Alleviation of DSS-induced colitis in mice by a new-isolated Lactobacillus acidophilus C4

IntroductionProbiotic is adjuvant therapy for traditional drug treatment of ulcerative colitis (UC). In the present study, Lactobacillus acidophilus C4 with high acid and bile salt resistance has been isolated and screened, and the beneficial effect of L. acidophilus C4 on Dextran Sulfate Sodium (DSS)-induced colitis in mice has been evaluated. Our data showed that oral administration of L. acidophilus C4 remarkably alleviated colitis symptoms in mice and minimized colon tissue damage.MethodsTo elucidate the underlying mechanism, we have investigated the levels of inflammatory cytokines and intestinal tight junction (TJ) related proteins (occludin and ZO-1) in colon tissue, as well as the intestinal microbiota and short-chain fatty acids (SCFAs) in feces.ResultsCompared to the DSS group, the inflammatory cytokines IL-1β, IL-6, and TNF-α in L. acidophilus C4 group were reduced, while the antioxidant enzymes superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) were found to be elevated. In addition, proteins linked to TJ were elevated after L. acidophilus C4 intervention. Further study revealed that L. acidophilus C4 reversed the decrease in intestinal microbiota diversity caused by colitis and promoted the levels of SCFAs.DiscussionThis study demonstrate that L. acidophilus C4 effectively alleviated DSS-induced colitis in mice by repairing the mucosal barrier and maintaining the intestinal microecological balance. L. acidophilus C4 could be of great potential for colitis therapy

Research on Prediction of Movable Fluid Percentage in Unconventional Reservoir Based on Deep Learning

In order to improve the measurement speed and prediction accuracy of unconventional reservoir parameters, the deep neural network (DNN) is used to predict movable fluid percentage of unconventional reservoirs. The Adam optimizer is used in the DNN model to ensure the stability and accuracy of the model in the gradient descent process, and the prediction effect is compared with the back propagation neural network (BPNN), K-nearest neighbor (KNN), and support vector regression model (SVR). During network training, L2 regularization is used to avoid over-fitting and improve the generalization ability of the model. Taking nuclear magnetic resonance (NMR) T2 spectrum data of laboratory unconventional core as input features, the influence of model hyperparameters on the prediction accuracy of reservoir movable fluids is also experimentally analyzed. Experimental results show that, compared with BPNN, KNN, and SVR, the deep neural network model has a better prediction effect on movable fluid percentage of unconventional reservoirs; when the model depth is five layers, the prediction accuracy of movable fluid percentage reaches the highest value, the predicted value of the DNN model is in high agreement with the laboratory measured value. Therefore, the movable fluid percentage prediction model of unconventional oil reservoirs based on the deep neural network model can provide certain guidance for the intelligent development of the laboratory’s reservoir parameter measurement

Organic Hollow Mesoporous Silica as a Promising Sandalwood Essential Oil Carrier

As film-forming agents, fillers and adsorbents, microplastics are often added to daily personal care products. Because of their chemical stability, they remain in the environment for thousands of years, endangering the safety of the environment and human health. Therefore, it is urgent to find an environmentally friendly substitute for microplastics. Using n-octyltrimethoxysilane (OTMS) and tetraethoxysilane (TEOS) as silicon sources, a novel, environmentally friendly, organic hollow mesoporous silica system is designed with a high loading capacity and excellent adsorption characteristics in this work. In our methodology, sandalwood essential oil (SEO) was successfully loaded into the nanoparticle cavities, and was involved in the formation of Pickering emulsion as well, with a content of up to 40% (w/w). The developed system was a stable carrier for the dispersion of SEO in water. This system can not only overcome the shortcomings of poor water solubility and volatility of sandalwood essential oil, but also act as a microplastic substitute with broad prospects in the cosmetics and personal care industry, laying a foundation for the preparation and applications of high loading capacity microcapsules in aqueous media

The Experience of Inhaled COVID-19 Vaccination among First-line Medical Staff in Epidemic Prevention Aged≥18 Years in Guiyang City: a Qualitative Study

Background Inhaled recombinant COVID-19 vaccine (type 5 adenoviral vector) (hereinafter referred to as the inhaled COVID-19 vaccine) is the first approved inhaled COVID-19 vaccine in China, with the advantages of good immunity, painlessness, and higher accessibility, which has been included in the WHO Emergency Use Listing and China's list of second-dose booster immunization vaccines. The real-world application of this vaccine deserves more attention due to the poor understanding of it by the public. Objective To understand the real experience in depth of first-line medical staff in epidemic prevention aged≥18 years in Guiyang city who received inhaled COVID-19 vaccine, so as to provide a reference for the promotion of this type of vaccine. Methods The recipients who completed the emergency vaccination with inhaled COVID-19 vaccine at a vaccination site of Guiyang city in October 2022 were selected as research subjects based on the the principle of booster immunization by using purposive sampling method. The sample size was determined by interviewing until no new case emerged which was data saturation. A total of 17 recipients were interviewed in this study. Semi-structured interviews were conducted with the research subjects, face-to-face interviews were conducted to understand the vaccination experience at that time firstly, and telephone interviews were conducted 5-7 days after vaccination. The Colaizzi seven-step analysis method was used for the data collection and analysis. Results A total of five themes were summarized including the convenience of vaccination, good vaccination experience, light psychological burden, low vaccine hesitancy and uncertain protective effect. The convenience of vaccination includes simple and time-saving vaccination process, fast vaccination speed, low cost, and no interruption of nucleic acid testing; the good vaccination experience includes comfortable feeling of vaccination, harmonious observation atmosphere, fewer adverse reactions, and no interference with daily life; light psychological burden includes reduction of tension and anxiety of vaccination, better mental health maintenance, non-invasive vaccination and elimination of vaccination fears; low vaccine hesitancy includes high vaccination accessibility, increase of vaccine acceptance, increase of public perception of epidemic outbreak risk; uncertain protective effect includes uncertain which vaccination method provides better protection between injection and inhalation, whether inhaled COVID-19 vaccine has a good protective effect against variant strains. Conclusion Inhaled COVID-19 vaccine is convenient to administer with fewer adverse reactions, which is highly accepted by first-line medical staff in epidemic prevention aged≥18 years in Guiyang city with good experience

Evaluation of Displacement Effects of Different Injection Media in Tight Oil Sandstone by Online Nuclear Magnetic Resonance

In order to evaluate the displacement effect of four kinds of injection media in tight oil sandstone, water, active water, CO2, N2 flooding experiments were carried out in laboratory. Online Nuclear Magnetic Resonance (NMR) spectrometers combine the advantages of NMR technology and core displacement experiments. In the displacement experiment, NMR data of different injection volumes were obtained and magnetic resonance imaging (MRI) was carried out. The results showed that micro and sub-micropores provided 62–97% of the produced crude oil. The enhanced oil recovery ratio of active water flooding was higher than that of conventional water flooding up to 10%. The recovery ratio of gas flooding in micro and sub-micropores was 60–70% higher than that of water flooding. The recovery ratio of CO2 flooding was 10% higher than that of N2 flooding. The remaining oil was mainly distributed in pores larger than 0.1 μm. Under the same permeability level, the remaining oil saturation of cores after gas flooding was 10–25% lower than water flooding. From MRI images, the displacement effects from good to bad were as follows: CO2 flooding, N2 flooding, active water flooding, and conventional water flooding

An Experimental Study on Stress Sensitivity of Tight Sandstones with Different Microfractures

Aiming at the stress sensitivity problem of tight reservoirs with different microfractures, the cores of H oilfield and J oilfield with different microfractures were obtained through the fractures experiment, so as to study the change of gas permeability in tight sandstone core plug during the change of confining pressure. Besides, we use the nuclear magnetic resonance (NMR) spectra of the core before and after saturation to verify whether the core has been successfully fractured. Based on Terzaghi’s effective stress principle, the permeability damage rate (D) and the stress sensitivity coefficient (Ss) are used to evaluate the stress sensitivity of the core, which show consistency in evaluating the stress sensitivity. At the same time, we have studied the petrological characteristics of tight sandstone in detail using thin section (TS) and scanning electron microscope (SEM). The results show that the existence of microfractures is the main factor for the high stress sensitivity of tight sandstone. In addition, because of the small throat of the tight reservoir core, the throat closes when the overlying stress increases. As a result, the tight sandstone pore size is greatly reduced and the permeability is gradually reduced. Therefore, in the development of tight reservoirs, we should not only consider the complex fracture network produced by fracturing, but also pay attention to the permanent damage of reservoirs caused by stress sensitivity

Influence of the filler dimensionality on the electrical, mechanical and electromagnetic shielding properties of isoprene rubber-based flexible conductive composites

Rubber-based conductive polymer composites are deformable and flexible, which have been demonstrated tremendous applications in electromagnetic interference (EMI) shielding materials. Here, we filled different dimensional carbonaceous fillers, including zero-dimensional carbon black (0D CB), one-dimensional carbon nanotubes (1D CNTs), two-dimensional graphene (2D GP), and their combinations, into isoprene rubber (IR) to fabricate the flexible EMI shielding composites. Both the electrical, mechanical, and EMI shielding properties were investigated. It was found that the EMI shielding properties of IR-based composites mainly dominated by the microwave absorption consumption. Since 1D CNTs possess the highest EMI shielding effectiveness for absorption, IR/CNTs composites exhibit the best electromagnetic interference shielding properties compared to other carbonaceous nanoparticles filled composites. Moreover, partially replacing CNTs with CB particles to fabricate hybrid IR/CB/CNTs composite is an effective route to improve the electrical properties and lower the cost of the composites. However, it is found that hybrid IR/CB/CNTs composite has a lower EMI shielding effectiveness than IR/CNTs composites, indicating that EMI shielding properties depend on a lot more than just the electrical conductivity of the resulting composites. Nevertheless, based on comprehensive consideration of cost, electrical, mechanical and EMI shielding properties of the composites, it is still an effective way to design the high-performance EMI shielding materials via the combination of different dimensional fillers.Peer reviewe