Search Results (5)

The Zanhuang Complex is situated on the eastern margin of the Trans-North China Orogen, with the Huangcha Pluton being a constituent of this complex. To ascertain the nature of the approximately 2.5-billion-year-old Huangcha Pluton, crucial evidence for understanding its extensional setting was sought through petrogenesis and dating investigations. LA-ICP-MS dating of zircon from the granite yielded an age of (2488 ± 6) Ma. Primarily composed of porphyritic monzonite with sporadic melanocratic enclaves, the Pluton’s phenocrysts are predominantly feldspar with minor quartz. The granite exhibits high SiO₂ content (72.64%–74.16%) and alkali levels, with Na₂O + K₂O ranging from 7.59% to 9.07%, classifying it as a shoshonitic series with a slightly peraluminous feature. Enrichment in large-ion lithophile (LIL) elements (Rb, Th, and U) and depletion in Sr, V, Cr, Co, and Ni were observed, with high Rb/Sr and Ga/Al ratios ranging from 0.73 to 2.72 and 2.75 × 10⁻⁴ to 3.11 × 10⁻⁴, respectively. The rock exhibits high εNd(t) values, ranging from −0.06 to 0.88, with TDM2 ages falling between 2.79 and 2.87 billion years. Zircon grains display ¹⁷⁶Hf/¹⁷⁷Hf ratios ranging from 0.281266 to 0.281412 and εHf(t) values spanning from 0.96 to 6.18, calculated using the ²⁰⁷Pb/²⁰⁶Pb age. It is suggested that the Huangcha Pluton represents A-type granite formed via anatexis of the Neoarchean TTG in an extensional setting following orogenic processes. The formation of the Huangcha Pluton further corroborates the stabilization of the North China Craton towards the end of the Neoarchean. This finding supports the hypothesis that the North China Craton may belong to the Rae-family cratons, sharing similar magmatic and tectono-metamorphic records around ~2.5 billion years ago. Full article

Lilium is a genus of important ornamental plants with many colouring pattern variations. Lilium auratum is the parent of Oriental hybrid lilies. A typical feature of L. auratum is the presence of red-orange special raised spots named papillae on the interior tepals. Unlike the usual raised spots, the papillae are slightly rounded or connected into sheets and usually have hairy tips. To elucidate the potential genes regulating papillae development in L. auratum, we performed high-throughput sequencing of its tepals at different stages. Genes involved in the flavonoid biosynthesis pathway were significantly enriched during the colouration of the papillae, and CHS, F3H, F3′H, FLS, DFR, ANS, and UFGT were significantly upregulated. To identify the key genes involved in the papillae development of L. auratum, we performed weighted gene coexpression network analysis (WGCNA) and further analysed four modules. In total, 51, 24, 1, and 6 hub genes were identified in four WGCNA modules, MEbrown, MEyellow, MEpurple, and MEred, respectively. Then, the coexpression networks were constructed, and important genes involved in trichome development and coexpressed with anthocyanin biosynthesis genes, such as TT8, TTG1, and GEM, were identified. These results indicated that the papillae are essentially trichomes that accumulate anthocyanins. Finally, we randomly selected 12 hub genes for qRT-PCR analysis to verify the accuracy of our RNA-Seq analysis. Our results provide new insights into the papillae development in L. auratum flowers. Full article

Serologic measures of tissue transglutaminase (tTG) immunoglobulin A (IgA) and deamidated gliadin peptide (DGP) IgA and immunoglobulin G (IgG) are hallmark tests utilized when diagnosing individuals for celiac disease (CeD) and for monitoring adherence to a gluten-free diet (GFD), currently the only available treatment for CeD. We address two issues in this study: (i) the relapse to seropositivity for CeD patients who resume a gluten containing diet and (ii) the correlation between two different tTG-IgA assays near the upper limit of normal (ULN) designated thresholds. Regarding the first issue, often a suspected CeD individual is put back on a gluten diet to return to their serologic levels. However, we show it requires a substantial amount of gluten for serology to return to a positive level. For example, in one study of 22 patients treated with placebo and taking 84 g of gluten over 6 weeks, only two converted from seronegative to seropositive for tTG-IgA. Regarding the second topic, we compare the relationship for different serologic assays, namely tTG-IgA AB (recombinant, ULN = 4 units/mL) vs. tTG-IgA (non-recombinant, ULN = 20 units). There is a strong correlation between both measurements as evidenced by a Pearson coefficient of R = 0.8584; however, we observed that the cross-correlation in terms of sensitivity and specificity improved substantially by using an ULN value of three instead of four for the tTG-IgA AB (recombinant) assay. This result suggests that assay thresholds used for initial diagnosis in patients who have not yet started a GFD may need to be adjusted for monitoring and in the setting of a diagnostic gluten challenge. Full article

Archean supracrustal rocks from the Qingyuan area of the northern Liaoning terrane, the North China Craton, occur as enclaves or rafts of various scales within tonalite–trondhjemite–granodiorite (TTG) domes. They were normally subjected to metamorphism at amphibolite facies with locally granulite facies. We collected biotite two-feldspar gneiss from the Hongtoushan of the Qingyuan area and conducted petrography, mineral chemistry, phase equilibrium modeling and monazite dating to reveal its metamorphic evolution. The peak condition was constrained to be 750–775 °C at ~7 kbar based on the stability of the inferred peak mineral assemblage and mineral compositions including the pyrite and grossular contents in the garnet core, and X_Mg in biotite. The final condition was constrained to be ~700 °C at ~6 kbar on the solidus based on the presence of muscovite in the final assemblage. The post-peak near-isobaric cooling process was consistent with the core→rim decreasing pyrite content in garnet. Monazite dating yielded a metamorphic age of ~2.50 Ga for the sample, coeval with the final magmatism of TTGs in the terrane. By combining other geological features, we suggest a vertical sagduction process to be responsible for the metamorphic evolution of the Qingyuan area. This process may be correlated with Archean mantle plume. Full article

The Moodies Group, the uppermost unit in the Barberton Greenstone Belt (BGB) in South Africa, is a ~3.7-km-thick coarse clastic succession accumulated on terrestrial-to-shallow marine settings at around 3.22 Ga. The multiple sulfur isotopic composition of pyrite of Moodies intervals was newly obtained to examine the influence of these depositional settings on the sulfur isotope record. Conglomerate and sandstone rocks were collected from three synclines north of the Inyoka Fault of the central BGB, namely, the Eureka, Dycedale, and Saddleback synclines. The sulfur isotopic composition of pyrite was analyzed by Secondary Ion Mass Spectrometry (SIMS) for 6 samples from the three synclines and by Isotope Ratio Mass Spectrometry (IR-MS) for 17 samples from a stratigraphic section in the Saddleback Syncline. The present results show a signal of mass-independent fractionation of sulfur isotopes (S-MIF), although t-tests statistically demonstrated that the Moodies S-MIF signals (mostly 0‰ < ∆³³S < +0.5‰) are significantly small compared to the signal of the older Paleoarchean (3.6–3.2 Ga) records. These peculiar signatures might be related to initial deposition of detrital pyrite of juvenile origin from the surrounding intrusive (tonalite–trondhjemite–granodiorite; TTG) and felsic volcanic rocks, and/or to secondary addition of hydrothermal sulfur during late metasomatism. Moreover, fast accumulation (~0.1–1 mm/year) of the Moodies sediments might have led to a reduced accumulation of sulfur derived from an atmospheric source during their deposition. As a result, the sulfur isotopic composition of the sediments may have become susceptible to the secondary addition of metasomatic sulfur on a mass balance point of view. The sulfur isotopic composition of Moodies pyrite is similar to the composition of sulfides from nearby gold mines. It suggests that, after the Moodies deposition, metasomatic pyrite formation commonly occurred north of the Inyoka Fault in the central BGB at 3.1–3.0 Ga. Full article