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Based on a combination of many-body potentials, an analysis of the inertia tensors and a Density Functional Theory framework, we use a method to harvest the lowest energy states of any set of cluster systems. Then, this methodology is applied to the Pt6Cu6 cluster case and the structural, chemical, electronic, anisotropy, magnetic and vibrational properties of the lowest energy isomers are studied. Unexpectedly, some tens of isomers with much lower energy than the precedent believed ground state [J. Chem. Phys., 131(4):044701] are found, which indicates the goodness of this methodology. Some of the isomers obtained present the point groups Cs, C2v according to Schoenflies notation, while others do not exhibit specific symmetry operations. The global chemical descriptors as the ionization potential, the electron affinity and the chemical hardness have oscillating behaviors with overall decreasing trends as the energy of the isomer grows up, indicating a higher rate of deactivation by sintering processes and a higher strength of the adsorption of small molecules on these systems. We present interesting results of the electronic, magnetic, anisotropy, vibrational and thermal properties of these clusters and discuss them; what can be useful information for future experiments and technical applications in varied fields as catalysis, spintronics, molecular magnetism or magnetic storage information.
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By means of Monte Carlo simulations we studied field driven nucleation and propagation of transverse domain walls (DWs) in magnetic nanowires subjected to temperature gradients. Simulations identified the existence of critical thermal gradients that allow the existence of reversal processes driven by a single DW. Critical thermal gradients depend on external parameters such as temperature, magnetic field and wire length, and can be experimentally obtained through the measurement of the mean velocity of the magnetization reversal as a function of the temperature gradient. Our results show that temperature gradients provide a high degree of control over DW propagation, which is of great importance for technological applications.
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In recent years, construction and characterization of core-shell structures have attracted great attention because of their unique functional properties and their integration into technological devices. However, some aspects of their basic physics still remain to be explored. In this study, we report on an extensive hierarchical multiscale modeling methodology applied to Fe-Ni core/shell nanostructures of technological interest. As a first step, supported on a first-principles study, we develop a methodology to compute primordial but unprecedented parameters such as the exchange coupling and the equilibrium bond distances at the interface, namely JFe-Ni = 35.48 meV and d = 2.5 Å. This methodology can be used for computing fundamental parameters in mixed systems by knowing the parameters in the bulk samples, and the so-obtained results can be used in higher size scale simulations. As a proof, the results obtained are used as input parameters for atomistic simulations on Fe-Ni samples made out of a Fe core surrounded by a Ni shell whose external diameter varies finely in the range 60-110 nm. The inner diameter and height are fixed to be 40 and 50 nm, respectively. We address the structural, electronic, static magnetic and hysteresis properties of the Fe-Ni core/shell cylindrical nanostructures in different size ranges. These nanostructures reveal different magnetic properties with novel complex states, which are studied in detail.
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The aims were to examine the association of sleep patterns with being overweight or obese and to analyze the association of cardiorespiratory fitness (CRF) with sleep patterns in children. The study involved 395 schoolchildren (12-13 years old). Sleep patterns were assessed with the Sleep Self-Report (SSR) questionnaire, grouped into four subscales: sleep quality, sleep-related anxiety, bedtime refusal, and sleep routines. CRF was predicted by the 20-m shuttle-run test. Logistic regression models showed that sleep-related anxiety problems predicted being overweight or obese in both sexes, and sleep quality problems predicted being overweight or obese in girls. Also, girls who had better CRF levels were less susceptible to sleep-related anxiety problems. Studies are required to determine if increasing CRF could be a possible strategy for improving sleep quality.
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Aptidão Cardiorrespiratória/fisiologia , Obesidade/fisiopatologia , Autorrelato , Sono/fisiologia , Adolescente , Ansiedade/complicações , Índice de Massa Corporal , Criança , Chile , Feminino , Humanos , Modelos Logísticos , Masculino , Obesidade/complicações , Sobrepeso/complicações , Sobrepeso/fisiopatologia , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Physical activity (PA), screen time (ST), and sleep are modifiable lifestyle habits for health. The objectives of this study were: a) to examine the association between PA, ST, and both, on sleep patterns; and b) to determine the influence of PA and ST on sleep problems in Chilean girls. PATIENTS AND METHODS: The study involved 196 children (12.2 years). Patterns and sleep problems were assessed using the Spanish version of the Sleep Self-Report, and the PA through the Physical Activity Questionnaire for Adolescents (PAQ-A), both in Castilian. The ST was assessed using several questions about television, game console and computer use. RESULTS: The ST recommendation (2h a day) was exceeded by 63.2% of the girls. In general, the most active girls (last quartile) that did not exceed the recommendations of ST reported higher sleep quality and total score values compared to those who did not meet both. The logistic regression analysis showed that girls who did not meet both habits were more likely to have sleep quality (odds ratio=17.8, P=.018), and general sleep problems (odds ratio=7.85, P=.025). CONCLUSIONS: Parents need to set limits on sedentary leisure time and encourage more active habits, as sleep is a parameter closely linked to a better health profile in youth.
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Computadores , Exercício Físico , Televisão , Criança , Chile , Feminino , Humanos , Comportamento SedentárioRESUMO
Acoso escolar es un continuo y deliberado uso de violencia que recibe un niño por parte de otro u otros, que se comportan cruelmente con él, a fin de someterlo, apocarlo, asustarlo, amenazarlo y que atentan contra su dignidad. Objetivo: Establecer los tipos de violencia escolar que sufren los estudiantes de educación primaria y secundaria del Instituto Cultura Nacional, Tegucigalpa, Honduras Mayo, 2011.Métodos: Se realizó un estudio descriptivo de corte transversal, la población fue de 504 estudiantes de diferentes edades y niveles escolares, con una muestra de 226 alumnos; el sistema de muestreo fue estratificado por grados escolares de primaria 4º, 5º y 6º y secundario de diferentes carreras. La unidad de análisis fue seleccionada en forma aleatoria. Para la recolección de datos se elaboró un instrumento organizado y estructurado con datos generales y los propios de la violencia escolar. Se utilizó una variación del Test de Cisneros que mide violencia escolar (fiabilidad de 0.96), se capacitó a los investigadores para la recolección de la información. Resultados: La prevalencia de violencia escolar fue 36% (81), el tipo de violencia enfrentada por los escolares fue: verbal 68(84%), psicológica 59(73%), física 57(70%), económica 39(48%), social 25(31%); predominó en el sexo masculino 47(42%); la violencia según rangos de edad de los escolares afectados ocurrió en; de 8 a 10 años 7(64%), de 11 a 13 22(51%) y en mayores de 17 años19(25%); las consecuencias emocionales en las víctimas de violencia fueron: tristeza 17(7%), llanto11(5%), sin deseo de asistir a clase 6(3%); 78 (47%) de los niños estudiados han observado actos de violencia escolar; 133 (59%) se perciben como agresores; el área física de la escuela donde ocurrió la agresión son aulas de clases 37(16%) y cancha deportiva 20(9%). Conclusión: La violencia escolar está presente en la población estudiantil, cuyo ámbito de expresión es el colegio, con participación de estudiantes...
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Humanos , Masculino , Feminino , Adolescente , Criança , Bullying/psicologia , Ensino Fundamental e Médio , Estudantes , Maus-Tratos Infantis , Transtornos Relacionados ao Uso de Substâncias/complicaçõesRESUMO
Introducción: (véanse partes I y II) esta publicación se enfoca en la prevalencia de bacilos entéricos y levaduras en muestras de placa subgingival de los 69 pacientes de la investigación. Estudios preliminares sugieren una asociación entre bacilos entéricos y algunos tipos de patógenos periodontales. Se realizó análisis microbiológico y se determinó la susceptibilidad a los siguientes antibióticos: Ciprofloxacina, Metronidazol, Amoxicilina, Tetraciclina y Clindamicina. Métodos: las características socio-demográficas (edad, género, tabaquismo y agrupación familiar) y los parámetros clínicos (profundidad sondeable, nivel de inserción, sangrado superficial y sangrado al sondaje) se evaluaron al comienzo, a los 3, 6, 12 y 24 meses, se tomaron muestras microbiológicas de 6 sitios por paciente al inicio del estudio, a los 12 y 18 meses. Los resultados de este estudio con relación a la presencia de bacilos entéricos y de Candida albicans sólo obedecen al primer cultivo, que es cuando se mide la prevalencia, aunque a todos los pacientes se les hizo seguimiento durante dos años, después de realizarles la terapia periodontal no quirúrgica convencional. Se realizó un análisis descriptivo en el cual se obtuvieron las frecuencias, proporciones y prevalencias de aparición de los bacilos entéricos y levaduras para el grupo total de pacientes, de buenos y malos respondedores mediante tablas de distribución de frecuencias y gráficos de barras compuestas. Resultados: se presentó una prevalencia de bacilos entéricos, entre ellos Escherichia coli, Klebsiella spp, Enterobacter spp y también de levaduras en la microflora subgingival de los pacientes con periodontitis n=69 (36.2%), tanto de buenos n=57 (33.3%) como de malos respondedores n=12 (49.9%). Conclusión: del estudio se puede concluir que E. coli fue el microorganismo que se presentó en mayor porcentaje en ambos grupos de pacientes. De acuerdo al test de...
Introduction (see parts I and II): this publication is focused on the prevalence of enteric rods and yeasts species in samples taken from subgingival plaque of 69 patients included in the investigation. Preliminary studies suggest an association between enteric rods and some types of periodontal pathogens. Microbiological analysis was realized by means of culture, and susceptibility was determined for the following antibiotics: Ciprofloxacin, Metronidazole, Amoxicillin, Tetracycline and Clindamycin. Methods: evaluations of the socio-demographic criteria (age, gender, tobacco use, and family grouping), and clinical parameters (probing depth, clinical attachment, superficial bleeding, and probing bleeding) were made at the beginning, 3, 6, 12, and 24 months. Microbiological samples of each patient were taken from 6 different sites at the beginning of the study, 12 and 18 months. The results corresponding to the presence of enteric rods, and Candida albicans are only part of the first sample, which measured the prevalence, although all the patients had a follow up of two years after conventional non surgical periodontal therapy. A descriptive analysis was made, which determined the frequency, proportion, and prevalence of enteric rods and yeasts in both groups, good and poor responders, shown in frequency distribution tables and compound bar charts. Results: the most prevalent species, found in subgingival microflora in patients with periodontitis n=69(36.2%) including both, good n=57 (33.3%) and poor responders n=12 (49.9%) were enteric rods, mainly Escherichia coli, Klebsiella spp and Enterobacter spp, and yeasts. Conclusion: Escherichia coli had the highest prevalence percentage in both, good and poor responders. According to antimicrobial susceptibility test, Ciprofloxacin would be the antibiotic of choice in subjects with periodontitis and with enteric rods.
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Humanos , Periodontia , OdontologiaRESUMO
Transitional cell carcinoma relapse in ileal conduit after radical cistectomy is a rare event, especially without upper urinary tract involvement. We describe a case of uretero-ileal transitional cell tumour five years after cistectomy for invasive urothelial tumour. Patient underwent endoscopic treatment with good results after 13 months of follow-up.
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Carcinoma de Células de Transição/cirurgia , Cistectomia , Neoplasias do Íleo , Recidiva Local de Neoplasia , Neoplasias Ureterais , Neoplasias da Bexiga Urinária/cirurgia , Derivação Urinária , Idoso , Cistectomia/métodos , Humanos , Neoplasias do Íleo/diagnóstico , Neoplasias do Íleo/cirurgia , Masculino , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/cirurgia , Neoplasias Ureterais/diagnóstico , Neoplasias Ureterais/cirurgiaRESUMO
La recidiva de un tumor urotelial en el conducto uretero-ileal tras una cistectomía es poco frecuente, especialmente sin afectación del tracto urinario superior. Presentamos un caso de afectación de la unión uretero-ileal por tumor urotelial en un paciente cistectomiazado desde hacía 5 años por un tumor vesical infiltrante, al cual se le somete a un tratamiento endoscópico de su lesión con buenos resultados a los 13meses de seguimiento (AU)
Transitional cell carcinoma relapse in ileal conduit after radical cistectomy is a rare event, especially without upper urinary tract involvement. We describe a case of uretero-ileal transitional cell tumour five years after cistectomy for invasive urothelial tumour. Patient underwent endoscopic treatment with good results after 13 months of follow-up (AU)
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Humanos , Masculino , Idoso , Neoplasias Ureterais/diagnóstico , Neoplasias Ureterais/cirurgia , Recidiva Local de Neoplasia , Seguimentos , Cistectomia/métodosRESUMO
El agua de mar natural se utiliza en algunos países iberoamericanos como elemento nutritivo y terapéutico, y en los países desarrollados se usa como complemento nutricional de forma refinada y comercial. Los estudios de ingesta de agua de mar tratada muestran que no hay toxicidad; sin embargo, el uso de agua cercana a las playas representa un riesgo para la salud debido a la polución de los centros urbanos. En este estudio se emplearon linfocitos humanos y la electroforesis de células individuales (ensayo cometa), para comparar la genotoxicidad de un extracto orgánico de agua de mar tomada de la orilla respecto a muestras obtenidas mar adentro en el pequeño municipio de Coveñas-Sucre, Colombia, que vierte sus aguas domésticas directamente al mar o a pozos sépticos. Se observa genotoxicidad a 37°C pero no a 4°C, este efecto es dependiente de la concentración del extracto (p<0.0001), del sitio de muestreo (p=0.0026) y de la interacción de estos dos factores (p=0.0001). La muestra orgánica que presenta menor genotoxicidad es la de mar adentro. La citotoxicidad del extracto orgánico de agua de mar es muy baja comparada con la obtenida de muestras del acueducto de Medellín (Colombia)
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Água do Mar , Ensaio CometaRESUMO
Introducción: (ver parte I:) El estudio se inició con 69 pacientes, de los cuales terminaron 55. Métodos: se realizó evaluación al comienzo, a los 3, 6, 12 y 24 meses, de las características sociodemográficas (edad, género, tabaquismo y agrupación familiar) y de los parámetros clínicos (profundidad sondeable, nivel de inserción, sangrado superficial, sangrado al sondaje y microflora subgingival). Se tomaron muestras microbiológicas de 6 sitios al inicio, 12 y 18 meses. En el análisis estadístico se utilizó la prueba Chi cuadrado y la t-student para comparar los promedios en el tiempo, ambos con un nivel de significancia del 5 por ciento. Se realizó análisis de regresión logística para buscar variables predictoras de la respuesta al tratamiento. Los objetivos de la presente investigación fueron determinar la composición microbiana de las bolsas periodontales y evaluar la respuesta de los pacientes malos respondedores a una segunda terapia alternativa con antimicrobianos sistémicos, dos años después de aplicarla y compararla con la de los buenos respondedores. Resultados: tres meses después del tratamiento, los cambios (pérdida o ganancia) en el nivel de inserción (NI), permitieron clasificar a los pacientes en buenos respondedores (BR) a 57 (82,6 por ciento) y malos respondedores (MR) a 12 (17,4 por ciento). Las variables estudiadas no mostraron asociación individual o agrupada con el tipo de respuesta al tratamiento excepto el índice de placa supragingival ≥ 2 (P = 0,05). Conclusiones: el seguimiento a dos años, indica que la terapia alternativa fue beneficiosa para los MR que se comportaron durante este período de igual manera que los BR, ambos mostrando estabilidad en su NI. Las bacterias mas prevalentes fueron: Porphyromonas gingivalis (P. g.), Prevotella intermedia (P. i.), Porphyromonas sp (P.s p.) El 45 por ciento de los pacientes presentaron entéricos y los MR 78 por ciento.
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Doenças Periodontais , Bolsa Periodontal , Periodontia , PeriodontiteRESUMO
Propósito. La osteoartritis temporomandibular es una enfermedad articular degenerativa, caracterizada por la destrucción del cartílago y hueso articular consecutiva a la respuesta inflamatoria e inmune desarrollada. En el presente trabajo se evalúa la expresión a nivel de ARN mensajero de diversas citoquinas proinflamatorias en los sinoviocitos articulares de individuos afectados por osteoartritis temporomandibular. Material y métodos. En 12 pacientes afectados de osteoartritis temporomandibular y en 6 sujetos sanos se evaluó la expresión de citoquinas en sinoviocitos de la articulación temporomandibular mediante la técnica de PCR cuantitativa en tiempo real. Resultados. Significativamente mayores niveles de IL-1Beta, IL-2, IL-12, IL-17, TNFalpha, TNFBeta e IFNGamma fueron observados en pacientes afectados de osteoartritis temporomandibular en comparación a sujetos sanos. En los sujetos enfermos la citoquina predominante fue IL-12 y en los sanos fue IL-10. Conclusión. Tomados en conjunto, nuestros datos demuestran una asociación de elevados niveles de citoquinas propias de una respuesta inmune Th1 y la destrucción observada durante la osteoartritis temporomandibular (AU)
Background. Temporomandibular osteoarthritis is a degenerative disease that affects the temporomandibular joint and is characterized by the cartilage and bone destruction caused by the inflammatory and immune response. This communication reports on the expression of proinflammatory cytokines in synovial cells of patients with temporomandibular osteoarthritis. Methods. In twelve temporomandibular osteoarthritis patients and six healthy control subjects, cytokine expression in synovial cells was evaluated by quantitative PCR. Results. Levels of IL-1Beta, IL-2, IL-12, IL-17, TNFalpha, TNFBeta e IFNGamma were significantly higher in synovial cells of patients than in controls. In particular, IL-12 was the predominant cytokine in patients and IL-12 in healthy subjects. Conclusion. Taken together, these data suggest that a Th1 immune response is associated to the destruction observed during the temporomandibular osteoarthritis (AU)
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Humanos , Transtornos da Articulação Temporomandibular/imunologia , Osteoartrite/imunologia , Células Th1 , Citocinas/imunologia , RNA Mensageiro/imunologiaRESUMO
BACKGROUND: The association of normal serum levels of immunoassayable gonadotrophins with anovulation during lactational amenorrhoea (LA) has not been fully explained. METHODS: Serum FSH polymorphism was analysed in 10 women during LA between days 60 and 70 post-partum and again, in the mid-follicular phase (MFP), after resuming menstrual cyclicity. FSH microheterogeneity was characterized according to charge, using preparative isoelectric focusing, and according to the inner structure of carbohydrate chains, using lectin chromatography. RESULTS: A significantly higher proportion of FSH charge isoforms isolated below pH 4.10 and a lower proportion of FSH isoforms bearing highly branched oligosaccharides were observed during LA when compared to MFP. Further analysis with higher resolution showed that FSH charge isoforms, isolated in the lower pH range in LA, corresponded to FSH molecules bearing highly branched and biantennary oligosaccharides. FSH isoforms bearing hybrid-type oligosaccharides were only present during LA. The circulating FSH isoform mix was significantly less bioactive in LA than in MFP. LA is characterized by a more acidic mix of FSH isoforms, containing hormone bearing less processed oligosaccharides, with decreased biopotency in comparison with the follicular phase. CONCLUSIONS: This FSH microheterogeneity may be one of the critical factors contributing to incomplete follicular development and anovulation during LA.
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Amenorreia/sangue , Hormônio Foliculoestimulante/sangue , Lactação/sangue , Ciclo Menstrual/sangue , Cromatografia , Feminino , Humanos , Estudos Longitudinais , Folículo Ovariano/crescimento & desenvolvimento , Hipófise/fisiologia , Período Pós-Parto/sangue , Isoformas de Proteínas/sangueRESUMO
BACKGROUND: Comparisons of follicular development and hormonal profile in the same women during and after lactational amenorrhoea (LA) are scarce. We report follicular growth, pituitary and ovarian hormone serum levels in the same women during LA and in follicular phases after resumption of menstrual cyclicity. METHODS: Serum samples were obtained from 10 women during LA between days 60 and 89 post-partum and between days 1 and 4 (early follicular phase; EFP) and 7 and 10 (mid-follicular phase; MFP) of the second and third cycles after LA. RESULTS: The number of follicles >3 mm and diameter of the largest follicle were significantly higher during LA when compared to EFP and MFP. Serum levels of inhibin B were similar in LA and EFP and increased significantly in MFP. Pro-alphaC was significantly higher in EFP than in LA and MFP. Estradiol was similar during all stages. In comparison with EFP and MFP, LA is associated with higher prolactin levels, normal or slightly elevated gonadotrophins and increased number and size of follicles without a parallel increase in estradiol, inhibin B and Pro-alphaC. CONCLUSIONS: During LA, there is a profound dissociation between follicular growth and follicular endocrine activity, which suggests an alteration in the stimulus-response relationship at the follicular level.
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Amenorreia/sangue , Hormônios Esteroides Gonadais/sangue , Gonadotropinas Hipofisárias/sangue , Inibinas/sangue , Folículo Ovariano/crescimento & desenvolvimento , Feminino , Gonadotropinas/sangue , Humanos , Lactação/sangue , Estudos Longitudinais , Ciclo Menstrual/sangue , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/metabolismo , Hipófise/fisiologia , Período Pós-Parto/sangue , UltrassonografiaRESUMO
En Colombia y América latina se ha iniciado recientemente el uso nutricional y terapéutico del agua de mar natural, por su contenido de minerales y oligoelementos, práctica ya reconocida en Europa desde hace más de un siglo. Objetivo: evaluar la posible toxicidad del agua de mar de Coveñas (costa atlántica colombiana). Materialesy métodos: se incubaron células humanas en agua de mar recogida en Coveñas para determinar fragilidad osmótica de eritrocitos, viabilidad celular y daño en el ADN de linfocitos (ensayo cometa); además, se determinó su capacidad antioxidante. Resultados: los eritrocitos en agua de mar presentaron hemólisis significativamente mayor respecto a la observada en amortiguador PBS hipertónico de concentración similar (4,3 y 2,8 por ciento respectivamente, P = 0,00001); sin embargo, la diferencia de los promedios fue muy pequeña. La viabilidad celular de los linfocitos en agua de mar fue de 95 por ciento, similar a la observada en PBS isotónico. Dicha agua de mar tampoco produjo daño en el ADN de linfocitos humanos, según los resultados de los promedios del momento de Olive del ensayo cometa. Tampoco presentó actividad antioxidante ni prooxidante. Conclusiones: según estos ensayos, el agua de mar obtenida en Coveñas presentó bioseguridad para el consumo humano; sin embargo, se deberá evaluar en el futuro la toxicidad de su componente orgánico concentrado y la genotoxicidad en personas que la consuman.
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Ensaio Cometa , Água do MarRESUMO
Secondary hypogonadism is more common than primary gonadal failure and is seen in chronic and acute illnesses. Although testosterone has a role in erections, its importance in erectile dysfunction (ED) has been controversial. Hypogonadism produced by functional suppression of pituitary gonadotropins has been shown to correct with clomiphene citrate, but with a modest effect on sexual function. We wondered if longer treatment would produce improved results. A total of 178 men with secondary hypogonadism and ED received clomiphene citrate for 4 months. Sexual function improved in 75%, with no change in 25%, while significant increases in luteinizing hormone (P<0.001) and free testosterone (P<0.001) occurred in all patients. Multivariable analysis showed that responses decreased significantly with aging (P<0.05). Decreased responses also occurred in men with diabetes, hypertension, coronary artery disease, and multiple medication use. Since these conditions are more prevalent with aging, chronic disease may be a more important determinant of sexual dysfunction. Men with anxiety-related disorders responded better to normalization of testosterone. Assessment of androgen status should be accomplished in all men with ED. For those with lower than normal age-matched levels of testosterone treatment directed at normalizing testosterone with clomiphene citrate is a viable alternative to giving androgen supplements.
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Clomifeno/uso terapêutico , Disfunção Erétil/etiologia , Hipogonadismo/sangue , Hipogonadismo/complicações , Testosterona/sangue , Envelhecimento , Transtornos de Ansiedade/complicações , Doenças Cardiovasculares/complicações , Coito , Complicações do Diabetes , Disfunção Erétil/sangue , Disfunção Erétil/fisiopatologia , Humanos , Hipogonadismo/tratamento farmacológico , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Resultado do TratamentoRESUMO
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