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DIN 16MnCr5 is commonly used in mechanical engineering contact applications such as gears, joint parts, shafts, gear wheels, camshafts, bolts, pins, and cardan joints, among others. This study examined the microstructural and mechanical properties and tribological behavior of different surface treatments applied to DIN 16MnCr5 steel. The samples were hardened at 870 °C for 15 min and then quenched in water. The surface conditions evaluated were as follows: quenched and tempered DIN 16MnCr5 steel samples without surface treatments (control group), quenched and tempered DIN 16MnCr5 steel samples with gas-nitriding at 560 °C for 6 h, quenched and tempered DIN 16MnCr5 steel samples with pack boriding at 950 °C for 4 h, and quenched and tempered DIN 16MnCr5 steel samples with duplex gas-nitriding and pack boriding. Microstructure characterization was carried out using metallographic techniques, optical microscopy, scanning electron microscopy with energy-dispersive spectroscopy, and X-ray diffraction. The mechanical properties were assessed through microhardness and elastic modulus tests using nanoindentation. The tribological behavior was evaluated using pin-on-disc tests following the ASTM G99-17 standard procedure under dry sliding conditions. The results indicated that the surface treated with duplex gas-nitriding and pack boriding exhibited the highest wear resistance and a reduced coefficient of friction due to improved mechanical properties, leading to increased hardness and elastic modulus.
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To determine if preoperative-intraoperative factors such as age, comorbidities, American Society of Anesthesiologists (ASA) classification, body mass index (BMI), and severity of peritonitis affect the rate of morbidity and mortality in patients undergoing a primary anastomosis (PA) or Hartmann Procedure (HP) for perforated diverticulitis. This is a systematic review and meta-analysis, conducted according to PRISMA, with an electronic search of the PubMed, Medline, Cochrane Library, and Google Scholar databases. The search retrieved 614 studies, of which 11 were included. Preoperative-Intraoperative factors including age, ASA classification, BMI, severity of peritonitis, and comorbidities were collected. Primary endpoints were mortality and postoperative complications including sepsis, surgical site infection, wound dehiscence, hemorrhage, postoperative ileus, stoma complications, anastomotic leak, and stump leakage. 133,304 patients were included, of whom 126,504 (94.9%) underwent a HP and 6800 (5.1%) underwent a PA. There was no difference between the groups with regards to comorbidities (p = 0.32), BMI (p = 0.28), or severity of peritonitis (p = 0.09). There was no difference in mortality [RR 0.76 (0.44-1.33); p = 0.33]; [RR 0.66 (0.33-1.35); p = 0.25]. More non-surgical postoperative complications occurred in the HP group (p = 0.02). There was a significant association in the HP group between the severity of peritonitis and mortality (p = 0.01), and surgical site infection (p = 0.01). In patients with perforated diverticulitis, PA can be chosen. Age, comorbidities, and BMI do not influence postoperative outcomes. The severity of peritonitis should be taken into account as a predictor of postoperative morbidity and mortality.
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Perfuração Intestinal , Peritonite , Complicações Pós-Operatórias , Humanos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/mortalidade , Perfuração Intestinal/mortalidade , Perfuração Intestinal/cirurgia , Peritonite/mortalidade , Peritonite/cirurgia , Peritonite/etiologia , Índice de Massa Corporal , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Período Pré-Operatório , Diverticulite/cirurgia , Diverticulite/complicações , Diverticulite/mortalidade , Índice de Gravidade de Doença , Fatores Etários , Comorbidade , Período Intraoperatório , MorbidadeRESUMO
Resumen: Objetivo: Analizar las diferencias de los polimorfismos de los genes ECA y ACTN3 en el rendimiento de una prueba de agilidad en jugadores élite de deportes colectivos pertenecientes a selecciones nacionales de Costa Rica. Metodología: Se contó con una muestra de 33 jugadores hombres, de deportes colectivos (fútbol sala, rugby, voleibol y balonmano). Para la evaluación de la agilidad se utilizó el test de Illinois. Se realizaron dos visitas, en la primera se obtuvo muestras de células por medio de un enjuague y en la segunda se aplicó la prueba de agilidad. Se utilizó la prueba de Chi-cuadrado (X2) para conocer las diferencias entre las frecuencias de los polimorfismos de los genes ECA y ACTN3 y el tipo de deporte. Resultados: La mayor distribución de los polimorfismos del gen ECA, de jugadores de selecciones nacionales de deportes de conjunto, se encuentra en el ID (X2= 6.87, p= .334) y en ACTN3 el RX (X2= 6.33, p= .388). Además, tampoco se encontraron diferencias significativas entre el tiempo efectuado en el test de Illinois y los polimorfismos del gen ECA (F= 2.150, p= .134), de igual forma para los polimorfismos del gen ACTN3 (F= .950, p= .339). Conclusiones: Los polimorfismos de los genes ECA y ACTN3 no se relacionaron estadísticamente con el tipo de deporte colectivo. La agilidad no se ve asociada por un tipo de polimorfismo, lo que indica que, de forma independiente al gen, esta cualidad física se puede entrenar y generar buenos resultados en la población en general.
Abstract: Objective: To analyze the differences in the polymorphisms of the ACE and ACTN3 genes on agility test performance in elite players of collective sports from National teams of Costa Rica. Methods: a sample of 33 male team sports players (futsal, rugby, volleyball, and handball). All subjects were tested with the Illinois Agility Test. Two days of measurements were made; on the first day, cell samples were obtained and on the second day, the agility test was applied. The Chi-square test (x2) was used to determine the differences between the frequencies of the polymorphisms of the ACE and ACTN3 genes and the type of sport. Results: The highest distribution of polymorphisms of the ECA gene of players from national teams of collective sports was found in the ACE ID (X2 = 6.87, p = .334), and in ACTN3 the RX (X2 = 6.33, p =. 388). Furthermore, no significant relationship was found between the Illinois test performance and the polymorphisms of the ECA gene (F = 2,150, p = .134). Conclusions: The ACE and ACTN3 genes polymorphisms were not statistically related to the type of team sport. Agility is not associated with the type of polymorphism, which indicates that regardless of the gene, this physical quality can be trained and generate good results in the general population.
Resumo: Objetivo: analisar as diferenças dos polimorfismos dos genes ECA e ACTN3 na realização de um teste de agilidade em jogadores de elite de equipes esportivas pertencentes a equipes nacionais costarriquenhas. Metodologia: foi utilizada uma amostra de 33 jogadores de futebol masculino (futsal, rúgbi, vôlei e handebol). O teste de Illinois foi usado para avaliar a agilidade. Foram feitas duas visitas; na primeira foram obtidas amostras de uma célula por lavagem e na segunda foi aplicado o teste de agilidade. O teste qui-quadrado (X2) foi usado para determinar as diferenças entre as frequências dos polimorfismos dos genes ECA e ACTN3 e o tipo de esporte. Resultados: A maior distribuição de polimorfismos do gene ECA em jogadores de equipes nacionais de esportes coletivos é encontrada no ID (X2= 6,87, p= 0,334) e no ACTN3 no RX (X2= 6,33, p= 0,388). Além disso, não foram encontradas diferenças significativas entre o tempo gasto no teste de Illinois e os polimorfismos do gene ECA (F= 2,150, p= 0,134), assim como para os polimorfismos do gene ACTN3 (F= 0,950, p= 0,339). Conclusões: Os polimorfismos dos genes ECA e ACTN3 não estavam estatisticamente relacionados com o tipo de esporte coletivo. A agilidade não está associada pelo tipo de polimorfismo, indicando que, independentemente do gene, essa qualidade física pode ser treinada e gerar bons resultados na população em geral.
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Humanos , Masculino , Adulto , Polimorfismo Genético , Esportes , Projetos Piloto , Costa RicaRESUMO
BACKGROUND: Previous studies have shown positive results of photobiomodulation (PBM) for improving performance and accelerating post-exercise recovery. However, the effects of PBM in healthy individuals who underwent a neuromuscular adaptation training remain unclear. OBJECTIVE: To investigate the effects of PBM during a training program combining sprints and explosive squats exercises on clinical, functional, and systemic outcomes in trained healthy individuals compared to a placebo intervention and a control. METHODS: We conducted a randomized placebo-controlled trial. Healthy males were randomly assigned to three groups: active PBM (30â¯J per site), placebo, or control (passive recovery). The participants performed a six-week (12 sessions) of a training program consisting of a combination of sprints and squats with recovery applied between sprints and squats. To prevent the influence of the primary neuromuscular adaptation to exercise on the results, all participants had to participate in a period of six weeks of exercise training program. Functional, clinical, and psychological outcomes and vascular endothelial growth factor (VEGF) were assessed at baseline and after six weeks. Results are expressed as mean difference (MD) and 95% confidence intervals (CI). RESULTS: Thirty-nine healthy male volunteers (aged 18-30 years; body mass index 23.9⯱â¯3â¯kg/m²) were recruited. There was no significant time by group interaction, and no significant effect of group, but there was a significant effect of time for maximal voluntary isometric contraction (primary outcome) (MD=22 Nm/kg; 95%CI: 3.9, 40) and for squat jump (MD=1.6â¯cm; 95CI%: 0.7, 2.5). There was no significant interaction (time*group), time, or group effect for the other outcomes. CONCLUSION: The addition of PBM to a combined training performed for six weeks in previously trained individuals did not result in additional benefits compared to placebo or no additional intervention.
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Terapia com Luz de Baixa Intensidade , Exercício Físico , Terapia por Exercício , Humanos , Contração Isométrica , Terapia com Luz de Baixa Intensidade/métodos , Masculino , Fator A de Crescimento do Endotélio VascularRESUMO
The use of guayusa (Ilex guayusa Loes.) leaves as functional food has increase recently. This work discusses the antioxidant activity and volatile compounds of guayusa leaves extract and fractions. The methanol crude extract was obtained by maceration, subsequently hexane, chloroform, ethyl acetate, and aqueous fractions were collected by solvent-solvent partition. Total phenolic content (TPC), total flavonol/flavone content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferric reducing antioxidant power (FRAP) were measured by ultraviolet-visible (UV-Vis) spectrophotometry. The results revealed that ethyl acetate fraction showed highest inhibition against DPPH radical (93.86 ± 0.95%) at 500 µg/mL, and reduce the ferric-tripyridyltriazine complex (Fe3+-TPTZ) at 1619.81 mg trolox equivalent (TE)/g, followed by aqueous fraction. This bioactivity could be related to phenolic acids, flavones and flavonols content, as well as the caffeine, dodecanoic acid isopropyl ester, caffeic acid, and malic acid identified by gas chromatography-mass spectrometry (GC-MS). These findings support the antioxidant properties of this plant material.
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Ilex guayusa , Antioxidantes/química , Cromatografia Gasosa-Espectrometria de Massas , Ilex guayusa/química , Extratos Vegetais/química , Folhas de Planta/química , SolventesRESUMO
BACKGROUND Recent studies have demonstrated that statins have anti-inflammatory and immunomodulatory properties, which could be considered beneficial in kidney transplantations. This study assesses the anti-inflammatory effect of atorvastatin on the kidney grafts of living donor transplants. MATERIAL AND METHODS In a randomized clinical trial, kidney donors were divided into 2 groups. The study group constituted 24 donors who received 40 mg atorvastatin, and 24 donors who received a placebo control, 4 weeks prior to transplantation. Serum C-reactive protein (CRP) levels were measured before and after atorvastatin administration. CRP and renal function of kidney recipients were measured at baseline and 1, 6, and 24 hours after transplantation. RESULTS After 4 weeks of treatment, the CRP level was 5.62±3.82 mg/dL in the control group and 3.27±0.62 mg/dL in the study group (P=0.007). Upon reperfusion, CRP levels in recipients at 1 hour were, 5.8±3.9 and 3.8±1.0 mg/dL, respectively (P=0.04). Twenty-four hours after the kidney transplantations, serum creatinine levels were 2.5±1.5 mg/dL in the study group and 3.7±2.4 mg/dL in the control group (P=0.04). CONCLUSIONS Our study suggests that the use of atorvastatin prior to allograft procurement of kidney transplant, reduces the acute kidney inflammatory burden profile, and promotes an improved kidney function recovery following transplantation.
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Anti-Inflamatórios/uso terapêutico , Atorvastatina/uso terapêutico , Inflamação/tratamento farmacológico , Transplante de Rim/métodos , Doadores Vivos , Adulto , Proteína C-Reativa/metabolismo , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
To evaluate the association of the -308 and -238 tumor necrosis factor alpha (TNF-α) gene polymorphisms with clinical manifestations of dengue and TNF-α serum levels in a northwestern Mexican population. The study populations included dengue fever (DF) and dengue hemorrhagic fever (DHF) patients, and a group of healthy controls (HCs) without history of dengue. Polymerase chain reaction-restriction fragment length polymorphism and Enzyme-Linked Immunosorbent Assay were performed to determine genotypes and serum concentration of TNF-α, respectively. There were no significant differences in alleles, genotypes, and haplotype frequencies between patients and HCs. However, when patients were separated into DF and DHF, there was an increased prevalence of the -308 GA genotype in HCs compared to DHF (odds ratio [OR] = 0.129, 95% confidence interval [CI] = 0.018-0.945, p = 0.025), as well as the GG haplotype (OR = 0.49, 95% CI = 0.273-0.880, p = 0.01757) in DF. The genotypes of both polymorphisms were not associated with hematologic manifestations. Serum TNF-α levels were significantly higher in patients than in HCs (p = 0.004). Our results suggest a minimal effect of the -308 and -238 TNF-α gene polymorphisms in dengue patients and that their increased serum levels of TNF-α are independent of genotypes.
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Dengue/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Dengue Grave/genética , Fator de Necrose Tumoral alfa/genética , Adulto , Alelos , Estudos de Casos e Controles , Dengue/sangue , Dengue/imunologia , Feminino , Genótipo , Haplótipos , Humanos , Masculino , México , Pessoa de Meia-Idade , Dengue Grave/sangue , Dengue Grave/imunologia , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Objetivo: estructurar una guía clínica tipo para el manejo de las fracturas en dedos de la mano en trabajadores. Material y métodos: se integró un grupo de trabajo con 15 mdicos especialistas de la Región Noroeste del Instituto Mexicano del Seguro Social (IMSS) involucrados en atender esta problemática. Por medio del consenso de dichos expertos, en la primera etapa se identificaron las principales fracturas, en la segunda se discutieron y consensaron las guías clínicas para el manejo de cada una de ellas, y en la tercera y última fueron validadas por otro grupo de expertos de 10 centros médicos nacionales y tres hospitales generales regionales del IMSS de todo el sistema. Resultados: se identificaron ocho diagnósticos de fracturas; las guías clínicas correspondientes describen seis tiempos críticos desde el momento del accidente hasta el alta médica, y cuatro puntos cardinales de atención para la reincorporación laboral del trabajador con o sin secuela valuable. Conclusiones: la propuesta está dirigida a mejorar globalmente la calidad en la atención de pacientes con fractura, lo cual no sólo reduciría los efectos negativos desde el punto de vista funcional sino conllevaría al trabajo grupal, contención de costos y satisfacción del trabajador por los servicios médicos otorgados
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Humanos , Masculino , Feminino , Manual de Referência , Traumatismos dos Dedos , Educação em Saúde/métodos , Traumatismos da Mão , Conselhos de Planejamento em Saúde/normasRESUMO
Objetivo. Identificar repercusiones clínicas y alteraciones electrocardiográficas inducidas por la infusión de placlitaxel durante 24 horas. Pacientes y métodos. De enero de 1993 a enero de 1996, en los Departamentos de Medicina Interna del Hospital ABC y de Oncología del Hospital General de México, se estudiaron a 35 pacientes entre 18 y 75 años de edad, con diversas neoplasias karnofsky > 60 por ciento, que previamente habrían recibido uno o más esquemas de quimioterapia. Todos recibieron paclitaxel en infusión continua de 24 horas, cada 21 días, con dosis de 125-225 mg/m², y profilaxis para tratamiento de hipersensibilidad con dexametasona, ranitidina y clorfeniramina. Se practicó electrocardiograma antes y después de cada infusión del taxano. El grado de cardiotoxicidad se calificó de acuerdo con los criterios del national Cancer Institute. Resultados. Treinta y cinco pacientes con edad promedio de 50 ñ 8.8 años, 28 mujeres (80 por ciento) y siete hombres (20 por ciento), recibieron 110 ciclos. Diecinueve pacientes (54.2 por ciento) habían recibido doxorrubicina previamente y 10 habían sido sometidos a radioterapia mediastinal. Un paciente presentó infarto agudo al miocardio un año antes del tratamiento. Se encontró disminución de la frecuencia cardiaca en 37.1 por ciento de los pacientes y 26.3 por ciento de los ciclos con dosis de 125 y 150 mg/m². En 25.7 por ciento de los pacientes y 19 ciclos se detectó prolongación del intervalo QTc con dosis mayores de 150 mg/m². Hubo extrasístoles supraventriculares en cuatro pacientes durante ocho ciclos de tratamiento y extrasístoles ventriculares, en un paciente, durante un ciclo. Se detectó disminusión del voltaje del complejo QRS en 3.6 por ciento de los ciclos y en 5.7 por ciento de los pacientes con dosis de 135 y 175 mg/m². La inversión de la onda T se presentó en tres casos durante cuatro ciclos, sin repercusión hemodinámica ni traducción enzímatica. Se registró aumento de la frecuencia cardiaca en 28.5 por ciento de los pacientes y 18.1 por ciento de los ciclos con dosis superiores a 175 mg/m². Hubo un caso de taquicardia supraventricular con dosis de 225 mg/m². Todas las alteraciones se calificaron como grado I, sin repercusión hemodinámica ni significancia estadística...
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Humanos , Masculino , Feminino , Adulto , Complexos Cardíacos Prematuros/etiologia , Coração , Eletrocardiografia , Frequência Cardíaca , Sistema de Condução Cardíaco/efeitos dos fármacos , Cardiopatias/induzido quimicamente , Cardiopatias/etiologia , Neoplasias/tratamento farmacológico , Paclitaxel , Paclitaxel/efeitos adversos , Paclitaxel , Paclitaxel/toxicidade , Fatores de RiscoRESUMO
Para describir los rasgos clínicos del Síndrome de Hiperactividad Simpática (S.H.S.) y los resultados obtenidos por la terapéutica alfa y beta bloqueante y destacar la importancia del control del S.H.S., se estudiaron 10 (diez) casos de tétanos internados en nuestra Unidad desde junio de 1979 hasta junio de 1981. Presentaron S.H.S. siete pacientes. Siguiendo normas del Servicio todos los pacientes recibieron tratamiento básico y de acuerdo con la severidad, tratamiento sintomático. Cuatro pacientes recibieron clorpromazina 100-150 mg/día (bloqueo alfa), los tres restantes recibieron, además de clorpromazina en iguales dosis, propanolol, 60-120 mg/día (bloqueo beta). Los siete pacientes con S.H.S. eran tétanos graves. Los 4 pacientes tratados con bloqueo alfa exclusivo fallecieron, tres por disturbios hemodinámicos incontrolables y uno por falla en la asistencia respiratoria mecánica. De los tres casos tratados con alfa y beta bloqueantes sólo uno falleció (distress pulmonar), pudiéndose controlar en él las manifestaciones de S.H.S. que habían aparecido. No obstante la pequeña población estudiada, podemos concluir, que: el bloqueo alfa exclusivo no brindó resultados favorables en lo que hace a la sobrevida. La adición del bloqueo beta al tratamiento en caso de evidencia de S.H.S. puede brindar una disminución de la mortalidad que el síndrome acarrea
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Sistema Nervoso Simpático , Tétano/fisiopatologia , Clorpromazina/uso terapêutico , Propranolol/uso terapêutico , Sistema Nervoso Simpático/patologia , Tétano/tratamento farmacológicoRESUMO
Para describir los rasgos clínicos del Síndrome de Hiperactividad Simpática (S.H.S.) y los resultados obtenidos por la terapéutica alfa y beta bloqueante y destacar la importancia del control del S.H.S., se estudiaron 10 (diez) casos de tétanos internados en nuestra Unidad desde junio de 1979 hasta junio de 1981. Presentaron S.H.S. siete pacientes. Siguiendo normas del Servicio todos los pacientes recibieron tratamiento básico y de acuerdo con la severidad, tratamiento sintomático. Cuatro pacientes recibieron clorpromazina 100-150 mg/día (bloqueo alfa), los tres restantes recibieron, además de clorpromazina en iguales dosis, propanolol, 60-120 mg/día (bloqueo beta). Los siete pacientes con S.H.S. eran tétanos graves. Los 4 pacientes tratados con bloqueo alfa exclusivo fallecieron, tres por disturbios hemodinámicos incontrolables y uno por falla en la asistencia respiratoria mecánica. De los tres casos tratados con alfa y beta bloqueantes sólo uno falleció (distress pulmonar), pudiéndose controlar en él las manifestaciones de S.H.S. que habían aparecido. No obstante la pequeña población estudiada, podemos concluir, que: el bloqueo alfa exclusivo no brindó resultados favorables en lo que hace a la sobrevida. La adición del bloqueo beta al tratamiento en caso de evidencia de S.H.S. puede brindar una disminución de la mortalidad que el síndrome acarrea