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1

Revascularization of human acellular dermis in full-thickness abdominal wall reconstruction in the rabbit model.  

PubMed

This study investigates whether human acellular dermis (Alloderm; LifeCell, Branchburg, NJ) revascularizes when used to reconstruct abdominal wall defects in rabbits. This could prove useful in infected situations in which prosthetic mesh is suboptimal. Twenty-five rabbits were randomly assigned to one of three groups: primary closure (n = 5), expanded polytetrafluoroethylene (GoreTex; W.L. Gore, Flagstaff, AZ) repair (n = 10), or AlloDerm (LifeCell) repair (n = 10). The rabbits in the primary closure group received a 7 cm x 0.5 cm full-thickness abdominal wall defect that was closed primarily. A 7 cm x 3 cm full-thickness abdominal wall defect was created in the other two groups. The defects were repaired with a GoreTex Mycromesh (W.L. Gore), or AlloDerm (LifeCell) patch. At 30 days, the following endpoints were evaluated: (1) incidence of herniation; (2) presence of intra-abdominal adhesions; (3) the breaking strength of the patch-fascial interface; and (4) evaluation of graft vascularization by fluorescein dye infusion and histological analysis. There was no incidence of herniation in any of the rabbits. Visceral adhesions to the patch were found in all animals in the Gore-Tex (W.L. Gore) group but in none in the AlloDerm (LifeCell) group. The size of the patch was unchanged in all the rabbits except for two rabbits in the AlloDerm (LifeCell) group that stretched 1 cm in the transverse dimension. The change in size was not statistically significant (p = 0.17) when compared with the change in size in the Gore-Tex (W.L. Gore) group. The mean breaking strength of the primary closure group was significantly higher (521.2 N/mm2 +/- 223.0) than that of the two patch-repair groups (p < 0.05). But there was no significant difference between the mean breaking strength of the AlloDerm (LifeCell) fascial interface (288.6 N/mm2 +/- 97.1 SD) and that of the Gore-Tex (W.L. Gore) fascial interface (337.0 N/mm2 +/- 141.2). Fluorescein dye infusion and histological analysis confirmed vascularization of the AlloDerm (LifeCell) graft. This study demonstrates that AlloDerm (LifeCell) does become vascularized when used as a fascial interposition graft for abdominal wall reconstruction. AlloDerm (LifeCell) also performs mechanically as effectively as Gore-Tex (W.L. Gore) in ventral hernia repair at 1 month after operation in the rabbit model. PMID:12792544

Menon, Nathan G; Rodriguez, Eduardo D; Byrnes, Colman K; Girotto, John A; Goldberg, Nelson H; Silverman, Ronald P

2003-05-01

2

Lateral Abdominal Wall Reconstruction  

PubMed Central

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.

Baumann, Donald P.; Butler, Charles E.

2012-01-01

3

Dynamic geometry and wall thickness of the aortic neck of abdominal aortic aneurysms with intravascular ultrasonography  

Microsoft Academic Search

Results: There was significant variation in infrarenal aortic wall movement about the circumference, with 1.7 0.6 mm (range, 0.6-2.7 mm) displacement in the AP direction and 0.9 0.5 mm (range, 0.3-1.5 mm) displacement in the lateral direction (P < .001). Aortic wall thickness was greater in the region of increased AP wall motion than in the area of lesser lateral

Frank R. Arko; Erin H. Murphy; Chad M. Davis III; Eric D. Johnson; Stephen T. Smith; Christopher K. Zarins

2007-01-01

4

Abdominal wall gossypiboma.  

PubMed

A 71-year-old woman, one year following a fleur-de-lis abdominoplasty and incisional hernia repair, presented with two chronic, draining peri-umbilical sinuses. Her immediate postoperative course was complicated by a superficial surgical site infection with central skin breakdown that was treated with vacuum assisted closure (VAC). After the wound had closed completely, two midline sinus tracts developed. A CT scan demonstrated an 8x3x1.6cm thick-walled collection along the anterior abdominal wall containing numerous air bubbles. Surgical debridement revealed a cavity containing an 8x3x1.6cm block of well incorporated VAC foam. With the increasing clinical use of VAC wound therapy, this image serves as an important reminder to include gossypiboma in the differential diagnosis for patients with chronic wound problems who have previously received VAC treatment. PMID:19683975

Huston, Tara L; Grant, Robert T

2009-08-15

5

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

PubMed

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. PMID:22214798

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

2013-03-01

6

Importance of initial aortic properties on the evolving regional anisotropy, stiffness and wall thickness of human abdominal aortic aneurysms  

PubMed Central

Complementary advances in medical imaging, vascular biology and biomechanics promise to enable computational modelling of abdominal aortic aneurysms to play increasingly important roles in clinical decision processes. Using a finite-element-based growth and remodelling model of evolving aneurysm geometry and material properties, we show that regional variations in material anisotropy, stiffness and wall thickness should be expected to arise naturally and thus should be included in analyses of aneurysmal enlargement or wall stress. In addition, by initiating the model from best-fit material parameters estimated for non-aneurysmal aortas from different subjects, we show that the initial state of the aorta may influence strongly the subsequent rate of enlargement, wall thickness, mechanical behaviour and thus stress in the lesion. We submit, therefore, that clinically reliable modelling of the enlargement and overall rupture-potential of aneurysms may require both a better understanding of the mechanobiological processes that govern the evolution of these lesions and new methods of determining the patient-specific state of the pre-aneurysmal aorta (or correlation to currently unaffected portions thereof) through knowledge of demographics, comorbidities, lifestyle, genetics and future non-invasive or minimally invasive tests.

Wilson, J. S.; Baek, S.; Humphrey, J. D.

2012-01-01

7

Traumatic abdominal wall hernia  

PubMed Central

INTRODUCTION Traumatic abdominal wall hernia (TAWH) is a rare entity. Most cases occur in children, following an injury from the bicycle handle bar. In adults, it usually results from road traffic accidents (RTA). We present one of the largest reported cases of TAWH following RTA managed by delayed mesh repair. PRESENTATION OF CASE A 35 yr old obese male with RTA was diagnosed with TAWH with 19 cm × 15 cm defect in left flank. As there were no intra abdominal injuries and overlying skin was abraded, he was planned for elective repair after 6 months. On exploration a defect of 30 cm × 45 cm was found extending from midline anteriorly to 8 cm short of midline posteriorly in transverse axis and costal margin to iliac crest in craniocaudal axis. After restoration of bowel into abdominal cavity, primary closure or even approximation of muscular defect was not possible thus a mesh closure using 60 cm × 60 cm prolene mesh in subcutaneous plane was done. After 4 months follow up, patient is healthy and has no recurrence. DISCUSSION Emergent surgical management of TAWH is usually favoured due to high incidence of associated intra abdominal injuries. Delayed repair may be undertaken in selected cases. CONCLUSION TAWH, although rare, should be suspected in cases of RTA with abdominal wall swellings. With time, the hernia defect may enlarge and muscles may undergo atrophy making delayed repair difficult.

Yadav, Siddharth; Jain, Sunil K.; Arora, Jainendra K.; Sharma, Piyush; Sharma, Abhinav; Bhagwan, Jai; Goyal, Kaushal; Sahoo, Bhabani S.

2012-01-01

8

Soft tissue coverage in abdominal wall reconstruction.  

PubMed

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. PMID:24035082

Baumann, Donald P; Butler, Charles E

2013-10-01

9

Pediatric abdominal wall defects.  

PubMed

This article reviews the incidence, presentation, anatomy, and surgical management of abdominal wall defects found in the pediatric population. Defects such as inguinal hernia and umbilical hernia are common and are encountered frequently by the pediatric surgeon. Recently developed techniques for repairing these hernias are aimed at improving cosmesis and decreasing pain while maintaining acceptably low recurrence rates. Less common conditions such as femoral hernia, Spigelian hernia, epigastric hernia, lumbar hernia, gastroschisis, and omphalocele are also discussed. The surgical treatment of gastroschisis and omphalocele has undergone some advancement with the use of various silos and meshes. PMID:24035087

Kelly, Katherine B; Ponsky, Todd A

2013-07-26

10

Acute traumatic abdominal wall hernia.  

PubMed

Although blunt abdominal trauma is frequent, traumatic abdominal wall hernias (TAWH) are rare. We describe a large TAWH with associated intra-abdominal lesions that were caused by high-energy trauma. The diagnosis was missed by clinical examination but was subsequently revealed by a computed tomography (CT) scan. Repair consisted of an open anatomical reconstruction of the abdominal wall layers with reinforcement by an intraperitoneal composite mesh. The patient recovered well and the results of a post-operative CT scan are presented. PMID:20440527

den Hartog, D; Tuinebreijer, W E; Oprel, P P; Patka, P

2010-05-04

11

Economics of abdominal wall reconstruction.  

PubMed

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. PMID:24035086

Bower, Curtis; Roth, J Scott

2013-07-30

12

Traumatic abdominal wall injuries: a review.  

PubMed

Traumatic abdominal wall injuries have been described in literature for over 100 years. These injuries involve abdominal wall from skin to the level of fascia. These are often associated with underlying visceral injuries. The diagnosis requires a high index of suspicion and is based on clinical examination and radiologic investigations. Management ranges from conservative management to complex abdominal wall reconstruction. In the following review we describe the incidence, clinical features, diagnosis, management and possible interventions for prevention of these injuries. PMID:23774087

Rathore, A; Murherjee, I; Kumar, P

2013-06-01

13

Autologous closure of giant abdominal wall defects.  

PubMed

Split-thickness skin graft coverage of exposed and granulating intestines within large abdominal wall defects provides a life-saving permanent biologic dressing. The resultant abdominal wall defect often is closed with mesh, which may infect and fistulize. This report describes bilateral advancement flaps of the external oblique and recti muscles in 11 patients treated over 3 years. The defects, which averaged 16 x 24 cm, were due to necrotizing fasciitis subsequent to trauma with bowel perforation (3 patients), multiple ventral herniorrhaphies (2 patients), perforated diverticulitis (4 patients), and perforated peptic ulcer (2 patients). Eight patients were initially treated elsewhere where closure was achieved by split-thickness skin graft in five patients or mesh in 3 patients; 3 developed enterocutaneous fistulae and were transferred for closure while receiving long-term antibiotic and total parenteral nutrition therapy. All 11 patients had successful primary closure. The 8 patients operated on electively had primary healing; 2 developed seromas. Two of the three patients operated on urgently developed superficial wound infections; both healed by second intent without compromise of the primary closure. The following conclusions can be drawn: (1) the linea alba survives despite necrotizing fasciitis, (2) a tension-free primary closure is feasible; (3) morbidity is minimal, and (4) the long-term result is excellent. PMID:9655268

Lucas, C E; Ledgerwood, A M

1998-07-01

14

Biphasic synovial sarcoma of the abdominal wall  

Microsoft Academic Search

Synovial sarcoma arising in the abdominal wall is a rare tumor. We report a case of a 38-year-old man who complained of abdominal\\u000a pain. Physical examination revealed a firm mobile mass, 25 cm in diameter, in the left lower abdominal wall. The tumor was\\u000a first thought to be a sarcoma arising from the omentum or mesentery. During surgery, a large tumor

Jesús Vera; María-Dolores García; Miguel Marigil; Manuel Abascal; Jose-Ignacio Lopez; Luis Ligorred

2006-01-01

15

Tube wall thickness measurement apparatus  

DOEpatents

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.

Lagasse, P.R.

1985-06-21

16

Evisceration through multiple abdominal wall defects following blunt abdominal injury.  

PubMed

We report an unusual case of a posttraumatic evisceration of small and large bowel through 2 holes in the anterior abdominal wall after a motor vehicle accident. Prompt adequate management consists of reestablishing the perfusion of the eviscerated organ if the blood supply is compromised, performing a full laparotomy to exclude intra-abdominal organ injury and meticulous cleaning of the eviscerated organs before reducing them in the abdomen and closing the abdomen in layers. PMID:14578838

van As, A B; Rode, H

2003-10-01

17

Bioprosthetic Mesh in Abdominal Wall Reconstruction  

PubMed Central

Mesh materials have undergone a considerable evolution over the last several decades. There has been enhancement of biomechanical properties, improvement in manufacturing processes, and development of antiadhesive laminate synthetic meshes. The evolution of bioprosthetic mesh materials has markedly changed our indications and methods for complex abdominal wall reconstruction. The authors review the optimal properties of bioprosthetic mesh materials, their evolution over time, and their indications for use. The techniques to optimize outcomes are described using bioprosthetic mesh for complex abdominal wall reconstruction. Bioprosthetic mesh materials clearly have certain advantages over other implantable mesh materials in select indications. Appropriate patient selection and surgical technique are critical to the successful use of bioprosthetic materials for abdominal wall repair.

Baumann, Donald P.; Butler, Charles E.

2012-01-01

18

Mature bone metaplasia in abdominal wall scar  

Microsoft Academic Search

A 58-year-old man who had had three laparotomies for gastric surgery, developed a painful mass in the abdominal wall scar. Radiology confirmed bone formation in the scar. The bone was excised and the wound repaired. Histology confirmed metaplastic mature bone formation. This case draws the attention to the clinical condition of bone formation in midline scars. Clinically, it should be

R A Daoud; M J Watkins; G Brown; N Carr

1999-01-01

19

Intraperitoneal haemorrhage from anterior abdominal wall varices.  

PubMed Central

Patients with oesophageal varices frequently present with gastrointestinal haemorrhage but bleeding from varices at other sites is rare. We present a patient with hepatitis C-induced cirrhosis and partial portal vein occlusion who developed spontaneous haemorrhage from anterior abdominal wall varices into the rectus abdominus muscle and peritoneal cavity. Images Figure 1

Hunt, J. B.; Appleyard, M.; Thursz, M.; Carey, P. D.; Guillou, P. J.; Thomas, H. C.

1993-01-01

20

Traumatic abdominal wall hernia: A reappraisal  

Microsoft Academic Search

Traumatic abdominal wall hernia, a rare cause of hernia, has a confusing clinical picture and requires a high index of suspicion for prompt diagnosis and management. Such hernias, if missed, can result in high morbidity and may prove fatal. Distinction from a pre-existing hernia is important as well. We report our experience in two such cases, which had presented in

A. Kumar; P. Hazrah; S. Bal; A. Seth; R. Parshad

2004-01-01

21

Abdominal wall desmoid tumors: A case report  

PubMed Central

Desmoid tumors (DTs) are rare lesions that do not possess any metastatic potential. However, they have a strong tendency to invade locally and recur. They constitute 3% of all soft tissue tumors and 0.03% of all neoplasms. Abdominal DTs occur sporadically or are associated with certain familial syndromes, such as familial adenomatous polyposis (FAP). The single form of this neoplasm most frequently occurs in females of reproductive age and during pregnancy. A female patient with a DT of the abdominal wall who had no relevant family history was admitted to hospital. The patient, who presented with a painless mass in the left anterolateral abdomen, had no history of trauma, surgery or childbearing. According to the medical history, physical examination and CT report, the patient was diagnosed with DT. Radical resection of the affected abdominal wall musculature was performed, and the defect was replaced with a polypropylene mesh. The histological diagnosis was of DT. The patient remains in good health and complete remission without any other treatment following surgery. DTs exhibit aggressive growth and have a high rate of recurrence. Surgery is the optimal treatment, and subsequent radiotherapy may decrease the local recurrence rate. Further research into their aetiology is required combined with multicentre clinical trials of new treatments in order to improve management of this disease. This case report provides general knowledge of DT, and may be used as a guidance for diagnosis and treatment.

MA, JIN-HUI; MA, ZHEN-HAI; DONG, XUE-FENG; YIN, HANG; ZHAO, YONG-FU

2013-01-01

22

Heterotopic ossification of the abdominal wall  

PubMed Central

INTRODUCTION Heterotopic ossification is a rare, benign condition which occurs when bone develops in tissues that do not normally ossify. PRESENTATION OF CASE We herein report the case of a 73-year-old gentleman who underwent a laparotomy for a large splenic flexure tumour considered unresectable at initial intervention. Following delivery of chemotherapy, he was referred for a second opinion and the tumour with adjacent structures was removed at a subsequent laparotomy. A segment of abnormal hard tissue present in the abdominal wall was also excised. Histopathology revealed metaplastic bone deposition. DISCUSSION Heterotopic ossification may occur at various sites and is a recognised but exceedingly infrequent sequela of abdominal surgery. CONCLUSION This case highlights clinical, aetiological and histopathological features of this rare finding.

Hogan, Niamh M.; Caffrey, Emer; Curran, Stephanie; Sheehan, Margaret; Joyce, Myles R.

2012-01-01

23

A single center experience of abdominal wall graft rejection after combined intestinal and abdominal wall transplantation.  

PubMed

We report our outcomes following combined intestinal and abdominal wall transplantation, focusing on the presentation and treatment of acute rejection of the abdominal wall vascularized composite allograft (VCA). Retrospective analysis of all patients with combined intestinal/VCA transplantation was undertaken. Graft abnormalities were documented photographically and biopsies taken, with histological classification of rejection according to Banff 2007 guidelines. We have performed five combined intestinal and abdominal wall transplants to date. Two patients developed erythematous, maculopapular to papular eruptions confined to the VCA, histologically confirmed as grade II/III rejection, yet with normal bowel on endoscopy. Both patients' rashes resolved within 72 h of increasing immunosuppressive treatment. One patient later developed a recurrence of the rash, confirmed as skin rejection, but did not immediately seek medical attention. Treatment was therefore delayed, and mild intestinal rejection developed. We describe the rash associated with VCA rejection, and propose that while the skin of an abdominal wall VCA may reject independently of the intestinal allograft, delay in treatment of rejection episodes may result in rejection of the intestinal graft. PMID:23837458

Allin, B S R; Ceresa, C D L; Issa, F; Casey, G; Espinoza, O; Reddy, S; Sinha, S; Giele, H; Friend, P; Vaidya, A

2013-07-09

24

Comparison of Two Porcine-Derived Materials for Repairing Abdominal Wall Defects in Rats  

Microsoft Academic Search

ObjectiveThe purpose of this study was to compare the mechanical properties, host responses and incorporation of porcine small intestine submucosa (PSIS) and porcine acellular dermal matrix (PADM) in a rat model of abdominal wall defect repair.Materials and MethodsPrior to implantation, PSIS and PADM were prepared and evaluated in terms of structure and mechanical properties. Full-thickness abdominal wall defects were created

Zhengni Liu; Rui Tang; Zhiyuan Zhou; Zhicheng Song; Huichun Wang; Yan Gu; Samuel J. Lin

2011-01-01

25

Combined abdominal wall paresis and incisional hernia after laparoscopic cholecystectomy.  

PubMed

A case of combined abdominal wall paresis and incisional hernia after laparoscopic cholecystectomy is reported. The paresis possibly occurred by a lesion of the N. intercostalis when extending the incision for stone extraction. Possibly the paresis was a predisposing factor for the development of an incisional hernia. The causes of abdominal wall paresis are explored with a review of the literature. In spite of minimal trauma to the anterior abdominal wall in laparoscopic procedures, the risk of iatrogenic lesions remains. PMID:10064761

Korenkov, M; Rixen, D; Paul, A; Köhler, L; Eypasch, E; Troidl, H

1999-03-01

26

Tensor fascia lata musculocutaneous flap for abdominal wall reconstruction  

SciTech Connect

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.

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

1983-08-01

27

Elasticity of the living abdominal wall in laparoscopic surgery  

Microsoft Academic Search

Laparoscopic surgery requires inflation of the abdominal cavity and this offers a unique opportunity to measure the mechanical properties of the living abdominal wall. We used a motion analysis system to study the abdominal wall motion of 18 patients undergoing laparoscopic surgery, and found that the mean Young's modulus was 27.7±4.5 and 21.0±3.7kPa for male and female, respectively. During inflation,

Chengli Song; Afshin Alijani; Tim Frank; George Hanna; Alfred Cuschieri

2006-01-01

28

Wall thickness measuring method and apparatus  

DOEpatents

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.

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

1987-10-06

29

Abdominal wall hemorrhage after intravenous thrombolysis for acute ischemic stroke  

PubMed Central

Background Thrombolysis is strongly recommended for patients with significant neurologic deficits secondary to acute ischemic stroke. Extracranial bleeding is a rare but major complication of thrombolysis. Case presentation A 78-year-old woman presented with acute ischemic stroke caused by occlusion of the basilar artery. Clinical recovery was observed after successful recanalization by intravenous thrombolysis and intraarterial thrombectomy. However, the patient complained of sudden abdominal pain following the intervention and a newly developed abdominal wall mass was found. CT scan and selective angiography confirmed active bleeding from the left epigastric artery into the abdominal muscle layer and the bleeding was successfully managed by selective embolization of the bleeding artery. Conclusions We report a rare case of abdominal wall hemorrhage after thrombolysis for acute ischemic stroke. The findings indicate that abdominal wall hemorrhage should be considered as a differential diagnosis in the presence of abdominal discomfort after thrombolysis for acute ischemic stroke.

2013-01-01

30

Abdominal wall paresis as a complication of laparoscopic surgery  

Microsoft Academic Search

Purpose  Abdominal wall nerve injury as a result of trocar placement for laparoscopic surgery is rare. We intend to discuss causes\\u000a of abdominal wall paresis as well as relevant anatomy.\\u000a \\u000a \\u000a \\u000a Methods  A review of the nerve supply of the abdominal wall is illustrated with a rare case of a patient presenting with paresis of\\u000a the internal oblique muscle due to a trocar

G. H. van Ramshorst; G.-J. Kleinrensink; J. J. Hermans; T. Terkivatan; J. F. Lange

2009-01-01

31

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

PubMed Central

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

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

2009-01-01

32

Wandering Ascaris Coming Out Through the Abdominal Wall  

PubMed Central

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.

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

33

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

PubMed

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

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

2009-01-20

34

Tissue engineering approach to repair abdominal wall defects using cell-seeded bovine tunica vaginalis in a rabbit model  

Microsoft Academic Search

The aim of this study was to engineer skeletal muscle tissue for repair abdominal wall defects. Myoblast were seeded onto\\u000a the scaffolds and cultivated in vitro for 5 days. Full thickness abdominal wall defects (3 × 4 cm) were created in 18 male\\u000a New Zealand white rabbits and randomly divided into two equal groups. The defects of the first group were repaired with myoblast-seeded-bovine\\u000a tunica

T. Ayele; A. B. Z. Zuki; B. M. A. Noorjahan; M. M. Noordin

2010-01-01

35

Conventional Pneumoperitoneum Compared with Abdominal Wall Lift for Laparoscopic Cholecystectomy  

Microsoft Academic Search

Summary We have compared, in a randomized study, con- ventional carbon dioxide pneumoperitoneum with abdominal wall lift in 25 patients undergoing laparoscopic cholecystectomy. Intra-abdominal pressure (IAP) (11 (SD 2) mm Hg vs 2.7 (9) mm Hg) (P ? 0.01) and total amount of carbon dioxide used (40 (23) litre vs 9 (7) litre) (P ? 0.001) were significantly less with

L. LINDGREN; A.-M. KOIVUSALO; I. KELLOKUMPU; Michele Joseph

1996-01-01

36

[Desmoid tumours in the abdominal wall].  

PubMed

Desmoid tumours are benign tumours originating from musculoaponeurotic structures and the fascia. They usually are slow-growing, without metastatic potential. However, their local behaviour can be infiltrative and aggressive, leading to damage of adjacent structures causing organ dysfunction. They carry a high risk of relapse. In this paper, three case studies of women aged 33, 35 and 42 years, respectively, illustrate the presentation, diagnostics and therapy of abdominal desmoid tumours. All three were surgically treated and recovered. Desmoid tumours occur most commonly in fertile women. Although the etiology is unknown, there is a correlation with scar tissue, pregnancy and radiotherapy. Abdominal desmoid tumours have the lowest relapse rate of all desmoid tumours. In toto resection is the treatment of choice. Radiotherapy in addition to surgery may be considered when risk of relapse is high. PMID:21262014

Eijsackers, Maaike F; Tijsterman, Jasper D; van de Linde, Pieter; van Rooden, Jan Kees; Merkus, Jos W S

2011-01-01

37

Takedown of enterocutaneous fistula and complex abdominal wall reconstruction.  

PubMed

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. PMID:24035080

Slade, Dominic Alexander James; Carlson, Gordon Lawrence

2013-07-26

38

Abdominal wall haematoma mimicking visceral injury: the role of CT scanning  

Microsoft Academic Search

Four patients are presented who were thought to have sustained visceral injury following blunt abdominal trauma. However, CT demonstrated abdominal wall haematomata and allowed non-operative management. Similarity between the clinical findings in visceral injury and abdominal wall haematoma can lead to diagnostic difficulty. The cases illustrate the need to consider abdominal wall haematoma as a possible diagnosis in patients with

S. A. Hill; M. A. Jackson; R. FitzGerald

1995-01-01

39

Laparoscopic repair of traumatic abdominal wall hernia from handlebar injury.  

PubMed

A 14-year-old boy was seen at an outside hospital after falling over the handlebar of his bicycle and was discharged home. He was subsequently seen in our emergency department with complaints of persistent abdominal pain. A computed tomography scan of the abdomen revealed disruption of the muscles of the upper right abdominal wall containing the hepatic flexure of the colon, with a small amount of intraperitoneal free fluid noted. The patient underwent laparoscopic exploration using 3 ports (2-5 mm and 1-12 mm) and 2 separate stab incisions. The traumatic abdominal wall hernia was repaired with interrupted sutures placed with an ENDO CLOSE (Covidien, Mansfield, MA) device, and a mesenteric defect in the colon was approximated with intracorporeal sutures. The trocar sites were sutured closed. The patient recovered well and was discharged home. Follow-up examination revealed no abdominal wall defect and resolution of his symptoms. Laparoscopic repair of a traumatic abdominal wall defect and exploratory laparoscopy after trauma is feasible and safe in the pediatric patient. It should be considered as an alternative approach with potentially less morbidity than an exploratory laparotomy for handlebar injuries in a stable patient. PMID:21616228

Rowell, Erin E; Chin, Anthony C

2011-05-01

40

Changes in lateral abdominal muscles' thickness immediately after the abdominal drawing-in maneuver and maximum expiration.  

PubMed

All lateral abdominal muscles contract more strongly during maximum expiration than during the abdominal drawing-in maneuver (ADIM). However, little is known about which of the lateral abdominal muscles is activated during maximum expiration. Thus, the purpose of this study is to quantify changes in the thickness of the lateral abdominal muscles immediately after the ADIM and maximum expiration. The thickness of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles was measured by ultrasound imaging in 30 healthy men before and after the ADIM and maximum expiration. After the ADIM, there was no significant change in the thickness of the lateral abdominal muscles. After maximum expiration, the thickness of the TrA muscle significantly increased, and there was no significant change in the thickness of the IO and EO muscles. Thus, maximum expiration may be an effective method for TrA, rather than IO and EO, muscle training. PMID:23561875

Ishida, Hiroshi; Watanabe, Susumu

2012-12-27

41

New portable pipe wall thickness measuring technique  

NASA Astrophysics Data System (ADS)

One of the biggest inspection challenges facing many of the process industries; namely the petrochemical, refining, fossil power, and pulp and paper industries is: How to effectively examine their insulated piping? While there are a number of failure mechanisms involved in various process piping systems, piping degradation through corrosion and erosion are by far the most prevalent. This degradation can be in the form of external corrosion under insulation, internal corrosion through a variety of mechanisms, and internal erosion caused by the flow of the product through the pipe. Refineries, chemical plants and electrical power plants have MANY thousands of miles of pipe that are insulated to prevent heat loss or heat absorption. This insulation is often made up of several materials, with calcium based material being the most dense. The insulating material is usually wrapped with an aluminum or stainless steel outer wrap. Verification of wall thickness of these pipes can be accomplished by removing the insulation and doing an ultrasound inspection or by taking x- rays at a tangent to the edge of the pipe through the insulation. Both of these processes are slow and expensive. The time required to obtain data is measured in hours per meter. The ultrasound method requires that the insulation be plugged after the inspection. The surface needs to be cleaned or the resulting data will not be accurate. The tangent x-ray only shows two thicknesses and requires that the area be roped off because of radiation safety.

Pascente, Joseph E.

1998-03-01

42

Abdominal wall trigger point case study.  

PubMed

Myofascial trigger points (TrPs) are posited to be an element in the etiology of both musculoskeletal and visceral pain. However, the recognition of TrPs as a causative factor in a patient's pain presentation varies amongst physicians and therapists. When myofascial pain syndrome is responsible for a patient's condition and is not recognized by the patient's medical advisors, the patient may be put through a plethora of testing procedures to find the cause of the patient's pain, and prescribed medications in an effort to treat the patient's symptoms. The case review presented here involves a patient with severe anterior abdominal pain, with a history of Crohn's disease, who experienced a long and difficult medical process before a diagnosis of myofascial pain syndrome was made. PMID:23561860

Muscolino, Joseph E

2013-01-03

43

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

PubMed

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. PMID:23836365

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

2013-07-09

44

Traumatic intermuscular hernia in the anterior abdominal wall.  

PubMed Central

Traumatic ventral herniae are uncommon. The authors present a patient with traumatic intermuscular hernia in the anterior abdominal wall. Early recognition and differentiation from haematoma is important. In this case, the overlying intact muscle layer masked the classical clinical signs. The incision should be adequate and all internal organs carefully examined. Primary repair is usually possible.

Rao, P S; Kapur, B M

1987-01-01

45

Tunnelled tensor fascia lata flap for complex abdominal wall reconstruction  

Microsoft Academic Search

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

Frederick Wang; Samuel Buonocore; Deepak Narayan

2011-01-01

46

Abdominal wall cellulitis and sepsis secondary to percutaneous cecostomy  

Microsoft Academic Search

We report 1 case of abdominal wall cellulitis and sepsis which developed following percutaneous placement of a Cope catheter\\u000a for cecal decompression in a patient with Ogilvie's syndrome. This case highlights that further laboratory investigation and\\u000a clinical evaluation are needed to determine the safest and most efficacious technique of percutaneous drainage.

Thomas J. Maginot; Philip N. Cascade

1993-01-01

47

Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.  

PubMed Central

BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a prospective study. RESULTS: In cystic fibrosis, wall thickness of both small intestine and colon was significantly (p < 0.0001) higher than in controls; 81% of patients with cystic fibrosis had a maximum colon wall thickness at any site of 2 mm or more, a value that was never reached by controls. The maximum colon wall thickness was 6.5 mm. Bowel wall thickness was unchanged at re-examination after one year. There was no progression even with high dose pancreatic supplements. There was no association between bowel wall thickness and clinical features such as previous meconium ileus, intestinal resection, distal intestinal obstruction syndrome, abdominal pain, or pancreatic enzyme dose. CONCLUSIONS: There is genuine intestinal involvement in cystic fibrosis; in a few cases this could lead to fibrosing colonopathy. Images

Haber, H P; Benda, N; Fitzke, G; Lang, A; Langenberg, M; Riethmuller, J; Stern, M

1997-01-01

48

Referred Pain in Right Arm from Abdominal Wall Pseudoaneurysm  

PubMed Central

Pseudoaneurysm of the abdominal wall is a possible but very rare clinical entity. It is a known complication of surgery, trauma, or arterial puncture, but it is rarely spontaneous. Even though it can usually present with a wide range of local symptoms, it can cause referred pain via spinal cord, which is cross-excited with afferent sympathetic nervous system. We report a case of right arm pain which was referred from a small abdominal pseudoaneurysm like a referred pain from gall bladder. This rare entity should be considered in the differential for pain management in case that the pain does not resolve with medication or interventional pain management.

Ahn, Seon Kyoung; Kim, Hye Young; Shin, Ji Yeon; Min, Sangil

2013-01-01

49

Report of three cases of unusual anterior abdominal wall defects in fallujah general hospital during the year 2010.  

PubMed

Abdominal wall defects occur when the normal sequence of the gastro intestinal tract development is interrupted. Gastroschisis represents a herniation of abdominal contents through a paramedian full-thickness abdominal wall fusion defect without involving the umbilical cord. Evisceration usually only contains intestinal loops and has no surrounding membrane unlike omphalocoele. It is unusual for a newborn with gastroschisis to have other serious birth defects. Neonates with gastroschisis have better prognosis than those with omphalocele. Very rarely is gastroschisis associated with herniation of other organs, and their presence makes the prognosis worse. I report three cases of unusual anterior abdominal wall defects during the year 2010, each having specific associated abnormalities. One was stillborn, and the other two died shortly after delivery. PMID:23864990

Alaani, Samira

2012-12-27

50

Report of Three Cases of Unusual Anterior Abdominal Wall Defects in Fallujah General Hospital During the Year 2010  

PubMed Central

Abdominal wall defects occur when the normal sequence of the gastro intestinal tract development is interrupted. Gastroschisis represents a herniation of abdominal contents through a paramedian full-thickness abdominal wall fusion defect without involving the umbilical cord. Evisceration usually only contains intestinal loops and has no surrounding membrane unlike omphalocoele. It is unusual for a newborn with gastroschisis to have other serious birth defects. Neonates with gastroschisis have better prognosis than those with omphalocele. Very rarely is gastroschisis associated with herniation of other organs, and their presence makes the prognosis worse. I report three cases of unusual anterior abdominal wall defects during the year 2010, each having specific associated abnormalities. One was stillborn, and the other two died shortly after delivery.

Alaani, Samira

2012-01-01

51

Abdominal wall desmoid tumor mimicking a subserosal uterine leiomyoma  

PubMed Central

Desmoid tumors are cytologically bland fibrous neoplasms originating from musculoaponeurotic structures throughout the body. The cause of desmoid tumors is uncertain, but may be related to trauma or hormonal factors, or may have a genetic association. These tumors can be found in some young women during pregnancy or just after giving birth. We report herein a case of desmoid tumor on the inner aspect of the abdominal wall that mimicked a large subserosal uterine leiomyoma. Initial clinical examination of the patient suggested a large abdominal wall tumor, while the imaging techniques including transabdominal ultrasound and magnetic resonance imaging suggested a large subserosal uterine leiomyoma as the initial diagnosis. This case emphasizes the importance of clinical examination during the diagnostic process.

Al-Jefout, Moamar; Walid, Alabed; Esam, Abomayale; Amin, Alqaisi; Nather, Hawa; Sultan, Nawayse; Maysa, Khadra

2011-01-01

52

Clear Cell Adenocarcinoma Arising from Abdominal Wall Endometriosis  

PubMed Central

Endometriosis is a frequent benign disorder. Malignancy arising in extraovarian endometriosis is a rare event. A 49-year-old woman is presented with a large painful abdominal wall mass. She underwent a myomectomy, 20 years before, for uterus leiomyoma. Computed tomography suggested that this was a desmoid tumor and she underwent surgery. Histological examination showed a clear cell adenocarcinoma associated with endometriosis foci. Pelvic ultrasound, computed tomography, and endometrial curettage did not show any malignancy or endometriosis in the uterus and ovaries. Adjuvant chemotherapy was recommended, but the patient was lost to follow up. Six months later, she returned with a recurrence of the abdominal wall mass. She was given chemotherapy and then she was reoperated.

Achach, Thouraya; Rammeh, Soumaya; Trabelsi, Amel; Ltaief, Rached; Ben Abdelkrim, Soumaya; Mokni, Moncef; Korbi, Sadok

2008-01-01

53

Postoperative necrotizing soft-tissue infections of the abdominal wall  

Microsoft Academic Search

Objective: The aim of the underlying study was the evaluation of an aggressive surgical regimen for treatment of postoperative necrotizing\\u000a soft-tissue infection (NSTI). Methods: Eight patients with postoperative NSTI of the abdominal wall after emergency (n=6) and elective (n=2) surgery were reviewed over a 9-year period. Results: Initially, three patients presented with general peritonitis. Cultured swabs from the necrotic tissue

P. Bertram; K.-H. Treutner; M. Stumpf; V. Schumpelick

2000-01-01

54

The effect of abdominal resistance training and energy restricted diet on lateral abdominal muscles thickness of overweight and obese women.  

PubMed

The role of transabdominal muscles (external oblique, internal oblique and transversus abdominis) on core stability has been shown previously. Energy restricted diet and abdominal resistance training are commonly used by overweight and obese people to reduce their weight. In this study we investigated the impact of 12 weeks concurrent energy restricted diet and abdominal resistance training on the thickness of the lateral abdominal muscles of 19 obese and overweight women employing ultrasonography in resting and drawing-in maneuvers. The results showed significant increase of the muscle thicknesses during drawing-in maneuver after 12 weeks intervention. Based on our findings, it can be concluded that 12 weeks concurrent abdominal resistance training and energy restricted diet in addition to weight loss lead to improvement of transabdominal muscles thickness in obese and overweight people. Considering the role of these muscles in core stability, using this therapeutic protocol in obese people, particularly in those who have weakness of these muscles might be helpful. PMID:22703744

Noormohammadpour, Pardis; Kordi, Ramin; Dehghani, Saeed; Rostami, Mohsen

2012-01-10

55

Reduction of abdominal wall blood flow by clamping or carbon dioxide insufflation increases tumor growth in the abdominal wall: an experimental study in rats  

Microsoft Academic Search

Background: We have previously demonstrated that there is a reduction of blood flow in the abdominal wall in rats insufflated with air concomitant with an increase in tumor growth. The present study was designed to examine whether a reduction of blood flow achieved by clamping or insufflation with carbon dioxide (CO2) would increase tumor growth in the abdominal wall. Methods:

O. Lundberg; A. Kristoffersson

2005-01-01

56

Abdominal aorta intima media thickness in obese children.  

PubMed

Abstract The aim of this study is to investigate whether abdominal aorta intima media thickness (aIMT), increases in obese children and to determine risk factors. Ninety-six children aged 5-16 (51 obese and 45 non-obese) were enrolled in this prospective and cross-sectional study. Age, gender, and relative body mass index (BMI) were recorded. Their serum lipids, thyrotropin, fasting glucose and insulin levels were analyzed. The homeostasis model assessment (HOMA-IR) score was calculated for insulin resistance. Anthropometric and biochemical data were assessed along with aIMT. Findings in obese children were compared with those of non-obese control subjects. The aIMT was significantly greater in obese children. Similar trends were observed in both prepubertal children and adolescents. In obese children, the mean aIMT (mm) was 0.021 (years of age) +0.519. In non-obese children, the mean aIMT (mm) was 0.017 (years of age) +0.381. Our data suggests a relationship between glucose metabolism and aIMT in obese children. BMI was an independent risk factor for increasing aIMT. In conclusion, when compared with non-obese controls, obese children demonstrated significantly increased aIMT. Higher BMI, insulin, HOMA-IR and increased systolic blood pressure seem to be the main factors contributing to increased aIMT and risk for developing vascular disease. Childhood obesity contributes to the development of an increased aIMT. PMID:23729540

Yücel, Oya; Cevik, Halime; Kinik, Sibel Tulgar; Tokel, Kursad; Aka, Sibel; Dinc, Feyza

2013-01-01

57

Abdominal Wall Hydatid Cyst: Case Report and Review of Literature  

PubMed Central

A 60-year-old woman presented with a swelling in right paraumbilical region of one-year duration. Examination revealed a painless cystic swelling 15 × 10?cm with cough impulse. Ultrasound and CECT abdomen showed a subcutaneous cystic swelling with intramuscular extension. No other intraabdominal cystic lesions were found. Surgical exploration showed a cystic lesion adherent to peritoneum without any intraperitoneal extension. Cyst was carefully excised without any spillage. Gross specimen on opening showed multiple daughter cysts consistent with hydatid cyst, confirming the diagnosis of solitary abdominal wall hydatid cyst.

Abhishek, V.; Patil, Vijayraj S.; Mohan, Ullikashi; Shivswamy, B. S.

2012-01-01

58

Reconstruction of full thickness chest wall defects.  

PubMed Central

Over the last 5 years, 14 patients were treated by wide en bloc resection of chest wall tumors with primary reconstruction. There were nine females and five male patients with an age range of 31-77 years. All patients had a skeletal resection of the chest wall. An average of 3.9 ribs were resected in the patients treated. In three patients a partial sternectomy was carried out in conjunction with the rib resections. Chest wall skeletal defects were reconstructed with Prolene mesh, which was placed under tension. Soft tissue reconstruction utilized selected portions of the latissimus dorsi musculocutaneous territory with fasciocutaneous extensions beyond the muscle itself. Primary healing was obtained in all patients and secondary procedures were not required. The average hospitalization was 23 days. All patients survived the resection and reconstruction and were alive 30 days after operation. In selected patients the preservation of a portion of the innervated muscle in situ or the transfer of the muscle with the preservation of its resting length has maintained the majority of the muscle function. Images Fig. 3A. Fig. 3C. Fig. 3D. Fig. 4A. Fig. 4C. Fig. 4D. Fig. 4E. Fig. 5A. Fig. 5B. Fig. 5D. Fig. 6A. Fig. 6C. Fig. 6D. Fig. 6E. Fig. 6F. Fig. 6G. Fig. 6H.

Morgan, R F; Edgerton, M T; Wanebo, H J; Daniel, T M; Spotnitz, W D; Kron, I L

1988-01-01

59

An analytic description of thick-wall bubbles  

SciTech Connect

A new approximation scheme to the false-vacuum decay is suggested. In this scheme the bounce solutions can be obtained in an explicit and analytic way even for thick-wall bubbles. The result is compared with Coleman`s thin-wall description, which shows that is nicely comprises the result of the latter prescription. Some applications are also discussed.

Hong, Jooyoo

1992-08-01

60

An analytic description of thick-wall bubbles  

SciTech Connect

A new approximation scheme to the false-vacuum decay is suggested. In this scheme the bounce solutions can be obtained in an explicit and analytic way even for thick-wall bubbles. The result is compared with Coleman's thin-wall description, which shows that is nicely comprises the result of the latter prescription. Some applications are also discussed.

Hong, Jooyoo.

1992-01-01

61

Heat Transfer Characteristics and Optimum Insulation Thickness for Cavity Walls  

Microsoft Academic Search

The optimum thickness of insulation layers in cavity walls in buildings is determined under steady periodic conditions using the climatic data of Riyadh, Saudi Arabia. Different insulation materials are investigated at different locations in the cavity for a west-facing wall. The yearly cooling and heating transmission loads are calculated by an implicit finite-volume procedure that has been previously validated. These

Sami A. Al-Sanea; M. F. Zedan; Saleh A. Al-Ajlan; Atif S. Abdul Hadi

2003-01-01

62

The Torsion of Thick-Walled Box-Beams.  

National Technical Information Service (NTIS)

The present methods of calculation of restrained torsion in box-beams are applicable to thin-walled cross-sections and provide rather inaccurate results for thick-walled box-beams of actual structures. In this investigation, there are presented two theori...

V. Penttala

1978-01-01

63

[Gasless laparoscopic cholecystectomy using retractor of the abdominal wall].  

PubMed

The Authors present a new gasless laparoscopic cholecystectomy method using an abdominal wall elevator with subcutaneous traction ("laparotenser"). Fifty patients between May 1994 and March 1995 were operated by videolaparoscopy using this new gasless method. Twenty of them were operated with Nagai's method while the laparotenser was used in the remaining thirty. The results obtained are similar to those using pneumoperitoneum. It has been observed a global reduction of costs, less postoperative pain, no influence in cardiovascular and metabolic indexes. No complications were reported during the postoperative period but two cases of conversion to laparotomy not related to the method used were needed. Laparoscopic cholecystectomy without pneumoperitoneum using the subcutaneous elevator of the abdominal wall ("laparotenser") has demonstrated that it's possible to operate in a working space similar to that created by the pneumoperitoneum. After an initial period of distrust towards the laparoscopic methods without pneumoperitoneum it has been accepted that gasless methods multiply the indications to minimally invasive surgery in patients with cardiorespiratory problems considered no ideal candidates to laparoscopic cholecystectomy with pneumoperitoneum. PMID:8679422

D'Urbano, C; Fuertes Guiro, F; Sampietro, R

1996-03-01

64

Repair of large abdominal wall defects with expanded polytetrafluoroethylene (PTFE).  

PubMed Central

Most abdominal wall incisional hernias can be repaired by primary closure. However, where the defect is large or there is tension on the closure, the use of a prosthetic material is indicated. Expanded polytetrafluoroethylene (PTFE) patches were used to repair incisional hernias in 28 patients between November 1983 and December 1986. Twelve of these patients (43%) had a prior failure of a primary repair. Reherniation occurred in three patients (10.7%). Wound infections developed in two patients (7.1%), both of whom had existing intestinal stomas, one with an intercurrent pelvic abscess. The prosthetic patch was removed in the patient with the abscess, but the infection was resolved in the other without sequelae. Septic complications did not occur after any operations performed in uncontaminated fields. None of the patients exhibited any undue discomfort, wound pain, erythema, or induration. Complications related to adhesions, erosion of the patch material into the viscera, bowel obstruction, or fistula formation did not occur. Based on this clinical experience, the authors believe that the PTFE patch appears to represent an advance in synthetic abdominal wall substitutes. Images Fig. 1. Fig. 2(left)., Fig. 3(right).

Bauer, J J; Salky, B A; Gelernt, I M; Kreel, I

1987-01-01

65

[The use of mesh in abdominal wall defects].  

PubMed

Today abdominal wall defect repair can't prescind from the use of prosthetic materials. Inguinal, femoral and incisional hernias represent more frequent events in which, only using prosthetic materials is it possible to perform "tension-free" repair. Prosthetic repairs "agree with" abdominal, wall physio-pathology, guarantee results and prevent recurrences. Permanent biomaterials like polypropylene and dacron mesh deserve special attention for their distinctive features are suitable for abdominal wall defect repair. Selection of material is an important step according to surgical technique and to avoid complications; the most alarming of which is a possible infection. However the average incidence of infection on prosthesis is about 0.5%. While infection risk is really scarce, the benefits of prosthetic repairs are clear: the recurrence rate of traditional hernia repairs is about 33% and 0-0.7% in prosthetic repairs. Likewise the recurrence rate for traditional incisional hernia repair is between 14% and 50%, whereas in prosthetic repairs it is 0-4.5%. Therefore it is necessary to use prosthesis for the following two reasons: firstly to avoid tension on the suture line, the prime cause of recurrence, and secondly to increase formation of collagen fibres on the transversalis fascia that appears histologically and biochemically altered. The authors report their experience of 660 prosthetic repairs, 600 for hernia and 60 for incisional hernia, performed, in the period April 1992-December 1994, at the General Surgery Department in San Giovanni Valdarno Hospital. The surgical techniques used were "tension-free" and "sutureless" and the prosthesis laid down always a polypropylene mesh. Complications only occurred in 33 patients, particularly 4 cases of infection (0.6%) however mesh remove was not required. The follow-up until today evidenced only two early recurrences owing to our technical mistakes in the beginning of our experience. For incisional hernia repair we laid down a giant dacron mesh on preperitoneal space. No complications were registered. The average stay in hospital was 5 days and follow-up showed no recurrence. The use of prosthetic materials in abdominal wall defect repair expressed large benefits with evident and clear reduction in recurrence rate. Traditional techniques produce tension on the suture line and high percentage of early and late recurrences since an essential surgical principle is transgressed. In fact traditionally repair has been accomplished by approximation of anatomical structures, that are not normally in apposition and by utilization of defective tissue. Metabolic alteration involving collagen turnover is evident in these patients. The answer to this problem is prosthetic repair. At present there is no ideal prosthesis, however the surgeon can use several suitable synthetic materials. The selection of prosthetic materials is a fundamental step also considering the possible infection; that however develops rarely. In conclusion the authors think that mesh repairs represent an overcoming of traditional surgical techniques in abdominal wall defect repair. PMID:9471567

Cappelletti, M; Attolini, G; Cangioni, G; Mascherini, G; Taddeucci, S; Gervino, L

1997-10-01

66

Bladder Wall Thickness Mapping for Magnetic Resonance Cystography  

PubMed Central

Clinical studies have shown the evidence that the bladder wall thickness is an effective biomarker for bladder abnormalities. The 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.

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

2013-01-01

67

Thickness of Rectus Abdominis Muscle and Abdominal Subcutaneous Fat Tissue in Adult Women: Correlation with Age, Pregnancy, Laparotomy, and Body Mass Index  

PubMed Central

Background Rectus abdominis muscle and abdominal subcutaneous fat tissue are useful for reconstruction of the chest wall, and abdominal, vaginal, and perianal defects. Thus, preoperative evaluation of rectus abdominis muscle and abdominal subcutaneous fat tissue is important. This is a retrospective study that measured the thickness of rectus abdominis muscle and abdominal subcutaneous fat tissue using computed tomography (CT) and analyzed the correlation with the patients' age, gestational history, history of laparotomy, and body mass index (BMI). Methods A total of 545 adult women were studied. Rectus abdominis muscle and abdominal subcutaneous fat thicknesses were measured with abdominopelvic CT. The results were analyzed to determine if the thickness of the rectus abdominis muscle or subcutaneous fat tissue was significantly correlated with age, number of pregnancies, history of laparotomy, and BMI. Results Rectus abdominis muscle thicknesses were 9.58 mm (right) and 9.73 mm (left) at the xiphoid level and 10.26 mm (right) and 10.26 mm (left) at the umbilicus level. Subcutaneous fat thicknesses were 24.31 mm (right) and 23.39 mm (left). Rectus abdominismuscle thickness decreased with age and pregnancy. History of laparotomy had a significant negative correlation with rectus abdominis muscle thickness at the xiphoid level. Abdominal subcutaneous fat thickness had no correlation with age, number of pregnancies, or history of laparotomy. Conclusions Age, gestational history, and history of laparotomy influenced rectus abdominis muscle thickness but did not influence abdominal subcutaneous fat thickness. These results are clinically valuable for planning a rectus abdominis muscle flap and safe elevation of muscle flap.

Kim, Jungmin; Lim, Hyoseob; Lee, Se Il

2012-01-01

68

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

PubMed

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

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

2012-09-07

69

Malignant Acrospiroma of Chest and Abdominal Wall Treated with Chemotherapy  

PubMed Central

Acrospiroma denotes a group of benign ductal tumours of the eccrine sweat glands that may or may not be connected to the skin. Although various eccrine sweat gland tumours including benign acrospiroma are widely reviewed, malignant acrospiroma is rarely reported. Malignant acrospiroma have the propensity to recur locally and metastasizes to regional lymph nodes. The primary treatment is wide local excision with or without lymph node dissection. Local radiation is added in the presence of high risk features to reduce the risk of recurrence. We describe a case of a malignant acrospiroma involving wide areas of chest and abdominal wall with metastases to bilateral axillary lymph nodes in a 47 year old man showing minimal clinical response to combination chemotherapy and paclitaxel.

Bandyopadhyay, Anis; Das, Mou; Jana, Sukumar; Das, Anuradha

2013-01-01

70

[The method of treatment choice for the abdominal wall hernia].  

PubMed

Experience of treatment of 975 patients with postoperative and recurrent abdominal wall hernia (AWH) and of 1473 patients with inguinal hernia was summarized. Intraoperative classification of Shevrel and Rets for AWH and of Gilbert and Rutkov for inguinal hernia were applied. The conventional methods of plasty, using local tissues, were performed up to 1998 in 648 patients with AWH and in 983--with inguinal hernia. Synthetic implants were used since 1999 in 327 patients with AWH and in 181--with inguinal hernia. In application of conventional methods recurrency had occurred after plasty for AWH in 26.6% and for inguinal hernia--in 5.8% of observations; hernial recurrency was not noted after usage of the modern plasty methods. PMID:11944300

Belokonev, V I; Kovaleva, Z V; Pushkin, S Iu; Nagapetian, S V; Supil'nikov, A A

2002-01-01

71

Histopathological reaction of the abdominal aorta wall to non-covered stents  

Microsoft Academic Search

Objective: To evaluate the histopathological reaction of the abdominal aorta wall in pigs' renal arteries to the presence of non-covered stainless steel stents. Methods: The abdominal aorta of ten pigs (6 months old and weighing 86.6 kg on average) was histopathologically studied 100 days after the implant of stainless steel stents in the abdominal aorta, with one segment of the

Rubio Bombonato; José Honório PALMA; José Augusto MARCONDES; Aury Nunes de MORAES; João Luiz da ROCHA; Márcio Rodrigo; Rodrigo Mezzalira; Enio Buffolo

2006-01-01

72

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

NASA Astrophysics Data System (ADS)

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.

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

2011-06-01

73

Dust thin shell limit of a thick wall  

NASA Astrophysics Data System (ADS)

We consider the vanishing thickness limit of a wall separating Minkowski spacetime from Schwarzschild or Friedmann spacetime with the purpose of obtaining the thin shell described by the Israel matching formalism. We show that the thin shell cannot be a limit of the wall consisting of Lemaitre-Tolman-Bondi dust. To successfully implement the required limit, it is necessary to add anisotropy to the stress tensor of the wall matter. For such anisotropic matter, we derive boundary conditions that allow carrying out the limit. Finally, we provide an example of a solution satisfying these conditions.

Drobov, I. V.; Tegai, S. Ph.

2013-01-01

74

Closure of chronic abdominal wall defects: a long-term evaluation of the components separation method.  

PubMed

Incisional hernias and abdominal wall defects are frequently iatrogenic problems that have been found to complicate as many as 11% of all abdominal operations. Current techniques for closure of large, chronic abdominal wall defects have limitations. The use of local musculofascial flaps rather than fascial patches (i.e., the tensor fascia lata) or synthetic material for the repair of chronic abdominal wall defects is preferable. The superiority of innervated muscle flaps that provide dynamic abdominal support has been demonstrated. This report focuses on patients with chronic abdominal wall defects in whom previous techniques have failed. An algorithmic approach to planned reconstruction is presented utilizing the "components separation" technique as its foundation. Thirty-seven patients who underwent abdominal reconstruction following this algorithm are reviewed and their clinical course is outlined. The components separation technique provides a compound innervated and vascularized muscle flap for dynamic support of the reconstructed abdominal wall. The experience documented here and by others suggests that this technique is a safe and effective method for reconstructing the abdominal wall in patients with recurrent herniation. Enterocutaneous fistulas, however, continue to present a challenge to the surgeon. PMID:10213399

Girotto, J A; Ko, M J; Redett, R; Muehlberger, T; Talamini, M; Chang, B

1999-04-01

75

Weekly Doxorubicin Increases Coronary Arteriolar Wall and Adventitial Thickness  

PubMed Central

Background Doxorubicin (DOX) is associated with premature cardiovascular events including myocardial infarction. This study was performed to determine if the weekly administration of DOX influenced coronary arteriolar medial and/or adventitial wall thickening. Methods Thirty-two male Sprague-Dawley rats aged 25.1± 2.4 weeks were randomly divided into three groups and received weekly intraperitoneal injections of normal saline (saline, n?=?7), or low (1.5 mg/kg to 1.75 mg/kg, n?=?14) or high (2.5 mg/kg, n?=?11) doses of DOX. The animals were treated for 2–12 weeks, and euthanized at pre-specified intervals (2, 4, 7, or 10+ weeks) to obtain histopathologic assessments of coronary arteriolar lumen diameter, medial wall thickness, adventitial wall thickness, and total wall thickness (medial thickness + adventitial thickness). Results Lumen diameter was similar across all groups (saline: 315±34 µm, low DOX: 286±24 µm, high DOX: 242±27 µm; p?=?0.22). In comparison to animals receiving weekly saline, animals receiving weekly injections of 2.5 mg/kg of DOX experienced an increase in medial (23±2µm vs. 13±3µm; p?=?0.005), and total wall thickness (51±4µm vs. 36±5µm; p?=?0.022), respectively. These increases, as well as adventitial thickening became more prominent after normalizing for lumen diameter (p<0.05 to p<0.001) and after adjusting for age, weight, and total cumulative DOX dose (p?=?0.02 to p?=?0.01). Animals receiving low dose DOX trended toward increases in adventitial and total wall thickness after normalization to lumen diameter and accounting for age, weight, and total cumulative DOX dose (p?=?0.06 and 0.09, respectively). Conclusion In conclusion, these data demonstrate that weekly treatment of rats with higher doses of DOX increases coronary arteriolar medial, adventitial, and total wall thickness. Future studies are warranted to determine if DOX related coronary arteriolar effects are reversible or preventable, exacerbate the known cardiomyopathic effects of DOX, influence altered resting or stress-induced myocardial perfusion, or contribute to the occurrence of myocardial infarction.

Rowe, Robert; D?Agostino, Ralph; Kock, Nancy D.; Sane, David C.; Torti, Frank M.; Yeboah, Joseph; Workman, Susan; Lane, Kimberly S.; Hundley, W. Gregory

2013-01-01

76

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

NASA Astrophysics Data System (ADS)

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.

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

2004-11-01

77

Tests prove strength of thick-walled casing  

SciTech Connect

Through a comprehensive test program, a reliable means for determining the maximum loads allowable for thick-walled casing has been developed. Results substantiate manufacturer's specifications and indicate that, with proper tool connections and steel grades, this type of casing may be subjected to even greater wellbore depths and pressures than are currently experienced.

Ott, H.; Schillinger, H.

1982-11-01

78

Optimum insulation thickness of external walls for energy saving  

Microsoft Academic Search

Most of energy is used up to space heating in the cold regions of Turkey. Insulation in external walls of buildings has been gaining much more interest in recent years not only for the environmental effect of the consumed energy but also the high cost of the energy. Therefore, the optimum insulation thickness was investigated in this study for the

Kemal Çomakl?; Bedri Yüksel

2003-01-01

79

Thick Liquid-Walled, Field-Reversed Configuration.  

National Technical Information Service (NTIS)

A thick flowing layer of liquid 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 l...

R. W. Moir R. H. Bulmer K. Gulec P. Fogarty B. Nelson M. Ohnishi

2000-01-01

80

Microballoon Wall Thickness Effects on Properties of Syntactic Foams  

Microsoft Academic Search

A novel approach for changing the density of syntactic foams, while keeping the microballoon (hollow particles) volume fraction constant, is adopted in this work. This is achieved by selecting microballoons of the same size but with different wall thickness. Five types of microballoons are selected to fabricate syntactic foams. All the types of microballoons have about 40 mm mean particle

Nikhil Gupta; Eyassu Woldesenbet

2004-01-01

81

Myocardial Wall Thickness and Left Ventricular Geometry in Hypertensives  

Microsoft Academic Search

In hypertensive patients the presence of left ventricular (LV) hypertrophy has been associated with a more severe degree of insulin resistance. Whether myocardial wall thickness or LV geometry are associated with a different degree of insulin resistance is still unknown in essential hypertensives. For this reason 26 men with new diagnosed essential hypertension were enrolled. All patients underwent echocardiographic examination

Giuseppe Paolisso; Maurizio Galderisi; Maria Rosaria Tagliamonte; Marcello de Divitis; Domenico Galzerano; Antonio Petrocelli; Pasquale Gualdiero; Oreste de Divitis; Michele Varricchio

1997-01-01

82

Ultrasonic Wall Thickness Monitoring at High Temperatures (>500 °C)  

NASA Astrophysics Data System (ADS)

Corrosion and erosion shorten the life of components that are used in the petrochemical industry. In order to mitigate the safety and financial risks posed by the degradation mechanisms, plant operators monitor wall thicknesses at regular inspection intervals. In high temperature locations inspections have to be carried out at plant shut downs because conventional ultrasonic sensors cannot withstand the high operating temperatures. The authors have developed a waveguide based high temperature thickness gauge for monitoring of wall thicknesses in high temperature areas. The waveguide allows the use of conventional transduction systems (max temp. 60 °C) at one end and guides ultrasonic waves into the high temperature region where the inspection is to be carried out. Slender stainless steel waveguides allow a temperature drop of ~500-600 °C per 200 mm length to be sustained simply by natural convection cooling. This paper describes the technical challenges that had to be overcome (dispersion and source/receiver characteristics) in order to implement this ``acoustic cable''. A range of experimental results of thickness measurements on components of different thickness, and furnace tests at different temperatures are presented. An accelerated corrosion test that demonstrates the effectiveness of the monitoring for corrosion is also presented.

Cegla, F. B.; Allin, J.; Davies, J. O.; Collins, P.; Cawley, P.

2011-06-01

83

A decoupled fluid structure approach for estimating wall stress in abdominal aortic aneurysms  

Microsoft Academic Search

Abdominal aortic aneurysm (AAA) is a localized dilatation of the aortic wall. The lack of an accurate AAA rupture risk index remains an important problem in the clinical management of the disease. To accurately estimate AAA rupture risk, detailed information on patient-specific wall stress distribution and aortic wall tissue yield stress is required. A complete fluid structure interaction (FSI) study

Yannis Papaharilaou; John A. Ekaterinaris; Eirini Manousaki; Asterios N. Katsamouris

2007-01-01

84

Stress characterization of autofrettaged thick-walled cylinders  

Microsoft Academic Search

The inaccessibility of commercial software has necessitated the development of low-cost, general-purpose finite element method (FEM) computer programs for structural analysis. Using the FEM program, the elastic, elastic-plastic, residual and service stresses and displacements in a closed ended, thick-walled cylinder under internal pressure were established. The displacement formulation was implemented and eight-noded brick isoparametric elements chosen. The frontal solution technique

J. M. Kihiu; S. M. Mutuli; G. O. Rading

85

Incidence and clinical significance of abdominal wall bruising in restrained children involved in motor vehicle crashes  

Microsoft Academic Search

BackgroundChildren involved in motor vehicle crashes (MVC) can sustain bruising of the abdominal wall associated with seat belt restraint. The incidence of bruising and its relationship with significant intraabdominal injuries are not known.

Nicolas Lutz; Michael L Nance; Michael J Kallan; Kristy B Arbogast; Dennis R Durbin; Flaura K Winston

2004-01-01

86

[Necrotizing dermohypodermitis of abdominal wall in obese. About two report cases indicative of abdominopelvic deep infection].  

PubMed

Necrotizing dermohypodermitis of abdominal wall in obese is a rare disease with high mortality. We report two cases of 50 and 62years old patients whose intra-abdominal infectious pathology (appendicular abscess for one and pyosalpinx for the other) was revealed by a necrotizing dermohypodermitis of the abdominal wall. The diagnosis has been established on the basis of converging clinical arguments (abdominal pain, crackles and necrotic appearance of abdominal wall in a septic shock context), linked with a CT-scan. The treatment consisted of a large excision of the abdominal wall necrosis and surgical eradication of deep infection source, with an intensive care and a broad spectrum antibiotic therapy. Both these patients present morbid obesity (BMI>40) whose implication must be taken into consideration in the way the disease appears. Indeed, the necrotizing dermohypodermitis of abdominal wall in these patients must lead first in looking for a deep infection with few symptoms. It must be identified quickly to propose an early and multidisciplinary surgical treatment. PMID:23410721

Pegot, A; Aktouf, A; Delpierre, V; Milliez, P-Y; Auquit-Auckbur, I

2013-02-12

87

Instant Abdominal Wall Reconstruction with Biologic Mesh following Resection of Locally Advanced Colonic Cancer  

PubMed Central

We present a case of immediate abdominal wall reconstruction with biologic mesh following the resection of locally advanced colonic cancer. The tumor in the right colon did not respond to neoadjuvant chemotherapy. Surgical enbloc excision, including excision of the invasion in the abdominal wall, was achieved, and the defect was reconstructed with porcine dermal collagen mesh. The patient was discharged with no complication, and adaptation of the mesh was excellent at the six-month followup.

Kaya, Oskay; Olcucuoglu, Engin; Seker, Gaye; Kulacoglu, Hakan

2012-01-01

88

Regeneration of Abdominal Wall Aponeurosis: New Dimension in Marlex Peritoneal Sandwich Repair of Incisional Hernia  

Microsoft Academic Search

.   Loss of abdominal wall substance is a major cause of incisional hernia formation. It makes repair of this iatrogenic human\\u000a ailment a difficult surgical problem. The abdominal wall substance loss has compelled the world's surgical community dealing\\u000a with this condition to substantiate the repair with extra material such as skin, fascia, wire mesh, and lately biocompatible\\u000a synthetic mesh. Even

B. G. Matapurkar; A. Bhargave; Leelawathi Dawson; B. Sonal

1999-01-01

89

Abdominal wall hernias: imaging features, complications, and diagnostic pitfalls at multi-detector row CT.  

PubMed

Abdominal wall hernias are a common imaging finding in the abdomen and may be complicated by strangulation, incarceration, or trauma. Because of the risk of developing complications, most abdominal wall hernias are surgically repaired, even if asymptomatic. However, post-surgical complications are also common and include hernia recurrence, infected and noninfected fluid collections, and complications related to prosthetic material. Multi-detector row computed tomography (CT) with its multiplanar capabilities is particularly useful for the evaluation of unrepaired and surgically repaired abdominal wall hernias. Multi-detector row CT provides exquisite anatomic detail of the abdominal wall, thereby allowing accurate identification of wall hernias and their contents, differentiation of hernias from other abdominal masses (tumors, hematomas, abscesses), and detection of pre- or postoperative complications. These findings improve the communication of imaging results to clinicians and help optimize treatment planning. Knowledge of multi-detector row CT findings in unrepaired and surgically repaired abdominal wall hernias and their complications is essential for making the correct diagnosis and may help guide clinical management. PMID:16284131

Aguirre, Diego A; Santosa, Agnes C; Casola, Giovanna; Sirlin, Claude B

90

Combination of tissue expansion and porcine mesh for secondary abdominal wall closure after pediatric liver transplantation.  

PubMed

We report the case of a two and a half yr boy hospitalized in our Pediatric Transplantation Unit for portal vein thrombosis following liver transplantation. After performing a meso-Rex shunt, abdominal wall closure was impossible without compressing the portal flow. A combination of two techniques was used to perform the reconstruction of the muscular fasciae and skin layers. The association of tissue expanders and porcine mesh (Surgisis(®)) allowed complete abdominal wall closure with good functional and esthetic results. Use of both techniques is a useful alternative for difficult abdominal closure after liver pediatric transplantation. PMID:21848529

Lafosse, Aurore; de Magnee, Catherine; Brunati, Andrea; Bayet, Bénédicte; Vanwijck, Romain; Manzanares, Javier; Reding, Raymond

2011-08-18

91

A technique for laparoscopic repair of herniation of the anterior abdominal wall using a composite mesh prosthesis  

Microsoft Academic Search

Improved laparoscopic techniques have engendered many new gastrointestinal and other intracavity abdominal procedures. Groin hernias have also been repaired with the assistance of the laparoscope via both transperitoneal and properitoneal approaches, but less emphasis has been placed upon repair of hernias of the anterior abdominal wall. A technique for the transperitoneal, laparoscopic repair of anterior abdominal wall hernias using a

Philip S. Barie; Charles A. Mack; William A. Thompson

1995-01-01

92

Giant Desmoid Tumor of the Anterior Abdominal Wall in a Young Female: A Case Report  

PubMed Central

Desmoid tumors (also called desmoids fibromatosis) are rare slow growing benign and musculoaponeurotic tumors. Although these tumors have a propensity to invade surrounding tissues, they are not malignant. These tumors are associated with women of fertile age, especially during and after pregnancy. We report a young female patient with a giant desmoid tumor of the anterior abdominal wall who underwent primary resection. The patient had no history of an earlier abdominal surgery. Preoperative evaluation included abdominal ultrasound, computed tomography, and magnetic resonance imaging. The histology revealed a desmoid tumor. Primary surgical resection with immediate reconstruction of abdominal defect is the best management of this rarity. To the best of our knowledge and PubMed search, this is the first case ever reported in the medical literature of such a giant desmoid tumor arising from anterior abdominal wall weighing 6.5?kg treated surgically with successful outcome.

Koshariya, Mahim; Shukla, Samir; Khan, Zuber; Vikas, Vaibhav; Pratap Singh, Avinash; Baghel, Puspendra; Pendro, Varun; Kirti Jain, Vishal; Jagdish Jai, Shrikant; Kumar, Sanjeev; Songra, M. C.

2013-01-01

93

Giant desmoid tumor of the anterior abdominal wall in a young female: a case report.  

PubMed

Desmoid tumors (also called desmoids fibromatosis) are rare slow growing benign and musculoaponeurotic tumors. Although these tumors have a propensity to invade surrounding tissues, they are not malignant. These tumors are associated with women of fertile age, especially during and after pregnancy. We report a young female patient with a giant desmoid tumor of the anterior abdominal wall who underwent primary resection. The patient had no history of an earlier abdominal surgery. Preoperative evaluation included abdominal ultrasound, computed tomography, and magnetic resonance imaging. The histology revealed a desmoid tumor. Primary surgical resection with immediate reconstruction of abdominal defect is the best management of this rarity. To the best of our knowledge and PubMed search, this is the first case ever reported in the medical literature of such a giant desmoid tumor arising from anterior abdominal wall weighing 6.5?kg treated surgically with successful outcome. PMID:23710408

Koshariya, Mahim; Shukla, Samir; Khan, Zuber; Vikas, Vaibhav; Pratap Singh, Avinash; Baghel, Puspendra; Pendro, Varun; Kirti Jain, Vishal; Jagdish Jai, Shrikant; Kumar, Sanjeev; Songra, M C

2013-04-21

94

One-Stage Reconstruction of Large Midline Abdominal Wall Defects Using a Composite Free Anterolateral Thigh Flap With Vascularized Fascia Lata  

PubMed Central

Objective: Large midline abdominal wall defects are continuously a challenge for reconstructive surgeons. Adequate skin coverage and fascia repair of the abdominal wall is necessary for achieving acceptable results. The purpose of this paper is to present a new approach to abdominal wall reconstruction using a free vascularized composite anterolateral thigh (ALT) flap with fascia lata. Methods: Seven patients with large full-thickness abdominal wall defects were successfully reconstructed by means of a composite ALT flap combined with vascularized fascia lata. The size of the skin islands ranged from 20 to 32 cm in length and 10 to 22 cm in width, and the vascularized fascia lata sheath measured 14 to 28 cm and 8 to 18 cm, respectively. Functional outcome of the abdominal wall strength and donor thigh morbidity were investigated by using a Cybex kinetic dynamometer. Results: All flaps survived. No postoperative ventral hernia occurred except for one mild inguinal incision hernia. Subjectively there were no significant donor site problems. Objective assessment was performed in 4 patients 2 years postoperatively. In the reconstructed abdomen, isokinetic concentric and eccentric measurements of extension/flexion ratios of the abdominal wall strength showed no apparent decrease compared with other references. Functional evaluation of quadriceps femoris muscle contraction forces after free ALT composite flap harvest showed an averaged deficit of 30% as compared with the contralateral legs. However, no difficulties in daily ambulating were reported by the patients. Conclusion: The free composite ALT myocutaneous flap with vascularized fascia lata provides an alternative option for a stable repair in complex abdominal wall defects.

Kuo, Yur-Ren; Kuo, Mei-Hui; Lutz, Barbara S.; Huang, Yu-Chi; Liu, Yi-Tien; Wu, Shih-Chi; Hsieh, Kun-Chou; Hsien, Ching-Hua; Jeng, Seng-Feng

2004-01-01

95

Thick-wall Kevlar 49/Epoxy pressure vessels  

SciTech Connect

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

Guess, T.R.

1984-01-01

96

Thick-wall effects on the rotational stabilization of resistive wall modes in tokamaks  

NASA Astrophysics Data System (ADS)

This paper is devoted to studying the combined effect of mode rotation and energy dissipation in the resistive wall on plasma stability. The problem is analysed on the basis of the energy approach complementing the standard methods of the traditional MHD theory of plasma stability. The key element that makes our model different from this theory and commonly used thin-wall approaches to the stability analysis of resistive wall modes (RWMs) is the incorporation of the skin effect. In the ideal MHD theory of plasma stability, the skin depth is, formally, zero. In contrast, the conventional thin-wall theory of RWM stability assumes a skin depth much larger than the wall thickness. The presented model considers the intermediate case with a finite skin depth compared with the wall thickness. This covers the modes in between the typical RWMs and the ideal MHD modes when wall resistivity still affects the mode dynamics. It is shown that, in this region, the growth rate of the locked modes must be substantially larger than that calculated in the thin-wall models. On the other hand, the fast RWMs can be completely stabilized by mode rotation above some critical level. Qualitatively, this corresponds to the rotational stabilization observed in the DIII-D tokamak and allowing the plasma operation above the no-wall stability limit (Strait et al 2003 Nucl. Fusion 43 430). This is the main result of this study, which is completely analytical with all dependences explicitly shown. In particular, the dispersion relations for the fast RWMs and the critical frequency of mode rotation necessary for rotational stabilization are expressed through quantities that depend on the plasma parameters or can be experimentally found by magnetic measurements outside the plasma.

Pustovitov, V. D.

2013-03-01

97

Avoidance of total abdominal wall loss despite torso soft tissue clostridial myonecrosis: a case report  

PubMed Central

Introduction Clostridial necrotizing soft tissue infections are often fatal. Myonecrosis of the torso is a particularly lethal combination given the classic need for radical debridement of the abdominal and thoracic walls, and therefore total exposure of the intraperitoneal and intrathoracic viscera. This case is unusual do to our ability to preserve anatomical separation between the viscera and the atmosphere. Case presentation We present a 42-year-old Caucasian man with obesity and diabetes who developed clostridial myonecrosis of his right torso following a mesenteric lymph node biopsy. This required an aggressive debridement (sparing subcutaneous flaps and internal oblique aponeurosis) followed by reconstruction of his right hemi-torso with a biologic prosthesis to prevent subsequent hernia formation. Conclusion Although basic principles associated with radical debridement were maintained, a full thickness torso wall resection was avoided. This provided reconstruction advantages that included endogenous subcutaneous flap coverage, separation of the peritoneal cavity by the internal oblique aponeurosis, and prevention of a subsequent hernia below the arcuate line. This technique would be of interest to any surgeon or clinician who treats patients with life-threatening torso soft tissue infections.

2013-01-01

98

Reconstruction of sternal and abdominal wall defects in a case of desmoid tumor.  

PubMed

A case of desmoid tumor of the anterior chest and abdominal wall is presented. The entire body of the sternum along with the upper abdominal wall and inner parts of both breasts was resected. The resulting defect over the pericardium and abdomen was reconstructed by the omentum and Marlex mesh. The large skin defect was covered by bilateral thoracoabdominal tube pedicles. The patient had a stable chest wall with uncompromised respiratory function 1 week after the operation. Prevention of local recurrences of desmoid tumors requires wide excision of the involved soft tissues and bony structures. The principles of wide resection of soft tissue tumors, reconstruction of the anterior chest and abdominal wall defects, and planning the skin coverage over the resulting defect are discussed. PMID:141547

Baffi, R R; Didolkar, M S; Bakamjian, V

1977-07-01

99

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

PubMed

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

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

1994-10-01

100

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

PubMed

"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. PMID:23628632

Kääriäinen, M; Kuokkanen, H

2013-01-01

101

Determination of abdominal fat thickness using dual electrode separation in the focused impedance method (FIM).  

PubMed

Subcutaneous fat layer thickness in the abdomen is a risk indicator of several diseases and disorders like diabetes and heart problems and could be used as a measure of fitness. Skinfold measurement using mechanical calipers is simple but prone to error. Ultrasound scanning techniques are yet to be established as accurate methods for this purpose. magnetic resonance imaging (MRI) and computed tomography (CT) scans can provide the answer but are expensive and not available widely. Some initiatives were made earlier to use electrical impedance to this end, but had inadequacies. In the first part of this paper, a 4-electrode focused impedance method (FIM) with different electrode separations has been studied for its possible use in the determination of abdominal fat thickness in a localized region. For this, a saline phantom was designed to provide different electrode separations and different layers of resistive materials adjacent to the electrodes. The background saline simulated the internal organs having low impedance while the resistive layers simulated the subcutaneous fat. The plot of the measured impedance with electrode separation had different 'slopes' for different thicknesses of resistive layers, which offered a method to obtain an unknown thickness of subcutaneous fat layer. In the second part, measurements were performed on seven human subjects using two electrode separations. Fat layer thickness was measured using mechanical calipers. A plot of the above 'slope' against fat thickness could be fitted using a straight line with an R(2) of 0.93. Then this could be used as a calibration curve for the determination of unknown fat thickness. Further work using more accurate CT and MRI measurements would give a better calibration curve for practical use of this non-invasive and low-cost technique in abdominal fat thickness measurement. PMID:22532314

Surovy, Nusrat Jahan; Billah, Md Masum; Haowlader, Salahuddin; Al-Quaderi, Golam Dastegir; Rabbani, K Siddique-e

2012-04-24

102

The Limb-Abdominal Wall Complex Defects, a form of Amniotic Band Sydrome: A Rare Case Report  

PubMed Central

The limb-body wall complex defects a form of amniotic band syndrome which consists of a polymal formation with a thoracic and /or an abdominal-schisis, eventration of the internal organ and anomalies of the extremities. We are presenting a case of a limb-body wall complex defect with the phenotype of a placenta-abdominal attachment, anomalies of the abdominal wall defect, absence of the right lower limb and genitourinary defects.

Das, Sudhanshu Ku.; Maharana, Sidharth Sankar; Subudhi, Monalisa; Rao, P. V. Subha

2013-01-01

103

The Limb-Abdominal Wall Complex Defects, a form of Amniotic Band Sydrome: A Rare Case Report.  

PubMed

The limb-body wall complex defects a form of amniotic band syndrome which consists of a polymal formation with a thoracic and /or an abdominal-schisis, eventration of the internal organ and anomalies of the extremities. We are presenting a case of a limb-body wall complex defect with the phenotype of a placenta-abdominal attachment, anomalies of the abdominal wall defect, absence of the right lower limb and genitourinary defects. PMID:23634417

Das, Sudhanshu Ku; Maharana, Sidharth Sankar; Subudhi, Monalisa; Rao, P V Subha

2013-03-01

104

Studying the visceral physiology of tadpoles through their naturally transparent abdominal walls  

NASA Astrophysics Data System (ADS)

We propose using anuran tadpoles with naturally transparent abdominal skin to study the visceral physiology of amphibian larvae under microgravity. The transparency of the abdominal wall in certain tadpoles enables one to evaluate the basal physiological state and temporal changes in viscera from their movements without any invasive treatment. In order to validate our experimental design, the intestinal motility and heart rate of Rhacophorus tadpoles were examined as indices of physiological responses to stepwise changes in temperature.

Naitoh, T.; Yamashita, M.; Wassersug, R. J.

2003-10-01

105

Changes in lateral abdominal muscle thickness during an abdominal drawing-in maneuver in individuals with and without low back pain.  

PubMed

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7) participated in this study. Bilateral measurements were made using ultrasound imaging to determine changes in thickness of the transversus abdominus (TrA) and external and internal oblique (EO+IO) muscles during an ADIM. There were no significant differences in relaxed muscle thickness values or contraction ratios for the TrA or EO+IO between groups or side. Individuals with stabilization classification LBP demonstrated no difference in lateral abdominal muscle thickness during an ADIM when compared with controls without LBP when using a pressure biofeedback device to monitor stability. PMID:21988269

Beazell, James R; Grindstaff, Terry L; Hart, Joseph M; Magrum, Eric M; Cullaty, Martha; Shen, Francis H

2011-10-01

106

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

PubMed Central

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.

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

1994-01-01

107

Factors Affecting Morbidity and Mortality in Patients Who Underwent Emergency Operation for Incarcerated Abdominal Wall Hernia  

PubMed Central

Patients with incarcerated abdominal wall hernias (AWHs) are often encountered in emergency care units. Despite advances in anesthesia, antisepsis, antibiotic therapy, and fluid therapy, the morbidity and mortality rates for these patients remain high. Between 2006 and 2011, we retrospectively analyzed the cases of 131 patients who underwent emergency surgery for incarcerated abdominal wall hernias. Of these, there were 70 women (53.4%) and 61 men (46.6%) with an average age of 63.3 ± 17.4 years (range, 17–91 years). Morbidity was observed in 28 patients (21.4%), and the mortality rate was 2.3%. Intestinal resection, presence of concomitant disease, and general anesthesia were the independent variants that affected morbidity of patients with incarcerated abdominal wall hernias.

Gul, Mesut; Aliosmanoglu, Ibrahim; Kapan, Murat; Onder, Akin; Taskesen, Fatih; Arikanoglu, Zulfu; Tacyildiz, Ibrahim

2012-01-01

108

Left-sided congenital abdominal wall defect and intestinal malformation--a rare case.  

PubMed

A case report of a female newborn with a rare congenital abdominal wall defect associated with intestinal malformation. To our knowledge, only a few case reports of left sided congenital abdominal wall defect with this type of anomalies have been reported in the world literatures and this is the first in Fiji. This case brought numerous challenges to the team in terms of defining the pathology, role of undertaking surgery, providing supportive and nutritional therapy to a neonate and the ethical dilemma with the management in a developing country. PMID:23008980

Cama, J; Nagra, S; Chang, A

2011-03-01

109

Herniation of the gallbladder within a hernia of the abdominal wall associated with Mirizzi Syndrome  

PubMed Central

A gallbladder incarcerated hernia associated with Mirizzi syndrome is a very rare entity and to our knowledge this is the first case ever described in literature. An 85-year-old man presented at the emergency department with a tender right upper quadrant mass. Computed Tomography (CT) revealed the presence of a gallbladder lithiasis with signs of acute cholecystitis, herniated through the abdominal wall with an associated Mirizzi syndrome. Laparoscopic cholecystectomy and repair of the abdominal wall defect were performed. The patient recovered very well and the postoperative period was uneventful.

Paolino, LA; Millan, M; Bossi, M; Champault, G; Barrat, C

2011-01-01

110

Single-center 10-year experience in the management of anterior abdominal wall defects  

Microsoft Academic Search

Background  Anterior abdominal wall defects can be managed with various techniques, since no one technique can be applied to all types\\u000a of defects. The aim of this study is to present a single-center experience using biomaterials and evaluate the outcomes.\\u000a \\u000a \\u000a \\u000a Methods  The clinical data obtained from 33 neonates (24 gastroschisis and 9 omphaloceles) managed for anterior abdominal wall defects\\u000a at a single

S. Rahn; M. Bahr; J. Schalamon; A. K. Saxena

2008-01-01

111

The logic behind thick, liquid-walled, fusion concepts  

NASA Astrophysics Data System (ADS)

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 (Li2BeF4), and molten Lil7Pb83 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.

Moir, R. W.

1994-04-01

112

Thick Liquid-Walled, Field-Reversed Configuration  

SciTech Connect

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.

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

113

Control on mine pressure of thick and strong roof stratum movement in long wall thick coal caving face  

Microsoft Academic Search

The caving of thick and strong roof stratum causes tremendous rock pressure in mine. The results of the analysis on dynamic\\u000a natures of actual measurements of some fields, of which the roof pressure can be caused by thick and strong stratum in long\\u000a wall thick coal caving face, could present the relation between the collapse and movement of thick and

Guang-zhe Deng; Jian-chang Zhang; Tao He

2008-01-01

114

The effect of wall thickness on the response of a spherical ionization chamber  

Microsoft Academic Search

Air-filled ionization chambers are used widely for radiation dosimetry. For some applications it is important to know the effect on the chamber response of photon attenuation and scattering in the chamber walls. Traditionally, the wall effect is determined by measuring the chamber response as a function of wall thickness and extrapolating linearly to zero thickness. We have constructed a spherical

K R Shortt; A F Bielajew; C K Ross; K J Stewart; J T Burke; M J Corsten

2002-01-01

115

Changes in Lateral Abdominal Muscle Thickness During an Abdominal Drawing-In Maneuver in Individuals With and Without Low Back Pain  

Microsoft Academic Search

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7)

James R. Beazell; Terry L. Grindstaff; Joseph M. Hart; Eric M. Magrum; Martha Cullaty; Francis H. Shen

2011-01-01

116

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

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. PMID:22115912

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

2011-11-23

117

Morphological and mechanical characteristics of the reconstructed rat abdominal wall following use of a wet electrospun biodegradable polyurethane elastomer scaffold  

Microsoft Academic Search

Although a variety of materials are currently used for abdominal wall repair, general complications encountered include herniation, infection, and mechanical mismatch with native tissue. An approach wherein a degradable synthetic material is ultimately replaced by tissue mechanically approximating the native state could obviate these complications. We report here on the generation of biodegradable scaffolds for abdominal wall replacement using a

Ryotaro Hashizume; Kazuro L. Fujimoto; Yi Hong; Nicholas J. Amoroso; Kimimasa Tobita; Toshio Miki; Bradley B. Keller; Michael S. Sacks; William R. Wagner

2010-01-01

118

Laparoscopic Repair of Incisional and Other Complex Abdominal Wall Hernias  

PubMed Central

Incisional hernia is one of the most common complications of abdominal surgery, with a reported occurrence rate of up to 20% after laparotomy. The high incidence of hernia formation significantly contributes to both patient morbidity and health care costs. Although a variety of approaches have been described to repair these defects, historically the results have been disappointing. Recurrence rates after primary repair have been reported to range from 24% to 54%. The recent advent of laparoscopic ventral hernia repair (LVHR) has offered promising outcomes by combining tension-free repair using a prosthesis with minimally invasive techniques, lowering reported recurrence rates to <10%. This review discusses standardized, well-researched techniques that have contributed to the success of LVHR. We also discuss how these techniques have been modified for laparoscopic repair of suprapubic lumbar hernias, hernias near the iliac crest, and parastomal hernias. In addition, we review our own experience with LVHR in the context of the principles discussed.

Craft, Randall O; Harold, Kristi L

2009-01-01

119

Traumatic abdominal wall hernia: case report and review of the literature.  

PubMed

Traumatic abdominal wall hernia (TAWH) is a rare type of hernia that occurs after an impact of the abdominal wall against a blunt object. The first case described was reported in 1906 and ever since, 46 cases have been reported. CT scan is mandatory in the diagnosis of TAWH but also because of a frequent association with significant intra-abdominal injuries. We report here the case of a 61-year-old man with a TAWH developed after impact against a bicycle handlebar. Hemodynamically stable and without associated injuries, the patient was monitored for 24 hours before hospital discharge. A successful elective hernia repair with a prosthetic mesh was performed 6 weeks later once cicatrisation was achieved. PMID:20919672

Henrotay, J; Honoré, C; Meurisse, M

120

Abdominal wall abscess containing gallstones as a late complication to laparoscopic cholecystectomy performed 17 years earlier  

PubMed Central

Laparoscopic cholecystectomy (LC) is the preferred surgical treatment for symptomatic gallstones. The laparoscopic procedure is superior to the open approach in many aspects. Intraperitoneal spillage of bile and gallstones is one of the most common accidental occurrences of LC. We present a case of a 53-year-old woman who developed two abscesses­—one intra-abdominally and one in the abdominal wall—17 years after an LC. Three gallstones were found during surgical excision of the abdominal wall abscess. Surgeons should strive to avoid perforation of the gall bladder during LC. If spillage is inevitable attempts should be made to laparoscopically extract as many stones as possible. Documentation of (suspected) spillage is paramount when evaluating the possibility of postoperative complications, even many years later.

Christensen, Anders Mark; Christensen, Mads Mark

2013-01-01

121

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

PubMed

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

Naimer, Sody A

2012-11-15

122

[Surgical management of abdominal-wall insufficiency in the female (report on 94 cases)].  

PubMed

A clinical report is given on 94 cases of operative reconstruction of the anterior abdominal wall. There are medical and cosmetic indications. The morphological and functional results of these operations are good. Attending to the contraindications the number of dangerous complications in the postoperative course is low. No case of death was seen. PMID:153690

Methfessel, G; Methfessel, H D

1978-01-01

123

Chronic abdominal wall pain: Clinical features, health care costs, and long-term outcome  

Microsoft Academic Search

Background & Aims: Chronic abdominal wall pain (CAWP) often is misdiagnosed. We evaluated CAWP patients regarding diagnosis accuracy, clinical features, comorbidity, referral frequency, use of care, and long-term outcome. Methods: We reviewed the records of all outpatients referred to a gastroenterologist in 5 years, recorded referral indications, and identified patients initially diagnosed with CAWP or irritable bowel syndrome (IBS). Charts

Christopher D Costanza; George F Longstreth; Amy L Liu

2004-01-01

124

Prosthetic abdominal wall hernia repair in emergency surgery: from polypropylene to biological meshes  

Microsoft Academic Search

The use of nonabsorbable prosthetic materials such as polypropylene, polyester, and ePTFE, have expanded and are now widely used in reparative surgery for abdominal wall hernias. There are still difficulties to find correct indication for prosthetic implant in emergency hernia surgery: as a matter of fact there is still a great debate if to use non-absorbable prostheses in potentially or

G Campanelli; F Catena; L Ansaloni

2008-01-01

125

Clinical significance of intraoperative cultures of aneurysm walls and contents in elective abdominal aortic aneurysmectomy  

Microsoft Academic Search

To investigate the clinical significance of intraoperative cultures in elective abdominal aortic aneurysmectomy, we cultured the aneuryrymml wall and contents in 90 patients undergoing vascular graft surgery. Prosthetic graft infection was documented in 1 out of 62 patients with negative cultures and in none of 28 patients with positive cultures (x2 = 0.4, p > 0.1). Bacterial growth was seen

C. Brandimarte; C. Santini; M. Venditti; P. Baiocchi; P. Serra; P. Gallo; G. d'Amati; L. Rizzo; F. Speziale; P. Fiorani

1989-01-01

126

Tissue response to polypropylene meshes used in the repair of abdominal wall defects  

Microsoft Academic Search

SynopsisThe degree of integration of biomaterials used in the repair of abdominal wall defects seems to depend upon the structure of the prosthesis. Several polypropylene (PP) prostheses are currently available which differ in the number of PP filaments, the type of weave and the porosity. The aim of this study was to evaluate the integration, adhesion formation and resistance to

J. M Bellón; L. A Contreras; J Buján; D Palomares; A Carrera-San Mart??n

1998-01-01

127

Versatility of Tissue Expander in Abdominal Wall Reconstruction After Removal of Vascular Malformations in Children.  

PubMed

BACKGROUND: Children who had extensive abdominal wall vascular anomalies (VAs) face 3 common reconstructive options: either tolerating the complications of these lesions, exposure to repeated laser therapy session with its sequelae, or excision followed by a color-matched skin graft. The use of serial tissue expansion and excision of the affected skin offers a potentially better option under the right circumstances. Tissue expanders (TEs) have broad applicability but are not without complications. OBJECTIVE: To study the versatility of use of TEs in the management of children who had extensive VAs in their abdominal wall with special emphasis to the complications and children and parental satisfaction. MATERIALS AND METHODS: Retrospective data collection of 12 patients' charts, operative data of 84 operative procedures, and follow-up visits. Statistical analysis done using Student t test significance and P < 0.05 was considered statistically significant. RESULTS: Using 35 different sizes of TEs and 84 operative procedures in 9 boys and 3 girls aged from 2 to 12 years with different types of abdominal wall VAs revealed an overall complications rate of 20%. Child and parental satisfaction was found to be good overall. CONCLUSIONS: Tissue expander is a useful and feasible tool for reconstruction of the abdominal wall with extensive VAs in children; parents and children were satisfied and body image is acceptable. PMID:23728247

Fahmy, Mohamed A Baky

2013-05-30

128

Evaluation of Acellular Dermis for Closure of Abdominal Wall Defects in a Rat Model  

Microsoft Academic Search

Background: Abdominal wall repair can be performed with synthetic or biological materials. Biological materials may reduce the risk of infections and fibrosis. The aim of this study was to evaluate two acellular human dermis products. Materials and Methods: A rat model was used to compare the two materials. One was prepared using low concentrations of NaOH; the other material was

A. Pirayesh; A. H. M. Dur; N. J. Paauw; S. Monstrey; R. W. Kreis; M. J. Hoekstra; C. D. Richters

2008-01-01

129

Use of human acellular dermal matrix in complex and contaminated abdominal wall reconstructions  

Microsoft Academic Search

BackgroundFew good surgical options exist for the repair of complex anterior abdominal wall defects, particularly those in which bacterial contamination is present. The use of prosthetic mesh increases complication rates when the mesh is placed directly over viscera or when the surgical site is contaminated from a pre-existing infection or enteric spillage. The use of an acellular dermal matrix (ADM),

Joe H. Patton; Stepheny Berry; Kurt A. Kralovich

2007-01-01

130

The influence of porosity on the integration histology of two polypropylene meshes for the treatment of abdominal wall defects in dogs  

Microsoft Academic Search

Two types of monofilament polypropylene mesh with different pore sizes, mass densities and burst strengths were used to repair\\u000a two identical paired full-thickness abdominal wall defects in ten dogs, in order to compare their integration histology 90 days\\u000a after implantation. On one side a standard mesh, Prolene® (Ethicon), was sutured to the borders of the defect, while on the other a

F. H. Greca; Z. A. Souza-Filho; A. Giovanini; M. R. Rubin; R. F. Kuenzer; F. B. Reese; L. M. Araujo

2008-01-01

131

A Novel Nonoperative Approach to Abdominal Compartment Syndrome After Abdominal Wall Reconstruction  

PubMed Central

Introduction: Intraabdominal hypertension and abdominal compartment syndrome have been increasingly recognized as significant causes of morbidity and mortality in both medical and surgical patients. The gold standard remains surgical intervention; however, nonoperative approaches have been investigated less. Here, we describe the successful treatment of a severe acute case by intubation, nasogastric decompression, and paralysis—a novel approach not previously described in the literature. Case Description: After the patient underwent laparoscopic bilateral component separation and repair of a large recurrent ventral hernia with a 20 × 30-cm Strattice mesh (LifeCell Corp, Branchburg, NJ), acute renal failure developed within 12 hours postoperatively, and was associated with oliguria, hyperkalemia, and elevated peak airway and bladder pressures. The patient was treated nonoperatively with intubation, nasogastric tube decompression, and paralysis with a vecuronium drip. Rapid reversal was seen, avoiding further surgery. Within 2 hours after intubation and paralysis, our patient's urine output improved dramatically with an initial diuresis of approximately 1 L, his bladder pressures decreased, and within 12 hours his creatinine level had normalized. Discussion: Although surgical intervention has traditionally been thought of as the most effective—and thus the gold standard—for abdominal compartment syndrome, this preliminary experience demonstrates nonoperative management as highly efficacious, with the added benefit of decreased morbidity. Therefore, nonoperative management could be considered first-line therapy, with laparotomy reserved for refractory cases only. This suggests a more complex pathology than the traditional teaching of congestion and edema alone.

Sorensen, G. Brent

2013-01-01

132

Abdominal fat thickness measurement using Focused Impedance Method (FIM) - phantom study  

NASA Astrophysics Data System (ADS)

Abdominal fat thickness is a risk indicator of heart diseases, diabetes, etc., and its measurement is therefore important from the point of view of preventive care. Tetrapolar electrical impedance measurements (TPIM) could offer a simple and low cost alternative for such measurement compared to conventional techniques using CT scan and MRI, and has been tried by different groups. Focused Impedance Method (FIM) appears attractive as it can give localised information. An intuitive physical model was developed and experimental work was performed on a phantom designed to simulate abdominal subcutaneous fat layer in a body. TPIM measurements were performed with varying electrode separations. For small separations of current and potential electrodes, the measured impedance changed little, but started to decrease sharply beyond a certain separation, eventually diminishing gradually to negligible values. The finding could be explained using the intuitive physical model and gives an important practical information. TPIM and FIM may be useful for measurement of SFL thickness only if the electrode separations are within a certain specific range, and will fail to give reliable results if beyond this range. Further work, both analytical and experimental, are needed to establish this technique on a sound footing.

Haowlader, Salahuddin; Baig, Tanveer Noor; Siddique-e Rabbani, K.

2010-04-01

133

THIN WALL LIQUID FILM THICKNESS MEASUREMENT: A VIDEO OPTICAL TECHNIQUE  

Microsoft Academic Search

Wall spray interactions play an important role in the combustion efficiency prediction of turbojet or ramjet. They generate complex physical phenomena such as rebound onto wall or rebound onto wetted surface, splashing, deposition, film formation, film streaming and film atomization. ONERA\\/DMAE has been working on these subjects for few years, and some wall-drop interaction models have been developed and integrated

G. Heid; G. Lavergne; O. Simonin

134

Early results on the use of biomaterials as adjuvant to abdominal wall closure following cytoreduction and hyperthermic intraperitoneal chemotherapy  

PubMed Central

Background Hyperthermic chemotherapy applies thermal energy to both abdominal wall as well as the intra-abdominal viscera. The combination of the hyperthemia, chemotherapy and cytoreductive surgery (CRS) is associated with a defined risk of abdominal wall and intestinal morbidity reported to be as high as 15%, respectively to date, no studies have evaluated the use of biomaterial mesh as adjuvant to abdominal wall closure in this group of patients. In the present report, we hypothesized that post HIPEC closure with a biomaterial can reduce abdominal wall morbidity after CRS and hyperthermic intraperitoneal chemotherapy. Materials and methods All patients treated with HIPEC in a tertiary care center over 12 months (2008-2009) period were included. Eight patients received cytoreductive surgery followed by HIPEC for 90 minutes using Mitomycin C (15 mg q 45 minutes × 2). Abdominal wall closure was performed using Surgisis (Cook Biotech.) mesh in an underlay position with 3 cm fascial overlap-closure. Operative time, hospital length of stay (LOS) as well as postoperative outcome with special attention to abdominal wall and bowel morbidity were assessed. Results Eight patients, mean age 59.7 ys (36-80) were treated according to the above protocol. The primary pathology was appendiceal mucinous adenocarcinoma (n = 3) colorectal cancer (n = 3), and ovarian cancer (n = 2). Four patients (50%) presented initially with abdominal wall morbidity including incisional ventral hernia (n = 3) and excessive abdominal wall metastatic implants (n = 1). The mean peritoneal cancer index (PCI) was 8.75. Twenty eight CRS were performed (3.5 CRS/patient). The mean operating time was 6 hours. Seven patients had no abdominal wall or bowel morbidity, the mean LOS for these patients was 8 days. During the follow up period (mean 6.3 months), one patient required exploratory laparotomy 2 weeks after surgery and subsequently developed an incisional hernia and enterocutaneous fistula. Conclusion The use of biomaterial mesh in concert with HIPEC enables the repair of concomitant abdominal wall hernia and facilitates abdominal wall closure following the liberal resection of abdominal wall tumors. Biomaterial mesh prevents evisceration on repeat laparotomy and resists infection in immunocompromised patients even when associated with bowel resection.

2010-01-01

135

Biological and biomechanical assessment of a long-term bioresorbable silk-derived surgical mesh in an abdominal body wall defect model  

Microsoft Academic Search

Background  The patient’s own repair of a body wall defect would be enhanced by a mechanically robust, physically tailorable, bioresorbable\\u000a mesh scaffold that: (1) supports rapid host tissue ingrowth and development, while (2) reducing the complications associated\\u000a with permanent synthetic and allogenic and xenogenic biological implants.\\u000a \\u000a \\u000a \\u000a Methods  A full-thickness 1-cm-diameter abdominal wall defect was made in 36 Sprague–Dawley rats, which were divided

R. L. Horan; D. S. Bramono; J. R. L. Stanley; Q. Simmons; J. Chen; H. E. Boepple; G. H. Altman

2009-01-01

136

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

Microsoft Academic Search

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).

W H Ramsden; E F Moya; J M Littlewood

1998-01-01

137

Using Magnetic Flux Density To Identify Anomalies In Pipe Wall Thickness  

Microsoft Academic Search

In making seamless pipe, there are certain inherent wall thickness anomalies and defects associated with the manufacturing processes. Similarly, both seamless and welded pipe that has been in use for a period of time develop areas of reduced wall thickness during their in-service life. By taking advantage of continued improvement in technology and relying on the basic principles of magnetism,

William Walters; David Steely

138

Intra-abdominal thickness by ultrasonography to predict risk factors for cardiovascular disease and its correlation with anthropometric measurements  

Microsoft Academic Search

The aim of this study was to determine if intra-abdominal thickness measured by ultrasonography (IATU) in men and women had a correlation with cardiovascular risk factors, to compare it with anthropometric measures (waist circumference [WC] and abdominal sagittal diameter [SDi]), and to find a cut-off value for IATU to predict risk factors for cardiovascular disease (CVD). In a cross-validation study,

Claudia Cozer Leite; Bernardo Leo Wajchenberg; Rosana Radominski; Daniela Matsuda; Giovanni Guido Cerri; Alfredo Halpern

2002-01-01

139

Reducing Effective Liquid Wall Thickness in a HYLIFE-II Fusion Breeder  

NASA Astrophysics Data System (ADS)

One of the major inertial fusion energy reactor designs is HYLIFE-II which uses protective flowing liquid wall between fusion plasma and solid first wall. The most attractive aspect of this reactor is that protective liquid wall eliminates the frequent replacement of the first wall structure during reactor lifetime. Liquid wall thickness must be at least the thickness required for supplying sufficient tritium for the deuterium-tritium (DT) driver and satisfying radiation damage on the first wall below the limits. Reducing this thickness results less pumping power requirements and cost of electricity. In this study, investigation on potential of utilizing refractory alloys (W-5Re, TZM and Nb-1Zr) as first wall to reduce effective liquid wall thickness in HYLIFE-II reactor using liquid wall of Flibe + 10 mol % UF4 mixture. Neutron transport calculations were carried out with the help of the SCALE4.3 system by solving the Boltzmann transport equation with the XSDRNPM code in 238 neutron groups and a S8-P3 approximation. Numerical results showed that using W-5Re or TZM as first wall was effective in decreasing liquid wall thickness in contrast to Nb-1Zr.

Übeyli, Mustafa

2004-09-01

140

Abdominal wall phlebitis due to Prevotella bivia following renal transplantation in a patient with an occluded inferior vena cava.  

PubMed

Pre-existing occlusion of the inferior vena cava may complicate renal transplantation. Suppurative abdominal wall phlebitis following renal transplantation was diagnosed in a patient with pre-existing thrombosis of the inferior vena cava of unknown cause. The phlebitis developed in the subcutaneous collateral veins of the abdominal wall contra-laterally to the renal transplant. Cultures from abdominal wall micro-abscesses yielded Prevotella bivia as the causative agent. This complication has not been described before in the context of renal transplantation. The pathogenesis and management of this serious complication are discussed in this paper. PMID:23001520

Janssen, S; van Donselaar-van der Pant, K A M I; van der Weerd, N C; Develter, W; Bemelman, F J; Grobusch, M P; Idu, M M; Ten Berge, I J M

2012-09-23

141

Sandifer syndrome posturing: relation to abdominal wall contractions, gastroesophageal reflux, and fundoplication.  

PubMed

Sandifer syndrome designates abnormal posturing in patients with gastroesophageal reflux. To explore its mechanisms via examining relationships among Sandifer syndrome posturing, abdominal wall contractions, and reflux episodes, we studied an affected child in detail. The study utilized esophageal pHmetry, surface electromyography, and split-screen videography. The multichannel physiologic study demonstrated association of rectus abdominis contraction with onset of reflux episodes (P < 0.001) and association of reflux episodes with Sandifer syndrome posturing. This child's subsequent course confirmed his diagnosis and suggested mechanisms of the association of reflux and Sandifer syndrome. We conclude that abdominal wall contractions may induce reflux episodes. Sandifer syndrome may be due to gastroesophageal reflux even without hiatal hernia, macroscopic esophagitis, or reflux symptoms. Despite the absence of more typical reflux symptoms and failure to respond to very aggressive medical therapy, Sandifer syndrome may resolve after fundoplication. PMID:16614981

Frankel, Eric A; Shalaby, Theresa M; Orenstein, Susan R

2006-04-01

142

Use of bovine pericardium graft for abdominal wall reconstruction in contaminated fields  

PubMed Central

AIM: To employ, in such conditions, a biological graft such as bovine pericardium that offers resistance to infection. METHODS: In our surgical department, from January 2006 to June 2010, 48 patients underwent abdominal wall reconstruction using acellular bovine pericardium; of these 34 patients had a contaminated wound due to diffuse peritonitis (complicated diverticulitis, bowel perforation, intestinal infarction, strangled hernia, etc.) and 14 patients had hernia relapse on infected synthetic mesh. RESULTS: In our series, one patient died of multi-organ failure 3 d after surgery. After placement of the pericardium mesh four cases of hernia relapse occurred. CONCLUSION: Recurrence rate is similar to that of prosthetic mesh repair and the application of acellular bovine pericardium (Tutomesh®, Tutogen Medical Gmbh Germany) is moreover a safe and feasible option that can be employed to manage complicated abdominal wall defects where prosthetic mesh is unsuitable.

D'Ambra, Luigi; Berti, Stefano; Feleppa, Cosimo; Magistrelli, Prospero; Bonfante, Pierfrancesco; Falco, Emilio

2012-01-01

143

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

PubMed Central

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.

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

2012-01-01

144

A new description of the anterior abdominal wall in man and mammals.  

PubMed Central

The ventral abdominal walls of 116 specimens (41 human and 75 from nine mammalian families) of various ages and both sexes were studied anatomically and histologically. In man, each abdominal aponeurosis was bilaminar, and each wall of the rectus sheath was trilaminar (plywood-like). The two layers of the internal oblique emerged, in part of its extent, superficial to the external oblique and also passed deep to the transversus abdominis. All the six aponeurotic layers were oblique and crossed the mid-line, forming the following digastric muscles: the two external obliques together, the two transversus abdominis muscles together, one internal oblique (anterior layer) with the opposite external oblique (posterior layer) and one internal oblique (posterior layer) with the opposite transversus abdominis (anterior layer). The linea alba might be considered less the insertion of the abdominal muscles, but rather the common area of decussation of their intermediate aponeuroses. In all mammals, the internal oblique aponeurosis passed either superficial to that of the external oblique or deep to that of the transversus. The transversus aponeurosis was always oblique and in all eutheria it split into two layers. All abdominal aponeuroses crossed the middle line forming digastric muscles between the two sides. The functional significance and surgical application of these findings are discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15

Rizk, N N

1980-01-01

145

Application of “cinch\\/tie” technique to robotic-assisted nephropexy for posterior abdominal wall fixation  

Microsoft Academic Search

Nephropexy remains standard for symptomatic nephroptosis, and several minimally-invasive techniques have been described. Triangulation\\u000a sutures placed between the abdominal wall and the renal capsule are often difficult to tie tightly due to the confined working\\u000a space. We propose a technique modification to fixate the kidney utilizing the da Vinci Surgical System robot and Lapra-Ty\\u000a absorbable suture clips. Four female patients

Scott M. Castle; Watid Karnjanawanichkul; Raymond J. Leveillee

146

Abdominal wall reconstruction following removal of a chronically infected mid-urethral tape  

Microsoft Academic Search

We report a rare postoperative complication of a mid-urethral tape. The patient presented with a chronic infection resistant\\u000a to treatment with several weeks of antibiotics, with eventual surgical removal, and the resulting complications of an infected\\u000a incisional hernia and vesico-cutaneous fistula required reconstruction of the abdominal wall with Permacol™ and excision of\\u000a the vesico-cutaneous fistula. We also look briefly at

Helen Walker; Thomas Brooker; Wolf Gelman

2009-01-01

147

The influence of delay in closure of the abdominal wall on outcome in gastroschisis  

Microsoft Academic Search

To evaluate the effect of a delay in closure of the abdominal wall (AWC) on outcome in the management of gastroschisis, a\\u000a retrospective analysis of 91 babies admitted over a 7-year period (1992–1998) to a single neonatal surgical unit with a diagnosis\\u000a of gastroschisis was carried out. Antenatal diagnosis was made in 89 (98%) cases. Surgical intervention occurred in 90

C. P. Driver; J. Bowen; C. M. Doig; A. Bianchi; A. P. Dickson; J. Bruce

2001-01-01

148

Current practice of abdominal wall closure in elective surgery - Is there any consensus?  

PubMed Central

Background Development of incisional hernia after open abdominal surgery remains a major cause of post-operative morbidity. The aim of this study was to determine the current practice of surgeons in terms of access to and closure of the abdominal cavity in elective open surgery. Methods Twelve surgical departments of the INSECT-Trial group documented the following variables for 50 consecutive patients undergoing abdominal surgery: fascial closure techniques, applied suture materials, application of subcutaneous sutures, subcutaneous drains, methods for skin closure. Descriptive analysis was performed and consensus of treatment variables was categorized into four levels: Strong consensus >95%, consensus 75–95%, overall agreement 50–75%, no consensus <50%. Results 157 out of 599 patients were eligible for analysis (85 (54%) midline, 54 (35%) transverse incisions). After midline incisions the fascia was closed continuously in 55 patients (65%), using slowly absorbable (n = 47, 55%), braided (n = 32, 38%) sutures with a strength of 1 (n = 48, 57%). In the transverse setting the fascia was closed continuously in 39 patients (72%) with slowly absorbable (n = 22, 41%) braided sutures (n = 27, 50%) with a strength of 1 (n = 30, 56%). Conclusion In the present evaluation midline incision was the most frequently applied access in elective open abdominal surgery. None of the treatments for abdominal wall closure (except skin closure in the midline group) is performed on a consensus level.

Rahbari, Nuh N; Knebel, Phillip; Diener, Markus K; Seidlmayer, Christoph; Ridwelski, Karsten; Stoltzing, Hartmut; Seiler, Christoph M

2009-01-01

149

Abdominal wall actinomycosis associated with prolonged use of an intrauterine device: a case report and review of the literature.  

PubMed

The relationship between pelvic actinomycosis and the presence of an intrauterine device is well known. Abdominal wall actinomycosis with no involvement of pelvic organs in the presence of an intrauterine device is extremely rare. We report a case of a 32-year-old woman with a long-standing intrauterine device who developed abdominal wall actinomycosis. The diagnosis was established late by histopathological examination after an initial surgical procedure during which the abscess was evacuated and all the necrotic tissue was excised. Postoperatively, the patient developed two intra-abdominal abscesses, which were treated by surgical drainage. The combination of long-term high-dose antibiotic therapy with surgery led to successful management of the condition. We highlight the difficulty in diagnosis, necessity for an early postoperative diagnosis, and the importance of high-dose intravenous antibiotic therapy to prevent recurrence. Abdominal wall actinomycosis should be considered in intrauterine device users who present with abdominal abscesses of unknown origin. PMID:16548322

Lunca, S; Bouras, G; Romedea, N S; Pertea, Mihaela

150

Delayed abdominal wall reconstruction of giant ventral hernias using the anterolateral thigh free flap for skin coverage.  

PubMed

Delayed abdominal wall reconstruction for extremely large ventral hernias can be exceedingly difficult if there is a concomitant skin deficiency. In the past decade, six such patients after restoration of the integrity of the musculofascial layer required vascularized tissues to accomplish closure of huge mid-abdominal defects using in all cases the anterolateral thigh free flap. As with all perforator flaps, this ensures function preservation of the intrinsic abdominal muscles to provide a reliable solution to a difficult challenge. PMID:23026918

Hallock, Geoffrey G

2012-10-01

151

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

NASA Astrophysics Data System (ADS)

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.

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

2009-11-01

152

Tissue Reaction to Polypropylene Mesh: A Study of Oedema, Blood Flow, and Inflammation in the Abdominal Wall  

Microsoft Academic Search

The purpose of the present work was to study the tissue reaction to polypropylene mesh (Marlex®) implanted in three different layers of the abdominal wall, comparable to common clinical practices. The reaction to mesh was compared in terms of tissue oedema, blood flow, and histological appearance in rats. When mesh was placed between muscle layers, blood flow in the abdominal

S. Dabrowiecki; K. Svanes; J. Lekven; K. Grong

1991-01-01

153

Impairment of Lung and Chest Wall Mechanics in Patients with Acute Respiratory Distress Syndrome Role of Abdominal Distension  

Microsoft Academic Search

Recent data have suggested that the elastic properties of the chest wall (CW) may be compromised in patients with ARDS because of abdominal distension (4). We partitioned CW and lung (L) mechan- ics, assessed the role of abdominal distension, and verified whether the underlying disease responsi- ble for ARDS affects the impairment of respiratory mechanics. Volume-pressure (V-P) curves (inter- rupter

V. MARCO RANIERI; NICOLA BRIENZA; SERGIO SANTOSTASI; FILOMENA PUNTILLO; LUCIANA MASCIA; NICOLA VITALE; ROCCO GIULIANI; VINCENZO MEMEO; FRANCESCO BRUNO; TOMMASO FIORE; ANTONIO BRIENZA; ARTHUR S. SLUTSKY

154

ZnO nanotubes: Controllable synthesis and tunable UV emission modulated by the wall thickness  

NASA Astrophysics Data System (ADS)

The ZnO nanotubes (ZNTs) with different wall thickness were fabricated by a simple wet chemical approach. Both indirect and direct transitions contribute to the UV emission of ZNTs. With the decrease of wall thickness, not only the indirect transition becomes more and more important during the emission process due to the stronger surface band bending effects and even turns into the main emission when the wall thickness decreases to 25 nm, but also the PL intensity is enhanced step by step due to the less defect density and higher carrier concentration caused by the introduction of chlorine in ZNTs during the etching process.

Yang, Lili; Zhang, Zhiqiang; Wang, Zhe; Sun, Yunfei; Gao, Ming; Yang, Jinghai; Yan, Yongsheng

2013-12-01

155

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

PubMed Central

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

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

1981-01-01

156

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

DOEpatents

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.

Steinman, David A. (Ann Arbor, MI)

1982-01-01

157

A decoupled fluid structure approach for estimating wall stress in abdominal aortic aneurysms.  

PubMed

Abdominal aortic aneurysm (AAA) is a localized dilatation of the aortic wall. The lack of an accurate AAA rupture risk index remains an important problem in the clinical management of the disease. To accurately estimate AAA rupture risk, detailed information on patient-specific wall stress distribution and aortic wall tissue yield stress is required. A complete fluid structure interaction (FSI) study is currently impractical and thus of limited clinical value. On the other hand, isolated static structural stress analysis based on a uniform wall loading is a widely used approach for AAA rupture risk estimation that, however, neglects the flow-induced wall stress variation. The aim of this study was to assess the merit of a decoupled fluid structure analysis of AAA wall stress. Anatomically correct, patient specific AAA wall models were created by 3D reconstruction of computed tomography images. Flow simulations were carried out with inflow and outflow boundary conditions obtained from patient extracted data. Static structural stress analysis was performed applying both a uniform pressure wall loading and a flow induced non-uniform pressure distribution obtained during early systolic deceleration. For the structural analysis, a hyperelastic arterial wall model and an elastic intraluminal thrombus model were assumed. The results of this study demonstrate that although the isolated static structural stress analysis approach captures the gross features of the stress distribution it underestimates the magnitude of the peak wall stress by as much as 12.5% compared to the proposed decoupled fluid structure approach. Furthermore, the decoupled approach provides potentially useful information on the nature of the aneurysmal sac flow. PMID:16500664

Papaharilaou, Yannis; Ekaterinaris, John A; Manousaki, Eirini; Katsamouris, Asterios N

2006-02-28

158

Bronchial wall thickness measurement in computed tomography: effect of intravenous contrast agent and reconstruction kernel.  

PubMed

Bronchial wall thickness measurements in computed tomography (CT) has become a useful tool for assessment of the severity of diseaseand the response to treatment in a large number of pulmonary diseases. However, there are only few reports evaluating its dependence on different scan protocols. The effect of intravenous contrast medium has not been analyzed. The aim of this study was to evaluate the influence of intravenous contrast medium application, the contrast phase (arterial and venous) and different reconstruction kernels on bronchial wall measurements of a newly developed algorithm. The bronchial wall thickness was analyzed in 630 bronchial sections of 56 CT examinations with dedicated software (MEVIS Airway Examiner, Fraunhofer MEVIS Bremen, Germany). Application of i.v. contrast agent significantly increased bronchial wall thickness (paired t-test, p<0.001). Comparing arterial and venous phase, bronchial wall thickness was significant higher in the arterial phase (paired t-test, p=0.045). Bronchial wall thickness also increased (ANOVA with Bonferroni correction, p<0.001) when using a softer reconstruction kernel. The absolute differences in bronchial wall thickness were independent of bronchial size and generation. PMID:22673777

Dettmer, S; Entrup, J; Schmidt, M; de Wall, C; Wacker, F; Shin, H

2012-06-04

159

Complex Abdominal Wall Reconstruction: A Comparison of Flap and Mesh Closure  

PubMed Central

Objective To analyze a series of patients treated for recurrent or chronic abdominal wall hernias and determine a treatment protocol for defect reconstruction. Summary Background Data Complex or recurrent abdominal wall defects may be the result of a failed prior attempt at closure, trauma, infection, radiation necrosis, or tumor resection. The use of prosthetic mesh as a fascial substitute or reinforcement has been widely reported. In wounds with unstable soft tissue coverage, however, the use of prosthetic mesh poses an increased risk for extrusion or infection, and vascularized autogenous tissue may be required to achieve herniorrhaphy and stable coverage. Methods Patients undergoing abdominal wall reconstruction for 106 recurrent or complex defects (104 patients) were retrospectively analyzed. For each patient, hernia etiology, size and location, average time present, technique of reconstruction, and postoperative results, including recurrence and complication rates, were reviewed. Patients were divided into two groups based on defect components: Type I defects with intact or stable skin coverage over hernia defect, and Type II defects with unstable or absent skin coverage over hernia defect. The defects were also assigned to one of the following zones based on primary defect location to assist in the selection and evaluation of their treatment: Zone 1A, upper midline; Zone IB, lower midline; Zone 2, upper quadrant; Zone 3, lower quadrant. Results A majority of the defects (68%) were incisional hernias. Of 50 Type I defects, 10 (20%) were repaired directly, 28 (56%) were repaired with mesh only, and 12 (24%) required flap reconstruction. For the 56 Type II defects reconstructed, flaps were used in the majority of patients (n = 48; 80%). The overall complication and recurrence rates for the series were 29% and 8%, respectively. Conclusions For Type I hernias with stable skin coverage, intraperitoneal placement of Prolene mesh is preferred, and has not been associated with visceral complications or failure of hernia repair. For Type II defects, the use of flaps is advisable, with tensor fascia lata representing the flap of choice, particularly in the lower abdomen. Rectus advancement procedures may be used for well-selected midline defects of either type. The concept of tissue expansion to increase both the fascial dimensions of the flap and zones safely reached by flap transposition is introduced. Overall failure is often is due to primary closure under tension, extraperitoneal placement of mesh, flap use for inappropriate zone, or technical error in flap use. With use of the proposed algorithm based on defect analysis and location, abdominal wall reconstruction has been achieved in 92% of patients with complex abdominal defects.

Mathes, Stephen J.; Steinwald, Paul M.; Foster, Robert D.; Hoffman, William Y.; Anthony, James P.

2000-01-01

160

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

PubMed

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. PMID:22254456

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

2011-01-01

161

Inflammatory Patterns and Cellular and Vascular Permeation in Rat Abdominal Wall Defects Using Alloderm, Permacol and CollaMend for Repair  

Microsoft Academic Search

Background: Abdominal wall defects secondary to hernias, trauma or disease are a common problem in surgery. Complications of closing these defects with synthetic meshes include foreign body reactions, infection, and adhesions to abdominal viscera. To minimize these problems, several acellular dermis derived collagen products are being used clinically for tissue replacement\\/reconstruction and repair of abdominal wall defects, including both animal

Joyce K. McIntyre

2008-01-01

162

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

SciTech Connect

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.

Cvetic, Mirjam [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia (United States); CAMTP - Center for Applied Mathematics and Theoretical Physics, University of Maribor, Krekova 2, SI-2000 Maribor (Slovenia); Robnik, Marko [CAMTP - Center for Applied Mathematics and Theoretical Physics, University of Maribor, Krekova 2, SI-2000 Maribor (Slovenia)

2008-06-15

163

The importance of bladder wall thickness in the assessment of overactive bladder  

Microsoft Academic Search

The assessment of bladder wall thickness using ultrasound has been postulated to contribute diagnostic information in patients\\u000a with voiding dysfunction. In particular, several studies have focused on this tool’s role in patients with overactive bladder\\u000a and detrusor overactivity. Given the evidence that increasing bladder outlet obstruction and detrusor overactivity cause detrusor\\u000a hypertrophy, bladder wall thickness and its derivative, ultrasound-estimated bladder

Alison H. Blatt; Lewis Chan

2009-01-01

164

Periapical radiographs overestimate root canal wall thickness during post space preparation  

Microsoft Academic Search

Souza EM, Bretas RT, Cenci MS, Maia-Filho EM, Bonetti-Filho I. Periapical radiographs overestimate root canal wall thickness during post space preparation. International Endodontic Journal, 41, 658-663, 2008. Aim To evaluate differences between anatomic and radiographic measurements of root canal wall thick- ness (RCWT) after each root canal preparation stage during post placement. Methodology Twenty mandibular premolars with a single canal

E. M. Souza; R. T. Bretas; M. S. Cenci; E. M. Maia-Filho; I. Bonetti-Filho

2008-01-01

165

Collapse mode transitions of thin tubes with wall thickness, end condition and shape eccentricity  

Microsoft Academic Search

Transition of deformation mode shapes of round aluminum tubes from axisymmetric concertina to non-axisymmetric diamond mode have been studied with varying tube wall thickness, boundary conditions and tube shape eccentricities. Quasi-static axial compression experiments were carried out on as received aluminum tubes and tubes with wall thickness eccentricity, incorporated by off center machining. Tubes were of D\\/t=29 and L\\/D=1.4. The

N. K. Gupta; Nagesh

2006-01-01

166

Mean wall thickness of trabecular bone packets in the human iliac crest: Changes with age  

Microsoft Academic Search

Summary The mean wall thickness (MWT) of packets of trabecular bone was measured in undecalcified iliac crest bone samples of 36 normal subjects (14 female and 22 male) under polarized light. The mean wall thickness was 49.7±8.7 ?m at a mean age of 50.9 years. There existed a significant decrease of MWT with advancing age. With an appositional rate of

P. Lips; P. Courpron; P. J. Meunier

1978-01-01

167

Experimental determination of stress-concentration factors in thick-walled cylinders with crossholes and sideholes  

Microsoft Academic Search

In a companion paper1 submitted to ASME, the theoretical determination of stress-concentration factors in thick-walled cylinders was reported.\\u000a The present paper reports the results of experiments conducted to check the predictions of the theory. The configuration is\\u000a a thick-walled cylinder with crossholes or sideholes oriented perpendicular to the bore. Stress concentrations occur at the\\u000a “tee” intersections of the holes with

J. C. Gerdeen; R. E. Smith

1972-01-01

168

The logic behind thick, liquid-walled, fusion concepts  

Microsoft Academic Search

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

Ralph W. Moir

1995-01-01

169

Analysis of Radiation-Induced Embrittlement Gradients on Fracture Characteristics of Thick-Walled Pressure Vessel Steels.  

National Technical Information Service (NTIS)

The fracture behavior of thick-walled nuclear vessels is considered for the case of a radiation-induced toughness gradient through the wall which characteristically results from neutron attenuation by the wall material itself. Fracture-safe design analyse...

F. J. Loss J. R. Hawthorne C. Z. Serpan P. P. Puzak

1971-01-01

170

Clad vent set cup open end (closure weld zone) wall-thickness study  

SciTech Connect

The wall thickness at the open end of Clad Vent Set (CVS) cups is a very important parameter for maintaining control of the fueled CVS closure weld process. Ideally, the wall thickness in the closure weld zone should be constant. The DOP-26 iridium alloy is very difficult to machine; therefore, key dimensional features are established during the two-draw warm-forming operation. Unfortunately, anisotropy in the forming blanks produces four ears at the open end of each cup. Formation of these ears produces axial and circumferential variations in wall thickness. The cup certification requirement is that the wall thickness in the closure weld zone, defined as the 2.5-mm band at the open end of a cup, measure from 0.63 to 0.73 mm. The wall thickness certification data for the open end of the CVS cups have been statistically evaluated. These data show that the cups recently produced for the Cassini mission have well-controlled open-end wall thicknesses.

Ulrich, G.B.; Sherrill, M.W.

1994-09-01

171

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

DOEpatents

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.

Jones, Raymond Joseph (Duanesburg, NY); Bojappa, Parvangada Ganapathy (Schenectady, NY); Kirkpatrick, Francis Lawrence (Galway, NY); Schotsch, Margaret Jones (Clifton Park, NY); Rajan, Rajiv (Guilderland, NY); Wei, Bin (Mechanicville, NY)

2002-01-01

172

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

Microsoft Academic Search

A thorough understanding of the relationship between local hemodynamics and plaque progression has been hindered by an inability to prospectively monitor these factors in vivo in humans. In this study a novel approach for noninvasively recon- structing artery wall thickness and local hemodynamics at the human carotid bifurcation is presented. Three-dimensional (3D) models of the lumen and wall boundaries, from

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

2002-01-01

173

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

SciTech Connect

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.

Bossi, Alberto [Department of Radiation Oncology, University Hospitals Gasthuisberg, Leuven (Belgium)]. E-mail: alberto.bossi@uz.kuleuven.ac.be; De Wever, Ivo [Department of Surgical Oncology, University Hospitals Gasthuisberg, Leuven (Belgium); Van Limbergen, Erik [Department of Radiation Oncology, University Hospitals Gasthuisberg, Leuven (Belgium); Vanstraelen, Bianca [Department of Medical Physics, University Hospitals Gasthuisberg, Leuven (Belgium)

2007-01-01

174

Repair of Giant Midline Abdominal Wall Hernias: "Components Separation Technique" versus Prosthetic Repair  

PubMed Central

Background Reconstruction of giant midline abdominal wall hernias is difficult, and no data are available to decide which technique should be used. It was the aim of this study to compare the “components separation technique” (CST) versus prosthetic repair with e-PTFE patch (PR). Method Patients with giant midline abdominal wall hernias were randomized for CST or PR. Patients underwent operation following standard procedures. Postoperative morbidity was scored on a standard form, and patients were followed for 36 months after operation for recurrent hernia. Results Between November 1999 and June 2001, 39 patients were randomized for the study, 19 for CST and 18 for PR. Two patients were excluded perioperatively because of gross contamination of the operative field. No differences were found between the groups at baseline with respect to demographic details, co-morbidity, and size of the defect. There was no in-hospital mortality. Wound complications were found in 10 of 19 patients after CST and 13 of 18 patients after PR. Seroma was found more frequently after PR. In 7 of 18 patients after PR, the prosthesis had to be removed as a consequence of early or late infection. Reherniation occurred in 10 patients after CST and in 4 patients after PR. Conclusions Repair of abdominal wall hernias with the component separation technique compares favorably with prosthetic repair. Although the reherniation rate after CST is relatively high, the consequences of wound healing disturbances in the presence of e-PTFE patch are far-reaching, often resulting in loss of the prosthesis.

van Goor, H.; Charbon, J. A.; Rosman, C.; Hesselink, E. J.; van der Wilt, G. J.; Bleichrodt, R. P.

2007-01-01

175

Wall thickness evaluation of single-crystal hollow blades by eddy current sensor  

Microsoft Academic Search

Advanced high-pressure turbine blades of jet engines are hollow and monocrystalline. The external wall thickness of these blades has to be checked systematically and quickly after manufacturing in order to guarantee the blade strength. Thickness evaluation is made difficult by the presence of internal partitions and by the crystalline anisotropy of the superalloy used in blade manufacturing. In this paper,

Y Le Bihan; P.-Y Joubert; D Placko

2001-01-01

176

Radwaste volume in lithium and Flibe thick liquid wall and comparison to conventional SW concepts  

Microsoft Academic Search

Among the advantages offered by the deployment of thick liquid walls (LW) in high power density reactors is the substantial reduction in radwaste volume and hazard that is mainly attributed to the extended lifetime of structural materials. In this paper, we quantitatively estimate the volume of the generated waste when different thick LWs are used. In particular, we make a

M. Z Youssef; M. E Sawan

2002-01-01

177

Hemodynamic and pulmonary changes during open, carbon dioxide pneumoperitoneum, and abdominal wall-lifting cholecystectomy  

Microsoft Academic Search

Background  Carbon dioxide (CO2) pneumoperitoneum effects are still controversial. The aim of this study was to investigate cardiopulmonary changes in patients\\u000a subjected to different surgical procedures for cholecystectomy.\\u000a \\u000a \\u000a \\u000a Methods  In this study, 15 patients were assigned randomly to three groups according to the surgical procedure to be used: open cholecystectomy\\u000a (OC), CO2 pneumoperitoneum cholecystectomy (PP), and laparoscopic gasless cholecystectomy (abdominal wall lifting

G. Galizia; G. Prizio; E. Lieto; P. Castellano; L. Pelosio; V. Imperatore; A. Ferrara; C. Pignatelli

2001-01-01

178

The Analysis of Infection after Polypropylene Mesh Repair of Abdominal Wall Hernia  

Microsoft Academic Search

Aim  The aim of the study was to evaluate the frequency of superficial and prosthetic mesh infection following polypropylene mesh\\u000a repair of different abdominal wall hernia in individual patients and to analyze the manifestation, clinical process and outcomes\\u000a in patients with prosthetic mesh infection.\\u000a \\u000a \\u000a \\u000a Methods  This was a retrospective analysis of 375 patients with 423 implanted meshes for groin, femoral, umbilical, incisional

Arnolds Jezupors; M?ris Mihelsons

2006-01-01

179

Left common iliac artery to inferior vena cava abdominal wall arteriovenous graft for hemodialysis access.  

PubMed

We describe a novel arteriovenous graft configuration in the abdominal wall for hemodialysis in a 51-year-old woman with sickle cell disease. Upper extremity access sites were exhausted, and intrathoracic central veins occluded. Because of diminished quality of the left groin due to scar tissue from previous infected access, inadequate vasculature, and the presence of functional femoral catheter in the right groin with common iliac vein stenosis, we decided to create an arteriovenous graft from the left common iliac artery to the inferior vena cava. Adequate thrill and uneventful postoperative recovery was observed. At 4 months, the patient has been successfully using her graft. PMID:22494692

Zamani, Nader; Anaya-Ayala, Javier E; Ismail, Nyla; Peden, Eric K

2012-04-10

180

Systematic review of the use of fibrin sealant in abdominal-wall repair surgery  

Microsoft Academic Search

Purpose  Our objective was to analyze the advantages and inconveniences associated with the use of fibrin sealant compared with mechanical\\u000a means for mesh fixation following abdominal-wall surgery.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Literature search was conducted in MedLine, EMBASE, and Cochrane Library Plus databases. Articles were randomized clinical\\u000a trials, nonrandomized comparative studies, and case series containing at least ten patients.\\u000a \\u000a \\u000a \\u000a \\u000a Results  The fibrin sealant was shown to

S. Morales-Conde; A. Barranco; M. Socas; I. Alarcón; M. Grau; M. A. Casado

181

Management of Anterior Abdominal Wall Defect Using a Pedicled Tensor Fascia Lata Flap: A Case Report  

PubMed Central

Degloving injuries to anterior abdominal wall are rare due to the mechanism of injury. Pedicled tensor fascia lata is known to be a versatile flap with ability to reach the lower anterior abdomen. A 34-year-old man who was involved in a road traffic accident presented with degloving injury and defect at the left inguinal region, sigmoid colon injury, and scrotal bruises. At investigation, he was found to have pelvic fracture. The management consisted of colostomy and tensor fascia lata to cover the defect at reversal. Though he developed burst abdomen on fifth postoperative day, the flap healed with no complications.

Ojuka, K. D.; Nangole, F.; Ngugi, M.

2012-01-01

182

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

PubMed

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

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

2002-01-01

183

Thick Liquid-Walled Spheromak Magnetic Fusion Power Plant  

SciTech Connect

We assume a spheromak configuration can be made and sustained by a steady plasma gun current, which injects particles, current and magnetic field, i.e., helicity injection. The magnetic configuration is evaluated with an axisymmetric free-boundary equilibrium code, where the current profile is tailored to support an average beta of 10%. An injection current of 100 kA (125 MW of gun power) sustains the toroidal current of 40 MA. The flux linking the gun is 1/1000th of the flux in the spheromak. The geometry allows a flow of liquid, either molten salt (flibe-Li{sub 2}BeF{sub 4} or flinabe-LiNaBeF{sub 4}) or liquid metal, such as SnLi, which protects most of the walls and structures from neutron damage. The free surface between the liquid and the burning plasma is heated by bremsstrahlung and optical radiation and neutrons from the plasma. The temperature of the free surface of the liquid is calculated and then the evaporation rate is estimated. The impurity concentration in the burning plasma is estimated and limited to a 20% reduction in the fusion power ({approx}0.8% fluorine impurity). The divertor power density of 620 MW/m{sup 2} is handled by high-speed (100 m/s) liquid jets. Calculations show that the tritium breeding is adequate with enriched {sup 6}Li and appropriate design of the walls not covered by flowing liquid (15% of the total). A number of problem areas need further study to make the design self consistent and workable, including lowering the divertor power density by expanding the flux tube size.

Moir, R W; Bulmer, R H; Fowler, T K; Rognlien, T D; Youssef, M Z

2003-04-28

184

Thick Liquid-Walled Spheromak Magnetic Fusion Power Plant  

SciTech Connect

We assume a spheromak configuration can be made and sustained by a steady gun current, which injects particles, current and magnetic field, i.e., helicity injection. The equilibrium is calculated with an MHD equilibrium code, where an average beta of 10% is found. The toroidal current of 40 MA is sustained by an injection current of 100 kA (125 MW of gun power). The flux linking the gun is 1/1000th that of the flux in the spheromak. The geometry allows a flow of liquid, either molten salt, (flibe-Li{sub 2}BeF{sub 4} or flinabe-LiNaBeF{sub 4}) or liquid metal such as SnLi which protects most of the walls and structures from neutron damage. The free surface between the liquid and the burning plasma is heated by bremsstrahlung and optical radiation and neutrons from the plasma. The temperature of the free surface of the liquid is calculated and then the evaporation rate is estimated. The impurity concentration in the burning plasma is estimated and limited to a 20% reduction in the fusion power. For a high radiating edge plasma, the divertor power density of 460 MW/m{sup 2} is handled by high-speed (20 m/s), liquid jets. For low radiating edge plasmas, the divertor-power density of 1860 MW/m{sup 2} is too high to handle for flibe but possibly acceptable for SnLi with jets of 100 m/s flow speed. Calculations show the tritium breeding is adequate with enriched Li and appropriate design of the walls not covered by flowing liquid 15% of the total. We have come up with a number of problem areas needing further study to make the design self consistent and workable.

Moir, R W; Bulmer, R H; Fowler, T K; Youssef, M Z

2002-04-08

185

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

PubMed

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

Brown, Stephen H M

2011-12-03

186

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

PubMed Central

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

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

2013-01-01

187

Loss of Mechanical Strain Impairs Abdominal Wall Fibroblast Proliferation, Orientation and Collagen Contraction Function  

PubMed Central

Background Laparotomy wound load forces are reduced when dehiscence and incisional hernia formation occur. The purpose of this study is to determine the effects of strain loss on abdominal fascial fibroblast proliferation, orientation and collagen compaction function. Methods Cultured rat linea alba fibroblasts were subjected to continuous cyclic strain (CS), cyclic strain interrupted at 24 or 48 hours followed by culture at rest (IS-24 and IS-48) or were cultured without mechanical strain (NS). Cell number was measured and images analyzed for cell orientation. Fibroblasts from these groups were seeded onto the surface of (FPCL-S) or mixed into (FPCL-M) a collagen gel matrix and gel area was measured over time. Results Continuous strain stimulated proliferation when compared to the non-strained cells. The loss of strain (IS) delayed proliferation compared to CS throughout (P<0.05). CS fibroblasts aligned perpendicular to the direction of strain within 12 hours. Within 12 hours of strain loss, IS-48 fibroblasts became significantly less aligned (P<.0001), and appeared similar to the randomly organized NS fibroblasts 48 hours after strain removal. The CS and IS-24 groups demonstrated faster and greater overall FPCL-M compaction than both the IS-48 and NS groups (P<.0002). The CS group contracted the gel faster than the NS group in FPCL-S (P=.029). Conclusions Mechanical strain rapidly induces a proliferative, morphological and functional response in abdominal wall fibroblasts that is dependent on the continued presence of the strain signal and quickly lost when the load force is removed. The loss of wound edge tension that occurs during laparotomy wound separation and hernia formation may contribute to impaired wound healing through loss of a key stimulatory mechanical signal with important implications for abdominal wall reconstruction.

Culbertson, Eric J.; Xing, Liyu; Wen, Yuan; Franz, Michael G.

2011-01-01

188

Acoustic scattering from a contrast agent microbubble near an elastic wall of finite thickness  

NASA Astrophysics Data System (ADS)

Interest in the problem under consideration in this study is motivated by targeted ultrasound imaging where one has to deal with microbubble contrast agents pulsating near blood vessel walls. A modified Rayleigh-Plesset equation is derived that describes the oscillation of a contrast agent microbubble near an elastic wall of finite thickness. It is assumed that the medium behind the wall is a fluid but it is shown that the equation obtained is easily transformable to the case that the medium behind the wall is an elastic solid. In contrast to the model of a rigid wall, which predicts decreasing natural frequency of a bubble near the wall, the elastic wall model reveals that the bubble natural frequency can both decrease and increase, and in cases of interest for medical applications, the bubble natural frequency usually increases. It is found that the influence of an elastic wall on the acoustic response of a bubble is determined by the ratio between a cumulative parameter, which integrally characterizes the mechanical properties of the wall and has the dimension of density, and the density of the liquid surrounding the bubble. It is shown that the acoustic influence of the arterial wall on the bubble is weak and apparently cannot be used to recognize the moment when the bubble approaches the wall. However, in experiments where the behavior of bubbles near various plastic walls is observed, changes in the bubble response, such as increasing natural frequency and decreasing oscillation amplitude, are detectable.

Doinikov, Alexander A.; Aired, Leila; Bouakaz, Ayache

2011-11-01

189

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

PubMed Central

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

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

2010-01-01

190

A Rehabilitative Ultrasound Imaging Investigation of Lateral Abdominal Muscle Thickness in h ealthy Aging Adults  

Microsoft Academic Search

Purpose: Rehabilitative ultrasound imaging (RUSI) is used to evaluate lateral abdominal muscle size and function during the abdominal drawing-in maneuver (ADIM), an exercise used to improve lumbar spine stability. Little is known about the size and performance of these muscles in healthy aging adults. The purpose of this study was to investigate, using RUSI, the size and symmetry of the

Deborah M. Stetts; Jane E. Freund; Stephen C. Allison

191

Eddy current technique applied to the nondestructive evaluation of turbine blade wall thickness  

NASA Astrophysics Data System (ADS)

The high pressure turbine blades of jet engines show internal channels designed for air cooling. These recesses define the internal walls (partitions) and external walls of the blade. The external wall thickness is a critical parameter which has to be systematically checked in order to ensure the blade strength. The thickness evaluation is usually lead by ultrasonic technique or by X-ray tomography. Nevertheless, both techniques present some drawbacks related to measurement speed and automation capability. These drawbacks are bypassed by the eddy current (EC) technique, well known for its robustness and reliability. However, the wall thickness evaluation is made difficult because of the complexity of the blade geometry. In particular, some disturbances appear in the thickness evaluation because of the partitions, which exclude the use of classical EC probes such as cup-core probe. In this paper, we show the main advantages of probes creating an uniformly oriented magnetic field in order to reduce the partition disturbances. Furthermore, we propose a measurement process allowing to separate the wall thickness parameter from the EC signals. Finally, we present some experimental results validating the proposed technique.

Le Bihan, Yann; Joubert, Pierre-Yves; Placko, Dominique

2000-05-01

192

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

NASA Astrophysics Data System (ADS)

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

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

2007-03-01

193

Computed tomographic assessment of maxillary sinus wall thickness in edentulous patients.  

PubMed

Posterior maxillary region is considered to be the most challenging area for dental implant placement. Lateral window opening is the gold standard procedure for maxillary sinus augmentation in this area. The purpose of this study is to evaluate lateral wall thickness of the maxillary sinus for sinus augmentation using computed tomography (CT) in edentulous patients. Computed tomography images of 302 patients were analysed. Using the maxillary sinus floor as the reference point in edentulous regions, lateral wall thickness was measured on CT scans. After drawing a tangent line at the lowest point of the sinus floor, another perpendicular line to the tangent line was drawn at the same point of the sinus floor. Thickness of the lateral wall of the maxillary sinus was measured using 10DR implant software at 3 (R1), 10 (R2) and 15 mm (R3) from the sinus floor. The mean thickness of the lateral wall of the maxillary sinus from the first premolar to second molar was 1·69 ± 0·71, 1·50 ± 0·72, 1·77 ± 0·78 and 1·89 ± 0·85 mm, respectively. The thickness differed significantly at the R2 and R3 points. Women had thinner lateral walls at the R1 and R2 points at the premolars than did men. At the R2 and R3 points at the second premolar, the mean thickness of smokers was larger than that of non-smokers. There were no significant differences on age or reasons for tooth loss. The changes in the thickness of the lateral wall at different reference points were observed, and CT examinations may help make lateral window without membrane perforation. PMID:22471834

Yang, S-M; Park, S-I; Kye, S-B; Shin, S-Y

2012-04-03

194

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

195

Quantitative evaluation of abdominal wall perfusion after different types of laparotomy closure using laser-fluorescence videography.  

PubMed

Laparotomy closure relies on the incisional edges as anchor for the suture material. The results of these techniques are not satisfying, with failure rates of up to 20%. To investigate the effect of different conventional closure techniques and a novel "bridging technique" on abdominal wall perfusion an animal study was performed in rabbits. Abdominal wall perfusion was measured using the method of dynamic laser-fluorescence videography in the first 72 h of incisional wound healing in 25 animals. Suture tension was controlled with a water-filled polyurethane balloon connected to a pressure detector. The effect of laparotomy closure on abdominal wall tissue perfusion depends significantly on the applied technique and suture tension. Avoiding direct sutures in the incisional edges during laparotomy closure leads to a better tissue perfusion of the incisional region than conventional suture techniques. Suture tension can be controlled and adjusted using a water-filled polyurethane balloon as a pressure sensor. PMID:12090573

Höer, J; Töns, C; Schachtrupp, A; Anurov, M; Titkova, S; Oettinger, A; Wetter, O; Schumpelick, V

2002-03-01

196

Isolated Abdominal Wall Actinomycosis Associated with an Intrauterine Contraceptive Device: A Case Report and Review of the Relevant Literature  

PubMed Central

Isolated abdominal wall actinomycosis in the presence of an intrauterine contraceptive device (IUCD) is extremely rare and only six such cases have been reported in the literature. We report a case where clinical and radiological examinations revealed a pseudotumor within the anterior abdominal wall. After being lost to follow-up, the patient presented two years later with the enlargement of the mass. The mass including the affected anterior abdominal wall was completely excised. The diagnosis of actinomycosis was established postoperatively by histopathological examination. Further questioning concerning her gynecological history revealed long-term use of the same IUCD. Surgical excision of the actinomycotic pseudotumour and removal of the IUCD followed by antibiotic therapy resulted in the full recovery of the patient.

Carkman, Sinan; Ozben, Volkan; Durak, Haydar; Karabulut, Kagan; Ipek, Turgut

2010-01-01

197

USING OF PROSTHETIC BIOMATERIALS IN LARGE ANIMALS: MODERN CONCEPTS ABOUT ABDOMINAL WALL DEFECTS APPROACH UTILIZAREA BIOMATERIALELOR PROTETICE LA ANIMALELE MARI: CONCEPTE MODERNE ASUPRA ABORD?RII DEFECTELOR PERETELUI ABDOMINAL  

Microsoft Academic Search

The development of prosthetic biomaterials revolutionized surgery for the repair of abdominal wall hernias in humans. A tensionfree mesh technique has drastically reduced recurrence rates for all hernias compared to tissue repairs and has made it possible to reconstruct large ventral defects that were previously irreparable. Abdominal wall defects (hernias, eventrations, eviscerations) in large animals (cattles, horses) present also o

Ciprian OBER; Aurel MUSTE; Liviu OANA

198

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

PubMed Central

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.

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

2013-01-01

199

The association of wall mechanics and morphology: a case study of abdominal aortic aneurysm growth.  

PubMed

The purpose of this study is to evaluate the potential correlation between peak wall stress (PWS) and abdominal aortic aneurysm (AAA) morphology and how it relates to aneurysm rupture potential. Using in-house segmentation and meshing software, six 3-dimensional (3D) AAA models from a single patient followed for 28 months were generated for finite element analysis. For the AAA wall, both isotropic and anisotropic materials were used, while an isotropic material was used for the intraluminal thrombus (ILT). These models were also used to calculate 36 geometric indices characteristic of the aneurysm morphology. Using least squares regression, seven significant geometric features (p?wall mechanics with geometry is nonlinear and reveals that PWS does not increase concomitantly with aneurysm diameter. This suggests that a quantitative characterization of AAA morphology may be advantageous in assessing rupture risk. PMID:22070335

Washington, Christopher B; Shum, Judy; Muluk, Satish C; Finol, Ender A

2011-10-01

200

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

Microsoft Academic Search

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

D. H. J. Thijssen; E. A. Dawson; I. C. van den Munckhof; T. M. Tinken; E. den Drijver; N. Hopkins; N. T. Cable; D. J. Green

2011-01-01

201

Correlation between thermal conductivity and the thickness of selected insulation materials for building wall  

Microsoft Academic Search

Correlation between thermal conductivity and the thickness of selected insulation materials for building wall has been analyzed. The study has found that a relationship between the thermal conductivity (k) and optimum thickness (xopt) of insulation material is non-linear which obeys a polynomial function of xopt=a+bk+ck2, where a=0.0818, b=?2.973, and c=64.6. This relationship will be very useful for practical use to

T. M. I. Mahlia; B. N. Taufiq; Ismail; H. H. Masjuki

2007-01-01

202

The use of Mersilene mesh in repair of abdominal wall hernias: a clinical and experimental study.  

PubMed Central

Use of synthetic materials in herniplasty has been a controversial issue. In order to determine the influence of Mersilene mesh on the strength of healing abdominal wounds and its effectiveness in repair of hernia, experimental and clinical studies were undertaken. Experimental study included 175 male rats divided into three groups subjected to either: 1) an incision made only through the skin and closed with 3-0 silk sutures; 2) a 2.5 cm midline incision through the musculature and peritoneum closed with 2-0 Mersilene suture; or 3) the same procedure as group 2 with the addition of a Mersilene mesh onlay graft. Bursting strength of abdominal wounds as determined in all groups at intervals. Wounds of the group treated with the mesh exhibited significantly greater (P less than 0.01) bursting strength. Clinical trial consisted of 100 consecutive adult patients in which an onlay graft of Mersilene mesh was used in the hernioplasty. Mesh was used as an adjunct in patients with: 1) large ventral hernias; 2) direct hernias resulting from severely attenuated transversialis fascia; 3) indirect hernias associated with a large internal ring and a weak posterior inguinal wall; or 4) combined direct and indirect hernias. All were followed for a minimum of one year to determine the incidence of complication and rate of recurrence. This study suggests that: 1) Mersilene mesh increases the strength of healing abdominal wounds in rats; and 2) repair of large hernias with Mersilene mesh results in an acceptable morbidity and a lowered rate of recurrence. Images Fig. 3.

Cerise, E J; Busuttil, R W; Craighead, C C; Ogden, W W

1975-01-01

203

Case report of a traumatic abdominal wall hernia resulting from falling onto a flat surface.  

PubMed

This article reports a case of high-energy type traumatic abdominal wall hernia (TAWH) associated with multiple organ injuries including pelvic fractures, liver laceration and ascending colon perforation. The cause of the trauma was falling to the ground from a height of approximately 8 meters. Since the forces affecting the abdomen are unique when falling on a flat surface, the mechanism of defect may be different between a low-energy type handlebar hernia and high-energy type TAWH. Only a few cases of high-energy type TAWH exist in the literature, all reporting falling on or hitting an angled or curved material. To our knowledge, this is the only report of TAWH resulting from falling onto a flat surface. The diagnosis and management are summarized, the literature data are reviewed, and the mechanism of action is discussed. PMID:21153955

Yücel, Neslihan; U?ra?, Murat Yahya; I??k, Burak; Turtay, Gökhan

2010-11-01

204

Abdominal wall port site metastasis after robotically staged endometrial carcinoma: A case report  

PubMed Central

INTRODUCTION The incidence of port-site metastasis following robotic-assisted laparoscopic hysterectomy is unknown. PRESENTATION OF CASE We present a case of a 78-year-old female diagnosed with an incidental grade 3 endometrial adenocarcinoma on a final hysterectomy specimen. She subsequently underwent a robotic staging surgery with a gynecologic oncologist where nodal pathology was found to be negative; her final stage was 1B. One year following diagnosis, she developed a recurrence on her abdominal wall at the former port-sites with concomitant vaginal cuff recurrence. DISCUSSION We hypothesize possible modes of metastasis and present limited published data to date on port site metastasis following robotic hysterectomy for endometrial cancer. CONCLUSION This is the second reported case of port-site metastasis following robotic surgery for endometrial cancer.

Nguyen, My-Linh T.; Friedman, Jaclyn; Pradhan, Tana S.; Pua, Tarah L.; Tedjarati, Sean S.

2013-01-01

205

Alpha-methylacyl-coenzyme a racemase-expressing urachal adenocarcinoma of the abdominal wall.  

PubMed

Urachal adenocarcinomas are very rare and about one third of these neoplasms arise in urachal remnants. To demonstrate the origin of the urachal adenocarcinoma is not easy, but it is very important for managing patient care. We report on a 35-year-old man who complained of a palpable mass in the periumbilical area. The mass was incidentally identified 10 days earlier. Computed tomography revealed a well-defined enhancing mass with internal calcification and septation abutting on the dome of the urinary bladder. The clinical diagnosis was urachal cancer, which seemed to invade the urinary bladder. Thus, we performed mass excision and partial resection of the bladder. Histopathologically, the mass was diagnosed as mucinous cystadenocarcinoma originating from urachal remnants that showed an unusual expression of alpha-methylacyl-coenzyme A racemase (AMACR). To our knowledge, this report is the first case of AMACR-expressing urachal adenocarcinoma arising in the abdominal wall. PMID:20664785

Ha, Yun-Sok; Kim, Young-Won; Min, Byung-Dal; Lee, Ok-Jun; Kim, Yong-June; Yun, Seok-Joong; Lee, Sang-Cheol; Kim, Wun-Jae

2010-07-20

206

[Malacoplakia involving the abdominal wall and urinary bladder: literature review and case report].  

PubMed

The authors describe a 44-year old woman's case where a tumor of her lower abdomen has been clinically found. CT of the abdomen showed involving the abdominal wall and urinary bladder. Histologically has been found the specific von Hansemann cells and Michaelis-Gutmann bodies warranting a diagnosis of malakoplakia Partial resection of urinary bladder and mm recti abdominis has been performed. The patient is clinically healthy until present (36 months) with normal laboratory indicators and CT find. The clinical symptoms of this very rare disease are different and depend upon the organ location. The soft tissue tumor-like lesions can mimic a variety of malignant, inflammatory, and infectious diseases. The accurate histologycal estimate leads to mild surgical intervention and postoperative comfort for the patient. PMID:18771139

Grudeva-Popova, Zh; Paskalev, G; Khubavenska, I; Tsekov, K

2006-01-01

207

Recalcitrant abdominal wall hernias: long-term superiority of autologous tissue repair.  

PubMed

Secondary repair of recurrent ventral hernia is difficult, and success depends on re-establishing the functional integrity of the abdominal wall. Current techniques used for closure of these defects have documented recurrence rates as high as 54 percent. The authors' 8-year experience utilizing variations of the components separation technique for autologous tissue repair of recalcitrant hernias emphasizes that recurrent or recalcitrant hernias benefit from the creation of a dynamic abdominal wall. A total of 389 patients were retrospectively identified as having abdominal wall defects, and 284 of these patients met the selection criteria. Study patients were grouped according to the type of surgical repair used. The recurrence rate was 20.7 percent over all study groups and was directly related to the extent of repair required. Group 1 patients (wide tissue undermining) had a recurrence rate of only 15 percent, while in group 2 (complete components separation), the recurrence rate was 22 percent. Group 3 patients (interpositional fascia lata graft) had a 29 percent recurrence rate. Time to recurrence was also significantly different across treatment groups, with study group 3 experiencing earlier hernia recurrence. The most frequent postoperative complication was wound infection, which was directly related to the repair performed. The relative odds of recurrence versus the risk factors of age, sex, perioperative steroid use, wound infection, defect size, and the presence of enterocutaneous fistula were studied with a logistic regression analysis. These factors did not possess statistical significance for predicting hernia recurrence. The preoperative presence of mesh was independently significant for hernia recurrence, increasing the relative odds 2.2 times (p = 0.01). Similarly, when other risk factors were controlled for, increasing the complexity of the treatment group, from study group 1 (wide tissue undermining) to study group 3 (interpositional fascia lata graft), also increased the odds of hernia recurrence 1.5-fold per group (p = 0.04). Average inpatient cost was $24,488. The length of inpatient stay ranged from 2 to 172 days (average, 12.8 days). The length of inpatient stay and costs were directly related to the extent of repair required. Using the analysis of variance test for multiple factors, the presence of an enterocutaneous fistula (p = 0.0014) or a postoperative wound infection (p = 0.008) independently increased the length of inpatient stay and hospital costs. A total of 108 successfully repaired patients were contacted by telephone and agreed to participate in a self-reported satisfaction survey. The patients noticed improvements in the appearance of their abdomen, in their postoperative emotional state, and in their ability to lift objects, arise from a chair or a bed, and exercise. These results suggest that recalcitrant hernia defects should be solved, when possible, by reconstructing a dynamic abdominal wall. PMID:12832883

Girotto, John A; Chiaramonte, Michael; Menon, Nathan G; Singh, Navin; Silverman, Ron; Tufaro, Anthony P; Nahabedian, Maurice; Goldberg, Nelson H; Manson, Paul N

2003-07-01

208

Safety and Efficacy of Laparoendoscopic Single-Site Surgery for Abdominal Wall Hernias  

PubMed Central

Background: Laparoendoscopic single-site surgery has rapidly progressed from the animal laboratory to clinical use since mass production of multichannel ports began in 2007. Indeed, it has now been shown to be feasible and safe for many commonly performed operations. Methods: This study cohort comprised 22 unselected patients with abdominal wall hernias of varying types: multiply recurrent inguinal (n=2), suprapubic (n=1), ventral/incisional (n=17), and parastomal hernias (n=2), who underwent laparoendoscopic single-site ventral hernia repair between December 2009 and February 2011. Standard dissecting instruments and a 52cm/5.5mm/30°angle laparoscope were used. Results: Patients included 14 men and 8 women, with a median age of 56 (range, 32 to 78) years and a mean body mass index of 31.5±4.7kg/m2. The mean mesh size was 460cm2 (range, 225 to 884cm2). Mean operation time was 125 minutes for ventral/incisional hernias and 270 minutes for parastomal hernias. No conversions to multiport or open surgeries were necessary. There was no mortality or morbidity, and no recurrence at 6- to 18-month follow-up. The mean satisfaction score was 2.7 (range, 2 to 3) with no patients reporting dissatisfaction with the procedure. Conclusion: This series, though relatively small, represents a diverse group of patients with varying abdominal wall hernias, including parastomal hernias. These successful laparoendoscopic single-site surgeries, with no complications, demonstrate safety and efficacy, albeit in a specialized hernia center. This study is a prelude to the eventual validation of laparoendoscopic single-site hernia surgery with prospective randomized controlled trials.

2012-01-01

209

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

PubMed Central

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

Pascual, Gemma; Sotomayor, Sandra; Rodriguez, Marta; Perez-Kohler, Barbara; Bellon, Juan M.

2012-01-01

210

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

ERIC Educational Resources Information Center

|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…

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

2009-01-01

211

Reduction in left ventricular wall thickness after deconditioning in highly trained Olympic athletes  

Microsoft Academic Search

BACKGROUND--Clinical distinction between athlete's heart and hypertrophic cardiomyopathy in a trained athlete is often difficult. In an effort to identify variables that may aid in this differential diagnosis, the effects of deconditioning on left ventricular wall thickness were assessed in six highly trained elite athletes who had competed in rowing or canoeing at the 1988 Seoul Olympic Games. Each of

B J Maron; A Pelliccia; A Spataro; M Granata

1993-01-01

212

Optimization of insulation thickness for external walls using different energy-sources  

Microsoft Academic Search

In countries that import most of their energy, like Turkey, energy saving and the effective usage of energy become much more important. Energy consumption for heating is too high in Turkey because buildings have almost no insulation. Also the high prices of heating energy in Turkey, emphasize the need for energy saving. Therefore, the optimum insulation-thickness of the external wall

Ö. Altan Dombayc?; Mustafa Gölcü; Ya?ar Pancar

2006-01-01

213

Fatigue design of an autofrettaged thick-walled pressure vessel using CAE techniques  

Microsoft Academic Search

In order to increase the fatigue life of an autofrettaged thick-walled pressure vessel, computer aided engineering techniques were applied. The fatigue life increase of the external grooved pressure vessel was achieved by relieving the high-stress concentration at the external groove. Shape optimization of the external groove incorporating the finite element stress analysis was performed, resulting in an optimized double grooved

S. K. Koh; S. I. Lee; S. H. Chung; K. Y. Lee

1997-01-01

214

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

SciTech Connect

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.

Endo, T.; Kobayashi, N.; Goto, K.; Yasuda, M.; Fujima, Y. [Nagoya University (Japan)

2003-05-15

215

Isotropic and Anisotropic Creep Characteristics of Thick-Walled Pressure Vessels under Elastic/Plastic Stress.  

National Technical Information Service (NTIS)

By using the theory of finite deformations the isochoric creep behaviour of thick-walled high-pressure containers (multi-layer containers) which have been deformed elastoplastically at the beginning of creep due to internal and external pressure is descri...

D. Knoerzer

1985-01-01

216

Differential effects of nebivolol and metoprolol on central aortic pressure and left ventricular wall thickness.  

PubMed

The aim of this study was to investigate the effects of the vasodilating ?-blocker nebivolol and the cardioselective ?-blocker metoprolol succinate on aortic blood pressure and left ventricular wall thickness. We conducted a randomized, double-blind study on 80 hypertensive patients. The patients received either 5 mg of nebivolol or 50 to 100 mg of metoprolol succinate daily for 1 year. Their heart rate, central and brachial blood pressures, mean arterial pressure, augmentation index, carotid-femoral pulse wave velocity, and left ventricular wall thickness were measured at baseline and at the end of the study. Nebivolol and metoprolol significantly reduced heart rate, brachial blood pressure, and mean arterial pressure to the same degree. However, reductions in central systolic and diastolic blood pressures, central pulse pressure, and left ventricular wall thickness were significant only in the nebivolol group. The change in left ventricular septal wall thickness was significantly correlated with central systolic blood pressure change (r=0.41; P=0.001) and with central pulse pressure change (r=0.32; P=0.01). No significant changes in augmentation index or carotid-femoral pulse wave velocity were detected in either treatment group. This proof-of-principle study provides evidence to suggest that ?-blockers with vasodilating properties may offer advantages over conventional ?-blockers in antihypertensive therapy; however, this remains to be tested in a larger trial. PMID:21536983

Kampus, Priit; Serg, Martin; Kals, Jaak; Zagura, Maksim; Muda, Piibe; Karu, Külliki; Zilmer, Mihkel; Eha, Jaan

2011-05-02

217

Electric and Magnetic Coupling through Small Apertures in Shield Walls of Any Thickness  

Microsoft Academic Search

A method is presented for evaluating the coupling between two identical resonant cavities coupled by a small aperture in a plane common wall of arbitrary thickness. The coupling is related to the frequencies of the symmetric and asymmetric modes of oscillation of the coupled cavity structure, and a variational technique is used to determine those frequencies. The method is applied

N. A. McDonald

1972-01-01

218

Aneurysm-Express: Human Abdominal Aortic Aneurysm Wall Expression in Relation to Heterogeneity and Vascular Events – Rationale and Design  

Microsoft Academic Search

Objective: Elective repair of abdominal aortic aneurysms (AAA) is associated with significant morbidity and mortality. Large amounts of AAA tissue are necessary to assess heterogeneity among AAA and to correct for potential confounders such as known risk factors. The Aneurysm-express study aims to identify different types of AAA using inflammatory markers in the aneurysm wall that predict postoperative cardiovascular adverse

R. Hurks; I. E. Hoefer; A. Vink; J.-P. P. M. de Vries; R. H. Heijmen; A. H. Schoneveld; M. Kerver; G. Pasterkamp; F. L. Moll

2010-01-01

219

Morphological and Mechanical Characteristics of the Reconstructed Rat Abdominal Wall Following use of a Wet Electrospun Biodegradable Polyurethane Elastomer Scaffold  

PubMed Central

Although a variety of materials are currently used for abdominal wall repair, general complications encountered include herniation, infection, and mechanical mismatch with native tissue. An approach wherein a degradable synthetic material is ultimately replaced by tissue mechanically approximating the native state could obviate these complications. We report here on the generation of biodegradable scaffolds for abdominal wall replacement using a wet electrospinning technique in which fibers of a biodegradable elastomer, poly(ester urethane)urea (PEUU), were concurrently deposited with electrosprayed serum-based culture medium. Wet electrospun PEUU (wet ePEUU) was found to exhibit markedly different mechanical behavior and to possess an altered microstructure relative to dry processed ePEUU. In a rat model for abdominal wall replacement, wet ePEUU scaffolds (1 × 2.5 cm) provided a healing result that developed toward approximating physiologic mechanical behavior at 8 wks. An extensive cellular infiltrate possessing contractile smooth muscle markers was observed together with extensive extracellular matrix (collagens, elastin) elaboration. Control implants of dry ePEUU and expanded polytetrafluoroethylene did not experience substantial cellular infiltration and did not take on the native mechanical anisotropy of the rat abdominal wall. These results illustrate the markedly different in vivo behavior observed with this newly reported wet electrospinning process, offering a potentially useful refinement of an increasingly common biomaterial processing technique.

Hashizume, Ryotaro; Fujimoto, Kazuro L.; Hong, Yi; Amoroso, Nicholas J.; Tobita, Kimimasa; Miki, Toshio; Keller, Bradley B.; Sacks, Michael S.; Wagner, William R.

2011-01-01

220

Chest wall thickness in military personnel: implications for needle thoracentesis in tension pneumothorax.  

PubMed

Needle thoracentesis is an emergency procedure to relieve tension pneumothorax. Published recommendations suggest use of angiocatheters or needles in the 5-cm range for emergency treatment. Multidetector computed tomography scans from 100 virtual autopsy cases were used to determine chest wall thickness in deployed male military personnel. Measurement was made in the second right intercostal space at the midclavicular line. The mean horizontal thickness was 5.36 cm (SD = 1.19 cm) with angled (perpendicular) thickness slightly less with a mean of 4.86 cm (SD 1.10 cm). Thickness was generally greater than previously reported. An 8-cm angiocatheter would have reached the pleural space in 99% of subjects in this series. Recommended procedures for needle thoracentesis to relieve tension pneumothorax should be adapted to reflect use of an angiocatheter or needle of sufficient length. PMID:18274025

Harcke, H Theodore; Pearse, Lisa A; Levy, Angela D; Getz, John M; Robinson, Stephen R

2007-12-01

221

The relationship between myocardial integrated backscatter, perfusion pressure and wall thickness during isovolumic contraction: An isolated pig heart study  

Microsoft Academic Search

To investigate the independent effect of myocardial wall thickness and myocardial perfusion pressure on integrated backscatter, experiments were designed in which integrated backscatter of normally perfused myocardial tissue was measured while changes in wall thickness during the cardiac cycle were reduced to a minimum. In nine blood-perfused isolated pig hearts, perfusion pressure was uncoupled from left ventricular pressure generation (Langendorff

H. Rijsterborgh; R. Krams; F. Mastik; C. T. Lancee; P. D. Verdouw; J. R. T. C. Roelandt; N. Bom

1996-01-01

222

Free-wave propagation in fluid-loaded thick-walled circular pipes  

NASA Astrophysics Data System (ADS)

Wave propagation and sound radiation by layered pipes is treated by analyzing the dispersion relation of an infinite thick-walled pipe which contains, and is surrounded by, and inviscid fluid. Pipe wall displacements satisfy the exact linear equations of elasticity. The interior and exterior fluids satisfy the scalar Helmholtz wave equation. The differential equations are solved by Fourier transforms, giving the dispersion relation which connects frequency with axial and circumferential wavenumbers. The dispersion relation is solved numerically, producing examples of axial wavenumber versus frequency plots for selected circumferential harmonics.

Lester, S. A.

1981-11-01

223

Elastic analysis of heterogeneous thick-walled spherical pressure vessels with parabolic varying properties  

NASA Astrophysics Data System (ADS)

On the basis of plane elasticity theory (PET), the displacement and stress components in a thick-walled spherical pressure vessels made of heterogeneous materials subjected to internal and external pressure is developed. The mechanical properties except the Poisson's ratio are assumed to obey the parabolic variations throughout the thickness. Effect of material inhomogeneity on the elastic deformations and stresses is investigated. The analytical solutions and the solutions carried out through the FEM have a good agreement. The values used in this study are arbitrary chosen to demonstrate the effect of inhomogeneity on displacements, and stresses distributions.

Karami, Keyhan; Abedi, Majid; Zamani Nejad, Mohammad; Lotfian, Mohammad Hassan

2012-12-01

224

Histological response to and immunogenicity of different material patches implanted in rabbit abdominal walls.  

PubMed

The high failure rate of traditional procedures of repairing pelvic organ prolapse by using sutures pushes multiple transvaginal mesh delivery systems into the marketplace; however, these are currently without optimal clinical results. We observed the short-term histological changes and the effects of Th1/Th2 cytokines after the implantation in rabbit abdominal walls of five materials, i.e., porcine urinary bladder matrix (UBM), cross-linked UBM, polypropylene mesh, composite cross-linked UBM, and composite UBM, and explored the feasibility of their application to pelvic reconstructive surgery. Grafts were harvested at 1, 2, 4, 8, and 12 weeks after surgery and were processed for histology in order to evaluate the host inflammatory response and the degree of tissue incorporation. Additionally, graft site cytokine levels were determined by reverse transcriptase polymerase chain reaction. The results demonstrate that the two composite groups were associated with an erosion response, whereas the other groups induced a milder response than the composite groups. The Th1/Th2 cytokine mRNA expression levels of the cross-linked UBM group at each time point were similar to that of the sham group, whereas the other groups elicited a more variable expression. The cross-linked UBM showed slow degradation, mild inflammatory response, and low immunogenicity. This suggests that cross-linked UBM is a better material of choice for pelvic reconstructive surgery. PMID:23633460

Fan, Xuemei; Xu, Senlin; Wang, Yanzhou; Li, Shengping; Wang, Yu; Xu, Huicheng

2013-08-01

225

Reaction of thick-walled cylindrical shell to a suddenly applied internal load  

Microsoft Academic Search

UDC 539.3 Thick-walled cylindrical sections are required structural elements for various machines and mechanisms. Irl the course of their operation, such sections are subjected to the action of pulsed loads. Examples of such processes include: the ignition of the working mixture in an internal-combustion engine, the detonation of an explosive gas mixture in a thermal detonation device, and the operation

A. I. Bezverkhii; V. P. Mukoid

1994-01-01

226

A simplified solution for stresses in thick-wall cylinders for various loading conditions  

Microsoft Academic Search

The determination of stresses in thick-wall cylinders, under non-uniform external pressure, may be performed by means of Airy's stress function approach. In this work a simplified closed-form solution has been obtained for hollow cylinders subjected to loads symmetrically distributed about an axis of the cross-section, acting in the radial direction over part of the circumference. The cylinder is considered to

A. Ch. Yiannopoulos

1996-01-01

227

Monte Carlo simulation of a charged fluid separated by a charged wall of finite thickness  

NASA Astrophysics Data System (ADS)

A charged fluid separated by a charged flat wall of finite thickness is studied by means of Monte Carlo computer simulations. Three different approaches of computer simulations are used. It is shown that in simulations of inhomogeneous charged fluids no local electroneutrality condition should be imposed. In agreement with previous studies [M. Lozada-Cassou and J. Yu, Phys. Rev. Lett. 77, 4019 (1996)] a correlation between the fluids at both sides of the plate is found. Good agreement with theory is obtained.

Degrève, Léo; Lozada-Cassou, Marcelo

1998-03-01

228

Water hammer with fluid–structure interaction in thick-walled pipes  

Microsoft Academic Search

A one-dimensional mathematical model is presented which describes the acoustic behaviour of thick-walled liquid-filled pipes. The model is based on conventional water-hammer and beam theories. Fluid–structure interaction (FSI) is taken into account. The equations governing straight pipes are derived by the cross-sectional integration of axisymmetric two-dimensional basic equations. The resulting FSI four-equation model has small correction terms and factors accounting

A. S. Tijsseling

2007-01-01

229

Finite-strain pressure-tension loading of thick-walled cylinders including temperature effects  

Microsoft Academic Search

Experimental data were obtained from thick-walled cylinders made of hot-rolled SAE 1045 steel at room temperature, annealed\\u000a OFHC copper at room temperature and at 500F (260C), and annealed aluminum alloy 1100 at room temperature and at 305 F (152\\u000a C). Experimental pressure-strain curves were compared with curves predicted by two different analytical solutions. One solution\\u000a is a finite-strain, incremental, compressible

S. C. Chu; O. M. Sidebottom

1976-01-01

230

Increased wall thickness using ultrasonography is associated with inflammation in an animal model of experimental colitis  

PubMed Central

Experimentally induced colitis is used in animals to investigate pathophysiological mechanisms in inflammatory bowel disease. When following disease course and treatment effects, it should be possible to perform repeated measurements without harming the animals. This pilot study was performed to investigate whether transabdominal ultrasound using a clinical scanner could be used on rats to demonstrate bowel inflammation in an experimental colitis model. Colitis was induced by either 5% dextran sodium sulfate (DSS) in drinking water for 7 days or a single dose of intracolonic trinitrobenzene sulfonic acid (TNBS). Using ultrasonography, wall thickness of distal colon, cecum, and small bowel was recorded prior to and after DSS, and prior to, 2, and 7 days after TNBS. Blood (tumor necrosis factor [TNF]-alpha) and fecal samples (HemoFEC occult blood) were taken from each group on the same days as sonography. Thereafter, rats were killed and specimens for histology were taken. Wall thickness of distal colon, not of cecum or small bowel, increased significantly after 7 days of DSS, and wall thickness of both distal colon and small bowel increased on day 2 and 7 after TNBS. TNF-alpha increased after 7 days in the latter group only. There was a significant correlation between ultrasonographic measurements and combined histology score of distal colon in the DSS group. HemoFEC was also positive in accordance with sonographic and histological features. Increased intestinal wall thickness in response to both DSS- and TNBS-induced colitis was able to be visualized by transabdominal sonography. Moreover, ultrasound findings, occult blood sampling, and histological findings supported each other, indicating that ultrasonography can be used to assess inflammation in a rat experimental model.

Lied, Gulen Arslan; Milde, Anne Marita; Nylund, Kim; Mujic, Maja; Grimstad, Tore; Hausken, Trygve; Gilja, Odd Helge

2012-01-01

231

Calculation of the pipeline wall thickness under internal pressure at an arbitrary law of hardening  

NASA Astrophysics Data System (ADS)

A semianalytical solution is obtained for the problem of the deformation of a hollow cylinder (tube) subjected to internal pressure for the material that meets the Tresca plasticity condition and obeys an arbitrary law of hardening. The solution is analytical for linear hardening. This solution can be used to take into account the bearing capacity of a material in strength calculations more completely and reliably as compared to the existing techniques by choosing the cylinder wall thickness.

Alexandrov, S. E.; Goldstein, R. V.

2012-10-01

232

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

PubMed

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

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

2011-11-10

233

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

PubMed Central

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

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

2012-01-01

234

Collapsing of Thick-Walled Cylinders Using Electro-Magnetic Driving Forces  

NASA Astrophysics Data System (ADS)

The Thick-Walled Cylinder technique, reported in the literature, uses explosive loading to enforce collapsing of the cylindrical sample. This experimental set-up has been established as a controlled and repeatable technique to create and study multiple adiabatic shear bands. Searching to establish a simpler experimental platform to perform large sets of experiments, we have designed an Electro-Magnetic (EM) set-up for the collapsing of thick walled cylinders. The EM set-up is based on a pulsed current generator using a capacitor bank system. The specimen is an assembly of coaxial cylinders, where the inner and outer cylinders, each attached to an opposite pole, are short-circuited. Upon discharge, a high current flows through the cylinders, in opposite directions, creating repulsive magnetic forces between them. This work presents the design procedure of the specimens using numerical simulations and some experimental results for SS304L thick-walled samples, using this set-up. The spatial distribution of the multiple adiabatic shear bands in these experiments is in good agreement with that reported in the literature for the explosive driven experiments with a similar material.

Lovinger, Zev; Rikanati, Avi; Rittel, Daniel; Rosenberg, Zvi

2009-06-01

235

Use of a pre-expanded "propeller" deep inferior epigastric perforator (DIEP) flap for a large abdominal wall defect.  

PubMed

Large abdominal wall soft tissue defects are traditionally reconstructed using loco-regional flaps and/or tissue expanders. Pedicled perforator flaps offer similar tissue coverage with minimal donor site morbidity and do not require microsurgical skills. The deep inferior epigastric perforator (DIEP) flap has become increasingly popular for breast reconstruction and offers abundant soft tissue while permitting primary donor site closure. To minimize operative sessions, recovery time, donor site morbidity, and avoid microsurgery, we combined tissue expansion with a "propeller" flap design and report this first case of a pre-expanded pedicled perforator flap based on the DIEP to address a large abdominal wall defect due to a burn injury. PMID:23031631

Cheng, Angela; Saint-Cyr, Michel

2012-09-30

236

The development of the anterior abdominal wall in the rat in the light of a new anatomical description.  

PubMed Central

The development of the ventral abdominal muscles of the albino rat was studied histologically in 60 embryos and 10 postnatal specimens. The lower thoracic myotomes were seen to migrate ventrally in the lateral body wall, cross the middle line and continue with their contralateral fellows of the opposite side, thus forming a digastric mesodermal primordium. Differentiation of this primordium into fleshy bellies and intermediate aponeuroses occurred later in the prenatal period. Similar to the bilaminar arrangement of each of the human abdominal aponeuroses, recently described, each of the ventral abdominal muscles of the rat embryo was temporarily bilaminar; and similar to the trilaminar (plywood) arrangement of each wall of the human rectus sheath, the three lateral abdominal muscles of the rat embryo were so arranged. The tendinous intersections of the rectus muscle were seen only postnatally. They might be considered less as the remnants of a segmental origin, but rather as the intermediate tendons of a multigastric longitudinal muscle column. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8

Rizk, N N; Adieb, N

1982-01-01

237

The use of composite meshes in laparoscopic repair of abdominal wall hernias: are there differences in biocompatibily?  

Microsoft Academic Search

Introduction  In recent years, laparoscopic repair of abdominal wall hernias has become increasingly established in routine clinical practice\\u000a thanks to the myriad advantages it confers. Apart from the risk of intestinal damage following adhesiolysis, to date no information\\u000a is available on the best way of preventing the formation of new adhesions in the vicinity of the implanted meshes. Numerous\\u000a experimental investigations,

Christine Schug-Pass; Florian Sommerer; Andrea Tannapfel; Hans Lippert; Ferdinand Köckerling

2009-01-01

238

Determination of abdominal fat thickness using dual electrode separation in the focused impedance method (FIM)  

Microsoft Academic Search

Subcutaneous fat layer thickness in the abdomen is a risk indicator of several diseases and disorders like diabetes and heart problems and could be used as a measure of fitness. Skinfold measurement using mechanical calipers is simple but prone to error. Ultrasound scanning techniques are yet to be established as accurate methods for this purpose. magnetic resonance imaging (MRI) and

Nusrat Jahan Surovy; Salahuddin Haowlader; Golam Dastegir Al-Quaderi; K Siddique-e Rabbani

2012-01-01

239

Abdominal muscle contraction thickness and function after specific and general exercises: A randomized controlled trial in chronic low back pain patients  

Microsoft Academic Search

The aim of this study was to assess changes in deep abdominal muscle function after 8 weeks of exercise in chronic low back pain patients. Patients (n = 109) were randomized to specific ultrasound guided, sling or general exercises. Contraction thickness ratio in transversus abdominis (TrA), obliquus internus (OI) and externus (OE), and TrA lateral slide were assessed during the abdominal drawing-in

Ottar Vasseljen; Anne Margrethe Fladmark

2010-01-01

240

Determination of right ventricular wall thickness in systole and diastole. Echocardiographic and necropsy correlation in 32 patients.  

PubMed Central

To show that right ventricular wall thickness (RVWT) measurements can be made with precision by echocardiography, we correlated these measurements with those obtained at necropsy in 32 terminal patients. The correlation between the echocardiographic diastolic right ventricular wall thickness (mean 4.0 +/- 1.62 mm) and the necropsy measurement (mean 4.3 +/- 1.52 mm) was good (r = 0.83) in all 32 patients with normal or increased right ventricular wall thickness at necropsy. In 19 patients without necropsy evidence of right ventricular hypertrophy (RVWT less than or equal to 4 mm), the mean diastole and systolic right ventricular wall thickness were 3.0 +/- 0.92 mm and 5.1 +/- 1.64 mm, respectively. In 13 patients with necropsy evidence of right ventricular hypertrophy (RVWT greater than or equal to 5 mm), the mean diastolic and systolic right ventricular wall thicknesses were 5.3 +/- 1.56mm and 8.2 +/- 1.88 mm, respectively. We conclude that technically satisfactory echocardiograms of the right ventricular wall thicknesses. Echocardiography can reliably estimate the diastolic wall thickness and may be helpful in the evaluation of right ventricular hypertrophy. Images

Prakash, R

1978-01-01

241

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

NASA Astrophysics Data System (ADS)

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.

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

2008-04-01

242

Abdominal Wall Lift Versus Positive-Pressure Capnoperitoneum for Laparoscopic Cholecystectomy  

PubMed Central

Objective: To compare intraoperative cardiac function, postoperative cognitive recovery, and surgical performance of laparoscopic cholecystectomy with abdominal wall lift (AWL) versus positive-pressure capnoperitoneum (PPCpn). Summary Background Data: AWL has been proposed as an alternative approach to PPCpn to avoid adverse cardio-respiratory changes. However, the workspace obtained with the AWL is less optimal than PPCpn and previous studies documenting delayed postoperative recovery of consciousness following PPCpn have not assessed mental alertness despite its importance. Methods: Forty operations were randomized into AWL and PPCpn. A standard anesthetic protocol was followed. Cardiac indices were measured with an esophageal Doppler machine. An auditory vigilance test was used to measure alertness level following extubation. All operations were videotaped and human reliability assessment techniques were used to identify surgical errors. Results: There was a significant reduction in cardiac output during the first 20 minutes following CO2 insufflation in the PPCpn group, whereas in the AWL group it did not exhibit any significant change. Patients in AWL arm had better vigilance scores at 90 and 180 minutes following extubation compared with the PPn group (P < 0.05). Significantly more surgical errors were observed during surgery with AWL than with PPCpn (7.1 ± 1.1; versus 2.9 ± 0.4; P = 0.001). Conclusions: The AWL approach avoids fall in cardiac output associated with PPCpn during laparoscopic surgery and is associated with a more rapid recovery of postoperative cognitive function compared with PPCpn. However, AWL increases the level of difficulty in the execution of the operation.

Alijani, Afshin; Hanna, George B.; Cuschieri, Alfred

2004-01-01

243

Measurement of Change in Wall Thickness of Cylindrical Shell at Multiple Frequencies Caused by Remote Actuation for Assessment of Regional Viscoelasticity of Arterial Wall  

Microsoft Academic Search

To characterize tissues in atherosclerotic plaque, we have developed a method, namely, the phased tracking method, for measuring the strain (change in wall thick- ness) and elasticity of the arterial wall. However, some types of tissue, such as lipids and blood clots, cannot be discriminatedfrom each otherbased onlyon elasticitybe- cause of the small difference in their elasticity. For more precise

Hideyuki Hasegawa; Hiroshi Kanai

244

Measurement of Change in Wall Thickness of Cylindrical Shell Due to Cyclic Remote Actuation for Assessment of Viscoelasticity of Arterial Wall  

Microsoft Academic Search

To characterize tissues in atherosclerotic plaques, we have developed a method, the phased tracking method, for measuring the strain (change in wall thickness) and elasticity of the arterial wall. However, some types of tissue, such as lipids and blood clots, cannot be discriminated from each other based only on elasticity because of the small difference in their elasticity. For more

Hideyuki Hasegawa; Hiroshi Kanai; Yoshiro Koiwa; James P. Butler

2003-01-01

245

Repair of Abdominal Wall Defects In Vitro and In Vivo Using VEGF Sustained-Release Multi-Walled Carbon Nanotubes (MWNT) Composite Scaffolds  

PubMed Central

Objective Porcine acellular dermal matrices (ADM) have been widely used in experimental and clinical research for abdominal wall repair. Compared to porcine small intestinal submucosa (SIS), the effect of these matrices on the regenerative capacity of blood vessels is still not ideal. Multi-walled carbon nanotubes (MWNTs) can more effectively transport VEGF to cells or tissues because of their large specific surface area and interior cavity. In this study, we explored the safety and efficacy of implanted VEGF-loaded MWNT composite scaffolds in vitro and vivo to repair abdominal wall defects. Materials and Methods VEGF-loaded MWNTs were prepared by a modified plasma polymerization treatment. Four composite scaffolds were evaluated for cytotoxicity, proliferation, and release dynamics. We created 3 cm×4 cm abdominal wall defects in 43 Sprague-Dawley rats. After implantation times of 2, 4, 8, and 12 weeks, the scaffolds and the surrounding tissues were collected and examined by gross inspection, biomechanical testing, and histological examination. Results A 5–10 nm poly(lactic-co-glycolic acid) (PLGA) film was evenly distributed on MWNTs. The 3% MWNT composite group showed lower cytotoxicity and appropriate release performance, and it was thus tested in vivo. In rats with the 3% composite implanted, host cells were prevented from migrating to the ADM at 2 weeks, vascularization was established more rapidly at 12 weeks, and the values for both the maximum load and the elastic modulus were significantly lower than in the ADM-alone group (p<0.01). Histological staining revealed that the MWNT was still not completely eliminated 12 weeks after implantation. Conclusion MWNTs were able to carry VEGF to cells or tissues, and the 3% MWNT composite material showed lower cytotoxicity and had an appropriate release performance, which prompted faster vascularization of the ADM than other scaffolds. Nevertheless, the MWNTs induced harmful effects that should be carefully considered in biomedical studies.

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

2013-01-01

246

The omentum–polypropylene sandwich technique: an attractive method to repair large abdominal-wall defects in the presence of contamination or infection  

Microsoft Academic Search

Background  Repair of abdominal wall defects in the presence of contamination or infection continues to be a significant problem for surgeons.\\u000a The loss of tissue warrants reinforcement of the abdominal wall, preferably by autologous material. However, autologous repair\\u000a often requires extensive operations that carry a high morbidity. Moreover, the lack of sufficient fascia may be so extensive\\u000a that insertion of a

R. P. Bleichrodt; A. W. Malyar; T. S. de Vries Reilingh; O. R. Buyne; J. J. Bonenkamp; H. van Goor

2007-01-01

247

Failure prediction method for hydro forming simulation of thick walled tubes  

NASA Astrophysics Data System (ADS)

The industrial production of thick walled hydro formed steel parts is a process difficult to control. In particular the prevention of cracks in the production of these parts is very important. It is of utmost importance to have a virtual tool to predict forming results. Standard methods for the simulation of hydro formed parts base upon processes using a shell element formulation and implement a forming limit curve (FLC) for crack prediction. But the forming limit curve is limited to the case of linear strain paths. The initial FLC is no longer valid in the case of nonlinear strain paths. Because of the geometric specifications of the investigated parts--thick walls, compact dimensions, high strains--and the known limitations of the forming limit curve--which don't accord to the hydro forming process-- these standard simulation methods are not applicable for the present investigations. A new approach to simulate thick walled hydro formed parts is the use of a volume element formulation in combination with a more complex failure criterion, which gives information about the risk of ductile normal fracture and ductile shear fractures with nonlinear strain paths. The onset of necking must be predicted directly by the volume elements. The aim of this work is to implement the failure criteria in a hydroforming simulation and to compare the results of the simulation with real cracked test parts. The commercial FEM code PamStamp 2G is used as a solver and a comprehensive fracture model is applied. This fracture model distinguishes between two mechanisms responsible for ductile fracture. One is the void growth and coalescence (ductile normal fracture) and the other one is the shear failure model (ductile shear fracture).

Kolleck, Ralf; Auer, Peter; Auer, Gerfried

2011-05-01

248

Bladder-wall-thickness ultrasound scan in the investigation of LUTS in women: challenges and limitations.  

PubMed

Bladder-wall-thickness (BWT) ultrasound assessment in lower urinary tract conditions has been studied extensively for the last 30 years. There is some evidence that it may have diagnostic utility in detrusor overactivity (DO). The cutoff value for BWT for diagnosing DO is still a matter of debate, with different studies using different values. Transvaginal scanning is the most accurate route of measuring BWT, with excellent interobserver variation and reproducibility. There is still ongoing evaluation of bladder ultrasound and its place in the investigation of overactive bladder symptoms. PMID:23376906

Rachaneni, S; Balogun, M; Latthe, P

2013-02-02

249

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

SciTech Connect

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.

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

250

Imaging of abdominal abscesses.  

PubMed

The aim of the study is presenting own experiences in using different diagnostic modalities in evaluating abdominal abscesses. Material comprises a group of nine patients with diagnosed abdominal abscess aged between 22 and 78 years. The plain abdominal radiograms, ultrasound examinations and computed tomography were performed in those patients. The CT examination was performed in 10-mm thick axial sections, before and after administering contrast agent. The perirenal abscesses were found in two patients. In US have showed various, inhomogeneous echogenicity, depending on the stage of the abscess. The contrast CT reveals enhancing septa, thick walls and oval, central area of lower density. The plane radiograms revealed abscesses in three cases. In two of them abscesses were complications of previouscholecystectomy. The large abscesses dislocated intestinal loops. CT was necessary to assess the extent, depth and shape of retroperitoneal fluid collections. Abdominal abscess is life threatening condition requiring quick diagnosis and proper management. The imaging methods are especially important in diagnosis of abscesses. Abscesses may by recognized on plain abdominal radiograms, but US and especially CT are much more sensitive and accurate. CT is imaging modality of choice in revealing abdominal abscess. CT and US are very useful in nonoperative therapies, including US and CT guided drainage. PMID:16146093

Pas?awski, Marek; Szafranek-Pyzel, Joanna; Z?omaniec, Janusz

2004-01-01

251

Thick-walled centrifugally cast 08X18H10T steel blank for seamless-pipe production  

Microsoft Academic Search

Thick-walled pipe blanks made by centrifugal casting of corrosion-resistant 08X18H10T steel are investigated. These blanks\\u000a are intended for subsequent hot pressing of pipe (diameter 89 mm, wall thickness 12 mm). The macrostructure of the castings\\u000a is studied, as well as the mechanical properties of cast and heat-treated tangential, transverse, and longitudinal samples.\\u000a The defects observed in the centrifugally cast pipe

V. N. Zaika; A. P. Shlyamnev; G. A. Filippov; K. V. Zakharchenko; A. F. Shevakin

2011-01-01

252

Abdominal muscle contraction thickness and function after specific and general exercises: a randomized controlled trial in chronic low back pain patients.  

PubMed

The aim of this study was to assess changes in deep abdominal muscle function after 8 weeks of exercise in chronic low back pain patients. Patients (n = 109) were randomized to specific ultrasound guided, sling or general exercises. Contraction thickness ratio in transversus abdominis (TrA), obliquus internus (OI) and externus (OE), and TrA lateral slide were assessed during the abdominal drawing-in maneuver by b-mode ultrasound. Changes in abdominal muscle function were also regressed on changes in pain. Only modest effects in deep abdominal muscle function were observed, mainly due to reduced activation of OI (contraction thickness ratio: 1.42-1.22, p = 0.01) and reduced TrA lateral slide (1.26-1.01 cm, p = 0.02) in the ultrasound group on the left side. Reduced pain was associated with increased TrA and reduced OI contraction ratio (R(2) = 0.18). It is concluded that 6-8 treatments with specific or general exercises for chronic low back patients attained only marginal changes in contraction thickness and slide in deep abdominal muscles, and could only to a limited extent account for reductions in pain. PMID:20621545

Vasseljen, Ottar; Fladmark, Anne Margrethe

2010-10-01

253

Coronary artery wall thickness of the left anterior descending artery using high resolution transthoracic echocardiography--normal range of values.  

PubMed

Recently it has been demonstrated that high resolution transthoracic echocardiography (HRTTE) is able to detect differences in the wall thickness of the left anterior descending coronary artery (LAD) between patients with coronary artery disease (CAD) and normal volunteers. We sought to validate this technique, develop a normal range of values and demonstrate the test-retest variability of each measurement. Two hundred forty-two volunteer participants had a HRTTE study to measure their LAD wall thickness, luminal, and external diameters. Thirty of these subjects had these measurements taken on 3 separate occasions by 2 different echosonographers. All subjects were free of clinical CAD, hypertension, hyperlipidemia, and diabetes mellitus. The average anterior wall thickness was 1.1 ± 0.2 mm; posterior wall thickness was 1.1 ± 0.2 mm, luminal diameter 2.2 ± 0.6 mm, and external elastic membrane (EEM) diameter 4.5 ± 0.9 mm. The bias of the measurements within the same operator for LAD wall thickness, luminal diameter, and EEM was 0.042, -0.06, and -0.077 mm, respectively. The bias of the measurements between 2 different operators for LAD wall thickness, luminal diameter, and EEM was 0.082, -0.077, and -0.027 mm, respectively. In conclusion, HRTTE measurement of the LAD vessel is reproducible within and between operators in normal volunteers. This technique therefore warrants further study as a potential screening modality for subclinical coronary atherosclerosis. PMID:23346915

Perry, Rebecca; Joseph, Majo X; Chew, Derek P; Aylward, Philip E; De Pasquale, Carmine G

2013-01-25

254

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress  

Microsoft Academic Search

BACKGROUND: To determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis. RESULTS: Between 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during

Thomas F Walsh; Erica Dall'Armellina; Haroon Chughtai; Timothy M Morgan; William Ntim; Kerry M Link; Craig A Hamilton; Dalane W Kitzman; W Gregory Hundley

2009-01-01

255

A single-institutional, multidisciplinary approach to primary sarcomas involving the chest wall requiring full-thickness resections  

Microsoft Academic Search

Objective: Primary sarcomas involving the chest wall requiring full-thickness excision are rare. We reviewed our experience with these lesions in a tertiary referral cancer center by using multidisciplinary approaches. Methods: A 10-year retrospective study identified 51 patients referred with primary sarcomas of the chest wall: 40 for initial treatment and 11 after previous unsuccessful surgical excisions elsewhere (secondary referral). Presenting

Garrett L. Walsh; Bryan M. Davis; Stephen G. Swisher; Ara A. Vaporciyan; W. Roy Smythe; Kelly Willis-Merriman; Jack A. Roth; Joe B. Putnam

2001-01-01

256

An examination of the effect of boundary layer thickness on vortex shedding from a square cylinder near a wall  

Microsoft Academic Search

A computational study has been undertaken to examine the effect of boundary layer thickness ?\\/D on vortex shedding from a square cylinder in proximity to a solid wall. The computations were carried out in a second-moment turbulence modeling framework using a finite-volume technique. The computed results show that, in general, thickening of the wall boundary layer causes wake periodicity to

Anthony G. Straatman; Robert J. Martinuzzi

2003-01-01

257

Cross-Sectional Elasticity Imaging of Arterial Wall by Comparing Measured Change in Thickness with Model Waveform  

Microsoft Academic Search

For the assessment of the elasticity of the arterial wall, we have developed the phased tracking method [H. Kanai et al.: IEEE Trans. Ultrason. Ferroelectr. Freq. Control 43 (1996) 791] for measuring the minute change in thickness due to heartbeats and the elasticity of the arterial wall with transcutaneous ultrasound. For various reasons, for example, an extremely small deformation of

Jiang Tang; Hideyuki Hasegawa; Hiroshi Kanai

2005-01-01

258

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

PubMed

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

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

2010-06-22

259

Reduction of residual stresses in thick-walled composite cylinders by smart cure cycle with cooling and reheating  

Microsoft Academic Search

The nozzle parts of solid rocket motors must endure both the internal pressure generated by high temperature exhaust gas and the mechanical load generated by steering operation. Therefore, the nozzle parts of solid rocket motors are fabricated with thick carbon fiber phenolic resin composites. When the thick-walled phenolic composite cylinder is cooled down from the curing temperature of about 155°C

Jong Woon Kim; Ji Hyung Lee; Hyoung Geun Kim; Hak Sung Kim; Dai Gil Lee

2006-01-01

260

Temperature increment in a current-heated nanowire for current-induced domain wall motion with finite thickness insulator layer  

Microsoft Academic Search

The authors investigate the insulator-layer-thickness-dependent temperature increment in the nanowire for the current-induced domain wall motion. Practically, a finite thickness insulator layer must be placed between the semi-infinite substrate and the metallic nanowire for an electric insulation. Since a good electric insulator is also a thermal insulator, the temperature increment of the nanowire depends on the insulator layer's thickness. An

Chun-Yeol You; Seung-Seok Ha

2007-01-01

261

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

NASA Astrophysics Data System (ADS)

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

Ghosh, Sudip; Kahrilas, Peter

2005-11-01

262

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

PubMed

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. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013. PMID:23661568

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

2013-05-10

263

Crack growth in the through-thickness direction of hydrided thin-wall Zircaloy sheet  

NASA Astrophysics Data System (ADS)

In a reactivity-initiated accident, cladding failure may occur by crack initiation within a defect such as a hydride rim or blister and subsequent crack propagation through the thickness of the thin-wall cladding. In such a circumstance, determining the cladding resistance to crack propagation in the through-thickness direction is crucial to predicting cladding failure. To address this issue, through-thickness crack propagation in hydrided Zircaloy-4 sheet was analyzed at 25 °C, 300 °C, and 375 °C. At 25 °C, the fracture toughness decreased with increasing hydrogen content and with an increasing fraction of radial hydrides. Hydride particles fractured ahead of the crack tip, creating a path for crack growth. At both 300 °C and 375 °C, the resistance to crack-growth initiation was sufficiently high that crack extension was often caused by crack-tip blunting. There was no evidence of hydride particles fracturing near the crack tip, and no significant effect of hydrogen content on fracture toughness was observed at these elevated temperatures.

Raynaud, Patrick A.; Koss, Donald A.; Motta, Arthur T.

2012-01-01

264

Ultrasound measurement of wall thickness in the carotid artery: fundamental principles and description of a computerized analysing system.  

PubMed

A B-mode [two-dimensional (2D)] image from the carotid artery may be described as containing seven echo zones. The aim of the present work is to discuss how lumen diameter and wall thickness can be measured from these zones, and to review some of the basic principles of ultrasound physics and imaging. Simple experiments were performed to identify the echoes defining intima-lumen interfaces. The results showed that: (1) The intima-media thickness of the near wall cannot be measured in a valid way. (2) The lumen diameter of a blood vessel is defined by the distance from the leading edge of the intima-lumen interface of the near wall (echo zone 3) to the leading edge of the lumen-intima interface of the fall wall (echo zone 5). (3) Previously published studies have validated the intima-media complex of the far wall as the distance from the leading edge of the lumen-intima interface of the far wall to the leading edge of the media-adventitia interface of the far wall (echo zone 7). We suggest that if measurements on the near wall are performed, measurements from the far wall should also be presented separately, and if lumen diameter is measured, that this measurement is carried out according to the leading edge principle. We describe a computerized analysing system for the measurement of wall thickness and plaque area on the carotid and femoral arteries. The system is based on a low-cost PC and a frame grabber board and calculates minimum, maximum and mean values of lumen diameter and wall thickness from a section of the artery. PMID:1769190

Wendelhag, I; Gustavsson, T; Suurküla, M; Berglund, G; Wikstrand, J

1991-11-01

265

Effect of multi-layer thermal insulation thickness and location on the hypervelocity impact response of dual-wall structures  

NASA Astrophysics Data System (ADS)

Traditional perforation-resistant wall design for long-duration spacecraft consists of a "bumper" that is placed a small distance away from the main "pressure wall" of a spacecraft compartment or module. This concept has been studied extensively as a means of reducing the perforation threat of hypervelocity projectiles such as meteoroids and orbital debris. If a dual-wall system is employed on an earth-orbiting spacecraft, then a blanket of multi-layer insulation (MLI) will typically be included within the dual-wall system for thermal protection purposes. This paper presents the results of an experimental study in which aluminum dual-wall structures were tested under a variety of high-speed impact conditions to study the effect of MLI thickness and location on perforation resistance. The results presented consist of test-by-test comparisons of the damage sustained by similar dual-wall systems with blanket MLI of various thicknesses and at various locations within the dual-wall systems under similar impact loading conditions. The analyses performed revealed that the placement of the MLI had a significant effect on the ballistic limit of the dual-wall structures considered while reducing the thickness of the MLI by as much as 1/3 did not.

Schonberg, William P.

266

A role of 18F-fluorodeoxyglucose positron emission/computed tomography in a strategy for abdominal wall metastasis of colorectal mucinous adenocarcinoma developed after laparoscopic surgery  

PubMed Central

Metastasis to the abdominal wall including port sites after laparoscopic surgery for colorectal cancer is rare. Resection of metastatic lesions may lead to greater survival benefit if the abdominal wall metastasis is the only manifestation of recurrent disease. A 57-year-old man, who underwent laparoscopic surgery for advanced mucinous adenocarcinoma of the cecum 6 years prior, developed a nodule in the surgical wound at the lower right abdomen. Although tumor markers were within normal limits, the metastasis to the abdominal wall and abdominal cavity from the previous cecal cancer was suspected. An abdominal computed tomography scan did not provide detective evidence of metastasis. 18F-fluorodeoxyglucose positron emission/computed tomography (18F-FDG PET/CT) was therefore performed, which demonstrated increased 18F-fluorodeoxyglucose uptake (maximum standardized uptake value: 3.1) in the small abdominal wall nodule alone. Histopathological examination of the resected nodule confirmed the diagnosis of metastatic mucinous adenocarcinoma. Prognosis of intestinal mucinous adenocarcinoma is reported to be poorer than that of non-mucinous adenocarcinoma. In conclusion, this case suggests an important role of 18F-FDG PET/CT in early diagnosis and decision-making regarding therapy for recurrent disease in cases where a firm diagnosis of recurrent colorectal cancer is difficult to make.

2011-01-01

267

The relationship between myocardial integrated backscatter, perfusion pressure and wall thickness during isovolumic contraction: an isolated pig heart study.  

PubMed

To investigate the independent effect of myocardial wall thickness and myocardial perfusion pressure on integrated backscatter, experiments were designed in which integrated backscatter of normally perfused myocardial tissue was measured while changes in wall thickness during the cardiac cycle were reduced to a minimum. In nine blood-perfused isolated pig hearts, perfusion pressure was uncoupled from left ventricular pressure generation (Langendorff method) and isovolumic contraction and relaxation were realized by inserting a noncompressible water-filled balloon into the left ventricle. In a first experiment, at constant perfusion pressure (85 mmHg), the integrated backscatter (3-7 MHz), the myocardial wall thickness and the left ventricular pressure were determined simultaneously at various balloon volumes (5-25 mL). A quasistatic increase of balloon volume by 50% resulted in an average decrease of wall thickness of 6.5% (p < 0.01) and a mean increase in the integrated backscatter level of 1.1 dB (p < 0.01). Integrated backscatter levels increased statistically significant by 0.14 +/- 0.014 dB per percent decrease of wall thickness. Measurements of percentage end-systolic myocardial wall thickening ranged from -10% to +10%, mean 0.15 +/- 4.5% (NS from zero); whereas cyclic variation of integrated backscatter ranged from -3.9 to +3.9 dB, mean 0.19 +/- 1.5 dB (NS from zero). In a second experiment, at a constant midrange balloon volume, the same parameters were determined simultaneously at various perfusion pressures (20-120 mmHg). An increase in perfusion pressure by 50% resulted in a small but statistically significant increase of 1.5% in myocardial wall thickness, which could be explained by an increase of intravascular volume. The integrated backscatter levels did not change statistically significantly. Measurements of percentage end-systolic myocardial wall thickening ranged from -8.9 to +7.8%, mean 0.13 +/- 4.0% (NS from zero); whereas cyclic variation of integrated backscatter ranged from -1.8 to +4.2 dB, mean 0.37 +/- 1.3 dB (NS from zero). The magnitude of cyclic variation of integrated backscatter of myocardial tissue in a contractile state is reduced if myocardial muscle is prevented from normal thickening. In addition, changes in intravascular volume during the cardiac cycle have a negligible influence on the absolute backscatter level or its cyclic variation. We conclude, if only wall thickness and perfusion pressure are involved, that integrated backscatter is mainly determined by myocardial wall thickness. PMID:8928316

Rijsterborgh, H; van der Steen, A F; Krams, R; Mastik, F; Lancée, C T; Verdouw, P D; Roelandt, J R; Bom, N

1996-01-01

268

Pressure induced radial diffusion of a fluid through a thick walled highly elastic cylinder  

NASA Astrophysics Data System (ADS)

Radial diffusion of a fluid through a highly elastic thick walled cylinder due to pressure differences at the inner and outer surfaces was considered. The interaction between the fluid diffusion and large solid deformation is accounted for by formulating the problem in the context of the theory of mixtures. The equation for the partial stresses and diffusive body force incorporate an expression for the specific internal energy function is suggested by the kinetic theory of rubber elasticity. Specification of the boundary condition for such a problem is resolved by a relation between surface traction and deformation when the mixture is in a saturated state. A radial mass flux pressure difference relation and the influence of axial stretch on this relation are presented.

Wineman, A. S.; Gandhi, M.; Rajagopal, D. R.

269

A defect of the abdominal wall with intestinal fistulas after the repair of incisional hernia using Composix Kugel Patch  

PubMed Central

INTRODUCTION In the present paper, we show a rare case of the large abdominal wall defect and enterocutaneous fistulas after the tension free repair using prostheses for incisional hernia. PRESENTATION OF CASE The patient, a 70-year-old man, had a history of a hemicolectomy for a perforating colon cancer, complicated by a large incisional hernia that was closed primarily but recurred. Three years later, the hernia was repaired at the time of a second colectomy using a Composix Kugel Patch. His course was complicated by a chronic postoperative wound infection with eventual development of enterocutaneous fistulas. The patient was successfully treated with extirpation of the prosthesis, resection of the fistulized bowel, and placement of a tensor fasciae latae myocutaneous flap. DISCUSSION Enterocutaneous fistulas are a known complication of incisional hernia repairs using prostheses. Additional clinical data are required to confirm the safety and efficacy of this procedure as it becomes more widely adopted. CONCLUSION Extirpation of the prosthesis should be performed without delay to prevent serious complications. Reconstruction with a tensor fasciae latae myocutaneous flap was useful for the large abdominal wall defect.

Kunishige, Tomohiro; Takayama, Tomoyoshi; Matumoto, Sohei; Wakatsuki, Kohei; Enomoto, Koji; Tanaka, Tetsuya; Migita, Kazuhiro; Kuwahara, Masamitsu; Iioka, Hiroshi; Nakajima, Yoshiyuki

2013-01-01

270

Tacrolimus Does Not Affect Early Wound Healing in a Rodent Model of Bowel Anastomoses and Abdominal Wall Closure  

PubMed Central

Background Use of immunosuppressant drugs has been associated with complications in wound healing. The calcineurin inhibitor tacrolimus is thought to have a relatively low complication rate, but preclinical research has yielded contradictory data, prompting the current comprehensive study Methods Three groups of 33 male Wistar rats received a daily subcutaneous dose of 0,5, 2 or 5 mg/kg tacrolimus. A control group received saline. On day 0 a resection of 1 cm ileum and 1 cm colon was performed, and end-to-end anastomoses were constructed. Ten rats of each group were killed on day 3 and day 5 and the remaining animals on day 7. Both anastomoses and the wound in the abdominal wall were analyzed. Wound strength was the primary outcome parameter. Results Mean strength of the abdominal wall increased significantly over time in all groups (p<0.0001). Both the breaking strength and the bursting pressure of the ileum and colon anastomoses followed the same pattern. No differences were observed between control and experimental groups. In addition, no consistent differences were found between groups regarding wound hydroxyproline content and the activities of matrix metalloproteinase-2 and -9. Conclusion Tacrolimus does not affect early wound healing.

Willems, Martine C. M.; van der Vliet, J. Adam; Lomme, Roger M. L. M.; Hendriks, Thijs

2013-01-01

271

Minilaparotomy with a gasless laparoscopic-assisted procedure by abdominal wall lifting for ileorectal anastomosis in patients with slow transit constipation.  

PubMed

Total colectomy with ileorectal anastomosis (IRA) is the most widely adopted procedure. The aim of this study was to introduce a minimally invasive procedure, i.e., minilaparotomy with laparoscopic-assisted procedure, by abdominal wall lifting for IRA in patients with slow transit constipation (STC). Six STC patients (6 women, aged 40-69 years, mean age 56.3 years) underwent minilaparotomy with gasless laparoscopic-assisted approach by abdominal wall lifting for IRA. The present procedure involved a 7-cm lower abdominal median incision made at the beginning of the operation. 12 mm ports were also placed in the right and left upper abdominal quadrant positions. The upper abdominal wall was lifted by a subcutaneous Kirshner wire. The small wound was pulled upward and/or laterally by retractors (abdominal lifting) and conventional surgical instruments were used through the wound. Occasionally laparoscopic assistance was employed. The terminal ileum with total colon was brought out through the small wound and transected, approximately 5 cm from the ileocecal valve. The colon was also resected at the level of promontrium. Then, IRA was performed in the instruments. The total surgical time was 197.7 +/- 33.9 min and the mean estimated blood loss was 176.8 +/- 42.2 ml. There was no surgical mortality. Post-operative hospitalization was 8.1 +/- 2.1 days. Six months after surgery, they defecated 1.8 +/- 2.1 times daily, have no abdominal distension, pain, and incontinence. The patients also take no laxatives. All subjects were satisfied with this procedure. Minilaparotomy with gasless laparoscopic-assisted IRA by abdominal wall lifting could be a safe and efficient technique in the treatment of STC. PMID:19760933

Tomita, Ryouichi; Fujisak, Shigeru

272

Use of surgisis for abdominal wall reconstruction/closure in battlefield casualties during Operation Iraqi Freedom.  

PubMed

A case series and discussion based on experiences gained during Operation Iraqi Freedom are presented. The Army previously published an article on the use of Gore-Tex mesh in the staged closure of open abdominal wounds. We thought that use of a biomaterial could shorten the overall course of abdominal closure and improve outcomes. This is mainly a "proof of concept" type of study. Although class I data are not presented, a useful concept is discussed. To our knowledge, no other report of the use of biomaterials for battle casualties has been published. Several issues that are faced by the military medical system are presented. The use of Surgisis (lyophilized porcine small intestinal submucosa; Cook Biotech, West Lafayette, Indiana) in the described setting is presented as one possible solution. PMID:17985779

Johnson, Eric K; Paquette, Edmond L

2007-10-01

273

Measurement of Change in Wall Thickness of Cylindrical Shell Due to Cyclic Remote Actuation for Assessment of Viscoelasticity of Arterial Wall  

NASA Astrophysics Data System (ADS)

To characterize tissues in atherosclerotic plaques, we have developed a method, the phased tracking method, for measuring the strain (change in wall thickness) and elasticity of the arterial wall. However, some types of tissue, such as lipids and blood clots, cannot be discriminated from each other based only on elasticity because of the small difference in their elasticity. For more precise tissue characterization, we are attempting to measure the regional viscoelasticity. To determine viscoelastic properties, elastic moduli at multiple frequencies were obtained by generating the change in internal pressure due to remote cyclic actuation. From basic experiments using a silicone rubber tube, it was found that the change in internal pressure at the ultrasonic beam position (for measurement of the elastic modulus) can be generated by remotely applied actuation. Furthermore, from the resultant minute changes in wall thickness of less than 10 ?m measured by the phased tracking method, elastic moduli were obtained at multiple actuation frequencies.

Hasegawa, Hideyuki; Kanai, Hiroshi; Koiwa, Yoshiro; Butler, James P.

2003-05-01

274

Distinct defects in collagen microarchitecture underlie vessel-wall failure in advanced abdominal aneurysms and aneurysms in Marfan syndrome.  

PubMed

An aneurysm of the aorta is a common pathology characterized by segmental weakening of the artery. Although it is generally accepted that the vessel-wall weakening is caused by an impaired collagen metabolism, a clear association has been demonstrated only for rare syndromes such as the vascular type Ehlers-Danlos syndrome. Here we show that vessel-wall failure in growing aneurysms of patients who have aortic abdominal aneurysm (AAA) or Marfan syndrome is not related to a collagen defect at the molecular level. On the contrary our findings indicate similar (Marfan) or even higher collagen concentrations (AAA) and increased collagen cross-linking in the aneurysms. Using 3D confocal imaging we show that the two conditions are associated with profound defects in collagen microarchitecture. Reconstructions of normal vessel wall show that adventitial collagen fibers are organized in a loose braiding of collagen ribbons. These ribbons encage the vessel, allowing the vessel to dilate easily but preventing overstretching. AAA and aneurysms in Marfan syndrome show dramatically altered collagen architectures with loss of the collagen knitting. Evaluations of the functional characteristics by atomic force microscopy showed that the wall has lost its ability to stretch easily and revealed a second defect: although vascular collagen in normal aortic wall behaves as a coherent network, in AAA and Marfan tissues it does not. As result, mechanical forces loaded on individual fibers are not distributed over the tissue. These studies demonstrate that the mechanical properties of tissue are strongly influenced by collagen microarchitecture and that perturbations in the collagen networks may lead to mechanical failure. PMID:20080766

Lindeman, Jan H N; Ashcroft, Brian A; Beenakker, Jan-Willem M; van Es, Maarten; Koekkoek, Nico B R; Prins, Frans A; Tielemans, Jarl F; Abdul-Hussien, Hazem; Bank, Ruud A; Oosterkamp, Tjerk H

2009-12-28

275

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

PubMed

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. PMID:20922446

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

2010-10-05

276

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

SciTech Connect

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.

Miyamoto, Y.; Hattori, T.; Niimoto, M.; Toge, T. (Hiroshima Univ. School of Medicine (Japan))

1986-02-01

277

Macrovascular arteriovenous shunts (MAS): a newly identified structure in the abdominal wall with implications for thermoregulation and free tissue transfer.  

PubMed

Microscopic arteriovenous anastomoses are known structures that have many clinical implications, with disease states such as Reynaud's phenomenon and erythromelalgia known consequences of their abnormal functioning. These pre-capillary arteriovenous communications result in increased regional blood flow at the time of capillary filling. Recent advances in imaging technology, providing physiological and anatomical data, have identified a previously undescribed anatomical structure, that of large-vessel (macroscopic) arteriovenous communications, with profoundly different implications. Computed tomographic angiography (CTA) of the abdominal wall vasculature was undertaken in 140 patients prior to reconstructive surgery. All scans were arterial phase, demonstrating functional arteriovenous communications in all patients. These communications identified vascular shunting occurring prior to capillary filling. Fine-cut slices were able to visualise the structures, demonstrate their size as macroscopic (>1 mm diameter) and map the course of the arteriovenous communications. The potential clinical implications and therapeutic possibilities in a range of medical and surgical conditions are described. PMID:19577528

Rozen, Warren M; Chubb, Daniel; Ashton, Mark W; Grinsell, Damien

2009-07-03

278

Beckwith-Wiedemann syndrome, delayed abdominal wall closure, and neonatal intussusception--case report and literature review.  

PubMed

We present the extremely rare case of a male newborn with Beckwith-Wiedemann Syndrome (BWS) presenting as delayed abdominal wall closure and neonatal intussusception. Fetal ultrasound had shown omphalocele that resolved spontaneously. When feeding was attempted, he had various episodes of vomiting. An x-ray showed signs of high bowel obstruction. Jejunal intussusception was found on laparotomy. Enterectomy and primary jejuno-jejunal anastomosis was performed. During post-operative period subtle physical findings became prominent: plain hemangioma, posterior helical indentations, and macroglossia. Cardiac ultrasonography showed a patent foramen oval with small left-to-right shunt. Ultrasonography showed renal hyperplasia. Genetic study showed hypomethylation of DMR2 region of 11p15 chromosome. PMID:22483344

Moreira-Pinto, João; Pereira, Joana; Osório, Angélica; Enes, Carlos; Mota, Céu R

2012-04-09

279

Stress intensity factors of two diametrically opposed edge cracks in a thick-walled functionally graded material cylinder  

Microsoft Academic Search

A method is developed to evaluate stress intensity factors for two diametrically-opposed edge cracks emanating from the inner surface of a thick-walled functionally graded material (FGM) cylinder. The crack and the cylinder inner surfaces are subjected to an internal pressure. The thermal eigenstrain induced in the cylinder material due to nonuniform coefficient of thermal expansion after cooling from the sintering

A. M. Afsar; M. Anisuzzaman

2007-01-01

280

Three-dimensional interaction effects in internally multicracked pressurized thick-walled cylinder. Part 2: Longitudinal coplanar crack arrays  

SciTech Connect

In the first part of this paper, the interaction effects among many radial, internal, semi-circular, and semi-elliptical cracks in a pressurized, thick-walled vessel were quantified. In the present paper, the mode 1 stress intensity factor (SIF) distribution for numerous longitudinal coplanar, internal, semi-circular, and semi-elliptical arrays of surface cracks in an infinite, pressurized, thick-walled cylinder are evaluated. The 3-D analysis is performed by the finite element (FE) method and the submodeling technique, employing singular elements along the crack front. The effects f dense and sparse interacting longitudinal coplanar crack arrays on the SIFs are studied for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.6; and, for various ellipticities of the crack, i.e., the ratio of the crack depth to semi-crack length, a/c, from 0.2 to 2.0. An analysis is performed to determine the influence of the three major parameters--crack density, crack ellipticity, and crack depth--on the interaction effects between adjacent cracks. The results clearly indicate that crack density, and, in some cases, ellipticity have opposing effects on the SIF of longitudinal crack arrays as compared to radial crack arrays. As a result of these contrasting behaviors, thick-walled cylinders having combined longitudinal and radial crack arrays would need further study.

Levy, C.; Kokkavessis, N. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering; Perl, M. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)

1996-08-01

281

Preparation of ordered 2-D hexagonal mesoporous silica with ultra thick pore walls using a novel nonionic organosilicon surfactant  

Microsoft Academic Search

Mesoporous silica was synthesized by modified nonionic organosilicon surfactant under acidic condition for the first time. The XRD patterns, HRTEM image and corresponding BET characterization show that it has ordered 2-D hexagonal pore channel and ultra thick pore wall (about 6 nm). The calcination can result in the vanishment of organic composite and the linkage of the hydrolyzed silica source and

Guodong Chen; Lingzhi Wang; Feng Chen; Jinlong Zhang; Mazakazu Anpo

2008-01-01

282

Determination of wall thickness and condition of asbestos cement pipes in sewer rising mains using Surface Penetrating Radar  

Microsoft Academic Search

Asbestos pipes are commonly used for water and sewage pressure mains. There are very few non-destructive ways of assessing the wall thickness and condition of these Asbestos Cement (AC) pipes. Traditionally, their examination was undertaken by tapping to remove a physical specimen (a 'coupon') of the pipe. This procedure is time consuming, costly and risky. Alternatively, the mains have to

Val Donazzolo; Richard Yelf

2010-01-01

283

Assessment of Local Decreases in Wall Thickness at the Connection Straight-Pipe\\/Bend Using Stress Concentration Factors  

Microsoft Academic Search

Welds are ground during manufacturing to free them from offset edges and notches and to obtain a more favorable stress curve. Apart from the above, welds are also ground to prepare them for and improve the conditions for periodic testing and inspection. The grinding of welds may result in a local decrease in wall thickness, so that there may be

Wieland Holzer; Robert Kauer; Christian Hüttner

284

Use of the photoelastic method and finite element analysis in the assessment of wall strain in abdominal aortic aneurysm models.  

PubMed

Abdominal aortic aneurysm (AAA) is a significant health problem. Current clinical rupture-risk relies primarily on the maximum diameter of the AAA and also growth rate. However, AAAs are a patient-specific problem and recently, numerical tools have been employed to estimate rupture-potential. Alternatively, experimental assessment of AAA biomechanics receives less attention, yet, rigorous validation of numerical tools is required prior to clinical acceptance. This paper examines the use of the photoelastic method to assess wall strain and its validation using finite element analysis (FEA) in a small number of patient-specific AAA models. Experimental models were manufactured in-house using the injection-moulding procedure together with a commercially available photoelastic material. The material was mechanically characterised prior to testing, with models examined under three loading regimes (80, 120 and 160mmHg). Each experimental model was imaged using computed tomography (CT) and reconstructed in three dimensions (3D) for numerical analyses. Experimental wall strain was measured and numerical wall strain calculated with finite element analysis (FEA). Results were qualitatively and quantitatively compared. There was good qualitative agreement between the experimental and numerical methods, with similar trends apparent throughout all models at all pressures. Overall, acceptable percentage errors between the techniques were observed for all models. Median errors of -6.5%, -0.4% and 3.9% for the models at 80, 120 and 160mmHg pressures, respectively, were determined. The photoelastic method is a very useful experimental tool that provides instant, easy to interpret, information regarding wall strain. The technique is useful for validation of numerical AAA studies. PMID:22633540

Doyle, Barry J; Killion, John; Callanan, Anthony

2012-05-25

285

Suitability of Pharmacokinetic Models for Dynamic Contrast-Enhanced MRI of Abdominal Aortic Aneurysm Vessel Wall: A Comparison  

PubMed Central

Purpose Increased microvascularization of the abdominal aortic aneurysm (AAA) vessel wall has been related to AAA progression and rupture. The aim of this study was to compare the suitability of three pharmacokinetic models to describe AAA vessel wall enhancement using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Materials and Methods Patients with AAA underwent DCE-MRI at 1.5 Tesla. The volume transfer constant (Ktrans), which reflects microvascular flow, permeability and surface area, was calculated by fitting the blood and aneurysm vessel wall gadolinium concentration curves. The relative fit errors, parameter uncertainties and parameter reproducibilities for the Patlak, Tofts and Extended Tofts model were compared to find the most suitable model. Scan-rescan reproducibility was assessed using the interclass correlation coefficient and coefficient of variation (CV). Further, the relationship between Ktrans and AAA size was investigated. Results DCE-MRI examinations from thirty-nine patients (mean age±SD: 72±6 years; M/F: 35/4) with an mean AAA maximal diameter of 49±6 mm could be included for pharmacokinetic analysis. Relative fit uncertainties for Ktrans based on the Patlak model (17%) were significantly lower compared to the Tofts (37%) and Extended Tofts model (42%) (p<0.001). Ktrans scan-rescan reproducibility for the Patlak model (ICC?=?0.61 and CV?=?22%) was comparable with the Tofts (ICC?=?0.61, CV?=?23%) and Extended Tofts model (ICC?=?0.76, CV?=?22%). Ktrans was positively correlated with maximal AAA diameter (Spearman’s ??=?0.38, p?=?0.02) using the Patlak model. Conclusion Using the presented imaging protocol, the Patlak model is most suited to describe DCE-MRI data of the AAA vessel wall with good Ktrans scan-rescan reproducibility.

Nguyen, V. Lai; Kooi, M. Eline; Backes, Walter H.; van Hoof, Raf H. M.; Saris, Anne E. C. M.; Wishaupt, Mirthe C. J.; Hellenthal, Femke A. M. V. I.; van der Geest, Rob J.; Kessels, Alfons G. H.; Schurink, Geert Willem H.; Leiner, Tim

2013-01-01

286

Time course of arterial remodelling in diameter and wall thickness above and below the lesion after a spinal cord injury.  

PubMed

Physical inactivity in response to a spinal cord injury (SCI) represents a potent stimulus for conduit artery remodelling. Changes in conduit artery characteristics may be induced by the local effects of denervation (and consequent extreme inactivity below the level of the lesion), and also by systemic adaptations due to whole body inactivity. Therefore, we assessed the time course of carotid (i.e. above lesion) and common femoral artery (i.e. below lesion) lumen diameter and wall thickness across the first 24 weeks after an SCI. Eight male subjects (mean age 35 ± 14 years) with a traumatic motor complete spinal cord lesion between T5 and L1 (i.e. paraplegia) were included. Four subjects were measured across the first 6 weeks after SCI, whilst another four subjects were measured from 8 until 24 weeks after SCI. Ultrasound was used to examine the diameter and wall thickness from the carotid and common femoral arteries. Carotid artery diameter did not change across 24 weeks, whilst femoral artery diameter stabilised after the rapid initial decrease during the first 3 weeks after the SCI. Carotid and femoral artery wall thickness showed no change during the first few weeks, but increased both between 6 and 24 weeks (P < 0.05). In conclusion, SCI leads to a rapid and localised decrease in conduit artery diameter which is isolated to the denervated and paralyzed region, whilst wall thickness gradually increases both above and below the lesion. This distinct time course of change in conduit arterial diameter and wall thickness suggests that distinct mechanisms may contribute to these adaptations. PMID:22526250

Thijssen, Dick H J; De Groot, Patricia C E; van den Bogerd, Arne; Veltmeijer, Matthijs; Cable, N Timothy; Green, Daniel J; Hopman, Maria T E

2012-04-17

287

Subcutaneous Splenosis of the Abdominal Wall: Report of a Case and Review of the Literature  

PubMed Central

Splenosis is a common benign condition that occurs after splenic rupture via trauma or surgery. The mechanism behind splenic cell autotransplantation begins with the splenic rupture, either from trauma or surgical removal. Splenosis is usually found incidentally and, unless symptomatic, surgical therapy is not indicated. Subcutaneous splenosis is an extremely rare form of splenosis, mostly observed in abdominal surgical scars. We report a case of subcutaneous splenosis, as well as a comprehensive review of the literature. In our case, a 43-year-old woman who had splenectomy after traumatic splenic rupture at the age of 7 years old presented for plastic reconstruction of her postoperative scar. Upon surgery, two asymptomatic subcutaneous nodules were incidentally discovered. The presence of splenic tissue was confirmed by the histological study. The nodules were not excised, as the patient was not symptomatic.

Papakonstantinou, Evangelia; Kalles, Vasileios; Papapanagiotou, Ioannis; Piperos, Theodoros; Karakaxas, Dimitrios; Bonatsos, Vasileios; Tsoumakas, Konstantinos; Orfanos, Filotheos; Mariolis-Sapsakos, Theodoros

2013-01-01

288

Neurovascular latissimus dorsi free-flap transfer for reconstruction of a major abdominal-wall defect in a 13-month-old child: late follow-up.  

PubMed

The authors present a late follow-up of a pediatric case originally reported in the Journal, involving a newborn with a left gastroschisis, exposure of the stomach, jejunum, and left colon. Subsequent to placement of silicone mesh, the child developed a nosocomial infection, which led to necrosis of the skin, subcutaneous tissue, and muscle. Post infection control, the abdominal viscera were covered with only skin and subcutaneous tissue. At 13 months, the abdominal-wall defect was reconstructed with a free latissimus dorsi microneurovascular flap. A current late follow-up at 9.5 years demonstrates mean normal growth, good abdominal-wall resistance and contraction, and caudal scar migration, with little visibility. PMID:15088208

Olvera-Caballero, Carlos; Victoria-Morales, Guillermo

2004-04-01

289

Haematogenous abdominal wall metastasis of differentiated, alpha-fetoprotein-negative hepatocellular carcinoma after previous antiandrogen therapy within a site of lipoma manifestation since childhood  

PubMed Central

Background Cases with subcutaneous metastasis of differentiated hepatocellular carcinoma to the abdominal wall without prior seeding as a consequence of local interventions with a negative or normal alpha-fetoprotein level in the serum are extremely rare. Case report This is the first report of a case with AFP-negative, differentiated hepatocellular carcinoma metastasis to the abdominal wall within a pre-existing subcutaneous lipoma since childhood after antiandrogen therapy with leuprorelin and buserelin acetate for prostate cancer without seeding. Methods Clinical features including histology, immunohistochemistry, clinical course and surgical approach are presented. Results Histological examination revealed a hepatocellular carcinoma with a trabecular and pseudoglandular growth pattern with moderately atypical hepatocytes with multifocal bile formation within a lipoma. The postoperative course of abdominal wall reconstruction with a monocryl-prolene mesh and a local flap after potentially curative resection was uncomplicated. Discussion and conclusion It may be that previous antiandrogen treatment for prostate carcinoma contributed to the fact that our patient developed alpha-fetoprotein-negative and androgen receptor-negative subcutaneous abdominal wall metastasis within a pre-existing lipoma since childhood.

2012-01-01

290

Incidence and Effect on Survival of Abdominal Wall Metastases at Trocar or Puncture Sites Following Laparoscopy or Paracentesis in Women with Ovarian Cancer  

Microsoft Academic Search

The aim of this retrospective study was to examine the incidence and prognostic significance of abdominal wall metastases in patients with ovarian cancer present at the primary debulking at the entry sites of previous laparoscopy or paracentesis. The clinical records of 219 patients were studied. In 7 of 43 patients (16%) who had undergone laparoscopy and 3 of 30 patients

R. F. P. M. Kruitwagen; B. M. Swinkels; K. G. G. Keyser; W. H. Doesburg; Ch. P. Th. Schijf

1996-01-01

291

Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative dobutamine stress  

PubMed Central

Background To determine if patients without dobutamine induced left ventricular wall motion abnormalities (WMA) but an increased LV end-diastolic wall thickness (EDWT) exhibit a favorable cardiac prognosis. Results Between 1999 and 2001, 175 patients underwent a dobutamine stress cardiovascular magnetic resonance (DCMR) procedure utilizing gradient-echo cines. Participants had a LV ejection fraction >55% without evidence of an inducible WMA during peak dobutamine/atropine stress. After an average of 5.5 years, all participants were contacted and medical records were reviewed to determine the post-DCMR occurrence of cardiac death, myocardial infarction (MI), and unstable angina (USA) or congestive heart failure (CHF) warranting hospitalization. In a multivariate analysis, that took into account Framingham and other risk factors associated with cardiac events, a cine gradient-echo derived LV EDWT ?12 mm was associated independently with an increase in cardiac death and MI (HR 6.0, p = 0.0016), and the combined end point of MI, cardiac death, and USA or CHF warranting hospitalization (HR 3.0, p = 0.0005). Conclusion Similar to echocardiography, CMR measures of increased LV wall thickness should be considered a risk factor for cardiac events in individuals receiving negative reports of inducible ischemia after dobutamine stress. Additional prognostic studies of the importance of LV wall thickness and mass measured with steady-state free precession techniques are warranted.

Walsh, Thomas F; Dall'Armellina, Erica; Chughtai, Haroon; Morgan, Timothy M; Ntim, William; Link, Kerry M; Hamilton, Craig A; Kitzman, Dalane W; Hundley, W Gregory

2009-01-01

292

Bladder wall thickness and ultrasound estimated bladder weight in healthy adults with portative ultrasound device  

PubMed Central

Background: The aim of this study was to investigate bladder wall thickness (BWT) and ultrasound estimated bladder weight (UEBW) values in healthy population with a portative ultrasound device and their relationship with demographic parameters. Materials and Methods: The study was carried out in Neurorehabilitation Clinic of Ege University Hospital. Ninety-five subjects (48 women and 47 men) aged between 18 and 56 were included in the study. BWT and UEBW were determined non-invasively with a portative ultrasound device; Bladder Scan BVM 6500 (Verathon Inc., WA, USA) at a frequency of 3.7 MHz at functional bladder capacity. These values were compared by gender, and their relation was assessed with age, body mass index (BMI) and parity. Results: Mean BWT was 2.0 ± 0.4 mm and UEBW was 44.6 ± 8.3 g at a mean volume of 338.0 ± 82.1 ml. Although higher results were obtained in men at higher bladder volumes, the results did not differ significantly by gender. Correlation analyses revealed statistically significant correlation between UEBW and age (r = 0.32). BWT was negatively correlated with volume (r = –0.50) and bladder surface area (r = –0.57). Also, statistically significant correlations were observed between UEBW and volume (r = 0.36), bladder surface area (r = 0.48) and BWT (r = 0.25). Conclusion: Determined values of BWT and UEBW in healthy population are estimated with portative ultrasound devices, which are future promising, for their convenient, easy, non-invasive, time-efficient hand-held use for screening.

Kanyilmaz, Selcen; Calis, Funda Atamaz; Cinar, Yasemin; Akkoc, Yesim

2013-01-01

293

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

SciTech Connect

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.

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

1983-01-01

294

Influence of data processing on cyclic variation of integrated backscatter and wall thickness in stunned porcine myocardium.  

PubMed

This study was performed to investigate the relationship between the cyclic variation of integrated backscatter and myocardial wall thickening in stunned myocardium. Different definitions of cyclic variation were evaluated to be able to compare with other studies. Ultrasound data were acquired from 10 open-chested Yorkshire pigs (25-33 kg) at baseline, during regional ischemia and during 30 min of stunning, using a broadband ultrasound transducer (3-7 MHz) sutured directly upon the left ventricular myocardial wall. Cyclic variation of integrated backscatter and myocardial wall thickening were calculated using three definitions obtained from the literature. Independent of the definition, cyclic variation of wall thickness and integrated backscatter were blunted during acute ischemia and returned transiently to or above baseline during the first minute of reperfusion, followed by a gradual decrease to a level under baseline during stunning. An early return of the cyclic variation of the integrated backscatter was not observed in pigs, independent of the data processing used. The relationship between integrated backscatter and wall thickness was maintained. PMID:9160908

van der Steen, A F; Rijsterborgh, H; Lancee, C T; Mastik, F; Krams, R; Verdouw, P D; Roelandt, J R; Bom, N

1997-01-01

295

Construction and validation of a questionnaire distinguishing a chronic abdominal wall pain syndrome from irritable bowel syndrome  

PubMed Central

Objective The irritable bowel syndrome (IBS) population is heterogeneous, harbouring a variety of abdominal symptoms. Therefore, IBS is often termed a ‘diagnosis of exclusion’. Chronic abdominal wall pain (CAWP) is a poorly recognized entity, frequently caused by the anterior cutaneous nerve entrapment syndrome (ACNES). Some patients may be misdiagnosed because IBS and CAWP share symptoms. Aim of this study was to construct and validate a questionnaire to distinguish patients with CAWP (including ACNES) patients with IBS. Design A questionnaire was designed of 17 ACNES characteristic items obtained from ACNES patients (n=33) and expert opinion of two specialized surgeons. Eleven IBS-related items (‘Rome III’ criteria) were added leading to a questionnaire containing 28 items. This was validated in a ‘gold standard’ ACNES group (successfully operated ACNES patients, n=68) and a ‘prospective’ IBS group (n=64) as well as in a ‘prospective’ ACNES group (n=47). Distinctive power of individual items was analyzed by ?2. Reliability was tested with Crohnbach's ?. ROC curve was used to determine cut-off values. Results Eighteen of 28 items were significantly distinctive (p<0.01) between ACNES and IBS patients leading to an 18-point ACNES score with good internal consistency (?=0.85). Cut-off value of 10 points resulted in 94% sensitivity, 92% specificity and areas under the curve (AUC) of 0.98. Evaluation of the prospective ACNES group led to 85% sensitivity, 92% specificity and AUC 0.95 indicating high discriminative properties of the questionnaire. Conclusions This novel questionnaire may be useful and valid as a simple tool distinguishing patients harbouring a CAWP syndrome from those having IBS.

van Assen, Tijmen; Boelens, Oliver B; Kamphuis, Jan T; Scheltinga, Marc R; Roumen, Rudi M

2012-01-01

296

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

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.

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

2013-01-01

297

Indications and outcomes of the components separation technique in the repair of complex abdominal wall hernias: experience from the cambridge plastic surgery department.  

PubMed

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

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

2013-09-16

298

Single-Gene Mutations and Increased Left Ventricular Wall Thickness in the Community The Framingham Heart Study  

Microsoft Academic Search

Background—Mutations in sarcomere protein, PRKAG2, LAMP2, -galactosidase A (GLA), and several mitochondrial genes can cause rare familial cardiomyopathies, but their contribution to increased left ventricular wall thickness (LVWT) in the community is unknown. Methods and Results—We studied 1862 unrelated participants (52% women; age, 599 years) from the community-based Framingham Heart Study who had echocardiograms and provided DNA samples but did

Hiroyuki Morita; Martin G. Larson; Scott C. Barr; Ramachandran S. Vasan; Christopher J. O'Donnell; Joel N. Hirschhorn; Daniel Levy; Diane Corey; Christine E. Seidman; J. G. Seidman; Emelia J. Benjamin

2010-01-01

299

Creep deformations and stresses in thick-walled cylindrical vessels of functionally graded materials subjected to internal pressure  

Microsoft Academic Search

Steady-state creep of thick-walled cylindrical vessels made of functionally graded materials subjected to internal pressure is investigated in this paper. Taking material parameters involved in Norton’s law to be the functions of the radial coordinate, a simple and accurate method is developed from the strain rate–stress relations, Norton’s law, deformation compatibility condition and equilibrium equation of axisymmetric, plane strain problems.

L. H. You; H. Ou; Z. Y. Zheng

2007-01-01

300

Investigation of Adiabatic Shear Bands in Thick-Walled Cylinders Collapsed by Electro-Magnetic Driving Forces  

NASA Astrophysics Data System (ADS)

The Thick-Walled Cylinder technique, reported in the literature, employs an explosive cylinder to create the driving force, collapsing the cylindrical sample. This experimental set-up has been established as a controlled and repeatable technique to create and study multiple adiabatic shear bands. Searching to establish a simpler experimental platform to perform large sets of experiments, we have designed an Electro-Magnetic (EM) set-up for the collapse of thick walled cylinders. The EM setup is based on a pulsed current generator using a capacitor bank system. The specimen is an assembly of coaxial cylinders, where the inner and outer cylinders, each attached to an opposite pole, are short-circuited. Upon discharge, a high current flows through the cylinders, in opposite directions, creating repulsive magnetic forces between them. This work presents the design procedure of the specimens using numerical simulations as well as some results for SS304L thick-walled specimens, using this setup. The spatial distribution of the multiple adiabatic shear bands in these experiments is in good agreement with that reported in the literature for the explosive driven experiments with SS304L specimens. Our numerical simulations show good agreement with the experimental results for both global behaviour and shear band distribution.

Lovinger, Z.; Rikanati, A.; Rittel, D.; Rosenberg, Z.

2009-12-01

301

Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls  

Microsoft Academic Search

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-LiâBeFâ), which protects the walls and structures from damage arising from neutrons and plasma particles. The free

R W Moir; T D Rognlien

2006-01-01

302

Abdominal Wall Haemorrhage After Robotic-Assisted Radical Prostatectomy: Is it a Complication of Robotic Surgery?  

PubMed

OBJECTIVE: Robotic-assisted radical prostatectomy (RARP) is the minimally invasive surgical treatment for patients with localized prostate cancer. Perioperative or postoperative complications following RARP have been reported in some studies and severe postoperative bleeding after RARP is rare, but hemodynamic instability may necessitate open surgical exploration and be associated with considerable morbidity. We reported postoperative bleeding cases, which is a kind of complication associated with robotic surgery and requiring massive transfusion after RARP. PATIENTS AND METHODS: From August 2009 to May 2012, 317 consecutive patients who underwent RARP performed at our institution were analyzed. Patients with serious postoperative bleeding that caused hemodynamic instability after surgery were enrolled. RESULTS: A total of 5 among 317 (1.6%) patients had bleeding requiring postoperative transfusion. In these cases, mean operative time was 114minutes. The mean estimated blood loss was 110ml during operation. In these patients, hematocrit (Hct) levels gradually fell after surgery and ecchymosis was detected on the side and posterior walls of the abdomen on the second day. The mean preoperative Hct was 44.3% and mean lowest Hct was 23.1%. All patients were successfully treatment without surgical exploration. CONCLUSIONS: Robotic radical prostatectomy has proven to be a safe surgical treatment with low morbidity. However, postoperative bleeding can reach serious problems. This is the first study to explain haemorrhage, associated with possible risk of robotic surgery. PMID:23768503

Tasci, A I; Simsek, A; Tugcu, V; Bitkin, A; Sonmezay, E; Torer, B D

2013-06-12

303

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

PubMed

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

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

1997-08-01

304

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

SciTech Connect

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.

Weier, Dennis R.; Pardini, Allan F.

2010-03-15

305

Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls.  

National Technical Information Service (NTIS)

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...

R. W. Moir T. D. Rognlien

2006-01-01

306

Experience with Porcine Acellular Dermal Collagen Implant in One-stage Tension-free Reconstruction of Acute and Chronic Abdominal Wall Defects  

Microsoft Academic Search

Background  Elective or emergency reconstruction of abdominal wall defects (AWD) is often difficult. Various techniques have been proposed\\u000a for reconstructing AWD, including the use of synthetic implants. Porcine acellular dermal collagen (PermacolTM) is a biologic implant (PADCI) derived from porcine dermis. We report our experience with the use of PADCI in the management\\u000a of large AWD in both emergency and elective

Faisal M. Shaikh; Subhasis K. Giri; Shaukat Durrani; David Waldron; Pierce A. Grace

2007-01-01

307

Association between Plasma Angiopoietin-Like Protein 3 and Arterial Wall Thickness in Healthy Subjects  

Microsoft Academic Search

Background: Angiopoietin-like protein 3 (ANGPTL3) is a liver-derived plasma protein that modulates plasma triglyceride clearance, angiogenesis and atherosclerosis in experimental models. So far, no study has examined its role in atherosclerosis in human subjects. We evaluated the possible association between plasma ANGPTL3 level and carotid artery intima-media thickness (CA-IMT) and femoral artery intima-media thickness (FA-IMT) in healthy human subjects. Methods:

Sawako Hatsuda; Tetsuo Shoji; Kayo Shinohara; Eiji Kimoto; Katsuhito Mori; Shinya Fukumoto; Hidenori Koyama; Masanori Emoto; Yoshiki Nishizawa

2007-01-01

308

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

NASA Astrophysics Data System (ADS)

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.

Gupta, Nikhil; Pinisetty, Dinesh

2013-02-01

309

The gender-specific chest wall thickness prediction equations for routine measurements of {sup 239}Pu and {sup 241}Am within the lungs using HPGE detectors  

SciTech Connect

The current chest wall thickness prediction equation is not applicable to use in routine lung counting measurements for detection of low energy photons (17-60 keV) within the lungs of male and female subjects. The current chest wall thickness prediction equation was derived for the NaI-CsI {open_quotes}phoswich{close_quotes} detection system, which is not the routine detection system in use; the subject position was supine, which is not the routine position; the equation did not account for the intercostal tissue thicknesses of muscle and adipose which significantly attenuate low energy photons (17-60 keV); it was derived from male subjects only and is used to predict the chest wall thickness of female subjects for whom it is not applicable. The current chest wall thickness prediction equation yields unacceptable percent errors in the HPGe detection efficiency calibration for {sup 239}Pu and {sup 241}Am (17- and 59.5-keV photons, respectively) relative to the gender-specific HPGe chest wall thickness prediction equations of this paper (+284% to -73% for {sup 239}Pu; +42% to -39% for {sup 241}Am). As a result, use of the current chest wall thickness prediction equation yields unacceptable percent errors (proportional in magnitude to the percent errors in the detection efficiency calibration) in the calculation of the minimum detectable activity (Bq) or in an initial assessment of a radioactive contamination exposure detected by a routine lung count measurement. 17 refs., 6 figs., 12 tabs.

Vickers, L.R. [Pantex Plant, Amarillo, TX (United States)

1996-03-01

310

Dynamics of domain walls in magnetically multiaxial films in the thickness range corresponding to the Bloch-Néel transformations of the structure  

NASA Astrophysics Data System (ADS)

The numerical minimization of the total energy functional and the solution of the nonlinear Landau-Lifshitz equation have been performed exactly taking into account the fundamental (including dipole-dipole) interactions in terms of the two-dimensional magnetization distribution. The equilibrium structure, energy, mobility, and scenario of the dynamic transformation of the domain walls (in their non- steady-state motion) have been determined as a function of the film thickness b and external magnetic field H for two different ((010) and (110)) orientations of the surfaces of magnetically triaxial films. The range of film thicknesses, including the thickness b = b N, for which the Néel domain walls can be transformed into the Bloch domain walls, has been investigated. The phenomena of anisotropy of the domain-wall energy, the domain-wall mobility, and the period of dynamic transformations of the domain walls have been analyzed as a function of the film thickness b and external magnetic field H. The range of film thicknesses has been determined, in which the non-steady-state motion of the Néel domain walls is accompanied by the creation and annihilation of vortex-like structures despite the one-dimensional character of the magnetization distribution in these walls.

Filippov, B. N.

2012-12-01

311

Lack of association between renin-angiotensin system, gene polymorphisms, and wall thickness of the radial and carotid arteries.  

PubMed

To investigate the relationship between polymorphisms of the angiotensin-converting enzyme (ACE) and the angiotensin II type 1 receptor (AT1R) genes and structural phenotypes of arteries, we studied a cohort of 340 subjects (aged 49+/-12 years) without evidence of cardiovascular disease and who had never been treated previously with any cardiovascular treatments. Structural phenotypes (wall thickness and internal diameter) were evaluated for the common carotid and the radial arteries using high-resolution echo-tracking devices (NIUS-02 and Wall Track System). The influence of ACE insertion/deletion (I/D) and AT1R A/C1166 polymorphism genotypes on structural parameters was tested by ANOVA and logistic regression analysis. For the radial artery, mean wall thickness among subjects according to the ACE I/D or AT1R A/C1166 genotypes was not different. This lack of association persisted in a logistic regression analysis or when the comparison was restricted to a subgroup of subjects potentially at high genetic risk (DD and CC or AC) compared with subjects at low genetic risk (AA and II or ID). Also, no association was observed between the carotid artery intima-media thickness and the 2 polymorphisms. In conclusion, the ACE I/D and the AT1R A/C1166 gene polymorphisms are not markers of vascular hypertrophy in subjects with no evidence of cardiovascular disease. These results suggest that these gene polymorphisms have an undetectable role in the geometry of the radial and carotid arteries compared with usual determinants such as blood pressure and age. PMID:9740630

Girerd, X; Hanon, O; Mourad, J J; Boutouyrie, P; Laurent, S; Jeunemaitre, X

1998-09-01

312

Zur Berechnung von Kriechverformung und Spannungen in Dickwandigen Rohren (The Calculation of Creep Deformations and Stresses in Thick-Walled Tubes).  

National Technical Information Service (NTIS)

Methods for the calculation of stresses and creep deformations in thick-walled tubes under compressive and additional axial loads were developed for heat exchangers for methane reforming processes in helium cooled high temperature reactors where temperatu...

G. Breitbach S. Kragl M. Roedig H. Penkalla

1986-01-01

313

Spheromak Magnetic Fusion Energy Power Plant with Thick Liquid-Walls  

Microsoft Academic Search

A power plant based on a spheromak device using liquid walls is analyzed. We assume a spheromak configuration can be made and sustained by a steady plasma gun current, which injects particles, current and magnetic field, i.e., helicity injection, which are transported into the core region. The magnetic configuration is evaluated with an axisymmetric freeboundary equilibrium code, where the current

R. W. Moir; R. H. Bulmer; T. K. Fowler; T. D. Rognlien; M. Z. Youssef

2003-01-01

314

Failure of Thick-Walled Concrete Spheres Subjected to Hydrostatic Loading.  

National Technical Information Service (NTIS)

Two modes of failure for hollow concrete spheres subjected to hydrostatic pressure loadings are discussed, and the experimental results are presented. The first mode of failure was crack development in the plane of the concrete wall, and the second mode w...

H. H. Haynes R. A. Hoofnagle

1970-01-01

315

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

NASA Astrophysics Data System (ADS)

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.

Gladshtein, V. I.

2011-02-01

316

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

PubMed Central

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

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

2013-01-01

317

Actinomycosis of the colon with invasion of the abdominal wall: An uncommon presentation of a colonic tumour.  

PubMed

Actinomycosis is an uncommon chronic suppurative infectious disease that is caused by Actinomycetes organisms, which are gram-positive, microaerophilic, anaerobic bacteria. The most common type causing disease in humans is Actinomyces israelii. This organism is a commensal of the human mouth and is seldom pathogenic. When it does cause disease, however, three main clinical types of involvement are recognized including cervico-facial, thoracic and abdominal actinomycosis.Herein, we present the case of a 79-year-old male patient who underwent surgical exploration following presentation with abdominal pain and an abdominal mass, initially thought to be a malignancy. Pathologic examination confirmed this as a case of abdominal actinomycosis. This diagnosis should always be included in the differential diagnosis of patients who present with an infiltrative abdominal mass. PMID:22096664

McFarlane, M E C; Coard, K C M

2010-08-26

318

Actinomycosis of the colon with invasion of the abdominal wall: An uncommon presentation of a colonic tumour  

PubMed Central

Actinomycosis is an uncommon chronic suppurative infectious disease that is caused by Actinomycetes organisms, which are gram-positive, microaerophilic, anaerobic bacteria. The most common type causing disease in humans is Actinomyces israelii. This organism is a commensal of the human mouth and is seldom pathogenic. When it does cause disease, however, three main clinical types of involvement are recognized including cervico-facial, thoracic and abdominal actinomycosis. Herein, we present the case of a 79-year-old male patient who underwent surgical exploration following presentation with abdominal pain and an abdominal mass, initially thought to be a malignancy. Pathologic examination confirmed this as a case of abdominal actinomycosis. This diagnosis should always be included in the differential diagnosis of patients who present with an infiltrative abdominal mass.

McFarlane, M.E.C.; Coard, K.C.M.

2010-01-01

319

Stress concentration analysis of thick-walled laminate composites with a loaded circular cut-out by using a first-order shear deformation theory  

Microsoft Academic Search

Stress concentrations in the vicinity of cut-outs can often be regarded as design drivers for the whole structure. Especially in thick-walled laminate composites not only the extension-bending coupling effects but as well the influence of the shear deformation has to be taken into account. For analyzing stress concentration effects in the vicinity of circular cut-outs in thick-walled anisotropic composites, sophisticated

W. Hufenbach; R. Gottwald; B. Grüber; M. Lepper; B. Zhou

2008-01-01

320

The effect of wall porosity and zeolite film thickness on the dynamic behavior of adsorbents in the form of coated monoliths  

Microsoft Academic Search

The effects of wall porosity, channel width distribution and zeolite film thickness on the performance of 400 and 1200 cells per square inch (cpsi) cordierite monoliths coated with zeolite X films with thicknesses of 1.5 and 2.5?m were examined. To investigate the effect of wall porosity and restrict growth of zeolite to the external surface of the monolith channels, the

F. Rezaei; A. Mosca; J. Hedlund; P. A. Webley; M. Grahn; J. Mouzon

2011-01-01

321

Investigations for deducing wall thickness of aluminium shell casting using three dimensional printing  

Microsoft Academic Search

Purpose: of the present study is to verify the feasibility of decreasing the shell thickness in rapid shell casting based upon 'three dimensional printing' technology in order to evaluate the dimensional accuracy for aluminum castings. Rapid prototyping has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and

R. Singh; M. Verma

2008-01-01

322

Carotid Wall Thickness is Predictive of Incident Clinical Stroke The Atherosclerosis Risk in Communities (ARIC) Study  

Microsoft Academic Search

Few studies have determined whether carotid artery intima-media thickness (IMT) is associated prospectively with risk of first ischemic stroke. In the Atherosclerosis Risk in Communities Study, carotid IMT, an index of generalized atherosclerosis, was defined as the mean of IMT measured by B-mode ultrasonography at six sites of the carotid arteries. The authors assessed the relation of mean IMT to

Lloyd E. Chambless; Aaron R. Folsom; Limin X. Clegg; A. Richey Sharrett; Eyal Shahar; F. Javier Nieto; Wayne D. Rosamond; Greg Evans

323

Development of automated welding process for field fabrication of thick walled pressure vessels. Final report  

SciTech Connect

The results review procedure development and qualification for narrow groove gas tungsten arc welding of SA 387 Grade 22 Class 2 steel (2 1/4% Cr-1% Mo) to 4 inch thickness. Welding was conducted in the horizontal (2G) and vertical (3G) position.

Stol, I.

1981-11-04

324

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

PubMed

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-cm(2) 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

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

2013-04-30

325

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

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.

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

2013-01-01

326

Abdominal Wall Hernias  

MedlinePLUS

... diagnosis is made by physical examination and sometimes ultrasonography or a computed tomography scan. Treatment involves surgery ... computed tomography epididymis inguinal inguinal hernia peritonitis spermatocele ultrasonography umbilical varicocele vas deferens Back to Top Previous: ...

327

Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats  

PubMed Central

AIM: To explore the influence of portal vein hemo-dynamic changes after portal venous arterialization (PVA) on peribiliary vascular plexus (PVP) morphological structure and hepatic pathology, and to establish a theoretical basis for the clinical application of PVA. METHODS: Sprague-Dawley rats were randomly divided into control and PVA groups. After PVA, hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound, liver function tests, ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization, and pathological examination was performed on tissue from the bile duct wall and the liver. RESULTS: After PVA, the cross-sectional area and blood flow of the portal vein were increased, and the increase became more significant over time, in a certain range. If the measure to limit the flow in PVA was not adopted, the high blood flow would lead to dilatation of intrahepatic portal vein and its branches, increase in collagen and fiber degeneration in tunica intima. Except glutamic pyruvic transaminase (GPT), other liver function tests were normal. CONCLUSION: Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall. After PVA, It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux. A adequate measure to limit blood flow is necessary in PVA.

Li, Wen-Gang; Chen, Yong-Liang; Chen, Jing-Xi; Qu, Lei; Xue, Bin-Dang; Peng, Zhi-Hai; Huang, Zhi-Qiang

2008-01-01

328

Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls  

SciTech Connect

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.

Moir, R W; Rognlien, T D

2006-04-26

329

RADIATION NECROSIS OF THE CHEST WALL: FULL-THICKNESS RECONSTRUCTION WITH PEDICLE FLAP AND DICED HOMOLOGOUS CARTILAGE OVER THE PERICARDIUM COMPLICATED BY CARDIAC ARREST  

Microsoft Academic Search

Successful repair by plastic surgery of nonhealing ulceration of the ; chest wall, induced by radiotherapy for breast cancer, is described. ; Reconstruction of the chest wali defect by pedicle flap coverage was carried out. ; Radiation injury extended through the entire thickness of the chest wall and ; osteoradionecrosis of the ribs was present. Reconstruction with thoracoabdominal ; tube

Rees

1961-01-01

330

Three-dimensional interaction effects in internally multicracked pressurized thick-walled cylinder. Part 1: Radial crack arrays  

SciTech Connect

Under certain conditions, numerous internal surface cracks develop in pressurized thick-walled cylinders, both in the radial and longitudinal directions. For fatigue life assessment of such vessels, the 3-D interaction effects among these cracks on the prevailing stress intensity factors (SIFs) need evaluation. In Part 1 of this paper, radial crack arrays are considered exclusively. The mode 1 SIF distribution for a wide range of semi-circular and semi-elliptical cracks are evaluated. The 3-D analysis is performed via the finite element method with the submodeling technique, employing singular elements along the crack front. SIFs are evaluated for arrays of up to n = 180 cracks; for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.6; and, for various ellipticities of the crack, i.e., the ratio of crack depth to semicrack length, a/c, from 0.2 to 2. Using a least-squares fit, two simple expressions for the most critical (n = 2) SIFs are obtained for sparse and dense crack arrays. The formulas, which are functions of a/t and a/c, are of very good engineering accuracy. The results clearly indicate that the SIFs are considerably affected by the interaction among the cracks in the array as well as the three-dimensionality of the problem. In Part 2 of this paper, the interaction effects between longitudinal coplanar cracks will be analyzed.

Perl, M. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel); Levy, C.; Pierola, J. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering

1996-08-01

331

Effect of electricity tariff on the optimum insulation-thickness in building walls as determined by a dynamic heat-transfer model  

Microsoft Academic Search

Thermal insulation is one of the most effective energy-conservation measures in buildings. Despite the widespread use of insulation materials in recent years, little is known regarding their optimum thickness under dynamic thermal conditions. Insulated concrete blocks are among the units most commonly used in the construction of building walls in Saudi Arabia. Typically, the insulation layer thickness is fixed at

Sami A. Al-Sanea; M. F. Zedan; Saleh A. Al-Ajlan

2005-01-01

332

Spheromak Magnetic Fusion Energy Power Plant with Thick Liquid-Walls  

SciTech Connect

A power plant based on a spheromak device using liquid walls is analyzed. We assume a spheromak configuration can be made and sustained by a steady plasma gun current, which injects particles, current and magnetic field, i.e., helicity injection, which are transported into the core region. The magnetic configuration is evaluated with an axisymmetric freeboundary equilibrium code, where the current profile is tailored to support an average beta of 10%. An injection current of 100 kA (125 MW of gun power) sustains the toroidal current of 40 MA. The magnetic flux linking the gun is 1/1000{sup th} of the flux in the spheromak. The geometry allows a flow of liquid, either molten salt, (flibe-Li{sub 2}BeF{sub 4} or flinabe-LiNaBeF{sub 4}), or liquid metal such as SnLi, which protects most of the walls and structures from damage arising from neutrons and plasma particles. The free surface between the liquid and the burning plasma is heated primarily by bremsstrahlung, line radiation, and some 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 impurity concentration in the burning plasma, about 0.8% fluorine, is limited to that giving a 20% reduction in the fusion power. The divertor power density of 620 MW/m{sup 2} is handled by high-speed (100 m/s) liquid jets. Calculations show the tritium breeding is adequate with enriched {sup 6}Li, and a design is given for the walls not covered by flowing liquid ({approx}15% of the total). We identified a number of problem areas needing further study to make the design more self-consistent and workable, including lowering the divertor power density by expanding the flux tube size.

Moir, R.W. [Lawrence Livermore National Laboratory (United States); Bulmer, R.H. [Lawrence Livermore National Laboratory (United States); Fowler, T.K. [University of California at Berkeley (United States); Rognlien, T.D. [Lawrence Livermore National Laboratory (United States); Youssef, M.Z. [University of California at Los Angeles (United States)

2003-09-15

333

Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs  

PubMed Central

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 intensive care therapy with a combination of antibiotics and adjuvant hyperbaric oxygen therapy (HBOT) was applied during the treatment. After stabilization of soft tissue wounds and the formation of fresh granulation tissue, soft tissue defect were reconstructed using simple to complex reconstructive methods.

2011-01-01

334

Necrotizing fasciitis: literature review of contemporary strategies for diagnosing and management with three case reports: torso, abdominal wall, upper and lower limbs.  

PubMed

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 intensive care therapy with a combination of antibiotics and adjuvant hyperbaric oxygen therapy (HBOT) was applied during the treatment. After stabilization of soft tissue wounds and the formation of fresh granulation tissue, soft tissue defect were reconstructed using simple to complex reconstructive methods. PMID:22196774

Roje, Zdravko; Roje, Zeljka; Mati?, Dario; Librenjak, Davor; Dokuzovi?, Stjepan; Varvodi?, Josip

2011-12-23

335

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

SciTech Connect

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

Stevens, Trevor; Johnson, Mikkel B. [Department of Physics, West Virginia Wesleyan College, Buckhannon, West Virginia 26201 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2009-10-15

336

Interaction effects in combined arrays of radial and longitudinal semi-elliptical surface cracks in pressurized thick-walled cylinder  

SciTech Connect

In two previous papers, the interaction effects for two separate cases of large arrays of semi-elliptical, internal, surface cracks in a thick-walled, cylindrical pressure vessel were studied. First, arrays of radial cracks were considered followed by the study of longitudinal-coplanar crack arrays. Circumferential crack density and longitudinal crack spacing were found to have opposing effects on the prevailing stress intensity factors (SIFs). Consequently, in the present paper, combined arrays of both radial and longitudinal cracks are considered, and their interaction effects are studied. The mode 1 stress intensity factor (SIF) distribution for numerous configurations of combined semi-circular and semi-elliptical crack arrays are evaluated. The 3-D analysis is performed by the finite element (FE) method and the submodeling technique, employing singular elements along the crack front. The effects of crack density in the circumferential direction and of relative spacing in the longitudinal direction on the SIFs are studied for combined arrays of up to 32 circumferentially equispaced, radial cracks and having longitudinal relative spacing of 2c/d of 0.25 to 0.99; for a wide range of crack depth to wall thickness ratios, a/t, from 0.05 to 0.4; and for various ellipticities of the crack, i.e., the ratio of crack depth to semicrack length, a/c, from 0.2 to 1.5. The results clearly indicate that the SIFs are considerably affected by the interaction among the cracks, and that the SIF values depend upon the circumferential density and longitudinal spacing, the crack depth and ellipticity, as well as the three-dimensional nature of the problem.

Perl, M. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel); Levy, C.; Wang, J. [Florida International Univ., Miami, FL (United States). Dept. of Mechanical Engineering

1997-05-01

337

Fracture behavior of shallow cracks in full-thickness clad beams from an RPV wall section  

SciTech Connect

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.

Keeney, J.A.; Bass, B.R.; McAfee, W.J.

1995-04-01

338

Ultrasound bladder wall thickness measurement in diagnosis of recurrent urinary tract infections and cystitis cystica in prepubertal girls.  

PubMed

OBJECTIVE: To evaluate urinary bladder wall thickness (BWT) assessed by ultrasound as a diagnostic tool for cystitis cystica. PATIENTS AND METHODS: This was a 9-year prospective study comprising 120 prepubertal girls. Sixty subjects of whom half underwent cystoscopy represented cases while the other 60 (those with a single urinary tract infection and healthy subjects) represented controls. RESULTS: Based on receiver operating characteristics (ROC) analysis, BWT discriminated very well between cases and controls with area under the ROC curve close to 1.0. At the optimum cut-off defined at 3.9 mm, negative predictive value (NPV) was 100% leaving no probability of cystic cystitis with BWT <3.9 mm. Positive predictive value (PPV) was also very high (95.2%), indicating only around 4.82% probability of no cystic cystitis in patients with BWT values ?3.9 mm. BWT could also distinguish between healthy subjects and those with a cured single urinary tract infection, although discriminatory properties were moderate (area under ROC 86.7%, PPV 78.8%, NPV 85.2%). CONCLUSION: Ultrasound mucosal bladder wall measurement is a non-invasive, simple and quite reliable method in diagnosis of cystitis cystica in prepubertal girls with recurrent urinary tract infections. PMID:23725853

Miloševi?, Danko; Trkulja, Vladimir; Turudi?, Daniel; Batini?, Danica; Spaji?, Borislav; Tešovi?, Goran

2013-05-29

339

How do hypertrophic cardiomyopathy mutations affect myocardial function in carriers with normal wall thickness? Assessment with cardiovascular magnetic resonance  

PubMed Central

Background Clinical data on myocardial function in HCM mutation carriers (carriers) is sparse but suggests that subtle functional abnormalities can be measured with tissue Doppler imaging before the development of overt hypertrophy. We aimed to confirm the presence of functional abnormalities using cardiovascular magnetic resonance (CMR), and to investigate if sensitive functional assessment could be employed to identify carriers. Results 28 carriers and 28 controls were studied. Global left atrial (LA) and left ventricular (LV) dimensions, segmental peak systolic circumferential strain (SCS) and peak diastolic circumferential strain rate (DCSR), as well as the presence of late Gadolinium enhancement (LGE) were determined with CMR. Septal and lateral myocardial velocities were measured with echocardiographic tissue Doppler imaging. lv mass and volumes were comparable between groups. Maximal septal to lateral wall thickness ratio (SL ratio) was larger in carriers than in controls (1.3 ± 0.2 versus 1.1 ± 0.1, p < 0.001). Also, LA volumes were larger in carriers compared to controls (p < 0.05). Both peak SCS (p < 0.05) and peak DCSR (p < 0.01) were lower in carriers compared to controls, particularly in the basal lateral wall. Focal LGE was present in 2 carriers and not in controls. The combination of a SL ratio >1.2 and a peak DCSR <105%.s-1 was present in 45% of carriers and in none of the controls, yielding a positive predictive value of 100%. Two carriers and 18 controls had a SL ratio < 1.2 and peak DCSR >105%.s-1, yielding a negative predictive value of 90%. With multivariate analysis, HCM mutation carriership was an independent determinant of reduced peak SCS and peak DCSR. Conclusions HCM mutation carriership is an independent determinant of reduced peak SCS and peak DCSR when LV wall thickness is within normal limits, and is associated with increased LA volumes and SL ratio. Using SL ratio and peak DCSR has a high accuracy to identify carriers. However, since carriers also display structural abnormalities and focal LGE, we advocate to also evaluate morphology and presence of LGE when screening for carriers.

2010-01-01

340

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

PubMed

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

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

341

An inexpensive and readily available alternative to the silastic “silo” for staged closure of abdominal wall defects  

Microsoft Academic Search

The successful use of 500 ml Viaflex polyvinylchloride (PVC) IV fluid infusion bags instead of traditional reinforced silastic “silos” is described in two infants with exomphalos who required staged abdominal closure. Although one infant did not survive, there were no complications related to the IV bag silo in either patient. In both cases the bag was in place for more

R. H. Pearl; E. H. Dykes

1995-01-01

342

How should an infected perinephric haematoma be drained in a tetraplegic patient with baclofen pump implanted in the abdominal wall? - A case report  

PubMed Central

Background We present a case to illustrate controversies in percutaneous drainage of infected, perinephric haematoma in a tetraplegic patient, who had implantation of baclofen pump in anterior abdominal wall on the same side as perinephric haematoma. Case presentation A 56-year-old male with C-4 tetraplegia had undergone implantation of programmable pump in the anterior abdominal wall for intrathecal infusion of baclofen to control spasticity. He developed perinephric haematoma while he was taking warfarin as prophylactic for deep vein thrombosis. Perinephric haematoma became infected with a resistant strain of Pseudomonas aeruginosa, and required percutaneous drainage. Positioning this patient on his abdomen without anaesthesia, for insertion of a catheter from behind, was not a realistic option. Administration of general anaesthesia in this patient in the radiology department would have been hazardous. Results and Conclusion Percutaneous drainage was carried out by anterior approach under propofol sedation. The site of entry of percutaneous catheter was close to cephalic end of baclofen pump. By carrying out drainage from anterior approach, and by keeping this catheter for ten weeks, we took a risk of causing infection of the baclofen pump site, and baclofen pump with a resistant strain of Pseudomonas aeruginosa. The alternative method would have been to anaesthetise the patient and position him prone for percutaneous drainage of perinephric collection from behind. This would have ensured that the drainage track was far away from the baclofen pump with minimal risk of infection of baclofen pump, but at the cost of incurring respiratory complications in a tetraplegic subject.

Vaidyanathan, Subramanian; Soni, Bakul M; Hughes, Peter L; Singh, Gurpreet; Watt, John WH; Oo, Tun; Sett, Pradipkumar

2002-01-01

343

Impact of Adjuvant Chemotherapy on Abdominal Wall Hernias and Bulges After Muscle-Sparing Free TRAM Flaps for Breast Reconstruction.  

PubMed

BACKGROUND: Free tissue transfer from an abdominal donor site has become a popular method for postmastectomy breast reconstruction. The detrimental effects of adjuvant chemotherapy on healing and the resulting clinical impact on patient outcome remains somewhat unclear for abdominal bulges and hernias resulting after free tissue transfer from the abdominal donor site. METHODS: An institutional review board-approved retrospective review of 155 free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flaps performed for breast reconstruction was undertaken to evaluate the effect of adjuvant chemotherapy on abdominal donor-site morbidity. The primary outcome studied was the development of hernias and bulges. Statistical analysis was performed using univariate and multivariate classification and regression tree (CART) analysis. RESULTS: Of the 155 patients, 51 underwent bilateral MS-TRAM flaps and 104 underwent unilateral MS-TRAM flap reconstruction. Thirty-nine patients underwent adjuvant chemotherapy. A statistically significant association was seen between chemotherapy treatment and the incidence of hernias alone (P < 0.05; odds ratio, 6.42; 95% confidence interval, 0.88-73.58). Multivariable CART analyses corroborated these findings and revealed that presence of diabetes mellitus (DM), bilaterality, and receiving chemotherapy treatment were related to increased incidence of hernias (P = 0.011, 0.005, and 0.017, respectively) after controlling for clinical variables such as smoking status, chronic obstructive pulmonary disease, and type of closure. Univariate analyses also revealed a statistically significant association between bilaterality in conjunction with chemotherapy treatment and the incidence of hernias alone (P = 0.0002; odds ratio, 37.56; 95% confidence interval, 4.56-476.35). This highly significant finding is further augmented by multivariable CART analyses, which found that patients who were bilateral and underwent chemotherapy treatment or those with DM were significantly more likely to develop hernias (P < 0.001 and P = 0.016, respectively). CONCLUSIONS: To date, our study is the single largest series of abdominal donor-site complications in patients receiving chemotherapy and free MS-TRAM breast reconstruction. We have demonstrated an increase in the incidence of abdominal donor-site complications, specifically abdominal bulges and hernias, in patients undergoing chemotherapy for advanced stages of breast cancer. This increased complication rate is most pronounced in patients requiring chemotherapy who undergo bilateral reconstruction, and is also a significant risk for patients receiving chemotherapy who have preexisting DM. PMID:23241806

Patel, Sameer A; Sandberg, Lars Johan; Ranganath, Bharat; Devarajan, Karthik; Toto, Julia; Topham, Neal S

2012-12-18

344

Fabrication of chitosan single-component microcapsules with a micrometer-thick and layered wall structure by stepwise core-mediated precipitation.  

PubMed

Incubation of CaCO(3) microparticles in chitosan (CS) solution at pH 5.2 and following with ethylenediaminetetraacetic acid disodium salt (EDTA) treatment resulted in CS single-component microcapsules with an ultra-thick wall structure. Repeating the incubation caused stepwise increase of wall thickness and finally resulted in CS microcapsules with a layered structure. This unique method is mediated by precipitation of CS on the CaCO(3) particles as a result of pH increase caused by the partial dissolution of CaCO(3) . The obtained CS capsules are stable at neutral pH. PMID:22258737

Han, Yuanyuan; Tong, Weijun; Zhang, Yuying; Gao, Changyou

2012-01-18

345

[Surgical treatment of the defects of the lumbar-lateral region of the abdominal wall in elderly and senile patients].  

PubMed

The results of surgical treatment of 44 patients with defects in the lumbar-lateral abdomen. Age of patients ranged from 60 to 78 years. Causes defects in 32 (72.7%) patients were hernia after surgical interventions on the urinary system using lumbotomic accesses; in 4 (9.1%)--hernias, in 2 (4.5%)--eventration after applying troakar lateral openings during laparoscopic surgery; in 2 (4.5%)--hernias, in 2 (4.5%)--eventration, and in 2 (4.5%)--evisceration through aperture after removing drains for drainage of the abdominal cavity. To prevent the development of the proposed method of drainage of the abdominal cavity during laparoscopic operations (patent for useful model No 51170 from 12.07.10). Autotransplantation own tissues justified by the size of the defect W1. If there is a defect larger aloplastyc shown by the method of sub lay in the proposed original method. PMID:23610821

Vorovs'ky?, O O

2012-12-01

346

Obesity-Associated Abdominal Elephantiasis  

PubMed Central

Abdominal elephantiasis is a rare entity. Abdominal elephantiasis is an uncommon, but deformative and progressive cutaneous disease caused by chronic lymphedema and recurrent streptococcal or Staphylococcus infections of the abdominal wall. We present 3 cases of patients with morbid obesity who presented to our hospital with abdominal wall swelling, thickening, erythema, and pain. The abdominal wall and legs were edematous, with cobblestone-like, thickened, hyperpigmented, and fissured plaques on the abdomen. Two patients had localised areas of skin erythema, tenderness, and increased warmth. There was purulent drainage from the abdominal wall in one patient. They were managed with antibiotics with some initial improvement. Meticulous skin care and local keratolytic treatment for the lesions were initiated with limited success due to their late presentation. All three patients refused surgical therapy. Conclusion. Early diagnosis is important for the treatment of abdominal elephantiasis and prevention of complications.

Kohli, Ritesh; Argento, Vivian; Amoateng-Adjepong, Yaw

2013-01-01

347

In Vivo Quantification of Blood Flow and Wall Shear Stress in the Human Abdominal Aorta During Lower Limb Exercise  

Microsoft Academic Search

Magnetic resonance (MR) imaging techniques and a custom MR-compatible exercise bicycle were used to measure, in vivo, the effects of exercise on hemodynamic conditions in the abdominal aorta of eleven young, healthy subjects. Heart rate increased from 73±6.2 beats\\/min at rest to 110±8.8 beats\\/min during exercise (p p p p 2 at rest to 6.2±0.5 dyn\\/cm2 during exercise (p 2

Charles A. Taylor; Christopher P. Cheng; Leandro A. Espinosa; Beverly T. Tang; David Parker; Robert J. Herfkens

2002-01-01

348

Quantitative assessment of glucose metabolism in the vessel wall of abdominal aortic aneurysms: correlation with histology and role of partial volume correction.  

PubMed

Inflammatory-proteolytic processes in the vessel wall are essential in the pathophysiology of abdominal aortic aneurysm (AAA). It has been demonstrated that, (18)F-FDG-PET/CT may be useful for detection of pathological wall metabolism and therefore risk stratification. Quantification of the FDG-uptake in AAA wall is hampered by partial-volume (PV)-effects. For correction and accurate quantitative (18)F-FDG-uptake analysis we designed and validated a novel IDL-based software in correlation to phantom studies, histopathology and clinical presentation of AAA patients. For in vivo studies 23 patients with symptomatic and asymptomatic AAA underwent (18)F-FDG-PET/CT before surgery. In areas with (18)F-FDG-uptake the maximum and mean standardized uptake values in the vessel wall with (PVC-SUV(max), PVC-SUV(mean)) and without (SUV(max), SUV(mean)) PV-correction were determined. Results were correlated with clinical presentation, corresponding macrophage-infiltration and MMP-2- and -9-expression in surgical specimens. In patients, SUV(max), SUV(mean) as well as PVC-SUV(max) or PVC-SUV(mean) enabled a highly significant (p < 0.005) discrimination of symptomatic and asymptomatic AAA. Uncorrected and corrected SUVs showed comparable correlations with macrophage-infiltration and MMP-9 expression. No correlation of (18)F-FDG-uptake and MMP-2 was found. In vivo correlations of detected FDG-uptake with clinical and histological results showed comparable results for corrected and uncorrected SUVs. PV-correction is not mandatory for qualitative clinical assessment of glucose metabolism in the vessel wall of AAA-patients but may be necessary to establish quantitative cut off values to stratify patients for aneurysm repair. PMID:22772434

Reeps, Christian; Bundschuh, Ralph A; Pellisek, Jaroslav; Herz, Michael; van Marwick, Sandra; Schwaiger, Markus; Eckstein, Hans-Henning; Nekolla, Stephan G; Essler, Markus

2012-07-07

349

Inverse problem of material distribution for desired fracture characteristics in a thick-walled functionally graded material cylinder with two diametrically-opposed edge cracks  

Microsoft Academic Search

This study concerns the inverse problem of evaluating the optimum material distribution for desired fracture characteristics in a thick-walled functionally graded material (FGM) cylinder containing two diametrically-opposed edge cracks emanating from the inner surface of the cylinder. The thermal eigenstrain developed in the cylinder material due to nonuniform coefficient of thermal expansion as a result of cooling from sintering temperature

A. M. Afsar; M. Anisuzzaman; J. I. Song

2009-01-01

350

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading  

Microsoft Academic Search

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio

Hideki Sekine; Kimiaki Yoshida

2007-01-01

351

A tale of two neglected systems--structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves  

PubMed Central

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.

Botha, C. E. J.

2013-01-01

352

Measurement of defect thickness of the wall thinning defect pipes by lock-in infrared thermography technique  

NASA Astrophysics Data System (ADS)

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.

Kim, Kyeongsuk; Kim, Kyungsu; Jung, Hyunchul; Chang, Hosub

2009-12-01

353

ENDOSCOPIC FULL THICKNESS BIOPSY OF THE GASTRIC WALL WITH DEFECT CLOSURE USING AN ENDOSCOPIC SUTURING DEVICE: SURVIVAL PORCINE STUDY  

PubMed Central

Background The pathogenesis of several common gastric motility diseases and functional gastrointestinal disorders remains essentially unexplained. Gastric wall biopsies that include the muscularis propria to evaluate the enteric nervous system, interstitial cells of Cajal and immune cells can provide important insights to our understanding of the etiology of these disorders. Objectives To determine 1. Technical feasibility, reproducibility and safety of performing a full thickness gastric biopsy (FTGB) using a submucosal endoscopy with mucosal flap (SEMF) technique; 2. Technical feasibility, reproducibility and safety of tissue closure using an endoscopic suturing device; 3. Ability to identify myenteric ganglia in resected specimens; 4. Long-term safety. Design Single center, pre-clinical survival study. Setting Animal research laboratory – Developmental Endoscopy Unit. Subjects Twelve domestic pigs. Interventions Animals underwent a SEMF procedure with gastric muscularis propria resection. The resultant offset mucosal entry site was closed using an endoscopic suturing device. Animals were survived for 2 weeks. Main Outcome Measurements 1. Technical feasibility, reproducibility and safety of the procedure 2. Clinical course of the animals 3. Histological and immunochemical evaluation of the resected specimen to determine if myenteric ganglia were present in the sample. Results FTGB was achieved using the SEMF technique in all 12 animals. The offset mucosal entry site was successfully closed using the suturing device in all animals. Mean resected tissue size was 11 mm. Mean total procedure time was 61 mins with 2–4 interrupted sutures placed per animal. Histology showed musclaris propria and serosa confirming full thickness resections in all animals. Myenteric ganglia were visualized in 11/12 animals. The clinical course was uneventful. Repeat endoscopy and necropsy at 2 weeks showed absence of ulceration at either the mucosal entry sites or overlying the more distal muscularis propria resection sites. There was complete healing of the serosa in all animals with minimal single band adhesions in 5/12 animals. Retained sutures were present in 10/12 animals. Limitations Animal experiment. Conclusion FTGB using the SEMF technique and endoscopic suturing device is technically feasible, reproducible and safe. The larger tissue specimens will allow for improved analysis of multiple cell types.

Rajan, E; Gostout, CJ; Bonin, E Aimore; Moran, EA; Locke, GR; Szarka, LA; Talley, NJ; Deters, JL; Miller, CA; Knipschield, MA; Lurken, MS; Stoltz, GJ; Bernard, CE; Grover, M; Farrugia, G

2013-01-01

354

Evaluation of Rate of Change in Thickness of Heart Wall by Measuring Time Variation of Ultrasonic Integrated Backscatter during a Cardiac Cycle  

NASA Astrophysics Data System (ADS)

Integrated backscatter (IB) from the heart wall is gaining attention as a quantitative tissue characterization method and the cyclic variation (CV) in IB during a cardiac cycle offers potential for the evaluation of myocardial contractility. Since there is large motion in the heart wall owing to the heartbeat, in the conventional method, the position of the region of interest (ROI) for calculating the IB is manually assigned in each frame during one cardiac cycle. Moreover, the change in the size of the ROI during contraction and relaxation of the myocardium is not considered. In this study, the phased tracking method was applied to multiple points in the heart wall for automatic tracking of the position and size of the ROI and, then, IB in the same site of the heart wall was measured in each frame by improving temporal resolution and spatial resolution in the axial direction. As a result, cyclic variations, which differed site by site, were found. Furthermore, the rate of change in thickness was estimated by using the interference cycle obtained by applying the discrete Fourier transform (DFT) to IB signals. According to the results, the rate of change in thickness estimated using the interference cycle of IB was in good agreement with that estimated by the phased tracking method. These results indicate the possibility of estimating the rate of change in thickness using the IB signal.

Shida, Hiro; Hasegawa, Hideyuki; Kanai, Hiroshi

2012-07-01

355

Application of elastic wave dispersion relations to estimate thermal properties of nanoscale wires and tubes of varying wall thickness and diameter  

NASA Astrophysics Data System (ADS)

This paper reports dependency of specific heat and ballistic thermal conductance on cross-sectional geometry (tube versus rod) and size (i.e., diameter and wall thickness), in free-standing isotropic non-metallic crystalline nanostructures. The analysis is performed using dispersion relations found by numerically solving the Pochhammer-Chree frequency equation for a tube. Estimates for the allowable phonon dispersion relations within the crystal lattice are obtained by modifying the elastic acoustic dispersion relations so as to account for the discrete nature of the material's crystal lattice. These phonon dispersion relations are then used to evaluate the specific heat and ballistic thermal conductance in the nanostructures as a function of the nanostructure geometry and size. Two major results are revealed in the analysis: increasing the outer diameter of a nanotube while keeping the ratio of the inner to outer tube radius (?) fixed increases the total number of available phonon modes capable of thermal population. Secondly, decreasing the wall thickness of a nanotube (i.e., increasing ?) while keeping its outer diameter fixed, results in a drastic decrease in the available phonon mode density and a reduction in the frequency of the longitudinal and flexural acoustic phonon modes in the nanostructure. The dependency of the nanostructure's specific heat on temperature indicates 1D, 2D, and 3D geometric phonon confinement regimes. Transition temperatures for each phonon confinement regime are shown to depend on both the nanostructure's wall thickness and outer radius. Compared to nanowires (? = 0), the frequency reduction of acoustic phonon modes in thinner walled nanotubes (? = 0.96) is shown to elevate the ballistic thermal conductance of the thin-walled nanotube between 0.2 and 150 K. At 20 K, the ballistic thermal conductance of the thin-walled nanotube (? = 0.96) becomes 300% greater than that of a solid nanowire. For temperatures above 150 K, the trend in ballistic thermal conductance inverts. The greater number of phonon modes in nanostructures with increased outer diameter and wall thickness is shown to have a larger contribution to ballistic thermal conductance when compared to the increased contribution from the frequency reduction of acoustic phonon modes in thinner walled nanotubes.

Bifano, Michael F. P.; Kaul, Pankaj B.; Prakash, Vikas

2010-06-01

356

Thickness dependence of current-induced domain wall motion in a Co/Ni multi-layer with out-of-plane anisotropy  

NASA Astrophysics Data System (ADS)

Thickness dependence of current-induced domain wall (DW) motion in a perpendicularly magnetized [Co/Ni]N multilayered wire containing Ta/Pt capping and Pt/Ta seed layers has been studied. The thickness of the magnetic layer was controlled by the stacking number, N. The threshold current density for driving DW had a local minimum at N = 3 and the velocity of DW motion decreased with N. Estimation of carrier spin polarization from measurements of DW velocity revealed that a thinner Co/Ni stack adjacent to the Pt layers reduced the carrier spin polarization and the strength of adiabatic spin transfer torque.

Tanigawa, Hironobu; Suzuki, Tetsuhiro; Fukami, Shunsuke; Suemitsu, Katsumi; Ohshima, Norikazu; Kariyada, Eiji

2013-04-01

357

Detraining-Related Changes in Left Ventricular Wall Thickness and Longitudinal Strain in a Young Athlete Likely to Have Hypertrophic Cardiomyopathy  

PubMed Central

One of the diagnostic criteria in order to differentiate between physiological and pathological left ventricular hypertrophy is the wall thickness reduction after at least 3-month detraining period, which is considered a marker of the athlete’s heart. This report describes detraining-related regression of LV hypertrophy and improvement in myocardial deformation in a junior athlete likely to have hypertrophic cardiomyopathy. Key pointsHypertrophic cardiomyopathy in adolescent athletes can be discovered by 12-lead ECGPhysical training is an important trigger for the clinical presentation of hypertrophic cardiomyopathyReverse LV remodeling (wall thickness reduction) with detraining is a common echocardiographic finding in athletes with physiological hypertrophyThis report demonstrates that reverse remodeling can also be found in adolescent athletes likely to have hypertrophic cardiomyopathy

de Gregorio, Cesare; Speranza, Giampiero; Magliarditi, Alberto; Pugliatti, Pietro; Ando, Giuseppe; Coglitore, Sebastiano

2012-01-01

358

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading  

NASA Astrophysics Data System (ADS)

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio by a distribution of equivalent eigenstrain, we present an approximation method to obtain the stress intensity factor of radial edge crack in the FGM circular pipes. The optimum material composition for minimizing the stress intensity factor of radial edge crack is determined using a nonlinear mathematical programming method. Numerical results obtained for a thick-walled TiC/Al2O3 FGM circular pipe reveal that it is possible to decrease remarkably the stress intensity factor of radial edge crack by setting the optimum material composition profile.

Sekine, Hideki; Yoshida, Kimiaki

359

The impact of a massive transfusion protocol (1:1:1) on major hepatic injuries: Does it increase abdominal wall closure rates?  

PubMed Central

Background Massive transfusion protocols (MTPs) using high plasma and platelet ratios for exsanguinating trauma patients are increasingly popular. Major liver injuries often require massive resuscitations and immediate hemorrhage control. Current published literature describes outcomes among patients with mixed patterns of injury. We sought to identify the effects of an MTP on patients with major liver trauma. Methods Patients with grade 3, 4 or 5 liver injuries who required a massive blood component transfusion were analyzed. We compared patients with high plasma:red blood cell:platelet ratio (1:1:1) transfusions (2007–2009) with patients injured before the creation of an institutional MTP (2005–2007). Results Among 60 patients with major hepatic injuries, 35 (58%) underwent resuscitation after the implementation of an MTP. Patient and injury characteristics were similar between cohorts. Implementation of the MTP significantly improved plasma: red blood cell:platelet ratios and decreased crystalloid fluid resuscitation (p = 0.026). Rapid improvement in early acidosis and coagulopathy was superior with an MTP (p = 0.009). More patients in the MTP group also underwent primary abdominal fascial closure during their hospital stay (p = 0.021). This was most evident with grade 4 injuries (89% vs. 14%). The mean time to fascial closure was 4.2 days. The overall survival rate for all major liver injuries was not affected by an MTP (p = 0.61). Conclusion The implementation of a formal MTP using high plasma and platelet ratios resulted in a substantial increase in abdominal wall approximation. This occurred concurrently to a decrease in the delivered volume of crystalloid fluid.

Ball, Chad G.; Dente, Christopher J.; Shaz, Beth; Wyrzykowski, Amy D.; Nicholas, Jeffrey M.; Kirkpatrick, Andrew W.; Feliciano, David V.

2013-01-01

360

Effect of ovality and variable wall thickness on collapse loads in pipe bends subjected to in-plane bending closing moment  

Microsoft Academic Search

The effect of ovality and variable wall thickness (thickening at intrados and thinning at extrados) on the collapse loads in pipe bends subjected to in-plane bending moment that tend to close the bend was investigated using finite element limit analyses based on elastic-perfectly plastic material with large geometry change option. The collapse moments were obtained from load–deflection curves of the

T. Christo Michael; A. R. Veerappan; S. Shanmugam

361

A Possible Role for the Thick-walled Epidermal Cells in the Mycorrhizal Hair Roots of Lysinema ciliatum R. Br. and other Epacridaceae  

Microsoft Academic Search

Hair roots ofLysinema ciliatumR. Br. and some other Epacridaceae have thick-walled cells in the epidermis. These are preferentially colonized with mycorrhizal fungi. Individual epidermal cells containing hyphal coils separate at the middle lamella and are released into the soil. Other colonized cells remain attached to the roots, usually in groups, surrounded by bare exodermis, where epidermal cells have either collapsed

A. E. ASHFORD; W. G. ALLAWAY; M. L. REED

1996-01-01

362

Low-background thick-walled gas-electron multiplier for measuring alpha-, beta-, and X-rays of ultralow intensity  

NASA Astrophysics Data System (ADS)

An experimental prototype of thick-walled gas-electron multiplier (THGEM) has been designed and manufactured using metal-coated fluoroplast as a low-background material. Working characteristics of the proposed device have been measured in detecting alpha-, beta-, and X-rays of ultralow intensity. Based on these data, the design of a low-background THGEM is developed for operating in the regime of counting single-electron pulses.

Kopylov, A. V.; Orekhov, I. V.; Petrov, E. P.; Petukhov, V. V.; Tikhonov, A. A.

2010-07-01

363

Comparison of cardiovascular magnetic resonance of late gadolinium enhancement and diastolic wall thickness to predict recovery of left ventricular function after coronary artery bypass surgery  

PubMed Central

Background The objective was to compare the value of late gadolinium enhancement (LGE) and end-diastolic wall thickness (EDWT) assessed by cardiovascular magnetic resonance (CMR) in predicting recovery of left ventricular function after coronary artery bypass surgery (CABG). Methods We enrolled patients with coronary artery disease and left ventricular ejection fraction < 45% who were scheduled for CABG. Regional contractility was assessed by cine CMR at baseline and 4 months after CABG. EDWT and LGE were assessed at baseline. Predictors for improvement of regional contractility were analyzed. Results We studied 46 men and 4 women with an average age of 61 years. Baseline left ventricular ejection fraction was 37 ± 13%. A total of 2,020 myocardial segments were analyzed. Abnormal wall motion and the LGE area were detected in 1,446 segments (71.6%) and 1,196 segments (59.2%) respectively. Wall motion improvement was demonstrated in 481 of 1,227 segments (39.2%) that initially had wall motion abnormalities at baseline. Logistic regression analysis showed that the LGE area, EDWT and resting wall motion grade predicted wall motion improvement. Comparison of Receiver-Operator-Characteristic (ROC) curves demonstrated that the LGE area was the most important predictor (p < 0.001). Adding information from LGE to the EDWT can decrease the number of false predictions by EDWT alone from 483 to 127 segments. Conclusion LGE and EDWT are independent predictors for functional recovery after revascularization. However, LGE appears to be a more important factor and independent of EDWT.

Krittayaphong, Rungroj; Laksanabunsong, Pansak; Maneesai, Adisak; Saiviroonporn, Pairash; Udompunturak, Suthipol; Chaithiraphan, Vithaya

2008-01-01

364

Analytical solution for spatially axisymmetric problem of thick-walled cylinder subjected to different linearly varying pressures along the axis and uniform pressures at two ends  

NASA Astrophysics Data System (ADS)

To our best knowledge, in the open literature, there is no analytical solution of thick-walled cylinder subjected to uniform pressures at two ends and different inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis. We now present such a solution. After repeated trials, we have finally succeeded in finding a necessary new displacement function. Based on A. E. H. Love method, the stress, displacement and volume strain formulas are derived by using the new displacement function. The present results include the Lamé’s formulas as special cases. Furthermore, the results obtained here can be applied to not only the thick-walled cylinders subjected to uniform pressures on the inner and outer surface of the thick-walled cylinder, respectively, but also the cylinders subjected to uniform pressures at two ends and different inner-and outer-surface pressures that are constant circumferentially but vary linearly at different rates along the axis, respectively. Finally we give a numerical example to compare our exact method with the approximate method.

Liang, Yaping; Wang, Huizhen; Ren, Xingmin

2008-01-01

365

Formation of Rhamnogalacturonan II-Borate Dimer in Pectin Determines Cell Wall Thickness of Pumpkin Tissue1  

Microsoft Academic Search

Boron (B) deficiency results in inhibition of pumpkin (Cucurbia moschata Duchesne) growth that is accompanied by swelling of the cell walls. Monomeric rhamnogalacturonan II (mRG-II) accounted for 80% to 90% of the total RG-II in B-deficient walls, whereas the borate ester cross-linked RG-II dimer (dRG-II-B) accounted for more than 80% of the RG-II in control plants. The results of glycosyl

Tadashi Ishii; Toshiro Matsunaga; Noriko Hayashi

2001-01-01

366

In Hypertrophic Cardiomyopathy Reduction of Relative Resting Myocardial Blood Flow Is Related to Late Enhancement, T2-Signal and LV Wall Thickness  

PubMed Central

Objectives To quantify resting myocardial blood flow (MBF) in the left ventricular (LV) wall of HCM patients and to determine the relationship to important parameters of disease: LV wall thickness, late gadolinium enhancement (LGE), T2-signal abnormalities (dark and bright signal), LV outflow tract obstruction and age. Materials and Methods Seventy patients with proven HCM underwent cardiac MRI. Absolute and relative resting MBF were calculated from cardiac perfusion MRI by using the Fermi function model. The relationship between relative MBF and LV wall thickness, T2-signal abnormalities (T2 dark and T2 bright signal), LGE, age and LV outflow gradient as determined by echocardiography was determined using simple and multiple linear regression analysis. Categories of reduced and elevated perfusion in relation to non- or mildly affected reference segments were defined, and T2-signal characteristics and extent as well as pattern of LGE were examined. Statistical testing included linear and logistic regression analysis, unpaired t-test, odds ratios, and Fisher’s exact test. Results 804 segments in 70 patients were included in the analysis. In a simple linear regression model LV wall thickness (p<0.001), extent of LGE (p<0.001), presence of edema, defined as focal T2 bright signal (p<0.001), T2 dark signal (p<0.001) and age (p?=?0.032) correlated inversely with relative resting MBF. The LV outflow gradient did not show any effect on resting perfusion (p?=?0.901). Multiple linear regression analysis revealed that LGE (p<0.001), edema (p?=?0.026) and T2 dark signal (p?=?0.019) were independent predictors of relative resting MBF. Segments with reduced resting perfusion demonstrated different LGE patterns compared to segments with elevated resting perfusion. Conclusion In HCM resting MBF is significantly reduced depending on LV wall thickness, extent of LGE, focal T2 signal abnormalities and age. Furthermore, different patterns of perfusion in HCM patients have been defined, which may represent different stages of disease.

Hueper, Katja; Zapf, Antonia; Skrok, Jan; Pinheiro, Aurelio; Goldstein, Thomas A.; Zheng, Jie; Zimmerman, Stefan L.; Kamel, Ihab R.; Abraham, Roselle; Wacker, Frank; Bluemke, David A.; Abraham, Theodore; Vogel-Claussen, Jens

2012-01-01

367

Left Ventricular Wall Thickness and Regional Systolic Function in Patients With Hypertrophic Cardiomyopathy. A Three-dimensional Tagged Magnetic Resonance Imaging Study  

PubMed Central

Background Regional performance of the hypertrophied left ventricle (LV) in hypertrophic cardiomyopathy (HCM) is still incompletely characterized with studies variably reporting that the hypertrophied myocardium is hypokinetic, akinetic, or has normal function. Different imaging modalities (M-mode or two-dimensional echocardiography) and methods of analysis (fixed or floating frame of reference for wall motion analysis) yield different results. We assessed regional function in terms of systolic wall thickening and shortening and related these parameters to end-diastolic thickness using tagged magnetic resonance imaging and the three-dimensional volume-element approach. Methods and Results In 17 patients with HCM and 6 healthy volunteers, four parallel short-axis images with 12 radial tags and two mutually orthogonal long-axis images with four parallel tags were obtained at end diastole and end systole. After the LV endocardial and epicardial borders were traced, three-dimensional volume elements were constructed by connecting two matched planar segments in two adjacent short-axis image planes, accounting for translation, twist, and long-axis shortening. A total of 72 such volume elements encompassed the entire LV. From each of these elements, end-diastolic thickness and systolic function (fractional thickening and circumferential shortening) were calculated. The average end-diastolic thickness was 15.8±4.2 mm in patients with HCM, which was significantly greater than that in healthy subjects (8.6±2.1 mm, P<.001). Fractional thickening was significantly less in patients with HCM than in healthy subjects (0.31±0.22 versus 0.56±0.23, P<.001). There was a highly significant inverse correlation between fractional thickening and end-diastolic thickness that was independent of the type of hypertrophy or age group. Similar inverse relations were observed between circumferential shortening and end-diastolic wall thickness. Conclusions The myocardium in patients with HCM is heterogeneously thickened and the fractional thickening and circumferential shortening of the abnormally thickened myocardium are reduced compared with healthy subjects. The decrease in fractional thickening and shortening is inversely related to the local thickness.

Dong, Sheng-Jing; MacGregor, John H.; Crawley, Adrian P.; McVeigh, Elliot; Belenkie, Israel; Smith, Eldon R.; Tyberg, John V.; Beyar, Rafael

2007-01-01

368

Measurement of change in thickness of cylindrical shell caused by remote actuation for assessment of viscoelasticity of arterial wall  

Microsoft Academic Search

In this paper, for assessment of the viscoelastic property of the arterial wall, a method is proposed for measuring elastic moduli at multiple frequencies by generating the change in internal pressure due to remote cyclic actuation. From basic experiments using a silicone rubber tube, it was found that the change in internal pressure at the ultrasonic beam position (for measurement

Hideyuki Hasegawa; Hiroshi Kanai; Yoshiro Koiwa; James P. Butler

2003-01-01

369

Analysis of growth, composition and thickness of the cell walls of transgenic tobacco plants expressing a yeast-derived invertase  

Microsoft Academic Search

Summary Transgenic tobacco (Nicotiana tabaccum L. cv. Samsun NN) expressing a yeast invertase in the vacuole provides a novel tool for studying the role of turgor, osmotic pressure, and cell wall properties during cell expansion. The plants used showed increased osmolarity and an increased cell size in young leaves. Their advantage is that they allow long-term analysis and undisturbed conditions.

S. Hoffmann-Benning; L. Willmitzer; J. Fisahn

1997-01-01

370

Influence of the thickness of a wall and of its thermophysical characteristics on the critical heat flux in boiling  

Microsoft Academic Search

The experimental data published by various authors who studied the burnout heat transfer in boiling have been analyzed. It\\u000a is shown that the critical heat flux depends substantially on the physical properties of both the boiling liquid and cooled\\u000a wall and its geometric parameters.

I. I. Gogonin

2009-01-01

371

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)

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.

Rubel, M.; Philipps, V.; Tanabe, T.; Wienhold, P.; Freisinger, M.; Linke, J.; von Seggern, J.; Wessel, E.

372

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

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.

Robert V. Kolarik II

2002-10-23

373

Low-background thick-walled gas-electron multiplier for measuring alpha-, beta-, and X-rays of ultralow intensity  

Microsoft Academic Search

An experimental prototype of thick-walled gas-electron multiplier (THGEM) has been designed and manufactured using metal-coated\\u000a fluoroplast as a low-background material. Working characteristics of the proposed device have been measured in detecting alpha-,\\u000a beta-, and X-rays of ultralow intensity. Based on these data, the design of a low-background THGEM is developed for operating\\u000a in the regime of counting single-electron pulses.

A. V. Kopylov; I. V. Orekhov; E. P. Petrov; V. V. Petukhov; A. A. Tikhonov

2010-01-01

374

Comparison of compressive properties of layered syntactic foams having gradient in microballoon volume fraction and wall thickness  

Microsoft Academic Search

The existing functionally graded syntactic foams (FGSFs) are based on creating a gradient of microballoon (hollow particles) volume fraction along the length or thickness of the composite to achieve a variation in density and mechanical properties. However, such an approach has several limitations. Variation in volume fractions of the constituents leads to the possibility of warping or localized swelling of

Nikhil Gupta; William Ricci

2006-01-01

375

A study on optimum insulation thicknesses of external walls in hot summer and cold winter zone of China  

Microsoft Academic Search

The employ of thermal insulation is one of the most effective ways of building energy conservation for cooling and heating. Therefore, the selection of a proper insulation material and the determination of optimum insulation thickness are particularly vital. Four typical cities of Shanghai, Changsha, Shaoguan and Chengdu are selected to represent A, B, C and D subzone of hot summer

Jinghua Yu; Changzhi Yang; Liwei Tian; Dan Liao

2009-01-01

376

RECURRENCE PATTERN IN SQUAMOUS CELL CARCINOMA OF SKIN OF LOWER EXTREMITIES AND ABDOMINAL WALL (KANGRI CANCER) IN KASHMIR VALLEY OF INDIAN SUBCONTINENT: IMPACT OF VARIOUS TREATMENT MODALITIES  

PubMed Central

Background: The spectrum of skin cancer in Kashmir valley is drastically different from the rest of the country. Maxwell was the first to report skin cancer of lower extremities in Kashmiri population, developing on/over erythema ab igne, and attributed it to the use/or exposure of Kangri. These tumors have an aggressive biological behavior with a substantial risk of loco-regional metastasis in 30-50% cases. Because of unique geographical distribution of Kangri cancer, there is dearth of literature regarding the natural history, loco-regional and distant metastatic pattern and treatment recommendations in these tumors. Aims: To study the metastatic pattern of these skin tumors and to assess the impact of various treatment modalities and use of prophylactic nodal treatment in this clinical entity. Methods: The retrospective study (study period 1993-2005) included 266 patients of squamous cell carcinoma of skin of lower extremities and abdominal wall. Two hundred and forty-four cases with a follow-up of 2-7 years were included for final analysis with stress on loco-regional relapse pattern and methods of treatment evolved and used at our institute from time to time. Statistical analysis was done using yates corrected Chi-square test and odds ratio analysis. Results: Our results favor the use of post operative radiotherapy to primary and prophylactic treatment of regional nodes on the lines of head and neck tumors in these cases. Conclusion: Post operative radiotherapy significantly decreases the loco-regional recurrences and a trial of prophylactic nodal irradiation is justified in a selected group of such patients.

Teli, Mohmad Ashraf; Khan, N A; Darzi, M Ashraf; Gupta, Meenu; Tufail, A

2009-01-01

377

Bulk and boundary critical behaviour of thin and thick domain walls in the two-dimensional Potts model  

Microsoft Academic Search

The geometrical critical behaviour of the two-dimensional Q-state Potts model is usually studied in terms of the Fortuin-Kasteleyn (FK) clusters, or their surrounding loops. In this paper we study a quite different geometrical object: the spin clusters, defined as connected domains where the spin takes a constant value. Unlike the usual loops, the domain walls separating different spin clusters can

Jérôme Dubail; Jesper Lykke Jacobsen; Hubert Saleur

2010-01-01

378

Low-alloy steels for thick-walled pressure vessels. Summary report, February 1, 1980January 31, 1982  

Microsoft Academic Search

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.

J. A. Todd; D. W. Chung; E. R. Parker

1982-01-01

379

Design of low alloy steels for thick walled pressure vessels. Final technical report, February 1, 1980May 30, 1985. [2-1\\/4Cr1Mo with minor additions of Cr, Ni, Mo and V  

Microsoft Academic Search

This report presents results of the five year research program ''Design of Low Alloy Steels for Thick Walled Pressure Vessels.'' The objective of the program was to modify existing commercial low alloy steels and to develop new alloys to satisfy the material requirements for thick section plate up to 400 mm (16 in.) to be used for construction of the

R. O. Ritchie; J. A. Todd; P. N. Spencer; E. R. Parker

1985-01-01

380

Low-alloy steels for thick-walled pressured vessels. Final report, October 1, 1978-March 31, 1980  

SciTech Connect

This program aims to modify existing commercially available pressure vessel steels and to develop new steels which can be field fabricated into thick sectioned pressure vessels for coal gasification and liquefaction systems. During 1978-79, transmission electron microscopy has been carried out on 2.25Cr-1Mo, samples of which have been cooled at rates simulating those obtained in commercial plates up to 16 in. thick. The tempering responses at different temperatures have also been fully characterised. These studies were repeated on the alloy modifications. Programs have been developed to eliminate temper embrittlement in 2.25Cr-1Mo and also in 3.5Ni-1.5Cr steels and a study of the microstructural aspects of weldability has also been initiated. Fracture mechanics studies have been initiated on A533B and its alloy modifications. Isothermal transformation of Alloy 4 (Fe-0.1%C-0.5V-0.5Mn) and Alloy 5 (Fe-0.1C-0.5V-0.5Mn-3Ni) showed that uniform VC particle dispersions with optimum strength and toughness properties could be achieved in Alloy (i.e. by addition of 3%Ni). Preliminary investigations indicate that this VC dispersion can also be produced during slow cooling, especially at rates equivalent to those for 12 to 16'' thick plates. 30 figures, 11 tables.

Todd, J.A.; Zackay, V.F.; Parker, E.R.

1980-01-01

381

The growth of low resistivity, heavily Al-doped 4H–SiC thick epilayers by hot-wall chemical vapor deposition  

NASA Astrophysics Data System (ADS)

Heavily Al-doped 4H–SiC thick epilayers (˜90 ?m) were grown on 3-in n+ 4H–SiC wafers by using the hot-wall CVD method. On the purpose of enhancing incorporated Al-dopant concentration, the growth condition dependence of the Al incorporation behavior in the heavy doping range near Al solubility limit in 4H–SiC was investigated by varying the growth parameters, i.e., growth rate, pressure, temperature and Al-dopant source flow rate. A series of thick epilayers possessing Al-dopant concentration from 9.6×1019 to 4.7×1020 cm?3 were obtained. Among them, the epilayer with Al-dopant concentration of 3.5×1020 cm?3 demonstrates a comparably low resistivity of 16.5 m? cm as that of commercial n+ 4H–SiC wafer. The incorporated Al-dopant concentration dependences on surface morphology, crystalline quality and crystal structures of the heavily Al-doped thick epilayers on n+ 4H–SiC substrates were characterized and discussed.

Ji, Shiyang; Kojima, Kazutoshi; Ishida, Yuuki; Saito, Shingo; Kato, Tomohisa; Tsuchida, Hidekazu; Yoshida, Sadafumi; Okumura, Hajime

2013-10-01

382

Clinical and Endoscopic Significance of Bowel-Wall Thickening Reported on Abdominal Computed Tomographies in Symptomatic Patients with No History of Gastrointestinal Disease.  

PubMed

BACKGROUND: Bowel-wall thickening (BWT) is a commonly reported finding on diagnostic abdominal pelvic computed tomographies (CT) in patients with no history of gastroenterologic disease. The significance of this nonspecific finding is not clear. METHODS: Medical records from the Vancouver General Hospital were reviewed from October 27, 1999, to October 27, 2009. The initial search yielded 5696 cases, of which 76 cases met the inclusion criteria for review. Inclusion criteria were the following: age older than 18 years, symptoms without a diagnosis of gastrointestinal disease before CT, the reported finding of terminal ileal and/or colonic BWT, colonoscopy after CT, and/or microbiologic investigations. Exclusion criteria included known gastrointestinal disease before CT. The primary objective was to determine if BWT could be associated with a significant endoscopic pathology. The secondary objective was to determine whether the pattern of abnormality on the CT was associated with a specific endoscopic finding. RESULTS: A total of 76 patients met the inclusion criteria of our study. Of those, 76% had various identifiable pathologies on colonoscopy. Only 24% had normal colonoscopic findings. Inflammatory bowel disease (IBD) and infectious colitis were the most common causes of BWT. A report of "skip lesions" on the CT (5%) was always associated with IBD. "Pancolitis" reported on the CT (11%) was associated with endoscopic findings of IBD in 25% of cases, infection in 50% of cases, and normal findings in 25% of cases. The report of "stranding" (36%) on CT in the presence of BWT was associated with many non-neoplastic endoscopic pathologic processes, including infectious colitis (22%), IBD (19%), and ischemia (15%), but also was associated with normal endoscopic findings in 26% of the cases. "Lymphadenopathy" was reported in 17% of the CTs and was associated with infectious colitis (30%), IBD (38%), or neoplastic processes (15%) but also normal endoscopic findings in 15%. CONCLUSION: Symptomatic patients who are found to have nonspecific BWT on CT should undergo definitive endoscopic investigation because the majority will have significant gastroenterologic disease, and only a minority will have a normal colonoscopy. PMID:23142403

Al-Khowaiter, Saad S; Brahmania, Mayur; Kim, Edward; Madden, Mark; Harris, Alison; Yoshida, Eric M; Gray, James R

2012-11-01

383

Effect of rimonabant on carotid intima–media thickness (CIMT) progression in patients with abdominal obesity and metabolic syndrome: the AUDITOR Trial  

Microsoft Academic Search

ObjectiveThe aim of this trial was to determine whether obese patients benefit from treatment with rimonabant in terms of progression of carotid atherosclerosis. Rimonabant, a selective cannabinoid-1 receptor blocker, reduces body weight and improves cardiometabolic risk factors in patients who are obese.Design, setting, patients, interventions and resultsA prospective, double-blind, placebo-controlled trial (Atherosclerosis Underlying Development assessed by Intima–media Thickness in patients

Daniel H OLeary; Anne Q Reuwer; Steven E Nissen; Jean-Pierre Després; John E Deanfield; Michael W Brown; Rong Zhou; Salvatore M Zabbatino; Bernard Job; John J P Kastelein; Frank L J Visseren

2011-01-01

384

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

PubMed Central

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

Ramos, Antonio; Bazan, Ivonne; Negreira, Carlos; Brum, Javier; Gomez, Tomas; Calas, Hector; Ruiz, Abelardo; de la Rosa, Jose Manuel

2012-01-01

385

The analysis of time-dependent creep in FGPM thick walled sphere under electro-magneto-thermo-mechanical loadings  

NASA Astrophysics Data System (ADS)

Time-dependent creep response of a smart sphere made of functionally graded piezoelectric material (FGPM) is investigated. The vessel is subjected to an internal pressure, a uniform temperature field, an electric potential and a uniform magnetic field. Under such a loading condition initial elastic stresses are locked in the vessel at zero time. Due to high temperature, creep evolution causes stress redistribution in the sphere which is followed by electric potential redistribution across the thickness of the sphere. History of radial stresses is always reflected by history of electric potential which can be used for condition monitoring of the smart sphere. From the initial elastic stresses it has been found that imposing an electric potential decreases effective stresses. It has also been concluded from history of electric potential that electric potential redistribution is decreasing due to creep evolution and therefore this is followed by increasing effective stresses.

Loghman, A.; Moradi, M.

2013-08-01

386

Low-alloy steels for thick-walled pressure vessels. Summary report, February 1, 1980-January 31, 1982  

SciTech Connect

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.

Todd, J.A.; Chung, D.W.; Parker, E.R.

1982-01-01

387

Effect of the abdominal draw-in manoeuvre in combination with ankle dorsiflexion in strengthening the transverse abdominal muscle in healthy young adults: A preliminary, randomised, controlled study  

Microsoft Academic Search

ObjectivesTo compare the effect of the abdominal draw-in manoeuvre with the abdominal draw-in manoeuvre in combination with ankle dorsiflexion on changes in muscle thickness and associated muscle activity in abdominal muscles.

Seung-Chul Chon; Ki-Yeon Chang

2010-01-01

388

Usefulness in NOTES of an intra-abdominal antifogging wireless charge-coupled device (CCD) camera with pantograph-type needle unit for placement to the intra-abdominal wall  

Microsoft Academic Search

Background  In natural orifice transluminal endoscopic surgery (NOTES), the endoscope has the disadvantages of an unstable visual field\\u000a and wide blind space. We developed a compact charge-coupled device (CCD) camera unit that can be transgastrointestinally placed\\u000a in the abdominal cavity.\\u000a \\u000a \\u000a \\u000a Methods  The requisites for a wireless CCD camera unit for use in NOTES have been cited as: monitoring performance, fixation to the

Takeshi Ohdaira; Kazuhiro Endo; Nozomi Abe; Yoshikazu Yasuda

2010-01-01

389

Abdominal trauma  

Microsoft Academic Search

Summary  \\u000a While a great part of the Anglo-American medical literature addresses the topic of penetrating trauma the German spreaking\\u000a countries rather publish on blunt abdominal injury. The presented paper discusses the strategic principles of acute clinical\\u000a management of abdominal trauma on the combined basis of own research results and a comprehensive review of the literature.\\u000a \\u000a \\u000a \\u000a Blunt abdominal injuries in most

D. Nast-Kolb; A. Trupka; S. Ruchholtz; L. Schweiberer

1998-01-01

390

The microscopic features of inflammatory abdominal aortic aneurysms: discriminant analysis.  

PubMed

Up to 15% of abdominal aortic aneurysms are designated as inflammatory. They are characterized by marked fibrous thickening of the aneurysmal wall, with the fibrosis extending into the adjacent retroperitoneum. Thirty-five abdominal aortic aneurysms were studied, 15 inflammatory and 20 atherosclerotic. Of the inflammatory group, 10 were symptomatic and five asymptomatic. For each resection specimen, 59 microscopic features (variables) were scored semi-quantitatively. Discriminant function analysis showed that endarteritis obliterans, fibrosis around nerves or ganglia at the outer margin of mural fibrosis, and the thickness of the combined fibrotic media and adventitia gave a satisfactory high discrimination between atherosclerotic and inflammatory aneurysms. When these three variables are used together, a histological diagnosis of inflammatory aneurysm can be made with an expected accuracy in excess of 80%. PMID:2376398

McMahon, J N; Davies, J D; Scott, D J; Tennant, W G; Powell, J E; Hughes, A O; Horrocks, M; Bradfield, J W

1990-06-01

391

Liquid Wall Chambers  

Microsoft Academic Search

The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions

2011-01-01

392

Regression of left ventricular wall thickness during ACE-inhibitor treatment of essential hypertension is associated with an increase in insulin mediated skeletal muscle blood flow.  

PubMed

Left ventricular hypertrophy (LVH) has been associated with insulin resistance, a condition with an impaired insulin-mediated vasodilation in skeletal muscle. ACE-inhibitors have been reported to be superior to most other antihypertensive drugs in inducing a regression of LVH. In a double-blind study with parallel groups, 50 patients with essential hypertension were randomized to treatment with either fosinopril (20 mg o.d.) or atenolol (50 mg o.d.) for 12-16 weeks. Left ventricle wall thickness (LVWT, defined as the sum of interventricular septum and posterior wall), diastolic function (represented by the ratio between the E-wave and the A-wave of mitral blood flow) and femoral artery blood flow (FBF) were evaluated using ultrasonic measurements. FBF was measured at normoinsulinemia and after 2 h of euglycemic hyperinsulinemia. Before treatment, the insulin-induced increase in FBF was inversely related to the LVWT (r = -0.52, p < 0.02). The reduction in ambulatory 24-h SBP/DBP was 13/9 mmHg for fosinopril and 15/14 for atenolol, ambulatory DBP being significantly more reduced by atenolol (p = 0.03 for difference in treatment effect). However, only fosinopril treatment resulted in a significant reduction in LVWT (from 20.5 mm to 19.4 mm, p < 0.05). The degree of reduction in LVWT was related to the increase in FBF in the fosinopril group (r = -0.45, p < 0.05). For fosinopril (but not for atenolol), there was a positive relationship between the change in E/A ratio and the change in femoral artery stroke volume (r = 0.80, p < 0.01). Conclusion: Impaired insulin-induced stimulation of leg blood flow was related to an increased LVWT. Furthermore, during fosinopril treatment, regression of LVWT was associated with enhanced skeletal muscle blood flow during hyperinsulinemia. This indicates that impaired peripheral blood flow (and thereby increased afterload) may be a possible mechanism explaining the previously found association between insulin resistance and cardiovascular hypertrophy. PMID:9657539

Andersson, P E; Lind, L; Andrén, B; Hänni, A; Reneland, R; Berne, C; Lithell, H

1998-05-01

393

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

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

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

394

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

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, which were subjected to treatment with NPWT using the VAC or ABThera dressing. The microvascular blood flow in the intestinal wall, were measured before and after the application at topical negative pressures of -50, -75 and -125?mmHg, 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?

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

2013-03-21

395

Investigating the effect of tamsulosin on the measurement of bladder wall thickness and International Prostate Symptom Score in benign prostatic hyperplasia  

PubMed Central

Introduction: According to previous studies, aging, gender, bladder volume and pathological states, such as bladder outflow obstruction, affect bladder wall thickness (BWT). The aim of this study was to evaluate the correlation between BWT and the International Prostatic Symptom Score (IPSS) in patients with benign prostatic hyperplasia (BPH) before and after tamsulosin treatment. Methods: In this study, 60 BPH patients were included. After obtaining informed consent, data were gathered using questionnaires to determine IPSS. After that, prostate-specific antigen was measured and a clinical examination, including a digital rectal examination, was performed for all patients. BWT was determined by transabdominal ultrasound. Finally, all patients were treated with tamsulosin (0.4 mg/day) for 2 months. After completing treatment, the IPSS and BWT were measured again and compared with the initial findings. Results: In total, 44 patients completed treatment. Patients aged 61.7 ± 9.2 years old. The mean ± standard deviation of IPSS and BWT were 14.6 ± 5.0 and 5.36 ± 1.28 mm before treatment, while they significantly (p < 0.0001) decreased to 8.2 ± 4.7 and 4.69 ± 1.23 mm, respectively, after treatment. Chi-square test showed that the decrease in BWT was significantly correlated with the improvement in IPSS (p = 0.002; r = 0.449). Conclusion: After treatment with tamsulosin, patients experienced a reduction in their BWT which was significantly correlated with improvement in their IPSS. We conclude that transabdominal evaluation of BWT could be included in the follow-up assessment in BPH.

Eghbali, Kamyar; Shayegan, Mohammad Reza; Kianoush, Sina

2013-01-01

396

Bladder Wall Thickness is Associated with Responsiveness of Storage Symptoms to Alpha-Blockers in Men with Lower Urinary Tract Symptoms  

PubMed Central

Purpose Bladder wall thickness (BWT) is reported to be related to detrusor overactivity and bladder outlet obstruction. We investigated the relationship between BWT and the responsiveness of storage symptoms to alpha-blockers in men with lower urinary tract symptoms (LUTS). Materials and Methods A total of 74 patients with LUTS were enrolled. International Prostate Symptom Score, uroflowmetry with post-void residual urine volume, and transrectal ultrasonography (TRUS) were investigated. BWT was measured by performing TRUS at the midsagittal plane view, and the average value of BWT at the anterior, dome, and trigone areas was used. After 4 weeks of alpha-blocker medication, patients were reevaluated and divided into two groups. The responder group consisted of patients who reported improvement in the storage symptom subscore of 2 points or more; the non-responder group consisted of patients who reported improvement of less than 2 points. Clinical parameters including BWT were compared between the two groups. Results A total of 52 patients were followed. BWT was positively correlated with intravesical prostate protrusion (IPP) (9.26±4.99, standardized beta=0.393, p=0.002) and storage symptom subscore (0.35±0.43, standardized beta=0.458, p=0.002). Compared with that in the responder group, BWT was thicker in the non-responder group, and improvement in the storage symptom score was correlated with BWT (0.58±0.09 cm vs. 0.65±0.11 cm, p=0.018) and prostate volume (27.08±16.26 ml vs. 36.44±10.1 ml, p=0.018). Conclusions BWT was correlated with IPP, the storage symptom subscore, and the responsiveness of storage symptoms to alpha-blockers in LUTS/benign prostatic hyperplasia (BPH) patients. As BWT increased, the responsiveness of storage symptoms to alpha-blocker decreased in LUTS/BPH patients.

Park, Jung Soo; Lee, Ho Won; Lee, Seung Wook; Moon, Hong Sang; Park, Hae Young

2012-01-01

397

Unexpected multiple intra-abdominal injuries after projectile fragmentation: report of three cases.  

PubMed

Explosives create and energize particles that act as projectiles prone to further fragmentation or create other secondary missiles in the body. These fragments may result in secondary injuries. This has been repeatedly described in the orthopedic and neurosurgical literature. We report the same process for abdominal injuries after fascial penetration in the military setting. This is an observational case series study. Local wound exploration as a standard approach was performed in conscious patients who sustained abdominal wall injuries. Patients with negative physical examination were excluded from the study. An intraperitoneal injury was assumed in those with a full-thickness fascial defect, and laparotomy was performed. Twenty patients met the study eligibility criteria. Of those 20 patients, 12 had negative wound exploration and were excluded from the study, while abdominal organ injuries were found in eight (40%) patients. During laparotomy, projectile-induced injuries in a sprayed distribution were found in three (38%) of these patients. These injuries were far from the predictable trajectory and in the absence of bone fragmentation. The overall mean number of peritoneal defects was 1.7, and a mean 6.8 intra-abdominal injuries for each peritoneal defect were found when through-and-through injuries were excluded.Despite a single peritoneal defect, there may be multiple intraperitoneal injuries due to further fragmentation of the projectile. Under mass casualties, wound exploration with a full-thickness fascial defect could serve as an indicator of possible intra-abdominal injuries, and consequently indicate exploratory laparotomy. PMID:23588915

Unlü, Aytekin; Petrone, Patrizio; Kar??da?, Tamer; Asensio, Juan A

2012-11-01

398

Abdominal exploration in captive collared peccaries (Tayassu tajacu) by ultrasonography.  

PubMed

This study determines the morphology and ultrasound features of the abdominal organs in male, nestling and healthy collared peccaries. The bladder wall is hyperechogenic, with a thickness of 0.2 ± 0.08 cm. The kidneys present a well-defined cortex, medulla and pelvis, and the dimensions are 2.56 ± 0.3 × 4.6 ± 0.8 cm for the left and 2.51 ± 0.4 × 4.86 ± 1.1 cm for the right kidney. The spleen has a uniform echotexture over its entire surface. The largest dimensions of the liver are 2.0 ± 0.57 cm for the left lobe and 1.42 ± 0.66 cm for the caudate lobe. The liver presents a homogeneous echotexture in the majority of cases, but sometimes some hyperechoic spots are present. The stomach wall has a thickness of 0.42 ± 0.28 cm. The bowel loops show alternate hyperechoic and hypoechoic layers with a uniform diameter and a wall thickness of 0.19 ± 0.07 cm. PMID:22220558

Peixoto, G C X; Oliveira, I R S; Alves, N D; Oliveira, M F; Silva, A R

2012-01-06

399

Successful treatment of abdominal cutaneous entrapment syndrome using ultrasound guided injection.  

PubMed

There are various origins for chronic abdominal pain. About 10-30% of patients with chronic abdominal pain have abdominal wall pain. Unfortunately, abdominal wall pain is not thought to be the first origin of chronic abdominal pain; therefore, patients usually undergo extensive examinations, including diagnostic laparoscopic surgery. Entrapment of abdominal cutaneous nerves at the muscular foramen of the rectus abdominis is a rare cause of abdominal wall pain. If abdominal wall pain is considered in earlier stage of chronic abdominal pain, unnecessary invasive procedures are not required and patients will reach symptom free condition as soon as the diagnosis is made. Here, we report a case of successful treatment of a patient with abdominal cutaneous nerve entrapment syndrome by ultrasound guided injection therapy. PMID:23862004

Hong, Myong Joo; Kim, Yeon Dong; Seo, Dong Hyuk

2013-07-01

400

Successful Treatment of Abdominal Cutaneous Entrapment Syndrome Using Ultrasound Guided Injection  

PubMed Central

There are various origins for chronic abdominal pain. About 10-30% of patients with chronic abdominal pain have abdominal wall pain. Unfortunately, abdominal wall pain is not thought to be the first origin of chronic abdominal pain; therefore, patients usually undergo extensive examinations, including diagnostic laparoscopic surgery. Entrapment of abdominal cutaneous nerves at the muscular foramen of the rectus abdominis is a rare cause of abdominal wall pain. If abdominal wall pain is considered in earlier stage of chronic abdominal pain, unnecessary invasive procedures are not required and patients will reach symptom free condition as soon as the diagnosis is made. Here, we report a case of successful treatment of a patient with abdominal cutaneous nerve entrapment syndrome by ultrasound guided injection therapy.

Hong, Myong Joo; Seo, Dong Hyuk

2013-01-01

401

Thrombosis of the portal venous system following blunt abdominal trauma  

Microsoft Academic Search

A 60-year-old man presented to the accident and emergency department with a 4-day history of abdominal pain following blunt abdominal trauma. An initial CT scan showed thickened walls of the proximal jejunum and thromboses in the portal, splenic and superior mesenteric veins. He was given warfarin and the abdominal pain resolved. A repeat CT scan 1 week later revealed significant

Vikram Rajkomar; Enoch Kyerematen; Prabhakar Mysore; James Penston

2010-01-01

402

On the influence of patient-specific material properties in computational simulations: a case study of a large ruptured abdominal aortic aneurysm.  

PubMed

Patient-specific modelling of abdominal aortic aneurysm has been shown to have clinical potential. This paper examines a large ruptured abdominal aortic aneurysm where the tissue from the diseased wall and the intraluminal thrombus was excised during open surgical repair and experimentally characterised. The mechanical data were used to develop material parameters that were incorporated into finite element models with measured nonuniform wall thickness. Implementation of the material data into the numerical model increased peak wall stress by 67%, wall strain by 320% and displacement by 177%, when compared with simulations based on material properties available in the literature. Distributions of numerical results were similar for both material data. Magnitudes of numerical results can differ significantly when using patient-specific material properties and therefore, care should be taken when interpreting numerical results derived from population-based data. PMID:23345202

Doyle, Barry J; Callanan, Anthony; Grace, Pierce A; Kavanagh, Eamon G

2012-10-05

403

Abdominal Adhesions  

MedlinePLUS

... one another or to the wall of the abdomen. In people living in developed countries, this scar tissue ... tests and X-rays of your chest and abdomen. In some people with suspected intestinal obstruction or strangulation, ...

404

Pelvic Floor and Abdominal Muscle Interaction: EMG Activity and Intra-abdominal Pressure  

Microsoft Academic Search

:   Pelvic floor muscle exercises prescribed for the treatment of incontinence commonly emphasize concurrent relaxation of the\\u000a abdominal muscles. The purpose of this study was to investigate the interaction between individual muscles of the abdominal\\u000a wall and the pelvic floor using surface and intramuscular electromyography, and the effect of their action on intra-abdominal\\u000a pressure. Four subjects were tested in the

P. Neumann; V. Gill

2002-01-01

405

Gastric tonometry and direct intraabdominal pressure monitoring in abdominal compartment syndrome  

Microsoft Academic Search

Background\\/Purpose: Abdominal compartment syndrome (ACS) may complicate abdominal closure in patients with abdominal wall defects, abdominal trauma, intraperitoneal bleeding, and infection. Increased intraabdominal pressure (IAP) leads to respiratory compromise, organ hypoperfusion, and a high mortality rate. This study evaluates the efficacy of continuous direct monitoring of IAP and gastric tissue pH in detecting impending ACS. Methods: Ten mongrel puppies weighing

S. A. Engum; B. Kogon; E. Jensen; J. Isch; C. Balanoff; J. L. Grosfeld

2002-01-01

406

Abdominal tuberculosis.  

PubMed Central

Tuberculosis has staged a global comeback and forms a dangerous combination with AIDS. The abdomen is one of the common sites of extrapulmonary involvement. Patients with abdominal tuberculosis have a wide range and spectrum of symptoms and signs; the disease is therefore a great mimic. Diagnosis, mainly radiological and supported by endoscopy, is difficult to make and laparotomy is required in a large number of patient. Management involves judicious combination of antitubercular therapy and surgery which may be required to treat complications such as intestinal obstruction and perforation. The disease, though potentially curable, carries a significant morbidity and mortality. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Kapoor, V. K.

1998-01-01

407

Paediatric case of a large gastric rupture after a blunt abdominal trauma: Report of a case in a District General Hospital  

PubMed Central

INTRODUCTION Isolated gastric rupture after blunt abdominal trauma is rare. In current literature gastric rupture from blunt abdominal trauma ranges between 0.02% and 1.7%. This document reports the first non-motor-vehicle case of an isolated gastric rapture after blunt abdominal injury, which repaired after early diagnosis and aggressive surgical treatment. PRESENTATION OF CASE A 14-year-old boy attended our emergency surgical department after sustained a blunt abdominal trauma following a fall from his bicycle. He presented with pain and left para-umbilical abdominal ecchymoses. Examination revealed subcutaneous emphysema and a palpable abdominal wall dimple. DISCUSSION Radiological examination with CT scan determined the need for exploratory laparotomy. Operation revealed, extensive rupture of the left lateral border of the rectus abdominus muscle, free intra-peritoneal position of the nasogastric tube with gross spillage of gastric contents and pneumo-peritoneum observed with 7-8cm full thickness rupture of anterior stomach wall, from the lesser towards the greater curvature. Primary, two-layer closure was performed. On the 5th post-operative day he developed gastrorrhagia. He was discharged on the 15th postoperative day. CONCLUSION We present this case report focusing on the paediatric patient to illustrate isolated gastric injury in terms of mechanism of injury, clinical presentation, and immediate surgical management.

Pafitanis, Georgios; Koulas, Spiros; Bikos, Stavros; Tsimoyiannis, Evangelos

2012-01-01

408

BIOMECHANICS OF ABDOMINAL AORTIC ANEURYSM  

PubMed Central

Abdominal aortic aneurysm (AAA) is a condition whereby the terminal aorta permanently dilates to dangerous proportions, risking rupture. The biomechanics of AAA has been studied with great interest since aneurysm rupture is a mechanical failure of the degenerated aortic wall and is a significant cause of death in developed countries. In this review article, the importance of considering the biomechanics of AAA is discussed, and then the history and the state-of-the-art of this field is reviewed - including investigations into the biomechanical behavior of AAA tissues, modeling AAA wall stress and factors which influence it, and the potential clinical utility of these estimates in predicting AAA rupture.

Vorp, David A.

2009-01-01

409

Development of Automated Welding Processes for Field Fabrication of Thick-Walled Pressure Vessels: Electron Beam Method. Eighth Quarterly Report, 1 July-30 September 1979.  

National Technical Information Service (NTIS)

Objective is to develop and demonstrate an electron beam welding procedure for welding 8-inch thick SA 387 Grade 22 Class (2-1/4 Cr-1 Mo) steel. A total of 469 experimental welds have been made to date. Efforts to develop welding procedures which produce ...

C. M. Weber

1979-01-01

410

As human pial arteries (internal diameter 200–1000 ?m) get smaller, their wall thickness and capacity to develop tension relative to their diameter increase  

Microsoft Academic Search

Pial arteries play a key role in the regulation of human cerebral blood flow. However, many of the features and mechanisms that regulate the tone and diameters of these vessels cannot be studied in situ. One approach is to study in vitro segments of arteries obtained during neurosurgical procedures. The ratios of arterial media thickness to lumen diameter and of

John A. Bevan; John Dodge; Carrie L. Walters; Terry Wellman; Rosemary D. Bevan

1999-01-01

411

Development of Automated Welding Processes for Field Fabrication of Thick-Walled Pressure Vessels: Electron Beam Method. Fourth Quarterly Report, July 1--September 30, 1978.  

National Technical Information Service (NTIS)

This report is the fourth quarterly report of a project to develop and demonstrate an electron beam welding procedure for welding 8'' thick SA 387 Grade 22 Class 2 (2-1/4 Cr--1 Mo) steel. Due to the late arrival of the steel to be used in this project, a ...

C. M. Weber

1978-01-01

412

Wall surveyor project report  

SciTech Connect

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

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

1996-02-22

413

Intestinal injury mechanisms after blunt abdominal impact.  

PubMed

Intestinal injury is frequent after non-penetrating abdominal trauma, particularly after modern, high-energy transfer impacts. Under these circumstances, delay in the diagnosis of perforation is a major contributor to morbidity and mortality. This study establishes patterns of intestinal injury after blunt trauma by non-penetrating projectiles and examines relationships between injury distribution and abdominal wall motion. Projectile impacts of variable momentum were produced in 31 anaesthetised pigs to cause abdominal wall motion of varying magnitude and velocity. No small bowel injury was observed at initial impact velocity of less than 40 m/s despite gross abdominal compression. At higher velocity, injury to the small bowel was frequent, irrespective of the degree of abdominal compression (P = 0.00044). Large bowel injury was observed at all impact velocities and at all degrees of abdominal compression. This study confirms the potential for intestinal injury in high velocity, low momentum impacts which do not greatly compress the abdominal cavity and demonstrates apparent differences in injury mechanisms for the small bowel and colon. Familiarity with injury mechanisms may reduce delays in the diagnosis of intestinal perforation in both military and civilian situations. PMID:9135238

Cripps, N P; Cooper, G J

1997-03-01

414

Individual Common Carotid Artery Wall Layer Dimensions, but Not Carotid Intima-Media Thickness, Indicate Increased Cardiovascular Risk in Women With Preeclampsia: An Investigation Using Noninvasive High-frequency Ultrasound.  

PubMed

Background- Preeclampsia (PE) is associated with increased risk of cardiovascular disease later in life. Ultrasound assessment of the common carotid artery intima-media thickness (IMT) during or after PE has not indicated any increased cardiovascular risk. Methods and Results- We used high-frequency ultrasound (22 MHz) to estimate the individual common carotid artery IMTs in 55 women at PE diagnosis and in 64 women with normal pregnancies at a similar stage. All were re-examined about 1 year postpartum. A thick intima, thin media, and high intima/media (I/M) ratio are signs of a less healthy artery wall. PE was associated with a significantly thicker mean common carotid artery intima, thinner media, and higher I/M ratio than in normal pregnancy (mean I/M difference, 0.21; 95% confidence interval, 0.17-0.25; P<0.0001). After adjustment for first trimester body mass index and mean arterial pressure, differences in intima thickness and I/M remained significant. About 1 year postpartum, these values had improved in both groups, but group differences remained significant (all adjusted P<0.0001). There were no significant differences in IMT between groups. In receiver-operating characteristic curve analysis, intima thickness and I/M were strongly predictive of prevalent PE (area under the curve, ?0.95), whereas IMT was not (area under the curve, 0.49). Conclusions- The arteries of women with PE were negatively affected during pregnancy and 1 year postpartum compared with women with normal pregnancies, indicating increased cardiovascular risk. Estimation of intima thickness and I/M ratio seem preferable to estimation of common carotid artery IMT in imaging cardiovascular risk in PE. Results from this pilot study warrant further confirmation. PMID:23811751

Akhter, Tansim; Wikström, Anna-Karin; Larsson, Marita; Naessen, Tord

2013-06-27

415

CT of abdominal tuberculosis  

SciTech Connect

Intraabdominal tuberculosis (TB) presents with a wide variety of clinical and radiologic features. Besides the reported computed tomographic (CT) finding of high-density ascites in tuberculous peritonitis, this report describes additional CT features highly suggestive of abdominal tuberculosis in eight cases: (1) irregular soft-tissue densities in the omental area; (2) low-density masses surrounded by thick solid rims; (3) a disorganized appearance of soft-tissue densities, fluid, and bowel loops forming a poorly defined mass; (4) low-density lymph nodes with a multilocular appearance after intravenous contrast administration; and (5) possibly high-density ascites. The differential diagnosis of these features include lymphoma, various forms of peritonitis, peritoneal carcinomatosis, and peritoneal mesothelioma. It is important that the CT features of intraabdominal tuberculosis be recognized in order that laparotomy be avoided and less invasive procedures (e.g., laparoscopy, biopsy, or a trial of antituberculous therapy) be instituted.

Epstein, B.M. (Univ. of the Witwatersrand, Johannesburg, South Africa); Mann, J.H.

1982-11-01

416

An Experimental and Numerical Comparison of the Rupture Locations of an Abdominal Aortic Aneurysm  

PubMed Central

Purpose: To identify the rupture locations of idealized physical models of abdominal aortic aneurysm (AAA) using an in-vitro setup and to compare the findings to those predicted numerically. Methods: Five idealized AAAs were manufactured using Sylgard 184 silicone rubber, which had been mechanically characterized from tensile tests, tear tests, and finite element analysis. The models were then inflated to the point of rupture and recorded using a high-speed camera. Numerical modeling attempted to confirm these rupture locations. Regional variations in wall thickness of the silicone models was also quantified and applied to numerical models. Results: Four of the 5 models tested ruptured at inflection points in the proximal and distal regions of the aneurysm sac and not at regions of maximum diameter. These findings agree with high stress regions computed numerically. Wall stress appears to be independent of wall thickness, with high stress occurring at regions of inflection regardless of wall thickness variations. Conclusion: According to these experimental and numerical findings, AAAs experience higher stresses at regions of inflection compared to regions of maximum diameter. Ruptures of the idealized silicone models occurred predominantly at the inflection points, as numerically predicted. Regions of inflection can be easily identified from basic 3-dimensional reconstruction; as ruptures appear to occur at inflection points, these findings may provide a useful insight into the clinical significance of inflection regions. This approach will be applied to patient-specific models in a future study.

Doyle, Barry J.; Corbett, Timothy J.; Callanan, Anthony; Walsh, Michael T.; Vorp, David A.; McGloughlin, Timothy M.

2009-01-01

417

Liquid Wall Chambers  

SciTech Connect

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