Interaction of Virus in Cancer Patients: A Theoretical Dynamic Model.

This study reports on a phase-space analysis of a mathematical model of tumor growth with the interaction between virus and immune response. In this study, a mathematical determination was attempted to demonstrate the relationship between uninfected cells, infected cells, effector immune cells, and free viruses using a dynamic model. We revealed the stability analysis of the system and the Lyapunov stability of the equilibrium points. Moreover, all endemic equilibrium point models are derived. We investigated the stability behavior and the range of attraction sets of the nonlinear systems concerning our model. Furthermore, a global stability analysis is proved either in the construction of a Lyapunov function showing the validity of the concerned disease-free equilibria or in endemic equilibria discussed by the model. Finally, a simulated solution is achieved and the relationship between cancer cells and other cells is drawn.

ADHD Symptoms as a Stressor Leading to Depressive Symptoms among University Students: The Mediating Role of Perceived Stress between ADHD and Depression.

Attention deficit hyperactivity disorder (ADHD) is a condition manifested in childhood and includes symptoms, such as attention deficit, impulsivity, difficulty in concentrating, hyperactivity, and aggressive behavior. Along with the negative effects of ADHD symptoms on individuals, various psychological factors are thought to be associated with these symptoms. However, ADHD in emerging adulthood is not rare and can be conceived as the continuation of discomfort that might emerge during childhood and adolescence. Our mediation study involved 613 undergraduate students in Istanbul. The participants filled out demographic information forms: Adult Attention Deficit and Hyperactivity Disorder Self-Reported Scale (ASRS), Perceived Stress Scale and Beck Depression Inventory (BDI). Our work stressed those positive correlations found among ASRS, Perceived Stress Scale, and BDI scores. Analysis by Model 4 of Hayes Process Macro and Sobel tests showed that ADHD symptoms predicted both perceived stress and depression scores of the participants and dimensions of perceived stress acted as partial mediators in the positive relationship between ADHD and depression scores.