Rare earths release from dissolving atmospheric dust and their accumulation into crystallising halite: The Dead Sea example.

The industrial extraction of Y and lanthanides (hereafter defined as Rare Earth Elements, REE) often requires the achievement of leaching procedures removing these metals from primary rocks and their transfer in aqueous leachates or incorporated in newly forming soluble solids. These procedures are the most dangerous to the environment in relation to the composition of leachates. Hence, the recognition of natural settings where these processes currently occur, represents a worthy challenge for learning how to carry out similar industrial procedures under natural and more eco-friendly conditions. Accordingly, the REE distribution was studied in the brine of Dead Sea, a terminal evaporating basin where brines dissolve atmospheric fallout particles and crystallise halite. Our results indicate that the shale-like fractionation of shale-normalised REE patterns in brines, inherited during the dissolution of atmospheric fallout, changes because of the halite crystallisation. This process leads to crystallising halite mainly enriched in elements from Sm to Ho (medium REE, MREE) and coexisting mother brines enriched in La and some other light REE (LREE). We suggest that the dissolution of atmospheric dust in brines corresponds to the REE extraction from primary silicate rocks, whereas halite crystallisation represents the REE transfer into a secondary more soluble deposit with reduced environmental health outcomes.

Trace element fractionation through halite crystallisation: Geochemical mechanisms and environmental implications.

Halite is an important mineral for industry, agriculture and food production. It crystallises during water evaporation, and the progressive increase of dissolved metal ions in the brine occurs simultaneously. Thus, halite exploitation may deliver metal ions into the environment and the mechanism of this trace element accumulation has to be studied. In this work, we investigate the distribution of lanthanides and Y (hereafter called rare earth elements, REE), Zr and Hf between crystallising halite and brines in the Dead Sea as geochemical tools for recognising the mechanism of metal ion removal from brines and accumulation in halite. Halite forms cubic crystals where octahedral planes sometimes occur under particular thermal gradient conditions. Our findings indicate that crystal morphology influences the mechanism of metal ion removal from brines because octahedral surfaces are polar unlike those that are cubic. Accordingly, octahedra preferentially fractionate aqueous charged species such as [Hf(OH)5]-, compared to neutral species such as [Zr(OH)4]0. Cubic surfaces do not fractionate aqueous species. In crystal cores, positive Eu anomalies occur suggesting Eu substitution for Na in the lattice. This substitution is energetically justified by ab initio calculations. Hf enrichment relative to Zr also occurs in primary halite-rich evaporites. It is not found in cubic halite from saltworks. The results of this study suggest that primary halite kinetically crystallised from brines can concentrate dissolved metal ions onto crystal surfaces where dissolved charged species are adsorbed. Accordingly, the dissolution of halite due to human activity can release these metal ions to the environment.

Long-term efficacy and safety of quetiapine in treatment-refractory schizophrenia: A case report.

The recent advent of atypical antipsychotics has provided new clinical options and set higher expectations for the treatment of schizophrenia. Such agents might more effectively prevent relapse because they are more effective against the full spectrum of schizophrenic symptoms, as well as having improved tolerability and leading to improved medication compliance. Quetiapine fumarate ('Seroquel') is a new dibenzothiazepine antipsychotic agent with a greater affinity for serotonin receptors than for dopamine receptors and with a lower propensity for producing extrapyramidal symptoms or increasing prolactin levels. It has recently been approved for the treatment of psychotic disorders; however, the long-term efficacy and safety of quetiapine for treating treatment-refractory schizophrenia is still being investigated. We present a case of a 58-year-old man suffering from chronic therapy-resistant schizophrenia, with both positive and negative symptoms, who was successfully treated with quetiapine for 5 years. To the best of our knowledge, this is the first report of such long beneficial use of quetiapine in a hospital clinical practice. (Int J Psych Clin Pract 2000; 4:77-80).

[Excretion of catecholamines and lipid composition of blood in patients with chronic pancreatitis]. / Ekskretsiia katekholaminov i lipidnyi sostav syvorotki krovi u bol'nykh khronicheskim pankreatitom.

Excretion of adrenaline was increased in patients with chronic recurrent pancreatitis, excretion of noradrenaline tended to decrease although the content of this amine exceeded 1.5-2-fold its normal concentration in individual patients; excretion of DOPA was unaltered. Hyperlipoproteinemia was found in the majority of the patients. Maximal level of the adrenaline excretion was mainly observed in the patients with high activity of the trypsin inhibitor in blood serum as well as with the high ratio trypsin inhibitor/trypsin. An increase in the adrenaline excretion correlated with hypercholesterolemia and to a lesser extent--with hypertriglyceridemia. The most pronounced hypertriglyceridemia was typical for the patients with alcoholic abuse. Relationship between catecholamines and extrasecretory functions of pancreatic gland as well as with hyperlipoproteinemia in pancreatitis is discussed. An increase in the total antitryptic activity might be caused by activation of the sympathoadrenal system or by hyperproduction of adrenaline.

[Excretion of catecholamines and DOPA in lipid metabolism disorders]. / Ekskretsiia katekholaminov i DOFA pri narusheniiakh metabolizma lipidov.

Excretion of catecholamines and DOPA was impaired in patients with metabolic-alimentary obesity, with ischemic disease of heart, with atherosclerosis and excessive weight. Distinct decrease in content of adrenaline, noradrenaline and DOPA was observed in patients with obesity; the phenomenon was less pronounced in ischemic disease of heart, mainly in aged patients. Correlation was found between the rate of excretion of catecholamines and DOPA and the extent of hyperlipidemia. Dietetics did not normalize completely the impairments studied. Additional administration of pyridoxine caused a favorable effect.

[Effect of an anti-atherosclerotic diet with different protein content on catecholamine and DOPA excretion in patients with ischemic heart disease and excess weight]. / Vliianie protivoateroskleroticheskoi diety s razlichnym soderzhaniem belka na ékskretsiiu katekholaminov i DOFA u bol'nykh ishemicheskoi bolezn'iu serdtsa s izbytochnya vesom.

In patients with ischemic heart disease (IHD) with excess body weight the excretion of catecholamines and DOPA was investigated. In patients of middle and advanced age the excretion of norepinephrine was found to be down, while in those of the young age the excretion of epinephrine and norepinephrine proved to be up. There exist a correlation between the rising level of norepinephrine and hyperlipidemia. In patients with IHD the blood serotonin content is elevated. The use of an antiatherosclerotic diet with a higher protein content tends to bring down the level of the norepinephrine and, partially, also of epinephrine excretion. With patients kept on an antiatherosclerotic diet with protein content the excretion of norepinephrine sharply decreases and that of epinephrine rises. Administration of pyridoxine superimposed upon dietary variants acts favorably on the catecholamines excretion. Under the effect of the diets in question the blood serotonin remains unchanged. The implication is that both the high- and low-protein quotas in the composition of antiatherosclerotic diets do not produce an optimal effect on the catecholamines and DOPA metabolism in patients with IHD and an excess body weight.

[Effect of pyridoxine on patterns of lipid metabolism in patients with alimentary obesity]. / Vliiani piridoksina na pokazateli lipidnogo obmena u bol'nykh c alimentarnym ozhireniem

Studies of patients with alimentary-metabolic obesity, which were treated with pyridoxine and were maintained on a reduced diet, revealed a normalizing effect of the vitamin on some patterns of lipid metabolism. In patients, treated with pyridoxine, body weight, content of total lipids, cholesterol, phospholipids, glycerids and beta-lipoproteins in blood serum were decreased more distinctly as compared with patients, which were only maintained on a reduced diet. In hyperlipidaemia the positive effect of pyridoxine was more pronounced than in the cases with normal content of lipids in blood.