991 resultados para ELECTRIC-ARC TECHNIQUE
Resumo:
This paper presents the implementation details of a coded structured light system for rapid shape acquisition of unknown surfaces. Such techniques are based on the projection of patterns onto a measuring surface and grabbing images of every projection with a camera. Analyzing the pattern deformations that appear in the images, 3D information of the surface can be calculated. The implemented technique projects a unique pattern so that it can be used to measure moving surfaces. The structure of the pattern is a grid where the color of the slits are selected using a De Bruijn sequence. Moreover, since both axis of the pattern are coded, the cross points of the grid have two codewords (which permits to reconstruct them very precisely), while pixels belonging to horizontal and vertical slits have also a codeword. Different sets of colors are used for horizontal and vertical slits, so the resulting pattern is invariant to rotation. Therefore, the alignment constraint between camera and projector considered by a lot of authors is not necessary
Resumo:
BACKGROUND Hirschsprung disease (HSCR) is a congenital malformation of the hindgut produced by a disruption in neural crest cell migration during embryonic development. HSCR has a complex genetic etiology and mutations in several genes, mainly the RET proto-oncogene, have been related to the disease. There is a clear predominance of missense/nonsense mutations in these genes whereas copy number variations (CNVs) have been seldom described, probably due to the limitations of conventional techniques usually employed for mutational analysis. METHODS In this study we have aimed to analyze the presence of CNVs in some HSCR genes (RET, EDN3, GDNF and ZFHX1B) using the Multiple Ligation-dependent Probe Amplification (MLPA) approach. RESULTS Two alterations in the MLPA profiles of RET and EDN3 were detected, but a detailed inspection showed that the decrease in the corresponding dosages were due to point mutations affecting the hybridization probes regions. CONCLUSION Our results indicate that CNVs of the gene coding regions analyzed here are not a common molecular cause of Hirschsprung disease. However, further studies are required to determine the presence of CNVs affecting non-coding regulatory regions, as well as other candidate genes.
Resumo:
OBJECTIVE: An animal model has been developed to compare the effects of suture technique on the luminal dimensions and compliance of end-to-side vascular anastomoses. METHODS: Carotid and internal mammalian arteries (IMAs) were exposed in three pigs (90 kg). IMAs were sectioned distally to perform end-to-side anastomoses on carotid arteries. One anastomosis was performed with 7/0 polypropylene running suture. The other was performed with the automated suture delivery device (Perclose/Abbott Labs Inc.) that makes a 7/0 polypropylene interrupted suture. Four piezoelectric crystals were sutured on toe, heel and both lateral sides of each anastomosis to measure anastomotic axes. Anastomotic cross-sectional area (CSAA) was calculated with: CSAA = pi x mM/4 where m and M are the minor and major axes of the elliptical anastomosis. Cross-sectional anastomotic compliance (CSAC) was calculated as CSAC=Delta CSAA/Delta P where Delta P is the mean pulse pressure and Delta CSAA is the mean CSAA during cardiac cycle. RESULTS: We collected a total of 1200000 pressure-length data per animal. For running suture we had a mean systolic CSAA of 26.94+/-0.4 mm(2) and a mean CSAA in diastole of 26.30+/-0.5 mm(2) (mean Delta CSAA was 0.64 mm(2)). CSAC for running suture was 4.5 x 10(-6)m(2)/kPa. For interrupted suture we had a mean CSAA in systole of 21.98+/-0.2 mm(2) and a mean CSAA in diastole of 17.38+/-0.3 mm(2) (mean Delta CSAA was 4.6+/-0.1 mm(2)). CSAC for interrupted suture was 11 x 10(-6) m(2)/kPa. CONCLUSIONS: This model, even with some limitations, can be a reliable source of information improving the outcome of vascular anastomoses. The study demonstrates that suture technique has a substantial effect on cross-sectional anastomotic compliance of end-to-side anastomoses. Interrupted suture may maximise the anastomotic lumen and provides a considerably higher CSAC than continuous suture, that reduces flow turbulence, shear stress and intimal hyperplasia. The Heartflo anastomosis device is a reliable instrument that facilitates performance of interrupted suture anastomoses.
Resumo:
La pose d'un cathéter veineux central peut se faire par plusieurs abords. La connaissance de l'anatomie, du matériel, la maîtrise des détails de la procédure pour chaque type d'abord et une attention particulière à l'asepsie sont des prérequis importants pour limiter les risques de complications et pour donner une information complète et exhaustive au patient. Cet article peut être utilisé comme base pour le développement d'une check-list, utile pour les médecins qui doivent procéder à la pose d'un cathéter veineux central mais qui ne possèdent pas encore une maîtrise du geste. Several approaches exist for central vein catheterization. Mastery of the various steps of this procedure and understanding of the basics of asepsis are critical to prevent any complication. They also built the basis for an exhaustive communication with the patient, to obtain an informed consent. This article can in addition be used to develop a checklist in order to (self-)assess competence in procedural skills
Resumo:
BACKGROUND AND OBJECTIVE: In bladder cancer, conventional white light endoscopic examination of the bladder does not provide adequate information about the presence of "flat" urothelial lesions such as carcinoma in situ. In the present investigation, we examine a new technique for the photodetection of such lesions by the imaging of protoporphyrin IX (PpIX) fluorescence following topical application of 5-aminolevulinic acid (ALA). STUDY DESIGN/MATERIALS AND METHODS: Several hours after bladder instillation of an aqueous solution of ALA in 34 patients, a Krypton ion laser or a filtered Xenon arc-lamp was used to excite PpIX fluorescence. Tissue samples for histological analysis were taken while observing the bladder wall either by means of a video camera, or by direct endoscopic observation. RESULTS: A good correlation was found between the PpIX fluorescence and the histopathological diagnosis. On a total of 215 biopsies, 143 in fluorescent and 72 in nonfluorescent areas, all visible tumors on white light cytoscopy appeared in a bright red fluorescence with the photodetection technique. In addition, this method permitted to discover 47 unsuspected carcinomatous lesions on white light observation, among which 40% were carcinoma in situ. CONCLUSION: PpIX fluorescence induced by instillation into the bladder of 5-ALA is an efficient method of mapping the mucosa in bladder carcinoma.
Resumo:
Référence bibliographique : Rol, 55020
Resumo:
Référence bibliographique : Rol, 55019
Resumo:
Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz's spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis.
Resumo:
Référence bibliographique : Rol, 54795