Quantum Oscillations in EuFe2As2 single crystals

Quantum oscillation measurements can provide important information about the Fermi surface (FS) properties of strongly correlated metals. Here, we report a Shubnikov-de Haas (SdH) effect study on the pnictide parent compounds EuFe$_{2}$As$_{2}$ (Eu122) and BaFe$_{2}$As$_{2}$ (Ba122) grown by In-flux. Although both members are isovalent compounds with approximately the same density of states at the Fermi level, our results reveal subtle changes in their fermiology. Eu122 displays a complex pattern in the Fourier spectrum, with band splitting, magnetic breakdown orbits, and effective masses sistematically larger when compared to Ba122, indicating that the former is a more correlated metal. Moreover, the observed pockets in Eu122 are more isotropic and 3D-like, suggesting an equal contribution from the Fe $3d$ orbitals to the FS. We speculate that these FS changes may be responsible for the higher spin-density wave ordering temperature in Eu122.Comment: 5 pages, 4 figure

Tumor-associated macrophages in gliomas—basic insights and treatment opportunities

Glioma refers to a group of primary brain tumors which includes glioblastoma (GBM), astrocytoma and oligodendroglioma as major entities. Among these, GBM is the most frequent and most malignant one. The highly infiltrative nature of gliomas, and their intrinsic intra- and intertumoral heterogeneity, pose challenges towards developing effective treatments. The glioma microenvironment, in addition, is also thought to play a critical role during tumor development and treatment course. Unlike most other solid tumors, the glioma microenvironment is dominated by macrophages and microglia—collectively known as tumor-associated macrophages (TAMs). TAMs, like their homeostatic counterparts, are plastic in nature and can polarize to either pro-inflammatory or immunosuppressive states. Many lines of evidence suggest that immunosuppressive TAMs dominate the glioma microenvironment, which fosters tumor development, contributes to tumor aggressiveness and recurrence and, very importantly, impedes the therapeutic effect of various treatment regimens. However, through the development of new therapeutic strategies, TAMs can potentially be shifted towards a proinflammatory state which is of great therapeutic interest. In this review, we will discuss various aspects of TAMs in the context of glioma. The focus will be on the basic biology of TAMs in the central nervous system (CNS), potential biomarkers, critical evaluation of model systems for studying TAMs and finally, special attention will be given to the potential targeted therapeutic options that involve the TAM compartment in gliomas.publishedVersio

A critical assessment of the pairing symmetry in NaxCoO2.yH2O

We examine each of the symmetry-allowed pairing states of NaxCoO2.yH2O and compare their properties to what is experimentally and theoretically established about the compound. In this way, we can eliminate the vast majority of states that are technically allowed and narrow the field to two, both of f-wave type states. We discuss the expected features of these states and suggest experiments that can distinguish between them. We also discuss odd-frequency gap pairing and how it relates to available experimental evidence

Impaired renal function is associated with greater urinary strong ion differences in critically ill patients with metabolic acidosis

Abstract Purpose: Urinary excretion of chloride corrects metabolic acidosis, but this may be hampered in patients with impaired renal function. We explored the effects of renal function on acid-base characteristics and urinary strong ion excretion using the Stewart approach in critically ill patients with metabolic acidosis. Materials and Methods: We examined the plasma and urine chemistry in 65 critically ill (mixed medical and surgical) patients with metabolic acidosis. The apparent strong ion difference, effective strong ion difference, strong ion gap, and urinary simplified strong ion difference (urinary SID) were calculated. Linear regression analyses were used (1) to assess whether plasma creatinine concentrations were related to urinary SIDs values, adjusted for blood pH levels, and (2) to determine whether urinary SID values were associated with blood pH levels. Results: Creatinine concentrations were positively and significantly (P b .001) associated with urinary SIDs values, adjusted for pH levels. Urinary simplified strong ion difference values were inversely and significantly (P b .001) related to pH levels. Conclusions: In critically ill patients with metabolic acidosis, impaired renal function was associated with greater urinary SIDs. Subsequently, the higher urinary SIDs values were related to lower pH levels, illustrating the importance of renal chloride excretion to correct for acidosis