Global glaciations and atmospheric change at ca. 2.3 Ga

AbstractThis paper compiles lithostratigraphic and geochronological data obtained for the Palaeoproterozoic glacial diamictite-bearing successions, and thereby provides insights into understanding the geological processes causing the Huronian Glaciation Event. The majority of evidence for appearances of this glaciation event can be related to the Kenorland supercontinent breakup, allied to significant atmospheric change, as well as blooms of biogeochemical oxygenic photosynthesis. In this paper, the Huronian Glaciation Event is constrained to have occurred synchronously during 2.29–2.25 Ga, accompanied by dramatic environmental changes characteristic of the Great Oxidation Event which includes the pre-2.3 Ga hydrosphere oxidation and the post-2.3 Ga atmosphere oxygenation

In situ LA-ICP-MS trace element analysis of magnetite from the late Neoarchean Gongchangling BIFs, NE China: Constraints on the genesis of high-grade iron ore

The Precambrian banded iron formations (BIFs) not only relate to the evolution of life, ocean, and atmosphere but also provide important reserves of iron around the world. The Gongchangling iron ore deposit located in the Anshan-Benxi area of Liaoning Province, China, is oxide facies Algoma-type BIFs, and the Gongchangling No.2 mining area is famous for the production of high-grade iron ore in China. Magnetite is the main ore mineral in the Gongchangling iron ore deposit, and the magnetite mainly exhibits three modes of occurrence: BIFs (without actinolite), actinolite-bearing BIFs, and high-grade iron ore. Trace elemental compositions of the magnetite with different occurrences of the Gongchangling iron ore deposit were obtained by laser ablation inductively coupled plasma mass spectrometry to constrain the genesis of the high-grade iron ore. The magnetite from actinolite-bearing BIFs shows relatively lower contents of Mg, Al, Mn, and Zn compared to the magnetite from BIFs (without actinolite), suggesting that coexisting minerals have played an important role in the trace element concentration in magnetite. The magnetite from high-grade iron ore has lower contents of Ti and V and higher contents of Al and Mn than counterpart from BIFs (with/without actinolite), indicating that the high-grade iron ore may be reformed by high temperature metamorphic hydrothermal fluid. The staurolite-garnet-biotite schist is the wall-rock of high-grade iron ore, and the garnet-biotite geothermometry is used to evaluate the metamorphic temperature of 593 +/- 17 degrees C. It is proposed that the metamorphic hydrothermal fluid produced during regional metamorphism reformed BIFs to generate high-grade iron ore

The Modulation of Regulatory T Cells via HMGB1/PTEN/β-Catenin Axis in LPS Induced Acute Lung Injury.

Sepsis-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) remains the leading complication for mortality caused by bacterial infection. The regulatory T (Treg) cells appear to be an important modulator in resolving lung injury. Despite the extensive studies, little is known about the role of macrophage HMGB1/PTEN/β-catenin signaling in Treg development during ALI. Objectives: This study was designed to determine the roles and molecular mechanisms of HMGB1/PTEN/β-catenin signaling in mediating CD4+CD25+Foxp3+ Treg development in sepsis-induced lung injury in mice. Setting: University laboratory research of First Affiliated Hospital of Anhui Medical University. Subjects: PTEN/β-catenin Loxp and myeloid-specific knockout mice. Interventions: Groups of PTENloxp/β-cateninloxp and myeloid-specific PTEN/β-catenin knockout (PTENM-KO/β-cateninM-KO) mice were treated with LPS or recombinant HMGB1 (rHMGB1) to induce ALI. The effects of HMGB1-PTEN axis were further analyzed by in vitro co-cultures. Measures and Main Results: In a mouse model of ALI, blocking HMGB1 or myeloid-specific PTEN knockout (PTENM-KO) increased animal survival/body weight, reduced lung damage, increased TGF-β production, inhibited the expression of RORγt and IL-17, while promoting β-catenin signaling and increasing CD4+CD25+Foxp3+ Tregs in LPS- or rHMGB-induced lung injury. Notably, myeloid-specific β-catenin ablation (β-cateninM-KO) resulted in reduced animal survival and increased lung injury, accompanied by reduced CD4+CD25+Foxp3+ Tregs in rHMGB-induced ALI. Furthermore, disruption of macrophage HMGB1/PTEN or activation of β-catenin significantly increased CD4+CD25+Foxp3+ Tregs in vitro. Conclusions: HMGB1/PTEN/β-catenin signaling is a novel pathway that regulates Treg development and provides a potential therapeutic target in sepsis-induced lung injury

The Modulation of Regulatory T Cells via HMGB1/PTEN/β-Catenin Axis in LPS Induced Acute Lung Injury.

Sepsis-induced acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) remains the leading complication for mortality caused by bacterial infection. The regulatory T (Treg) cells appear to be an important modulator in resolving lung injury. Despite the extensive studies, little is known about the role of macrophage HMGB1/PTEN/β-catenin signaling in Treg development during ALI. Objectives: This study was designed to determine the roles and molecular mechanisms of HMGB1/PTEN/β-catenin signaling in mediating CD4+CD25+Foxp3+ Treg development in sepsis-induced lung injury in mice. Setting: University laboratory research of First Affiliated Hospital of Anhui Medical University. Subjects: PTEN/β-catenin Loxp and myeloid-specific knockout mice. Interventions: Groups of PTENloxp/β-cateninloxp and myeloid-specific PTEN/β-catenin knockout (PTENM-KO/β-cateninM-KO) mice were treated with LPS or recombinant HMGB1 (rHMGB1) to induce ALI. The effects of HMGB1-PTEN axis were further analyzed by in vitro co-cultures. Measures and Main Results: In a mouse model of ALI, blocking HMGB1 or myeloid-specific PTEN knockout (PTENM-KO) increased animal survival/body weight, reduced lung damage, increased TGF-β production, inhibited the expression of RORγt and IL-17, while promoting β-catenin signaling and increasing CD4+CD25+Foxp3+ Tregs in LPS- or rHMGB-induced lung injury. Notably, myeloid-specific β-catenin ablation (β-cateninM-KO) resulted in reduced animal survival and increased lung injury, accompanied by reduced CD4+CD25+Foxp3+ Tregs in rHMGB-induced ALI. Furthermore, disruption of macrophage HMGB1/PTEN or activation of β-catenin significantly increased CD4+CD25+Foxp3+ Tregs in vitro. Conclusions: HMGB1/PTEN/β-catenin signaling is a novel pathway that regulates Treg development and provides a potential therapeutic target in sepsis-induced lung injury

Geochronology, geochemistry and tectonic significance of the ore-associated granites at the Kaladawan Fe-Mo ore field (Altyn), NW China

The Kaladawan Fe-Mo ore field (Altyn, Xinjiang) in Northwest (NW) China contains six deposits, with a total reserve of 60 Mt Fe and 10 Kt Mo metal. The orebodies are hosted in lower Paleozoic andesite, dacite, phyllite and marble with well-developed skarn alteration. The Kaladawan granites are newly U-Pb dated to be Early Ordovician (476.1 +/- 3.3 Ma), largely coeval with the Fe-Mo mineralization (molybdenite Re-Os: 480.3 +/- 3.2 Ma). The granites contain high SiO2, K2O and Al2O3 , low TiO2, MgO and CaO, with high K2O/Na2O ratios (1.26-1.58) and A/CNK values (1.00-1.08), showing peraluminous high-K calc-alkaline affinity. The rocks are characterized by large ion lithophile element (LILE) and light rare earth element (LREE) enrichments and depletions of Sr, Ba, Nb, Ta, Ti and P, and with negative Eu anomalies. The rocks have initial Sr-87/Sr-86 ratios of 0.7066 to 0.7112 and epsilon(Nd)(t) values of -1.4 to -1.1, with T-DM2(Nd) ages of 1.32-1.30 Ga. Zircon epsilon(Hf)(t) values range from 2.9 to 6.4, with T-DM2(Hf) ages of 1.26-1.04 Ga. The new geochemical and isotopic data suggest that the Kaladawan granites are highly fractionated I-type, and likely formed by fractional crystallization of a magma that was derived from partial melting of a mixture of crustal and mantle materials. Deposits in the Kaladawan Fe-Mo field are skarn-type and may have occurred in an active continental margin, via the contact metamorphism and metasomatic reaction between granite-derived fluids and the wall rocks. (C) 2017 Published by Elsevier B.V