Strong transverse magnetic fields can produce very large dose enhancements and reductions in localized regions of a patient under irradiation by a photon beam. In this work we consider planar-current-induced magnetic fields ("PCIMFs") generated by arbitrary electric currents in one or two parallel planes, and pose two questions: how much arbitrariness is there in specifying a PCIMF, and how can we solve the "inverse problem" of determining the current distribution which generates a chosen PCIMF? We have completely answered both questions, and have applied the general formulas which we have developed to the case of cylindrical symmetry, giving a concrete example of our method. The present work provides the theoretical tools for designing PCIMFs, but a great deal of systematic research will be required in order to understand and design magnetic fields which produce desired distributions of dose enhancement and dose reduction in photon beams treating patients.
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http://dx.doi.org/10.1118/1.1536154 | DOI Listing |
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December 2024
Department of Applied Physics and Center of Quantum Materials and Devices, Chongqing University, Chongqing, 401331, China.
The observation of both resonant quantum tunneling of magnetization (RQTM) and resonant quantum magnetodielectric (RQMD) effect in the perovskite multiferroic metal-organic framework [CHNH]Co(HCOO).is reported. An intrinsic magnetic phase separation emerges at low temperatures due to the hydrogen-bond-modified long-range super-exchange interaction, leading to the coexistence of canted antiferromagnetic order and single-ion (Co) magnets.
View Article and Find Full Text PDFLangmuir
December 2024
Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Magnetic fluorescent nanomaterials have broad application prospects as taggants in fields such as anticounterfeiting identification, suspicious object tracking, and potential fingerprint recognition in forensic medicine. It is a common method to synthesize magnetic fluorescent composite nanoparticles by preparing a shell on the surface of magnetic particles to load fluorescent materials. In this work, a magnetic fluorescence nanohybrid was synthesized by in situ encapsulation of carbon quantum dots (CQDs) during the preparation of a SiO shell on the surface of FeO nanoparticles.
View Article and Find Full Text PDFElectromagn Biol Med
December 2024
Department of Electrical and Electronics Engineering, Recep Tayyip Erdoğan University, Rize, Türkiye.
Due to the increase in data rate in mobile communication and the widespread use of mobile internet, electromagnetic communication systems are increasing daily. This situation causes increases in the use of more mobile communication devices and environmental non-ionizing Electromagnetic Field (EMF) levels. The rise of bee deaths and colony losses in beekeeping parallel to the increase of the EMF sources cause the concept of "electromagnetic pollution" to be considered among the reasons.
View Article and Find Full Text PDFHum Brain Mapp
December 2024
Rehab Neural Engineering Labs, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Intracortical microstimulation (ICMS) is a method for restoring sensation to people with paralysis as part of a bidirectional brain-computer interface (BCI) to restore upper limb function. Evoking tactile sensations of the hand through ICMS requires precise targeting of implanted electrodes. Here we describe the presurgical imaging procedures used to generate functional maps of the hand area of the somatosensory cortex and subsequent planning that guided the implantation of intracortical microelectrode arrays.
View Article and Find Full Text PDFVopr Kurortol Fizioter Lech Fiz Kult
December 2024
Saratov State Medical University named after V. I. Razumovsky, Saratov, Russia.
Unlabelled: The problem of rational activation of functions of the central nervous system of a human remains highly relevant.
Objective: To analyze scientific data on the use of transcranial exposure method in obesity.
Results: The literature review presents current data on the effectiveness of non-invasive hardware brain neurostimulation in obese patients.
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