Effects of Organic Matter Graphitization on Shale Gas Accumulation in the Lower Paleozoic Longmaxi Formation from the Changning Area, Southern Sichuan Basin

AbstractTo investigate the characteristics of graphitized shale and the influence of organic matter graphitization on shale gas accumulation, Raman spectroscopy analysis, hydrocarbon generation simulation technique, reservoir physical property test, rock mechanics experiment, and field emission scanning electron microscopy (FE-SEM) were carried out on graphitized and nongraphitized shales of Longmaxi Formation in Changning area, southern Sichuan Basin. The results indicate that organic matter graphitization is a result of the thermal metamorphism of organic matter, and the resistivity of graphitized shale is generally lower than 10 Ω·m. The logging resistivity curves of the low-resistivity wells in the Wufeng Formation (O3w), Long11 sublayer (S1l11(1))-Long12 sublayer (S1l11(2)), Long13 sublayer (S1l11(3)), and Long14 sublayer (S1l11(4)) show box-shaped characteristics, and the logging resistivity curves at the boundary of the S1l11(3) and S1l11(4) exhibit a sharp drop. The graphitization of organic matter has great damage to hydrocarbon generation and reservoir capacity of shale, which is mainly manifested as the following: (1) the reduction of residual hydrocarbon caused by excessive thermal evolution weakens the gas generation capacity of shale, and the thermal evolution rate of graphitized shale is faster than that of nongraphitized shale; (2) the brittleness of graphitized shale increases due to the evolution of organic matter from a viscoelastic state to a glassy state; (3) organic pores and clay intercrystalline pores are destroyed or even disappeared during graphitization, which results in the deterioration of reservoir physical properties. Graphitized organic matter has good electrical conductivity, which is the reason for the formation of low-resistivity shale in the study area; (4) early hydrocarbon generation, poor reservoir physical properties, and unfavorable preservation are the main factors for the low gas content of graphitized shale. Therefore, it is of great significance to strengthen the study on organic matter graphitization and identify the graphitization area of organic matter for clarifying the next exploration direction and avoiding the risks of Lower Paleozoic shale gas exploration

Hot deformation behavior and microstructural evolution for dual-phase Mg–9Li–3Al alloys

The hot deformation behavior of dual-phase Mg–9Li–3Al alloys was investigated by the isothermal hot compression tests using the Gleeble-3500 thermal-mechanical simulation testing system over a temperature range from 473 to 623 K and a strain rate range of 0.001–1 s−1. The flow curves exhibited obvious serrations of periodic fluctuation at high strain rates, which can be considered as the Portevin-Le Chatelier effect. The relationship among flow stress, strain rate, and deformation temperature was analyzed. The deformation activation energy (Q) and some basic material factors (A, n, and α) were calculated based on the Zener–Hollomon equation. An approach of processing map composed of power dissipation and instability domains was established by the dynamic material model to reveal the hot workability. The flow instability domain only occurred at low temperatures and high strain rates. When the Mg–9Li–3Al alloy was deformed at 473 K and the strain rate of 1 s-1, numerous deformation twins were formed in α-Mg phases and, meanwhile, the β-Li phase was deformed and broken. When the temperature was increased to 573 K, the synergetic deformability between α-Mg and β-Li phases was improved due to the activation of more slip systems. However, the proportion of dynamic recrystallization was still low at the strain rate of 0.001 s-1. The needle-shaped α-Mg phase precipitated out in the β-Li matrix when the alloy was deformed at 623 K and the strain rate of 0.001 s-1. Its formation was attributed to the deformation-induced transformation. Moreover, the α-Mg phase can retard the dislocation movement and grain growth during deformation, leading to the precipitation/dispersion hardening

Regulating Th17/Treg Balance Contributes to the Therapeutic Effect of Ziyuglycoside I on Collagen-Induced Arthritis

To investigate the therapeutic effect and primary pharmacological mechanism of Ziyuglycoside I (Ziyu I) on collagen-induced arthritis (CIA) mice. CIA mice were treated with 5, 10, or 20 mg/kg of Ziyu I or 2 mg/kg of methotrexate (MTX), and clinical manifestations, as well as pathological changes, were observed. T cell viability and subset type were determined, and serum levels of transforming growth factor-beta (TGF-β) and interleukin-17 (IL-17) were detected. The mRNA expression of retinoid-related orphan receptor-γt (RORγt) and transcription factor forkhead box protein 3 (Foxp3) in mouse spleen lymphocytes was ascertained by the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). Molecular docking was used to detect whether there was a molecular interaction between Ziyu I and protein kinase B (Akt). The activation of mechanistic target of rapamycin (mTOR) in T cells was verified by Western blotting or immunofluorescence. Ziyu I treatment effectively alleviated arthritis symptoms of CIA mice, including body weight, global score, arthritis index, and a number of swollen joints. Similarly, pathological changes of joints and spleens in arthritic mice were improved. The thymic index, T cell activity, and RORγt production of Ziyu I-treated mice were significantly reduced. Notably, through molecular docking, western blotting, and immunofluorescence data analysis, it was found that Ziyu I could interact directly with Akt to reduce downstream mTOR activation and inhibit helper T cell 17 (Th17) differentiation, thereby regulating Th17/regulatory T cell (Treg) balance and improving arthritis symptoms. Ziyu I effectively improves arthritic symptoms in CIA mice by inhibiting mTOR activation, thereby affecting Th17 differentiation and regulating Th17/Treg balance

Biodegradation performance and diversity of enriched bacterial consortia capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high molecular weight (HMW) PAHs by enriched bacterial consortia has been previously studied, while the involved metabolisms and microbial communities are still unclear and warrant further investigations. In this study, five bacterial consortia capable of utilizing different PAHs (naphthalene, anthracene, and pyrene) as the sole carbon and energy sources were enriched from PAH-contaminated soil samples. Among the five consortia, consortium TC exhibited the highest pyrene degradation efficiency (91%) after 19 d of incubation. The degradation efficiency was further enhanced up to 99% by supplementing yeast extract. Besides, consortium TC showed tolerances to high concentrations of pyrene (up to 1000 mg/L) and different heavy metal stresses (including Zn2+, Cd2+, and Pb2+). The dominant genus in consortium TC, GS, and PL showing relatively higher degradation efficiency for anthracene and pyrene was Pseudomonas, whereas consortium PG and GD were predominated by genus Achromobacter and class Enterobacteriaceae, respectively. Consortium TC, as a highly efficient HMW PAH-degrading consortium, could be applied for synergistic biodegradation of HMW PAHs and in situ bioremediation of the sites contaminated with both PAHs and heavy metals

GRK2 mediated degradation of SAV1 initiates hyperplasia of fibroblast-like synoviocytes in rheumatoid arthritis

Hyperplasia and migration of fibroblast-like synoviocytes (FLSs) are the key drivers in the pathogenesis of rheumatoid arthritis (RA) and joint destruction. Abundant Yes-associated protein (YAP), which is a powerful transcription co-activator for proliferative genes, was observed in the nucleus of inflammatory FLSs with unknown upstream mechanisms. Using Gene Expression Omnibus database analysis, it was found that Salvador homolog-1 (SAV1), the pivotal negative regulator of the Hippo-YAP pathway, was slightly downregulated in RA synovium. However, SAV1 protein expression is extremely reduced. Subsequently, it was revealed that SAV1 is phosphorylated, ubiquitinated, and degraded by interacting with an important serine-threonine kinase, G protein-coupled receptor (GPCR) kinase 2 (GRK2), which was predominately upregulated by GPCR activation induced by ligands such as prostaglandin E2 (PGE2) in RA. This process further contributes to the decreased phosphorylation, nuclear translocation, and transcriptional potency of YAP, and leads to aberrant FLSs proliferation. Genetic depletion of GRK2 or inhibition of GRK2 by paroxetine rescued SAV1 expression and restored YAP phosphorylation and finally inhibited RA FLSs proliferation and migration. Similarly, paroxetine treatment effectively reduced the abnormal proliferation of FLSs in a rat model of collagen-induced arthritis which was accompanied by a significant improvement in clinical manifestations. Collectively, these results elucidate the significance of GRK2 regulation of Hippo-YAP signaling in FLSs proliferation and migration and the potential application of GRK2 inhibition in the treatment of FLSs-driven joint destruction in RA