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Nature Communications Jun 2024Dynamic nuclear polarization (DNP) is one of the most powerful and versatile hyperpolarization methods to enhance nuclear magnetic resonance (NMR) signals. A major...
Dynamic nuclear polarization (DNP) is one of the most powerful and versatile hyperpolarization methods to enhance nuclear magnetic resonance (NMR) signals. A major drawback of DNP is the cost and complexity of the required microwave hardware, especially at high magnetic fields and low temperatures. To overcome this drawback and with the focus on the study of nanoliter and subnanoliter samples, this work demonstrates 200 GHz single chip DNP microsystems where the microwave excitation/detection are performed locally on chip without the need of external microwave generators and transmission lines. The single chip integrated microsystems consist of a single or an array of microwave oscillators operating at about 200 GHz for ESR excitation/detection and an RF receiver operating at about 300 MHz for NMR detection. This work demonstrates the possibility of using the single chip approach for the realization of probes for DNP studies at high frequency, high field, and low temperature.
PubMed: 38942752
DOI: 10.1038/s41467-024-49767-z -
Diagnostic and Interventional Imaging Jun 2024Radiology in Canada is advancing through innovations in clinical practices and research methodologies. Recent developments focus on refining evidence-based practice... (Review)
Review
Radiology in Canada is advancing through innovations in clinical practices and research methodologies. Recent developments focus on refining evidence-based practice guidelines, exploring innovative imaging techniques and enhancing diagnostic processes through artificial intelligence. Within the global radiology community, Canadian institutions play an important role by engaging in international collaborations, such as with the American College of Radiology to refine implementation of the Ovarian-Adnexal Reporting and Data System for ultrasound and magnetic resonance imaging. Additionally, researchers have participated in multidisciplinary collaborations to evaluate the performance of artificial intelligence-driven diagnostic tools for chronic liver disease and pediatric brain tumors. Beyond clinical radiology, efforts extend to addressing gender disparities in the field, improving educational practices, and enhancing the environmental sustainability of radiology departments. These advancements highlight Canada's role in the global radiology community, showcasing a commitment to improving patient outcomes and advancing the field through research and innovation. This update underscores the importance of continued collaboration and innovation to address emerging challenges and further enhance the quality and efficacy of radiology practices worldwide.
PubMed: 38942638
DOI: 10.1016/j.diii.2024.06.004 -
Neuroimaging Clinics of North America Aug 2024Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease of the central nervous system, commonly featuring disability and cognitive impairment. The... (Review)
Review
Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease of the central nervous system, commonly featuring disability and cognitive impairment. The pathologic hallmark of MS lies in demyelination and hence impaired structural and functional neuronal pathways. Recent studies have shown that MS shows extensive structural disconnection of key network hub areas like the thalamus, combined with a functional network reorganization that can mostly be related to poorer clinical functioning. As MS can, therefore, be considered a network disorder, this review outlines recent innovations in the field of network neuroscience in MS.
Topics: Humans; Multiple Sclerosis; Brain; Nerve Net; Magnetic Resonance Imaging; Neuroimaging
PubMed: 38942522
DOI: 10.1016/j.nic.2024.03.008 -
Neuroimaging Clinics of North America Aug 2024Concepts of multiple sclerosis (MS) biology continue to evolve, with observations such as "progression independent of disease activity" challenging traditional... (Review)
Review
Concepts of multiple sclerosis (MS) biology continue to evolve, with observations such as "progression independent of disease activity" challenging traditional phenotypic categorization. Iron-sensitive, susceptibility-based imaging techniques are emerging as highly translatable MR imaging sequences that allow for visualization of at least 2 clinically useful biomarkers: the central vein sign and the paramagnetic rim lesion (PRL). Both biomarkers demonstrate high specificity in the discrimination of MS from other mimics and can be seen at 1.5 T and 3 T field strengths. Additionally, PRLs represent a subset of chronic active lesions engaged in "smoldering" compartmentalized inflammation behind an intact blood-brain barrier.
Topics: Humans; Multiple Sclerosis; Magnetic Resonance Imaging; Brain; Biomarkers; Inflammation; Neuroimaging; Cerebral Veins
PubMed: 38942521
DOI: 10.1016/j.nic.2024.03.004 -
Nanomedicine : Nanotechnology, Biology,... Jun 2024In equine medicine, assisted bone regeneration, including use of biomaterial substitutes like hydroxyapatite (HAP), is crucial for addressing bone defects. To follow-up...
In equine medicine, assisted bone regeneration, including use of biomaterial substitutes like hydroxyapatite (HAP), is crucial for addressing bone defects. To follow-up on the outcome of HAP-based bone defect treatment, the advancement in quantified diagnostic imaging protocols is needed. This study aimed to quantify and compare the radiological properties of the HAP graft and natural equine bone using Magnetic Resonance (MR) and Computed Tomography (CT), both Single (SECT) and Dual Energy (DECT). SECT and DECT, allow for the differentiation of three HAP grain sizes, by progressive increase in relative density (RD). SECT, DECT, and MR enable the differentiation between natural cortical bone and synthetic HAP graft by augmentation in Effective Z and material density (MD) in HAP/Water, Calcium/Water, and Water/Calcium reconstructions, alongside the reduction in T2 relaxation time. The proposed quantification provided valuable radiological insights into the composition of HAP grafts, which may be useful in follow-up bone defect treatment.
PubMed: 38942131
DOI: 10.1016/j.nano.2024.102765 -
Journal of Physics. Condensed Matter :... Jun 2024We present a theoretical study of the magnetic properties for the pyrochlore-like NaCuFcompound, which surprisingly experience little or no frustration. The magnetic...
We present a theoretical study of the magnetic properties for the pyrochlore-like NaCuFcompound, which surprisingly experience little or no frustration. The magnetic effective exchange interactions were calculated usingmethods explicitly treating the electronic correlation. A model Hamiltonian was built from these interactions and used to determine the zero temperature magnetic order versus magnetic field, using a quantum Heisenberg Hamiltonian or, for comparison, a spin 1/2 Ising Hamiltonian. The magnetic order at zero magnetic field is non frustrated and associated with the propagation vector= (0,0,0). The magnetization versus magnetic field reveals the existence of a 1/3 plateau that could be observed in high-pulsed magnetic field experiments. Analysing the magnetic interactions, we highlight the importance of the magnetic-ion nature and the lattice distortion, in the non-frustrated nature of the NaCuFmagnetic structure, despite its triangular/Kagome subnetworks. We believe that this non-frustrated behaviour could also take place in other triangular copper-based systems. .
PubMed: 38942003
DOI: 10.1088/1361-648X/ad5d39 -
Journal of Physics. Condensed Matter :... Jun 2024Quantum anomalous Hall insulators are topologically characterized by non-zero integer Chern numbers, the sign of which depends on the direction of the exchange field...
Quantum anomalous Hall insulators are topologically characterized by non-zero integer Chern numbers, the sign of which depends on the direction of the exchange field that breaks time-reversal symmetry. This feature allows the manipulation of the conducting chiral edge states present at the interface of two magnetic domains with opposite magnetization and opposite Chern numbers. Motivated by this broad understanding, the present study investigates the quantum transport properties of a magnetized $Bi_2Se_3$ topological insulator nanoribbon with a domain wall oriented either parallel or perpendicular to the transport direction. Employing an atomistic tight-binding model and a non-equilibrium Green's function formalism, we calculate the quantum conductance and explore the nature of the edge states. We elucidate the conditions leading to exact conductance quantization and identify the origin of deviations from this behavior. Our analysis shows that although the conductance is quantized in the presence of the horizontal domain wall, the quantization is absent in the perpendicular domain wall case. Furthermore, the investigation of the spin character of the edge modes confirms that the conductance in the horizontal domain wall configuration is spin polarized. This finding underscores the potential of our system as a simple three dimensional spin-filter device.
PubMed: 38941992
DOI: 10.1088/1361-648X/ad5d34 -
Biomedical Physics & Engineering Express Jun 2024The magneto-plethysmograph method is a combination of magnetic field and sensors used to detect changes in blood flow pulsation. However, to detect the magnetic...
The magneto-plethysmograph method is a combination of magnetic field and sensors used to detect changes in blood flow pulsation. However, to detect the magnetic properties of blood related to hemoglobin concentration, physical modeling and simulation are required. This approach involves designing simulations using magnetic field equations and magnetic susceptibility, where a permanent magnet is placed on the surface of blood vessels, and sensors based on giant magnetoresistance are placed at a distance r. The design originates from a simple approach involving the magnetization and detection of Fe atoms in hemoglobin. Parameters involved include the magnetic susceptibility of oxyhemoglobin and deoxyhemoglobin, with an external magnetic field exceeding 1 Tesla. From the physical modeling and simulation, graphs are obtained depicting the influence of hemoglobin concentration on the number of Fe atoms and its magnetization. This enables the design of non-invasive hemoglobin measurement sensor devices. The uniqueness of this simple physical model and simulation lies in its ability to produce specially designed device models for measuring hemoglobin concentration. This differs from other research focusing on blood flow pulse measurements; the results of this study provide new insights into the benefits of simple physics equations that can be developed for medical diagnostic research and device development.
PubMed: 38941984
DOI: 10.1088/2057-1976/ad5cf7 -
Biosensors & Bioelectronics Jun 2024Programmed cell death-ligand 1 positive (PD-L1) exosomes play a crucial role in the realm of cancer diagnosis and treatment. Nevertheless, due to the intricate nature of...
Programmed cell death-ligand 1 positive (PD-L1) exosomes play a crucial role in the realm of cancer diagnosis and treatment. Nevertheless, due to the intricate nature of biological specimens, coupled with the heterogeneity, low refractive index (RI), and scant surface coverage density of exosomes, traditional surface plasmon resonance (SPR) sensors still do not meet clinical detection requirements. This study utilizes the exceptional electrical and optical attributes of single-walled carbon nanotubes (SWCNTs) as the substrate for SPR sensing, thereby markedly enhancing sensitivity. Furthermore, sp hybridized SWCNTs have the ability to load specific recognition elements. Additionally, through the coordination interaction of Ti with phosphate groups and the ferromagnetism of FeO, efficient exosomes isolation and enrichment in complex samples are achievable with the aid of an external magnetic field. Owing to the high-quality and high-RI of FeO@TiO, the response signal experiences amplification, thus further improving the performance of the SPR biosensor. The linear range of the SPR biosensor constructed by this method is 1.0 × 10 to 1.0 × 10 particles/mL, with a limit of detection (LOD) of 31.9 particles/mL. In the analysis of clinical serum samples, cancer patients can be differentiated from healthy individuals with an Area Under Curve (AUC) of 0.9835. This study not only establishes a novel platform for exosomes direct detection but also offers new perspectives for the sensitive detection of other biomarkers.
PubMed: 38941687
DOI: 10.1016/j.bios.2024.116527 -
Nature Communications Jun 2024Understanding spin-lattice interactions in antiferromagnets is a critical element of the fields of antiferromagnetic spintronics and magnonics. Recently, coherent...
Understanding spin-lattice interactions in antiferromagnets is a critical element of the fields of antiferromagnetic spintronics and magnonics. Recently, coherent nonlinear phonon dynamics mediated by a magnon state were discovered in an antiferromagnet. Here, we suggest that a strongly coupled two-magnon-one phonon state in this prototypical system opens a novel pathway to coherently control magnon-phonon dynamics. Utilizing intense narrow-band terahertz (THz) pulses and tunable magnetic fields up to μH = 7 T, we experimentally realize the conditions of magnon-phonon Fermi resonance in antiferromagnetic CoF. These conditions imply that both the spin and the lattice anharmonicities harvest energy from the transfer between the subsystems if the magnon eigenfrequency f is half the frequency of the phonon 2f = f. Performing THz pump-infrared probe spectroscopy in conjunction with simulations, we explore the coupled magnon-phonon dynamics in the vicinity of the Fermi-resonance and reveal the corresponding fingerprints of nonlinear interaction facilitating energy exchange between these subsystems.
PubMed: 38942783
DOI: 10.1038/s41467-024-49716-w