Partition coefficient of Ca among leucite, sanidine, silicic-sanidinic melt, and hydrothermal solution at 2Kb and high temperatures (920º and 1030ºC)

Results of synthesis experiments of leucite (Lc), sanidine (San) and fused sanidine, the latter with slightly excess SiO2 are reported. Starting materiais were amorphous oxide gels with the appropriate stoichiometric compositions in contact with KCl hydrothermal solutions (HS) containing variable amounts of tagged CaCl2(45Ca) at pressures of 2 kbars and temperatures of 930º and 1030ºC. The distribution coefficients ; were obtained from the Ca/K ratios measured in both ideal synthesized materiais and solutions. The results were as follows: ; and ;Foram realizadas séries de experimentos de síntese de leucita, sanidina e de sanidina fundida com pequeno excesso de sílica a partir de gels amorfos dos óxidos na estequiometria desejada, em contato com solução hidrotermal de KCl, contendo proporções variáveis de traços de cloreto de cálcio "marcado" (45Ca). As relações Ca/K determinadas nos matérias sintetizados e na solução hidrotermal após os experimentos permitiram a obtenção dos coeficientes de partição médios Kd = Ca/K do material sintetizado/Ca/K da solução hidrotermal, dentro de intervalo de comportamento ideal das soluções hidrotermais, das soluções sólidas (minerais) e da fusão sílico-sanidínica (sanidina fundida). Os valores de Kd obtidos foram: ; e

Constraints on F vs. OH incorporation in synthetic [6]Al-bearing monoclinic amphiboles

In this work we have systematically replaced OH with F in an amphibole composition intermediate between richterite and pargasite [60% richterite and 40% pargasite in molar proportion; nominal composition Na(Na0.6Ca1.4)(Mg4.6Al0.4)(Si7.2Al0.8)O-22(OH,F)(2)]. Syntheses have been done at 3 kbar P-H2O and 900 degreesC, and for all compositions an assemblage of amphibole plus minor Na-phlogopite has been obtained. Crystal-chemical variations in the amphibole as a function of F have been characterized by a combination of EMPA, X-ray powder diffraction, and infrared spectroscopy. EMPA analyses show that for increasing F in the system (i) the Al-[6] content decreases to 0.13 apfu for the nominal fluorine end-member whereas the Al-[4] content is virtually constant and close to the nominal value; (ii) the fluorine content is systematically lower than expected. The infrared OH-stretching spectra show that those OH-groups locally bonded to (MgMgMg)-Mg-M1-Mg-M1-Mg-M3 configurations are preferentially replaced by F whereas those OH-groups locally bonded to (MgMgAl)-Mg-M1-Mg-M1-Al-M3 configurations are not replaced by F

Application of orientation imaging microscopy to study cyclic plasticity Frontiers in Materials Processing Applications

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Effect of periodontal treatment on the glomerular filtration rate, reduction of inflammatory markers and mortality in patients with chronic kidney disease: A systematic review

International audienceAIM: To assess the effect of periodontal treatment (PT) on glomerular filtration rate (GFR), systemic inflammation, or mortality in patients with chronic kidney disease (CKD). METHODS: A literature search was performed on PubMed and Web of Science databases on articles published until December 2019. The PRISMA guidelines were used throughout the manuscript. RESULTS: Of the total studies found, only 18 met the inclusion criteria; four retrospective and 14 prospective studies (including 3 randomized controlled trials-RCT). After PT, 3 studies investigated GFR, 2 found significant improvement; 11 (including 2 RCTs) investigated C-reactive protein levels, 9 found a significant improvement (including the 2 RCTs); 5 (including 3 RCTs) investigated Interleukine-6 level, 4 found a significant improvement (including 2 RCTs) and 2 studies evaluated mortality, one (retrospective study) found a significant difference. CONCLUSIONS: Within the limitations of the present study, PT seems to improve CKD status, especially by reducing the systemic inflammation. Further RCTs are needed to confirm the results and specifically assess the influence of different types of PT in CKD patients. Taking into consideration the ability of PT to prevent further tooth loss and denutrition, early management of periodontitis is extremely important in patients with impaired renal function