Altermagnetic lifting of Kramers spin degeneracy.

Lifted Kramers spin degeneracy (LKSD) has been among the central topics of condensed-matter physics since the dawn of the band theory of solids1,2. It underpins established practical applications as well as current frontier research, ranging from magnetic-memory technology3-7 to topological quantum matter8-14. Traditionally, LKSD has been considered to originate from two possible internal symmetry-breaking mechanisms. The first refers to time-reversal symmetry breaking by magnetization of ferromagnets and tends to be strong because of the non-relativistic exchange origin15. The second applies to crystals with broken inversion symmetry and tends to be comparatively weaker, as it originates from the relativistic spin-orbit coupling (SOC)16-19. A recent theory work based on spin-symmetry classification has identified an unconventional magnetic phase, dubbed altermagnetic20,21, that allows for LKSD without net magnetization and inversion-symmetry breaking. Here we provide the confirmation using photoemission spectroscopy and ab initio calculations. We identify two distinct unconventional mechanisms of LKSD generated by the altermagnetic phase of centrosymmetric MnTe with vanishing net magnetization20-23. Our observation of the altermagnetic LKSD can have broad consequences in magnetism. It motivates exploration and exploitation of the unconventional nature of this magnetic phase in an extended family of materials, ranging from insulators and semiconductors to metals and superconductors20,21, that have been either identified recently or perceived for many decades as conventional antiferromagnets21,24,25.

Physicochemical and Biological Evaluation of Curdlan-Poly(Lactic-Co-Glycolic Acid) Nanoparticles as a Host-Directed Therapy Against Mycobacterium Tuberculosis.

Nanoparticles (NPs) that can activate macrophages infected with the tuberculosis causative pathogen Mycobacterium tuberculosis, could be an effective host directed therapy for the disease. In this study, curdlan was conjugated to poly(lactic-co-glycolic acid) (PLGA) to produce immunotherapeutic NPs. Various physicochemical characterizations were used to evaluate the curdlan-PLGA copolymer and the NPs. Molecular dynamics and simulation studies were used to characterize the interaction between curdlan, on the polymer and on NPs, with the Dectin-1 macrophage receptor. NPs with varying curdlan densities were evaluated for their effects on the production of pro- and anti-inflammatory cytokines in M. tuberculosis infected RAW264.7 macrophages. The killing efficacy of the NPs against intracellular M. tuberculosis was assessed. Physicochemical characterization of the curdlan-PLGA copolymer and NPs indicated successful formation of curdlan-PLGA copolymer and NPs of varying curdlan density (0-8% w/w) had sizes between 330 and 453 nm. Modelling studies showed curdlan to have a strong affinity for Dectin-1. Cytotoxicity assays showed the NPs to be non-toxic over 72 h. The proinflammatory cytokine TNF-α was found to be significantly upregulated by the NPs. The NPs reduced intracellular M. tuberculosis burden over 72 h. These NPs are a promising host directed therapy for intracellular eradication of M. tuberculosis.

YouTube as a source of medical information about epidural analgesia for labor pain.

BACKGROUND: Large gaps remain in our understanding of the role of social media platforms in the dissemination of medical information. This cross-sectional study quantitatively assessed the accuracy and quality of information on YouTube regarding epidural labor analgesia. METHODS: YouTube was searched on May 23, 2020 using keywords 'epidural,' 'epidural for labor,' 'epidural for pregnancy,' 'epidural experience,' and 'epidural risks,' and the top 50 viewed videos from each search were screened. Primary outcomes included the proportion of videos containing non-factual information, and video quality analyzed using the modified DISCERN (mDISCERN) score. RESULTS: Thirteen of 60 (21.7%) videos included non-factual information about epidural analgesia; these videos were viewed more than 16.5 million times (60% of total viewership of the videos analyzed). Mean (standard deviation) mDISCERN score for all included videos was 1.9 (1.3), which is below the threshold for high video-quality. Videos from medical sources (hospitals, medical practices, physicians, other medical professionals) had a higher mDISCERN score compared with videos by non-medical sources (P <0.001). Educational videos from professional societies of obstetrics or obstetric anesthesiology were not captured. CONCLUSION: YouTube is an accessible platform for medical information on epidural labor analgesia, although a significant proportion of videos studied contained non-factual information and presented low video quality. Increased efforts by reputable sources including hospitals, physicians, other medical professionals, and professional societies, to disseminate accurate information, are warranted.

Néel Vector Induced Manipulation of Valence States in the Collinear Antiferromagnet Mn2Au.

The coupling of real and momentum space is utilized to tailor electronic properties of the collinear metallic antiferromagnet Mn2Au by aligning the real space Néel vector indicating the direction of the staggered magnetization. Pulsed magnetic fields of 60 T were used to orient the sublattice magnetizations of capped epitaxial Mn2Au(001) thin films perpendicular to the applied field direction by a spin-flop transition. The electronic structure and its corresponding changes were investigated by angular-resolved photoemission spectroscopy with photon energies in the vacuum-ultraviolet, soft, and hard X-ray range. The results reveal an energetic rearrangement of conduction electrons propagating perpendicular to the Néel vector. They confirm previous predictions on the origin of the Néel spin-orbit torque and anisotropic magnetoresistance in Mn2Au and reflect the combined antiferromagnetic and spin-orbit interaction in this compound leading to inversion symmetry breaking.

Standardizing the approach to late onset sepsis in neonates through antimicrobial stewardship: a quality improvement initiative.

BACKGROUND: Antibiotics are the most prescribed medication in the neonatal intensive care unit (NICU) and there is marked variation in their use. While they are vital for treatment of infections, they put infants at risk for infections with drug resistant organisms, alteration in their microbiome and several other morbidities. Specific guidelines for neonates are often lacking and our NICU is not compliant with late onset sepsis (LOS) guidelines. OBJECTIVE: By January 2019, there will be >75% compliance with our LOS bundle for any infant admitted to Tampa General Hospital's (TGH) NICU undergoing a LOS evaluation at >72 h of life. The bundle includes documented reason for LOS evaluation, appropriate initial antibiotic selection, appropriate initial evaluation considered, and appropriate de-escalation of antibiotics. STUDY DESIGN: The project was implemented in the NICU at TGH, the academic medical center affiliated with the University of South Florida in Tampa, FL. The multidisciplinary antimicrobial stewardship (ASP) team responsible for the project consists of a neonatology attending, three neonatology fellows, a pediatric infectious disease attending, and two NICU pharmacists. The project was started in January 2017 and all data were collected prospectively. We implemented multiple Plan-Do-Study-Act cycles in a stepwise manner; outcome measures included compliance with the LOS bundle and ASP team recommendations. Our process measures were the documented reason for sepsis evaluation, appropriate initial evaluation considered, appropriate antibiotic selection and appropriate antibiotic de-escalation. Patient length of stay was the balancing measure studied. RESULTS: During this 20-month initiative, there were 232 infants who underwent LOS evaluation and there were 98 true positive cultures from blood (28%), urine (35%), and cerebrospinal fluid (3%). Commonly documented rationales for treatment of culture negative sepsis were clinical pneumonia (38%) and necrotizing enterocolitis (38%). Common indications for LOS evaluations were increased respiratory support (51%) and abdominal distension (17%). There was improvement in appropriate initial antibiotic selection (70% vs. 94%); appropriate consideration of initial evaluation (63% vs. 94%, respectively); appropriate de-escalation of antibiotics (86% vs. 100%, respectively) and increase in LOS bundle compliance (44% vs. 87%, respectively). The overall antibiotic utilization rate and length of treatment did not change significantly. CONCLUSIONS: Developing and engaging a NICU ASP team improves compliance with late onset sepsis guidelines through the implementation of a LOS bundle of care.

Economic burden of specific learning disability: A prevalence-based cost of illness study of its direct, indirect, and intangible costs.

Aims: The primary objective of the present study was to evaluate the economic burden of specific learning disability (SpLD) by estimating its direct, indirect, and intangible costs. A secondary objective was to assess the impact of variables on the economic burden. Settings and Design: Cross-sectional single-arm descriptive study. Setting: Learning disability clinic in a public medical college in Mumbai. Subjects and Methods: The study cases (aged ≥8 years) were recruited by non-probability sampling. A structured questionnaire was used to interview the parent/guardian to collect data related to direct and indirect costs. Intangible costs data were collected by documenting the willingness-to-pay value using the contingent valuation technique. Statistical Analysis Used: A quantile regression model was used to assess the impact of predictor variables on the costs. Results: The direct, indirect, and intangible costs due to SpLD were Indian Rupees (INR) 5,936,053, 29,261,220, and 42,295,000, respectively. Indirect costs comprised 83.1% of the total costs. Expenditure on tuitions and remedial education comprised 61.61% and 64.39% of the indirect and direct costs, respectively. The average annual learning disability clinic costs were INR 2,169,888. The average annual total costs per student were INR 90,773. Longer duration of poor school performance was predictive of higher direct, indirect, and total costs; and higher socioeconomic status was predictive of lower intangible costs. Conclusion: SpLD is a cost-intensive disability (intangible > indirect > direct costs). Tuitions, which are not the therapy for SpLD, are the most costly component of indirect costs. Remedial education is the most costly component of direct costs.

Robust Bain distortion in the premartensite phase of a platinum-substituted Ni2MnGa magnetic shape memory alloy.

The premartensite phase of shape memory and magnetic shape memory alloys (MSMAs) is believed to be a precursor state of the martensite phase with preserved austenite phase symmetry. The thermodynamic stability of the premartensite phase and its relation to the martensitic phase is still an unresolved issue, even though it is critical to the understanding of the functional properties of MSMAs. We present here unambiguous evidence for macroscopic symmetry breaking leading to robust Bain distortion in the premartensite phase of 10% Pt-substituted Ni2MnGa. We show that the robust Bain-distorted premartensite (T2) phase results from another premartensite (T1) phase with preserved cubic-like symmetry through an isostructural phase transition. The T2 phase finally transforms to the martensite phase with additional Bain distortion on further cooling. Our results demonstrate that the premartensite phase should not be considered as a precursor state with the preserved symmetry of the cubic austenite phase.

Genetic Variants Identified from GWAS for Predisposition to Type 2 Diabetes Predict Sulfonylurea Drug Response.

BACKGROUND: Several SNPs were identified through GWAS for their association with type 2 diabetes which has implications to pancreatic ß-cell physiology. OBJECTIVE: We aimed to study the role of risk alleles of TCF7L2, KCNJ11, CDKN2A, CDKAL1, IGF2BP2, SLC30A8 and KCNQ1 along with pharmacokinetic variants in response to sulfonylureas. METHOD: We performed a prospective study on 209 newly diagnosed subjects; treatment naive T2D subjects were recruited. Individuals were started with glibenclamide monotherapy and followed-up for 12 weeks. Genotyping was done, using PCR-RFLP and TETRA-ARMS PCR and confirmed by DNA sequencing. RESULTS: In univariate regression analysis, KCNJ11 (rs5219) was only the predictor for glibenclamide treatment failure. CONCLUSION: The present data suggests a possible role of KCNJ11 gene in altered response to glibenclamide.

The Alfred Hospital experience of resumption of cardiac activity after withdrawal of life-sustaining therapy.

With the advent of donation after circulatory death programs in Australia and New Zealand, greater knowledge is needed about physiologic variation in haemodynamic activity following withdrawal of cardiorespiratory support. The ANZICS Statement on Death and Organ Donation allows provision for variation in the observation times between two and five minutes after cessation of the circulation prior to declaration of death. We report our experience of two cases, the first where electrical activity and pulse returned after a 102 second pause and the second where electrical activity returned after a three minute pause; both longer than previously reported cases.

Room-temperature tetragonal non-collinear Heusler antiferromagnet Pt2MnGa.

Antiferromagnetic spintronics is a rapidly growing field, which actively introduces new principles of magnetic storage. Despite that, most applications have been suggested for collinear antiferromagnets. In this study, we consider an alternative mechanism based on long-range helical order, which allows for direct manipulation of the helicity vector. As the helicity of long-range homogeneous spirals is typically fixed by the Dzyaloshinskii-Moriya interactions, bi-stable spirals (left- and right-handed) are rare. Here, we report a non-collinear room-temperature antiferromagnet in the tetragonal Heusler group. Neutron diffraction reveals a long-period helix propagating along its tetragonal axis. Ab-initio analysis suggests its pure exchange origin and explains its helical character resulting from a large basal plane magnetocrystalline anisotropy. The actual energy barrier between the left- and right-handed spirals is relatively small and might be easily overcome by magnetic pulse, suggesting Pt2MnGa as a potential candidate for non-volatile magnetic memory.