uncommon soft tissue infection, usually caused by toxin-producing virulent bacteria. It is characterized by widespread fascial necrosis primarily caused by Streptococcus hemolyticus. Shortly after the onset of the disease, patients become colonized with their own aerobic and anaerobic microflora from the gastrointestinal and/or urogenital tracts. Early diagnosis with aggressive multidisciplinary treatment is mandatory. We describe three clinical cases with NF. The first is a 69 years old man with diabetes mellitus type II, who presented with NF on the posterior chest wall, shoulder and arm. He was admitted to the intensive care unit (ICU) with a clinical picture of severe sepsis. Outpatient treatment and early surgical debridement of the affected zones (inside 3 hours after admittance) and critical care therapy were performed. The second case is of a 63 years old paraplegic man with diabetes mellitus type I. Pressure sores and perineal abscesses progressed to Fournier's gangrene of the perineum and scrotum. He had NF of the anterior abdominal wall and the right thigh. Outpatient treatment and early surgical debridement of the affected zones (inside 6 hour after admittance) and critical care therapy were performed. The third patient was a 56 year old man who had NF of the anterior abdominal wall, flank and retroperitoneal space. He had an operation of the direct inguinal hernia, which was complicated with a bowel perforation and secondary peritonitis. After establishing the diagnosis of NF of the abdominal wall and retroperitoneal space (RS), he was transferred to the ICU. There he first received intensive care therapy, after which emergency surgical debridement of the abdominal wall, left colectomy, and extensive debridement of the RS were done (72 hours after operation of inquinal hernia). On average, 4 serial debridements were performed in each patient. The median of serial debridement in all three cases was four times. Other

  20. Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs

    PubMed Central

    2011-01-01

    Necrotizing fasciitis (NF) is an uncommon soft tissue infection, usually caused by toxin-producing virulent bacteria. It is characterized by widespread fascial necrosis primarily caused by Streptococcus hemolyticus. Shortly after the onset of the disease, patients become colonized with their own aerobic and anaerobic microflora from the gastrointestinal and/or urogenital tracts. Early diagnosis with aggressive multidisciplinary treatment is mandatory. We describe three clinical cases with NF. The first is a 69 years old man with diabetes mellitus type II, who presented with NF on the posterior chest wall, shoulder and arm. He was admitted to the intensive care unit (ICU) with a clinical picture of severe sepsis. Outpatient treatment and early surgical debridement of the affected zones (inside 3 hours after admittance) and critical care therapy were performed. The second case is of a 63 years old paraplegic man with diabetes mellitus type I. Pressure sores and perineal abscesses progressed to Fournier's gangrene of the perineum and scrotum. He had NF of the anterior abdominal wall and the right thigh. Outpatient treatment and early surgical debridement of the affected zones (inside 6 hour after admittance) and critical care therapy were performed. The third patient was a 56 year old man who had NF of the anterior abdominal wall, flank and retroperitoneal space. He had an operation of the direct inguinal hernia, which was complicated with a bowel perforation and secondary peritonitis. After establishing the diagnosis of NF of the abdominal wall and retroperitoneal space (RS), he was transferred to the ICU. There he first received intensive care therapy, after which emergency surgical debridement of the abdominal wall, left colectomy, and extensive debridement of the RS were done (72 hours after operation of inquinal hernia). On average, 4 serial debridements were performed in each patient. The median of serial debridement in all three cases was four times. Other

  1. Estimation of emission cone wall thickness of Jupiter's decametric radio emission using stereoscopic STEREO/WAVES observations

    NASA Astrophysics Data System (ADS)

    Panchenko, M.; Rucker, H. O.

    2016-11-01

    Aims: Stereoscopic observations by the WAVES instrument onboard two STEREO spacecraft have been used with the aim of estimating wall thickness of an emission cone of Jovian decametric radio emission (DAM). Methods: Stereoscopic observations provided by STEREO-A and -B facilitate unambiguous recognition of the Jovian DAM in observed dynamic spectra as well as identification of its components (Io DAM or non-Io DAM). The dynamic spectra of radio emissions recorded by STEREO/WAVES have been analyzed using the method of cross-correlation of the radio dynamic spectra. Results: Altogether, 139 radio events, in particular 91 Io- and 48 non-Io-related radio events were observed. The averaged width of the emission cone wall for Io-DAM as well as for non-Io DAM is about 1.1° ± 0.2°. These results are in agreement with previous findings.

  2. Space- and time-resolved resistive measurements of liquid metal wall thickness

    NASA Astrophysics Data System (ADS)

    Mirhoseini, S. M. H.; Volpe, F. A.

    2016-11-01

    In a fusion reactor internally coated with liquid metal, it will be important to diagnose the thickness of the liquid at various locations in the vessel, as a function of time, and possibly respond to counteract undesired bulging or depletion. The electrical conductance between electrodes immersed in the liquid metal can be used as a simple proxy for the local thickness. Here a matrix of electrodes is shown to provide spatially and temporally resolved measurements of liquid metal thickness in the absence of plasma. First a theory is developed for m × n electrodes, and then it is experimentally demonstrated for 3 × 1 electrodes, as the liquid stands still or is agitated by means of a shaker. The experiments were carried out with Galinstan, but are easily extended to lithium or other liquid metals.

  3. Ureteral wall thickness at the impacted ureteral stone site: a critical predictor for success rates after SWL.

    PubMed

    Sarica, Kemal; Kafkasli, Alper; Yazici, Özgür; Çetinel, Ali Cihangir; Demirkol, Mehmet Kutlu; Tuncer, Murat; Şahin, Cahit; Eryildirim, Bilal

    2015-02-01

    The aim of the study was to determine the possible predictive value of certain patient- and stone-related factors on the stone-free rates and auxiliary procedures after extracorporeal shock wave lithotripsy in patients with impacted proximal ureteral calculi. A total of 111 patients (86 male, 25 females M/F: 3.44/1) with impacted proximal ureteral stones treated with shock wave lithotripsy were evaluated. Cases were retrieved from a departmental shock wave lithotripsy database. Variables analyzed included BMI of the case, diameter of proximal ureter and renal pelvis, stone size and Hounsfield unit, ureteral wall thickness at the impacted stone site. Stone-free status on follow-up imaging at 3 months was considered a successful outcome. All patients had a single impacted proximal ureteral stone. While the mean age of the cases was 46 ± 13 years (range 26-79 years), mean stone size was 8.95 mm (5.3-15.1 mm). Following shock wave lithotripsy although 87 patients (78.4%) were completely stone-free at 3-month follow-up visit, 24 (21.6%) cases had residual fragments requiring further repeat procedures. Prediction of the final outcome of SWL in patients with impacted proximal ureteral stones is a challenging issue and our data did clearly indicate a highly significant relationship between ureteral wall thickness and the success rates of shock wave lithotripsy particularly in cases requiring additional procedures. Of all the evaluated stone- and patient-related factors, only ureteral wall thickness at the impacted stone site independently predicted shock wave lithotripsy success.

  4. The thickness and the lengths of the anterior wall of adult maxilla of the West Anatolian Turkish people.

    PubMed

    Arman, Candan; Ergür, Ipek; Atabey, Atay; Güvencer, Mustafa; Kiray, Amac; Korman, Esin; Tetik, Suleyman

    2006-12-01

    The maxilla is the key structure on facial formation and stability. The knowledge about maxillary thickness and dimensions is crucial during facial reconstruction including this bone. In this study, anthropometric measurements of anterior wall of the maxilla on the dry human skulls were aimed. Sixty maxillae of 30 adult dry skulls of West Anatolian people were evaluated. Four vertical lines were drawn between the piriform aperture and lateral border of the bone and six horizontal lines between the infra-orbital margin and the inferior border of the piriform aperture. After establishing the lines, maxillary thicknesses on the intersection points of the vertical and horizontal lines and the lengths of the vertical lines from the infra-orbital margin to alveolar arch were measured by using a fine caliper. It was found that the thickest point of the anterior wall of the maxillae is on the lateral of the infra-orbital margin (5.17 +/- 2.27 mm), and thinnest one is on the inferior of the infra-orbital foramen (0.92 +/- 1.06 mm). The length of the vertical line tangent to piriform aperture (47.66 +/- 3.61 mm) is the longest. The corresponding data of the left and right maxillae were compared by Student's t test. There was no significant difference between both sides. After collecting the data, a thickness map of anterior wall of the maxilla was drawn. This data may be helpful in clinic during osteotomies, bone reconstructions, screw, or other reconstruction apparatus applications on the maxilla.

  5. 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.

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

    NASA Technical Reports Server (NTRS)

    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.

  7. Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls

    SciTech Connect

    Moir, R W; Rognlien, T D

    2006-04-26

    A fusion power plant is described that utilizes a new version of the tandem mirror device including spinning liquid walls. The magnetic configuration is evaluated with an axisymmetric equilibrium code predicting an average beta of 60%. The geometry allows a flowing molten salt, (flibe-Li{sub 2}BeF{sub 4}), which protects the walls and structures from damage arising from neutrons and plasma particles. The free surface between the liquid and the burning plasma is heated by bremsstrahlung radiation, line radiation, and by neutrons. The temperature of the free surface of the liquid is calculated, and then the evaporation rate is estimated from vapor-pressure data. The allowed impurity concentration in the burning plasma is taken as 1% fluorine, which gives a 17% reduction in the fusion power owing to D/T fuel dilution, with F line-radiation causing minor power degradation. The end leakage power density of 0.6 MW/m{sup 2} is readily handled by liquid jets. The tritium breeding is adequate with natural lithium. A number of problem areas are identified that need further study to make the design more self-consistent and workable; however, the simple geometry and the use of liquid walls promise the cost of power competitive with that from fission and coal.

  8. Omental infarction and its mimics: imaging features of acute abdominal conditions presenting with fat stranding greater than the degree of bowel wall thickening.

    PubMed

    Tonerini, Michele; Calcagni, Francesca; Lorenzi, Silvia; Scalise, Paola; Grigolini, Alessandro; Bemi, Pietro

    2015-08-01

    The segmental omental infarction is a rare self-limited disorder presenting with aspecific clinical symptoms that may mimic several acute abdominal conditions. Therefore, a correct noninvasive diagnosis is important because treatment approaches range from monitoring to surgery. As omental infarction results in an important fat stranding that is much greater than the degree of bowel wall thickening, it suggests a narrower differential diagnosis: appendicitis, diverticulitis, epiploic appendagitis, and mesenteric panniculitis. In this pictorial essay, we point out the importance of imaging in identifying this typical sign allowing alternate diagnoses such as segmental omental infarction that can be conservatively managed.

  9. Instrumented thick-walled tube method for measuring thermal pressure in fluids and isotropic stresses in thermosetting resins

    NASA Astrophysics Data System (ADS)

    Merzlyakov, Mikhail; Simon, Sindee L.; McKenna, Gregory B.

    2005-06-01

    We have developed a method for measuring the thermal pressure coefficient and cure-induced and thermally induced stresses based on an instrumented thick-walled tube vessel. The device has been demonstrated at pressures up to 330 MPa and temperatures to 300 °C. The method uses a sealed stainless steel thick-walled tube to impose three-dimensional isotropic constraints. The tube is instrumented with strain gauges in hoop and in axial directions and can be used in open or closed configurations. By making measurements of the isotropic stresses as a function of temperature, the method allows determination of the thermal pressure coefficient in both the glassy and rubbery (or liquid) states. The method also can be used to measure isotropic stress development in thermosetting resins during cure and subsequent thermal cycling. Experimental results are presented for sucrose benzoate, di-2-ethylhexylsebacate, and an epoxy resin. The current report shows that the method provides reliable estimates for the thermal pressure coefficient. The thermal pressure coefficient is determined with resolution on the order of 10kPa/K. Among advantages of the method is that the tubes are reusable, even when measurements are made for cure response of thermosetting resins.

  10. 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

  11. 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

  12. SU-C-BRA-04: Use of Esophageal Wall Thickness in Evaluation of the Response to Chemoradiation Therapy for Esophageal Cancer

    SciTech Connect

    Wang, J; Kligerman, S; Lu, W; Kang, M

    2015-06-15

    Purpose: To quantitatively evaluate the esophageal cancer response to chemoradiation therapy (CRT) by measuring the esophageal wall thickness in CT. Method: Two datasets were used in this study. The first dataset is composed of CT scans of 15 esophageal cancer patients and 15 normal controls. The second dataset is composed of 20 esophageal cancer patients who underwent PET/CT scans before (Pre-CRT) and after CRT (Post-CRT). We first segmented the esophagus using a multi-atlas-based algorithm. The esophageal wall thickness was then computed, on each slice, as the equivalent circle radius of the segmented esophagus excluding the lumen. To evaluate the changes of wall thickness, we computed the standard deviation (SD), coefficient of variation (COV, SD/Mean), and flatness [(Max–Min)/Mean] of wall thickness along the entire esophagus. Results: For the first dataset, the mean wall thickness of cancer patients and normal controls were 6.35 mm and 6.03 mm, respectively. The mean SD, COV, and flatness of the wall thickness were 2.59, 0.21, and 1.27 for the cancer patients and 1.99, 0.16, and 1.13 for normal controls. Statistically significant differences (p < 0.05) were identified in SD and flatness. For the second dataset, the mean wall thickness of pre-CRT and post-CRT patients was 7.13 mm and 6.84 mm, respectively. The mean SD, COV, and flatness were 1.81, 0.26, and 1.06 for pre-CRT and 1.69, 0.26, and 1.06 for post-CRT. Statistically significant difference was not identified for these measurements. Current results are based on the entire esophagus. We believe significant differences between pre- and post-CRT scans could be obtained, if we conduct the measurements at tumor sites. Conclusion: Results show thicker wall thickness in pre-CRT scans and differences in wall thickness changes between normal and abnormal esophagus. This demonstrated the potential of esophageal wall thickness as a marker in the tumor CRT response evaluation. This work was supported in part by

  13. The hypertrophy of the lateral abdominal wall and quadratus lumborum is sport-specific: an MRI segmental study in professional tennis and soccer players.

    PubMed

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A; Dorado, Cecilia

    2013-03-01

    The aim was to determine the volume and degree of asymmetry of quadratus lumborum (QL), obliques, and transversus abdominis; the last two considered conjointly (OT), in tennis and soccer players. The volume of QL and OT was determined using magnetic resonance imaging in professional tennis and soccer players, and in non-active controls (n = 8, 14, and 6, respectively). In tennis players the hypertrophy of OT was limited to proximal segments (cephalic segments), while in soccer players it was similar along longitudinal axis. In tennis players the hypertrophy was asymmetric (18% greater volume in the non-dominant than in the dominant OT, p = 0.001), while in soccer players and controls both sides had similar volumes (p > 0.05). In controls, the non-dominant QL was 15% greater than that of the dominant (p = 0.049). Tennis and soccer players had similar volumes in both sides of QL. Tennis alters the dominant-to-non-dominant balance in the muscle volume of the lateral abdominal wall. In tennis the hypertrophy is limited to proximal segments and is greater in the non-dominant side. Soccer, however, is associated to a symmetric hypertrophy of the lateral abdominal wall. Tennis and soccer elicit an asymmetric hypertrophy of QL.

  14. The impact of transcatheter aortic valve implantation on left ventricular performance and wall thickness – single-centre experience

    PubMed Central

    Szymański, Piotr; Dąbrowski, Maciej; Zakrzewski, Dariusz; Michałek, Piotr; Orłowska-Baranowska, Ewa; El-Hassan, Kamal; Chmielak, Zbigniew; Witkowski, Adam; Hryniewiecki, Tomasz

    2015-01-01

    Introduction Transcatheter aortic valve implantation (TAVI) is a treatment alternative for the elderly population with severe symptomatic aortic stenosis (AS) at high risk for surgical aortic valve replacement (SAVR). Aim To assess the impact of TAVI on echocardiographic parameters of left ventricular (LV) performance and wall thickness in patients subjected to the procedure in a single-centre between 2009 and 2013. Material and methods The initial group consisted of 170 consecutive patients with severe AS unsuitable for SAVR. Logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 21.73 ±12.42% and mean age was 79.9 ±7.5 years. Results The TAVI was performed in 167 (98.2%) patients. Mean aortic gradient decreased significantly more rapidly after the procedure (from 58.6 ±16.7 mm Hg to 11.9 ±4.9 mm Hg, p < 0.001). The LV ejection fraction (LVEF) significantly increased in both short-term and long-term follow-up (57 ±14% vs. 59 ±13%, p < 0.001 and 56 ±14% vs. 60 ±12%, p < 0.001, respectively). Significant regression of interventricular septum diameter at end-diastole (IVSDD) and end-diastolic posterior wall thickness (EDPWth) was noted in early (15.0 ±2.4 mm vs. 14.5 ±2.3 mm, p < 0.001 and 12.7 ±2.1 mm vs. 12.4 ±1.9 mm, p < 0.028, respectively) and late post-TAVI period (15.1 ±2.5 mm to 14.3 ±2.5 mm, p < 0.001 and 12.8 ±2.0 mm to 12.4 ±1.9 mm, p < 0.007, respectively). Significant paravalvular leak (PL) was noted in 21 (13.1%) patients immediately after TAVI and in 13 (9.6%) patients in follow-up (p < 0.001). Moderate or severe mitral regurgitation (msMR) was seen in 24 (14.9%) patients from the initial group and in 19 (11.8%) patients after TAVI (p < 0.001). Conclusions The TAVI had an immediate beneficial effect on LVEF, LV walls thickness, and the incidence of msMR. The results of the procedure are comparable with those described in other centres. PMID:25848369

  15. Environmentally-controlled fracture of an overstrained A723 steel thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Underwood, J. H.; Olmstead, V. J.; Askew, J. C.; Kapusta, A. A.; Young, G. A.

    1992-08-01

    A through-wall, 1.7 m long crack grew suddenly from a notch in a 285 mm outer diameter (OD) of an A723 steel overstrained tube that was undergoing plating operations with no externally applied loads. The fracture mechanics tests and analyses and the fractography performed to characterize the cracking are described. The tube had a yield strength of 1200 MPa, fracture toughness of 150 MPavm, and a tensile residual stress at the OD of about 600 MPa. The composition was typical of an air-melt A723 steel, and the electropolishing bath, consisting of sulfuric and phosphoric acids, was held at 54 C. The bolt-loaded test for the threshold stress intensity factor for environmentally controlled cracking described by Wei and Novak was used here with two significant modifications. Some tests included only a notch with the radius matching that of the tube, and a new expression for K in terms of crack-mouth displacement was developed and used. Scanning electron microscope fractography and energy dispersive x ray spectra were used to identify crack mechanisms. Results of the study include: (1) a measured threshold of hydrogen stress cracking for the material/environment below 20 MPavm; (2) da/dt versus K behavior typical of classic environmental control; and (3) an improved K/v expression for the bolt-loaded specimen and associated criteria for determining plane-strain test conditions in relation to the Irwin plastic zone.

  16. Quantitative evaluation of the relationship between dorsal wall length, sole thickness, and rotation of the distal phalanx in the bovine claw using computed tomography.

    PubMed

    Tsuka, T; Murahata, Y; Azuma, K; Osaki, T; Ito, N; Okamoto, Y; Imagawa, T

    2014-10-01

    Computed tomography (CT) was performed on 800 untrimmed claws (400 inner claws and 400 outer claws) of 200 pairs of bovine hindlimbs to investigate the relationships between dorsal wall length and sole thickness, and between dorsal wall length and the relative rotation angle of distal phalanx-to-sole surface (S-D angle). Sole thickness was 3.8 and 4.0 mm at the apex of the inner claws and outer claws, respectively, with dorsal wall lengths <70 mm. These sole thickness values were less than the critical limit of 5 mm, which is associated with a softer surface following thinning of the soles. A sole thickness of 5 mm at the apex was estimated to correlate with dorsal wall lengths of 72.1 and 72.7 mm for the inner and outer claws, respectively. Sole thickness was 6.1 and 6.4 mm at the apex of the inner and outer claws, respectively, with dorsal wall lengths of 75 mm. These sole thickness values were less than the recommended sole thickness of 7 mm based on the protective function of the soles. A sole thickness >7 mm at the apex was estimated to correlate with a dorsal wall length of 79.8 and 78.4mm for the inner and outer claws, respectively. The S-D angles were recorded as anteversions of 2.9° and 4.7° for the inner and outer claws, respectively, with a dorsal wall length of 75 mm. These values indicate that the distal phalanx is likely to have rotated naturally forward toward the sole surface. The distal phalanx rotated backward to the sole surface at 3.2° and 7.6° for inner claws with dorsal wall lengths of 90-99 and ≥100 mm, respectively; and at 3.5° for outer claws with a dorsal wall length ≥100 mm. Dorsal wall lengths of 85.7 and 97.2 mm were estimated to correlate with a parallel positional relationship of the distal phalanx to the sole surface in the inner and outer claws, respectively.

  17. Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section

    SciTech Connect

    Keeney, J.A.; Bass, B.R.; McAfee, W.J.

    1995-04-01

    A testing program is described that utilizes full-thickness clad beam specimens to quantify fracture toughness for shallow cracks in weld material for which metallurgical conditions are prototypic of those found in reactor pressure vessels (RPVs). The beam specimens are fabricated from an RPV shell segment that includes weld, plate and clad material. Metallurgical factors potentially influencing fracture toughness for shallow cracks in the beam specimens include material gradients and material inhomogeneities in welded regions. The shallow-crack clad beam specimens showed a significant loss of constraint similar to that of other shallow-crack single-edge notch bend (SENB) specimens. The stress-based Dodds-Anderson scaling model appears to be effective in adjusting the test data to account for in-plane loss of constraint for uniaxially tested beams, but cannot predict the observed effects of out-of-plane biaxial loading on shallow-crack fracture toughness. A strain-based dual-parameter fracture toughness correlation (based on plastic zone width) performed acceptably when applied to the uniaxial and biaxial shallow-crack fracture toughness data.

  18. 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.

  19. Left ventricular wall thickness in patients with hypertrophic cardiomyopathy: a comparison between cardiac magnetic resonance imaging and echocardiography.

    PubMed

    Corona-Villalobos, Celia P; Sorensen, Lars L; Pozios, Iraklis; Chu, Linda; Eng, John; Abraham, Maria Roselle; Abraham, Theodore P; Kamel, Ihab R; Zimmerman, Stefan L

    2016-06-01

    We assessed whether cardiac MRI (CMR) and echocardiography (echo) have significant differences measuring left ventricular (LV) wall thickness (WT) in hypertrophic cardiomyopathy (HCM) as performed in the clinical routine. Retrospectively identified, clinically diagnosed HCM patients with interventricular-septal (IVS) pattern hypertrophy who underwent CMR and echo within the same day were included. Left Ventricular WT was measured by CMR in two planes and compared to both echo and contrast echo (cecho). 72 subjects, mean age 50.7 ± 16.2 years, 68 % males. Interventricular septal WT by echo and CMR planes showed good to excellent correlation. However, measurements of the postero-lateral wall showed poor correlation. Bland-Altman plots showed greater maximal IVS WT by echo compared to CMR measurement [SAX = 1.7 mm (-5.8, 9.3); LVOT = 1.1 mm (-5.6, 7.8)]. Differences were smaller between cecho and CMR [SAX = 0.8 mm (-9.2, 10.8); LVOT = -0.2 mm (-10.0, 9.6)]. Severity of WT by quartiles showed greater differences between echo and SAX CMR WT compared to cecho. Echocardiography typically measures greater WT than CMR, with the largest differences in moderate to severe hypertrophy. Contrast echocardiography more closely approximates CMR measurements of WT. These findings have potential clinical implications for risk stratification of subjects with HCM.

  20. Wall irregularity rather than intima-media thickness is associated with nearby atherosclerosis.

    PubMed

    Graf, Iulia M; Schreuder, Floris H B M; Hameleers, Jeroen M; Mess, Werner H; Reneman, Robert S; Hoeks, Arnold P G

    2009-06-01

    In addition to intima-media thickness (IMT), IMT inhomogeneity may carry information about atherosclerosis progression. In 147 vascular diseased patients (mean 66 y, 48% male), we determined the carotid bulb stenosis degree based on local Doppler blood flow velocities. Common carotid artery (CCA) morphologic characteristics, i.e. IMT, IMT-inhomogeneity (intraregistration variation) and IMT uni- and bilateral intrasubject variation (DeltaIMT), were measured using multiple M-mode. Associations of morphologic characteristics, stenosis degree and Framingham score were evaluated with Pearson correlation (r) and multiple regression analysis. The IMT distributions for subjects without and with stenosis were not similar. The stenosis degree score correlated significantly to unilateral (r=0.68) and bilateral DeltaIMT (r=0.62), IMT (r=0.41) and IMT-inhomogeneity (r=0.45). The averaged IMT and IMT-inhomogeneity increased slightly for singular stenosis and abruptly for multiple stenoses. Mean uni- and bilateral DeltaIMT per stenosis degree increased linearly with this degree, reaching a correlation close to 1 (r=0.98 and r=0.97). Interestingly, the majority of the subjects with a moderate to severe bulb stenosis exhibited a carotid IMT lower than the considered critical threshold of 0.9 mm. In conclusion, although CCA is not prone to plaques, its morphologic characteristics are positively correlated with stenosis degree score and other risk scores. DeltaIMT can be more reliable derived from inter-registration rather than from intra-registration variation. In the CCA, DeltaIMT substantiates vascular alteration better than IMT.

  1. Application of a Silicone Sheet in Negative-Pressure Wound Therapy to Treat an Abdominal Wall Defect after Necrotizing Fasciitis

    PubMed Central

    Shin, Jin Su

    2017-01-01

    Necrotizing fasciitis (NF) is an aggressive soft-tissue infection involving the deep fascia and is characterized by extensive deterioration of the surrounding tissue. Immediate diagnosis and intensive treatment, including debridement and systemic antibiotics, represent the most important factors influencing the survival of NF patients. In this report, we present a case of NF in the abdomen due to an infection caused by a perforated small bowel after abdominal liposuction. It was successfully treated using negative-pressure wound therapy, in which a silicone sheet functioned as a barrier between the sponge and internal organs to protect the small bowel. PMID:28194352

  2. Constitutive activation of ectodermal β-catenin induces ectopic outgrowths at various positions in mouse embryo and affects abdominal ventral body wall closure.

    PubMed

    Zhu, Xuming; Huang, Sixia; Zhang, Lingling; Wu, Yumei; Chen, Yingwei; Tao, Yixin; Wang, Yushu; He, Shigang; Shen, Sanbing; Wu, Ji; Li, Baojie; Guo, Xizhi; He, Lin; Ma, Gang

    2014-01-01

    Vertebrate limbs originate from the lateral plate mesoderm (LPM) and the overlying ectoderm. While normal limb formation in defined regions has been well studied, the question of whether other positions retain limb-forming potential has not been fully investigated in mice. By ectopically activating β-catenin in the ectoderm with Msx2-cre, we observed that local tissue outgrowths were induced, which either progressed into limb-like structure within the inter-limb flank or formed extra tissues in other parts of the mouse embryo. In the presumptive abdominal region of severely affected embryos, ectopic limb formation was coupled with impaired abdominal ventral body wall (AVBW) closure, which indicates the existence of a potential counterbalance of limb formation and AVBW closure. At the molecular level, constitutive β-catenin activation was sufficient to trigger, but insufficient to maintain the ectopic expression of a putative limb-inducing factor, Fgf8, in the ectoderm. These findings provide new insight into the mechanism of limb formation and AVBW closure, and the crosstalk between the Wnt/β-catenin pathway and Fgf signal.

  3. Effects of finite wall thickness and sinusoidal heating on convection in nanofluid-saturated local thermal non-equilibrium porous cavity

    NASA Astrophysics Data System (ADS)

    Alsabery, A. I.; Chamkha, A. J.; Saleh, H.; Hashim, I.; Chanane, B.

    2017-03-01

    The effects of finite wall thickness and sinusoidal heating on convection in a nanofluid-saturated local thermal non-equilibrium (LTNE) porous cavity are studied numerically using the finite difference method. The finite thickness vertical wall of the cavity is maintained at a constant temperature and the right wall is heated sinusoidally. The horizontal insulated walls allow no heat transfer to the surrounding. The Darcy law is used along with the Boussinesq approximation for the flow. Water-based nanofluids with Cu nanoparticles are chosen for investigation. The results of this study are obtained for various parameters such as the Rayleigh number, periodicity parameter, nanoparticles volume fraction, thermal conductivity ratio, ratio of wall thickness to its height and the modified conductivity ratio. Explanation for the influence of the various above-mentioned parameters on the streamlines, isotherms, local Nusselt number and the weighted average heat transfer is provided with regards to the thermal conductivities of nanoparticles suspended in the pure fluid and the porous medium. It is shown that the overall heat transfer is significantly increased with the relative non-uniform heating. Further, the convection heat transfer is shown to be inhibited by the presence of the solid wall. The results have possible applications in the heat-storage fluid-saturated porous systems and the applications of the high power heat transfer.

  4. Numerical study of the coupling of two identification methods - thermal and electromagnetic - for the reconstruction of inclusions in thick walls

    NASA Astrophysics Data System (ADS)

    Le Touz, Nicolas; Dumoulin, Jean; Soldovieri, Francesco

    2016-04-01

    In this numerical study we present an approach allowing introducing a priori information in an identification method of internal thermal properties field for a thick wall using infrared thermography measurements. This method is based on a coupling with an electromagnetic reconstructing method which data are obtained from measurements of Ground Penetrating Radar (GPR) ([1], [2]). This new method aims at improving the accuracy of reconstructions performed by using only the thermal reconstruction method under quasi-periodic natural solicitation ([3], [4]). Indeed, these thermal reconstructions, without a priori information, have the disadvantage of being performed on the entire studied wall. Through the intake of information from GPR, it becomes possible to focus on the internal zones that may contain defects. These areas are obtained by defining subdomains around remarkable points identified with the GPR reconstruction and considered as belonging to a discontinuity. For thermal reconstruction without providing a priori information, we need to minimize a functional equal to a quadratic residue issued from the difference between the measurements and the results of the direct model. By defining search fields around these potential defects, and thus by forcing the thermal parameters further thereof, we provide information to the data to reconstruct. The minimization of the functional is then modified through the contribution of these constraints. We do not seek only to minimize a residue, but to minimize the overall residue and constraints, what changes the direction followed by the optimization algorithm in the space of thermal parameters to reconstruct. Providing a priori information may then allow to obtain reconstruction with higher residues but whose thermal parameters are better estimated, whether for locating potential defects or for the reconstructed values of these parameters. In particular, it is the case for air defects or more generally for defects having a

  5. 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 ≤150μm 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

  6. Analysis of the effect of osteon diameter on the potential relationship of osteocyte lacuna density and osteon wall thickness.

    PubMed

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

    2011-09-01

    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 μm diameter or less than or equal to 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 nonuniform (e.g., increased near the central canal).

  7. Effects of Ceramic Fibre Insulation Thickness on Skin Formation and Nodule Characteristics of Thin Wall Ductile Iron Casting

    NASA Astrophysics Data System (ADS)

    Dhaneswara, D.; Suharno, B.; Nugraha, N. D.; Ariobimo, R. D. S.; Sofyan, N.

    2017-02-01

    Skin formation has become one of the problems in the thin wall ductile iron casting because it will reduce the mechanical properties of the materials. One of the solutions to reduce this skin formation is by using heat insulator to control the cooling rate. One of the insulators used for this purpose is ceramic fibre. In this research, the thickness of the ceramic fibre heat insulator used in the mould was varied, i.e. 50 mm on one side and 37.5 mm on the other side (A), no heat insulator (B), and 37.5 mm on both sides (C). After the casting process, the results were characterized in terms of metallography by using scanning electron microscope (SEM) and tensile test for mechanical properties. The results showed that the skin thickness formed in A is 34.21 μm, 23.38 μm in B, and 27.78 μm in C. The nodule count in A is 541.98 nodule/mm2 (84.7%) with an average diameter of 15.14 μm, 590 nodule/mm2 (86.7%) with an average diameter of 13.18 μm in B, and 549.73 nodule/mm2 (87.2%) with an average diameter of 13.95 μm in C. The average ultimate tensile strength for A was 399 MPa, B was 314 MPa, and C was 415 MPa. Microstructural examination under SEM showed that the materials have a ductile fracture with matrix full of ferrite.

  8. Ultrasound imaging of the lateral abdominal wall muscles in individuals with lumbopelvic pain and signs of concurrent hypocapnia.

    PubMed

    Whittaker, Jackie L

    2008-10-01

    The purpose of this study was to compare the change in thickness of transversus abdominis (TrA) and internal oblique (IO) muscles, during resting supine respiration, in individuals with lumbopelvic pain (LP) to those who in addition to LP, demonstrate signs of concurrent hypocapnia (LP&HYPO). B-mode ultrasound images were obtained at the height of inspiration, and at the end of expiration, over three subsequent breaths during a single session. The average percent change in thickness of TrA during resting respiration in the LP&HYPO group (20.8+/-7.6%) was found to be statistically greater (P<0.001) than that of the LP only group (1.3+/-5.8%), while the difference between the groups for the percent change in thickness of IO (LP&HYPO 9.2+/-8.1%, LP 2.0+/-7.2%) did not differ (P=0.073). These findings suggest that respiratory modulation of TrA thickness, as measured by ultrasound imaging, greater than 20%, detected in a resting supine position, may be associated with an episode of hypocapnia, and if present warrants further investigation.

  9. 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.

  10. Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique

    NASA Astrophysics Data System (ADS)

    Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

    2009-12-01

    Mostly piping which is using for the nuclear power plants are made up of carbon steel pipes. The wall thinning defects occurs by the effect of the flow accelerated corrosion of fluid that flows in carbon steel pipes. The defects could be found on the welding part and anywhere in the pipes. The infrared thermography technique which is one of the non-destructive testing method has used for detecting the defects of various kinds of materials over the years. There is a limitation for measuring the defect of metals that have a big coefficient of thermal diffusion. However, a technique using lock-in method gets over the difficulty. Consequently, the lock-in infrared thermography technique has been applied to the various industry fields. In this paper, the defect thickness of the straight pipe which has an artificial defect the inside of the pipes was measured by using the lock-in infrared thermography technique and the result could be utilized in detecting defects of carbon steel pipes.

  11. Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique

    NASA Astrophysics Data System (ADS)

    Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

    2010-03-01

    Mostly piping which is using for the nuclear power plants are made up of carbon steel pipes. The wall thinning defects occurs by the effect of the flow accelerated corrosion of fluid that flows in carbon steel pipes. The defects could be found on the welding part and anywhere in the pipes. The infrared thermography technique which is one of the non-destructive testing method has used for detecting the defects of various kinds of materials over the years. There is a limitation for measuring the defect of metals that have a big coefficient of thermal diffusion. However, a technique using lock-in method gets over the difficulty. Consequently, the lock-in infrared thermography technique has been applied to the various industry fields. In this paper, the defect thickness of the straight pipe which has an artificial defect the inside of the pipes was measured by using the lock-in infrared thermography technique and the result could be utilized in detecting defects of carbon steel pipes.

  12. A numerical study of multiple adiabatic shear bands evolution in a 304LSS thick-walled cylinder

    NASA Astrophysics Data System (ADS)

    Liu, Mingtao; Hu, Haibo; Fan, Cheng; Tang, Tiegang

    2017-01-01

    The self-organization of multiple shear bands in a 304L stainless steel(304LSS) thick-walled cylinder (TWC) was numerically studied. The microstructures of material lead to the non-uniform distribution of the local yield stress, which play a key role in the formation of spontaneous shear localization. We introduced a probability factor satisfied the Gaussian distribution into the macroscopic constitutive relationship to describe the non-uniformity of local yield stress. Using the probability factor, the initiation and propagation of multiple shear bands in TWC were numerically replicated in our 2D FEM simulation. Experimental results in the literature indicated that the machined surface at the internal boundary of a 304L stainless steel cylinder provides a work-hardened layer (about 20˜30μm) which has significantly different microstructures from the base material. The work-hardened layer leads to the phenomenon that most shear bands propagate along a given direction, clockwise or counterclockwise. In our simulation, periodical single direction spiral perturbations were applied to describe the grain orientation in the work-hardened layer, and the single direction spiral pattern of shear bands was successfully replicated.

  13. On the thermal convection in a viscoelastic Jeffreys fluid layer heated from below confined between walls of finite thickness and thermal conductivity

    NASA Astrophysics Data System (ADS)

    Pérez-Reyes, Ildebrando; Vargas-Aguilar, René O.

    2016-11-01

    The thickness and thermal conductivity of the bounding walls are of interest in the hydrodynamic stability of a viscoelastic fluid layer. In this work the linear hydrodynamic stability is studied by means of the Galerkin method. The two ideal cases of thermal insulating and perfect thermal conducting walls are bridged by taking into account these two properties. Curves of criticality for the Rayleigh number, the wavenumber and the frequency of oscillation against the thermal conductivity for fixed wall thickness, Prandtl number and relaxation and retardation times are presented. Here, the dimensionless retardation time E was set to 0.05 and 0.1 while the dimensionless relaxation time F was set to 0.1 and 100. The role of the thermal conductivity and of the thickness of the walls are discussed. One important result of this investigation is that for non ideal thermal conducting conditions the system is more stable when the thickness of the fluid layer is larger in comparison to that of the boundaries. A discussion on the effect of E and F on the stability is given as well. Ciencia Básica - Conacyt through Project No. 255839.

  14. Development of automated welding process for field fabrication of thick walled pressure vessels. Fourth quarter technical progress report for period ending September 28, 1980

    SciTech Connect

    Not Available

    1980-01-01

    Progress is reported in research aimed at optimizing an automated welding process for the field fabrication of thick-walled pressure vessels and for evaluating the welded joints. Information is included on the welding equipment, mechanical control of the process, joint design, filler wire optimization, in-process nondestructive testing of welds, and repair techniques. (LCL)

  15. A tale of two neglected systems-structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves.

    PubMed

    Botha, C E J

    2013-01-01

    There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5-7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.

  16. Ultrasonographic abdominal anatomy of healthy captive caracals (Caracal caracal).

    PubMed

    Makungu, Modesta; du Plessis, Wencke M; Barrows, Michelle; Koeppel, Katja N; Groenewald, Hermanus B

    2012-09-01

    Abdominal ultrasonography was performed in six adult captive caracals (Caracal caracal) to describe the normal abdominal ultrasonographic anatomy. Consistently, the splenic parenchyma was hyperechoic to the liver and kidneys. The relative echogenicity of the right kidney's cortex was inconsistent to the liver. The gall bladder was prominent in five animals and surrounded by a clearly visualized thin, smooth, regular echogenic wall. The wall thickness of the duodenum measured significantly greater compared with that of the jejunum and colon. The duodenum had a significantly thicker mucosal layer compared with that of the stomach. Such knowledge of the normal abdominal ultrasonographic anatomy of individual species is important for accurate diagnosis and interpretation of routine health examinations.

  17. Research of the process of axisymmetric forming of thin-walled flat blanks into the conical parts with minimal thickness variation

    NASA Astrophysics Data System (ADS)

    Demyanenko, E. G.; Popov, I. P.; Menshikov, V. S.

    2017-02-01

    In this paper, the method based on the process of forming a flat blank into the thin-walled conical part is proposed. The forming method is based on two stages. At the first stage, forming of the free portion of the blank is carried out until it fully contacts the conical surface of the punch. During this stage, thickness unevenness is created, which can be compensated during the second stage by the action of active friction forces. The shaping of the workpiece during the forming of the conical part is performed by thinning. The thinning increases with the increase of the penetration depth of the punch, i.e. the final part will be thinner, but its thickness variation will be reduced. This method allows achieving minimal thickness variation in the walls of the part.

  18. Recurrent incisional hernia, enterocutaneous fistula and loss of the substance of the abdominal wall: plastic with organic prosthesis, skin graft and VAC therapy. Clinical case.

    PubMed

    Nicodemi, Sara; Corelli, Sergio; Sacchi, Marco; Ricciardi, Edoardo; Costantino, Annarita; Di Legge, Pietro; Ceci, Francesco; Cipriani, Benedetta; Martellucci, Annunziata; Santilli, Mario; Orsini, Silvia; Tudisco, Antonella; Stagnitti, Franco

    2015-01-01

    Surgical wounds dehiscence is a serious post-operatory complication, with an incidence between 0.4% and 3.5%. Mortality is more than 45%. Complex wounds treatment may require a multidisciplinary management. VAC Therapy could be an alternative treatment regarding complex wound. VAC therapy has been recently introduced on skin's graft tissue management reducing skin graft rejection. The use of biological prosthesis has been tested in a contaminated field, better than synthetic meshes, which often need to be removed. The Permacol is more resistant to degradation by proteases due to its cross-links. Surgery is still considered the best treatment for digestive fistula. A 58 years old obese woman come to our attention, she was operated for an abdominal hernia. She had a post-operatory entero-cutaneous fistula. She was submitted to bowel resection, the anastomosis has been tailored and the hernia of the abdominal wall has been repaired with biological mesh for managing such condition. She had a wound dehiscence with loss of substance and the exposure of the biological prosthesis, nearly 20 cm diameter. She was treated first with antibiotic therapy and simple medications. In addiction, antibiotic therapy was necessary late associated to 7 months with advanced medications allowed a small reduction's defect. Because of its, treatment went on for two more months using VAC therapy. Antibiotic's therapy was finally suspended. The VAC therapy allowed the reduction of the gap, between skin and subcutaneous tissue, and the defect's size preparing a suitable ground for the skin graft. The graft, managed with the vac therapy, was necessary to complete the healing process.

  19. Lotus petal flaps for scrotal reconstruction combined with Integra resurfacing of the penis and anterior abdominal wall following necrotising fasciitis.

    PubMed

    Payne, Caroline E; Williams, Andrew M; Hart, Nicholas B

    2009-03-01

    Necrotising fasciitis of the external genitalia following routine circumcision is uncommon. We describe reconstruction of the scrotum with local perforator flaps and a dermal regeneration template (Integra) to cover the penile shaft after debridement. Lotus petal flaps were originally designed to cover vulvo-vaginal defects, but in this instance integrated well with the remaining scrotal sac to produce a good volume neoscrotum for testicular cover. Integra creates an acceptable neodermis usually to cover areas of debrided full thickness burns. In this case, Integra adequately replaced the mobile dermal layer over Bucks fascia over the penis to create a pliable and cosmetically acceptable result with erectile capability.

  20. 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.

    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.

  1. CLOSTRIDIAL PARAPROCTITIS WITH GAS GANGRENE OF FRONT-LATERAL ABDOMINAL WALLS AND NECROTIC FASCIO-MYOSITIS (CASE REPORT).

    PubMed

    Didbaridze, N; Lomidze, N; Abuladze, T; Qiliptari, G; Didbaridze, T; Gvasalia, I; Mkervalishvili, Z; Gogokhia, N

    2016-09-01

    Anaerobic clostridial infection is the most severe form of paraproctitis. The incubation period is very short, from 3 to 6 hours, sometimes lasting for 1-2 days. Clostridial infection spreads rapidly and induces gas gangrene, causes destruction of cells and other intermediate substances, and impedes blood circulation. This paper presents a case study of an extremely severe form of anaerobic infection with spontaneous gas gangrene, cellulitis, fasciomyositic necrosis, severe intoxication and septic shock on the abdominal front and lateral surfaces. This patient presented as infected with Clostridium septicum, a rare and highly toxic Gram-positive, spore-forming, obligate anaerobic bacillus that progresses and migrates rapidly, affecting all soft tissues (muscle, fascia), and produces four toxins which cause gas gangrene, intravascular hemolysis, tissue necrosis, and septic shock. The mortality rate is typically 80%. In this case study, a positive clinical outcome was achieved by aggressive identification of the microbe, appropriate and immediate therapy, and vigorous surgical intervention. Specifically, immediate surgery was conducted to ensure a wide excision of damaged tissues, necrectomy, curettage, wide drainage, readjustment, oxygenation through drainages, further additional surgical corrections through CT control with wide bandages in the operating area. Further, the diagnostic workup was thorough, identifying the microbe through a properly constructed diagnostic algorithm, ultrasound and CT studies, infectious agent assessments, and bacteriological monitoring carried out on the 1st-2nd-5th-7th-12th-15th-21st-25th days. Rational antibiotic therapy with permanent susceptibility testing informed the selection of an appropriate agent. Finally, markers for the evaluation of severity (Apache scale) were assessed, as they were for stage of infection (prokalcitonin), inflammation (CRP) and other indicators.

  2. 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 ϕe are correlated with age, and Group-II in which the parameters cm1, Ghm, G1e, G2e, and α 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.

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

    SciTech Connect

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

    2015-10-15

    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 (Veo{sup TM}, 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

  4. 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

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

    PubMed

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

    2015-01-01

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

  6. High vancomycin MICs within the susceptible range in Staphylococcus aureus bacteraemia isolates are associated with increased cell wall thickness and reduced intracellular killing by human phagocytes.

    PubMed

    Falcón, Rocío; Martínez, Alba; Albert, Eliseo; Madrid, Silvia; Oltra, Rosa; Giménez, Estela; Soriano, Mario; Vinuesa, Víctor; Gozalbo, Daniel; Gil, María Luisa; Navarro, David

    2016-05-01

    Vancomycin minimum inhibitory concentrations (MICs) at the upper end of the susceptible range for Staphylococcus aureus have been associated with poor clinical outcomes of bloodstream infections. We tested the hypothesis that high vancomycin MICs in S. aureus bacteraemia isolates are associated with increased cell wall thickness and suboptimal bacterial internalisation or lysis by human phagocytes. In total, 95 isolates were evaluated. Original vancomycin MICs were determined by Etest. The susceptibility of S. aureus isolates to killing by phagocytes was assessed in a human whole blood assay. Internalisation of bacterial cells by phagocytes was investigated by flow cytometry. Cell wall thickness was evaluated by transmission electron microscopy. Genotypic analysis of S. aureus isolates was performed using a DNA microarray system. Vancomycin MICs were significantly higher (P=0.006) in isolates that were killed suboptimally (killing index <60%) compared with those killed efficiently (killing index >70%) and tended to correlate inversely (P=0.08) with the killing indices. Isolates in both killing groups were internalised by human neutrophils and monocytes with comparable efficiency. The cell wall was significantly thicker (P=0.03) in isolates in the low killing group. No genotypic differences were found between the isolates in both killing groups. In summary, high vancomycin MICs in S. aureus bacteraemia isolates were associated with increased cell wall thickness and reduced intracellular killing by phagocytes.

  7. Accurate method for measurement of pipe wall thickness using a circumferential guided wave generated and detected by a pair of noncontact transducers

    NASA Astrophysics Data System (ADS)

    Nishino, H.; Taniguchi, Y.; Yoshida, K.

    2012-05-01

    A noncontact method of an accurate estimation of a pipe wall thickness using a circumferential (C-) Lamb wave is presented. The C-Lamb waves circling along the circumference of pipes are transmitted and received by the critical angle method using a pair of noncontact air-coupled ultrasonic transducers. For the accurate estimation of a pipe wall thickness, the accurate measurement of the angular wave number that changes minutely owing to the thickness must be achieved. To achieve the accurate measurement, a large number of tone-burst cycles are used so as to superpose the C-Lamb wave on itself along its circumferential orbit. In this setting, the amplitude of the superposed region changes considerably with the angular wave number, from which the wall thickness can be estimated. This paper presents the principle of the method and experimental verifications. As results of the experimental verifications, it was confirmed that the maximum error between the estimates and the theoretical model was less than 10 micrometers.

  8. Remodeling characteristics and collagen distribution in synthetic mesh materials explanted from human subjects after abdominal wall reconstruction: an analysis of remodeling characteristics by patient risk factors and surgical site classifications

    PubMed Central

    Cavallo, Jaime A.; Roma, Andres A.; Jasielec, Mateusz S.; Ousley, Jenny; Creamer, Jennifer; Pichert, Matthew D.; Baalman, Sara; Frisella, Margaret M.; Matthews, Brent D.

    2014-01-01

    Background The purpose of this study was to evaluate the associations between patient characteristics or surgical site classifications and the histologic remodeling scores of synthetic meshes biopsied from their abdominal wall repair sites in the first attempt to generate a multivariable risk prediction model of non-constructive remodeling. Methods Biopsies of the synthetic meshes were obtained from the abdominal wall repair sites of 51 patients during a subsequent abdominal re-exploration. Biopsies were stained with hematoxylin and eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell infiltration, cell types, extracellular matrix deposition, inflammation, fibrous encapsulation, and neovascularization) and a mean composite score (CR). Biopsies were also stained with Sirius Red and Fast Green, and analyzed to determine the collagen I:III ratio. Based on univariate analyses between subject clinical characteristics or surgical site classification and the histologic remodeling scores, cohort variables were selected for multivariable regression models using a threshold p value of ≤0.200. Results The model selection process for the extracellular matrix score yielded two variables: subject age at time of mesh implantation, and mesh classification (c-statistic = 0.842). For CR score, the model selection process yielded two variables: subject age at time of mesh implantation and mesh classification (r2 = 0.464). The model selection process for the collagen III area yielded a model with two variables: subject body mass index at time of mesh explantation and pack-year history (r2 = 0.244). Conclusion Host characteristics and surgical site assessments may predict degree of remodeling for synthetic meshes used to reinforce abdominal wall repair sites. These preliminary results constitute the first steps in generating a risk prediction model that predicts the patients and clinical circumstances for which non

  9. Ultrasound and differential diagnosis of fetal abdominal cysts

    PubMed Central

    Tu, Chang-Yu

    2017-01-01

    The present study aimed to investigate the use of ultrasound and differential diagnosis to diagnose a fetal abdominal cyst. A retrospective analysis of 41 cases of fetal abdominal cyst, which included ovarian cysts, choledochal cysts, intestinal duplication and mesenteric cysts, was performed. Imaging characteristics of various types of cysts were summarized, compared and discussed. Among 41 fetal abdominal cyst cases, there were 21 cases of ovarian cysts, 11 cases of bile duct cyst, six cases of intestinal duplication and three cases of mesenteric cyst. Each type of fetal cyst had its own distinctive characteristics on abdominal ultrasound examination. Ovarian cysts were located at one side of the bladder, round-shaped and observed in female fetuses; choledochal cysts were located in the hilar, were oblong- or oval-shaped and connected to the bile duct; intestinal duplication was located in the middle of abdomen, close to the intestine, and presented as an intestinal wall-like structure; mesenteric cysts were round-shaped with thin tensionless wall, presented with multiple chambers, and were easily deformable on compression. The findings of the present study demonstrated that a comprehensive analysis of the association between the cyst and its adjacent location, shape, wall thickness, motility and other aspects of dynamic changes via ultrasonography may provide a differential diagnosis of different types of fetal abdominal cysts. PMID:28123506

  10. Ultrasound and differential diagnosis of fetal abdominal cysts.

    PubMed

    Tu, Chang-Yu

    2017-01-01

    The present study aimed to investigate the use of ultrasound and differential diagnosis to diagnose a fetal abdominal cyst. A retrospective analysis of 41 cases of fetal abdominal cyst, which included ovarian cysts, choledochal cysts, intestinal duplication and mesenteric cysts, was performed. Imaging characteristics of various types of cysts were summarized, compared and discussed. Among 41 fetal abdominal cyst cases, there were 21 cases of ovarian cysts, 11 cases of bile duct cyst, six cases of intestinal duplication and three cases of mesenteric cyst. Each type of fetal cyst had its own distinctive characteristics on abdominal ultrasound examination. Ovarian cysts were located at one side of the bladder, round-shaped and observed in female fetuses; choledochal cysts were located in the hilar, were oblong- or oval-shaped and connected to the bile duct; intestinal duplication was located in the middle of abdomen, close to the intestine, and presented as an intestinal wall-like structure; mesenteric cysts were round-shaped with thin tensionless wall, presented with multiple chambers, and were easily deformable on compression. The findings of the present study demonstrated that a comprehensive analysis of the association between the cyst and its adjacent location, shape, wall thickness, motility and other aspects of dynamic changes via ultrasonography may provide a differential diagnosis of different types of fetal abdominal cysts.

  11. Numerical Study about the Influence of Wall Angle about Main Strains, Thickness Reduction and Forces on Single Point Incremental Forming Process

    NASA Astrophysics Data System (ADS)

    Oleksik, Valentin

    2016-12-01

    The current paper aims to study, using numerical simulation, the influence of the wall angle on the single point incremental forming process. For the analysis there has been used the LS-Dyna software and three explicit dynamic analyses were run for three parts with wall angles of 450, 550 and 650. The factors taken into account are the main strains, the thickness reduction and the forces on three directions. The material data introduced into the simulation were determined based on an uniaxial traction test on an Instron 5587 testing machine and the Aramis system was used as optical extensometer.

  12. 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.

  13. Fracture resistance of welded thick-walled high-pressure vessels in power plants. Report No. 1. Statistical analysis of defects and fracture resistance of vessel materials

    SciTech Connect

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

    1986-07-01

    Data from plant radiographic inspection of reactor vessels and boilers in power plants of 440- and 1000-MW capacity were subjected to statistical analysis. It was found that, given the current technology for making and constructing 440- and 1000-MW power plants, the limiting defect size in the vessels of the plants is no more than 10% of the wall thickness according to the results of statistical analysis. This finding makes it possible to increase the tolerable stresses by a factor of 1.6 compared to the current estimate of resistance to brittle fracture, which presumes the presence of a semielliptical surface crack of a depth corresponding to 25% of the wall thickness. The fracture resistance of steel increase with a decrease in defect size and as a result of the damping capacity of the anticorrosive hardfacing applied.

  14. [Abdominal actinomycosis with IUD].

    PubMed

    Kamprath, S; Merker, A; Kühne-Heid, R; Schneider, A

    1997-01-01

    We report a case of abdominal actinomycosis in a 54 year old woman using an intrauterine device for a period of 8 years. The most important finding was a tuboovarialabscess at the left pelvic side with involvement of the serosa of the jejunum, ileum, sigma, and omentum majus. Intraoperative exploration showed a solid retroperitoneal infiltration between the pelvic side wall and sigma. Another infiltration was found on the left side of the abdominal wall. The diagnosis was confirmed by histopathological examination and the patient was treated by a combination of Aminopenicillin and Metronidazol. After a period of three months we observed a complete regression of the clinical and the MRI findings.

  15. Short-axis epicardial volume change is a measure of cardiac left ventricular short-axis function, which is independent of myocardial wall thickness.

    PubMed

    Ugander, Martin; Carlsson, Marcus; Arheden, Håkan

    2010-02-01

    Fractional shortening (FS) by echocardiography is considered to represent the short-axis contribution to the stroke volume (SV), also called short-axis function. However, FS is mathematically coupled to the amount of myocardium, since it rearranges during atrioventricular plane displacement (AVPD). The SV is the sum of the volumes generated by 1) reduction in outer volume of the heart, and 2) inner AVPD. The long-axis contribution to the SV is generated by AVPD, and thus the short-axis contribution is the remaining outer volume change of the heart, which should be unrelated to myocardial wall thickness. We hypothesized that both endocardial and midwall shortening indexed to SV are dependent on myocardial wall thickness, whereas epicardial volume change (EVC) indexed to SV is not. Twelve healthy volunteers (normals), 12 athletes, and 12 patients with dilated cardiomyopathy (ejection fraction < 30%) underwent cine cardiac magnetic resonance imaging. Left ventricular long-axis function was measured as the portion of the SV, in milliliters, generated by AVPD. EVC was defined as SV minus long-axis function. Endocardial and midwall shortening were measured in a midventricular short-axis slice. Endocardial shortening/SV and midwall shortening/SV both varied in relation to end-diastolic myocardial wall thickness (R(2) = 0.16, P = 0.008 and R(2) = 0.14, P = 0.012, respectively), whereas EVC/SV did not (R(2) = 0.00, P = 0.37). FS is dependent on myocardial wall thickness, whereas EVC is not and therefore represents true short-axis function. This is not surprising considering that FS is mainly caused by rearrangement of myocardium secondary to long-axis function. FS is therefore not synonymous with short-axis function.

  16. BOTULINUM TOXIN A INDUCED PARALYSIS OF THE LATERAL ABDOMINAL WALL AFTER DAMAGE CONTROL LAPAROTOMY: A MULTIINSTITUTIONAL, PROSPECTIVE, RANDOMIZED, PLACEBO CONTROLLED PILOT STUDY

    PubMed Central

    Zielinski, Martin D.; Kuntz, Melissa; Zhang, Xiaoming; Zagar, Abigail E.; Khasawneh, Mohammad A.; Zendejas, Benjamin; Polites, Stephanie F.; Ferrara, Michael; Harmsen, William S.; Ballman, Karla S.; Park, Myung S.; Schiller, Henry J.; Dries, David; Jenkins, Donald H.

    2015-01-01

    INTRODUCTION Damage control laparotomy (DCL) is a life-saving operation used in critically ill patients; however, interval primary fascial closure remains a challenge. We hypothesized that flaccid paralysis of the lateral abdominal wall musculature induced by Botulinum Toxin A (BTX), would improve of rates of primary fascial closure, decrease duration of hospital stay (LOS), and enhance pain control. METHODS Consenting adults who had undergone a DCL at two institutions were prospectively randomized to receive ultrasound-guided injections of their external oblique, internal oblique, and transversus abdominus muscles with either BTX (150cc, 2units/cc) or placebo (150cc 0.9%NaCl). Patients were excluded if they had a BMI>50, remained unstable or coagulopathic, were home O2 dependent or had an existing neuromuscular disorder. Outcomes were assessed in a double-blinded manner. Univariate and Kaplan Meier estimates of cumulative probability of abdominal closure were performed. RESULTS We randomized 46 patients (24 BTX, 22 placebo). There were no significant differences in demographics, comorbidities, and physiological status. Injections were performed on average 1.8 ± 2.8 days after DCL (range 0-14). The 10-day cumulative probability of primary fascial closure was similar between groups: 96% for BTX (95% CI 72%-99%) and 93% for placebo (95% CI 61%-99%); HR =1.0 (95% CI 0.5-1.8). No difference between BTX and placebo groups was observed for LOS (37 vs 26 days, p=0.30) or intensive care unit stay (17 vs 11 days, p=0.27). There was no difference in median morphine equivalents following DCL. The overall complication rate was similar (63% vs 68%, p=0.69), with 2 deaths in the placebo group and 0 in the BTX group. No BTX or injection procedure complications were observed. CONCLUSION Use of BTX after DCL was safe but did not appear to affect primary fascial closure, LOS, or pain modulation after DCL. Given higher than expected rates of primary fascial closure, type II error

  17. A case report on a full-thickness chest wall reconstruction with polypropylene mesh and stainless steel mesh concurrently using a transverse rectus abdominis myocutaneous flap.

    PubMed

    Yoshino, Naoyuki; Yamauchi, Shigeo; Akimoto, Masataka; Hisayoshi, Takao; Koizumi, Kiyoshi; Shimizu, Kazuo

    2006-12-01

    A full-thickness chest wall resection requires subsequent chest wall reconstruction. A chest wall resection and reconstruction was performed using a transverse rectus abdominis myocutaneous (TRAM) flap, together with polypropylene mesh (Marlex mesh) and stainless steel mesh (SSM). A 71-year-old man was diagnosed as having recurrent lung cancer in the chest wall, and underwent surgical resection. Marlex mesh was sutured to the posterior wall of the surgical defect. A portion of the SSM was adjusted to the size of the defect and cut out. Its edges were folded to make the portion into a plate. This SSM plate was placed anteriorly to the Marlex mesh and sutured to the ribs. The Marlex mesh was folded back on the SSM plate by 2 cm and fixed. After the above procedures, a left-sided TRAM flap was raised through a subcutaneous tunnel up to the defect and sutured to the region. The patient was discharged from hospital 19 days postoperatively. The wound was fine and he had no flail chest or dyspnea, and carcinomatous pain resolved.

  18. A population-level analysis of abdominal wall reconstruction by component separation in the morbidly obese patient: can it be performed safely?

    PubMed

    Nelson, Jonas A; Fischer, John P; Wink, Jason D; Kovach, Stephen J

    2014-10-01

    Morbid obesity is increasing at an alarming rate and a significant portion of patients presenting for complex abdominal wall reconstruction (AWR) and component separation fall into this category, creating added medical and surgical challenges to an already difficult operation. The goal of this study was to utilise the Nationwide 2005-2010 American College of Surgeons National Surgical Quality Improvement database (ACS-NSQIP) to perform a population level analysis of the role of morbid obesity on 30-day perioperative morbidity with the hope of improving patient care, counselling and risk stratification. Morbidly obese patients (BMI > 40 kg/m(2)) were compared to non-obese patients (BMI < 30 kg/m(2)). Outcome variables assessed included major surgical complications, major medical complications, major renal complications, major wound complications, return to OR (ROR), and venous thromboembolism (VTE). Significant variables in a univariate analysis were included in a multivariate logistic regression controlling for patient characteristics (p < 0.05). In total, 1695 patients undergoing AWR were identified in the ACS-NSQIP database. Of these, 614 patients were non-obese (average BMI = 25.7 ± 3.0 kg/m(2)) and 314 were morbidly obese (average BMI = 45.9 ± 5.8 kg/m(2)). Multivariate analyses determined that morbid obesity did not significantly contribute to major surgical, medical, renal or wound complications. However, it was significantly associated with ROR (OR = 2.8, p < 0.001) and VTE (OR = 5.2, p = 0.04). Morbid obesity is an independent risk factor for ROR and VTE related complications, in the 30 day post-operative period. Additional perioperative care is warranted to decrease such early re-operations and for preventable complications.

  19. Abdominal ultrasound

    MedlinePlus

    ... Kidney - blood and urine flow Abdominal ultrasound References Chen L. Abdominal ultrasound imaging. In: Sahani DV, Samir ... the Health on the Net Foundation (www.hon.ch). The information provided herein should not be used ...

  20. Abdominal tap

    MedlinePlus

    ... tap; Cirrhosis - abdominal tap; Malignant ascites - abdominal tap Images Digestive system Peritoneal sample References Garcia-Tiso G. ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  1. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Ziaja, K; Sedlak, L; Urbanek, T; Kostyra, J; Ludyga, T

    2000-01-01

    The reported incidence of inflammatory abdominal aortic aneurysm (IAAA) is from 2% to 14% of patients with abdominal aortic aneurysm and the etiology of this disease is still discussed--according to the literature several pathogenic theories have been proposed. From 1992 to 1997 32 patients with IAAA were operated on. The patients were mostly symptomatic--abdominal pain was present in 68.75% cases, back pain in 31.25%, fever in 12.5% and weight loss in 6.25% of the operated patients. In all the patients ultrasound examination was performed, in 4 patients CT and in 3 cases urography. All the patients were operated on and characteristic signs of inflammatory abdominal aortic aneurysm like: thickened aortic wall, perianeurysmal infiltration or retroperitoneal fibrosis with involvement of retroperitoneal structures were found. In all cases surgery was performed using transperitoneal approach; in three cases intraoperatively contiguous abdominal organs were injured, which was connected with their involvement into periaortic inflammation. In 4 cases clamping of the aorta was done at the level of the diaphragmatic hiatus. 3 patients (9.37%) died (one patient with ruptured abdominal aortic aneurysm). Authors present diagnostic procedures and the differences in the surgical tactic, emphasizing the necessity of the surgical therapy in patients with inflammatory abdominal aortic aneurysm.

  2. Interfacial heat transfer in squeeze casting of magnesium alloy AM60 with variation of applied pressures and casting wall-thicknesses

    NASA Astrophysics Data System (ADS)

    Zhang, Xuezhi; Fang, Li; Sun, Zhizhong; Hu, Henry; Nie, Xueyuan; Tjong, Jimi

    2016-10-01

    The heat transfer coefficient at the casting-die interface is the most important factor on the solidification process. With the 75-ton hydraulic press machine and P20 steel die mold, 5-step castings of magnesium alloy AM60 with different wall-thicknesses (3, 5, 8, 12, 20 mm) were poured under various hydraulic pressures (30, 60, and 90 MPa) using an indirect squeeze casting process. Thermal histories throughout the die wall and the casting surface have been recorded by fine type-K thermocouples. The in-cavity local pressures measured by pressure transducers were explored at the casting-die interfaces of 5 steps. The casting-die interfacial heat transfer coefficients (IHTC) initially reached a maximum peak value followed by a gradually decline to the lower level. Similar characteristics of IHTC peak values can be observed at the applied pressures of 30, 60 and 90 MPa. With the applied pressure of 90 MPa, the peak IHTC values from steps 1 to 5 varied from 5623 to 10,649 W/m2 K. As the applied hydraulic pressure increased, the IHTC peak value of each step was increased accordingly. The wall thickness also affected IHTC peak values significantly. The peak IHTC value and heat flux increased as the step became thicker. The empirical equations relating the IHTCs to the local pressures and the solidification temperature at the casting surface were developed based on the multivariate linear and polynomial regression.

  3. Abdominal Pain

    MedlinePlus

    ... call your doctor. In Spanish— Dolor abdominal en niños menores de 12 años What is recurrent abdominal ... Functional abdominal pain (FAP) typically affects kids ages 4-12, and is quite common, affecting up to ...

  4. A prospective, controlled evaluation of the abdominal reapproximation anchor abdominal wall closure system in combination with VAC therapy compared with VAC alone in the management of an open abdomen.

    PubMed

    Long, Kristin L; Hamilton, David A; Davenport, Daniel L; Bernard, Andrew C; Kearney, Paul A; Chang, Phillip K

    2014-06-01

    Dramatic increases in damage control and decompressive laparotomies and a significant increase in patients with open abdominal cavities have resulted in numerous techniques to facilitate fascial closure. We hypothesized addition of the abdominal reapproximation anchor system (ABRA) to the KCI Abdominal Wound Vac™ (VAC) or KCI ABThera™ would increase successful primary closure rates and reduce operative costs. Fourteen patients with open abdomens were prospectively randomized into a control group using VAC alone (control) or a study group using VAC plus ABRA (VAC-ABRA). All patients underwent regular VAC changes; patients receiving VAC-ABRA also underwent concomitant daily elastomer adjustment of the ABRA system. Primary end points included abdominal closure, number of operating room (OR) visits, and OR time use. Eight patients were included in the VAC-ABRA group and six patients in the control group. Primary closure rates between groups were not statistically different; however, the number of trips to the OR and OR time use were different. Despite higher Acute Physiology and Chronic Health Evaluation II scores, larger starting wound size, and higher rates of abdominal compartment syndrome, closure rates in the VAC-ABRA group were similar to VAC alone. Importantly, however, fewer OR trips and less OR time were required for the VAC-ABRA group.

  5. Thickness estimation of the subcutaneous fat using coaxial probe.

    PubMed

    Ramezani, Mohammad Hossein; Nadimi, Esmaeil S

    2016-03-01

    In this Letter, a non-invasive method for thickness estimation of the subcutaneous fat layer of abdominal wall is presented by using a coaxial probe. Fat layer has the highest impact on the averaged attenuation parameter of the abdominal wall due to its high thickness and low permittivity. The abdominal wall is modelled as a multi-layer medium and an analytical model for the probe is derived by calculation of its aperture admittance facing to this multi-layer medium. The performance of this model is then validated by a numerical simulation using finite-difference-time-domain (FDTD) analysis. Simulation results show the high impact of the probe dimension and fat layer thickness on the sensitivity of the measured permittivity. The authors further investigate this sensitivity by statistical analysis of the permittivity variations. Finally, measuring in different locations relative to the body surface is presented as a solution to estimate the fat layer thickness in the presence of uncertainty of model parameters.

  6. Thickness estimation of the subcutaneous fat using coaxial probe

    PubMed Central

    Nadimi, Esmaeil S.

    2016-01-01

    In this Letter, a non-invasive method for thickness estimation of the subcutaneous fat layer of abdominal wall is presented by using a coaxial probe. Fat layer has the highest impact on the averaged attenuation parameter of the abdominal wall due to its high thickness and low permittivity. The abdominal wall is modelled as a multi-layer medium and an analytical model for the probe is derived by calculation of its aperture admittance facing to this multi-layer medium. The performance of this model is then validated by a numerical simulation using finite-difference-time-domain (FDTD) analysis. Simulation results show the high impact of the probe dimension and fat layer thickness on the sensitivity of the measured permittivity. The authors further investigate this sensitivity by statistical analysis of the permittivity variations. Finally, measuring in different locations relative to the body surface is presented as a solution to estimate the fat layer thickness in the presence of uncertainty of model parameters. PMID:27222737

  7. The effect of lumbar posture on abdominal muscle thickness during an isometric leg task in people with and without non-specific low back pain.

    PubMed

    Pinto, Rafael Zambelli; Ferreira, Paulo Henrique; Franco, Marcia Rodrigues; Ferreira, Mariana Calais; Ferreira, Manuela Loureiro; Teixeira-Salmela, Luci Fuscaldi; Oliveira, Vinicius C; Maher, Christopher

    2011-12-01

    This study investigated the effect of lumbar posture on function of transversus abdominis (TrA) and obliquus internus (OI) in people with and without non-specific low back pain (LBP) during a lower limb task. Rehabilitative ultrasound was used to measure thickness change of TrA and OI during a lower limb task that challenged the stability of the spine. Measures were taken in supine in neutral and flexed lumbar postures in 30 patients and 30 healthy subjects. Data were analysed using a two-way (groups, postures) ANOVA. Our results showed that lumbar posture influenced percent thickness change of the TRA muscle but not for OI. An interaction between group and posture was found for TrA thickness change (F(1,56) = 6.818, p = 0.012). For this muscle, only healthy participants showed greater thickness change with neutral posture compared to flexed (mean difference = 6.2%; 95% CI: 3.1-9.3%; p < 0.001). Comparisons between groups for both muscles were not significant. Neutral lumbar posture can facilitate an increase in thickness of the TrA muscle while performing a leg task, however this effect was not observed for this muscle in patients with LBP. No significant difference in TrA and OI thickness change between people with and without non-specific LBP was found.

  8. Analysis of Round Robin Test for Ultrasonic Thickness Measurement of Wall Thinned Pipe in Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Hoon; Lee, Seung-Joon; Lee, Joon-Hyun; Lee, Sung-Ho

    2008-02-01

    It is well recognized that one of the most serious problems on the maintenance of piping system in Nuclear Power Plants (NPPs) is the wall thinning of carbon steel pipe components. The objective of this research is to verify confidence of wall thinning measurement system by conducting Round Robin Test (RRT). 23 specimens with different size and shape of pipe were used according to standard practice in RRT. The gage R&R analysis was introduced for each sigma quality level, so that repeatability and reproducibility can be estimated from RRT results.

  9. [Abdominal approaches and drainages of the abdominal cavity].

    PubMed

    Hagel, C; Schilling, M

    2006-04-01

    Appropriate access to the abdominal cavity is the first and crucial step for successful abdominal surgical intervention. In planning the incision, several variables have to be considered, such as anatomy of the abdominal wall, localization of the target organ, and individual conditions (previous incisions, minimal access surgery, etc). Medial laparotomy is the preferred incision for emergency cases and ill-defined pathologies, allowing access and hence exploration to all quadrants. Transverse laparotomies give superior access to the dorsal and right aspects of the liver and cause less pain in patients unfit for regional anesthetic procedures. Draining of the abdominal cavity is used after various resective and reconstructive procedures, but there is little evidence for its use in a number of operations such as gastric, hepatic, and colorectal resections. Advantages and disadvantages of different abdominal wall incisions and drainages are discussed.

  10. Quantitative Assessment of Abdominal Aortic Aneurysm Geometry

    PubMed Central

    Shum, Judy; Martufi, Giampaolo; Di Martino, Elena; Washington, Christopher B.; Grisafi, Joseph; Muluk, Satish C.; Finol, Ender A.

    2011-01-01

    Recent studies have shown that the maximum transverse diameter of an abdominal aortic aneurysm (AAA) and expansion rate are not entirely reliable indicators of rupture potential. We hypothesize that aneurysm morphology and wall thickness are more predictive of rupture risk and can be the deciding factors in the clinical management of the disease. A non-invasive, image-based evaluation of AAA shape was implemented on a retrospective study of 10 ruptured and 66 unruptured aneurysms. Three-dimensional models were generated from segmented, contrast-enhanced computed tomography images. Geometric indices and regional variations in wall thickness were estimated based on novel segmentation algorithms. A model was created using a J48 decision tree algorithm and its performance was assessed using ten-fold cross validation. Feature selection was performed using the χ2-test. The model correctly classified 65 datasets and had an average prediction accuracy of 86.6% (κ = 0.37). The highest ranked features were sac length, sac height, volume, surface area, maximum diameter, bulge height, and intra-luminal thrombus volume. Given that individual AAAs have complex shapes with local changes in surface curvature and wall thickness, the assessment of AAA rupture risk should be based on the accurate quantification of aneurysmal sac shape and size. PMID:20890661

  11. 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.

  12. 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.

  13. Thick Co-Deposits and Dust in Controlled Fusion Devices with Carbon Walls: Fuel Inventory and Growth Rate of Co-Deposited Layers

    NASA Astrophysics Data System (ADS)

    Rubel, M.; Philipps, V.; Tanabe, T.; Wienhold, P.; Freisinger, M.; Linke, J.; von Seggern, J.; Wessel, E.

    Recent results regarding the formation of co-deposits, fuel accumulation and overall material transport at the TEXTOR tokamak are described. Two categories of brittle flaking co-deposits were identified: (i) smooth stratified layers of a thickness of up to 50 mm and a fuel content of up to 16 at.% , (ii) granular and columnar structures reaching 1 mm in thickness and con-taining around 0.5 at.% of fuel species. They were formed on the blades of the toroidal belt pump limiter (˜15000 s of plasma operation) and on the neutral-iser plates of this limiter (˜90000 s), respectively. A comparison is made to the fuel inventory measured in other controlled fusion devices with carbon walls.

  14. Optimization of wall thickness and lay-up for the shell-like composite structure loaded by non-uniform pressure field

    NASA Astrophysics Data System (ADS)

    Shevtsov, S.; Zhilyaev, I.; Oganesyan, P.; Axenov, V.

    2017-01-01

    The glass/carbon fiber composites are widely used in the design of various aircraft and rotorcraft components such as fairings and cowlings, which have predominantly a shell-like geometry and are made of quasi-isotropic laminates. The main requirements to such the composite parts are the specified mechanical stiffness to withstand the non-uniform air pressure at the different flight conditions and reduce a level of noise caused by the airflow-induced vibrations at the constrained weight of the part. The main objective of present study is the optimization of wall thickness and lay-up of composite shell-like cowling. The present approach assumes conversion of the CAD model of the cowling surface to finite element (FE) representation, then its wind tunnel testing simulation at the different orientation of airflow to find the most stressed mode of flight. Numerical solutions of the Reynolds averaged Navier-Stokes (RANS) equations supplemented by k-w turbulence model provide the spatial distributions of air pressure applied to the shell surface. At the formulation of optimization problem the global strain energy calculated within the optimized shell was assumed as the objective. A wall thickness of the shell had to change over its surface to minimize the objective at the constrained weight. We used a parameterization of the problem that assumes an initiation of auxiliary sphere with varied radius and coordinates of the center, which were the design variables. Curve that formed by the intersection of the shell with sphere defined boundary of area, which should be reinforced by local thickening the shell wall. To eliminate a local stress concentration this increment was defined as the smooth function defined on the shell surface. As a result of structural optimization we obtained the thickness of shell's wall distribution, which then was used to design the draping and lay-up of composite prepreg layers. The global strain energy in the optimized cowling was reduced in2

  15. Ordered hexagonal mesoporous aluminosilicates synthesized using zeolite as precursor and the wall-thickness tuned by pH control

    NASA Astrophysics Data System (ADS)

    Wang, Chunlei; Zhu, Guangshang; Shang, Tiecun; Cai, Xiaohui; Liu, Chengzhan; Li, Nan; Wei, Yuhong; Li, Jian; Zhang, Weiwei; Qiu, Shilun

    2005-07-01

    High aluminium content mesoporous aluminosilicates MAS-X1 and MAS-X3 have been successfully synthesized using zeolite FAU-X as precursors and triblock copolymer pluronic P123 as structure directing agent. Samples have been characterized by XRD, TEM, nitrogen adsorption/desorption, 27Al MAS NMR, and ICP element analysis techniques. The salt, NaCl, which was introduced by dissolving the zeolite FAU-X, played an important role in the synthesis of high order sample. The secondary growth of the wall was considered to occur after the pH value had been increased up to five.

  16. [Abdominal paracentesis].

    PubMed

    Glauser, Frédéric; Barras, Anne-Catherine; Pache, Isabelle; Monti, Matteo

    2008-10-29

    Abdominal paracentesis is frequently performed in the clinical setting. Every newly developed ascites need to be investigated by abdominal paracentesis. Any clinical or biological deterioration in patients with chronic ascites also requires a new paracentesis. Therapeutically abdominal paracentesis is performed for refractory or symptomatic ascites. As other invasive procedures, it is critical to master its indications, contra-indications and complications. The aim of this article is to review the basics of abdominal paracentesis in order to help physicians to carry out this technical skill.

  17. Increased Infarct Wall Thickness by a Bio-Inert Material Is Insufficient to Prevent Negative Left Ventricular Remodeling after Myocardial Infarction

    PubMed Central

    Rane, Aboli A.; Chuang, Joyce S.; Shah, Amul; Hu, Diane P.; Dalton, Nancy D.; Gu, Yusu; Peterson, Kirk L.; Omens, Jeffrey H.; Christman, Karen L.

    2011-01-01

    Background Several injectable materials have been shown to preserve or improve cardiac function as well as prevent or slow left ventricular (LV) remodeling post-myocardial infarction (MI). However, it is unclear as to whether it is the structural support or the bioactivity of these polymers that lead to beneficial effects. Herein, we examine how passive structural enhancement of the LV wall by an increase in wall thickness affects cardiac function post-MI using a bio-inert, non-degradable synthetic polymer in an effort to better understand the mechanisms by which injectable materials affect LV remodeling. Methods and Results Poly(ethylene glycol) (PEG) gels of storage modulus G′ = 0.5±0.1 kPa were injected and polymerized in situ one week after total occlusion of the left coronary artery in female Sprague Dawley rats. The animals were imaged using magnetic resonance imaging (MRI) at 7±1 day(s) post-MI as a baseline and again post-injection 49±4 days after MI. Infarct wall thickness was statistically increased in PEG gel injected vs. control animals (p<0.01). However, animals in the polymer and control groups showed decreases in cardiac function in terms of end diastolic volume, end systolic volume and ejection fraction compared to baseline (p<0.01). The cellular response to injection was also similar in both groups. Conclusion The results of this study demonstrate that passive structural reinforcement alone was insufficient to prevent post-MI remodeling, suggesting that bioactivity and/or cell infiltration due to degradation of injectable materials are likely playing a key role in the preservation of cardiac function, thus providing a deeper understanding of the influencing properties of biomaterials necessary to prevent post-MI negative remodeling. PMID:21731777

  18. Direct measurement of wall slip and slip layer thickness of non-Brownian hard-sphere suspensions in rectangular channel flows

    NASA Astrophysics Data System (ADS)

    Jesinghausen, Steffen; Weiffen, Rene; Schmid, Hans-Joachim

    2016-09-01

    Wall slip is a long-known phenomenon in the field of rheology. Nevertheless, the origin and the evolution are not completely clear yet. Regarding suspensions, the effect becomes even more complicated, because different mechanisms like pure slip or slip due to particle migration have to be taken into account. Furthermore, suspensions themselves show many flow anomalies and the isolation of slip is complicated. In order to develop working physical models, further insight is necessary. In this work, we measured experimentally the wall slip velocities of different highly filled suspensions in a rectangular slit die directly with respect to the particle concentration and the particle size. The slip velocities were obtained using a particle image velocimetry (PIV) system. The suspensions consisting of a castor oil-cinnamon oil blend and PMMA particles were matched in terms of refractive indexes to appear transparent. Hereby, possible optical path lengths larger than 15 mm were achieved. The slip velocities were found to be in a quadratic relation to the wall shear stress. Furthermore, the overall flow rate as well as the particle concentration has a direct influence on the slip. Concerning the shear stress, there seem to be two regions of slip with different physical characteristics. Furthermore, we estimated the slip layer thickness directly from the velocity profiles and propose a new interpretation. The PIV technique is used to investigate the viscosity and implicit the concentration profile in the slit die. It is shown that the particle migration process is quite fast.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

    Kakehi, Kazunori; Noda, Suguru; Maruyama, Shigeo; Yamaguchi, Yukio

    2008-08-01

    The relationships among the nominal thickness of Co catalyst, the structure of the catalyst particles, and the structure of carbon nanotubes (CNTs) growing from the catalyst during chemical vapor deposition were investigated. Various morphologies of CNTs such as individuals, random networks parallel to the surface of the substrate ('grasses'), and vertically aligned forests of single- and multi-walled carbon nanotubes were grown by only varying the nominal thickness of catalyst under the same reaction condition. These different morphologies at the same growth time were due to the different areal density rather than to the length of CNTs. With increasing nominal thickness of catalyst, the catalyst particles changed in diameter while their areal density remained relatively almost constant. The change in diameter possibly affected the number ratio of active catalyst particles to the whole particles, which in turn affected the areal density of CNTs and yielded the various morphologies. Longer growth time increased the CNT length, which caused further change in CNT morphologies from individuals to grasses and grasses to forests.

  1. [Inflammatory abdominal aortic aneurysm].

    PubMed

    Mikami, Y; Kyogoku, M

    1994-08-01

    Inflammatory abdominal aortic aneurysm (IAAA) is a distinct clinicopathological entity, characterized by: (1) clinical presentation, such as back pain, weight loss, and increased ESR, (2) patchy and/or diffuse lymphoplasmacytic infiltration, and (3) marked periaortic fibrosis resulting in thickening of the aneurysmal wall and occasional retroperitoneal fibrosis. Its pathogenesis is unknown, but some authors support the theory that IAAA is a subtype of atherosclerotic abdominal aortic aneurysm because of close relationship between IAAA and atherosclerotic change. In this article, we describe clinical and histological features of IAAA on the basis of the literature and our review of 6 cases of IAAA, emphasizing the similarity and difference between IAAA and atherosclerotic abdominal aortic aneurysm. Our review supports that marked lamellar fibrosis completely replacing the media and adventitia, patchy lymphocytic infiltration (mostly B cells) and endarteritis obliterans are characteristic features of IAAA.

  2. 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

  3. Steam-assisted crystallization of TPA{sup +}-exchanged MCM-41 type mesoporous materials with thick pore walls

    SciTech Connect

    Chen, Hong Li; Zhang, Kun; Wang, Yi Meng

    2012-07-15

    Highlights: ► Mesoporous Ti-containing silica with thicker pore walls was synthesized. ► Ion-exchange and steam-assisted crystallization led to MCM-41/MFI composite. ► The introduction of Ti inhibited the formation of separated MFI particles. ► Lower temperature favored retaining mesoporous characteristics and morphology. -- Abstract: Hierarchical MCM-41/MFI composites were synthesized through ion-exchange of as-made MCM-41 type mesoporous materials with tetrapropylammonium bromide and subsequent steam-assisted recrystallization. The obtained samples were characterized by powder X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis, FT-IR, {sup 1}H–{sup 13}C CP/MAS and nitrogen adsorption–desorption. The XRD patterns show that the MCM-41/MFI composite possesses both ordered MCM-41 phase and zeolite MFI phase. SEM and TEM images indicate that the recrystallized materials retained the mesoporous characteristics and the morphology of as-made mesoporous materials without the formation of bulky zeolite, quite different from the mechanical mixture of MCM-41 and MFI structured zeolite. Among others, lower recrystallization temperature and the introduction of the titanium to the parent materials are beneficial to preserve the mesoporous structure during the recrystallization process.

  4. Single-Walled Carbon Nanotube Film Supported Nanofiltration Membrane with a Nearly 10 nm Thick Polyamide Selective Layer for High-Flux and High-Rejection Desalination.

    PubMed

    Zhu, Yuzhang; Xie, Wei; Gao, Shoujian; Zhang, Feng; Zhang, Wenbin; Liu, Zhaoyang; Jin, Jian

    2016-09-01

    Fabricating nanofiltration (NF) membranes with high permeating flux and simultaneous high rejection rate for desalination is rather significant and highly desired. A new avenue is reported in this work to design NF membrane by using polydopamine wrapped single-walled carbon nanotube (PD/SWCNTs) ultrathin film as support layer instead of the use of traditional polymer-based underlying layers. Thanks to the high porosity, smooth surface, and more importantly optimal hydrophilic surface of PD/SWCNTs film, a defect-free polyamide selective layer for NF membrane with thickness of as thin as 12 nm is achieved. The obtained NF membrane exhibits an extremely high performance with a permeating flux of 32 L m(-2) h(-1) bar(-1) and a rejection rate of 95.9% to divalent ions. This value is two to five times higher than the traditional NF membranes with similar rejection rate.

  5. Effect of alpha lipoic acid co-administration on structural and immunohistochemical changes in subcutaneous tissue of anterior abdominal wall of adult male albino rat in response to polypropylene mesh implantation.

    PubMed

    Mazroa, Shireen A; Asker, Samar A; Asker, Waleed; Abd Ellatif, Mohamed

    2015-06-01

    Polypropylene mesh is commonly used in the treatment of abdominal hernia. Different approaches were addressed to improve their tissue integration and consequently reduce long-term complications. This study aimed to investigate the effect of alpha-lipoic acid (ALA) co-administration on structural and immunohistochemical (IHC) changes in the subcutaneous tissues of the anterior abdominal wall of the adult rat in response to polypropylene mesh implantation. Forty adult male albino rats were divided into: group I (control), group II (receiving ALA), group III (polypropylene mesh implantation) and group IV (mesh implantation + ALA co-administration). After 4 weeks, subcutaneous tissue samples were prepared for light microscopy and IHC study of CD34 as a marker for angiogenesis. In groups I and II rats, positive CD34 expression was demonstrated by IHC reaction, localized to endothelial cells lining small blood vessels. Group III showed an excess inflammatory reaction, deposition of both regular and irregularly arranged collagen fibres around mesh pores and few elastic fibres. CD34-positive was detected not only in cells lining small blood vessels but also in other cells scattered in the connective tissue indicating angiogenesis. In group IV, ALA co-administration resulted in less inflammatory reaction, regular collagen deposition, enhanced elastic fibres synthesis and a significant increase in CD34-positive cells and small blood vessels reflecting improved angiogenesis. ALA co-administration with polypropylene mesh implantation controlled the inflammatory reaction, helped regular collagen deposition, enhanced elastic fibres synthesis and improved angiogenesis in the subcutaneous tissue of anterior abdominal wall of adult albino rats, suggesting a possible role of ALA in optimizing mesh integration in subcutaneous tissue.

  6. Effect of alpha lipoic acid co-administration on structural and immunohistochemical changes in subcutaneous tissue of anterior abdominal wall of adult male albino rat in response to polypropylene mesh implantation

    PubMed Central

    Mazroa, Shireen A; Asker, Samar A; Asker, Waleed; Abd Ellatif, Mohamed

    2015-01-01

    Polypropylene mesh is commonly used in the treatment of abdominal hernia. Different approaches were addressed to improve their tissue integration and consequently reduce long-term complications. This study aimed to investigate the effect of alpha-lipoic acid (ALA) co-administration on structural and immunohistochemical (IHC) changes in the subcutaneous tissues of the anterior abdominal wall of the adult rat in response to polypropylene mesh implantation. Forty adult male albino rats were divided into: group I (control), group II (receiving ALA), group III (polypropylene mesh implantation) and group IV (mesh implantation + ALA co-administration). After 4 weeks, subcutaneous tissue samples were prepared for light microscopy and IHC study of CD34 as a marker for angiogenesis. In groups I and II rats, positive CD34 expression was demonstrated by IHC reaction, localized to endothelial cells lining small blood vessels. Group III showed an excess inflammatory reaction, deposition of both regular and irregularly arranged collagen fibres around mesh pores and few elastic fibres. CD34-positive was detected not only in cells lining small blood vessels but also in other cells scattered in the connective tissue indicating angiogenesis. In group IV, ALA co-administration resulted in less inflammatory reaction, regular collagen deposition, enhanced elastic fibres synthesis and a significant increase in CD34-positive cells and small blood vessels reflecting improved angiogenesis. ALA co-administration with polypropylene mesh implantation controlled the inflammatory reaction, helped regular collagen deposition, enhanced elastic fibres synthesis and improved angiogenesis in the subcutaneous tissue of anterior abdominal wall of adult albino rats, suggesting a possible role of ALA in optimizing mesh integration in subcutaneous tissue. PMID:25891652

  7. Low-alloy steels for thick-walled pressure vessels. Summary report, February 1, 1980-January 31, 1982

    SciTech Connect

    Todd, J.A.; Chung, D.W.; Parker, E.R.

    1982-01-01

    This program aimed to modify existing commercial pressure vessel steels to provide strong, tough, creep resistant materials, with low hydrogen attack and temper embrittlement susceptibilities, which can also be field-fabricated into thick-section vessels for coal conversion systems. Emphasis was placed on determining the effects of Mn, Ni and Cr on the creep rupture and hydrogen attack susceptibilities of Cr-Mo steels. Hydrogen attack studies were also carried out on A533B and model alloy systems to investigate the role of alloy carbides in promoting resistance to hydrogen damage. Creep rupture fracture times were determined at 500, 560 and 600/sup 0/C for periods up to 2000 hours. The effects of cooling rate from the austenitizing temperature and tempering response on the microstructure of 3Cr-1Mo-1Mn-1Ni steel were studied. The carbide structures in all the alloy modifications were carefully characterized. Data were collected from preliminary weld bead-on-plate tests of A387 and temper embrittlement studies of A543 with mischmetal addition. The unloading compliance test technique for J/sub Ic/ measurements was completed for A533B specimens but shortage of material prevented testing of A387. The mechanical property, elevated temperature creep and hydrogen attack data suggested that addition of 0.75 Cr + 0.5 Mn + 1Ni was beneficial in reducing susceptibility to hydrogen damage but was detrimental to creep rupture properties. 44 figures, 14 tables.

  8. 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.

  9. A new multichannel time reversal focusing method for circumferential Lamb waves and its applications for defect detection in thick-walled pipe with large-diameter.

    PubMed

    Liu, Zenghua; Xu, Qinglong; Gong, Yu; He, Cunfu; Wu, Bin

    2014-09-01

    This paper proposes a new multichannel time reversal focusing (MTRF) method for circumferential Lamb waves which is based on modified time reversal algorithm and applies this method for detecting different kinds of defects in thick-walled pipe with large-diameter. The principle of time reversal of circumferential Lamb waves in pipe is presented along with the influence from multiple guided wave modes and propagation paths. Experimental study is carried out in a thick-walled and large-diameter pipe with three artificial defects, namely two axial notches on its inner and outer surface respectively, and a corrosion-like defect on its outer surface. By using the proposed MTRF method, the multichannel signals focus at the defects, leading to the amplitude improvement of the defect scattered signal. Besides, another energy focus arises in the direct signal due to the partial compensation of dispersion and multimode of circumferential Lamb waves, alongside the multichannel focusing, during MTRF process. By taking the direct focus as a time base, accurate defect localization is implemented. Secondly, a new phenomenon is exhibited in this paper that defect scattered wave packet appears just before the right boundary of truncation window after time reversal, and to which two feasible explanations are given. Moreover, this phenomenon can be used as the theoretical basis in the determination of defect scattered waves in time reversal response signal. At last, in order to detect defects without prior knowing their exact position, a large-range truncation window is used in the proposed method. As a result, the experimental operation of MTRF method is simplified and defect detection and localization are well accomplished.

  10. 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.

  11. 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.

  12. 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 ...

  13. [Abdominal pain].

    PubMed

    Gschossmann, J M; Holtmann, G; Netzer, P; Essig, M; Balsiger, B M; Scheurer, U

    2005-10-01

    Abdominal pain can result from a variety of different intra- and extra-abdominal disorders. Given the wide variety of etiological triggers for this pain, the primary task during the first stage of the diagnostic work-up is to determine as soon as possible the underlying cause and the degree of emergency. The aim of this evaluation is to adapt the therapeutic measures which are necessary for a causal treatment to the individual situation. Contrary to somatic causes of abdominal pain, the availability of such a causal therapy for functional bowel disorders is still very limited. Given this dilemma, the therapeutic focus of abdominal pain associated with these functional syndromes has to be placed on symptom-oriented treatment.

  14. Acute incarcerated external abdominal hernia

    PubMed Central

    Yang, Xue-Fei

    2014-01-01

    External abdominal hernia occurs when abdominal organs or tissues leave their normal anatomic site and protrude outside the skin through the congenital or acquired weakness, defects or holes on the abdominal wall, including inguinal hernia, umbilical hernia, femoral hernia and so on. Acute incarcerated hernia is a common surgical emergency. With advances in minimally invasive devices and techniques, the diagnosis and treatment have witnessed major changes, such as the use of laparoscopic surgery in some cases to achieve minimally invasive treatment. However, strict adherence to the indications and contraindications is still required. PMID:25489584

  15. A prospective, randomized clinical trial of antiretroviral therapies on carotid wall thickness: AIDS Clinical Trial Group Study A5260s

    PubMed Central

    Stein, James H.; Ribaudo, Heather J.; Hodis, Howard N.; Brown, Todd T.; Tran, Thuy Tien T.; Yan, Mingzhu; Brodell, Elizabeth Lauer; Kelesidis, Theodore; McComsey, Grace A.; Dube, Michael P.; Murphy, Robert L.; Currier, Judith S.

    2015-01-01

    Objective This article compares the effects of initiating three contemporary antiretroviral therapy (ART) regimens on progression of carotid artery intima-media thickness (IMT) over 3 years. Design Randomized clinical trial. Setting Multicenter (26 institutions). Patients ART-naïve HIV-infected individuals (n = 328) without known cardiovascular disease or diabetes mellitus. Intervention Random assignment to tenofovir/emtricitabine along with atazanavir/ritonavir (ATV/r), darunavir/ritonavir (DRV/r), or raltegravir (RAL). Main outcome measures Right-sided carotid IMT was evaluated by B-mode ultra-sonography before ART initiation, and then after 48, 96, and 144 weeks. Comparisons of yearly rates of change in carotid IMT used mixed-effects linear regression models that permitted not only evaluation of the effects of ART on carotid IMT progression but also how ART-associated changes in traditional risk factors, bilirubin, and markers of HIV infection were associated carotid IMT progression. Results HIV-1 RNA suppression rates were high in all arms (>85%) over 144 weeks. Modest increases in triglycerides and non-high-density lipoprotein cholesterol levels were observed in the protease inhibitor containing arms compared with decreases with RAL. In contrast, carotid IMT progressed more slowly on ATV/r [8.2, 95% confidence interval (5.6, 10.8) μm/year] than DRV/r [12.9 (10.3, 15.5) μm/year, P = 0.013]; changes with RAL were intermediate [10.7 (9.2, 12.2) μm/year, P = 0.15 vs. ATV/r; P = 0.31 vs. DRV/r]. Bilirubin and non-high-density lipoprotein cholesterol levels appeared to influence carotid IMT progression rates. Conclusion In ART-naïve HIV-infected individuals at low cardiovascular disease risk, carotid IMT progressed more slowly in participants initiating ATV/r than those initiating DRV/r, with intermediate changes associated with RAL. This effect may be due, in part, to hyperbilirubinemia. PMID:26372383

  16. "Abdominal crunch"-induced rhabdomyolysis presenting as right upper quadrant pain.

    PubMed

    Haas, D C; Bohnker, B K

    1999-02-01

    A young, active duty sailor presented with right upper quadrant abdominal pain. History, physical, and laboratory findings initially suggested cholecystitis or related disease. Further evaluation found myoglobinuria and a recently increased exercise program, leading to the diagnosis of exercise-induced right upper abdominal wall rhabdomyolysis. Although not a common cause of abdominal pain, this diagnosis should be considered in the patient with abdominal pain and a recently increased exercise program, particularly exercises of the abdominal wall such as "abdominal crunches."

  17. [The effect of ionizing radiation on the blood plasma and erythrocytes and on the wall of the abdominal aorta of rats].

    PubMed

    Nikulin, A A; Pustovalov, A P; Voronkov, I F

    1988-01-01

    On days 7 and 15 after gamma-irradiation (4 Gy) changes were noted in the temperature dependence of the erythrocyte suspension viscosity coefficient, in the electrolyte composition of the abdominal aorta, plasma, and erythrocytes, in Na, K- and Mg-ATPase activity, and in the intensity of fluorescence of 1.8 ANS of erythrocyte ghost of albino rats. The changes were a function of the stage of radiation sickness and were more pronounced on the 15th day following irradiation.

  18. Correlation of left ventricular wall thickness, heart mass, serological parameters and late gadolinium enhancement in cardiovascular magnetic resonance imaging of myocardial inflammation in an experimental animal model of autoimmune myocarditis.

    PubMed

    Kromen, Wolfgang; Korkusuz, Huedayi; Korkusuz, Yuecel; Esters, Philip; Bauer, Ralf W; Huebner, Frank; Lindemayr, Sebastian; Vogl, Thomas J

    2012-12-01

    For a definitive diagnosis of myocarditis, different strategies like analysis of late gadolinium enhancement (LGE) in cardiovascular magnetic resonance imaging (CMR) up to invasive endomyocardial biopsy have been applied. The objective of the study was to investigate inflammatory changes like left ventricular wall thickening and increase of ventricular mass and to quantitatively analyse their correlation with extent and localisation of myocardial damage in CMR and with subsequent changes of serological markers in an animal model of an experimental autoimmune myocarditis (EAM). In the current study, an EAM was induced in 10 male Lewis rats, 10 rats served as control. On day 21, animals were examined with four CMR protocols to assess the extent of LGE in a 12 segment model of the rat heart. Left myocardial wall thickness and mass and histological grade of inflammation were measured to determine localisation and severity of the induced myocarditis. Depending on the CMR sequence, LGE was mostly found in the left anterior (9.6%) and left lateral (8.7%) myocardial wall segments. Wall thickness correlated with the LGE area in CMR imaging and the histopathological severity of myocarditis for the left lateral myocardial wall segment. In a similar way, the heart mass correlated to the extent of LGE for the left lateral segment. We conclude that in our animal model left ventricular wall thickness and mass reflect the severity of myocardial changes in myocarditis and that the EAM rat model is well suited for further investigations of myocarditis.

  19. Right ventricular relative wall thickness as a predictor of outcomes and of right ventricular reverse remodeling for patients with pulmonary hypertension.

    PubMed

    Sano, Hiroyuki; Tanaka, Hidekazu; Motoji, Yoshiki; Fukuda, Yuko; Mochizuki, Yasuhide; Hatani, Yutaka; Matsuzoe, Hiroki; Hatazawa, Keiko; Shimoura, Hiroyuki; Ooka, Junichi; Ryo-Koriyama, Keiko; Nakayama, Kazuhiko; Matsumoto, Kensuke; Emoto, Noriaki; Hirata, Ken-Ichi

    2017-03-01

    Mid-term right ventricular (RV) reverse remodeling after treatment in patients with pulmonary hypertension (PH) is associated with long-term outcome as well as baseline RV remodeling. However, baseline factors influencing mid-term RV reverse remodeling after treatment and its prognostic capability remain unclear. We studied 54 PH patients. Mid-term RV remodeling was assessed in terms of the RV area, which was traced planimetrically at the end-systole (RVESA). RV reverse remodeling was defined as a relative decrease in the RVESA of at least 15% at 10.2 ± 9.4 months after treatment. Long-term follow-up was 5 years. Adverse events occurred in ten patients (19%) and mid-term RV reverse remodeling after treatment was observed in 37 (69%). Patients with mid-term RV reverse remodeling had more favorable long-term outcomes than those without (log-rank: p = 0.01). Multivariate logistic regression analysis showed that RV relative wall thickness (RV-RWT), as calculated as RV free-wall thickness/RV basal linear dimension at end-diastole, was an independent predictor of mid-term RV reverse remodeling (OR 1.334; 95% CI, 1.039-1.713; p = 0.03). Moreover, patients with RV-RWT ≥0.21 showed better long-term outcomes than did those without (log-rank p = 0.03), while those with RV-RWT ≥0.21 and mid-term RV reverse remodeling had the best long-term outcomes. Patients with RV-RWT <0.21 and without mid-term RV reverse remodeling, on the other hand, had worse long-term outcomes than other sub-groups. In conclusions, RV-RWT could predict mid-term RV reverse remodeling after treatment in PH patients, and was associated with long-term outcomes. Our finding may have clinical implications for better management of PH patients.

  20. Abdominal Sepsis.

    PubMed

    De Waele, Jan J

    2016-08-01

    Abdominal infections are an important challenge for the intensive care physician. In an era of increasing antimicrobial resistance, selecting the appropriate regimen is important and, with new drugs coming to the market, correct use is important more than ever before and abdominal infections are an excellent target for antimicrobial stewardship programs. Biomarkers may be helpful, but their exact role in managing abdominal infections remains incompletely understood. Source control also remains an ongoing conundrum, and evidence is increasing that its importance supersedes the impact of antibiotic therapy. New strategies such as open abdomen management may offer added benefit in severely ill patients, but more data are needed to identify its exact role. The role of fungi and the need for antifungal coverage, on the other hand, have been investigated extensively in recent years, but at this point, it remains unclear who requires empirical as well as directed therapy.

  1. [Differential surgical treatment of victims with damage to the small and large intestines in a closed abdominal injury combined, depending on the prediction of traumatic disease course and morphological changes of the intestinal wall].

    PubMed

    Zaruts'kyĭ, Ia L; Denysenko, V M; Khomenko, I P; Levkivskyĭ, R H

    2013-08-01

    Use of differentiated surgical approach to the management of surgical treatment, depending on the degree of violation of systemic hemodynamics, the timing and volume of surgical procedures, depending on the prognosis of traumatic disease course of cardiac index, interventions in the small and large intestine depending on morphological changes of the intestinal wall by cardiac and stroke indexes, put method extra-enteric anastomosis in patients with damage to the small intestine and colon combined with closed abdominal injury permitted to reduce the rate of postoperative complications from 22.2 to 10.1%, mortality at 2.1 times in shock period (from 19.3 to 9.2%) and the overall mortality from 33.3 to 21.1%.

  2. 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.

  3. Abdominal Adhesions

    MedlinePlus

    ... Adhesions 1 Ward BC, Panitch A. Abdominal adhesions: current and novel therapies. Journal of Surgical Research. 2011;165(1):91–111. Seek Help for ... and how to participate, visit the NIH Clinical Research Trials and You website ... Foundation for Functional Gastrointestinal Disorders 700 West Virginia ...

  4. Repair of Large Abdominal Wall Defects Using Total Anterior Aponeurotic Flap: Anatomical Feasibility Study and Comparison with Ramirez’s Technique

    PubMed Central

    Assalino, Michela; Morel, Philippe; Fasel, Jean H. D.; Stimec, Bojan V.; Tobalem, Mickael

    2016-01-01

    Summary: In this cadaveric study, we explored the feasibility of a maximal mobilization of the superficial abdominal fascia, in a continuous flap, to achieve a tension-free covering of midline defects. The aponeurosis of the external oblique muscle was incised along the anterior axillary line and then detached up to the anterior rectus sheath. The latter was opened between the external and the internal oblique aponeurosis while keeping the continuity with the external oblique fascia. The obtained flap was solid and uninterrupted. The width gain reached 15 ± 3 cm on each sides, providing tissue advancement 60% longer than Ramirez’s technique (n = 8). The described technique allows large covering with respect to the anatomical planes. Further clinical tests should evaluate the validity of such concept in the repair of giant and asymmetrical hernias.

  5. [Morphological and functional parameters of the left ventricle (mass, wall thickness and end-systolic stress) in school children with different levels of blood pressure, at rest and during maximal exercise].

    PubMed

    Muñoz, S; Soltero, I; Onorato, E; Pietri, C; Zambrano, F

    1990-01-01

    Echocardiographically determined left ventricular mass, diastolic septal and posterior wall thickness and end-systolic wall stress, as well as electrocardiographic indexes of left ventricular enlargement (Sokolow-Lyon index and Romhilt-Estes score) and of left atrial enlargement (P terminal index) were correlated with resting and exercise systolic and diastolic blood pressures, and with several parameters of body size (weight, height, body surface area, Quetelet index), in 130 school children (61 boys, 69 girls) 6 to 15 years of age. Parameters of body size had a positive correlation both with systolic and diastolic blood pressures and with parameters of left ventricular size. Thus, the latter were adjusted for body surface area, for correlation with blood pressure. Left ventricular mass and diastolic septal and posterior wall thickness had a very poor correlation with resting and exercise diastolic blood pressures. Left ventricular mass and diastolic posterior wall thickness had a significantly higher correlation with peak exercise systolic blood pressure than with resting systolic blood pressure. End-systolic wall stress had a positive correlation with resting diastolic and systolic blood pressures. Electrocardiographic parameters of left ventricular and left atrial enlargement had a very poor correlation with resting and exercise blood pressure. Our findings suggest that early in life left ventricular mass and wall thickness are more closely related to maximal systolic blood pressure during physical exercise than to blood pressure in basal conditions. The electrocardiogram is an insensitive method to detect early modifications of left ventricular size in relation to different levels of blood pressure. The echocardiogram is the method of choice for this purpose.

  6. 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

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

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-06

    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.

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

    PubMed Central

    Polzer, Stanislav; Gasser, T. Christian

    2015-01-01

    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

  9. Longitudinal changes in structural abnormalities using MDCT in COPD: do the CT measurements of airway wall thickness and small pulmonary vessels change in parallel with emphysematous progression?

    PubMed Central

    Takayanagi, Shin; Kawata, Naoko; Tada, Yuji; Ikari, Jun; Matsuura, Yukiko; Matsuoka, Shin; Matsushita, Shoichiro; Yanagawa, Noriyuki; Kasahara, Yasunori; Tatsumi, Koichiro

    2017-01-01

    Background Recent advances in multidetector computed tomography (MDCT) facilitate acquiring important clinical information for managing patients with COPD. MDCT can detect the loss of lung tissue associated with emphysema as a low-attenuation area (LAA) and the thickness of airways as the wall area percentage (WA%). The percentage of small pulmonary vessels <5 mm2 (% cross-sectional area [CSA] <5) has been recently recognized as