Geochemistry of platinum-group elements in the podiform chromitites and associated peridotites of the Nain ophiolites,Central Iran:Implications for geotectonic setting

The Nain ophiolite complex with an extent of[600 km2 is a part of the Central Iranian ophiolite,which is related to the opening and subsequent closure of the Neo-Tethys Ocean.Dunite and serpentinized harzburgite in the Nain area host podiform chromitites that occur as three(eastern Hajhossein,western Hajhossein,and Soheil Pakuh)schlieren-type tabular and aligned massive lenses with various sizes.The most common chromitite ore textures are massive,nodular,disseminated,and banded,reflecting crystal settling processes.The Cr#[Cr/(Cr+Al)]ranges from 0.43 to 0.81(average 0.63).The Mg#[Mg/(Mg+Fe2+)]varies from 0.25 to 0.78(average0.62).The Nain ophiolite and hosted chromitite are generally characterized by high Cr#,reflecting crystallization from a very hot boninite magma in a MORB setting.The high Cr#in the Nain chromitite also indicates a high degree of melting(15%–35%)of the depleted peridotite.The average total PGE content in the ophiolitic host rock(harzburgite and dunite)and chromite are 107 and 221 ppb,respectively.The Nain ophiolite and chromitite have high IPGE/PPGE and negative Pt*(Pt/Pt*=0.6)anomaly,which is a characteristic of high Cr#chromitite.The U-shaped REE pattern of dunite host rock suggests the interaction of depleted mantle peridotite with boninitic melt.Geochemical data suggest that the Nain chromitites are related to the boninitic magma emplacement in a suprasubduction zone.

Association between hemoglobin glycation index and 5-year major adverse cardiovascular events:the REACTION cohort study

Background:The hemoglobin glycation index(HGI)was developed to quantify glucose metabolism and individual differences and proved to be a robust measure of individual glycosylated hemoglobin(HbA1c)bias.Here,we aimed to explore the relationship between different HGIs and the risk of 5-year major adverse cardiovascular events(MACEs)by performing a large multicenter cohort study in China.Methods:A total of 9791 subjects from the Risk Evaluation of Cancers in Chinese Diabetic Individuals:a Longitudinal Study(the REACTION study)were divided into five subgroups(Q1-Q5)with the HGI quantiles(≤5th,>5th and≤33.3th,>33.3th and≤66.7th,>66.7th and≤95th,and>95th percentile).A multivariate logistic regression model constructed by the restricted cubic spline method was used to evaluate the relationship between the HGI and the 5-year MACE risk.Subgroup analysis between the HGI and covariates were explored to detect differences among the five subgroups.Results:The total 5-year MACE rate in the nationwide cohort was 6.87%(673/9791).Restricted cubic spline analysis suggested a U-shaped correlation between the HGI values and MACE risk after adjustment for cardiovascular risk factors(x^(2)=29.5,P<0.001).After adjustment for potential confounders,subjects with HGIs≤-0.75 or>0.82 showed odds ratios(ORs)for MACE of 1.471(95%confidence interval[CI],1.027-2.069)and 2.222(95%CI,1.641-3.026)compared to subjects with HGIs of>-0.75 and≤-0.20.In the subgroup with non-coronary heart disease,the risk of MACE was significantly higher in subjects with HGIs≤-0.75(OR,1.540[1.039-2.234];P=0.027)and>0.82(OR,2.022[1.392-2.890];P<0.001)compared to those with HGIs of≤-0.75 or>0.82 after adjustment for potential confounders.Conclusions:We found a U-shaped correlation between the HGI values and the risk of 5-year MACE.Both low and high HGIs were associated with an increased risk of MACE.Therefore,the HGI may predict the 5-year MACE risk.