Energy Dispersive X-Ray Analysis of Ocean Ferromanganese Crusts Using Conventional ZAF Corrections

Ocean ferromanganese crusts are composed of interlayered phases of manganese oxide, iron oxide and oxyhydroxide, calcium carbonate/phosphate, silica, and alumino-silicates. These interlayers are so thin and fine-grained that each phase could not be isolated under the beam of a scanning electron microscope for quantitative x-ray microanalysis. A test was conducted to determine if the grain size of the phases was small enough to allow conventional ZAF techniques to be used without serious errors in the results. A synthetic ferromanganese crust was prepared by pelletization of a 1:1 mix of two fine-grained (\u3c5 \u3emicrometer) components. The mean of the energy dispersive analyses of the mix, using an area-scan method (25 x 30 μm square), shows good agreement (generally within 5 to 10 percent, relative) to the arithmetic combination of the x-ray analyses of each component. Analyses performed by x-ray fluorescence, inductively-coupled argon plasma spectroscopy, flame atomic absorption spectrometry, ion chromatography, spectrophotometry and sulfur analyzer are provided for the purposes of comparison. The results of the energy dispersive analyses were normalized using ignition-loss values and a calculation of fluorine from the P2O5 content to reflect the presence of light elements (Z\u3c11). The results were reasonably consistent with other methods of bulk analyses, demonstrating that this method can be used where other instrumentation is not available or where sample size is too small for other methods

Ferromanganese micronodules from the surficial sediments of Georges Bank

Ferromanganese micronodules have been found on Georges Bank, off the U.S. northeast coast, distributed throughout the surficial sediments within an area about 125 km long and at least 12 km wide. These coarse, sand-sized concretions have precipitated from metal-rich interstitial waters and contain many of the textural and structural features common to other neritic nodules. Most of the nodules have accreted around detrital grains, and X-ray powder diffraction analyses indicate the presence of geothite and vernadite (δ-MnO2) in the ferromanganese layers. Chemical analyses of the micronodules, when compared with similar data on deep-sea manganese nodules, reveal lower Mn/Fe ratios, significantly higher concentrations of V and As, comparable values of Mo, and an order of magnitude less of Co, Ni, Ce and most other metals

Association of the PHACTR1/EDN1 genetic locus with spontaneous coronary artery dissection

Background: Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndromes (ACS) afflicting predominantly younger to middle-aged women. Observational studies have reported a high prevalence of extracoronary vascular anomalies, especially fibromuscular dysplasia (FMD) and a low prevalence of coincidental cases of atherosclerosis. PHACTR1/EDN1 is a genetic risk locus for several vascular diseases, including FMD and coronary artery disease, with the putative causal noncoding variant at the rs9349379 locus acting as a potential enhancer for the endothelin-1 (EDN1) gene. Objectives: This study sought to test the association between the rs9349379 genotype and SCAD. Methods: Results from case control studies from France, United Kingdom, United States, and Australia were analyzed to test the association with SCAD risk, including age at first event, pregnancy-associated SCAD (P-SCAD), and recurrent SCAD. Results: The previously reported risk allele for FMD (rs9349379-A) was associated with a higher risk of SCAD in all studies. In a meta-analysis of 1,055 SCAD patients and 7,190 controls, the odds ratio (OR) was 1.67 (95% confidence interval [CI]: 1.50 to 1.86) per copy of rs9349379-A. In a subset of 491 SCAD patients, the OR estimate was found to be higher for the association with SCAD in patients without FMD (OR: 1.89; 95% CI: 1.53 to 2.33) than in SCAD cases with FMD (OR: 1.60; 95% CI: 1.28 to 1.99). There was no effect of genotype on age at first event, P-SCAD, or recurrence. Conclusions: The first genetic risk factor for SCAD was identified in the largest study conducted to date for this condition. This genetic link may contribute to the clinical overlap between SCAD and FMD

Annotated record of the detailed examination of Mn micronodules from stations over George Bank, Atlantic Ocean

Ferromanganese micronodules have been found on Georges Bank, off the U.S. northeast coast, distributed throughout the surficial sediments within an area about 125 km long and at least 12 km wide. These coarse, sand-sized concretions have precipitated from metal-rich interstitial waters and contain many of the textural and structural features common to other neritic nodules. Most of the nodules have accreted around detrital grains, and X-ray powder diffraction analyses indicate the presence of geothite and vernadite ( delta -MnO sub(2)) in the ferromanganese layers. Chemical analyses of the micronodules, when compared with similar data on deep-sea manganese nodules, reveal lower Mn/Fe ratios, significantly higher concentrations of V and As, comparable values of Mo, and an order of magnitude less of Co, Ni, Ce and most other, metals

Two‐year outcomes after percutaneous coronary intervention with drug‐eluting stents or bare‐metal stents in elderly patients with coronary artery disease

International audienceObjectives Report the results at 2 years of the patients included in the SENIOR trial. Background Patients above 75 years of age represent a fast-growing population in the cathlab. In the SENIOR trial, patients treated by percutaneous coronary intervention (PCI) with drug eluting stent (DES) and a short duration of P2Y12 inhibitor (1 and 6 months for stable and unstable coronary syndromes, respectively) compared with bare metal stents (BMS) was associated with a 29% reduction in the rate of all-cause mortality, myocardial infarction (MI), stroke, and ischaemia-driven target lesion revascularization (ID-TLR) at 1 year. The results at 2 years are reported here. Methods and Results We randomly assigned 1,200 patients (596[50%] to the DES group and 604[50%] to the BMS group). At 2 years, the composite endpoint of all-cause mortality, MI, stroke and ID-TLR had occurred in 116 (20%) patients in the DES group and 131 (22%) patients in the BMS group (RR 0.90 [95%CI 0.72-1.13],p= .37). IDTLR occurred in 14 (2%) patients in the DES group and 41 (7%) patients in the BMS group (RR 0.35 [95%CI 0.16-0.60],p= .0002). Major bleedings (BARC 3-5) occurred in 27(5%) patients in both groups (RR 1.00, [95%CI 0.58-1.75],p= .99). Stent thrombosis rates were low and similar between DES and BMS (0.8 vs 1.3%, (RR 0.52 [95%CI 0.01-1.95],p= .27). Conclusion Among elderly PCI patients, a strategy combining a DES together with a short duration of DAPT is associated with a reduction in revascularization up to 2 years compared with BMS with very few late events and without any increased in bleeding complications or stent thrombosis

Dual antiplatelet therapy duration after coronary stenting in clinical practice: results of an EAPCI survey

Aims: Our aim was to report on a survey initiated by the EuropeanAssociation of Percutaneous Cardiovascular Interventions (EAPCI) concerning opinion on the evidence relating to dual antiplatelet therapy (DAPT) duration after coronary stenting.Methods and results: Results from three randomised clinical trials were scheduled to be presented at the American Heart Association Scientific Sessions 2014 (ARIA 2014). A web-based survey was distributed to all individuals registered in the EuroIntervention mailing list (n=15,200) both before and after ARIA 2014. A total of 1,134 physicians responded to the first (i.e., before AHA 2014) and 542 to the second (i.e., after ARIA 2014) survey. The majority of respondents interpreted trial results consistent with a substantial equipoise regarding the benefits and risks of an extended versus a standard DAPT strategy. Two respondents out of ten believed extended DAFT should be implemented in selected patients. After ARIA 2014, 46.1% of participants expressed uncertainty about the available evidence on DAFT duration, and 40.0% the need for clinical guidance.Conclusions: This EAPCI survey highlights considerable uncertainty within the medical community with regard to the optimal duration of DAFT after coronary stenting in the light of recent reported trial results. Updated recommendations for practising physicians to guide treatment decisions in routine clinical practice should be provided by international societies