42 research outputs found

    Genesis and preservation of a uranium-rich Paleozoic epithermal system with a surface expression (Northern Flinders Ranges, South Australia): radiogenic heat driving regional hydrothermal circulation over geological timescales

    Get PDF
    The surface expressions of hydrothermal systems are prime targets for astrobiological exploration, and fossil systems on Earth provide an analogue to guide this endeavor. The Paleozoic Mt. Gee–Mt. Painter system (MGPS) in the Northern Flinders Ranges of South Australia is exceptionally well preserved and displays both a subsurface quartz sinter (boiling horizon) and remnants of aerial sinter pools that lie in near-original position. The energy source for the MGPS is not related to volcanism but to radiogenic heat produced by U-Th-K-rich host rocks. This radiogenic heat source drove hydrothermal circulation over a long period of time (hundreds of millions of years, from Permian to present), with peaks in hydrothermal activity during periods of uplift and high water supply. This process is reflected by ongoing hot spring activity along a nearby fault. The exceptional preservation of the MGPS resulted from the lack of proximal volcanism, coupled with tectonics driven by an oscillating far-field stress that resulted in episodic basement uplift. Hydrothermal activity caused the remobilization of U and rare earth elements (REE) in host rocks into (sub)economic concentrations. Radiogenic-heat-driven systems are attractive analogues for environments that can sustain life over geological times; the MGPS preserves evidence of episodic fluid flow for the past 300 million years. During periods of reduced hydrothermal activity (e.g., limited water supply, quiet tectonics), radiolytic H2 production has the potential to support an ecosystem indefinitely. Remote exploration for deposits similar to those at the MGPS systems can be achieved by combining hyperspectral and gamma-ray spectroscopy.Joël Brugger, Pierre-Alain Wülser and John Fode

    The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

    Get PDF
    Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

    Responder analysis for improvement in 6-min walk test with ferric carboxymaltose in patients with heart failure with reduced ejection fraction and iron deficiency

    No full text
    Aim: Improving functional capacity is a key goal in heart failure (HF). This pooled analysis of FAIR-HF and CONFIRM-HF assessed the likelihood of improvement or deterioration in 6-min walk test (6MWT) among iron-deficient patients with chronic HF with reduced ejection fraction (HFrEF) receiving ferric carboxymaltose (FCM). Methods and results: Data for 760 patients (FCM: n = 454; placebo: n = 306) were analysed. The proportions of patients receiving FCM or placebo who had ≥20, ≥30, and ≥40 m improvements or ≥10 m deterioration in 6MWT at 12 and 24 weeks were assessed. Patients receiving FCM experienced a mean (standard deviation) 31.1 (62.3) m improvement in 6MWT versus 0.1 (77.1) m improvement for placebo at week 12 (difference in mean changes 26.8 [16.6–37.0]). At week 12, the odds [95% confidence interval] of 6MWT improvements of ≥20 m (odds ratio 2.16 [1.57–2.96]; p &lt; 0.0001), ≥30 m (2.00 [1.44–2.78]; p &lt; 0.0001), and ≥40 m (2.29 [1.60–3.27]; p &lt; 0.0001) were greater with FCM versus placebo, while the odds of a deterioration ≥10 m were reduced with FCM versus placebo (0.55 [0.38–0.80]; p = 0.0019). Among patients who experienced 6MWT improvements of ≥20, ≥30, or ≥40 m with FCM at week 12, more than 80% sustained this improvement at week 24. Conclusion: Ferric carboxymaltose resulted in a significantly higher likelihood of improvement and a reduced likelihood of deterioration in 6MWT versus placebo among iron-deficient patients with HF. Of the patients experiencing clinically significant improvements at week 12, the majority sustained this improvement at week 24. These results are supportive of FCM to improve exercise capacity in HF. © 2022 The Authors. European Journal of Heart Failure published by John Wiley &amp; Sons Ltd on behalf of European Society of Cardiology

    Clinical practice update on heart failure 2019: pharmacotherapy, procedures, devices and patient management. An expert consensus meeting report of the Heart Failure Association of the European Society of Cardiology

    No full text
    The European Society of Cardiology (ESC) has published a series of guidelines on heart failure (HF) over the last 25 years, most recently in 2016. Given the amount of new information that has become available since then, the Heart Failure Association (HFA) of the ESC recognized the need to review and summarise recent developments in a consensus document. Here we report from the HFA workshop that was held in January 2019 in Frankfurt, Germany. This expert consensus report is neither a guideline update nor a position statement, but rather a summary and consensus view in the form of consensus recommendations. The report describes how these guidance statements are supported by evidence, it makes some practical comments, and it highlights new research areas and how progress might change the clinical management of HF. We have avoided re-interpretation of information already considered in the 2016 ESC/HFA guidelines. Specific new recommendations have been made based on the evidence from major trials published since 2016, including sodium–glucose co-transporter 2 inhibitors in type 2 diabetes mellitus, MitraClip for functional mitral regurgitation, atrial fibrillation ablation in HF, tafamidis in cardiac transthyretin amyloidosis, rivaroxaban in HF, implantable cardioverter-defibrillators in non-ischaemic HF, and telemedicine for HF. In addition, new trial evidence from smaller trials and updated meta-analyses have given us the chance to provide refined recommendations in selected other areas. Further, new trial evidence is due in many of these areas and others over the next 2 years, in time for the planned 2021 ESC guidelines on the diagnosis and treatment of acute and chronic heart failure. © 2019 The Authors. European Journal of Heart Failure © 2019 European Society of Cardiolog

    Patient profiling in heart failure for tailoring medical therapy. A consensus document of the Heart Failure Association of the European Society of Cardiology

    No full text
    Despite guideline recommendations and available evidence, implementation of treatment in heart failure (HF) is poor. The majority of patients are not prescribed drugs at target doses that have been proven to positively impact morbidity and mortality. Among others, tolerability issues related to low blood pressure, heart rate, impaired renal function or hyperkalaemia are responsible. Chronic kidney disease plays an important role as it affects up to 50% of patients with HF. Also, dynamic changes in estimated glomerular filtration rate may occur during the course of HF, resulting in inappropriate dose reduction or even discontinuation of decongestive or neurohormonal modulating therapy in clinical practice. As patients with HF are rarely naïve to pharmacologic therapies, the challenge is to adequately prioritize or select the most appropriate up-titration schedule according to patient profile. In this consensus document, we identified nine patient profiles that may be relevant for treatment implementation in HF patients with a reduced ejection fraction. These profiles take into account heart rate (&amp;lt;60 bpm or &amp;gt;70 bpm), the presence of atrial fibrillation, symptomatic low blood pressure, estimated glomerular filtration rate (&amp;lt;30 or &amp;gt;30 mL/min/1.73 m2) or hyperkalaemia. The pre-discharge patient, frequently still congestive, is also addressed. A personalized approach, adjusting guideline-directed medical therapy to patient profile, may allow to achieve a better and more comprehensive therapy for each individual patient than the more traditional, forced titration of each drug class before initiating treatment with the next. © 2021 European Society of Cardiolog
    corecore