Estudio experimental de la vibración de un parche de tambor mediante el modelo de membrana bidimensional

En este trabajo tratamos de estudiar el comportamiento convencional de un tambor bajo un golpeo de una baqueta. Para ello, hemos grabado el sonido producido en distintos puntos de la membrana y, mediante la transformada de Fourier, hemos obtenido unos patrones de intensidad espectral sobre la membrana, identificables como los modos normales de esta. Partiendo del modelo teórico dado por la resolución de la ecuación de onda para una membrana circular bidi- mensional, podemos comparar la forma, ratio de aparición y relación de frecuencia entre los patrones y los modos normales teóricos. De esta forma, podemos estudiar la viabilidad de las aproximaciones tomadas en el modelo teórico en un caso real, así como observar la influencia de fenómenos físicos reales no tenidos en cuenta por este en los datos grabados experimentalmente.In this work we try to study the conventional behaviour of a drum stricken by a drumstick. In order to do this we recorded the sound produced in different points of the membrane and, by means of the Fourier transform, we obtained some spectral intensity patterns identifiable as the normal modes of the latter. Starting from the theoretical model given by the resolution of the wave equation for a bi-dimensional circular membrane, we can compare the shape, appearance ratio and frequency relationship between the patterns and the theoretical normal modes. In this way we can study the viability of the approximations taken by the model in a real case scenario, as well as observing the influence of physical phenomena not taken into account by the latter in the experimental data.Grado en Físic

Improvement of functional neurological disorder after administration of esketamine nasal spray: a case report

Esketamina; Trastorn neurològic funcional; Paràlisi mixtaEsketamina; Trastorno neurológico funcional; Parálisis mixtaEsketamine; Functional neurological disorder; Mixed paralysisFunctional neurological disorder (FND) is a complex neuropsychiatric condition characterized by the presence of neurological symptoms and signs (either motor or sensory) that cannot be explained by any known medical or mental disease. It is frequently presented with psychiatric comorbidities, such as major depression. Its prognosis is poor, with low improvement or recovery rates at 1 year after their onset, and no particular treatment has demonstrated significant efficacy in this regard. Here, we describe the management of a patient affected by treatment-resistant depression (TRD) and FND characterized by mixed paralysis (sensory and motor) in the left arm, and who was successfully treated with esketamine nasal spray, achieving remission in both disorders. The US Food and Drug Administration and the European Medicines Agency recently approved esketamine, the S-enantiomer of ketamine, for treatment of TRD. It is a fast-acting drug that provides a rapid-onset improvement of depressive symptoms. We have presented the first case, to our knowledge, of functional neurological symptoms being successfully treated with esketamine in a patient with comorbid TRD. While the novelty of this data implies a clear need for further research, it is suggested that esketamine might be a useful tool for the treatment of FND, acting through different theorized mechanisms that are in tune with recent advances in knowledge of the etiopathology of FND.The authors received no financial support for the research, authorship, and/or publication of this article

Non-alcoholic fatty liver disease (NAFLD) as a neglected metabolic companion of psychiatric disorders: common pathways and future approaches

Background: Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis in over 5% of the parenchyma in the absence of excessive alcohol consumption. It is more prevalent in patients with diverse mental disorders, being part of the comorbidity driving loss of life expectancy and quality of life, yet remains a neglected entity. NAFLD can progress to non-alcoholic steatohepatitis (NASH) and increases the risk for cirrhosis and hepatic carcinoma. Both NAFLD and mental disorders share pathophysiological pathways, and also present a complex, bidirectional relationship with the metabolic syndrome (MetS) and related cardiometabolic diseases. Main text: This review compares the demographic data on NAFLD and NASH among the global population and the psychiatric population, finding differences that suggest a higher incidence of this disease among the latter. It also analyzes the link between NAFLD and psychiatric disorders, looking into common pathophysiological pathways, such as metabolic, genetic, and lifestyle factors. Finally, possible treatments, tailored approaches, and future research directions are suggested. Conclusion: NAFLD is part of a complex system of mental and non-communicable somatic disorders with a common pathogenesis, based on shared lifestyle and environmental risks, mediated by dysregulation of inflammation, oxidative stress pathways, and mitochondrial function. The recognition of the prevalent comorbidity between NAFLD and mental disorders is required to inform clinical practice and develop novel interventions to prevent and treat these complex and interacting disorders

Inhaled Loxapine as a Rapid Treatment for Agitation in Patients with Personality Disorder : A Prospective Study on the Effects of Time

Agitation in patients diagnosed with personality disorders (PD) is one of the most frequent crises in emergency departments (ED). Although many medications have been tested, their effectiveness has been small or non-significant, and no specific drugs are supported by the available evidence. This study aimed to evaluate the efficacy of Inhaled loxapine (IL) as a therapeutic option for agitated patients with PD. A naturalistic, unicentric, prospective study was carried out. Thirty subjects diagnosed with PD and attending the ED with episodes of agitation were recruited most of whom were women diagnosed with Borderline Personality Disorder. Subjects were treated with a single dose of IL (9.1 mg). Efficacy was assessed with the Clinical Global Impression scale, the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC) and the Agitation-Calmness Evaluation Scale (ACES). Patients were followed 60 minutes after administration to measure IL effect and its duration. IL exhibited an overall efficacy in managing mild to severe agitation, with a quick onset of effect and persistence. 'Effect of time', where IL efficacy is maintained over time, is more marked in higher-severity agitation. No additional treatments were needed to improve agitation during the follow-up time. Results suggest that IL could be a safe and effective option to manage agitation in PD

Cambios funcionales en esquizofrenia

Estudios recientes correlacionan la esquizofrenia con varias causas subyacentes que justifican sus diferentes manifestaciones clínicas. Esto causaría que un paciente con esquizofrenia tuviese un cerebro cuyas regiones corticales estarían conectadas de una manera diferente, con una conectividad afectada con respecto al caso de una persona sana (control). Para probar esto, hemos utilizado resonancia magnética, con un método llamado resonancia de difusión, que permite detectar diferencias en la difusión del agua, y a partir de ello describir características de las conexiones entre diferentes áreas. Después de obtener estas imágenes de 21 pacientes y 21 controles, las hemos procesado digitalmente con el fin de obtener una matriz de conectividad con el número de streamlines (líneas obtenidas de tractografía que representan las direcciones de difusión predominantes) entre diversas áreas relevantes para la esquizofrenia. Los resultados muestran diferencias significativas entre controles y pacientes con esquizofrenia, sobre todo en las conexiones entre el hipocampo y las regiones frontales; además, se han tenido en cuenta las diferencias entre primeros episodios de esquizofrenia y pacientes de larga evolución, para descartar cambios causados por la medicación, y se han seguido encontrando diferencias similares (aunque en un número más reducido de áreas) entre primeros episodios y controles. Estos resultados podrían ayudar a conocer mejor el sustrato neurobiológico de esta enfermedad, y establecer métodos diagnósticos objetivos basados en la neuroimagen, aunque queda un largo camino por recorrer que pasa por validar los resultados de esta técnica de una forma más eficaz y contrastable.Grado en Medicin

Non-alcoholic fatty liver disease (NAFLD) as a neglected metabolic companion of psychiatric disorders: Common pathways and future approaches

Background: Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis in over 5% of the parenchyma in the absence of excessive alcohol consumption. It is more prevalent in patients with diverse mental disorders, being part of the comorbidity driving loss of life expectancy and quality of life, yet remains a neglected entity. NAFLD can progress to non-alcoholic steatohepatitis (NASH) and increases the risk for cirrhosis and hepatic carcinoma. Both NAFLD and mental disorders share pathophysiological pathways, and also present a complex, bidirectional relationship with the metabolic syndrome (MetS) and related cardiometabolic diseases. Main text: This review compares the demographic data on NAFLD and NASH among the global population and the psychiatric population, finding differences that suggest a higher incidence of this disease among the latter. It also analyzes the link between NAFLD and psychiatric disorders, looking into common pathophysiological pathways, such as metabolic, genetic, and lifestyle factors. Finally, possible treatments, tailored approaches, and future research directions are suggested. Conclusion: NAFLD is part of a complex system of mental and non-communicable somatic disorders with a common pathogenesis, based on shared lifestyle and environmental risks, mediated by dysregulation of inflammation, oxidative stress pathways, and mitochondrial function. The recognition of the prevalent comorbidity between NAFLD and mental disorders is required to inform clinical practice and develop novel interventions to prevent and treat these complex and interacting disorders