Electromyographic validation of the double pulley equipment during movements of the lower limbs

The double pulley equipment was tested on ten male volunteers during contraction of the semitendinosus and biceps femoris (caput longum) muscles in the following movements of the lower limbs: 1) hip extension with extended knee and erect trunk, 2) hip extension with flexed knee and erect trunk, 3) hip extension with flexed knee and erect trunk, 3) hip extension with extended knee and inclined trunk, 5) hip abduction along the midline, 7) hip abduction with extension beyond the midline, 8) adduction with hip flexion beyond the midline, 8) adduction with hip flexion beyond the midline, and 9) adduction with hip extension beyond the midline. The myoelectric signals were taken up by Lec Tec surface electrodes connected to a 6-channel Lynx electromyographic signal amplifier coupled with a computer equipped with a model CAD 10/26 analogue digital conversion board and with a specific software for signal recording and analysis. The semitendinosus and biceps femoris muscles presented the highest potentials in movements 1; 2; 7, 8 and 9, whereas the potentials in the remaining movements were negligible. The pattern of activity of the semitendinosus and the biceps femoris was similar in exercises 1, 2, 3, 4 and 8. The potentials of the semitendinosus prevailed in movements 5, 6 and 7, and the strongest potentials observed in movement 9 were those of the biceps femoris.

Multipath reduction from GPS double differences using wavelets: How far can we go?

Wavelets are being extensively used in Geodetic applications. In this paper, the Multi-Resolution Analysis (MRA) using wavelets is applied to pseudorange and carrier phase GPS double differences (DDs) in order to reduce multipath effects. The wavelets were already applied to GPS carrier phase DDs, but some questions remain: How good can be the results, and are all multipath effects reduced? The answers to these questions are discussed in this paper. Thus, the wavelet transform is used to decompose the DD signals, splitting them in lower resolution components. After the decomposition process, the wavelet shrinkage is performed by thresholding to eliminate the components relative to multipath effects. Then, the DD observation can be reconstructed. This new DD signal is used to perform the baseline processing. The daily multipath repeatability was verified. With the application of the proposed approach, the results showed that the reliability of the ambiguity resolution and accuracy of the results improved when compared with the standard procedure. Furthermore, the method showed to be very efficient computationally, because, it is not noticed, at practical level, difference in the time span between the processing with and without application of the proposed method. However, only the high frequency multipath was eliminated.

Low intensity laser therapy in the treatment of temporomandibular disorders: A double-blind study

This study aimed to evaluate the effectiveness of low intensity laser therapy (LILT) in 30 patients presenting temporomandibular joint (TMJ) pain and mandibular dysfunction in a random and double-blind research design. The sample, divided into experimental group (1) and placebo group (2), was submitted to the treatment with infrared laser (780 nm, 30 mW, 10 s, 6.3 J/cm2) at three TMJ points. The treatment was evaluated throughout six sessions and 15, 30 and 60 days after the end of the therapy, through visual analogue scale (VAS), range of mandibular movements and TMJ pressure pain threshold. The results showed a reduction in VAS (p < 0.001) and through the ANOVA with repeated measures it was observed that the groups did not present statistically significant differences (P = 0.2060), as the averages of the evaluation times (P = 0.3955) and the interaction groups evaluation times (P = 0.3024), considering the MVO. The same occurred for RLE (P = 0.2988, P = 0.1762 and P = 0.7970), LLE (P = 0.3265, P = 0.4143 and P = 0.0696), PPTD (P = 0.1558, P = 0.4695 and P = 0.0737) and PPTE (P = 0.2376, P = 0.3203 and P = 0.0624). For PE, there were not statistically significant differences for groups (P = 0.7017) and the interaction groups evaluation times (P = 0.6678), even so in both groups the PE varied with time (P = 0.0069). © 2005 Blackwell Publishing Ltd.

Double optical monitoring of time-dependent film formation

A brief overview of optical monitoring for vacuum and wet bench film deposition processes is presented. Interferometric and polarimetric measurements are combined with regard to simultaneous real-time monitoring of refractive index and physical thickness. Monitor stability and accuracy are verified with transparent oil standards. This double optical technique is applied to dip coating with a multi-component Zirconyl Chloride aqueous solution, whose time varying refractive index and physical thickness curves indicate significant sensitivity to changes of film flow properties during the process.

Double Higgs production at the LHC as a robust test of little Higgs models

We analyze double Higgs boson production at the LHC in the context of Little Higgs models. In double Higgs production, the diagrams involved are directly related to those that cause the cancellation of the quadratic divergence of the Higgs self-energy, so this mode provides a robust prediction for this class of models. We find that in extensions of this model with the inclusion of a so-called T-parity, there is a significant enhancement in the cross sections as compared to the Standard Model. © 2006 American Institute of Physics.

Efficacy of hormone therapy with and without methyltestosterone augmentation of venlafaxine in the treatment of postmenopausal depression: A double-blind controlled pilot study

Objective: This study evaluated the augmentation of venlafaxine with hormone therapy in the treatment of postmenopausal depression. The hormones evaluated were estrogen (0.625 mg) in combination with medroxyprogesterone acetate (2.5 mg) and methyltestosterone (2.5 mg). Design: Seventy-two menopausal women (mean age: 53.6 ± 4.27 years) diagnosed with depression (Montgomery-Åsberg Depression Rating Scale [MADRS] scores ≥ 20) were treated with venlafaxine and one of the following hormone therapy combinations, in a double-blind regimen: estrogen + medroxyprogesterone + methyltestosterone (group 1, n = 20); estrogen + medroxyprogesterone acetate (group 2, n = 20); methyltestosterone only (group 3, n = 16); and no hormone therapy (group 4, n = 16). Study duration was 24 weeks. Primary efficacy outcome was remission according to the MADRS, whereas secondary efficacy measures included the Clinical Global Impression (CGI), Blatt-Kupperman Index, and Women's Health Questionnaire (WHQ). Results: Forty-eight patients completed the study. All groups showed significant improvement from baseline. Group 3 demonstrated significant improvement on the MADRS compared with placebo (group 4) at weeks 20 (P = 0.048) and 24 (P = 0.030); effect size 8.04 (0.83; 15.26) (P = 0.029), but also had the highest dropout rate. Groups 1 and 3 had significant CGI improvement rates compared with placebo: 42.23% (P = 0.012) and 44.45% (P = 0.08), respectively. There were no differences in the WHQ or BKI scores among the groups. Conclusions: Methyltestosterone 2.5 mg had the highest effect size compared with placebo, but the high dropout rate prevented its efficacy from being determined. Estrogen plus medroxyprogesterone, combined with methyltestosterone or otherwise, demonstrated a trend toward increased efficacy of venlafaxine. Further larger-scale clinical trials are needed to elucidate the findings of this pilot study. © 2006 by The North American Menopause Society.

Double Higgs production and quadratic divergence cancellation in little Higgs models with T-parity

We analyze double Higgs boson production at the Large Hadron Collider in the context of Little Higgs models. In double Higgs production, the diagrams involved are directly related to those that cause the cancellation of the quadratic divergence of the Higgs self-energy, providing a robust prediction for this class of models. We find that in extensions of this model with the inclusion of a so-called T-parity, there is a significant enhancement in the cross sections as compared to the Standard Model. © SISSA 2006.

Articaine and mepivacaine efficacy in postoperative analgesia for lower third molar removal: a double-blind, randomized, crossover study

Objective: Comparison of the clinical efficacy of 4% articaine in relation to 2% mepivacaine, both with 1:100,000 epinephrine, in the prevention of postoperative pain after lower third molar removal. Study design: Twenty patients underwent removal of bilateral lower third molars under local anesthesia (articaine or mepivacaine) in 2 separate appointments, in a double-blind, randomized, and crossed manner. Objective and subjective parameters were recorded for paired comparison of postoperative courses. Results: Duration of analgesia provided by articaine and mepivacaine was 198.00 ± 25.86, and 125.40 ± 13.96 min, respectively (P = .02), whereas the duration of anesthesia was 273.80 ± 15.94 and 216.85 ± 20.15 min, respectively (P = .06). Both solutions exerted no important effects upon arterial pressure, heart rate, or oxygen saturation (P > .05). Conclusions: Articaine provides a longer period of analgesic effect and a tendency for a longer period of anesthesia as compared to mepivacaine. The presence of a vasoconstrictor agent in local anesthetic solutions does not seem to influence hemodynamic parameters during lower third molar removal in healthy subjects. © 2006 Mosby, Inc. All rights reserved.

Characteristics of the double-torsion test to determine the R-curve of ceramic materials

Double-torsion tests were carried out on a commercial ceramic floor tile to verify whether this test is suitable for determining the R-curve of ceramics. The instantaneous crack length was obtained by means of compliance calibration, and it was found that the experimental compliance underestimates the real crack length. The load vs. displacement curves were also found to drop after maximum loading, causing the stress intensity factor to decline. The R-curves were calculated by two methods: linear elastic fracture mechanics and the energetic method. It was obtained that the average values of crack resistance, R, and the double of the work of fracture, 2 · γwof, did not depend on notch length, a0, which is a highly relevant finding, indicating that these parameters were less dependent on the test specimen's geometry. The proposal was to use small notches, which produce long stable crack propagation paths that in turn are particularly important in the case of coarse microstructures.

Electromyographyc evaluation of movements of lower limb in double pulley system equipment: Comparison between gastrocnemius (caput laterale) and gluteus maximus

It was evaluated movements of lower limb in the double pulley system equipment on ten male volunteers during contraction of gastrocnemius (caput laterale ) and gluteus maximus muscles in the following movements: 1) hip extension with extended knee and erect trunk, 2) hip extension with flexed knee and erect trunk, 3) hip extension with flexed knee and erect trunk, 3) hip extension with extended knee and inclined trunk, 5) hip abduction along the midline, 7) hip abduction with extension beyond the midline, 8) adduction with hip flexion beyond the midline, 8) adduction with hip flexion beyond the midline, and 9) adduction with hip extension beyond the midline. Myoelectric signals were taken up by Lec Tec surface electrodes connected to a 6-channel Lynx electromyographic signal amplifier coupled with a computer equipped with a model CAD 10/26 analogue digital conversion board and with a specific software for signal recording and analysis. We observed weak gastrocnemius muscle activity for all movements studied. In the case of gluteus maximus, the most important potentials were observed for movement 2, while for the remaining movements the actions were of reasonable intensity. Compared to gluteus, gastrocnemius was less required for all movements.

Comparative Analysis of 2 Techniques of Double-Gloving Protection During Arch Bar Placement for Intermaxillary Fixation

Purpose: This study was conducted to comparatively evaluate, in a prospective and randomized manner, 2 techniques for providing double-gloving protection during arch bar placement for intermaxillary fixation. Materials and Methods: A total of 42 consecutive patients in whom application of an Erich bar was indicated for intermaxillary fixation were equally divided into 2 groups. In group 1, 2 sterile surgical gloves were used; in group 2, a nonsterile disposable inner glove was used under a sterile surgical glove. Wilcoxon, Mann-Whitney, Kruskal-Wallis, and binomial statistical tests were used to analyze the findings. Results: A total of 103 perforations were found in the outer gloves (47 in group 1 and 56 in group 2), along with 5 perforations in inner gloves in both groups (α = .01). No significant statistical difference was found between groups in terms of inner glove perforations (α = .05). The nondominant hand presented with 70.9% of the perforations, statistically significant to 1%. Conclusions: Both double-gloving techniques were found to provide effective clinician protection. The use of a nonsterile disposable glove under the surgical glove is possible for less-invasive procedures, offering the same safety as using 2 sterile surgical gloves while decreasing operational costs. This method does not eliminate the need to change gloves when a perforation is suspected or noted during the surgery, however. © 2007 American Association of Oral and Maxillofacial Surgeons.

Double sampling X̄ control chart for a first order autoregressive process

In this paper we propose the Double Sampling X̄ control chart for monitoring processes in which the observations follow a first order autoregressive model. We consider sampling intervals that are sufficiently long to meet the rational subgroup concept. The Double Sampling X̄ chart is substantially more efficient than the Shewhart chart and the Variable Sample Size chart. To study the properties of these charts we derived closed-form expressions for the average run length (ARL) taking into account the within-subgroup correlation. Numerical results show that this correlation has a significant impact on the chart properties.

Preemptive dexamethasone and etoricoxib for pain and discomfort prevention after periodontal surgery: A double-masked, crossover, controlled clinical trial

Background: Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. Methods: For this prospective, double-masked, crossover, placebo-controlled, randomized clinical trial, open-flap debridement surgeries were performed on 15 patients (eight males and seven females, age range 20 to 56 years: mean age ± SD: 40 ± 9.7 years) who presented with chronic periodontitis after nonsurgical periodontal therapy at three quadrants. Each patient underwent three surgical procedures at intervals of 30 days and received one of the following premedication protocols 1-hour before surgery: group 1 = placebo, group 2 = 8 mg dexamethasone, and group 3 = 120 mg etoricoxib. Rescue medication (750 mg acetaminophen) was given to each patient who was instructed to take it when necessary. Pain intensity and discomfort were evaluated by a 101-point numeric rate scale and a four-point verbal rate scale, respectively, hourly for the first 8 hours after surgery and three times a day on the following 3 days. Results: The results demonstrate that groups 2 and 3 present reduced postoperative pain-intensity levels compared to group 1. There were statistically significant differences at the 4, 5, 6, 7, and 8 hour-periods after surgery (Friedman test; P<0.05). Furthermore, rescue-medication intake was significantly lower for groups 2 and 3 than for group 1 (analysis of variance; P<0.02). Conclusion: The adoption of a preemptive medication protocol using etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

A comparison between diuretics and angiotensin-receptor blocker agents in patients with stage I hypertension (PREVER-treatment trial): Study protocol for a randomized double-blind controlled trial

Background: Cardiovascular disease is the leading cause of death in Brazil, and hypertension is its major risk factor. The benefit of its drug treatment to prevent major cardiovascular events was consistently demonstrated. Angiotensin-receptor blockers (ARB) have been the preferential drugs in the management of hypertension worldwide, despite the absence of any consistent evidence of advantage over older agents, and the concern that they may be associated with lower renal protection and risk for cancer. Diuretics are as efficacious as other agents, are well tolerated, have longer duration of action and low cost, but have been scarcely compared with ARBs. A study comparing diuretic and ARB is therefore warranted.Methods/design: This is a randomized, double-blind, clinical trial, comparing the association of chlorthalidone and amiloride with losartan as first drug option in patients aged 30 to 70 years, with stage I hypertension. The primary outcomes will be variation of blood pressure by time, adverse events and development or worsening of microalbuminuria and of left ventricular hypertrophy in the EKG. The secondary outcomes will be fatal or non-fatal cardiovascular events: myocardial infarction, stroke, heart failure, evidence of new subclinical atherosclerosis and sudden death. The study will last 18 months. The sample size will be of 1200 participants for group in order to confer enough power to test for all primary outcomes. The project was approved by the Ethics committee of each participating institution.Discussion: The putative pleiotropic effects of ARB agents, particularly renal protection, have been disputed, and they have been scarcely compared with diuretics in large clinical trials, despite that they have been at least as efficacious as newer agents in managing hypertension. Even if the null hypothesis is not rejected, the information will be useful for health care policy to treat hypertension in Brazil. Clinical trials registration number: ClinicalTrials.gov: NCT00971165. © 2011 Fuchs et al; licensee BioMed Central Ltd.

Postural control under visual and proprioceptive perturbations during double and single limb stances: Insights for balance training

Single Limb Stance under visual and proprioceptive disturbances is largely used in clinical settings in order to improve balance in a wide range of functional disabilities. However, the proper role of vision and proprioception in SLS is not completely understood. The objectives of this study were to test the hypotheses that when ankle proprioception is perturbed, the role of vision in postural control increases according to the difficulty of the standing task. And to test the effect of vision during postural adaptation after withdrawal of the somesthetic perturbation during double and single limb stance. Eleven males were submitted to double (DLS) and single limb (SLS) stances under conditions of normal or reduced vision, both with normal and perturbed proprioception. Center of pressure parameters were analyzed across conditions. Vision had a main effect in SLS, whereas proprioception perturbation showed effects only during DLS. Baseline stability was promptly achieved independently of visual input after proprioception reintegration. In conclusion, the role of vision increases in SLS. After proprioception reintegration, vision does not affect postural recovery. Balance training programs must take that into account. © 2011 Elsevier Ltd.