Numerical simulation and thermo-hydro-mechanical coupling model of in situ mining of low-mature organic-rich shale by convection heating

The in situ efficient exploitation of low-mature organic-rich shale resources is critical for alleviating the current oil shortage. Convection heating is the most critical and feasible method for in situ retortion of shale. In this study, a thermo-hydro-mechanical coupling mathematical model for in situ exploitation of shale by convection heating is developed. The dynamic distribution of the temperature, seepage, and stress fields during the in situ heat injection of shale and the coupling effect between multiple physical fields are studied. When the operation time increases from 1 to 2.5 years, the temperature of most shale formations between heat injection and production wells increases significantly (from less than 400 to 500 °C), which is a period of significant production of shale oil and pyrolysis gas. The fluid pore pressure gradually decreases from the peak point of the heat injection well to the surrounding. Compared with shale formation, bedrock permeability is poor, pore pressure increases slowly, and a lag phenomenon exists. The pore pressure difference between bedrock and shale is minimal by 1 year. When the heat injection time is 2.5 years, the permeability coefficient of shale formation in the area from the heat injection well to the production wells increases nearly 100 times the initial permeability coefficient. With increasing formation temperature, the vertical stress gradually evolves from compressive stress to tensile stress. Meanwhile, the action area of tensile stress expands outward with time with the heat injection well as the center. In general, increasing tensile stress enlarges the pore volume. It extends the fracture width, creating favorable conditions for the injection of high-temperature fluids and the production of oil and gas.Cited as: Zhao, J., Wang, L., Liu, S., Kang, Z., Yang, D., Zhao, Y. Numerical simulation and thermo-hydro-mechanical coupling model of in situ mining of low-mature organic-rich shale by convection heating. Advances in Geo-Energy Research, 2022, 6(6): 502-514. https://doi.org/10.46690/ager.2022.06.0

Interferometric Radar for Activity Recognition and Benchmarking in Different Radar Geometries

Radar micro-Doppler signatures have been proposed for human activity classification for surveillance and ambient assisted living in healthcare-related applications. A known issue is the performance reduction when the target is moving tangentially to the line-of-sight of the radar. Multiple techniques have been proposed to address this, such as multistatic radar and to some extent, interferometric radar. A simulator is presented to generate synthetic data representative of 8 different radar systems (including configurations as monostatic, multistatic, and interferometric) to quantify classification performances as a function of aspect angles and deployment geometries. This simulator allows an unbiased performance evaluation of the different radar systems. 6 human activities are considered with signatures originating from motion-captured data of 14 different subjects. The results show that interferometric radar data with fusion outperforms the other methods with over 97.6% accuracy consistently across all aspect angles, as well as the potential for simplified indoor deployment

Eight-Port Modified E-Slot MIMO Antenna Array with Enhanced Isolation for 5G Mobile Phone

An eight-element antenna system operating at sub 6 GHz is presented in this work for a future multiple-input multiple-output (MIMO) system based on a modified E-slot on the ground. The modified E-slot significantly lowers the coupling among the antenna components by suppressing the ground current effect. The design concept is validated by accurately measuring and carefully fabricating an eight-element MIMO antenna. The experimentation yields higher element isolation greater than −21 dB in the 3.5 GHz band and the desired band is achieved at −6 dB impedance bandwidth. The E-shape slot occupies an area of 17.8 mm × 5.6 mm designed on an FR-4 substrate with dimensions of 150 mm × 75 mm × 0.8 mm. We fed the I-antenna element with an L-shape micro-strip feedline, the size of the I-antenna is 20.4 × 5.2 mm2, which operates in the (3.4–3.65 GHz) band. Moreover, our method obtained an envelope correlation coefficient (ECC) of <0.01 and an ergodic channel capacity of 43.50 bps/Hz. The ECC and ergodic channel capacity are important metrics for evaluating MIMO system performance. Results indicate that the proposed antenna system is a good option to be used in 5G mobile phone applications

ADAR2-dependent RNA editing of GluR2 is involved in thiamine deficiency-induced alteration of calcium dynamics

BACKGROUND: Thiamine (vitamin B1) deficiency (TD) causes mild impairment of oxidative metabolism and region-selective neuronal loss in the central nervous system (CNS). TD in animals has been used to model aging-associated neurodegeneration in the brain. The mechanisms of TD-induced neuron death are complex, and it is likely multiple mechanisms interplay and contribute to the action of TD. In this study, we demonstrated that TD significantly increased intracellular calcium concentrations [Ca2+]i in cultured cortical neurons. RESULTS: TD drastically potentiated AMPA-triggered calcium influx and inhibited pre-mRNA editing of GluR2, a Ca2+-permeable subtype of AMPA receptors. The Ca2+ permeability of GluR2 is regulated by RNA editing at the Q/R site. Edited GluR2 (R) subunits form Ca2+-impermeable channels, whereas unedited GluR2 (Q) channels are permeable to Ca2+ flow. TD inhibited Q/R editing of GluR2 and increased the ratio of unedited GluR2. The Q/R editing of GluR2 is mediated by adenosine deaminase acting on RNA 2 (ADAR2). TD selectively decreased ADAR2 expression and its self-editing ability without affecting ADAR1 in cultured neurons and in the brain tissue. Over-expression of ADAR2 reduced AMPA-mediated rise of [Ca2+]i and protected cortical neurons against TD-induced cytotoxicity, whereas down-regulation of ADAR2 increased AMPA-elicited Ca2+ influx and exacerbated TD-induced death of cortical neurons. CONCLUSIONS: Our findings suggest that TD-induced neuronal damage may be mediated by the modulation of ADAR2-dependent RNA Editing of GluR2

Application of CRISPR-Cas system in the diagnosis and therapy of ESKAPE infections

Antimicrobial-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. ESKAPE pathogens are the most common opportunistic pathogens in nosocomial infections, and a considerable number of their clinical isolates are not susceptible to conventional antimicrobial therapy. Therefore, innovative therapeutic strategies that can effectively deal with ESKAPE pathogens will bring huge social and economic benefits and ease the suffering of tens of thousands of patients. Among these strategies, CRISPR (clustered regularly interspaced short palindromic repeats) system has received extra attention due to its high specificity. Regrettably, there is currently no direct CRISPR-system-based anti-infective treatment. This paper reviews the applications of CRISPR-Cas system in the study of ESKAPE pathogens, aiming to provide directions for the research of ideal new drugs and provide a reference for solving a series of problems caused by multidrug-resistant bacteria (MDR) in the post-antibiotic era. However, most research is still far from clinical application

Construction and Mechanism of Action of Gelatin/Sodium Hexametaphosphate/Glutamine Aminotransferase Based Composite Hydrogel System

In this study, a composite hydrogel system was constructed by cross-linking of primary network hydrogels of gelatin (GE) and sodium hexametaphosphate (SHMP) by transglutaminase (TGase) after addition of Lactobacillus plantarum in order to improve its viability and bioavailability. The experimental results showed that the modification by SHMP and TGase changed the gel strength, water distribution state, and gel network structure of gelatin, and reduced the gelation rate, so that the three-dimensional network structure of the gel was more stable, and the intermolecular forces of the composite hydrogel was stronger, contributing to the resistance of the encapsulated L. plantarum to adverse environments. The presence of L. plantarum was found to slightly disrupt the ordered structure of the hydrogel by scanning electron microscopy (SEM). Endogenous fluorescence spectroscopy analysis showed that addition of L. plantarum resulted in the exposure of the extended region containing tryptophan within the GE molecule to a more polar environment. The steric effect occurred during the gelling process, delaying the formation of covalent crosslinks and physical interactions between the biopolymer molecules, which led to changes in their microstructure. Simulated gastrointestinal digestion tests and storage tests showed that L. plantarum encapsulated in GE/SHMP/TGase gels had better survival rates and gastrointestinal release properties compared to single GE-based hydrogels. It was confirmed that GE/SHMP/TGase hydrogels had a better protective effect on L. plantarum. In conclusion, this study has explored a new method for preparing GE-based hydrogels as a delivery system for probiotics, which will provide a theoretical basis for the development of probiotic functional foods

Translocase of the Outer Mitochondrial Membrane 40 Is Required for Mitochondrial Biogenesis and Embryo Development in Arabidopsis

In eukaryotes, mitochondrion is an essential organelle which is surrounded by a double membrane system, including the outer membrane, intermembrane space and the inner membrane. The translocase of the outer mitochondrial membrane (TOM) complex has attracted enormous interest for its role in importing the preprotein from the cytoplasm into the mitochondrion. However, little is understood about the potential biological function of the TOM complex in Arabidopsis. The aim of the present study was to investigate how AtTOM40, a gene encoding the core subunit of the TOM complex, works in Arabidopsis. As a result, we found that lack of AtTOM40 disturbed embryo development and its pattern formation after the globular embryo stage, and finally caused albino ovules and seed abortion at the ratio of a quarter in the homozygous tom40 plants. Further investigation demonstrated that AtTOM40 is wildly expressed in different tissues, especially in cotyledons primordium during Arabidopsis embryogenesis. Moreover, we confirmed that the encoded protein AtTOM40 is localized in mitochondrion, and the observation of the ultrastructure revealed that mitochondrion biogenesis was impaired in tom40-1 embryo cells. Quantitative real-time PCR was utilized to determine the expression of genes encoding outer mitochondrial membrane proteins in the homozygous tom40-1 mutant embryos, including the genes known to be involved in import, assembly and transport of mitochondrial proteins, and the results demonstrated that most of the gene expressions were abnormal. Similarly, the expression of genes relevant to embryo development and pattern formation, such as SAM (shoot apical meristem), cotyledon, vascular primordium and hypophysis, was also affected in homozygous tom40-1 mutant embryos. Taken together, we draw the conclusion that the AtTOM40 gene is essential for the normal structure of the mitochondrion, and participates in early embryo development and pattern formation through maintaining the biogenesis of mitochondria. The findings of this study may provide new insight into the biological function of the TOM40 subunit in higher plants