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We study a graphene Hall probe located on top of a magnetic surface as a detector of skyrmions, using as working principle the anomalous Hall effect produced by the exchange interaction of the graphene electrons with the non-coplanar magnetization of the skyrmion. We study the magnitude of the effect as a function of the exchange interaction, skyrmion size and device dimensions. Our calculations for multiterminal graphene nanodevices, working in the ballistic regime, indicate that for realistic exchange interactions a single skyrmion would give Hall voltages well within reach of the experimental state of the art. The proposed device could act as an electrical transducer that marks the presence of a single skyrmion in a nanoscale region, paving the way towards the integration of skyrmion-based spintronics and graphene electronics.

We study the nature of spin excitations of individual transition metal atoms (Ti, V, Cr, Mn, Fe, Co and Ni) deposited on a Cu\\(_2\\)N/Cu(100) surface using both spin-polarized density functional theory (DFT) and exact diagonalization of an Anderson model derived from DFT. We use DFT to compare the structural, electronic and magnetic properties of different transition metal adatoms on the surface. We find that the average occupation of the transition metal d shell, main contributor to the magnetic moment, is not quantized, in contrast with the quantized spin in the model Hamiltonians that successfully describe spin excitations in this system. In order to reconcile these two pictures, we build a multi-orbital Anderson Hamiltonian for the d shell of the transition metal hybridized with the p orbitals of the adjacent Nitrogen atoms, by means of maximally localized Wannier function representation of the DFT Hamiltonian. The exact solutions of this model have quantized total spin, without quantized charge at the d shell. We propose that the quantized spin of the models actually belongs to many-body states with two different charge configurations in the d shell, hybridized with the p orbital of the adjacent Nitrogen atoms. This scenario implies that the measured spin excitations are not fully localized at the transition metal.

We report on the large-scale synthesis of highly oriented ultrathin MoO3 layers using a simple and low-cost atmospheric pressure by van der Waals epitaxy growth on muscovite mica substrates. By this method we are able to synthetize high quality centimeter-scale MoO3 crystals with thicknesses ranging from 1.4 nm (two layers) up to a few nanometers. The crystals can be easily transferred to an arbitrary substrate (such as SiO2) by a deterministic transfer method and extensively characterized to demonstrate the high quality of the resulting crystal. We also study the electronic band structure of the material by density functional theory calculations. Interestingly, the calculations demonstrate that bulk MoO3 has a rather weak electronic interlayer interaction and thus it presents a monolayer-like band structure. Finally, we demonstrate the potential of this synthesis method for optoelectronic applications by fabricating large-area field-effect devices (10 micrometers by 110 micrometers in lateral dimensions), finding responsivities of 30 mA/W for a laser power density of 13 mW/cm2 in the UV region of the spectrum and also as an electron acceptor in a MoS2-based field-effect transistor.

INTRODUCTION: Diagnosis of pleural infection (PI) may be challenging. The purpose of this paper is to develop and validate a clinical prediction model for the diagnosis of PI based on pleural fluid (PF) biomarkers. METHODS: A prospective study was conducted on pleural effusion. Logistic regression was used to estimate the likelihood of having PI. Two models were built using PF biomarkers. The power of discrimination (area under the curve) and calibration of the two models were evaluated. RESULTS: The sample was composed of 706 pleural effusion (248 malignant; 28 tuberculous; 177 infectious; 48 miscellaneous exudates; and 212 transudates). Areas under the curve for Model 1 (leukocytes, percentage of neutrophils, and C-reactive protein) and Model 2 (the same markers plus interleukin-6 [IL-6]) were 0.896 and 0.909, respectively (not significant differences). However, both models showed higher capacity of discrimination than their biomarkers when used separately (P < 0.001 for all). Rates of correct classification for Models 1 and 2 were 88.2% (623/706: 160/177 [90.4%] with infectious pleural effusion [IPE] and 463/529 [87.5%] with non-IPE) and 89.2% (630/706: 153/177 [86.4%] of IPE and 477/529 [90.2%] of non-IPE), respectively. CONCLUSIONS: The two predictive models developed for IPE showed a good diagnostic performance, superior to that of any of the markers when used separately. Although IL-6 contributes a slight greater capacity of discrimination to the model that includes it, its routine determination does not seem justified.

Obesity poses a global health challenge, demanding a deeper understanding of adipose tissue (AT) and its mitochondria. This study describes the role of the mitochondrial protein Methylation-controlled J protein (MCJ/DnaJC15) in orchestrating brown adipose tissue (BAT) thermogenesis. Here we show how MCJ expression decreases during obesity, as evident in human and mouse adipose tissue samples. MCJ KO mice, even without UCP1, a fundamental thermogenic protein, exhibit elevated BAT thermogenesis. Electron microscopy unveils changes in mitochondrial morphology resembling BAT activation. Proteomic analysis confirms these findings and suggests involvement of the eIF2α mediated stress response. The pivotal role of eIF2α is scrutinized by in vivo CRISPR deletion of eIF2α in MCJ KO mice, abrogating thermogenesis. These findings uncover the importance of MCJ as a regulator of BAT thermogenesis, presenting it as a promising target for obesity therapy. How adipose mitochondria activity is fine-tuned in response to obesity is an active area of study. Here, the authors show that mitochondrial protein MCJ can block thermogenesis and that silencing this gene can correct obesity-related comorbidities.

Dopamine signalling is a crucial part of the brain reward system and can affect feeding behaviour. Dopamine receptors are also expressed in the hypothalamus, which is known to control energy metabolism in peripheral tissues. Here we show that pharmacological or chemogenetic stimulation of dopamine receptor 2 (D2R) expressing cells in the lateral hypothalamic area (LHA) and the zona incerta (ZI) decreases body weight and stimulates brown fat activity in rodents in a feeding-independent manner. LHA/ZI D2R stimulation requires an intact sympathetic nervous system and orexin system to exert its action and involves inhibition of PI3K in the LHA/ZI. We further demonstrate that, as early as 3 months after the onset of treatment, patients treated with the D2R agonist cabergoline experience an increase in energy expenditure that persists for one year, leading to total body weight and fat loss through a prolactin-independent mechanism. Our results may provide a mechanistic explanation for how clinically used D2R agonists act in the central nervous system to regulate energy balance. Folgueira et al. show that dopamine signalling in the lateral hypothalamic area and the zona incerta reduces body weight and increases energy expenditure by increasing brown adipose tissue thermogenesis in rodents. Weight loss and increased energy expenditure were also observed in patients treated with a dopamine receptor 2 agonist.

BACKGROUND: Although pulmonary rehabilitation (PR) is recommended in patients with chronic obstructive pulmonary disease (COPD), there is a scarcity of data demonstrating the cost-effectiveness and effectiveness of PR in reducing exacerbations. METHODS: A quasi-experimental study in 200 patients with COPD was conducted to determine the number of exacerbations 1 year before and after their participation in a PR program. Quality of life was measured using the COPD assessment test and EuroQol-5D. The costs of the program and exacerbations were assessed the year before and after participation in the PR program. The incremental cost-effectiveness ratio (ICER) was estimated in terms of quality-adjusted life years (QALYs). RESULTS: The number of admissions, length of hospital stay, and admissions to the emergency department decreased after participation in the PR program by 48.2%, 46.6%, and 42.5%, respectively (P < 0.001 for all). Results on quality of life tests improved significantly (P < 0.001 for the two tests). The cost of PR per patient and the cost of pre-PR and post-PR exacerbations were €1867.7 and €7895.2 and €4201.9, respectively. The PR resulted in a cost saving of €1826 (total, €365,200) per patient/year, and the gain in QALYs was+0.107. ICER was −€17,056. The total cost was <€20,000/QALY in 78% of patients. CONCLUSIONS: PR contributes to reducing the number of exacerbations in patients with COPD, thereby slowing clinical deterioration. In addition, it is cost-effective in terms of QALYs.

In the southern cone of South America different haplotypes of Borrelia burgdorferi sensu lato (Bbsl) have been detected in Ixodes spp. from Argentina, southern Brazil, Chile, and Uruguay. So far, Lyme borreliosis has not been diagnosed in Uruguay and the medical relevance of the genus Ixodes in South America is uncertain. However, the growing number of new genospecies of Bbsl in the southern cone region and the scarce information about its pathogenicity, reservoirs and vectors, highlights the importance of further studies about spirochetes present in Uruguay and the region. The aim of this study was to determine the presence of Bbsl in Ixodes auritulus ticks collected from birds and vegetation in two localities of southeastern Uruguay. In total 306 I. auritulus were collected from 392 passerine birds sampled and 1110 ticks were collected by flagging in vegetation. Nymphs and females were analyzed for Borrelia spp. by PCR targeting the flagellin (fla) gene and the rrfA-rrlB intergenic spacer region (IGS). The phylogenetic analysis of Borrelia spp. positive samples from passerine birds and vegetation revealed the presence of four fla haplotypes that form a clade within the Bbsl complex. They were closely related to isolates of Borrelia sp. detected in I. auritulus from Argentina and Canada.

Twisted graphene bilayers develop highly localised states around AA-stacked regions for small twist angles. We show that interaction effects may induce either an antiferromagnetic (AF) and a ferromagnetic (F) polarization of said regions, depending on the electrical bias between layers. Remarkably, F-polarised AA regions under bias develop spiral magnetic ordering, with a relative \\(120^\\) misalignment between neighbouring regions due to a frustrated antiferromagnetic exchange. This remarkable spiral magnetism emerges naturally without the need of spin-orbit coupling, and competes with the more conventional lattice-antiferromagnetic instability, which interestingly develops at smaller bias under weaker interactions than in monolayer graphene, due to Fermi velocity suppression. This rich and electrically controllable magnetism could turn twisted bilayer graphene into an ideal system to study frustrated magnetism in two dimensions, with interesting potential also for a range of applications.