Influence of light transmission through fiber posts: Quantitative analysis, microhardness, and on bond strength of a resin cement.

Context: Light transmission (LT) into deeper areas of the dentin root is limited.

Aim: The aim of this study is to perform a quantitative investigation of the radial transmission of light (LT) through different fiber posts and its influence on the Knoop hardness number (KHN) and bond strength (BS) of a dual-cure self-adhesive resin cement at 3 different depths.

Materials And Methods: Four types of fiber posts (2 translucent and 2 conventional) were used.

Clinical evaluation of a low-cost robot for use in physiotherapy and gait training.

Background: Robotic-assisted gait training, a viable and promising therapeutic option for neurological rehabilitation, is not widely adopted in developing countries because of its high cost. In this paper, we describe the concept and construction of a low-cost robot prototype to restore walking ability in children with neurological dysfunction.

Methods: The proposed robot consists of an orthosis, a treadmill, a body weight support system and two ankle guidance systems that move the ankles along a physiological kinematic trajectory.

Quantification and Analysis of Leaflet Flutter on Biological Prosthetic Cardiac Valves.

The use of porcine or bovine pericardium biological cardiac valves has as its main disadvantage a relatively short lifespan, with failures due to calcification and fatigue. Increasing these valves' durability constitutes a great challenge. An understudied phenomenon is the effect of flutter, an oscillation of the leaflets that can cause regurgitation and accelerate calcification and fatigue.

Melanin protects Paracoccidioides brasiliensis from the effects of antimicrobial photodynamic inhibition and antifungal drugs.

Paracoccidioidomycosis (PCM) is a public health concern in Latin America and South America that when not correctly treated can lead to patient death. In this study, the influence of melanin produced by Paracoccidioides spp. on the effects of treatment with antimicrobial photodynamic inhibition (aPI) and antifungal drugs was evaluated.

Effects of low-power light therapy on wound healing: LASER x LED.

Several studies demonstrate the benefits of low-power light therapy on wound healing. However, the use of LED as a therapeutic resource remains controversial. There are questions regarding the equality or not of biological effects promoted by LED and LASER.

The influence of dynamic orthosis training on upper extremity function after stroke: a pilot study.

The goal of this study was to assess the use of a dynamic orthosis on upper extremity function in chronic stroke patients. A case series approach was utilized, with provision of a training program (3x/week, 50 minutes/session for 8 weeks) and employment of a dynamic orthosis. Six volunteers with persistent hemiparesis due to a single, unilateral stroke performed task-oriented movements with the aid of a dynamic orthosis.

A computational model for dynamic analysis of the human gait.

Biomechanical models are important tools in the study of human motion. This work proposes a computational model to analyse the dynamics of lower limb motion using a kinematic chain to represent the body segments and rotational joints linked by viscoelastic elements. The model uses anthropometric parameters, ground reaction forces and joint Cardan angles from subjects to analyse lower limb motion during the gait.

Photodynamic inhibition of Trichophyton rubrum: in vitro activity and the role of oxidative and nitrosative bursts in fungal death.

Objectives: Antimicrobial photodynamic inhibition (aPI) is based on the use of a light source and a photosensitizer to kill pathogens. Little is known about aPI of dermatophytic fungi and its mechanism of action. We aimed to evaluate aPI of Trichophyton rubrum.

Phototoxic action of light emitting diode in the in vitro viability of Trichophyton rubrum.

Background: Trichophyton rubrum is the most common agent of superficial mycosis of the skin and nails causing long lasting infections and high recurrence rates. Current treatment drawbacks involve topical medications not being able to reach the nail bed at therapeutic concentrations, systemic antifungal drugs failing to eradicate the fungus before the nails are renewed, severe side effects and selection of resistant fungal isolates. Photodynamic therapy (PDT) has been a promising alternative to conventional treatments.

LED phototherapy improves healing of nipple trauma: a pilot study.

Objective: The purpose of this study was to evaluate the clinical effectiveness of a LED phototherapy prototype apparatus in the healing of nipple trauma in breastfeeding women.

Background Data: There is no scientific evidence of an effective treatment for nipple trauma.

Methods: The experimental group was treated with orientation on nipple care and adequate breastfeeding techniques in addition to active LED phototherapy.

Effects of intensive arm training with an electromechanical orthosis in chronic stroke patients: a preliminary study.

Objectives: To evaluate the use of an electromechanical device, comprising an exoskeleton, a static orthosis, and a glove, for functional rehabilitation of the elbow and hand in patients with hemiparesis, and to compare it with physical therapy rehabilitation.

Design: Pretest-posttest design.

Setting: Rehabilitation laboratory.

Vaginal tissue properties versus increased intra-abdominal pressure: a preliminary biomechanical study.

Background/aims: This study aims to evaluate the pelvic floor (PF) tension response during simulated increased intra-abdominal pressure (IAP) and the vaginal biomechanical properties.

Methods: A 3-dimensional computational finite element model for PF was developed based on magnetic resonance imaging from a nulliparous healthy volunteer. The model was used to simulate an IAP of 90 cm H(2)O and to evaluate the PF stresses in the longitudinal and transversal axes.

Cryptococcus gattii: in vitro susceptibility to photodynamic inactivation.

Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, contributes to therapy failure and has a poor prognosis. Photodynamic inactivation (PDI) offers a promising possibility for the alternative treatment of cryptococcosis.

Translation of biomechanics research to urogynecology.

Introduction: Pelvic floor (PF) dysfunctions represent a frequent and complex problem for women. The interaction between the vagina and its supportive structures, that are designed to support increases in abdominal pressure, can be considered a biomechanical system. Recent advances in imaging technology have improved the assessment of PF structures.

Multidirectional pelvic floor muscle strength measurement.

Pelvic floor muscle (PFM) strength measurement provides useful information for the study of pelvic floor dysfunctions. Vaginal digital palpation, intravaginal pressure measurements, and the use of a dynamometric speculum represent currently available clinical methods for evaluating PFM strength. However, none of these methods provide a dynamic measurement of pelvic floor strength in multiple directions simultaneously.

In vitro photodynamic inactivation of Candida spp. growth and adhesion to buccal epithelial cells.

In this study, photodynamic inactivation (PDI) was used to inhibit in vitro growth and adhesion of different Candida isolates to buccal epithelial cells (BEC). Experimental conditions were optimized and 25muM toluidine blue O (TBO) and 15min of irradiation time by light emitting diode (LED) (energy density of 180J/cm(2)) were selected due to higher reductions in cellular viability obtained after treatment. Reduction media of Log(10) 3.

Hip orthosis powered by pneumatic artificial muscle: voluntary activation in absence of myoelectrical signal.

Powered orthosis is a special class of gait assist device that employs a mechanical or electromechanical actuator to enhance movement of hip, knee, or ankle articulations. Pneumatic artificial muscle (PAM) has been suggested as a pneumatic actuator because its performance is similar to biological muscle. The electromyography (EMG) signal interpretation is the most popular and simplest method to establish the patient voluntary control of the orthosis.

Light transmission through a translucent fiber post.

This study is a quantitative assessment of the luminous energy transmitted through different translucent fiber posts. After embedding the posts in black resin, the blocks were submitted to sequential cuts in a precision machine, and depths of 16 mm, 12 mm, 8 mm, and 4 mm were assessed for light transmission with a digital photometer. The quantitative analysis showed significant differences between different posts and depths.

Clinical study of the gingiva healing after gingivectomy and low-level laser therapy.

Objective: The purpose of this study was to investigate gingival healing after gingivectomy and adjunctive use of low-level laser therapy (LLLT).

Background Data: LLLT has been used in animal experiments to examine the influence of laser radiation on the wound healing process since the 1960s. However, clinical trials in dentistry are scarce, and most of them refer to treatment after extraction of the third molars, with only a few reports in the area of periodontics.

Particle image velocimetry for flow analysis in longitudinal planes across a mechanical artificial heart valve.

In the last decades a great number of in vitro studies have been conducted to improve the design and to understand the transvalvular flow patterns under steady-state and pulsating flow conditions. Steady-state tests are useful for studying the flow established upstream and downstream of the valve prosthesis in different flow conditions and, in particular, at the peak flow rate. In the present study, the particle image velocimetry (PIV) technique is employed to visualize the flow patterns in a precommercial model of a bi-leaflet mechanical heart valve prosthesis in a steady-state flow regime.

Modeling and simulation of pulsatile blood flow with a physiologic wave pattern.

This article presents a computational fluid dynamics (CFD) model to analyze pulsatile blood flow in a human artery. The model assumes the vessel as being a straight wall tube, and the blood flow is considered to be incompressible, Newtonian, and axisymmetric. Physiologically realistic resting conditions were adopted for the simulation tests.

Improvement on the auxiliary total artificial heart (ATAH) left chamber design.

The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow.

Estimating Mechanical Blood Trauma in a Centrifugal Blood Pump: Laser Doppler Anemometer Measurements of the Mean Velocity Field.

A laser Doppler anemometer (LDA) was used to obtain the mean velocity and the Reynolds stress fields in the inner channels of a well-known centrifugal vaneless pump (Bio-pump). Effects of the excessive flow resistance against which an occlusive pump operates in some surgical situations, such as cardiopulmonary bypass, are illustrated. The velocity vector field obtained from LDA measurements reveals that the constraint-forced vortex provides pumping action in a restricted area in the core of the pump.