Magnetic Density Research Articles

Stereoselective synthesis of geminal bromofluoroalkenes by kinetically controlled selective conversion of oxaphosphetane intermediates.

Geminal bromofluoroalkenes are an important subclass of versatile organic interhalide, which can serve as useful synthetic precursors to monofluoroalkenes that are valuable amide group isosteres. Nonetheless, despite the vast advancement of olefination methodologies, the broadly applicable stereoselective synthesis remained elusive for geminal bromofluoroalkenes before our work. In particular, the seemingly straightforward Wittig-type approach with interhalogenated phosphorus ylide has been unsuccessful because of the difficulty in the diastereoselective oxaphosphetane formation. Here, we describe a conceptually distinctive strategy, by which the stereoselectivity is gained via the selective decomposition of the oxaphosphetane intermediates. The suitably identified phosphorus(III) reagent and reaction medium enabled efficient kinetic differentiation, which was supported by nuclear magnetic resonance analysis and density functional theory calculation. Through our method, the highly diastereoselective synthesis of geminal E-bromofluoroalkenes was accomplished in one step. Furthermore, the generality was demonstrated by accommodating a wide range of readily available carbonyl compounds, including ketones and pharmaceutical substrates.

Fabrication of Ultrafine L10-FePt-Based Magnetic Patterns Enabled by Single-Step Nanoimprint-Assisted Block Copolymer Self-Assembly.

The bit islands in magnetic patterns play a crucial role in advancing magnetic recording density, but the trade-off issues between miniaturization and scalable production are still challenging. Here we present a two-in-one technique of nanoimprint lithography (NIL)-assisted self-assembly using a specially engineered FePt-containing block copolymer (BCP), offering a simple one-step fabrication for L10-FePt bit-patterned media with high throughput. This method combines top-down NIL with bottom-up self-assembly to precisely control the ultrafine magnetic bits in the nanoscale patterns. The FePt-derived BCPs, designed with an equal atomic ratio of Fe and Pt, ensure the preparation of homogeneously dispersed L10-FePt nanoparticles (NPs). Subsequent BCP pyrolysis results in NPs with enhanced magnetic properties, significantly advancing high-density data storage devices. This strategy offers a novel approach to drive the innovative creation of ordered magnetic metal alloy NPs arrays for practical applications.

Analysis of the Samos Earthquake Using Swarm Satellite Data

Making use of the geomagnetic field and the electron density data from the ionosphere observed by the three Swarm satellites that were recorded through 2020, 303 days before and 62 days after the Samos earthquake were investigated, which occurred at 11:51 UTC on Oct 30, 2020, happened in an offshore location around 60 km southwest of Izmir, western Turkey, and 16 km north of Samos Island, Greece 37.897°N 26.784°E. Magnetic and electron density data abnormalities were examined using the Analysis of Magnetic Swarm (AMSW) and the Analysis of Electron Density Swarm (AEDSW) algorithms. The quiet time abnormalities during nighttime within the Dobrovisky region showed exciting results. It showed an enhancement in the cumulative number of tracks (acceleration) approximately 150 days before the mainshock of the earthquake in the magnetic and electron density data. In addition, magnetic and electron density data results matched the ground-based observatory data recorded within the same period and the Dobrovisky region.

Kinetic Alfvén wave cascade in sub-ion range plasma turbulence

Kinetic Alfvén waves (KAWs) are simulated with a 3D particle-in-cell (PIC) code by using the eigenvector relations of density, velocity, electric, and magnetic field fluctuations derived from a two-fluid KAW model. Similar simulations are also performed with a whistler waves setup. The 2D two-fluid eigenvector relations are converted into 3D by using rotation of the reference frame. The initial condition for the simulations is a superposition of several waves at scales slightly larger than the ion skin depth. The nonlinear interactions produce a transfer of energy to smaller scales. The magnetic field perturbation ratios, velocity perturbation, and density perturbation ratios are calculated from the simulation at higher wavenumbers and compared with the analytically expected ratios for KAWs and whistler waves. We find that in both types of simulations, initialized either with an ensemble of KAWs or with whistlers, the observed polarization relations at later times match better with the KAW relations compared to whistlers. This indicates a preference for excitation of KAW fluctuations at smaller scales. The power spectrum in the perpendicular direction is calculated, and it shows similar indices as measured in the solar wind power spectrum in the transition (sub-ion) region. The power law extends to smaller scales when a higher ion-to-electron mass ratio is taken. The 2D magnetic power spectrum in magnetic field parallel and perpendicular directions shows typical anisotropy where the power spreads more in the perpendicular direction than in the parallel direction. This study shows that KAWs can explain features of the sub-ion range plasma turbulence in the solar wind.

Quantifying the Expanding and Cooling Effects into the Double Adiabatic Evolution of the Solar Wind Through the Expanding Box Model

One of the fundamental problems in space physics is the expansion dynamics of the solar wind, strongly correlated with collective plasma reactions, such as wave instabilities that tend to relax kinetic anisotropies. The expansion is in general described through the double adiabatic or Chew–Goldberger–Low (CGL) theory, which sets the main ideas and plasma expansion’s major role in describing plasma cooling/heating dynamics. Here, using the expanding box model (EBM) we revisit the CGL description including plasma expansion. Our primary objective is to isolate the expanding effects into the conservation of the double adiabatic invariants, a key aspect of the CGL theory. Following the same approximations and assumptions as in EBM and CGL theory, we developed a CGL-like description in which the expansion modifies the conservation of the double adiabatic invariants. Our results show that the double adiabatic equations are no longer conserved if plasma cooling is introduced through the EBM, with explicit dependence on expanding parameters, magnetic field profiles, and velocity gradients. Solving the equations for different magnetic field and density profiles (obtained self-consistently through the equations), we compute the evolution of temperature anisotropy and plasma beta, which deviates from CGL predictions and empirical observations. This deviation is attributed to the plasma cooling effect induced by the expansion of the plasma. The results suggest that heating mechanisms even play a major role in counteracting plasma cooling during expansion.

Detection of Extensive Equatorial Plasma Depletions After the 2022 Tongan Volcanic Eruption From Multiple Geodetic Satellite Ranging Systems

AbstractWe present a number of unique observations of ionospheric anomalies following the Hunga‐Tonga Hunga‐Ha'apai (HTHH) volcanic eruption on 15 January 2022. All are based on non‐dedicated geodetic satellite systems: Global Positioning System tracking of Low Earth Orbit (LEO) CubeSats, intersatellite tracking between two GRACE Follow‐On satellites, satellite radar altimeters to the ocean surface, and Doppler radio beacons from ground stations to LEO geodetic satellites. Their observations revealed the development of anomalously large trough‐like plasma depletions, along with plasma bubbles, in the equatorial regions of the Pacific and East Asian sectors. Trough‐like plasma depletions appeared to be confined within approximately ±20° magnetic latitude, accompanied by density enhancements just outside this latitude range. These plasma depletions and enhancements were aligned with the magnetic equator and occurred across broad longitudes. They were detected in regions where atmospheric waves from the HTHH eruption passed through around the time of the sunset terminator. We interpret these phenomena in terms of the E dynamo electric fields driven by atmospheric waves from the eruption. The uplift of the ionosphere beyond satellite altitudes, followed by subsequent plasma diffusion to higher latitudes along magnetic field lines, results in the formation of trough‐like plasma depletions around the magnetic equator and density enhancement at higher latitudes. The detection of plasma bubbles in the Asian sector during the non‐bubble season (January) is likely associated with the uplift of the ionosphere at the sunset terminator.

Rationale and design of the SHASTA-3 and SHASTA-4 studies: randomized, double-blind, placebo-controlled, phase 3 studies of plozasiran in patients with severe hypertriglyceridemia

Abstract Severe hypertriglyceridemia (sHTG) confers an increased risk of atherosclerotic cardiovascular disease (ASCVD) and acute pancreatitis (AP). sHTG-associated AP is a substantial source of morbidity, mortality, reduced quality of life and financial burden to health care systems. Currently available therapeutic approaches for sHTG are often insufficient to reduce triglyceride (TG) levels and prevent AP. Plozasiran, an investigational siRNA therapeutic, inhibits hepatic production of apolipoprotein C3 (APOC3), a key regulator of lipoprotein lipase-mediated TG metabolism and clearance. In a phase 2 study of sHTG patients [TG ≥500 mg/dL (≥5.65 mmol/L)], plozasiran demonstrated durable reductions in TG levels of up to -80%, 12 weeks after the last dose, and decreased TG below 500 mg/dL (5.65 mmol/L), a threshold of increased risk for AP in most participants. The SHASTA-3 and SHASTA-4 trials will evaluate safety and efficacy of plozasiran, including AP rates, in patients with sHTG. SHASTA-3 and SHASTA-4 are phase 3, randomized, double-blind, placebo-controlled, multi-center trials. Key inclusion criteria are prior sHTG and fasting TG ≥500 mg/dL (≥5.65 mmol/L), at screening. Key exclusion criteria include use of any hepatocyte targeted siRNA treatments that target lipids and/or TGs within 1 year (except inclisiran at least 4 weeks prior to enrollment), siRNA or ASO within 60 days, known FCS diagnosis, and AP within 4 weeks of screening. 700 adults with sHTG will be enrolled in these two trials in several sites across multiple countries. Patients will be randomized 2:1 to receive 4 quarterly subcutaneous injections of plozasiran 25 mg or matching placebo over a 1-year double-blinded period, followed by post-treatment evaluation or entry into the open-label extension study. The randomization will be stratified based on TG levels (≥880 mg/dL vs <880 mg/dL [≥ vs <10 mmol/L]) and prior history of AP, within 5 years of screening. The primary efficacy endpoint of the studies is placebo-adjusted percent change in fasting TG from baseline to month 12 with plozasiran. Secondary endpoints include percent change in fasting TG from baseline to month 10 compared to placebo, percent of patients achieving fasting TGs of <500 mg/dL (<5.65 mmol/L) and TGs of <150 mg/dL (<1.69 mmol/L) at month 10 and 12 compared to placebo, and event rate of adjudicated abdominal clinical events including ER visits and hospitalization for abdominal pain attributed to HTG and events of documented pancreatitis. The effect of plozasiran on other lipids and lipoproteins, inflammatory biomarkers, and liver fat content using magnetic resonance imaging-proton density fat fraction will be assessed. Adjudicated major adverse cardiovascular event rates, safety and tolerability will be assessed. SHASTA-3 and SHASTA-4 are designed to determine whether the quarterly-dosed APOC3 siRNA plozasiran, added to standard of care, safely reduces TG levels and the rate of AP in patients with sHTG.

Thermal gradient-induced critical current degradation in mesoscopic superconducting thin film

Abstract Superconducting materials inevitably suffer from the sudden change of temperature in localized areas in practical applications, and the concomitant thermal gradient may be detrimental to their performance. Critical current density is a key factor affecting the performance of superconductors. However, the effect of thermal gradient on the critical current density has not been identified. Here, by combining the time-dependent Ginzburg–Landau equations and the heat transfer equation, the thermal gradient and magnetic field dependence of the critical current density are systematically investigated and rationalized by exploring the behavior of vortex and magnetization. For lower magnetic fields, it is found that the thermal gradients strongly reduce the local surface barriers, which inhibits vortex entry and movement, leading to a rapid deterioration of the current-carrying capability. Under moderate magnetic fields, the critical current density corresponding to higher thermal gradients decreases more slowly with increasing magnetic field, which results from the thermal gradient-induced entry and moving of vortices along the current direction. As the magnetic field continues to increase, the variation of the critical current density transitions into a platform period and even slightly rises. The enhanced critical current is primarily attributed to the excess entry of vortices, which increases the surface barrier of the sample. With the further increase in the magnetic field, the critical current density continues to decrease due to increased magnetic field penetration. These results unveil the fundamental interplay between thermal gradients, external magnetic field, vortex, magnetization and critical current density, and provide a theoretical basis for understanding the heat-induced quenching of mesoscopic superconducting thin films in practical applications.

Association Between Ultraprocessed Food Consumption and Metabolic Disorders in Children and Adolescents with Obesity.

We investigated the effects of ultraprocessed food (UPF) consumption on metabolic disorders (e.g., adiposity, metabolic associated steatotic liver disease [MASLD], and insulin resistance) in children and adolescents with obesity to improve dietary guidelines and public health strategies. The dietary intake of 149 participants (aged 8-17 years) was assessed with food diaries. The NOVA classification system was used to classify food according to the degree of processing. Metabolic outcomes, including the fat mass index (FMI), hepatic fat percentage, and insulin resistance, were measured via dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging proton density fat fraction (MRI-PDFF), and biochemical analysis, respectively. Greater UPF consumption from baseline to the 6-month follow-up was significantly associated with increased insulin and decreased total cholesterol and LDL-cholesterol. UPF consumption was positively associated with the prevalence of MASLD (liver MRI-PDFF ≥ 5%; odds ratio T3 vs. T1 = 1.75; 95% confidence interval [CI] 1.03, 3.00), moderate-to-severe MASLD (liver MRI-PDFF ≥ 10%; OR T3 vs. T1 = 4.19; 95% CI 1.72, 10.22), and insulin resistance (OR T3 vs. T1 = 2.44; 95% CI 1.33, 4.48), after adjusting for covariates. A linear dose-response relationship was observed between UPF consumption and the odds of moderate-to-severe MASLD and insulin resistance. Greater UPF consumption was strongly associated with MASLD and insulin resistance in children and adolescents with obesity, underscoring the importance of reducing UPF consumption through dietary guidelines and public health interventions to mitigate the risk of obesity-related metabolic conditions in young populations.

Comparing ultrasound-derived fat fraction and MRI-PDFF for quantifying hepatic steatosis: a real-world prospective study.

To compare the agreement between ultrasound-derived fat fraction (UDFF) with magnetic resonance proton density fat fraction (MRI-PDFF) for quantification of hepatic steatosis and verify its reliability and diagnostic performance by comparing with MRI-PDFF as the reference standard. This prospective study included a primary analysis of 191 patients who underwent MRI-PDFF and UDFF from February 2023 to February 2024. MRI-PDFF were derived from three liver segment measurements with calculation of an overall median PDFF. UDFF was performed by two different sonographers for each of the six measurements, and the median was taken. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to assess agreement. Receiver operating characteristics (ROC) curves were used to evaluate the diagnostic performance of UDFF in detecting different degrees of hepatic steatosis. A total of 176 participants were enrolled in the final cohort of this study (median age, 36.0 years; 82 men, 94 women). The median MRI-PDFF value was 11.3% (interquartile range (IQR) 7.5-18.9); 84.7% patients had a median MRI-PDFF value ≥ 6.4%. The median UDFF measured by different sonographers were 9.5% (IQR: 5.0-18.0) and 9.0% (IQR: 5.0-18.0), respectively. The interobserver agreement of UDFF measurement was excellent agreement (ICC = 0.951 [95% CI: 0.934-0.964], p < 0.001). UDFF was positively strongly correlated with MRI-PDFF with ICC of 0.899 (95% CI: 0.852-0.930). The Bland-Altman analysis showed high agreement between UDFF and MRI-PDFF measurements, with a mean bias of 1.7% (95% LOA, -8.7 to 12.2%). The optimal UDFF cutoff values were 5.5%, 15.5% and 17.5% for detecting MRI-PDFF at historic thresholds of 6.4%, 17.4%, and 22.1%, with AUC of 0.851, 0.952, and 0.948, respectively. The sensitivity was 79.2%, 87.5%, 88.9%, and specificity was 81.5%, 90.6%, 90.0%, respectively. UDFF is a reliable and accurate method for quantification and classification of hepatic steatosis, with strong agreement to MRI-PDFF. The UDFF cutoff values of 5.5%, 15.5%, and 17.5% provide high sensitivity and specificity for the detection of mild, moderate, and severe hepatic steatosis, respectively. Question Is ultrasound-derived fat fraction (UDFF) reliable for the quantitative detection of hepatic steatosis compared to MRI proton density fat fraction (MRI-PDFF)? Findings UDFF cutoff values of 5.5%, 15.5%, and 17.5% provided high sensitivity and specificity for the detection of mild, moderate, and severe hepatic steatosis, respectively. Clinical relevance UDFF is a reliable and accurate method for quantification and classification of hepatic steatosis, with strong agreement to MRI-PDFF and high reproducibility of liver fat content by different sonographers.

Evaluating the efficacy of 8 non-invasive models in predicting MASLD and progression: a prospective study

BackgroundSelecting the optimal non-invasive diagnostic model for MASLD (Metabolic Dysfunction-Associated Steatosis Liver Disease) and steatosis progression is a critical issue given the variety of available models. We aimed to compare the performance of eight clinical prediction models for diagnosing and predicting the progression of hepatic steatosis using MRI-PDFF (Magnetic Resonance Imaging-Derived Proton Density Fat Fraction), and validate the findings with FibroScan and histopathological results.MethodsIn this study, 846 participants were initially enrolled, with 108 undergoing liver biopsy and 706 completing one-year follow-up, including 26 who underwent repeat biopsy. We calculated scores for eight clinical prediction models (FAST, KNAFLD, HSI, FLI, Liver Fat Score, Liver Fat Equation, BAAT, LAP) using collected clinical data and defined steatosis progression as a 30% relative increase in liver fat content (LFC) measured by MRI-PDFF. CAP(Controlled Attenuation Parameter) and LSM (Liver Stiffness Measurement) were obtained by Fibroscan. MRI-PDFF served as the reference standard for evaluating model accuracy, and sensitivity analyses were performed using liver biopsy and Fibroscan results.ResultsAmong the eight clinical models, NAS (nonalcoholic fatty liver disease activity score) showed higher correlation with the FAST and KNAFLD models (r: 0.62 and 0.52, respectively). Among the whole cohort (N = 846), KNAFLD was the best model for predicting different degrees of hepatic steatosis (AUC = 0.84). When the KNAFLD score was above 2.935, LFC was significantly higher (4.4% vs. 19.7%, P < 0.001). After 1 year of follow-up (N = 706), FAST performed best in predicting MASLD progression (AUC = 0.84); with dFAST > -0.02, LFC increased (8.6–10.9%, P < 0.05), mean LSM increased by 0.51 kPa, and with dFAST < -0.02, LFC significantly decreased (11.5–8.5%, P < 0.05), mean LSM and NAS decreased by 0.87 kPa and 0.76, respectively (both P < 0.05).ConclusionsMost models demonstrated good diagnostic and prognostic capabilities for hepatic steatosis, with FAST and KNAFLD showing particular promise as primary non-invasive tools in clinical practice.Trail RegistrationChinese Clinical Trial Registry NO: ChiCTR2100054743, Registered December 26, 2021.

Research on Performance of Interior Permanent Magnet Synchronous Motor with Fractional Slot Concentrated Winding for Electric Vehicles Applications

The fractional-slot, concentrated-winding, interior permanent magnet synchronous motor (FSCW IPMSM) has advantages, such as reducing motor copper consumption, improving flux-weakening capability, and motor fault tolerance, and has certain development potential in application fields such as electric vehicles. However, fractional-slot concentrated-winding motors often contain rich harmonic components due to their winding characteristics, leading to increased motor losses and back electromotive force harmonics, thereby affecting the efficiency and constant power speed regulation range of the motor. Based on this, this article first uses the winding function method to explore the inductance and saliency ratio of the interior permanent magnet synchronous motor with different slot pole combinations in the fractional-slot concentrated- winding of electric vehicles. Secondly, this article will establish a 2D finite element parameterized model to analyze and compare the performance of fractional-slot concentrated-winding motors with different slot pole combinations, including air gap magnetic density, back electromotive force distortion rate, overload multiple, and torque. The structural parameters of the motor were optimized with the objective of minimizing the torque ripple under the constraint of minimizing the average torque reduction. The motor slot width, permanent magnet angle, and permanent magnet pole arc angle were analyzed and optimized. The simulation results showed that 12 slots and 8 poles were the optimal design schemes, providing a theoretical basis for the selection of slot pole coordination in the fractional-slot concentrated-winding interior permanent magnet synchronous motor for electric vehicles.

Magneto-viscoelastic rod model for hard-magnetic soft rods under 3D large deformation: Theory and numerical implementation

The main purpose of this work is to develop a three-dimensional (3D) viscoelastic rod model for hard-magnetic soft (HMS) rods under large deformation which are widely used active structures in soft robotics. To do so, the Simo’s viscoelasticity theory has been rationally incorporated into the geometrically exact 3D curved rod model. The proposed model includes the deformation modes of axial tension, shear, bending, and torsion, which is applicable to the HMS rods with arbitrarily initial curved and twisted geometries under 3D large deformation. The viscoelastic constitutive equations of the HMS rod in the present formulation are formulated, which include the general relaxation functions. To obtain the expression for the magnetic load, the rotation-based magnetic free energy density is introduced, and the governing equations of the HMS rod with magnetic load and body force are presented. To obtain the numerical implementation, an implicit time integration algorithm that simply extends the generalized-α method for the rotation group, and the corresponding variational formulation and its linearization of the rod model are derived. To validate the model, five numerical examples, including 2D dynamic buckling, 3D static, and 3D dynamic problem are presented. The dynamic problems include the dynamic snap-through behavior of a bistable HMS arch and damped oscillation of a quarter arc cantilever under 3D deformation. The simulation results show good agreement with the results reported in the literature.

Enhanced Joule heat release at surface irregularities

The heat release that occurs in a cylindrical conductor carrying an alternating current is analyzed for the cases when the conductor has axisymmetric surface irregularities of one of three types: local bumps, local pits, and sequences of alternating bumps and pits (wavy irregularities). The magnetic field and current density distributions over the conductor cross section have been simulated. The simulation parameters were chosen to match the conditions of experiments on the generation of strong magnetic fields. However, due to the analysis of the initial heating stage, the problem is solved neglecting the temperature dependence of the resistivity of the material. A multiple increase in heat release power in the vicinity of a surface irregularity has been revealed for the three types of irregularities.

Magneto-inductive positioning network based on magnetic energy density

The magneto-inductive positioning system (MPS) is considered a promising solution for realizing accurate positioning in challenging environments, particularly to support the development of emerging technologies. However, obtaining the position of magnetic beacons increases the system’s complexity and the sensor’s attitude error lowers the positioning performance. To solve the above problems, this paper proposes an improved magneto-inductive positioning network system (MPNS) based on magnetic energy density (MED). An orientation model without the sensor’s attitude is derived from MED. An incrementally deployed magneto-inductive positioning network is developed with the orientation model, which reduces the system complexity. An advanced resampling method of particle filter is employed in the MPNS to improve the positioning accuracy. The realized system displays the max error of no more than 0.13 m for the static target . The performance of MPNS that tracks moving targets is examined with simulation. The results exhibit that 99% of tracking errors are less than 0.25 m.

A Magnetized Strongly Turbulent Corona as the Source of Neutrinos from NGC 1068

The cores of active galactic nuclei are potential accelerators of 10–100 TeV cosmic rays, in turn producing high-energy neutrinos. This picture was confirmed by the compelling evidence of a TeV neutrino signal from the nearby active galaxy NGC 1068, leaving open the question of what is the site and mechanism of cosmic-ray acceleration. One candidate is the magnetized turbulence surrounding the central supermassive black hole. Recent particle-in-cell simulations of magnetized turbulence indicate that stochastic cosmic-ray acceleration is nonresonant, in contrast to the assumptions of previous studies. We show that this has important consequences on a self-consistent theory of neutrino production in the corona, leading to a more rapid cosmic-ray acceleration than previously considered. The turbulent magnetic-field fluctuations needed to explain the neutrino signal are consistent with a magnetically powered corona. We find that strong turbulence, with turbulent magnetic energy density higher than 1% of the rest-mass energy density, naturally explains the normalization of the IceCube neutrino flux, in addition to the neutrino spectral shape. Only a fraction of the protons in the corona, which can be directly inferred from the neutrino signal, are accelerated to high energies. Thus, in this framework, the neutrino signal from NGC 1068 provides a testbed for particle acceleration in magnetized turbulence.

Ultrasound normalized local variance to assess metabolic dysfunction-associated steatotic liver disease

PurposeIncreased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) highlights a desire for screening with liver ultrasound normalized local variance (NLV). We aimed to assess variations in NLV values measured at different sampling depths and discuss common technical considerations in measuring liver NLV. MethodsWe retrospectively measured liver NLVs at variable depths on ultrasound images pre-recorded in 116 participants who underwent liver magnetic resonance imaging-proton density fat fraction (MRI-PDFF) and ultrasound to screen for MASLD. Liver NLVs were measured and differences at variable depths were tested using one-way analysis of variance (ANOVA) and multiple paired comparisons using post hoc Tukey honestly significant difference (HSD), Scheffé, Bonferroni, and Holm multiple comparisons. Diagnostic performance of NLV values were analyzed by area under the receiver operating characteristics (AUROC) curve. ResultsThe NLV measured at a depth of 10 cm significantly differed from those measured near the liver capsule and at depths of 6 cm and 8 cm (p < 0.001) from the skin. There was no significant difference in NLV value in other paired groups (p > 0.05). The difference in the area under AUROCs for NLVs measured at variable depths was not significant (p > 0.05). ConclusionsThe best diagnostic performance of liver NLV was measured at depth of 8 cm from the skin, although NLV measured at variable depth showed similar diagnostic performance for assessing ≥ mild hepatic steatosis. The study results provide a reference that can be used in the development of standardized scanning protocols and technical considerations in measuring liver NLV.

The Intrabinary Shock and Companion Star of Redback Pulsar J2215+5135

PSR J2215+5135 (J2215) is a “redback” spider pulsar, where the intrabinary shock (IBS) wraps around the pulsar rather than the stellar-mass companion. Spider orbital light curves are modulated, dominated by their binary companion thermal emission in the optical bands and by IBS synchrotron emission in the X-rays. We report on new XMM-Newton X-ray and U-band observations of J2215. We produce orbital light curves and use them to model the system properties. Our best-fit optical light model gives a neutron star mass M NS = 1.98 ± 0.08 M ⊙, lower than previously reported. However, uncertainty in the stellar atmosphere metallicity, a parameter to which J2215 is unusually sensitive, requires us to consider an acceptable systematic plus statistical range of M NS ∼ 1.85–2.3 M ⊙. From the X-ray analysis, we find that the IBS wraps around the pulsar but with a pulsar-wind-to-companion-wind-momentum ratio unusually close to unity, implying a flatter IBS geometry than seen in other spiders. Estimating the companion wind momentum and speed from the X-ray light curve, we find a companion mass-loss rate of Ṁc≳10−10M⊙ yr−1 so that J2215 may become an isolated millisecond pulsar in ∼1 Gyr. Our X-ray analyses place constraints on the magnetization and particle density of the pulsar wind and support models of magnetic reconnection and particle acceleration in the highly magnetized relativistic IBS.

Comparative efficacy of THR-β agonists, FGF-21 analogues, GLP-1R agonists, GLP-1-based polyagonists, and Pan-PPAR agonists for MASLD: A systematic review and network meta-analysis

AimsTo compare the efficacy of thyroid hormone receptor beta (THR-β) agonists, fibroblast growth factor 21 (FGF-21) analogues, glucagon-like peptide-1 receptor agonists (GLP-1RAs), GLP-1-based polyagonists, and pan-peroxisome proliferator-activated receptor (Pan-PPAR) agonists in the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). MethodsA database search for relevant randomized double-blind controlled trials published until July 11, 2024, was conducted. Primary outcomes were the relative change in hepatic fat fraction (HFF) and liver stiffness assessed non-invasively by magnetic resonance imaging proton density fat fraction and elastography. Secondary outcomes included histology, liver injury index, lipid profile, glucose metabolism, blood pressure, and body weight. ResultsTwenty-seven trials (5357 patients with MASLD) were identified. For HFF reduction, GLP-1-based polyagonists were most potentially effective (mean difference [MD] −51.47; 95 % confidence interval [CI]: −68.25 to −34.68; surface under the cumulative ranking curve [SUCRA] 84.9) vs. placebo, followed by FGF-21 analogues (MD −47.08; 95 % CI: −58.83 to −35.34; SUCRA 75.5), GLP-1R agonists (MD −37.36; 95 % CI: −69.52 to −5.21; SUCRA 52.3) and THR-β agonists (MD −33.20; 95 % CI: −43.90 to −22.51; SUCRA 36.9). For liver stiffness, FGF-21 analogues were most potentially effective (MD −9.65; 95 % CI: −19.28 to −0.01; SUCRA 82.2) vs. placebo, followed by THR-β agonists (MD −5.79; 95 % CI: −9.50 to −2.09; SUCRA 58.2), and GLP-1RAs (MD −5.58; 95 % CI: −15.02 to 3.86; SUCRA 54.7). For fibrosis improvement in histology, GLP-1-based polyagonists were most potentially effective, followed by FGF-21 analogues, THR-β agonists, Pan-PPAR agonists, and GLP-1R agonists; For MASH resolution in histology, GLP-1-based polyagonists were most potentially effective, followed by THR-β agonists, GLP-1R agonists, FGF-21 analogues, and Pan-PPAR agonists. THR-β agonists are well-balanced in liver steatosis and fibrosis, and excel at improving lipid profiles; FGF-21 analogues are effective at improving steatosis and particularly exhibit strong antifibrotic abilities. GLP-1R agonists showed significant benefits in improving liver steatosis, glucose metabolism, and body weight. GLP-1-based polyagonists have demonstrated the most potential efficacy overall in terms of comprehensive curative effect. Pan-PPAR agonists showed distinct advantages in improving liver function and glucose metabolism. ConclusionThese results illustrate the relative superiority of the five classes of therapy in the treatment of MASLD and may serve as guidance for the development of combination therapies.

Improving the steering performance of microrobots by using a magnetically actuated technique

Mobile microrobots show the significance of potential medical procedures and challenge areas within the human body. An applied electromagnetic field is used as a precise magnetic actuation system for controllable steering mobility, and positioning is used. In this work, an adaptable microrobot is developed with an effective technique to enhance steering. An electromagnetic system is employed to produce an external magnetic field that guides a microrobot to improve its steerability. In particular, a driving system of eight coils creates a magnetic field that actuates the microrobot and enables upward and downward motion. Accordingly, three types of microrobot designs are proposed. Consequently, an efficient variation of steering in terms of deformation angle is achieved. The corresponding performance is determined mathematically in terms of the main system parameters, such as external magnetic field and microrobot geometry. In addition, finite element model is used for comparison and validation. Simulation results show that for a relatively high value of magnet field, namely, 15 mT and 90°, the deformation angles were 36.98° for the first design, 39.11° for the second design, and 34.48° for the third design in upward deformation. By contrast, the downward deformation ranges were –40.42°, –39.46°, and –37.04° for the first, second, and third designs, respectively, at –90° The error between the upward and downward steering of the second design had the lowest value of 0.35° The second design of the microrobots has the least error between the upward and downward deformation ratio at 0.89 %. In comparison, the first design has a 9.3 % error, and the third design has a 7.42 % error, with a relatively high value of magnetic field density (15 mT). Simulations have shown that the proposed second design is suitable for navigating narrow artery branches with the least error ratio and more precise control. This work verifies that the model could accurately control the steering of microrobots.