High Pressure Melting of Iron with Nonmetals Sulfur, Carbon, Oxygen, and Hydrogen: Implications for Planetary Cores

The earth's core consists of a solid metallic center surrounded by a liquid metallic outer layer. Understanding the compositions of the inner and outer cores allows us to better understand the dynamics of the earth's core, as well as the dynamics of the cores of other terrestrial planets and moons. The density and size of the earth's core indicate that it is approximately 90% metallic, predominantly iron, with about 10% light elements. Iron meteorites, believed to be the remnants of planetary cores, provide further constraints on the composition of the earth's core, indicating a composition of 86% iron, 4% nickel, and 10% light elements. Any potential candidate for the major light element core component must meet two criteria: first, it must have high cosmic abundances and second, it must be compatible with Fe. Given these two constraints there are five plausible elements that could be the major light element in the core: H, O, C, S, and Si. Of these five possible candidates this thesis focuses on S and C as well exploring the effect of minor amounts of O and H on the eutectic temperature in a Fe-FeS core. We look at two specific aspects of the Fe-FeS system: first, the shape of the liquidus as a function of pressure, second, a possible cause for the reported variations in the eutectic temperature, which draws on the effect of H and O. Finally we look at the effect of S and C on partitioning behavior of Ni, Pt, Re,Co, Os and W between cohenite and metallic liquid. We are interested in constraining the shape of the Fe-FeS liquidus because as a planet with a S-enriched core cools, the thermal and compositional evolution of its core is constrained by this liquidus. In Chapter 1 I present an equation that allows for calculation of the temperature along the liquidus as a function of pressure and composition for Fe-rich compositions and pressures from 1 bar to 10 GPa. One particularly interesting feature of the Fe -rich side of the Fe-FeS eutectic is the sigmoidal shape of the liquidus. This morphology indicates non-ideal liquid solution behavior and suggests the presence of a metastable solvus beneath the liquidus. An important consequence of such curved liquidi is that isobaric, uniform cooling requires substantial variations in the solidification rate of the core. Additionally, in bodies large enough for P variation within the core to be significant, solidification behavior is further complicated by the P dependence of the liquidus shape. Brett and Bell (1969) show that at 3 GPa, the liquidus curvature relaxes, implying that the liquid solution becomes more ideal. By 10 GPa, the liquidus approaches nearly ideal behavior (Chen et al., 2008b). However, at 14 GPa, the liquidus again assumes a sigmoidal curvature (Chen et al., 2008a; Chen et al., 2008b), suggesting a fundamental change in the thermodynamic behavior of the liquid. Chapter 1 of this thesis accounts for the observed complexity in the liquidus up to 10 GPa thus enabling more accurate modeling of the evolution of the cores of small planets (Buono and Walker, 2011). Accurately knowing the eutectic temperature for the Fe-FeS system is important because it places a minimum bound on the temperature of a S-enriched core that has a solid and liquid component which are in equilibrium. Unfortunately literature values for the 1 bar to 10 GPa eutectic temperature in the Fe-FeS system are highly variable making the estimation of core temperature, an important geodynamic parameter, very difficult. In Chapter 2 we look at a possible cause of this observed variation by experimentally investigating the effects of H on the eutectic temperature in the Fe-FeS system at 6 and 8 GPa. We find that H causes a decrease in the eutectic temperature (but that O does not) and that this decrease can explain some of the observed scatter in the available data. The effect of H on the eutectic temperature increases with increasing pressure (i.e. the eutectic temperature is more depressed at higher pressures), matching the trend reported for the Fe-FeS system (Fei et al., 1997). Our work suggests a significantly higher eutectic temperature than is commonly used in the Fe-S system and explains the lower observed eutectic temperatures by employing the ternary Fe-S-H system. Additionally, we report an equation which allows for accurate prediction of the composition of the eutectic in the Fe-FeS system. The constraints presented here (eutectic temperature in the Fe-FeS system are 990 °C up to at least 8 GPa in conjunction with the equation presented in Chapter 1, allows for complete prediction of the Fe-rich liquidus in the Fe-FeS system to 8 GPa. It is important to understand the partitioning behavior of trace elements between the solid and liquid components of a system because it fundamentally informs our understanding of that systems chemical evolution. In light of this, we investigate partitioning behavior in the context of the Fe-S-Ni-C system in Chapter 3. Choice of this system was motivated by work outside the scope of this thesis investigating the liquidus relationships in the Fe-S-C system (Dasgupta et al., 2009). In these experiments, cohenite (Fe3C) is the stable solid phase, instead of Fe-metal and we find that the partition coefficients between cohenite and Fe-C-S liquids are significantly lower than those between Fe-metal and Fe-S liquids. There are two potential situations to which this work can be applied. With respect to core formation, although it is unlikely that any planets entire inner core is carbide, it is possible that in a C-rich planet, as the Fe core crystallizes, C in the liquid phase could be enriched to the point where cohenite is a stable crystalizing phase. Under these circumstances, we would predict smaller depletions of the elements studied in the outer core than would be the case for Fe-metal crystallization. This work can also be applied to the earth's upper mantle which is thought to become Fe-Ni metal-saturated as shallow as 250 km. Under these circumstances, the sub-system Fe-Ni-C (diamond) -S (sulfide) becomes relevant and Fe-Ni carbide rather than metallic Fe-Ni alloy could become the crystalline phase of interest. Our study implies that if cohenite and Fe-C-S melt are present in the mantle, the mantle budget of Ni, Co, and Pt may be dominated by Fe-C-S liquid. Additionally, in the case of a S-free system, W, Re, and Os will also be slightly enriched in Fe-Ni-C liquid over cohenite. In total this body of work better constrains several key aspects of the compositional and thermal evolution of cores in small planetary bodies and has potential implications for the earth's mantle

Diagnosi molecolare di sindrome di Brugada in un giovane atleta mediante il sequenziamento di un pannello multigenico con tecniche di nuova generazione

Mutations in genes driving the molecular pathways that regulate myocardial functions can predispose to many independent cardiopathies and also to sudden cardiac death (SCD) even in asymptomatic subjects. The overlapping clinical signs or symptoms or even silent phenotypes make it difficult to diagnose these diseases, therefore the risk of undiagnosed disease could be high especially in young adults and athletes, which may then incur in SCD. We describe the case of a clinical asymptomatic eight-year-old child, practicing soccer game, who underwent a screening medical examination to undertake the path of an increasing physical activity to become a competitive athlete, where abnormal signs at ECG indicated a suspicion of an arrhythmogenic heart disease. Molecular screening analysis, to discriminate among the various predisposing gene alterations, was performed using a 75 gene-panel for arrhythmias customized in our laboratory. The child resulted carrier of a loss-of-function mutation in the SCN5A gene (c.1126C>T). About 25% of Brugada patients carry mutations in this gene coding for the cardiac sodium channel. The loss-of-function mutations in SCN5A gene induce alterations of sodium ion conduction in cardiomyocytes, compatible with the Brugada Syndrome. This case report highlights the importance of the implementation of a rapid, sensitive and wide molecular screening to shed light on possible genetic alterations present also in asymptomatic athletes with negative family history, which may often remain undiagnosed, thus exposed to high risk of sudden death

Low NT-proBNP levels in overweight and obese patients do not rule out a diagnosis of heart failure with preserved ejection fraction

Background Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome that presents clinicians with a diagnostic challenge. The use of natriuretic peptides to exclude a diagnosis of HFpEF has been proposed. We sought to compare HFpEF patients with N-terminal pro-brain natriuretic peptide (NT-proBNP) level above and below the proposed cut-off. Methods Stable patients (n = 30) with left ventricular (LV) ejection fraction ≥ 50% were eligible if they had a diagnosis of HF according to the European Society of Cardiology diagnostic criteria. Characteristics of patients with NT-proBNP below (≤125 pg/mL) and above (\u3e125 pg/mL) the diagnostic criterion were compared. Results There were 19 (66%) women with median age 54 years. Half were African American (16, 53%), and most were obese. There were no significant differences in clinical characteristics or medication use between groups. LV end-diastolic volume index was greater in high NT-proBNP patients (P = 0.03). Left atrial volume index, E/e\u27 ratio, and E/e\u27 ratio at peak exercise were not significantly different between NT-proBNP groups. Peak oxygen consumption (VO2), VO2 at ventilatory threshold, and ventilatory efficiency measures were impaired in all patients and were not significantly different between high and low NT-proBNP patients. Conclusions NT-proBNP was below the proposed diagnostic cut-off point of 125 pg/mL in half of this obese study cohort. Cardiac diastolic dysfunction and cardiorespiratory fitness were not significantly different between high and low NT-proBNP patients. These data indicate that excluding the diagnosis of HFpEF based solely on NT-proBNP levels should be discouraged

Efficacy and Safety of Neem Oil for the Topical Treatment of Bloodsucking Lice Linognathus stenopsis in Goats under Field Conditions

: The aim of the present study was to evaluate the efficacy and safety of neem oil on caprine pediculosis and on kids' growth performances. The neem (Azadirachta indica) belongs to the Meliaceae family, and in Eastern countries it is mainly considered for the insecticidal activities of the kernel oil. The neem seeds contain bioactive principles, such as azadirachtin A, salannin, nimbin, and nimbolide. The trial was carried out on 24 kids, 120 days old, maintained in open yards. Animals were divided in 4 homogeneous groups (n = 6 animals/group) based on age, louse count, body condition score (BCS) and live body weight: Control Group (C, saline NaCl, 0.9%), Neem Group 1 (NO-100, 100 mL of neem oil per 10 kg), Neem Group 2 (NO-200, 200 mL/10 kg), Neem Group 3 (NO-300, 300 mL/10 kg). The treatments were performed by spraying the insecticide on the goat's body. The study lasted 56 days, and weekly, the kids underwent louse count, BCS and body weight determination, and FAMACHA score. Data were analyzed by ANOVA for repeated measures. The species of lice identified was Linognathus stenopsis. Kids belonging to NO-200 and NO-300 showed a stronger reduction of louse count throughout the study (>95%). The daily weight gain recorded was significantly higher (p < 0.05) in NO-300 than C. No differences were found for BCS and FAMACHA scores. The results of this trial showed that the administration of neem oil to control caprine pediculosis caused by sucking lice represents an alternative to synthetic compounds

Effect of Interleukin-1 Blockade With Anakinra on Leukocyte Count in Patients With ST-Segment Elevation Acute Myocardial Infarction

Leukocytosis is a common finding in patients with ST elevation myocardial infarction (STEMI) and portends a poor prognosis. Interleukin 1-β regulates leukopoiesis and pre-clinical studies suggest that anakinra (recombinant human interleukin-1 [IL-1] receptor antagonist) suppresses leukocytosis in myocardial infarction. However, the effect of IL-1 blockade with anakinra on leukocyte count in patients with STEMI is unknown. We reviewed the white blood cell (WBC) and differential count of 99 patients enrolled in a clinical trial of anakinra (n = 64) versus placebo (n = 35) for 14 days after STEMI. A complete blood cell count with differential count were obtained at admission, and after 72 h, 14 days and 3 months. After 72 h from treatment, anakinra compared to placebo led to a statistically significant greater percent reduction in total WBC count (− 35% [− 48 to − 24] vs. − 21% [− 34 to − 10], P = 0.008), absolute neutrophil count (− 48% [− 60 to − 22] vs. − 27% [− 46 to − 5], P = 0.004) and to an increase in absolute eosinophil count (+ 50% [0 to + 100] vs. 0% [− 50 to + 62], P = 0.022). These changes persisted while on treatment at 14 days and were no longer apparent at 3 months after treatment discontinuation. We found that in patients with STEMI IL-1 blockade with anakinra accelerates resolution of leukocytosis and neutrophilia. This modulation may represent one of the mechanisms by which IL-1 blockade improves clinical outcomes

C-Reactive Protein and N-Terminal Pro-brain Natriuretic Peptide Levels Correlate With Impaired Cardiorespiratory Fitness in Patients With Heart Failure Across a Wide Range of Ejection Fraction

Background: Impaired cardiorespiratory fitness (CRF) is a hallmark of heart failure (HF). Serum levels of C-reactive protein (CRP), a systemic inflammatory marker, and of N-terminal pro-brain natriuretic peptide (NT-proBNP), a biomarker of myocardial strain, independently predict adverse outcomes in HF patients. Whether CRP and/or NT-proBNP also predict the degree of CRF impairment in HF patients across a wide range of ejection fraction is not yet established.Methods: Using retrospective analysis, 200 patients with symptomatic HF who completed one or more treadmill cardiopulmonary exercise tests (CPX) using a symptom-limited ramp protocol and had paired measurements of serum high-sensitivity CRP and NT-proBNP on the same day were evaluated. Univariate and multivariate correlations were evaluated with linear regression after logarithmic transformation of CRP (log10) and NT-proBNP (logN).Results: Mean age of patients was 57 ± 10 years and 55% were male. Median CRP levels were 3.7 [1.5–9.0] mg/L, and NT-proBNP levels were 377 [106–1,464] pg/ml, respectively. Mean peak oxygen consumption (peak VO2) was 16 ± 4 mlO2•kg−1•min−1. CRP levels significantly correlated with peakVO2 in all patients (R = −0.350, p &lt; 0.001) and also separately in the subgroup of patients with reduced left ventricular ejection fraction (LVEF) (HFrEF, N = 109) (R = −0.282, p &lt; 0.001) and in those with preserved EF (HFpEF, N = 57) (R = −0.459, p &lt; 0.001). NT-proBNP levels also significantly correlated with peak VO2 in all patients (R = −0.330, p &lt; 0.001) and separately in patients with HFrEF (R = −0.342, p &lt; 0.001) and HFpEF (R = −0.275, p = 0.032). CRP and NT-proBNP did not correlate with each other (R = 0.05, p = 0.426), but independently predicted peak VO2 (R = 0.421, p &lt; 0.001 and p &lt; 0.001, respectively).Conclusions: Biomarkers of inflammation and myocardial strain independently predict peak VO2 in HF patients. Anti-inflammatory therapies and therapies alleviating myocardial strain may independently improve CRF in HF patients across a large spectrum of LVEF

Interleukin‐1 Blockade Inhibits the Acute Inflammatory Response in Patients With ST‐Segment–Elevation Myocardial Infarction

Background ST‐segment–elevation myocardial infarction is associated with an intense acute inflammatory response and risk of heart failure. We tested whether interleukin‐1 blockade with anakinra significantly reduced the area under the curve for hsCRP (high sensitivity C‐reactive protein) levels during the first 14 days in patients with ST‐segment–elevation myocardial infarction (VCUART3 [Virginia Commonwealth University Anakinra Remodeling Trial 3]). Methods and Results We conducted a randomized, placebo‐controlled, double‐blind, clinical trial in 99 patients with ST‐segment–elevation myocardial infarction in which patients were assigned to 2 weeks treatment with anakinra once daily (N=33), anakinra twice daily (N=31), or placebo (N=35). hsCRP area under the curve was significantly lower in patients receiving anakinra versus placebo (median, 67 [interquartile range, 39–120] versus 214 [interquartile range, 131–394] mg·day/L; P\u3c0.001), without significant differences between the anakinra arms. No significant differences were found between anakinra and placebo groups in the interval changes in left ventricular end‐systolic volume (median, 1.4 [interquartile range, −9.8 to 9.8] versus −3.9 [interquartile range, −15.4 to 1.4] mL; P=0.21) or left ventricular ejection fraction (median, 3.9% [interquartile range, −1.6% to 10.2%] versus 2.7% [interquartile range, −1.8% to 9.3%]; P=0.61) at 12 months. The incidence of death or new‐onset heart failure or of death and hospitalization for heart failure was significantly lower with anakinra versus placebo (9.4% versus 25.7% [P=0.046] and 0% versus 11.4% [P=0.011], respectively), without difference between the anakinra arms. The incidence of serious infection was not different between anakinra and placebo groups (14% versus 14%; P=0.98). Injection site reactions occurred more frequently in patients receiving anakinra (22%) versus placebo (3%; P=0.016). Conclusions In patients presenting with ST‐segment–elevation myocardial infarction, interleukin‐1 blockade with anakinra significantly reduces the systemic inflammatory response compared with placebo. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01950299

Notulae to the Italian alien vascular flora: 11

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1

Clinical Features, Cardiovascular Risk Profile, and Therapeutic Trajectories of Patients with Type 2 Diabetes Candidate for Oral Semaglutide Therapy in the Italian Specialist Care

Introduction: This study aimed to address therapeutic inertia in the management of type 2 diabetes (T2D) by investigating the potential of early treatment with oral semaglutide. Methods: A cross-sectional survey was conducted between October 2021 and April 2022 among specialists treating individuals with T2D. A scientific committee designed a data collection form covering demographics, cardiovascular risk, glucose control metrics, ongoing therapies, and physician judgments on treatment appropriateness. Participants completed anonymous patient questionnaires reflecting routine clinical encounters. The preferred therapeutic regimen for each patient was also identified. Results: The analysis was conducted on 4449 patients initiating oral semaglutide. The population had a relatively short disease duration (42%  60% of patients, and more often than sitagliptin or empagliflozin. Conclusion: The study supports the potential of early implementation of oral semaglutide as a strategy to overcome therapeutic inertia and enhance T2D management