Understanding the re-entrant phase transition in a non-magnetic scheelite

The stereochemical activity of lone pair electrons plays a central role in determining the structural and electronic properties of both chemically simple materials such as H2O, as well as more complex condensed phases such as photocatalysts or thermoelectrics. TlReO4 is a rare example of a non-magnetic material exhibiting a re-entrant phase transition and emphanitic behavior in the long-range structure. Here, we describe the role of the Tl+ 6s2 lone pair electrons in these unusual phase transitions and illustrate its tunability by chemical doping, which has broad implications for functional materials containing lone pair bearing cations. First-principles density functional calculations clearly show the contribution of the Tl+ 6s2 in the valence band region. Local structure analysis, via neutron total scattering, revealed that changes in the long-range structure of TlReO4 occur due to changes in the correlation length of the Tl+ lone pairs. This has a significant effect on the anion interactions, with long-range ordered lone pairs creating a more densely packed structure. This resulted in a trade-off between anionic repulsions and lone pair correlations that lead to symmetry lowering upon heating in the long-range structure, whereby lattice expansion was necessary for the Tl+ lone pairs to become highly correlated. Similarly, introducing lattice expansion through chemical pressure allowed long-range lone pair correlations to occur over a wider temperature range, demonstrating a method for tuning the energy landscape of lone pair containing functional materials

Autonomous cortisol secretion in patients with primary aldosteronism: prevalence and implications on cardiometabolic profile and on surgical outcomes

Purpose: The aim of this study was to evaluate the prevalence of autonomous cortisol secretion (ACS) in patients with primary aldosteronism (PA) and its implications on cardiometabolic and surgical outcomes. Methods: This is a retrospective multicenter study of PA patients who underwent 1 mg dexamethasone-suppression test (DST) during diagnostic workup in 21 Spanish tertiary hospitals. ACS was defined as a cortisol post-DST >1.8 μg/dL (confirmed ACS if >5 μg/dL and possible ACS if 1.8–5 μg/dL) in the absence of spe cific clinical features of hypercortisolism. The cardiometabolic profile was compared with a control group with ACS without PA (ACS group) matched for age and DST levels. Results: The prevalence of ACS in the global cohort of patients with PA (n = 176) was 29% (ACS–PA; n = 51). Ten patients had confirmed ACS and 41 possible ACS. The cardiometabolic profile of ACS–PA and PA-only patients was simil ar, except for older age and larger tumor size of the adrenal lesion in the ACS–PA group. When comparing the ACS–PA group (n = 51) and the ACS group (n = 78), the prevalence of hypertension (OR 7.7 (2.64–22.32)) and cardiovascular events (OR 5.0 (2.29–11.07)) was higher in ACS–PA patients than in ACS patients. The coexistence of ACS in patien ts with PA did not affect the surgical outcomes, the proportion of biochemical cure and clinical cure being similar between ACS–PA and PA-only groups. Conclusion: Co-secretion of cortisol and aldosterone affects almost one-thi rd of patients with PA. Its occurrence is more frequent in patients with larger tumors and advanced age. However, the cardiometabolic and surgical outcomes of patients with ACS–PA and PA-only are similar