Nonisothermal chemical oscillators are poorly studied systems because chemical oscillations are conventionally studied under isothermal conditions. Coupling chemical reactions with heat generation and removal in a nonisothermal oscillatory system can lead to a highly nontrivial nonlinear dynamic behavior. For the current study, we considered the three-variable Oregonator model with the temperature incorporated as a variable (not a parameter), thus adding an energy balance to the set of equations. The effect of temperature on reaction rates is included through the temperature-dependent reaction rate coefficients (Arrhenius law). To model a continuous operation in a laboratory environment, the system was subjected to external forcing through the coolant temperature and infrared irradiation. By conducting numerical simulations and parametric studies, we found that the system is capable of a resonant behavior exhibiting induced oscillations. Our findings indicate that an external source of heat (e.g., via an infrared light emitting diode) can be used to induce a Hopf bifurcation under resonant conditions in an experimental Belousov-Zhabotinsky reactor.
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http://dx.doi.org/10.1021/acs.jpca.9b05238 | DOI Listing |
Itching tends to worsen at night in patients with itchy skin diseases, such as atopic dermatitis. Unconscious scratching during sleep can exacerbate symptoms, cause sleep disturbances, or reduce quality of life. Therefore, evaluating nocturnal scratching behaviour is important for better patient care.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China, 154 Anshan Road Tianjin 300052, PR China; Department of Neurology, Tianjin Medical University General Hospital Airport Site, Tianjin 300052, PR China. Electronic address:
Background: Changes in cerebral blood flow (CBF) may contribute to the initial stages of the pathophysiological process in patients with Alzheimer's disease (AD). Hypoperfusion has been observed in several brain regions in patients with mild cognitive impairment (MCI). However, the clinical significance of CBF changes in the early stages of AD is currently unclear.
View Article and Find Full Text PDFJ Thorac Cardiovasc Surg
January 2025
Division of Cardiology, The Hospital for Sick Children, Toronto, ON, Canada; Center for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, ON, Canada.
Objectives: Mixed reality (MixR) is an innovative visualization tool that presents virtual elements in a real-world environment, enabling real-time interaction between the user and the combined digital/physical reality. We aimed to explore the feasibility of MixR in enhancing preoperative planning and intraoperative guidance for the correction of various complex congenital heart defects (CHDs).
Methods: Patients underwent cardiac computed tomography or cardiac magnetic resonance and segmentation of digital imaging and communications in medicine (DICOM) images was performed.
Neuroimage
January 2025
Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
When engaged in dynamic or continuous movements, action initiation involves modifying an ongoing motor program rather than initiating it from rest. Event-related theta synchronization over sensorimotor areas is a neurophysiological marker for modifying motor programs. We used electroencephalography (EEG) to examine how task complexity and age affect event-related synchronization (ERS) in the theta band during a dynamic bimanual, visuomotor pinch force task.
View Article and Find Full Text PDFNeuroimage
January 2025
State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern, Institute for Brain Research, Beijing Normal University, Beijing 100875, PR China. Electronic address:
Many theories suggest that creative thinking involves a dynamic transition between different mental states, yet empirical evidence supporting this notion remains scarce. The dual process model proposes that spontaneous thinking and deliberate thinking drive the dwell in and the transitions between different mental states during creative thinking, but there is a debate over whether the two types of thinking operate in parallel or in sequence. To address these gaps, we conducted a functional magnetic resonance imaging (fMRI) study in 41 college students during a creative storytelling task.
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