Geochemistry of biotites and host granitoid plutons from the Proterozoic Mahakoshal Belt, central India tectonic zone: implication for nature and tectonic setting of magmatism

<div><p>The northern part of the central India tectonic zone (CITZ) is occupied by the Proterozoic Mahakoshal Belt, which is mainly comprised of granitoids and volcano-sedimentary lithounits. The granitoids (ca. 1880–1710 Ma) are exposed as small circular to elliptical-shaped, stock-like intrusive bodies, such as Nerueadamar granitoids (NG), Tumiya granitoids (TG), Jhirgadandi granitoids (JG), Dudhi granite gneiss (DG), Raspahari granitoids (RG), Katoli granitoids (KG), and Harnakachar granitoids (HG), collectively forming the granite gneissic complex (GGC). The geochemistry of biotites, host granitoids, and enclaves from these plutons has been investigated in order to understand the redox condition and likely tectonic affinity of host granitoids. The Al₂O₃–MgO–FeO^t contents and operated elemental substitution in biotites strongly suggest the diverse nature of host magmas such as calc-alkaline, metaluminous (I-type), peraluminous (S-type), and transitional between I- and S-types, which appear to have formed in subduction zone and syn-collisional tectonic settings. The transitional (I-S)-type granitoids inferred based on biotite compositions, however, represent both metaluminous (HG) and peraluminous (DG and KG) granitoids in terms of whole-rock molar A/CNK (Al₂O₃/CaO + Na₂O + K₂O) ratios. Ages of granitoid magmatism and its field association with contemporaneous volcano-sedimentary lithounits clearly mark the post-collisional tectonic setting, which contradicts the subduction-related tectonic setting inferred from biotites of JG and microgranular enclave (JE) hosted in JG. Whole-rock major and trace elements broadly suggest the existence of collision tectonics during the formation of granitoid plutons. The JG, KG, and DG contain a bt-Kf-mag-qtz assemblage, and their parental magmas evolved under moderate oxidizing environments (ƒO₂ = −12.03 to −13.27 bars). On the other hand, RG (bt-gt-Kf-pl-qtz), NG (bt-ms-Kf-pl-qtz), and TG (bt-ms-Kf-pl-qtz) represent pure crustal-derived magmas evolved in strongly reducing conditions formed under a syn-collisional tectonic setting as evident from their mineral assemblages and biotite and whole-rock compositions. Granitoid plutons of the Mahakoshal Belt were most likely formed during amalgamation of the Columbian supercontinent.</p></div

Time-gated luminescence acquisition for biochemical sensing: miRNA detection*Relacionar en OpeAire*

Luminescence emission is a multidimensional phenomenon comprising a time-domain layer defined by its excited-state kinetics and corresponding lifetime, which is specific to each luminophore and depends on environmental conditions. This feature allows for the discrimination of luminescence signals from species with a similar spectral profile but different lifetimes by time-gating (TG) the acquisition of luminescence. This approach represents an efficient tool for removing unwanted, usually short-lived, signals from scattered light and fluorescence interferents using luminophores with a long lifetime. Due to the emergence of time-resolved techniques using rapid excitation and acquisition methods (i.e., pulsed lasers and single-photon timing acquisition) and new long-lifetime luminophores (i.e., acridones, lanthanide complexes, nanoparticles, etc.), TG analyses can be easily applied to relevant chemical and biochemical issues. The successful application of TG to important biomedical topics has attracted the attention of the R&D industry due to its potential in the development and patenting of new probes, methods and techniques for drug discovery, immunoassays, biomarker discovery and biomolecular interactions, etc. Here, we review the technological efforts of innovative companies in the application of TG-based techniques. Among the many currently available biomarkers, circulating microRNAs (miRNAs) have received attention since they are highly specific and sensitive to different pathological stages of numerous diseases and easily accessible from biological fluids. qPCR is a powerful and routine technique used for the detection and quantification of miRNAs, but qPCR may introduce numerous artefacts and low reproducibility during the amplification process, particularly using complex samples. Thus, due to the efficiency of TG in separating short- lived sources of fluorescence common in biological fluids, TG is an ideal approach for the direct detection of miRNAs in liquid biopsies. Recently, great efforts in the use of TG have been achieved. Our contribution is the proposal of a direct detection approach using TG- imagining with single nucleobase resolution.European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 690866 (miRNA-DisEASY)Proyecto CTQ2017-85658-R. Ministerio de Economía y Competitividad/Agencia Estatal deInvestigación/Fondo Europeo de Desarrollo Regional (FEDER