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1.
PLoS One ; 19(7): e0304794, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38990925

RESUMEN

The present examination of mass and heat communication looks at the impact of induced magnetic field, variable thermal conductivity, and activation energy on the flow of second-order liquid across a stretched surface. The mass-heat transfer is also treated using the Model for generalized Fourier and Fick's Laws. The model equations are transformed as needed to produce a system of nonlinear ODEs, which are then numerically solved with the help of BVP4C integrated MATLAB approach. The heat-mass flow parameters are analyzed by the table and graphs. An increment in the estimations of 2nd grade fluid parameter (ß) with magnetic field parameter (M) increase the speed sketch. For the stronger estimations of Schmidt number (Sc), parameter of magnetic field (M) and Eckert number (Ec) have the growing behavior on the temperature profile.


Asunto(s)
Calor , Modelos Teóricos , Conductividad Térmica , Campos Magnéticos , Hidrodinámica
2.
Biointerphases ; 19(4)2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38994898

RESUMEN

Magnetic motors are a class of out-of-equilibrium particles that exhibit controlled and fast motion overcoming Brownian fluctuations by harnessing external magnetic fields. The advances in this field resulted in motors that have been used for different applications, such as biomedicine or environmental remediation. In this Perspective, an overview of the recent advancements of magnetic motors is provided, with a special focus on controlled motion. This aspect extends from trapping, steering, and guidance to organized motor grouping and degrouping, which is known as swarm control. Further, the integration of magnetic motors in soft robots to actuate their motion is also discussed. Finally, some remarks and perspectives of the field are outlined.


Asunto(s)
Robótica , Robótica/métodos , Movimiento (Física) , Campos Magnéticos , Magnetismo , Proteínas Motoras Moleculares/química , Proteínas Motoras Moleculares/metabolismo , Fenómenos Magnéticos
3.
J Acoust Soc Am ; 156(1): 214-228, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38980099

RESUMEN

Media that contain ultrasound scatterers arranged in a regular spatial distribution can be considered as structured. Structural effects affect quantitative ultrasound parameters that reflect the microstructure properties. Prior studies examined structural effects using simulations or phantoms with fixed microarchitecture, focusing on a limited set of ultrasound parameters, with limited attention given to their underlying physical significance. This study aims to investigate the concordance of the physical interpretations of multiple quantitative ultrasound parameters experimentally by introducing a phantom type with an adjustable microarchitecture. The phantom consists of an aqueous solution containing superparamagnetic microspheres, acting as scatterers. The spatial arrangement of the magnetic particles is modified by applying an external magnetic field, therefore changing the degree of structure of the phantom. Quantitative ultrasound parameters are estimated in three different configurations: the magnetic field intensity is varied over time, strength, and orientation. In each experiment, the backscatter coefficient and the envelope quantitative ultrasound parameters are successfully extracted (R2 ≈ 0.94). Their physical interpretations are supported by microphotographs and geometrical considerations through concordant hypotheses. This study paves the way for the use of magnetic phantoms. This methodology could be followed to validate theoretical scattering models and the physical meanings of quantitative ultrasound parameters.


Asunto(s)
Fantasmas de Imagen , Ultrasonografía , Ultrasonografía/métodos , Ultrasonografía/instrumentación , Campos Magnéticos , Ondas Ultrasónicas , Dispersión de Radiación , Modelos Teóricos
4.
Phys Med ; 123: 103403, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38870643

RESUMEN

PURPOSE: Although plastic scintillator detectors (PSDs) are considered ideal dosimeters for small field dosimetry in conventional linear accelerators (linacs), the impact of the magnetic field strength on the response of the PSD must be investigated. METHODS: A linac Monte Carlo (MC) head model for a low-field MR-linac was validated for small field dosimetry and utilized to calculate field output factors (OFs). The MC-calculated OFs were compared with the treatment planning system (TPS)-calculated OFs and measured OFs using a Blue Physics (BP) Model 10 commercial PSD and a synthetic diamond detector. The field-specific correction factors, [Formula: see text] , were calculated for the PSD in the presence of a 0.35 T and magnetic field. The impact of the source focal spot size and initial electron energy on the MC-calculated OFs was investigated. RESULTS: Good agreement to within 2 % was found between the MC-calculated OFs and BP PSD OFs except for the 0.415 × 0.415 cm2 field size. The BP PSD [Formula: see text] correction factors were calculated to be within 1 % of unity. For field sizes ≥1.66 × 1.66 cm2, the MC-calculated OFs were relatively insensitive to the focal spot size and initial electron energy to within 2.5 %. However, for smaller field sizes, the MC-calculated OFs were found to differ up to 9.50 % and 7.00 % when the focal spot size and initial electron energy was varied, respectively. CONCLUSIONS: The BP PSD was deemed suitable for small field dosimetry in MR-linacs without requiring any [Formula: see text] correction factors.


Asunto(s)
Método de Montecarlo , Aceleradores de Partículas , Plásticos , Radiometría , Conteo por Cintilación , Conteo por Cintilación/instrumentación , Radiometría/instrumentación , Imagen por Resonancia Magnética/instrumentación , Campos Magnéticos
5.
Phys Med ; 123: 103406, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38875931

RESUMEN

PURPOSE: Ionisation chamber based reference dosimetry in magnetic resonance linear accelerators (MRL) aimed for radiotherapy requires correction for recombination losses. Published studies have found that such corrections can be carried out using the two-voltage method. These studies have, however, not included comparison with recombination corrections based on the Niatel method, which can be seen as a robust reference method due to its clear separation of initial and volume recombination and its explicit account of the pulsed nature of the dose delivery. The primary objective of this work therefore was to carry out such a comparison. MATERIALS AND METHODS: Four Farmer-type chambers (PTW-30006 and PTW-30013) were placed in a water phantom in 1.5 T Elekta Unity MRL. The chambers were oriented antiparallel or perpendicular to the static magnetic field B0 and irradiated at a source-to-surface distance of 133.5 cm with a 10 × 10 cm2 field size. RESULTS: The two-voltage method gave results in agreement (within 0.1%) with the recombination corrections derived from the Niatel method. The recombination corrections from three Niatel parameter sets (one based on a Varian Truebeam and two obtained directly in the MRL) deviated less than 0.1% from each other. A systematic shift in the recombination correction of less than 0.05% was observed if polarity corrections were not applied. CONCLUSIONS: The study supports the use of the two-voltage method in MRLs based on its excellent agreement with the Niatel method. This work, therefore, complements existing knowledge as previous studies have not included a comparison with the Niatel method.


Asunto(s)
Campos Magnéticos , Radiometría , Radiometría/instrumentación , Aceleradores de Partículas , Fantasmas de Imagen
6.
ACS Appl Mater Interfaces ; 16(24): 30755-30765, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38847111

RESUMEN

In recent years, enveloped micro-nanobubbles have garnered significant attention in research due to their commendable stability, biocompatibility, and other notable properties. Currently, the preparation methods of enveloped micro-nanobubbles have limitations such as complicated preparation process, large bubble size, wide distribution range, low yield, etc. There exists an urgent demand to devise a simple and efficient method for the preparation of enveloped micro-nanobubbles, ensuring both high concentration and a uniform particle size distribution. Magnetic lipid bubbles (MLBs) are a multifunctional type of enveloped micro-nanobubble combining magnetic nanoparticles with lipid-coated bubbles. In this study, MLBs are prepared simply and efficiently by a magneto internal heat bubble generation process based on the interfacial self-assembly of iron oxide nanoparticles induced by the thermogenic effect in an alternating magnetic field. The mean hydrodynamic diameter of the MLBs obtained was 384.9 ± 8.5 nm, with a polydispersity index (PDI) of 0.248 ± 0.021, a zeta potential of -30.5 ± 1.0 mV, and a concentration of (7.92 ± 0.46) × 109 bubbles/mL. Electron microscopy results show that the MLBs have a regular spherical stable core-shell structure. The superparamagnetic iron oxide nanoparticles (SPIONs) and phospholipid layers adsorbed around the spherical gas nuclei of the MLBs, leading the particles to demonstrate commendable superparamagnetic and magnetic properties. In addition, the effects of process parameters on the morphology of MLBs, including phospholipid concentration, phospholipid proportiona, current intensity, magnetothermal time, and SPION concentration, were investigated and discussed to achieve controlled preparation of MLBs. In vitro imaging results reveal that the higher the concentration of MLBs loaded with iron oxide nanoparticles, the better the in vitro ultrasound (US) imaging and magnetic resonance imaging (MRI) results. This study proves that the magneto internal heat bubble generation process is a simple and efficient technique for preparing MLBs with high concentration, regular structure, and commendable properties. These findings lay a robust foundation for the mass production and application of enveloped micro-nanobubbles, particularly in biomedical fields and other related domains.


Asunto(s)
Fosfolípidos , Fosfolípidos/química , Tamaño de la Partícula , Nanopartículas Magnéticas de Óxido de Hierro/química , Nanopartículas de Magnetita/química , Gases/química , Microburbujas , Campos Magnéticos
7.
ACS Appl Mater Interfaces ; 16(24): 30874-30889, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38856922

RESUMEN

A new composite sponge assisted by magnetic field-mediated guidance was developed for effective hemostasis. It was based on polydopamine capillary-channel agarose (PDA-CAGA) sponge as matrix; meanwhile, the combination of deep eutectic solvent (DES, choline chloride:glycerol = 1:1, M/M)-dispersed Fe3O4 nanoparticles after fabrication by tannic acid (DES-Fe3O4@TA) was applied as hemostatic magnetic fluid. This sponge had oriented and aligned capillary channels realized by a 3D printed pattern, which endowed them with obvious shape memory and liquid absorption performance. Computational simulation was performed to describe the fluid status in channels; DES-Fe3O4@TA exhibited good magnetic properties, fluidity, and stability. In addition, the sponge driven to react rapidly with the bleeding site under the effect of a magnetic field presented a shorter hemostasis time (reduced by 85.02% in the tail and 81.07% in the liver of rats) and less blood loss (reduced by 97.08% in the tail and 91.50% in the liver) than those of medical gelatin sponge (GS). Meanwhile, the multifunctional material also exhibited better biocompatibility, procoagulant performance, and significant inhibition on S. aureus and E. coli than GS. As a whole, this work proposed a new strategy for rapid hemostasis by designing a magnetic field assisted composite bacteriostatic material, which also expanded the applications of green solvents in the clinical management field.


Asunto(s)
Escherichia coli , Sefarosa , Staphylococcus aureus , Animales , Ratas , Sefarosa/química , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Solventes/química , Hemostasis/efectos de los fármacos , Polímeros/química , Polímeros/farmacología , Indoles/química , Antibacterianos/química , Antibacterianos/farmacología , Hemostáticos/química , Hemostáticos/farmacología , Campos Magnéticos , Masculino , Ratas Sprague-Dawley
8.
Anal Chem ; 96(24): 9790-9798, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38829167

RESUMEN

Quantum mechanics (QM)-driven 1H iterative functionalized spin analysis produces HifSA profiles, which encode the complete 1H spin parameters ("nuclear genotype") of analytes of interest. HifSA profiles enable the establishment of digital reference standards (dRS) that are portable, FAIR (findable - accessible - interoperable - reusable), and fit for the purpose of quantitative 1H NMR (qHNMR) analysis at any magnetic field. This approach enhances the sustainability of analytical standards. Moreover, the analyte-specific complete chemical shift and J-coupling information in HifSA-based dRS enable computational quantitation of substances in mixtures via QM-total-line-shape fitting (QM-qHNMR). We present the proof of concept for HifSA-based dRS by resolving the highly overlapping NMR resonances in the experimental spectra ("nuclear phenotypes") of the diastereomeric mixture of (2RS, 4RS)- and (2RS, 4SR)-difenoconazole (DFZ), a widely used antifouling food additive. The underlying 1H spin parameters are highly conserved in various solvents, are robust against variation in measurement temperature, and work across a wide range of magnetic fields. QM-qHNMR analysis of DFZ samples at 80, 400, 600, and 800 MHz showed high congruence with metrological reference values. Furthermore, this study introduces QM-qHNMR combined with chiral shift reagents for the analysis of all four DFZ stereoisomers: (2R, 4R)-, (2S, 4S)-, (2R, 4S)-, and (2S, 4R)-DFZ to perform chiral qHNMR measurements.


Asunto(s)
Campos Magnéticos , Espectroscopía de Resonancia Magnética , Teoría Cuántica , Estándares de Referencia , Espectroscopía de Resonancia Magnética/métodos , Triazoles/química , Triazoles/análisis
9.
Molecules ; 29(11)2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38893510

RESUMEN

Cancer cells have higher heat sensitivity compared to normal cells; therefore, hyperthermia is a promising approach for cancer therapy because of its ability to selectively kill cancer cells by heating them. However, the specific and rapid heating of tumor tissues remains challenging. This study investigated the potential of magnetic nanoparticles (MNPs) modified with tumor-homing peptides (THPs), specifically PL1 and PL3, for tumor-specific magnetic hyperthermia therapy. The synthesis of THP-modified MNPs involved the attachment of PL1 and PL3 peptides to the surface of the MNPs, which facilitated enhanced tumor cell binding and internalization. Cell specificity studies revealed an increased uptake of PL1- and PL3-MNPs by tumor cells compared to unmodified MNPs, indicating their potential for targeted delivery. In vitro hyperthermia experiments demonstrated the efficacy of PL3-MNPs in inducing tumor cell death when exposed to an alternating magnetic field (AMF). Even without exposure to an AMF, an additional ferroptotic pathway was suggested to be mediated by the nanoparticles. Thus, this study suggests that THP-modified MNPs, particularly PL3-MNPs, hold promise as a targeted approach for tumor-specific magnetic hyperthermia therapy.


Asunto(s)
Hipertermia Inducida , Nanopartículas de Magnetita , Péptidos , Hipertermia Inducida/métodos , Humanos , Nanopartículas de Magnetita/química , Péptidos/química , Péptidos/farmacología , Línea Celular Tumoral , Neoplasias/terapia , Neoplasias/patología , Campos Magnéticos
10.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(3): 455-460, 2024 Jun 25.
Artículo en Chino | MEDLINE | ID: mdl-38932530

RESUMEN

The main magnetic field, generated by the excitation coil of the magnetic induction phase shift technology detection system, is mostly dispersed field with small field strength, and the offset effect needs to be further improved, which makes the detection signal weak and the detection system difficult to achieve quantitative detection, thus the technology is rarely used in vivo experiments and clinical trials. In order to improve problems mentioned above, a new Helmholtz birdcage sensor was designed. Stimulation experiment was carried out to analyze the main magnetic field in aspects of intensity and magnetic distribution, then different bleeding volume and bleeding rates experiments were conducted to compared with traditional sensors. The results showed that magnetic field intensity in detection region was 2.5 times than that of traditional sensors, cancellation effect of the main magnetic field was achieved, the mean value of phase difference of 10 mL rabbit blood was (-3.34 ± 0.21)°, and exponential fitting adjusted R 2 between phase difference and bleeding volumes and bleeding rates were both 0.99. The proposed Helmholtz birdcage sensor has a uniform magnetic field with a higher field strength, enable more accurate quantification of hemorrhage and monitored change of bleeding rates, providing significance in magnetic induced technology research for cerebral hemorrhage detection.


Asunto(s)
Hemorragia Cerebral , Campos Magnéticos , Animales , Conejos
11.
Nature ; 631(8019): 60-66, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38867046

RESUMEN

Broken time-reversal symmetry in the absence of spin order indicates the presence of unusual phases such as orbital magnetism and loop currents1-4. The recently discovered kagome superconductors AV3Sb5 (where A is K, Rb or Cs)5,6 display an exotic charge-density-wave (CDW) state and have emerged as a strong candidate for materials hosting a loop current phase. The idea that the CDW breaks time-reversal symmetry7-14 is, however, being intensely debated due to conflicting experimental data15-17. Here we use laser-coupled scanning tunnelling microscopy to study RbV3Sb5. By applying linearly polarized light along high-symmetry directions, we show that the relative intensities of the CDW peaks can be reversibly switched, implying a substantial electro-striction response, indicative of strong nonlinear electron-phonon coupling. A similar CDW intensity switching is observed with perpendicular magnetic fields, which implies an unusual piezo-magnetic response that, in turn, requires time-reversal symmetry breaking. We show that the simplest CDW that satisfies these constraints is an out-of-phase combination of bond charge order and loop currents that we dub a congruent CDW flux phase. Our laser scanning tunnelling microscopy data open the door to the possibility of dynamic optical control of complex quantum phenomenon in correlated materials.


Asunto(s)
Superconductividad , Microscopía de Túnel de Rastreo , Campos Magnéticos , Fonones , Electrones , Luz
12.
Biochem Biophys Res Commun ; 725: 150265, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-38901225

RESUMEN

With the substantial increase in the overuse of glucocorticoids (GCs) in clinical medicine, the prevalence of glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH) continues to rise in recent years. However, the optimal treatment for GC-ONFH remains elusive. Rotating magnetic field (RMF), considered as a non-invasive, safe and effective approach, has been proved to have multiple beneficial biological effects including improving bone diseases. To verify the effects of RMF on GC-ONFH, a lipopolysaccharide (LPS) and methylprednisolone (MPS)-induced invivo rat model, and an MPS-induced invitro cell model have been employed. The results demonstrate that RMF alleviated bone mineral loss and femoral head collapse in GC-ONFH rats. Meanwhile, RMF reduced serum lipid levels, attenuated cystic lesions, raised the expression of anti-apoptotic proteins and osteoprotegerin (OPG), while suppressed the expression of pro-apoptotic proteins and nuclear factor receptor activator-κB (RANK) in GC-ONFH rats. Besides, RMF also facilitated the generation of ALP, attenuated apoptosis and inhibits the expression of pro-apoptotic proteins, facilitated the expression of OPG, and inhibited the expression of RANK in MPS-stimulated MC3T3-E1 cells. Thus, this study indicates that RMF can improve GC-ONFH in rat and cell models, suggesting that RMF have the potential in the treatment of clinical GC-ONFH.


Asunto(s)
Diferenciación Celular , Necrosis de la Cabeza Femoral , Glucocorticoides , Osteoblastos , Ratas Sprague-Dawley , Animales , Osteoblastos/metabolismo , Osteoblastos/efectos de los fármacos , Necrosis de la Cabeza Femoral/inducido químicamente , Necrosis de la Cabeza Femoral/patología , Necrosis de la Cabeza Femoral/metabolismo , Necrosis de la Cabeza Femoral/terapia , Ratas , Diferenciación Celular/efectos de los fármacos , Masculino , Campos Magnéticos , Magnetoterapia/métodos , Cabeza Femoral/patología , Cabeza Femoral/metabolismo , Modelos Animales de Enfermedad , Rotación , Ratones
13.
J Nanobiotechnology ; 22(1): 327, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858689

RESUMEN

Magnetogenetics emerges as a transformative approach for modulating cellular signaling pathways through the strategic application of magnetic fields and nanoparticles. This technique leverages the unique properties of magnetic nanoparticles (MNPs) to induce mechanical or thermal stimuli within cells, facilitating the activation of mechano- and thermosensitive proteins without the need for traditional ligand-receptor interactions. Unlike traditional modalities that often require invasive interventions and lack precision in targeting specific cellular functions, magnetogenetics offers a non-invasive alternative with the capacity for deep tissue penetration and the potential for targeting a broad spectrum of cellular processes. This review underscores magnetogenetics' broad applicability, from steering stem cell differentiation to manipulating neuronal activity and immune responses, highlighting its potential in regenerative medicine, neuroscience, and cancer therapy. Furthermore, the review explores the challenges and future directions of magnetogenetics, including the development of genetically programmed magnetic nanoparticles and the integration of magnetic field-sensitive cells for in vivo applications. Magnetogenetics stands at the forefront of cellular manipulation technologies, offering novel insights into cellular signaling and opening new avenues for therapeutic interventions.


Asunto(s)
Campos Magnéticos , Nanopartículas de Magnetita , Transducción de Señal , Humanos , Animales , Nanopartículas de Magnetita/química , Diferenciación Celular , Medicina Regenerativa/métodos , Neuronas/metabolismo , Células Madre/metabolismo , Neoplasias
14.
Int J Nanomedicine ; 19: 5227-5243, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38855734

RESUMEN

Purpose: This study aimed to construct targeting drug-loading nanocomposites (FA-FePt/DDP nanoliposomes) to explore their potential in ovarian cancer therapy and molecular magnetic resonance imaging (MMRI). Methods: FA-FePt-NPs were prepared by coupling folate (FA) with polyethylene-glycol (PEG)-coated ferroplatinum nanoparticles and characterized. Then cisplatin (DDP) was encapsulated in FA-FePt-NPs to synthesize FA-PEG-FePt/DDP nanoliposomes by thin film-ultrasonic method and high-speed stirring, of which MMRI potential, magnetothermal effect, and the other involved performance were analyzed. The therapeutic effect of FA-FePt/DDP nanoliposomes combined with magnetic fluid hyperthermia (MFH) on ovarian cancer in vitro and in vivo was evaluated. The expression levels of Bax and epithelial-mesenchymal transition related proteins were detected. The biosafety was also preliminarily observed. Results: The average diameter of FA-FePt-NPs was about 30 nm, FA-FePt/DDP nanoliposomes were about 70 nm in hydrated particle size, with drug slow-release and good cell-specific targeted uptake. In an alternating magnetic field (AMF), FA-FePt/DDP nanoliposomes could rapidly reach the ideal tumor hyperthermia temperature (42~44 °C). MRI scan showed that FA-FePt-NPs and FA-FePt/DDP nanoliposomes both could suppress the T2 signal, indicating a good potential for MMRI. The in vitro and in vivo experiments showed that FA-FePt/DDP-NPs in AMF could effectively inhibit the growth of ovarian cancer by inhibiting cancer cell proliferation, invasion, and migration, and inducing cancer cell apoptosis, much better than that of the other individual therapies; molecularly, E-cadherin and Bax proteins in ovarian cancer cells and tissues were significantly increased, while N-cadherin, Vimentin, and Bcl-2 proteins were inhibited, effectively inhibiting the malignant progression of ovarian cancer. In addition, no significant pathological injury and dysfunction was observed in major visceras. Conclusion: We successfully synthesized FA-FePt/DDP nanoliposomes and confirmed their good thermochemotherapeutic effect in AMF and MMRI potential on ovarian cancer, with no obvious side effects, providing a favorable strategy of integrated targeting therapy and diagnosis for ovarian cancer.


Asunto(s)
Antineoplásicos , Cisplatino , Ácido Fólico , Liposomas , Imagen por Resonancia Magnética , Neoplasias Ováricas , Polietilenglicoles , Femenino , Neoplasias Ováricas/diagnóstico por imagen , Neoplasias Ováricas/terapia , Liposomas/química , Cisplatino/farmacología , Cisplatino/química , Cisplatino/administración & dosificación , Cisplatino/farmacocinética , Animales , Ácido Fólico/química , Ácido Fólico/farmacología , Ácido Fólico/farmacocinética , Humanos , Imagen por Resonancia Magnética/métodos , Polietilenglicoles/química , Línea Celular Tumoral , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Ratones , Platino (Metal)/química , Platino (Metal)/farmacología , Hipertermia Inducida/métodos , Nanocompuestos/química , Ratones Desnudos , Ratones Endogámicos BALB C , Nanopartículas del Metal/química , Campos Magnéticos , Tamaño de la Partícula
15.
J R Soc Interface ; 21(215): 20240035, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38835248

RESUMEN

The Earth's magnetic field can provide reliable directional information, allowing migrating animals to orient themselves using a magnetic compass or estimate their position relative to a target using map-based orientation. Here we show for the first time that young, inexperienced herring (Clupea harengus, Ch) have a magnetic compass when they migrate hundreds of kilometres to their feeding grounds. In birds, such as the European robin (Erithacus rubecula), radical pair-based magnetoreception involving cryptochrome 4 (ErCRY4) was demonstrated; the molecular basis of magnetoreception in fish is still elusive. We show that cry4 expression in the eye of herring is upregulated during the migratory season, but not before, indicating a possible use for migration. The amino acid structure of herring ChCRY4 shows four tryptophans and a flavin adenine dinucleotide-binding site, a prerequisite for a magnetic receptor. Using homology modelling, we successfully reconstructed ChCRY4 of herring, DrCRY4 of zebrafish (Danio rerio) and StCRY4 of brown trout (Salmo trutta) and showed that ChCRY4, DrCRY4 and ErCRY4a, but not StCRY4, exhibit very comparable dynamic behaviour. The electron transfer could take place in ChCRY4 in a similar way to ErCRY4a. The combined behavioural, transcriptomic and simulation experiments provide evidence that CRY4 could act as a magnetoreceptor in Atlantic herring.


Asunto(s)
Criptocromos , Peces , Animales , Criptocromos/metabolismo , Criptocromos/química , Peces/fisiología , Migración Animal/fisiología , Campos Magnéticos , Proteínas de Peces/metabolismo , Proteínas de Peces/genética , Proteínas de Peces/química , Orientación/fisiología
16.
Analyst ; 149(14): 3732-3738, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38842499

RESUMEN

Chiral recognition of enantiomers with identical mirror-symmetric molecular structures is important for the analysis of biomolecules, and it conventionally relies on stereoselective interactions in chiral chemical environments. Here, we develop a magneto-electrochemical method for the enhanced detection of chiral amino acids (AAs), that combines the advantages of the high sensitivity of electrochemiluminescent (ECL) biosensors and chirality-induced effects under a magnetic field. The ECL difference between L- and D-enantiomers can be amplified over 35-fold under a field of 3.5 kG, and the chiral discrimination can be achieved in dilute AA solutions down to the nM level. The field-dependent ECL and chronocoulometry measurements suggest that chiral AAs can lock the spins on their radicals and thus enlarge the ECL change under applied magnetic fields (magneto-ECL, MECL), which explains the field-enhanced chiral discrimination of AA enantiomers. Finally, a detailed protocol is demonstrated for the identification of unknown AA solutions, in which the species, chirality and concentration of AAs can be determined simultaneously from the 2D plots of the ECL and MECL results. This work benefits the development of field-assisted detection methods and represents a promising and universal strategy for the comprehensive analysis of chiral biomolecules.


Asunto(s)
Aminoácidos , Técnicas Electroquímicas , Estereoisomerismo , Aminoácidos/química , Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Técnicas Biosensibles/métodos , Campos Magnéticos , Límite de Detección
17.
PLoS One ; 19(6): e0304279, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38837968

RESUMEN

This paper delves into the intricate relationship between changes in Magnetic inclination and declination at specific geographical locations and the navigational decisions of migratory birds. Leveraging a dataset sourced from a prominent bird path tracking web resource, encompassing six distinct bird species' migratory trajectories, latitudes, longitudes, and observation timestamps, we meticulously analyzed the interplay between these avian movements and corresponding alterations in Magnetic inclination and declination. Employing a circular von Mises distribution assumption for the latitude and longitude distributions within each subdivision, we introduced a pioneering circular-circular regression model, accounting for von Mises error, to scrutinize our hypothesis. Our findings, predominantly supported by hypothesis tests conducted through circular-circular regression analysis, underscore the profound influence of Magnetic inclination and declination shifts on the dynamic adjustments observed in bird migration paths. Moreover, our meticulous examination revealed a consistent adherence to von Mises distribution across all bird directions. Notably, we unearthed compelling correlations between specific bird species, such as the Black Crowned Night Heron and Brown Pelican, exhibiting a noteworthy negative correlation with Magnetic inclination and a contrasting positive correlation with Magnetic declination. Similarly, the Pacific loon demonstrated a distinct negative correlation with Magnetic inclination and a positive association with Magnetic declination. Conversely, other avian counterparts showcased positive correlations with both Magnetic declination and inclination, further elucidating the nuanced dynamics between avian navigation and the Earth's magnetic field parameters.


Asunto(s)
Migración Animal , Aves , Planeta Tierra , Campos Magnéticos , Animales , Aves/fisiología , Migración Animal/fisiología , Navegación Espacial/fisiología
18.
Sci Rep ; 14(1): 12869, 2024 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-38834614

RESUMEN

In this work, the effect of moderate electromagnetic fields (2.5, 10, and 15 mT) was studied using an immersed coil inserted directly into a bioreactor on batch cultivation of yeast under both aerobic and anaerobic conditions. Throughout the cultivation, parameters, including CO2 levels, O2 saturation, nitrogen consumption, glucose uptake, ethanol production, and yeast growth (using OD 600 measurements at 1-h intervals), were analysed. The results showed that 10 and 15 mT magnetic fields not only statistically significantly boosted and sped up biomass production (by 38-70%), but also accelerated overall metabolism, accelerating glucose, oxygen, and nitrogen consumption, by 1-2 h. The carbon balance analysis revealed an acceleration in ethanol and glycerol production, albeit with final concentrations by 22-28% lower, with a more pronounced effect in aerobic cultivation. These findings suggest that magnetic fields shift the metabolic balance toward biomass formation rather than ethanol production, showcasing their potential to modulate yeast metabolism. Considering coil heating, opting for the 10 mT magnetic field is preferable due to its lower heat generation. In these terms, we propose that magnetic field can be used as novel tool to increase biomass yield and accelerate yeast metabolism.


Asunto(s)
Biomasa , Etanol , Fermentación , Campos Magnéticos , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/crecimiento & desarrollo , Aerobiosis , Anaerobiosis , Etanol/metabolismo , Glucosa/metabolismo , Reactores Biológicos/microbiología , Glicerol/metabolismo , Oxígeno/metabolismo , Nitrógeno/metabolismo
19.
Drug Dev Ind Pharm ; 50(6): 561-575, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38832870

RESUMEN

INTRODUCTION: Breast cancer (BC) is the most common malignancy in women globally. Significant progress has been made in developing structural nanoparticles (NPs) and formulations for targeted smart drug delivery (SDD) of pharmaceuticals, improving the precision of tumor cell targeting in therapy. SIGNIFICANCE: Magnetic hyperthermia (MHT) treatment using magneto-liposomes (MLs) has emerged as a promising adjuvant cancer therapy. METHODS: CoFe2O4 magnetic NPs (MNPs) were conjugated with nanoliposomes to form MLs, and the anticancer drug quercetin (Que) was loaded into MLs, forming Que-MLs composites for antitumor approach. The aim was to prepare Que-MLs for DD systems (DDS) under an alternating magnetic field (AMF), termed chemotherapy/hyperthermia (chemo-HT) techniques. The encapsulation efficiency (EE), drug loading capacity (DL), and drug release (DR) of Que and Que-MLs were evaluated. RESULTS: The results confirmed successful Que-loading on the surface of MLs, with an average diameter of 38 nm and efficient encapsulation into MLs (69%). In vitro, experimental results on MCF-7 breast cells using MHT showed high cytotoxic effects of novel Que-MLs on MCF-7 cells. Various analyses, including cytotoxicity, apoptosis, cell migration, western blotting, fluorescence imaging, and cell membrane internalization, were conducted. The Acridine Orange-ethidium bromide double fluorescence test identified 35% early and 55% late apoptosis resulting from Que-MLs under the chemo-HT group. TEM results indicated MCF-7 cell membrane internalization and digestion of Que-MLs, suggesting the presence of early endosome-like vesicles on the cytoplasmic periphery. CONCLUSIONS: Que-MLs exhibited multi-modal chemo-HT effects, displaying high toxicity against MCF-7 BC cells and showing promise as a potent cytotoxic agent for BC chemotherapy.


Asunto(s)
Apoptosis , Neoplasias de la Mama , Daño del ADN , Hipertermia Inducida , Liposomas , Quercetina , Humanos , Quercetina/farmacología , Quercetina/administración & dosificación , Quercetina/química , Células MCF-7 , Apoptosis/efectos de los fármacos , Hipertermia Inducida/métodos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Daño del ADN/efectos de los fármacos , Cobalto/química , Cobalto/administración & dosificación , Cobalto/farmacología , Femenino , Compuestos Férricos/química , Liberación de Fármacos , Antineoplásicos/farmacología , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas de Magnetita/química , Supervivencia Celular/efectos de los fármacos , Campos Magnéticos
20.
Eur Radiol Exp ; 8(1): 73, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38945979

RESUMEN

Presurgical evaluation with functional magnetic resonance imaging (fMRI) can reduce postsurgical morbidity. Here, we discuss presurgical fMRI mapping at ultra-high magnetic fields (UHF), i.e., ≥ 7 T, in the light of the current growing interest in artificial intelligence (AI) and robot-assisted neurosurgery. The potential of submillimetre fMRI mapping can help better appreciate uncertainty on resection margins, though geometric distortions at UHF might lessen the accuracy of fMRI maps. A useful trade-off for UHF fMRI is to collect data with 1-mm isotropic resolution to ensure high sensitivity and subsequently a low risk of false negatives. Scanning at UHF might yield a revival interest in slow event-related fMRI, thereby offering a richer depiction of the dynamics of fMRI responses. The potential applications of AI concern denoising and artefact removal, generation of super-resolution fMRI maps, and accurate fusion or coregistration between anatomical and fMRI maps. The latter can benefit from the use of T1-weighted echo-planar imaging for better visualization of brain activations. Such AI-augmented fMRI maps would provide high-quality input data to robotic surgery systems, thereby improving the accuracy and reliability of robot-assisted neurosurgery. Ultimately, the advancement in fMRI at UHF would promote clinically useful synergies between fMRI, AI, and robotic neurosurgery.Relevance statement This review highlights the potential synergies between fMRI at UHF, AI, and robotic neurosurgery in improving the accuracy and reliability of fMRI-based presurgical mapping.Key points• Presurgical fMRI mapping at UHF improves spatial resolution and sensitivity.• Slow event-related designs offer a richer depiction of fMRI responses dynamics.• AI can support denoising, artefact removal, and generation of super-resolution fMRI maps.• AI-augmented fMRI maps can provide high-quality input data to robotic surgery systems.


Asunto(s)
Inteligencia Artificial , Mapeo Encefálico , Imagen por Resonancia Magnética , Procedimientos Quirúrgicos Robotizados , Humanos , Imagen por Resonancia Magnética/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Mapeo Encefálico/métodos , Procedimientos Neuroquirúrgicos/métodos , Campos Magnéticos , Cuidados Preoperatorios/métodos , Neoplasias Encefálicas/cirugía , Neoplasias Encefálicas/diagnóstico por imagen
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