The deposition and significance of an Ediacaran non-glacial iron formation.

Most Neoproterozoic iron formations (NIF) are closely associated with global or near-global "Snowball Earth" glaciations. Increasingly, however, studies indicate that some NIFs show no robust evidence of glacial association. Many aspects of non-glacial NIF genesis, including the paleo-environmental setting, Fe(II) source, and oxidation mechanisms, are poorly understood. Here, we present a detailed case study of the Jiapigou NIF, a major non-glacial NIF within a Neoproterozoic volcano-sedimentary sequence in North Qilian, northwestern China. New U-Pb geochronological data place the depositional age of the Jiapigou NIF at ~600 Ma. Petrographic and geochemical evidence supports its identification as a primary chemical sediment with significant detrital input. Major and trace element concentrations, REE + Y systematics, and εNd (t) values indicate that iron was sourced from mixed seawater and hydrothermal fluids. Iron isotopic values (δ56 Fe = -0.04‰-1.43‰) are indicative of partial oxidation of an Fe(II) reservoir. We infer that the Jiapigou NIF was deposited in a redox stratified water column, where hydrothermally sourced Fe(II)-rich fluids underwent oxidation under suboxic conditions. Lastly, the Jiapigou NIF has strong phosphorous enrichments, which in other iron formations are typically interpreted as signals for high marine phosphate concentrations. This suggests that oceanic phosphorus concentrations could have been enriched throughout the Neoproterozoic, as opposed to simply during glacial intervals.

LncRNA H19 promotes keloid formation through targeting the miR-769-5p/EIF3A pathway.

Keloid is a skin disease characterized by fibrous hyperplasia, which is often difficult to cure. Long non-coding RNAs (lncRNAs) have been shown to be associated with the development of many diseases. However, the role and mechanism of lncRNA H19 in keloid has been less studied. Our study found that lncRNA H19 expression was increased in keloid tissues and fibroblasts. Besides, H19 knockdown hindered the proliferation, migration, invasion, extracellular matrix (ECM) deposition, and enhanced the apoptosis of keloid fibroblasts. Further experiments showed that microRNA (miR)-769-5p could be sponged by H19, and its knockdown reversed the suppression effect of H19 knockdown on keloid formation. Eukaryotic initiation factor 3A (EIF3A) was found to be a target of miR-769-5p, and its overexpression inverted the inhibition effect of miR-769-5p overexpression on keloid formation. Moreover, the expression of EIF3A was regulated by H19 and miR-769-5p in keloid fibroblasts. Collectively, LncRNA H19 might play an active role in keloid formation, which might provide a new target for the treatment of keloid.

Subtle Cr isotope signals track the variably anoxic Cryogenian interglacial period with voluminous manganese accumulation and decrease in biodiversity.

Earth's atmosphere experienced a step of profound oxygenation during the Neoproterozoic era, accompanied by diversification of animals. However, during the Cryogenian period (720-635 million years ago) Earth experienced its most severe glaciations which likely impacted marine ecosystems and multicellular life in the oceans. In particular, large volumes of Mn and Fe accumulated during the interglacial intervals of the Cryogenian glaciations, indicating large anoxic marine metal reservoirs. Here we present chromium isotope-, rare earth element-, and redox-sensitive trace element data of sedimentary rocks from the interglacial Datangpo Formation deposited between the Sturtian and Marinoan glaciations in South China, in an attempt to investigate the oxidation state of the oceans and atmosphere. Both the Cr isotope and trace element data indicate mainly anoxic water conditions with cryptic oxic surface water incursions after the Sturtian glaciation. Glacial-fed manganese precipitated as manganese carbonate in anoxic basins, and the non-fractionated δ53Cr record of -0.10 ± 0.06‰ identifies anoxic conditions with a cryptic component of slightly fractionated Cr isotope composition in manganese ore, in line with distinctly fractionated Mo isotope composition. Both the manganese carbonate ore and the black shales exhibit very low redox-sensitive element concentrations. Our study demonstrates that the oxygenation of the seawater, and inferably of the atmosphere, at the beginning of the Cryogenian interglacial interval was much subdued. The post-glacial rebound then allowed the Ediacaran biological diversity.

[Relationship between CT findings and immunohistochemical types of gastrointestinal stromal tumors].

OBJECTIVE: To evaluate the relationship between CT findings and immunohistochemical types of gastrointestinal stromal tumors (GIST). METHODS: CT imaging and clinicopathological data of 85 patients with GIST were analyzed retrospectively. The CT findings of GIST including lesion location, size, contour, boundary, tumor growth pattern, degree of enhancement, necrosis and calcification, were summarized and compared with the immunohistochemical types of the GIST. RESULTS: Of the 85 patients, smooth muscle differentiation was in 26 cases (30.6%), neural differentiation in 20 (23.5%) , both smooth muscle and neural differentiation in 10 (11.8%) and no obvious differentiation in 29 (34.1%) cases. GISTs occurred in the duodenum were more frequently seen in muscle type than in any other types, GIST with smooth muscle differentiation had higher prevalence of huge mass (larger than 10 cm), distinctive enhancement and extensive necrosis than other types (P < 0.05). There was no significant difference in the relationships of immunohistochemical types with tumor contour, boundary, growth pattern and calcification among the four groups of GIST (P > 0.05). CONCLUSIONS: CT scan is the most important and effective method for diagnosis of GIST. Analyzing CT signs has some potential value in judgmet of immunohistochemical types of GIST.

[Biologic effect of transforming growth factor-ß1 on urethra cells cultured in vitro].

OBJECTIVE: To investigate the effects of transforming growth factor-ß1 (TGF-ß1) on growth controlling and the expression of connective tissue growth factor mRNA(CTGF mRNA) in urethra epithelium cells and fibroblasts cultured in vitro. METHODS: Urethra epithelial cells and fibroblasts were cultured in vitro and identified. The fourth generation cells were divided into control group (cultured by cell medium without TGF-ß1) and experimental groups(cultured by cell medium containing TGF-ß1 1, 2, 4 and 8 µg/L), the vital force of cells were examined by MTT and cell counting, the expression of CTGF mRNA were examined by RT-PCR after 24 hours. RESULTS: The optical density and cell count decreased in experimental groups of urethra epithelium cells and increased in experimental groups of fibroblasts with the concentration of TGF-ß1 being heightened compared with the control group (P < 0.05). The expression of CTGF mRNA increased with the heightening concentration of TGF-ß1 in all experimental groups of urethra epithelium cells and fibroblasts by RT-PCR (P < 0.05). CONCLUSIONS: TGF-ß1 can inhibit the growth of urethra epithelium cells and promote the growth of fibroblasts in vitro, it can induce the expression of CTGF mRNA in two cells above-mentioned.