RESUMEN
The flow through a Hele-Shaw cell is an experimental prototype to study the flow through a porous medium as well as the flow in microfluidic devices. In context with porous medium flows, it is used to visualize and understand hydrodynamic instabilities like viscous fingering (VF). The gap between the plates of the cell is an important parameter affecting the flow dynamics. However, the effect of the gap on the Hele-Shaw cell flows has been minimally explored. We perform experiments to understand the effect of the gap on VF dynamics. It is observed that a minimum gap is required to observe rigorous fingering instability. The onset time of instability, as well as the width of the fingers, increases with an increment in the gap due to a decrease in the convection. The instability increases with an increase in Péclet number, but the effect of gap width on fingering patterns is evident with broader fingers observed for larger b. The results are validated by performing numerical simulations. It is further shown that the gap-averaged three-dimensional simulations using the Stokes law approach and the two-dimensional Darcy's law result in a small gap Hele-Shaw cell.
RESUMEN
Metacognitive therapy (MCT) is a transdiagnostic intervention used to treat different psychiatric disorders. This intervention is based on the concept that persistent emotional distress is a consequence of a particular way of responding to negative thoughts and emotions. MCT for depression and anxiety aims at targeting rumination, worry, and the dysfunctional metacognitive beliefs underlying these thought processes. The purpose of this study was to explore MCT as a treatment for adult patients with depression (either major depressive disorder (MDD) or recurrent depressive disorder, dysthymia, or mixed anxiety depressive disorder) with comorbid anxiety symptoms. Four men diagnosed with depressive disorder with comorbid anxiety symptoms seeking treatment from the outpatient clinic of the Department of Psychiatry at the All India Institute of Medical Sciences, New Delhi, were recruited for the study. Each patient received 10 individual weekly sessions of MCT, lasting up to 1 hour each. Participants were assessed at baseline, post-intervention (right after completing MCT), and at one-month and two-month follow-ups. Primary outcome measures were a reduction in the severity of depression, anxiety, worry, and rumination. Secondary outcome measures were changes in dysfunctional metacognitive beliefs about worry and rumination. All outcomes were assessed via self-report using standardized questionnaires at baseline, post-intervention, one-month, and two-month follow-up. Data for all the outcome measures (at baseline, post-intervention, one month, and two-month follow-up) were plotted on a graph for visual examination. Additionally, we calculated clinically significant change (≥50% reduction in symptom severity and one other standardized criteria for clinically significant changes) for all the primary outcome measures across the above-mentioned four time points. All four men were single, well-educated, and had a mean age of 25.5±4.79 years. Their mean illness duration was 21±0.64 months. None of them had ever received any psychotherapy for their current illness. They had severe depressive and anxiety symptoms at baseline. Three participants had high scores on the rumination and worry scales. At post-intervention, all the participants had significant improvement on all the primary outcome measures, and they maintained their gains on follow-up assessments. Our study generated preliminary evidence supporting the effectiveness of MCT in treating depressive disorders with comorbid anxiety symptoms in the Indian context.
RESUMEN
Metacognitive therapy (MCT) is a novel and promising transdiagnostic psychotherapy intervention based on the Self-Regulatory Executive Function model of conceptualizing emotional disorders. It was developed by Adrian Wells in 2009. Its therapeutic response occurs by reducing dysfunctional metacognitive beliefs regarding worry and rumination, often seen in patients with psychiatric disorders. Since its inception, it has been increasingly applied to a wide spectrum of psychiatric illnesses, but mainly focusing on mood and anxiety disorders. To our knowledge, no study has detailed its existing therapeutic scope in psychiatry. In this comprehensive narrative review, we describe the various psychiatric illnesses in which MCT has been used, the advantages of MCT, and the limitations of the MCT research. In addition, we propose some solutions to systematically examine its place in psychiatry. We encountered its potential role in treating trauma and stress-related disorders, obsessive-compulsive spectrum disorders, personality disorders, psychotic disorders, substance use disorders, and sexual disorders.
