Changes In Axis Research Articles

Preoperative Cervical Range of Motion in Flexion as a Risk Factor for Postoperative Cervical Sagittal Imbalance After Laminoplasty.

Retrospective study. To investigate factors associated with cervical sagittal imbalance (CSI) after cervical laminoplasty (LMP). Preoperative dynamic cervical sagittal alignment is an important predictor for changes in cervical sagittal alignment and clinical outcomes after LMP. However, the impact of preoperative dynamic cervical sagittal alignment on postoperative changes in the cervical sagittal vertical axis (cSVA) after LMP remains unclear. We hypothesized that preoperative cervical flexion and extension function are associated with the changes in cSVA and clinical outcomes and found potential risk factors for post-LMP CSI. Patients undergoing LMP at a single institution between January 2019 and December 2021 were retrospectively reviewed. The average follow-up period was 19 months. The parameters were collected before the surgery and at the final follow-up. We defined the changes in cSVA (△cSVA) ≤ -10 mm as the improvement group, -10 mm < △cSVA ≤ 10 mm as the stable group, and △cSVA > 10 mm as the deterioration group. Multivariate logistic regression was used to evaluate factors associated with postoperative CSI. The χ 2 test was used to compare categorical data between groups. T tests, analysis of variance, Kruskal-Wallis tests, and Mann-Whitney Wilcoxon tests were used to assess the differences between radiographic and clinical parameters among groups. A receiver operating characteristic curve analysis was used to identify optimal cutoff values. The study comprised 102 patients with cervical spondylotic myelopathy. The Japanese Orthopedic Association recovery rate was better in the improvement group and a significant aggravation in neck pain was observed in the deterioration group after surgery. Cervical Flex range of motion (ROM; spine range of flexion) was significantly higher in the deterioration group. The multivariate logistic regression model suggested that greater Flex ROM and starting LMP at C3 were significant risk factors for postoperative deterioration of cervical sagittal balance. Receiver operating characteristic curves showed that the cutoff value for preoperative Flex ROM was 34.10°. Preoperative dynamic cervical sagittal alignment influences postoperative cervical sagittal balance after LMP. Cervical LMP should be carefully considered for patients with a preoperative high Flex ROM, as CSI is likely to occur after surgery. Level 3.

INFLUENCE OF RADIATION FORCES ON THE OBSERVED POSITION AND EVOLUTION OF THE ORBIT OF SPACE DEBRIS OBJECTS WITH A HIGH AREA-TO-MASS RATIO

This study is devoted to assessing the effect of light pressure on the observed position and orbital elements of space debris objects with a large area-to-mass ratio \(A{\text{/}}m\) in the region of medium-high, geostationary and highly elliptical orbits over short time intervals (up to 1 year). Numerical integration of the orbits of 78 model objects was performed at 8 values of \(A{\text{/}}m\) from \(0.01\) to \(125\) m2/kg and two values of the reflection coefficient \(k = 1.0\) and 1.44. The maximum (during the given time periods) angular distances relative to the sub-satellite point on the Earth’s surface between the positions found with and without radiation forces, as well as the maximum changes in the semi-major axis, eccentricity and inclination of the orbit under the influence of radiation forces during the integration time, are determined. It is found that for all objects there is a negative drift of the semi-major axis. For models with semi-major axes of 10 000, 15 000, and 20 000km, the inclination variations do not exceed \(15^\circ \). Among other objects, at \(\gamma = kA{\text{/}}m \geqslant 50\) m2/kg, cases of transitions from direct to reverse motion (and vice versa) due to light pressure, were recorded, which indicates the possibility of flips of the orbital plane under the influence of radiation forces even in the short term. The duration of successful integration (the lifetime of an object in orbit) is given; it was less than \(1\) year for most models with \(\gamma \geqslant 50.0\) m2/kg. Also the time intervals during which the displacement of the position perturbed under the influence of radiation forces from the unperturbed one does not exceed \(5\prime \), \(45\prime \), and \(3^\circ \) are presented, depending on the value of \(\gamma \), semi-major axis, and eccentricity in the initial epoch. Based on the results of the article, it is possible to estimate the required frequency of observations of objects with large \(A{\text{/}}m\).

Effect of the hydroalcoholic extract of melon seeds (Cucumis melo L.) on the pituitary-gonadal axis and testicular tissue changes in adult male rats

Effect of the hydroalcoholic extract of melon seeds (Cucumis melo L.) on the pituitary-gonadal axis and testicular tissue changes in adult male rats

Concurrent Brain Subregion Microgliosis in an HLA-II Mouse Model of Group A Streptococcal Skin Infection.

The broad range of clinical manifestations and life-threatening infections caused by the Gram-positive bacterium, Streptococcus pyogenes or Group A Streptococcus (GAS), remains a significant concern to public health, with a subset of individuals developing neurological complications. Here, we examined the concurrent neuroimmune effects of subcutaneous GAS infections in an HLA-Class II (HLA) transgenic mouse model of subcutaneous GAS infection. To investigate changes in the skin-brain axis, HLA-DQ8 (DQA1*0301/DQB1*0302) mice (DQ8) were randomly divided into three groups: uninfected controls (No Inf), GAS infected and untreated (No Tx), and GAS infected with a resolution by clindamycin (CLN) treatment (CLN Tx) (10 mg/kg/5 days) and were monitored for 16 days post-infection. While the skin GAS burden was significantly reduced by CLN, the cortical and hippocampal GAS burden in the male DQ8 mice was not significantly reduced with CLN. Immunoreactivity to anti-GAS antibody revealed the presence of GAS bacteria in the vicinity of the neuronal nucleus in the neocortex of both No Tx and CLN Tx male DQ8 mice. GAS infection-mediated cortical cytokine changes were modest; however, compared to No Inf or No Tx groups, a significant increase in IL-2, IL-13, IL-22, and IL-10 levels was observed in CLN Tx females despite the lack of GAS burden. Western blot analysis of cortical and hippocampal homogenates showed significantly higher ionized calcium-binding adaptor-1 (Iba-1, microglia marker) protein levels in No Tx females and males and CLN Tx males compared to the No Inf group. Immunohistochemical analysis showed that Iba-1 immunoreactivity in the hippocampal CA3 and CA1 subregions was significantly higher in the CLN Tx males compared to the No Tx group. Our data support the possibility that the subcutaneous GAS infection communicates to the brain and is characterized by intraneuronal GAS sequestration, brain cytokine changes, Iba-1 protein levels, and concurrent CA3 and CA1 subregion-specific microgliosis, even without bacteremia.

Perioperative Complications and Radiographic Outcomes Following Cervical Laminoplasty: A Review of 105 Cases from a Single Academic Center

To assess complications and to compare preoperative and postoperative radiographic measures in patients who underwent cervical laminoplasty. We evaluated patients undergoing cervical laminoplasty between 2011 and 2022 at an academic medical center. Patient demographics, intraoperative and postoperative complications, and preoperative and postoperative radiographic parameters were recorded. Of 150 patients undergoing cervical laminoplasty during 2011-2022, 105 met the inclusion criteria. We identified 22 (21.0%) adverse events in 20 patients: 4 intraoperative (3.8%), 10 perioperative (9.5%), and 8 delayed postoperative (7.6%). Among adverse events, 13 (12.4%) were judged to be minor and 9 (8.6%) were judged to be major complications. Revision surgery was required in 6 (5.7%) patients. Both preoperative and postoperative cervical spine radiographic imaging was available in 47 (44.8%) of the 105 patients. Mean preoperative and postoperative C2-7 Cobb angles were 14.7° and 12.3°, respectively (P= 0.04). Mean preoperative and postoperative sagittal vertical axis measurements were 29.2 mm and 33.3 mm, respectively (P= 0.07). Mean preoperative and postoperative T1 slopes were 32.3° and 30.2°, respectively (P= 0.07). Cervical laminoplasty carries a significant risk of adverse events, the majority of which are minor, and has a low rate of reoperation (5.7%). The procedure does not result in significant changes in sagittal vertical axis or T1 slope. Cervical laminoplasty remains a valuable surgical option for selected patients with cervical myelopathy.

PDT-Induced Activation Enhanced by Hormone Response to Treatment.

Photodynamic therapy (PDT) is a medical treatment with the use of a photosensitizing agent (PS), which, when activated by light, results in selective tissue damage with a cytotoxic effect on tumor cells. PDT leads to the induction of an acute-phase response, which results in the involvement of adrenal glucocorticoid (GC) hormones. PDT, by activating the hormonal response, affects the treatment of cancer. GC release is observed due to adrenal activity, which is driven by changes in the hypothalamic pituitary-adrenal axis triggered by stress signals emanating from the PDT treated tumor. The hormones released in this process in the context of the PDT-induced acute-phase response perform many important functions during anticancer therapy. They lead, among other things, to the systemic mobilization of neutrophils and the production of acute-phase reagents, and also control the production of immunoregulatory proteins and proteins that modulate inflammation. GCs can radically affect the activity of various inflammatory and immune cells, including the apoptosis of cancer cells. A better understanding of the modulation of GC activity could improve the outcomes of cancer patients treated with PDT.

Gut microbiota contribution to selenium deficiency-induced gut-liver inflammation.

There is limited knowledge about the factors that drive gut-liver axis changes after selenium (Se) deficiency-induced gut or liver injuries. Thus, we tested Se deficiency in mice to determine its effects on intestinal bacterial balance and whether it induced liver injury. Serum Se concentration, lipopolysaccharide (LPS) level, and liver injury biomarkers were tested using a biochemical method, while pathological changes in the liver and jejunum were observed via hematoxylin and eosin stain, and a fluorescence spectrophotometer was used to evaluate intestinal permeability. Tight junction (TJ)-related and toll-like receptor (TLR) signaling-related pathway genes and proteins were tested using quantitative polymerase chain reaction, western blotting, immunohistochemistry, and 16S ribosomal ribonucleic acid gene-targeted sequencing of jejunum microorganisms. Se deficiency significantly decreased glutathione peroxidase activity and disrupted the intestinal flora, with the most significant effect being a decrease in Lactobacillus reuteri. The expression of TJ-related genes and proteins decreased significantly with increased treatment time, whereas supplementation with Se, fecal microbiota transplantation, or L. reuteri reversed these decreases. Signs of liver injury and LPS content were significantly increased after intestinal flora imbalance or jejunum injury, and the levels of TLR signaling-related genes were significantly increased. The results indicated that Se deficiency disrupted the microbiota balance, decreased the expression of intestinal TJ factors, and increased intestinal permeability. By contrast, LPS increased due to a bacterial imbalance, which may induce inflammatory liver injury via the TLR4 signaling pathway.

IGF-1 axis changes with ADT and docetaxel in metastatic prostate cancer.

Androgen deprivation therapy (ADT) forms the cornerstone of treatment in locally advanced and metastatic prostate cancer (PCa). Since the growth hormone-insulin-like growth factor (GH-IGF-1) axis has been implicated in prostate tumorigenesis, we aimed to evaluate the association between IGF-1 and its binding proteins on outcomes in men with metastatic PCa treated with ADT, with or without docetaxel (D). We analyzed serum samples for IGF-1 and its family proteins from baseline, 6 months post-randomization, and at the time of progression in men enrolled to receive ADT +/- D in the phase 3 CHAARTED trial. The key outcomes were time to the development of castrate-resistant prostate cancer and overall survival (OS). About 560 patients had samples available for analysis. At 6 months, significant increases in IGF-BP1 (mean Δ+27.4%, P = 0.033), IGF-BP3 (mean Δ+10.3%, P < 0.001), and IGF-BP4 (mean Δ+31.1%, P < 0.001) were seen in the ADT + D group, while the ADT group showed an increase in IGF-BP3 (mean Δ+5.5%, P = 0.015). A higher IGF-1:IGF-BP1 ratio at baseline and after 6 months was associated with improved OS in both the ADT (baseline: hazard ratio (HR) = 0.77, P = 0.026; 6 months: HR = 0.83, P = 0.036) and ADT + D groups (baseline: HR = 0.78, P = 0.04; 6 months: HR = 0.81, P = 0.018). Patients with a log10IGF-1:IGF-BP1 ratio >1.3 at baseline had improved OS when meta-analyzed with data from a prior cohort (HR = 0.71). A higher baseline and 6-month IGF-1:IGF-BP1 ratio was associated with better OS. Further exploration of the IGF-1 axis will be important to assess its role as a predictive biomarker and to target this axis in therapeutic trials.

Unravelling the Link between Psychological Distress and Liver Disease: Insights from an Anxiety-like Rat Model and Metabolomics Analysis.

Psychological distress is associated with an increase in liver disease mortality. This association highlights the close relationship between psychological and physical health. The underlying mechanism of this association needs to be elucidated. In this study, a rat model of anxiety was developed via compound stress. Changes in the HPA axis and inflammatory factors in the brains of the rats were evaluated for behavioral tests and liver function, respectively. The liver metabolic profiles of the rats were characterized through liquid chromatography-mass spectrometry (LC-MS). Differential metabolites were screened based on the conditions of p < 0.05 and VIP > 1. A pathway enrichment analysis was performed on the metabolomics data using the Ingenuity Pathway Analysis (IPA). Immunofluorescence (IF), immunohistochemistry (IHC), and Western blotting assays were performed to examine the expression of the screened target epidermal growth factor receptor (EGFR) and to elucidate the pathway associated with the mechanism. The results showed the impairment of liver function among the rats in an anxiety-like state. Additionally, 61 differential metabolites in the control and anxiety groups were screened using metabolomics (p < 0.05, VIP > 1). The results of the IPA analysis showed that the key target was EGFR. We also found that an anxiety-like state in rats may cause liver injury through the EFGR/PI3K/AKT/NF-κB pathway, which can lead to the production of inflammatory factors in the liver. Our results revealed a mechanism by which anxiety-like behavior leads to liver damage in rats. The findings of this study provided new insights into the deleterious effects of psychological problems on physical health.

Glucagon and Its Receptors in the Mammalian Heart.

Glucagon exerts effects on the mammalian heart. These effects include alterations in the force of contraction, beating rate, and changes in the cardiac conduction system axis. The cardiac effects of glucagon vary according to species, region, age, and concomitant disease. Depending on the species and region studied, the contractile effects of glucagon can be robust, modest, or even absent. Glucagon is detected in the mammalian heart and might act with an autocrine or paracrine effect on the cardiac glucagon receptors. The glucagon levels in the blood and glucagon receptor levels in the heart can change with disease or simultaneous drug application. Glucagon might signal via the glucagon receptors but, albeit less potently, glucagon might also signal via glucagon-like-peptide-1-receptors (GLP1-receptors). Glucagon receptors signal in a species- and region-dependent fashion. Small molecules or antibodies act as antagonists to glucagon receptors, which may become an additional treatment option for diabetes mellitus. Hence, a novel review of the role of glucagon and the glucagon receptors in the mammalian heart, with an eye on the mouse and human heart, appears relevant. Mouse hearts are addressed here because they can be easily genetically modified to generate mice that may serve as models for better studying the human glucagon receptor.

Hypothalamic-Pituitary Adrenal Axis Status 3 Months After Recovery From COVID-19 Infection

ABSTRACT Context Coronavirus disease 2019 (COVID-19) predominantly involves the lungs, albeit many other organ systems, including the hypothalamic-pituitary-adrenal (HPA) axis, can be affected due to the expression of the angiotensin-converting enzyme 2 (ACE2) binding receptor. Few studies have reported the involvement of adrenal gland and the HPA axis during the acute phase of COVID-19; however, the data on the long-term effect of COVID-19 on the HPA axis after acute infection is scarce. Objective To assess and compare the changes in HPA axis in mild, moderate and severe COVID-19 categories at ≥ 3 months after acute infection. Methods A prospective, observational study was conducted to assess the HPA axis status among COVID-19 subjects at least 3 months after recovery from acute infection. The study was conducted from June 2021 to May 2022. Subjects visited the hospital in the fasting state (8.00–9.00am), serum cortisol levels were measured at baseline, 30 and 60 minutes after a 1-μg short Synacthen test (SST). Results A total of 66 subjects ≥ 18 years of age were included in the study. The mean age (SD) was 49.13 ± 11.9 years, 45(68.18%) were male and 21 (31.81%) were female subjects. The mean BMI in the study was 25.91 ± 4.26 kg/m2. Seventeen (25.8%) subjects had mild, twelve (18.2%) had moderate and thirty-seven (56.1%) subjects had severe COVID-19 infection. Out of the sixty-six subjects with COVID-19, nine subjects (9/66, 13.63%) had peak serum cortisol < 496.62 nmol/L suggestive of adrenal insufficiency (AI). SST peak serum cortisol levels did not differ significantly across the disease severity [Mild, (628.50 ± 214.65 nmol/L) vs moderate, [603.39 ± 161.95 nmol/L) vs severe, (597.59 ± 163.05 nmol/L), P = 0.617]. Six subjects with AI came for follow-up at 12 months, and all had normal HPA axis. Conclusion HPA axis is affected in 13.63% (9/66) of subjects at least 3 months after recovery from COVID-19 infection. AI in COVID-19 might be transient and would recover spontaneously. These findings have important implications for the clinical care and long-term follow-up of subjects after COVID-19 infection.

Ectopic Eruption of the Maxillary Permanent First Molar: A Brief Review and Clinical Case Report

The Ectopic Eruption of the Maxillary Permanent First Molar (EEMPFM) is an eruption anomaly, characterized for the maxillary permanent first molar’s impaction in the distal surface of the deciduous second molar. The etiology is related with change of the axial axis of eruption of the permanent first molar associated with missing space in the maxilla. The diagnosis is the combination of clinical and complementary examination. There are two types of Ectopic Eruption: the reversible and the irreversible. The irreversible type requires orthodontics treatment, because it causes root resorption of the deciduous second molar, causing its premature loss. For the treatment, procedures can be used with the aim of promoting distal inclination of the ectopic first molar, using separator elastics, removable or fixed appliances. The aim of this work is to report a clinical case of a patient of 9 years and 6 months old, female gender, who attended the Clinic presenting EEMPFM of the maxillary right permanent first molar. The treatment was a removable appliance composed with an acrylic base plate with clasps and a finger spring activated against a resin button bonded on the mesiobuccal cusp of the maxillary right permanent first molar. The correction of this anomaly was obtained with 35 days of treatment. Therefore, the sequence of procedures from diagnosis to the indication of an adequate treatment method is fundamental to obtain satisfactory results.

The Perturbed Full Two-body Problem: Application to Post-DART Didymos

With the successful impact of the NASA Double Asteroid Redirection Test (DART) spacecraft in the Didymos–Dimorphos binary asteroid system, we provide an initial analysis of the post-impact perturbed binary asteroid dynamics. To compare our simulation results with observations, we introduce a set of “observable elements” calculated using only the physical separation of the binary asteroid, rather than traditional Keplerian elements. Using numerical methods that treat the fully spin–orbit-coupled dynamics, we estimate the system’s mass and the impact-induced changes in orbital velocity, semimajor axis, and eccentricity. We find that the changes to the mutual orbit depend strongly on the separation distance between Didymos and Dimorphos at the time of impact. If Dimorphos enters a tumbling state after the impact, this may be observable through changes in the system’s eccentricity and orbit period. We also find that any DART-induced reshaping of Dimorphos would generally reduce the required change in orbital velocity to achieve the measured post-impact orbit period, and will be assessed by the ESA Hera mission in 2027.

CYCLICAL CONNECTION BETWEEN TRANSGENERATIONAL TRAUMA, HOSTILE ENVIRONMENT, EPIGENETIC MECHANISMS AND CORTISOL HORMONE

This narrative review demonstrates the close connection between the impact of traumas experienced across generations, added to an environment of unpredictability during an organism’s life history. The effects of trauma can be passed on to subsequent generations through epigenetic mechanisms and changes in the stress response axis, sensitivity to glucocorticoid receptors, and cortisol release. When associated, they form a line of continuous cause and effect in the life history of the individuals involved and their future generations, favoring new environments of unpredictability and risks that lead to more adverse situations and traumas. Consequently, descendants and nearby people can be impacted by cascading effects related to existing difficulties in environments considered hostile or unpredictable.

Clinicoradiological Risk Factors Associated with Inability to Achieve Minimum Clinically Important Difference in Operated Cases of Cervical Spondylotic Myelopathy.

This is a retrospective cohort study. This study aimed to identify the clinicoradiological risk factors associated with the inability to achieve minimum clinically important difference (MCID) on the modified Japanese Orthopaedic Association (mJOA) Scale in operated cases of cervical spondylotic myelopathy (CSM). Only a few studies have evaluated the outcomes of surgery performed for CSM using MCID on the mJOA scale. We analyzed 124 operated CSM cases from March 2019 to April 2021 for preoperative clinical features, cervical sagittal radiographic parameters, and magnetic resonance imaging (MRI) signal intensities (SI). The risk factors associated with missing the MCID (poor outcome) on mJOA at the final follow-up were identified using binary logistic regression. Multivariate analysis was used to find significant risk factors, and odds ratios (OR) were computed. A total of 110 men (89.2%) and 14 women (10.8%) with an average age of 53.5±13.2 years were included in the analysis. During the last follow-up, 89 cases (72.1%) achieved MCID (meaningful gains following surgery) while 35 (27.9%) could not. The final model identified the following parameters as significant risk factors for poor outcome: increased duration of symptoms (OR, 6.77; p=0.001), lower preoperative mJOA scale (OR, 0.75; p=0.029), the presence of multilevel T2-weighted (T2W) MRI SI (OR, 4.79; p=0.004), and larger change in cervical sagittal vertical axis (ΔcSVA) (OR, 1.06; p=0.013). Also, an increase in cSVA postoperatively correlated with a reduced functional recovery rate (r=-0.4, p<0.001). Surgery for CSM leads to significant functional benefits. However, poorer outcomes are observed in cases of greater duration of symptoms, higher preoperative severity with multilevel T2W MRI SI, and a larger increase in the postoperative cSVA (sagittal imbalance).

The role of gut-brain axis in a rotenone-induced rat model of Parkinson's disease

Parkinson's disease (PD) is a widespread neurodegenerative condition affecting millions globally. This investigation centered on the gut-brain axis in a rotenone-induced PD rat model. Researchers monitored behavioral shifts, histological modifications, neurodegeneration, and inflammation markers throughout the rats' bodies. Results revealed that rotenone-treated rats displayed reduced exploration (p = 0.004) and motor coordination (p < 0.001), accompanied by decreased Nissl staining and increased alpha-synuclein immunoreactivity in the striatum (p = 0.009). Additionally, these rats exhibited weight loss (T3, mean = 291.9 ± 23.67; T19, mean = 317.5 ± 17.53; p < 0.05) and substantial intestinal histological alterations, such as shortened villi, crypt architecture loss, and inflammation. In various regions, researchers noted elevated immunoreactivity to ionized binding adapter molecule (IBA)-1 (p < 0.05) and reduced immunoreactivity to glial fibrillary acidic protein (p < 0.05) and S100B (p < 0.001), indicating altered glial cell activity. Overall, these findings imply that PD is influenced by gut-brain axis changes and may originate in the intestine, impacting bidirectional gut-brain communication.

Biomechanics of transverse axis of medial longitudinal arch of children's foot based on 3D scanning.

To explore the application value of 3D scanning to obtain the parameters of transverse axis of medial longitudinal arch of foot in the biomechanical evaluation of transverse axis of medial longitudinal arch of foot in children. The feet of children with flat foot, normal foot and high arched foot were scanned with the Foot Secret 3D scanner in the sitting and standing positions. The scanning data were imported into CATIA v5 software for measurement, to obtain four parameters of transverse axis of medial longitudinal arch from transverse arch angle, external transverse arch angle, curvature and transverse arch cross-sectional area. There were statistically significant difference in transverse arch angle, external transverse arch angle and cross-sectional area between sitting and standing positions (p < 0.05). There were statistically significant differences in transverse arch angle, external transverse arch angle, curvature and transverse arch cross-sectional area among children with flat foot, normal foot and high arch foot (p < 0.05). The four parameters of transverse arch angle, external transverse arch angle, maximum curvature and cross-sectional area obtained by three-dimensional scanning can detect the changes of transverse axis of children's foot arch in different body positions with different foot types, which can be effectively used for the biomechanical evaluation of transverse axis of children's foot arch.

Strain and voltage control of the magnetic anisotropy in Co2MnSi thin film

The strain effect on the magnetic anisotropy (MA) in free-standing Co2MnSi(001) thin film and the voltage control MA in Au-capped MgO/Co2MnSi thin film are investigated within the framework of density functional theory. We find that the MA of free-standing film with MnSi-termination is sensitive upon strain, while the magnetic easy axis changes from in-plane to out-of-plane under the applied in-plane 1% extension strain. The MA of Au-capped Co2MnSi/MgO shows a ∧-shaped electric-field dependence and a large voltage-controlled MA value (VCMA) of 225 fJ (Vm)−1. The VCMA is caused by the change of the spin-flip term, which is related to the energy shift of the Co dz 2 minority-spin band near the Fermi level. Based on this study, it is expected that Co2MnSi can potentially be used in magnetoelectric spintronic devices.

Two-dimensional 4f magnetic EuSn2X2 (X = P, As) monolayers: A first-principles study

Two-dimensional (2D) ferromagnetic semiconductors (FMSs) hold exciting and promising potential for application in spintronic devices at the nanoscale. Currently, most 2D FMSs are based on 3d electrons; 4f electrons can provide nontrivial magnetism but have been much less studied to date. This paper presents a theoretical study, via first-principles calculations, of EuSn2X2 (X = P, As) monolayers based on rare-earth cations with f-electrons. The results show that EuSn2X2 monolayers possess a large magnetization (7 μB/Eu), a controllable magnetic anisotropy energy, and a unique d-electron-mediated f–f exchange mechanism. Both types of EuSn2X2 (X = P, As) monolayers are FMSs with indirect bandgaps of 1.00 and 0.99 eV, respectively, based on the Heyd–Scuseria–Ernzerhof (HSE06) method, which can be transform to direct bandgap semiconductors under biaxial strain. Interestingly, under the latter, spin–orbit coupling interaction gradually replaces the dipole–dipole interaction in the dominant position of magnetic anisotropy, resulting in the magnetic easy axis changing from in-plane to the more desirable out-of-plane. Considering their excellent dynamic, thermal, and mechanical stabilities and small cleavage energy, these EuSn2X2 monolayers can be exfoliated from their synthesized bulk. Our study not only helps to understand the properties of 2D 4f rare-earth magnets but also signposts a route toward improving the performance of EuSn2X2 monolayers in nano-electronic devices.

Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS

Constraining the physical and chemical structure of young embedded disks is crucial for understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program, we present high spatial resolution (∼0.″1 or ∼15 au) observations of the 1.3 mm continuum and 13CO J = 2–1, C18O J = 2–1, and SO J N = 65–54 molecular lines toward the disk around the Class I protostar L1489 IRS. The continuum emission shows a ring-like structure at 56 au from the central protostar and tenuous, optically thin emission extending beyond ∼300 au. The 13CO emission traces the warm disk surface, while the C18O emission originates from near the disk midplane. The coincidence of the radial emission peak of C18O with the dust ring may indicate a gap-ring structure in the gaseous disk as well. The SO emission shows a highly complex distribution, including a compact, prominent component at ≲30 au, which is likely to originate from thermally sublimated SO molecules. The compact SO emission also shows a velocity gradient along a direction tilted slightly (∼15°) with respect to the major axis of the dust disk, which we interpret as an inner warped disk in addition to the warp around ∼200 au suggested by previous work. These warped structures may be formed by a planet or companion with an inclined orbit, or by a gradual change in the angular momentum axis during gas infall.