Experience with the sandwich technique in endovascular thoracoabdominal aortic aneurysm repair

Background: The sandwich technique is an endovascular off-the-shelf solution for patients with thoracoabdominal aortic aneurysms (TAAAs). In a sandwich configuration, the chimney stent runs in the middle of a space created by two or three aortic endografts.Methods: All patients with TAAAs who were treated with the sandwich technique were included in the study. Self-expanding Viabahn grafts (W. L. Gore and Associates Inc, Flagstaff, Ariz) were used as parallel grafts in the renal arteries and visceral vessels. Caudad-facing chimney grafts were used for the visceral arteries and cephalad-facing periscope grafts for the renal arteries.Results: During the study period, 32 patients with TAAAs were treated with sandwich grafts. Indication for the procedure in 43% was an acute onset of symptoms, including two patients with a rupture and a retroperitoneal hematoma. Three patients required an additional debranching procedure. A total of 104 chimney grafts were implanted. Two patients died postoperatively because of the operation. Major adverse events were recorded in five patients, including one patient with persistent paraplegia and two with permanent renal failure requiring dialysis. The incidence of chimney graft occlusion was higher in patients with three or four parallel grafts than in those with two chimney grafts only. Patients with chronic dissections had a 12-times higher incidence of chimney graft occlusion than aneurysm patients. The number of patients with type I or III endoleaks was higher in the group with three or four parallel grafts.Conclusions: The sandwich technique is an off-the-shelf endovascular alternative to treat patients with TAAAs in an emergent setting. The combination of chimney grafts with a periscope configuration enables a rapid endovascular aneurysm exclusion with acceptable midterm results.

Testicular arteries systematization based on different levels of scrotal configuration in caprines

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A doorway to Borromean halo nuclei: the Samba configuration

We exploit the possibility of new configurations in three-body halo nuclei, Samba type (the neutron-core form a bound system) as a doorway to Borromean systems. The nuclei Be-12, B-15, N-23 and F-27 are of such nature, in particular N-23 with a half-life of 37.7 s and a halo radius of 6.07 fm is an excellent example of Samba-halo configuration. The fusion below the barrier of the Samba halo nuclei with heavy targets could reveal the so far elusive enhancement and a dominance of one-neutron over two-neutron transfers, in contrast to what was found recently for the Borromean halo nucleus He-6 + U-238.

Detection of infectious bronchitis virus and specific anti-viral antibodies using a concanavalin A-Sandwich-ELISA

Concanavalin A-Sandwich ELISA (Con A-S-ELISA) was developed for the detection of infectious bronchitis virus (IBV) or chicken specific anti-viral antibodies. The antigen detection limit for the Con A-S-ELISA was 10(5,1) EID50/mL. Three homologous and four heterologous IBV strains were similarly detected. This assay was highly effective in detecting the virus after infected tissue homogenates were passed once in embryonated chicken eggs, showing a good agreement with virus isolation technique. The Con A-S-ELISA was also used to measure anti-IBV chicken antibodies and showed a high coefficient of correlation (r = 0.85) and an agreement of k = 0.80 with the commercially available Indirect-ELISA. The relative sensitivity and specificity between these two tests were, respectively, 92.86% and 95.65% with an accuracy of 93.39%. Thus, the Con A-S-ELISA proved to be able to detect alternatively homologous and heterologous IBV strains or specific chicken anti-IBV antibodies, using the Con A as capture reagent of this assay.

Resistivity in the dynamic current sheath of a field reversed configuration

The resistivity of a field reversed configuration in a theta-pinch with slow rising current was investigated during the turbulent phase from the moment of field reversal until end of plasma radial implosion. This transport coefficient was obtained in a hydrogen plasma by local measurements with magnetic probe and compared to numerical calculations with Chodura resistivity and evolution of lower hybrid drift instability. The values of resistivity are higher than those predicted by classical binary collision. During early phase of confinement, the doubly layer structure of current sheath in the low electric field machine was theoretically well reproduced with anomalous collision frequency calculated with Chodura resistivity that provides appropriate conditions for onset of lower hybrid drift instability and the regular evolution of pinch. The plasma dynamic, radial profiles of magnetic field during the radial compression and resistivity values were equally close to those observed by the measurements. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698405]

Neural network based on adaptive resonance theory with continuous training for multi-configuration transient stability analysis of electric power systems

This work presents a methodology to analyze electric power systems transient stability for first swing using a neural network based on adaptive resonance theory (ART) architecture, called Euclidean ARTMAP neural network. The ART architectures present plasticity and stability characteristics, which are very important for the training and to execute the analysis in a fast way. The Euclidean ARTMAP version provides more accurate and faster solutions, when compared to the fuzzy ARTMAP configuration. Three steps are necessary for the network working, training, analysis and continuous training. The training step requires much effort (processing) while the analysis is effectuated almost without computational effort. The proposed network allows approaching several topologies of the electric system at the same time; therefore it is an alternative for real time transient stability of electric power systems. To illustrate the proposed neural network an application is presented for a multi-machine electric power systems composed of 10 synchronous machines, 45 buses and 73 transmission lines. (C) 2010 Elsevier B.V. All rights reserved.

Urgent Endovascular Treatment of Thoraco-abdominal Aneurysms Using a Sandwich Technique and Chimney Grafts - A Technical Description

Introduction: So far the only endovascular option to treat patients with thoraco abdominal aortic aneurysms is the deployment of branched grafts. We describe a technique consisting of the deployment of standard off-the- shelf grafts to treat urgent cases.Material and Methods: The sandwich technique consists of the deployment of ViaBahn chimney grafts in combination with standard thoracic and abdominal aortic stent grafts. The chimney grafts are deployed using a transbrachial and transaxillary access. These coaxial grafts are placed inside the thoracic tube graft. After deployment of the infrarenal bifurcated abdominal graft a bridging stent-a short tube graft is positioned inside the thoracic graft further stabilizing the chimney grafts.Results: 5 patients with symptomatic thoraco abdominal aneurysms were treated. There was one Type I endoleak that resolved after 2 months. In all patients 3 stentgrafts had to be used When possible all visceral and renal branches were revascularized. A total number of 17 arteries were reconnected with covered branches. During follow up we lost one target vessel the right renal artery.Conclusion: The sandwich technique in combination with chimney grafts permits a total endovascular exclusion of thoraco abdominal aortic aneurysms. In all cases off-the shelf products and grafts could be used. The number of patients treated so far is still too small to draw further more robust conclusions with regard to long term performance and durability. (C) 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Modified 'Stent-Graft Sandwich' Technique for Treatment of Isolated Common Iliac Artery Aneurysm in Patient With Marfan Syndrome

Isolated iliac artery aneurysms are rare in the general population (0.03%) and represent 2% of all abdominal aneurysms, and the association with Marfan syndrome is even rarer. We report a Marfan syndrome case with an isolated common iliac artery aneurysm treated by using a modified 'stent-graft sandwich' technique, with preservation of the internal iliac artery perfusion. The modified 'stent-graft sandwich' technique involves building an appropriate proximal neck just in the common iliac artery for fittingly housing two new stent-grafts inside, both deployed simultaneously and each one going to both distal iliac arteries (internal and external).

A double antibody sandwich ELISA for rapid diagnosis of virus infection and to measure the humoral response against infectious bursal disease on clinical material

A double antibody sandwich ELISA (DAS-ELISA) was developed and employed for simultaneous direct detection of infectious bursal disease virus (IBDV) from bursal samples and to measure the humoral response, using the same basic immunoreagents, the purified and non-purified antigen, capture antibody and chicken hyperimmune sera were prepared, and standardized for this purpose, the DAS-ELISA was applied to both 80 bursal suspensions and 224 corresponding serum samples from vaccinated and non-vaccinated commercial hocks, Bursae samples were collected at 2 weeks of age, and submitted to histological examination, virus isolation in specific pathogen-free chickens embryos, and the DAS-ELISA technique, Serum titres obtained in indirect ELISA and serum neutralization test were compared with those in DAS-ELISA, the agreement was 80% between DAS-ELISA, and the conventional techniques, with high sensitivity (87%) and specificity (90%).

Influence of microgap location and configuration on the periimplant bone morphology in submerged implants. An experimental study in dogs

Objectives: The vertical location of the implant-abutment connection influences the periimplant bone morphology. It is unknown, however, whether different microgap configurations cause different bone reactions. Therefore, in this study the bone morphologies of two different implant systems were compared.Material and methods: Three months after tooth extraction in eight mongrel dogs, two grit-blasted screw implants with internal Morse taper connection (ANK group) were placed on one side whereas the contralateral side received two oxidized screw implants with external hex (TIU group). One implant on each side was placed level with the bone (equicrestal), the second implant was inserted 1.5mm below bone level (subcrestal). After 3 months the implants were uncovered. Three months after stage two surgery, histometrical evaluations were performed in order to assess the periimplant bone levels (PBL), the first bone-to-implant contact points (BICP), the width (HBD) and the steepness (SLO) of the bone defect.Results: All implants osseointegrated clinically and histologically. Bone overgrowth of the microgap was seen in ANK implants only. No significant differences between ANK and TIU could be detected in neither vertical position for PBL and BICP. However, a tendency in favor of ANK was visible when the implants were placed subcrestally. In the parameters HBD (ANK equicrestal -0.23mm; TIU equicrestal -0.51mm; ANK subcrestal +0.19mm; TIU subcrestal -0.57mm) and SLO (ANK equicrestal 35.36 degrees; TIU equicrestal 63.22 degrees; ANK subcrestal 20.40 degrees; TIU subcrestal 44.43 degrees) more pronounced and significant differences were noted.Conclusions: Within the limits of this study, it is concluded that different microgap designs cause different shapes and sizes of the periimplant ('dish-shaped') bone defect in submerged implants both in equicrestal and subcrestal positions.

Influence of Microgap Location and Configuration on Radiographic Bone Loss Around Submerged Implants: An Experimental Study in Dogs

Purpose: The vertical location of the implant-abutment connection influences the subsequent reaction of the peri-implant bone. It is not known, however, whether any additional influence is exerted by different microgap configurations. Therefore, the radiographic bone reactions of two different implant systems were monitored for 6 months. Materials and Methods: In eight mongrel dogs, two implants with an internal Morse-taper connection (INT group) were placed on one side of the mandible; the contralateral side received two implants with an external-hex connection (EXT group). on each side, one implant was aligned at the bone level (equicrestal) and the second implant was placed 1.5 mm subcrestal. Healing abutments were placed 3 months after submerged healing, and the implants were maintained for another 3 months without prosthetic loading. At implant placement and after 1, 2, 3, 4, 5, and 6 months, standardized radiographs were obtained, and peri-implant bone levels were measured with regard to microgap location and evaluated statistically. Results: All implants osseointegrated clinically and radiographically. The overall mean bone loss was 0.68 +/- 0.59 mm in the equicrestal INT group, 1.32 +/- 0.49 mm in the equicrestal EXT group, 0.76 +/- 0.49 mm in the subcrestal INT group, and 1.88 +/- 0.81 mm in the subcrestal EXT group. The differences between the INT and EXT groups were statistically significant (paired t tests). The first significant differences between the internal and external groups were seen at month 1 in the subcrestal groups and at 3 months in the equicrestal groups. Bone loss was most pronounced in the subcrestal EXT group. Conclusions: Within the limits of this study, different microgap configurations can cause different amounts of bone loss, even before prosthetic loading. Subcrestal placement of a butt-joint microgap design may lead to more pronounced radiographic bone loss. INT J ORAL MAXILLOFAC IMPLANTS 2011;26:941-946

Influence of Microgap Location and Configuration on Radiographic Bone Loss in Nonsubmerged Implants: An Experimental Study in Dogs

Purpose: The implant-abutment connection (microgap) influences the pen-implant bone morphology. However, it is unclear if different microgap configurations additionally modify bone reactions. This preliminary study aimed to radiographically monitor pen-implant bone levels in two different microgap configurations during 3 months of nonsubmerged healing. Materials and Methods: Six dogs received two implants with internal Morse taper connection (INT group) on one side of the mandible and two implants with external-hex connection (EXT group) on the other side. One implant on each side was positioned at bone level (equicrestal); the second implant was inserted 1.5 mm below the bone crest (subcrestal). Healing abutments were attached directly after implant insertion, and the implants were maintained for 3 months without prosthetic loading. At implant placement and 1, 2, and 3 months, standardized radiographs were taken to monitor pen-implant bone levels. Results: All implants osseointegrated. A total bone loss of 0.48 +/- 0.66 mm was measured in the equicrestal INT group, 0.69 +/- 0.43 mm in the equicrestal EXT group, 0.79 +/- 0.93 mm in the subcrestal INT group, and 1.56 +/- 0.53 mm in the subcrestal EXT group (P>.05, paired t tests). Within the four groups, bone loss over time became significantly greater in the EXT groups than in the INT groups. The greatest bone loss was noted in the subcrestal EXT group. Conclusion: Within the limits of this animal study, it seems that even without prosthetic loading, different microgap configurations exhibit different patterns of bone loss during nonsubmerged healing. Subcrestal positioning of an external butt joint microgap may lead to faster radiographic bone loss. Int J Prosthodont 2011;24:445-452.

Influence of Microgap Location and Configuration on Peri-implant Bone Morphology in Nonsubmerged Implants: An Experimental Study in Dogs

Purpose: It is unknown whether different micro gap configurations can cause different pen-implant bone reactions. Therefore, this study sought to compare the peri-implant bone morphologies of two implant systems with different implant-abutment connections. Materials and Methods: Three months after mandibular tooth extractions in six mongrel dogs, two oxidized screw implants with an external-hex connection were inserted (hexed group) on one side, whereas on the contralateral side two grit-blasted screw implants with an internal Morse-taper connection (Morse group) were placed. on each side, one implant was inserted level with the bone (equicrestal) and the second implant was inserted 1.5 mm below the bony crest (subcrestal). Healing abutments were inserted immediately after implant placement. Three months later, the peri-implant bone levels, the first bone-to-implant contact points, and the width and steepness of the peri-implant bone defects were evaluated histometrically. Results: All 24 implants osseointegrated clinically and histologically. No statistically significant differences between the hexed group and Morse group were detected for either the vertical position for peri-implant bone levels (Morse equicrestal -0.16 mm, hexed equicrestal -0.22 mm, Morse subcrestal 1.50 mm, hexed subcrestal 0.94 mm) or for the first bone-to-implant contact points (Morse equicrestal -2.08 mm, hexed equicrestal -0.98 mm, Morse subcrestal -1.26 mm, hexed subcrestal -0.76 mm). For the parameters width (Morse equicrestal -0.15 mm, hexed equicrestal -0.59 mm, Morse subcrestal 0.28 mm, hexed subcrestal -0.70 mm) and steepness (Morse equicrestal 25.27 degree, hexed equicrestal 57.21 degree, Morse subcrestal 15.35 degree, hexed subcrestal 37.97 degree) of the pen-implant defect, highly significant differences were noted between the Morse group and the hexed group. Conclusion: Within the limits of this experiment, it can be concluded that different microgap configurations influence the size and shape of the peri-implant bone defect in nonsubmerged implants placed both at the crest and subcrestally. INT J ORAL MAXILLOFAC IMPLANTS 2010;25:540-547

Rapid configuration analysis of the solenopsins

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Complex meiotic configuration of the holocentric chromosomes: the intriguing case of the scorpion Tityus bahiensis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)