956 resultados para excised axes
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By Monte Carlo simulations, we study the character of the spinglass (SG) phase in dense disordered packings of magnetic nanoparticles (NPs). We focus on NPs which have large uniaxial anisotropies and can be well represented as Ising dipoles. Dipoles are placed on SC lattices and point along randomly oriented axes. From the behaviour of a SG correlation length we determine the transition temperature Tc between the paramagnetic and a SG phase. For temperatures well below Tc we find distributions of the SG overlap parameter q that are strongly sample-dependent and exhibit several spikes. We find that the average width of spikes, and the fraction of samples with spikes higher than a certain threshold does not vary appreciably with the system sizes studied. We compare these results with the ones found previously for 3D site-diluted systems of parallel Ising dipoles and with the behaviour of the Sherrington-Kirkpatrick model.
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This paper adds two analytical devices to domain analysis, claiming that for domain analysis to work cumulatively transferable definitions of domains must be written. To establish this definition the author provides two axes to consider: Ar- eas of Modulation and Degrees of Specialization. These axes may serve as analytical devices for the domain analyst to delineate what is being studied and what is not being studied in a domain analysis.
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2016
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Although several treatments for tendon lesions have been proposed, successful tendon repair remains a great challenge for orthopedics, especially considering the high incidence of re-rupture of injured tendons. Our aim was to evaluate the pharmacological potential of Aloe vera on the content and arrangement of glycosaminoglycans (GAGs) during tendon healing, which was based on the effectiveness of A. vera on collagen organization previously observed by our group. In rats, a partial calcaneal tendon transection was performed with subsequent topical A. vera application at the injury site. The tendons were treated with A. vera ointment for 7 days and excised on the 7(th) , 14(th) , or 21(st) day post-surgery. Control rats received ointment without A. vera. A higher content of GAGs and a lower amount of dermatan sulfate were detected in the A. vera-treated group on the 14(th) day compared with the control. Also at 14 days post-surgery, a lower dichroic ratio in toluidine blue stained sections was observed in A. vera-treated tendons compared with the control. No differences were observed in the chondroitin-6-sulfate and TGF-β1 levels between the groups, and higher amount of non-collagenous proteins was detected in the A. vera-treated group on the 21(st) day, compared with the control group. No differences were observed in the number of fibroblasts, inflammatory cells and blood vessels between the groups. The application of A. vera during tendon healing modified the arrangement of GAGs and increased the content of GAGs and non-collagenous proteins.
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Minor structural alterations of the vocal fold cover are frequent causes of voice abnormalities. They may be difficult to diagnose, and are expressed in different manners. Cases of intracordal cysts, sulcus vocalis, mucosal bridge, and laryngeal micro-diaphragm form the group of minor structural alterations of the vocal fold cover investigated in the present study. The etiopathogenesis and epidemiology of these alterations are poorly known. To evaluate the existence and anatomical characterization of minor structural alterations in the vocal folds of newborns. 56 larynxes excised from neonates of both genders were studied. They were examined fresh, or defrosted after conservation via freezing, under a microscope at magnifications of 25× and 40×. The vocal folds were inspected and palpated by two examiners, with the aim of finding minor structural alterations similar to those described classically, and other undetermined minor structural alterations. Larynges presenting abnormalities were submitted to histological examination. Six cases of abnormalities were found in different larynges: one (1.79%) compatible with a sulcus vocalis and five (8.93%) compatible with a laryngeal micro-diaphragm. No cases of cysts or mucosal bridges were found. The observed abnormalities had characteristics similar to those described in other age groups. Abnormalities similar to sulcus vocalis or micro-diaphragm may be present at birth.
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Maxillofacial trauma resulting from falls in elderly patients is a major social and health care concern. Most of these traumatic events involve mandibular fractures. The aim of this study was to analyze stress distributions from traumatic loads applied on the symphyseal, parasymphyseal, and mandibular body regions in the elderly edentulous mandible using finite-element analysis (FEA). Computerized tomographic analysis of an edentulous macerated human mandible of a patient approximately 65 years old was performed. The bone structure was converted into a 3-dimensional stereolithographic model, which was used to construct the computer-aided design (CAD) geometry for FEA. The mechanical properties of cortical and cancellous bone were characterized as isotropic and elastic structures, respectively, in the CAD model. The condyles were constrained to prevent free movement in the x-, y-, and z-axes during simulation. This enabled the simulation to include the presence of masticatory muscles during trauma. Three different simulations were performed. Loads of 700 N were applied perpendicular to the surface of the cortical bone in the symphyseal, parasymphyseal, and mandibular body regions. The simulation results were evaluated according to equivalent von Mises stress distributions. Traumatic load at the symphyseal region generated low stress levels in the mental region and high stress levels in the mandibular neck. Traumatic load at the parasymphyseal region concentrated the resulting stress close to the mental foramen. Traumatic load in the mandibular body generated extensive stress in the mandibular body, angle, and ramus. FEA enabled precise mapping of the stress distribution in a human elderly edentulous mandible (neck and mandibular angle) in response to 3 different traumatic load conditions. This knowledge can help guide emergency responders as they evaluate patients after a traumatic event.
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BACKGROUND: Total rectocolectomy and ileal pouch-anal anastomosis is the choice surgical procedure for patients with ulcerative colitis. In cases of Crohn's disease post-operative diagnosis, it can be followed by pouch failure. AIM: To evaluate ileal pouch-anal anastomosis long-term outcome in patients with Crohn's disease. METHODS: Between February 1983 and March 2007, 151 patients were submitted to ileal pouch-anal anastomosis by Campinas State University Colorectal Unit, Campinas, SP, Brazil, 76 had pre-operative ulcerative colitis diagnosis and 11 had post-operative Crohn's disease diagnosis. Crohn's disease diagnosis was made by histopathological biopsies in nine cases, being one in surgical specimen, two cases in rectal stump, small bowel in two cases, ileal pouch in three and in perianal abscess in one of them. The median age was 30.6 years and eight (72.7%) were female. RESULTS: All patients had previous ulcerative colitis diagnosis and in five cases emergency colectomy was done by toxic megacolon. The mean time until of Crohn's disease diagnosis was 30.6 (6-80) months after ileal pouch-anal anastomosis. Ileostomy closure was possible in 10 cases except in one that had ileal pouch fistula, perianal disease and small bowel involvement. In the long-term follow-up, three patients had perineal fistulas and one had also a pouch-vaginal fistula. All of them were submitted to a new ileostomy and one had the pouch excised. Another patient presented pouch-vaginal fistula which was successfully treated by mucosal flap. Three patients had small bowel involvement and three others, pouch involvement. All improved with medical treatment. Presently, the mean follow-up is 76.5 months and all patients are in clinical remission, and four have fecal diversion. The remaining patients have good functional results with 6-10 bowel movements/day. CONCLUSION: Crohn's disease diagnosis after ileal pouch-anal anastomosis for ulcerative colitis may be usual and later complications such fistulas and stenosis are common. However, when left in situ ileal pouch is associated with good function.
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OBJECTIVE: To analyze if female Wistar rats at 56 weeks of age are a suitable model to study osteoporosis. MATERIALS AND METHODS: Female rats with 6 and 36 weeks of age (n = 8 per group) were kept over a 20-week period and fed a diet for mature rodents complete in terms of Ca, phosphorous, and vitamin D. Excised femurs were measured for bone mass using dual-energy x-ray absorptiometry, morphometry, and biomechanical properties. The following serum mar-kers of bone metabolism were analyzed: parathyroid hormone (PTH), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor Κappa B ligand (RANKL), C-terminal peptides of type I collagen (CTX-I), total calcium, and alkaline phosphatase (ALP) activity. RESULTS: Rats at 56 weeks of age showed important bone metabolism differences when compared with the younger group, such as, highest diaphysis energy to failure, lowest levels of OC, CTX-I, and ALP, and elevated PTH, even with adequate dietary Ca. CONCLUSION: Rats at 26-week-old rats may be too young to study age-related bone loss, whereas the 56-week-old rats may be good models to represent the early stages of age-related changes in bone metabolism.
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PURPOSE: To evaluate the ocular surface toxicity of two nitric oxide donors in ex vivo and in vivo animal models: S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylcysteine (SNAC) in a hydroxypropyl methylcellulose (HPMC) matrix at final concentrations 1.0 and 10.0 mM. METHODS: Ex vivo GSNO and SNAC toxicities were clinically and histologically analyzed using freshly excised pig eyeballs. In vivo experiments were performed with 20 albino rabbits which were randomized into 4 groups (5 animals each): Groups 1 and 2 received instillations of 150 µL of aqueous HPMC solution containing GSNO 1.0 and 10.0 mM, respectively, in one of the eyes; Groups 3 and 4 received instillations of 150 µL of aqueous HPMC solution-containing SNAC 1.0 and 10.0 mM, respectively, in one of the eyes. The contralateral eyes in each group received aqueous HPMC as a control. All animals underwent clinical evaluation on a slit lamp and the eyes were scored according to a modified Draize eye test and were histologically analyzed. RESULTS: Pig eyeballs showed no signs of perforation, erosion, corneal opacity or other gross damage. These findings were confirmed by histological analysis. There was no difference between control and treated rabbit eyes according to the Draize eye test score in all groups (p>0.05). All formulations showed a mean score under 1 and were classified as non-irritating. There was no evidence of tissue toxicity in the histological analysis in all animals. CONCLUSION: Aqueous HPMC solutions containing GSNO and SNAC at concentrations up to 10.0 mM do not induce ocular irritation.
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Universidade Estadual de Campinas. Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 ± 0.26, B=0.32 ± 0.25 and C=0.32 ± 0.23). For the anteroposterior displacement (A=2.76 ± 1.43, B=2.46 ± 1.48 and C=2.97 ± 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.
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This study evaluated the flexural strength (sf) and the diametral tensile strength (st) of light-cured composite resins, testing the hypothesis that there is a positive relation between these properties. Twenty specimens were fabricated for each material (Filtek Z250- 3M-Espe; AM- Amelogen, Ultradent; VE- Vit-l-escence, Ultradent; EX- Esthet-X, Dentsply/Caulk), following ISO 4049 and ANSI/ADA 27 specifications and the manufacturers’ instructions. For the st test, cylindrical shaped (4 mm x 6 mm) specimens (n = 10) were placed with their long axes perpendicular to the applied compressive load at a crosshead speed of 1.0 mm/min. The sf was measured using the 3-point bending test, in which bar shaped specimens (n = 10) were tested at a crosshead speed of 0.5 mm/min. Both tests were performed in a universal testing machine (EMIC 2000) recording the fracture load (N). Strength values (MPa) were calculated and statistically analyzed by ANOVA and Tukey (a = 0.05). The mean and standard deviation values (MPa) were Z250-45.06 ± 5.7; AM-35.61 ± 5.4; VE-34.45 ± 7.8; and EX-42.87 ± 6.6 for st; and Z250-126.52 ± 3.3; AM-87.75 ± 3.8; VE-104.66 ± 4.4; and EX-119.48 ± 2.1 for sf. EX and Z250 showed higher st and sf values than the other materials evaluated (p < 0.05), which followed a decreasing trend of mean values. The results confirmed the study hypothesis, showing a positive relation between the material properties examined.
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Os autores discutem, a partir do conceito evolutivo, como a resposta de estresse, nas suas possibilidades de fuga e luta e de imobilidade tônica, pode levar a uma nova compreensão etiológica do transtorno de estresse pós-traumático. Através da análise dos agrupamentos de sintomas desse diagnóstico - revivência, evitação e hiperexcitação -, procuram correlacionar os achados neurobiológicos e evolutivos. As descobertas atuais sobre a genética do transtorno de estresse pós-traumático são resumidas e colocadas nessa perspectiva evolutiva, dentro de conceitos que possibilitam o entendimento da interação gene/ambiente, como a epigenética. Propõem que a pesquisa dos fatores de risco do transtorno de estresse pós-traumático deva ser investigada do ponto de vista fatorial, onde a somatória destes aumenta o risco de desenvolvimento do quadro, não sendo possível a procura da causa do transtorno de forma única. A pesquisa de genes candidatos no transtorno de estresse pós-traumático deve levar em consideração todos os sistemas associados aos processos de respostas ao estresse, sistemas dos eixos hipotálamo-hipofisário-adrenal e simpático, mecanismos de aprendizado, formação de memórias declarativas, de extinção e esquecimento, da neurogênese e da apoptose, que envolvem vários sistemas de neurotransmissores, neuropeptídeos e neuro-hormônios.
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Um eqüino de nove anos de idade apresentou ausência de ar expirado e secreção serossanguinolenta na narina direita, associado a ruído respiratório. Os exames endoscópico e radiológico mostraram uma formação de aproximadamente seis centímetros de diâmetro recoberta por mucosa amarelada, que obstruía a cavidade nasal direita e insinuava-se para a cavidade nasal esquerda. Tal massa foi ressecada por meio de sinusotomia frontal direita. O exame histológico e a cultura revelaram lesão granulomatosa causada por fungos. O tratamento pós-operatório compreendeu associação de antibiótico e antiinflamatório, assim como de lavagens com água destilada e chá de camomila.