Noninvasive tracking of biochemical processes in the body is paramount in diagnostic medicine. Among the leading techniques is spectroscopic magnetic resonance imaging (MRI), which tracks metabolites with an amplified (hyperpolarized) magnetization signal injected into the subject just before scanning. Traditionally, the brief enhanced magnetization period of these agents limited clinical imaging. We propose a solution based on amalgamating two materials-one having diagnostic-metabolic activity and the other characterized by robust magnetization retention. This combination slows the magnetization decay in the diagnostic metabolic probe, which receives continuously replenished magnetization from the companion material. Thus, it extends the magnetization lifetime in some of our measurements to beyond 4 min, with net magnetization enhanced by more than four orders of magnitude. This could allow the metabolic probes to remain magnetized from injection until they reach the targeted organ, improving tissue signatures in clinical imaging. Upon validation, this metabolic MRI technique promises wide-ranging clinical applications, including diagnostic imaging, therapeutic monitoring, and posttreatment surveillance.

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.

With the increasing application of magnetic compression anastomosis (MCA) in gastrointestinal anastomosis, we identified an interesting phenomenon that an anastomosis is more prone to stenosis after endoscopic gastrointestinal MCA. We hypothesized that the increase in tissue tension during endoscopic procedures is the cause of anastomotic stenosis. In this study, we investigated the effect of tissue tension on gastroduodenal bypass MCA in Sprague-Dawley (SD) rats. Twenty SD rats were divided into the study group (high-tension group, n = 10) and control group (no tension group, n = 10), wherein the rats underwent complete gastroduodenal bypass magnetic anastomosis under high tension and no tension of the digestive tract, respectively. Anastomotic specimens were obtained 4 weeks after the operation, and anastomotic diameters of the two groups were observed and measured. The histological difference was observed by hematoxylin & eosin and Masson staining. The operation was successfully completed in all rats, and all survived until 4 weeks postoperatively. Anastomotic measurements revealed that the anastomosis diameter was significantly smaller in the study group than in the control group, and there were three cases of severe anastomotic stenosis. Histological observation showed that the amount of collagen fibers in the anastomosis was greater in the study group than in the control group. The results suggest that the high-tension state of the digestive tract is an important factor leading to anastomotic stenosis, and thus, we put forward the Yan-Zhang\'s Tissue Tension Theory of MCA to explain this phenomenon.

In this review article, a perspective on the immobilization of various hydrolytic enzymes onto magnetic nanoparticles for synthetic organic chemistry applications is presented. After a first part giving short overview on nanomagnetism and highlighting advantages and disadvantages of immobilizing enzymes on magnetic nanoparticles (MNPs), the most important hydrolytic enzymes and their applications were summarized. A section reviewing the immobilization techniques with a particular focus on supporting enzymes on MNPs introduces the reader to the final chapter describing synthetic organic chemistry applications of small molecules (flavour esters) and polymers (polyesters and polyamides). Finally, the conclusion and perspective section gives the author\'s personal view on further research discussing the new idea of a synergistic rational design of the magnetic and biocatalytic component to produce novel magnetic nano-architectures.

Protein phosphorylation plays an important role in cellular signaling and disease development. Advances in mass spectrometry-based proteomics have enabled qualitative and quantitative phosphorylation studies as well as in-depth biological explorations for biomarker discovery and signaling pathway analysis. However, the dynamic changes that occur during phosphorylation and the low abundance of target analytes render direct analysis difficult because mass spectral detection offers no selectivity, unlike immunoassays such as Western blot and enzyme-linked immunosorbent assay (ELISA). The present study aimed to solve one of the key problems in the specific and efficient isolation of phosphorylated peptides. A method based on a magnetic carbon nitride composite coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was developed for the enrichment and analysis of phosphopeptides with low abundance in complex samples. Magnetic carbon nitride composite was synthesized and characterized by electron microscopy, infrared spectroscopy, and X-ray diffractometry. The composite showed a well-distributed two-dimensional layered structure and functional groups with excellent paramagnetic performance. Two classical phosphoproteins, namely, α- and β-caseins, were selected as model phosphorylated samples to assess the performance of the proposed enrichment technique. The magnetic carbon nitride composite exhibited high selectivity and sensitivity for phosphopeptide enrichment. The limit of detection was determined by MALDI-TOF-MS analysis to be 0.1 fmol. The selectivity of the method was investigated using the digest mixtures of α-casein, β-casein, and bovine serum albumin (BSA) with different mass ratios (1∶1∶1000, 1∶1∶2000, and 1∶1∶5000). Direct analysis of the samples revealed the dominance of spectral signals from the abundant peptides in BSA. After enrichment with the magnetic carbon nitride composite, the high concentration of background proteins was washed away and only the signals of the phosphopeptides were captured. The signals from the casein proteins were clearly observed with little background noise, indicating the high selectivity of the composite material. The robustness of the method was tested by assessing the reusability of the same batch of magnetic carbon nitride materials over 20 cycles of enrichment. The composite showed nearly the same enrichment ability even after several cycles of reuse, demonstrating its potential applicability for a large number of clinical samples. Finally, the method was applied to the analysis of phosphopeptides from several commonly used phosphoprotein-containing samples, including skimmed milk digest, human serum, and human saliva; these samples are significant in the analysis of food quality, disease biomarkers, and liquid biopsies for cancer. Without enrichment, no phosphopeptide was detected because of the high abundance of nonphosphopeptide materials dominating the spectral signals obtained. After pretreatment with the developed magnetic carbon nitride composite, most of the phosphosites were identified with high selectivity and sensitivity via MALDI-TOF-MS. These results revealed the practicality of the developed approach for clinical applications. In addition, our method may potentially be employed for phosphoproteomics with real complex biological samples.

The traction converter modulation generates switching-frequencies current harmonics. The trapped filters can eliminate these switching harmonics, reducing total inductance and filter size. Nonetheless, in comparison with the typical inductor-capacitor-inductor (LCL) filter, the trap inductor needs a larger magnetic core. Moreover, the trapped filter has not been analyzed in the traction systems. This paper proposes a magnetic integrated inductor-trap-inductor (LLCL) filter to decrease the filter\'s size and investigate its application in traction converters. In fact, the application range of this filter is quite broad, and it can be used in various electrical power systems, including industrial power systems, renewable energy systems, transportation systems, and building power systems. The LC-trap may be formed by connecting the equivalent trap inductor, introduced through the magnetic coupling between inverter-side and grid-side inductors, in series with the filter capacitor. Furthermore, for H-bridge unipolar pulse width modulation (PWM) traction converters, the prominent switching harmonics are concentrated at the double switching frequencies. Therefore, the stability zone is expanded by moving the resonance above the Nyquist frequency. The presented filter\'s features and design are thoroughly analyzed. The proposed method is finally validated by the MATLAB/Simulink simulation and hardware-in-the-loop (HIL) experimental results. Compared to the discrete windings, the integrated ones can save two magnetic cores. Furthermore, the proposed filter can meet IEEE criteria with 0.3% for all the harmonics and total harmonic distortion (THD) of 2.15% of the grid-side current.

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Magnetic iron concentrate (MIC) and nonmagnetic tailings (NT) are obtained from magnetization roasting of iron tailings (IT). MIC containing Pb adversely affects blast furnace ironmaking, while Cu in NT poses leaching risks. This study utilizes fast pyrolysis-suspension magnetization roasting to recover iron from IT. The enrichment of Pb, Cu, and the phase transformation mechanism of Cu in the process of suspension magnetization roasting and magnetic separation were clarified. Results show 96.13 % of Cu in IT is in limonite and 47.23 % of Pb is associated with iron. At 750 °C, with 10 % dosage of biomass pyrolysis and 10 min roasting, Pb, Cu and Fe contents in MIC are 0.96, 2.14 and 3.17 times that of NT. Increasing roasting temperature enhances Cu associated with iron enrichment into the MIC, while oxidation of free copper oxide associated with iron forms magnetic copper ferrite. Increased pyrolyzed biomass leads to over-reduction of magnetite associated with Cu to FeO associated with Cu, promoting magnetic copper ferrite decomposition into FeO and free copper oxide. This research holds significant importance in controlling the quality of MIC and the storage risk of IT, and provides theoretical guidance for the regulation and recovery of valuable metals in subsequent processes.

Aims and objectives: This research aims to develop a kinetic model that accurately captures the dynamics of nanoparticle impact and penetration into cell membranes, specifically in magnetically-driven drug delivery. The primary objective is to determine the minimum initial kinetic energy and constant external magnetic force necessary for successful penetration of the cell membrane.Model Development: Built upon our previous research on quasi-static nanoneedle penetration, the current model development is based on continuum mechanics. The modeling approach incorporates a finite element method and explicit dynamic solver to accurately represent the rapid dynamics involved in the phenomenon. Within the model, the cell is modeled as an isotropic elastic shell with a hemiellipsoidal geometry and a thickness of 200 nm, reflecting the properties of the lipid membrane and actin cortex. The surrounding cytoplasm is treated as a fluid-like Eulerian body.Scenarios and Results: This study explores three distinct scenarios to investigate the penetration of nanoneedles into cell membranes. Firstly, we examine two scenarios in which the particles are solely subjected to either a constant external force or an initial velocity. Secondly, we explore a scenario that considers the combined effects of both parameters simultaneously. In each scenario, we analyze the critical values required to induce membrane puncture and present comprehensive diagrams illustrating the results.Findings and significance: The findings of this research provide valuable insights into the mechanics of nanoneedle penetration into cell membranes and offer guidelines for optimizing magnetically-driven drug delivery systems, supporting the design of efficient and targeted drug delivery strategies.