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WAG flooding is a dynamic process of continuous reservoir flow field reconstruction. The unique advantages of WAG flooding cannot be utilized, due to the fixed water–gas ratio. Therefore, we must investigate the dynamic adjustment of the water–gas ratio for WAG flooding. Using nine cases of long-core displacement experiments in low-permeability reservoirs, the development effects of three different displacement methods, namely, continuous gas flooding, WAG flooding with a fixed water–gas ratio, and WAG flooding with a dynamic water–gas ratio, were investigated after elastic development, water flooding, and gas flooding. This study shows that for early elastic development in low-permeability reservoirs, WAG flooding can significantly improve oil recovery, but WAG flooding with a dynamic water–gas ratio is not conducive to the control of the water cut rise and gas channeling. As a result, it is more suitable to adopt WAG flooding with a fixed water–gas ratio. For early water flooding in low-permeability reservoirs, WAG flooding more clearly improves oil recovery and suppresses gas channeling, but WAG flooding with a dynamic water–gas ratio exhibits a higher oil recovery and thus is recommended. For early gas flooding in low-permeability reservoirs, whether the development effect of WAG flooding can improve oil recovery and inhibit gas channeling strongly depends on whether the water–gas ratio is adjusted. The development effect of WAG flooding with a dynamic water–gas ratio is significantly better than that with a fixed water–gas ratio. Therefore, WAG flooding with a dynamic water–gas ratio is recommended to achieve the best displacement effect. This research has important practical significance for further improving the development effect of WAG flooding in low-permeability reservoirs. [ABSTRACT FROM AUTHOR]

Oxidative stress linked to the etiology of Parkinson’s disease, which is characterized by chronic and progressive neurodegeneration of dopamine neurons. Superoxide dismutase enzymes (SODs) regarded as the first line of defense against oxidative damage. This study assessed the potential associations of gene polymorphisms in SOD1 (encoding Cu/Zn-SOD), SOD2 (encoding Mn-SOD) and SOD3 (encoding extracellular-SOD) with susceptibility to Parkinson’s disease. A case-control study, including Parkinson’s disease cases (n = 356) and controls (n = 370). Single nucleotide polymorphisms of SOD1 (rs2070424 A/G), SOD2 (rs4880 T/C) and SOD3 (rs1799895, C/G) were genotyped. Results indicated that AG or GG genotype carriers in SOD1 had a much greater risk of Parkinson’s disease compared to corresponding AA genotypes, and allele G carriers had increased risk versus allele A carriers in the single nucleotide polymorphism (rs2070424 A/G) in SOD1. Further, TC or CC genotype carriers in SOD2 had a much higher risk of Parkinson’s disease compared with corresponding TT genotypes, and the C carriers had an increased risk over allele T carriers in the single nucleotide polymorphism (rs4880 T/C) in SOD2. Together, carrying allele G in the single nucleotide polymorphism (rs2070424 A/G) in SOD1, or allele C in the single nucleotide polymorphism (rs4880 T/C) in SOD2, enhances genetic susceptibility to Parkinson’s disease.

In this work, a novel workflow has been proposed, validated and applied to interpret the early time transient pressure data in tight oil reservoirs with physical constraints. More specifically, the theoretical model was developed to obtain the transient pressure response for a vertical well in tight oil reservoirs with consideration of pseudo threshold pressure gradient (TPG). Then, a physical constraint between the skin factor and formation permeability has been proposed based on the physical meaning of percolation theory. This physical constraint can be applied to determine the lower limit of the skin factor which can reduce the uncertainty during the interpretation process. It is found that the influence range of the skin factor and permeability may partially overlap during the interpretation process without consideration of physical constraints. Additionally, it is found that the equivalent wellbore radius is more reasonable by considering the skin factor constraints. Furthermore, the short-time asymptotic method was applied to separate the small pressure signal at the early time period and a novel type curve was proposed to better analyze the early time pressure response. Subsequently, sensitivity analyses were conducted to investigate the influence of different parameters on the new type curves. It is found that the new type curves are more dispersed and sensitive to the parameters at the early time period which can be beneficial for the early time transient pressure analysis in a tight formation. The proposed method has been validated and then extended to a field application, demonstrating that the transient pressure for a vertical well in a tight formation can be analyzed in a reasonable and accurate manner with only early time transient pressure data. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the effects of synuclein-γ (SNCG) silencing on gastric cancer SGC7901 cells and to elucidate the associated mechanisms. pGCSIL-lentiviral siRNA targeting of the SNCG gene was employed to inhibit SNCG expression. Several experiments such as quantitative real-time PCR, Western blotting, MTT, colony formation, migration assay, and flow cytometry were performed to investigate the biological behavior of infected SGC7901 cells. BALB/c nude mice were used as tumor xenograft models to assess the effects of SNCG silencing on tumor growth. Western blot analysis was carried out to determine the relative levels of AKT, p-AKT, ERK, and p-ERK expression. Our results showed that SNCG was overexpressed in SGC7901 cells as compared to normal gastric mucosal epithelial cells. SGC7901 cells transfected with SNCG siRNA demonstrated significantly decreased gastric cancer growth (p < 0.01), reduced cell migration, cell cycle arrest in the G0/G1 phase, promoted tumor cell apoptosis (p < 0.01), and inhibited tumorigenesis in xenograft animal models. Western blot analysis indicated that the protein levels of p-AKT and p-ERK were much lower in the SNCG siRNA group than in the control groups. The results of the present study suggest that SNCG siRNA plays a significant role in the proliferation, migration, and tumorigenesis of gastric cancer by downregulating the phosphorylation of AKT and ERK. RNA interference-mediated silencing of SNCG may provide an opportunity to develop a novel treatment strategy for gastric cancer. [ABSTRACT FROM AUTHOR]