53 resultados para Lateral sizes
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
Alumina ceramics with high in-line transmittance at 0.5-1.0 mm-thickness were prepared with different doping additives by sintering at 1850 degrees C in vacuum for 1-8 h. Depending on the additive contents and sintering variables bi-dimensionally large surface grains, caused by surface evaporation of MgO, had grown parallel to the surface with similar to 100 mu m thickness and lateral sizes up to the millimeter range. The abnormal grain-growth process also resulted in the formation of pores entrapped inside the large surface grains within a narrow zone at 10-20 mu m distance from the surface. The fraction of these pores is thickness-invariant. Scattering factors associated to the pores entrapped inside the bi-dimensionally large surface grains, second-phase particles, grain-boundaries, and microstructural surface defects are derived from the results of in-line transmission (at 600 nm) and are used together with microstructural characteristics to explain the light transmittance in these materials. (C) 2008 Elsevier Ltd. All rights reserved.
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Aging affects peripheral nerve function and regeneration in experimental models but few literature reports deal with animals aged more than one year. We investigated morphological and morphometric aspects of the sural nerve in aging rats. Female Wistar rats 360, 640 and 720 days old were killed, proximal and distal segments of the right and left sural nerves were prepared for light microscopy and computerized morphometry. No morphometric differences between proximal and distal segments or between right and left sides at the same levels were found in all experimental groups. No increase in fiber and axon sizes was observed from 360 to 720 days. Likewise, no difference in total myelinated fiber number was observed between groups. Myelinated fiber population distribution was bimodal, being the 720-days old animals` distribution shifted to the left, indicating a reduction of the fiber diameters. The 9 ratio distribution of the 720-days old animals` myelinated fiber was also shifted to the left, which suggests axonal atrophy. Morphological alterations due to aging were observed, mainly related to the myelin sheath, which suggests demyelination. Large fibers were more affected than the smaller ones. Axon abnormalities were not as common or as obvious as the myelin changes and Wallerian degeneration was rarely found. These alterations were observed in all experimental groups but were much less pronounced in rats 360 days old and their severity increased with aging. in conclusion, the present study indicates that the aging neuropathy present in the sural nerve of female rats is both axonal and demyelinating. (C) 2008 Elsevier B.V. All rights reserved.
Resumo:
Conventional radiography has shown limitation in acquiring image of the ATM region, thus, computed tomography (CT) scanning has been the best option to the present date for diagnosis, surgical planning and treatment of bone lesions, owing to its specific properties. OBJECTIVE: The aim of the study was to evaluate images of simulated bone lesions at the head of the mandible by multislice CT. MATERIAL AND METHODS: Spherical lesions were made with dental spherical drills (sizes 1, 3, and 6) and were evaluated by using multislice CT (64 rows), by two observers in two different occasions, deploying two protocols: axial, coronal, and sagittal images, and parasagittal images for pole visualization (anterior, lateral, posterior, medial and superior). Acquired images were then compared with those lesions in the dry mandible (gold standard) to evaluate the specificity and sensibility of both protocols. Statistical methods included: Kappa statistics, validity test and chi-square test. Results demonstrated the advantage of associating axial, coronal, and sagittal slices with parasagittal slices for lesion detection at the head of the mandible. RESULTS: There was no statistically significant difference between the types of protocols regarding a particular localization of lesions at the poles. CONCLUSIONS: Protocols for the assessment of the head of the mandible were established to improve the visualization of alterations of each of the poles of the mandible's head. The anterior and posterior poles were better visualized in lateral-medial planes while lateral, medial and superior poles were better visualized in the anterior-posterior plane.
Resumo:
The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling).
Resumo:
OBJETIVO: Realizar estudo histológico comparando o crescimento axonal após neurorrafia término-lateral com e sem epineurectomia. MÉTODOS: foram utilizados vinte ratos Wistar, machos, divididos em dois grupos de 10 ratos cada. Um segmento de 1,0cm do nervo tibial e, foi transposto para o lado contralateral, sendo suturado no nervo ciático D. No grupo I, a sutura foi realizada diretamente no epineuro, enquanto que no grupo II foi realizado epineurectomia. Após 4 semanas foi realizado avaliação histológica do segmento transposto e no nervo ciático D, no sitio distal à lesão. RESULTADOS: demonstrou-se baixa quantidade de fibras remielinizadas, variando de 7 a 51 fibras no Grupo I e de 10 a 91 fibras no Grupo II. Utilizou-se o teste U de Mann-Whitney, com p=0,31, demonstrando que não há diferença estatisticamente significante entre os dois grupos. Não há relação positiva entre o número de fibras remielinizadas no enxerto e no sitio distal à lesão do ciático. CONCLUSÃO: A neurorrafia término-lateral, com e sem janela epineural, não promove remielinização eficiente. Nivel de evidência: Nível II: Estudo prospectivo comparativo
Resumo:
We recently demonstrated that automatic attention favors the right side of space and, in the present study, we investigated whether voluntary attention also favors this side. Six reaction time experiments were conducted. In each experiment, 12 new 18-25-year-old male right-handed individuals were tested. In Experiments 1, 2, 3 (a, b) and 4 (a, b), tasks with increasing attentional demands were used. In Experiments 1, 2, 3a, and 4a, attention was oriented to one or both sides by means of a central spatially informative visual cue. A left or right side visual target appeared 100, 300, or 500 ms later. Attentional effects were observed in the four experiments. In Experiments 2, 3a and 4a, these effects were greater when the cue indicated the right side than when it indicated the left side (respectively: 16 ± 10 and 44 ± 6 ms, P = 0.015, for stimulus onset asynchrony of 500 ms in Experiment 2; 38 ± 10 and 70 ± 7 ms, P = 0.011, for Experiment 3a, and 23 ± 11 and 61 ± 10 ms, P = 0.009, for Experiment 4a). In Experiments 3b and 4b, the central cue pointed to both sides and was said to be non-relevant for task performance. In these experiments right and left reaction times did not differ. The most conservative interpretation of the present findings is that voluntary attention orienting favors the right side of space, particularly when a difficult task has to be performed.
Resumo:
Desembocaduras são ambientes bastante dinâmicos e sujeitos à complexa interação entre fatores estabilizadores e desestabilizadores. Dependendo dessa interação, desembocaduras podem apresentar a tendência de migração ao longo de barreiras arenosas. Um dos mecanismos mais eficientes de transporte de sedimento paralelo à costa, e consequentemente migração de canais, são as correntes longitudinais geradas pelas ondas se aproximando obliquamente à costa. A motivação do presente trabalho é entender o comportamento morfodinâmico do sistema de desembocadura do rio Itapocú, localizado no centro-norte de Santa Catarina (SC), frente aos processos forçantes que atuam na sua migração ao longo da linha de costa. A morfologia dos pontais arenosos foi obtida a partir de levantamentos morfológicos com o uso de DGPS. Para analisar a refração de ondas foi utilizado o modelo numérico MIKE 21 SW, sendo considerados como condições de contorno os dados de ondas referentes ao ano de 2002 e os dados de ondas previstos referentes ao período de coleta. Os dados de saída do modelo foram utilizados para estimar a deriva litorânea potencial na região. Os resultados morfológicos obtidos demonstraram uma migração da desembocadura para o norte durante o período analisado, sendo mais intenso durante o inverno e o verão. Ondas incidentes do quadrante sul sofreram mais o fenômeno da refração e as ondas de leste apresentaram menor variação angular ao se aproximarem à costa. A deriva litorânea potencial anual para os dados de ondas de 2002 apresentou sentido norte-sul, com inversão de sentido durante o outono. Utilizando os dados de ondas previstas para o período dos levantamentos, a deriva litorânea potencial estimada apresentou sentido sul-norte, concordando com a migração observada. Na região próxima a desembocadura, nos pontais arenosos, a deriva potencial apresentou direção para o norte durante todas as estações. Os dados de descarga fluvial não apresentaram influência na migração do canal, porém apresentaram uma relação com a largura do mesmo sazonalmente.Os dados de morfologia juntamente com os dados de deriva litorânea referentes às ondas de 2004/2005 mostraram claramente a migração do canal para o norte sendo a deriva a principal contribuinte para a migração da desembocadura.
Resumo:
The action of the parasympathetic nerves on the heart is made through a group of neurons located on the surface of the atria. This study evaluated the effect of a chronic training protocol on the number and sizes of the cardiac neurons of Wistar rats. Whole mount preparations of the atria of 12-month old male sedentary and trained rats (40 weeks of running on a treadmill 3 times a week, 16 m/min) were assessed for number and size (maximal cellular profile area) of the cardiac neurons. The cardiac neurons were ascertained by using the NADH-diaphorase technique that stains the cell bodies of the neurons in dark blue. The, number of cardiac neurons in the trained rats (P>0.05) did not change significantly. In the sedentary group there were small, medium sized and large neurons. However there was a notable increase in the percentage of small neurons in the rats submitted to the training compared to the sedentary group (P<0.05). Previous studies have shown that electrophysiologically, the small neurons are more easily excitable than the large neurons. It is possible that the results of the present work reflect an adaptation mechanism of the cardiac neurons presumably with the objective of increasing the excitability of the neurons for the vagal action and resulting facilitation of the sinusal bradycardia observed at rest and in the exercise. We concluded that the training affects significantly the size of the cardiac neurons in Wistar rats. (Biol.Sport 26.245-254, 2009)
Resumo:
Background: The Lateral Septal Area (LSA) is involved with autonomic and behavior responses associated to stress. In rats, acute restraint (RS) is an unavoidable stress situation that causes autonomic (body temperature, mean arterial pressure (MAP) and heart rate (HR) increases) and behavioral (increased anxiety-like behavior) changes in rats. The LSA is one of several brain regions that have been involved in stress responses. The aim of the present study was to investigate if the neurotransmission blockade in the LSA would interfere in the autonomic and behavioral changes induced by RS. Methodology/Principal Findings: Male Wistar rats with bilateral cannulae aimed at the LSA, an intra-abdominal datalogger (for recording internal body temperature), and an implanted catheter into the femoral artery (for recording and cardiovascular parameters) were used. They received bilateral microinjections of the non-selective synapse blocker cobalt chloride (CoCl(2), 1 mM/ 100 nL) or vehicle 10 min before RS session. The tail temperature was measured by an infrared thermal imager during the session. Twenty-four h after the RS session the rats were tested in the elevated plus maze (EPM). Conclusions/Significance: Inhibition of LSA neurotransmission reduced the MAP and HR increases observed during RS. However, no changes were observed in the decrease in skin temperature and increase in internal body temperature observed during this period. Also, LSA inhibition did not change the anxiogenic effect induced by RS observed 24 h later in the EPM. The present results suggest that LSA neurotransmission is involved in the cardiovascular but not the temperature and behavioral changes induced by restraint stress.
Resumo:
Objective: To determine if the magnitude of the force used to induce incisor tooth movement promotes distinct activation in cells in the central amygdala (CEA) and lateral hypothalamus (LH) of rats. Also, the effect of morphine on Fos immunoreactivity (Fos-IR) was investigated in these nuclei. Materials and Methods: Adult male rats were anesthetized and divided into six groups: only anesthetized (control), without orthodontic appliance (OA), OA but without force, OA activated with 30g or 70g, OA with 70g in animals pretreated with morphine (2 mg/kg, intraperitoneal). Three hours after the onset of the experiment the rats were reanesthetized and perfused with 4% paraformaldehyde. The brains were removed and fixed, and sections containing CEA and LH were processed for Fos protein immunohistochemistry. Results: The results show that in the control group, the intramuscular injection of a ketamine/xylazine mixture did not induce Fos-IR cells in the CEA or in the LH. Again, the without force group showed a little Fos-IR. However, in the 70g group the Fos-IR was the biggest observed (P < .05, Tukey) in the CEA and LH compared with the other groups. In the 30g group, the Fos-IR did not differ from the control group, the without OA group, and the without force group. Furthermore, pretreatment with morphine in the 70g group reduced Fos-IR in these regions. Conclusions: Tooth movement promotes Fos-IR in the CEA and LH according to the magnitude of the force applied. (Angle Orthod. 2010;80:111-115.)
Resumo:
Background: Recent reviews have indicated that low level level laser therapy (LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing validity of treatment procedures and doses or the influence of prior steroid injections. Methods: Systematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures. Results: 18 randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730 patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Egger's graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p < 0.02). No serious side-effects were reported. Conclusion: LLLT administered with optimal doses of 904 nm and possibly 632 nm wavelengths directly to the lateral elbow tendon insertions, seem to offer short-term pain relief and less disability in LET, both alone and in conjunction with an exercise regimen. This finding contradicts the conclusions of previous reviews which failed to assess treatment procedures, wavelengths and optimal doses.
Resumo:
The paired fronto-lateral gland pores and lattice organs (LO1, 2, 3, 4, and 5) of seven species of pedunculate barnacles belonging to two thoracican suborders, Heteralepadomorpha (family Heteralepadidae: Heteralepas sp. 1 and 2) and Lepadomorpha (families Poecilasmatidae: Poecilasma inaequilaterale and Octolasmis aymonini geryonophila and Lepadidae: Lepas pacifica, Dosima fascicularis, and Conchoderma virgatum), were investigated by scanning electron microscopy (SEM). While the fronto-lateral gland pores exhibit slight variation among species, with only L. pacifica showing a different morphology, the variations in the arrangement of LOs are phylogenetically instructive. The lattice organs in the foregoing species correspond in general to the inferred advanced type (Type C), but the distinct keel in the pore field in P. inaequilaterale and L. pacifica is reminiscent of, but not necessarily identical with the less advanced Type B. The arrangement of the anterior LOs (1-2) is rhomboidal in the two heteralepadomorph species, the two poecilasmatid species, and two of the three lepadid species, as it is in all previously and presently known lepadomorph cyprids except D. fascicularis. In this last species, they are deployed linearly along the hinge line. A linear arrangement of all the lattice organs is presumably the plesiomorphic condition for the Thoracica; an obvious exception being the pattern seen in Ibla cumingi. The arrangement of the first two pairs of posterior LOs (3-4) in O. a. geryonophila and C. virgatum differs from that of all previously described Lepadomorpha in being rhomboidal rather than aligned linearly along the hinge line. This same arrangement of LOs 3 and 4 in the two heteralepadomorph species is notable since it is not known in other thoracicans. Our results concerning variation in lattice organs of the lower Pedunculata are more or less consistent with current phylogenetic speculations and genetic information that ally Heteralepadomorpha with Lepadomorpha. Significance of this variation at lower taxonomic levels is also evident in the two similar forms of Heteralepas.
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Objective: Postural assessment through photography is a simple method that allows the acquisition of quantitative values to define the alignment of body segments. The purpose of this study was to quantitatively assess the postural alignment of several body segments in standing through anterior, posterior, and lateral views. Methods: In this cross-sectional study, 122 subjects were initially evaluated. Seven subjects were excluded from the study after cluster analysis. The final sample had 115 subjects, 75% women with a mean age of 26 + 7 years. Photographs were taken from anterior, posterior, and lateral views after placement of markers on specific anatomical points. Photographs were analyzed using free Postural Analysis Software/Software of Postural Analysis (PAS/SAPO). Quantitative values for postural analysis variables were ascertained for head, upper and lower limbs, and trunk, along with the frequency of inclinations to the left and to the right. Results: Regarding the head, 88% of the sample presented some inclination, 67% of which was to the right. There was a predominance of right inclination of the shoulder and pelvis in 68% and 43% of study subjects, respectively. Lower limbs presented mean alignment of 178 in the anterior view, and the trunk showed predominant right inclination in 66% of participants. Conclusion: Small asymmetries were observed in anterior and posterior views. This study suggests that there is no symmetry in postural alignment and that small asymmetries represent the normative standard for posture in standing. (J Manipulative Physiol Ther 2011;34:371-380)
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Objectives: To study the effect of additional strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise rehabilitation programme for patients with the patellofemoral pain syndrome. Design: Randomized controlled pilot trial. Setting: Clinical setting with home programme. Participants: Fourteen patients with patellofemoral pain syndrome. Intervention: The subjects were randomly assigned to the intervention group (strengthening of quadriceps plus strengthening of hip abductor and lateral rotator muscles) or to the control group (strengthening of quadriceps). Both groups participated in a six-week home exercise protocol. Main outcome measures: The perceived pain symptoms, isokinetic eccentric knee extensor, hip abductor and lateral rotator torques and the gluteus medius electromyographic activity were assessed before and after treatment. Parametric and non-parametric tests were used to compare the groups before and after treatment with alpha = 0.05. Results: Only the intervention group improved perceived pain symptoms during functional activities (P=0.02-0.04) and also increased their gluteus medius electromyographic activity during isometric voluntary contraction (P=0.03), Eccentric knee extensors torque increased in both groups (P=0.04 and P=0.02). There was no statistically significant difference in the hip muscles torque in either group. Conclusion: Supplementation of strengthening of hip abductor and lateral rotator muscles in a strengthening quadriceps exercise programme provided additional benefits with respect to the perceived pain symptoms during functional activities in patients with patellofemoral pain syndrome after six weeks of treatment.