Publications by authors named "Rodrigo Villar"

Article Synopsis
  • - Dr. William J. Mills Jr. is an Alaskan orthopedic surgeon who transformed frostbite treatment protocols, challenging a long-standing approach set by Napoleon's surgeon general in the early 1800s.
  • - After recognizing the limitations of existing methods in his practice, he researched and advocated for rapid warming of frozen body parts, resulting in significant publication contributions in the 1960s that established this as the new standard treatment.
  • - Mills and his team developed a simplified 2-tier classification system for frostbite (superficial and deep) that is still widely used in clinical and non-hospital settings today.
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Firefighters operating in hot environments face challenges from protective garments that restrict heat dissipation, resulting in increased core temperature, thermal discomfort, and performance decline. Cooling vests represent a viable solution. The study aim was to compare effectiveness of the same amount of cooling power to the upper body (UB) or whole body (WB) in alleviating thermoregulatory and physiological stress, enhancing cognitive function, and reducing ratings of thermal discomfort and exertion, during 60 min of exercise in a hot environment (40°C, 40% relative humidity) while wearing firefighter turnout gear.

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Objectives: To determine the test-retest reliability and agreement of home-based functional capacity self-administered assessments in socially isolated older adults.

Methods: Fourteen community-dwelling older adults (eight females, 67.9 ± 7.

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Background: Paralympic powerlifting (PP) is performed on a bench press, aiming to lift as much weight as possible in a single repetition.

Purpose: To evaluate thermal asymmetry and dynamic force parameters with 45 and 80% 1 Repetition Maximum (1 RM) in PP athletes.

Methods: Twelve elite PP male athletes were evaluated before and after a training session regarding skin temperature (thermography) and dynamic force indicators (Average Propulsive Velocity-MPV, Maximum Velocity-VMax, and Power).

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Powerlifting competitions require consistent and symmetric lifting of heavy loads and maximal effort, in which, asymmetric lifting results in trial invalidation. Symmetry during this very high intensity movement is determinant to athletes' performance and success in competitions. This study aimed to compare the asymmetry between Conventional Powerlifting athletes (CP) and Paralympic (PP) athletes at intensities of 45 and 80% 1RM before and after a training session.

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Skeletal muscle dysfunction after critical illness, defined as ICU-acquired weakness (ICU-AW), is a complex and multifactorial syndrome that contributes significantly to long-term morbidity and reduced quality of life for ICU survivors and caregivers. Historically, research in this field has focused on pathological changes within the muscle itself, without much consideration for their physiological environment. Skeletal muscle has the widest range of oxygen metabolism of any organ, and regulation of oxygen supply with tissue demand is a fundamental requirement for locomotion and muscle function.

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Older adults often experience episodes of a sudden drop in blood pressure when standing, known as orthostatic hypotension (OH). OH is associated with an increased risk of life-threatening health problems, falls, and death. Although OH has been studied in older adults, the integrated dynamic autonomic and cardiovascular regulation during postural transitions in older adults with frailty remains scarce and poorly understood.

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This study aimed to determine whether body fat distribution and physical fitness would be associated with risk factors for cardiovascular diseases (CVDs) in post-menopausal females. Android fat distribution were more likely to have altered total cholesterol (TC), high-density lipoprotein (HDL-C), triglycerides (TG), glycemic levels (GL) body fat percentage (%BF), and body mass index (BMI), and those with inadequate physical fitness showed clear alterations in TC, HDL-C, and TG. Gynoid fat distribution group fared better regarding CVD risk.

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Air pollution inhaled dose is the product of pollutant concentration and minute ventilation ([Formula: see text]). Previous studies have parameterized the relationship between [Formula: see text] and variables such as heart rate (HR) and have observed substantial inter-subject variability. In this paper, we evaluate a method to estimate [Formula: see text] with easy-to-measure variables in an analysis of pooled-data from eight independent studies.

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Previous studies in children and older adults demonstrated faster oxygen uptake (V̇O) kinetics in males compared with females, but young healthy adults have not been studied. We hypothesized that young men would have faster aerobic system dynamics in response to the onset of exercise than women. Interactions between oxygen supply and utilization were characterized by the dynamics of V̇O, deoxyhemoglobin (HHb), tissue saturation index (TSI), cardiac output (Q̇), and calculated arteriovenous O difference (a-vO) in women and men.

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We tested the hypothesis during the combined challenges of altered inspired O fraction (FO) and posture changes at lower power output regardless of body position that the vascular conductance (VC) recruitment to the exercising muscle would not limit muscle perfusion and estimated O delivery (DO ). However, in head-down tilt at the higher power output exercise in hypoxia, the recruitment of VC would have a functional limitation which would restrict muscle blood flow (MBF) leading to a limitation in DO with consequent increases in metabolic stress. Ten healthy volunteers repeated plantar flexion contractions at 20% (low power output = LPO) and 30% (higher power output = HPO) of their maximal voluntary contraction in horizontal (HOR), 35° head-down-tilt (HDT) and 45° head-up-tilt (HUT).

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AbstractThe Department of Santa Rosa, Guatemala, is targeted for malaria elimination. However, compared with 2011, a 13-fold increase in cases was reported in 2012. To describe the epidemiology of malaria in Santa Rosa in the setting of the apparent outbreak, demographic and microscopic data from 2008 to 2013 were analyzed.

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The study of oxygen uptake (V̇o) dynamics during walking exercise transitions adds valuable information regarding fitness. However, direct V̇o measurements are not practical for general population under realistic settings. Devices to measure V̇o are associated with elevated cost, uncomfortable use of a mask, need of trained technicians, and impossibility of long-term data collection.

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Villar, R, Gillis, J, Santana, G, Pinheiro, DS, and Almeida, ALRA. Association between anaerobic metabolic demands during simulated Brazilian jiu-jitsu combat and specific jiu-jitsu anaerobic performance test. J Strength Cond Res 32(2): 432-440, 2018-The aims of this study were to design a specific Jiu-Jitsu anaerobic performance test (JJAPT) and investigate the relationship between blood lactate ([La]), heart rate (HR), and rating of perceived exertion (RPE) during simulated Brazilian Jiu-Jitsu combat (SBJJC) and JJAPT.

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Purpose: The objective of this study was to assess the effectiveness of graduated compression socks (GCS) on enhancing muscle blood flow and oxygenation during exercise and recovery in healthy subjects.

Methods: Twelve healthy volunteers completed a protocol involving baseline, exercise, and recovery periods with and without GCS. Each test was repeated twice to assess repeatability of the results.

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We tested the validity of the Hexoskin wearable vest to monitor heart rate (HR), breathing rate (BR), tidal volume (VT), minute ventilation, and hip motion intensity (HMI) in comparison with laboratory standard devices during lying, sitting, standing, and walking. Twenty healthy young volunteers participated in this study. First, participants walked 6 min on a treadmill at speeds of 1, 3, and 4.

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The hypothesis that cerebrovascular autoregulation was not impaired during head-up tilt (HUT) that followed brief exposures to varying degrees of prior head-down tilt (HDT) was tested in 10 healthy young men and women. Cerebral mean flow velocity (MFV) and cardiovascular responses were measured in transitions to a 60-s period of 75° HUT that followed supine rest (control) or 15 s HDT at -10°, -25°, and -55°. During HDT, heart rate (HR) was reduced for -25° and -55°, and cardiac output was lower at -55° HDT.

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This study was undertaken to examine the effect on the rat embryonic heart of two experimental drugs (AZA and AZB) which are known to block the sodium channel Nav1.5, the hERG potassium channel and the l-type calcium channel. The sodium channel blockers bupivacaine, lidocaine, and the l-type calcium channel blocker nifedipine were used as reference substances.

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This study hypothesized that central and local reflex mechanisms affecting vascular conductance (VC) through the popliteal artery compensated for the reduction in muscle perfusion pressure (MPP) to maintain popliteal blood flow (PBF) during head-down tilt (35˚ HDT), but not in head-up tilt (45˚ HUT). Resting measurements were made on 15 healthy men in prone position to facilitate the access to the popliteal artery, on two separate days in random order during horizontal (HOR), HDT or HUT. In each body position, the body was supported, and the ankles were maintained in relaxed state so that there was no muscle tension, as with normal standing.

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Changes in vascular conductance (VC) are required to counter changes in muscle perfusion pressure (MPP) to maintain muscle blood flow (MBF) during exercise. We investigated the recruitment of VC as a function of peak VC measured in three body positions at two different work rates to test the hypothesis that adaptations in VC compensated changes in MPP at low-power output (LPO), but not at high-power output (HPO). Eleven healthy volunteers exercised at LPO and HPO (repeated plantar flexion contractions at 20-30% maximal voluntary contraction, respectively) in horizontal (HOR), 35° head-down tilt (HDT), and 45° head-up tilt (HUT).

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Background: Capillary microsampling was recently introduced as a new technique for simplified collection and handling of small, exact volumes of liquid matrices. In this article, a bioanalytical method was developed and fully validated for 8 µl plasma samples and applied to a toxicology study in mice.

Results: The method was validated in the concentration range 0.

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Purpose: The Candidate Physical Ability Test (CPAT) is used by fire departments across North America to screen for minimal physical capabilities in potential candidates, but its physiological demands are unknown.

Methods And Results: We examined oxygen uptake and carbon dioxide output (V x O2, V x CO2) and heart rate (HR) responses with the portable system in 57 subjects (23 females) who were familiarized before completing the CPAT in times similar to those of actual candidates. Two men and nine women failed to complete the circuit because of fatigue.

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Resident continuity clinics are an integral and mandated component of the pediatric core curriculum. Hospital-based and community-based settings have been traditionally used, with varied success. This article proposes the use and testing of an additional site, the primary care clinic housed at the Children's Clinic for Rehabilitative Services.

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