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Increasing oil production is crucial for multilayer co-production. When there are significant differences in the permeability of each layer, an interlayer contradiction arises that can impact the recovery efficiency. After a number of tests and the establishment of a mathematical model, the effects of permeability contrast on oil production for water flooding were revealed. In the meantime, the developed mathematical model was solved using the Buckley–Lever seepage equation. Ultimately, the accuracy of the established model was confirmed by comparing the simulated outcomes of the mathematical model with the experimental results. The findings indicate that when permeability contrast increases, the production ratio of the high-permeability layer will improve. This is primarily due to the low-permeability layer’s production contribution rate decreasing. The accuracy of the established model is ensured by an error of less than 5% between the results of the experiment and the simulation. When the permeability contrast is less than three, the low-permeability layer can be effectively used for three-layer commingled production. However, when the permeability contrast exceeds six, the production coefficient of the low-permeability layer will be less than 5%, which has a significant impact on the layer’s development.

Understanding and manipulating geological pore structures is of paramount importance for geo-energy productions and underground energy storages in porous media. Nevertheless, research emphases for long time have been focused on understanding the pore configurations, while few work conducted to modify and restructure the porous media. This study deploys ultrasonic treatments on typical geological in-situ core samples, with follow-up processes of high-pressure mercury injections and nitrogen adsorptions and interpretations from nuclear magnetic resonance and x-ray diffraction. The core permeability and porosity are found to increase by 8.3 mD, from 4.1 to 12.4 mD, and by 0.95%, from 14.03% to 14.98%, respectively. Meanwhile, the number and size of the micro- and mesopore are increased with progressing of ultrasonic treatment, while those of the macropore decrease, which finally increase the permeability and porosity. The increase of micro- and mesopore number, from x-ray diffraction results, is attributed to the migration and precipitation of clay minerals caused through ultrasonic wave. The relocation of clay minerals also helps to improve the pore-throat connectivity and modify the micro-scale heterogeneity. Basically, this study reveals the characterizations of geological pore reconfigurations post-ultrasonic treatments and interprets the associated mechanisms, which provides guidance to manipulate the geological pores and be of benefit for further porous media use in science and engineering.

CO2 flooding can effectively enhance the recovery of low-permeability reservoirs and realize CO2 geological storage. During the displacement process, the minimum miscible pressure (MMP) of CO2 and oil is an important parameter that affects the displacement effect and storage efficiency. However, the microscopic pore-throat structure of low-permeability reservoirs has significant influences on the fluids and phase behaviors. This paper presented a method to determine the miscible state of CO2 flooding based on the microscopic pore-throat structure. Firstly, a physic model was established to quantitatively characterize the microscopic pore-throat structure. Secondly, taking into consideration the P-R equation of state, the gas-liquid equilibrium in the narrow pore-throat was calculated. On this basis, a MMP prediction model was established correspongdingly by considering the multi-stage contact and mass transfer of CO2-oil. Finally, the results obtained by the proposed model were compared with the experimental results of CO2 flooding, and then the model was applied to the actual reservoir to predict plane distribution of MMP. The curves of MMP distribution and pressure drawdown between wells were combined to determine the position of miscible front and non-miscible area at different production stages. The results have shown that the MMP of core sample calculated by the model was 20.3 MPa, which was comparable to that of CO2 flooding experiment, e.g., 20 MPa, and thus indicatesd a high accuracy of the model. The MMP in the well control area of the Y29-101 well group was 19.8 MPa. During the unsteady flow stage, the miscible-phase front was 430 m from the injection well, while it was 310 m from the injection well during the stable flow stage. This method can accurately determine the specific phase distribution of CO2-oil in the formation, which is of great significance to promote the development of CO2 flooding and storage technology, improve the recovery of low permeability reservoirs, ensure energy supply and reduce carbon emission.

Low-salinity water (LSW) and CO2 could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery (EOR); however, its microscopic recovery mechanisms have not been well understood due to the nature of these two fluids and their physical reactions in the presence of reservoir fluids and porous media. In this work, well-designed and integrated experiments have been performed for the first time to characterize the in-situ formation of micro-dispersions and identify their EOR roles during a LSW-alternating-CO2 (CO2-LSWAG) process under various conditions. Firstly, by measuring water concentration and performing the Fourier transform infrared spectroscopy (FT-IR) analysis, the in-situ formation of micro-dispersions induced by polar and acidic materials was identified. Then, displacement experiments combining with nuclear magnetic resonance (NMR) analysis were performed with two crude oil samples, during which wettability, interfacial tension (IFT), CO2 dissolution, and CO2 diffusion were quantified. During a CO2-LSWAG process, the in-situ formed micro-dispersions dictate the oil recovery, while the presence of clay minerals, electrical double-layer (EDL) expansion and multiple ion exchange (MIE) are found to contribute less. Such formed micro-dispersions are induced by CO2 via diffusion to mobilize the CO2-diluted oil, alter the rock wettability towards more water-wet, and minimize the density contrast between crude oil and water. [ABSTRACT FROM AUTHOR]

Diabetic kidney disease (DKD) is a common complication of diabetes and has become the leading cause of end-stage kidney disease. The pathogenesis of DKD is complicated, and oxidative stress is considered as a core of DKD onset. High glucose can lead to increased production of reactive oxygen species (ROS) via the polyol, PKC, AGE/RAGE and hexosamine pathways, resulting in enhanced oxidative stress response. In this way, pathways such as PI3K/Akt, TGF-β1/p38-MAPK and NF-κB are activated, inducing endothelial cell apoptosis, inflammation, autophagy and fibrosis that cause histologic and functional abnormalities of the kidney and finally result in kidney injury. Presently, the treatment for DKD remains an unresolved issue. Traditional Chinese medicine (TCM) has unique advantages for DKD prevention and treatment attributed to its multi-target, multi-component, and multi-pathway characteristics. Numerous studies have proved that Chinese herbs (e.g., Golden Thread, Kudzuvine Root, Tripterygium glycosides, and Ginseng) and patent medicines (e.g., Shenshuaining Tablet, Compound Rhizoma Coptidis Capsule, and Zishen Tongluo Granule) are effective for DKD treatment. The present review described the role of oxidative stress in DKD pathogenesis and the effect of TCM intervention for DKD prevention and treatment, in an attempt to provide evidence for clinical practice. [ABSTRACT FROM AUTHOR]

KB-R7943, an isothiourea derivative, is widely used as a pharmacological inhibitor of reverse sodium–calcium exchanger (NCX). It has been shown to have neuroprotective and analgesic effects in animal models; however, the detailed molecular mechanisms remain elusive. In the current study, we investigated whether KB-R7943 modulates acid-sensing ion channels (ASICs), a group of proton-gated cation channels implicated in the pathophysiology of various neurological disorders, using the whole-cell patch clamp techniques. Our data show that KB-R7943 irreversibly inhibits homomeric ASIC1a channels heterologously expressed in Chinese Hamster Ovary (CHO) cells in a use- and concentration-dependent manner. It also reversibly inhibits homomeric ASIC2a and ASIC3 channels in CHO cells. Both the transient and sustained current components of ASIC3 are inhibited. Furthermore, KB-R7943 inhibits ASICs in primary cultured peripheral and central neurons. It inhibits the ASIC-like currents in mouse dorsal root ganglion (DRG) neurons and the ASIC1a-like currents in mouse cortical neurons. The inhibition of the ASIC1a-like current is use-dependent and unrelated to its effect on NCX since neither of the other two well-characterized NCX inhibitors, including SEA0400 and SN-6, shows an effect on ASIC. Our data also suggest that the isothiourea group, which is lacking in other structurally related analogs that do not affect ASIC1a-like current, may serve as a critical functional group. In summary, we characterize KB-R7943 as a new ASIC inhibitor. It provides a novel pharmacological tool for the investigation of the functions of ASICs and could serve as a lead compound for developing small-molecule drugs for treating ASIC-related disorders. [ABSTRACT FROM AUTHOR]

Objective: To compare the consistency and accuracy of a rapid test method and a traditional test method for pathogen identification, antimicrobial susceptibility and carbapenemase type identification of positive blood culture samples., Methods: A total of 51 positive blood culture samples of bloodstream infection (BSI) were collected between March 2022 and May 2022. All samples were found to be "positive for Gram-negative bacilli" according to the blood smear results. The rapid method was adopted to perform rapid antimicrobial susceptibility test (RAST) and analysis of the positive blood culture samples. According to the RAST result interpretation standards, NG-Test® CARBA 5 was used for rapid carbapenemase detection of the imipenem-resistant strains and the results were confirmed by PCR. In addition, mass spectrometry, VITEK 2 Compact drug sensitivity analysis, and carbapenemase type identification were performed with the colonies cultured with positive samples according to the traditional method., Results: In the identification of bacteria, the rapid method and the traditional method had 100% consistency rate in the identification results of Escherichia coli , Klebsiella pneumoniae , Pseudomonas aeruginosa , and Acinetobacter baumannii . In the antimicrobial susceptibility test, the consistency rate between the results of the two methods was high and the consistency rate for results for susceptibility to imipenem was 100%. In the identification of carbapenemase type, 18 serinase-producing strains and 3 metal-β-lactamase-producing strains of Enterobacterales were detected by the traditional method. With the rapid method, 18 Klebsiella pneumoniae carbapenemase (KPC)-producing strains, 2 New Delhi metallo-betalactamase (NDM)-producing strains, and 1 imipenem enzyme (IMP)-producing strain were identified in the blood culture samples by using a testing kit. Compared with the PCR results, the sensitivity and specificity of the rapid test for determining carbapenemase types were 100%. In this study, we investigated a rapid method for bacteria and carbapenemase type identification of positive blood culture specimens and found that the turnaround time (TAT) of the rapid method was reduced by 1.94 days on average in comparison with the TAT of the traditional method., Conclusion: The rapid method established in the study can effectively shorten the TAT for pathogenic microorganism identification and antimicrobial susceptibility test of blood culture samples, and the joint report of colloidal gold carbapenemase type identification results can provide a reference for clinicians to use antibiotics appropriately and accurately manage multi-drug resistant bacterial infections., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)