The beat in physical systems is a transparent and well-understood phenomenon. It may occur in forced oscillatory systems and as a result of the interference of two waves of slightly different frequencies. However, in chemical systems, the realization of the latter type of the beat phenomenon has been lacking. Here we show that a periodic titration of acid and alkaline solutions with each other using programmable syringe pumps in a continuous stirred-tank reactor exhibits the beat phenomenon in the temporal pH oscillation pattern if the time periods of sinusoidal inflow rates of the reagents are slightly different. Interestingly, the frequency of the chemical beat pattern follows the well-known relationship from physics, namely the frequency of the beat is equal to the absolute value of the difference of the two wave frequencies. Based on our strategy, we can design and engineer non-autonomous pH oscillatory systems, in which the characteristics of the temporal oscillations (amplitude, time period) can easily and precisely be controlled by the experimental conditions such as the inflow rates and feed concentrations. The demonstrated phenomena can be exploited in practical applications, we use the non-autonomous pH oscillators to drive the reversible assembly and disassembly of pH-sensitive building blocks (oleic acid and gold nanoparticles), both highly relevant in nanotechnology and biomedical applications.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8155044 | PMC |
http://dx.doi.org/10.1038/s41598-021-90301-8 | DOI Listing |
J Chem Phys
January 2025
School of Physics and Astronomy, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, China.
Two-dimensional electronic spectroscopy (2DES) has high spectral resolution and is a useful tool for studying atomic dynamics. In this paper, we show a smallest unit of electromagnetically induced transparency (EIT) for 2DES, i.e.
View Article and Find Full Text PDFPhysiol Rep
December 2024
Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan.
Cardiac alternans (C-ALT) is a phenomenon of alternating strong and weak contractions in the heart and is considered a risk factor for the development of heart failure and arrhythmias. However, no model has been reported that can induce C-ALT in vitro using human cells, and the developmental mechanism of C-ALT has not been studied using human cells. In this study, we successfully induced C-ALT in vitro using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).
View Article and Find Full Text PDFExp Physiol
November 2024
Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
Gravity, an invisible but constant force , challenges the regulation of blood pressure when transitioning between postures. As physiological reserve diminishes with age, individuals grow more susceptible to such stressors over time, risking inadequate haemodynamic control observed in orthostatic hypotension. This prevalent condition is characterized by drops in blood pressure upon standing; however, the contrary phenomenon of blood pressure rises has recently piqued interest.
View Article and Find Full Text PDFCureus
October 2024
Cardiology, Beaumont Hospital, Royal Oak, USA.
Proc Natl Acad Sci U S A
November 2024
Department of Molecular, Cellular, and Developmental Biology, and the Neuroscience Research Institute, University of California, Santa Barbara, CA 93106.
Attraction and mating between male and female animals depend on effective communication between conspecifics. However, in mosquitoes, we have only a rudimentary understanding of the sensory cues and receptors critical for the communication that is essential for reproductive behavior. While it is known that male use sound to help them identify females, it is not unclear whether sound detection is absolutely required since other cues such as vision may also participate in mating behavior.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!