498 resultados para rib
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This work presents for the first time to our knowledge the fabrication and characterization of rib waveguides produced with PbO-GeO(2) (PGO) thin films. The target was manufactured using pure oxides ( 60 PbO-40 GeO(2), in wt%) and amorphous thin films were produced with the RF sputtering technique. PGO thin films present small absorption in the visible and in the near infrared and refractive index of similar to 2.0. The definition of the rib waveguide structure was made using conventional optical lithography followed by plasma etching, performed in a Reactive Ion Etching (RIE) reactor. Light propagation mode in the waveguide structure was analyzed using integrated optic simulation software. Optical loss measurements were performed to determine the propagation loss at 633 nm, for ribs with height of 70 nm and width of 3-5 mu m; experimental values around 2 dB/cm were found for the propagation loss and confirmed the theoretical calculations. The results obtained demonstrate that PGO thin films are potential candidates for application in integrated optics. Published by Elsevier B.V.
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Paracoccidioidomycosis is a systemic mycosis with a geographic distribution that is limited to Central and South America; Brazil has the highest number of cases. Severe disseminated disease caused by paracoccidioidomycosis was observed in acquired immunodeficiency syndrome patients who live or have resided in endemic paracoccidioidomycosis areas. Here we describe a male patient admitted to a large public hospital with diffuse nodular infiltrates observed in chest radiographs and with erosion at the second rib near the sternum. Blood tests showed anti human immunodeficiency virus antibodies, a human immunodeficiency virus viral load of 59 700 (4.8 log), and CD4 144/mm(3), with negative serology result for fungal infections. Aspirate of the rib lesion showed cells with a typical morphology of Paracoccidioides brasiliensis, aside from benign inflammatory cells. The histology of the rib biopsy showed typical granulomas and immunostained fungal cells. Although there was no growth in the Sabouraud cultures, Paracoccidioides brasiliensis gp43 and rDNA genes were detected in the aspirate by polymerase chain reaction. Therapy with amphotericin resulted in complete recovery. This type of bone lesion is rare and has been described primarily in the juvenile form of paracoccidioidomycosis; it must be included in the differential diagnosis of bone lesions in adult acquired immunodeficiency syndrome patients of endemic areas. (C) 2010 Elsevier Inc. All rights reserved.
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Objectives: Severe glottic/subglottic stenosis (complex laryngotracheal stenosis) is a rare but challenging complication of endotracheal intubation. Laryngotracheal reconstruction with cartilage graft and an intralaryngeal stent is a procedure described for complex laryngotracheal stenosis management in children; however, for adults, few options remain. Our aim was to analyze the results of laryngotracheal reconstruction as a treatment for complex laryngotracheal stenosis in adults, considering postoperative and long-term outcome. Methods: Laryngotracheal reconstruction (laryngeal split with anterior and posterior interposition of a rib cartilage graft) has been used in our institution to manage glottic/subglottic stenosis restricted to the larynx; laryngotracheal reconstruction associated with cricotracheal resection has been used to treat glottic/subglottic/upper tracheal stenosis (extending beyond the second tracheal ring). A retrospective study was conducted, including all patients with complex laryngotracheal stenosis treated surgically in our institution from January of 2002 until December of 2005. Results: Twenty patients (10 male and 10 female patients; average age, 36.13 years; age range, 18-54 years) were included. There were no deaths, and the postoperative complications were as follows: dysphonia, 25%; subcutaneous emphysema, 10%; tracheocutaneous fistula, 20%; wound infection, 15%; and bleeding, 5.0%. Eighty percent of the patients were completely decannulated after a mean of 23.4 months of follow-up (range, 4 -55 months). Conclusions: Laryngeal split with anterior and posterior cartilage graft interposition as an isolated procedure or associated with a cricotracheal resection is a feasible and low-morbidity alternative for complex laryngotracheal stenosis treatment.
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An asymptomatic 48-year-old woman presented to our hospital with a tumor of the rib incidentally diagnosed on a chest roentgenogram. The patient was investigated and underwent tumor resection of the chest wall. The pathologic study revealed that it was cavernous hemangioma. This tumor of the bone is a distinctly uncommon benign vascular tumor, generally occurring in the spine or skull. Hemangiomas involving the rib are even more rare, with only 22 cases described in the literature. However, we suggest that this tumor of the rib should be considered in the differential diagnosis, principally in asymptomatic patients. (Ann Thorac Surg 2011;91:595-6) (C) 2011 by The Society of Thoracic Surgeons
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A true neurogenic thoracic outlet syndrome (TOS) associated with a cervical rib is considered extremely rare. The authors present their experience with 5 cases of true neurogenic TOS associated with a cervical rib. All patients were female and had a cervical rib confirmed radiographically pre-operatively. Average age was 34,8 years. Although all patients had been treated with several combinations of diverse drugs and a rehabilitation program before referral to surgery, all described their pain as intense and debilitating before surgical treatment. All patients had pre-operative electromyographic abnormalities. Patients were operated on via a supraclavicular approach and the cervical rib was resected. No intra-operative or postoperative complications were noted. Two years postoperatively, all patients mentioned improvement. However, only 2 were symptomless, and on no medication. In one patient there was significant improvement, and in the remaining 2 patients some residual pain persisted that had to be dealt with pharmacologically. All patients were able to resume their daily life activities. Recovery was poorer in the 2 patients that had been referred to surgery after a longer period of time since the beginning of symptoms.
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1. The author suggests a tecnique for the determination of vitamin A on shark liver oils in industrial plants. The advantages of using oly four ml. of reagent and of permitting a quickly rigorous reading by photoeletric cell, contribute to the possibility of the examination of a great number of samples daily; 2. It is described a survey on the vitamin A content of oils from shark livers, which has been made at the Finishing School Darcy Vargas, Marammaia Is., Rio de Janeiro State. The conclusions are the following: a) Male individuals have showed generally tendency for higher vitamin A pontency oils; b) The size of the fish does not interfere in the vitamin content of the oil (graphic 4); c) The data collected upon 3.085 individuals led to the conclusion that some species are richer in the reservated vitamin although it was possible to catch in the same specie fishes with widely variable potency in vitamin A. One fish belonging to the specie C. lamia produced the highest vitamin potency oil with 167.712 international units per gram; d) The fishing season appears to have no influence on the oils; e) The adventitous food seems to be the most important factor affecting the content of vitamin A of the shark-liver oils; 3. The presence and the quantity of vitamin D in those oils was investigated and two of the determinations are presented.
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Field-work in the sierras near the sea-board of south-eastern Brazil continues to yield new or rare frogs. Four more of these forms are presented here. Two of them, both new, are put into the genus Eleutherodactylus, to which they belong by their general habitat, morphology, and also by the osteological characters. They differs from the known regional species of this genus only by the wider and shorter disks of some of the digits and the more lanceolate build. The other two species belong to the very little known genus Holoaden, established by MIRANDA RIBEIRO in 1920. One of them is his type-species, H. lüderwaldti, which continues to be very rare. The other, H. bradei, is new. It seems endemic to the Upper Itatiaia and is very plentiful there.
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We report on the study and modeling of the structural and optical properties of rib-loaded waveguides working in the 600-900-nm spectral range. A Si nanocrystal (Si-nc) rich SiO2 layer with nominal Si excess ranging from 10% to 20% was produced by quadrupole ion implantation of Si into thermal SiO2 formed on a silicon substrate. Si-ncs were precipitated by annealing at 1100°C, forming a 0.4-um-thick core layer in the waveguide. The Si content, the Si-nc density and size, the Si-nc emission, and the active layer effective refractive index were determined by dedicated experiments using x-ray photoelectron spectroscopy, Raman spectroscopy, energy-filtered transmission electron microscopy, photoluminescence and m-lines spectroscopy. Rib-loaded waveguides were fabricated by photolithographic and reactive ion etching processes, with patterned rib widths ranging from 1¿to¿8¿¿m. Light propagation in the waveguide was observed and losses of 11dB/cm at 633 and 780 nm were measured, modeled and interpreted.
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Power leakage properties and guiding conditions of rib antiresonant reflecting optical waveguides (rib-ARROW) have been theoretically and experimentally studied as a function of wavelength and polarization of the light for different geometrical and optical parameters that characterize the rib-ARROW structure. Obtained results show that rib-ARROWs can only be fabricated with low losses in a wavelength range when determined rib configurations are adopted. Furthermore, these waveguides exhibit a polarization sensitivity that largely depends on the core-substrate refractive index difference. Together with the experimental results, theoretical calculations from different modeling methods are also presented and discussed.
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The Simpson-Golabi-Behmel syndrome type 1 (SGBS1, OMIM #312870) is an X-linked overgrowth condition comprising abnormal facial appearance, supernumerary nipples, congenital heart defects, polydactyly, fingernail hypoplasia, increased risk of neonatal death and of neoplasia. It is caused by mutation/deletion of the GPC3 gene. We describe a macrosomic 27-week preterm newborn with SGBS1 who presents a novel GPC3 mutation and emphasize the phenotypic aspects which allow a correct diagnosis neonatally in particular the rib malformations, hypoplasia of index finger and of the same fingernail, and 2nd-3rd finger syndactyly.
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To evaluate the sensitivity of postmortem computed tomography (PMCT) in rib fracture detection validated against autopsy. Fifty-one forensic cases underwent a postmortem CT prior to forensic autopsy. Two image readers (radiologist and forensic pathologist) assessed high resolution CT data sets for rib fractures. Correct recognition rates (CRR), sensitivity and specificity values were calculated over all observations as well as individually for every rib and region. Additionally, for partial rib fractures the sensitivity of autopsy was calculated vice versa. 3876 entries in each study protocol (autopsy, PMCT radiologist and PMCT forensic pathologist) were investigated. A total of 690 fractures (autopsy), 491 (PMCT and radiologist) and 559 (PMCT and forensic pathologist) were detected. The CRR was 0.85. Sensitivity and specificity of PMCT for rib fracture detection were 0.63 (0.58 radiologist, 0.68 forensic pathologist) and 0.97 (both readers 0.97), respectively. Low CRR and sensitivity values were obtained for antero-lateral fractures. Partial rib fractures were better detected by PMCT. PMCT has a rather low sensitivity for rib fracture detection when validated against autopsy and indicates that clinical CT may also demonstrate a reasonable number of false negatives. Partial rib fractures often remain undetected at autopsy.
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Focused ion beam milling is a processing technology which allows flexible direct writing of nanometer scale features efficiently substituting electron beam lithography. No mask need results in ability for patterns writing even on fragile micromechanical devices. In this work we studied the abilities of the tool for fabrication of diffraction grating couplers in silicon nitride waveguides. The gratings were fabricated on a chip with extra fragile cantilevers of sub micron thickness. Optical characterization of the couplers was done using excitation of the waveguides in visible range by focused Gaussian beams of different waist sizes. Influence of Ga+ implantation on the device performance was studied.
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Ewing sarcoma or primitive neuroectodermal tumor (PNET) of bone is the second most common pediatric malignant bone tumor. The median age at diagnosis is 15 years and there is a male predilection of 1.5/1. The authors present the case of a 14-year-old boy with Ewing sarcoma situated on the left ninth rib which was being investigated for respiratory tract infection. Pleurisy is the most common misdiagnosis. Our case illustrates the importance of recognizing exceptional features when interpreting FDG PET or scintigraphy to prevent the misinterpretation of metastases as other etiologies, such as infection.