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Sensitive magnetic nucleic acid (NA) detection via frequency mixing magnetic detection (FMMD) requires amplified NA samples for which a reliable temperature control is necessary. The feasibility of recombinase polymerase amplification (RPA) was studied within a newly integrated temperature-controlled sensor unit of a mobile FMMD based setup. It has been demonstrated that the inherently generated heat of the low frequency (LF) excitation signal of FMMD can be utilized and controlled by means of pulse width modulation (PWM). To test control performance in a point of care (PoC) setting with changing ambient conditions, a steady state and dynamic response model for the thermal behavior at the sample position of the sensor were developed. We confirmed that in the sensor unit of the FMMD device, RPA performs similar as in a temperature-controlled water bath. For narrow steady state temperature regions, a linear extrapolation suffices for estimation of the sample position temperature, based on the temperature feedback sensor for PWM control. For any other ambient conditions, we identified and validated a lumped parameter model (LPM) performing with high estimation accuracy. We expect that the method can be used for NA amplification and magnetic detection using FMMD in resource-limited settings. [ABSTRACT FROM AUTHOR]

Magnetic nanoparticles (MNPs), particularly iron oxide nanoparticles (IONPs), play a pivotal role in biomedical applications ranging from magnetic resonance imaging (MRI) enhancement and cancer hyperthermia treatments to biosensing. This study focuses on the synthesis, characterization, and application of IONPs with two different size distributions for frequency mixing magnetic detection (FMMD), a technique that leverages the nonlinear magnetization properties of MNPs for sensitive biosensing. IONPs are synthesized through thermal decomposition and subsequent growth steps. Our findings highlight the critical influence of IONP size on the FMMD signal, demonstrating that larger particles contribute dominantly to the FMMD signal. This research advances our understanding of IONP behavior, underscoring the importance of size in their application in advanced diagnostic tools. [ABSTRACT FROM AUTHOR]

We report on the first preliminary result of our 129Xe EDM measurement performed by the MIXed collaboration. The aim of this report is to demonstrate the feasibility of a new method to set limits on nuclear EDMs by investigating the EDM of the diamagnetic 129Xe atoms. In our setup, hyperpolarized 3He serves as a comagnetometer needed to suppress magnetic field fluctuations. The free induction decay of the two polarized spin species is directly measured by low noise DC SQUIDs, and the weighted phase difference extracted from these measurements is used to determine a preliminary upper limit on the 129Xe EDM.

A study is conducted to show that the two effects such as 'frequency dependence of the stacked time transients on the repetition frequency of the transmitter', and 'the appearance of so-called signal reversal' could be attributed to the stacking procedure performed by transient electromagnetics (TEM). The result shows that despite the step function inductive response decaying monotonically and being positive at all times, sign reversible due to the TEM stacking procedure is possible over the class of targets.

A testing technique based on recording the remnant magnetic field of particles using HTS SQUID sensors was developed. The sensitivity of the SQUID system for very small magnetic particles was experimentally determined using spheres of different materials and diameters and it was found that the sensitivity is not impaired by wrappings with metalization such as tablet blister technique of tdmetal detectorshe SQUID system.

An experiment with a multi-channel HTS radio-frequency (rf) SQUID gradiometer for recording fetal and adult magnetocardiograms is reported. A 4 channel real-time heart signal recordings of a fetus in the 33rd week of gestation is demonstrated by using a first-order gradiometer configurations with an ultra-long baseline of about 20 cm.