Effects of pore connectivity and water saturation on matrix permeability of deep gas shale

Shale matrix permeability is an important indicator for evaluating gas transport and production. However, the effects of pore connectivity and water saturation on the matrix permeability in deep gas shales have not been adequately studied. In this study, the permeability of deep shales in the Yichang area of the Middle Yangtze was characterized using three methods. These included the determination of apparent permeability in different directions via pulse-decay, also matrix permeability obtained via the Gas Research Institute method, and the connected pore network permeability via the mercury injection capillary pressure technique. The results revealed a significant difference between the horizontal and vertical permeability of deep shales. The smaller the size of the multiple connected pore network, the larger was the effective tortuosity and the lower the permeability. Comparison of the three permeabilities and combined microscopic observations revealed that microfractures and laminae were the dominant gas transport channels. Importantly, the matrix permeability decreased exponentially with increasing water saturation, with water vapor adsorption experiments revealing that water occupation of pores and pore-throat spaces smaller than 10 nm in diameter was the main reason for this decrease in matrix permeability. Collectively, proposed method of evaluating effective permeability with an index for shale gas reservoirs is significant for sweet spot selection and production prediction of shale gas reservoirs around the globe.Cited as: Zhao, J., Sun, M., Pan, Z., Liu, B., Ostadhassan, M., Hu, Q. Effects of pore connectivity and water saturation on matrix permeability of deep gas shale. Advances in Geo-Energy Research, 2022, 6(1): 54-68. https://doi.org/10.46690/ager.2022.01.0

Reliability Assessment of Nanoscale System on Chip Depending on Neturon Irradiation

The atmospheric neutron poses a serious hazard to nanoscale electronics reliability. Spallation neutron irradiations on a nanoscale system on chip (SoC) were conducted applying the China Spallation Neutron Source (CSNS), and the results were compared and analyzed using Monte Carlo simulation. The contribution from thermal neutron on the SoC single event effect (SEE) was analyzed. Analysis indicated the SoC atmospheric neutron SEE vulnerability can be reduced by 44.4% if the thermal neutron was absorbed. The influences of the B and Hf elements on the SEEs were evaluated, too. It can be concluded that 10 B interacting with thermal neutron is the reason for thermal neutron inducing SEE in the SoC. Although the Hf element has no contribution to the 28 nm SoC atmospheric neutron SEE cross section, it increases the total dose risk 5 times during atmospheric neutron irradiation

Establishment and phenotype verification of mouse oviductal epithelial organoids

Objective·To establish a culture system of oviductal epithelial organoids from wild type (WT) mice and miR-34b/c-/- and miR-449-/- double knockout (dKO) mice, and verify the phenotypes.Methods·The oviduct epithelial cells of WT mice and dKO mice were isolated and purified by enzyme digestion and differential adhesion method, and the purity of the isolated oviduct epithelial cells was identified by immunofluorescence staining. The numbers, growth rates and sizes of oviductal epithelial organoids between WT mice and dKO mice were compared by counting and diameter measurement. Hematoxylin-eosin (H-E) staining and transmission electron microscope (TEM) were used to observe the morphology and structure of the oviductal epithelial organoids. The proportions of ciliated cells and secretory cells in the oviductal epithelial organoids from WT mice and dKO mice were observed and counted by immunofluorescence staining. Immunohistochemistry (IHC), real-time quantitative PCR (RT-qPCR) and Western blotting were used to observe the expression levels of marker genes of ciliated cells and secretory cells in the oviductal epithelial organoids.Results·The purity of the isolated and purified oviduct epithelial cells was high. Compared with the organoids from WT mice, the oviductal epithelial organoids from dKO mice grew faster and larger, and were more in number. But they developed more slowly than those from WT mice, as the invaginations of the dKO mice organoids appeared on the 28th day of culture, while the WT mice organoids exhibited the same structures on the 16th day. The oviductal epithelial organoids showed similar structures as those of the oviduct in vivo under hematoxylin-eosin (H-E) staining and TEM. Immunofluorescence staining showed that the ciliated cells of oviductal epithelial organoids from dKO mice were significantly reduced and the secretory cells were significantly increased (both P<0.05). IHC showed that the molecular expression patterns of the oviductal epithelial organoids were consistent with those of the oviducts in vivo, i.e. the expression levels of ciliated cell markers acetylated α-tubulin (Ac-α-tubulin) and forkhead box J1 (FOXJ1) decreased, and the expression level of the secretory cell marker paired box 8 (PAX8) increased. RT-qPCR showed that the mRNA levels of Foxj1 and tubulin β class Ⅳa (Tubb4a) decreased (both P<0.05), while Pax8 increased in the oviductal epithelial organoids of dKO mice (P<0.05). Western blotting results showed that the protein expression level of FOXJ1 in the organoids of dKO mice significantly decreased, while the expression of PAX8 significantly increased (both P<0.05).Conclusion·The culture system of oviductal epithelial organoids of WT mice and dKO mice are successfully constructed, which can simulate the phenotypes of mouse oviduct in vivo

Defense Responses to Short-term Hypoxia and Seawater Acidification in the Thick Shell Mussel Mytilus coruscus

The rising anthropogenic atmospheric CO2 results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell mussel Mytilus coruscus were exposed to three pH/pCO2 levels (7.3/2800 μatm, 7.7/1020 μatm, 8.1/376 μatm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L−1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments

Pre-Operative Prediction of Mediastinal Node Metastasis Using Radiomics Model Based on 18F-FDG PET/CT of the Primary Tumor in Non-Small Cell Lung Cancer Patients

Purpose: We investigated whether a fluorine-18-fluorodeoxy glucose positron emission tomography/computed tomography (18F-FDG PET/CT)-based radiomics model (RM) could predict the pathological mediastinal lymph node staging (pN staging) in patients with non-small cell lung cancer (NSCLC) undergoing surgery.Methods: A total of 716 patients with a clinicopathological diagnosis of NSCLC were included in this retrospective study. The prediction model was developed in a training cohort that consisted of 501 patients. Radiomics features were extracted from the 18F-FDG PET/CT of the primary tumor. Support vector machine and extremely randomized trees were used to build the RM. Internal validation was assessed. An independent testing cohort contained the remaining 215 patients. The performances of the RM and clinical node staging (cN staging) in predicting pN staging (pN0 vs. pN1 and N2) were compared for each cohort. The area under the curve (AUC) of the receiver operating characteristic curve was applied to assess the model's performance.Results: The AUC of the RM [0.81 (95% CI, 0.771–0.848); sensitivity: 0.794; specificity: 0.704] for the predictive performance of pN1 and N2 was significantly better than that of cN in the training cohort [0.685 (95% CI, 0.644–0.728); sensitivity: 0.804; specificity: 0.568], (P-value = 8.29e-07, as assessed by the Delong test). In the testing cohort, the AUC of the RM [0.766 (95% CI, 0.702–0.830); sensitivity: 0.688; specificity: 0.704] was also significantly higher than that of cN [0.685 (95% CI, 0.619–0.747); sensitivity: 0.799; specificity: 0.568], (P = 0.0371, Delong test).Conclusions: The RM based on 18F-FDG PET/CT has a potential for the pN staging in patients with NSCLC, suggesting that therapeutic planning could be tailored according to the predictions

Characteristics and distribution of geohazards since the middle miocene of the Xisha sea area, South China Sea

Geological hazards can cause significant harm to the construction and maintenance of reef infrastructure projects in the Xisha Sea area. This study uses high-resolution multichannel earthquake data, single-channel seismic profiles, and multi-beam survey data to identify and analyze the geological hazards in the Xisha Sea area since the Miocene. Based on the geophysical data interpretation, the destructive geological disaster factors that are active, such as active faults, shallow gas, diapers, landslides, multistage scarps (steps), scouring troughs, and canyons, as well as the restrictive geological disaster factors without activity ability, such as buried paleochannels, pockmarks, reefs, and undersea volcanoes, are identified and analyzed. This paper discusses the causes and hazards of geological hazards and, for the first time, draws a comprehensive plane layout of the geological hazards. The above analysis demonstrates that the scarps are mainly located around the atolls or platforms, and the slope of the southeast seabed topography is significantly higher than that of the northwest. There are seven medium and large landslides, mainly located around Yongxing Plateau and Yongle Plateau, caused by gravity and faulting. Shallow gas is mainly developed in the southern part of the North Reef and is indicated by diaper structures, faults, and gas chimneys. A series of shallow faults are developed in the study area, mainly steep normal faults. The scouring troughs are primarily distributed near the Yongxing Platform, Zhongjian North Platform, and Huaguang Platform. Submarine canyons are primarily located in the northern and southern parts of the Shidao Platform. Affected by multiple factors such as hydrodynamic conditions, the stability of sedimentary layers, and sediment supply, the scour degree varies, with the general depth ranging from several meters to several hundred meters. Underwater infrastructure in the study area should not be constructed in areas with active and destructive geological hazards. The results of this study can serve as a guide for further exploration in the Xisha area and disaster prevention and mitigation during construction activity in the area

Overexpression of DBT suppresses the aggressiveness of renal clear cell carcinoma and correlates with immune infiltration

Conventional therapy for kidney renal clear cell carcinoma (KIRC) is unpromising. The tumor microenvironment (TME) is intimately linked to the invasiveness of a variety of tumor forms, including KIRC. The purpose of this research is to establish the prognostic and immune-related significance of dihydrolipoamide branched chain transacylase E2 (DBT) in individuals with KIRC. In this investigation, we discovered that DBT expression was down-regulated in a range of human malignancies, and low DBT expression in KIRC was linked to higher-level clinicopathological characteristics as well as a poor prognosis for KIRC patients. Based on the findings of univariate and multivariate Cox regression analyses, DBT might be employed as an independent prognostic factor in KIRC patients. Furthermore, we developed a nomogram to better investigate DBT’s predictive usefulness. To confirm DBT expression, we examined KIRC cell lines using RT-qPCR and Western blotting. We also examined the role of DBT in KIRC using colony formation, CCK-8, EdU, transwell, and wound healing assays. We discovered that plasmid-mediated overexpression of DBT in KIRC cells slowed cell proliferation and decreased migration and invasion. Multiple enrichment analyses revealed that DBT may be involved in processes and pathways related to immunotherapy and drug metabolism. We computed the immune infiltration score and discovered that the immunological score and the ESTIMATE score were both greater in the DBT low expression group. According to the CIBERSORT algorithm, DBT seems to promote anti-cancer immune responses in KIRC by activating M1 macrophages, mast cells, and dendritic cells while inhibiting regulatory T cells. Finally, in KIRC, DBT expression was found to be highly linked to immunological checkpoints, targeted medicines, and immunotherapeutic agents. Our findings suggest that DBT is a distinct predictive biomarker for KIRC patients, playing a significant role in the TME of KIRC and serving as a reference for the selection of targeted treatment and immunotherapy