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.

Boron and lithium behaviour in river waters under semiarid climatic conditions.

Boron (B) and Lithium (Li) concentrations were studied in the Platani river, one of the most important catchments of South-Central Sicily which is under semiarid climatic conditions for roughly eight months to a year. In this area, evaporites result in potential B and Li sources for surface waters. Results from river waters have measured ionic strength values between 0.1 and 4.54 M. B and Li distributions in these waters were studied in colloidal (CF, extracted by ultrafiltration from the 0.45 µm filtrate) and total dissolved (TDF) fractions and in fractions extracted from corresponding riverbed sediments, according to changes of the B/Li ratio. In river waters, CF and TDF showed very similar B/Li values, suggesting that only negligible fractionation occurs between Li and B in the aqueous phase. Similar evidence was observed between B/Li values in TDF and the labile sediment fraction, whereas an inverse relationship arose between B/Li values in TDF and in the easily reducible sediment fraction. This relationship indicates that Mn oxy-hydroxides preferentially react with aqueous B species relative to Li at the riverbed sediment interface. The extent of the B-Mn oxy-hydroxide reactions is influenced by the ionic strength, so that only B/Li values below 4 are measured in river waters with ionic strength values above 0.5 M. Comparing B/Li and ionic strength values measured in the Platani river with those from oxic brines worldwide, the same preferential B removal relative to Li is observed. This evidence suggests that B is removed as positively-charged borate ion-pairs, formed in the aqueous phase under higher ionic strength conditions, reacting with negatively charged surfaces of Mn oxy-hydroxides. The observed B reactivity relative to Li could be exploited to bring down the B excess from natural or waste waters, allowing the natural reactions with Mn oxy-hydroxides to take place under natural conditions.

A meta-regression study of the clinical significance of serum aminotransferases in COVID-19.

OBJECTIVE: The aim of the study was to appraise the capacity of serum aminotransferases to discriminate between hepatic and other extra-pulmonary COVID-19-related manifestations and, potentially, to serve as predictors of poor clinical outcomes. MATERIALS AND METHODS: Ninety-eight studies were identified (79% from China), including 43,554 patients (57% males), 9,983 (62% males) with poor outcomes and 33,571 (50% males) with favorable outcomes. After splitting studies depending on whether serum alanine aminotransferase (ALT) concentrations were statistically different between patients with poor vs. favorable outcomes, the 35 'hepatic involvement' articles (p<0.05) included 28,510 patients (51% males), 5,279 (66% males) and 23,231 subjects (48% males) with poor and favorable outcomes, respectively. The 63 'extra-hepatic involvement' studies (p>0.05) included 15,044 patients (54% males), 4,704 (60% males) with poor outcomes and 10,340 (51% males) with favorable outcomes. RESULTS: The meta-analysis shows that serum aspartate aminotransferase (AST) concentrations were significantly higher in patients with poor outcomes than those with favorable outcomes (WMD 12.5 UI/L, 95% CI 10.9 to 14.1 p<0.001). Similarly, AST concentrations were significantly higher in the 'hepatic involvement' studies (WMD 16.3 UI/L, 95% CI 13.4 to 19.2 p<0.001) and in the 'extra-hepatic involvement' studies (WMD 10.3 UI/L, 95% CI 8.6 to 12.0 p<0.001). CONCLUSIONS: The different association of serum AST concentrations with some clinical, demographic, and biochemical factors in the two clusters suggests that in COVID-19 patients, serum AST elevation is not necessarily linked to real liver damage.

Predictive Value of CD8 Expression and FoxP3 Methylation in Nasopharyngeal Carcinoma Patients Treated with Chemoradiotherapy in a Non-endemic Area.

Undifferentiated Nasopharyngeal Carcinoma (UNPC) is associated with Epstein-Barr Virus (EBV) and characterized by an abundant immune infiltrate potentially influencing the prognosis. Thus, we retrospectively assessed the significance of immunosuppression in the UNPC microenvironment as prognostic biomarker of treatment failure in a non-endemic area, and monitored the variation of systemic EBV-specific immunity before and after chemoradiotherapy (CRT). DNA and RNA were extracted from diagnostic biopsies obtained by tumor and adjacent mucosa from 63 consecutive EBV+ UNPC patients who underwent radical CRT. Among these patients 11 relapsed within 2 years. The expression of the EBV-derived UNPC-specific BARF1 gene and several immune-related genes was monitored through quantitative RT-PCR and methylation-specific PCR analyses. Peripheral T cell responses against EBV and BARF1 were measured in 14 patients (7 relapses) through IFN-γ ELISPOT assay. We found significantly higher expression levels of BARF1, CD8, IFN-γ, IDO, PD-L1, and PD-1 in UNPC samples compared to healthy tissues. CD8 expression was significantly reduced in both tumor and healthy tissues in UNPC patients who relapsed within two years. We observed a hypomethylated FOXP3 intron 1 exclusively in relapsed UNPC patients. Finally, we noticed a significant decrease in EBV- and BARF1-specific T-cells after CRT only in relapsing patients. Our data suggest that a high level of immunosuppression (low CD8, hypomethylated FoxP3) in UNPC microenvironment may predict treatment failure and may allow an early identification of patients who could benefit from the addition of immune modulating strategies to improve first line CRT.

1991 Magadan, USSR/Alaska, USA Dental Exchange Program Report.

In August 1991, three rural Alaska Public Health dentists made a professionally significant return visit to the Soviet Far East. The city of Magadan was the site for the first actual demonstration of portable American dental equipment and treatment techniques in this remote region of Russia. This exchange was held at several clinical locations and took place during the time of the attempted USSR government coup.