Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 172
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Chaos ; 34(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38805322

RESUMO

The advection of passive scalars in time-independent two-dimensional incompressible fluid flows is an integrable Hamiltonian system. It becomes non-integrable if the corresponding stream function depends explicitly on time, allowing the possibility of chaotic advection of particles. We consider for a specific model (double gyre flow), a given number of exits through which advected particles can leak, without disturbing the flow itself. We investigate fractal escape basins in this problem and characterize fractality by computing the uncertainty exponent and basin entropy. Furthermore, we observe the presence of basin boundaries with points exhibiting the Wada property, i.e., boundary points that separate three or more escape basins.

2.
Chaos ; 34(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271628

RESUMO

We study three different strategies of vaccination in an SEIRS (Susceptible-Exposed-Infected-Recovered-Susceptible) seasonal forced model, which are (i) continuous vaccination; (ii) periodic short-time localized vaccination, and (iii) periodic pulsed width campaign. Considering the first strategy, we obtain an expression for the basic reproduction number and infer a minimum vaccination rate necessary to ensure the stability of the disease-free equilibrium (DFE) solution. In the second strategy, short duration pulses are added to a constant baseline vaccination rate. The pulse is applied according to the seasonal forcing phases. The best outcome is obtained by locating intensive immunization at inflection of the transmissivity curve. Therefore, a vaccination rate of 44.4% of susceptible individuals is enough to ensure DFE. For the third vaccination proposal, additionally to the amplitude, the pulses have a prolonged time width. We obtain a non-linear relationship between vaccination rates and the duration of the campaign. Our simulations show that the baseline rates, as well as the pulse duration, can substantially improve the vaccination campaign effectiveness. These findings are in agreement with our analytical expression. We show a relationship between the vaccination parameters and the accumulated number of infected individuals, over the years, and show the relevance of the immunization campaign annual reaching for controlling the infection spreading. Regarding the dynamical behavior of the model, our simulations show that chaotic and periodic solutions as well as bi-stable regions depend on the vaccination parameters range.


Assuntos
Modelos Biológicos , Vacinação , Humanos , Estações do Ano , Simulação por Computador , Número Básico de Reprodução , Suscetibilidade a Doenças
3.
ScientificWorldJournal ; 2024: 8991384, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38957454

RESUMO

The medicinal plant Bredemeyera floribunda Willd. is used to treat cardiovascular disease, chronic fatigue, low libido, as well as increased diuresis. However, studies considering the toxicity of this plant are scarce. Develop an aqueous extract of B. floribunda considering traditional use and determine the average lethality (LD50), signs, and symptoms of toxicity. The B. floribunda extract was obtained by immersing the root bark in ultrapure water for 18 hours at 4°C, under constant stirring. The test extract was administered in a single dose of 2.000 mg/kg by gavage to rats. Signs and symptoms of toxicity were determined according to the Hippocratic screening test and compared with the control group. In addition, a necropsy was performed for macroscopic evaluation of the organs in the abdominal cavity. A powder was obtained from aqueous extracts that showed the same organoleptic characteristics and emulsification capacity as those presented by the fresh root when prepared according to popular tradition. The LD50 was greater than the test dose with three animals surviving. On the other hand, necropsy of dead rats showed necrosis and reduction in lung mass, in addition to the presence of foam and excessive distension of the stomach and intestines. The main symptoms of toxicity were anesthesia, ataxia, sedation, loss of muscle strength, and excessive drowsiness in the first 24 hours. There was no difference between the control and extract groups with regard to body mass, food, and water intake, as well as in macroscopy of the heart, liver, lungs, intestines, spleen, pancreas, and kidneys. The aqueous extract of the B. floribunda was considered nontoxic or of very low toxicity. However, it is capable of altering the activity of the central nervous system and causing disorders in the respiratory and digestive systems.


Assuntos
Casca de Planta , Extratos Vegetais , Raízes de Plantas , Animais , Extratos Vegetais/toxicidade , Extratos Vegetais/química , Ratos , Casca de Planta/química , Masculino , Raízes de Plantas/química , Dose Letal Mediana , Feminino , Testes de Toxicidade Aguda , Ratos Wistar , Modelos Animais
4.
Qual Life Res ; 32(7): 1871-1881, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36757573

RESUMO

PURPOSE: Adults with dysvascular lower extremity amputation (LEA) experience a large number of secondary health conditions yet there is a gap in the literature on health utility scores for this population. A health utility score relates to a person's state of well-being, and is a single metric anchored at 0 (death) and 1 (perfect health). This study aimed to provide a descriptive account of health utility scores in community-dwelling adults with dysvascular LEA. METHODS: Participants were adults with dysvascular LEA who were 3 months post-amputation. Data collected included socio-demographic characteristics, the Special Interest Group in Amputee Medicine (SIGAM) grades, the dysvascular conditions scale (DCS), which is a scale developed for this study, and the Short Form-36 (SF-36). SF-6D health utility scores were derived from the SF-36 using a software algorithm. Participants were grouped into low-impact and high-impact groups based on self-reported severity of symptoms using the DCS. Health utility scores were compared between the low-impact and high-impact groups using independent t-tests. RESULTS: A total of 231 participants were enrolled in the study. The mean SF-6D health utility score was 0.689 (0.127). A significant association was found between health utility score and SIGAM grade (p < 0.001, η2 = .09). Health utility was positively associated with age (r = 0.137, p = 0.037) and months post-amputation (r = 0.141, p = 0.032), and negatively associated with DCS severity (r = -0.526, p < 0.001). Health utility scores were lower for participants in the DCS high-impact groups for conditions such as diabetes mellitus, phantom limb pain, musculoskeletal pain, back pain, psychological distress, depression, vision problems, and other pain. CONCLUSION: Cost-utility analyses rely on health utility estimates and our findings provide data for future economic evaluations that may assist policy makers in evidence informed allocation of healthcare resources for this population.


Assuntos
Amputados , Qualidade de Vida , Adulto , Humanos , Recém-Nascido , Qualidade de Vida/psicologia , Vida Independente , Inquéritos e Questionários , Extremidade Inferior , Dor nas Costas
5.
Arch Phys Med Rehabil ; 104(11): 1827-1832, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37119956

RESUMO

OBJECTIVE: To evaluate the effect of age on functional outcomes at discharge from prosthetic rehabilitation. DESIGN: Retrospective chart audit. SETTING: Rehabilitation hospital. PARTICIPANTS: Individuals ≥50 years with a transtibial level lower limb amputation (LLA) and above admitted to the inpatient prosthetic rehabilitation program from 2012 to 2019 (n=504). A secondary analysis included a subset of matched participants (n=156). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The L-Test of Functional Mobility (L-Test), 2-Minute Walk Test (2MWT), 6-Minute Walk Test (6MWT), and Activities-specific Balance Confidence scale. RESULTS: A total of 504 participants (66.7±10.1 years) met the inclusion criteria, 63 participants (84.9±3.7 years) were part of the oldest old group. The sample was stratified into 4 age groups (50-59, 60-69, 70-79, and 80+) for data analysis. The analysis of variances were statistically significant for all outcome measures (P<.001). Post-hoc testing for the L-Test, 2MWT, and 6MWT demonstrated that the oldest old had significantly reduced performance compared with people 50-59 years old (P<.05), but there were no significant differences between the oldest old and the 60-69 [(L-Test, P=.802), (2MWT, P=.570), (6MWT, P=.772)] and 70-79 [(L-Test, P=.148), (2MWT, P=.338), (6MWT, P=.300)] age groups. The oldest old reported significantly lower balance confidence compared with all 3 age groups (P<.05). CONCLUSION: The oldest old achieved similar functional mobility outcomes as people 60-79 years, the most common age group of people with an LLA. Advanced age alone should not disqualify individuals from prosthetic rehabilitation.


Assuntos
Amputados , Membros Artificiais , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Amputados/reabilitação , Extremidade Inferior/cirurgia , Pacientes Internados , Estudos Retrospectivos , Amputação Cirúrgica , Caminhada
6.
Chaos ; 33(3): 033140, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37003817

RESUMO

The stickiness effect is a fundamental feature of quasi-integrable Hamiltonian systems. We propose the use of an entropy-based measure of the recurrence plots (RPs), namely, the entropy of the distribution of the recurrence times (estimated from the RP), to characterize the dynamics of a typical quasi-integrable Hamiltonian system with coexisting regular and chaotic regions. We show that the recurrence time entropy (RTE) is positively correlated to the largest Lyapunov exponent, with a high correlation coefficient. We obtain a multi-modal distribution of the finite-time RTE and find that each mode corresponds to the motion around islands of different hierarchical levels.

7.
Chaos ; 33(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085232

RESUMO

In this work, we study the dynamics of a susceptible-exposed-infectious-recovered-susceptible epidemic model with a periodic time-dependent transmission rate. Emphasizing the influence of the seasonality frequency on the system dynamics, we analyze the largest Lyapunov exponent along parameter planes finding large chaotic regions. Furthermore, in some ranges, there are shrimp-like periodic structures. We highlight the system multistability, identifying the coexistence of periodic orbits for the same parameter values, with the infections maximum distinguishing by up one order of magnitude, depending only on the initial conditions. In this case, the basins of attraction have self-similarity. Parametric configurations, for which both periodic and non-periodic orbits occur, cover 13.20% of the evaluated range. We also identified the coexistence of periodic and chaotic attractors with different maxima of infectious cases, where the periodic scenario peak reaches approximately 50% higher than the chaotic one.

8.
Entropy (Basel) ; 25(8)2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-37628172

RESUMO

We consider open non-twist Hamiltonian systems represented by an area-preserving two-dimensional map describing incompressible planar flows in the reference frame of a propagating wave, and possessing exits through which map orbits can escape. The corresponding escape basins have a fractal nature that can be revealed by the so-called basin entropy, a novel concept developed to quantify final-state uncertainty in dynamical systems. Since the map considered violates locally the twist condition, there is a shearless barrier that prevents global chaotic transport. In this paper, we show that it is possible to determine the shearless barrier breakup by considering the variation in the escape basin entropy with a tunable parameter.

9.
Ann Hematol ; 101(9): 1915-1924, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35849155

RESUMO

Administrative claims provide a rich data source for retrospective studies of real-world clinical practice, yet some important data may be inconsistent or unavailable. This study explored factors influencing discontinuation of thrombopoietin receptor agonists (TPO-RAs) among patients with immune thrombocytopenia (ITP), by adding medical chart abstraction for additional details. Adult (≥ 18 years) patients with continuous commercial or Medicare Advantage with Part D health insurance coverage were included. Inclusion criteria were ≥ 1 claim for eltrombopag or romiplostim and ≥ 2 diagnoses of ITP between December 31, 2017, and January 1, 2020. Providers were asked to provide access to medical charts for abstraction. The analyses included only patients who discontinued TPO-RA and described patient characteristics, treatment patterns, platelet values, and reasons for discontinuation. Among 207 ITP patients treated with a TPO-RA, 137 (66%) discontinued treatment during the observation period. The mean TPO-RA treatment duration was 185 days. Mean platelet count at the time of discontinuation was 197 × 109/L. The most common reason for discontinuation was improvement of the patient's condition (42%). Other reasons included worsening of ITP/lack of response (12%), adverse events (12%), and cost-related or social reasons (23%). No reason was reported for 10%. Notably 26% of patients who discontinued remained off all ITP therapy for the remainder of the study, with a mean treatment-free period of 262 days. These results emphasize that some patients with ITP are able to discontinue TPO-RA therapy and achieve durable treatment-free periods.


Assuntos
Fármacos Hematológicos , Púrpura Trombocitopênica Idiopática , Adulto , Idoso , Benzoatos , Fármacos Hematológicos/uso terapêutico , Humanos , Hidrazinas , Medicare , Contagem de Plaquetas , Púrpura Trombocitopênica Idiopática/induzido quimicamente , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/epidemiologia , Receptores Fc/uso terapêutico , Receptores de Trombopoetina/agonistas , Proteínas Recombinantes de Fusão/uso terapêutico , Estudos Retrospectivos , Trombopoetina/efeitos adversos , Estados Unidos/epidemiologia
10.
Appl Psychophysiol Biofeedback ; 47(2): 85-94, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35006474

RESUMO

To evaluate the heart rate response, emotion and changes in anxiety and anger levels after exposure to unpleasant pictures from the International Assessment Pictures System (IAPS) compared with neutral picture exposure in healthy individuals. Forty participants (23 women) visited the laboratory on two occasions. State anger and state anxiety levels were evaluated pre- and post-visualization of a set of IAPS pictures and heart rate was monitored during exposure. Two different picture sets were utilized-one with neutral pictures (that served as the control) and the other with unpleasant pictures. State anxiety and state anger were higher in post-unpleasant session for women than before (p < 0.001). For men, only state anxiety was higher in the post-unpleasant session (p < 0.001). State anxiety (p = 0.004) and state anger (p < 0.001) post-unpleasant session was higher for women than in men. The pleasure and dominance domains were lower in the unpleasant session for both men and women (p < 0.001), and the arousal domain was higher for both men and women (p < 0.001) than in the neutral session. In the unpleasant session, arousal was higher (p = 0.004), and dominance was lower (p < 0.001) among women than among men, but no difference in pleasure was found (p > 0.05). For women, average heart rate was higher on unpleasant session, compared to neutral (p = 0.01), but not for men (p > 0.05). Women are more sensitive and react strongly to unpleasant picture exposure. The IAPS unpleasant session was not able to induce anger levels in men.


Assuntos
Nível de Alerta , Emoções , Ira , Ansiedade , Nível de Alerta/fisiologia , Emoções/fisiologia , Feminino , Frequência Cardíaca , Humanos , Masculino
11.
J Strength Cond Res ; 36(4): 1147-1152, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32732773

RESUMO

ABSTRACT: Wong, V, Dankel, SJ, Spitz, RW, Bell, ZW, Viana, RB, Chatakondi, RN, Abe, T, and Loenneke, JP. The effect of blood flow restriction therapy on recovery after experimentally induced muscle weakness and pain. J Strength Cond Res 36(4): 1147-1152, 2022-The purpose was to determine if blood flow restriction with no external load could be used as a means of active therapy after experimentally induced fatigue and soreness. Twelve women and 7 men (aged 18-35 years) participated in a randomized controlled trial using a within-subject design. The study intervention was 3 consecutive visits. Visit 1 included the fatiguing/soreness-inducing protocol for the elbow flexors, which was performed only once during the study. Torque was measured before/after to confirm individuals began in a weakened state. Subjects then completed blood flow restriction therapy on one arm and the sham therapy on the other. Subjects performed elbow flexion/contraction with no external load on both arms. Torque was measured once more 10 minutes after the fatiguing/soreness-inducing protocol. Twenty-four hours later, soreness and torque were assessed in each arm, followed by another bout of therapy. Forty-eight hours after the initial visit, soreness and torque were measured again. There were no differences (median difference [95% credible interval]) in the recovery of torque between the blood flow restriction and sham therapy conditions at 10 minutes (0.5 [-2.7, 3.8] N·m), 24 hours (-2.34 [-6, 1.14] N·m), or 48 hours (-1.94 [-5.45, 1.33] N·m). There were also no differences in ratings of soreness at 24 hours (-2.48 [-10.05, 5.05]) or 48 hours (2.58 [-4.96, 10.09]). Our results indicate that this specific model of blood flow restriction therapy did not enhance the recovery of the muscle compared with a sham condition without the application of pressure.


Assuntos
Terapia de Restrição de Fluxo Sanguíneo , Debilidade Muscular , Adolescente , Adulto , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Dor/etiologia , Torque , Adulto Jovem
12.
J Strength Cond Res ; 36(3): 871-879, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32058360

RESUMO

ABSTRACT: Spitz, RW, Wong, V, Bell, ZW, Viana, RB, Chatakondi, RN, Abe, T, and Loenneke, JP. Blood flow restricted exercise and discomfort: A review. J Strength Cond Res 36(3): 871-879, 2022-Blood flow restriction exercise involves using a pneumatic cuff or elastic band to restrict arterial inflow into the muscle and block venous return out of the muscle during the exercise bout. The resultant ischemia in conjunction with low-load exercise has shown to be beneficial with increasing muscle size and strength. However, a limitation of using blood flow restriction (BFR) is the accompanying discomfort associated with this type of exercise. Factors that may influence discomfort are applied pressure, width of the cuff, cuff material, sex, and training to failure. The goal of this review was to evaluate the existing literature and elucidate how these factors can be manipulated to reduce discomfort during exercise as well as provide possible directions for future research. Thirty-eight different studies were located investigating BFR and discomfort. It was found that BFR training causes more discomfort than exercise without BFR. However, chronic use of BFR may increase tolerability, but discomfort may still be elevated over traditional non-blood flow restricted exercise. Discomfort can be attenuated by the application of lower applied pressures and stopping short of task failure. Finally, in the upper body, wider cuffs seem to increase ratings of discomfort compared with more narrow cuffs. In conclusion, applying the proper-sized cuff and making the applied pressure relative to both the individual and the cuff applied may attenuate discomfort. Reducing discomfort during exercise may help increase adherence to exercise and rehabilitation programs.


Assuntos
Músculo Esquelético , Treinamento Resistido , Artérias/fisiologia , Exercício Físico , Hemodinâmica , Humanos , Músculo Esquelético/fisiologia , Fluxo Sanguíneo Regional/fisiologia
13.
Br J Haematol ; 194(4): 759-766, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34263940

RESUMO

Immune thrombocytopenia (ITP) is an acquired immune-mediated disorder. Bleeding is the primary symptom that presents in varying severities. ITP has a negative impact on health-related quality of life (HRQoL). The ITP Life Quality Index (ILQI) was developed as a 10-item patient-reported outcome measure to assess impact on HRQoL in ITP. The objective of the present study was to confirm the content validity of the ILQI with a qualitative interview study in the UK involving 15 adult participants with ITP. Combined concept elicitation (CE) and cognitive debriefing (CD) interviews were conducted to explore the symptoms and impacts associated with ITP and confirm content validity of the draft ILQI. The CE phase elicited 14 ITP symptom concepts, including: bruising (all 15 patients, 100%), fatigue (14, 93·3%) and bleeding gums/blood blisters (13, 86·7%). Impacts included decreased ability to participate in sport (all 15 patients, 100%) and anxiety (12, 80%). The CD phase resulted in an adjustment to the ILQI recall period from 1 week to 'the past month'. Updates were made to improve relevance and response options. The qualitative interviews support the content validity of the ILQI and confirm that the concepts assessed are relevant and consistently understood and interpreted by adult patients with ITP.


Assuntos
Púrpura Trombocitopênica Idiopática/complicações , Qualidade de Vida , Adulto , Idoso , Ansiedade/epidemiologia , Contusões/epidemiologia , Fadiga/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Púrpura Trombocitopênica Idiopática/fisiopatologia , Pesquisa Qualitativa , Adulto Jovem
14.
Scand J Med Sci Sports ; 31(8): 1592-1611, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33797115

RESUMO

This systematic review and meta-analysis examined studies on the chronic effects of exergames on muscle strength in humans. PubMed, Scopus, CENTRAL, Web of Science, SciELO, Biblioteca Virtual em Saúde, and Google Scholar were searched, and manual searches of the reference lists of included studies and hand-searches on Physiotherapy Evidence Database and ResearchGate were conducted from inception to August 10, 2020. Randomized and non-randomized exergame intervention studies with or without a non-exercise group and/or a "usual care intervention group" (any other intervention that did not incorporate exergames), which evaluated muscle strength through direct measurements, were included. Forty-seven and 25 studies were included in the qualitative review and meta-analysis, respectively. The between-groups meta-analyses showed no significant differences between exergames and non-exercise control groups for handgrip strength in heathy/unhealthy middle-aged/older adults or knee extension maximum voluntary isometric contraction (MVIC) in healthy older adults. However, exergames provided a greater increase in handgrip strength, knee flexion MVIC, and elbow extension MVIC, but not knee extension MVIC or elbow flexion MVIC, in individuals with different health statuses when compared to usual care interventions. Also, there was a greater increase in handgrip strength in children with hemiplegic cerebral palsy favouring usual care plus exergames compared to usual care interventions. These results suggest that exergames may improve upper and lower limb muscle strength in individuals with different heath statuses compared to usual care interventions, but not muscle strength in middle age/older adults after accounting for random error. Also, exergames appear to be a useful tool for improving handgrip strength in children with hemiplegic cerebral palsy when added to usual care. However, as the exergame interventions were applied in different populations and there currently are many different approaches to perform exergames, future randomized controlled trials with high methodological quality and large sample sizes are needed to provide more compelling evidence in favour of a specific exergame protocol, or to elucidate exergame protocol design principles that appear to strongly influence outcomes.


Assuntos
Terapia por Exercício/métodos , Força Muscular/fisiologia , Jogos de Vídeo , Humanos
15.
Chaos ; 31(8): 083128, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34470231

RESUMO

Oscillatory activities in the brain, detected by electroencephalograms, have identified synchronization patterns. These synchronized activities in neurons are related to cognitive processes. Additionally, experimental research studies on neuronal rhythms have shown synchronous oscillations in brain disorders. Mathematical modeling of networks has been used to mimic these neuronal synchronizations. Actually, networks with scale-free properties were identified in some regions of the cortex. In this work, to investigate these brain synchronizations, we focus on neuronal synchronization in a network with coupled scale-free networks. The networks are connected according to a topological organization in the structural cortical regions of the human brain. The neuronal dynamic is given by the Rulkov model, which is a two-dimensional iterated map. The Rulkov neuron can generate quiescence, tonic spiking, and bursting. Depending on the parameters, we identify synchronous behavior among the neurons in the clustered networks. In this work, we aim to suppress the neuronal burst synchronization by the application of an external perturbation as a function of the mean-field of membrane potential. We found that the method we used to suppress synchronization presents better results when compared to the time-delayed feedback method when applied to the same model of the neuronal network.


Assuntos
Modelos Neurológicos , Rede Nervosa , Potenciais de Ação , Retroalimentação , Humanos , Neurônios
16.
Chaos ; 31(2): 023125, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33653060

RESUMO

The routes to chaos play an important role in predictions about the transitions from regular to irregular behavior in nonlinear dynamical systems, such as electrical oscillators, chemical reactions, biomedical rhythms, and nonlinear wave coupling. Of special interest are dissipative systems obtained by adding a dissipation term in a given Hamiltonian system. If the latter satisfies the so-called twist property, the corresponding dissipative version can be called a "dissipative twist system." Transitions to chaos in these systems are well established; for instance, the Curry-Yorke route describes the transition from a quasiperiodic attractor on torus to chaos passing by a chaotic banded attractor. In this paper, we study the transitions from an attractor on torus to chaotic motion in dissipative nontwist systems. We choose the dissipative standard nontwist map, which is a non-conservative version of the standard nontwist map. In our simulations, we observe the same transition to chaos that happens in twist systems, known as a soft one, where the quasiperiodic attractor becomes wrinkled and then chaotic through the Curry-Yorke route. By the Lyapunov exponent, we study the nature of the orbits for a different set of parameters, and we observe that quasiperiodic motion and periodic and chaotic behavior are possible in the system. We observe that they can coexist in the phase space, implying in multistability. The different coexistence scenarios were studied by the basin entropy and by the boundary basin entropy.

17.
J Strength Cond Res ; 35(12): 3296-3299, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31567790

RESUMO

ABSTRACT: Alves, RR, Viana, RB, Silva, MH, Guimarães, TC, Vieira, CA, Santos, DdAT, and Gentil, PRV. Postactivation potentiation improves performance in a resistance training session in trained men. J Strength Cond Res 35(12): 3296-3299, 2021-This study aims to analyze the influence of postactivation potentiation (PAP) on performance during a resistance training (RT) session in trained individuals. Fourteen trained men (25.0 ± 3.5 years; 89.9 ± 16.3 kg; 1.77 ± 0:08 m; 28.0 ± 4.0 kg·m-2; and 5 ± 4 years of RT experience) were tested in 2 situations: with PAP and without PAP (CON). Both situations involved 3 sets of the bench press exercise performed to muscle failure at 75% of the 1 repetition maximum load and with 1.5-minute interval between sets. Total work was greater (p < 0.001) for PAP (1,601 ± 504 kg) than for CON (1,379 ± 364 kg). The number of repetitions performed in the first and second sets of PAP (11.5 ± 3.1 and 6.5 ± 1.9, respectively) were greater (p < 0.05) than those performed in CON (10.4 ± 2.7, 5.5 ± 1.8, respectively). No significant difference was found in the number of repetitions in the last set between the situations. The present study suggests that PAP might be beneficial to improve total work and performance during multiple sets of RT in trained men. Therefore, PAP might be used during RT to promote higher total work and potentially increase results over long term. Thus, the protocol can use in sports centers, fitness centers, and gyms per coaches and athletes to increase performance and total work in trained individuals.


Assuntos
Treinamento Resistido , Atletas , Exercício Físico , Terapia por Exercício , Humanos , Masculino , Força Muscular , Músculo Esquelético
18.
Cancer Sci ; 111(7): 2526-2535, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32324296

RESUMO

Treatment-free remission (TFR), in which patients discontinue pharmacotherapy and remain in molecular remission, is an emerging treatment goal for patients with chronic myeloid leukemia (CML). Attainment of TFR requires an increased frequency of molecular monitoring, to ensure that patients maintain a deep molecular response. The objective of this analysis was to assess the economic impact of stopping nilotinib among Japanese TFR-eligible patients. A Markov model evaluated the economic impact of TFR among the study population, TFR-eligible CML patients diagnosed since 2012. The model compared patients who had discontinued tyrosine kinase inhibitor (TKI) treatment (ie, attempted TFR) with patients that continued TKI treatment. A 3-y time horizon was modeled from a Japanese public payer perspective. Costs associated with drug treatment, hospital/physician visits, and molecular monitoring were considered. TFR-eligible patients were calculated from Japanese CML incidence rates and efficacy was derived from nilotinib trials. Japanese co-payment maximums were utilized to assess the patient perspective. An estimated 761 and 140 patients were eligible for first- and second-line nilotinib, respectively, in 2019. Assuming that 100% of eligible patients complied, TFR was associated with cost savings of ¥7 625 174 640 (US$66 567 775) over 3 y. In scenarios with reduced willingness to attempt TFR, cost savings persisted. Achievement of TFR was estimated to markedly reduce out-of-pocket expenses for CML patients, regardless of the timing of relapse. Stopping nilotinib for TFR-eligible patients in Japan may result in significant cost savings to both payers and patients. Monitoring costs contributed little to overall annual costs and decreased over time.


Assuntos
Orçamentos , Análise Custo-Benefício , Leucemia Mielogênica Crônica BCR-ABL Positiva/epidemiologia , Custos de Cuidados de Saúde , Humanos , Japão/epidemiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Cadeias de Markov , Modelos Teóricos , Pirimidinas/administração & dosagem , Pirimidinas/efeitos adversos , Pirimidinas/uso terapêutico , Indução de Remissão , Resultado do Tratamento
19.
Am J Hum Biol ; 32(6): e23401, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32030840

RESUMO

OBJECTIVE: To compare the orofacial muscle strength and facial muscle thickness between resistance-trained and non-resistance trained men and women. METHODS: Resistance-trained (25 men and 22 women) and non-resistance trained (21 men and 30 women) adults (18-40 years) had standard measurements of orofacial muscle strength (ie, anterior tongue elevation, cheek compression, and lip compression) and ultrasound measurements of facial muscle thickness. Body composition (percent fat, etc.) was estimated using ultrasound prediction Equations. A Bayesian analysis of variance (ANOVA) with between subject factors of training status (yes/no) and sex (man/woman) were used to determine differences in muscle size and strength. RESULTS: Body mass, height, and percent fat were similar between resistance-trained and non-resistance trained individuals, while appendicular lean mass was higher in resistance-trained. There were no differences in orofacial muscle strength between resistance-trained and non-resistance trained. However, men had greater strength in every task except for anterior tongue strength which was similar between sexes (men: 66 vs women: 64 kPa). Handgrip strength was greater in men and in those who were resistance-trained. The frontalis muscle was greater in women than in men and in those who were non-resistance-trained than those resistance-trained. None of the other muscles differed by training status, however, all were greater in men. CONCLUSION: Results from our cross-sectional study would suggest that exercise-stimulation to the facial muscles during resistance training of the limbs and trunk did not reach a level where orofacial muscle strength could be changed. Sex differences in facial muscle thickness are very unique, although the reasons are unclear.


Assuntos
Músculos Faciais/anatomia & histologia , Músculos Faciais/fisiologia , Força Muscular , Treinamento Resistido , Adulto , Análise de Variância , Teorema de Bayes , Estudos Transversais , Feminino , Humanos , Masculino , Caracteres Sexuais , Fatores Sexuais , Ultrassonografia , Adulto Jovem
20.
Am J Hum Biol ; 32(2): e23333, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31750989

RESUMO

OBJECTIVES: To examine the absolute and relative skeletal muscle mass (SM) in female athletes and to discuss the potential upper limit of whole-body muscle mass between large sized female and male athletes. METHODS: Forty-five female athletes and forty-five recreationally active females (control) had muscle thickness measured by ultrasound at nine sites on the anterior and posterior aspects of the body. SM was estimated from an ultrasound-derived prediction equation. Body fat percentage and fat-free mass (FFM) were calculated from ultrasound measured subcutaneous fat thickness. To eliminate fat-free component of adipose tissue (FFAT), we calculated FFM minus FFAT (FFM-FFAT). RESULTS: FFM, FFM-FFAT, and muscle mass were markedly higher in athletes. Fat Mass was similar (Athlete: 14.9 kg vs Control: 12.9 kg [median value]). The large-sized female athletes had approximately 9 to 11 kg FFAT which corresponds to about 10% to 15% of FFM. Seven of the female athletes had more than 60 kg of FFM-FFAT, the largest of whom had 77.0 kg of FFM-FFAT. SM increased in a parabolic fashion reaching a value of 35 kg SM beyond 100 kg body mass. Only one of the athletes had a SM index of more than 13 kg/m2 . CONCLUSIONS: Female athletes had much greater muscle mass than controls. In large-sized female athletes, the influence of FFAT needs to be considered when interpreting their FFM. In addition, the largest SM index in female athletes was 13.2 kg/m2 , which was approximately 77% of that observed with the largest male athlete ever recorded. This difference appears similar to that observed in nonathletes.


Assuntos
Atletas/estatística & dados numéricos , Composição Corporal/fisiologia , Tamanho Corporal , Músculo Esquelético/fisiologia , Adulto , Feminino , Humanos , Modelos Biológicos , Ultrassonografia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA