115 resultados para Modelo Soft Soil Creep


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Joint pedological, geochemical, hydrological and geophysical investigations were performed to study the coexistence or saline and freshwater lakes in close proximity and similar climatic conditions in the Nhecolandia region, Pantanal wetlands in Brazil. The saline lakes are concentrically surrounded by green sandy loam horizons, which cause differential hydrological regimes. Mg-calcite, K-silicates, and amorphous silica precipitate in the soil cover, whereas Mg-silicates and more soluble Na-carbonates are concentrated in the topsoil along the shore of the saline lake. In saline solutions, some minor elements (As, Se) reach values above the water quality recommendations, whereas others are controlled and incorporated in solid phases (Ba, Sr). Locally, the destruction of the sandy loam horizons generates very acidic soil solution (pH similar to 3.5) through a process not yet understood. The soil distributions indicate that some freshwater lakes are former saline lakes. They are invaded by freshwater after destruction of the sandy loam green horizons, then the freshwater becomes enriched in K(+), SO(4)(2-), Fe, Al, and a stream of minor and trace elements. The formation of these green sandy loam horizons in the saline environment and their destruction in the non-saline one emphasizes the dynamic nature of this environment (C) 2008 Elsevier B.V. All rights reserved.

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Adipose tissue tumors of the retroperitoneum showing no identifiable cytologic atypia are usually classified as lipoma-like well-differentiated liposarcoma. Whether a subset of these tumors represents true examples of retroperitoneal lipoma remains a controversial subject, because the diagnostic liposarcoma cells may be of difficult identification, even after extensive sampling. Herein, we describe a large retroperitoneal lipoma with classic histopathologic, cytogenetic, molecular cytogenetic, and molecular genetic features. Extensive morphologic inspection showed no evidence of cytologic atypia. Cytogenetic analysis performed on fresh tissue material revealed the classic lipoma chromosome t(3;12)(q27;q14-15). Fluorescence in situ hybridization on multiple sections excluded the presence of MDM2 and CDK4 amplification, but showed HMGA2 balanced rearrangement in most cells. Reverse-transcriptase polymerase chain reaction followed by sequencing analysis confirmed the presence of the HMGA2-LPP fusion gene, a characteristic and the most common fusion product found in lipoma. The patient has been followed for 2.5 years without evidence of recurrence or metastasis. These results indicate that retroperitoneal lipomata do exist, but their diagnosis must rely on stringent histologic, cytogenetic, and molecular genetic analysis.

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A 44-year-old man presented with progressive dyspnea and a previous pneumothorax. Chest CT scan showed a mediastinal shift due to giant bullae containing soft tissue and fatty components in the left lower lung Lobe, and a right upper lung lobe partially collapsed. The pulmonary function tests revealed forced vital capacity (FVC) 53% (of the predicted) and forced vital capacity in 1 s (FEV1) 52%. Then, resection of the lower lobe was performed with intention to prevent other pneumothoraxes and to revert the upper lobe collapse. The pathological examination showed a placental. transmogrification of the lung (PTL). One month after the surgery, the patient was asymptomatic, the pulmonary function tests normalized and the upper lobe was well expanded. In conclusion, we described the first CT finding of soft tissue and fatty components within the PTL-related bullae, and the PTL should be considered in the differential diagnosis of pulmonary lesions with soft-fatty and air components. (c) 2007 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

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Knee osteoarthritis (OA) has to be considered a whole joint disease. Magnetic resonance imaging (MRI) allows superior assessment of all joint tissues that may be involved in OA, such as the subchondral bone, synovium, ligaments, and periarticular soft tissues. Reliable MRI-based scoring systems are available to assess and quantify these structures and associated pathology. Cross-sectional and longitudinal evaluation has enabled practitioners to understand their relevance in explaining pain and structural progression.

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The biological cause of broiler PSE meat seems to be an excessive release of Ca(2+), promoted by a genetic mutation of ryanodine receptors located in the sarcoplasmic reticulum of skeletal muscle cells. Excessive Ca(2+), associated with protein denaturation in meat, enhances protease activity and influences the functional properties of PSE meat. Twenty-four-hour post-mortem Pectoralis major m. samples exhibited lower values for pH, water-holding capacity, and shear force than did control samples, in contrast to colour (L*) and cooking loss values. Protease activity, measured as myofibril fragmentation index, presented higher values in PSE meat than in control samples. Ultrastructural examination revealed shrinking and depolymerisation of myofilaments and Z-lines disorganisation within the sarcomere in PSE meat. Intense calpain activity was also observed, indicating that the process may initiate at the filaments, because of protein denaturation, and spread through Z-lines, resulting in the collapse of the sarcomere structure. (C) 2009 Elsevier Ltd. All rights reserved.

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Background: Matrix metalloproteinase (MMP) inhibitors reduce dentine erosion. This in vitro study evaluated the effect of the supplementation of soft drinks with green tea extract, a natural inhibitor of MMPs, on their erosive potential against dentine. Methods: For each drink tested (Coca-Cola (TM), Kuat (TM) guarana, Sprite (TM) and light Coca-Cola (TM)), 40 dentine specimens were divided into two subgroups differing with respect to supplementation with green tea extract at 1.2% (OM24 (R), 100% Camellia sinensis leaf extract, containing 30 +/- 3% of catechin; Omnimedica, Switzerland) or not (control). Specimens were subjected to four pH cycles, alternating de-and remineralization in one day. For each cycle, samples were immersed in pure or supplemented drink (10 minutes, 30 mL per block) and in artificial saliva (60 minutes, 30 mL per block) at 37 degrees C, under agitation. Dentine alterations were determined by profilometry (mu m). Data were analysed by two-way ANOVA and Bonferroni`s test (p < 0.05). Results: A significant difference was observed among the drinks tested with Sprite (TM) leading to the highest surface loss and light Coca-Cola (TM) to the lowest. Supplementation with green tea extract reduced the surface loss by 15% to 40% but the difference was significant for Coca-Cola (TM) only. Conclusions: Supplementation of soft drinks with green tea extract might be a viable alternative to reduce their erosive potential against dentine.

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Acidic soft drinks are potentially erosive for dental hard tissues. This in vitro study evaluated the effect of calcium, fluoride, iron and phosphate, supplemented alone or in combination to a commercial citric acid-based carbonated beverage on dental erosion. Ninety enamel samples (4 x 4 x 3 mm) were randomly allocated to nine groups (n = 10): G1 - pure beverage (control); G2 - with 1 mM Ca; G3 - with 0.047 mM F; G4 - with 1 mM Fe; G5 - with 1 mM P; G6 - with 1 mM Ca and 0.047 mM F; G7 - with 1 mM Ca and 1 mM P; G8 - with 1 mM Fe and 0.047 mM F; and G9 - with 1 mM Ca, 1 mM P, 0.047 mM F and 1.0 mM Fe. The samples were subjected to six pH cycles over a 24-h period. In each cycle, the samples were immersed in pure or modified beverage (1 min) and in artificial saliva (59 min). During the remaining period (18 h), the samples were maintained in artificial saliva. Enamel loss was assessed by profilometry (mm). Data were tested using ANOVA and Tukey`s tests (p < 0.05). Highest enamel losses were observed in the control group (G1) and in the groups containing Fe (G4 and G8). The groups containing Ca (G2 and G6) showed significantly less wear compared to control. In conclusion, the modification of an erosive soft drink with low concentrations of Ca with or without F may reduced its erosive potential.

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Objective: This in situ/ex vivo study assessed the effect of titanium tetrafluoride (TiF4) on permanent human enamel subjected to erosion. Design: Ten volunteers took part in this study performed in two phases. In the first phase (ERO), they wore acrylic palatal appliances containing two enamel blocks, divided into two rows: TiF4 (F) and no-TiF4 (no-F). During the 1st day, the formation of a salivary pellicle was allowed. In the 2nd day, the TiF4 solution was applied on one row (ERO + F), whereas on the other row no treatment was performed (ERO + no-F). From 3rd until 7th day, the blocks were subjected to erosion, 4x per day. In the 2nd phase (no-ERO), the volunteers wore acrylic palatal appliances containing one enamel block, during 2 days, to assess the effect of TiF4 only (no-ERO + F). Enamel alterations were determined using profilometry (wear), microhardness (%SMHC) tests, scanning electron microscope and microprobe analysis. The %SMHC and wear were tested using ANOVA and Tukey`s post hoc tests (p < 0.05). Results: The mean of %SMHC and wear ( mu m) values ( +/- S.D.) were, respectively: ERO + F -73.32 +/- 5.16(A)/2.40 +/- 0.60(a); ERO + no-F -83.49 +/- 4.59B/1.17 +/- 0.48(b) and no-ERO + F -67.92 +/- 6.16(A)/0.21:E 0.09(c). In microscope analysis, the no-F group showed enamel with honeycomb appearance. For F groups, it was observed a surface coating with microcracks. The microprobe analysis revealed the presence of the following elements (%) in groups ERO + F, ERO + no-F and no-ERO + F, respectively: Ca (69.9, 72.5, 66.25); P (25.9, 26.5, 26.06); Ti (3.0, 0, 5.93). Conclusions: The TiF4 was unable to reduce dental erosion. (c) 2007 Elsevier Ltd. All rights reserved.

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OBJECTIVE: The G/BBB syndrome is an X-linked recessive disorder characterized by eye anomalies, laryngotracheoesophageal cleft, congenital heart disease, genitourinary anomalies and gastrointestinal disorders. Patients may also present cleft lip and palate, high-arched palate and thin upper lip. This study aimed to investigate the occurrence of tooth abnormalities and soft tissue changes in patients with G/BBB syndrome. DESIGN: Cross-sectional. SUBJECTS AND METHODS: Twenty-one patients with G/BBB syndrome were analyzed as to the presence of tooth abnormalities and soft tissue alterations. MAIN OUTCOME MEASURES: The prevalence of tooth agenesis and supernumerary teeth was compared to patients without morphofunctional alterations, matched for gender and age. RESULTS: All patients had complete cleft lip and palate; 95.23% of patients presented tooth abnormalities, mainly hypoplastic alterations, with predominance of alterations of number, followed by alterations of structure, shape and position. The frequency of tooth agenesis and supernumerary teeth was significantly higher compared with the control group; 11 patients presented incisiform supernumerary teeth in the mandibular anterior region. Ankyloglossia was observed in 11 of 21 patients. CONCLUSION: The presence of mandibular anterior supernumerary teeth and ankyloglossia should be investigated in the clinical evaluation of patients with suspected diagnosis of the G/BBB syndrome. Oral Diseases (2008) 14, 747-753

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Objective. The objective of this study was to investigate the prevalence of tooth abnormalities and soft tissue changes in patients with velocardiofacial syndrome. Study design. Twenty-six patients with velocardiofacial syndrome were examined to investigate the presence of tooth abnormalities and soft tissue alterations. The occurrence of tooth agenesis and supernumerary teeth was compared to patients without morphofunctional alterations, matched for gender and age. Results. Of all patients, 76.92% exhibited at least one tooth abnormality, with predominance of hypoplastic alterations, especially represented by hypodevelopment of the lingual cusp of mandibular first premolars and enamel opacities. The occurrence of tooth agenesis and supernumerary teeth was similar in both study and control groups. Conclusion. the present results suggest an association between hypodevelopment of the lingual cusp of mandibular first premolars and enamel opacities, yet these findings still require corroboration. Future studies should further investigate these aspects in larger samples compared to control groups, as well as employing molecular genetics techniques.