Anisotropic 2D van der Waals Magnets Hosting 1D Spin Chains.

The exploration of 1D magnetism, frequently portrayed as spin chains, constitutes an actively pursued research field that illuminates fundamental principles in many-body problems and applications in magnonics and spintronics. The inherent reduction in dimensionality often leads to robust spin fluctuations, impacting magnetic ordering and resulting in novel magnetic phenomena. Here, structural, magnetic, and optical properties of highly anisotropic 2D van der Waals antiferromagnets that uniquely host spin chains are explored. First-principle calculations reveal that the weakest interaction is interchain, leading to essentially 1D magnetic behavior in each layer. With the additional degree of freedom arising from its anisotropic structure, the structure is engineered by alloying, varying the 1D spin chain lengths using electron beam irradiation, or twisting for localized patterning, and spin textures are calculated, predicting robust stability of the antiferromagnetic ordering. Comparing with other spin chain magnets, these materials are anticipated to bring fresh perspectives on harvesting low-dimensional magnetism.

Potential Role of Bone Scintigraphy in the Diagnosis of Calciphylaxis.

Nonosseous abnormalities are often seen on bone scans and can be related to a wide variety of pathology ranging across vascular, infection, and inflammatory etiology. Diffuse soft tissue radiotracer uptake on bone scans is typically attributed to renal or metabolic derangements. Calciphylaxis is the deposition of calcium in small blood vessels, skin, and other organs leading to vascular obstruction and skin necrosis. It is a rare disorder with unknown pathophysiology. Diagnosis of calciphylaxis is challenging and requires an interdisciplinary approach including clinical findings, laboratory results, medical imaging, and skin biopsy. An early diagnosis is important as the disease is associated with high morbidity and mortality. The purpose of this review article is to highlight the role of bone scintigraphy in the evaluation of calciphylaxis and to correlate the findings with other imaging modalities and histopathology.

A Randomised Controlled Trial Comparing Ketamine versus Fentanyl for Procedural Sedation in the Emergency Department for Adults with Isolated Extremity Injury.

Introduction: Alleviating pain and anxiety of patients during procedures is an essential skill for an Emergency Physician (EP). Several sedatives and dissociative agents are used for PSA (Procedural Sedation and Analgesia). In this study, we aimed to compare two drugs that is, ketamine and fentanyl for procedural sedation in adults with isolated limb injuries in the Emergency Department (ED). Materials and methods: In this prospective, randomised controlled interventional trial, patients aged between 18 to 65 years with isolated extremity injury requiring PSA in the ED were recruited. A total of 200 subjects were included in the study and randomly allocated to either the fentanyl (n=100) or the ketamine (n=100) group. Patients were blinded to the intervention and subsequently premedicated with Midazolam. Following this, they received either ketamine or fentanyl based on the group they were allocated to. Vital signs, including but not limited to the level of sedation, were measured at predetermined time intervals. A Modified Aldrete Score of >8 was used as a criterion for disposition from the ED. Data were collected in a pre-designed proforma. We aimed to compare the effectiveness as well as ascertain the safety profile of the two drugs for PSA in the ED. Results: There was no significant difference between the two groups when age, gender, mechanism of injury and comorbidities were compared. We found that there was no statistically significant difference between the two groups when blood pressure, respiratory rate and depth of sedation were compared. In both groups, there was a significant decrease in pain on the Numerical Rating Scale (NRS) following drug administration from 8 to 3 (p<0.001). Patients in the fentanyl group had an increased incidence of transient oxygen desaturation (p<0.001). Vomiting was more common in the ketamine group (p<0.001). Conclusion: PSA is a safe and efficacious procedure for patients undergoing painful procedures in ED. Patients in both the groups maintained hemodynamic stability throughout the procedure. From our study, we were able to conclude that both ketamine and fentanyl are similar in efficacy for PSA in the ED for adults with isolated limb injuries. In addition, no significant cardiovascular adverse events were noted in either group in our study.

Role of 18F-Fluorocholine Positron Emission Tomography (PET)/Computed Tomography (CT) in Diagnosis of Elusive Parathyroid Adenoma.

Accurate localization of parathyroid adenomas is paramount in hypercalcemia and elevated parathyroid hormone (PTH) levels. This narrative of a 56-year-old female diagnosed with primary hyperparathyroidism underscores the intricacies faced when conventional imaging falls short. Despite a series of diagnostic and surgical endeavors, including an initial nuclear sestamibi scan and diverse imaging examinations like ultrasound, 4D CT, and MRI, it was the 18F-Fluorocholine positron emission tomography (PET)/computed tomography (CT) scan that illuminated the presence of the elusive adenoma in the left para esophageal superior mediastinum. The surgical outcome reinforced the diagnosis, marking the resolution of the adenoma. This case accentuates the necessity of a multifaceted diagnostic methodology, especially in convoluted primary hyperparathyroidism presentations. It highlights the yet-to-be widely adopted 18F-Fluorocholine PET/CT scan, emphasizing its prospective significance awaiting Food and Drug Administration (FDA) endorsement.

Merkel Cell Carcinoma of the Left Cheek With Testicular Metastasis: An Uncommon Occurrence.

Merkel cell carcinoma (MCC) is an infrequent and aggressive neuroendocrine tumor of the skin. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is an effective imaging technique with good diagnostic accuracy that may be used to help stage MCC and for detecting unexpected recurrences and distant metastatic disease. Other causes of testicular neoplasms, such as primary testicular tumors, lymphomas, or anaplastic small cell melanomas, are difficult to differentiate from MCC testicular metastases on imaging, and tumor markers and histopathology will help confirm it. The current case is a 65-year-old non-immunocompromised male with Merkel cell carcinoma who was incidentally identified with testicular metastases on PET/CT and confirmed on histopathology.

Ubiquitous Superconducting Diode Effect in Superconductor Thin Films.

The macroscopic coherence in superconductors supports dissipationless supercurrents that could play a central role in emerging quantum technologies. Accomplishing unequal supercurrents in the forward and backward directions would enable unprecedented functionalities. This nonreciprocity of critical supercurrents is called the superconducting (SC) diode effect. We demonstrate the strong SC diode effect in conventional SC thin films, such as niobium and vanadium, employing external magnetic fields as small as 1 Oe. Interfacing the SC layer with a ferromagnetic semiconductor EuS, we further accomplish the nonvolatile SC diode effect reaching a giant efficiency of 65%. By careful control experiments and theoretical modeling, we demonstrate that the critical supercurrent nonreciprocity in SC thin films could be easily accomplished with asymmetrical vortex edge and surface barriers and the universal Meissner screening current governing the critical currents. Our engineering of the SC diode effect in simple systems opens the door for novel technologies while revealing the ubiquity of the Meissner screening effect induced SC diode effect in superconducting films, and it should be eliminated with great care in the search for exotic superconducting states harboring finite-momentum Cooper pairing.

Strain-tunable Berry curvature in quasi-two-dimensional chromium telluride.

Magnetic transition metal chalcogenides form an emerging platform for exploring spin-orbit driven Berry phase phenomena owing to the nontrivial interplay between topology and magnetism. Here we show that the anomalous Hall effect in pristine Cr2Te3 thin films manifests a unique temperature-dependent sign reversal at nonzero magnetization, resulting from the momentum-space Berry curvature as established by first-principles simulations. The sign change is strain tunable, enabled by the sharp and well-defined substrate/film interface in the quasi-two-dimensional Cr2Te3 epitaxial films, revealed by scanning transmission electron microscopy and depth-sensitive polarized neutron reflectometry. This Berry phase effect further introduces hump-shaped Hall peaks in pristine Cr2Te3 near the coercive field during the magnetization switching process, owing to the presence of strain-modulated magnetic layers/domains. The versatile interface tunability of Berry curvature in Cr2Te3 thin films offers new opportunities for topological electronics.

Sensing the Local Magnetic Environment through Optically Active Defects in a Layered Magnetic Semiconductor.

Atomic-level defects in van der Waals (vdW) materials are essential building blocks for quantum technologies and quantum sensing applications. The layered magnetic semiconductor CrSBr is an outstanding candidate for exploring optically active defects because of a direct gap, in addition to a rich magnetic phase diagram, including a recently hypothesized defect-induced magnetic order at low temperature. Here, we show optically active defects in CrSBr that are probes of the local magnetic environment. We observe a spectrally narrow (1 meV) defect emission in CrSBr that is correlated with both the bulk magnetic order and an additional low-temperature, defect-induced magnetic order. We elucidate the origin of this magnetic order in the context of local and nonlocal exchange coupling effects. Our work establishes vdW magnets like CrSBr as an exceptional platform to optically study defects that are correlated with the magnetic lattice. We anticipate that controlled defect creation allows for tailor-made complex magnetic textures and phases with direct optical access.

Ultra-high performance liquid chromatography Q-Orbitrap MS/MS-based profiling and quantification of limonoids in Meliaceae plants.

Meliaceae plants have been extensively used in agriculture, folklore, and traditional medicine. They are the major storehouses for structurally diverse limonoids (meliacins) possessing various bioactivities like antifeedant, insecticidal, antimicrobial, etc. However accurate detection of these tetranortriterpenes from the vast pool of metabolites in plant tissue extracts or biological sample is a crucial challenge. Though the mass spectrum (MS) provides the molecular mass and the corresponding elemental composition, it cannot be relied precisely. The exact identification of a specific metabolite demands the MS/MS spectrum containing the signature product ions. In the present study, we have developed the UHPLC Q-Orbitrap-based method for identification, quantification, and characterization of limonoids in different plant tissue extracts requiring minimum plant material. Using this method, we carried out the limonoid profiling in different tissue extracts of sixteen Meliaceae plants and the identification of limonoids was performed by comparing the retention time (RT), ESI-( +)-MS spectrum, and HCD-MS/MS of the purified fifteen limonoids used as reference standards. Our results revealed that early intermediates of the limonoid biosynthetic pathway such as azadiradione, epoxyazadiradione, and gedunin occurred more commonly in Meliaceae plants. The MS/MS spectrum library of the fifteen limonoids generated in this study can be utilized for identification of these limonoids in other plant tissue extracts, botanical fertilizers, agrochemical formulations, and bio pesticides.

A Van der Waals Interface Hosting Two Groups of Magnetic Skyrmions.

Multiple magnetic skyrmion phases add an additional degree of freedom for skyrmion-based ultrahigh-density spin memory devices. Extending the field to 2D van der Waals magnets is a rewarding challenge, where the realizable degree of freedoms (e.g., thickness, twist angle, and electrical gating) and high skyrmion density result in intriguing new properties and enhanced functionality. In this work, a van der Waals interface, formed by two 2D ferromagnets Cr2 Ge2 Te6 and Fe3 GeTe2 with a Curie temperature of ≈65 and ≈205 K, respectively, hosting two groups of magnetic skyrmions, is reported. Two sets of topological Hall effect signals are observed below 6s0 K when Cr2 Ge2 Te6 is magnetically ordered. These two groups of skyrmions are directly imaged using magnetic force microscopy, and supported by micromagnetic simulations. Interestingly, the magnetic skyrmions persist in the heterostructure with zero applied magnetic field. The results are promising for the realization of skyrmionic devices based on van der Waals heterostructures hosting multiple skyrmion phases.

18F-FDG PET/CT Imaging Features of Cardiac Arrhythmia in a Patient Treated with Panitumumab.

Panitumumab is a new humanized antiepidermal growth factor receptor monoclonal antibody (mAb) approved for the treatment of advanced colorectal cancer. There is an increase in the use of this drug due to a good response rate and possible secondary resection in advanced colorectal cancer. Here, we present 18F-FDG PET/CT imaging findings of cardiac arrhythmia in a patient receiving panitumumab for the treatment of metastatic infiltrating rectal adenocarcinoma. Cardiotoxicity is a known adverse effect associated with panitumumab. So far, to our knowledge, no documented imaging findings for the same are available in the literature.

Large Enhancement of Critical Current in Superconducting Devices by Gate Voltage.

Significant control over the properties of a high-carrier density superconductor via an applied electric field has been considered infeasible due to screening of the field over atomic length scales. Here, we demonstrate an enhancement of up to 30% in critical current in a back-gate tunable NbN micro- and nano superconducting bridges. Our suggested plausible mechanism of this enhancement in critical current based on surface nucleation and pinning of Abrikosov vortices is consistent with expectations and observations for type-II superconductor films with thicknesses comparable to their coherence length. Furthermore, we demonstrate an applied electric field-dependent infinite electroresistance and hysteretic resistance. Our work presents an electric field driven enhancement in the superconducting property in type-II superconductors which is a crucial step toward the understanding of field-effects on the fundamental properties of a superconductor and its exploitation for logic and memory applications in a superconductor-based low-dissipation digital computing paradigm.

Extra storage capacity in transition metal oxide lithium-ion batteries revealed by in situ magnetometry.

In lithium-ion batteries (LIBs), many promising electrodes that are based on transition metal oxides exhibit anomalously high storage capacities beyond their theoretical values. Although this phenomenon has been widely reported, the underlying physicochemical mechanism in such materials remains elusive and is still a matter of debate. In this work, we use in situ magnetometry to demonstrate the existence of strong surface capacitance on metal nanoparticles, and to show that a large number of spin-polarized electrons can be stored in the already-reduced metallic nanoparticles (that are formed during discharge at low potentials in transition metal oxide LIBs), which is consistent with a space charge mechanism. Through quantification of the surface capacitance by the variation in magnetism, we further show that this charge capacity of the surface is the dominant source of the extra capacity in the Fe3O4/Li model system, and that it also exists in CoO, NiO, FeF2 and Fe2N systems. The space charge mechanism revealed by in situ magnetometry can therefore be generalized to a broad range of transition metal compounds for which a large electron density of states is accessible, and provides pivotal guidance for creating advanced energy storage systems.

Self-care practices among type II diabetics in rural area of Kancheepuram district, Tamil Nadu.

INTRODUCTION: Type 2 diabetes mellitus is one of the most prevalent noncommunicable diseases in India. The acute and chronic complications of diabetes impact the physical, mental, and social well-being of the patients, thereby, placing a major burden on the health care system. Studies have shown that adequate self-care practices among the patients will facilitate good glycemic control and prevent complications. OBJECTIVES: To study the patterns of self-care practice among diabetic patients and the factors associated with them. METHODS: This descriptive cross-sectional study was carried out among 250 diabetics in the rural field practice area of a Tertiary Medical College and Hospital in Chennai. The participants were interviewed on their diabetic status and various components of self-care practices adopted from The Summary of Diabetes Self-care Activities (SDSCA) Measure. Adherence to medication was assessed by using Morisky Medication Adherence Scale-4 (MMAS-4). RESULTS: Our study observed that the overall prevalence of good self-care practices was very low (5.6%). Moderate self-care practices were prevalent in 42% of the study participants whereas the majority (52.4%) of the study population had poor self-care practices. In our study, the association between self-care activity with educational status and occupation was found to be statistically significant. Adherence was high for blood sugar testing (75.2%) and medication (70.4%) in the study population whereas adherence for foot care was poor (17.6%). CONCLUSION: Our study emphasized on the need for knowledge and awareness to be provided in rural areas regarding diabetes care management and self-care practices. Structured programs need to be planned to improve the attitude and practices of diabetic patients to promote better compliance towards diet, exercise, adherence to drugs, and appropriate foot care.

Signature of a pair of Majorana zero modes in superconducting gold surface states.

Under certain conditions, a fermion in a superconductor can separate in space into two parts known as Majorana zero modes, which are immune to decoherence from local noise sources and are attractive building blocks for quantum computers. Promising experimental progress has been made to demonstrate Majorana zero modes in materials with strong spin-orbit coupling proximity coupled to superconductors. Here we report signatures of Majorana zero modes in a material platform utilizing the surface states of gold. Using scanning tunneling microscope to probe EuS islands grown on top of gold nanowires, we observe two well-separated zero-bias tunneling conductance peaks aligned along the direction of the applied magnetic field, as expected for a pair of Majorana zero modes. This platform has the advantage of having a robust energy scale and the possibility of realizing complex designs using lithographic methods.

Toxicity evaluation of 6-mercaptopurine-Chitosan nanoparticles in rats.

BACKGROUND: The 6-mercaptopurine (6-MP) is an effective immunosuppressant and anti-cancer drug. However, the usage of 6-MP is limited due to its well-known side effects, such as myelotoxicity and hepato-renal toxicity. To curtail the potential toxic effects, we have used chitosan as a natural biodegradable and biocompatible polysaccharide to synthesize 6-Mercaptopurine-Chitosan Nanoparticles (6-MP-CNPs). METHODS: The 6-MP-CNPssize, morphology, physicochemical interactions, and thermal stability were characterized using Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC), respectively. The loading efficiency of the 6-MP in CNPs was estimated using LCMS/MS. Then, the 6-MP-CNPs were subjected to in vivo acute and sub-acute oral toxicity evaluations. RESULTS: The DLS and SEM analysis respectively indicated size (70.0 nm to 400.0 nm), polydispersity index (0.462), and zeta potential (54.9 mV) with improved morphology of 6-MP-CNPs. The FTIR and DSC results showed the efficient interactive and stable nature of the 6-MP-CNPs, which sustained the drug-delivery process. The loading efficiency of 6-MP-CNPs was found to be 25.23%. The chitosan improved the lethal dose (LD50 cut off) of 6-MP-CNPs (1000 mg/kg b.w) against 6-MP (500 mg/kg b.w) and also significantly (p ≤ 0.05) reduces the toxic adverse effect (28-day repeated oral dose) on hemato-biochemical and hepato-renal histological profiles. CONCLUSION: The findings suggest that chitosan, as a prime drug-delivery carrier, significantly alleviates the acute and sub-acute toxic effects of 6-MP.

Should 68Ga-DOTATATE PET/CT be Performed Routinely in Patients with Neuroendocrine Tumors Before Surgical Resection?

BACKGROUND: The only potential cure for neuroendocrine tumors (NETs) is operative resection, which may also offer a survival benefit for advanced disease. We aimed to assess the role of 68Ga-DOTATATE PET/CT in preoperative planning and compared its performance to CT with IV contrast and MRI with Eovist®, for abdominal NETs. METHODS: Records of patients who underwent 68Ga-DOTATATE PET/CT in addition to MRI with Eovist® and/or CT with IV contrast were retrospectively evaluated. The effect of imaging findings on surgical management and characteristics of detected lesions were analyzed. Descriptive statistics were used. RESULTS: Of 21 patients who underwent 68Ga-DOTATATE PET/CT prior to surgical resection, five (24%) had a change in surgical management due to findings. In three patients, 68Ga-DOTATATE PET/CT identified the primary tumor. In two patients, 68Ga-DOTATATE PET/CT helped clarify equivocal hepatic lesions seen on MRI with Eovist®. MRI with Eovist® had the highest number of lesions found (median 13, versus 9 on CT and 9.5 on 68Ga-DOTATATE PET/CT). DOTATATE-avid lesions were on average larger than lesions seen only on MRI with Eovist® (1.6 cm versus 0.6 cm, p = 0.0002). The optimal cutoff point for detection by 68Ga-DOTATATE PET/CT was a size of 0.95 cm, with a sensitivity of 56% and specificity of 98%. CONCLUSIONS: Preoperative 68Ga-DOTATATE PET/CT is useful only in a subset of patients undergoing surgical resection for NETs. MRI with Eovist® is superior at identifying liver metastases when compared to 68Ga-DOTATATE PET/CT and should therefore be used routinely before hepatic cytoreduction of NETs.

Toward the Absolute Spin-Valve Effect in Superconducting Tunnel Junctions.

A superconductor with a spin-split excitation spectrum behaves as an ideal ferromagnetic spin-injector in a tunneling junction. It was theoretically predicted that the combination of two such spin-split superconductors with independently tunable magnetizations may be used as an ideal absolute spin-valve. Here, we report on the first switchable superconducting spin-valve based on two EuS/Al bilayers coupled through an aluminum oxide tunnel barrier. The spin-valve shows a relative resistance change between the parallel and antiparallel configuration of the EuS layers up to 900% that demonstrates a highly spin-polarized current through the junction. Our device may be pivotal for realization of thermoelectric radiation detectors, a logical element for a memory cell in cryogenics, superconductor-based computers, and superconducting spintronics in general.

Dirac surface state-modulated spin dynamics in a ferrimagnetic insulator at room temperature.

This work demonstrates markedly modified spin dynamics of magnetic insulator (MI) by the spin momentum-locked Dirac surface states of the adjacent topological insulator (TI), which can be harnessed for spintronic applications. As the Bi concentration x is systematically tuned in 5-nm-thick (Bi x Sb1-x )2Te3 TI films, the weight of the surface relative to bulk states peaks at x = 0.32 when the chemical potential approaches the Dirac point. At this concentration, the Gilbert damping constant of the precessing magnetization in 10-nm-thick Y3Fe5O12 MI films in the MI/TI heterostructures is enhanced by an order of magnitude, the largest among all concentrations. In addition, the MI acquires additional strong magnetic anisotropy that favors the in-plane orientation with similar Bi concentration dependence. These extraordinary effects of the Dirac surface states distinguish TI from other materials such as heavy metals in modulating spin dynamics of the neighboring magnetic layer.