832 resultados para Micro parallel kinematic manipulator


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This article presents a proposal of a systemic model composed for the micro and small companies (MSE) of the region of Ribeiro Preto and the agents which influenced their environment. The proposed model was based on Stafford Beer`s (Diagnosing the system for organizations. Chichester, Wiley, 1985) systemic methodologies VSM (Viable System Model) and on Werner Ulrich`s (1983) CSH (Critical Systems Heuristics). The VSM is a model for the diagnosis of the structure of an organization and of its flows of information through the application of the cybernetics concepts (Narvarte, In El Modelo del Sistema Viable-MSV: experiencias de su aplicacin en Chile. Proyecto Cerebro Colectivo del IAS, Santiago, 2001). On the other hand, CSH focus on the context of the social group applied to the systemic vision as a counterpoint to the organizational management view considered by the VSM. MSE of Ribeiro Preto and Sertozinho had been analyzed as organizations inserted in systems that relate and integrate with other systems concerning the public administration, entities of representation and promotion agencies. The research questions: which are the bonds of interaction among the subsystems in this process and who are the agents involved? The systemic approach not only diagnosed a social group, formed by MSE of Ribeiro Preto and Sertozinho, public authorities and support entities, but could also delineate answers that aimed the clarification of obscure questions generating financial assistance to the formularization of efficient actions for the development of this system.

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Telecanthus, the lateral displacement of the medial canthus, can be a congenital deformity or can occur after facial trauma or tumor resection. Treatment of telecanthus remains a challenge for plastic surgeons. For proper correction, it is necessary to shift the medial canthus medially, fixing its tendon to the bone. The ideal technique would allow easy, safe, and stable fixation of the tendon, permit a unilateral approach with minimal incisions, and be cost-effective. The purpose of this study was to evaluate the feasibility and results (immediate and long-term) of medial telecanthus repair using ipsilateral titanium microanchor fixation. Nine patients, 7 with unilateral telecanthus and 2 with bilateral telecanthus, underwent ipsilateral canthopexy involving a microanchor device. Anthropometric measurements of the orbital regions were taken before, immediately after, and at 1 year after surgery. Data for the affected sides were compared with those for the unaffected sides, and the evolution of those values was assessed throughout the 1-year follow-up period. For all patients, the final values were lower than those initially obtained. At 1 year after surgery, the intercanthal distance was reduced to age-adjusted normal values in all cases. On the operated side, stable improvement was observed in terms of the distance from the medial canthus to the midline, although some degree of recurrence was noted in most of the patients. The use of a microanchor system for medial canthopexy can be considered an easily performed and effective option for treating canthal dystopia, especially when an ipsilateral approach is preferred.

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Although planning is important for the functioning of patients with dementia of the Alzheimer Type (DAT), little is known about response programming in DAT. This study used a cueing paradigm coupled with quantitative kinematic analysis to document the preparation and execution of movements made by a group of 12 DAT patients and their age and sex matched controls. Participants connected a series of targets placed upon a WACOM SD420 graphics tablet, in response to the pattern of illumination of a set of light emitting diodes (LEDs). In one condition, participants could programme the upcoming movement, whilst in another they were forced to reprogramme this movement on-line (i.e. they were not provided with advance information about the location of the upcoming target). DAT patients were found to have programming deficits, taking longer to initiate movements; particularly in the absence of cues. While problems spontaneously programming a movement might cause a greater reliance upon on-line guidance, when both groups were required to guide the movement on-line, DAT patients continued to show slower and less efficient movements implying declining sensori-motor function; these differences were not simply due to strategy or medication status. (C) 1997 Elsevier Science Ltd.

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Numerical methods related to Krylov subspaces are widely used in large sparse numerical linear algebra. Vectors in these subspaces are manipulated via their representation onto orthonormal bases. Nowadays, on serial computers, the method of Arnoldi is considered as a reliable technique for constructing such bases. However, although easily parallelizable, this technique is not as scalable as expected for communications. In this work we examine alternative methods aimed at overcoming this drawback. Since they retrieve upon completion the same information as Arnoldi's algorithm does, they enable us to design a wide family of stable and scalable Krylov approximation methods for various parallel environments. We present timing results obtained from their implementation on two distributed-memory multiprocessor supercomputers: the Intel Paragon and the IBM Scalable POWERparallel SP2. (C) 1997 by John Wiley & Sons, Ltd.

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Introduction: Changes in gait cadence caused by challenging situations in daily life might induce higher demand for strength and propulsion in diabetic neuropathic (DN) subjects. Methods: Forty-six subjects (healthy and DN) walked at two cadences (self-selected and 25% higher). Kinematic and electromyographic data were obtained from lower limbs and compared across the gait cycle. Results: DN subjects showed a delayed peak in plantarflexor activity along the whole cycle (irrespective of cadence) compared with healthy subjects. However, during the imposed cadence, DN individuals showed reduced ankle range of motion along the entire cycle compared with the self-selected condition and healthy individuals walking at both cadences (P = 0.002). Conclusions: These findings suggest that when diabetic individuals face a new challenging situation that induces a higher demand for muscle strength and propulsion, the necessary range of motion and neuromuscular control around distal joints are insufficient. Muscle Nerve 44: 258-268, 2011

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Soil structure is generally defined as the arrangement, orientation, and organization of the primary particles of sand, silt, and clay into compound aggregates, which exhibit properties that are unequal to the properties of a mass of nonaggregated material with a similar texture.6 Therefore the nature of soil structure is that it conveys specific properties to the soil and any alteration, i.e., breakdown or structural development, to the soil structural units will affect the physical properties of the soil. The aggregation and organization of the soil particles tend to form a hierarchical order4, 5 where the lower orders tend to have higher densities and greater internal strength than the higher orders. A schematic diagram of the hierarchical nature of soil structural elements in a clay soil is given in Fig. 1.4 Clay particles tend to form domains (packets of parallel clay sheets, generally consisting of 5-7 sheets), in turn several domains form clusters, followed by several orders of clusters, micro- and macroaggregates. The hierarchical nature implies that the destruction of a lower order will result in the destruction of all higher hierarchical orders. An example is the dispersion of sodic clay domains which results in the destruction of all higher orders, resulting in a dense soil with low hydraulic conductivity. Hence the clay domains are the fundamental building blocks of the soil and its integrity may determine the soil's physical properties and behavior.

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Purpose: To compare the efficacy and tolerability of the fixed combination of timolol maleate 0.5%/brimonidine tartrate 0.2% versus fixed combination of timolol maleate 0.5%/dorzolamide 2% in patients with elevated intraocular pressure (IOP) over 8 weeks. Patients and Methods: This 8-week, multicentric. interventional, randomized, open-label, parallel group study was conducted Lit 4 centers in Brazil and 1 center in Argentina. Patients with open-angle glaucoma or ocular hypertension were randomized to receive bilaterally fixed combination of brimonidine/timolol maleate 0.5% or fixed combination of dorzolamide 2%/timolol 0.5% twice daily at 8:00 AM and 8:00 PM. A modified diurnal tension curve (8:00 AM 10:30 AM, 02:00 PM, and 4:00 PM) followed by the water drinking test (WDT), which estimates IOP peak of diurnal tension curve, were performed in the baseline and week-8 visits. Adverse events data were recorded at each visit. Results: A total of 210 patients were randomized (brimonidine/timolol, n = 111; dorzolamide/timolol, n = 99). Mean baseline IOP was 23.43 +/- 3.22 mm Hg and 23.43 +/- 4.06 mm Hg in the patients treated with brimonidine/timolol and dorzolamide/timolol, respectively (P = 0.993). Mean diurnal IOP reduction after 8 weeks were 7.02 +/- 3.06 mm Hg and 6.91 +/- 3.67 mm Hg. respectively (P = 0.811). The adjusted difference between groups (analysis of covariance) Lit week 8 was not statistically significant (P = 0.847). Mean baseline WDT peak was 27.79 +/- 4.29 mm Hg in the brimonidine/timolol group and 27.68 +/- 5.46 mm Hg in the dorzolamide/timolol group. After 8 weeks of treatment, mean WDT peaks were 20.94 +/- 3.76 mm Hg (P < 0.001) and 20.98 +/- 4.19 (P < 0.001), respectively. The adjusted difference between groups (analysis of covariance) was not statistically significant (P = 0.469). No statistical difference in terms of adverse events was Found between groups. Conclusions: Both fixed combinations were capable of significantly reducing the mean diurnal IOP, mean diurnal peak, and mean WDT peak after 8 weeks of treatment. Also, both fixed combinations are well tolerated with few side effects.

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Psychosocial manifestations of erectile dysfunction (ED) differ across cultures. Understanding the treatment response to ED medications within cultural groups can aid in resource allocation and in developing treatment strategies. Evaluate the effect of sildenafil treatment on self-esteem, confidence, and sexual relationship satisfaction in Brazilian men with ED. The Self-Esteem and Relationship (SEAR) questionnaire, a validated, 14-question instrument developed to specifically address self-esteem and relationship issues within the context of ED. Men aged 18 years or older with a clinical diagnosis of ED (<= 21 on the Sexual Health Inventory for Men) and in a stable relationship with a partner during the study were eligible. The primary end point was a change from baseline in the self-esteem subscale of the SEAR questionnaire. Thirteen Brazilian sites participated in a randomized, double-blind, placebo-controlled trial of sildenafil treatment for ED. Patients were randomized to receive either 50 mg of sildenafil (adjustable to 25 mg or 100 mg based on patient response) or matching placebo approximately 1 hour before anticipated sexual activity but not more than once a day. At the end of double-blind treatment, 63 and 66 patients in the placebo and sildenafil groups, respectively, from 13 Brazilian sites were assessed for efficacy. Brazilian patients receiving sildenafil had significantly greater improvements in their scores on the SEAR self-esteem subscale (42.9 [95% confidence interval 35.7-50.0]) compared with placebo (21.1 [95% confidence interval 13.7-28.6]; P < 0.0001). Effect sizes ranged from 0.91 to 1.25 for individual SEAR components. The psychosocial parameters in Brazilian men with ED assessed by the SEAR questionnaire showed significant improvements in self-esteem, confidence, and relationships after treatment with sildenafil. Glina S, Damiao R, Abdo C, Afif-Abdo J, Tseng L-J, and Stecher V. Self-esteem, confidence, and relationships in Brazilian men with erectile dysfunction receiving sildenafil citrate: A randomized, parallel-group, double-blind, placebo-controlled study in Brazil. J Sex Med 2009;6:268-275.

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Purpose: The differential diagnosis in children who walk on their toes includes mild spastic diplegia and idiopathic toe walking (ITW). A diagnosis of ITW is often one of exclusion. To better characterize the diagnosis of ITW, quantitative gait analysis was utilized in a series of patients with an established diagnosis of ITW. Study Design: Patients with an established diagnosis of ITW were analyzed by quantitative gait analysis. Data were recorded as each subject walked in a self-selected toe-walking pattern. The subject was then asked to ambulate making every effort to walk in a normal heel-toe reciprocating fashion. Data were collected to determine if this group of idiopathic toe walkers was able to normalize their gait. Data sets were compared with each other and with historical normal controls. Results: Fifty-one neurologically normal children ( 102 extremities) with ITW were studied in the Motion Analysis Laboratory at a mean age of 9.3 years. In the self-selected trials, significant deviations in both kinematics and kinetics at the level of the ankle were identified. Disruption of all 3 ankle rockers and a plantar flexion bias of the ankle throughout the gait cycle were most commonly seen. When asked to attempt a normal heel-toe gait, 17% of the children were able to normalize both stance and swing variables. In addition, 70% were able to normalize some but not all of the stance and swing variables. Conclusion: Quantitative gait analysis is an effective tool for differentiating mild cerebral palsy from ITW. Kinematic and kinetic distinctions between the diagnoses are evident at the knee and ankle. The ability to normalize on demand at least some of the kinematic and kinetic variables associated with toe walking is seen in most children with ITW.

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Noninvasive assessment of cardiac structure and function is essential to understand the natural course of murine infection with Trypanosoma cruzi. Magnetic resonance imaging (MRI) and echocardiography have been used to monitor anatomy and function; positron emission tomography (PET) is ideal for monitoring metabolic events in the myocardium. Mice infected with T. cruzi (Brazil strain) were imaged 15-100 days post infection (dpi). Quantitative (18)F-FDG microPET imaging, MRI and echocardiography were performed and compared. Tracer ((18)F-FDG) uptake was significantly higher in infected mice at all days of infection, from 15 to 100 dpi. Dilatation of the right ventricular chamber was observed by MRI from 30 to 100 dpi in infected mice. Echocardiography revealed significantly reduced ejection fraction by 60 dpi. Combination of these three complementary imaging modalities makes it possible to noninvasively quantify cardiovascular function, morphology, and metabolism from the earliest days of infection through the chronic phase.

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This in vitro study aimed to determine whether the micro-hardness of a composite resin is modified by the light units or by the thickness of the increment. Composite resin disks were divided into 15 groups (n = 5), according to the factors under study: composite resin thickness (0 mm, 1 mm, 2 mm , 3 mm and 4 mm) and light units. The light activation was performed with halogen light (HL) (40 s, 500 mW/cm(2)), argon ion laser (AL) (30 s, 600 mW/cm(2)) or light-emitting diode (LED) (30 s, 400 mW/cm(2)). Vickers micro-hardness tests were performed after 1 week and were carried out on the top surface (0 mm-control) and at different depths of the samples. Analysis of variance (ANOVA) and Tukey tests (P a parts per thousand currency signaEuro parts per thousand 0.05) revealed no statistically significant difference among the light units for the groups of 0 mm and 1 mm thickness. At 2 mm depth, the AL was not statistically different from the HL, but the latter showed higher micro-hardness values than the LED. In groups with 3 mm and 4 mm thickness, the HL also showed higher micro-hardness values than the groups activated by the AL and the LED. Only the HL presented satisfactory polymerization with 3 mm of thickness. With a 4 mm increment no light unit was able to promote satisfactory polymerization.

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Objective: The objective of this study was to evaluate the influence of the surface treatment and acid conditioning (AC) time of bovine sclerotic dentine on the micro-tensile bond strength (mu-TBS) to an etch and rinse adhesive system. Materials and method: Thirty-six bovine incisors were divided into six groups (n = 6): G1 sound dentine submitted to AC for 15 s; G2-G6 sclerotic dentine: G2-AC for 15 s; G3-AC for 30 s; G4-EDTA and AC for 15 s; G5-diamond bur and AC for 15 s; G6-diamond paste and AC for 15 s. An adhesive system was applied to the treated dentine surfaces followed by a hybrid composite inserted in increments and light cured. After 24 h storage in water at 37 degrees C, the specimens were perpendicularly cut with a low-speed diamond saw to obtain beams (0.8 mm x 0.8 mm cross-sectional dimensions) for mu-TBS testing. Data was compared by ANOVA followed by Tukey`s test (P <= 0.05). Results: The mean L-TBS was G1: 18.87 +/- 5.36 MPa; G2: 12.94 +/- 2.09 MPa; G3: 11.73 +/- 0.64 MPa; G4: 11.14 +/- 1.50 MPa; G5: 22.75 +/- 4.10 MPa; G6: 22.48 +/- 2.71 MPa. G1, G5 and G6 presented similar bond strengths significantly higher than those of all other groups. Conclusion: The surface treatment of sclerotic dentine significantly influenced the bond strength to an adhesive system. Mechanical treatment, either using a diamond bur or a diamond paste was able to improve bonding to bovine sclerotic dentine, reaching values similar to bonding to sound dentine. (C) 2008 Elsevier Ltd. All rights reserved.

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This study tested if dentin adhesion is affected by Er:YAG laser. Ninety dentin disks were divided in groups (n=10): G1, control; G2, Er:YAG laser 150 mJ, 90 degrees contact, 38.8 J/cm(2); G3, Er:YAG laser 70 mJ, 90 degrees contact, 18.1 J/cm(2); G4, Er:YAG laser 150 mJ, 90 degrees non-contact, 1.44 J/cm(2); G5, Er:YAG laser 70 mJ, 90 degrees non-contact, 0.67 J/cm(2); G6, Er:YAG laser 150 mJ, 45 degrees contact, 37.5 J/cm(2); G7, Er:YAG laser 70 mJ, 45 degrees contact, 17.5 J/cm(2); G8, Er:YAG laser 150 mJ, 45 degrees non-contact, 1.55 J/cm(2); and G9, Er:YAG laser 70 mJ, 45 degrees non-contact, 0.72 J/cm(2). Bonding procedures were carried out and the micro-shear-bond strength (MSBS) test was performed. The adhesive surfaces were analyzed under SEM. Two-way ANOVA and multiple comparison tests revealed that MSBS was significantly influenced by the laser irradiation (p < 0.05). Mean values (MPa) of the MSBS test were: G1 (44.97 +/- 6.36), G2 (23.83 +/- 2.46), G3 (30.26 +/- 2.57), G4 (35.29 +/- 3.74), G5 (41.90 +/- 4.95), G6 (27.48 +/- 2.11), G7 (34.61 +/- 2.91), G8 (37.16 +/- 1.96), and G9 (41.74 +/- 1.60). It was concluded that the Er:YAG laser can constitute an alternative tool for dentin treatment before bonding procedures.