New method for initial density reconstruction

Science.gov (United States)

Shi, Yanlong; Cautun, Marius; Li, Baojiu

2018-01-01

A theoretically interesting and practically important question in cosmology is the reconstruction of the initial density distribution provided a late-time density field. This is a long-standing question with a revived interest recently, especially in the context of optimally extracting the baryonic acoustic oscillation (BAO) signals from observed galaxy distributions. We present a new efficient method to carry out this reconstruction, which is based on numerical solutions to the nonlinear partial differential equation that governs the mapping between the initial Lagrangian and final Eulerian coordinates of particles in evolved density fields. This is motivated by numerical simulations of the quartic Galileon gravity model, which has similar equations that can be solved effectively by multigrid Gauss-Seidel relaxation. The method is based on mass conservation, and does not assume any specific cosmological model. Our test shows that it has a performance comparable to that of state-of-the-art algorithms that were very recently put forward in the literature, with the reconstructed density field over ˜80 % (50%) correlated with the initial condition at k ≲0.6 h /Mpc (1.0 h /Mpc ). With an example, we demonstrate that this method can significantly improve the accuracy of BAO reconstruction.

Application of individually performed titanium mesh in infraorbital wall fracture reconstruction

Directory of Open Access Journals (Sweden)

Kai-Jian Sun

2016-04-01

Full Text Available AIM:To discuss the application effect of individually performed titanium mesh in infraorbital wall fracture reconstruction. METHODS:Sixty-seven patients(67 eyesdiagnosed as infraorbital fracture from January 2011 to February 2014 were performed reconstruction with individually performed titanium mesh. The recovery of incision, visual acuity, eyeball mobility, diplopia and proptosis were monitored by post-operation follow-up which lasted for 1a. RESULTS:No infection, titanium mesh transposition, prolapse, deformities, exclusion or ectropion were occurred in the follow-up period. The eyeball embole was less than 2mm by bilateral proptosis contrast. The diplopia in 5 eyes were disappeared in 4 and approved in one. The eyeball descent in 2 cases was disappeared. The visual acuity was the same compared with pre-operation. The rate of disappeared diplopia at primary position was 93% and improved significantly in the other 3 patients. The rate of disappeared diplopia at peripheral visual field was 86% and improved significantly in the other 2 patients.CONCLUSION:The reconstruction effect of individually performed titanium mesh in infraorbital wall fracture was satisfied and safe.

Initial phase wall conditioning in KSTAR

International Nuclear Information System (INIS)

Hong, Suk-Ho; Kim, Kwang-Pyo; Kim, Sungwoo; Lee, Dong-Su; Kim, Kyung-Min; Lee, Kun-Su; Kim, Jong-Su; Park, Jae-Min; Kim, Woong-Chae; Kim, Hak-Kun; Park, Kap-Rai; Yang, Hyung-Lyeol; Sun, Jong-Ho; Woo, Hyun-Jong; Lee, Sang-Yong; Lee, Sang-Hwa; Park, Eun-Kyung; Park, Sang-Joon; Kim, Sun-Ho; Wang, Sun-Jung

2011-01-01

The initial phase wall conditioning in KSTAR is depicted. The KSTAR wall conditioning procedure consists of vessel baking, glow discharge cleaning (GDC), ICRH wall conditioning (ICWC) and boronization (Bz). Vessel baking is performed for the initial vacuum conditioning in order to remove various kinds of impurities including H 2 O, carbon and oxygen and for the plasma operation. The total outgassing rates after vessel baking in three successive KSTAR campaigns are compared. GDC is regularly performed as a standard wall cleaning procedure. Another cleaning technique is ICWC, which is useful for inter-shot wall conditioning under a strong magnetic field. In order to optimize the operation time and removal efficiency of ICWC, a parameter scan is performed. Bz is a standard technique to remove oxygen impurity from a vacuum vessel. KSTAR has used carborane powder which is a non-toxic boron-containing material. The KSTAR Bz has been successfully performed through two campaigns: water and oxygen levels in the vacuum vessel are reduced significantly. As a result, KSTAR has achieved its first L-H mode transition, although the input power was marginal for the L-H transition threshold. The characteristics of boron-containing thin films deposited for boronization are investigated.

Free gracilis flap for chest wall reconstruction in male patient with Poland syndrome after implant failure.

Science.gov (United States)

Cherubino, Mario; Maggiulli, Francesca; Pellegatta, Igor; Valdatta, Luigi

2016-01-01

Poland's syndrome (PS) is a congenital monolateral deformity that may involve breast, chest wall, and upper limb with different degrees of clinical expressions. In some cases, the problem is mainly cosmetic, and the reconstruction should be performed to achieve minimal scarring and donor site morbidity. The authors describe a case report of a male patient with PS who developed a severe capsular contraction after 25 years implant reconstruction, who was treated after explantation using free gracilis flap (FGF). In this patient, only the pectoralis major muscle was missing. An FGF was performed to reconstruct the anterior axillary fold and the soft tissue defect. There was no flap loss, the patient had a clearly improved appearance of the chest wall, and the pain syndrome was solved. In this case report, we demonstrate our experience with the use of an FGF for chest wall reconstruction in male patients with PS after prosthesis explantation.

Evaluation of Three Cases Using a Novel Titanium Mesh System-Skull-Fit with Orbital Wall (Skull-Fit WOW)-For Cranial Base Reconstructions.

Science.gov (United States)

Hattori, Noriko; Nakajima, Hideo; Tamada, Ikkei; Sakamoto, Yoshiaki; Ohira, Takayuki; Yoshida, Kazunari; Kawase, Takeshi; Kishi, Kazuo

2011-09-01

Cranial base reconstructions associated with tumor resections around the orbital wall often require that both the upper and lateral orbital walls be reconstructed during a single procedure. Previously, we used titanium mesh plates that were preoperatively fabricated based on three-dimensional models. Although these plates are precise and do not increase the probability of infection, we still had to use autologous bones to reconstruct the orbital walls. Recently, we developed a new titanium mesh plate-called Skull-Fit(®)-with orbital wall (Skull-Fit WOW(®)), enabling us to reconstruct the cranial base and orbital walls without bone grafts. Here, we report on three reconstruction cases in which the novel titanium mesh-orbital wall system was used. In all three cases, the customized titanium mesh system performed satisfactorily with little, if any, complications.

Ifcwall Reconstruction from Unstructured Point Clouds

Science.gov (United States)

Bassier, M.; Klein, R.; Van Genechten, B.; Vergauwen, M.

2018-05-01

The automated reconstruction of Building Information Modeling (BIM) objects from point cloud data is still ongoing research. A key aspect is the creation of accurate wall geometry as it forms the basis for further reconstruction of objects in a BIM. After segmenting and classifying the initial point cloud, the labelled segments are processed and the wall topology is reconstructed. However, the preocedure is challenging due to noise, occlusions and the complexity of the input data.In this work, a method is presented to automatically reconstruct consistent wall geometry from point clouds. More specifically, the use of room information is proposed to aid the wall topology creation. First, a set of partial walls is constructed based on classified planar primitives. Next, the rooms are identified using the retrieved wall information along with the floors and ceilings. The wall topology is computed by the intersection of the partial walls conditioned on the room information. The final wall geometry is defined by creating IfcWallStandardCase objects conform the IFC4 standard. The result is a set of walls according to the as-built conditions of a building. The experiments prove that the used method is a reliable framework for wall reconstruction from unstructured point cloud data. Also, the implementation of room information reduces the rate of false positives for the wall topology. Given the walls, ceilings and floors, 94% of the rooms is correctly identified. A key advantage of the proposed method is that it deals with complex rooms and is not bound to single storeys.

Free gracilis flap for chest wall reconstruction in male patient with Poland syndrome after implant failure

Directory of Open Access Journals (Sweden)

Mario Cherubino

2016-01-01

Full Text Available Poland's syndrome (PS is a congenital monolateral deformity that may involve breast, chest wall, and upper limb with different degrees of clinical expressions. In some cases, the problem is mainly cosmetic, and the reconstruction should be performed to achieve minimal scarring and donor site morbidity. The authors describe a case report of a male patient with PS who developed a severe capsular contraction after 25 years implant reconstruction, who was treated after explantation using free gracilis flap (FGF. In this patient, only the pectoralis major muscle was missing. An FGF was performed to reconstruct the anterior axillary fold and the soft tissue defect. There was no flap loss, the patient had a clearly improved appearance of the chest wall, and the pain syndrome was solved. In this case report, we demonstrate our experience with the use of an FGF for chest wall reconstruction in male patients with PS after prosthesis explantation.

Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note

Science.gov (United States)

Mommaerts, Maurice Y.; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

2015-01-01

The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

Evaluation of Three Cases Using a Novel Titanium Mesh System—Skull-Fit® with Orbital Wall (Skull-Fit WOW®)—For Cranial Base Reconstructions

Science.gov (United States)

Hattori, Noriko; Nakajima, Hideo; Tamada, Ikkei; Sakamoto, Yoshiaki; Ohira, Takayuki; Yoshida, Kazunari; Kawase, Takeshi; Kishi, Kazuo

2011-01-01

Cranial base reconstructions associated with tumor resections around the orbital wall often require that both the upper and lateral orbital walls be reconstructed during a single procedure. Previously, we used titanium mesh plates that were preoperatively fabricated based on three-dimensional models. Although these plates are precise and do not increase the probability of infection, we still had to use autologous bones to reconstruct the orbital walls. Recently, we developed a new titanium mesh plate—called Skull-Fit®—with orbital wall (Skull-Fit WOW®), enabling us to reconstruct the cranial base and orbital walls without bone grafts. Here, we report on three reconstruction cases in which the novel titanium mesh-orbital wall system was used. In all three cases, the customized titanium mesh system performed satisfactorily with little, if any, complications. PMID:22451827

Extended Resection of Chest Wall Tumors with Reconstruction Using Poly Methyl Methacrylate-Mesh Prosthesis

International Nuclear Information System (INIS)

Abo Sedira, M.; Nassar, O.; Al-Ariny, A.

2003-01-01

This prospective study evaluates the early result of patients with massive chest wall tumors treated by extended resection and reconstruction using Prolene or Marlex mesh-enforced with Poly Methyl Methacrylate Bone Cement (PMMC) prosthesis. Material and Methods: This surgery was performed on 40 patients with a mean age of 45±18 (12-62) at the Department of Surgery, National Cancer Institute, Cairo University between 1998-2001. Primary chest wall tumors were the indications of surgery in 42.5%, while secondary involvement extending from other sites principally breast cancer were the indications for 57.5%. In 85% of patients more than 3 ribs were involved by tumors and lesions were more than 10 cm in the greatest dimension in 50% of cases. Resection involved sternum in 15 (37.5%) cases and in 45% of cases complete extensive rib resections extended between costovertebral junctions and the costochondral junctions were performed. Additional resections of nearby organs were needed in 20 (50%) of cases including partial lung resection in 14 cases, partial vertebral resection in 3 cases and diaphragm resection for 3 cases. Immediate bony reconstruction by inserting Prolene or Marlex mesh-enforced with Poly Methyl Methacrylate Bone Cement (PMMC) prosthesis to the resulting chest wall defect was performed in 36 cases, whereas, 4 cases had delayed reconstruction. Primary simple soft tissue closure was sufficient for 37.5% of patients; whereas 35% were covered by local rotational flap and 27.5% needed myocutaneous flaps. No patient with this immediate reconstruction needed ventilatory support or tracheostomy and flail chest was not noticed ICU stay was markedly reduced; whereas 85% required less than 7 days. Immediate post operative (40 days) complications were found in 14 patients (35%) and cases with additional lung resection had more complication rate than others (64% vs 19%). Infection occurred in 3 patients and conservative treatment for 3-4 weeks using frequent

Abdominal wall reconstruction for incisional hernia optimizes truncal function and quality of life

DEFF Research Database (Denmark)

Jensen, Kristian K.; Munim, Kanzah; Kjaer, Michael

2017-01-01

Objective: The aim of the study was to examine abdominal wall function in patients undergoing abdominal wall reconstruction (AWR) for incisional hernia. Background: The literature on abdominal wall function in patients with incisional hernia is sparse. It has been suggested that AWR leads...... to improvement in function, but it is unknown whether this is specific to the abdominal wall or due to an improvement in overall physical fitness. Methods: We performed a prospective case-control study of 18 consecutive patients with large incisional hernia undergoing AWR with linea alba restoration. Truncal...... flexion and extension strength, hand grip strength, leg extension power, and quality of life (SF-36 and Carolinas Comfort Scale) were assessed preoperatively and 1 year postoperatively. Patients were compared with a control group of patients with an intact abdominal wall undergoing colorectal resection (n...

The use of cone beam computed tomography in the postoperative assessment of orbital wall fracture reconstruction.

Science.gov (United States)

Tsao, Kim; Cheng, Andrew; Goss, Alastair; Donovan, David

2014-07-01

Computed tomography (CT) is currently the standard in postoperative evaluation of orbital wall fracture reconstruction, but cone beam computed tomography (CBCT) offers potential advantages including reduced radiation dose and cost. The purpose of this study is to examine objectively the image quality of CBCT in the postoperative evaluation of orbital fracture reconstruction, its radiation dose, and cost compared with CT. Four consecutive patients with orbital wall fractures in whom surgery was indicated underwent orbital reconstruction with radio-opaque grafts (bone, titanium-reinforced polyethylene, and titanium plate) and were assessed postoperatively with orbital CBCT. CBCT was evaluated for its ability to provide objective information regarding the adequacy of orbital reconstruction, radiation dose, and cost. In all patients, CBCT was feasible and provided hard tissue image quality comparable to CT with significantly reduced radiation dose and cost. However, it has poorer soft tissue resolution, which limits its ability to identify the extraocular muscles, their relationship to the reconstructive graft, and potential muscle entrapment. CBCT is a viable alternative to CT in the routine postoperative evaluation of orbital fracture reconstruction. However, in the patient who develops gaze restriction postoperatively, conventional CT is preferred over CBCT for its superior soft tissue resolution to exclude extraocular muscle entrapment.

Reconstruction of the radiation-damaged chest wall

International Nuclear Information System (INIS)

Arnold, P.G.; Pairolero, P.C.

1989-01-01

In the patient with a radiation ulcer of the chest wall, the first question is whether the lesion contains persistent or recurrent cancer. It is also important to determine whether any other local problems such as mediastinal abscess may interfere with the reconstruction. Whether or not cancer is present, all nonviable tissue must be removed. If cancer is not present, and a partial thickness of the chest remains, the authors prefer transposition of the greater omentum for repair. If cancer is present, the physiologic defect resulting from cancer resection and wound debridement is far more severe, and a muscle or musculocutaneous flap usually is appropriate. The pectoralis major, latissimus dorsi, external oblique, rectus abdominis, and trapezius muscles have been utilized; the authors most often use the pectoralis or latissimus muscles. 27 references

An iterative reconstruction of cosmological initial density fields

Science.gov (United States)

Hada, Ryuichiro; Eisenstein, Daniel J.

2018-05-01

We present an iterative method to reconstruct the linear-theory initial conditions from the late-time cosmological matter density field, with the intent of improving the recovery of the cosmic distance scale from the baryon acoustic oscillations (BAOs). We present tests using the dark matter density field in both real and redshift space generated from an N-body simulation. In redshift space at z = 0.5, we find that the reconstructed displacement field using our iterative method are more than 80% correlated with the true displacement field of the dark matter particles on scales k < 0.10h Mpc-1. Furthermore, we show that the two-point correlation function of our reconstructed density field matches that of the initial density field substantially better, especially on small scales (<40h-1 Mpc). Our redshift-space results are improved if we use an anisotropic smoothing so as to account for the reduced small-scale information along the line of sight in redshift space.

Desmoid Fibromatosis of the Abdominal Wall: Surgical Resection and Reconstruction with Biological Matrix Egis®

Directory of Open Access Journals (Sweden)

Saveria Tropea

2017-02-01

Full Text Available Desmoid tumor is a rare monoclonal fibroblast proliferation that is regarded as benign. The clinical management of desmoid tumors is very complex and requires a multidisciplinary approach because of the unpredictable disease course. For those cases localized in the anterior abdominal wall, symptomatic and unresponsive to medical treatment, radical resection and reconstruction with a prosthetic device are indicated. We present here a case of desmoid fibromatosis of the left anterolateral abdominal wall with a marked increase of the mass that required a large excision followed by reconstruction with biological matrix. The fact that it can be incorporated in patient tissue without a fibrotic response and that it can resist future infections, together with a very competetive price, made the new collagen matrix Egis® our first choice.

Desmoid Fibromatosis of the Abdominal Wall: Surgical Resection and Reconstruction with Biological Matrix Egis®

Science.gov (United States)

Tropea, Saveria; Mocellin, Simone; Stramare, Roberto; Bonavina, Maria Giuseppina; Rossi, Carlo Riccardo; Rastrelli, Marco

2017-01-01

Desmoid tumor is a rare monoclonal fibroblast proliferation that is regarded as benign. The clinical management of desmoid tumors is very complex and requires a multidisciplinary approach because of the unpredictable disease course. For those cases localized in the anterior abdominal wall, symptomatic and unresponsive to medical treatment, radical resection and reconstruction with a prosthetic device are indicated. We present here a case of desmoid fibromatosis of the left anterolateral abdominal wall with a marked increase of the mass that required a large excision followed by reconstruction with biological matrix. The fact that it can be incorporated in patient tissue without a fibrotic response and that it can resist future infections, together with a very competetive price, made the new collagen matrix Egis® our first choice. PMID:28413398

Comparative study of W-shaped angular plate and reconstruction plate in treating posterior wall fractures of the acetabulum.

Directory of Open Access Journals (Sweden)

Qi Zhang

Full Text Available OBJECTIVE: This study aims to assess the medium-term results of the reconstruction of posterior wall fractures using a W-shaped acetabular angular plate (WAAP compared to those fixed using a reconstruction plate. METHODS: Between July 2006 and March 2009, we performed a retrospective study, which collected data for any patient treated for a posterior acetabular wall fracture. At the time of treatment, patients were either treated using a WAAP or a pelvic reconstruction plate. The intraoperative fluoroscopic images for both groups were compared. The quality of reduction and radiological grading were assessed according to the criteria developed by Matta. The clinical assessment was based on a modified Merle d'Aubigne and Postel scoring. RESULTS: 53 patients met the inclusion criteria and were followed up for an average of 38 months. 25 patients were treated with a WAAP (study group, and 28 patients were treated with a pelvic reconstruction plate (control group. The intraoperative fluoroscopic images of the study group confirmed extra-articular screw placement in all cases. In the control group, intra-articular screw placement was observed intraoperatively in 5 patients (17.86%, and the definitive location of the periarticular hardware could not be determined in 4 patients (14.29% during the operation. The differences between the two groups were statistically significant (p = 0.002. In contrast, the quality of fracture reduction, clinical outcomes, and radiological grading in the study group were not significantly different from those of the control group (p>0.05. The radiographic grade was strongly associated with the clinical outcomes in both the study and control groups (p<0.05. CONCLUSION: Reconstruction of posterior wall fractures of the acetabulum using a WAAP can help avoid screw penetration of the hip joint, provide a stable fixation of the posterior wall, and ensure good clinical outcomes.

Initial Ferritic Wall Mode studies on HBT-EP

Science.gov (United States)

Hughes, Paul; Bialek, J.; Boozer, A.; Mauel, M. E.; Levesque, J. P.; Navratil, G. A.

2013-10-01

Low-activation ferritic steels are leading material candidates for use in next-generation fusion development experiments such as a prospective US component test facility and DEMO. Understanding the interaction of plasmas with a ferromagnetic wall will provide crucial physics for these experiments. Although the ferritic wall mode (FWM) was seen in a linear machine, the FWM was not observed in JFT-2M, probably due to eddy current stabilization. Using its high-resolution magnetic diagnostics and positionable walls, HBT-EP has begun exploring the dynamics and stability of plasma interacting with high-permeability ferritic materials tiled to reduce eddy currents. We summarize a simple model for plasma-wall interaction in the presence of ferromagnetic material, describe the design of a recently-installed set of ferritic shell segments, and report initial results. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Structure reconstruction of TiO2-based multi-wall nanotubes: first-principles calculations.

Science.gov (United States)

Bandura, A V; Evarestov, R A; Lukyanov, S I

2014-07-28

A new method of theoretical modelling of polyhedral single-walled nanotubes based on the consolidation of walls in the rolled-up multi-walled nanotubes is proposed. Molecular mechanics and ab initio quantum mechanics methods are applied to investigate the merging of walls in nanotubes constructed from the different phases of titania. The combination of two methods allows us to simulate the structures which are difficult to find only by ab initio calculations. For nanotube folding we have used (1) the 3-plane fluorite TiO2 layer; (2) the anatase (101) 6-plane layer; (3) the rutile (110) 6-plane layer; and (4) the 6-plane layer with lepidocrocite morphology. The symmetry of the resulting single-walled nanotubes is significantly lower than the symmetry of initial coaxial cylindrical double- or triple-walled nanotubes. These merged nanotubes acquire higher stability in comparison with the initial multi-walled nanotubes. The wall thickness of the merged nanotubes exceeds 1 nm and approaches the corresponding parameter of the experimental patterns. The present investigation demonstrates that the merged nanotubes can integrate the two different crystalline phases in one and the same wall structure.

Laparoscopic-assisted surgical reconstruction of a rare congenital abdominal wall defect in two children misdiagnosed with prune-belly syndrome.

Science.gov (United States)

Fishman, Andrew I; Franco, Israel

2013-08-01

Abdominal wall laxity is typically associated with prune-belly syndrome (PBS). Incomplete forms of PBS have been rarely reported with only the abdominal wall laxity. Herein, we describe a rare congenital abdominal wall defect that has been confused with PBS and illustrate the laparoscopic-assisted surgical technique used for reconstruction. Two boys with symmetrical, bilateral absence or hypoplasia of the internal and external oblique muscles and no genitourinary abnormalities underwent a laparoscopic-assisted abdominal wall reconstruction utilizing the technique previously described by Firlit. Each patient had a Ct scan which confirmed the absence of the oblique muscles. In one patient EMG data confirmed no electrical activity of the obliques. Radiologic evaluation of the urinary tracts revealed no abnormalities. The abdominal wall was plicated utilizing bilateral subcostal incisions. Both patients had excellent cosmetic and functional results with no weakness or bulging of the lateral abdominal wall and improvement of associated symptoms. We believe these two cases and their congenital abdominal wall defects are a rare and often misdiagnosed muscular deficiency separate from PBS. The novel laparoscopic-assisted surgical technique illustrated is feasible and highly successful for these and possible other patients with similar rare congenital abdominal wall defects. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Chest-wall reconstruction in case of infection of the operative site: is there any interest in titanium rib osteosynthesis?

Science.gov (United States)

Berthet, Jean-Philippe; Solovei, Laurence; Tiffet, Olivier; Gomez-Caro, Abel; Bommart, Sébastien; Canaud, Ludovic; Alric, Pierre; Marty-Ané, Charles-Henri

2013-11-01

To describe the management of thoracic reconstructions in the presence of primary chest-wall infection (PCWI) or secondary deep chest-wall infection (SCWI), focussing on local tolerance of a titanium rib osteosynthesis system. PCWI included infected chest wall tumours (CWT), infected T3 non-small-cell lung carcinoma (NSCLC) and open flail chest. SCWI was defined by deep infection of previous thoracic-wall reconstructions. Infection was identified by preoperative bacterial analysis of the tumour or surgical site. In PCWI, a one-step procedure combined extensive resection of infected tissues and rigid reconstruction of the defect; skeletal rigidity was achieved using titanium implants. In SCWI, we removed all synthetic material except titanium implants. In both groups, the surgical field was thoroughly cleaned and implants were wrapped or covered by flaps. From January 2005 to December 2011, 11 patients (54 ± 10.2 years) with either PCWI (3 CWT, 3 T3 NSCLC, 1 open flail chest) or SCWI (3 CWT, 1 funnel chest) were treated. Infection was polymicrobial in all but 1 case. Bacteria observed in PCWI patients were multidrug resistant. In PCWI, we resected 4.2 ± 0.6 ribs en bloc with the lung (n = 5), the skin and the pectoralis major and then used mesh and 2.1 ± 1.2 titanium implants for reconstruction (n = 6). The mean defect was 1154.4 ± 318 cm(3). Surgical SCWI management removed polytetrafluoroethylene-mesh and preserved the titanium implants. A Vicryl mesh (n = 3) and greater omentum flap (n = 3) were added. One of the 2 postoperative deaths in the PCWI group was related to infection recurrence. No other patient had infection at the 6-month follow-up with leucocyte-labelled scintigraphy. Titanium rib osteosynthesis is reliable in two complex and life-threatening situations: PCWIs and SCWIs. In combination with a flap, this allows rapid, reliable, rigid reconstruction of infected full-thickness chest-wall defects in a single-step procedure.

Reconstruction of initial pressure from limited view photoacoustic images using deep learning

Science.gov (United States)

Waibel, Dominik; Gröhl, Janek; Isensee, Fabian; Kirchner, Thomas; Maier-Hein, Klaus; Maier-Hein, Lena

2018-02-01

Quantification of tissue properties with photoacoustic (PA) imaging typically requires a highly accurate representation of the initial pressure distribution in tissue. Almost all PA scanners reconstruct the PA image only from a partial scan of the emitted sound waves. Especially handheld devices, which have become increasingly popular due to their versatility and ease of use, only provide limited view data because of their geometry. Owing to such limitations in hardware as well as to the acoustic attenuation in tissue, state-of-the-art reconstruction methods deliver only approximations of the initial pressure distribution. To overcome the limited view problem, we present a machine learning-based approach to the reconstruction of initial pressure from limited view PA data. Our method involves a fully convolutional deep neural network based on a U-Net-like architecture with pixel-wise regression loss on the acquired PA images. It is trained and validated on in silico data generated with Monte Carlo simulations. In an initial study we found an increase in accuracy over the state-of-the-art when reconstructing simulated linear-array scans of blood vessels.

The Use of Tensor Fascia Lata Pedicled Flap in Reconstructing Full Thickness Abdominal Wall Defects and Groin Defects Following Tumor Ablation

International Nuclear Information System (INIS)

Rifaat, M.A.; Abdel Gawad, W.S.

2005-01-01

The tensor fascia lata is a versatile flap with many uses in reconstructive plastic surgery. As a pedicled flap its reach to the lower abdomen and groin made it an attractive option for reconstructing soft tissue defects after tumor ablation. However, debate exists on the safe dimension of the flap, as distal tip necrosis is common. Also, the adequacy of the fascia lata as a sole substitute for abdominal wall muscles has been disputable. The aim of the current study is to report our experience and clinical observations with this flap in reconstructing those challenging defects and to discuss the possible options to minimize the latter disputable issues. Patients and Methods: From April 2001 to April 2004, 12 pedicled TFL flaps were used to reconstruct 5 central abdominal wall full thickness defects and 6 groin soft tissue defects following tumor resection. ]n one case, bilateral flaps were used to reconstruct a large central abdominal wall defect. There were 4 males and 7 females. Their age ranged from 19 to 60. From the abdominal wall defects group, all repairs were enforced primarily with a prolene mesh except for one patient who was the first in this study. Patients presenting with groin defects required coverage of exposed vessels following tumor resection. All patients in the current study underwent immediate reconstruction. The resulting soft tissue defects in this study were due to resection of 4 abdominal wall desmoid tumors, a colonic carcinoma infiltrating the abdominal wall, 4 primary groin soft developed in a flap used to cover a groin defect. In the former 3 cases, The flap was simply transposed without complete islanding of the flap. In the latter case, a very large flap was harvested beyond the safe limits with its distal edge just above the knee. In addition, wound dehiscence of the flap occurred in 2 other cases from the groin group. Nevertheless, all the wounds healed spontaneously with repeated dressings. Out of the 5 cases that underwent

Chest-wall reconstruction with a customized titanium-alloy prosthesis fabricated by 3D printing and rapid prototyping.

Science.gov (United States)

Wen, Xiaopeng; Gao, Shan; Feng, Jinteng; Li, Shuo; Gao, Rui; Zhang, Guangjian

2018-01-08

As 3D printing technology emerge, there is increasing demand for a more customizable implant in the repair of chest-wall bony defects. This article aims to present a custom design and fabrication method for repairing bony defects of the chest wall following tumour resection, which utilizes three-dimensional (3D) printing and rapid-prototyping technology. A 3D model of the bony defect was generated after acquiring helical CT data. A customized prosthesis was then designed using computer-aided design (CAD) and mirroring technology, and fabricated using titanium-alloy powder. The mechanical properties of the printed prosthesis were investigated using ANSYS software. The yield strength of the titanium-alloy prosthesis was 950 ± 14 MPa (mean ± SD), and its ultimate strength was 1005 ± 26 MPa. The 3D finite element analyses revealed that the equivalent stress distribution of each prosthesis was unifrom. The symmetry and reconstruction quality contour of the repaired chest wall was satisfactory. No rejection or infection occurred during the 6-month follow-up period. Chest-wall reconstruction with a customized titanium-alloy prosthesis is a reliable technique for repairing bony defects.

Measurement of vascular wall attenuation: Comparison of CT angiography using model-based iterative reconstruction with standard filtered back-projection algorithm CT in vitro

International Nuclear Information System (INIS)

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

2012-01-01

Objectives: To compare the performance of model-based iterative reconstruction (MBIR) with that of standard filtered back projection (FBP) for measuring vascular wall attenuation. Study design: After subjecting 9 vascular models (actual attenuation value of wall, 89 HU) with wall thickness of 0.5, 1.0, or 1.5 mm that we filled with contrast material of 275, 396, or 542 HU to scanning using 64-detector computed tomography (CT), we reconstructed images using MBIR and FBP (Bone, Detail kernels) and measured wall attenuation at the center of the wall for each model. We performed attenuation measurements for each model and additional supportive measurements by a differentiation curve. We analyzed statistics using analyzes of variance with repeated measures. Results: Using the Bone kernel, standard deviation of the measurement exceeded 30 HU in most conditions. In measurements at the wall center, the attenuation values obtained using MBIR were comparable to or significantly closer to the actual wall attenuation than those acquired using Detail kernel. Using differentiation curves, we could measure attenuation for models with walls of 1.0- or 1.5-mm thickness using MBIR but only those of 1.5-mm thickness using Detail kernel. We detected no significant differences among the attenuation values of the vascular walls of either thickness (MBIR, P = 0.1606) or among the 3 densities of intravascular contrast material (MBIR, P = 0.8185; Detail kernel, P = 0.0802). Conclusions: Compared with FBP, MBIR reduces both reconstruction blur and image noise simultaneously, facilitates recognition of vascular wall boundaries, and can improve accuracy in measuring wall attenuation.

Free gracilis flap for chest wall reconstruction in male patient with Poland syndrome after implant failure

OpenAIRE

Cherubino, Mario; Maggiulli, Francesca; Pellegatta, Igor; Valdatta, Luigi

2016-01-01

Poland's syndrome (PS) is a congenital monolateral deformity that may involve breast, chest wall, and upper limb with different degrees of clinical expressions. In some cases, the problem is mainly cosmetic, and the reconstruction should be performed to achieve minimal scarring and donor site morbidity. The authors describe a case report of a male patient with PS who developed a severe capsular contraction after 25 years implant reconstruction, who was treated after explantation using free gr...

Chest wall reconstruction in a canine model using polydioxanone mesh, demineralized bone matrix and bone marrow stromal cells.

Science.gov (United States)

Tang, Hua; Xu, Zhifei; Qin, Xiong; Wu, Bin; Wu, Lihui; Zhao, XueWei; Li, Yulin

2009-07-01

Extensive chest wall defect reconstruction remains a challenging problem for surgeons. In the past several years, little progress has been made in this area. In this study, a biodegradable polydioxanone (PDO) mesh and demineralized bone matrix (DBM) seeded with osteogenically induced bone marrow stromal cells (BMSCs) were used to reconstruct a 6 cm x 5.5 cm chest wall defect. Four experimental groups were evaluated (n=6 per group): polydioxanone (PDO) mesh/DBMs/BMSCs group, polydioxanone (PDO) mesh/DBMs group, polydioxanone (PDO) mesh group, and a blank group (no materials) in a canine model. All the animals survived except those in the blank group. In all groups receiving biomaterial implants, the polydioxanone (PDO) mesh completely degraded at 24 weeks and was replaced by fibrous tissue with thickness close to that of the normal intercostal tissue (P>0.05). In the polydioxanone (PDO) mesh/DBMs/BMSCs group, new bone formation and bone-union were observed by radiographic and histological examination. More importantly, the reconstructed rib could maintain its original radian and achieve satisfactory biomechanics close to normal ribs in terms of bending stress (P>0.05). However, in the other two groups, fibrous tissue was observed in the defect and junctions, and the reconstructed ribs were easily distorted under an outer force. Based on these results, a surgical approach utilizing biodegradable polydioxanone (PDO) mesh in combination with DBMs and BMSCs could repair the chest wall defect not only in function but also in structure.

Measurement of vascular wall attenuation: comparison of CT angiography using model-based iterative reconstruction with standard filtered back-projection algorithm CT in vitro.

Science.gov (United States)

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

2012-11-01

To compare the performance of model-based iterative reconstruction (MBIR) with that of standard filtered back projection (FBP) for measuring vascular wall attenuation. After subjecting 9 vascular models (actual attenuation value of wall, 89 HU) with wall thickness of 0.5, 1.0, or 1.5 mm that we filled with contrast material of 275, 396, or 542 HU to scanning using 64-detector computed tomography (CT), we reconstructed images using MBIR and FBP (Bone, Detail kernels) and measured wall attenuation at the center of the wall for each model. We performed attenuation measurements for each model and additional supportive measurements by a differentiation curve. We analyzed statistics using analyzes of variance with repeated measures. Using the Bone kernel, standard deviation of the measurement exceeded 30 HU in most conditions. In measurements at the wall center, the attenuation values obtained using MBIR were comparable to or significantly closer to the actual wall attenuation than those acquired using Detail kernel. Using differentiation curves, we could measure attenuation for models with walls of 1.0- or 1.5-mm thickness using MBIR but only those of 1.5-mm thickness using Detail kernel. We detected no significant differences among the attenuation values of the vascular walls of either thickness (MBIR, P=0.1606) or among the 3 densities of intravascular contrast material (MBIR, P=0.8185; Detail kernel, P=0.0802). Compared with FBP, MBIR reduces both reconstruction blur and image noise simultaneously, facilitates recognition of vascular wall boundaries, and can improve accuracy in measuring wall attenuation. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Reconstruction of Chest Wall by Cryopreserved Sternal Allograft after Resection of Aneurysmal Bone Cyst of Sternum

Directory of Open Access Journals (Sweden)

Kambiz Sheikhy

2017-01-01

Full Text Available A 20-year-old female was referred to our hospital due to deformity and bulging in anterior aspect of chest wall in sternal area. Chest X-ray and CT scan confirmed a large mass with destruction of sternum. Pathologic diagnosis after incisional biopsy was compatible with aneurysmal bone cyst. We resected sternum completely and reconstructed large anterior defect by a cryopreserved sternal allograft. In follow-up of patient there was no unstability of chest wall with good cosmetic result.

Prospective cohort comparison of bioactive glass implants and conchal cartilage in reconstruction of the posterior canal wall during tympanomastoidectomy

NARCIS (Netherlands)

Abramovich, S.; Hannan, S. A.; Huins, C. T.; Georgalas, C.; McGuinness, J.; Vats, A.; Thompson, I.

2008-01-01

OBJECTIVE: To compare the effectiveness of bioactive glass implants and conchal cartilage in reconstructing the posterior canal wall during tympanomastoidectomy. STUDY DESIGN: Prospective cohort clinical study. SETTING: Teaching hospital. PATIENTS: Patients with clinically diagnosed chronic

Extended Plate and Beam Wall System: Concept Investigation and Initial Evaluation

Energy Technology Data Exchange (ETDEWEB)

Wiehagen, J. [Partnership for Home Innovation, Upper Marlboro, MD (United States); Kochkin, V. [Partnership for Home Innovation, Upper Marlboro, MD (United States)

2015-08-01

A new and innovative High-R wall design, referred to as the Extended Plate & Beam (EP&B), is under development. The EP&B system uniquely integrates foam sheathing insulation with wall framing such that wood structural panels are installed exterior of the foam sheathing, enabling the use of standard practices for installation of drainage plane, windows and doors, claddings, cavity insulation, and the standard exterior foam sheathing installation approach prone to damage of the foam during transportation of prefabricated wall panels. As part of the ongoing work, the EP&B wall system concept has undergone structural verification testing and has been positively vetted by a group of industry stakeholders. Having passed these initial milestone markers, the advanced wall system design has been analyzed to assess cost implications relative to other advanced wall systems, undergone design assessment to develop construction details, and has been evaluated to develop representative prescriptive requirements for the building code. This report summarizes the assessment steps conducted to-date and provides details of the concept development.

In Situ Splitting of a Rib Bone Graft for Reconstruction of Orbital Floor and Medial Wall.

Science.gov (United States)

Uemura, Tetsuji; Yanai, Tetsu; Yasuta, Masato; Harada, Yoshimi; Morikawa, Aya; Watanabe, Hidetaka; Kurokawa, Masato

2017-06-01

In situ splitting of rib bone graft was conducted in 22 patients for the repair of orbital fracture with no other complicating fractures. A bone graft was harvested from the sixth or seventh rib in the right side. The repair of the orbital floor and medial wall was successful in all the cases. Ten patients had bone grafting to the orbital floor, eight had it done onto medial wall, and 4 onto both floor and wall after reduction. The mean length of in situ rib bone graft was 40.9 mm (range, 20-70 mm), the mean width of these was 14.9 mm (range, 8-20 mm). The bone grafting was done by one leaf for 15 cases and two leafs for 7 cases in size of defects. The technique of in situ splitting of a rib bone graft for the repair of the orbital floor and medial wall is a simple and safe procedure, easily taking out the in situ splitting of a rib, and less pain in donor site. It has proved to be an optimal choice in craniofacial reconstruction, especially the defects of orbital floor and medial wall.

Evaluation of Medial Acetabular Wall Bone Stock in Patients with Developmental Dysplasia of the Hip Using a Helical Computed Tomography Multiplanar Reconstruction Technique

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Rui Yu Liu; Kun Zheng Wang; Chun Sheng Wang; Xiao Qian Dang; Zhi Qin Tong (Second Hospital Affiliated to the Medical College of Xi' an Jiaotong Univ., Xi' an Shaanxi (China))

2009-08-15

Background: The technique of medialization has been used to reconstruct acetabula at the level of true acetabula in total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Appreciation of the bone stock in the medial acetabular wall is significant for making an optimal acetabular reconstruction plan and avoiding complications. Purpose: To evaluate the bone stock of the medial acetabular wall and its relation to the degree of subluxation in patients with DDH using computed tomography (CT). Material and Methods: Helical CT scans of 27 hips were obtained from 21 patients with osteoarthritis secondary to DDH who were scheduled for total hip arthroplasty. Eleven hips belonged to Crowe class I, while 16 hips belonged to Crowe class II/III. The raw CT data were reprocessed in various planes by scrolling multiplanar reformation (MPR). Acetabular opening, depth, and medial bone stock, as indicated by the minimum thickness of the medial acetabular wall, were measured in the transverse reformed MPR plane. Results: The minimum thicknesses of the medial acetabular wall in Crowe-I and Crowe-II/III hips were 3.8+-2.1 mm and 7.1+-3.1 mm, respectively, with statistically significant differences between the groups (P<0.05). Furthermore, the bone stock in the medial acetabular wall correlated with the degree of subluxation (R=0.69) and the acetabular depth (R= ;- ;0.71). Conclusion: There was significantly more bone stock in the medial acetabular wall in patients with higher-degree subluxation than there was in the less-severe class. This difference should be taken into consideration when reconstructing acetabula in THA in patients with DDH using the technique of medialization

Evaluation of Medial Acetabular Wall Bone Stock in Patients with Developmental Dysplasia of the Hip Using a Helical Computed Tomography Multiplanar Reconstruction Technique

International Nuclear Information System (INIS)

Rui Yu Liu; Kun Zheng Wang; Chun Sheng Wang; Xiao Qian Dang; Zhi Qin Tong

2009-01-01

Background: The technique of medialization has been used to reconstruct acetabula at the level of true acetabula in total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Appreciation of the bone stock in the medial acetabular wall is significant for making an optimal acetabular reconstruction plan and avoiding complications. Purpose: To evaluate the bone stock of the medial acetabular wall and its relation to the degree of subluxation in patients with DDH using computed tomography (CT). Material and Methods: Helical CT scans of 27 hips were obtained from 21 patients with osteoarthritis secondary to DDH who were scheduled for total hip arthroplasty. Eleven hips belonged to Crowe class I, while 16 hips belonged to Crowe class II/III. The raw CT data were reprocessed in various planes by scrolling multiplanar reformation (MPR). Acetabular opening, depth, and medial bone stock, as indicated by the minimum thickness of the medial acetabular wall, were measured in the transverse reformed MPR plane. Results: The minimum thicknesses of the medial acetabular wall in Crowe-I and Crowe-II/III hips were 3.8±2.1 mm and 7.1±3.1 mm, respectively, with statistically significant differences between the groups (P<0.05). Furthermore, the bone stock in the medial acetabular wall correlated with the degree of subluxation (R=0.69) and the acetabular depth (R= ;- ;0.71). Conclusion: There was significantly more bone stock in the medial acetabular wall in patients with higher-degree subluxation than there was in the less-severe class. This difference should be taken into consideration when reconstructing acetabula in THA in patients with DDH using the technique of medialization

Investigation of practical initial attenuation image estimates in TOF-MLAA reconstruction for PET/MR

International Nuclear Information System (INIS)

Cheng, Ju-Chieh; Yaqub, Maqsood; Boellaard, Ronald; Salomon, Andre

2016-01-01

Purpose: Time-of-flight joint attenuation and activity positron emission tomography reconstruction requires additional calibration (scale factors) or constraints during or post-reconstruction to produce a quantitative μ-map. In this work, the impact of various initializations of the joint reconstruction was investigated, and the initial average mu-value (IAM) method was introduced such that the forward-projection of the initial μ-map is already very close to that of the reference μ-map, thus reducing/minimizing the offset (scale factor) during the early iterations of the joint reconstruction. Consequently, the accuracy and efficiency of unconstrained joint reconstruction such as time-of-flight maximum likelihood estimation of attenuation and activity (TOF-MLAA) can be improved by the proposed IAM method. Methods: 2D simulations of brain and chest were used to evaluate TOF-MLAA with various initial estimates which include the object filled with water uniformly (conventional initial estimate), bone uniformly, the average μ-value uniformly (IAM magnitude initialization method), and the perfect spatial μ-distribution but with a wrong magnitude (initialization in terms of distribution). 3D GATE simulation was also performed for the chest phantom under a typical clinical scanning condition, and the simulated data were reconstructed with a fully corrected list-mode TOF-MLAA algorithm with various initial estimates. The accuracy of the average μ-values within the brain, chest, and abdomen regions obtained from the MR derived μ-maps was also evaluated using computed tomography μ-maps as the gold-standard. Results: The estimated μ-map with the initialization in terms of magnitude (i.e., average μ-value) was observed to reach the reference more quickly and naturally as compared to all other cases. Both 2D and 3D GATE simulations produced similar results, and it was observed that the proposed IAM approach can produce quantitative μ-map/emission when the corrections

[Plastic surgery of the thoracic wall as a method of thoracic wall reconstruction after complete surgical wound disintegration after sternotomy].

Science.gov (United States)

Hájek, T; Jirásek, K; Urban, M; Straka, Z

1998-12-01

During the period between January 1996 and July 1998 in our department 1920 patients were operated on account of heart disease from median sternotomy. In 17 patients, i.e. in 0.9% during the early postoperative period the surgical wound disintegrated incl. dehiscence of the sternum and the development of postoperative mediastinitis. In 14 of these patients the authors reconstructed the defect of the thoracic wall by their own modification of Jurkiewicz plastic operation using the pectoral muscles. One patient from this group died, in the remaining 13 patients the wound healed without deformity of the chest and without signs of instability, without restriction of movement and function.

Histological Observation of Regions around Bone Tunnels after Compression of the Bone Tunnel Wall in Ligament Reconstruction

International Nuclear Information System (INIS)

Maeda, Shintaro; Ishikawa, Hiroki; Tanigawa, Naoaki; Miyazaki, Kyosuke; Shioda, Seiji

2012-01-01

The objectives of this study were to investigate the time-course of influence of compression of bone tunnel wall in ligament reconstruction on tissue around the bone tunnel and to histologically examine the mechanism of preventing the complication of bone tunnel dilation, using rabbit tibia. A model in which the femoral origin of the extensor digitorum longus tendon was cut and inserted into a bone tunnel made proximal to the tibia was prepared in the bilateral hind legs of 20 Japanese white rabbits. In each animal, a tunnel was made using a drill only in the right leg, while an undersized bone tunnel was made by drilling and then dilated by compression using a dilator to the same tunnel size as that in the right leg. Animals were sacrificed at 0, 2, 4, 8 and 12 weeks after surgery (4 animals at each time point). Observation of bone tunnels by X-ray radiography showed osteosclerosis in the 2- and 4-week dilation groups. Osteosclerosis appeared as white lines around the bone tunnel on X-ray radiography. This suggests that dilation promotes callus formation in the bone tunnel wall and prevents the complication of bone tunnel enlargement after ligament reconstruction

Abdominal Wall Reconstruction with Concomitant Ostomy-Associated Hernia Repair: Outcomes and Propensity Score Analysis.

Science.gov (United States)

Mericli, Alexander F; Garvey, Patrick B; Giordano, Salvatore; Liu, Jun; Baumann, Donald P; Butler, Charles E

2017-03-01

The optimal strategy for abdominal wall reconstruction in the presence of a stomal-site hernia is unclear. We hypothesized that the rate of ventral hernia recurrence in patients undergoing a combined ventral hernia repair and stomal-site herniorraphy would not differ clinically from the ventral hernia recurrence rate in patients undergoing an isolated ventral hernia repair. We also hypothesized that bridged ventral hernia repairs result in worse outcomes compared with reinforced repairs, regardless of stomal hernia. We retrospectively reviewed prospectively collected data from consecutive abdominal wall reconstructions performed with acellular dermal matrix (ADM) at a single center between 2000 and 2015. We compared patients who underwent a ventral hernia repair alone (AWR) and those who underwent both a ventral hernia repair and ostomy-associated herniorraphy (AWR+O). We conducted a propensity score matched analysis to compare the outcomes between the 2 groups. Multivariable Cox proportional hazards and logistic regression models were used to study associations between potential predictive or protective reconstructive strategies and surgical outcomes. We included 499 patients (median follow-up 27.2 months; interquartile range [IQR] 12.4 to 46.6 months), 118 AWR+O and 381 AWR. After propensity score matching, 91 pairs were obtained. Ventral hernia recurrence was not statistically associated with ostomy-associated herniorraphy (adjusted hazard ratio [HR] 0.7; 95% CI 0.3 to 1.5; p = 0.34). However, the AWR+O group experienced a significantly higher percentage of surgical site occurrences (34.1%) than the AWR group (18.7%; adjusted odds ratio 2.3; 95% CI 1.4 to 3.7; p < 0.001). In the AWR group, there were significantly fewer ventral hernia recurrences when the repair was reinforced compared with bridged (5.3% vs 38.5%; p < 0.001). There was no statistically significant difference in ventral hernia recurrence between the AWR and AWR+O groups. Bridging was associated

Early initiation of alcohol consumption by adolescents in reconstructed families may be explained by parenting style

Directory of Open Access Journals (Sweden)

Iakunchykova, Olena

2011-05-01

Full Text Available BACKGROUND. Literature about risk factors of alcohol use points at the association between alcohol use and parenting style. This study investigates the relationship between family structure of adolescents in Ukraine and their initiation of alcohol use with parenting style as a mediating variable.METHODS: Pooled data from the repeated cross-sectional nationally representative survey of classes in Ukrainian secondary schools with target group of all 15-16 year old students, held in 1999, 2003, and 2007, were used for this analysis. Complete data were available for 11019 participants. Main exposures were family structure (full, single parent and reconstructed and perceptions of the relationships with mother and father, rule-setting, control, and support provided by parents. Outcome measure was age when students started consuming alcohol.RESULTS: In bivariate analysis, children in reconstructed families had higher risk for initiating alcohol use at age of 13 or younger (odds ratio 1.37, confidence interval 1,15-1,63 compared to full families. In reconstructed families, adolescents were more likely to be dissatisfied with their relationships with mother compared to intact family structure (8.7% vs. 4.7% and dissatisfied with their relationships with father compared to intact family structure (19,8% vs. 9,1%. Parental support was lacking in higher proportion of reconstructed families, compared to intact family structure (20.7% vs. 15.1%. In the multivariate analysis, controlling for relationship with mother and father, support received from parents, and socio-demographic characteristics, the association between family structure and alcohol drinking initiation was attenuated.CONCLUSIONS: Children in reconstructed families have higher risk of early drinking initiation. This study also supports the hypothesis that dissatisfaction with relationships with parents and lack of support received from parents may mediate the association between family structure

ELUCID—Exploring the Local Universe with the reConstructed Initial Density Field. II. Reconstruction Diagnostics, Applied to Numerical Halo Catalogs

Energy Technology Data Exchange (ETDEWEB)

Tweed, Dylan; Yang, Xiaohu; Li, Shijie; Jing, Y. P. [Center for Astronomy and Astrophysics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Huiyuan [Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Cui, Weiguang [Departamento de Física Teórica, Módulo 15, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Zhang, Youcai [Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China); Mo, H. J., E-mail: dtweed@sjtu.edu.cn [Department of Astronomy, University of Massachusetts, Amherst MA, 01003-9305 (United States)

2017-05-20

The ELUCID project aims to build a series of realistic cosmological simulations that reproduce the spatial and mass distributions of the galaxies as observed in the Sloan Digital Sky Survey. This requires powerful reconstruction techniques to create constrained initial conditions (ICs). We test the reconstruction method by applying it to several N -body simulations. We use two medium-resolution simulations, which each produced three additional constrained N -body simulations. We compare the resulting friend-of-friend catalogs by using the particle indexes as tracers, and quantify the quality of the reconstruction by varying the main smoothing parameter. The cross-identification method we use proves to be efficient, and the results suggest that the most massive reconstructed halos are effectively traced from the same Lagrangian regions in the ICs. A preliminary time-dependence analysis indicates that high-mass-end halos converge only at a redshift close to the reconstruction redshift. This suggests that, for earlier snapshots, only collections of progenitors may be effectively cross-identified.

SU-F-T-261: Reconstruction of Initial Photon Fluence Based On EPID Images

Energy Technology Data Exchange (ETDEWEB)

Seliger, T; Engenhart-Cabillic, R [Philipp University of Marburg, Marburg (Germany); Czarnecki, D; Maeder, U; Zink, K [Technische Hochschule Mittelhessen - University of Applied Sciences, Giessen (Germany); Kussaether, R [MedCom GmbH, Darmstadt (Germany); Poppe, B [University Hospital for Medical Radiation Physics, Pius-Hospital, Medical Campus, Carl von Ossietzky University of Oldenburg (Germany)

2016-06-15

Purpose: Verifying an algorithm to reconstruct relative initial photon fluence for clinical use. Clinical EPID and CT images were acquired to reconstruct an external photon radiation treatment field. The reconstructed initial photon fluence could be used to verify the treatment or calculate the applied dose to the patient. Methods: The acquired EPID images were corrected for scatter caused by the patient and the EPID with an iterative reconstruction algorithm. The transmitted photon fluence behind the patient was calculated subsequently. Based on the transmitted fluence the initial photon fluence was calculated using a back-projection algorithm which takes the patient geometry and its energy dependent linear attenuation into account. This attenuation was gained from the acquired cone-beam CT or the planning CT by calculating a water-equivalent radiological thickness for each irradiation direction. To verify the algorithm an inhomogeneous phantom consisting of three inhomogeneities was irradiated by a static 6 MV photon field and compared to a reference flood field image. Results: The mean deviation between the reconstructed relative photon fluence for the inhomogeneous phantom and the flood field EPID image was 3% rising up to 7% for off-axis fluence. This was probably caused by the used clinical EPID calibration, which flattens the inhomogeneous fluence profile of the beam. Conclusion: In this clinical experiment the algorithm achieved good results in the center of the field while it showed high deviation of the lateral fluence. This could be reduced by optimizing the EPID calibration, considering the off-axis differential energy response. In further progress this and other aspects of the EPID, eg. field size dependency, CT and dose calibration have to be studied to realize a clinical acceptable accuracy of 2%.

Improvement of mesh recolonization in abdominal wall reconstruction with adipose vs. bone marrow mesenchymal stem cells in a rodent model.

Science.gov (United States)

van Steenberghe, M; Schubert, T; Guiot, Y; Goebbels, R M; Gianello, P

2017-08-01

Reconstruction of muscle defects remains a challenge. Our work assessed the potential of an engineered construct made of a human acellular collagen matrix (HACM) seeded with porcine mesenchymal stem cells (MSCs) to reconstruct abdominal wall muscle defects in a rodent model. This study compared 2 sources of MSCs (bone-marrow, BMSCs, and adipose, ASCs) in vitro and in vivo for parietal defect reconstruction. Cellular viability and growth factor release (VEGF, FGF-Beta, HGF, IGF-1, TGF-Beta) were investigated under normoxic/hypoxic culture conditions. Processed and recellularized HACMs were mechanically assessed. The construct was tested in vivo in full thickness abdominal wall defect treated with HACM alone vs. HACM+ASCs or BMSCs (n=14). Tissue remodeling was studied at day 30 for neo-angiogenesis and muscular reconstruction. A significantly lower secretion of IGF was observed with ASCs vs. BMSCs under hypoxic conditions (-97.6%, p<0.005) whereas significantly higher VEGF/FGF secretions were found with ASCs (+92%, p<0.001 and +72%, p<0.05, respectively). Processing and recellularization did not impair the mechanical properties of the HACM. In vivo, angiogenesis and muscle healing were significantly improved by the HACM+ASCs in comparison to BMSCs (p<0.05) at day 30. A composite graft made of an HACM seeded with ASCs can improve muscle repair by specific growth factor release in hypoxic conditions and by in vivo remodeling (neo-angiogenesis/graft integration) while maintaining mechanical properties. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of a Porcine Dermal Collagen (Permacol Implant for Abdominal Wall Reconstruction in a Pediatric Multitrauma Patient

Directory of Open Access Journals (Sweden)

Idit Melnik

2014-01-01

Full Text Available The presence of a contaminated surgical field in abdominal wall defects caused by trauma presents a challenge for surgeons. Both primary suture and synthetic meshes are strongly discouraged as surgical treatments in such cases. We describe the use of a porcine dermal collagen (Permacol implant in an eight-year-old patient with multiple injuries. Three months after discharge, the child remains well with good cosmetic results. He is free of pain and has returned to full activity levels with complete wound closure and without any evidence of residual hernia. In conclusion, our experience indicates that the use of Permacol can be considered an efficient technique for reconstructing an infected abdominal wall defect of a pediatric multitrauma patient.

X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers

Energy Technology Data Exchange (ETDEWEB)

Willey, T. M., E-mail: willey1@llnl.gov; Champley, K., E-mail: champley1@llnl.gov; Hodgin, R.; Lauderbach, L.; Bagge-Hansen, M.; May, C.; Buuren, T. van [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Sanchez, N.; Jensen, B. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Iverson, A. [National Security Technologies, LLC, Las Vegas, Nevada 89193 (United States)

2016-06-21

Exploding foil initiators (EFIs), also known as slapper initiators or detonators, offer clear safety and timing advantages over other means of initiating detonation in high explosives. This work outlines a new capability for imaging and reconstructing three-dimensional images of operating EFIs. Flyer size and intended velocity were chosen based on parameters of the imaging system. The EFI metal plasma and plastic flyer traveling at 2.5 km/s were imaged with short ∼80 ps pulses spaced 153.4 ns apart. A four-camera system acquired 4 images from successive x-ray pulses from each shot. The first frame was prior to bridge burst, the 2nd images the flyer about 0.16 mm above the surface but edges of the foil and/or flyer are still attached to the substrate. The 3rd frame captures the flyer in flight, while the 4th shows a completely detached flyer in a position that is typically beyond where slappers strike initiating explosives. Multiple acquisitions at different incident angles and advanced computed tomography reconstruction algorithms were used to produce a 3-dimensional image of the flyer at 0.16 and 0.53 mm above the surface. Both the x-ray images and the 3D reconstruction show a strong anisotropy in the shape of the flyer and underlying foil parallel vs. perpendicular to the initiating current and electrical contacts. These results provide detailed flyer morphology during the operation of the EFI.

The pedicled omentoplasty and split skin graft (POSSG) for reconstruction of large chest wall defects. A validity study of 34 patients

NARCIS (Netherlands)

C.M.E. Contant; A.N. van Geel (Albert); B. van der Holt (Bronno); T. Wiggers (Theo)

1996-01-01

textabstractThe aim of this study was to evaluate retrospectively the results of pedicled omentoplasty and split skin graft (POSSG) in reconstructing (full thickness) chest wall defects, and to define its role as a palliative procedure for local symptom control. Thirty-four patients with recurrent

Joint reconstruction of the initial pressure and speed of sound distributions from combined photoacoustic and ultrasound tomography measurements

Science.gov (United States)

Matthews, Thomas P.; Anastasio, Mark A.

2017-12-01

The initial pressure and speed of sound (SOS) distributions cannot both be stably recovered from photoacoustic computed tomography (PACT) measurements alone. Adjunct ultrasound computed tomography (USCT) measurements can be employed to estimate the SOS distribution. Under the conventional image reconstruction approach for combined PACT/USCT systems, the SOS is estimated from the USCT measurements alone and the initial pressure is estimated from the PACT measurements by use of the previously estimated SOS. This approach ignores the acoustic information in the PACT measurements and may require many USCT measurements to accurately reconstruct the SOS. In this work, a joint reconstruction method where the SOS and initial pressure distributions are simultaneously estimated from combined PACT/USCT measurements is proposed. This approach allows accurate estimation of both the initial pressure distribution and the SOS distribution while requiring few USCT measurements.

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

International Nuclear Information System (INIS)

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

2015-01-01

Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo TM , GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

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

Energy Technology Data Exchange (ETDEWEB)

Gomez-Cardona, Daniel [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Nagle, Scott K. [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Robinson, Terry E. [Department of Pediatrics, Stanford School of Medicine, 770 Welch Road, Palo Alto, California 94304 (United States)

2015-10-15

Purpose: Wall thickness (WT) is an airway feature of great interest for the assessment of morphological changes in the lung parenchyma. Multidetector computed tomography (MDCT) has recently been used to evaluate airway WT, but the potential risk of radiation-induced carcinogenesis—particularly in younger patients—might limit a wider use of this imaging method in clinical practice. The recent commercial implementation of the statistical model-based iterative reconstruction (MBIR) algorithm, instead of the conventional filtered back projection (FBP) algorithm, has enabled considerable radiation dose reduction in many other clinical applications of MDCT. The purpose of this work was to study the impact of radiation dose and MBIR in the MDCT assessment of airway WT. Methods: An airway phantom was scanned using a clinical MDCT system (Discovery CT750 HD, GE Healthcare) at 4 kV levels and 5 mAs levels. Both FBP and a commercial implementation of MBIR (Veo{sup TM}, GE Healthcare) were used to reconstruct CT images of the airways. For each kV–mAs combination and each reconstruction algorithm, the contrast-to-noise ratio (CNR) of the airways was measured, and the WT of each airway was measured and compared with the nominal value; the relative bias and the angular standard deviation in the measured WT were calculated. For each airway and reconstruction algorithm, the overall performance of WT quantification across all of the 20 kV–mAs combinations was quantified by the sum of squares (SSQs) of the difference between the measured and nominal WT values. Finally, the particular kV–mAs combination and reconstruction algorithm that minimized radiation dose while still achieving a reference WT quantification accuracy level was chosen as the optimal acquisition and reconstruction settings. Results: The wall thicknesses of seven airways of different sizes were analyzed in the study. Compared with FBP, MBIR improved the CNR of the airways, particularly at low radiation dose

Suppression of intensity transition artifacts in statistical x-ray computer tomography reconstruction through Radon inversion initialization

International Nuclear Information System (INIS)

Zbijewski, Wojciech; Beekman, Freek J.

2004-01-01

Statistical reconstruction (SR) methods provide a general and flexible framework for obtaining tomographic images from projections. For several applications SR has been shown to outperform analytical algorithms in terms of resolution-noise trade-off achieved in the reconstructions. A disadvantage of SR is the long computational time required to obtain the reconstructions, in particular when large data sets characteristic for x-ray computer tomography (CT) are involved. As was shown recently, by combining statistical methods with block iterative acceleration schemes [e.g., like in the ordered subsets convex (OSC) algorithm], the reconstruction time for x-ray CT applications can be reduced by about two orders of magnitude. There are, however, some factors lengthening the reconstruction process that hamper both accelerated and standard statistical algorithms to similar degree. In this simulation study based on monoenergetic and scatter-free projection data, we demonstrate that one of these factors is the extremely high number of iterations needed to remove artifacts that can appear around high-contrast structures. We also show (using the OSC method) that these artifacts can be adequately suppressed if statistical reconstruction is initialized with images generated by means of Radon inversion algorithms like filtered back projection (FBP). This allows the reconstruction time to be shortened by even as much as one order of magnitude. Although the initialization of the statistical algorithm with FBP image introduces some additional noise into the first iteration of OSC reconstruction, the resolution-noise trade-off and the contrast-to-noise ratio of final images are not markedly compromised

Carotid Intraplaque Hemorrhage Imaging with Quantitative Vessel Wall T1 Mapping: Technical Development and Initial Experience.

Science.gov (United States)

Qi, Haikun; Sun, Jie; Qiao, Huiyu; Chen, Shuo; Zhou, Zechen; Pan, Xinlei; Wang, Yishi; Zhao, Xihai; Li, Rui; Yuan, Chun; Chen, Huijun

2018-04-01

Purpose To develop a three-dimensional (3D) high-spatial-resolution time-efficient sequence for use in quantitative vessel wall T1 mapping. Materials and Methods A previously described sequence, simultaneous noncontrast angiography and intraplaque hemorrhage (SNAP) imaging, was extended by introducing 3D golden angle radial k-space sampling (GOAL-SNAP). Sliding window reconstruction was adopted to reconstruct images at different inversion delay times (different T1 contrasts) for voxelwise T1 fitting. Phantom studies were performed to test the accuracy of T1 mapping with GOAL-SNAP against a two-dimensional inversion recovery (IR) spin-echo (SE) sequence. In vivo studies were performed in six healthy volunteers (mean age, 27.8 years ± 3.0 [standard deviation]; age range, 24-32 years; five male) and five patients with atherosclerosis (mean age, 66.4 years ± 5.5; range, 60-73 years; five male) to compare T1 measurements between vessel wall sections (five per artery) with and without intraplaque hemorrhage (IPH). Statistical analyses included Pearson correlation coefficient, Bland-Altman analysis, and Wilcoxon rank-sum test with data permutation by subject. Results Phantom T1 measurements with GOAL-SNAP and IR SE sequences showed excellent correlation (R 2 = 0.99), with a mean bias of -25.8 msec ± 43.6 and a mean percentage error of 4.3% ± 2.5. Minimum T1 was significantly different between sections with IPH and those without it (mean, 371 msec ± 93 vs 944 msec ± 120; P = .01). Estimated T1 of normal vessel wall and muscle were 1195 msec ± 136 and 1117 msec ± 153, respectively. Conclusion High-spatial-resolution (0.8 mm isotropic) time-efficient (5 minutes) vessel wall T1 mapping is achieved by using the GOAL-SNAP sequence. This sequence may yield more quantitative reproducible biomarkers with which to characterize IPH and monitor its progression. © RSNA, 2017.

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

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Jeffrey CY Chan

2016-12-01

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

Neural network modeling for near wall turbulent flow

International Nuclear Information System (INIS)

Milano, Michele; Koumoutsakos, Petros

2002-01-01

A neural network methodology is developed in order to reconstruct the near wall field in a turbulent flow by exploiting flow fields provided by direct numerical simulations. The results obtained from the neural network methodology are compared with the results obtained from prediction and reconstruction using proper orthogonal decomposition (POD). Using the property that the POD is equivalent to a specific linear neural network, a nonlinear neural network extension is presented. It is shown that for a relatively small additional computational cost nonlinear neural networks provide us with improved reconstruction and prediction capabilities for the near wall velocity fields. Based on these results advantages and drawbacks of both approaches are discussed with an outlook toward the development of near wall models for turbulence modeling and control

Reconstruction of Abdominal Wall of a Chronically Infected Postoperative Wound with a Rectus Abdominis Myofascial Splitting Flap

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Sung Kyu Bae

2013-01-01

Full Text Available Background If a chronically infected abdominal wound develops, complications such asperitonitis and an abdominal wall defect could occur. This could prolong the patient’s hospitalstay and increase the possibility of re-operation or another infection as well. For this reason,a solution for infection control is necessary. In this study, surgery using a rectus abdominismuscle myofascial splitting flap was performed on an abdominal wall defect.Methods From 2009 to 2012, 5 patients who underwent surgery due to ovarian rupture,cesarean section, or uterine myoma were chosen. In each case, during the first week afteroperation, the wound showed signs of infection. Surgery was chosen because the wounds didnot resolve with dressing. Debridement was performed along the previous operation woundand dissection of the skin was performed to separate the skin and subcutaneous tissue fromthe attenuated rectus muscle and Scarpa’s fascial layers. Once the anterior rectus sheath andmuscle were adequately mobilized, the fascia and muscle flap were advanced medially sothat the skin defect could be covered for reconstruction.Results Upon 3-week follow-up after a rectus abdominis myofascial splitting flap operation,no major complication occurred. In addition, all of the patients showed satisfaction in termsof function and esthetics at 3 to 6 months post-surgery.Conclusions Using a rectus abdominis myofascial splitting flap has many esthetic andfunctional benefits over previous methods of abdominal defect treatment, and notably, itenabled infection control by reconstruction using muscle.

Reconstruction of Abdominal Wall of a Chronically Infected Postoperative Wound with a Rectus Abdominis Myofascial Splitting Flap

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Sung Kyu Bae

2013-01-01

Full Text Available BackgroundIf a chronically infected abdominal wound develops, complications such as peritonitis and an abdominal wall defect could occur. This could prolong the patient's hospital stay and increase the possibility of re-operation or another infection as well. For this reason, a solution for infection control is necessary. In this study, surgery using a rectus abdominis muscle myofascial splitting flap was performed on an abdominal wall defect.MethodsFrom 2009 to 2012, 5 patients who underwent surgery due to ovarian rupture, cesarean section, or uterine myoma were chosen. In each case, during the first week after operation, the wound showed signs of infection. Surgery was chosen because the wounds did not resolve with dressing. Debridement was performed along the previous operation wound and dissection of the skin was performed to separate the skin and subcutaneous tissue from the attenuated rectus muscle and Scarpa's fascial layers. Once the anterior rectus sheath and muscle were adequately mobilized, the fascia and muscle flap were advanced medially so that the skin defect could be covered for reconstruction.ResultsUpon 3-week follow-up after a rectus abdominis myofascial splitting flap operation, no major complication occurred. In addition, all of the patients showed satisfaction in terms of function and esthetics at 3 to 6 months post-surgery.ConclusionsUsing a rectus abdominis myofascial splitting flap has many esthetic and functional benefits over previous methods of abdominal defect treatment, and notably, it enabled infection control by reconstruction using muscle.

Research Status of the Skeletalre Construction of Chest Wall

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Daixing ZHONG

2018-04-01

Full Text Available Chest wall defect may be caused by many factors such as the resection of tumor and trauma, and the reconstruction of bone-defection is still the key point of thoracic surgery. With the development of material science, more and more new materials have been used in medical practice, which makes huge progress in the surgery of chest wall. However, none of these materials satisfy all the practical needs of the reconstruction. Recently, with the development of the capacity of computer, 3D-printing technology has been gradually used in clinical work, and the idea of individual treatment has been accepted by more and more people. The weakness of these materials may be solved by the new material and the application of individual treatment, which could also make great advance in chest wall surgery. This article will make a summary of the research on the reconstruction of chest wall.

RECONSTRUCTING THE INITIAL DENSITY FIELD OF THE LOCAL UNIVERSE: METHODS AND TESTS WITH MOCK CATALOGS

International Nuclear Information System (INIS)

Wang Huiyuan; Mo, H. J.; Yang Xiaohu; Van den Bosch, Frank C.

2013-01-01

Our research objective in this paper is to reconstruct an initial linear density field, which follows the multivariate Gaussian distribution with variances given by the linear power spectrum of the current cold dark matter model and evolves through gravitational instabilities to the present-day density field in the local universe. For this purpose, we develop a Hamiltonian Markov Chain Monte Carlo method to obtain the linear density field from a posterior probability function that consists of two components: a prior of a Gaussian density field with a given linear spectrum and a likelihood term that is given by the current density field. The present-day density field can be reconstructed from galaxy groups using the method developed in Wang et al. Using a realistic mock Sloan Digital Sky Survey DR7, obtained by populating dark matter halos in the Millennium simulation (MS) with galaxies, we show that our method can effectively and accurately recover both the amplitudes and phases of the initial, linear density field. To examine the accuracy of our method, we use N-body simulations to evolve these reconstructed initial conditions to the present day. The resimulated density field thus obtained accurately matches the original density field of the MS in the density range 0.3∼ –1 , much smaller than the translinear scale, which corresponds to a wavenumber of ∼0.15 h Mpc –1

Fractal analysis on a classical hard-wall billiard with openings using a two-dimensional set of initial conditions

International Nuclear Information System (INIS)

Ree, Suhan

2003-01-01

Fractal analysis is performed to measure the chaoticity of a classical hard-wall billiard with openings. We use the circular billiard with a straight cut with two openings, and a two-dimensional (2D) set of initial conditions that produce all possible trajectories of a particle injected from one opening. We numerically compute the fractal dimension of singular points of the function that maps an initial condition to the number of collisions with the wall before the exit, using the box-counting algorithm that uses uniformly distributed points inside the 2D set of initial conditions. Finally, the classical chaotic properties are observed while the parameters of the billiard are varied, and the results are compared with those with the one-dimensional set of initial conditions

Transient debris freezing and potential wall melting during a severe reactivity initiated accident experiment

International Nuclear Information System (INIS)

El-Genk, M.S.; Moore, R.L.

1981-01-01

It is important to light water reactor (LWR) safety analysis to understand the transient freezing of molten core debris on cold structures following a hypothetical core meltdown accident. The purpose of this paper is to (a) present the results of a severe reactivity initiated accident (RIA) in-pile experiment with regard to molten debris distribution and freezing following test fuel rod failure, (b) analyze the transient freezing of molten debris (primarily a mixture of UO/sub 2/ fuel and Zircaloy cladding) deposited on the inner surface of the test shroud wall upon rod failure, and (c) assess the potential for wall melting upon being contacted by the molten debris. 26 refs

Anatomic double-bundle anterior cruciate ligament reconstruction using hamstring tendons with minimally required initial tension.

Science.gov (United States)

Mae, Tatsuo; Shino, Konsei; Matsumoto, Norinao; Natsu-Ume, Takashi; Yoneda, Kenji; Yoshikawa, Hideki; Yoneda, Minoru

2010-10-01

Our purpose was to clarify the clinical outcomes at 2 years after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction with 20 N of the initial tension, which was the minimally required initial tension to perform the reconstruction successfully according to our previous report about the pre-tension necessary to restore the laxity found in the opposite knee (7.3 N; range, 2.2 to 14 N). Of 64 patients who underwent anatomic double-bundle ACL reconstruction with autogenous semitendinosus tendon, 45 were periodically examined for 2 years. Two double-looped grafts were fixed with EndoButton CL devices (Smith & Nephew Endoscopy, Andover, MA) on the femoral side and Double Spike Plates (Smith & Nephew Endoscopy) on the tibial side, while a total of 20 N of initial tension (10 N to each graft) was applied at 20° of knee flexion. The International Knee Documentation Committee Knee Examination Form and Lysholm score were used for the subjective assessment, whereas range of motion and knee stability were evaluated as the objective assessment. Grafts were evaluated in 25 patients with second-look arthroscopy. According to the International Knee Documentation Committee subjective assessment, 62% of knees were graded as normal and 38% as nearly normal. The Lysholm score was 72 points in the preoperative period and improved to 99 points at 2 years' follow-up. A loss of knee extension of less than 3° was found in 2 patients. The pivot-shift test was evaluated as negative in all patients except for 5 as a glide. KT-2000 knee arthrometer side-to-side difference (MEDmetric, San Diego, CA) was 0.1 ± 0.9 mm at 2 years' follow-up. Of the subset of grafts evaluated by second-look arthroscopy, most were considered to have good synovial coverage and to be taut. The anatomic double-bundle ACL reconstruction with 20 N of low initial tension yielded good clinical outcomes at 2 years postoperatively, and second-look arthroscopic findings were excellent. Level IV

Mental constructs and the cognitive reconstruction of the Berlin wall.

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Tijus, C A; Santolini, A

1996-07-01

In this study of how to change people's conceptions of certain facts (i.e., the position of the Berlin Wall), a surprising psychological phenomenon was discovered. In the trial test, instead of designing a wall to enclose West Berlin, most people described and drew a short and straight wall that divided the city from north to south. Two methods were created, based on two general information-processing components involved in problem solving, to study how people might repair their misconceptions by themselves. The do-it-yourself method consisted of providing people with the task of thinking about how to build the wall and then drawing it, instead of just asking them to draw it. The distance-to-goal evaluation method consisted of asking the participants how the wall they had drawn would actually prevent passage from East Germany to West Berlin. The results showed that both methods had important effects in repairing misconceptions, but improvement in performance with the distance-to-goal method was less significant for those participants who were first provided the task of thinking about how to build the wall. These findings are consistent with the hypothesis that awareness of functional properties plays an important role in structuring and restructuring mental constructs.

A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner

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Thoeni, K.; Giacomini, A.; Murtagh, R.; Kniest, E.

2014-06-01

This work presents a comparative study between multi-view 3D reconstruction using various digital cameras and a terrestrial laser scanner (TLS). Five different digital cameras were used in order to estimate the limits related to the camera type and to establish the minimum camera requirements to obtain comparable results to the ones of the TLS. The cameras used for this study range from commercial grade to professional grade and included a GoPro Hero 1080 (5 Mp), iPhone 4S (8 Mp), Panasonic Lumix LX5 (9.5 Mp), Panasonic Lumix ZS20 (14.1 Mp) and Canon EOS 7D (18 Mp). The TLS used for this work was a FARO Focus 3D laser scanner with a range accuracy of ±2 mm. The study area is a small rock wall of about 6 m height and 20 m length. The wall is partly smooth with some evident geological features, such as non-persistent joints and sharp edges. Eight control points were placed on the wall and their coordinates were measured by using a total station. These coordinates were then used to georeference all models. A similar number of images was acquired from a distance of between approximately 5 to 10 m, depending on field of view of each camera. The commercial software package PhotoScan was used to process the images, georeference and scale the models, and to generate the dense point clouds. Finally, the open-source package CloudCompare was used to assess the accuracy of the multi-view results. Each point cloud obtained from a specific camera was compared to the point cloud obtained with the TLS. The latter is taken as ground truth. The result is a coloured point cloud for each camera showing the deviation in relation to the TLS data. The main goal of this study is to quantify the quality of the multi-view 3D reconstruction results obtained with various cameras as objectively as possible and to evaluate its applicability to geotechnical problems.

A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner

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K. Thoeni

2014-06-01

Full Text Available This work presents a comparative study between multi-view 3D reconstruction using various digital cameras and a terrestrial laser scanner (TLS. Five different digital cameras were used in order to estimate the limits related to the camera type and to establish the minimum camera requirements to obtain comparable results to the ones of the TLS. The cameras used for this study range from commercial grade to professional grade and included a GoPro Hero 1080 (5 Mp, iPhone 4S (8 Mp, Panasonic Lumix LX5 (9.5 Mp, Panasonic Lumix ZS20 (14.1 Mp and Canon EOS 7D (18 Mp. The TLS used for this work was a FARO Focus 3D laser scanner with a range accuracy of ±2 mm. The study area is a small rock wall of about 6 m height and 20 m length. The wall is partly smooth with some evident geological features, such as non-persistent joints and sharp edges. Eight control points were placed on the wall and their coordinates were measured by using a total station. These coordinates were then used to georeference all models. A similar number of images was acquired from a distance of between approximately 5 to 10 m, depending on field of view of each camera. The commercial software package PhotoScan was used to process the images, georeference and scale the models, and to generate the dense point clouds. Finally, the open-source package CloudCompare was used to assess the accuracy of the multi-view results. Each point cloud obtained from a specific camera was compared to the point cloud obtained with the TLS. The latter is taken as ground truth. The result is a coloured point cloud for each camera showing the deviation in relation to the TLS data. The main goal of this study is to quantify the quality of the multi-view 3D reconstruction results obtained with various cameras as objectively as possible and to evaluate its applicability to geotechnical problems.

Recurrent desmoid tumor of the abdominal wall | Toughrai | Pan ...

African Journals Online (AJOL)

Desmoid tumors most often occur in abdominal wall. Their tendency to recur lead to repeated operations which can make the abdominal wall reconstruction difficult. We report a 28-year-old female history. The patient was referred to our hospital for a recurrent desmoid tumor of the abdominal wall. The tumor was totally ...

Reconstructing the Initial Density Field of the Local Universe: Methods and Tests with Mock Catalogs

Science.gov (United States)

Wang, Huiyuan; Mo, H. J.; Yang, Xiaohu; van den Bosch, Frank C.

2013-07-01

Our research objective in this paper is to reconstruct an initial linear density field, which follows the multivariate Gaussian distribution with variances given by the linear power spectrum of the current cold dark matter model and evolves through gravitational instabilities to the present-day density field in the local universe. For this purpose, we develop a Hamiltonian Markov Chain Monte Carlo method to obtain the linear density field from a posterior probability function that consists of two components: a prior of a Gaussian density field with a given linear spectrum and a likelihood term that is given by the current density field. The present-day density field can be reconstructed from galaxy groups using the method developed in Wang et al. Using a realistic mock Sloan Digital Sky Survey DR7, obtained by populating dark matter halos in the Millennium simulation (MS) with galaxies, we show that our method can effectively and accurately recover both the amplitudes and phases of the initial, linear density field. To examine the accuracy of our method, we use N-body simulations to evolve these reconstructed initial conditions to the present day. The resimulated density field thus obtained accurately matches the original density field of the MS in the density range 0.3 \\lesssim \\rho /\\bar{\\rho } \\lesssim 20 without any significant bias. In particular, the Fourier phases of the resimulated density fields are tightly correlated with those of the original simulation down to a scale corresponding to a wavenumber of ~1 h Mpc-1, much smaller than the translinear scale, which corresponds to a wavenumber of ~0.15 h Mpc-1.

Quantitative analysis of emphysema and airway measurements according to iterative reconstruction algorithms: comparison of filtered back projection, adaptive statistical iterative reconstruction and model-based iterative reconstruction

International Nuclear Information System (INIS)

Choo, Ji Yung; Goo, Jin Mo; Park, Chang Min; Park, Sang Joon; Lee, Chang Hyun; Shim, Mi-Suk

2014-01-01

To evaluate filtered back projection (FBP) and two iterative reconstruction (IR) algorithms and their effects on the quantitative analysis of lung parenchyma and airway measurements on computed tomography (CT) images. Low-dose chest CT obtained in 281 adult patients were reconstructed using three algorithms: FBP, adaptive statistical IR (ASIR) and model-based IR (MBIR). Measurements of each dataset were compared: total lung volume, emphysema index (EI), airway measurements of the lumen and wall area as well as average wall thickness. Accuracy of airway measurements of each algorithm was also evaluated using an airway phantom. EI using a threshold of -950 HU was significantly different among the three algorithms in decreasing order of FBP (2.30 %), ASIR (1.49 %) and MBIR (1.20 %) (P < 0.01). Wall thickness was also significantly different among the three algorithms with FBP (2.09 mm) demonstrating thicker walls than ASIR (2.00 mm) and MBIR (1.88 mm) (P < 0.01). Airway phantom analysis revealed that MBIR showed the most accurate value for airway measurements. The three algorithms presented different EIs and wall thicknesses, decreasing in the order of FBP, ASIR and MBIR. Thus, care should be taken in selecting the appropriate IR algorithm on quantitative analysis of the lung. (orig.)

Quantitative analysis of emphysema and airway measurements according to iterative reconstruction algorithms: comparison of filtered back projection, adaptive statistical iterative reconstruction and model-based iterative reconstruction

Energy Technology Data Exchange (ETDEWEB)

Choo, Ji Yung [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Korea University Ansan Hospital, Ansan-si, Department of Radiology, Gyeonggi-do (Korea, Republic of); Goo, Jin Mo; Park, Chang Min; Park, Sang Joon [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of); Seoul National University, Cancer Research Institute, Seoul (Korea, Republic of); Lee, Chang Hyun; Shim, Mi-Suk [Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, Seoul (Korea, Republic of)

2014-04-15

To evaluate filtered back projection (FBP) and two iterative reconstruction (IR) algorithms and their effects on the quantitative analysis of lung parenchyma and airway measurements on computed tomography (CT) images. Low-dose chest CT obtained in 281 adult patients were reconstructed using three algorithms: FBP, adaptive statistical IR (ASIR) and model-based IR (MBIR). Measurements of each dataset were compared: total lung volume, emphysema index (EI), airway measurements of the lumen and wall area as well as average wall thickness. Accuracy of airway measurements of each algorithm was also evaluated using an airway phantom. EI using a threshold of -950 HU was significantly different among the three algorithms in decreasing order of FBP (2.30 %), ASIR (1.49 %) and MBIR (1.20 %) (P < 0.01). Wall thickness was also significantly different among the three algorithms with FBP (2.09 mm) demonstrating thicker walls than ASIR (2.00 mm) and MBIR (1.88 mm) (P < 0.01). Airway phantom analysis revealed that MBIR showed the most accurate value for airway measurements. The three algorithms presented different EIs and wall thicknesses, decreasing in the order of FBP, ASIR and MBIR. Thus, care should be taken in selecting the appropriate IR algorithm on quantitative analysis of the lung. (orig.)

A case of radiation ulcer of chest wall with osteomyelitis

International Nuclear Information System (INIS)

Baba, Kyoko; Shibata, Hirotatsu; Mouri, Mari; Uchinuma, Eiju

2005-01-01

We report a case of anterior chest skin ulcer with rib and sternum osteomyelitis following radiation therapy for post operative mammary carcinoma. Operation was performed six times including debridement with sternum and rib resection reconstruction and skin grafting. It took about one and a half years after first operation to heal the ulcer with osteomyelitis. Principle of treatment for radiation ulcer accompanied by osteomyelitis is complete resection of the damaged lesion. However, it is difficult to evaluate the exact area of the damaged lesion. Therefore it is not rare to repeat its recurrence and have trouble with its treatment. In this case, it was considered that the resected area was insufficient on the initial operation. In order to treat for radiation ulcers accompanied by osteomyelitis, enough resection of the damaged lesion in the initial operation is necessary. Ultimately, in our case, the resection of all sternum, part of the right second to fifth rib and part of left second to seventh rib was necessary. It is generally said that reconstructing bone structure is required in the case of wide defect of chest wall. Though, we did not perform reconstruction of the bone structures, there is no problem in the condition of respiratory system. The surrounding soft tissues changed to hard enough to avoid paradoxical breathing. (author)

Influence of the Accuracy of Angiography-Based Reconstructions on Velocity and Wall Shear Stress Computations in Coronary Bifurcations: A Phantom Study

Science.gov (United States)

Schrauwen, Jelle T. C.; Karanasos, Antonios; van Ditzhuijzen, Nienke S.; Aben, Jean-Paul; van der Steen, Antonius F. W.

2015-01-01

Introduction Wall shear stress (WSS) plays a key role in the onset and progression of atherosclerosis in human coronary arteries. Especially sites with low and oscillating WSS near bifurcations have a higher propensity to develop atherosclerosis. WSS computations in coronary bifurcations can be performed in angiography-based 3D reconstructions. It is essential to evaluate how reconstruction errors influence WSS computations in mildly-diseased coronary bifurcations. In mildly-diseased lesions WSS could potentially provide more insight in plaque progression. Materials Methods Four Plexiglas phantom models of coronary bifurcations were imaged with bi-plane angiography. The lumens were segmented by two clinically experienced readers. Based on the segmentations 3D models were generated. This resulted in three models per phantom: one gold-standard from the phantom model itself, and one from each reader. Steady-state and transient simulations were performed with computational fluid dynamics to compute the WSS. A similarity index and a noninferiority test were used to compare the WSS in the phantoms and their reconstructions. The margin for this test was based on the resolution constraints of angiography. Results The reconstruction errors were similar to previously reported data; in seven out of eight reconstructions less than 0.10 mm. WSS in the regions proximal and far distal of the stenosis showed a good agreement. However, the low WSS areas directly distal of the stenosis showed some disagreement between the phantoms and the readers. This was due to small deviations in the reconstruction of the stenosis that caused differences in the resulting jet, and consequently the size and location of the low WSS area. Discussion This study showed that WSS can accurately be computed within angiography-based 3D reconstructions of coronary arteries with early stage atherosclerosis. Qualitatively, there was a good agreement between the phantoms and the readers. Quantitatively, the

Influence of the Accuracy of Angiography-Based Reconstructions on Velocity and Wall Shear Stress Computations in Coronary Bifurcations: A Phantom Study.

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Jelle T C Schrauwen

Full Text Available Wall shear stress (WSS plays a key role in the onset and progression of atherosclerosis in human coronary arteries. Especially sites with low and oscillating WSS near bifurcations have a higher propensity to develop atherosclerosis. WSS computations in coronary bifurcations can be performed in angiography-based 3D reconstructions. It is essential to evaluate how reconstruction errors influence WSS computations in mildly-diseased coronary bifurcations. In mildly-diseased lesions WSS could potentially provide more insight in plaque progression.Four Plexiglas phantom models of coronary bifurcations were imaged with bi-plane angiography. The lumens were segmented by two clinically experienced readers. Based on the segmentations 3D models were generated. This resulted in three models per phantom: one gold-standard from the phantom model itself, and one from each reader. Steady-state and transient simulations were performed with computational fluid dynamics to compute the WSS. A similarity index and a noninferiority test were used to compare the WSS in the phantoms and their reconstructions. The margin for this test was based on the resolution constraints of angiography.The reconstruction errors were similar to previously reported data; in seven out of eight reconstructions less than 0.10 mm. WSS in the regions proximal and far distal of the stenosis showed a good agreement. However, the low WSS areas directly distal of the stenosis showed some disagreement between the phantoms and the readers. This was due to small deviations in the reconstruction of the stenosis that caused differences in the resulting jet, and consequently the size and location of the low WSS area.This study showed that WSS can accurately be computed within angiography-based 3D reconstructions of coronary arteries with early stage atherosclerosis. Qualitatively, there was a good agreement between the phantoms and the readers. Quantitatively, the low WSS regions directly distal to

High-R Walls for Remodeling: Wall Cavity Moisture Monitoring

Energy Technology Data Exchange (ETDEWEB)

Wiehagen, J.; Kochkin, V.

2012-12-01

The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

High-R Walls for Remodeling. Wall Cavity Moisture Monitoring

Energy Technology Data Exchange (ETDEWEB)

Wiehagen, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Kochkin, V. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

2012-12-01

The focus of the study is on the performance of wall systems, and in particular, the moisture characteristics inside the wall cavity and in the wood sheathing. Furthermore, while this research will initially address new home construction, the goal is to address potential moisture issues in wall cavities of existing homes when insulation and air sealing improvements are made.

Reconstruction of the chest wall after excision of a giant malignant ...

African Journals Online (AJOL)

Primary chest wall tumors are uncommon and constitute 0.2-2% of all tumors. Metastatic tumors and tumors of local extension are more common. Malignant peripheral nerve sheath tumor (MPNST) of the chest wall is even rarer and its incidence on the chest wall not stated in the literature. The incidence in the general ...

Patient-specific AAA wall stress analysis: 99-percentile versus peak stress

NARCIS (Netherlands)

Speelman, L.; Bosboom, E.M.H.; Schurink, G.W.H.; Hellenthal, F.A.M.V.I.; Buth, J.; Breeuwer, M.; Jacobs, M.J.; Vosse, van de F.N.

2008-01-01

Objective Biomechanically, rupture of an Abdominal Aortic Aneurysm (AAA) occurs when the stress acting on the wall due to the blood pressure, exceeds the strength of the wall. Peak wall stress estimations, based on CT reconstruction, may be prone to observer variation. This study focuses on the

Clinical applications of iterative reconstruction

International Nuclear Information System (INIS)

Eberl, S.

1998-01-01

Expectation maximisation (EM) reconstruction largely eliminates the hot and cold streaking artifacts characteristic of filtered-back projection (FBP) reconstruction around localised hot areas, such as the bladder. It also substantially reduces the problem of decreased inferior wall counts in MIBI myocardial perfusion studies due to ''streaking'' from high liver uptake. Non-uniform attenuation and scatter correction, resolution recovery, anatomical information, e.g. from MRI or CT tracer kinetic modelling, can all be built into the EM reconstruction imaging model. The properties of ordered subset EM (OSEM) have also been used to correct for known patient motion as part of the reconstruction process. These uses of EM are elaborated more fully in some of the other abstracts of this meeting. Currently we use OSEM routinely for: (i) studies where streaking is a problem, including all MIBI myocardial perfusion studies, to avoid hot liver inferior wall artifact, (ii) all whole body FDG PET, all lung V/Q SPECT (which have a short acquisition time) and all gated 201 TI myocardial perfusion studies due to improved noise characteristics of OSEM in these studies; (iii) studies with measured, non-uniform attenuation correction. With the accelerated OSEM algorithm, iterative reconstruction is practical for routine clinical applications and we have found OSEM to provide clearly superior reconstructions for the areas listed above and are investigating its application to other studies. In clinical use, we have not found OSEM to introduce artifacts which would not also occur with FBP, e.g. uncorrected patient motion will cause artifacts with both OSEM and FBP

Time evolution of one-dimensional gapless models from a domain wall initial state: stochastic Loewner evolution continued?

International Nuclear Information System (INIS)

Calabrese, Pasquale; Hagendorf, Christian; Doussal, Pierre Le

2008-01-01

We study the time evolution of quantum one-dimensional gapless systems evolving from initial states with a domain wall. We generalize the path integral imaginary time approach that together with boundary conformal field theory allows us to derive the time and space dependence of general correlation functions. The latter are explicitly obtained for the Ising universality class, and the typical behavior of one- and two-point functions is derived for the general case. Possible connections with the stochastic Loewner evolution are discussed and explicit results for one-point time dependent averages are obtained for generic κ for boundary conditions corresponding to stochastic Loewner evolution. We use this set of results to predict the time evolution of the entanglement entropy and obtain the universal constant shift due to the presence of a domain wall in the initial state

Improvements for real-time magnetic equilibrium reconstruction on ASDEX Upgrade

International Nuclear Information System (INIS)

Giannone, L.; Fischer, R.; McCarthy, P.J.; Odstrcil, T.; Zammuto, I.; Bock, A.; Conway, G.; Fuchs, J.C.; Gude, A.; Igochine, V.; Kallenbach, A.; Lackner, K.; Maraschek, M.; Rapson, C.; Ruan, Q.; Schuhbeck, K.H.; Suttrop, W.; Wenzel, L.

2015-01-01

Highlights: • Spline basis current functions with second-order linear regularisation. • Perturbations of magnetic probe measurements due to ferromagnetic tiles on the inner wall and from oscillations in the fast position coil current are corrected. • A constraint of the safety factor on the magnetic axis is introduced. Soft X-ray tomography is used to assess the quality of the real-time magnetic equilibrium reconstruction. • External loop voltage measurements and magnetic probe pairs inside and outside the vessel wall were used to measure the vacuum vessel wall resistivity. - Abstract: Real-time magnetic equilibria are needed for NTM stabilization and disruption avoidance experiments on ASDEX Upgrade. Five improvements to real-time magnetic equilibrium reconstruction on ASDEX Upgrade have been investigated. The aim is to include as many features of the offline magnetic equilibrium reconstruction code in the real-time equilibrium reconstruction code. Firstly, spline current density basis functions with regularization are used in the offline equilibrium reconstruction code, CLISTE [1]. It is now possible to have the same number of spline basis functions in the real-time code. Secondly, in the presence of edge localized modes, (ELM's), it is found to be necessary to include the low pass filter effect of the vacuum vessel on the fast position control coil currents to correctly compensate the magnetic probes for current oscillations in these coils. Thirdly, the introduction of ferromagnetic tiles in ASDEX Upgrade means that a real-time algorithm for including the perturbations of the magnetic equilibrium generated by these tiles is required. A methodology based on tile surface currents is described. Fourthly, during current ramps it was seen that the difference between fitted and measured magnetic measurements in the equilibrium reconstruction were larger than in the constant current phase. External loop voltage measurements and magnetic probe pairs inside and

Improvements for real-time magnetic equilibrium reconstruction on ASDEX Upgrade

Energy Technology Data Exchange (ETDEWEB)

Giannone, L.; Fischer, R. [Max Planck Institute for Plasma Physics, 85748 Garching (Germany); McCarthy, P.J. [Department of Physics, University College Cork, Cork (Ireland); Odstrcil, T.; Zammuto, I.; Bock, A.; Conway, G.; Fuchs, J.C.; Gude, A.; Igochine, V.; Kallenbach, A.; Lackner, K.; Maraschek, M.; Rapson, C. [Max Planck Institute for Plasma Physics, 85748 Garching (Germany); Ruan, Q. [National Instruments, Austin, TX 78759-3504 (United States); Schuhbeck, K.H.; Suttrop, W. [Max Planck Institute for Plasma Physics, 85748 Garching (Germany); Wenzel, L. [National Instruments, Austin, TX 78759-3504 (United States)

2015-11-15

Highlights: • Spline basis current functions with second-order linear regularisation. • Perturbations of magnetic probe measurements due to ferromagnetic tiles on the inner wall and from oscillations in the fast position coil current are corrected. • A constraint of the safety factor on the magnetic axis is introduced. Soft X-ray tomography is used to assess the quality of the real-time magnetic equilibrium reconstruction. • External loop voltage measurements and magnetic probe pairs inside and outside the vessel wall were used to measure the vacuum vessel wall resistivity. - Abstract: Real-time magnetic equilibria are needed for NTM stabilization and disruption avoidance experiments on ASDEX Upgrade. Five improvements to real-time magnetic equilibrium reconstruction on ASDEX Upgrade have been investigated. The aim is to include as many features of the offline magnetic equilibrium reconstruction code in the real-time equilibrium reconstruction code. Firstly, spline current density basis functions with regularization are used in the offline equilibrium reconstruction code, CLISTE [1]. It is now possible to have the same number of spline basis functions in the real-time code. Secondly, in the presence of edge localized modes, (ELM's), it is found to be necessary to include the low pass filter effect of the vacuum vessel on the fast position control coil currents to correctly compensate the magnetic probes for current oscillations in these coils. Thirdly, the introduction of ferromagnetic tiles in ASDEX Upgrade means that a real-time algorithm for including the perturbations of the magnetic equilibrium generated by these tiles is required. A methodology based on tile surface currents is described. Fourthly, during current ramps it was seen that the difference between fitted and measured magnetic measurements in the equilibrium reconstruction were larger than in the constant current phase. External loop voltage measurements and magnetic probe pairs inside

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

International Nuclear Information System (INIS)

Lee, H.; Choi, S.; Kim, Y.-S.; Park, H.-S.; Seo, C.-W.; Kim, H.-J.; Lee, D.; Lee, Y.

2017-01-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

Investigation of various reconstruction parameters for algebraic reconstruction technique in a newly developed chest digital tomosynthesis

Science.gov (United States)

Lee, H.; Choi, S.; Lee, D.; Kim, Y.-s.; Park, H.-S.; Lee, Y.; Seo, C.-W.; Kim, H.-J.

2017-08-01

Chest digital tomosynthesis (CDT) is a promising new modality that provides 3D information by reconstructing limited projection views. CDT systems have been developed to improve the limitations of conventional radiography such as image degradation and low sensitivity. However, the development of reconstruction methods is challenging because of the limited projection views within various angular ranges. Optimization of reconstruction parameters for various reconsturction methods in CDT system also is needed. The purpose of this study was to investigate the feasibility of algebraic reconstruction technique (ART) method, and to evaluate the effect of the reconstruction parameters for our newly developed CDT system. We designed ART method with 41 projection views over an angular range of ±20°. To investigate the effect of reconstruction parameters, we measured the contrast-to-noise ratio (CNR), artifact spread function (ASF), and quality factor (QF) using LUNGMAN phantom included tumors. We found that the proper choice of reconstruction parameters such as relaxation parameter, initial guess, and number of iterations improved the quality of reconstructed images from the same projection views. Optimal values of ART relaxation parameter with uniform (UI) and back-projection (BP) initial guesses were 0.4 and 0.6, respectively. BP initial guess improved image quality in comparison with UI initial guess, in terms of providing a higher CNR and QF values with a faster speed. CNR and QF values improved with increasing number of iteration. Particularly, ART method with BP initial guess (when β = 0.6) after 3-terations provide satisfactory reconstructed image. In conclusion, the use of ART method with proper reconstruction parameters provided better image quality than FBP method as well as conventional radiography. These results indicated that the ART method with optimal reconstruction parameters could improve image quality for nodule detection using the CDT system.

Chest wall stabilization and reconstruction: short and long-term results 5 years after the introduction of a new titanium plates system.

Science.gov (United States)

De Palma, Angela; Sollitto, Francesco; Loizzi, Domenico; Di Gennaro, Francesco; Scarascia, Daniele; Carlucci, Annalisa; Giudice, Giuseppe; Armenio, Andrea; Ludovico, Rossana; Loizzi, Michele

2016-03-01

We report short and long-term results with the dedicated Synthes(®) titanium plates system, introduced 5 years ago, for chest wall stabilization and reconstruction. We retrospectively analyzed (January 2010 to December 2014) 27 consecutive patients (22 males, 5 females; range 16-83 years, median age 60 years), treated with this system: primary [3] and secondary [8] chest wall tumor; flail chest [5]; multiple ribs fractures [5]; sternal dehiscence-diastasis [3]; sternal fracture [1]; sternoclavicular joint dislocation [1]; Poland syndrome [1]. Short-term results were evaluated as: operating time, post-operative morbidity, mortality, hospital stay; long-term results as: survival, plates-related morbidity, spirometric values, chest pain [measured with Verbal Rating Scale (VRS) and SF12 standard V1 questionnaire]. Each patient received from 1 to 10 (median 2) titanium plates/splints; median operating time was 150 min (range: 115-430 min). Post-operative course: 15 patients (55.6%) uneventful, 10 (37%) minor complications, 2 (7.4%) major complications; no post-operative mortality. Median post-operative hospital stay was 13 days (range: 5-129 days). At a median follow-up of 20 months (range: 1-59 months), 21 patients (78%) were alive, 6 (22%) died. Three patients presented long-term plates-related morbidity: plates rupture [2], pin plate dislodgment [1]; two required a second surgical look. One-year from surgery median spirometric values were: FVC 3.31 L (90%), FEV1 2.46 L (78%), DLCO 20.9 mL/mmHg/min (76%). On 21 alive patients, 7 (33.3%) reported no pain (VRS score 0), 10 (47.6%) mild (score 2), 4 (19.1%) moderate (score 4), no-one severe (score >4); 15 (71.5%) reported none or mild, 6 (28.5%) moderate pain influencing quality of life. An optimal chest wall stabilization and reconstruction was achieved with the Synthes(®) titanium plates system, with minimal morbidity, no post-operative mortality, acceptable operating time and post-operative hospital stay. Long

Inferior vena cava leiomyosarcoma: vascular reconstruction is not ...

African Journals Online (AJOL)

... vena cava is a rare and aggressive tumor, arising from the smooth muscle cells in the vessel wall. A large complete surgical resection is the essential treatment. The need of vascular reconstruction is not always mandatory. It's above all to understand the place of the reconstruction with artificial vascular patch prosthetics of ...

Differentiation of human endometrial stem cells into urothelial cells on a three-dimensional nanofibrous silk-collagen scaffold: an autologous cell resource for reconstruction of the urinary bladder wall.

Science.gov (United States)

Shoae-Hassani, Alireza; Mortazavi-Tabatabaei, Seyed Abdolreza; Sharif, Shiva; Seifalian, Alexander Marcus; Azimi, Alireza; Samadikuchaksaraei, Ali; Verdi, Javad

2015-11-01

Reconstruction of the bladder wall via in vitro differentiated stem cells on an appropriate scaffold could be used in such conditions as cancer and neurogenic urinary bladder. This study aimed to examine the potential of human endometrial stem cells (EnSCs) to form urinary bladder epithelial cells (urothelium) on nanofibrous silk-collagen scaffolds, for construction of the urinary bladder wall. After passage 4, EnSCs were induced by keratinocyte growth factor (KGF) and epidermal growth factor (EGF) and seeded on electrospun collagen-V, silk and silk-collagen nanofibres. Later we tested urothelium-specific genes and proteins (uroplakin-Ia, uroplakin-Ib, uroplakin-II, uroplakin-III and cytokeratin 20) by immunocytochemistry, RT-PCR and western blot analyses. Scanning electron microscopy (SEM) and histology were used to detect cell-matrix interactions. DMEM/F12 supplemented by KGF and EGF induced EnSCs to express urothelial cell-specific genes and proteins. Either collagen, silk or silk-collagen scaffolds promoted cell proliferation. The nanofibrous silk-collagen scaffolds provided a three-dimensional (3D) structure to maximize cell-matrix penetration and increase differentiation of the EnSCs. Human EnSCs seeded on 3D nanofibrous silk-collagen scaffolds and differentiated to urothelial cells provide a suitable source for potential use in bladder wall reconstruction in women. Copyright © 2013 John Wiley & Sons, Ltd.

Application of Rapid Prototyping Technique and Intraoperative Navigation System for the Repair and Reconstruction of Orbital Wall Fractures

Science.gov (United States)

Cha, Jong Hyun; Lee, Yong Hae; Ruy, Wan Chul; Roe, Young; Moon, Myung Ho

2016-01-01

Background Restoring the orbital cavity in large blow out fractures is a challenge for surgeons due to the anatomical complexity. This study evaluated the clinical outcomes and orbital volume after orbital wall fracture repair using a rapid prototyping (RP) technique and intraoperative navigation system. Methods This prospective study was conducted on the medical records and radiology records of 12 patients who had undergone a unilateral blow out fracture reconstruction using a RP technique and an intraoperative navigation system from November 2014 to March 2015. The surgical results were assessed by an ophthalmic examination and a comparison of the preoperative and postoperative orbital volume ratio (OVR) values. Results All patients had a successful treatment outcome without complications. Volumetric analysis revealed a significant decrease in the mean OVR from 1.0952±0.0662 (ranging from 0.9917 to 1.2509) preoperatively to 0.9942±0.0427 (ranging from 0.9394 to 1.0680) postoperatively. Conclusion The application of a RP technique for the repair of orbital wall fractures is a useful tool that may help improve the clinical outcomes by understanding the individual anatomy, determining the operability, and restoring the orbital cavity volume through optimal implant positioning along with an intraoperative navigation system. PMID:28913272

Automatic Indoor Building Reconstruction from Mobile Laser Scanning Data

Science.gov (United States)

Xie, L.; Wang, R.

2017-09-01

Indoor reconstruction from point clouds is a hot topic in photogrammetry, computer vision and computer graphics. Reconstructing indoor scene from point clouds is challenging due to complex room floorplan and line-of-sight occlusions. Most of existing methods deal with stationary terrestrial laser scanning point clouds or RGB-D point clouds. In this paper, we propose an automatic method for reconstructing indoor 3D building models from mobile laser scanning point clouds. The method includes 2D floorplan generation, 3D building modeling, door detection and room segmentation. The main idea behind our approach is to separate wall structure into two different types as the inner wall and the outer wall based on the observation of point distribution. Then we utilize a graph cut based optimization method to solve the labeling problem and generate the 2D floorplan based on the optimization result. Subsequently, we leverage an ?-shape based method to detect the doors on the 2D projected point clouds and utilize the floorplan to segment the individual room. The experiments show that this door detection method can achieve a recognition rate at 97% and the room segmentation method can attain the correct segmentation results. We also evaluate the reconstruction accuracy on the synthetic data, which indicates the accuracy of our method is comparable to the state-of-the art.

Increasing efficiency of reconstruction and technological development of coking enterprises

Energy Technology Data Exchange (ETDEWEB)

Rozenfel' d, M.S.; Martynenko, V.M.; Tytyuk, Yu.A.; Ivanov, V.V.; Svyatogorov, A.A.; Kolomiets, A.F. (NIISP, Voroshilovgrad (USSR))

1989-07-01

Discusses problems associated with reconstruction of coking plants in the USSR. Planning coking plant reconstruction is analyzed. Duration of individual stages of plant reconstruction is considered. A method developed by the Giprokoks research institute for calculating reconstruction time considering duration of individual stages of coke oven battery repair is analyzed: construction of storage facilities, transport of materials and equipment, safety requirements, coke oven cooling, dismantling, construction of coke oven walls, installation of machines and equipment. Advantages of using the methods for analysis of coke oven battery reconstruction and optimization of repair time are discussed.

Reconstructing the science teaching in initial series through continuing education

Directory of Open Access Journals (Sweden)

Suzana Margarete Kurzmann Fagundes

2015-11-01

Full Text Available This paper presents the report of an investigation whose aim was to know the focus on Science teaching in initial series of elementary school and to understand the contributions of teacher’s participation in study groups for transformation of teaching practice in Sciences classes. It’s believed that the role of teachers is to give to their students opportunities for construction/reconstruction of knowledge. Thus, there is essential that teachers keep themselves in constant training The study was conducted with teachers of initial series (to 1st from 4th from a school from the Rio Grande do Sul (RS state in the 2006 / 2007 period. A qualitative analysis methodology was employed in this study, and data was obtained in the natural environment, namely,the school. Through Discoursive Textual Analysis (MORAES and GALIAZZI, 2007 about the data that was collected, it was concluded that the study groups can contribute to transformation and to development of pedagogical teacher’s practice, particularly in regard to Sciences classes, as well on student learning, ie the construction of their knowledge. It has been observed a growth of the group in the course of the meetings, not only by the concern of the teachers in changing their classes, but also to taking the necessary decisions to make it possible.

A Wrapping Method for Inserting Titanium Micro-Mesh Implants in the Reconstruction of Blowout Fractures

Directory of Open Access Journals (Sweden)

Tae Joon Choi

2016-01-01

Full Text Available Titanium micro-mesh implants are widely used in orbital wall reconstructions because they have several advantageous characteristics. However, the rough and irregular marginal spurs of the cut edges of the titanium mesh sheet impede the efficacious and minimally traumatic insertion of the implant, because these spurs may catch or hook the orbital soft tissue, skin, or conjunctiva during the insertion procedure. In order to prevent this problem, we developed an easy method of inserting a titanium micro-mesh, in which it is wrapped with the aseptic transparent plastic film that is used to pack surgical instruments or is attached to one side of the inner suture package. Fifty-four patients underwent orbital wall reconstruction using a transconjunctival or transcutaneous approach. The wrapped implant was easily inserted without catching or injuring the orbital soft tissue, skin, or conjunctiva. In most cases, the implant was inserted in one attempt. Postoperative computed tomographic scans showed excellent placement of the titanium micro-mesh and adequate anatomic reconstruction of the orbital walls. This wrapping insertion method may be useful for making the insertion of titanium micro-mesh implants in the reconstruction of orbital wall fractures easier and less traumatic.

Detection of thin wall regions of unruptured cerebral aneurysms by ECG synchronous reconstruction 3D-CT angiography (4D-CTA) using 16 slices per rotation CT

International Nuclear Information System (INIS)

Fujita, Shigekiyo

2004-01-01

The objective of this study was to evaluate the capability of electrocardiogram (ECG) synchronous reconstruction 3D-CT angiography (4D-CTA) using 16 sequence MD-CT to detect weak portions of unruptured cerebral aneurysm. 4D-CT angiography of unruptured cerebral aneurysms was performed on 26 patients, 28 cerebral aneurysms, using 16 sequence MD-CT (GE, HiLight Matrix II). Contrast material of iodine (300 mg/ml) was injected over 30 sec period into the ante-cubital vein with a rate of 0.06 ml/Kg/sec. ECG synchronous reconstruction images (10 images at intervals of 10% between R-R of ECG) were generated (GE, Workstation Advantage 4.1). After careful inspection of the wall motion of an aneurysm from many aspects, cine images were made from several directions. Acquisition of data required 9 seconds, total volume data were generated within 15 minutes, and ECG synchronous reconstruction image processing was performed in about 5 minutes. Animation creation for one direction was completed within one minute. Even in 3-mm aneurysms, changes of its form and size within a heartbeat were fully observed. Timing of maximum and minimum sizes were also recognized. The pulsatile changes and nipple extent, bleb, daughter, and dome of aneurysms were well visualized. The projecting motion of the pulsatory enlargement of nipple was detected in nine cases, and definite increases in bleb sizes were detected in five cases. Since the easily reptured thin walled portion of a cerebral aneurysm can be recognized by this method, 4D-CT angiography is likely to become indispensable in judging how to cope with unruptured cerebral aneurysms, in deciding whether to operate or observe. (author)

Tissue - engineering as an adjunct to pelvic reconstructive surgery.

Science.gov (United States)

Jangö, Hanna

2017-08-01

PCL construct with strength comparable to that of normal rat abdominal wall. The foreign-body inflammatory response did not differ between the groups in terms of cellularity, cell types or thickness, and no differences were found between groups when comparing biomechanical properties. In study 4, we modified a new transabdominal rabbit vaginal model to avoid the erosions known to occur following vaginal mesh implantation. A partial defect was created on the anterior vaginal wall in the vesico-vaginal space and on the anterior vaginal wall close to the cervix. This was a feasibility study aimed at obtaining results comparable to those seen in the rat model. The model was easy to perform and no vaginal erosions were observed. In two rat abdominal wall models, cells from autologous MFFs, seeded on the quickly degradable MPEG-PLGA scaf-fold, survived implantation and contributed to the regenerative process by forming extra striated muscle fibers and influencing the biomechanical properties of the regenerated tissue. Consequently, MFFs seeded on an MPEG-PLGA scaffold is a potentially advantageous cell-delivering strategy to regenerate tissue at pelvic reconstructive surgery. In three rat abdominal wall models, a long-term degradable PCL scaffold caused a marked foreign-body response and formed a neo-tissue PCL construct that provided biomechanical tissue reinforcement to the abdominal wall, even at maximal load. Consequently, the PCL scaffold might be beneficial in pelvic reconstructive surgery, providing initial biomechanical rein-forcement, although long-term studies showing the tissue response at full degradation are required. Cells from the MFFs did not survive in or around the neo-tissue PCL construct, possibly because of the massive inflammatory response. Consequently, as a scaffold material, with the purpose of delivering cells to a specific anatomical site, the PCL scaffold seems poor. A transabdominal rabbit vaginal model was feasible and might be advantageous in

Reconstrucción de las secuelas de la pared abdominal en pacientes con extrofia de cloaca Reconstruction of abdominal wall sequelae in patients with cloacal extrophy

Directory of Open Access Journals (Sweden)

P. Iwanyk

2009-06-01

Full Text Available Los defectos abdominales congénitos de la línea media inferior, como la extrofia cloacal, se producen por fallos en el mesodermo entre la región umbilical y la membrana cloacal provocando severos defectos viscerales, musculares y óseos. Los reiterados intentos para la reconstrucción de los tractos intestinal y génitourinario en este tipo de malformaciones, pueden ocasionar secuelas graves en la pared malformada. La complejidad de esta malformación y los numerosos procedimientos a los que deben ser sometidos estos pacientes, requieren de un abordaje interdisciplinario desde el inicio del tratamiento y en cada una de las etapas reconstructivas a fin de evitar, al máximo, las lesiones de los tejidos abdominales para lograr, al final, una pared adecuada. Presentamos 2 casos de reconstrucción de la pared abdominal en sendos pacientes de sexo femenino con secuelas importantes de extrofia cloacal, utilizando tejidos expandidos, colgajos musculares y complementando el tratamiento en una de las pacientes con una malla protésica. En ambos casos, y a pesar de la falta de tejido provocada por la malformación y las secuelas de múltiples cirugías, obtuvimos un buen resultado funcional y estético.Abdominal congenital defects of the middle line have their origin in developmental faults of mesoderm between the umbilical region and the cloacal membrane, originating visceral, muscular and osseous defects in the abdominal wall. Repeated attempts to reconstruct the intestinal and genitourinary tract here and in other malformations, can cause serious sequeals in the previously deformed abdominal wall. We present 2 cases of abdominal wall reconstruction in patients with serious sequelae of cloacal extrophy. Complexity of this malformation calls for an interdisciplinary treatment to avoid the severe damage that may be caused during reconstructive attempts. In spite of lack of tissue because of the malformation and the sequelae of multiple surgeries we

Reconstruction of medial patellofemoral ligament using quadriceps tendon combined with reconstruction of medial patellotibial ligament using patellar tendon: initial experience

Directory of Open Access Journals (Sweden)

Betina Bremer Hinckel

2016-02-01

Full Text Available ABSTRACT OBJECTIVE: To describe a surgical technique for anatomical reconstruction of the medial patellofemoral ligament using the quadriceps tendon, combined with reconstruction of the medial patellotibial ligament using the patellar tendon; and to present the initial results from a case series. METHOD: The proposed technique was used on a series of cases of patients with diagnoses of patellofemoral instability and indications for surgical treatment, who were attended by the Knee Group of HC-IOT, University of São Paulo. The following were evaluated before and after the operation: range of motion (ROM, apprehension test, lateral translation test, patellar inclination test, inverted J sign, subluxation upon extension, pain from compression of the patella and pain from contraction of the quadriceps. After the operation, the patients were asked whether any new episode of dislocation had occurred, what their degree of satisfaction with the surgery was (on a scale from 0 to 10 and whether they would be prepared to go through this operation again. RESULTS: Seven knees were operated, in seven patients, with a mean follow-up of 5.46 months (±2.07. Four patients who presented apprehension before the operation did not show this after the operation. The lateral translation test became normal for all the patients, while the patellar inclination test remained positive for two patients. The patients with an inverted J sign continued to be positive for this sign. Five patients were positive for subluxation upon extension before the operation, but all patients were negative for this after the operation. None of the patients presented any new episode of dislocation of the patella. All of them stated that they were satisfied: five gave a satisfaction score of 9 and two, a score of 10. All of them said that they would undergo the operation again. Only one patient presented a postoperative complication: dehiscence of the wound. CONCLUSION: Reconstruction of the

Efficacy of transversus abdominis plane block with liposomal bupivacaine during open abdominal wall reconstruction.

Science.gov (United States)

Fayezizadeh, Mojtaba; Majumder, Arnab; Neupane, Ruel; Elliott, Heidi L; Novitsky, Yuri W

2016-09-01

Transversus abdominis plane block (TAPb) is an analgesic adjunct used for abdominal surgical procedures. Liposomal bupivacaine (LB) demonstrates prolonged analgesic effects, up to 72 hours. We evaluated the analgesic efficacy of TAPb using LB for patients undergoing open abdominal wall reconstruction (AWR). Fifty patients undergoing AWR with TAPb using LB (TAP-group) were compared with a matched historical cohort undergoing AWR without TAPb (control group). Outcome measures included postoperative utilization of morphine equivalents, numerical rating scale pain scores, time to oral narcotics, and length of stay (LOS). Cohorts were matched demographically. No complications were associated with TAPb or LB. TAP-group evidenced significantly reduced narcotic requirements on operative day (9.5 mg vs 16.5 mg, P = .004), postoperative day (POD) 1 (26.7 mg vs 39.5 mg, P = .01) and POD2 (29.6 mg vs 40.7 mg, P = .047) and pain scores on operative day (5.1 vs 7.0, P consumption and improved pain control. TAPb allowed for earlier discontinuation of intravenous narcotics and shorter LOS. Intraoperative TAPb with LB appears to be an effective adjunct for perioperative analgesia in patients undergoing open AWR. Copyright © 2016 Elsevier Inc. All rights reserved.

Three-dimensional, three-component wall-PIV

Science.gov (United States)

Berthe, André; Kondermann, Daniel; Christensen, Carolyn; Goubergrits, Leonid; Garbe, Christoph; Affeld, Klaus; Kertzscher, Ulrich

2010-06-01

This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert’s law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle’s projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set simulating a rotating sphere.

Abdominal wall reconstruction using De-epithelialized dermal flap: A ...

African Journals Online (AJOL)

Background: Although autogenous materials have been used in abdominal wall hernioplasty for a long time, the introduction of prosthetic materials diminished their popularity. However, these materials may be expensive, inappropriate or unavailable. The aim of this study is to determine the place of de-epithelialized dermal ...

Effects of Piecewise Spatial Smoothing in 4-D SPECT Reconstruction

Science.gov (United States)

Qi, Wenyuan; Yang, Yongyi; King, Michael A.

2014-02-01

In nuclear medicine, cardiac gated SPECT images are known to suffer from significantly increased noise owing to limited data counts. Consequently, spatial (and temporal) smoothing has been indispensable for suppressing the noise artifacts in SPECT reconstruction. However, recently we demonstrated that the benefit of spatial processing in motion-compensated reconstruction of gated SPECT (aka 4-D) could be outweighed by its adverse effects on the myocardium, which included degraded wall motion and perfusion defect detectability. In this work, we investigate whether we can alleviate these adverse effects by exploiting an alternative spatial smoothing prior in 4-D based on image total variation (TV). TV based prior is known to induce piecewise smoothing which can preserve edge features (such as boundaries of the heart wall) in reconstruction. However, it is not clear whether such a property would necessarily be beneficial for improving the accuracy of the myocardium in 4-D reconstruction. In particular, it is unknown whether it would adversely affect the detectability of perfusion defects that are small in size or low in contrast. In our evaluation study, we first use Monte Carlo simulated imaging with 4-D NURBS-based cardiac-torso (NCAT) phantom wherein the ground truth is known for quantitative comparison. We evaluated the accuracy of the reconstructed myocardium using a number of metrics, including regional and overall accuracy of the myocardium, accuracy of the phase activity curve (PAC) of the LV wall for wall motion, uniformity and spatial resolution of the LV wall, and detectability of perfusion defects using a channelized Hotelling observer (CHO). For lesion detection, we simulated perfusion defects with different sizes and contrast levels with the focus being on perfusion defects that are subtle. As a preliminary demonstration, we also tested on three sets of clinical acquisitions. From the quantitative results, it was demonstrated that TV smoothing could

Staged management of giant traumatic abdominal wall defect: A rare case report

Directory of Open Access Journals (Sweden)

Somendra Bansal

2013-12-01

Full Text Available Blunt traumatic abdominal wall disruptions associated with evisceration (abdominal wall injury grade type VI are very rare. We describe a case of large traumatic abdominal wall disruption with bowel evisceration and complete transection of jejunum and sigmoid colon that occurred after a 30-year-old male sustained run over injury to abdomen. Abdominal exploration and primary end to end jejuno-jejunal and colo-colic anastomosis were done. Staged management of giant abdominal wall defect was performed without any plastic reconstruction with good clinical outcome.

Bone and bone marrow function of reconstructed chest wall after surgical correction of pectus excavatum

International Nuclear Information System (INIS)

Watanabe, Yoh; Magara, Tatsuo; Kobayashi, Hiroaki; Ichihashi, Takumi; Hikishima, Hiroshi

1984-01-01

Bone and Bone marrow functions of the reconstructed chest wall after surgical correction of the funnel chest deformities were evaluated by scanning method. In our series, three kinds of operative procedures were employed; strut method for adult cases, sternal turnover method with and without muscle pedicle for infant cases. Bone function was scanned by sup(99m)Tc-methylene-diphosphonate and bone marrow function was evaluated by sup(99m)Tc-sulfur-colloid. For the cases undergone each surgical procedure, bone and bone marrow scan were done at short term after surgery (within 30 days), at intermediate stage (one month to 12 months), and at long term stage (beyond one year). The results were as follows: By the evaluation at the long term stage of the cases undergoing strut method, bone as well as bone marrow scan visualized normal view of the reconstructed sternum. Regarding the cases undergone sternal turnover method without muscle pedicle, or free graft implantation of the plastron, the bone scan at the long term follow-up stage showed abnormal finding, i.e. hypo-, or defect-visualization of the inverted sternum, in 11.5% of the cases. Furthermore, bone marrow scan showed abnormality in 33.3% of the cases. On the other hand, the cases undergone sternal turnover method with muscle pedicle, in which blood supply to the plastron were preserved by the connection from superior epigastric artery to internal mammary artery, showed no abnormality as far as at the long term follow-up study neither in bone scan nor bone marrow scan. However, in the evaluation at short term after surgery, 50% of the cases undergoing bone scan showed abnormality. In addition, in this stage 85.7% of the bone marrow scan showed abnormal finding. These abnormality, however, normalized within 6 months for bone scan and 12 months for bone marrow scan, in contrast to the results of the cases undergone sternal turnover without pedicle. (J.P.N.)

Cine-MRI swallowing evaluation after tongue reconstruction

Energy Technology Data Exchange (ETDEWEB)

Hartl, Dana M. [Department of Otolaryngology-Head and Neck Surgery, Institute Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: dmhartl@aol.com; Kolb, Frederic; Bretagne, Evelyne [Department of Otolaryngology-Head and Neck Surgery, Institute Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France); Bidault, Francois; Sigal, Robert [Department of Radiology, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex (France)

2010-01-15

Objective: To determine the feasibility of cine-MRI for non-invasive swallowing evaluation after surgery for lingual carcinoma with reconstruction using microvascular free flaps. Methods: Ten patients with stage IV carcinoma of the mobile tongue and/or tongue base treated by surgical resection and reconstruction with a free flap were evaluated after an average of 4.3 years (range: 1.5-11 years), using cine-MRI in 'single-shot fast spin echo' (SSFSE) mode. Fiberoptic laryngoscopy of swallowing was performed before MRI to detect aspiration. The tolerance and ability to complete the exam were noted. The mobilities of the oral and pharyngeal structures visualized were evaluated as normal, reduced or increased. Results: Cine-MRI was well tolerated in all cases; 'dry' swallow was performed for the 2 patients with clinical aspiration. Tongue base-pharyngeal wall contact was observed in 5 cases. An increased anterior tongue recoil, increased mandibular recoil, increased posterior oropharyngeal wall advancement and an increased laryngeal elevation were observed in 4 cases. One case of a passive 'slide' mechanism was observed. Conclusions: Cine-MRI is a safe, non-invasive technique for the evaluation of the mobility of oral and oropharyngeal structures after free-flap reconstruction of the tongue. For selected cases, it may be complementary to clinical examination for evaluation of dysphagia after surgery and free-flap reconstruction. Further technical advances will be necessary before cine-MRI can replace videofluoroscopy, however.

Cine-MRI swallowing evaluation after tongue reconstruction

International Nuclear Information System (INIS)

Hartl, Dana M.; Kolb, Frederic; Bretagne, Evelyne; Bidault, Francois; Sigal, Robert

2010-01-01

Objective: To determine the feasibility of cine-MRI for non-invasive swallowing evaluation after surgery for lingual carcinoma with reconstruction using microvascular free flaps. Methods: Ten patients with stage IV carcinoma of the mobile tongue and/or tongue base treated by surgical resection and reconstruction with a free flap were evaluated after an average of 4.3 years (range: 1.5-11 years), using cine-MRI in 'single-shot fast spin echo' (SSFSE) mode. Fiberoptic laryngoscopy of swallowing was performed before MRI to detect aspiration. The tolerance and ability to complete the exam were noted. The mobilities of the oral and pharyngeal structures visualized were evaluated as normal, reduced or increased. Results: Cine-MRI was well tolerated in all cases; 'dry' swallow was performed for the 2 patients with clinical aspiration. Tongue base-pharyngeal wall contact was observed in 5 cases. An increased anterior tongue recoil, increased mandibular recoil, increased posterior oropharyngeal wall advancement and an increased laryngeal elevation were observed in 4 cases. One case of a passive 'slide' mechanism was observed. Conclusions: Cine-MRI is a safe, non-invasive technique for the evaluation of the mobility of oral and oropharyngeal structures after free-flap reconstruction of the tongue. For selected cases, it may be complementary to clinical examination for evaluation of dysphagia after surgery and free-flap reconstruction. Further technical advances will be necessary before cine-MRI can replace videofluoroscopy, however.

Fournier?s gangrene - delayed pedicle flap based upon the anterior abdominal wall

Directory of Open Access Journals (Sweden)

Ania Sliwinski

2014-06-01

Full Text Available Introduction Fournier’s gangrene is a poly-microbial necrotizing fasciitis that involves the perineum and/or external genitalia. Urgent surgical debridement is well recognized as essential acute treatment yet unique challenges arise for plastic surgical reconstruction to obtain a complete functional recovery. This case describes a successful delayed pedicle flap repair based upon the anterior abdominal wall. Case description A 24 year old man was admitted to ICU ten days after elective circumcision with Fournier’s gangrene. He underwent a number of surgical debridements, and was referred for plastic surgical management. He had penile reconstruction using a random pattern abdominal flap, which was performed as a three stage procedure including flap vascular delay technique. Discussion Perineal and penile skin loss can be significant and is difficult to repair. Various techniques have been used to reconstruct lost tissue: skin grafts, transposition of the testes and spermatic cords to the thigh, flaps, and other types of pediculated myocutaneous flaps. Muscle flap reconstruction provides an environment that allows for complete regeneration of the urethral epithelium but is bulky and unsightly. Skin grafts contract and may produce painful and dysfunctional reconstructions. This novel technique produces a functional, and aesthetic reconstruction. Conclusion Penile skin recovery following Fournier’s gangrene recovery is problematic. This case demonstrates the functionality of a delayed flap repair using the anterior abdominal wall.

Wall shear stress measurement of near-wall flow over inclined and curved boundaries by stereo interfacial particle image velocimetry

International Nuclear Information System (INIS)

Nguyen, Thien Duy; Wells, John Craig; Nguyen, Chuong Vinh

2010-01-01

In investigations of laminar or turbulent flows, wall shear is often important. Nevertheless, conventional particle image velocimetry (PIV) is difficult in near-wall regions. A near-wall measurement technique, named interfacial PIV (IPIV) [Nguyen, C., Nguyen, T., Wells, J., Nakayama, A., 2008. Proposals for PIV of near-wall flow over curved boundaries. In: Proceedings of 14th International Symposium on Applications of Laser Technique to Fluid Mechanics], handles curved boundaries by means of conformal transformation, directly measures the wall gradient, and yields the near-wall tangential velocity profile at one-pixel resolution. In this paper, we show the feasibility of extending IPIV to measure wall gradients by stereo reconstruction. First, we perform a test on synthetic images generated from a direct numerical simulation (DNS) snapshot of turbulent flow over sinusoidal bed. Comparative assessment of wall gradients derived by IPIV, stereo-IPIV and particle image distortion (PID) [Huang, H.T., Fiedler, H.E., Wang, J.J., 1993. Limitation and improvement of PIV. Experiments in Fluids 15(4), 263-273] is evaluated with DNS data. Also, the sensitivity of IPIV and stereo-IPIV results to the uncertainty of identified wall position is examined. As a practical application of IPIV and stereo-IPIV to experimental images, results from turbulent open channel flow over a backward-facing step are discussed in detail.

CT Imaging of facial trauma. The role of different types of reconstruction. Part II - soft tissues

International Nuclear Information System (INIS)

Myga-Porosilo, J.; Sraga, W.; Borowiak, H.; Jackowska, Z.; Kluczewska, E.; Skrzelewski, S.

2011-01-01

Background: Injury to facial soft tissues as a complication of skeleton fractures is an important problem among patients with facial trauma. The aim of this work was to assess the value of multiplanar and three-dimensional (3D) reconstruction computed tomography (CT) images obtained by using multi-detector row technology in spiral data acquisition in patients with facial injuries of soft tissue. Material/Methods: Sixty-seven patients diagnosed with injury to the facial skeleton underwent a CT scan with the use of GE Hispeed Qx/i scanner. For each patient: a two-dimensional (2D) multiplanar reconstruction (MPR), maximum intensity projection (MIP), and 3D volume rendering (VR) were conducted. Post-injury lesions of soft tissues were assessed. During the assessment of the post-injury lesions of soft tissues, the following features were evaluated: Extra ocular muscle and fat tissue herniation through fractures in the medial and inferior orbital walls. Fluid in the sinuses and in the nasal cavity. Subcutaneous tissue emphysema. Results: For subcutaneous emphysema and sinus fluid imaging, both the axial and the 2D image reconstruction proved comparably effective. However, 2D reconstructions were superior to transverse plane images with regard to herniations into fractures of the inferior orbital wall. 3D reconstruction has no importance in diagnosing soft tissue injuries. Conclusions: Multiplanar CT reconstructions increase the effectiveness of imaging of orbital tissue herniations, especially in case of fractures in the inferior orbital wall. In suspected soft tissue herniations, as well as prior to surgical treatment, spiral CT with 2D multiplanar reconstructions should be the method of choice. (authors)

Treatment of necrotic infection on the anterior chest wall secondary to mastectomy and postoperative radiotherapy by the application of omentum and mesh skin grafting. Report of a case

International Nuclear Information System (INIS)

Sato, Masaaki; Tanaka, Fumihiro; Wada, Hiromi

2002-01-01

We report herein the case of a patient who initially underwent right radical mastectomy for breast carcinoma in 1988, followed by left breast-conserving surgery in 1997. On both occasions she was given postoperative radiation therapy of 50 Gy. Repeated dressings and the administration of antibiotics failed to heal ulcerative infected lesions that had formed on the anterior chest wall in early 1998. In 1999, the sternum and surrounding tissue were debrided and the anterior chest wall was reconstructed by omentum transposition and mesh skin grafting. The patient is currently well and alive without any evidence of recurrence of either infection or breast cancer. (author)

Simulation of the ultrasound-induced growth and collapse of a near-wall bubble

Science.gov (United States)

Boyd, Bradley; Becker, Sid

2017-11-01

In this study, we consider the acoustically driven growth and collapse of a cavitation bubble in a fluid medium exposed to an ultrasound field. The bubble dynamics are modelled using a compressible, inviscid, multiphase model. The numerical scheme consists of a conservative interface capturing scheme which uses the fifth-order WENO reconstruction with a maximum-principle-satisfying and positivity-preserving limiter, and the HLLC approximate Riemann flux. To model the ultrasound input, a moving boundary oscillates through a fixed grid of finite-volume cells. The growth phase of the simulation shows the rapid non-spherical growth of the near-wall bubble. Once the bubble reaches its maximum size and the collapse phase begins, the simulation shows the formation of a jet which penetrates the bubble towards the wall at the later stages of the collapse. For a bubble with an initial radius of 50 μ m and an ultrasound pressure amplitude of 200 kPa, the pressure experienced by the wall increased rapidly nearing the end of the collapse, reaching a peak pressure of 13 MPa. This model is an important development in the field as it represents the physics of acoustic cavitation in more detail than before. This work was supported by the Royal Society of New Zealand's Marsden Fund.

DIEP breast reconstruction following multiple abdominal liposuction procedures.

Science.gov (United States)

Farid, Mohammed; Nicholson, Simon; Kotwal, Ashutosh; Akali, Augustine

2014-01-01

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

Cardiac-gated parametric images from 82 Rb PET from dynamic frames and direct 4D reconstruction.

Science.gov (United States)

Germino, Mary; Carson, Richard E

2018-02-01

function of iteration. Convergence of direct reconstruction was slow with uniform initialization; lower bias was achieved in fewer iterations by initializing with the filtered indirect iteration 1 images. For most parameters and regions evaluated, the direct method achieved the same or lower absolute bias at matched iteration as the indirect method, with 23%-65% lower noise. Additionally, the direct method gave better contrast between the perfusion defect and surrounding normal tissue than the indirect method. Gated parametric images from the human dataset had comparable relative performance of indirect and direct, in terms of mean parameter values per iteration. Changes in myocardial wall thickness and blood pool size across gates were readily visible in the gated parametric images, with higher contrast between myocardium and left ventricle blood pool in parametric images than gated SUV images. Direct reconstruction can produce parametric images with less noise than the indirect method, opening the potential utility of gated parametric imaging for perfusion PET. © 2017 American Association of Physicists in Medicine.

Delayed vaginal reconstruction in the fibrotic pelvis following radiation or previous reconstruction

International Nuclear Information System (INIS)

Berek, J.S.; Hacker, N.F.; Lagasse, L.D.; Smith, M.L.

1983-01-01

Vaginal reconstruction was performed in 14 patients who had developed vaginal stenosis secondary to extensive pelvic fibrosis after pelvic radiation therapy (12 patients) or prior vaginal reconstruction (2 patients). Sixteen procedures were performed using a split-thickness skin graft. All patients had satisfactory vaginal restoration, and 12 patients reported good vaginal function. No fistula developed as a result of the operative procedure, but one patient later developed a rectovaginal fistula resulting from tumor recurrence. Successful vaginal reconstruction can be achieved even years after initial therapy in patients who develop an obliterated vagina from previous radiation or surgery

Multi-Detector CT Findings of Palpable Chest Wall Masses in Children: A Pictorial Essay

Energy Technology Data Exchange (ETDEWEB)

Park, Chan Ho; Kim, Young Tong [Dept. of Radiology, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan (Korea, Republic of); Hong, Hyun Sook [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon (Korea, Republic of)

2013-03-15

A wide variety of diseases manifest as palpable chest wall masses in children. These include normal variation, congenital anomalies, trauma, infection, axillary lymphadenopathies, soft tissue tumors and bone tumors. Given that most of these diseases are associated with chest wall deformity, diagnosis is difficult by physical examination or ultrasonography alone. However, multi-detector CT with three dimensional reconstruction is useful in the characterization and differential diagnosis of palpable chest wall lesions. In this article, we review the spectrum of palpable chest wall diseases and illustrate their multi-detector CT presentation.

Reconstruction of the full thickness chest wall defect. A case report

Energy Technology Data Exchange (ETDEWEB)

Moriguchi, T; Sano, S; Ogawa, Y; Fujimori, Y [Kyoto Univ. (Japan). Faculty of Medicine; Abe, R

1977-03-01

To treat the chest wall defect following the postoperative radiotherapy for breast cancer, we used an island flap prepared from the opposite mammary region preserving the perforating vessels from the internal thoracic artery.

Adsorbate induced domain-wall ordering on silicon(111); Adsorbatinduzierte Domaenenwandordnung auf Silizium(111)

Energy Technology Data Exchange (ETDEWEB)

Seifert, C.

2006-09-14

The gold-induced (5 x 2)-reconstruction on the Si(111) surface has been investigated in detail. Investigations with scanning tunneling microscopy, electron diffraction and simple electron diffraction simulation as combining element are presented. The defect density in the (5 x 2)-reconstructed areas has been analysed in dependency on temperature and gold density on the surface. One important result is the categorization of this reconstruction as domain-wall reconstruction like the other gold induced reconstructions on this surface in the submonolayer-coverage regime. The correlation of the adatoms on the (5 x 2)-reconstructed areas is analysed and the silicon coverage in the areas is determined from the growth dynamics of the reconstruction. Based on this, a new model, which has been developed in cooperation with Steve Erwin from the Naval Research Center, Washington, is presented. (orig.)

Matching Biological Mesh and Negative Pressure Wound Therapy in Reconstructing an Open Abdomen Defect

Directory of Open Access Journals (Sweden)

Fabio Caviggioli

2014-01-01

Full Text Available Reconstruction of open abdominal defects is a clinical problem which general and plastic surgeons have to address in cooperation. We report the case of a 66-year-old man who presented an abdominal dehiscence after multiple laparotomies for a sigmoid-rectal adenocarcinoma that infiltrated into the abdominal wall, subsequently complicated by peritonitis and enteric fistula. A cutaneous dehiscence and an incontinent abdominal wall resulted after the last surgery. The abdominal wall was reconstructed using a biological porcine cross-linked mesh Permacol (Covidien Inc., Norwalk, CT. Negative Pressure Wound Therapy (NPWT, instead, was used on the mesh in order to reduce wound dimensions, promote granulation tissue formation, and obtain secondary closure of cutaneous dehiscence which was finally achieved with a split-thickness skin graft. Biological mesh behaved like a scaffold for the granulation tissue that was stimulated by the negative pressure. The biological mesh was rapidly integrated in the abdominal wall restoring abdominal wall continence, while the small dehiscence, still present in the central area, was subsequently covered with a split-thickness skin graft. The combination of these different procedures led us to solve this complicated case obtaining complete wound closure after less than 2 months.

Reconstruction of the chest wall after excision of a giant malignant ...

African Journals Online (AJOL)

2011-07-29

Jul 29, 2011 ... Malignant peripheral nerve sheath tumor (MPNST) of the chest wall is even rarer and its incidence on ... manubrium. There was no preceding history of trauma, fever, ... were related to pneumothorax and respiratory failures.[5].

Position reconstruction in LUX

Science.gov (United States)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Druszkiewicz, E.; Edwards, B. N.; Fallon, S. R.; Fan, A.; Fiorucci, S.; Gaitskell, R. J.; Genovesi, J.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.

2018-02-01

The (x, y) position reconstruction method used in the analysis of the complete exposure of the Large Underground Xenon (LUX) experiment is presented. The algorithm is based on a statistical test that makes use of an iterative method to recover the photomultiplier tube (PMT) light response directly from the calibration data. The light response functions make use of a two dimensional functional form to account for the photons reflected on the inner walls of the detector. To increase the resolution for small pulses, a photon counting technique was employed to describe the response of the PMTs. The reconstruction was assessed with calibration data including 83mKr (releasing a total energy of 41.5 keV) and 3H (β- with Q = 18.6 keV) decays, and a deuterium-deuterium (D-D) neutron beam (2.45 MeV) . Within the detector's fiducial volume, the reconstruction has achieved an (x, y) position uncertainty of σ = 0.82 cm and σ = 0.17 cm for events of only 200 and 4,000 detected electroluminescence photons respectively. Such signals are associated with electron recoils of energies ~0.25 keV and ~10 keV, respectively. The reconstructed position of the smallest events with a single electron emitted from the liquid surface (22 detected photons) has a horizontal (x, y) uncertainty of 2.13 cm.

Diagnosis of multidetector spiral CT and its reconstruction techniques in trachea and principal bronchus tumors

Energy Technology Data Exchange (ETDEWEB)

Mingyue, Luo; Hong, Shan; Zaibo, Jiang; Lufang, Li; Jiansheng, Zhang [Zhongshan Univ., Guangzhou (China). The Third Univ. Hospital, Dept. of Radiology; Lijia, Gu; Shaohong, Huang; Yi, Jin; Zhiqiang, Hou

2003-12-01

Objective: To investigate the clinical diagnostic value of multidetector spiral CT (MSCT) and its reconstruction techniques including multiplanar volume reformation (MPVR), volume rendering (VR), and virtual bronchoscopy (VB) in the trachea and principal bronchus tumors. Methods: Thin slice MSCT scanning was performed in 31 patients with suspected trachea or principal bronchus tumors, and image reconstruction data were formed after retro-reconstructing of initial scanning data. MPVR, VR, and VB images were obtained respectively by postprocessing of image reconstruction data with MPVR, VR, and VB image processing software in AW workstation. The findings of MSCT initial axial images, MPVR, VR, and VB images were compared with surgical and pathological results. Results: MSCT initial axial images combined with MPVR, VR, and VB images displayed the locations (tracheae, n=19; right principal bronchi, n=6; left principal bronchi, n=6), morphologies (endoluminal nodular tumors with narrow bases, n=2; endoluminal nodular tumors with wide bases, n=13; intraluminal and extraluminal massive tumors, n=16), internal features (1 had homogeneous density, 1 had low density, they both without obvious enhancement; 23 squamous cell carcinomas and 3 adenocarcinomas had fairly homogeneous density and rather obvious enhancement; 1 had homogeneous density, 1 had inhomogeneous density, 1 had punctate calcification, all with obvious enhancement), extramural invasion situations (broke through only serous membrane, n=1; no clear border with right atelectatic lung tissue, n=1; ranges of extramural invasion 4-56 mm, n=14), morphologies of luminal stenoses (eccentric, n=1; irregular, n=26; circular, n=3; conical interruption, n=1), extents (mild, n=5; moderate, n=7; severe, n=19); measured longitudinal invasion ranges (only 3 mm, n=1; invaded the whole right principal bronchus wall and carina, n=1; 5-68 mm, n=29), and distances between principal bronchus tumors and carina (invaded carina, n=1

Overview of impurity control and wall conditioning in NSTX

International Nuclear Information System (INIS)

Kugel, H.W.; Maingi, R.; Wampler, W.; Barry, R.E.; Bell, M.; Blanchard, W.; Gates, D.; Johnson, D.; Kaita, R.; Kaye, S.; Maqueda, R.; Menard, J.; Menon, M.M.; Mueller, D.; Ono, M.; Paul, S.; Peng, Y-K.M.; Raman, R.; Roquemore, A.; Skinner, C. H.; Sabbagh, S.; Stratton, B.; Stutman, D.; Wilson, J. R.; Zweben, S.

2000-01-01

The National Spherical Torus Experiment (NSTX) started plasma operations i n February 1999. In the first extended period of experiments, NSTX achieved high current, inner wall limited, double null, and single null plasma discharges, initial Coaxial Helicity Injection, and High Harmonic Fast Wave results. As expected, discharge reproducibility and performance were strongly affected by wall conditions. In this paper, the authors describe the internal geometry, and initial plasma discharge, impurity control, wall conditioning, erosion, and deposition results

Quantifying the Impact of Immediate Reconstruction in Postmastectomy Radiation: A Large, Dose-Volume Histogram-Based Analysis

Energy Technology Data Exchange (ETDEWEB)

Ohri, Nisha [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Cordeiro, Peter G. [Department of Plastic Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Keam, Jennifer [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ballangrud, Ase [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shi Weiji; Zhang Zhigang [Department of Biostatistics and Epidemiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Nerbun, Claire T.; Woch, Katherine M.; Stein, Nicholas F.; Zhou Ying [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); McCormick, Beryl; Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ho, Alice Y., E-mail: HoA1234@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-10-01

Purpose: To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data. Methods and Materials: Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment. Results: Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P<.0001). These associations persisted on propensity-matched analysis (all P<.0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 >98%). IMN coverage was superior in patients with reconstruction (D95 >92.0 vs 75.7%, P<.001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P<.05) but minimally affected those without reconstruction (all P>.05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P=.022), and mean and maximum heart doses were higher than in patients without reconstruction (P=.006, P=.015, respectively). Conclusions: Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary

Early one-stage surgical reconstruction of the extremely high vagina in patients with congenital adrenal hyperplasia.

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Donahoe, P K; Gustafson, M L

1994-02-01

High vaginal atresia is a very rare anomaly seen in the most severely masculinized females with congenital adrenal hyperplasia. These children have a foreshortened vagina conjoining the urogenital sinus proximal to the external urethral sphincter. In the past, they have undergone early clitoral recession and labioscrotal reduction, followed by vaginal pull-through at 2 to 4 years of age. Cumulative experience with repair of this anomaly has led us to attempt earlier one-stage intervention and to develop techniques that circumvent previously encountered vaginal stenoses. One-stage reconstruction of three older children (ages 2 to 9 years) involved: closure of the urethrovaginal fistula, mobilization of the vagina from the rectum and urethra, use of bilateral buttock flaps to augment the anterior vaginal wall, augmentation of the posterior wall with an inverted perineal U flap, clitoral recession, and advancement of labioscrotal and clitoral shaft flaps inferiorly to create labia majora and minora (respectively). The introiti were quite capacious after employing such flaps, did not require postoperative dilatation, and were free of strictures or urethrovaginal fistulae during long-term follow-up. Three younger patients were seen for initial evaluation at 8 to 12 months of age, when early one-stage reconstruction was undertaken. Paradoxically, these repairs were technically less difficult and did not require buttock flap augmentation because an island of anterior perineal skin could be rotated in to reach the anterior vaginal wall. A nerve stimulator was used to identify the external urethral sphincter, while the vagina was aggressively mobilized and advanced forward beyond the site of fistula closure on the urethra to avert formation of a urethro-vaginal fistula.2 +

Could new reconstruction CT techniques challenge MRI for the detection of brain metastases in the context of initial lung cancer staging?

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Millon, Domitille; Byl, David; Coche, Emmanuel E. [Universite Catholique de Louvain, Department of Radiology and Medical Imaging, Cliniques Universitaires Saint Luc, Brussels (Belgium); Collard, Philippe [Universite Catholique de Louvain, Department of Pneumology, Cliniques Universitaires Saint Luc, Brussels (Belgium); Cambier, Samantha E.; Maanen, Aline G. van [Universite Catholique de Louvain, Statistic Unit, King Albert II Cancer Institute, Brussels (Belgium); Vlassenbroek, Alain [Philips Healthcare, Brussels (Belgium)

2018-02-15

To evaluate the diagnostic performance of brain CT images reconstructed with a model-based iterative algorithm performed at usual and reduced dose. 115 patients with histologically proven lung cancer were prospectively included over 15 months. Patients underwent two CT acquisitions at the initial staging, performed on a 256-slice MDCT, at standard (CTDIvol: 41.4 mGy) and half dose (CTDIvol: 20.7 mGy). Both image datasets were reconstructed with filtered back projection (FBP) and iterative model-based reconstruction (IMR) algorithms. Brain MRI was considered as the reference. Two blinded independent readers analysed the images. Ninety-three patients underwent all examinations. At the standard dose, eight patients presented 17 and 15 lesions on IMR and FBP CT images, respectively. At half-dose, seven patients presented 15 and 13 lesions on IMR and FBP CT images, respectively. The test could not highlight any significant difference between the standard dose IMR and the half-dose FBP techniques (p-value = 0.12). MRI showed 46 metastases on 11 patients. Specificity, negative and positive predictive values were calculated (98.9-100 %, 93.6-94.6 %, 75-100 %, respectively, for all CT techniques). No significant difference could be demonstrated between the two CT reconstruction techniques. (orig.)

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

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

2013-03-01

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

Urgent reconstruction and re-equipping of coking plants

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Kvitkin, I.A.; Martynenko, V.M.; Rozenfel' d, M.S.; Svyatogorov, A.A.; Shvartsman, I.G.

1986-03-01

This paper discusses the various options involved: complete or partial reconstruction of existing buildings and equipment or new construction with new equipment and new underground and surface communications. It explains that reconstruction work is divided into three phases: initial phase (clearance, dismantling, closing down coking batteries); basic phase (fitting heat-resistant materials, prestart-up assembly work); final phase (drying out, heating up, adjustments, start-up). A structured scheme for a typical initial phase is described and a method of calculating the durations of the various phases is discussed. Conclusion is that there is an urgent requirement for a document to be produced for the control of reconstruction work; it should contain standard durations and could serve as a standard for coking plant reconstruction work.

Trends in Orbital Decompression Techniques of Surveyed American Society of Ophthalmic Plastic and Reconstructive Surgery Members.

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Reich, Shani S; Null, Robert C; Timoney, Peter J; Sokol, Jason A

To assess current members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) regarding preference in surgical techniques for orbital decompression in Graves' disease. A 10-question web-based, anonymous survey was distributed to oculoplastic surgeons utilizing the ASOPRS listserv. The questions addressed the number of years of experience performing orbital decompression surgery, preferred surgical techniques, and whether orbital decompression was performed in collaboration with an ENT surgeon. Ninety ASOPRS members participated in the study. Most that completed the survey have performed orbital decompression surgery for >15 years. The majority of responders preferred a combined approach of floor and medial wall decompression or balanced lateral and medial wall decompression; only a minority selected a technique limited to 1 wall. Those surgeons who perform fat decompression were more likely to operate in collaboration with ENT. Most surgeons rarely remove the orbital strut, citing risk of worsening diplopia or orbital dystopia except in cases of optic nerve compression or severe proptosis. The most common reason given for performing orbital decompression was exposure keratopathy. The majority of surgeons perform the surgery without ENT involvement, and number of years of experience did not correlate significantly with collaboration with ENT. The majority of surveyed ASOPRS surgeons prefer a combined wall approach over single wall approach to initial orbital decompression. Despite the technological advances made in the field of modern endoscopic surgery, no single approach has been adopted by the ASOPRS community as the gold standard.

Thoracic Wall Necrotizing Fasccitiss in a Neonate: a Case Report

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Serdar Onat

2010-09-01

Full Text Available Necrotizing fasciitis (NF is a rapidly progressive and potentially life-threatening infection of superficial fascia and subcutaneous tissue. Thoracic wall is one of the rarest locations for NF. Broadspectrum antibiotics receiving, early surgical debridement, and skin grafting are life saving in NF. We report a 7-day-old female neonate who had left sided thoracic wall NF. She had undergone extensive surgical debridement within 4 hours of hospital admission, and reconstruction of skin defect by split-thickness skin grafting later. Early diagnosis is important, as prompt surgical debridement offers the best chance for survival. Early and extensive surgical debridement is a widely accepted clinical approach and the mainstay of effective treatment. The goals of surgical intervention are to remove all necrotic tissues, and to help control the progression of NF. Reconstruction of skin defects should be performed by early split-thickness skin grafting like our patient or primary closure. Because early wound resurfacing prevents fluid, electrolyte, and protein loss from the wound site, and decreases secondary infection. Although chest wall NF is rare in neonates, it is a rapidly spreading, highly lethal infection. A high index of suspicion, early diagnosis, and aggressive approach are essential to its successful treatment.

Comparison of Absorbable Mesh Plate versus Titanium-Dynamic Mesh Plate in Reconstruction of Blow-Out Fracture: An Analysis of Long-Term Outcomes

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Woon Il Baek

2014-07-01

Full Text Available Background A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction. Methods From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia. Results For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group, there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group. However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types. Conclusions Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures.

Mirror-Imaged Rapid Prototype Skull Model and Pre-Molded Synthetic Scaffold to Achieve Optimal Orbital Cavity Reconstruction.

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Park, Sung Woo; Choi, Jong Woo; Koh, Kyung S; Oh, Tae Suk

2015-08-01

Reconstruction of traumatic orbital wall defects has evolved to restore the original complex anatomy with the rapidly growing use of computer-aided design and prototyping. This study evaluated a mirror-imaged rapid prototype skull model and a pre-molded synthetic scaffold for traumatic orbital wall reconstruction. A single-center retrospective review was performed of patients who underwent orbital wall reconstruction after trauma from 2012 to 2014. Patients were included by admission through the emergency department after facial trauma or by a tertiary referral for post-traumatic orbital deformity. Three-dimensional (3D) computed tomogram-based mirror-imaged reconstruction images of the orbit and an individually manufactured rapid prototype skull model by a 3D printing technique were obtained for each case. Synthetic scaffolds were anatomically pre-molded using the skull model as guide and inserted at the individual orbital defect. Postoperative complications were assessed and 3D volumetric measurements of the orbital cavity were performed. Paired samples t test was used for statistical analysis. One hundred four patients with immediate orbital defect reconstructions and 23 post-traumatic orbital deformity reconstructions were included in this study. All reconstructions were successful without immediate postoperative complications, although there were 10 cases with mild enophthalmos and 2 cases with persistent diplopia. Reoperations were performed for 2 cases of persistent diplopia and secondary touchup procedures were performed to contour soft tissue in 4 cases. Postoperative volumetric measurement of the orbital cavity showed nonsignificant volume differences between the damaged orbit and the reconstructed orbit (21.35 ± 1.93 vs 20.93 ± 2.07 cm(2); P = .98). This protocol was extended to severe cases in which more than 40% of the orbital frame was lost and combined with extensive soft tissue defects. Traumatic orbital reconstruction can be optimized and

Assessment of dry-stone terrace wall degradation with a 3D approach

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Djuma, Hakan; Camera, Corrado; Faka, Marina; Bruggeman, Adriana; Hermon, Sorin

2016-04-01

In the Mediterranean basin, terracing is a common element of agricultural lands. Terraces retained by dry-stone walls are used to conserve arable soil, delay erosion processes and retain rainfall runoff. Currently, agricultural land abandonment is widespread in the Mediterranean region leading to terrace wall failure due to lack of maintenance and consequently an increase in soil erosion. The objective of this study is to test the applicability of digital 3D documentation on mountainous agricultural areas for assessing changes in terrace wall geometry, including terrace wall failures and associated soil erosion. The study area is located at 800-1100 m above sea level, in the Ophiolite complex of the Troodos Mountains in Cyprus. Average annual precipitation is 750 mm. Two sites with dry-stone terraces were selected for this study. The first site had a sequence of three terrace walls that were surveyed. The uppermost terrace wall was collapsed at several locations; the middle at few locations; and the lowest was still intact. Three fieldwork campaigns were conducted at this site: during the dry season (initial conditions), the middle and end of the wet season. The second site had one terrace wall that was almost completely collapsed. This terrace was restored during a communal terrace rehabilitation event. Two fieldwork campaigns were conducted for this terrace: before and after the terrace wall restoration. Terrace walls were documented with a set of digital images, and transformed into a 3D point cloud (using web-based services and commercial software - Autodesk 123D catch and Menci Software uMap, respectively). A set of points, registered with the total station and geo-referenced with a GPS, enabled the scaling of the 3D model and aligning the terrace walls within the same reference system. The density (distance between each point) of the reconstructed point clouds is 0.005 m by Umap and 0.025 m by 123D Catch. On the first site, the model analysis identified wall

Arterial cross-section reconstruction from bi-plane X-ray shadowgraphs

International Nuclear Information System (INIS)

Fenster, P.; Barba, J.; Suardiaz, M.; Wong, K.K.; Herrold, E.M.; Kenet, R.O.; Borer, J.S.

1987-01-01

An iterative algorithm was used to reconstruct the cross-section of a crescent-shaped vessel lumen. The accuracy of this method was evaluated by comparing reconstruction error in the presence of Gaussian noise of different magnitudes. The sensitivity of the reconstruction algorithm to initial boundary constraint error was also evaluated. Using this algorithm, the reconstruction error was 1.7% when applied to crescent shaped lumen. This error was found to increase significantly with increasing Gaussian noise (error range: 5.75 - 20.75% for noise variance 1-8 pixels). Median filtering of the noise-degraded density profiles improved the reconstruction error (error range: 3.25 - 10.5% for noise variance 1-8 pixels). The mean reconstruction error was not strongly influenced by initial boundary constraint error. The algorithm provided reasonable reconstruction results when applied to X-ray image derived density profiles of known luminal shapes

Image quality of CT angiography in young children with congenital heart disease: a comparison between the sinogram-affirmed iterative reconstruction (SAFIRE) and advanced modelled iterative reconstruction (ADMIRE) algorithms.

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Nam, S B; Jeong, D W; Choo, K S; Nam, K J; Hwang, J-Y; Lee, J W; Kim, J Y; Lim, S J

2017-12-01

To compare the image quality of computed tomography angiography (CTA) reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE) with that of advanced modelled iterative reconstruction (ADMIRE) in children with congenital heart disease (CHD). Thirty-one children (8.23±13.92 months) with CHD who underwent CTA were enrolled. Images were reconstructed using SAFIRE (strength 5) and ADMIRE (strength 5). Objective image qualities (attenuation, noise) were measured in the great vessels and heart chambers. Two radiologists independently calculated the contrast-to-noise ratio (CNR) by measuring the intensity and noise of the myocardial walls. Subjective noise, diagnostic confidence, and sharpness at the level prior to the first branch of the main pulmonary artery were also graded by the two radiologists independently. The objective image noise of ADMIRE was significantly lower than that of SAFIRE in the right atrium, right ventricle, and myocardial wall (p0.05). The mean CNR values were 21.56±10.80 for ADMIRE and 18.21±6.98 for SAFIRE, which were significantly different (p0.05). CTA using ADMIRE was superior to SAFIRE when comparing the objective and subjective image quality in children with CHD. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Domain walls in the extensions of the Standard Model

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Krajewski, Tomasz; Lalak, Zygmunt; Lewicki, Marek; Olszewski, Paweł

2018-05-01

Our main interest is the evolution of domain walls of the Higgs field in the early Universe. The aim of this paper is to understand how dynamics of Higgs domain walls could be influenced by yet unknown interactions from beyond the Standard Model. We assume that the Standard Model is valid up to certain, high, energy scale Λ and use the framework of the effective field theory to describe physics below that scale. Performing numerical simulations with different values of the scale Λ we are able to extend our previous analysis [1]. Our recent numerical simulations show that evolution of Higgs domain walls is rather insensitive to interactions beyond the Standard Model as long as masses of new particles are grater than 1012 GeV. For lower values of Λ the RG improved effective potential is strongly modified at field strengths crucial to the evolution of domain walls. However, we find that even for low values of Λ, Higgs domain walls decayed shortly after their formation for generic initial conditions. On the other hand, in simulations with specifically chosen initial conditions Higgs domain walls can live longer and enter the scaling regime. We also determine the energy spectrum of gravitational waves produced by decaying domain walls of the Higgs field. For generic initial field configurations the amplitude of the signal is too small to be observed in planned detectors.

New archeointensity results from the reconstructed ancient kiln by the Tsunakawa-Shaw method

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Yamamoto, Y.; Hatakeyama, T.; Kitahara, Y.; Saito, T.

2017-12-01

Yamamoto et al. (2015) reported that baked clay samples from the floor of a reconstructed ancient kiln provided a reliable Tsunakawa-Shaw (LTD-DHT Shaw) archeointensity (AI) estimate of 47.3 +/- 2.2 microT which is fairly consistent with the in situ geomagnetic field of 46.4 microT at the time of the reconstruction. The reconstruction was conducted to reproduce an excavated kiln of the seventh century in Japan and Sue-type potteries of contemporary style were also fired (Nakajima et al., 1974). Two of the potteries with reddish color were recently subjected to the Tsunakawa-Shaw archeointensity determinations, resulting in reliable AI estimates of 45.4 +/- 2.3 (N=6) and 48.2 +/- 2.7 microT (N=15) when specimens were heated in air in laboratory (Yamamoto et al., 2017 JpGU-AGU Joint Meeting). We have had another opportunity to take samples from a new reconstructed ancient kiln in Japan which was fired in autumn 2016. The samples were two Sue-type potteries with grayish color (bowl-type and plate-type) and some blocks collected from inner wall of the kiln body. They were cut into mini specimens and then subjected to the Tsunakawa-Shaw experiment. Heating in laboratory was done either in air or vacuum.For the bowl-type pottery, AIs of 46.9 +/- 2.8 (N=6, air) and 45.3 +/- 2.3 microT (N=6, vacuum) are obtained. They are indistinguishable each other and consistent with the IGRF field of 47.4 microT at the reconstructed location in 2016. For the plate-type pottery, AIs result in 41.8 +/- 1.3 (N=4, air) and 43.9 +/- 3.9 microT (N=4, vacuum). They are also indistinguishable each other but the former AI is slightly lower than the IGRF field.For the inner wall, AIs of 45.0 (N=1, air) and 46.8 microT (N=1, vacuum) are obtained from a right-side wall, and those of 45.5 +/- 2.5 (N=2, air) and 47.7 +/- 3.0 microT (N=2, vacuum) are observed from a left-side wall. They are all indistinguishable and consistent with the IGRF field.

Sensibility of vagina reconstructed by McIndoe method in Mayer-Küster-Rokitansky-Hauser syndrome

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Vesanović Svetlana

2008-01-01

Full Text Available Background/Aim. Congenital absence of vagina is a failure present in Mayer-Küster-Rokitansky-Hauser syndrome. Treatment of this anomaly includes nonoperative and operative procedures. McIndoe procedure uses split skin graft by Thiersch. The aim of this study was to determine sensitivity (touch, warmness, coldness of a vagina reconstructed by McIndoe method in Mayer-Küster-Rokitansky-Hauser syndrome and compare it with the normal vagina. Methods. A total of 21 female persons with reconstructed vagina by McIndoe method and 21 female persons with normal vagina were observed. All female persons were divided into groups and subgroups (according to age. Sensibility to touch, warmness and coldness were examined, applying VonFrey's esthesiometer and termoesthesiometer for warmness and coldness in three regions of vagina (enter, middle wall, bothom. The number of positive answers was registrated by touching the mucosa regions for five seconds, five times. Results. The obtained results showed that female patients with a reconstructed vagina by McIndoe method, felt touch at the middle part of wall and in the bottom of vagina better than patients with normal one. Also, the first ones felt warmness at the middle part of wall and coldness in the bottom of vagina, better than the patients with normal vagina. Other results showed no difference in sensibility between reconstructed and normal vagina. Conclusion. Various types of sensibility (touch, warmness, coldness are better or the same in vaginas reconstructed by McIndoe method, in comparison with normal ones. This could be explained by the fact that skin grafts are capable of recovering sensibility.

Coronary CT angiography: Comparison of a novel iterative reconstruction with filtered back projection for reconstruction of low-dose CT—Initial experience

International Nuclear Information System (INIS)

Takx, Richard A.P.; Schoepf, U. Joseph; Moscariello, Antonio; Das, Marco; Rowe, Garrett; Schoenberg, Stefan O.; Fink, Christian; Henzler, Thomas

2013-01-01

Objective: To prospectively compare subjective and objective image quality in 20% tube current coronary CT angiography (cCTA) datasets between an iterative reconstruction algorithm (SAFIRE) and traditional filtered back projection (FBP). Materials and methods: Twenty patients underwent a prospectively ECG-triggered dual-step cCTA protocol using 2nd generation dual-source CT (DSCT). CT raw data was reconstructed using standard FBP at full-dose (Group 1 a) and 80% tube current reduced low-dose (Group 1 b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group 2 ). Attenuation and image noise were measured in three regions of interest and signal-to-noise-ratio (SNR) as well as contrast-to-noise-ratio (CNR) was calculated. Subjective diagnostic image quality was evaluated using a 4-point Likert scale. Results: Mean image noise of group 2 was lowered by 22% on average when compared to group 1 b (p 2 compared to group 1 b (p 2 (1.88 ± 0.63) was also rated significantly higher when compared to group 1 b (1.58 ± 0.63, p = 0.004). Conclusions: Image quality of 80% tube current reduced iteratively reconstructed cCTA raw data is significantly improved when compared to standard FBP and consequently may improve the diagnostic accuracy of cCTA

Incomplete projection reconstruction of computed tomography based on the modified discrete algebraic reconstruction technique

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Yang, Fuqiang; Zhang, Dinghua; Huang, Kuidong; Gao, Zongzhao; Yang, YaFei

2018-02-01

Based on the discrete algebraic reconstruction technique (DART), this study aims to address and test a new improved algorithm applied to incomplete projection data to generate a high quality reconstruction image by reducing the artifacts and noise in computed tomography. For the incomplete projections, an augmented Lagrangian based on compressed sensing is first used in the initial reconstruction for segmentation of the DART to get higher contrast graphics for boundary and non-boundary pixels. Then, the block matching 3D filtering operator was used to suppress the noise and to improve the gray distribution of the reconstructed image. Finally, simulation studies on the polychromatic spectrum were performed to test the performance of the new algorithm. Study results show a significant improvement in the signal-to-noise ratios (SNRs) and average gradients (AGs) of the images reconstructed from incomplete data. The SNRs and AGs of the new images reconstructed by DART-ALBM were on average 30%-40% and 10% higher than the images reconstructed by DART algorithms. Since the improved DART-ALBM algorithm has a better robustness to limited-view reconstruction, which not only makes the edge of the image clear but also makes the gray distribution of non-boundary pixels better, it has the potential to improve image quality from incomplete projections or sparse projections.

GEODESIC RECONSTRUCTION, SADDLE ZONES & HIERARCHICAL SEGMENTATION

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Serge Beucher

2011-05-01

Full Text Available The morphological reconstruction based on geodesic operators, is a powerful tool in mathematical morphology. The general definition of this reconstruction supposes the use of a marker function f which is not necessarily related to the function g to be built. However, this paper deals with operations where the marker function is defined from given characteristic regions of the initial function f, as it is the case, for instance, for the extrema (maxima or minima but also for the saddle zones. Firstly, we show that the intuitive definition of a saddle zone is not easy to handle, especially when digitised images are involved. However, some of these saddle zones (regional ones also called overflow zones can be defined, this definition providing a simple algorithm to extract them. The second part of the paper is devoted to the use of these overflow zones as markers in image reconstruction. This reconstruction provides a new function which exhibits a new hierarchy of extrema. This hierarchy is equivalent to the hierarchy produced by the so-called waterfall algorithm. We explain why the waterfall algorithm can be achieved by performing a watershed transform of the function reconstructed by its initial watershed lines. Finally, some examples of use of this hierarchical segmentation are described.

Humidity Distributions in Multilayered Walls of High-rise Buildings

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Gamayunova, Olga; Musorina, Tatiana; Ishkov, Alexander

2018-03-01

The limitation of free territories in large cities is the main reason for the active development of high-rise construction. Given the large-scale projects of high-rise buildings in recent years in Russia and abroad and their huge energy consumption, one of the fundamental principles in the design and reconstruction is the use of energy-efficient technologies. The main heat loss in buildings occurs through enclosing structures. However, not always the heat-resistant wall will be energy-efficient and dry at the same time (perhaps waterlogging). Temperature and humidity distributions in multilayer walls were studied in the paper, and the interrelation of other thermophysical characteristics was analyzed.

Hanford environmental dose reconstruction project - an overview

International Nuclear Information System (INIS)

Shipler, D.B.; Napier, B.A.; Farris, W.T.

1996-01-01

The Hanford Environmental Dose Reconstruction Project was initiated because of public interest in the historical releases of radioactive materials from the Hanford Site, located in southcentral Washington State. By 1986, over 38,000 pages of environmental monitoring documentation from the early years of Hanford operations had been released. Special committees reviewing the documents recommended initiation of the Hanford Environmental Dose Reconstruction Project, which began in October 1987, and is conducted by Battelle, Pacific Northwest Laboratories. The technical approach taken was to reconstruct releases of radioactive materials based on facility operating information; develop and/or adapt transport, pathway, and dose models and computer codes; reconstruct environmental, meterological, and hydrological monitoring information; reconstruct demographic, agricultural, and lifestyle characteristics; apply statistical methods to all forms of uncertainty in the information, parameters, and models; and perform scientific investigation that were technically defensible. The geographic area for the study includes ∼2 x 10 5 km 2 (75,000 mi 2 ) in eastern Washington, western Idaho, and northeastern Oregon (essentially the Mid-columbia Basin of the Pacific Northwest). Three exposure pathways were considered: the atmosphere, the Columbia River, and ground water

3D cardiac wall thickening assessment for acute myocardial infarction

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Khalid, A.; Chan, B. T.; Lim, E.; Liew, Y. M.

2017-06-01

Acute myocardial infarction (AMI) is the most severe form of coronary artery disease leading to localized myocardial injury and therefore irregularities in the cardiac wall contractility. Studies have found very limited differences in global indices (such as ejection fraction, myocardial mass and volume) between healthy subjects and AMI patients, and therefore suggested regional assessment. Regional index, specifically cardiac wall thickness (WT) and thickening is closely related to cardiac function and could reveal regional abnormality due to AMI. In this study, we developed a 3D wall thickening assessment method to identify regional wall contractility dysfunction due to localized myocardial injury from infarction. Wall thickness and thickening were assessed from 3D personalized cardiac models reconstructed from cine MRI images by fitting inscribed sphere between endocardial and epicardial wall. The thickening analysis was performed in 5 patients and 3 healthy subjects and the results were compared against the gold standard 2D late-gadolinium-enhanced (LGE) images for infarct localization. The notable finding of this study is the highly accurate estimation and visual representation of the infarct size and location in 3D. This study provides clinicians with an intuitive way to visually and qualitatively assess regional cardiac wall dysfunction due to infarction in AMI patients.

Reproducibility and quantitativity of oblique-angle reconstruction in single photon emission computed tomography using Tl-201 myocardial phantom

International Nuclear Information System (INIS)

Bunko, Hisashi; Nanbu, Ichiro; Seki, Hiroyasu

1984-01-01

This study was carried out in order to evaluate reproducibility and quantitativity of oblique-angle reconstruction of myocardial phantom SPECT. Myocardial phantom with transmural and subendcardial defects, and off-axis phantom with wall thickness changing continuously from 0 to 23 mm were used. Sixty projection data in every 6 0 were aquired using dual-camera (ZLC) with high resolution collimators connected to Scintipac-2400 computer system. Oblique-angle reconstructed images were obtained by indicating the long axis of the phantom manually in the transaxial and vertical long axial tomograms. Reproducibility and quantitativity were evaluated by creating circumferential profile (CFP) of the finally reconstructed short axial images. Inter- and intra-operater reproducibility of relative counting ratio were less than 6.7% (C.V.) and 3.3% (C.V.), respectively. Both inter- and intraoperater reproducibility of absolute counts were better than that of counting ratio (less than 5.1% (C.V.) and 2.9% (C.V.), respectively). Variation of defect location in the reconstructed image and between the slices were less than 1 sampling interval of CFP (6 0 ) and 0.6 slice, respectively. Quantitativity of counts in the reconstructed images was poor in the transmulal defect, but was fair in the subendocardial defect. Counting ratio was greatly affected by wall thickness. Temporal quantitatibity or linearity of the counts in sequential SPECTs was good in non-defect area, especially when wall thickness was greater than 70% (16 mm) of maximum. In conclusion, three-dimensional oblique-angle reconstruction in Tl-201 myocardial SPECT could be applicable to relative and temporal quantitation of local myocardial activity other than defect area for the quantitative evaluation of Tl-201 myocardial wash-out. (J.P.N.)

[From the French Society of Plastic and Reconstructive Surgery to the French Society of Plastic Reconstructive and Aesthetic Surgery].

Science.gov (United States)

Glicenstein, J

2004-04-01

(The) 3rd December 1952, 11 surgeons and other specialists found the French Society of Plastic and Reconstructive Surgery (SFCPR) which was officially published on (the) 28 September 1953. The first congress was during October 1953 and the first president as Maurice Aubry. The first secretary was Daniel Morel Fatio. The symposiums were after about three of four times each year and the thematic subjects were initially according the reconstructive surgery. The review "Annales de chirurgie plastique" was free in 1956. The members of the Society were about 30 initially, but their plastic surgery in the big hospitals at Paris and other big towns in France. The "specialty" of plastic surgery was created in 1971. On "syndicate", one French board of plastic reconstructive and aesthetic surgery, the increasing of departments of plastic surgery were the front of increasing of the plastic surgery in French and of the number of the French Society of Plastic Reconstructive surgery (580 in 2003). The French Society organized the International Congress of Plastic Surgery in 1975. The society SFCPR became the French Society of plastic reconstruction and Aesthetic Surgery (SFCPRE) in 1983 and the "logo" (front view) was in the 1994 SOF.CPRE.

Reconstruction of boundary conditions from internal conditions using viability theory

KAUST Repository

Hofleitner, Aude; Claudel, Christian G.; Bayen, Alexandre M.

2012-01-01

This article presents a method for reconstructing downstream boundary conditions to a HamiltonJacobi partial differential equation for which initial and upstream boundary conditions are prescribed as piecewise affine functions and an internal condition is prescribed as an affine function. Based on viability theory, we reconstruct the downstream boundary condition such that the solution of the Hamilton-Jacobi equation with the prescribed initial and upstream conditions and reconstructed downstream boundary condition satisfies the internal value condition. This work has important applications for estimation in flow networks with unknown capacity reductions. It is applied to urban traffic, to reconstruct signal timings and temporary capacity reductions at intersections, using Lagrangian sensing such as GPS devices onboard vehicles.

Reconstruction of boundary conditions from internal conditions using viability theory

KAUST Repository

Hofleitner, Aude

2012-06-01

This article presents a method for reconstructing downstream boundary conditions to a HamiltonJacobi partial differential equation for which initial and upstream boundary conditions are prescribed as piecewise affine functions and an internal condition is prescribed as an affine function. Based on viability theory, we reconstruct the downstream boundary condition such that the solution of the Hamilton-Jacobi equation with the prescribed initial and upstream conditions and reconstructed downstream boundary condition satisfies the internal value condition. This work has important applications for estimation in flow networks with unknown capacity reductions. It is applied to urban traffic, to reconstruct signal timings and temporary capacity reductions at intersections, using Lagrangian sensing such as GPS devices onboard vehicles.

ICRF heating in JET during initial operations with the ITER-like wall

Energy Technology Data Exchange (ETDEWEB)

Jacquet, P.; Brix, M.; Graham, M.; Mayoral, M.-L.; Meigs, A.; Monakhov, I.; Sirinelli, A. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Bobkov, V.; Drewelow, P.; Pütterich, T. [Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Garching (Germany); Brezinsek, S. [IEK-4, Forschungszentrum Jülich, Association EURATOM-FZJ (Germany); Campergue, A-L. [Ecole Nationale des Ponts et Chaussées, F77455 Marne-la-Vallée (France); Colas, L. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Czarnecka, A. [Association Euratom-IPPLM, Hery 23, 01-497 Warsaw (Poland); Klepper, C. C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Lerche, E.; Van-Eester, D. [Association EURATOM-Belgian State, ERM-KMS, Brussels (Belgium); Milanesio, D. [Politecnico di Torino, Department of Electronics, Torino (Italy); Mlynar, J. [Association EURATOM-IPP.CR, Za Slovankou 3, 182 21 Praha 8 (Czech Republic); Collaboration: JET-EFDA Contributors

2014-02-12

In 2011/12, JET started operation with its new ITER-Like Wall (ILW) made of a tungsten (W) divertor and a beryllium (Be) main chamber wall. The impact of the new wall material on the JET Ion Cyclotron Resonance Frequency (ICRF) operation was assessed and also the properties of JET plasmas heated with ICRF were studied. No substantial change of the antenna coupling resistance was observed with the ILW as compared with the carbon wall. Heat-fluxes on the protecting limiters close the antennas quantified using Infra-Red (IR) thermography (maximum 4.5 MW/m{sup 2} in current drive phasing) are within the wall power load handling capabilities. A simple RF sheath rectification model using the antenna near-fields calculated with the TOPICA code can well reproduce the heat-flux pattern around the antennas. ICRF heating results in larger tungsten and nickel (Ni) contents in the plasma and in a larger core radiation when compared to Neutral Beam Injection (NBI) heating. Some experimental facts indicate that main-chamber W components could be an important impurity source: the divertor W influx deduced from spectroscopy is comparable when using RF or NBI at same power and comparable divertor conditions; the W content is also increased in ICRF-heated limiter plasmas; and Be evaporation in the main chamber results in a strong and long lasting reduction of the impurity level. The ICRF specific high-Z impurity content decreased when operating at higher plasma density and when increasing the hydrogen concentration from 5% to 20%. Despite the higher plasma bulk radiation, ICRF exhibited overall good plasma heating efficiency; The ICRF power can be deposited at plasma centre and the radiation is mainly from the outer part of the plasma. Application of ICRF heating in H-mode plasmas started, and the beneficial effect of ICRF central electron heating to prevent W accumulation in the plasma core could be observed.

Seismic behavior and design of wall-EDD-frame systems

Directory of Open Access Journals (Sweden)

Oren eLavan

2015-06-01

Full Text Available Walls and frames have different deflection lines and, depending on the seismic mass they support, may often poses different natural periods. In many cases, wall-frame structures present an advantageous behavior. In these structures the walls and the frames are rigidly connected. Nevertheless, if the walls and the frames were not rigidly connected, an opportunity for an efficient passive control strategy would arise: Connecting the two systems by energy dissipation devices (EDDs to result in wall-EDD-frame systems. This, depending on the parameters of the system, is expected to lead to an efficient energy dissipation mechanism.This paper studies the seismic behavior of wall-EDD-frame systems in the context of retrofitting existing frame structures. The controlling non-dimensional parameters of such systems are first identified. This is followed by a rigorous and extensive parametric study that reveals the pros and cons of the new system versus wall-frame systems. The effect of the controlling parameters on the behavior of the new system are analyzed and discussed. Finally, tools are given for initial design of such retrofitting schemes. These enable both choosing the most appropriate retrofitting alternative and selecting initial values for its parameters.

Challenges in the reconstruction of bilateral maxillectomy defects.

Science.gov (United States)

Joseph, Shawn T; Thankappan, Krishnakumar; Buggaveeti, Rahul; Sharma, Mohit; Mathew, Jimmy; Iyer, Subramania

2015-02-01

Bilateral maxillectomy defects, if not adequately reconstructed, can result in grave esthetic and functional problems. The purpose of this study was to investigate the outcome of reconstruction of such defects. This is a retrospective case series. The defects were analyzed for their components and the flaps used for reconstruction. Outcomes for flap loss and functional indices, including oral diet, speech, and dental rehabilitation, also were evaluated. Ten consecutive patients who underwent bilateral maxillectomy reconstruction received 14 flaps. Six patients had malignancies of the maxilla, and 4 patients had nonmalignant indications. Ten bony free flaps were used. Four soft tissue flaps were used. The fibula free flap was the most common flap used. Three patients had total flap loss. Seven patients were alive and available for functional evaluation. Of these, 4 were taking an oral diet with altered consistency and 2 were on a regular diet. Speech was intelligible in all patients. Only 2 patients opted for dental rehabilitation with removable dentures. Reconstruction after bilateral maxillectomy is essential to prevent esthetic and functional problems. Bony reconstruction is ideal. The fibula bone free flap is commonly used. The complexity of the defect makes reconstruction difficult and the initial success rate of free flaps is low. Secondary reconstructions after the initial flap failures were successful. A satisfactory functional outcome can be achieved. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dynamics of cylindrical domain walls in smectic C liquid crystals

International Nuclear Information System (INIS)

Stewart, I W; Wigham, E J

2009-01-01

An analysis of the dynamics of cylindrical domain walls in planar aligned samples of smectic C liquid crystals is presented. A circular magnetic field, induced by an electric current, drives a time-dependent reorientation of the corresponding radially dependent director field. Nonlinear approximations to the relevant nonlinear dynamic equation, derived from smectic continuum theory, are solved in a comoving coordinated frame: exact solutions are found for a π-wall and numerical solutions are calculated for π/2-walls. Each calculation begins with an assumed initial state for the director that is a prescribed cylindrical domain wall. Such an initial wall will proceed to expand or contract as its central core propagates radially inwards or outwards, depending on the boundary conditions for the director, the elastic constants, the magnitude of the field and the sign of the magnetic anisotropy of the liquid crystal

High Performance Walls in Hot-Dry Climates

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, David [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, Bill [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, Alea [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

2015-01-01

High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist. To support this activity, in 2013 the Pacific Gas & Electric Company initiated a project with Davis Energy Group (lead for the Building America team, Alliance for Residential Building Innovation) to solicit builder involvement in California to participate in field demonstrations of high performance wall systems. Builders were given incentives and design support in exchange for providing site access for construction observation, cost information, and builder survey feedback. Information from the project was designed to feed into the 2016 Title 24 process, but also to serve as an initial mechanism to engage builders in more high performance construction strategies. This Building America project utilized information collected in the California project.

Sensory nerve function and auto-mutilation after reconstruction of various gap lengths with nerve guides and autologous nerve grafts

NARCIS (Netherlands)

den Dunnen, WFA; Meek, MF

The aim of this study was to evaluate sensory nerve recovery and auto-mutilation after reconstruction of various lengths of nerve gaps in the sciatic nerve of the rat, using different techniques. Group 4, in which the longest nerve gap (15 mm) was reconstructed with a thin-walled

Reconstruction of the cervical spine with two osteocutaneous fibular flap after radiotherapy and resection of osteoclastoma

DEFF Research Database (Denmark)

Kaltoft, Britta; Kruse, Anders; Jensen, Lisa Toft

2012-01-01

to C3. Two months later, rupture of the pharyngeal wall was noted with exposure of the anterior cage. A few days later, the posterior scar ruptured. The anterior cage was removed and the pharyngeal wall was sutured. Revision of the posterior wound was performed, leaving the implants in place. To secure...... stability of the spine, the patient was treated with a HALO. Once again, the pharyngeal wall ruptured. Reconstruction of the posterior pharyngeal wall and the anterior column of the spine was performed with an osteocutaneous fibular flap from the skull base to C3. Five months later, a computed tomography...

Near Wall measurement in Turbulent Flow over Rough Wall using microscopic HPIV

Science.gov (United States)

Talapatra, Siddharth; Hong, Jiarong; Katz, Joseph

2009-11-01

Using holographic PIV, 3D velocity measurements are being performed in a turbulent rough wall channel flow. Our objective is to examine the contribution of coherent structures to the flow dynamics, momentum and energy fluxes in the roughness sublayer. The 0.45mm high, pyramid-shaped roughness is uniformly distributed on the top and bottom surfaces of a 5X20cm rectangular channel flow, where the Reτ is 3400. To facilitate recording of holograms through a rough plate, the working fluid is a concentrated solution of NaI in water, whose optical refractive index is matched with that of the acrylic rough plates. The test section is illuminated by a collimated laser beam from the top, and the sample volume extends from the bottom wall up to 7 roughness heights. After passing through the sample volume, the in-line hologram is magnified and recorded on a 4864X3248 pixels camera at a resolution of 0.74μm/pixel. The flow is locally seeded with 2μm particles. Reconstruction, spatial filtering and particle tracking provide the 3D velocity field. This approach has been successfully implemented recently, as preliminary data demonstrate.

Rehanging Reynolds at the British Institution: Methods for Reconstructing Ephemeral Displays

Directory of Open Access Journals (Sweden)

Catherine Roach

2016-11-01

Full Text Available Reconstructions of historic exhibitions made with current technologies can present beguiling illusions, but they also put us in danger of recreating the past in our own image. This article and the accompanying reconstruction explore methods for representing lost displays, with an emphasis on visualizing uncertainty, illuminating process, and understanding the mediated nature of period images. These issues are highlighted in a partial recreation of a loan show held at the British Institution, London, in 1823, which featured the works of Sir Joshua Reynolds alongside continental old masters. This recreation demonstrates how speculative reconstructions can nonetheless shed light on ephemeral displays, revealing powerful visual and conceptual dialogues that took place on the crowded walls of nineteenth-century exhibitions.

Three-dimensional reconstruction of colorectal tumors from serial tissue sections by computer graphics: a preliminary study.

Science.gov (United States)

Kikuchi, S; Matsuzaki, H; Kondo, K; Ohtani, Y; Ihara, A; Hiki, Y; Kakita, A; Kuwao, S

2000-01-01

We present herein the three-dimensional reconstruction of colorectal tumors, with particular reference to growth pattern into each layer of the colorectal wall, and measurement of tumor volume and surface area. Conventional tissue section images of colorectal tumors were analyzed using a computer graphics analysis program. The two-dimensional extent of invasion by each tumor into each layer of intestinal wall were determined from the images of each section. Based on data from multiple sections, tumor and surrounding normal tissue layers were reconstructed three-dimensionally, and volume and surface area of the tumors were determined. Using this technique, three-dimensional morphology of tumor and tumor progression into colorectal wall could be determined. Volume and surface area of the colon tumor were 4871 mm3 and 1741 mm2, respectively. Volume and surface area of the rectal tumor were 1090 mm3 and 877 mm2, respectively. This technique may provide a new approach for pathological analysis of colorectal carcinoma.

A Rare Case of Giant Basal Cell Carcinoma of the Abdominal Wall: Excision and Immediate Reconstruction with a Pedicled Deep Inferior Epigastric Artery Perforator (DIEP) Flap.

Science.gov (United States)

Di Lorenzo, Sara; Zabbia, Giovanni; Corradino, Bartolo; Tripoli, Massimiliano; Pirrello, Roberto; Cordova, Adriana

2017-12-04

BACKGROUND Basal cell carcinoma (BCC) greater than 5 cm in diameter is called giant basal cell carcinoma (GBCC), or super giant basal cell carcinoma if it has a diameter larger than 20 cm. Giant BCC only accounts for 0.5% of BCCs and super giant BCC is exceedingly rare. On account of their rarity, there are no established guidelines for GBCC treatment. CASE REPORT We describe a peculiar case of an 82-year-old woman with a GBCC carcinoma of the lower abdominal wall. The tumor was surgically removed with ipsilateral inguinal lymph nodes and the abdominal wall was reconstructed immediately with a pedicled deep inferior epigastric artery perforator (DIEP) flap. CONCLUSIONS Treatment of giant basal cell carcinoma is often difficult, especially in elderly patients with poor general health and multiple pathologies. The pedicled DIEP flap is rotated to cover the loss of substance without tension, and it is easy to harvest and transfer. This flap allowed a good result without local or systemic complication. We present this report as a reminder of the occasional occurrence of extremely aggressive BCCs. We believe that, especially for rare tumors like these, it is very useful for the entire scientific community to publish these cases and the therapeutic strategies used to treat them.

Indoor Modelling from Slam-Based Laser Scanner: Door Detection to Envelope Reconstruction

Science.gov (United States)

Díaz-Vilariño, L.; Verbree, E.; Zlatanova, S.; Diakité, A.

2017-09-01

Updated and detailed indoor models are being increasingly demanded for various applications such as emergency management or navigational assistance. The consolidation of new portable and mobile acquisition systems has led to a higher availability of 3D point cloud data from indoors. In this work, we explore the combined use of point clouds and trajectories from SLAM-based laser scanner to automate the reconstruction of building indoors. The methodology starts by door detection, since doors represent transitions from one indoor space to other, which constitutes an initial approach about the global configuration of the point cloud into building rooms. For this purpose, the trajectory is used to create a vertical point cloud profile in which doors are detected as local minimum of vertical distances. As point cloud and trajectory are related by time stamp, this feature is used to subdivide the point cloud into subspaces according to the location of the doors. The correspondence between subspaces and building rooms is not unambiguous. One subspace always corresponds to one room, but one room is not necessarily depicted by just one subspace, for example, in case of a room containing several doors and in which the acquisition is performed in a discontinue way. The labelling problem is formulated as combinatorial approach solved as a minimum energy optimization. Once the point cloud is subdivided into building rooms, envelop (conformed by walls, ceilings and floors) is reconstructed for each space. The connectivity between spaces is included by adding the previously detected doors to the reconstructed model. The methodology is tested in a real case study.

Overview of impurity control and wall conditioning in NSTX

Energy Technology Data Exchange (ETDEWEB)

KUGEL,H.W.; MAINGI,R.; BELL,M.; BLANCHARD,W.; GATES,D.; JOHNSON,D.; KAITA,R.; KAYE,S.; MARQUEDA,R.; MENARD,J.; MUELLER,D.; ONO,M.; PENG,Y-K.M.; RAMAN,R.; RAMSEY,A.; ROQUEMORE,A.; SKINNER,C.; SABBAGH,S.; STUTMAN,D.; WAMPLER,WILLIAM R.; WILSON,J.R.; ZWEBEN,S.

2000-05-25

The National Spherical Torus Experiment (NSTX) started plasma operations in February 1999, and promptly achieved high current, inner wall limited, double null, and single null plasma discharges, initial Coaxial Helicity Injection, and High Harmonic Fast Wave results. NSTX is designed to study the physics of Spherical Tori (ST) in a device that can produce non-inductively sustained high-{beta} discharges in the 1 MA regime and to explore approaches toward a small, economical high power density ST reactor core. As expected, discharge reproducibility and performance were strongly affected by wall conditions. In this paper, the authors describe the internal geometry, and initial plasma discharge, impurity control, wall conditioning, erosion, and deposition results.

Reconstruction after complex facial trauma: achieving optimal outcome through multiple contemporary surgeries.

Science.gov (United States)

Jaiswal, Rohit; Pu, Lee L Q

2013-04-01

Major facial trauma injuries often require complex repair. Traditionally, the reconstruction of such injuries has primarily utilized only free tissue transfer. However, the advent of newer, contemporary procedures may lead to potential reconstructive improvement through the use of complementary procedures after free flap reconstruction. An 18-year-old male patient suffered a major left facial degloving injury resulting in soft-tissue defect with exposed zygoma, and parietal bone. Multiple operations were undertaken in a staged manner for reconstruction. A state-of-the-art free anterolateral thigh (ALT) perforator flap and Medpor implant reconstruction of the midface were initially performed, followed by flap debulking, lateral canthopexy, midface lift with redo canthopexy, scalp tissue expansion for hairline reconstruction, and epidermal skin grafting for optimal skin color matching. Over a follow-up period of 2 years, a good and impressive reconstructive result was achieved through the use of multiple contemporary reconstructive procedures following an excellent free ALT flap reconstruction. Multiple staged reconstructions are essential in producing an optimal outcome in this complex facial injury that would likely not have been produced through a 1-stage traditional free flap reconstruction. Utilizing multiple, sequential contemporary surgeries may substantially improve outcome through the enhancement and refinement of results based on possibly the best initial soft-tissue reconstruction.

Combining wood anatomy and stable isotope variations in a 600-year multi-parameter climate reconstruction from Corsican black pine

Science.gov (United States)

Szymczak, Sonja; Hetzer, Timo; Bräuning, Achim; Joachimski, Michael M.; Leuschner, Hanns-Hubert; Kuhlemann, Joachim

2014-10-01

We present a new multi-parameter dataset from Corsican black pine growing on the island of Corsica in the Western Mediterranean basin covering the period AD 1410-2008. Wood parameters measured include tree-ring width, latewood width, earlywood width, cell lumen area, cell width, cell wall thickness, modelled wood density, as well as stable carbon and oxygen isotopes. We evaluated the relationships between different parameters and determined the value of the dataset for climate reconstructions. Correlation analyses revealed that carbon isotope ratios are influenced by cell parameters determining cell size, whereas oxygen isotope ratios are influenced by cell parameters determining the amount of transportable water in the xylem. A summer (June to August) precipitation reconstruction dating back to AD 1185 was established based on tree-ring width. No long-term trends or pronounced periods with extreme high/low precipitation are recorded in our reconstruction, indicating relatively stable moisture conditions over the entire time period. By comparing the precipitation reconstruction with a summer temperature reconstruction derived from the carbon isotope chronologies, we identified summers with extreme climate conditions, i.e. warm-dry, warm-wet, cold-dry and cold-wet. Extreme climate conditions during summer months were found to influence cell parameter characteristics. Cold-wet summers promote the production of broad latewood composed of wide and thin-walled tracheids, while warm-wet summers promote the production of latewood with small thick-walled cells. The presented dataset emphasizes the potential of multi-parameter wood analysis from one tree species over long time scales.

Initial reconstruction results from a simulated adaptive small animal C shaped PET/MR insert

Energy Technology Data Exchange (ETDEWEB)

Efthimiou, Nikos [Technological Educational Institute of Athens (Greece); Kostou, Theodora; Papadimitroulas, Panagiotis [Technological Educational Institute of Athens (Greece); Department of Medical Physics, School of Medicine, University of Patras (Greece); Charalampos, Tsoumpas [Division of Biomedical Imaging, University of Leeds, Leeds (United Kingdom); Loudos, George [Technological Educational Institute of Athens (Greece)

2015-05-18

Traditionally, most clinical and preclinical PET scanners, rely on full cylindrical geometry for whole body as well as dedicated organ scans, which is not optimized with regards to sensitivity and resolution. Several groups proposed the construction of dedicated PET inserts for MR scanners, rather than the construction of new integrated PET/MR scanners. The space inside an MR scanner is a limiting factor which can be reduced further with the use of extra coils, and render the use of non-flexible cylindrical PET scanners difficult if not impossible. The incorporation of small SiPM arrays, can provide the means to design adaptive PET scanners to fit in tight locations, which, makes imaging possible and improve the sensitivity, due to the closer approximation to the organ of interest. In order to assess the performance of such a device we simulated the geometry of a C shaped PET, using GATE. The design of the C-PET was based on a realistic SiPM-BGO scenario. In order reconstruct the simulated data, with STIR, we had to calculate system probability matrix which corresponds to this non standard geometry. For this purpose we developed an efficient multi threaded ray tracing technique to calculate the line integral paths in voxel arrays. One of the major features is the ability to automatically adjust the size of FOV according to the geometry of the detectors. The initial results showed that the sensitivity improved as the angle between the detector arrays increases, thus better angular sampling the scanner's field of view (FOV). The more complete angular coverage helped in improving the shape of the source in the reconstructed images, as well. Furthermore, by adapting the FOV to the closer to the size of the source, the sensitivity per voxel is improved.

Initial reconstruction results from a simulated adaptive small animal C shaped PET/MR insert

International Nuclear Information System (INIS)

Efthimiou, Nikos; Kostou, Theodora; Papadimitroulas, Panagiotis; Charalampos, Tsoumpas; Loudos, George

2015-01-01

Traditionally, most clinical and preclinical PET scanners, rely on full cylindrical geometry for whole body as well as dedicated organ scans, which is not optimized with regards to sensitivity and resolution. Several groups proposed the construction of dedicated PET inserts for MR scanners, rather than the construction of new integrated PET/MR scanners. The space inside an MR scanner is a limiting factor which can be reduced further with the use of extra coils, and render the use of non-flexible cylindrical PET scanners difficult if not impossible. The incorporation of small SiPM arrays, can provide the means to design adaptive PET scanners to fit in tight locations, which, makes imaging possible and improve the sensitivity, due to the closer approximation to the organ of interest. In order to assess the performance of such a device we simulated the geometry of a C shaped PET, using GATE. The design of the C-PET was based on a realistic SiPM-BGO scenario. In order reconstruct the simulated data, with STIR, we had to calculate system probability matrix which corresponds to this non standard geometry. For this purpose we developed an efficient multi threaded ray tracing technique to calculate the line integral paths in voxel arrays. One of the major features is the ability to automatically adjust the size of FOV according to the geometry of the detectors. The initial results showed that the sensitivity improved as the angle between the detector arrays increases, thus better angular sampling the scanner's field of view (FOV). The more complete angular coverage helped in improving the shape of the source in the reconstructed images, as well. Furthermore, by adapting the FOV to the closer to the size of the source, the sensitivity per voxel is improved.

Ways of improving preparatory stage and reconstruction of coking plants

Energy Technology Data Exchange (ETDEWEB)

Rozenfel' d, M.S.; Martynenko, V.M.; Svyatogorov, A.A.; Kvitkin, I.A.; Zhurba, A.I.; Gurtovnik, P.F.

1987-06-01

Discusses economic and technological aspects of coking plant reconstruction and modernization in the USSR. Effects of standardized technologies on plant reconstruction are analyzed. A standardized planning procedure jointly developed by research institutes in the USSR for plant modernization or reconstruction is discussed: selecting the optimum reconstruction and repair time, sequence of operations without stoppage of a coke oven battery, coke oven cooling, repair of coke oven liners, heating systems, coke oven equipment, drying, initial heating, testing battery equipment. The procedure is aimed at reducing coke losses and eliminating delays during reconstruction operations. A graphic method for modelling plant reconstruction is discussed.

Experimental and Numerical Analysis of Screw Fixation in Anterior Cruciate Ligament Reconstruction

Science.gov (United States)

Chizari, Mahmoud; Wang, Bin; Snow, Martyn; Barrett, Mel

2008-09-01

This paper reports the results of an experimental and finite element analysis of tibial screw fixation in anterior cruciate ligament (ACL) reconstruction. The mechanical properties of the bone and tendon graft are obtained from experiments using porcine bone and bovine tendon. The results of the numerical study are compared with those from mechanical testing. Analysis shows that the model may be used to establish the optimum placement of the tunnel in anterior cruciate ligament reconstruction by predicting mechanical parameters such as stress, strain and displacement at regions in the tunnel wall.

Prevalence of Body Dysmorphic Disorder Among Patients Seeking Breast Reconstruction.

Science.gov (United States)

Metcalfe, Drew B; Duggal, Claire S; Gabriel, Allen; Nahabedian, Maurice Y; Carlson, Grant W; Losken, Albert

2014-07-01

Body dysmorphic disorder (BDD) is characterized by a preoccupation with a slight or imagined defect in physical appearance. It has significant implications for patients who desire breast reconstruction, because patient satisfaction with the aesthetic outcome is a substantial contributor to the success of the procedure. The authors estimated the prevalence of BDD among women seeking breast reconstruction by surveying patients with the previously validated Dysmorphic Concerns Questionnaire (DCQ). One hundred eighty-eight women who presented for immediate or delayed breast reconstruction completed the DCQ anonymously, during initial consultation with a plastic surgeon. Two groups of respondents were identified: those who desired immediate reconstruction and those who planned to undergo delayed reconstruction. The prevalence of BDD among breast reconstruction patients was compared between the 2 groups, and the overall prevalence was compared with published rates for the general public. Body dysmorphic disorder was significantly more prevalent in breast reconstruction patients than in the general population (17% vs 2%; P < .001). It also was much more common among patients who planned to undergo delayed (vs immediate) reconstruction (34% vs 13%; P = .004). Relative to the general public, significantly more women who sought breast reconstruction were diagnosed as having BDD. Awareness of the potential for BDD will enable clinicians to better understand their patients' perspectives and discuss realistic expectations at the initial consultation. Future studies are warranted to examine the implications of BDD on patient satisfaction with reconstructive surgery. 3. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

The Palestinian Wall – two perspectives. Jehuda Amichai and Mahmud Darwish

Directory of Open Access Journals (Sweden)

Joanna Roszak

2015-12-01

Full Text Available The article is a reflection on the wall being built since 2002 between Israel and the Palestinian Authority. The paper presents this structure, its history and how it is reflected in poetry (Yehuda Amichai and Mahmud Darwish, reportage (Raja Shehadeh and film. Artists’ initiatives once focussed on the Berlin Wall and more recently on the initiatives related to the Palestinian wall prompt the question how the media report on the present situation of the excluded. It is worth bearing in mind that memory or post-memory of our European wall and ghettos does not shape the discourse about the Middle-East. The preferred method of talking about walls has become geocritics (based more broadly on cultural and postcolonial studies; it is significant that the foundations of the theory of postcolonialism were put forward by a Palestinian – Edward Said.

The ongoing emergence of robotics in plastic and reconstructive surgery.

Science.gov (United States)

Struk, S; Qassemyar, Q; Leymarie, N; Honart, J-F; Alkhashnam, H; De Fremicourt, K; Conversano, A; Schaff, J-B; Rimareix, F; Kolb, F; Sarfati, B

2018-04-01

Robot-assisted surgery is more and more widely used in urology, general surgery and gynecological surgery. The interest of robotics in plastic and reconstructive surgery, a discipline that operates primarily on surfaces, has yet to be conclusively proved. However, the initial applications of robotic surgery in plastic and reconstructive surgery have been emerging in a number of fields including transoral reconstruction of posterior oropharyngeal defects, nipple-sparing mastectomy with immediate breast reconstruction, microsurgery, muscle harvesting for pelvic reconstruction and coverage of the scalp or the extremities. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Computational fluid dynamics comparisons of wall shear stress in patient-specific coronary artery bifurcation using coronary angiography and optical coherence tomography

Science.gov (United States)

Poon, Eric; Thondapu, Vikas; Chin, Cheng; Scheerlinck, Cedric; Zahtila, Tony; Mamon, Chris; Nguyen, Wilson; Ooi, Andrew; Barlis, Peter

2016-11-01

Blood flow dynamics directly influence biology of the arterial wall, and are closely linked with the development of coronary artery disease. Computational fluid dynamics (CFD) solvers may be employed to analyze the hemodynamic environment in patient-specific reconstructions of coronary arteries. Although coronary X-ray angiography (CA) is the most common medical imaging modality for 3D arterial reconstruction, models reconstructed from CA assume a circular or elliptical cross-sectional area. This limitation can be overcome with a reconstruction technique fusing CA with intravascular optical coherence tomography (OCT). OCT scans the interior of an artery using near-infrared light, achieving a 10-micron resolution and providing unprecedented detail of vessel geometry. We compared 3D coronary artery bifurcation models generated using CA alone versus OCT-angiography fusion. The model reconstructed from CA alone is unable to identify the detailed geometrical variations of diseased arteries, and also under-estimates the cross-sectional vessel area compared to OCT-angiography fusion. CFD was performed in both models under pulsatile flow in order to identify and compare regions of low wall shear stress, a hemodynamic parameter directly linked with progression of atherosclerosis. Supported by ARC LP150100233 and VLSCI VR0210.

Reconstrucción de defectos torácicos de espesor total: Presentación de 8 casos de especial complejidad Reconstruction of full thickness defects on the chest wall: Presentation of 8 complex cases

Directory of Open Access Journals (Sweden)

J.M. Lasso

2009-12-01

Full Text Available Las lesiones de gran tamaño en el tórax, requieren casi siempre para su reparación plastias complejas, que en algunos casos han de combinar el uso de tejidos autólogos y/o materiales sintéticos. Por tanto, la reconstrucción de la pared torácica supone un desafío desde el punto de vista reconstructivo en el que es fundamental el papel de los cirujanos plásticos. Los grandes defectos torácicos suelen ser secundarios a exéresis tumoral (tumores parietales de origen primario o secundario, infecciones, radionecrosis, traumatismos y malformaciones congénitas. Si bien los principios de la reconstrucción del tórax exigen una escisión amplia de la lesión, desbridamiento de los tejidos desvitalizados o irradiados y control de la infección local, dichas actuaciones no podrían abordarse con seguridad si no dispusiéramos de un amplio arsenal de técnicas reconstructivas, capaces de aportar tejidos sanos y bien vascularizados o voluminosos y amplios en superficie, junto con soportes rígidos mediante materiales aloplásticos. Gracias a estos avances, en la mayoría de los casos conseguimos el objetivo con sólo una intervención, cuando hace unos años necesitábamos varios procedimientos quirúrgicos. Presentamos una muestra variada de la experiencia de nuestro Servicio en el tratamiento de grandes defectos del tórax, en el que resumimos las distintas posibilidades que podemos encontrar en la práctica clínica diaria, y las soluciones que mejor se adaptan a las mismas.Reconstruction of full thickness defects on the chest wall is controversial and require the use of complex techniques that combine autologous tissue and/or alloplastic materials. Thus it is a challenge for plastic surgeons since it needs a suitable and functional reconstruction. The aethiology for these defects include tumoral surgery (primary wall tumors, or recurrences or metastasis, infections, radiation injury, trauma and congenital defects. Otherwise, first surgical

Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

Science.gov (United States)

Li, Liang; Wang, Bigong; Wang, Ge

2016-01-01

In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

Sideways wall force produced during tokamak disruptions

Science.gov (United States)

Strauss, H.; Paccagnella, R.; Breslau, J.; Sugiyama, L.; Jardin, S.

2013-07-01

A critical issue for ITER is to evaluate the forces produced on the surrounding conducting structures during plasma disruptions. We calculate the non-axisymmetric ‘sideways’ wall force Fx, produced in disruptions. Simulations were carried out of disruptions produced by destabilization of n = 1 modes by a vertical displacement event (VDE). The force depends strongly on γτwall, where γ is the mode growth rate and τwall is the wall penetration time, and is largest for γτwall = constant, which depends on initial conditions. Simulations of disruptions caused by a model of massive gas injection were also performed. It was found that the wall force increases approximately offset linearly with the displacement from the magnetic axis produced by a VDE. These results are also obtained with an analytical model. Disruptions are accompanied by toroidal variation of the plasma current Iφ. This is caused by toroidal variation of the halo current, as verified computationally and analytically.

CT Imaging of facial trauma. Role of different types of reconstruction. Part I - bones

International Nuclear Information System (INIS)

Myga-Porosilo, J.; Sraga, W.; Borowiak, H.; Jackowska, Z.; Kluczewska, E.; Skrzelewski, S.

2011-01-01

Background: Injury to the facial skeleton and the adjoining soft tissues is a frequently occurring condition. The main aim of this work was to assess the value of multiplanar and three-dimensional (3D) reconstruction computed tomography (CT) images obtained by using multi-detector row technology in spiral data acquisition in patients with facial skeleton injury. The authors attempted to answer the following questions: Are there particular mechanisms and types of injuries or locations of fractures which can be diagnosed significantly more effectively by conducting additional multiplanar image reconstructions? Do 3D image reconstructions contribute to the diagnostic process, to what extent? Compared to other imaging techniques, is the spiral CT data acquisition a more convenient for the patient and a faster investigation method of diagnosing post-injury lesions involving the facial skeleton? Material/Methods: Sixty-seven patients diagnosed with injury to the facial skeleton were referred for emergent CT scanning. Each patient underwent a CT scan with the use of a GE HiSpeed Qx/i scanner. The scans were conducted with the use of spiral data acquisition technique in the transverse plane. The following secondary image reconstructions were conducted for each patient: a two dimensional (2D) multiplanar reconstruction (MPR), maximum intensity projection (MIP), and 3D volume rendering (VR). Post-injury lesions of the facial skeleton were assessed and the presence of any loose displaced bone fragments was taken into consideration. Results: As far as fracture imaging is concerned, the 2D image reconstruction and volume rendering proved to be the most effective in the majority of locations. 3D image reconstructions proved the most sensitive in most cases of loose displaced bone fragments, except for fine structures such as the ethmoid bone and the inferior orbital wall. Conclusions: 1. Multiplanar computer reconstructions increase the effectiveness of visualisation of

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

Directory of Open Access Journals (Sweden)

S. Voß

2016-01-01

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

Walker-type velocity oscillations of magnetic domain walls

International Nuclear Information System (INIS)

Vella-Coleiro, G.P.

1976-01-01

We report stroboscopic observations of the radial motion of a magnetic bubble domain wall in an epitaxial LuGdAl iron garnet film. At high drive fields, initial velocities up to 9500 cm/sec were measured, and the domain wall was observed to move backwards during the field pulse, in agreement with calculations based on the Walker model

Botulinum Toxin A as an Adjunct to Abdominal Wall Reconstruction for Incisional Hernia

DEFF Research Database (Denmark)

Soltanizadeh, Sinor; Helgstrand, Frederik; Jorgensen, Lars N

2017-01-01

BACKGROUND: Repair of large incisional hernias remains a surgical and costly challenge. Temporary paralysis of the lateral abdominal wall muscles with topical administration of botulinum toxin A (BTA) is a new therapeutic concept, which may obviate the need for component separation technique (CST...

Ultralow percolation threshold of single walled carbon nanotube-epoxy composites synthesized via an ionic liquid dispersant/initiator

Science.gov (United States)

Watters, Arianna L.; Palmese, Giuseppe R.

2014-09-01

Uniform dispersion of single walled carbon nanotubes (SWNTs) in an epoxy was achieved by a streamlined mechano-chemical processing method. SWNT-epoxy composites were synthesized using a room temperature ionic liquid (IL) with an imidazolium cation and dicyanamide anion. The novel approach of using ionic liquid that behaves as a dispersant for SWNTs and initiator for epoxy polymerization greatly simplifies nanocomposite synthesis. The material was processed using simple and scalable three roll milling. The SWNT dispersion of the resultant composite was evaluated by electron microscopy and electrical conductivity measurements in conjunction with percolation theory. Processing conditions were optimized to achieve the lowest possible percolation threshold, 4.29 × 10-5 volume fraction SWNTs. This percolation threshold is among the best reported in literature yet it was obtained using a streamlined method that greatly simplifies processing.

Reconstruction of crustal blocks of California on the basis of initial strontium isotopic compositions of Mesozoic granitic rocks

Science.gov (United States)

Kistler, Ronald Wayne; Peterman, Zell E.

1978-01-01

Initial 87Sr/ 86 Sr was determined for samples of Mesozoic granitic rocks in the vicinity of the Garlock fault zone in California. These data along with similar data from the Sierra Nevada and along the San Andreas fault system permit a reconstruction of basement rocks offset by the Cenozoic lateral faulting along both the San Andreas and Garlock fault systems. The location of the line of initial 87Sr/ 86 Sr = 0.7060 can be related to the edge of the Precambrian continental crust in the western United States. Our model explains the present configuration of the edge of Precambrian continental crust as the result of two stages of rifting that occurred about 1,250 to 800 m.y. ago, during Belt sedimentation, and about 600 to 350 m.y. ago, prior to and during the development of the Cordilleran geosyncline and to left-lateral translation along a locus of disturbance identified in the central Mojave Desert. The variations in Rb, Sr, and initial 87Sr/ 86 Sr of the Mesozoic granitic rocks are interpreted as due to variations in composition and age of the source materials of the granitic rocks. The variations of Rb, Sr, and initial 87Sr/ 86 Sr in Mesozoic granitic rocks, the sedimentation history during the late Precambrian and Paleozoic, and the geographic position of loci of Mesozoic magmatism in the western United States are related to the development of the continental margin and different types of lithosphere during rifting.

Reconstruction of the mouse extrahepatic biliary tree using primary human extrahepatic cholangiocyte organoids

DEFF Research Database (Denmark)

Sampaziotis, Fotios; Justin, Alexander W; Tysoe, Olivia C

2017-01-01

The treatment of common bile duct (CBD) disorders, such as biliary atresia or ischemic strictures, is restricted by the lack of biliary tissue from healthy donors suitable for surgical reconstruction. Here we report a new method for the isolation and propagation of human cholangiocytes from....... The resulting bioengineered tissue can reconstruct the gallbladder wall and repair the biliary epithelium following transplantation into a mouse model of injury. Furthermore, bioengineered artificial ducts can replace the native CBD, with no evidence of cholestasis or occlusion of the lumen. In conclusion, ECOs...

Initial phantom study comparing image quality in computed tomography using adaptive statistical iterative reconstruction and new adaptive statistical iterative reconstruction v.

Science.gov (United States)

Lim, Kyungjae; Kwon, Heejin; Cho, Jinhan; Oh, Jongyoung; Yoon, Seongkuk; Kang, Myungjin; Ha, Dongho; Lee, Jinhwa; Kang, Eunju

2015-01-01

The purpose of this study was to assess the image quality of a novel advanced iterative reconstruction (IR) method called as "adaptive statistical IR V" (ASIR-V) by comparing the image noise, contrast-to-noise ratio (CNR), and spatial resolution from those of filtered back projection (FBP) and adaptive statistical IR (ASIR) on computed tomography (CT) phantom image. We performed CT scans at 5 different tube currents (50, 70, 100, 150, and 200 mA) using 3 types of CT phantoms. Scanned images were subsequently reconstructed in 7 different scan settings, such as FBP, and 3 levels of ASIR and ASIR-V (30%, 50%, and 70%). The image noise was measured in the first study using body phantom. The CNR was measured in the second study using contrast phantom and the spatial resolutions were measured in the third study using a high-resolution phantom. We compared the image noise, CNR, and spatial resolution among the 7 reconstructed image scan settings to determine whether noise reduction, high CNR, and high spatial resolution could be achieved at ASIR-V. At quantitative analysis of the first and second studies, it showed that the images reconstructed using ASIR-V had reduced image noise and improved CNR compared with those of FBP and ASIR (P ASIR-V had significantly improved spatial resolution than those of FBP and ASIR (P ASIR-V provides a significant reduction in image noise and a significant improvement in CNR as well as spatial resolution. Therefore, this technique has the potential to reduce the radiation dose further without compromising image quality.

Transitional Flow in an Arteriovenous Fistula: Effect of Wall Distensibility

Science.gov (United States)

McGah, Patrick; Leotta, Daniel; Beach, Kirk; Aliseda, Alberto

2012-11-01

Arteriovenous fistulae are created surgically to provide adequate access for dialysis in patients with end-stage renal disease. Transitional flow and the subsequent pressure and shear stress fluctuations are thought to be causative in the fistula failure. Since 50% of fistulae require surgical intervention before year one, understanding the altered hemodynamic stresses is an important step toward improving clinical outcomes. We perform numerical simulations of a patient-specific model of a functioning fistula reconstructed from 3D ultrasound scans. Rigid wall simulations and fluid-structure interaction simulations using an in-house finite element solver for the wall deformations were performed and compared. In both the rigid and distensible wall cases, transitional flow is computed in fistula as evidenced by aperiodic high frequency velocity and pressure fluctuations. The spectrum of the fluctuations is much more narrow-banded in the distensible case, however, suggesting a partial stabilizing effect by the vessel elasticity. As a result, the distensible wall simulations predict shear stresses that are systematically 10-30% lower than the rigid cases. We propose a possible mechanism for stabilization involving the phase lag in the fluid work needed to deform the vessel wall. Support from an NIDDK R21 - DK08-1823.

The plant cell wall integrity maintenance mechanism--a case study of a cell wall plasma membrane signaling network.

Science.gov (United States)

Hamann, Thorsten

2015-04-01

Some of the most important functions of plant cell walls are protection against biotic/abiotic stress and structural support during growth and development. A prerequisite for plant cell walls to perform these functions is the ability to perceive different types of stimuli in both qualitative and quantitative manners and initiate appropriate responses. The responses in turn involve adaptive changes in cellular and cell wall metabolism leading to modifications in the structures originally required for perception. While our knowledge about the underlying plant mechanisms is limited, results from Saccharomyces cerevisiae suggest the cell wall integrity maintenance mechanism represents an excellent example to illustrate how the molecular mechanisms responsible for stimulus perception, signal transduction and integration can function. Here I will review the available knowledge about the yeast cell wall integrity maintenance system for illustration purposes, summarize the limited knowledge available about the corresponding plant mechanism and discuss the relevance of the plant cell wall integrity maintenance mechanism in biotic stress responses. Copyright © 2014 Elsevier Ltd. All rights reserved.

A fast 4D cone beam CT reconstruction method based on the OSC-TV algorithm.

Science.gov (United States)

Mascolo-Fortin, Julia; Matenine, Dmitri; Archambault, Louis; Després, Philippe

2018-01-01

Four-dimensional cone beam computed tomography allows for temporally resolved imaging with useful applications in radiotherapy, but raises particular challenges in terms of image quality and computation time. The purpose of this work is to develop a fast and accurate 4D algorithm by adapting a GPU-accelerated ordered subsets convex algorithm (OSC), combined with the total variation minimization regularization technique (TV). Different initialization schemes were studied to adapt the OSC-TV algorithm to 4D reconstruction: each respiratory phase was initialized either with a 3D reconstruction or a blank image. Reconstruction algorithms were tested on a dynamic numerical phantom and on a clinical dataset. 4D iterations were implemented for a cluster of 8 GPUs. All developed methods allowed for an adequate visualization of the respiratory movement and compared favorably to the McKinnon-Bates and adaptive steepest descent projection onto convex sets algorithms, while the 4D reconstructions initialized from a prior 3D reconstruction led to better overall image quality. The most suitable adaptation of OSC-TV to 4D CBCT was found to be a combination of a prior FDK reconstruction and a 4D OSC-TV reconstruction with a reconstruction time of 4.5 minutes. This relatively short reconstruction time could facilitate a clinical use.

New directions in hydro-climatic histories: observational data recovery, proxy records and the atmospheric circulation reconstructions over the earth (ACRE) initiative in Southeast Asia

Science.gov (United States)

Williamson, Fiona; Allan, Rob; Switzer, Adam D.; Chan, Johnny C. L.; Wasson, Robert James; D'Arrigo, Rosanne; Gartner, Richard

2015-12-01

The value of historic observational weather data for reconstructing long-term climate patterns and the detailed analysis of extreme weather events has long been recognized (Le Roy Ladurie, 1972; Lamb, 1977). In some regions however, observational data has not been kept regularly over time, or its preservation and archiving has not been considered a priority by governmental agencies. This has been a particular problem in Southeast Asia where there has been no systematic country-by-country method of keeping or preserving such data, the keeping of data only reaches back a few decades, or where instability has threatened the survival of historic records. As a result, past observational data are fragmentary, scattered, or even absent altogether. The further we go back in time, the more obvious the gaps. Observational data can be complimented however by historical documentary or proxy records of extreme events such as floods, droughts and other climatic anomalies. This review article highlights recent initiatives in sourcing, recovering, and preserving historical weather data and the potential for integrating the same with proxy (and other) records. In so doing, it focuses on regional initiatives for data research and recovery - particularly the work of the international Atmospheric Circulation Reconstructions over the Earth's (ACRE) Southeast Asian regional arm (ACRE SEA) - and the latter's role in bringing together disparate, but interrelated, projects working within this region. The overarching goal of the ACRE SEA initiative is to connect regional efforts and to build capacity within Southeast Asian institutions, agencies and National Meteorological and Hydrological Services (NMHS) to improve and extend historical instrumental, documentary and proxy databases of Southeast Asian hydroclimate, in order to contribute to the generation of high-quality, high-resolution historical hydroclimatic reconstructions (reanalyses) and, to build linkages with humanities researchers

Reconstructing weak values without weak measurements

International Nuclear Information System (INIS)

Johansen, Lars M.

2007-01-01

I propose a scheme for reconstructing the weak value of an observable without the need for weak measurements. The post-selection in weak measurements is replaced by an initial projector measurement. The observable can be measured using any form of interaction, including projective measurements. The reconstruction is effected by measuring the change in the expectation value of the observable due to the projector measurement. The weak value may take nonclassical values if the projector measurement disturbs the expectation value of the observable

Reconstruction CT imaging of the hypopharynx and the larynx

International Nuclear Information System (INIS)

Okuno, Tetsuji; Fujimura, Akiko; Murakami, Yasushi; Shiga, Hayao

1986-01-01

The multiplanar reconstruction CT imaging of the hypopharynx and the larynx was performed on a total of 20 cases: 8 with laryngeal carcinomas, 6 with hypopharyngeal carcinomas, 4 with vocal cord paralyses due to various causes, 1 with laryngeal amyloidosis, 1 with inflammatory granuloma of the hypopharynx. Coronal, segittal, and parasagittal reconstruction images were obtained from either 1 or 2 mm overlapping axial scans with 4 or 5 mm slice thickness (3 cases) using 5 sec scan times during queit breathing. In 15 cases with coronal reconstruction imaging, the anatomical derangements of the laryngopharyngeal structures especially along the undersurface of the true vocal cord to the false cord level, the lateral wall of the pyriform sinus, and the paraglottic space were demonstrated more clearly than the axial CT imaging. In 5 cases with sagittal reconstruction imaging, the vertical extension of the lesions through the anterior commisure was more clearly depicted than the axial CT imaging. In 8 cases with parasagittal reconstruction imaging, which is along the vocal fold or across the aryepiglottic fold, pathological changes along the aryepiglottic fold, the arytenoid-corniculate cartilage complex, and the tip of the pyriform sinus were more clearly demonstrated than the axial CT imaging. In determining the feasibility of conservation surgery of the larynx and the hypopharynx, reconstruction CT imaging is recommended as the diagnostic procedure of a choice, which would supplement the findings of the routine axial CT imaging. (author)

PIV Measurement of Wall Shear Stress and Flow Structures within an Intracranial Aneurysm Model

Science.gov (United States)

Chow, Ricky; Sparrow, Eph; Campbell, Gary; Divani, Afshin; Sheng, Jian

2012-11-01

The formation and rupture of an intracranial aneurysm (IA) is a debilitating and often lethal event. Geometric features of the aneurysm bulb and upstream artery, such as bulb size, bulb shape, and curvature of the artery, are two groups of factors that define the flow and stresses within an IA. Abnormal flow stresses are related to rupture. This presentation discusses the development of a quasi-3D PIV technique and its application in various glass models at Re = 275 and 550 to experimentally assess at a preliminary level the impact of geometry and flow rate. Some conclusions are to be drawn linking geometry of the flow domain to rupture risk. The extracted results also serve as the baseline case and as a precursor to a companion presentation by the authors discussing the impact of flow diverters, a new class of medical devices. The PIV experiments were performed in a fully index-matched flow facility, allowing for unobstructed observations over complex geometry. A reconstruction and analysis method was devised to obtain 3D mean wall stress distributions and flow fields. The quasi 3D measurements were reconstructed from orthogonal planes encompassing the entire glass model, spaced 0.4mm apart. Wall shear stresses were evaluated from the near-wall flow viscous stresses.

Orbital apex syndrome associated with fractures of the inferomedial orbital wall

Directory of Open Access Journals (Sweden)

Sugamata A

2013-03-01

Full Text Available Akira SugamataDepartment of Plastic and Reconstructive Surgery, Tokyo Medical University Hachioji Medical Center, Tokyo, JapanAbstract: Although trauma is one of the main causes of orbital apex syndrome (OAS, reports of OAS associated with orbital fractures are relatively rare. We recently treated two patients who sustained severe visual impairment with damage to multiple cranial nerves (third to sixth associated with inferomedial orbital wall fractures. In these patients, posterior movement of the globe caused neuropathy of the cranial and optic nerves by posterior globe edema and hemorrhage, or direct impact between the globe and wall, which might then have induced OAS in the cases described in this report. Steroid therapy was unsuccessful for optic neuropathy due to the delay between injury and administration. When treating patients with inferomedial orbital blowout fractures due to globe-to-wall contact, it is necessary to routinely assess and monitor visual acuity since there may be a delay between the injury and OAS onset.Keywords: orbital apex syndrome, orbital fracture, blowout fracture, optic nerve, globe-to-wall contact mechanism

Template Assembly for Detailed Urban Reconstruction

KAUST Repository

Nan, Liangliang

2015-05-04

We propose a new framework to reconstruct building details by automatically assembling 3D templates on coarse textured building models. In a preprocessing step, we generate an initial coarse model to approximate a point cloud computed using Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed by assembling templates on the textured faces of the coarse model. The 3D templates are automatically chosen and located by our optimization-based template assembly algorithm that balances image matching and structural regularity. In the results, we demonstrate how our framework can enrich the details of coarse models using various data sets.

INDOOR MODELLING FROM SLAM-BASED LASER SCANNER: DOOR DETECTION TO ENVELOPE RECONSTRUCTION

Directory of Open Access Journals (Sweden)

L. Díaz-Vilariño

2017-09-01

Full Text Available Updated and detailed indoor models are being increasingly demanded for various applications such as emergency management or navigational assistance. The consolidation of new portable and mobile acquisition systems has led to a higher availability of 3D point cloud data from indoors. In this work, we explore the combined use of point clouds and trajectories from SLAM-based laser scanner to automate the reconstruction of building indoors. The methodology starts by door detection, since doors represent transitions from one indoor space to other, which constitutes an initial approach about the global configuration of the point cloud into building rooms. For this purpose, the trajectory is used to create a vertical point cloud profile in which doors are detected as local minimum of vertical distances. As point cloud and trajectory are related by time stamp, this feature is used to subdivide the point cloud into subspaces according to the location of the doors. The correspondence between subspaces and building rooms is not unambiguous. One subspace always corresponds to one room, but one room is not necessarily depicted by just one subspace, for example, in case of a room containing several doors and in which the acquisition is performed in a discontinue way. The labelling problem is formulated as combinatorial approach solved as a minimum energy optimization. Once the point cloud is subdivided into building rooms, envelop (conformed by walls, ceilings and floors is reconstructed for each space. The connectivity between spaces is included by adding the previously detected doors to the reconstructed model. The methodology is tested in a real case study.

A comparison in the reconstruction of neutron spectrums using classical iterative techniques

International Nuclear Information System (INIS)

Ortiz R, J. M.; Martinez B, M. R.; Vega C, H. R.; Gallego, E.

2009-10-01

One of the key drawbacks to the use of BUNKI code is that the process begins the reconstruction of the spectrum based on a priori knowledge as close as possible to the solution that is sought. The user has to specify the initial spectrum or do it through a subroutine called MAXIET to calculate a Maxwellian and a 1/E spectrum as initial spectrum. Because the application of iterative procedures by to resolve the reconstruction of neutron spectrum needs an initial spectrum, it is necessary to have new proposals for the election of the same. Based on the experience gained with a widely used method of reconstruction, called BUNKI, has developed a new computational tools for neutron spectrometry and dosimetry, which was first introduced, which operates by means of an iterative algorithm for the reconstruction of neutron spectra. The main feature of this tool is that unlike the existing iterative codes, the choice of the initial spectrum is performed automatically by the program, through a neutron spectra catalog. To develop the code, the algorithm was selected as the routine iterative SPUNIT be used in computing tool and response matrix UTA4 for 31 energy groups. (author)

Bayesian inference of the heat transfer properties of a wall using experimental data

KAUST Repository

Iglesias, Marco

2016-01-06

A hierarchical Bayesian inference method is developed to estimate the thermal resistance and volumetric heat capacity of a wall. We apply our methodology to a real case study where measurements are recorded each minute from two temperature probes and two heat flux sensors placed on both sides of a solid brick wall along a period of almost five days. We model the heat transfer through the wall by means of the one-dimensional heat equation with Dirichlet boundary conditions. The initial/boundary conditions for the temperature are approximated by piecewise linear functions. We assume that temperature and heat flux measurements have independent Gaussian noise and derive the joint likelihood of the wall parameters and the initial/boundary conditions. Under the model assumptions, the boundary conditions are marginalized analytically from the joint likelihood. ApproximatedGaussian posterior distributions for the wall parameters and the initial condition parameter are obtained using the Laplace method, after incorporating the available prior information. The information gain is estimated under different experimental setups, to determine the best allocation of resources.

From Point Clouds to Building Information Models: 3D Semi-Automatic Reconstruction of Indoors of Existing Buildings

Directory of Open Access Journals (Sweden)

Hélène Macher

2017-10-01

Full Text Available The creation of as-built Building Information Models requires the acquisition of the as-is state of existing buildings. Laser scanners are widely used to achieve this goal since they permit to collect information about object geometry in form of point clouds and provide a large amount of accurate data in a very fast way and with a high level of details. Unfortunately, the scan-to-BIM (Building Information Model process remains currently largely a manual process which is time consuming and error-prone. In this paper, a semi-automatic approach is presented for the 3D reconstruction of indoors of existing buildings from point clouds. Several segmentations are performed so that point clouds corresponding to grounds, ceilings and walls are extracted. Based on these point clouds, walls and slabs of buildings are reconstructed and described in the IFC format in order to be integrated into BIM software. The assessment of the approach is proposed thanks to two datasets. The evaluation items are the degree of automation, the transferability of the approach and the geometric quality of results of the 3D reconstruction. Additionally, quality indexes are introduced to inspect the results in order to be able to detect potential errors of reconstruction.

Analysis of packing microstructure and wall effects in a narrow-bore ultrahigh pressure liquid chromatography column using focused ion-beam scanning electron microscopy.

Science.gov (United States)

Reising, Arved E; Schlabach, Sabine; Baranau, Vasili; Stoeckel, Daniela; Tallarek, Ulrich

2017-09-01

Column wall effects are well recognized as major limiting factor in achieving high separation efficiency in HPLC. This is especially important for modern analytical columns packed with small particles, where wall effects dominate the band broadening. Detailed knowledge about the packing microstructure of packed analytical columns has so far not been acquired. Here, we present the first three-dimensional reconstruction protocol for these columns utilizing focused ion-beam scanning electron microscopy (FIB-SEM) on a commercial 2.1mm inner diameter×50mm length narrow-bore analytical column packed with 1.7μm bridged-ethyl hybrid silica particles. Two sections from the packed bed are chosen for reconstruction by FIB-SEM: one from the bulk packing region of the column and one from its critical wall region. This allows quantification of structural differences between the wall region and the center of the bed due to effects induced by the hard, confining column wall. Consequences of these effects on local flow velocity in the column are analyzed with flow simulations utilizing the lattice-Boltzmann method. The reconstructions of the bed structures reveal significant structural differences in the wall region (extending radially over approximately 62 particle diameters) compared to the center of the column. It includes the local reduction of the external porosity by up to 10% and an increase of the mean particle diameter by up to 3%, resulting in a decrease of the local flow velocity by up to 23%. In addition, four (more ordered) layers of particles in the direct vicinity of the column wall induce local velocity fluctuations by up to a factor of three regarding the involved velocity amplitudes. These observations highlight the impact of radial variations in packing microstructure on band migration and column performance. This knowledge on morphological peculiarities of column wall effects helps guiding us towards further optimization of the packing process for analytical

First wall costs of an ion-beam fusion reactor

International Nuclear Information System (INIS)

Hovingh, J.

1977-08-01

This paper parametrically investigates the effects of microexplosion energy on the first wall costs of a 4000 MW/sub t/ ion-beam initiated, inertially confined fusion reactor for several first wall materials. The thermodynamic models and the results for microexplosion energies between 400 and 4000 MJ are presented. A solid stainless steel or a composite isotropic graphite over stainless steel first wall can operate for a year at a cost of 0.6 mills per kWh gross electric power output

Influence of the initial rupture size and tendon subregion on three-dimensional biomechanical properties of single-row and double-row rotator cuff reconstructions.

Science.gov (United States)

Lorbach, O; Pape, D; Raber, F; Busch, L C; Kohn, D; Kieb, M

2012-11-01

Influence of the initial rotator cuff tear size and of different subregions of the SSP tendon on the cyclic loading behavior of a modified single-row reconstruction compared to a suture-bridging double-row repair. Artificial tears (25 and 35 mm) were created in the rotator cuff of 24 human cadaver shoulders. The reconstructions were performed as a single-row repair (SR) using a modified suture configuration or a suture-bridge double-row repair (DR). Radiostereometric analysis was used under cyclic loading (50 cycles, 10–180 N, 10–250 N) to calculate cyclic displacement in three different planes (anteroposterior (x), craniocaudal (y) and mediolateral (z) level). Cyclic displacement was recorded, and differences in cyclic displacement of the anterior compared to the posterior subregions of the tendon were calculated. In small-to-medium tears (25 mm) and medium-to-large tears (35 mm), significant lower cyclic displacement was seen for the SR-reconstruction compared to the DR-repair at 180 N (p ≤ 0.0001; p = 0.001) and 250 N (p = 0.001; p = 0.007) in the x-level. These results were confirmed in the y-level at 180 N (p = 0.001; p = 0.0022) and 250 N (p = 0.005; p = 0.0018). Comparison of the initial tear sizes demonstrated significant differences in cyclic displacement for the DR technique in the x-level at 180 N (p = 0.002) and 250 N (p = 0.004). Comparison of the anterior versus the posterior subregion of the tendon revealed significant lower gap formation in the posterior compared to the anterior subregions in the x-level for both tested rotator cuff repairs (p ≤ 0.05). The tested single-row repair using a modified suture configuration achieved superior results in three-dimensional measurements of cyclic displacement compared to the tested double-row suture-bridge repair. The results were dependent on the initial rupture size of the rotator cuff tear. Furthermore, significant differences were found between tendon subregions of the rotator cuff with

Ultralow percolation threshold of single walled carbon nanotube-epoxy composites synthesized via an ionic liquid dispersant/initiator

International Nuclear Information System (INIS)

Watters, Arianna L; Palmese, Giuseppe R

2014-01-01

Uniform dispersion of single walled carbon nanotubes (SWNTs) in an epoxy was achieved by a streamlined mechano-chemical processing method. SWNT-epoxy composites were synthesized using a room temperature ionic liquid (IL) with an imidazolium cation and dicyanamide anion. The novel approach of using ionic liquid that behaves as a dispersant for SWNTs and initiator for epoxy polymerization greatly simplifies nanocomposite synthesis. The material was processed using simple and scalable three roll milling. The SWNT dispersion of the resultant composite was evaluated by electron microscopy and electrical conductivity measurements in conjunction with percolation theory. Processing conditions were optimized to achieve the lowest possible percolation threshold, 4.29 × 10 −5 volume fraction SWNTs. This percolation threshold is among the best reported in literature yet it was obtained using a streamlined method that greatly simplifies processing. (paper)

Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

Science.gov (United States)

van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

2015-01-01

Non-invasive electrocardiographic imaging (ECGI) of the cardiac muscle can help the pre-procedure planning of the ablation of ventricular arrhythmias by reducing the time to localize the origin. Our non-invasive ECGI system, the cardiac isochrone positioning system (CIPS), requires non-intersecting meshes of the heart, lungs and torso. However, software to reconstruct the meshes of the heart, lungs and torso with the capability to check and prevent these intersections is currently lacking. Consequently the reconstruction of a patient specific model with realistic atrial and ventricular wall thickness and incorporating blood cavities, lungs and torso usually requires additional several days of manual work. Therefore new software was developed that checks and prevents any intersections, and thus enables the use of accurate reconstructed anatomical models within CIPS. In this preliminary study we investigated the accuracy of the created patient specific anatomical models from MRI or CT. During the manual segmentation of the MRI data the boundaries of the relevant tissues are determined. The resulting contour lines are used to automatically morph reference meshes of the heart, lungs or torso to match the boundaries of the morphed tissue. Five patients were included in the study; models of the heart, lungs and torso were reconstructed from standard cardiac MRI images. The accuracy was determined by computing the distance between the segmentation contours and the morphed meshes. The average accuracy of the reconstructed cardiac geometry was within 2mm with respect to the manual segmentation contours on the MRI images. Derived wall volumes and left ventricular wall thickness were within the range reported in literature. For each reconstructed heart model the anatomical heart axis was computed using the automatically determined anatomical landmarks of the left apex and the mitral valve. The accuracy of the reconstructed heart models was well within the accuracy of the used

Rib cage deformity during two-stage tissue expander breast reconstruction in patient with previous radiotherapy: a case report

Directory of Open Access Journals (Sweden)

Aleš Porčnik

2016-02-01

Full Text Available Patients undergoing two-stage breast reconstruction with tissue expander and a history of previous irradiation are predisposed to a various chest-wall deformations more than non-irradiated patients. If chest-wall depression with/without rib fracture is found intra-operatively, bigger implant should be used, with a subsequent radiologic evaluation. In the future, the development of a new, modified expander with a harder base could minimise such complications.

Extragenital malignant mixed Mullerian tumor in the incisional hernia - primary carcinosarcoma in the abdominal wall: Case report

Directory of Open Access Journals (Sweden)

Žuvela Marinko

2015-01-01

Full Text Available Introduction. This report presents a primary Mullerian carcinosarcoma localized in the incisional hernia i.e. anterior abdominal wall. There is no data in the literature about this localization of extragenital Mullerian carcinosarcoma. Case Outline. The patient had previous medical history of right-sided ovarian cystadenocarcinoma managed by hysterectomy, bilateral ovariectomy and chemotherapy. An incisional hernia occurred 1 year after the operation and Mullerian carcinosarcoma at the right border of the incisional hernia 16 years later. There was no tumor spreading into the abdominal cavity and pelvis. Full thickness of the abdominal wall resection and coexisting incisional hernia resulted in a large 25x20 cm abdominal wall defect managed by the modified components separation technique and implanting meshes. Conclusion. Major abdominal wall resection and abdominal wall reconstruction using the modified components separation technique reinforced with meshes could be one of possible solutions in the surgical treatment of primary malignant mixed Mullerian tumor localized in the abdominal wall. [Projekat Ministarstva nauke Republike Srbije, br. 41030

Plant cell walls throughout evolution: towards a molecular understanding of their design principles.

Science.gov (United States)

Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

2009-01-01

Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche, which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

Plant cell walls throughout evolution: towards a molecular understanding of their design principles

Energy Technology Data Exchange (ETDEWEB)

Sarkar, Purbasha; Bosneaga, Elena; Auer, Manfred

2009-02-16

Throughout their life, plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche,which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informative imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway.

Template Assembly for Detailed Urban Reconstruction

KAUST Repository

Nan, Liangliang; Wonka, Peter; Ghanem, Bernard; Jiang, Caigui

2015-01-01

Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed

The Value of Attenuation Correction in Hybrid Cardiac SPECT/CT on Inferior Wall According to Body Mass Index

International Nuclear Information System (INIS)

Tamam, Muge; Mulazimoglu, Mehmet; Edis, Nurcan; Ozpacaci, Tevfik

2016-01-01

The purpose of this study was to evaluate the diagnostic value of attenuation-corrected single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) on the inferior wall compared to uncorrected (NC) SPECT MPI between obese and nonobese patients. A total of 157 consecutive patients (122 males and 35 females, with median age: 57.4 ± 11 years) who underwent AC technetium 99m-methoxyisobutylisonitrile (AC Tc99m-sestamibi) SPECT MPI were included to the study. A hybrid SPECT and transmission computed tomography (CT) system was used for the diagnosis with 1-day protocol, and stress imaging was performed first. During attenuation correction (AC) processing on a Xeleris Workstation using Myovation cardiac software with ordered subset expectation maximization (OSEM), iterative reconstruction with attenuation correction (IRAC) and NC images filtered back projection (FBP) were used. For statistical purposes, P < 0.05 was considered significant. This study included 73 patients with body mass index (BMI) <30 and 84 patients with BMI ≥ 30. In patients with higher BMI, increased amount of both visual and semiquantitative attenuation of the inferior wall was detected. IRAC reconstruction corrects the diaphragm attenuation of the inferior wall better than FBP. AC with OSEM iterative reconstruction significantly improves the diagnostic value of stress-only SPECT MPI in patients with normal weight and those who are obese, but the improvements are significantly greater in obese patients. Stress-only SPECT imaging with AC provides shorter and lower radiation exposure

High-definition computed tomography for coronary artery stents imaging: Initial evaluation of the optimal reconstruction algorithm

Energy Technology Data Exchange (ETDEWEB)

Cui, Xiaoming, E-mail: mmayzy2008@126.com; Li, Tao, E-mail: litaofeivip@163.com; Li, Xin, E-mail: lx0803@sina.com.cn; Zhou, Weihua, E-mail: wangxue0606@gmail.com

2015-05-15

Highlights: • High-resolution scan mode is appropriate for imaging coronary stent. • HD-detail reconstruction algorithm is stent-dedicated kernel. • The intrastent lumen visibility also depends on stent diameter and material. - Abstract: Objective: The aim of this study was to evaluate the in vivo performance of four image reconstruction algorithms in a high-definition CT (HDCT) scanner with improved spatial resolution for the evaluation of coronary artery stents and intrastent lumina. Materials and methods: Thirty-nine consecutive patients with a total of 71 implanted coronary stents underwent coronary CT angiography (CCTA) on a HDCT (Discovery CT 750 HD; GE Healthcare) with the high-resolution scanning mode. Four different reconstruction algorithms (HD-stand, HD-detail; HD-stand-plus; HD-detail-plus) were applied to reconstruct the stented coronary arteries. Image quality for stent characterization was assessed. Image noise and intrastent luminal diameter were measured. The relationship between the measurement of inner stent diameter (ISD) and the true stent diameter (TSD) and stent type were analysed. Results: The stent-dedicated kernel (HD-detail) offered the highest percentage (53.5%) of good image quality for stent characterization and the highest ratio (68.0 ± 8.4%) of visible stent lumen/true stent lumen for luminal diameter measurement at the expense of an increased overall image noise. The Pearson correlation coefficient between the ISD and TSD measurement and spearman correlation coefficient between the ISD measurement and stent type were 0.83 and 0.48, respectively. Conclusions: Compared with standard reconstruction algorithms, high-definition CT imaging technique with dedicated high-resolution reconstruction algorithm provides more accurate stent characterization and intrastent luminal diameter measurement.

“Walls of Words”: Paperscape in Charles Dickens’s Novels

OpenAIRE

PREST, Céline

2016-01-01

The walls of Dickens’s city are covered in posters, bills, signs and inscriptions, resulting in the disappearance of those very walls behind the accumulation of messages. Simultaneously, these words go beyond the space allotted to them, erecting walls of words in the public space, constantly modifying the cityscape. This new urban landscape became possible with the lifting of paper taxes and the technological evolutions of the nineteenth century. This change initiates a new urban experience: ...

Characterization of wall conditions in DIII-D

International Nuclear Information System (INIS)

Holtrop, K.L.; Jackson, G.L.; Kellman, A.G.; Lee, R.L.; West, W.P.; Wood, R.D.; Whyte, D.G.

1996-10-01

Wall conditioning in DIII-D is one of the most important factors in achieving reproducible high confinement discharges. For example, the very high confinement mode (VH-mode) was only discovered after boronization, a CVD technique to deposit a thin boron film over the entire surface of the tokamak. In order to evaluate wall conditions and provide a data base to correlate these wall conditions with tokamak discharge performance, a series of nominally identical reference VH-mode discharges (1.6 MA, 2.1 T, double-null diverted) were taken at various times during a series of experimental campaigns with evolving wall conditions. These reference discharges have allowed a quantitative determination of how the wall conditions have evolved. For instance, core carbon and oxygen levels in the VH-mode phase remains at historically low levels during the 1995 run year and there was also a steady decrease in the oxygen levels at plasma initiation during this period. The authors discuss the long term changes in low Z impurities and the effect of wall conditioning techniques such as boronization and baking on these impurities. In addition, the evolution of the deuterium recycling rates will be discussed

NR-code: Nonlinear reconstruction code

Science.gov (United States)

Yu, Yu; Pen, Ue-Li; Zhu, Hong-Ming

2018-04-01

NR-code applies nonlinear reconstruction to the dark matter density field in redshift space and solves for the nonlinear mapping from the initial Lagrangian positions to the final redshift space positions; this reverses the large-scale bulk flows and improves the precision measurement of the baryon acoustic oscillations (BAO) scale.

Magnetization reversal in ferromagnetic spirals via domain wall motion

Science.gov (United States)

Schumm, Ryan D.; Kunz, Andrew

2016-11-01

Domain wall dynamics have been investigated in a variety of ferromagnetic nanostructures for potential applications in logic, sensing, and recording. We present a combination of analytic and simulated results describing the reliable field driven motion of a domain wall through the arms of a ferromagnetic spiral nanowire. The spiral geometry is capable of taking advantage of the benefits of both straight and circular wires. Measurements of the in-plane components of the spirals' magnetization can be used to determine the angular location of the domain wall, impacting the magnetoresistive applications dependent on the domain wall location. The spirals' magnetization components are found to depend on the spiral parameters: the initial radius and spacing between spiral arms, along with the domain wall location. The magnetization is independent of the parameters of the rotating field used to move the domain wall, and therefore the model is valid for current induced domain wall motion as well. The speed of the domain wall is found to depend on the frequency of the rotating driving field, and the domain wall speeds can be reliably varied over several orders of magnitude. We further demonstrate a technique capable of injecting multiple domain walls and show the reliable and unidirectional motion of domain walls through the arms of the spiral.

The effect of iterative reconstruction on computed tomography assessment of emphysema, air trapping and airway dimensions

NARCIS (Netherlands)

Mets, Onno M.; Willemink, Martin J.; de Kort, Freek P. L.; Mol, Christian P.; Leiner, Tim; Oudkerk, Matthijs; Prokop, Mathias; de Jong, Pim A.

2012-01-01

To determine the influence of iterative reconstruction (IR) on quantitative computed tomography (CT) measurements of emphysema, air trapping, and airway wall and lumen dimensions, compared to filtered back-projection (FBP). Inspiratory and expiratory chest CTs of 75 patients (37 male, 38 female;

Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

Science.gov (United States)

Schwemmer, C.; Rohkohl, C.; Lauritsch, G.; Müller, K.; Hornegger, J.

2013-06-01

Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D-2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average.

Maximum Likelihood Reconstruction for Magnetic Resonance Fingerprinting.

Science.gov (United States)

Zhao, Bo; Setsompop, Kawin; Ye, Huihui; Cauley, Stephen F; Wald, Lawrence L

2016-08-01

This paper introduces a statistical estimation framework for magnetic resonance (MR) fingerprinting, a recently proposed quantitative imaging paradigm. Within this framework, we present a maximum likelihood (ML) formalism to estimate multiple MR tissue parameter maps directly from highly undersampled, noisy k-space data. A novel algorithm, based on variable splitting, the alternating direction method of multipliers, and the variable projection method, is developed to solve the resulting optimization problem. Representative results from both simulations and in vivo experiments demonstrate that the proposed approach yields significantly improved accuracy in parameter estimation, compared to the conventional MR fingerprinting reconstruction. Moreover, the proposed framework provides new theoretical insights into the conventional approach. We show analytically that the conventional approach is an approximation to the ML reconstruction; more precisely, it is exactly equivalent to the first iteration of the proposed algorithm for the ML reconstruction, provided that a gridding reconstruction is used as an initialization.

Sternal plate fixation for sternal wound reconstruction: initial experience (Retrospective study

Directory of Open Access Journals (Sweden)

Musgrave Melinda

2011-04-01

Full Text Available Abstract Background Median sternotomy infection and bony nonunion are two commonly described complications which occur in 0.4 - 5.1% of cardiac procedures. Although relatively infrequent, these complications can lead to significant morbidity and mortality. The aim of this retrospective study is to evaluate the initial experience of a transverse plate fixation system following wound complications associated with sternal dehiscence with or without infection following cardiac surgery. Methods A retrospective chart review of 40 consecutive patients who required sternal wound reconstruction post sternotomy was performed. Soft tissue debridement with removal of all compromised tissue was performed. Sternal debridement was carried using ronguers to healthy bleeding bone. All patients underwent sternal fixation using three rib plates combined with a single manubrial plate (Titanium Sternal Fixation System®, Synthes. Incisions were closed in a layered fashion with the pectoral muscles being advanced to the midline. Data were expressed as mean ± SD, Median (range or number (%. Statistical analyses were made by using Excel 2003 for Windows (Microsoft, Redmond, WA, USA. Results There were 40 consecutive patients, 31 males and 9 females. Twenty two patients (55% were diagnosed with sternal dehiscence alone and 18 patients (45% with associated wound discharge. Thirty eight patients went on to heal their wounds. Two patients developed recurrent wound infection and required VAC therapy. Both were immunocompromised. Median post-op ICU stay was one day with the median hospital stay of 18 days after plating. Conclusion Sternal plating appears to be an effective option for the treatment of sternal wound dehiscence associated with sternal instability. Long-term follow-up and further larger studies are needed to address the indications, benefits and complications of sternal plating.

Surgical management of the radiated chest wall

International Nuclear Information System (INIS)

Arnold, P.G.; Pairolero, P.C.

1986-01-01

Fifty consecutive patients with radiation-related problems of the chest wall were treated between 1976 and 1984. There were 40 women and 10 men with an average age of 54 years (range 26 to 78 years). Twenty-three patients had radiation ulcers alone, 20 had recurrent cancer, and 7 had infected median sternotomy wounds. Thirty-six had skeletal resections and 44 had soft-tissue resections. The skeleton was reconstructed with Prolene mesh in 12 patients and with autogenous rib in 3. Sixty-three muscles were transposed in 43 patients. Twelve omental transpositions were performed (8 for primary treatment and 4 for salvage of a failed muscle flap). Hospitalization averaged 20.2 days. There was one operative death (at 29 days). Partial flap necrosis occurred in 10 patients. Mesh was removed in three patients. There were 14 late deaths, most from recurrent tumor. The remaining patients had well-healed wounds and a generally improved quality of life. We conclude that aggressive resection and reliable reconstruction are critical considerations in the surgical management of this perplexing clinical problem

Comparison of theoretical and test results on shear wall seismic response

International Nuclear Information System (INIS)

Gantenbein, F.; Wang, F.; Dalbera, J.

1991-01-01

As reinforced concrete shear walls are important resisting components of buildings in nuclear power facilities, it is important to study their ultimate behavior under dynamic loading. An experimental and analytical work has been undertaken on shear walls with and without openings, in order to develop and validate their model. This paper is related to the walls without openings. While pretest calculations have already been reported (Wang and al. 1989) and the test results are given in Gantenbein and al. 1991, this paper is mainly related to the comparison of test and calculation results on the wall initial stiffness and the time history of the wall motion

The JET ITER-like wall experiment: First results and lessons for ITER

Energy Technology Data Exchange (ETDEWEB)

Horton, Lorne, E-mail: Lorne.Horton@jet.efda.org [EFDA-CSU Culham, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); European Commission, B-1049 Brussels (Belgium)

2013-10-15

Highlights: ► JET has recently completed the installation of an ITER-like wall. ► Important operational aspects have changed with the new wall. ► Initial experiments have confirmed the expected low fuel retention. ► Disruption dynamics have change dramatically. ► Development of wall-compatible, ITER-relevant regimes of operation has begun. -- Abstract: The JET programme is strongly focused on preparations for ITER construction and exploitation. To this end, a major programme of machine enhancements has recently been completed, including a new ITER-like wall, in which the plasma-facing armour in the main vacuum chamber is beryllium while that in the divertor is tungsten—the same combination of plasma-facing materials foreseen for ITER. The goal of the initial experimental campaigns is to fully characterise operation with the new wall, concentrating in particular on plasma-material interactions, and to make direct comparisons of plasma performance with the previous, carbon wall. This is being done in a progressive manner, with the input power and plasma performance being increased in combination with the commissioning of a comprehensive new real-time protection system. Progress achieved during the first set of experimental campaigns with the new wall, which took place from September 2011 to July 2012, is reported.

Surgical reconstruction of pressure ulcer defects: a single- or two-stage procedure?

LENUS (Irish Health Repository)

Laing, Tereze A

2012-02-01

BACKGROUND: The surgical management of pressure ulcers traditionally involved staged procedures, with initial debridement of necrotic or infected material followed by reconstruction at a later date when the wound was deemed viable and free of gross infection. However, over the past decade, it has been suggested that a single-stage procedure, combining initial debridement and definitive reconstruction, may provide advantages over staged surgery. We present our experience with the staged approach and review the current evidence for both methods. SUBJECTS AND SETTINGS: : We reviewed medical records of all patients referred to our service for pressure ulcer management between October 2001 and October 2007. The National Rehabilitation Hospital is the national center in Ireland for primary rehabilitation of adults and children suffering from spinal and brain injury, serving patients locally and from around the country. METHODS: All subjects who were managed surgically underwent a 2-stage procedure, with initial debridement and subsequent reconstruction. The main outcome measures were length of hospital stay, postoperative morbidity and mortality, and time to complete ulcer healing. RESULTS: Forty-one of 108 patients with 58 pressure ulcers were managed surgically. All patients underwent initial surgical debridement and 20 patients underwent subsequent pressure ulcer reconstruction. Postreconstructive complications occurred in 5 patients (20%). The mean time to complete ulcer healing was 17.4 weeks. Partial flap necrosis occurred in 3 patients, but there were no episodes of flap failure. CONCLUSIONS: We achieved favorable results with a 2-stage reconstruction technique and suggest that the paucity of evidence related to single-stage procedures does not support a change in surgical management.

GNSS troposphere tomography based on two-step reconstructions using GPS observations and COSMIC profiles

Directory of Open Access Journals (Sweden)

P. Xia

2013-10-01

Full Text Available Traditionally, balloon-based radiosonde soundings are used to study the spatial distribution of atmospheric water vapour. However, this approach cannot be frequently employed due to its high cost. In contrast, GPS tomography technique can obtain water vapour in a high temporal resolution. In the tomography technique, an iterative or non-iterative reconstruction algorithm is usually utilised to overcome rank deficiency of observation equations for water vapour inversion. However, the single iterative or non-iterative reconstruction algorithm has their limitations. For instance, the iterative reconstruction algorithm requires accurate initial values of water vapour while the non-iterative reconstruction algorithm needs proper constraint conditions. To overcome these drawbacks, we present a combined iterative and non-iterative reconstruction approach for the three-dimensional (3-D water vapour inversion using GPS observations and COSMIC profiles. In this approach, the non-iterative reconstruction algorithm is first used to estimate water vapour density based on a priori water vapour information derived from COSMIC radio occultation data. The estimates are then employed as initial values in the iterative reconstruction algorithm. The largest advantage of this approach is that precise initial values of water vapour density that are essential in the iterative reconstruction algorithm can be obtained. This combined reconstruction algorithm (CRA is evaluated using 10-day GPS observations in Hong Kong and COSMIC profiles. The test results indicate that the water vapor accuracy from CRA is 16 and 14% higher than that of iterative and non-iterative reconstruction approaches, respectively. In addition, the tomography results obtained from the CRA are further validated using radiosonde data. Results indicate that water vapour densities derived from the CRA agree with radiosonde results very well at altitudes above 2.5 km. The average RMS value of their

High-definition computed tomography for coronary artery stents imaging: Initial evaluation of the optimal reconstruction algorithm.

Science.gov (United States)

Cui, Xiaoming; Li, Tao; Li, Xin; Zhou, Weihua

2015-05-01

The aim of this study was to evaluate the in vivo performance of four image reconstruction algorithms in a high-definition CT (HDCT) scanner with improved spatial resolution for the evaluation of coronary artery stents and intrastent lumina. Thirty-nine consecutive patients with a total of 71 implanted coronary stents underwent coronary CT angiography (CCTA) on a HDCT (Discovery CT 750 HD; GE Healthcare) with the high-resolution scanning mode. Four different reconstruction algorithms (HD-stand, HD-detail; HD-stand-plus; HD-detail-plus) were applied to reconstruct the stented coronary arteries. Image quality for stent characterization was assessed. Image noise and intrastent luminal diameter were measured. The relationship between the measurement of inner stent diameter (ISD) and the true stent diameter (TSD) and stent type were analysed. The stent-dedicated kernel (HD-detail) offered the highest percentage (53.5%) of good image quality for stent characterization and the highest ratio (68.0±8.4%) of visible stent lumen/true stent lumen for luminal diameter measurement at the expense of an increased overall image noise. The Pearson correlation coefficient between the ISD and TSD measurement and spearman correlation coefficient between the ISD measurement and stent type were 0.83 and 0.48, respectively. Compared with standard reconstruction algorithms, high-definition CT imaging technique with dedicated high-resolution reconstruction algorithm provides more accurate stent characterization and intrastent luminal diameter measurement. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Active numerical model of human body for reconstruction of falls from height.

Science.gov (United States)

Milanowicz, Marcin; Kędzior, Krzysztof

2017-01-01

Falls from height constitute the largest group of incidents out of approximately 90,000 occupational accidents occurring each year in Poland. Reconstruction of the exact course of a fall from height is generally difficult due to lack of sufficient information from the accident scene. This usually results in several contradictory versions of an incident and impedes, for example, determination of the liability in a judicial process. In similar situations, in many areas of human activity, researchers apply numerical simulation. They use it to model physical phenomena to reconstruct their real course over time; e.g. numerical human body models are frequently used for investigation and reconstruction of road accidents. However, they are validated in terms of specific road traffic accidents and are considerably limited when applied to the reconstruction of other types of accidents. The objective of the study was to develop an active numerical human body model to be used for reconstruction of accidents associated with falling from height. Development of the model involved extension and adaptation of the existing Pedestrian human body model (available in the MADYMO package database) for the purposes of reconstruction of falls from height by taking into account the human reaction to the loss of balance. The model was developed by using the results of experimental tests of the initial phase of the fall from height. The active numerical human body model covering 28 sets of initial conditions related to various human reactions to the loss of balance was developed. The application of the model was illustrated by using it to reconstruct a real fall from height. From among the 28 sets of initial conditions, those whose application made it possible to reconstruct the most probable version of the incident was selected. The selection was based on comparison of the results of the reconstruction with information contained in the accident report. Results in the form of estimated

Effects of biases in domain wall network evolution. II. Quantitative analysis

Science.gov (United States)

Correia, J. R. C. C. C.; Leite, I. S. C. R.; Martins, C. J. A. P.

2018-04-01

Domain walls form at phase transitions which break discrete symmetries. In a cosmological context, they often overclose the Universe (contrary to observational evidence), although one may prevent this by introducing biases or forcing anisotropic evolution of the walls. In a previous work [Correia et al., Phys. Rev. D 90, 023521 (2014), 10.1103/PhysRevD.90.023521], we numerically studied the evolution of various types of biased domain wall networks in the early Universe, confirming that anisotropic networks ultimately reach scaling while those with a biased potential or biased initial conditions decay. We also found that the analytic decay law obtained by Hindmarsh was in good agreement with simulations of biased potentials, but not of biased initial conditions, and suggested that the difference was related to the Gaussian approximation underlying the analytic law. Here, we extend our previous work in several ways. For the cases of biased potential and biased initial conditions, we study in detail the field distributions in the simulations, confirming that the validity (or not) of the Gaussian approximation is the key difference between the two cases. For anisotropic walls, we carry out a more extensive set of numerical simulations and compare them to the canonical velocity-dependent one-scale model for domain walls, finding that the model accurately predicts the linear scaling regime after isotropization. Overall, our analysis provides a quantitative description of the cosmological evolution of these networks.

Analysis of three loss-of-flow accidents in the first wall cooling system of NET/ITER

International Nuclear Information System (INIS)

Komen, E.M.J.; Koning, H.

1993-05-01

This report presents the thermal-hydraulic analysis of three Loss-of-Flow Accidents (LOFAs) in the first wall cooling system of the Next European Torus (NET) design or the International Thermonuclear Experimental Reactor (ITER) design. The LOFAs considered result from a loss of the forced coolant flow caused by a loss of electrical power for the recirculation pump in the primary circuit. The analyses have been performed using the thermal-hydraulic system analysis code RELAP5/MOD3. In the analyses, special attention has been paid to the transient thermal-hydraulic behaviour of the cooling system and the temperature development in the first wall. In the LOFA case without plasma shutdown, melting starts in the first wall about 150 s after accident initiation. In the LOFA case with delayed plasma shutdown, melting starts in the first wall when the plasma shutdown is initiated later than about 110 s after accident initiation. Melting does not occur in the first wall during a LOFA with prompt plasma scram. (orig.)

Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

International Nuclear Information System (INIS)

Schwemmer, C; Müller, K; Hornegger, J; Rohkohl, C; Lauritsch, G

2013-01-01

Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D–2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average. (paper)

Effects of magnetized walls on the particle structure and the yield stress of magnetorheological fluids

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jianfeng, E-mail: zhoujianfeng@njtech.edu.cn [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu (China); Mo, Jingwen [Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Shao, Chunlei [School of Mechanical and Power Engineering, Nanjing Tech University, Nanjing 211816, Jiangsu (China); Li, Zhigang [Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2015-09-01

In this work, we investigate the quasi-static shear deformation of magnetic particles (MPs) in a Couette flow of magnetorheological (MR) fluids through Stokesian dynamic simulations. The magnetized walls are modeled by a congregation of magnetic dipoles and their effects on the MPs are considered. The simple shear flow of the base fluid with linear velocity distribution is used to generate the shear deformation of the MP structure and the yield stresses under different shear rates are obtained. Comparing with the relatively long chains forming in base fluid without the effect of magnetized walls, the initial structure of MPs is mainly in the form of short chains due to the attractive force of walls. At the beginning of the shear deformation of the MP structure, the concentration of MPs near the walls is found. As the shear deformation develops, however, the chains concentrate at the center of the simulation domain and the MPs near wall boundaries are attracted to the center. The yield stress depends on the initial structure of MPs which is affected by the magnetized walls. It is revealed that the larger shear rate of base fluid results in the larger yield stress, and the effects of the magnetization intensity of the walls and their space distance on the yield stress are also investigated. - Highlights: • We model a Couette flow of magnetorheological fluid considering magnetized walls. • The walls are modeled by a congregation of magnetic dipoles. • Initial structure of MPs is remarkably affected by the walls, so is yield stress. • Larger base fluid shear rate causes the larger shear deformation and larger yield stress.

Effects of magnetized walls on the particle structure and the yield stress of magnetorheological fluids

International Nuclear Information System (INIS)

Zhou, Jianfeng; Mo, Jingwen; Shao, Chunlei; Li, Zhigang

2015-01-01

In this work, we investigate the quasi-static shear deformation of magnetic particles (MPs) in a Couette flow of magnetorheological (MR) fluids through Stokesian dynamic simulations. The magnetized walls are modeled by a congregation of magnetic dipoles and their effects on the MPs are considered. The simple shear flow of the base fluid with linear velocity distribution is used to generate the shear deformation of the MP structure and the yield stresses under different shear rates are obtained. Comparing with the relatively long chains forming in base fluid without the effect of magnetized walls, the initial structure of MPs is mainly in the form of short chains due to the attractive force of walls. At the beginning of the shear deformation of the MP structure, the concentration of MPs near the walls is found. As the shear deformation develops, however, the chains concentrate at the center of the simulation domain and the MPs near wall boundaries are attracted to the center. The yield stress depends on the initial structure of MPs which is affected by the magnetized walls. It is revealed that the larger shear rate of base fluid results in the larger yield stress, and the effects of the magnetization intensity of the walls and their space distance on the yield stress are also investigated. - Highlights: • We model a Couette flow of magnetorheological fluid considering magnetized walls. • The walls are modeled by a congregation of magnetic dipoles. • Initial structure of MPs is remarkably affected by the walls, so is yield stress. • Larger base fluid shear rate causes the larger shear deformation and larger yield stress

Coronary Stent Artifact Reduction with an Edge-Enhancing Reconstruction Kernel - A Prospective Cross-Sectional Study with 256-Slice CT.

Science.gov (United States)

Tan, Stéphanie; Soulez, Gilles; Diez Martinez, Patricia; Larrivée, Sandra; Stevens, Louis-Mathieu; Goussard, Yves; Mansour, Samer; Chartrand-Lefebvre, Carl

2016-01-01

Metallic artifacts can result in an artificial thickening of the coronary stent wall which can significantly impair computed tomography (CT) imaging in patients with coronary stents. The objective of this study is to assess in vivo visualization of coronary stent wall and lumen with an edge-enhancing CT reconstruction kernel, as compared to a standard kernel. This is a prospective cross-sectional study involving the assessment of 71 coronary stents (24 patients), with blinded observers. After 256-slice CT angiography, image reconstruction was done with medium-smooth and edge-enhancing kernels. Stent wall thickness was measured with both orthogonal and circumference methods, averaging thickness from diameter and circumference measurements, respectively. Image quality was assessed quantitatively using objective parameters (noise, signal to noise (SNR) and contrast to noise (CNR) ratios), as well as visually using a 5-point Likert scale. Stent wall thickness was decreased with the edge-enhancing kernel in comparison to the standard kernel, either with the orthogonal (0.97 ± 0.02 versus 1.09 ± 0.03 mm, respectively; pkernel generated less overestimation from nominal thickness compared to the standard kernel, both with the orthogonal (0.89 ± 0.19 versus 1.00 ± 0.26 mm, respectively; pkernel was associated with lower SNR and CNR, as well as higher background noise (all p kernel. Stent visual scores were higher with the edge-enhancing kernel (pkernel generates thinner stent walls, less overestimation from nominal thickness, and better image quality scores than the standard kernel.

Reconstruction method for data protection in telemedicine systems

Science.gov (United States)

Buldakova, T. I.; Suyatinov, S. I.

2015-03-01

In the report the approach to protection of transmitted data by creation of pair symmetric keys for the sensor and the receiver is offered. Since biosignals are unique for each person, their corresponding processing allows to receive necessary information for creation of cryptographic keys. Processing is based on reconstruction of the mathematical model generating time series that are diagnostically equivalent to initial biosignals. Information about the model is transmitted to the receiver, where the restoration of physiological time series is performed using the reconstructed model. Thus, information about structure and parameters of biosystem model received in the reconstruction process can be used not only for its diagnostics, but also for protection of transmitted data in telemedicine complexes.

CT reconstruction techniques for improved accuracy of lung CT airway measurement

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 (United States); Ranallo, F. N. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 (United States); Judy, P. F. [Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Gierada, D. S. [Department of Radiology, Washington University, St. Louis, Missouri 63110 (United States); Fain, S. B., E-mail: sfain@wisc.edu [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 (United States); Department of Biomedical Engineering,University of Wisconsin School of Engineering, Madison, Wisconsin 53706 (United States)

2014-11-01

Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12–100 mA s current–time product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Women’s Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD

CT reconstruction techniques for improved accuracy of lung CT airway measurement

International Nuclear Information System (INIS)

Rodriguez, A.; Ranallo, F. N.; Judy, P. F.; Gierada, D. S.; Fain, S. B.

2014-01-01

Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12–100 mA s current–time product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Women’s Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD

LiveWall Operational Evaluation: Seattle Law Enforcement Pilot

Energy Technology Data Exchange (ETDEWEB)

Barr, Jonathan L.; Burtner, Edwin R.; Stein, Steven L.

2013-10-01

The LiveWall concept envisioned as an outgrowth of the Precision Information Environment (PIE) project allows communications between separate groups using interactive video, audio, and a shared desktop environment; this allows everyone to participate and collaborate in real time, regardless of location. The LiveWall concept provides a virtual window to other locations, where all parties can interact and collaboratively work with each other. This functionality is intended to improve multi-site coordination amongst emergency operations centers (EOC), field operations sites and across organizations and jurisdictions to accommodate communications during routine and emergency events. For the initial LiveWall operational evaluation PNNL partnered with the Seattle Police Department (SPD). This partnership allowed for the creation of an excellent LiveWall test bed specific to law enforcement. This partnership made it possible to test the LiveWall concept with scenarios involving the many facets of the law enforcement work done by SPD. PNNL and SPD agreed that integrating the systems into operations for a real event would be the best test of the technology and give SPD staff greater visibility into the functionality and benefits offered by the LiveWall concept.

Two-dimensional void reconstruction by neutron transmission

International Nuclear Information System (INIS)

Zakaib, G.D.; Harms, A.A.; Vlachopoulos, J.

1978-01-01

Contemporary algebraic reconstruction methods are utilized in investigating the two-dimensional void distribution in a water analog from neutron transmission measurements. It is sought to ultimately apply these techniques to the determination of time-averaged void distribution in two-phase flow systems as well as for potential usage in neutron radiography. Initially, projection data were obtained from a digitized model of a hypothetical two-phase representation and later from neutron beam traverses across a voided methacrylate plastic model. From 10 to 15 views were incorporated, and decoupling of overlapped measurements was utilized to afford greater resolution. In general, the additive Algebraic Reconstruction Technique yielded the best reconstructions, with others showing promise for noisy data. Results indicate the need for some further development of the method in interpreting real data

Time Resolved Tomographic PIV Measurements of Rough-Wall Turbulent Channel Flow

Science.gov (United States)

Miorini, Rinaldo; Zhang, Cao; Katz, Joseph

2013-11-01

Time resolved tomographic PIV is used to study flow structures in the outer region of a rough-wall turbulent boundary layer, focusing on imprints of the roughness on the outer layer. Measurements are performed in a transparent channel installed in the JHU optically index matched facility. The roughness consists of pyramids with height, k = 0.46 mm, and wavelength, λ = 3.2 mm, satisfying h/k = 55 (h = 25.4 mm is the channel half-height), k + = 64 and Re = 40000. The TPIV setup consists of four high-speed cameras operating at 3 kHz, which view the sample volume through acrylic prisms. The flow field is illuminated by an Nd:YLF laser. Following enhancement, calibration, and reconstruction, 643 voxels interrogation volumes with 0.75 overlap provide 3D velocity fields with spacing of 0.5883 mm3. Formation and transport of near-wall 3D U-shaped vortex structures, with base in front of the pyramids, and quasi-streamwise legs extending between pyramid crest lines are evident from the data. Extended streamwise regions of high wall-normal vorticity appear ``latched'' to the roughness elements close to the wall, but are transported downstream at higher elevations. Also evident are traveling streamwise low velocity streaks, which cover many roughness elements. Sponsored by NSF CBET and ONR.

Near wall combustion modeling in spark ignition engines. Part A: Flame–wall interaction

International Nuclear Information System (INIS)

Demesoukas, Sokratis; Caillol, Christian; Higelin, Pascal; Boiarciuc, Andrei; Floch, Alain

2015-01-01

tip sparkplug. Results show that the position of the sparkplug has a greater influence than its length. The heat release rate was significantly altered in the lateral sparkplug position, when running the model with flame wall interaction. With the projected tip sparkplug, the impact of the wall on the initial flame kernel was delayed, since the flame is not close to the cylinder head. The maximum pressure was reduced when using the flame–wall interaction model for all four configurations. The attenuation of the wrinkling factor and of the mean flame surface at the end of combustion was captured by taking into account the impact of the chamber geometry, while this is not the case in global models, which impose an exponential decay of the heat release rate. The measured values for the four sparkplug configurations gave consistent results in terms of cylinder pressure and heat release.

[Trachea repair and reconstruction with new composite artificial trachea transplantation].

Science.gov (United States)

Liu, Wenliang; Xiao, Peng; Liang, Hengxing; An, Ran; Cheng, Gang; Yu, Fenglei

2013-03-01

To construct a new composite artificial trachea and to investigate the feasibility of trachea repair and reconstruction with the new composite artificial trachea transplantation in dogs. The basic skeleton of the new composite artificial trachea was polytetrafluoroethylene vascular prosthesis linked with titanium rings at both ends. Dualmesh was sutured on titanium rings. Sixteen dogs, weighing (14.9 +/- 2.0) kg, female or male, were selected. The 5 cm cervical trachea was resected to prepare the cervical trachea defect model. The trachea repair and reconstruction was performed with the new composite artificial trachea. Then fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction were conducted at immediate, 1 month, and 6 months after operation. Gross observation and histological examination were conducted at 14 months to evaluate the repair and reconstruction efficacy. No dog died during operation of trachea reconstruction. One dog died of dyspnea at 37, 41, 55, 66, 140, and 274 days respectively because of anastomotic dehiscence and artificial trachea displacement; the other 10 dogs survived until 14 months. The fiberoptic bronchoscope examination, CT scan and three-dimensinal reconstruction showed that artificial tracheas were all in good location without twisting at immediate after operation; mild stenosis occurred and anastomoses had slight granulation in 6 dogs at 1 month; severe stenosis developed and anastomosis had more granulation in 1 dog and the other dogs were well alive without anastomotic stenosis at 6 months. At 14 months, gross observation revealed that outer surface of the artificial trachea were encapsulated by fibrous connective tissue in all of 10 dogs. Histological examination showed inflammatory infiltration and hyperplasia of fibrous tissue and no epithelium growth on the inner wall of the artificial trachea. The new composite artificial trachea can be used to repair and reconstruct defect of the trachea for a short

Phylogenetic reconstruction methods: an overview.

Science.gov (United States)

De Bruyn, Alexandre; Martin, Darren P; Lefeuvre, Pierre

2014-01-01

Initially designed to infer evolutionary relationships based on morphological and physiological characters, phylogenetic reconstruction methods have greatly benefited from recent developments in molecular biology and sequencing technologies with a number of powerful methods having been developed specifically to infer phylogenies from macromolecular data. This chapter, while presenting an overview of basic concepts and methods used in phylogenetic reconstruction, is primarily intended as a simplified step-by-step guide to the construction of phylogenetic trees from nucleotide sequences using fairly up-to-date maximum likelihood methods implemented in freely available computer programs. While the analysis of chloroplast sequences from various Vanilla species is used as an illustrative example, the techniques covered here are relevant to the comparative analysis of homologous sequences datasets sampled from any group of organisms.

Brachytherapy reconstruction using orthogonal scout views from the CT

International Nuclear Information System (INIS)

Perez, J.; Lliso, F.; Carmona, V.; Bea, J.; Tormo, A.; Petschen, I.

1996-01-01

Introduction: CT assisted brachytherapy planning is demonstrating to have great advantages as external RT planning does. One of the problems we have found in this approach with the conventional gynecological Fletcher applicators is the high amount of artefacts (ovoids with rectal and vessical protections) in the CT slice. We have introduced a reconstruction method based on scout views in order to avoid this problem, allowing us to perform brachytherapy reconstruction completely CT assisted. We use a virtual simulation chain by General Electric Medical Systems. Method and discussion: Two orthogonal scout views (0 and 90 tube positions) are performed. The reconstruction method takes into account the virtual position of the focus and the fact that there is only divergence in the transverse plane. Algorithms developed for sources as well as for reference points localisation (A, B, lymphatic Fletcher trapezoid, pelvic wall, etc.) are presented. This method has the following practical advantages: the porte-cassette is not necessary, the image quality can be improved (it is very helpful in pelvic lateral views that are critical in conventional radiographs), the total time to get the data is smaller than for conventional radiographs (reduction of patient motion effects) and problems that appear in CT-slice based reconstruction in the case of strongly curved intrauterine applicators are avoided. Even though the resolution is smaller than in conventional radiographs it is good enough for brachytherapy. Regarding the CT planning this method presents the interesting feature that the co-ordinate system is the same for the reconstruction process that for the CT-slices set. As the application can be reconstructed from scout views and the doses can be evaluated on CT slices it is easier to correlate the dose values obtained for the traditional points with those provided by the CT information

Restoring a functional and mobile shoulder following reconstruction of the sternoclavicular joint with a free vascularized fibular flap

Directory of Open Access Journals (Sweden)

Abby Choke

2018-06-01

Full Text Available Infection of the sternoclavicular joint (SCJ is rare and often missed at early stage. In extensive disease with bony and soft tissue destruction, radical excision is indicated. The loss of SCJ results in exposure of vital structures of the anterior mediastinum and instability of the shoulder girdle. SCJ reconstruction using locoregional muscle flaps like the pectoralis major or latissimus dorsi flap has been well described. While these options can provide soft tissue coverage, they do not restore the structural framework of the SCJ which is important for shoulder excursion and chest wall movement. We describe a case of SCJ reconstruction using a free vascularized fibular flap following the resection of sternoclavicular tubercular osteomyelitis. The fibula bone was used to restore the clavicular strut by anchoring it to the remaining manubrium with a steel wire and by plating the lateral end to the remnant clavicle. The steel wire served as a “defunctioning” cerclage that allowed motion of the joint to induce fibrous union. A strict post-operative rehabilitation protocol keeping the shoulder adducted at the initial phase was prescribed. At one year follow up, the patient achieved good shoulder function with 140 degrees of shoulder abduction and 110 degrees flexion.

Three-dimensional computed tomography reconstruction for operative planning in robotic segmentectomy: a pilot study.

Science.gov (United States)

Le Moal, Julien; Peillon, Christophe; Dacher, Jean-Nicolas; Baste, Jean-Marc

2018-01-01

The objective of our pilot study was to assess if three-dimensional (3D) reconstruction performed by Visible Patient™ could be helpful for the operative planning, efficiency and safety of robot-assisted segmentectomy. Between 2014 and 2015, 3D reconstructions were provided by the Visible Patient™ online service and used for the operative planning of robotic segmentectomy. To obtain 3D reconstruction, the surgeon uploaded the anonymized computed tomography (CT) image of the patient to the secured Visible Patient™ server and then downloaded the model after completion. Nine segmentectomies were performed between 2014 and 2015 using a pre-operative 3D model. All 3D reconstructions met our expectations: anatomical accuracy (bronchi, arteries, veins, tumor, and the thoracic wall with intercostal spaces), accurate delimitation of each segment in the lobe of interest, margin resection, free space rotation, portability (smartphone, tablet) and time saving technique. We have shown that operative planning by 3D CT using Visible Patient™ reconstruction is useful in our practice of robot-assisted segmentectomy. The main disadvantage is the high cost. Its impact on reducing complications and improving surgical efficiency is the object of an ongoing study.

Carinal resection and reconstruction following inflammatory myofibroblastic tumor resection: A case report

Directory of Open Access Journals (Sweden)

Julia G. Lyon

2016-02-01

Full Text Available Inflammatory myofibroblastic tumors (IMT are rare tumors of the respiratory tract that most commonly occur in the lung and are rarely seen in the trachea. They present most often in young patients. We report on a case of an IMT of the carina in a seven year old girl, requiring carinal resection and reconstruction with a novel technique in pediatric airway surgery. Attempts at endoscopic excision of the carinal IMT were unsuccessful. An open approach for resection of the involved carina, distal trachea, and proximal mainstem bronchi was performed via sternotomy and cardiopulmonary bypass. The resulting triangular defect in the trachea and bronchi was reconstructed with anastomosis of the proximal trachea and left mainstem bronchus using a rotational flap of the right lateral mainstem bronchial wall. The remaining right mainstem bronchus was anastomosed, end to side, to the intact trachea proximal to the primary anastomosis. Bronchoscopy and MRI 22 months post resection and reconstruction revealed a healthy neo-carina and patent distal airway with no evidence of recurrent IMT. Pediatric patients with carinal inflammatory myofibroblastic tumors can be successfully managed with open resection and reconstruction of the airway.

CHALLENGES IN FLYING QUADROTOR UNMANNED AERIAL VEHICLE FOR 3D INDOOR RECONSTRUCTION

Directory of Open Access Journals (Sweden)

J. Yan

2017-09-01

Full Text Available Three-dimensional modelling plays a vital role in indoor 3D tracking, navigation, guidance and emergency evacuation. Reconstruction of indoor 3D models is still problematic, in part, because indoor spaces provide challenges less-documented than their outdoor counterparts. Challenges include obstacles curtailing image and point cloud capture, restricted accessibility and a wide array of indoor objects, each with unique semantics. Reconstruction of indoor environments can be achieved through a photogrammetric approach, e.g. by using image frames, aligned using recurring corresponding image points (CIP to build coloured point clouds. Our experiments were conducted by flying a QUAV in three indoor environments and later reconstructing 3D models which were analysed under different conditions. Point clouds and meshes were created using Agisoft PhotoScan Professional. We concentrated on flight paths from two vantage points: 1 safety and security while flying indoors and 2 data collection needed for reconstruction of 3D models. We surmised that the main challenges in providing safe flight paths are related to the physical configuration of indoor environments, privacy issues, the presence of people and light conditions. We observed that the quality of recorded video used for 3D reconstruction has a high dependency on surface materials, wall textures and object types being reconstructed. Our results show that 3D indoor reconstruction predicated on video capture using a QUAV is indeed feasible, but close attention should be paid to flight paths and conditions ultimately influencing the quality of 3D models. Moreover, it should be decided in advance which objects need to be reconstructed, e.g. bare rooms or detailed furniture.

Challenges in Flying Quadrotor Unmanned Aerial Vehicle for 3d Indoor Reconstruction

Science.gov (United States)

Yan, J.; Grasso, N.; Zlatanova, S.; Braggaar, R. C.; Marx, D. B.

2017-09-01

Three-dimensional modelling plays a vital role in indoor 3D tracking, navigation, guidance and emergency evacuation. Reconstruction of indoor 3D models is still problematic, in part, because indoor spaces provide challenges less-documented than their outdoor counterparts. Challenges include obstacles curtailing image and point cloud capture, restricted accessibility and a wide array of indoor objects, each with unique semantics. Reconstruction of indoor environments can be achieved through a photogrammetric approach, e.g. by using image frames, aligned using recurring corresponding image points (CIP) to build coloured point clouds. Our experiments were conducted by flying a QUAV in three indoor environments and later reconstructing 3D models which were analysed under different conditions. Point clouds and meshes were created using Agisoft PhotoScan Professional. We concentrated on flight paths from two vantage points: 1) safety and security while flying indoors and 2) data collection needed for reconstruction of 3D models. We surmised that the main challenges in providing safe flight paths are related to the physical configuration of indoor environments, privacy issues, the presence of people and light conditions. We observed that the quality of recorded video used for 3D reconstruction has a high dependency on surface materials, wall textures and object types being reconstructed. Our results show that 3D indoor reconstruction predicated on video capture using a QUAV is indeed feasible, but close attention should be paid to flight paths and conditions ultimately influencing the quality of 3D models. Moreover, it should be decided in advance which objects need to be reconstructed, e.g. bare rooms or detailed furniture.

Reconstructing the muscular ground pattern of phylactolaemate bryozoans: first data from gelatinous representatives.

Science.gov (United States)

Gawin, Natalie; Wanninger, Andreas; Schwaha, Thomas

2017-11-07

Phylactolaemata is commonly regarded the earliest branch within Bryozoa and thus the sister group to the other bryozoan taxa, Cyclostomata and Gymnolaemata. Therefore, the taxon is important for the reconstruction of the bryozoan morphological ground pattern. In this study the myoanatomy of Pectinatella magnifica, Cristatella mucedo and Hyalinella punctata was analysed by means of histology, f-actin staining and confocal laser-scanning microscopy in order to fill gaps in knowledge concerning the myoanatomy of Phylactolaemata. The retractor muscles and muscles of the aperture, gut, body wall, tentacle sheath, lophophore constitute the most prominent muscular subsets in these species. The lophophore shows longitudinal muscle bands in the tentacles, lophophoral arm muscles, epistome musculature and hitherto undescribed muscles of the ring canal. In general the muscular system of the three species is very similar with differences mainly in the body wall, tentacle sheath and epistome. The body wall contains an orthogonal grid of musculature. The epistome exhibits either a muscular meshwork in the epistomal wall or muscle fibers traversing the epistomal cavity. The whole tentacle sheath possesses a regular mesh of muscles in Pectinatella and Cristatella, whereas circular muscles are limited to the tentacle sheath base in Hyalinella. This study is the first to describe muscles of the ring canal and contributes to reconstructing muscular features for the last common ancestor of all bryozoans. The data available suggest that two longitudinal muscle bands in the tentacles, as well as retractor muscles and longitudinal and circular muscles in the tentacle sheath, were present in the last common bryozoan ancestor. Comparisons among bryozoans shows that several apomorphies are present in the myoanatomy of each class- level taxon such as the epistomal musculature and musculature of the lophophoral arms in phylactolaemates, annular muscles in cyclostomes and parietal muscles in

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

Science.gov (United States)

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

2017-01-01

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

Reconstructing Laomedon’s Reign in Homer: Olympiomachia, Poseidon’s Wall, and the Earlier Trojan War

Directory of Open Access Journals (Sweden)

Andrew Porter

2014-11-01

Full Text Available Homeric allusions to Laomedon, the walls of Troy, and the first Trojan War reflect a backstory of previous fighting among the Olympians, which helps to explain the Iliadic portrait of Zeus’s fear of insubordination among the other gods.

Diffuse mirrors: 3D reconstruction from diffuse indirect illumination using inexpensive time-of-flight sensors

KAUST Repository

Heide, Felix

2014-06-01

The functional difference between a diffuse wall and a mirror is well understood: one scatters back into all directions, and the other one preserves the directionality of reflected light. The temporal structure of the light, however, is left intact by both: assuming simple surface reflection, photons that arrive first are reflected first. In this paper, we exploit this insight to recover objects outside the line of sight from second-order diffuse reflections, effectively turning walls into mirrors. We formulate the reconstruction task as a linear inverse problem on the transient response of a scene, which we acquire using an affordable setup consisting of a modulated light source and a time-of-flight image sensor. By exploiting sparsity in the reconstruction domain, we achieve resolutions in the order of a few centimeters for object shape (depth and laterally) and albedo. Our method is robust to ambient light and works for large room-sized scenes. It is drastically faster and less expensive than previous approaches using femtosecond lasers and streak cameras, and does not require any moving parts.

Diffuse mirrors: 3D reconstruction from diffuse indirect illumination using inexpensive time-of-flight sensors

KAUST Repository

Heide, Felix; Xiao, Lei; Heidrich, Wolfgang; Hullin, Matthias B.

2014-01-01

The functional difference between a diffuse wall and a mirror is well understood: one scatters back into all directions, and the other one preserves the directionality of reflected light. The temporal structure of the light, however, is left intact by both: assuming simple surface reflection, photons that arrive first are reflected first. In this paper, we exploit this insight to recover objects outside the line of sight from second-order diffuse reflections, effectively turning walls into mirrors. We formulate the reconstruction task as a linear inverse problem on the transient response of a scene, which we acquire using an affordable setup consisting of a modulated light source and a time-of-flight image sensor. By exploiting sparsity in the reconstruction domain, we achieve resolutions in the order of a few centimeters for object shape (depth and laterally) and albedo. Our method is robust to ambient light and works for large room-sized scenes. It is drastically faster and less expensive than previous approaches using femtosecond lasers and streak cameras, and does not require any moving parts.

A numerical investigation into the performance of the soil nail wall and pile foundation at the Swift Delta I-5 Interchange.

Science.gov (United States)

1993-12-01

Finite Difference Methods (FDM) and Finite Element Methods (FEM) studies are reported studying the soil nail wall construction at the Swift Delta I-5 Interchange bridge reconstruction in North Portland, Oregon. Five layers of soil nails were installe...

Comparison of 4-chloro-2-nitrophenol adsorption on single-walled and multi-walled carbon nanotubes

Directory of Open Access Journals (Sweden)

Mehrizad Ali

2012-09-01

Full Text Available Abstract The adsorption characteristics of 4-chloro-2-nitrophenol (4C2NP onto single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs from aqueous solution were investigated with respect to the changes in the contact time, pH of solution, carbon nanotubes dosage and initial 4C2NP concentration. Experimental results showed that the adsorption efficiency of 4C2NP by carbon nanotubes (both of SWCNTs and MWCNTs increased with increasing the initial 4C2NP concentration. The maximum adsorption took place in the pH range of 2–6. The linear correlation coefficients of different isotherm models were obtained. Results revealed that the Langmuir isotherm fitted the experimental data better than the others and based on the Langmuir model equation, maximum adsorption capacity of 4C2NP onto SWCNTs and MWCNTs were 1.44 and 4.42 mg/g, respectively. The observed changes in the standard Gibbs free energy, standard enthalpy and standard entropy showed that the adsorption of 4C2NP onto SWCNTs and MWCNTs is spontaneous and exothermic in the temperature range of 298–328 K.

Breast reconstruction: current and future options

Directory of Open Access Journals (Sweden)

Paul Jr H

2011-08-01

Full Text Available Henry Paul Jr1, Tahira I Prendergast2, Bryson Nicholson2, Shenita White2, Wayne AI Frederick2,31Departments of Plastic Surgery, 2General Surgery, Howard University Hospital, 3Cancer Center, Howard University, Washington, DC, USAAbstract: When initiated by the devastating diagnosis of cancer, post ablative breast restoration has at its core the goal of restoring anatomic normalcy. The concepts of body image, wholeness, and overall well-being have been introduced to explain the paramount psychological influence the breast has on both individuals and society as a whole. Hence, a growing subspecialty has been established to recreate or simulate the lost breast. At least one third of breast cancer victims consider breast reconstruction. Breast reconstruction post mastectomy may be offered at the time of mastectomy or delayed post mastectomy after adjuvant therapy. This may be utilizing autologous tissues or implants and each has risks and benefits, especially when considering adjuvant therapy. In addition, there has been a move away from a traditional mastectomy to less invasive, but still curative procedures, such as skin-sparing and nipple-sparing mastectomy. These procedures provide the breast envelope to facilitate reconstruction. This paper reviews the primary issues in breast reconstruction, as well as their psychologic, oncologic, and social impact.Keywords: breast restoration, body image, breast reconstruction, mastectomy

Distance weighting for improved tomographic reconstructions

International Nuclear Information System (INIS)

Koeppe, R.A.; Holden, J.E.

1984-01-01

An improved method for the reconstruction of emission computed axial tomography images has been developed. The method is a modification of filtered back-projection, where the back projected values are weighted to reflect the loss of formation, with distance from the camera, which is inherent in gamma camera imaging. This information loss is a result of: loss of spatial resolution with distance, attenuation, and scatter. The weighting scheme can best be described by considering the contributions of any two opposing views to the reconstruction image pixels. The weight applied to the projections of one view is set to equal the relative amount of the original activity that was initially received in that projection, assuming a uniform attenuating medium. This yields a weighting value which is a function of distance into the image with a value of one for pixels ''near the camera'', a value of .5 at the image center, and a value of zero on the opposite side. Tomographic reconstructions produced with this method show improved spatial resolution when compared to conventional 360 0 reconstructions. The improvement is in the tangential direction, where simulations have indicated a FWHM improvement of 1 to 1.5 millimeters. The resolution in the radial direction is essentially the same for both methods. Visual inspection of the reconstructed images show improved resolution and contrast

VIDEOGRAMMETRIC RECONSTRUCTION APPLIED TO VOLCANOLOGY: PERSPECTIVES FOR A NEW MEASUREMENT TECHNIQUE IN VOLCANO MONITORING

Directory of Open Access Journals (Sweden)

Emmanuelle Cecchi

2011-05-01

Full Text Available This article deals with videogrammetric reconstruction of volcanic structures. As a first step, the method is tested in laboratory. The objective is to reconstruct small sand and plaster cones, analogous to volcanoes, that deform with time. The initial stage consists in modelling the sensor (internal parameters and calculating its orientation and position in space, using a multi-view calibration method. In practice two sets of views are taken: a first one around a calibration target and a second one around the studied object. Both sets are combined in the calibration software to simultaneously compute the internal parameters modelling the sensor, and the external parameters giving the spatial location of each view around the cone. Following this first stage, a N-view reconstruction process is carried out. The principle is as follows: an initial 3D model of the cone is created and then iteratively deformed to fit the real object. The deformation of the meshed model is based on a texture coherence criterion. At present, this reconstruction method and its precision are being validated at laboratory scale. The objective will be then to follow analogue model deformation with time using successive reconstructions. In the future, the method will be applied to real volcanic structures. Modifications of the initial code will certainly be required, however excellent reconstruction accuracy, valuable simplicity and flexibility of the technique are expected, compared to classic stereophotogrammetric techniques used in volcanology.

Initial stress and nonlinear material behavior in patient-specific AAA wall stress analysis

NARCIS (Netherlands)

Speelman, L.; Bosboom, E.M.H.; Schurink, G.W.H.; Buth, J.; Breeuwer, M.; Jacobs, M.J.; Vosse, van de F.N.

2009-01-01

Rupture risk estimation of abdominal aortic aneurysms (AAA) is currently based on the maximum diameter of the AAA. A more critical approach is based on AAA wall stress analysis. For that, in most cases, the AAA geometry is obtained from CT-data and treated as a stress free geometry. However, during

DIACHRONIC RECONSTRUCTION OF LOST CULTURAL HERITAGE SITES. STUDY CASE OF THE MEDIEVAL WALL OF AVILA (SPAIN

Directory of Open Access Journals (Sweden)

P. Rodríguez-Gonzálvez

2018-05-01

Full Text Available The integration of the fourth dimension into the geospatial data allows to generate a diachronic model of Cultural Heritage (CH assets, namely, a set of 3D models to represent it in various historical phases. This kind of reconstruction pursues a better understanding of the CH site/scenario, enriching the historical hypotheses as well as contributing to the conservation and decisionmaking process. Although the new geotechnologies have reduced the amount of fieldwork, the generation of 4D model implies the interpretation of heterogeneous historical information sources and their integration. However, this situation could reach a critical point when the study elements are no longer present. Their reconstruction will allow the digital preservation and maintenance of our culture. The main challenge is to harmonize the different historical and archaeological data sources available in relation with the current remains, to recover the lost CH assets with a high degree of reliability. This manuscript aims to examine the study case of a diachronic reconstruction by means of the use of the geotechnology Mobile Laser System (MLS and reverse engineering techniques for a lost urban CH element, the citadel or Alcázar Gate of Ávila. Within this aim, the derived product is evaluated in terms of the achieved accuracy to assess its suitability on the basis of constructive interpretations required to integrate the historical sources in relation to current remains and the surrounding.

A GeoWall with Physics and Astronomy Applications

Science.gov (United States)

Dukes, Phillip; Bruton, Dan

2008-03-01

A GeoWall is a passive stereoscopic projection system that can be used by students, teachers, and researchers for visualization of the structure and dynamics of three-dimensional systems and data. The type of system described here adequately provides 3-D visualization in natural color for large or small groups of viewers. The name ``GeoWall'' derives from its initial development to visualize data in the geosciences.1 An early GeoWall system was developed by Paul Morin at the electronic visualization laboratory at the University of Minnesota and was applied in an introductory geology course in spring of 2001. Since that time, several stereoscopic media, which are applicable to introductory-level physics and astronomy classes, have been developed and released into the public domain. In addition to the GeoWall's application in the classroom, there is considerable value in its use as part of a general science outreach program. In this paper we briefly describe the theory of operation of stereoscopic projection and the basic necessary components of a GeoWall system. Then we briefly describe how we are using a GeoWall as an instructional tool for the classroom and informal astronomy education and in research. Finally, we list sources for several of the free software media in physics and astronomy available for use with a GeoWall system.

Trends in breast reconstruction: Implications for the National Health Insurance Service.

Science.gov (United States)

Hong, Ki Yong; Son, Yoosung; Chang, Hak; Jin, Ung Sik

2018-05-01

Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS) began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR) cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR) cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases) in 2012 to 18.3% (76 cases) in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (PNHIS coverage (PNHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

City Walls as Historic Urban Landscape: a Case study on Participatory Education

Directory of Open Access Journals (Sweden)

Rossana Bonadei

2017-03-01

Full Text Available The concept of Historic Urban Landscape, which now guides the conservation and promotion of numerous heritage sites across the world, is based on the recognition of the complexity of the urban environment, seen as a dynamic system of cultural and natural features. This paper aims at presenting an ongoing reassessment of the meaning of a historic artefact in the city of Bergamo, Italy, which is part of a broader system of defence built by the Venetian Republic between the 15th and 17th centuries. Among the many related initiatives, one was launched by the University of Bergamo and involved nearly a hundred primary school children in a series of multidisciplinary workshops. Children worked to produce a guidebook and a short animated film aimed at reconstructing the meanings and the values embodied by the Venetian Walls, an enduring cultural icon surrounding the medieval upper town. This project is triggering both downscaling and upscaling dynamics in the regeneration process of this historic urban infrastructure. It also contributes to the creation and sharing of new meanings around this heritage, which are strongly related to its value for the citizenship as well as for the visitors.

Cultural Heritage Through Time: a Case Study at Hadrian's Wall, United Kingdom

Science.gov (United States)

Fieber, K. D.; Mills, J. P.; Peppa, M. V.; Haynes, I.; Turner, S.; Turner, A.; Douglas, M.; Bryan, P. G.

2017-02-01

Diachronic studies are central to cultural heritage research for the investigation of change, from landscape to architectural scales. Temporal analyses and multi-temporal 3D reconstruction are fundamental for maintaining and safeguarding all forms of cultural heritage. Such studies form the basis for any kind of decision regarding intervention on cultural heritage, helping assess the risks and issues involved. This article introduces a European-wide project, entitled "Cultural Heritage Through Time", and the case study research carried out as a component of the project in the UK. The paper outlines the initial stages of the case study of landscape change at three locations on Hadrian's Wall, namely Beckfoot Roman Fort, Birdoswald Roman Fort and Corbridge Roman Station, all once part of the Roman Empire's north-west frontier. The main aim of the case study is to integrate heterogeneous information derived from a range of sources to help inform understanding of temporal aspects of landscape change. In particular, the study sites are at risk from natural hazards, notably erosion and flooding. The paper focuses on data collection and collation aspects, including an extensive archive search and field survey, as well as the methodology and preliminary data processing.

Speculation about near-wall turbulence scales

International Nuclear Information System (INIS)

Yurchenko, N F

2008-01-01

A strategy to control near-wall turbulence modifying scales of fluid motion is developed. The boundary-layer flow is shown to respond selectively to the scale of streamwise vortices initiated, e.g. with the spanwise regular temperature distribution over a model surface. It is used to generate sustainable streamwise vortices and thus to optimize integral flow characteristics.

The Cost-Effectiveness of Anterior Cruciate Ligament Reconstruction in Competitive Athletes.

Science.gov (United States)

Stewart, Bruce A; Momaya, Amit M; Silverstein, Marc D; Lintner, David

2017-01-01

Competitive athletes value the ability to return to competitive play after the treatment of anterior cruciate ligament (ACL) injuries. ACL reconstruction has high success rates for return to play, but some studies indicate that patients may do well with nonoperative physical therapy treatment. To evaluate the cost-effectiveness of the treatment of acute ACL tears with either initial surgical reconstruction or physical therapy in competitive athletes. Economic and decision analysis; Level of evidence, 2. The incremental cost, incremental effectiveness, and incremental cost-effectiveness ratio (ICER) of ACL reconstruction compared with physical therapy were calculated from a cost-effectiveness analysis of ACL reconstruction compared with physical therapy for the initial management of acute ACL injuries in competitive athletes. The ACL reconstruction strategy and the physical therapy strategy were represented as Markov models. Costs and quality-adjusted life-years (QALYs) were evaluated over a 6-year time horizon and were analyzed from a societal perspective. Quality of life and probabilities of clinical outcomes were obtained from the peer-reviewed literature, and costs were compiled from a large academic hospital in the United States. One-way, 2-way, and probabilistic sensitivity analyses were used to assess the effect of uncertainty in variables on the ICER of ACL reconstruction. The ICER of ACL reconstruction compared with physical therapy was $22,702 per QALY gained. The ICER was most sensitive to the quality of life of returning to play or not returning to play, costs, and duration of follow-up but relatively insensitive to the rates and costs of complications, probabilities of return to play for both operative and nonoperative treatments, and discount rate. ACL reconstruction is a cost-effective strategy for competitive athletes with an ACL injury.

Experimental evaluation of the ‘transport-of-intensity’ equation for magnetic phase reconstruction in Lorentz transmission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Kohn, Amit, E-mail: akohn@post.tau.ac.il [Department of Materials Science and Engineering, Faculty of Engineering, Tel Aviv University, 69978 Tel Aviv (Israel); Habibi, Avihay; Mayo, Martin [Department of Materials Engineering, Ben-Gurion University of the Negev, 84105 Beer Sheva (Israel)

2016-01-15

The ‘transport-of-intensity’ equation (TIE) is a general phase reconstruction methodology that can be applied to Lorentz transmission electron microscopy (TEM) through the use of Fresnel-contrast (defocused) images. We present an experimental study to test the application of the TIE for quantitative magnetic mapping in Lorentz TEM without aberration correction by examining sub-micrometer sized Ni{sub 80}Fe{sub 20} (Permalloy) elements. For a JEOL JEM 2100F adapted for Lorentz microscopy, we find that quantitative magnetic phase reconstructions are possible for defoci distances ranging between approximately 200 μm and 800 μm. The lower limit originates from competing sources of image intensity variations in Fresnel-contrast images, namely structural defects and diffraction contrast. The upper defocus limit is due to a numerical error in the estimation of the intensity derivative based on three images. For magnetic domains, we show quantitative reconstructions of the product of the magnetic induction vector and thickness in element sizes down to approximately 100 nm in lateral size and 5 nm thick resulting in a minimal detection of 5 T nm. Three types of magnetic structures are tested in terms of phase reconstruction: vortex cores, domain walls, and element edges. We quantify vortex core structures at a diameter of 12 nm while the structures of domain walls and element edges are characterized qualitatively. Finally, we show by image simulations that the conclusions of this experimental study are relevant to other Lorentz TEM in which spherical aberration and defocus are dominant aberrations. - Highlights: • Testing TIE for quantitative magnetic phase reconstruction in Lorentz TEM. • Quantitative magnetic phase reconstructions for defoci distances in 200–800 μm range. • Minimal detection of the product of the magnetic induction and thickness is 5 T nm. • Quantitative phase reconstruction for vortex core structures at 12 nm diameter. • Observations

Latissimus-sparing thoracotomy in the pediatric patient: a valuable asset for thoracic reconstruction.

Science.gov (United States)

Malczewski, M C; Colony, L; Cobb, L M

1994-03-01

The traditional posterolateral thoracotomy involves division of the latissimus dorsi muscle (LD). While the division results in no functional disability, it does negate the potential for possible future thoracic reconstruction if required in individual cases (eg, bronchopleural fistula, empyema, etc). A latissimus-sparing thoracotomy (LST) mobilizes the muscle dorsad and does not compromise the operation. Thus, the ipsilateral LD can be used when chest wall reconstruction is required. This option has been used frequently for adults; however, its use in children has not been extensively documented. Microvascular anastomoses for a contralateral LD free-flap may be tenuous in the small vessels of the child; thus, reconstruction using the ipsilateral LD could be beneficial and safer. The feasibility of LST has not been established with regard to the chest of the child. The authors present three pediatric thoracic cases that illustrate the value of this procedure, and discuss different situations in which latissimus-sparing thoracotomy is advantageous.

Structural domain walls in polar hexagonal manganites

Science.gov (United States)

Kumagai, Yu

2014-03-01

The domain structure in the multiferroic hexagonal manganites is currently intensely investigated, motivated by the observation of intriguing sixfold topological defects at their meeting points [Choi, T. et al,. Nature Mater. 9, 253 (2010).] and nanoscale electrical conductivity at the domain walls [Wu, W. et al., Phys. Rev. Lett. 108, 077203 (2012).; Meier, D. et al., Nature Mater. 11, 284 (2012).], as well as reports of coupling between ferroelectricity, magnetism and structural antiphase domains [Geng, Y. et al., Nano Lett. 12, 6055 (2012).]. The detailed structure of the domain walls, as well as the origin of such couplings, however, was previously not fully understood. In the present study, we have used first-principles density functional theory to calculate the structure and properties of the low-energy structural domain walls in the hexagonal manganites [Kumagai, Y. and Spaldin, N. A., Nature Commun. 4, 1540 (2013).]. We find that the lowest energy domain walls are atomically sharp, with {210}orientation, explaining the orientation of recently observed stripe domains and suggesting their topological protection [Chae, S. C. et al., Phys. Rev. Lett. 108, 167603 (2012).]. We also explain why ferroelectric domain walls are always simultaneously antiphase walls, propose a mechanism for ferroelectric switching through domain-wall motion, and suggest an atomistic structure for the cores of the sixfold topological defects. This work was supported by ETH Zurich, the European Research Council FP7 Advanced Grants program me (grant number 291151), the JSPS Postdoctoral Fellowships for Research Abroad, and the MEXT Elements Strategy Initiative to Form Core Research Center TIES.

D Survey and Augmented Reality for Cultural Heritage. The Case Study of Aurelian Wall at Castra Praetoria in Rome

Science.gov (United States)

Canciani, M.; Conigliaro, E.; Del Grasso, M.; Papalini, P.; Saccone, M.

2016-06-01

The development of close-range photogrammetry has produced a lot of new possibility to study cultural heritage. 3D data acquired with conventional and low cost cameras can be used to document, investigate the full appearance, materials and conservation status, to help the restoration process and identify intervention priorities. At the same time, with 3D survey a lot of three-dimensional data are collected and analyzed by researchers, but there are a very few possibility of 3D output. The augmented reality is one of this possible output with a very low cost technology but a very interesting result. Using simple mobile technology (for iPad and Android Tablets) and shareware software (in the case presented "Augment") it is possible to share and visualize a large number of 3D models with your own device. The case study presented is a part of an architecture graduate thesis, made in Rome at Department of Architecture of Roma Tre University. We have developed a photogrammetric survey to study the Aurelian Wall at Castra Praetoria in Rome. The surveys of 8000 square meters of surface have allowed to identify stratigraphy and construction phases of a complex portion of Aurelian Wall, specially about the Northern door of Castra. During this study, the data coming out of 3D survey (photogrammetric and topographic), are stored and used to create a reverse 3D model, or virtual reconstruction, of the Northern door of Castra. This virtual reconstruction shows the door in the Tiberian period, nowadays it's totally hidden by a curtain wall but, little and significative architectural details allow to know its original feature. The 3D model of the ancient walls has been mapped with the exact type of bricks and mortar, oriented and scaled according to the existing one to use augmented reality. Finally, two kind of application have been developed, one on site, were you can see superimposed the virtual reconstruction on the existing walls using the image recognition. On the other hand

The adventitia: essential regulator of vascular wall structure and function.

Science.gov (United States)

Stenmark, Kurt R; Yeager, Michael E; El Kasmi, Karim C; Nozik-Grayck, Eva; Gerasimovskaya, Evgenia V; Li, Min; Riddle, Suzette R; Frid, Maria G

2013-01-01

The vascular adventitia acts as a biological processing center for the retrieval, integration, storage, and release of key regulators of vessel wall function. It is the most complex compartment of the vessel wall and is composed of a variety of cells, including fibroblasts, immunomodulatory cells (dendritic cells and macrophages), progenitor cells, vasa vasorum endothelial cells and pericytes, and adrenergic nerves. In response to vascular stress or injury, resident adventitial cells are often the first to be activated and reprogrammed to influence the tone and structure of the vessel wall; to initiate and perpetuate chronic vascular inflammation; and to stimulate expansion of the vasa vasorum, which can act as a conduit for continued inflammatory and progenitor cell delivery to the vessel wall. This review presents the current evidence demonstrating that the adventitia acts as a key regulator of vascular wall function and structure from the outside in.

Iterative CT reconstruction via minimizing adaptively reweighted total variation.

Science.gov (United States)

Zhu, Lei; Niu, Tianye; Petrongolo, Michael

2014-01-01

Iterative reconstruction via total variation (TV) minimization has demonstrated great successes in accurate CT imaging from under-sampled projections. When projections are further reduced, over-smoothing artifacts appear in the current reconstruction especially around the structure boundaries. We propose a practical algorithm to improve TV-minimization based CT reconstruction on very few projection data. Based on the theory of compressed sensing, the L-0 norm approach is more desirable to further reduce the projection views. To overcome the computational difficulty of the non-convex optimization of the L-0 norm, we implement an adaptive weighting scheme to approximate the solution via a series of TV minimizations for practical use in CT reconstruction. The weight on TV is initialized as uniform ones, and is automatically changed based on the gradient of the reconstructed image from the previous iteration. The iteration stops when a small difference between the weighted TV values is observed on two consecutive reconstructed images. We evaluate the proposed algorithm on both a digital phantom and a physical phantom. Using 20 equiangular projections, our method reduces reconstruction errors in the conventional TV minimization by a factor of more than 5, with improved spatial resolution. By adaptively reweighting TV in iterative CT reconstruction, we successfully further reduce the projection number for the same or better image quality.

X-ray initiated polymerization of wood impregnants

Energy Technology Data Exchange (ETDEWEB)

Cleland, Marshall R.; Galloway, Richard A. [IBA Industrial, Inc., Edgewood, NY (United States); Berejka, Anthony J. [Ionicorp, Huntington, NY 11743 (United States)], E-mail: berejka@msn.com; Montoney, Daniel [Strathmore Products, Syracuse, NY (United States); Driscoll, Mark; Smith, Leonard; Scott Larsen, L. [State University of New York, SUNY-ESF, Syracuse, NY (United States)

2009-07-15

X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

X-ray initiated polymerization of wood impregnants

International Nuclear Information System (INIS)

Cleland, Marshall R.; Galloway, Richard A.; Berejka, Anthony J.; Montoney, Daniel; Driscoll, Mark; Smith, Leonard; Scott Larsen, L.

2009-01-01

X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

4D RECONSTRUCTIONS FROM LOW-COUNT SPECT DATA USING DEFORMABLE MODELS WITH SMOOTH INTERIOR INTENSITY VARIATIONS

International Nuclear Information System (INIS)

Cunningham, G. S.; Lehovich, A.

2000-01-01

The Bayes Inference Engine (BIE) has been used to perform a 4D reconstruction of a first-pass radiotracer bolus distribution inside a CardioWest Total Artificial Heart, imaged with the University of Arizona's FastSPECT system. The BIE estimates parameter values that define the 3D model of the radiotracer distribution at each of 41 times spanning about two seconds. The 3D models have two components: a closed surface, composed of hi-quadratic Bezier triangular surface patches, that defines the interface between the part of the blood pool that contains radiotracer and the part that contains no radiotracer, and smooth voxel-to-voxel variations in intensity within the closed surface. Ideally, the surface estimates the ventricular wall location where the bolus is infused throughout the part of the blood pool contained by the right ventricle. The voxel-to-voxel variations are needed to model an inhomogeneously-mixed bolus. Maximum a posterior (MAP) estimates of the Bezier control points and voxel values are obtained for each time frame. We show new reconstructions using the Bezier surface models, and discuss estimates of ventricular volume as a function of time, ejection fraction, and wall motion. The computation time for our reconstruction process, which directly estimates complex 3D model parameters from the raw data, is performed in a time that is competitive with more traditional voxel-based methods (ML-EM, e.g.)

Anterior cruciate ligament reconstruction with a novel porcine xenograft: the initial Italian experience

Science.gov (United States)

ZAFFAGNINI, STEFANO; GRASSI, ALBERTO; MUCCIOLI, GIULIO MARIA MARCHEGGIANI; DI SARSINA, TOMMASO ROBERTI; RAGGI, FEDERICO; BENZI, ANDREA; MARCACCI, MAURILIO

2015-01-01

At the current state of the art in anterior cruciate ligament (ACL) reconstruction, multiple techniques have been presented but none has given clearly defined and improved results. One of the main issues concerns the choice of graft. The concept of using xenograft tissue, defined as a graft tissue from one species and destined for implantation in an unlike species, was introduced in order to try to overcome the mechanical and biological concerns associated with synthetic materials and the safety and quality concerns and availability problems of allograft tissue. Xenograft tissue carries the risk of producing an immunological reaction. In order to try to overcome or attenuate the immune response against porcine xenograft tissue, the Z-Process® (Aperion Biologics Inc, San Antonio, Texas, USA) has been developed and used to produce the Z-Lig® family of devices for ACL reconstruction procedures. Z-Lig® is a tendon graft with or without bone blocks, sourced from animal tissue in a manner consistent with what has normally been sourced from human tissue, and processed to overcome anti-Gal-mediated rejection and to attenuate other immunological recognition in humans. All this while ensuring sterility, viral inactivation and preservation of mechanical proprieties appropriate for an ACL reconstruction device. The Z-Lig® device has been tested in skeletally mature monkeys and given interesting and promising results from the preclinical performance and safety profile point of view. On this basis, it was possible to proceed with the first clinical trial involving humans, which gave similar encouraging results. The Z-Lig® device has also been implanted in Italy at the Rizzoli Orthopaedic Institute in Bologna, as a part of international multicenter prospective randomized blinded controlled study aimed at comparing xenograft with allograft tissue. PMID:26605257

Behavior of deep flaws in a thick-wall cylinder under thermal shock loading

International Nuclear Information System (INIS)

Cheverton, R.D.

1979-01-01

Behavior of inner-surface flaws in thick-walled vessels was studied in a 991-mm OD x 152 mm wall x 1220 mm length cylinder with toughness properties similar to those for HSST Plate. The initial temperature of 93 0 C and a thermal shock medium of liquid nitrogen (-197 0 C) were employed. The initial flaw selected was a sharp, 16 mm deep, long (1220 mm) axial crack. Crack arrest methodology was shown to be valid for deep flaws under severe thermal shock

Progress Towards an LES Wall Model Including Unresolved Roughness

Science.gov (United States)

Craft, Kyle; Redman, Andrew; Aikens, Kurt

2015-11-01

Wall models used in large eddy simulations (LES) are often based on theories for hydraulically smooth walls. While this is reasonable for many applications, there are also many where the impact of surface roughness is important. A previously developed wall model has been used primarily for jet engine aeroacoustics. However, jet simulations have not accurately captured thick initial shear layers found in some experimental data. This may partly be due to nozzle wall roughness used in the experiments to promote turbulent boundary layers. As a result, the wall model is extended to include the effects of unresolved wall roughness through appropriate alterations to the log-law. The methodology is tested for incompressible flat plate boundary layers with different surface roughness. Correct trends are noted for the impact of surface roughness on the velocity profile. However, velocity deficit profiles and the Reynolds stresses do not collapse as well as expected. Possible reasons for the discrepancies as well as future work will be presented. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Computational resources on TACC Stampede were provided under XSEDE allocation ENG150001.

Unsteady MHD stagnation flow over a moving wall

International Nuclear Information System (INIS)

Kumari, M.; Nath, G.

2006-01-01

The unsteady viscous stagnation flow of an electrically conducting fluid over a continuously moving wall with an applied magnetic field has been investigated when the free stream and wall velocities increase arbitrarily with time. The flow is initially (t = 0) steady and at time t > 0, it becomes unsteady. The semi-similar solution of the unsteady Navier-Stokes equations along with the energy equation governing the flow and heat transfer has been obtained numerically. Also the self-similar solution is obtained when the surface and free stream velocities vary inversely as a linear function of time. The shear stress and the heat transfer increase with time and magnetic field. The surface shear stress vanishes for certain value of the ratio of the wall velocity to the free stream velocity. (author)

About Modern Graphic Reconstruction Wall Painting Of The Throne -Room Of Afrasiab

Directory of Open Access Journals (Sweden)

Sultanova Dilshoda

2015-07-01

Full Text Available Abstract In article are considered bases scientifically-creative reconstruction of pre-Islamic paintings hall of ambassadors of Afrasiab executed in interior foyer of institute of Archaeology RUZ.As a result of benchmark analysis modern painting with original museum of Afrasiab possible to define not before our days of a part and fragments in holistic type that is to say in beginning what looked before destruction arabic conqueror. Afrasiab paintings as specific facility more than 16 centuries is studied in our republic and has a questions which wait their own decisions.The author presents for the first time in picturesque manner to your attention its interpretation painting coming from its scientifically-creative experience.Given exploratory work possible consider as significant contribution to science on archaeology architecture and art.

The use of dermal autograft as an adjunct to breast reconstruction with tissue expanders.

Science.gov (United States)

Rinker, Brian

2012-12-01

Acellular dermal matrices are commonly used in breast reconstruction but add cost to the procedure and have been associated with complications. Dermal autograft may represent a useful alternative to matrices. Sixteen patients (26 breasts) underwent breast reconstruction using tissue expanders and dermal autograft. Their ages ranged from 41 to 66 years (median, 51 years). Autografts were harvested by wide excision of preexisting abdominal scars. Demographic data, clinical history, and harvest and preparation time were recorded. The initial fill volume, number of expansions, and complications were recorded and compared with published data for acellular dermal matrix-assisted reconstruction. Patients rated their satisfaction with scar appearance on a seven-point scale. Follow-up ranged from 6 to 16 months (mean, 10 months). Three patients were smokers. Mean body mass index was 30.5 (range, 19.1 to 48.8). Three patients received chemotherapy between reconstructive stages, and none required irradiation. The mean time of autograft harvest was 38 minutes, the mean initial fill was 190 cc, and the average number of expansions was 3.5. There were no implant losses. There were three minor complications (19 percent). Initial expander fill, number of expansions, and complication rate were equivalent to historical values for matrix-assisted breast reconstruction. Fourteen of 16 patients (88 percent) were "very satisfied" with their scars. The use of dermal autograft in tissue expander breast reconstruction offers the advantages of acellular dermal matrix, without the associated expense. The technique adds minimally to the operative time and morbidity and is associated with a low complication rate. Therapeutic, IV.

Imaging the Intracranial Atherosclerotic Vessel Wall Using 7T MRI : Initial Comparison with Histopathology

NARCIS (Netherlands)

van der Kolk, A. G.; Zwanenburg, J. J. M.; Denswil, N. P.; Vink, A.; Spliet, W. G. M.; Daemen, M. J. A. P.; Visser, F.; Klomp, D. W. J.; Luijten, P. R.; Hendrikse, J.

In this preliminary study, 7T imaging was capable of identifying not only intracranial wall thickening but different plaque components such as foamy macrophages and collagen. Signal heterogeneity was typical of advanced atherosclerotic disease. BACKGROUND AND PURPOSE: Several studies have attempted

Design, manufacture and initial operation of the beryllium components of the JET ITER-like wall

Energy Technology Data Exchange (ETDEWEB)

Riccardo, V., E-mail: valeria.riccardo@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Lomas, P.; Matthews, G.F. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Nunes, I. [Associação EURATOM-IST, IPFN – Laboratório Associado, IST, Lisbon (Portugal); JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Thompson, V. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Villedieu, E. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

2013-10-15

Highlights: ► 40 m{sup 2} of plasma facing surface covered with bulk Be re-using existing supports, designed for C-based tiles (hence for much lower disruption loads). ► Optimization of power handling to allow compatibility with higher (×1.5) and longer (×2) neutral beam power. ► Beryllium re-cycling. ► Machining and cleaning to ultra high vacuum standards of <350 μm thin castellations in Be. ► Quality control to minimize installation problems (proto-types, full scale jigs, inspections). -- Abstract: The aim of the JET ITER-like wall project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma facing components had to be compatible with increased heating power and pulse length, as well as to reuse the existing tile supports originally designed to cope with disruption loads from carbon based tiles and be installed by remote handling. Risk reduction measures (prototypes, jigs, etc.) were implemented to maximize efficiency during the shutdown. However, a large number of clashes with existing components not fully captured by the configuration model occurred. Restarting the plasma on the ITER-like Wall proved much easier than for the carbon wall and no deconditioning by disruptions was observed. Disruptions have been more threatening than expected due to the reduced radiative losses compared to carbon, leaving most of the plasma magnetic energy to be conducted to the wall and requiring routine disruption mitigation. The main chamber power handling has achieved and possibly exceeded the design targets.

Design, manufacture and initial operation of the beryllium components of the JET ITER-like wall

International Nuclear Information System (INIS)

Riccardo, V.; Lomas, P.; Matthews, G.F.; Nunes, I.; Thompson, V.; Villedieu, E.

2013-01-01

Highlights: ► 40 m 2 of plasma facing surface covered with bulk Be re-using existing supports, designed for C-based tiles (hence for much lower disruption loads). ► Optimization of power handling to allow compatibility with higher (×1.5) and longer (×2) neutral beam power. ► Beryllium re-cycling. ► Machining and cleaning to ultra high vacuum standards of <350 μm thin castellations in Be. ► Quality control to minimize installation problems (proto-types, full scale jigs, inspections). -- Abstract: The aim of the JET ITER-like wall project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma facing components had to be compatible with increased heating power and pulse length, as well as to reuse the existing tile supports originally designed to cope with disruption loads from carbon based tiles and be installed by remote handling. Risk reduction measures (prototypes, jigs, etc.) were implemented to maximize efficiency during the shutdown. However, a large number of clashes with existing components not fully captured by the configuration model occurred. Restarting the plasma on the ITER-like Wall proved much easier than for the carbon wall and no deconditioning by disruptions was observed. Disruptions have been more threatening than expected due to the reduced radiative losses compared to carbon, leaving most of the plasma magnetic energy to be conducted to the wall and requiring routine disruption mitigation. The main chamber power handling has achieved and possibly exceeded the design targets

Failure mode and fracture behavior evaluation of pipes with local wall thinning subjected to bending load

International Nuclear Information System (INIS)

Ahn, Seok Hwan; Nam, Ki Woo; Kim, Seon Jin; Kim, Jin Hwan; Kim, Hyun Soo; Do, Jae Yoon

2003-01-01

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe Erosion-Corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiating/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated

Association Mapping of Cell Wall Synthesis Regulatory Genes and Cell Wall Quality in Switchgrass

Energy Technology Data Exchange (ETDEWEB)

Bartley, Laura [Univ. of Oklahoma, Norman, OK (United States). Dept. of Microbiology and Plant Biology; Wu, Y. [Oklahoma State Univ., Stillwater, OK (United States); Zhu, L. [Oklahoma State Univ., Stillwater, OK (United States); Brummer, E. C. [Noble Foundation, Ardmore, OK (United States); Saha, M. [Noble Foundation, Ardmore, OK (United States)

2016-05-31

Inefficient conversion of biomass to biofuels is one of the main barriers for biofuel production from such materials. Approximately half of polysaccharides in biomass remain unused by typical biochemical conversion methods. Conversion efficiency is influenced by the composition and structure of cell walls of biomass. Grasses such as wheat, maize, and rice, as well as dedicated perennial bioenergy crops, like switchgrass, make up ~55% of biomass that can be produced in the United States. Grass cell walls have a different composition and patterning compared with dicotyledonous plants, including the well-studied model plant, Arabidopsis. This project identified genetic determinants of cell wall composition in grasses using both naturally occurring genetic variation of switchgrass and gene network reconstruction and functional assays in rice. In addition, the project linked functional data in rice and other species to switchgrass improvement efforts through curation of the most abundant class of regulators in the switchgrass genome. Characterizing natural diversity of switchgrass for variation in cell wall composition and properties, also known as quality, provides an unbiased avenue for identifying biologically viable diversity in switchgrass cell walls. To characterizing natural diversity, this project generated cell wall composition and enzymatic deconstruction data for ~450 genotypes of the Switchgrass Southern Association Collection (SSAC), a diverse collection composed of 36 switchgrass accessions from the southern U.S. distribution of switchgrass. Comparing these data with other measures of cell wall quality for the same samples demonstrated the complementary nature of the diverse characterization platforms now being used for biomass characterization. Association of the composition data with ~3.2K single nucleotide variant markers identified six significant single nucleotide variant markers co-associated with digestibility and another compositional trait. These

Algorithm Validation of the Current Profile Reconstruction of EAST Based on Polarimeter/Interferometer

International Nuclear Information System (INIS)

Qian Jinping; Ren Qilong; Wan Baonian; Liu Haiqin; Zeng Long; Luo Zhengping; Chen Dalong; Shi Tonghui; Sun Youwen; Shen Biao; Xiao Bingjia; Lao, L. L.; Hanada, K.

2015-01-01

The method of plasma current profile reconstruction using the polarimeter/interferometer (POINT) data from a simulated equilibrium is explored and validated. It is shown that the safety factor (q) profile can be generally reconstructed from the external magnetic and POINT data. The reconstructed q profile is found to reasonably agree with the initial equilibriums. Comparisons of reconstructed q and density profiles using the magnetic data and the POINT data with 3%, 5% and 10% random errors are investigated. The result shows that the POINT data could be used to a reasonably accurate determination of the q profile. (fusion engineering)

Wall-attached structures of streamwise velocity fluctuations in turbulent boundary layer

Science.gov (United States)

Hwang, Jinyul; Sung, Hyung Jin

2017-11-01

The wall-attached structures of streamwise velocity fluctuations (u) are explored using direct numerical simulation data of turbulent boundary layer at Reτ = 1000 . We identify the structures of u, which are extended close to the wall. Their height (ly) ranges from the near-wall region to the edge of turbulent boundary layer. They are geometrically self-similar in a sense that the length and width of the structures are proportional to the distance from the wall. The population density of the attached structures shows that the tall attached structures (290 wall. The wall-attached structures of u identified in the present work are a proper candidate for Townsend's attached eddy hypothesis and these structures exist in the low Reynolds number turbulent boundary layer. This work was supported by the Creative Research Initiatives (No. 2017-013369) program of the National Research Foundation of Korea (MSIP) and supported by the Supercomputing Center (KISTI).

Reconstruction of bremsstrahlung spectra from attenuation data using generalized simulated annealing

International Nuclear Information System (INIS)

Menin, O.H.; Martinez, A.S.; Costa, A.M.

2016-01-01

A generalized simulated annealing algorithm, combined with a suitable smoothing regularization function is used to solve the inverse problem of X-ray spectrum reconstruction from attenuation data. The approach is to set the initial acceptance and visitation temperatures and to standardize the terms of objective function to automate the algorithm to accommodate different spectra ranges. Experiments with both numerical and measured attenuation data are presented. Results show that the algorithm reconstructs spectra shapes accurately. It should be noted that in this algorithm, the regularization function was formulated to guarantee a smooth spectrum, thus, the presented technique does not apply to X-ray spectrum where characteristic radiation are present. - Highlights: • X-ray spectra reconstruction from attenuation data using generalized simulated annealing. • Algorithm employs a smoothing regularization function, and sets the initial acceptance and visitation temperatures. • Algorithmic is automated by standardizing the terms of the objective function. • Algorithm is compared with classical methods.

Virtual 3D bladder reconstruction for augmented medical records from white light cystoscopy (Conference Presentation)

Science.gov (United States)

Lurie, Kristen L.; Zlatev, Dimitar V.; Angst, Roland; Liao, Joseph C.; Ellerbee, Audrey K.

2016-02-01

Bladder cancer has a high recurrence rate that necessitates lifelong surveillance to detect mucosal lesions. Examination with white light cystoscopy (WLC), the standard of care, is inherently subjective and data storage limited to clinical notes, diagrams, and still images. A visual history of the bladder wall can enhance clinical and surgical management. To address this clinical need, we developed a tool to transform in vivo WLC videos into virtual 3-dimensional (3D) bladder models using advanced computer vision techniques. WLC videos from rigid cystoscopies (1280 x 720 pixels) were recorded at 30 Hz followed by immediate camera calibration to control for image distortions. Video data were fed into an automated structure-from-motion algorithm that generated a 3D point cloud followed by a 3D mesh to approximate the bladder surface. The highest quality cystoscopic images were projected onto the approximated bladder surface to generate a virtual 3D bladder reconstruction. In intraoperative WLC videos from 36 patients undergoing transurethral resection of suspected bladder tumors, optimal reconstruction was achieved from frames depicting well-focused vasculature, when the bladder was maintained at constant volume with minimal debris, and when regions of the bladder wall were imaged multiple times. A significant innovation of this work is the ability to perform the reconstruction using video from a clinical procedure collected with standard equipment, thereby facilitating rapid clinical translation, application to other forms of endoscopy and new opportunities for longitudinal studies of cancer recurrence.

Enhanced dielectric-wall linear accelerator

Science.gov (United States)

Sampayan, Stephen E.; Caporaso, George J.; Kirbie, Hugh C.

1998-01-01

A dielectric-wall linear accelerator is enhanced by a high-voltage, fast e-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.

Two Complementary Mechanisms Underpin Cell Wall Patterning during Xylem Vessel Development.

Science.gov (United States)

Schneider, Rene; Tang, Lu; Lampugnani, Edwin R; Barkwill, Sarah; Lathe, Rahul; Zhang, Yi; McFarlane, Heather E; Pesquet, Edouard; Niittyla, Totte; Mansfield, Shawn D; Zhou, Yihua; Persson, Staffan

2017-10-01

The evolution of the plant vasculature was essential for the emergence of terrestrial life. Xylem vessels are solute-transporting elements in the vasculature that possess secondary wall thickenings deposited in intricate patterns. Evenly dispersed microtubule (MT) bands support the formation of these wall thickenings, but how the MTs direct cell wall synthesis during this process remains largely unknown. Cellulose is the major secondary wall constituent and is synthesized by plasma membrane-localized cellulose synthases (CesAs) whose catalytic activity propels them through the membrane. We show that the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1)/POM2 is necessary to align the secondary wall CesAs and MTs during the initial phase of xylem vessel development in Arabidopsis thaliana and rice ( Oryza sativa ). Surprisingly, these MT-driven patterns successively become imprinted and sufficient to sustain the continued progression of wall thickening in the absence of MTs and CSI1/POM2 function. Hence, two complementary principles underpin wall patterning during xylem vessel development. © 2017 American Society of Plant Biologists. All rights reserved.

War damages and reconstruction of Peruca dam

International Nuclear Information System (INIS)

Nonveiller, E.; Sever, Z.

1999-01-01

The paper describes the heavy damages caused by blasting in the Peruca rockfill dam in Croatia in January 1993. Complete collapse of the dam by overtopping was prevented through quick action of the dam owner by dumping clayey gravel on the lowest sections of the dam crest and opening the bottom outlet of the reservoir, thus efficiently lowering the water level. After the damages were sufficiently established and alternatives for restoration of the dam were evaluated, it was decided to construct a diaphragm wall through the damaged core in the central dam part as the impermeable dam element and to rebuild the central clay core at the dam abutments. Reconstruction works are described

3D SURVEY AND AUGMENTED REALITY FOR CULTURAL HERITAGE. THE CASE STUDY OF AURELIAN WALL AT CASTRA PRAETORIA IN ROME

Directory of Open Access Journals (Sweden)

M. Canciani

2016-06-01

Full Text Available The development of close-range photogrammetry has produced a lot of new possibility to study cultural heritage. 3D data acquired with conventional and low cost cameras can be used to document, investigate the full appearance, materials and conservation status, to help the restoration process and identify intervention priorities. At the same time, with 3D survey a lot of three-dimensional data are collected and analyzed by researchers, but there are a very few possibility of 3D output. The augmented reality is one of this possible output with a very low cost technology but a very interesting result. Using simple mobile technology (for iPad and Android Tablets and shareware software (in the case presented “Augment” it is possible to share and visualize a large number of 3D models with your own device. The case study presented is a part of an architecture graduate thesis, made in Rome at Department of Architecture of Roma Tre University. We have developed a photogrammetric survey to study the Aurelian Wall at Castra Praetoria in Rome. The surveys of 8000 square meters of surface have allowed to identify stratigraphy and construction phases of a complex portion of Aurelian Wall, specially about the Northern door of Castra. During this study, the data coming out of 3D survey (photogrammetric and topographic, are stored and used to create a reverse 3D model, or virtual reconstruction, of the Northern door of Castra. This virtual reconstruction shows the door in the Tiberian period, nowadays it's totally hidden by a curtain wall but, little and significative architectural details allow to know its original feature. The 3D model of the ancient walls has been mapped with the exact type of bricks and mortar, oriented and scaled according to the existing one to use augmented reality. Finally, two kind of application have been developed, one on site, were you can see superimposed the virtual reconstruction on the existing walls using the image

Characteristics of wall pressure over wall with permeable coating

Energy Technology Data Exchange (ETDEWEB)

Song, Woo Seog; Shin, Seungyeol; Lee, Seungbae [Inha Univ., Incheon (Korea, Republic of)

2012-11-15

Fluctuating wall pressures were measured using an array of 16 piezoelectric transducers beneath a turbulent boundary layer. The coating used in this experiment was an open cell, urethane type foam with a porosity of approximately 50 ppi. The ultimate objective of the coating is to provide a mechanical filter to reduce the wall pressure fluctuations. The ultimate objective of the coating is to provide a mechanical filter to reduce the wall pressure fluctuations. The boundary layer on the flat plate was measured by using a hot wire probe, and the CPM method was used to determine the skin friction coefficient. The wall pressure autospectra and streamwise wavenumber frequency spectra were compared to assess the attenuation of the wall pressure field by the coating. The coating is shown to attenuate the convective wall pressure energy. However, the relatively rough surface of the coating in this investigation resulted in a higher mean wall shear stress, thicker boundary layer, and higher low frequency wall pressure spectral levels compared to a smooth wall.

Mastectomy Skin Necrosis After Breast Reconstruction: A Comparative Analysis Between Autologous Reconstruction and Implant-Based Reconstruction.

Science.gov (United States)

Sue, Gloria R; Lee, Gordon K

2018-05-01

Mastectomy skin necrosis is a significant problem after breast reconstruction. We sought to perform a comparative analysis on this complication between patients undergoing autologous breast reconstruction and patients undergoing 2-stage expander implant breast reconstruction. A retrospective review was performed on consecutive patients undergoing autologous breast reconstruction or 2-stage expander implant breast reconstruction by the senior author from 2006 through 2015. Patient demographic factors including age, body mass index, history of diabetes, history of smoking, and history of radiation to the breast were collected. Our primary outcome measure was mastectomy skin necrosis. Fisher exact test was used for statistical analysis between the 2 patient cohorts. The treatment patterns of mastectomy skin necrosis were then analyzed. We identified 204 patients who underwent autologous breast reconstruction and 293 patients who underwent 2-stage expander implant breast reconstruction. Patients undergoing autologous breast reconstruction were older, heavier, more likely to have diabetes, and more likely to have had prior radiation to the breast compared with patients undergoing implant-based reconstruction. The incidence of mastectomy skin necrosis was 30.4% of patients in the autologous group compared with only 10.6% of patients in the tissue expander group (P care in the autologous group, only 3.2% were treated with local wound care in the tissue expander group (P skin necrosis is significantly more likely to occur after autologous breast reconstruction compared with 2-stage expander implant-based breast reconstruction. Patients with autologous reconstructions are more readily treated with local wound care compared with patients with tissue expanders, who tended to require operative treatment of this complication. Patients considering breast reconstruction should be counseled appropriately regarding the differences in incidence and management of mastectomy skin

Scrotal reconstruction with superomedial fasciocutaneous thigh flap

Directory of Open Access Journals (Sweden)

DANIEL FRANCISCO MELLO

2018-02-01

Full Text Available ABSTRACT Objective: to describe the use of a superomedial fasciocutaneous thigh flap for scrotal reconstruction in open areas secondary to the surgical treatment of perineal necrotizing fasciitis (Fournier’s gangrene. Methods: retrospective analysis of cases treated at the Plastic Surgery Service of Santa Casa de Misericórdia, São Paulo, from 2009 to 2015. Results: fifteen patients underwent scrotal reconstruction using the proposed flap. The mean age was 48.9 years (28 to 66. Skin loss estimates in the scrotal region ranged from 60 to 100%. Definitive reconstruction was performed on average 30.6 days (22 to 44 after the initial surgical treatment. The mean surgical time was 76 minutes (65 to 90 to obtain the flaps, bilateral in all cases. Flap size ranged from 10cm to 13cm in the longitudinal direction and 8cm to 10cm in the cross-sectional direction. The complication rate was 26.6% (four cases, related to the occurrence of segmental and partial dehiscence. Conclusion: the superomedial fasciocutaneous flap of thigh is a reliable and versatile option for the reconstruction of open areas in the scrotal region, showing adequate esthetic and functional results.

Immunocytochemical characterization of the cell walls of bean cell suspensions during habituation and dehabituation to dichlobenil

DEFF Research Database (Denmark)

Garcia-Angulo, P.; Willats, W. G. T.; Encina, A. E.

2006-01-01

The effects of the cellulose inhibitor dichlobenil on the cell wall composition and structure during the habituation/dehabituation process of suspension-cultured bean cells were assessed. A range of techniques were used including cell wall fractionation, sugar analysis, immunofluorescence...... and fluorochrome labelling of resin-embedded sections, and immunodot assays (IDAs) of cell wall fractions. The cell walls from bean cell suspensions with initial levels of habituation to dichlobenil had decreased levels of cellulose, but this effect lessened with increasing numbers of subcultures. All cell walls...

A comparison of hydrogen vs. helium glow discharge effects on fusion device first-wall conditioning

International Nuclear Information System (INIS)

Dylla, H.F.

1989-09-01

Hydrogen- and deuterium-fueled glow discharges are used for the initial conditioning of magnetic fusion device vacuum vessels following evacuation from atmospheric pressure. Hydrogenic glow discharge conditioning (GDC) significantly reduces the near-surface concentration of simple adsorbates, such as H 2 O, CO, and CH 4 , and lowers ion-induced desorption coefficients by typically three orders of magnitude. The time evolution of the residual gas production observed during hydrogen-glow discharge conditioning of the carbon first-wall structure of the TFTR device is similar to the time evolution observed during hydrogen GDC of the initial first-wall configuration in TFTR, which was primarily stainless steel. Recently, helium GDC has been investigated for several wall-conditioning tasks on a number of tokamaks including TFTR. Helium GDC shows negligible impurity removal with stainless steel walls. For impurity conditioning with carbon walls, helium GDC shows significant desorption of H 2 O, CO, and CO 2 ; however, the total desorption yield is limited to the monolayer range. In addition, helium GDC can be used to displace hydrogen isotopes from the near-surface region of carbon first-walls in order to lower hydrogenic retention and recycling. 38 refs., 6 figs

Reconstruction of Defects After Fournier Gangrene: A Systematic Review.

Science.gov (United States)

Karian, Laurel S; Chung, Stella Y; Lee, Edward S

2015-01-01

Reconstruction of scrotal defects after Fournier gangrene is often achieved with skin grafts or flaps, but there is no general consensus on the best method of reconstruction or how to approach the exposed testicle. We systematically reviewed the literature addressing methods of reconstruction of Fournier defects after debridement. PubMed and Cochrane databases were searched from 1950 to 2013. Inclusion criteria were reconstruction for Fournier defects, patients 18 to 90 years old, and reconstructive complication rates reported as whole numbers or percentages. Exclusion criteria were studies focused on methods of debridement or other phases of care rather than reconstruction, studies with fewer than 5 male patients with Fournier defects, literature reviews, and articles not in English. The initial search yielded 982 studies, which was refined to 16 studies with a total pool of 425 patients. There were 25 (5.9%) patients with defects that healed by secondary intention, 44 (10.4%) with delayed primary closure, 36 (8.5%) with implantation of the testicle in a medial thigh pocket, 6 (1.4%) with loose wound approximation, 96 (22.6%) with skin grafts, 68 (16.0%) with scrotal advancement flaps, 128 (30.1%) with flaps, and 22 (5.2%) with flaps or skin grafts in combination with tissue adhesives. Four outcomes were evaluated: number of patients, defect size, method of reconstruction, and wound-healing complications. Most reconstructive techniques provide reliable coverage and protection of testicular function with an acceptable cosmetic result. There is no conclusive evidence to support flap coverage of exposed testes rather than skin graft. A reconstructive algorithm is proposed. Skin grafting or flap reconstruction is recommended for defects larger than 50% of the scrotum or extending beyond the scrotum, whereas scrotal advancement flap reconstruction or healing by secondary intention is best for defects confined to less than 50% of the scrotum that cannot be closed

Correlation between vortices and wall shear stress in a curved artery model under pulsatile flow conditions

Science.gov (United States)

Cox, Christopher; Plesniak, Michael W.

2017-11-01

One of the most physiologically relevant factors within the cardiovascular system is the wall shear stress. The wall shear stress affects endothelial cells via mechanotransduction and atherosclerotic regions are strongly correlated with curvature and branching in the human vasculature, where the shear stress is both oscillatory and multidirectional. Also, the combined effect of curvature and pulsatility in cardiovascular flows produces unsteady vortices. In this work, our goal is to assess the correlation between multiple vortex pairs and wall shear stress. To accomplish this, we use an in-house high-order flux reconstruction Navier-Stokes solver to simulate pulsatile flow of a Newtonian blood-analog fluid through a rigid 180° curved artery model. We use a physiologically relevant flow rate and generate results using both fully developed and uniform entrance conditions, the latter motivated by the fact that flow upstream to a curved artery may not be fully developed. Under these two inflow conditions, we characterize the evolution of various vortex pairs and their subsequent effect on several wall shear stress metrics. Supported by GW Center for Biomimetics and Bioinspired Engineering.

Fournier gangrene: a review of 41 patients and strategies for reconstruction.

Science.gov (United States)

Chen, Shih-Yi; Fu, Ju-Peng; Wang, Chih-Hsin; Lee, Tzu-Peng; Chen, Shyi-Gen

2010-06-01

Fournier gangrene is an acute and potentially fatal infection of the scrotum, perineum, and abdominal wall. It is characterized by necrotizing fasciitis with loss of subcutaneous tissue and skin. The aim of this study was to analyze the prognosis and treatment effectiveness of this fulminant infectious disease. Forty-one patients were admitted to our hospital with the diagnosis of Fournier gangrene between January 1998 and December 2006. The patients' age, sex, predisposing factors, duration of symptoms and hospital stay, time to operation, size of the skin defect, bacteria isolated, treatment modalities, and outcomes were reviewed. The data were analyzed by chi2 analysis and Student t test. A P-value Fournier gangrene undergoing debridement and reconstructive procedure. Because of the fulminant course of Fournier gangrene, it may be difficult to design a prospective study. Fournier gangrene is a severe infectious disease with a high mortality rate. Early and aggressive debridement is a significant prognostic factor in the management of Fournier gangrene. Several reconstructive modalities are useful to correct the tissue defect. Early debridement and reconstructive surgery for wound coverage improve the quality of life.

Reconstruction of 3D flow structures in a cylindrical cavity with a rotating lid using time-resolved stereo PIV

DEFF Research Database (Denmark)

Meyer, Knud Erik; Sørensen, Jens Nørkær; Naumov, Igor

2009-01-01

variations. The flow in a cylindrical cavity with a rotating lid of a height of three radii and a Reynolds number of about 3500 is used as example. The reconstruction identifies a series of flow structures including axisymmetric vortex breakdown and distinct vortex structures along the cylinder wall....

What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction?

Science.gov (United States)

Köckerling, F; Alam, N N; Antoniou, S A; Daniels, I R; Famiglietti, F; Fortelny, R H; Heiss, M M; Kallinowski, F; Kyle-Leinhase, I; Mayer, F; Miserez, M; Montgomery, A; Morales-Conde, S; Muysoms, F; Narang, S K; Petter-Puchner, A; Reinpold, W; Scheuerlein, H; Smietanski, M; Stechemesser, B; Strey, C; Woeste, G; Smart, N J

2018-04-01

Although many surgeons have adopted the use of biologic and biosynthetic meshes in complex abdominal wall hernia repair, others have questioned the use of these products. Criticism is addressed in several review articles on the poor standard of studies reporting on the use of biologic meshes for different abdominal wall repairs. The aim of this consensus review is to conduct an evidence-based analysis of the efficacy of biologic and biosynthetic meshes in predefined clinical situations. A European working group, "BioMesh Study Group", composed of invited surgeons with a special interest in surgical meshes, formulated key questions, and forwarded them for processing in subgroups. In January 2016, a workshop was held in Berlin where the findings were presented, discussed, and voted on for consensus. Findings were set out in writing by the subgroups followed by consensus being reached. For the review, 114 studies and background analyses were used. The cumulative data regarding biologic mesh under contaminated conditions do not support the claim that it is better than synthetic mesh. Biologic mesh use should be avoided when bridging is needed. In inguinal hernia repair biologic and biosynthetic meshes do not have a clear advantage over the synthetic meshes. For prevention of incisional or parastomal hernias, there is no evidence to support the use of biologic/biosynthetic meshes. In complex abdominal wall hernia repairs (incarcerated hernia, parastomal hernia, infected mesh, open abdomen, enterocutaneous fistula, and component separation technique), biologic and biosynthetic meshes do not provide a superior alternative to synthetic meshes. The routine use of biologic and biosynthetic meshes cannot be recommended.

Reinforcement mechanism of multi-anchor wall with double wall facing

Science.gov (United States)

Suzuki, Kouta; Kobayashi, Makoto; Miura, Kinya; Konami, Takeharu; Hayashi, Taketo

2017-10-01

The reinforced soil wall has high seismic performance as generally known. However, the seismic behavior has not been clarified accurately yet, especially on multi-anchor wall with double wall facing. Indefinite behavior of reinforced soil wall during earthquake make us complicated in case with adopting to the abutment, because of arrangement of anchor plate as reinforcement often different according to the width of roads. In this study, a series of centrifuge model tests were carried out to investigate the reinforcement mechanism of multi anchor wall with double wall facing from the perspective of the vertical earth pressure. Several types of reinforce arrangement and rigid wall were applied in order to verify the arch function in the reinforced regions. The test results show unique behavior of vertical earth pressure, which was affected by arch action. All the vertical earth pressure placed behind facing panel, are larger than that of middle part between facing panel despite of friction between backfill and facing panel. Similar results were obtained in case using rigid wall. On the other hands, the vertical earth pressure, which were measured at the 3cm high from bottom of model container, shows larger than that of bottom. This results show the existence of arch action between double walls. In addition, it implies that the wall facing of such soil structure confined the backfill as pseudo wall, which is very reason that the multi anchor wall with double wall facing has high seismic performance.

Effects of point configuration on the accuracy in 3D reconstruction from biplane images

International Nuclear Information System (INIS)

Dmochowski, Jacek; Hoffmann, Kenneth R.; Singh, Vikas; Xu Jinhui; Nazareth, Daryl P.

2005-01-01

Two or more angiograms are being used frequently in medical imaging to reconstruct locations in three-dimensional (3D) space, e.g., for reconstruction of 3D vascular trees, implanted electrodes, or patient positioning. A number of techniques have been proposed for this task. In this simulation study, we investigate the effect of the shape of the configuration of the points in 3D (the 'cloud' of points) on reconstruction errors for one of these techniques developed in our laboratory. Five types of configurations (a ball, an elongated ellipsoid (cigar), flattened ball (pancake), flattened cigar, and a flattened ball with a single distant point) are used in the evaluations. For each shape, 100 random configurations were generated, with point coordinates chosen from Gaussian distributions having a covariance matrix corresponding to the desired shape. The 3D data were projected into the image planes using a known imaging geometry. Gaussian distributed errors were introduced in the x and y coordinates of these projected points. Gaussian distributed errors were also introduced into the gantry information used to calculate the initial imaging geometry. The imaging geometries and 3D positions were iteratively refined using the enhanced-Metz-Fencil technique. The image data were also used to evaluate the feasible R-t solution volume. The 3D errors between the calculated and true positions were determined. The effects of the shape of the configuration, the number of points, the initial geometry error, and the input image error were evaluated. The results for the number of points, initial geometry error, and image error are in agreement with previously reported results, i.e., increasing the number of points and reducing initial geometry and/or image error, improves the accuracy of the reconstructed data. The shape of the 3D configuration of points also affects the error of reconstructed 3D configuration; specifically, errors decrease as the 'volume' of the 3D configuration

Qualitative Reliability Issues for Solid and Liquid Wall Fusion Design

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, Lee Charles

2001-01-01

This report is an initial effort to identify issues affecting reliability and availability of solid and liquid wall designs for magnetic fusion power plant designs. A qualitative approach has been used to identify the possible failure modes of major system components and their effects on the systems. A general set of design attributes known to affect the service reliability has been examined for the overview solid and liquid wall designs, and some specific features of good first wall design have been discussed and applied to these designs as well. The two generalized designs compare well in regard to these design attributes. The strengths and weaknesses of each design approach are seen in the comparison of specific features.

Qualitative Reliability Issues for Solid and Liquid Wall Fusion Designs

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, L.C.

2001-01-31

This report is an initial effort to identify issues affecting reliability and availability of solid and liquid wall designs for magnetic fusion power plant designs. A qualitative approach has been used to identify the possible failure modes of major system components and their effects on the systems. A general set of design attributes known to affect the service reliability has been examined for the overview solid and liquid wall designs, and some specific features of good first wall design have been discussed and applied to these designs as well. The two generalized designs compare well in regard to these design attributes. The strengths and weaknesses of each design approach are seen in the comparison of specific features.

Qualitative Reliability Issues for Solid and Liquid Wall Fusion Designs

International Nuclear Information System (INIS)

Cadwallader, L.C.

2001-01-01

This report is an initial effort to identify issues affecting reliability and availability of solid and liquid wall designs for magnetic fusion power plant designs. A qualitative approach has been used to identify the possible failure modes of major system components and their effects on the systems. A general set of design attributes known to affect the service reliability has been examined for the overview solid and liquid wall designs, and some specific features of good first wall design have been discussed and applied to these designs as well. The two generalized designs compare well in regard to these design attributes. The strengths and weaknesses of each design approach are seen in the comparison of specific features

Dual-source CT cardiac imaging: initial experience

International Nuclear Information System (INIS)

Johnson, Thorsten R.C.; Nikolaou, Konstantin; Wintersperger, Bernd J.; Rist, Carsten; Buhmann, Sonja; Reiser, Maximilian F.; Becker, Christoph R.; Leber, Alexander W.; Ziegler, Franz von; Knez, Andreas

2006-01-01

The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24±0.42 for the right and 1.09±0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible. (orig.)

An approximate method for lateral stability analysis of wall-frame ...

Indian Academy of Sciences (India)

Initially the stability differential equation of this equivalent sandwich beam is ... buckling loads of coupled shear-wall structures using continuous medium ... In this study, an approximate method based on continuum system model and transfer.

Near wall turbulence: An experimental view

Science.gov (United States)

Stanislas, Michel

2017-10-01

The present paper draws upon the experience of the author to illustrate the potential of advanced optical metrology for understanding near-wall-turbulence physics. First the canonical flat plate boundary layer problem is addressed, initially very near to the wall and then in the outer region when the Reynolds number is high enough to generate an outer turbulence peak. The coherent structure organization is examined in detail with the help of stereoscopic particle image velocimetry (PIV). Then the case of a turbulent boundary layer subjected to a mild adverse pressure gradient is considered. The results obtained show the great potential of a joint experimental-numerical approach. The conclusion is that the insight provided by today's optical metrology opens the way for significant improvements in turbulence modeling in upcoming years.

Reduction in Left Ventricular Wall Stress and Improvement in Function in Failing Hearts using Algisyl-LVR

Science.gov (United States)

Lee, Lik Chuan; Zhihong, Zhang; Hinson, Andrew; Guccione, Julius M.

2013-01-01

Injection of Algisyl-LVR, a treatment under clinical development, is intended to treat patients with dilated cardiomyopathy. This treatment was recently used for the first time in patients who had symptomatic heart failure. In all patients, cardiac function of the left ventricle (LV) improved significantly, as manifested by consistent reduction of the LV volume and wall stress. Here we describe this novel treatment procedure and the methods used to quantify its effects on LV wall stress and function. Algisyl-LVR is a biopolymer gel consisting of Na+-Alginate and Ca2+-Alginate. The treatment procedure was carried out by mixing these two components and then combining them into one syringe for intramyocardial injections. This mixture was injected at 10 to 19 locations mid-way between the base and apex of the LV free wall in patients. Magnetic resonance imaging (MRI), together with mathematical modeling, was used to quantify the effects of this treatment in patients before treatment and at various time points during recovery. The epicardial and endocardial surfaces were first digitized from the MR images to reconstruct the LV geometry at end-systole and at end-diastole. Left ventricular cavity volumes were then measured from these reconstructed surfaces. Mathematical models of the LV were created from these MRI-reconstructed surfaces to calculate regional myofiber stress. Each LV model was constructed so that 1) it deforms according to a previously validated stress-strain relationship of the myocardium, and 2) the predicted LV cavity volume from these models matches the corresponding MRI-measured volume at end-diastole and end-systole. Diastolic filling was simulated by loading the LV endocardial surface with a prescribed end-diastolic pressure. Systolic contraction was simulated by concurrently loading the endocardial surface with a prescribed end-systolic pressure and adding active contraction in the myofiber direction. Regional myofiber stress at end-diastole and

Scattered and Fluorescent Photon Track Reconstruction in a Biological Tissue

Directory of Open Access Journals (Sweden)

Maria N. Kholodtsova

2014-01-01

Full Text Available Appropriate analysis of biological tissue deep regions is important for tumor targeting. This paper is concentrated on photons’ paths analysis in such biotissue as brain, because optical probing depth of fluorescent and excitation radiation differs. A method for photon track reconstruction was developed. Images were captured focusing on the transparent wall close and parallel to the source fibres, placed in brain tissue phantoms. The images were processed to reconstruct the photons most probable paths between two fibres. Results were compared with Monte Carlo simulations and diffusion approximation of the radiative transfer equation. It was shown that the excitation radiation optical probing depth is twice more than for the fluorescent photons. The way of fluorescent radiation spreading was discussed. Because of fluorescent and excitation radiation spreads in different ways, and the effective anisotropy factor, geff, was proposed for fluorescent radiation. For the brain tissue phantoms it were found to be 0.62±0.05 and 0.66±0.05 for the irradiation wavelengths 532 nm and 632.8 nm, respectively. These calculations give more accurate information about the tumor location in biotissue. Reconstruction of photon paths allows fluorescent and excitation probing depths determination. The geff can be used as simplified parameter for calculations of fluorescence probing depth.

Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

Energy Technology Data Exchange (ETDEWEB)

Braden, Jonathan [CITA, University of Toronto,60 St. George Street, Toronto, ON, M5S 3H8 (Canada); Department of Physics, University of Toronto,60 St. George Street, Toronto, ON, M5S 3H8 (Canada); Department of Physics and Astronomy, University College London,Gower Street, London, WC1E 6BT (United Kingdom); Bond, J. Richard [CITA, University of Toronto,60 St. George Street, Toronto, ON, M5S 3H8 (Canada); Mersini-Houghton, Laura [Department of Physics and Astronomy, University of North Carolina-Chapel Hill,1 Phillips Hall, 120 E. Cameron Avenue, Chapel Hill, NC 27599-3255 (United States)

2015-08-26

We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

Energy Technology Data Exchange (ETDEWEB)

Braden, Jonathan; Bond, J. Richard [CITA, University of Toronto, 60 St. George Street, Toronto, ON, M5S 3H8 (Canada); Mersini-Houghton, Laura, E-mail: j.braden@ucl.ac.uk, E-mail: bond@cita.utoronto.ca, E-mail: mersini@physics.unc.edu [Department of Physics and Astronomy, University of North Carolina-Chapel Hill, 1 Phillips Hall, 120 E. Cameron Avenue, Chapel Hill, NC 27599-3255 (United States)

2015-08-01

We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation.

Cosmic bubble and domain wall instabilities II: fracturing of colliding walls

International Nuclear Information System (INIS)

Braden, Jonathan; Bond, J. Richard; Mersini-Houghton, Laura

2015-01-01

We study collisions between nearly planar domain walls including the effects of small initial nonplanar fluctuations. These perturbations represent the small fluctuations that must exist in a quantum treatment of the problem. In a previous paper, we demonstrated that at the linear level a subset of these fluctuations experience parametric amplification as a result of their coupling to the planar symmetric background. Here we study the full three-dimensional nonlinear dynamics using lattice simulations, including both the early time regime when the fluctuations are well described by linear perturbation theory as well as the subsequent stage of fully nonlinear evolution. We find that the nonplanar fluctuations have a dramatic effect on the overall evolution of the system. Specifically, once these fluctuations begin to interact nonlinearly the split into a planar symmetric part of the field and the nonplanar fluctuations loses its utility. At this point the colliding domain walls dissolve, with the endpoint of this being the creation of a population of oscillons in the collision region. The original (nearly) planar symmetry has been completely destroyed at this point and an accurate study of the system requires the full three-dimensional simulation

The effect of iterative reconstruction on computed tomography assessment of emphysema, air trapping and airway dimensions

International Nuclear Information System (INIS)

Mets, Onno M.; Willemink, Martin J.; Kort, Freek P.L. de; Leiner, Tim; Jong, Pim A. de; Mol, Christian P.; Oudkerk, Matthijs; Prokop, Mathias

2012-01-01

To determine the influence of iterative reconstruction (IR) on quantitative computed tomography (CT) measurements of emphysema, air trapping, and airway wall and lumen dimensions, compared to filtered back-projection (FBP). Inspiratory and expiratory chest CTs of 75 patients (37 male, 38 female; mean age 64.0 ± 5.7 years) were reconstructed using FBP and IR. CT emphysema, CT air trapping and airway dimensions of a segmental bronchus were quantified using several commonly used quantification methods. The two algorithms were compared using the concordance correlation coefficient (p c ) and Wilcoxon signed rank test. Only the E/I-ratio MLD as a measure of CT air trapping and airway dimensions showed no significant differences between the algorithms, whereas all CT emphysema and the other CT air trapping measures were significantly different at IR when compared to FBP (P MLD as a measure of CT air trapping, as well as the airway measurements, is unaffected by this reconstruction method. Quantitative CT of the lungs should be performed with careful attention to the CT protocol, especially when iterative reconstruction is introduced. (orig.)

Giant desmoid tumour of the thorax following latissimus dorsi and implant breast reconstruction: case report and review of the literature

LENUS (Irish Health Repository)

Collins, AM

2017-03-01

The case of a giant thoracic desmoid tumour in a 44-year-old woman, who presented two years following a breast reconstruction with a latissimus dorsi (LD) flap and implant, is reported. Clinical findings included a rapidly growing, painless mass. Computed tomography (CT) suggested skin and intercostal soft tissue invasion. The tumour was resected en bloc with the LD muscle, implant capsule and underlying rib segments. The resultant thoracic and abdominal wall defects were reconstructed with Dualmesh® and polypropylene meshes respectively. There was no evidence of recurrence at thirty-six months follow-up.

Diffusion archeology for diffusion progression history reconstruction.

Science.gov (United States)

Sefer, Emre; Kingsford, Carl

2016-11-01

Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.

A fundamental study of fission product deposition on the wall surface

International Nuclear Information System (INIS)

Ishiguro, R.; Sakashita, H.; Sugiyama, K.

1987-01-01

Deposition of soluble matters on wall surfaces is studied in the present report for the purpose to understand a mechanism of fission product deposition on the wall surface in a molten salt reactor. Calcium carbonate solution is used to observe the fundamental mechanism of deposition. The experiments are performed under conditions of turbulent flow of the solution over a heated wall. According to the experimental results a model is proposed to estimate deposition rate. The model consists of two parts, one is the initial nucleus formation on a clean wall surface and the other is the constant increase of deposition succeeding to the first stage. The model is assessed by comparing it with the experimental results. Both results coincide well in some parameters, but not so well in others. (author)

Psychosocial reconstruction inventory : a postdictal instrument in aircraft accident investigation.

Science.gov (United States)

1972-01-01

A new approach to the investigation of aviation accidents has recently been initiated, utilizing a follow-on to the psychological autopsy. This approach, the psychosocial reconstruction inventory, enables the development of a dynamic, retrospective p...

Two dimensional fall of granular columns controlled by slow horizontal withdrawal of a retaining wall

Science.gov (United States)

Mériaux, Catherine

2006-09-01

This paper describes a series of experiments designed to investigate the fall of granular columns in a quasi-static regime. Columns made of alternatively green and red sand layers were initially laid out in a box and then released when a retaining wall was set in slow motion with constant speed. The dependence of the dynamics of the fall on the initial aspect ratio of the columns, the velocity of the wall, and the material properties was investigated within the quasi-static regime. A change in the behavior of the columns was identified to be a function of the aspect ratio (height/length) of the initial sand column. Columns of high aspect ratio first subsided before sliding along failure planes, while columns of small aspect ratio were only observed to slide along failure planes. The transition between these two characteristic falls occurred regardless of the material and the velocity of the wall in the context of the quasi-static regime. When the final height and length of the piles were analyzed, we found power-law relations of the ratio of initial to final height and final run-out to initial length with the aspect ratio of the column. The dissipation of energy is also shown to increase with the run-out length of the pile until it reaches a plateau. Finally, we find that the structure of the slip planes that develop in our experiments are not well described by the failure of Coulomb's wedges for twin retaining rough walls.

An Optimized Method for Terrain Reconstruction Based on Descent Images

Directory of Open Access Journals (Sweden)

Xu Xinchao

2016-02-01

Full Text Available An optimization method is proposed to perform high-accuracy terrain reconstruction of the landing area of Chang’e III. First, feature matching is conducted using geometric model constraints. Then, the initial terrain is obtained and the initial normal vector of each point is solved on the basis of the initial terrain. By changing the vector around the initial normal vector in small steps a set of new vectors is obtained. By combining these vectors with the direction of light and camera, the functions are set up on the basis of a surface reflection model. Then, a series of gray values is derived by solving the equations. The new optimized vector is recorded when the obtained gray value is closest to the corresponding pixel. Finally, the optimized terrain is obtained after iteration of the vector field. Experiments were conducted using the laboratory images and descent images of Chang’e III. The results showed that the performance of the proposed method was better than that of the classical feature matching method. It can provide a reference for terrain reconstruction of the landing area in subsequent moon exploration missions.

Experiences of reconstruction of the epithermal neutron beam at THOR

International Nuclear Information System (INIS)

Liu Hongming; Hsu Pinchieh; Liu Chaochin; Jiang Shianghuei; Liu Yenwan Hsueh; Kai Jijung

2006-01-01

Tsing Hua Open-pool Reactor (THOR) had completed the renovation for an epithermal neutron beam in August 2004. The major tasks for this renovation were moderator/filter design and assembling, and concrete cutting for a better beam quality and larger irradiation room. Besides moderator/filter design, the associated works involved radiation monitoring, structure analysis, and shielding design. The radiation monitoring was performed to predict the probable accumulated dose for the workers involved in this reconstruction project. Special shielding design and construction processes were adopted to lower the radiation level and the probable accumulated dose for the workers. Before concrete cutting, structure analysis based on SAP-2000 code was performed to assure the structure is safe from the earthquake in Taiwan. A wall saw was then used for concrete cutting to enlarge the space of the irradiation room. Moderator/filter components were assembled on a trolley outside the beam exit prior to installation, which can effectively reduce the duration of a worker staying inside the reconstruction area and thereby reduce the accumulated dose. The shielding for the irradiation room was designed based on MCNP simulation using a pre-calculated source plane at the beam exit. The thickness of the concrete (density=3 g/cm 3 ) of the walls and ceiling of the irradiation room were designed to be 100cm. On-going tasks include beam parameters measurement and in vitro/ in vivo study and calibration of treatment planning system, with the hope that the team can be ready for clinical trials in 2-3 years. (author)

Wind tunnels with adapted walls for reducing wall interference

Science.gov (United States)

Ganzer, U.

1979-01-01

The basic principle of adaptable wind tunnel walls is explained. First results of an investigation carried out at the Aero-Space Institute of Berlin Technical University are presented for two dimensional flexible walls and a NACA 0012 airfoil. With five examples exhibiting very different flow conditions it is demonstrated that it is possible to reduce wall interference and to avoid blockage at transonic speeds by wall adaptation.

Inverse measurement of wall pressure field in flexible-wall wind tunnels using global wall deformation data

Science.gov (United States)

Brown, Kenneth; Brown, Julian; Patil, Mayuresh; Devenport, William

2018-02-01

The Kevlar-wall anechoic wind tunnel offers great value to the aeroacoustics research community, affording the capability to make simultaneous aeroacoustic and aerodynamic measurements. While the aeroacoustic potential of the Kevlar-wall test section is already being leveraged, the aerodynamic capability of these test sections is still to be fully realized. The flexibility of the Kevlar walls suggests the possibility that the internal test section flow may be characterized by precisely measuring small deflections of the flexible walls. Treating the Kevlar fabric walls as tensioned membranes with known pre-tension and material properties, an inverse stress problem arises where the pressure distribution over the wall is sought as a function of the measured wall deflection. Experimental wall deformations produced by the wind loading of an airfoil model are measured using digital image correlation and subsequently projected onto polynomial basis functions which have been formulated to mitigate the impact of measurement noise based on a finite-element study. Inserting analytic derivatives of the basis functions into the equilibrium relations for a membrane, full-field pressure distributions across the Kevlar walls are computed. These inversely calculated pressures, after being validated against an independent measurement technique, can then be integrated along the length of the test section to give the sectional lift of the airfoil. Notably, these first-time results are achieved with a non-contact technique and in an anechoic environment.

Eccentricities: Outlying Poems that Reconstruct the Modern City

Directory of Open Access Journals (Sweden)

Carlos Pittella

2017-12-01

Full Text Available This article, using Cesário Verde as a point of reference, presents diverse strategies of poetic reconstruction of the city via scansion and formal analysis of representative poems: “cidade/city/cité” by Augusto de Campos, “Ode Triunfal” by Álvaro de Campos (heteronym of Fernando Pessoa, “As Scismas do Destino” by Augusto dos Anjos, “Paisaje de la Juventud que Vomita (Anochecer en Coney Island” by Federico García Lorca and “O Inferno de Wall Street” by Joaquim de Sousândrade. These poems are taken from Portuguese, Brazilian, Spanish and US-American literature and provide a fertile line of inquiry into urban poetics.

Design and installation of a ferromagnetic wall in tokamak geometry

International Nuclear Information System (INIS)

Hughes, P. E.; Levesque, J. P.; Rivera, N.; Mauel, M. E.; Navratil, G. A.

2015-01-01

Low-activation ferritic steels are leading material candidates for use in next-generation fusion development experiments such as a prospective component test facility and DEMO power reactor. Understanding the interaction of plasmas with a ferromagnetic wall will provide crucial physics for these facilities. In order to study ferromagnetic effects in toroidal geometry, a ferritic wall upgrade was designed and installed in the High Beta Tokamak–Extended Pulse (HBT-EP). Several material options were investigated based on conductivity, magnetic permeability, vacuum compatibility, and other criteria, and the material of choice (high-cobalt steel) is characterized. Installation was accomplished quickly, with minimal impact on existing diagnostics and overall machine performance, and initial results demonstrate the effects of the ferritic wall on plasma stability

Design and installation of a ferromagnetic wall in tokamak geometry

Energy Technology Data Exchange (ETDEWEB)

Hughes, P. E., E-mail: peh2109@columbia.edu; Levesque, J. P.; Rivera, N.; Mauel, M. E.; Navratil, G. A. [Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027 (United States)

2015-10-15

Low-activation ferritic steels are leading material candidates for use in next-generation fusion development experiments such as a prospective component test facility and DEMO power reactor. Understanding the interaction of plasmas with a ferromagnetic wall will provide crucial physics for these facilities. In order to study ferromagnetic effects in toroidal geometry, a ferritic wall upgrade was designed and installed in the High Beta Tokamak–Extended Pulse (HBT-EP). Several material options were investigated based on conductivity, magnetic permeability, vacuum compatibility, and other criteria, and the material of choice (high-cobalt steel) is characterized. Installation was accomplished quickly, with minimal impact on existing diagnostics and overall machine performance, and initial results demonstrate the effects of the ferritic wall on plasma stability.

Quantification of the right ventricular wall using stress myocardial emission computed tomography with thallium-201 in normal subjects

International Nuclear Information System (INIS)

Akanabe, Hiroshi; Oshima, Motoo; Sakuma, Sadayuki; Yamamoto, Shuhei; Kawai, Naoki; Sotobata, Iwao

1985-01-01

Although many studies of quantitative analysis of left ventricular myocardial wall (LVMW) have been reported using stress thallium-201 (Tl-201), few reports of right ventricular myocardial wall (RVMW) have been estimated. In this study we determined whether single photon emission computed tomography (SPECT) with Tl-201 could accurately define normal range of RVMW in normal subjects. Twelve persons who have no valvular disease, nor coronary artery disease were included in this study. Stress SPECT study was reconstructed to make a short axial images of ventricles. RVMW and LVMW were flagged by mamual. Each ventricle was divided into 36 parts at every 10 degree. Relative activity counts in each ventricle were calculated as a percent counts of maximum counts in left ventricle. The normal range of RVMW with stress SPECT was as follows: anterior wall (33.2 +- 11.4 %, mean +- 2 standard deviation, -62.7 +- 18.4 %), free wall (30.1 +- 12.4 % - 38.5 +- 8.8 %), inferior wall (40.4 +- 7.8 % - 60.0 +- 21.4 %), septal wall (65.2 +- 17.2 % - 71.1 +- 14.2 %). Above the results, SPECT with Tl-201 can accurately define the normal range of RVMW, and this method is usefull to quantify the degree of ischemia and hypertrophy in RVMW. (author)

The receptor-like kinase AtVRLK1 regulates secondary cell wall thickening.

Science.gov (United States)

Huang, Cheng; Zhang, Rui; Gui, Jinshan; Zhong, Yu; Li, Laigeng

2018-04-20

During the growth and development of land plants, some specialized cells, such as tracheary elements, undergo secondary cell wall thickening. Secondary cell walls contain additional lignin, compared with primary cell walls, thus providing mechanical strength and potentially improving defenses against pathogens. However, the molecular mechanisms that initiate wall thickening are unknown. In this study, we identified an Arabidopsis thaliana leucine-rich repeat receptor-like kinase, encoded by AtVRLK1 (Vascular-Related RLK 1), that is specifically expressed in cells undergoing secondary cell wall thickening. Suppression of AtVRLK1expression resulted in a range of phenotypes that included retarded early elongation of the inflorescence stem, shorter fibers, slower root growth, and shorter flower filaments. In contrast, upregulation of AtVRLK1 led to longer fiber cells, reduced secondary cell wall thickening in fiber and vessel cells, and defects in anther dehiscence. Molecular and cellular analyses showed that downregulation of AtVRLK1 promoted secondary cell wall thickening and upregulation of AtVRLK1 enhanced cell elongation and inhibited secondary cell wall thickening. We propose that AtVRLK1 functions as a signaling component in coordinating cell elongation and cell wall thickening during growth and development. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

An Algorithmic Approach for the Reconstruction of Nasal Skin Defects: Retrospective Analysis of 130 Cases

Directory of Open Access Journals (Sweden)

Berrak Akşam

2016-06-01

Full Text Available Objective: Most of the malignant cutaneous carcinomas are seen in the nasal region. Reconstruction of nasal defects is challenging because of the unique anatomic properties and complex structure of this region. In this study, we present our algorithm for the nasal skin defects that occurred after malignant skin tumor excisions. Material and Methods: Patients whose nasal skin was reconstructed after malignant skin tumor excision were included in the study. These patients were evaluated by their age, gender, comorbities, tumor location, tumor size, reconstruction type, histopathological diagnosis, and tumor recurrence. Results: A total of 130 patients (70 female, 60 male were evaluated. The average age of the patients was 67.8 years. Tumors were located mostly at the dorsum, alar region, and tip of the nose. When reconstruction methods were evaluated, primary closure was preferred in 14.6% patients, full thickness skin grafts were used in 25.3% patients, and reconstruction with flaps were the choice in 60% patients. Different flaps were used according to the subunits. Mostly, dorsal nasal flaps, bilobed flaps, nasolabial flaps, and forehead flaps were used. Conclusion: The defect-only reconstruction principle was accepted in this study. Previously described subunits, such as the dorsum, tip, alar region, lateral wall, columella, and soft triangles, of the nose were further divided into subregions by their anatomical relations. An algorithm was planned with these sub regions. In nasal skin reconstruction, this algorithm helps in selection the methods for the best results and minimize the complications.

Near-field interaction of colloid near wavy walls

Science.gov (United States)

Luo, Yimin; Serra, Francesca; Wong, Denise; Steager, Edward; Stebe, Kathleen

Anisotropic media can be used to manipulate colloids, in tandem with carefully designed boundary conditions. For example, in bulk nematic liquid crystal, a wall with homeotropic anchoring repels a colloid with the same anchoring; yet by changing the surface topography from planar to concave, one can turn repulsion into attraction. We explore the behaviors of micro-particles with associated topological defects (hedgehogs or Saturn rings) near wavy walls. The walls locally excite disturbance, which decays into bulk. The range of influence is related to the curvature. The distortion can be used to position particles, either directly on the structure or at a distance away, based on the ``splay-matching'' rules. When distortion becomes stronger through the deepening of the well, the splay field created by the wall can prompt transformation from a Saturn ring to a hedgehog. We combine wells of different wavelength and depth to direct colloid movement. We apply a magnetic field to reset the initial position of ferromagnetic colloids and subsequently release them to probe the elastic energy landscape. Our platform enables manipulation, particle selection, and a detailed study of defect structure under the influence of curvature. Army Research Office.

Information Communications Technology Support to Reconstruction and Development: Some Observations from Afghanistan

National Research Council Canada - National Science Library

Kramer, Frank; Starr, Stuart; Wentz, Larry

2007-01-01

...) and information technology (IT) reconstruction initiatives continue to suffer from a lack of adequate understanding of the affected nation information culture and telecoms and IT business cultures...

Effects of opening in shear walls of 30- storey building

Directory of Open Access Journals (Sweden)

Ruchi Sharma

2015-03-01

Full Text Available Tall towers and multi-storey buildings have fascinated mankind from the beginning of civilization, their construction being initially for defense and subsequently for ecclesiastical purposes. These tall buildings because of its height, is affected by lateral forces due to wind or earthquake actions tends to snap the building in shear and push it over in bending. In general, the rigidity (i.e. Resistance to lateral deflection and stability (i.e. Resistance to overturning moments requirement become more important. Shear walls (Structural walls contribute significant lateral stiffness, strength, and overall ductility and energy dissipation capacity. In many structural walls a regular pattern of openings has to be provided due to various functional requirements such as to accommodate doors, windows and service ducts. Such type of openings reduces the stiffness of the shear wall to some extent depending on the shape and size of the opening. In the present parametric study, efforts are made to investigate and critically assess the effects of various size of openings in shear walls on the responses and behaviors of multi-storey buildings. The 30 storey Prototype buildings with different types of openings in shear wall with and without incorporating the volume of shear wall reduced in the boundary elements are analyzed using software E-TABS using Response spectrum method (1893(Part-1-2002 and Time history method.

MDCT assessment of airway wall thickness in COPD patients using a new method: correlations with pulmonary function tests

International Nuclear Information System (INIS)

Achenbach, Tobias; Weinheimer, Oliver; Schmitt, Sabine; Freudenstein, Daniela; Kunz, Richard Peter; Dueber, Christoph; Biedermann, Alexander; Buhl, Roland; Goutham, Edula; Heussel, Claus Peter

2008-01-01

Quantitative assessment of airway-wall dimensions by computed tomography (CT) has proven to be a marker of airway-wall remodelling in chronic obstructive pulmonary disease (COPD) patients. The objective was to correlate the wall thickness of large and small airways with functional parameters of airflow obstruction in COPD patients on multi-detector (MD) CT images using a new quantification procedure from a three-dimensional (3D) approach of the bronchial tree. In 31 patients (smokers/COPD, non-smokers/controls), we quantitatively assessed contiguous MDCT cross-sections reconstructed orthogonally along the airway axis, taking the point-spread function into account to circumvent over-estimation. Wall thickness and wall percentage were measured and the per-patient mean/median correlated with FEV1 and FEV1%. A median of 619 orthogonal airway locations was assessed per patient. Mean wall percentage/mean wall thickness/median wall thickness in non-smokers (29.6%/0.69 mm/0.37 mm) was significantly different from the COPD group (38.9%/0.83 mm/0.54 mm). Correlation coefficients (r) between FEV1 or FEV1% predicted and intra-individual means of the wall percentage were -0.569 and -0.560, respectively, with p<0.001. Depending on the parameter, they were increased for airways of 4 mm and smaller in total diameter, being -0.621 (FEV1) and -0.537 (FEV1%) with p < 0.002. The wall thickness was significantly higher in smokers than in non-smokers. In COPD patients, the wall thickness measured as a mean for a given patient correlated with the values of FEV1 and FEV1% predicted. Correlation with FEV1 was higher when only small airways were considered. (orig.)

Reconstruction of Complex Post-Traumatic Perineal/Pelvic Defects ...

African Journals Online (AJOL)

of the pelvic diaphragm). A composite pedicled. ALT flap was considered adequate for the initial reconstruction and stabilization, with the option of using a free fibular flap later, should the pelvic ring remain unstable. The fascia was used to complete the pelvic ring. It also provided anterior support to the pelvic diaphragm.

Concomitant surgical correction of severe stress urinary incontinence and anterior vaginal wall prolapse by anterior vaginal wall wrap: 18 months outcomes

Science.gov (United States)

Zargham, Mahtab; Alizadeh, Farshid; Tadayyon, Farhad; Khorrami, Mohammad-Hatef; Nouri-Mahdavi, Kia; Gharaati, Mohammad Reza; Izadpanahi, Mohammad Hossein; Yazdani, Mohammad; Mazdak, Hamid

2013-01-01

Background: The aim of this study is to evaluate the outcome of an innovative, minimally invasive sling technique with autologous tissue in women with concomitant incontinence and anterior vaginal wall prolapse (AVWP). Materials and Methods: Fifty-six women with stress urinary incontinence (SUI) or mixed urinary incontinence and AVWP were randomly assigned into two groups: In Group A (26 patients), anterior colporrhaphy (Kelly placation) and sling placement using a strip of anterior vaginal wall were performed, and in Group B (30 patients), transvaginal mesh correction of AVWP and tension-free vaginal tape (TVT) insertion (retropubic – craniocaudal route) using polypropylene mesh were carried out. The patients were followed-up for over 18 months and were assessed objectively using a 48 h frequency-volume chart, a 48 h pad test and a standardized stress test. Related surgical complications and outcomes were recorded and compared. Results: Surgical cure rates for Group A and Group B at the first (3 days) and last (18 months) post-operative visits were 62% and 84%; and 54%, and 72%, respectively (P = 0.09 and 0.31). Complications occurred in 9 patients (44%) of Group B, but only 3 patients (12%) in Group A. Conclusion: Vaginal sling surgery using an anterior vaginal wall strip can improve SUI and in comparison with propylene mesh is associated with lower complication rates. Although, the surgical success rate of this technique is lower than T-Sling, larger studies with selected patients will help assess the suitable patients for this pelvic reconstructive surgery. PMID:24516492

Concomitant surgical correction of severe stress urinary incontinence and anterior vaginal wall prolapse by anterior vaginal wall wrap: 18 months outcomes

Directory of Open Access Journals (Sweden)

Mahtab Zargham

2013-01-01

Full Text Available Background: The aim of this study is to evaluate the outcome of an innovative, minimally invasive sling technique with autologous tissue in women with concomitant incontinence and anterior vaginal wall prolapse (AVWP. Materials and Methods : Fifty-six women with stress urinary incontinence (SUI or mixed urinary incontinence and AVWP were randomly assigned into two groups: In Group A (26 patients, anterior colporrhaphy (Kelly placation and sling placement using a strip of anterior vaginal wall were performed, and in Group B (30 patients, transvaginal mesh correction of AVWP and tension-free vaginal tape (TVT insertion (retropubic - craniocaudal route using polypropylene mesh were carried out. The patients were followed-up for over 18 months and were assessed objectively using a 48 h frequency-volume chart, a 48 h pad test and a standardized stress test. Related surgical complications and outcomes were recorded and compared. Results: Surgical cure rates for Group A and Group B at the first (3 days and last (18 months post-operative visits were 62% and 84%; and 54%, and 72%, respectively (P = 0.09 and 0.31. Complications occurred in 9 patients (44% of Group B, but only 3 patients (12% in Group A. Conclusion: Vaginal sling surgery using an anterior vaginal wall strip can improve SUI and in comparison with propylene mesh is associated with lower complication rates. Although, the surgical success rate of this technique is lower than T-Sling, larger studies with selected patients will help assess the suitable patients for this pelvic reconstructive surgery.

An improved muon reconstruction algorithm for INO-ICAL experiment

International Nuclear Information System (INIS)

Bhattacharya, Kolahal; MandaI, Naba K.

2013-01-01

The charge current interaction of neutrino in INO-ICAL detector will be identified with a muon (μ ± ) in the detector whose kinematics is related with the kinematics of the neutrino. So, muon reconstruction is a very important step in achieving INO physics goals. The existing muon reconstruction package for INO-ICAL has poor performance in specific regimes of experimental interest: (a) for larger zenith angle (θ > 50°), (b) for lower energies (E < 1 GeV); mainly due to poor error propagation scheme insensitive to energy E, angle (θ, φ) and inhomogeneous magnetic field along the muon track. Since, a significant fraction of muons from atmospheric neutrino interactions will have initial energy < 1 GeV and almost uniform distribution in cosθ a robust package for muon reconstruction is essential. We have implemented higher order correction terms in the propagation of the state and error covariance matrices of the Kalman Iter. The algorithm ensures track element merging in most cases and also increases reconstruction efficiency. The performance of this package will be presented in comparison with the previous one. (author)

Instrument Variables for Reducing Noise in Parallel MRI Reconstruction

Directory of Open Access Journals (Sweden)

Yuchou Chang

2017-01-01

Full Text Available Generalized autocalibrating partially parallel acquisition (GRAPPA has been a widely used parallel MRI technique. However, noise deteriorates the reconstructed image when reduction factor increases or even at low reduction factor for some noisy datasets. Noise, initially generated from scanner, propagates noise-related errors during fitting and interpolation procedures of GRAPPA to distort the final reconstructed image quality. The basic idea we proposed to improve GRAPPA is to remove noise from a system identification perspective. In this paper, we first analyze the GRAPPA noise problem from a noisy input-output system perspective; then, a new framework based on errors-in-variables (EIV model is developed for analyzing noise generation mechanism in GRAPPA and designing a concrete method—instrument variables (IV GRAPPA to remove noise. The proposed EIV framework provides possibilities that noiseless GRAPPA reconstruction could be achieved by existing methods that solve EIV problem other than IV method. Experimental results show that the proposed reconstruction algorithm can better remove the noise compared to the conventional GRAPPA, as validated with both of phantom and in vivo brain data.

Reconstructing Laomedon’s Reign in Homer: Olympiomachia, Poseidon’s Wall, and the Earlier Trojan War

OpenAIRE

Andrew Porter

2014-01-01

Homeric allusions to Laomedon, the walls of Troy, and the first Trojan War reflect a backstory of previous fighting among the Olympians, which helps to explain the Iliadic portrait of Zeus’s fear of insubordination among the other gods.

Pilot study on objective measurement of abdominal wall strength in patients with ventral incisional hernia.

Science.gov (United States)

Parker, Michael; Goldberg, Ross F; Dinkins, Maryane M; Asbun, Horacio J; Daniel Smith, C; Preissler, Susanne; Bowers, Steven P

2011-11-01

Outcomes after ventral incisional hernia (VIH) repair are measured by recurrence rate and subjective measures. No objective metrics evaluate functional outcomes after abdominal wall reconstruction. This study aimed to develop testing of abdominal wall strength (AWS) that could be validated as a useful metric. Data were prospectively collected during 9 months from 35 patients. A total of 10 patients were evaluated before and after VIH repair, for a total of 45 encounters. The patients were tested simultaneously or in succession by two of three examiners. Data were collected for three tests: double leg lowering (DLL), trunk raising (TR), and supine reaching (SR). Raw data were compared and tested for validity, and continuous data were transformed to categorical data. Agreement was measured using the intraclass correlation coefficient (ICC) for DLL and using kappa for the ordinal measures. Simultaneous testing yielded the following interobserver reliability: DLL (0.96 and 0.87), TR (1.00 and 0.95), and SR (0.76). Reproducibility was assessed by consecutive tests, with correlation as follows: DLL (0.81), TR (0.81), and RCH (0.21). Due to poor interobserver reliability for the SR test compared with the DLL and TR tests, the SR test was excluded from calculation of an overall score. Based on raw data distribution from the DLL and TR tests, the DLL data were categorized into 10º increments, allowing construction of a 10-point score. The median AWS score was 5 (interquartile range [IQR], 4-7), and there was agreement within 1 point for 42 of the 45 encounters (93%). The findings from this study demonstrate that the 10-point AWS score may measure AWS in an accurate and reproducible fashion, with potential for objective description of abdominal wall function of VIH patients. This score may help to identify patients suited for abdominal wall reconstruction while measuring progress after VIH repair. Further longitudinal outcomes studies are needed.

Trends in breast reconstruction: Implications for the National Health Insurance Service

Directory of Open Access Journals (Sweden)

Ki Yong Hong

2018-05-01

Full Text Available Background Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Methods Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. Results At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases in 2012 to 18.3% (76 cases in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (P<0.05. Among the IBR cases, the percentage of prosthesis-based reconstructions increased significantly (P<0.05, but this trend was not found with DBR. Total mastectomy became significantly more common after the expansion of NHIS coverage (P<0.05. Conclusions Over the last decade, there has been an increase in mastectomy and breast reconstruction, and the pace of increase accelerated after the expansion of NHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.

An experimental investigation for external RC shear wall applications

Science.gov (United States)

Kaltakci, M. Y.; Ozturk, M.; Arslan, M. H.

2010-09-01

The strength and rigidity of most reinforced concrete (RC) buildings in Turkey, which are frequently hit by destructive earthquakes, is not at a sufficient level. Therefore, the result of earthquakes is a significant loss of life and property. The strengthening method most commonly preferred for these type of RC buildings is the application of RC infilled walls (shear walls) in the frame openings of the building. However, since the whole building has to be emptied and additional heavy costs arise during this type of strengthening, users prefer not to strengthen their buildings despite the heavy risk they are exposed to. Therefore, it is necessary to develop easier-to-apply and more effective methods for the rapid strengthening of housing and the heavily-used public buildings which cannot be emptied during the strengthening process (such as hospitals and schools). This study empirically analyses the different methods of a new system which can meet this need. In this new system, named "external shear wall application", RC shear walls are applied on the external surface of the building, along the frame plane rather than in the building. To this end, 7 test samples in 1/2 and 1/3 geometrical scale were designed to analyse the efficiency of the strengthening technique where the shear wall leans on the frame from outside of the building (external shear wall application) and of the strengthening technique where a specific space is left between the frame and the external shear wall by using a coupling beam to connect elements (application of external shear wall with coupling beam). Test results showed that the maximum lateral load capacity, initial rigidity and energy dissipation behaviours of the samples strengthened with external shear wall were much better than those of the bare frames.

An experimental investigation for external RC shear wall applications

Directory of Open Access Journals (Sweden)

M. Y. Kaltakci

2010-09-01

Full Text Available The strength and rigidity of most reinforced concrete (RC buildings in Turkey, which are frequently hit by destructive earthquakes, is not at a sufficient level. Therefore, the result of earthquakes is a significant loss of life and property. The strengthening method most commonly preferred for these type of RC buildings is the application of RC infilled walls (shear walls in the frame openings of the building. However, since the whole building has to be emptied and additional heavy costs arise during this type of strengthening, users prefer not to strengthen their buildings despite the heavy risk they are exposed to. Therefore, it is necessary to develop easier-to-apply and more effective methods for the rapid strengthening of housing and the heavily-used public buildings which cannot be emptied during the strengthening process (such as hospitals and schools. This study empirically analyses the different methods of a new system which can meet this need. In this new system, named "external shear wall application", RC shear walls are applied on the external surface of the building, along the frame plane rather than in the building. To this end, 7 test samples in 1/2 and 1/3 geometrical scale were designed to analyse the efficiency of the strengthening technique where the shear wall leans on the frame from outside of the building (external shear wall application and of the strengthening technique where a specific space is left between the frame and the external shear wall by using a coupling beam to connect elements (application of external shear wall with coupling beam. Test results showed that the maximum lateral load capacity, initial rigidity and energy dissipation behaviours of the samples strengthened with external shear wall were much better than those of the bare frames.

Measurement of defects on the wall by use of the inclination angle of laser slit beam and position tracking algorithm of camera

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Hwan; Yoon, Ji Sup; Jung, Jae Hoo; Hong, Dong Hee; Park, Gee Yong

2001-01-01

In this paper, a method of measuring the size of defects on the wall and restructuring the defect image is proposed based on the estimation algorithm of a camera orientation which uses the declination angle of the line slit beam. To reconstruct the image, an algorithm of estimating the horizontally inclined angle of CCD camera is presented. This algorithm adopts a 3-dimensional coordinate transformation of the image plane where both the LASER beam and the original image of the defects exist. The estimation equation is obtained by using the information of the beam projected on the wall and the parameters of this equation are experimentally obtained. With this algorithm, the original image of the defect can be reconstructed into the image which is obtained by a camera normal to the wall. From the result of a series of experiment shows that the measuring accuracy of the defect is within 0.5% error bound of real defect size under 30 degree of the horizontally inclined angle. Also, the accuracy is deteriorates with the error rate of 1% for every 10 degree increase of the horizontally inclined angle. The estimation error increases in the range of 30{approx}50 degree due to the existence of dead zone of defect depth, and defect length can not be measured due to the disappearance of image data above 70 degree. In case of under water condition, the measuring accuracy is also influenced due to the changed field of view of both the camera and the laser slit beam caused by the refraction rate in the water. The proposed algorithm provides the method of reconstructing the image taken at any arbitrary camera orientation into the image which is obtained by a camera normal to the wall and thus it enables the accurate measurement of the defect lengths only by using a single camera and a laser slit beam.

Primordial black hole and wormhole formation by domain walls

Energy Technology Data Exchange (ETDEWEB)

Deng, Heling; Garriga, Jaume; Vilenkin, Alexander, E-mail: heling.deng@tufts.edu, E-mail: garriga@cosmos.phy.tufts.edu, E-mail: vilenkin@cosmos.phy.tufts.edu [Institute of Cosmology, Tufts University, 574 Boston Ave, Medford, MA, 02155 (United States)

2017-04-01

In theories with a broken discrete symmetry, Hubble sized spherical domain walls may spontaneously nucleate during inflation. These objects are subsequently stretched by the inflationary expansion, resulting in a broad distribution of sizes. The fate of the walls after inflation depends on their radius. Walls smaller than a critical radius fall within the cosmological horizon early on and collapse due to their own tension, forming ordinary black holes. But if a wall is large enough, its repulsive gravitational field becomes dominant much before the wall can fall within the cosmological horizon. In this ''supercritical'' case, a wormhole throat develops, connecting the ambient exterior FRW universe with an interior baby universe, where the exponential growth of the wall radius takes place. The wormhole pinches off in a time-scale comparable to its light-crossing time, and black holes are formed at its two mouths. As discussed in previous work, the resulting black hole population has a wide distribution of masses and can have significant astrophysical effects. The mechanism of black hole formation has been previously studied for a dust-dominated universe. Here we investigate the case of a radiation-dominated universe, which is more relevant cosmologically, by using numerical simulations in order to find the initial mass of a black hole as a function of the wall size at the end of inflation. For large supercritical domain walls, this mass nearly saturates the upper bound according to which the black hole cannot be larger than the cosmological horizon. We also find that the subsequent accretion of radiation satisfies a scaling relation, resulting in a mass increase by about a factor of 2.

Nonmassive acute pulmonary embolism: evaluation of the impact of pulmonary arterial wall distensibility on the assessment of the CT obstruction score.

Science.gov (United States)

Bigot, Julien; Rémy-Jardin, Martine; Duhamel, Alain; Gorgos, Andréi-Bogdan; Faivre, Jean-Baptiste; Rémy, Jacques

2010-02-01

To evaluate the impact of pulmonary arterial wall distensibility on the assessment of a computed tomography (CT) score in patients with nonmassive pulmonary embolism (PE) (ie, Mastora score). The arterial wall distensibility of five central pulmonary arteries (pulmonary artery trunk, right and left main pulmonary arteries, right and left interlobar pulmonary arteries) was studied on ECG-gated CT angiographic studies of the chest in 15 patients with no pulmonary arterial hypertension (group 1; mean pulmonary artery pressure: 17.2 mm Hg) and 9 patients with nonmassive PE (group 2), using 2D reconstructions at every 10% of the R-R interval. The systolic and diastolic reconstruction time windows of the examined arteries were identical in the 2 groups, obtained at 20% and 80% of the R-R interval, respectively. No statistically significant difference was observed between the mean values of the pulmonary arterial wall distensibility between the 2 groups, varying between 20.5% and 24% in group 1 and between 23.3% and 25.9% in group 2. The coefficients of variation of the average arterial surfaces were found to vary between 4.30% and 6.50% in group 1 and 4.2% and 8.4% in group 2. Except the pulmonary artery trunk in group 2, all the intraclass correlation coefficients were around 0.8 or greater than 0.8, that is the cutoff for good homogeneity of measurements. The pulmonary arterial wall systolic-diastolic distensibility does not interfere with the assessment of a CT obstruction score in the setting of nonmassive PE.

Intraoperative CT in the assessment of posterior wall acetabular fracture stability.

Science.gov (United States)

Cunningham, Brian; Jackson, Kelly; Ortega, Gil

2014-04-01

Posterior wall acetabular fractures that involve 10% to 40% of the posterior wall may or may not require an open reduction and internal fixation. Dynamic stress examination of the acetabular fracture under fluoroscopy has been used as an intraoperative method to assess joint stability. The aim of this study was to demonstrate the value of intraoperative ISO computed tomography (CT) examination using the Siemens ISO-C imaging system (Siemens Corp, Malvern, Pennsylvania) in the assessment of posterior wall acetabular fracture stability during stress examination under anesthesia. In 5 posterior wall acetabular fractures, standard fluoroscopic images (including anteroposterior pelvis and Judet radiographs) with dynamic stress examinations were compared with the ISO-C CT imaging system to assess posterior wall fracture stability during stress examination. After review of standard intraoperative fluoroscopic images under dynamic stress examination, all 5 cases appeared to demonstrate posterior wall stability; however, when the intraoperative images from the ISO-C CT imaging system demonstrated that 1 case showed fracture instability of the posterior wall segment during stress examination, open reduction and internal fixation was performed. The use of intraoperative ISO CT imaging has shown an initial improvement in the surgeon's ability to assess the intraoperative stability of posterior wall acetabular fractures during stress examination when compared with standard fluoroscopic images. Copyright 2014, SLACK Incorporated.

The influence of hemodynamic forces on biomarkers in the walls of elastase-induced aneurysms in rabbits

Energy Technology Data Exchange (ETDEWEB)

Kadirvel, Ramanathan; Ding, Yong-Hong; Dai, Daying; Danielson, Mark A.; Lewis, Debra A.; Cloft, Harry J.; Kallmes, David F. [Mayo Clinic College of Medicine, Department of Radiology, Rochester, MN (United States); Zakaria, Hasballah; Robertson, Anne M. [University of Pittsburgh, Department of Mechanical Engineering, Pittsburgh, PA (United States)

2007-12-15

Biological and biophysical factors have been shown to play an important role in the initiation, progression, and rupture of intracranial aneurysms. The purpose of this study was to evaluate the association between hemodynamic forces and markers of vascular remodeling in elastase-induced saccular aneurysms in rabbits. Elastase-induced aneurysms were created at the origin of the right common carotid artery in rabbits. Hemodynamic parameters were estimated using computational fluid dynamic simulations based on 3-D-reconstructed models of the vasculature. Expression of matrix metalloproteinases (MMPs), their inhibitors (TIMPs) and markers of vascular remodeling were measured in different spatial regions within the aneurysms. Altered expression of biological markers relative to controls was correlated with the locations of subnormal time-averaged wall shear stress (WSS) but not with the magnitude of pressure. In the aneurysms, WSS was low and expression of biological markers was significantly altered in a time-dependent fashion. At 2 weeks, an upregulation of active-MMP-2, downregulation of TIMP-1 and TIMP-2, and intact endothelium were found in aneurysm cavities. However, by 12 weeks, endothelial cells were absent or scattered, and levels of pro- and active-MMP-2 were not different from those in control arteries, but pro-MMP-9 and both TIMPs were upregulated. These results reveal a strong, spatially localized correlation between diminished WSS and differential expression of biological markers of vascular remodeling in elastase-induced saccular aneurysms. The ability of the wall to function and maintain a healthy endothelium in a low shear environment appears to be significantly impaired by chronic exposure to low WSS. (orig.)

R(and)D on full tungsten divertor and beryllium wall for JET ITER-like Wall Project

International Nuclear Information System (INIS)

Hirai, T.; Maier, H.; Rubel, M.

2006-01-01

The ITER-like Wall Project was initiated at JET, with the goal of testing the reference material combination chosen for ITER: beryllium (Be) in the main chamber (wall and limiters) and tungsten (W) in the divertor. The major aims are to study the tritium retention, material mixing, melt layer behavior and to optimize plasma operation scenarios with a full metal wall. The project requires major design and engineering efforts in R(and)D: (i) bulk W tile, (ii) W coatings on carbon fibre composites (CFC) (iii) Be coatings on Inconel, (iv) Be marker tiles. For the W divertor, two R(and)D tasks were initiated: (1) development of a conceptual design for a bulk W tile as the main outer divertor target plate, and (2) W coating selection from 14 different samples produced by various techniques for the other divertor plates and neutral beam shine. The bulk W tile must withstand power loads of 7 MW/m 2 for 10 s. JET divertor plates are not actively cooled, therefore, heat capacity of the tiles is an important design parameter. In addition to power handling, mechanical structural stability under electromagnetic forces and compatibility with remote handling are the key requirements in the design. The design has been completed. The test-tile survived 100 pulses at 7 MW/m 2 for 10 s in the electron beam facility, JUDITH. The W coatings with different thickness, thin ( 2 and 200 pulses at 10 MW/m 2 for 5 s. In all tested samples cracks developed perpendicularly to the fiber bundles in CFC because of contraction of the coating in the cooling phase. Coatings were also exposed to 1000 ELM-like loading pulses. The thin coatings showed fatigue leading to delamination, whereas for thick coatings better resistance in ELM-like loading. As a result of R(and)D a full W divertor was decided: bulk metal at the outer divertor and W coating at other areas. Be-related R(and)D activities are in two areas. Production of 8-9 μm layers on inner wall cladding Inconel tiles ensures the full coating of

The plant cell wall in the feeding sites of cyst nematodes.

Science.gov (United States)

Bohlmann, Holger; Sobczak, Miroslaw

2014-01-01

Plant parasitic cyst nematodes (genera Heterodera and Globodera) are serious pests for many crops. They enter the host roots as migratory second stage juveniles (J2) and migrate intracellularly toward the vascular cylinder using their stylet and a set of cell wall degrading enzymes produced in the pharyngeal glands. They select an initial syncytial cell (ISC) within the vascular cylinder or inner cortex layers to induce the formation of a multicellular feeding site called a syncytium, which is the only source of nutrients for the parasite during its entire life. A syncytium can consist of more than hundred cells whose protoplasts are fused together through local cell wall dissolutions. While the nematode produces a cocktail of cell wall degrading and modifying enzymes during migration through the root, the cell wall degradations occurring during syncytium development are due to the plants own cell wall modifying and degrading proteins. The outer syncytial cell wall thickens to withstand the increasing osmotic pressure inside the syncytium. Furthermore, pronounced cell wall ingrowths can be formed on the outer syncytial wall at the interface with xylem vessels. They increase the surface of the symplast-apoplast interface, thus enhancing nutrient uptake into the syncytium. Processes of cell wall degradation, synthesis and modification in the syncytium are facilitated by a variety of plant proteins and enzymes including expansins, glucanases, pectate lyases and cellulose synthases, which are produced inside the syncytium or in cells surrounding the syncytium.

The plant cell wall in the feeding sites of cyst nematodes

Directory of Open Access Journals (Sweden)

Holger eBohlmann

2014-03-01

Full Text Available Plant parasitic cyst nematodes (genera Heterodera and Globodera are serious pests for many crops. They enter the host roots as migratory second stage juveniles (J2 and migrate intracellularly towards the vascular cylinder using their stylet and a set of cell wall degrading enzymes produced in the pharyngeal glands. They select an initial syncytial cell (ISC within the vascular cylinder or inner cortex layers to induce the formation of a multicellular feeding site called a syncytium, which is the only source of nutrients for the parasite during its entire life. A syncytium can consist of more than hundred cells whose protoplasts are fused together through local cell wall dissolutions. While the nematode produces a cocktail of cell wall degrading and modifying enzymes during migration through the root, the cell wall degradations occurring during syncytium development are due to the plants own cell wall modifying and degrading proteins. The outer syncytial cell wall thickens to withstand the increasing osmotic pressure inside the syncytium. Furthermore, pronounced cell wall ingrowths can be formed on the outer syncytial wall at the interface with xylem vessels. They increase the surface of the symplast-apoplast interface, thus enhancing nutrient uptake into the syncytium. Processes of cell wall degradation, synthesis and modification in the syncytium are facilitated by a variety of plant proteins and enzymes including expansins, glucanases, pectate lyases and cellulose synthases, which are produced inside the syncytium or in cells surrounding the syncytium.

Wall-based identification of coherent structures in wall-bounded turbulence

Science.gov (United States)

Sanmiguel Vila, C.; Flores, O.

2018-04-01

During the last decades, a number of reduced order models based on coherent structures have been proposed to describe wall-bounded turbulence. Many of these models emphasize the importance of coherent wall-normal velocity eddies (ν-eddies), which drive the generation of the very long streamwise velocity structures observed in the logarithmic and outer region. In order to use these models to improve our ability to control wall-bounded turbulence in realistic applications, these ν-eddies need to be identified from the wall in a non-intrusive way. In this paper, the possibility of using the pressure signal at the wall to identify these ν-eddies is explored, analyzing the cross-correlation between the wall-normal velocity component and the pressure fluctuations at the wall in a DNS of a turbulent channel flow at Reτ = 939. The results show that the cross-correlation has a region of negative correlation upstream, and a region of positive correlation backwards. In the spanwise direction the correlation decays monotonously, except very close to the wall where a change of sign of the correlation coefficient is observed. Moreover, filtering the pressure fluctuations at the wall in space results in an increase of the region where the cross-correlation is strong, both for the positively and the negatively correlated regions. The use of a time filter for the pressure fluctuations at the wall yields different results, displacing the regions of strong correlation without changing much their sizes. The results suggest that space-filtering the pressure at the wall is a feasible way to identify ν-eddies of different sizes, which could be used to trigger turbulent control strategies.

Improved immediate breast reconstruction as a result of oncoplastic multidisciplinary meeting

Directory of Open Access Journals (Sweden)

El Gammal MM

2017-04-01

Full Text Available Mohsen M El Gammal,1 Maria Lim,1 Rajan Uppal,2 Richard Sainsbury1 1Department of Breast Surgery, Parapet Breast Centre, Frimley Health Foundation Trust, Windsor, 2Department of Plastic and Reconstructive Surgery, Wexham and Heatherwood Hospital, Frimley Health Foundation Trust, Slough, UK Introduction: The National Institute for Health and Clinical Excellence guidelines recommend that breast reconstruction should be available to all women undergoing mastectomy and discussed at the initial surgical consultation (2002, and updated 2009. The National Mastectomy and Breast Reconstruction Audit (2009 showed that 21% of mastectomy patients underwent immediate breast reconstruction (IBR and 11% had delayed breast reconstruction (DBR. Breast reconstruction has been shown to have a positive effect on quality of life postmastectomy. This retrospective study investigated the impact of the introduction of a dedicated oncoplastic multidisciplinary meeting (OP MDM on our unit’s breast reconstruction rate.Patients and methods: A retrospective analysis of 229 women who underwent mastectomy, of whom 81 (35% underwent breast reconstruction between April 2014 and March 2016. Data were analyzed before and after introduction of OP MDM in April 2015. Data on patient age, type of surgery (mastectomy only, mastectomy and reconstruction, timing of reconstruction (IBR, DBR, and type of reconstruction (implant, autologous were collected.Results: Between April 2015 and March 2016, following establishment of OP multidisciplinary team in April 2015, of the 120 patients who had mastectomy, 50 (42% underwent breast reconstruction with 78% (39/50 choosing IBR (56% implant reconstruction and 22% autologous. Compared to the period between April 2014 and March 2015 preceding the OP MDM, of 109 patients who underwent mastectomy, only 31 (28% had breast reconstruction with 64% (20/31 choosing IBR (45% implant reconstruction and 19% autologous. The rate of DBR was lower, 22% (11

The performance of the ATLAS initial detector layout for B-physics channels

International Nuclear Information System (INIS)

Epp, B.; Ghete, V.M.; Kuhn, D.; Zhang, Y.J.

2004-01-01

At the start-up of LHC one expects parts of the ATLAS detector to be missing. This layout is called initial layout, whereas the fully staged detector is called complete layout. B-physics channels were simulated, reconstructed and analyzed using the software tools of ATLAS data challenge-1 (DC1). The performance of the detector with respect to quantities relevant to the analysis of the B s → D s π channel and the validation of the full chain generation-simulation-reconstruction-analysis were evaluated for the initial and complete layout. (author)

Study of heat transfer in the heating wall during nucleate pool boiling

International Nuclear Information System (INIS)

Bergez, W.

1991-12-01

The subject of this these is to show the role of heat transfer in the wall during saturated pool boiling. This effect, usually neglected in the modelizations of boiling, can explain some behaviours of the ebullition cycle and of the activities of nucleation sites. Il has been found that the ebullition cycle can be described by two steps: (1) during bubble growth, the wall temperature decreases due to the evaporation of the micro-layer at the base of the bubble; (2) initial superheat is re-established mainly by radial heat conduction in the wall. It is then possible to account for the variations of the wall temperature displayed by liquid crystals put a the bottom of the heating surface, and for the influence of the contact angle on the heat transfer. In the case of the infinitely thick wall the main results are that the thermal transfer during the growth of the bubble depends on the thermal properties of both wall and liquid and that the time separating the detachment of a bubble and its replacement by a new one is proportional to the cross-section of the bubble and to the thermal diffusivity of the wall

Algebraic reconstruction techniques for spectral reconstruction in diffuse optical tomography

International Nuclear Information System (INIS)

Brendel, Bernhard; Ziegler, Ronny; Nielsen, Tim

2008-01-01

Reconstruction in diffuse optical tomography (DOT) necessitates solving the diffusion equation, which is nonlinear with respect to the parameters that have to be reconstructed. Currently applied solving methods are based on the linearization of the equation. For spectral three-dimensional reconstruction, the emerging equation system is too large for direct inversion, but the application of iterative methods is feasible. Computational effort and speed of convergence of these iterative methods are crucial since they determine the computation time of the reconstruction. In this paper, the iterative methods algebraic reconstruction technique (ART) and conjugated gradients (CGs) as well as a new modified ART method are investigated for spectral DOT reconstruction. The aim of the modified ART scheme is to speed up the convergence by considering the specific conditions of spectral reconstruction. As a result, it converges much faster to favorable results than conventional ART and CG methods

SCF analysis of a pressurized vessel-nozzle intersection with wall thinning damage

International Nuclear Information System (INIS)

Qadir, M.; Redekop, D.

2009-01-01

A three-dimensional finite element analysis is carried out of a pressurized vessel-nozzle intersection (tee joint), with wall thinning damage. A convergence-validation study is first carried out for undamaged intersections, in which comparisons are made with previously published work for the stress concentration factor (SCF), and good agreement is observed. A study is then carried out for specific tee joints to examine the effect on the SCF of varying the extent of the wall thinning damage. Finally, a parametric study is conducted in which the SCF is computed for a wide range of tee joints, initially considered undamaged, and then with wall thinning damage.

Clinical evaluation of left ventricular wall thickness by combined technique with gated planer 201Tl image and gated cardiac pool image

International Nuclear Information System (INIS)

Nakai, Kenji; Katsuragawa, Shigehiko; Takahashi, Tsuneo; Matsushita, Kazuo; Kawamura, Akiyoshi

1983-01-01

To evaluate the left ventricular (LV) wall thickness, combined technique with gated planer 201-Thallium image and gated cardiac pool image was applied to 6 patients with hypertrophic cardiomyopathy (HCM) and 4 patients with secondary hypertrophy due to hypertension (HHD) proven by electrocardiography and ultrasonic-echocardiography. Scintigraphic pattern of hypertrophy on reconstructed planer 201 Tl image showed diffuse or asymmetrical apical hypertrophy in HHD, asymmetrical septal hypertrophy in HCM. It was very interesting that abnormal perfusion was shown in 201 Tl image, despite symmetrical hypertrophy in echocardiography. This techniques provided useful information for evaluating the LV wall thickness and cardiac performance. (author)

Outcome of different facial nerve reconstruction techniques

Directory of Open Access Journals (Sweden)

Aboshanif Mohamed

Full Text Available Abstract Introduction: There is no technique of facial nerve reconstruction that guarantees facial function recovery up to grade III. Objective: To evaluate the efficacy and safety of different facial nerve reconstruction techniques. Methods: Facial nerve reconstruction was performed in 22 patients (facial nerve interpositional graft in 11 patients and hypoglossal-facial nerve transfer in another 11 patients. All patients had facial function House-Brackmann (HB grade VI, either caused by trauma or after resection of a tumor. All patients were submitted to a primary nerve reconstruction except 7 patients, where late reconstruction was performed two weeks to four months after the initial surgery. The follow-up period was at least two years. Results: For facial nerve interpositional graft technique, we achieved facial function HB grade III in eight patients and grade IV in three patients. Synkinesis was found in eight patients, and facial contracture with synkinesis was found in two patients. In regards to hypoglossal-facial nerve transfer using different modifications, we achieved facial function HB grade III in nine patients and grade IV in two patients. Facial contracture, synkinesis and tongue atrophy were found in three patients, and synkinesis was found in five patients. However, those who had primary direct facial-hypoglossal end-to-side anastomosis showed the best result without any neurological deficit. Conclusion: Among various reanimation techniques, when indicated, direct end-to-side facial-hypoglossal anastomosis through epineural suturing is the most effective technique with excellent outcomes for facial reanimation and preservation of tongue movement, particularly when performed as a primary technique.

Enhanced temporal resolution at cardiac CT with a novel CT image reconstruction algorithm: Initial patient experience

Energy Technology Data Exchange (ETDEWEB)

Apfaltrer, Paul, E-mail: paul.apfaltrer@medma.uni-heidelberg.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Schoendube, Harald, E-mail: harald.schoendube@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Allmendinger, Thomas, E-mail: thomas.allmendinger@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Tricarico, Francesco, E-mail: francescotricarico82@gmail.com [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Department of Bioimaging and Radiological Sciences, Catholic University of the Sacred Heart, “A. Gemelli” Hospital, Largo A. Gemelli 8, Rome (Italy); Schindler, Andreas, E-mail: andreas.schindler@campus.lmu.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Vogt, Sebastian, E-mail: sebastian.vogt@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Sunnegårdh, Johan, E-mail: johan.sunnegardh@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); and others

2013-02-15

Objective: To evaluate the effect of a temporal resolution improvement method (TRIM) for cardiac CT on diagnostic image quality for coronary artery assessment. Materials and methods: The TRIM-algorithm employs an iterative approach to reconstruct images from less than 180° of projections and uses a histogram constraint to prevent the occurrence of limited-angle artifacts. This algorithm was applied in 11 obese patients (7 men, 67.2 ± 9.8 years) who had undergone second generation dual-source cardiac CT with 120 kV, 175–426 mAs, and 500 ms gantry rotation. All data were reconstructed with a temporal resolution of 250 ms using traditional filtered-back projection (FBP) and of 200 ms using the TRIM-algorithm. Contrast attenuation and contrast-to-noise-ratio (CNR) were measured in the ascending aorta. The presence and severity of coronary motion artifacts was rated on a 4-point Likert scale. Results: All scans were considered of diagnostic quality. Mean BMI was 36 ± 3.6 kg/m{sup 2}. Average heart rate was 60 ± 9 bpm. Mean effective dose was 13.5 ± 4.6 mSv. When comparing FBP- and TRIM reconstructed series, the attenuation within the ascending aorta (392 ± 70.7 vs. 396.8 ± 70.1 HU, p > 0.05) and CNR (13.2 ± 3.2 vs. 11.7 ± 3.1, p > 0.05) were not significantly different. A total of 110 coronary segments were evaluated. All studies were deemed diagnostic; however, there was a significant (p < 0.05) difference in the severity score distribution of coronary motion artifacts between FBP (median = 2.5) and TRIM (median = 2.0) reconstructions. Conclusion: The algorithm evaluated here delivers diagnostic imaging quality of the coronary arteries despite 500 ms gantry rotation. Possible applications include improvement of cardiac imaging on slower gantry rotation systems or mitigation of the trade-off between temporal resolution and CNR in obese patients.

Long-Term Data Reveal Rate and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction

Science.gov (United States)

... Rupture of the knee’s ACL is a common sports-related injury. It is associated with other knee problems, such as meniscal tears and knee instability. ... after anterior cruciate ligament reconstruction. Am J of Sports Med. 2013; ... treatment and prevention of arthritis and musculoskeletal and skin diseases; the ...

Volumetric three-dimensional reconstruction and segmentation of spectral-domain OCT.

Science.gov (United States)

Aaker, Grant D; Gracia, Luis; Myung, Jane S; Borcherding, Vanessa; Banfelder, Jason R; D'Amico, Donald J; Kiss, Szilárd

2011-07-01

Despite advances in optical coherence tomography (OCT), three-dimensional (3D) renderings of OCT images remain limited to scanning consecutive two-dimensional (2D) OCT slices. The authors describe a method of reconstructing 2D OCT data for 3D retinal analysis and visualization in a Computer Assisted Virtual Environment (CAVE). Using customized signal processing software, raw data from 2D slice-based spectral-domain OCT images were rendered into high-resolution 3D images for segmentation and quantification analysis. Reconstructed OCT images were projected onto a four-walled space and viewed through stereoscopic glasses, resulting in a virtual reality perception of the retina. These 3D retinal renderings offer a novel method for segmentation and isolation of volumetric images. The ability to manipulate the images in a virtual reality environment allows visualization of complex spatial relationships that may aid our understanding of retinal pathology. More importantly, these 3D retinal renderings can be viewed, manipulated, and analyzed on traditional 2D monitors independent of the CAVE. Copyright 2011, SLACK Incorporated.

2D fall of granular columns controlled by slow horizontal withdrawal of a retaining wall

Science.gov (United States)

Mériaux, C. A.

2006-12-01

This paper describes a series of experiments designed to investigate the fall of granular columns in quasi- static regime. Columns made of alternatively green and red sand layers were initially laid out in a box and then released when a retaining wall was set in slow motion with constant speed. The dependence of the dynamics of the fall on the initial aspect ratio of the columns, the velocity of the wall and the material properties was investigated within the quasi-static regime. A change in the behaviour of the columns was identified to be a function of the aspect ratio (height/length) of the initial sand column. Columns of high aspect ratio first subsided before sliding along failure planes, while columns of small aspect ratio were only observed to slide along failure planes. The transition between these two characteristic falls occurred regardless of the material and the velocity of the wall in the context of the quasi-static regime. When the final height and length of the piles were analyzed, we found power-law relations of the ratio of initial to final height and final run-out to initial length with the aspect ratio of the column. The dissipation of energy is also shown to increase with the run-out length of the pile until it reaches a plateau.

Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

Science.gov (United States)

Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

1996-01-01

The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

Overview of the JET results with the ITER-like wall

Science.gov (United States)

Romanelli, F.; EFDA Contributors, JET

2013-10-01

Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Zeff (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H98,y2 close to 1 and βN ˜ 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.

Overview of the JET results with the ITER-like wall

International Nuclear Information System (INIS)

Romanelli, F.

2013-01-01

Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z eff (1.2–1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H 98,y2 close to 1 and β N ∼ 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential. (paper)

Domain Walls and Matter-Antimatter Domains in the Early Universe

Directory of Open Access Journals (Sweden)

Dolgov A.D.

2017-01-01

Full Text Available We suggest a scenario of spontaneous (or dynamical C and CP violation according to which it is possible to generate domains of matter and antimatter separated by cosmologically large distances. Such C(CP violation existed only in the early universe and later it disappeared with the only trace of generated matter and antimatter domains. So this scenario does not suffer from the problem of domain walls. According to this scenario the width of the domain wall should grow exponentially to prevent annihilation at the domain boundaries. Though there is a classical result obtained by Basu and Vilenkin that the width of the wall tends to the one of the stationary solution (constant physical width. That is why we considered thick domain walls in a de Sitter universe following paper by Basu and Vilenkin. However, we were interested not only in stationary solutions found therein, but also investigated the general case of domain wall evolution with time. When the wall thickness parameter, δ0 , is smaller than H−1/2 where H is the Hubble parameter in de Sitter space-time, then the stationary solutions exist, and initial field configurations tend with time to the stationary ones. However, there are no stationary solutions for δ0>H−1/2 We have calculated numerically the rate of the wall expansion in this case and have found that the width of the wall grows exponentially fast for δ0≫H−1 An explanation for the critical value δ0c=H−1/2 is also proposed.

Analyzing octopus movements using three-dimensional reconstruction.

Science.gov (United States)

Yekutieli, Yoram; Mitelman, Rea; Hochner, Binyamin; Flash, Tamar

2007-09-01

Octopus arms, as well as other muscular hydrostats, are characterized by a very large number of degrees of freedom and a rich motion repertoire. Over the years, several attempts have been made to elucidate the interplay between the biomechanics of these organs and their control systems. Recent developments in electrophysiological recordings from both the arms and brains of behaving octopuses mark significant progress in this direction. The next stage is relating these recordings to the octopus arm movements, which requires an accurate and reliable method of movement description and analysis. Here we describe a semiautomatic computerized system for 3D reconstruction of an octopus arm during motion. It consists of two digital video cameras and a PC computer running custom-made software. The system overcomes the difficulty of extracting the motion of smooth, nonrigid objects in poor viewing conditions. Some of the trouble is explained by the problem of light refraction in recording underwater motion. Here we use both experiments and simulations to analyze the refraction problem and show that accurate reconstruction is possible. We have used this system successfully to reconstruct different types of octopus arm movements, such as reaching and bend initiation movements. Our system is noninvasive and does not require attaching any artificial markers to the octopus arm. It may therefore be of more general use in reconstructing other nonrigid, elongated objects in motion.

[Mandibular reconstruction with fibula free flap. Experience of virtual reconstruction using Osirix®, a free and open source software for medical imagery].

Science.gov (United States)

Albert, S; Cristofari, J-P; Cox, A; Bensimon, J-L; Guedon, C; Barry, B

2011-12-01

The techniques of free tissue transfers are mainly used for mandibular reconstruction by specialized surgical teams. This type of reconstruction is mostly realized in matters of head and neck cancers affecting mandibular bone and requiring a wide surgical resection and interruption of the mandible. To decrease the duration of the operation, surgical procedure involves generally two teams, one devoted to cancer resection and the other one to raise the fibular flap and making the reconstruction. For a better preparation of this surgical procedure, we propose here the use of a medical imaging software enabling mandibular reconstructions in three dimensions using the CT-scan done during the initial disease-staging checkup. The software used is Osirix®, developed since 2004 by a team of radiologists from Geneva and UCLA, working on Apple® computers and downloadable free of charge in its basic version. We report here our experience of this software in 17 patients, with a preoperative modelling in three dimensions of the mandible, of the segment of mandible to be removed. It also forecasts the numbers of fragments of fibula needed and the location of osteotomies. Copyright © 2009 Elsevier Masson SAS. All rights reserved.

Ambiguous walls

DEFF Research Database (Denmark)

Mody, Astrid

2012-01-01

The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how walls...... have encouraged architectural thinking of enclosure, materiality, construction and inhabitation in architectural history, the paper’s aim is to define new directions for the integration of LEDs in walls, challenging the thinking of inhabitation and program. This paper introduces the notion...... of “ambiguous walls” as a more “critical” approach to design [1]. The concept of ambiguous walls refers to the diffuse status a lumious and possibly responsive wall will have. Instead of confining it can open up. Instead of having a static appearance, it becomes a context over time. Instead of being hard...

Aesthetic refinements and reoperative procedures following 370 consecutive DIEP and SIEA flap breast reconstructions: important considerations for patient consent.

Science.gov (United States)

Enajat, Morteza; Smit, Jeroen M; Rozen, Warren M; Hartman, Ed H M; Liss, Anders; Kildal, Morten; Audolfsson, Thorir; Acosta, Rafael

2010-06-01

Breast reconstruction often requires multiple operations. In addition to potential complications requiring reoperation, additional procedures are frequently essential in order to complete the reconstructive process, with aesthetic outcome and breast symmetry shown to be the most important factors in patient satisfaction. Despite the importance of these reoperations in decision-making and the consent process, a thorough review of the need for such operations has not been definitively explored. A review of 370 consecutive autologous breast reconstructions (326 patients) was undertaken, comprising 365 deep inferior epigastric artery perforator (DIEP) flaps and 5 superficial inferior epigastric artery (SIEA) flaps. The need for additional procedures for either complications or aesthetic refinement following initial breast reconstruction was assessed. Overall, there was an average of 1.06 additional interventions for every patient carried out after primary reconstructive surgery. Of 326 patients, 46 underwent early postoperative operations for surgical complications (0.17 additional operations per patient as a consequence of complications). Procedures for aesthetic refinement included those performed on the reconstructed breast, contralateral breast, or abdominal donor site. Procedures for aesthetic refinement included nipple reconstruction, nipple-areola complex tattooing, dog-ear correction, liposuction, lipofilling, scar revision, mastopexy, and reduction mammaplasty. While DIEP flap surgery for breast reconstruction provides favorable results, patients frequently require additional procedures to improve aesthetic outcomes. The need for reoperation is an important part of the consent process prior to reconstructive surgery, and patients should recognize the likelihood of at least one additional procedure following initial reconstruction.

A compressed sensing based approach on Discrete Algebraic Reconstruction Technique.

Science.gov (United States)

Demircan-Tureyen, Ezgi; Kamasak, Mustafa E

2015-01-01

Discrete tomography (DT) techniques are capable of computing better results, even using less number of projections than the continuous tomography techniques. Discrete Algebraic Reconstruction Technique (DART) is an iterative reconstruction method proposed to achieve this goal by exploiting a prior knowledge on the gray levels and assuming that the scanned object is composed from a few different densities. In this paper, DART method is combined with an initial total variation minimization (TvMin) phase to ensure a better initial guess and extended with a segmentation procedure in which the threshold values are estimated from a finite set of candidates to minimize both the projection error and the total variation (TV) simultaneously. The accuracy and the robustness of the algorithm is compared with the original DART by the simulation experiments which are done under (1) limited number of projections, (2) limited view problem and (3) noisy projections conditions.

Robust linearized image reconstruction for multifrequency EIT of the breast.

Science.gov (United States)

Boverman, Gregory; Kao, Tzu-Jen; Kulkarni, Rujuta; Kim, Bong Seok; Isaacson, David; Saulnier, Gary J; Newell, Jonathan C

2008-10-01

Electrical impedance tomography (EIT) is a developing imaging modality that is beginning to show promise for detecting and characterizing tumors in the breast. At Rensselaer Polytechnic Institute, we have developed a combined EIT-tomosynthesis system that allows for the coregistered and simultaneous analysis of the breast using EIT and X-ray imaging. A significant challenge in EIT is the design of computationally efficient image reconstruction algorithms which are robust to various forms of model mismatch. Specifically, we have implemented a scaling procedure that is robust to the presence of a thin highly-resistive layer of skin at the boundary of the breast and we have developed an algorithm to detect and exclude from the image reconstruction electrodes that are in poor contact with the breast. In our initial clinical studies, it has been difficult to ensure that all electrodes make adequate contact with the breast, and thus procedures for the use of data sets containing poorly contacting electrodes are particularly important. We also present a novel, efficient method to compute the Jacobian matrix for our linearized image reconstruction algorithm by reducing the computation of the sensitivity for each voxel to a quadratic form. Initial clinical results are presented, showing the potential of our algorithms to detect and localize breast tumors.

Extended-Search, Bézier Curve-Based Lane Detection and Reconstruction System for an Intelligent Vehicle

Directory of Open Access Journals (Sweden)

Xiaoyun Huang

2015-09-01

Full Text Available To improve the real-time performance and detection rate of a Lane Detection and Reconstruction (LDR system, an extended-search-based lane detection method and a Bézier curve-based lane reconstruction algorithm are proposed in this paper. The extended-search-based lane detection method is designed to search boundary blocks from the initial position, in an upwards direction and along the lane, with small search areas including continuous search, discontinuous search and bending search in order to detect different lane boundaries. The Bézier curve-based lane reconstruction algorithm is employed to describe a wide range of lane boundary forms with comparatively simple expressions. In addition, two Bézier curves are adopted to reconstruct the lanes' outer boundaries with large curvature variation. The lane detection and reconstruction algorithm — including initial-blocks' determining, extended search, binarization processing and lane boundaries' fitting in different scenarios — is verified in road tests. The results show that this algorithm is robust against different shadows and illumination variations; the average processing time per frame is 13 ms. Significantly, it presents an 88.6% high-detection rate on curved lanes with large or variable curvatures, where the accident rate is higher than that of straight lanes.

Chest reconstruction using a custom-designed polyethylene 3D implant after resection of the sternal manubrium

Directory of Open Access Journals (Sweden)

Lipińska J

2017-08-01

Full Text Available Joanna Lipińska,1 Leszek Kutwin,1 Marcin Wawrzycki,1 Leszek Olbrzymek,2 Sławomir Jabłoński1 1Department of Thoracic Surgery, General and Oncological Surgery, Medical University of Lodz, 2Ledo, Lodz, Poland Introduction: Resection of manubrium or body of the sternum is associated with a necessity of chest wall reconstruction. Large sternal defects require the use of different types of implants to ensure acceptable esthetic effect for the patient and chest stabilization. Aim: The purpose of this case report is to present a novel method of reconstruction of manubrium removed due to renal cancer metastasis to the sternum.Case: We present the case of a patient, who had underwent right nephrectomy for clear cell kidney cancer, diagnosed with a metastatic tumor in the sternum resulting in destruction of manubrium. The patient undergone tumor resection with primary reconstruction with an individual prosthesis. Sternal defect was filled with a personalized, computed tomography scan-based 3D-milled implant made of polyethylene.Results: Sternal reconstruction was uneventful. The patient endured surgery well, and has been under surveillance in outpatient clinic, without any respiration disorders, implant movement or local recurrence.Conclusion: Custom-designed sternal implants created by 3D technique constitute an interesting alternative for previous methods of filling defects after resection of a tumor in this location. Keywords: 3D-milled implant, thoracoplasty, reconstructive surgery, chest reconstruction, sternal metastasis, sternal implant, sternal tumor 

Optimization of the alpha image reconstruction. An iterative CT-image reconstruction with well-defined image quality metrics

Energy Technology Data Exchange (ETDEWEB)

Lebedev, Sergej; Sawall, Stefan; Knaup, Michael; Kachelriess, Marc [German Cancer Research Center, Heidelberg (Germany).

2017-10-01

Optimization of the AIR-algorithm for improved convergence and performance. TThe AIR method is an iterative algorithm for CT image reconstruction. As a result of its linearity with respect to the basis images, the AIR algorithm possesses well defined, regular image quality metrics, e.g. point spread function (PSF) or modulation transfer function (MTF), unlike other iterative reconstruction algorithms. The AIR algorithm computes weighting images α to blend between a set of basis images that preferably have mutually exclusive properties, e.g. high spatial resolution or low noise. The optimized algorithm uses an approach that alternates between the optimization of rawdata fidelity using an OSSART like update and regularization using gradient descent, as opposed to the initially proposed AIR using a straightforward gradient descent implementation. A regularization strength for a given task is chosen by formulating a requirement for the noise reduction and checking whether it is fulfilled for different regularization strengths, while monitoring the spatial resolution using the voxel-wise defined modulation transfer function for the AIR image. The optimized algorithm computes similar images in a shorter time compared to the initial gradient descent implementation of AIR. The result can be influenced by multiple parameters that can be narrowed down to a relatively simple framework to compute high quality images. The AIR images, for instance, can have at least a 50% lower noise level compared to the sharpest basis image, while the spatial resolution is mostly maintained. The optimization improves performance by a factor of 6, while maintaining image quality. Furthermore, it was demonstrated that the spatial resolution for AIR can be determined using regular image quality metrics, given smooth weighting images. This is not possible for other iterative reconstructions as a result of their non linearity. A simple set of parameters for the algorithm is discussed that provides

Optimization of the alpha image reconstruction. An iterative CT-image reconstruction with well-defined image quality metrics

International Nuclear Information System (INIS)

Lebedev, Sergej; Sawall, Stefan; Knaup, Michael; Kachelriess, Marc

2017-01-01

Optimization of the AIR-algorithm for improved convergence and performance. TThe AIR method is an iterative algorithm for CT image reconstruction. As a result of its linearity with respect to the basis images, the AIR algorithm possesses well defined, regular image quality metrics, e.g. point spread function (PSF) or modulation transfer function (MTF), unlike other iterative reconstruction algorithms. The AIR algorithm computes weighting images α to blend between a set of basis images that preferably have mutually exclusive properties, e.g. high spatial resolution or low noise. The optimized algorithm uses an approach that alternates between the optimization of rawdata fidelity using an OSSART like update and regularization using gradient descent, as opposed to the initially proposed AIR using a straightforward gradient descent implementation. A regularization strength for a given task is chosen by formulating a requirement for the noise reduction and checking whether it is fulfilled for different regularization strengths, while monitoring the spatial resolution using the voxel-wise defined modulation transfer function for the AIR image. The optimized algorithm computes similar images in a shorter time compared to the initial gradient descent implementation of AIR. The result can be influenced by multiple parameters that can be narrowed down to a relatively simple framework to compute high quality images. The AIR images, for instance, can have at least a 50% lower noise level compared to the sharpest basis image, while the spatial resolution is mostly maintained. The optimization improves performance by a factor of 6, while maintaining image quality. Furthermore, it was demonstrated that the spatial resolution for AIR can be determined using regular image quality metrics, given smooth weighting images. This is not possible for other iterative reconstructions as a result of their non linearity. A simple set of parameters for the algorithm is discussed that provides

ACL graft re-rupture after double-bundle reconstruction: factors that influence the intra-articular pattern of injury

NARCIS (Netherlands)

van Eck, Carola F.; Kropf, Eric J.; Romanowski, James R.; Lesniak, Bryson P.; Tranovich, Michael J.; van Dijk, C. Niek; Fu, Freddie H.

2011-01-01

To determine the most common rupture patterns of previously reconstructed DB-ACL cases, seen at the time of revision surgery, and to determine the influence of age, gender, time between the initial ACL reconstruction and re-injury, tunnel angle and etiology of failure. Forty patients who presented

Liquid Wall Chambers

Energy Technology Data Exchange (ETDEWEB)

Meier, W R

2011-02-24

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

Reinforced concrete wall under hydrogen detonation

International Nuclear Information System (INIS)

Saarenheimo, A.

2000-11-01

The structural integrity of a reinforced concrete wall in the BWR reactor building under hydrogen detonation conditions has been analysed. Of particular interest is whether the containment integrity can be jeopardised by an external hydrogen detonation. The load carrying capacity of a reinforced concrete wall was studied. The detonation pressure loads were estimated with computerised hand calculations assuming a direct initiation of detonation and applying the strong explosion theory. The results can be considered as rough and conservative estimates for the first shock pressure impact induced by a reflecting detonation wave. Structural integrity may be endangered due to slow pressurisation or dynamic impulse loads associated with local detonations. The static pressure following the passage of a shock front may be relatively high, thus this static or slowly decreasing pressure after a detonation may damage the structure severely. The mitigating effects of the opening of a door on pressure history and structural response were also studied. The non-linear behaviour of the wall was studied under detonations corresponding a detonable hydrogen mass of 0.5 kg and 1.428 kg. Non-linear finite element analyses of the reinforced concrete structure were carried out by the ABAQUS/Explicit program. The reinforcement and its non-linear material behaviour and the tensile cracking of concrete were modelled. Reinforcement was defined as layers of uniformly spaced reinforcing bars in shell elements. In these studies the surrounding structures of the non-linearly modelled reinforced concrete wall were modelled using idealised boundary conditions. Especially concrete cracking and yielding of the reinforcement was monitored during the numerical simulation. (au)

Postmastectomy Chest Wall Radiation to a Temporary Tissue Expander or Permanent Breast Implant-Is There a Difference in Complication Rates?

International Nuclear Information System (INIS)

Anderson, Penny R.; Freedman, Gary; Nicolaou, Nicos; Sharma, Navesh; Li Tianyu; Topham, Neal; Morrow, Monica

2009-01-01

Purpose: The purpose of this study was to evaluate the likelihood of complications and cosmetic results among breast cancer patients who underwent modified radical mastectomy (MRM) and breast reconstruction followed by radiation therapy (RT) to either a temporary tissue expander (TTE) or permanent breast implant (PI). Methods and Materials: Records were reviewed of 74 patients with breast cancer who underwent MRM followed by breast reconstruction and RT. Reconstruction consisted of a TTE usually followed by exchange to a PI. RT was delivered to the TTE in 62 patients and to the PI in 12 patients. Dose to the reconstructed chest wall was 50 Gy. Median follow-up was 48 months. The primary end point was the incidence of complications involving the reconstruction. Results: There was no significant difference in the rate of major complications in the PI group (0%) vs. 4.8% in the TTE group. No patients lost the reconstruction in the PI group. Three patients lost the reconstruction in the TTE group. There were excellent/good cosmetic scores in 90% of the TTE group and 80% of the PI group (p = 0.22). On multivariate regression models, the type of reconstruction irradiated had no statistically significant impact on complication rates. Conclusions: Patients treated with breast reconstruction and RT can experience low rates of major complications. We demonstrate no significant difference in the overall rate of major or minor complications between the TTE and PI groups. Postmastectomy RT to either the TTE or the PI should be considered as acceptable treatment options in all eligible patients.

Muon reconstruction in the Daya Bay water pools

International Nuclear Information System (INIS)

Hackenburg, R. W.

2017-01-01

Muon reconstruction in the Daya Bay water pools would serve to verify the simulated muon fluxes and offer the possibility of studying cosmic muons in general. This reconstruction is, however, complicated by many optical obstacles and the small coverage of photomultiplier tubes (PMTs) as compared to other large water Cherenkov detectors. The PMTs’ timing information is useful only in the case of direct, unreflected Cherenkov light. This requires PMTs to be added and removed as an hypothesized muon trajectory is iteratively improved, to account for the changing effects of obstacles and direction of light. Therefore, muon reconstruction in the Daya Bay water pools does not lend itself to a general fitting procedure employing smoothly varying functions with continuous derivatives. Here, we describe an algorithm which overcomes these complications. It employs the method of Least Mean Squares to determine an hypothesized trajectory from the PMTs’ charge-weighted positions. This initially hypothesized trajectory is then iteratively refined using the PMTs’ timing information. Reconstructions with simulated data reproduce the simulated trajectory to within about 5° in direction and about 45 cm in position at the pool surface, with a bias that tends to pull tracks away from the vertical by about 3°.

Breast sensation after breast reconstruction: a systematic review.

Science.gov (United States)

Shridharani, Sachin M; Magarakis, Michael; Stapleton, Sahael M; Basdag, Basak; Seal, Stella M; Rosson, Gedge D

2010-07-01

Studies show some return of breast sensation after breast reconstruction; however, recovery is variable and unpredictable. Efforts are being made to restore innervation by reattaching nerves (neurotization). We sought to systematically review the literature addressing breast sensation after reconstruction. The following databases were searched: EMBASE, Cochrane, and PubMed. Additionally, the PLASTIC AND RECONSTRUCTIVE SURGERY journal was hand searched from 1960 to 2009. Inclusion criteria included breast reconstruction for cancer, return of sensation with objective results, and patients aged 18 to 90 years. Studies with purely cosmetic procedures, case reports, studies with less than 10 patients, and studies involving male patients were excluded. The initial search yielded 109 studies, which was refined to 20 studies with a total pool of 638 patients. Innervated flaps have a greater magnitude of recovery, which occurs at an earlier stage compared with the noninnervated flaps. Overall, sensation to deep inferior epigastric artery perforator flaps may recover better sensation than transverse rectus abdominis myocutaneous flaps, followed by latissimus dorsi flaps, and finally implants. Women's needs and expectations for sensation have led plastic surgeons to investigate ways to facilitate its return. Studies, however, depict conflicting data. Larger series are needed to define the role of neurotization as a modality for improving sensory restoration. Thieme Medical Publishers.

Direct cone-beam cardiac reconstruction algorithm with cardiac banding artifact correction

International Nuclear Information System (INIS)

Taguchi, Katsuyuki; Chiang, Beshan S.; Hein, Ilmar A.

2006-01-01

Multislice helical computed tomography (CT) is a promising noninvasive technique for coronary artery imaging. Various factors can cause inconsistencies in cardiac CT data, which can result in degraded image quality. These inconsistencies may be the result of the patient physiology (e.g., heart rate variations), the nature of the data (e.g., cone-angle), or the reconstruction algorithm itself. An algorithm which provides the best temporal resolution for each slice, for example, often provides suboptimal image quality for the entire volume since the cardiac temporal resolution (TRc) changes from slice to slice. Such variations in TRc can generate strong banding artifacts in multi-planar reconstruction images or three-dimensional images. Discontinuous heart walls and coronary arteries may compromise the accuracy of the diagnosis. A β-blocker is often used to reduce and stabilize patients' heart rate but cannot eliminate the variation. In order to obtain robust and optimal image quality, a software solution that increases the temporal resolution and decreases the effect of heart rate is highly desirable. This paper proposes an ECG-correlated direct cone-beam reconstruction algorithm (TCOT-EGR) with cardiac banding artifact correction (CBC) and disconnected projections redundancy compensation technique (DIRECT). First the theory and analytical model of the cardiac temporal resolution is outlined. Next, the performance of the proposed algorithms is evaluated by using computer simulations as well as patient data. It will be shown that the proposed algorithms enhance the robustness of the image quality against inconsistencies by guaranteeing smooth transition of heart cycles used in reconstruction

Entropy Stable Wall Boundary Conditions for the Three-Dimensional Compressible Navier-Stokes Equations

Science.gov (United States)

Parsani, Matteo; Carpenter, Mark H.; Nielsen, Eric J.

2015-01-01

Non-linear entropy stability and a summation-by-parts framework are used to derive entropy stable wall boundary conditions for the three-dimensional compressible Navier-Stokes equations. A semi-discrete entropy estimate for the entire domain is achieved when the new boundary conditions are coupled with an entropy stable discrete interior operator. The data at the boundary are weakly imposed using a penalty flux approach and a simultaneous-approximation-term penalty technique. Although discontinuous spectral collocation operators on unstructured grids are used herein for the purpose of demonstrating their robustness and efficacy, the new boundary conditions are compatible with any diagonal norm summation-by-parts spatial operator, including finite element, finite difference, finite volume, discontinuous Galerkin, and flux reconstruction/correction procedure via reconstruction schemes. The proposed boundary treatment is tested for three-dimensional subsonic and supersonic flows. The numerical computations corroborate the non-linear stability (entropy stability) and accuracy of the boundary conditions.

Reconstruction of Sound Source Pressures in an Enclosure Using the Phased Beam Tracing Method

DEFF Research Database (Denmark)

Jeong, Cheol-Ho; Ih, Jeong-Guon

2009-01-01

. First, surfaces of an extended source are divided into reasonably small segments. From each source segment, one beam is projected into the field and all emitted beams are traced. Radiated beams from the source reach array sensors after traveling various paths including the wall reflections. Collecting...... all the pressure histories at the field points, source-observer relations can be constructed in a matrix-vector form for each frequency. By multiplying the measured field data with the pseudo-inverse of the calculated transfer function, one obtains the distribution of source pressure. An omni......-directional sphere and a cubic source in a rectangular enclosure were taken as examples in the simulation tests. A reconstruction error was investigated by Monte Carlo simulation in terms of field point locations. When the source information was reconstructed by the present method, it was shown that the sound power...

Acid base activity of live bacteria: Implications for quantifying cell wall charge

Science.gov (United States)

Claessens, Jacqueline; van Lith, Yvonne; Laverman, Anniet M.; Van Cappellen, Philippe

2006-01-01

To distinguish the buffering capacity associated with functional groups in the cell wall from that resulting from metabolic processes, base or acid consumption by live and dead cells of the Gram-negative bacterium Shewanella putrefaciens was measured in a pH stat system. Live cells exhibited fast consumption of acid (pH 4) or base (pH 7, 8, 9, and 10) during the first few minutes of the experiments. At pH 5.5, no acid or base was required to maintain the initial pH constant. The initial amounts of acid or base consumed by the live cells at pH 4, 8, and 10 were of comparable magnitudes as those neutralized at the same pHs by intact cells killed by exposure to gamma radiation or ethanol. Cells disrupted in a French press required higher amounts of acid or base, due to additional buffering by intracellular constituents. At pH 4, acid neutralization by suspensions of live cells stopped after 50 min, because of loss of viability. In contrast, under neutral and alkaline conditions, base consumption continued for the entire duration of the experiments (5 h). This long-term base neutralization was, at least partly, due to active respiration by the cells, as indicated by the build-up of succinate in solution. Qualitatively, the acid-base activity of live cells of the Gram-positive bacterium Bacillus subtilis resembled that of S. putrefaciens. The pH-dependent charging of ionizable functional groups in the cell walls of the live bacteria was estimated from the initial amounts of acid or base consumed in the pH stat experiments. From pH 4 to 10, the cell wall charge increased from near-zero values to about -4 × 10 -16 mol cell -1 and -6.5 × 10 -16 mol cell -1 for S. putrefaciens and B. subtilis, respectively. The similar cell wall charging of the two bacterial strains is consistent with the inferred low contribution of lipopolysaccharides to the buffering capacity of the Gram-negative cell wall (of the order of 10%).

Reconstruction of Midface and Orbital Wall Defects After Maxillectomy and Orbital Content Preservation With Titanium Mesh and Fascia Lata: 3-Year Follow-Up.

Science.gov (United States)

Motiee-Langroudi, Maziar; Harirchi, Iraj; Amali, Amin; Jafari, Mehrdad

2015-12-01

To describe the authors' experience in the reconstruction of patients after total maxillectomy with preservation of orbital contents for maxillary tumors using titanium mesh and autogenous fascia lata, where no setting for free flap reconstruction is available. Twelve consecutive patients with paranasal sinus tumors underwent total maxillectomy without orbital exenterations and primary reconstruction. The defects were reconstructed by titanium mesh in combination with autogenous fascia lata in the orbital floor performed by 1 surgical team. Titanium mesh (0.2 mm thick) was contoured and fixed to reconstruct the orbital floor and obtain midface projection. Fascia lata was used to cover the titanium mesh along the orbital floor to prevent fat entrapment in the mesh holes. The most common pathology was squamous cell carcinoma (50%). Patients' mean age was 45.66 years (33 to 74 yr). The mean follow-up period was 35.2 months (30 to 49 months). During follow-up, no infection or foreign body reaction was encountered. Extrusion of titanium mesh occurred in 4 patients who underwent postoperative radiotherapy. Two cases of mild diplopia at extreme gaze occurred early during the postoperative period that resolved after a few months. Placing fascia lata between the titanium mesh surface of the orbital implant and the orbital contents was successful in preventing long-term diplopia or dystopia. Nevertheless, exposure of the titanium implant through the skin surface represented a complication of this technique in 25% of patients. Further studies are required with head-to-head comparisons of artificial materials and free flaps for reconstruction of maxillectomy defects. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Evidence for differentiation of cell wall poles in Bacillus subtilis

International Nuclear Information System (INIS)

Sonnenfeld, E.M.

1985-01-01

Previous data have suggested that the chromosome of Bacillus subtilis was found to the cell surface at polar regions. A significant corollary of DNA attachment to cell poles is the role of the cell wall in chromosome segregation. This project was mainly concerned with visualizing the DNA-cell wall association through autoradiography. The origin and terminus of replication were labelled with ( 3 H)-thymidine using a temperature-sensitive DNA initiation mutant. It was found that most of the radioactivity was associated with cell poles. Ultrastructural analyses of cell walls stained with dilute cationized ferritin showed that the polar area contained a site of dense electronegativity. It is not immediately apparent why cell wall poles would contain an area with a high concentration of negative charge. This finding may be related to the cell pole functioning as the site of chromosome attachment. An additional observation encountered in this study was that cell wall exhibited asymmetry with regard to negative charge, the outside surface being more electronegative than the inside. A significant consequence of this finding is that both teichoic acid and muramyl peptides are situated perpendicularly to the cell surface. This favored arrangement may facilitate cell separation during the division process due to opposition of like charges at septa. The results of this work provide further convincing evidence that the cell wall of B. subtilis is differentiated

MINIMALLY INVASIVE SINGLE FLAP APPROACH WITH CONNECTIVE TISSUE WALL FOR PERIODONTAL REGENERATION

Directory of Open Access Journals (Sweden)

Kamen Kotsilkov

2017-09-01

Full Text Available INTRODUCTION: The destructive periodontal diseases are among the most prevalent in the human population. In some cases, bony defects are formed during the disease progression, thus sustaining deep periodontal pockets. The reconstruction of these defects is usually done with the classical techniques of bone substitutes placement and guided tissue regeneration. The clinical and histological data from the recent years, however, demonstrate the relatively low regenerative potential of these techniques. The contemporary approaches for periodontal regeneration rely on minimally invasive surgical protocols, aimed at complete tissue preservation in order to achieve and maintain primary closure and at stimulating the natural regenerative potential of the periodontal tissues. AIM: This presentation demonstrates the application of a new, minimally invasive, single flap surgical technique for periodontal regeneration in a clinical case with periodontitis and a residual deep intrabony defect. MATERIALS AND METHODS: A 37 years old patient presented with chronic generalised periodontitis. The initial therapy led to good control of the periodontal infection with a single residual deep periodontal pocket medially at 11 due to a deep intrabony defect. A single flap approach with an enamel matrix derivate application and a connective tissue wall technique were performed. The proper primary closure was obtained. RESULT: One month after surgery an initial mineralisation process in the defect was detected. At the third month, a complete clinical healing was observed. The radiographic control showed finished bone mineralisation and periodontal space recreation. CONCLUSION: In the limitation of the presented case, the minimally invasive surgical approach led to complete clinical healing and new bone formation, which could be proof for periodontal regeneration.

Initial Results of the SSPX Transient Internal Probe System for Measuring Toroidal Field Profiles

Science.gov (United States)

Holcomb, C. T.; Jarboe, T. R.; Mattick, A. T.; Hill, D. N.; McLean, H. S.; Wood, R. D.; Cellamare, V.

2000-10-01

Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. The Sustained Spheromak Physics Experiment (SSPX) is using a field profile diagnostic called the Transient Internal Probe (TIP). TIP consists of a verdet-glass bullet that is used to measure the magnetic field by Faraday rotation. This probe is shot through the spheromak by a light gas gun at speeds near 2 km/s. An argon laser is aligned along the path of the probe. The light passes through the probe and is retro-reflected to an ellipsometer that measures the change in polarization angle. The measurement is spatially resolved down to the probes’ 1 cm length to within 15 Gauss. Initial testing results are given. This and future data will be used to determine the field profile for equilibrium reconstruction. TIP can also be used in conjunction with wall probes to map out toroidal mode amplitudes and phases internally. This work was performed under the auspices of US DOE by the University of California Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.

Capabilities of wind tunnels with two-adaptive walls to minimize boundary interference in 3-D model testing

Science.gov (United States)

Rebstock, Rainer; Lee, Edwin E., Jr.

1989-01-01

An initial wind tunnel test was made to validate a new wall adaptation method for 3-D models in test sections with two adaptive walls. First part of the adaptation strategy is an on-line assessment of wall interference at the model position. The wall induced blockage was very small at all test conditions. Lift interference occurred at higher angles of attack with the walls set aerodynamically straight. The adaptation of the top and bottom tunnel walls is aimed at achieving a correctable flow condition. The blockage was virtually zero throughout the wing planform after the wall adjustment. The lift curve measured with the walls adapted agreed very well with interference free data for Mach 0.7, regardless of the vertical position of the wing in the test section. The 2-D wall adaptation can significantly improve the correctability of 3-D model data. Nevertheless, residual spanwise variations of wall interference are inevitable.

Rising damp in building walls: the wall base ventilation system

Energy Technology Data Exchange (ETDEWEB)

Guimaraes, A.S.; Delgado, J.M.P.Q.; Freitas, V.P. de [Faculdade de Engenharia da Universidade do Porto, Laboratorio de Fisica das Construcoes (LFC), Departamento de Engenharia Civil, Porto (Portugal)

2012-12-15

This work intends to validate a new system for treating rising damp in historic buildings walls. The results of laboratory experiments show that an efficient way of treating rising damp is by ventilating the wall base, using the HUMIVENT technique. The analytical model presented describes very well the observed features of rising damp in walls, verified by laboratory tests, who contributed for a simple sizing of the wall base ventilation system that will be implemented in historic buildings. (orig.)

A three-step reconstruction method for fluorescence molecular tomography based on compressive sensing

DEFF Research Database (Denmark)

Zhu, Yansong; Jha, Abhinav K.; Dreyer, Jakob K.

2017-01-01

Fluorescence molecular tomography (FMT) is a promising tool for real time in vivo quantification of neurotransmission (NT) as we pursue in our BRAIN initiative effort. However, the acquired image data are noisy and the reconstruction problem is ill-posed. Further, while spatial sparsity of the NT...... matrix coherence. The resultant image data are input to a homotopy-based reconstruction strategy that exploits sparsity via ℓ1 regularization. The reconstructed image is then input to a maximum-likelihood expectation maximization (MLEM) algorithm that retains the sparseness of the input estimate...... and improves upon the quantitation by accurate Poisson noise modeling. The proposed reconstruction method was evaluated in a three-dimensional simulated setup with fluorescent sources in a cuboidal scattering medium with optical properties simulating human brain cortex (reduced scattering coefficient: 9.2 cm-1...

SU-F-T-517: Determining the Tissue Equivalence of a Brass Mesh Bolus in a Reconstructed Chest Wall Irradiation

Energy Technology Data Exchange (ETDEWEB)

Shekel, E; Epstein, D; Levin, D [Dept of radiotherapy, Assuta Medical Centers, Tel Aviv (Israel)

2016-06-15

Purpose: To determine the tissue equivalence of a brass mesh bolus (RPD) in the setting of a reconstructed chest wall irradiation Methods: We measured breast skin dose delivered by a tangential field plan on an anthropomorphic phantom using Mosfet and nanoDot (Landauer) dosimeters in five different locations on the breast. We also measured skin dose using no bolus, 5mm and 10 mm superflab bolus. In the Eclipse treatment planning system (Varian, Palo Alto, CA) we calculated skin dose for different bolus thicknesses, ranging from 0 to 10 mm, in order to evaluate which calculation best matches the brass mesh measurements, as the brass mesh cannot be simulated due to artefacts.Finally, we measured depth dose behavior with the brass mesh bolus to verify that the bolus does not affect the dose to the breast itself beyond the build-up region. Results: Mosfet and nanoDot measurements were consistent with each other.As expected, skin dose measurements with no bolus had the least agreement with Eclipse calculation, while measurements for 5 and 10 mm agreed well with the calculation despite the difficulty in conforming superflab bolus to the breast contour. For the brass mesh the best agreement was for 3 mm bolus Eclipse calculation. For Mosfets, the average measurement was 90.8% of the expected dose, and for nanoDots 88.33% compared to 83.34%, 88.64% and 93.94% (2,3 and 5 mm bolus calculation respectively).The brass mesh bolus increased skin dose by approximately 25% but there was no dose increase beyond the build-up region. Conclusion: Brass mesh bolus is most equivalent to a 3 mm bolus, and does not affect the dose beyond the build-up region. The brass mesh cannot be directly calculated in Eclipse, hence a 3mm bolus calculation is a good reflection of the dose response to the brass mesh bolus.

Spatio-temporal characteristics of large scale motions in a turbulent boundary layer from direct wall shear stress measurement

Science.gov (United States)

Pabon, Rommel; Barnard, Casey; Ukeiley, Lawrence; Sheplak, Mark

2016-11-01

Particle image velocimetry (PIV) and fluctuating wall shear stress experiments were performed on a flat plate turbulent boundary layer (TBL) under zero pressure gradient conditions. The fluctuating wall shear stress was measured using a microelectromechanical 1mm × 1mm floating element capacitive shear stress sensor (CSSS) developed at the University of Florida. The experiments elucidated the imprint of the organized motions in a TBL on the wall shear stress through its direct measurement. Spatial autocorrelation of the streamwise velocity from the PIV snapshots revealed large scale motions that scale on the order of boundary layer thickness. However, the captured inclination angle was lower than that determined using the classic method by means of wall shear stress and hot-wire anemometry (HWA) temporal cross-correlations and a frozen field hypothesis using a convection velocity. The current study suggests the large size of these motions begins to degrade the applicability of the frozen field hypothesis for the time resolved HWA experiments. The simultaneous PIV and CSSS measurements are also used for spatial reconstruction of the velocity field during conditionally sampled intense wall shear stress events. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138.

3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells.

Directory of Open Access Journals (Sweden)

Tong Luo

Full Text Available The 3D geometry of individual vascular smooth muscle cells (VSMCs, which are essential for understanding the mechanical function of blood vessels, are currently not available. This paper introduces a new 3D segmentation algorithm to determine VSMC morphology and orientation.A total of 112 VSMCs from six porcine coronary arteries were used in the analysis. A 3D semi-automatic segmentation method was developed to reconstruct individual VSMCs from cell clumps as well as to extract the 3D geometry of VSMCs. A new edge blocking model was introduced to recognize cell boundary while an edge growing was developed for optimal interpolation and edge verification. The proposed methods were designed based on Region of Interest (ROI selected by user and interactive responses of limited key edges. Enhanced cell boundary features were used to construct the cell's initial boundary for further edge growing. A unified framework of morphological parameters (dimensions and orientations was proposed for the 3D volume data. Virtual phantom was designed to validate the tilt angle measurements, while other parameters extracted from 3D segmentations were compared with manual measurements to assess the accuracy of the algorithm. The length, width and thickness of VSMCs were 62.9±14.9 μm, 4.6±0.6 μm and 6.2±1.8 μm (mean±SD. In longitudinal-circumferential plane of blood vessel, VSMCs align off the circumferential direction with two mean angles of -19.4±9.3° and 10.9±4.7°, while an out-of-plane angle (i.e., radial tilt angle was found to be 8±7.6° with median as 5.7°.A 3D segmentation algorithm was developed to reconstruct individual VSMCs of blood vessel walls based on optical image stacks. The results were validated by a virtual phantom and manual measurement. The obtained 3D geometries can be utilized in mathematical models and leads a better understanding of vascular mechanical properties and function.

Endoscope-assisted breast reconstruction. 1. Immediate breast reconstruction after lateral quadrantectomy with endoscopically harvested latissimus dorsi muscle flap

International Nuclear Information System (INIS)

Satake, Toshihiko; Hasegawa, Takamitsu; Kurihara, Kazunao; Kudo, Tetsuya; Kim, Shiei; Wakamatsu, Shingo.

1996-01-01

Breast conserving therapy (BCT) now is widely accepted in Japan. Quadrantectomy has been chosen from among the several available breast conserving operations for its minimal recurrence rate. Quadrantectomy, or excision of one-quarter volume of the breast, leaves a moderate degree of deformity which diminishes the quality of life. The authors have introduced immediate post-ectomy breast reconstruction utilizing an endoscopically harvested latissimus dorsi (LD) muscle flap which results in a minimal donor site scar. Five cases of endoscope-assisted LD muscle reconstruction of a quadrantectomized breast have been followed by irradiation therapy. Prior to reconstruction, with the patient in the supine position, quadrantectomy and dissection of axillary lymphnodes are performed through an incision extending from the anterior axillary to the inflamammary line. The patient then is placed in the lateral supine position. LD muscle flap dissection by electrocautery begins through the initial incision. Dissections of posterior portions of the muscle continue, under endoscopic visualization, through one or two ports along the anterior margin of the muscle. Moderate amount of adipose tissue is left attached to the muscle to obtain full augmentation. The raised flap then is transferred and secured to the post-quandrantectomy defect. Some post-irradiation shrinkage of the inserted LD muscle has been a common occurrence of breast reconstruction. An ample amount of adipose tissue left attached to the muscle margin will solve this matter since fatty tissue is more resistant to post-irradiation atrophy. (J.P.N.)

Endoscope-assisted breast reconstruction. 1. Immediate breast reconstruction after lateral quadrantectomy with endoscopically harvested latissimus dorsi muscle flap

Energy Technology Data Exchange (ETDEWEB)

Satake, Toshihiko; Hasegawa, Takamitsu; Kurihara, Kazunao; Kudo, Tetsuya; Kim, Shiei [Kawaguchi Municipal Medical Center, Saitama (Japan); Wakamatsu, Shingo

1996-08-01

Breast conserving therapy (BCT) now is widely accepted in Japan. Quadrantectomy has been chosen from among the several available breast conserving operations for its minimal recurrence rate. Quadrantectomy, or excision of one-quarter volume of the breast, leaves a moderate degree of deformity which diminishes the quality of life. The authors have introduced immediate post-ectomy breast reconstruction utilizing an endoscopically harvested latissimus dorsi (LD) muscle flap which results in a minimal donor site scar. Five cases of endoscope-assisted LD muscle reconstruction of a quadrantectomized breast have been followed by irradiation therapy. Prior to reconstruction, with the patient in the supine position, quadrantectomy and dissection of axillary lymphnodes are performed through an incision extending from the anterior axillary to the inflamammary line. The patient then is placed in the lateral supine position. LD muscle flap dissection by electrocautery begins through the initial incision. Dissections of posterior portions of the muscle continue, under endoscopic visualization, through one or two ports along the anterior margin of the muscle. Moderate amount of adipose tissue is left attached to the muscle to obtain full augmentation. The raised flap then is transferred and secured to the post-quandrantectomy defect. Some post-irradiation shrinkage of the inserted LD muscle has been a common occurrence of breast reconstruction. An ample amount of adipose tissue left attached to the muscle margin will solve this matter since fatty tissue is more resistant to post-irradiation atrophy. (J.P.N.)

Noninvasive Vascular Displacement Estimation for Relative Elastic Modulus Reconstruction in Transversal Imaging Planes

Directory of Open Access Journals (Sweden)

Chris L. de Korte

2013-03-01

Full Text Available Atherosclerotic plaque rupture can initiate stroke or myocardial infarction. Lipid-rich plaques with thin fibrous caps have a higher risk to rupture than fibrotic plaques. Elastic moduli differ for lipid-rich and fibrous tissue and can be reconstructed using tissue displacements estimated from intravascular ultrasound radiofrequency (RF data acquisitions. This study investigated if modulus reconstruction is possible for noninvasive RF acquisitions of vessels in transverse imaging planes using an iterative 2D cross-correlation based displacement estimation algorithm. Furthermore, since it is known that displacements can be improved by compounding of displacements estimated at various beam steering angles, we compared the performance of the modulus reconstruction with and without compounding. For the comparison, simulated and experimental RF data were generated of various vessel-mimicking phantoms. Reconstruction errors were less than 10%, which seems adequate for distinguishing lipid-rich from fibrous tissue. Compounding outperformed single-angle reconstruction: the interquartile range of the reconstructed moduli for the various homogeneous phantom layers was approximately two times smaller. Additionally, the estimated lateral displacements were a factor of 2–3 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding.

RMP: Reduced-set matching pursuit approach for efficient compressed sensing signal reconstruction

Directory of Open Access Journals (Sweden)

Michael M. Abdel-Sayed

2016-11-01

Full Text Available Compressed sensing enables the acquisition of sparse signals at a rate that is much lower than the Nyquist rate. Compressed sensing initially adopted ℓ1 minimization for signal reconstruction which is computationally expensive. Several greedy recovery algorithms have been recently proposed for signal reconstruction at a lower computational complexity compared to the optimal ℓ1 minimization, while maintaining a good reconstruction accuracy. In this paper, the Reduced-set Matching Pursuit (RMP greedy recovery algorithm is proposed for compressed sensing. Unlike existing approaches which either select too many or too few values per iteration, RMP aims at selecting the most sufficient number of correlation values per iteration, which improves both the reconstruction time and error. Furthermore, RMP prunes the estimated signal, and hence, excludes the incorrectly selected values. The RMP algorithm achieves a higher reconstruction accuracy at a significantly low computational complexity compared to existing greedy recovery algorithms. It is even superior to ℓ1 minimization in terms of the normalized time-error product, a new metric introduced to measure the trade-off between the reconstruction time and error. RMP superior performance is illustrated with both noiseless and noisy samples.

RMP: Reduced-set matching pursuit approach for efficient compressed sensing signal reconstruction.

Science.gov (United States)

Abdel-Sayed, Michael M; Khattab, Ahmed; Abu-Elyazeed, Mohamed F

2016-11-01

Compressed sensing enables the acquisition of sparse signals at a rate that is much lower than the Nyquist rate. Compressed sensing initially adopted [Formula: see text] minimization for signal reconstruction which is computationally expensive. Several greedy recovery algorithms have been recently proposed for signal reconstruction at a lower computational complexity compared to the optimal [Formula: see text] minimization, while maintaining a good reconstruction accuracy. In this paper, the Reduced-set Matching Pursuit (RMP) greedy recovery algorithm is proposed for compressed sensing. Unlike existing approaches which either select too many or too few values per iteration, RMP aims at selecting the most sufficient number of correlation values per iteration, which improves both the reconstruction time and error. Furthermore, RMP prunes the estimated signal, and hence, excludes the incorrectly selected values. The RMP algorithm achieves a higher reconstruction accuracy at a significantly low computational complexity compared to existing greedy recovery algorithms. It is even superior to [Formula: see text] minimization in terms of the normalized time-error product, a new metric introduced to measure the trade-off between the reconstruction time and error. RMP superior performance is illustrated with both noiseless and noisy samples.

Conceptual thermal-mechanical design of the TFTR first wall armor against neutral beam impingement

International Nuclear Information System (INIS)

Chi, J.W.H.; Flaherty, R.

1976-01-01

The Tokamak Fusion Test Reactor (TFTR) is designed to operate in a pulsed mode with relatively low duty cycles. Each pulse consists of a short plasma heat-up period, a reaction period, followed by a relatively long cooldown period. Plasma heating is accomplished by ohmic heating by a current induced change in the magnetically linked ohmic heating coils, followed by neutral beam injection for further preheat and the initiation of fusion reactions. During normal operation, the bulk of the neutral beam energy will be absorbed by the plasma, while the remainder will impinge on the vacuum vessel wall. The amount of thermal energy deposited on an unprotected wall is expected to be excessive, limiting the frequency of pulses and requiring frequent wall replacement. A faulted condition would cause penetration of an unprotected wall. As a consequence, a wall armoring (or liner) concept was developed to protect the vacuum vessel wall and to permit ease of liner replacement

Improved iterative image reconstruction algorithm for the exterior problem of computed tomography

International Nuclear Information System (INIS)

Guo, Yumeng; Zeng, Li

2017-01-01

In industrial applications that are limited by the angle of a fan-beam and the length of a detector, the exterior problem of computed tomography (CT) uses only the projection data that correspond to the external annulus of the objects to reconstruct an image. Because the reconstructions are not affected by the projection data that correspond to the interior of the objects, the exterior problem is widely applied to detect cracks in the outer wall of large-sized objects, such as in-service pipelines. However, image reconstruction in the exterior problem is still a challenging problem due to truncated projection data and beam-hardening, both of which can lead to distortions and artifacts. Thus, developing an effective algorithm and adopting a scanning trajectory suited for the exterior problem may be valuable. In this study, an improved iterative algorithm that combines total variation minimization (TVM) with a region scalable fitting (RSF) model was developed for a unilateral off-centered scanning trajectory and can be utilized to inspect large-sized objects for defects. Experiments involving simulated phantoms and real projection data were conducted to validate the practicality of our algorithm. Furthermore, comparative experiments show that our algorithm outperforms others in suppressing the artifacts caused by truncated projection data and beam-hardening.

Improved iterative image reconstruction algorithm for the exterior problem of computed tomography

Energy Technology Data Exchange (ETDEWEB)

Guo, Yumeng [Chongqing University, College of Mathematics and Statistics, Chongqing 401331 (China); Chongqing University, ICT Research Center, Key Laboratory of Optoelectronic Technology and System of the Education Ministry of China, Chongqing 400044 (China); Zeng, Li, E-mail: drlizeng@cqu.edu.cn [Chongqing University, College of Mathematics and Statistics, Chongqing 401331 (China); Chongqing University, ICT Research Center, Key Laboratory of Optoelectronic Technology and System of the Education Ministry of China, Chongqing 400044 (China)

2017-01-11

In industrial applications that are limited by the angle of a fan-beam and the length of a detector, the exterior problem of computed tomography (CT) uses only the projection data that correspond to the external annulus of the objects to reconstruct an image. Because the reconstructions are not affected by the projection data that correspond to the interior of the objects, the exterior problem is widely applied to detect cracks in the outer wall of large-sized objects, such as in-service pipelines. However, image reconstruction in the exterior problem is still a challenging problem due to truncated projection data and beam-hardening, both of which can lead to distortions and artifacts. Thus, developing an effective algorithm and adopting a scanning trajectory suited for the exterior problem may be valuable. In this study, an improved iterative algorithm that combines total variation minimization (TVM) with a region scalable fitting (RSF) model was developed for a unilateral off-centered scanning trajectory and can be utilized to inspect large-sized objects for defects. Experiments involving simulated phantoms and real projection data were conducted to validate the practicality of our algorithm. Furthermore, comparative experiments show that our algorithm outperforms others in suppressing the artifacts caused by truncated projection data and beam-hardening.

Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT.

Science.gov (United States)

Matenine, Dmitri; Mascolo-Fortin, Julia; Goussard, Yves; Després, Philippe

2015-11-01

The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can potentially improve the rendering of

Air permeability for a concrete shear wall after a damaging seismic load simulation cycle

International Nuclear Information System (INIS)

Girrens, S.P.; Farrar, C.R.

1991-01-01

A study was initiated to estimate air leakage, driven by wind-generated pressure gradients, from a seismically damaged concrete structure. This paper describes an experiment performed to measure the air permeability in a reinforced concrete shear wall, both before and after simulated seismic loading. Static load-cycle testing was used to simulate earthquake loading. Permeability measurements were made by pressurizing one side of the shear wall above atmospheric conditions and recording the transient-pressure decay. Air permeability measurements made on the shear wall before loading fell within the range of values for concrete permeability published in the literature. As long as the structure exhibited linear load-displacement response, no variation in the air permeability was detected. However, experimental results indicate that the air permeability in the shear wall increased by a factor of 40 after the wall had been damaged (cracked)

Reconstructive breast implantation after mastectomy for breast cancer

DEFF Research Database (Denmark)

Henriksen, Trine F; Fryzek, Jon P; Hölmich, Lisbet R

2005-01-01

BACKGROUND: Clinical reports have raised concern about local complications following breast implantation used in reconstructive or cosmetic surgery, but there is a shortage of epidemiological studies in this area. OBJECTIVE: To assess in a prospective epidemiological manner the occurrence of short......-term local complications in a nationwide implantation registry. DESIGN, SETTING, AND PARTICIPANTS: The Danish Registry for Plastic Surgery of the Breast prospectively collects preoperative, perioperative, and postoperative information on Danish women undergoing breast augmentation. Through the registry, we...... collected data on short-term local complications among 574 women who underwent postmastectomy reconstruction with breast implants from June 1, 1999, through July 24, 2003. MAIN OUTCOME MEASURES: Complication incidence rates. RESULTS: Thirty-one percent of the women who underwent initial implantation...

A Case of Pediatric Abdominal Wall Reconstruction: Components Separation within the Austere War Environment

Directory of Open Access Journals (Sweden)

Ian Valerio, MD, MS, MBA, FACS

2014-07-01

Full Text Available Summary: Reconstructive surgeons supporting military operations are required to definitively treat severe pediatric abdominal injuries in austere environments. The safety and efficacy of using a components separation technique to treat large ventral hernias in pediatric patients in this setting remains understudied. Components separation technique was required to achieve definitive closure in a 12-month-old pediatric patient in Kandahar, Afghanistan. Her course was complicated by an anastomotic leak after small bowel resection. Her abdominal was successfully reopened, the leak repaired, and closed primarily without incident on postinjury day 9. Abdominal trauma with a large ventral hernia requiring components separation is extremely rare. A pediatric patient treated with components separation demonstrated minimal complications, avoidance of abdominal compartment syndrome, and no mortality.

MHD Effects of a Ferritic Wall on Tokamak Plasmas

Science.gov (United States)

Hughes, Paul E.

It has been recognized for some time that the very high fluence of fast (14.1MeV) neutrons produced by deuterium-tritium fusion will represent a major materials challenge for the development of next-generation fusion energy projects such as a fusion component test facility and demonstration fusion power reactor. The best-understood and most promising solutions presently available are a family of low-activation steels originally developed for use in fission reactors, but the ferromagnetic properties of these steels represent a danger to plasma confinement through enhancement of magnetohydrodynamic instabilities and increased susceptibility to error fields. At present, experimental research into the effects of ferromagnetic materials on MHD stability in toroidal geometry has been confined to demonstrating that it is still possible to operate an advanced tokamak in the presence of ferromagnetic components. In order to better quantify the effects of ferromagnetic materials on tokamak plasma stability, a new ferritic wall has been installated in the High Beta Tokamak---Extended Pulse (HBT-EP) device. The development, assembly, installation, and testing of this wall as a modular upgrade is described, and the effect of the wall on machine performance is characterized. Comparative studies of plasma dynamics with the ferritic wall close-fitting against similar plasmas with the ferritic wall retracted demonstrate substantial effects on plasma stability. Resonant magnetic perturbations (RMPs) are applied, demonstrating a 50% increase in n = 1 plasma response amplitude when the ferritic wall is near the plasma. Susceptibility of plasmas to disruption events increases by a factor of 2 or more with the ferritic wall inserted, as disruptions are observed earlier with greater frequency. Growth rates of external kink instabilities are observed to be twice as large in the presence of a close-fitting ferritic wall. Initial studies are made of the influence of mode rotation frequency

Mandibular reconstruction with composite microvascular tissue transfer

International Nuclear Information System (INIS)

Coleman, J.J. III; Wooden, W.A.

1990-01-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons [lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)]. Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure

Mandibular reconstruction with composite microvascular tissue transfer

Energy Technology Data Exchange (ETDEWEB)

Coleman, J.J. III; Wooden, W.A. (Emory Univ. School of Medicine, Atlanta, GA (USA))

1990-10-01

Microvascular free tissue transfer has provided a variety of methods of restoring vascularized bone and soft tissue to difficult defects created by tumor resection and trauma. Over 7 years, 26 patients have undergone 28 free flaps for mandibular reconstruction, 15 for primary squamous cell carcinoma of the floor of the mouth or tongue, 7 for recurrent tumor, and 6 for other reasons (lymphangioma (1), infection (1), gunshot wound (1), and osteoradionecrosis (3)). Primary reconstruction was performed in 19 cases and secondary in 9. All repairs were composite flaps including 12 scapula, 5 radial forearm, 3 fibula, 2 serratus, and 6 deep circumflex iliac artery. Mandibular defects included the symphysis alone (7), symphysis and body (5), symphysis-body-ramus condyle (2), body or ramus (13), and bilateral body (1). Fourteen patients had received prior radiotherapy to adjuvant or curative doses. Eight received postoperative radiotherapy. All patients had initially successful vascularized reconstruction by clinical examination (28) and positive radionuclide scan (22 of 22). Bony stability was achieved in 25 of 26 patients and oral continence in 24 of 26. One complete flap loss occurred at 14 days. Complications of some degree developed in 22 patients including partial skin necrosis (3), orocutaneous fistula (3), plate exposure (1), donor site infection (3), fracture of reconstruction (1), and fracture of the radius (1). Microvascular transfer of bone and soft tissue allows a reliable reconstruction--despite previous radiotherapy, infection, foreign body, or surgery--in almost every situation in which mandible and soft tissue are absent. Bony union, a healed wound, and reasonable function and appearance are likely despite early fistula, skin loss, or metal plate or bone exposure.

Outcome of different facial nerve reconstruction techniques.

Science.gov (United States)

Mohamed, Aboshanif; Omi, Eigo; Honda, Kohei; Suzuki, Shinsuke; Ishikawa, Kazuo

There is no technique of facial nerve reconstruction that guarantees facial function recovery up to grade III. To evaluate the efficacy and safety of different facial nerve reconstruction techniques. Facial nerve reconstruction was performed in 22 patients (facial nerve interpositional graft in 11 patients and hypoglossal-facial nerve transfer in another 11 patients). All patients had facial function House-Brackmann (HB) grade VI, either caused by trauma or after resection of a tumor. All patients were submitted to a primary nerve reconstruction except 7 patients, where late reconstruction was performed two weeks to four months after the initial surgery. The follow-up period was at least two years. For facial nerve interpositional graft technique, we achieved facial function HB grade III in eight patients and grade IV in three patients. Synkinesis was found in eight patients, and facial contracture with synkinesis was found in two patients. In regards to hypoglossal-facial nerve transfer using different modifications, we achieved facial function HB grade III in nine patients and grade IV in two patients. Facial contracture, synkinesis and tongue atrophy were found in three patients, and synkinesis was found in five patients. However, those who had primary direct facial-hypoglossal end-to-side anastomosis showed the best result without any neurological deficit. Among various reanimation techniques, when indicated, direct end-to-side facial-hypoglossal anastomosis through epineural suturing is the most effective technique with excellent outcomes for facial reanimation and preservation of tongue movement, particularly when performed as a primary technique. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Vaginal estrogen: a dual-edged sword in postoperative healing of the vaginal wall.

Science.gov (United States)

Ripperda, Christopher M; Maldonado, Pedro Antonio; Acevedo, Jesus F; Keller, Patrick W; Akgul, Yucel; Shelton, John M; Word, Ruth Ann

2017-07-01

Reconstructive surgery for pelvic organ prolapse is plagued with high failure rates possibly due to impaired healing or regeneration of the vaginal wall. Here, we tested the hypothesis that postoperative administration of local estrogen, direct injection of mesenchymal stem cells (MSCs), or both lead to improved wound healing of the injured vagina in a menopausal rat model. Ovariectomized rats underwent surgical injury to the posterior vaginal wall and were randomized to treatment with placebo (n = 41), estrogen cream (n = 47), direct injection of MSCs (n = 39), or both (n = 43). MSCs did not survive after injection and had no appreciable effects on healing of the vaginal wall. Acute postoperative administration of vaginal estrogen altered the response of the vaginal wall to injury with decreased stiffness, decreased collagen content, and decreased expression of transcripts for matrix components in the stromal compartment. Conversely, vaginal estrogen resulted in marked proliferation of the epithelial layer and increased expression of genes related to epithelial barrier function and protease inhibition. Transcripts for genes involved in chronic inflammation and adaptive immunity were also down-regulated in the estrogenized epithelium. Collectively, these data indicate that, in contrast to the reported positive effects of preoperative estrogen on the uninjured vagina, acute administration of postoperative vaginal estrogen has adverse effects on the early phase of healing of the stromal layer. In contrast, postoperative estrogen plays a positive role in healing of the vaginal epithelium after injury.

Current management of posterior wall fractures of the acetabulum.

Science.gov (United States)

Moed, Berton R; Kregor, Philip J; Reilly, Mark C; Stover, Michael D; Vrahas, Mark S

2015-01-01

The general goals for treating an acetabular fracture are to restore congruity and stability of the hip joint. These goals are no different from those for the subset of fractures of the posterior wall. Nevertheless, posterior wall fractures present unique problems compared with other types of acetabular fractures. Successful treatment of these fractures depends on a multitude of factors. The physician must understand their distinctive radiologic features, in conjunction with patient factors, to determine the appropriate treatment. By knowing the important points of posterior surgical approaches to the hip, particularly the posterior wall, specific techniques can be used for fracture reduction and fixation in these often challenging fractures. In addition, it is important to develop a complete grasp of potential complications and their treatment. The evaluation and treatment protocols initially developed by Letournel and Judet continue to be important; however, the surgeon also should be aware of new information published and presented in the past decade.

A full-scale porous reactive wall for prevention of acid mine drainage

International Nuclear Information System (INIS)

Benner, S.G.; Blowes, D.W.; Ptacek, C.J.

1997-01-01

The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years

Functional Properties at Domain Walls in BiFeO3: Electrical, Magnetic, and Structural investigations

Science.gov (United States)

He, Qing; Yang, C.-H.; Yu, P.; Gajek, M.; Seidel, J.; Ramesh, R.; Wang, F.; Chu, Y.-H.; Martin, L. W.; Spaldin, N.; Rother, A.

2009-03-01

BiFeO3 (BFO) is a widely studied robust ferroelectric, antiferromagnetic multiferroic. Conducting-atomic force microscopy studies reveal the presence of enhanced conductivity at certain types of domain walls in BFO. We have completed detailed TEM studies of the physical structure at these domain walls as well as in-depth DFT calculations of the evolution of electronic structure at these domain walls. These studies reveal two major contributions to the observed conduction: the formation of an electrostatic potential at the domain walls as well as a structurally-driven change in the electronic structure (i.e., a lower band gap locally) at the domain walls. We will discuss the use of optical characterization techniques as a way of probing this change in electronic structure at domain walls as well as detailed IV characterization both in atmospheric and UHV environments. Finally, the evolution of magnetism at these domain walls has been studied through the use of photoemission measurements. Initial findings point to a significant change in the magnetic order at these domain walls in BFO.

Statistical shape model-based reconstruction of a scaled, patient-specific surface model of the pelvis from a single standard AP x-ray radiograph

Energy Technology Data Exchange (ETDEWEB)

Zheng Guoyan [Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, CH-3014 Bern (Switzerland)

2010-04-15

Purpose: The aim of this article is to investigate the feasibility of using a statistical shape model (SSM)-based reconstruction technique to derive a scaled, patient-specific surface model of the pelvis from a single standard anteroposterior (AP) x-ray radiograph and the feasibility of estimating the scale of the reconstructed surface model by performing a surface-based 3D/3D matching. Methods: Data sets of 14 pelvises (one plastic bone, 12 cadavers, and one patient) were used to validate the single-image based reconstruction technique. This reconstruction technique is based on a hybrid 2D/3D deformable registration process combining a landmark-to-ray registration with a SSM-based 2D/3D reconstruction. The landmark-to-ray registration was used to find an initial scale and an initial rigid transformation between the x-ray image and the SSM. The estimated scale and rigid transformation were used to initialize the SSM-based 2D/3D reconstruction. The optimal reconstruction was then achieved in three stages by iteratively matching the projections of the apparent contours extracted from a 3D model derived from the SSM to the image contours extracted from the x-ray radiograph: Iterative affine registration, statistical instantiation, and iterative regularized shape deformation. The image contours are first detected by using a semiautomatic segmentation tool based on the Livewire algorithm and then approximated by a set of sparse dominant points that are adaptively sampled from the detected contours. The unknown scales of the reconstructed models were estimated by performing a surface-based 3D/3D matching between the reconstructed models and the associated ground truth models that were derived from a CT-based reconstruction method. Such a matching also allowed for computing the errors between the reconstructed models and the associated ground truth models. Results: The technique could reconstruct the surface models of all 14 pelvises directly from the landmark