ABSTRACT
The development of efficient electrocatalysts for the oxygen evolution reaction (OER) is of paramount importance in sustainable water-splitting technology for hydrogen production. In this context, this work reports mixed-valence oxide samples of the MnXCo3-XO4 type (0 ≤ X ≤ 1) synthesized for the first time by the proteic sol-gel method using Agar-Agar as a polymerizing agent. The powders were calcined at 1173 K, characterized by FESEM, XRD, RAMAN, UV-Vis, FT-IR, VSM, and XPS analyses, and were investigated as electrocatalysts for the oxygen evolution reaction (OER). Through XRD analysis, it was observed that the pure cubic phase was obtained for all samples. The presence of Co3+, Co2+, Mn2+, Mn3+, and Mn4+ was confirmed by X-ray spectroscopy (XPS). Regarding the magnetic measurements, a paramagnetic behavior at 300 K was observed for all samples. As far as OER is concerned, it was investigated in an alkaline medium, where the best overpotential of 299 mV vs. RHE was observed for the sample (MnCo2O4), which is a lower value than those of noble metal electrocatalysts in the literature, together with a Tafel slope of 52 mV dec-1, and excellent electrochemical stability for 15 h. Therefore, the green synthesis method presented in this work showed great potential for obtaining electrocatalysts used in the oxygen evolution reaction for water splitting.
ABSTRACT
The purpose of this study was to evaluate the strength of the knee flexors and extensors and hip abductor and adductor muscles in young soccer players. Twenty-three male under-19 soccer players participated in this study (age: 17.7 ± 0.2 years; height: 173.0 ± 1.1 cm; body mass: 66.1 ± 1.3 kg). Body composition was measured using a bioelectrical impedance (InBody770), and the dynamometry was performed by an isokinetic dynamometer (Biodex System 3) for knee flexion and extension, and by an isometric dynamometer (Smart Groin Trainer), for hip adduction and abduction. Comparisons were made between dominant members (D) vs. non-dominant members (ND) and adductors vs. abductors (ADD:ABD) using the Wilcoxon test. There were statistically significant differences in the peak torques between the dominant and non-dominant members in the flexion function (Z = -4.198, p < 0.01) and in the extension function (Z = -4.197, p < 0.01) of the knee in concentric muscular action, and the flexion (Z = -4.198, p < 0.01) and in the extension (Z = -4.198, p < 0.01) of the knee in eccentric muscular action. No statistically significant differences were obtained in the conventional ratio (Z = -0.456, p = 0.648) nor the functional ratio (Z = -0.335, p = 0.738) between D and ND members. There were no statistically significant differences between adductors and abductors at the moment of strength for absolute values (N). The reference absolute and normalized to the weight values and the ADD:ABD can be used as a guideline for classifying players in screening and comparison in return tests to sports practice after an injury.
Subject(s)
Soccer , Adolescent , Humans , Knee/physiology , Knee Joint , Male , Muscle Strength/physiology , Muscle, Skeletal/physiology , Soccer/physiology , TorqueABSTRACT
Resumo Objetivo: Avaliar a prevalência e o perfil clinico-epidemiológico dos pacientes acometidos pelo glaucoma em Santarém-PA, no período de janeiro de 2016 a dezembro de 2017. Métodos: Estudo descritivo, retrospectivo e quantitativo em que foram analisados os prontuários de 718 pacientes, de ambos os gêneros, atendidos pelo SUS no ambulatório de uma clínica oftalmológica em Santarém - PA. Foi utilizada uma ficha adaptada pelos pesquisadores a partir de um modelo pré-existente no local de coleta e, depois de colhidos, os dados foram sistematizados. Resultados: O estudo encontrou uma prevalência de 6% (n=43), distribuída em 6,8% (n=21) em 2016 e 5,4% (n=22) em 2017. Quanto ao gênero, a maior parte correspondeu ao sexo feminino (53,5%, n=23) e 46,5% (n=20) ao sexo masculino. O Glaucoma Primário de Ângulo Aberto demonstrou maior prevalência, acometendo 2,5% (n=18) dos pacientes. A faixa etária demonstrou predominância do público acima dos 40 anos, 96% (n=24) dos 25 com a idade disponibilizada. Também foi observado que 42% manifestavam hipertensão arterial isoladamente, 2% diabetes mellitus isoladamente, 5% combinação entre as duas e 51% não possuíam nenhuma comorbidade. Conclusão: A prevalência encontrada para os casos de glaucoma foi superior àquelas observadas em estudos nacionais e internacionais. O Glaucoma Primário de Ângulo Aberto teve maior prevalência, principalmente em indivíduos acima dos 40 anos. A relação entre doenças crônicas e a manifestação do glaucoma ou elevação da PIO apontou uma sútil indicação da HAS como fator de risco por conta de sua maior prevalência, semelhante aos estudos sobre o tema.
Abstract Objective: To evaluate the prevalence and clinical-epidemiological profile of patients with glaucoma in Santarém-PA, from January 2016 to December 2017. Methods: Study descriptive, retrospective, quantitative and cross-sectional that was analyzed the medical records of 718 patients, both genders, attended by SUS in an ophthalmologic clinic from Santarém-PA. Was used an adapted record from a pre-existing model in the clinic and, after being searched, the data was systematized. Results: The study was found a prevalence of 6% (n=43), distributed in 6.8%(n=21) in 2016 and 5.4%(n=22) in 2017. Regarding gender, the majority corresponded to women (53.5% n=23) and 46.5%(n=20) were men. Primary open angle glaucoma demonstrated a higher prevalence, affecting 2.5% (n=18) of the patients. The age group demonstrated the predominance of the public over 40 years, 96% (n=24) of the 25 with the age was informed. Regarding chronic diseases, 42% had only arterial hypertension, 2% only diabetes mellitus, 5% had bot comorbidities, and 51% had no one. Conclusion: The prevalence found for glaucoma cases was higher than values of other studies about the subject in Brazil and abroad. Primary open angle glaucoma was the more prevalent in the public studied, especially in individuals over 40 years. The relation between chronic diseases and the manifestation of glaucoma or IOP elevation, reached a subtle indication to hypertension as a risk factor due to its higher prevalence, similar to the studies on the subject.
