Solubility of apatite, monazite, zircon, and rutile in supercritical aqueous fluids with implications for subduction zone geochemistry

1991 ◽  
Vol 335 (1638) ◽  
pp. 365-375 ◽  
Keyword(s):  
Subduction Zone ◽  
Aqueous Fluid ◽  
Element Distribution ◽  
Accessory Mineral ◽  
Limited Data ◽  
Accessory Minerals ◽  
Nacl Concentration ◽  
Decreasing Ph ◽  
Dissolved Silicate

Solubilities of accessory minerals (apatite, monazite, zircon and rutile) in supercritical aqueous fluids have been measured to evaluate the role of these fluids in the mobilization of accessory mineral-hosted trace elements. We have characterized the effects on solubility of pH, X H 2 O (addition of CO 2 ), pressure ( P = 1.0-3.0 GPa), temperature ( T =800-1200 °C), and dissolved silicate and NaCl concentration. Fluorapatite solubility in pure H 2 O is low, not more than 0.4 wt% at all conditions studied, but increases strongly with decreasing pH. Changes in P, T, X H 2 O M NaCl (the molality of NaCl), and dissolved silicate concentration have comparatively little effect on apatite solubility. Monazite is even less soluble in H 2 O (not more than 0.2 wt% ). Limited data suggests that monazite solubility increases with increasing P and T and with decreasing pH, but is insensitive to M NaCl . Zircon reacts with H 2 O to form baddeleyite (ZrO 2 ) + silica-rich fluid. ZrO 2 solubility in H 2 O and 1 m HCl is less than 0.2 wt% . Zircon, and therefore ZrO 2 , solubility in quartz-saturated fluids± HCl ±NaCl and in H 2 O -CO 2 fluids is also very low. Rutile is more soluble than the other minerals examined, in the wt% range, and its solubility increases with increasing P and T . Results indicate that high P-T aqueous fluids can dissolve significant amounts of Ti but very little Zr, and little phosphate unless the fluids are acidic. In most cases, apatite, monazite and zircon will remain present during episodes of aqueous fluid metasomatism and therefore will exert control, as ‘residual phases’, over element distribution. The higher solubility of rutile relative to other accessory minerals at high pressure may result in the depletion of high field strength elements relative to large ion lithophile elements observed in subduction zone volcanics.

Von Willebrand disease and Weibel-Palade bodies

2010 ◽  
Vol 30 (03) ◽  
pp. 150-155 ◽  
Author(s):  
J. W. Wang ◽  
J. Eikenboom
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Inflammatory Factors ◽  
Limited Data ◽  
Storage Organelle ◽  
And Function ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryVon Willebrand factor (VWF) is a pivotal haemostatic protein mediating platelet adhesion to injured endothelium and carrying coagulation factor VIII (FVIII) in the circulation to protect it from premature clearance. Apart from the roles in haemostasis, VWF drives the formation of the endothelial cell specific Weibel-Palade bodies (WPBs), which serve as a regulated storage of VWF and other thrombotic and inflammatory factors. Defects in VWF could lead to the bleeding disorder von Willebrand disease (VWD).Extensive studies have shown that several mutations identified in VWD patients cause an intracellular retention of VWF. However, the effects of such mutations on the formation and function of its storage organelle are largely unknown. This review gives an overview on the role of VWF in WPB biogenesis and summarizes the limited data on the WPBs formed by VWD-causing mutant VWF.

Constraints on the formation of the giant Daheishan porphyry Mo deposit (NE China) from whole-rock and accessory mineral geochemistry

2021 ◽  
Author(s):  
Kai Xing ◽  
Qihai Shu ◽  
David R Lentz
Keyword(s):  
High Water ◽  
Accessory Mineral ◽  
Ne China ◽  
Accessory Minerals ◽  
Slab Rollback ◽  
Continental Arc ◽  
Arc Setting ◽  
Porphyry Mo Deposit ◽  
T Values ◽  
Water Contents

Abstract There are more than 90 porphyry (or skarn) Mo deposits in northeastern China with Jurassic or Cretaceous ages. These are thought to have formed mainly in a continental arc setting related to the subduction of the Paleo-Pacific oceanic plate in the Jurassic and subsequent slab rollback in the early Cretaceous. The Jurassic Daheishan porphyry Mo deposit is one of the largest Mo deposits in NE China, which contains 1.09 Mt Mo with an average Mo grade of 0.07%. To better understand the factors that could have controlled Mo mineralization at Daheishan, and potentially in other similar porphyry Mo deposits in NE China, the geochemical and isotopic compositions of the ore-related granite porphyry and biotite granodiorite, and the magmatic accessory minerals apatite, titanite and zircon from the Daheishan intrusions, were investigated so as to evaluate the potential roles that magma oxidation states, water contents, sulfur and metal concentrations could have played in the formation of the deposit. Magmatic apatite and titanite from the causative intrusions show similar εNd(t) values from -1.1 to 1.4, corresponding to TDM2 ages ranging from 1040 to 840 Ma, which could be accounted for by a mixing model through the interaction of mantle-derived basaltic melts with the Precambrian lower crust. The Ce and Eu anomalies of the magmatic accessory minerals have been used as proxies for magma redox state, and the results suggest that the ore-forming magmas are highly oxidized, with an estimated ΔFMQ range of + 1.8 to + 4.1 (+2.7 in average). This is also consistent with the high whole-rock Fe2O3/FeO ratios (1.3–26.4). The Daheishan intrusions display negligible Eu anomalies (Eu/Eu* = 0.7–1.1) and have relatively high Sr/Y ratios (40–94) with adakitic signatures; they also have relatively high Sr/Y ratios in apatite and titanite. These suggest that the fractionation of amphibole rather than plagioclase is dominant during the crystallization of the ore-related magmas, which further indicates a high magmatic water content (e.g., >5 wt%). The magmatic sulfur concentrations were calculated using available partitioning models for apatite from granitoids, and the results (9–125 ppm) are indistinguishable from other mineralized, subeconomic and barren intrusions. Furthermore, Monte Carlo modelling has been conducted to simulate the magmatic processes associated with the formation of the Daheishan Mo deposit, and the result reveals that a magma volume of ∼280 km3 with ∼10 ppm Mo was required to form the Mo ores containing 1.09 Mt Mo in Daheishan. The present study suggests that a relatively large volume of parental magmas with high oxygen fugacities and high water contents is essential for the generation of a giant porphyry Mo deposit like Daheishan, whereas a specific magma composition (e.g., with unusually high Mo and/or S concentrations), might be less critical.

scholarly journals Separation of supercritical slab-fluids to form aqueous fluid and melt components in subduction zone magmatism

2012 ◽  
Vol 109 (46) ◽  
pp. 18695-18700 ◽  
Author(s):  
T. Kawamoto ◽  
M. Kanzaki ◽  
K. Mibe ◽  
K. N. Matsukage ◽  
S. Ono
Keyword(s):  
Subduction Zone ◽  
Aqueous Fluid ◽  
Subduction Zone Magmatism

scholarly journals Heparin-induced thrombocytopenia: research and clinical updates

Hematology ◽  
2016 ◽  
Vol 2016 (1) ◽  
pp. 262-268 ◽  
Author(s):  
Oluwatoyosi Onwuemene ◽  
Gowthami M. Arepally
Keyword(s):  
Limited Data ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
Diagnostic Strategies ◽  
Immune Mediated ◽  
Emerging Therapies ◽  
Current Perspective ◽  
Clinical Advances ◽  
A Current

Abstract Heparin-induced thrombocytopenia (HIT) remains an important diagnosis to consider in hospitalized patients developing thrombocytopenia. HIT is an immune-mediated prothrombotic disorder caused by antibodies to platelet factor 4 (PF4) and heparin. Recent basic scientific studies have advanced our understanding of disease pathogenesis through studies of the PF4/heparin structure, immune mechanisms, and cellular basis of thrombosis. Clinical advances have also occurred in areas of HIT prevention, description of disease variants, and diagnostic strategies. Emerging anticoagulants with the potential to change HIT treatment are evolving, although with limited data. This review will provide a current perspective on HIT pathogenesis, disease features, diagnostic strategies, and role of emerging therapies for the management of HIT.

The Role of ECT in Schizophrenia

2002 ◽  
Vol 10 (4) ◽  
pp. 385-388 ◽  
Author(s):  
Richard Keuneman ◽  
Rajiv Weerasundera ◽  
David Castle
Keyword(s):  
Acute Onset ◽  
Clinical Settings ◽  
Limited Data ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Affective Symptoms ◽  
Maintenance Ect ◽  
The Subject

Objective: To review the place of electroconvulsive therapy (ECT) in the treatment of schizophrenia. Conclusions: ECT is as effective, if not more so, than the antipsychotic drugs in certain clinical settings. It can be rapidly effective in acute episodes. When used alone, antipsychotics have comparable or superior efficacy to ECT alone in the short term. However, ECT possibly confers better long-term outcome. Combination treatment with antipsychotic medications and ECT is superior to either treatment alone, and is safe and effective, notably in medication resistant schizophrenia. Benefits of acute courses of ECT may be short-lived unless maintenance ECT is instituted, although there are limited data on the subject. Clinically, patients with acute onset, shorter episodes are more likely to respond to ECT. Catatonia, preoccupation with delusions and hallucinations, and a relative absence of premorbid schizoid and paranoid personality traits, are other clinical factors less strongly predictive of positive response. The presence of affective symptoms is often thought to be predictive of clinical response. However, there is little research evidence for this. While medications remain the mainstay of treatment in schizophrenia, ECT does have a clear and increasingly recognised role which requires further evaluation.

scholarly journals The Role of Immune-Related miRNAs in the Pathology of Kidney Transplantation

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1198
Author(s):  
Emanuela Boštjančič ◽  
Željka Večerić-Haler ◽  
Nika Kojc
Keyword(s):  
Immune Response ◽  
Kidney Transplantation ◽  
Kidney Diseases ◽  
Experimental Models ◽  
Regulatory Rna ◽  
Limited Data ◽  
Pathological Conditions ◽  
Monitoring Response ◽  
Disease Specific

MicroRNAs (miRNAs) are members of the non-coding regulatory RNA family that play pivotal roles in physiological and pathological conditions, including immune response. They are particularly interesting as promising therapeutic targets, prognostic and diagnostic markers due to their easy detection in body fluids and stability. There is accumulating evidence that different miRNAs provide disease-specific signatures in liquid samples of distinct kidney injuries. Using experimental models and human samples, there have been numerous suggestions that immune-related miRNAs are also important contributors to the development of different kidney diseases as well as important markers for monitoring response after kidney transplantation. However, there are limited data for understanding their function in the molecular pathways of allograft pathologies. In our review, we focused on microRNAs that are related to different aspects of immune response after kidney transplantation.

scholarly journals Role of single and mixed culture of Pseudomonas aeruginosa and Serratia ficaria in utilization of petroleum wastes of Dora- refineries.

2007 ◽  
Vol 4 (4) ◽  
pp. 542-548
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mixed Culture ◽  
Bacterial Culture ◽  
Bacterial Cultures ◽  
Viable Cells ◽  
Nacl Concentration ◽  
Agitated Culture ◽  
Growth Of Bacteria ◽  
Better Than

The ability of single and mixed bacterial culture to utilize Dora-refineries petroleum wastes was compared. Pseudomonas aeruginosa and Serratia ficaria mixed culture consumed the wastes better than the single bacterial cultures. The highest log. number of viable cells in mixed culture was 6.842 , while in single bacterial cultures it was 6.683 and 5.631, respectively. after 3 days in API medium containing the refinery wastes. The effect of some environmental conditions on the degradation of petroleum wastes was studied included aeration , NaCl concentration , pH and temperature. The growth of bacteria in the agitated culture was higher than stagnant culture the log. of cell no. was 6.021 in the first culture. The highest log. of cell no. stagnant culture was 5.771. Pseudomonas aeruginosa AA22 and Serratia ficaria AA39 were able to grow in medium containing 5 , 7 % NaCl , they favorite pH 7. The mixed culture of the two bacteria grew well of 45 oC.

scholarly journals Association Between Diabetes Medications and the Risk of Parkinson's Disease: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaocui Qin ◽  
Xia Zhang ◽  
Pinyu Li ◽  
Min Wang ◽  
Li Yan ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Meta Analysis ◽  
Limited Data ◽  
Dipeptidyl Peptidase 4 ◽  
Single Study ◽  
Dipeptidyl Peptidase 4 Inhibitors ◽  
Glucagon Like Peptide 1

Background: Diabetes mellitus (DM) increases the risk of Parkinson's disease (PD). However, whether DM medications play a part on that increased PD risk is unclear. We designed this meta-analysis to assess the influence of different oral DM medications on the PD risk in patients with DM.Methods: We searched PubMed, Embase, and CENTRAL databases for relevant studies up until January 2021. We pooled adjusted outcomes to assess the PD risk in patients using different DM medications including sulfonylurea, metformin, glitazones (GTZ), dipeptidyl peptidase-4 inhibitors (DPP4i), and glucagon-like peptide-1 agonists (GLP1a).Results: We included 10 studies in our analysis. Our results indicate a lack of significant association between the PD risk and the use of sulfonylureas (three studies; HR, 1.26; 95% CI, 0.95 to 1.66; I2, 70%; p = 0.11), DPP4i (three studies; HR, 0.69; 95% CI, 0.35 to 1.38; I2, 88%; p = 0.30), metformin (five studies; HR, 1.23; 95% CI, 0.98 to 1.78; I2, 84%; p = 0.13), and GTZ (six studies; HR, 0.88; 95% CI, 0.66 to 1.16; I2, 92%; p = 0.35). After exclusion of a single study in the GTZ analysis, our results indicate a significantly reduced PD risk with GTZ use (HR, 0.78; 95% CI, 0.65 to 0.93; I2, 59%; p = 0.06). Similarly, after the exclusion of a single study, our results indicate a significantly increased PD risk with the use of metformin (HR, 1.50; 95% CI, 1.11 to 2.02; I2, 80%; p = 0.008). We also found a significantly reduced PD risk with the use of GLP1a (two studies; HR, 0.41; 95% CI, 0.19 to 0.87; I2, 0%; p = 0.02).Conclusion: The role of different DM medications on the PD risk remains unclear, and the quality of studies is low. While our analysis suggests a lack of association between the use of metformin, GTZ, DPP4i, and sulfonylureas and the PD risk, metformin (to a higher degree) and GTZ may still increase the risk. Limited data suggest a protective effect of GLP1a on the PD risk.

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