Search Results (2,169)

Low-permeability reservoirs have poor reservoir properties and are difficult to develop by conventional water flooding. CO₂ flooding can significantly improve oil recovery while achieving carbon storage, and is widely recognized as an effective solution for the development of low-permeability oil reservoirs. In order to address the lack of a comparative quantitative analysis of the tradeoff between oil recovery factor, CO₂ storage rate, and total CO₂ storage volume for the main injection modes in low-permeability reservoirs, this study systematically evaluated the performance of CO₂-enhanced oil recovery (EOR) and geological storage under different pressures and injection modes through core flooding experiments. The results indicate that displacement pressure and injection strategy significantly influence the CO₂ flooding performance. Continuous miscible flooding (30 MPa) substantially reduced the displacement pressure differential (maximum 6.1 MPa) and achieved the highest oil recovery (78.96%) and the greatest CO₂ storage capacity (5916 cm³). Miscible WAG flooding effectively delayed gas breakthrough (extended to 1.90 pore volumes), homogenized the displacement front, and yielded the best overall outcome: the highest ultimate oil recovery (83.8%) coupled with the optimal CO₂ storage rate (89.1%). The study further reveals that the pre-breakthrough stage is critical for contributing to oil recovery and achieving efficient storage, regardless of the injection modes. These findings clarify the technical characteristics and applicable conditions of different injection modes, providing crucial theoretical insights and practical guidance for optimizing CO₂ EOR and storage projects in low-permeability reservoirs. Full article

Coronary artery bypass grafting (CABG) remains the gold standard for patients with advanced multivessel coronary artery disease. Optimal myocardial protection versus ischemia during reversible and controlled cardiac arrest is a cornerstone of successful outcomes. Myocardial ischemia represents a state of reduced coronary perfusion with oxygenated blood, insufficient to meet the metabolic demands of the myocardium. Conventional cardioplegic solutions offer controlled and reversible cardiac arrest while actively modulating the molecular and cellular mechanisms that mediate ischemia–reperfusion injury. Cardioplegia dramatically elongates the reversible period of ischemic injury and restricts cardiomyocyte death by shutting down electromechanical activity, lowering metabolic demand, stabilizing ionic homeostasis, protecting mitochondrial integrity, and slowing oxidative stress and inflammatory signaling. During ischemia, cardiomyocytes shift from aerobic to anaerobic metabolism, resulting in adenosine triphosphate (ATP) depletion, loss of ionic homeostasis and calcium overload that activate proteases, phospholipases and membrane damage. Reperfusion restores oxygen supply and prevents irreversible necrosis but paradoxically initiates additional injury in marginally viable myocardium. The reoxygenation phase induces excessive production of reactive oxygen species (ROS), endothelial dysfunction and a strong inflammatory response mediated by neutrophils, platelets and cytokines. Mitochondrial dysfunction and opening of the mitochondrial permeability transition pore (mPTP) further amplify oxidative stress and inflammation, and trigger apoptosis and necroptosis. Understanding these intertwined cellular and molecular mechanisms remains essential for identifying novel therapeutic targets aimed at reducing reperfusion injury and improving myocardial recovery after ischemic events, particularly in coronary surgery. Full article

Characterizing tight reservoirs is challenging due to the complex pore structure and strong heterogeneity at various scales. Current digital rock physics often struggles to reconcile high-resolution imaging with representative sample sizes, and 3D digital cores are frequently used primarily as visualization tools rather than predictive, computable platforms. Thus, a clear methodological gap persists: high-resolution models typically lack macroscopic geological features, while existing 3D digital models are seldom leveraged for quantitative, predictive analysis. This study, based on a full-diameter core sample of a single lithology (gray-black shale), aims to bridge this gap by developing an integrated workflow to construct a high-fidelity, computable 3D model that connects the micro–nano to the macroscopic scale. The core was scanned using high-resolution X-ray computed tomography (CT) at 0.4 μm resolution. The raw CT images were processed through a dedicated pipeline to mitigate artifacts and noise, followed by segmentation using Otsu’s algorithm and region-growing techniques in Avizo 9.0 to isolate minerals, pores, and the matrix. The segmented model was converted into an unstructured tetrahedral finite element mesh within ANSYS 2024 Workbench, with quality control (aspect ratio ≤ 3; skewness ≤ 0.4), enabling mechanical property assignment and simulation. The digital core model was rigorously validated against physical laboratory measurements, showing excellent agreement with relative errors below 5% for key properties, including porosity (4.52% vs. 4.615%), permeability (0.0186 mD vs. 0.0192 mD), and elastic modulus (38.2 GPa vs. 39.5 GPa). Pore network analysis quantified the poor connectivity of the tight reservoir, revealing an average coordination number of 2.8 and a pore throat radius distribution of 0.05–0.32 μm. The presented workflow successfully creates a quantitatively validated “digital twin” of a full-diameter core. It provides a tangible solution to the scale-representativeness trade-off and transitions digital core analysis from a visualization tool to a computable platform for predicting key reservoir properties, such as permeability and elastic modulus, through numerical simulation, offering a robust technical means for the accurate evaluation of tight reservoirs. Full article

Background/Objectives: One-dose packaging is beneficial for older adults and those on multiple medications because it ensures that no doses are missed and supports medication adherence. However, conventional one-dose packaging materials have high moisture permeability, making them unsuitable for the storage of hygroscopic medications. We evaluated the barrier performance of food packaging materials against moisture and oxygen and investigated their potential to enhance the physical stability of the highly hygroscopic sodium valproate, under stressed storage conditions. Methods: Barrier performance was evaluated by measuring the water vapor transmission (WVTR) and oxygen transmission rates of each packaging material. Then, we evaluated the stability of sodium valproate tablets in different food packaging films by measuring weight change, breaking force, and visual appearance over 14 days under stressed storage conditions (35 °C and 75% relative humidity). Conventional cellophane-laminated polyethylene was used as the reference. Results: The WVTR of the food packaging films were below 2 g/m²/day, less than that of the conventional material. Tablets stored in Materials A and B showed weight increases of no more than 1.2% after 3 days, whereas the maximum increase among all food films was 3.7% (Material C). For Materials A and B, the breaking force remained measurable and the visual appearance unchanged throughout the 14-day period, whereas Material C became unmeasurable by day 14. Tablets packaged in cellophane-laminated polyethylene exhibited deliquescence, with visible deformation and stickiness within 3 days, rendering them unmeasurable. Conclusions: Food packaging materials with high barrier performance offer a practical, safe, and effective solution for one-dose packaging of hygroscopic medications, potentially expanding their clinical use and improving adherence. Full article

This study investigates the application of nanofluid (iNanoW)–polymer binary flooding system to enhance oil recovery efficiency in medium-to-high permeability reservoirs. Traditional polymer flooding technologies still have the potential for further improvement in these types of reservoirs. Therefore, this study combines iNanoW with the polymer flooding system to examine its effects on the rheological properties, injectability, interfacial performance, sweep volume, and recovery factor of the polymer solution. Experimental results show that iNanoW significantly improves the injectability of the polymer solution. The introduction of iNanoW reduces the size of polymer aggregates, as demonstrated by aggregate size and rheological performance experiments. Power-law model analysis reveals that the flow behavior of the polymer solution is further improved with the introduction of iNanoW, manifested by weakened shear-thinning behavior, reduced viscosity, and optimized flowability, which in turn helps to improve oil recovery efficiency. Moreover, iNanoW interacts with polymer molecules, lowering the surface tension and enhancing wettability, thereby improving oil–water separation efficiency. Core flooding experiments show that the introduction of iNanoW significantly increases sweep volume, particularly in medium- and small-pore spaces, where oil recovery efficiencies reached 57.97% and 61.54%, respectively. These results indicate that iNanoW not only optimizes the rheological properties of the polymer solution but also improves fluid distribution during the flooding process, significantly enhancing the overall oil recovery performance. This study provides a new approach to optimizing polymer flooding technology and highlights the potential of iNanoW in improving oil recovery efficiency. Full article

Background/Objectives: Capric acid (CA)–therapeutic deep eutectic systems (THEDES) are emerging as a distinct class of biofunctional matrices capable of reshaping drug solubilization, permeability, and bioactivity. Methods: Relevant studies on CA–THEDES were identified through targeted database searches and screened for evidence on their design, mechanisms, and pharmaceutical performance. Results: This review synthesizes current evidence on their structural design, mechanistic behavior, and pharmaceutical performance, revealing several unifying principles. Across multiple drug classes, CA consistently drives strong, directional hydrogen bonding and drug amorphization, resulting in marked solubility enhancement and stabilization of non-crystalline or supersaturated states relative to crystalline drugs or conventional solvent systems. Its amphiphilic C10 chain further contributes to membrane fluidization, which explains the improved transdermal and transmucosal permeation repeatedly observed in CA-THEDES. Additionally, synergistic antimicrobial and anticancer effects reported in several systems confirm that CA acts not only as a solvent component but as a bioactive co-therapeutic. Collectively, the reviewed data show that CA serves as a structurally determinant element whose dual hydrogen-bonding and membrane-interacting roles underpin the high pharmaceutical performance of these systems. However, gaps remain in long-term stability, toxicological profiling, and regulatory classification. Emerging Artificial Intelligence (AI) and Machine Learning (ML)-guided predictive approaches offer promising solutions by enabling rational selection of eutectic partners, optimal ratios, and property optimization through computational screening. Conclusions: Overall, CA-THEDES represent a rationally designable platform for next-generation drug delivery, where solvent functionality and therapeutic activity converge within a single, green formulation system. Full article

Lost circulation in oil-based drilling fluids (OBDFs) remains difficult to mitigate because particulate lost circulation materials depend on bridging/packing and gel systems for aqueous media often lack OBDF compatibility and controllable in situ sealing. A dual-precursor oil–water biphasic metal–organic supramolecular gel enables rapid in situ sealing in OBDF loss zones. The optimized formulation uses an oil-phase to aqueous gelling-solution volume ratio of 10:3, with 2.0 wt% Span 85, 12.5 wt% TXP-4, and 5.0 wt% NaAlO₂. Apparent-viscosity measurements and ATR–FTIR analysis were used to evaluate the effects of temperature, time, pH, and shear on MOSG gelation. Furthermore, the structural characteristics and performances of MOSGs were systematically investigated by combining microstructural characterization, thermogravimetric analysis, rheological tests, simulated fracture-plugging experiments, and anti-shear evaluations. The results indicate that elevated temperatures (30–70 °C) and mildly alkaline conditions in the aqueous gelling solution (pH ≈ 8.10–8.30) promote P–O–Al coordination and strengthen hydrogen bonding, thereby facilitating the formation of a three-dimensional network. In contrast, strong shear disrupts the nascent network and delays gelation. The optimized MOSGs rapidly exhibit pronounced viscoelasticity and thermal resistance (~193 °C); under high shear (380 rpm), the viscosity retention exceeds 60% and the viscosity recovery exceeds 70%. In plugging tests, MOSG forms a dense sealing layer, achieving a pressure-bearing gradient of 2.27 MPa/m in simulated permeable formations and markedly improving the fracture pressure-bearing capacity in simulated fractured formations. Full article

Dimethyl sulfoxide (DMSO) is widely utilized in the vitrification of oocytes, but DMSO exhibits concentration-dependent toxicity, which can compromise oocyte developmental potential by disrupting key cellular processes. This study reports the first successful use of cold shock protein B (CspB protein) as a substitute for DMSO in vitrification solutions for oocyte vitrification. Combining dynamics simulations and experimental validation, we demonstrated CspB’s ability to inhibit ice crystallization and recrystallization by stabilizing its position at the ice–water interface and reducing ice formation rates. Recombinant CspB was successfully expressed and shown to bind to the oolemma. In vitrification solutions, CspB (1–2 mg/mL) effectively reduced ice crystal size and enabled a significant reduction or complete replacement of DMSO. This strategy markedly improved the post-thaw survival rates of both mouse and bovine metaphase II (MII) oocytes. Furthermore, oocytes vitrified with an optimized formulation (15% ethylene glycol + 2 mg/mL CspB) exhibited developmental competence (cleavage and blastocyst rates), oxidative stress markers (ROS, GSH), mitochondrial function (membrane potential and content), and apoptosis levels (Caspase-3/9) comparable to those treated with a standard DMSO-containing system. Transcriptomic analysis revealed that CspB’s cryoprotection involves the modulation of the mTOR signaling pathway. This role was functionally confirmed, as activation of mTOR abolished CspB’s beneficial effects, reinstating oxidative damage, mitochondrial dysfunction, and apoptosis. Thus, the CspB protein replaces DMSO with direct ice crystal formation suppression and mTOR-mediated oxidative stress regulation. This study offers a protein-based alternative to conventional permeable cryoprotectants. This approach holds promise for improving reproductive biotechnologies across species. Full article

Hydrophilic modification of polymeric membranes by employing TiO₂ nanoparticles has attracted much attention in enhancing antifouling performance. Micelles of PVPylated-TiO₂ nanoparticles were designed to alleviate the agglomeration of TiO₂ nanoparticles via steric hindrance and electrostatic stabilization effect. Herein, Poly(vinyl pyrrolidone) (PVP) was used as a surfactant to mitigate the thorny agglomeration of nanoparticles in the casting solution and simultaneously as a pore-forming additive during the membrane preparation process. The lowest backscattering (BS) peak and turbiscan stability index (TSI) of the composite casting solution indicated the effective dispersion and stabilization under the steric interaction of 4 wt.% PVP. Properties such as the fully developed finger-like structure of cross-sectional morphologies, water permeability, negative Zeta potential, and hydrophilicity were enhanced evidently by the optimal modification of PVPylated-TiO₂ materials. High interaction energy indicated by classic extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) theory as well as the high relative flux during the filtration of various model foulants demonstrated the effective antifouling modification. The results of critical flux and fouling rate in 30 min also verified the enhancement of the antifouling performance of PVDF/PVPylated-TiO₂ composite membrane. This work provides a feasible strategy to construct composite membranes with high antifouling performance for wastewater treatment. Full article

In this study, pectin packaging films were enhanced with selected phenolic acids, including caffeic, coumaric, ferulic, gallic, protocatechuic, and sinapic acids. Edible films were created from apple pectin aqueous solutions that were plasticised with glycerol. The evaluation covered various properties, including optical, barrier, mechanical, thermal, structural, and antioxidant activity. The findings showed that phenolic acids are beneficial and compatible components for pectin films. A higher barrier against UV-VIS light and mechanical strength, as well as a more resilient structure, was observed. All the films exhibited a compact and uniform structure, along with transparency and a light colour. The addition of phenolic acids caused greater permeability to oxygen and carbon. Except for caffeic and protocatechuic acids, which resulted in lower values of permeability for both gases, the other acids improved gas transmission. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed several functional groups, including hydroxyl (−OH) and carbonyl (C=O) groups. All films containing phenolic acids demonstrated increased antioxidant activity, with variations depending on the specific compound. Full article

Tightness of homogeneous embankment dams is often ensured by means of upstream water barriers, such as bituminous concrete facings, concrete slabs, shotcrete membranes, metallic sheets, geomembranes, and cement blankets. The stability analysis of these dams, especially in areas with high seismicity, must include the hydraulic and mechanical effects resulting from an extensive, sudden cracking of the impervious facing. To this purpose, in this paper, simple, original analytical solutions are proposed to estimate the position of the exit point on the downstream slope of the dam, the maximum height of the saturation front at the downstream face, and the time required for the saturation front to reach the downstream face. These variables generally depend on several factors, such as the geometry of the dam, homogeneity or heterogeneity, the permeability coefficient of the dam body materials, and resistance laws to describe the seepage flow. The high number of these factors requires the development of advanced 2D/3D FEM analyses, often computationally heavy and complex to implement. Although approximate, the proposed solutions may however allow us to define the role of the various factors and their interaction, to quickly deduce the main, preliminary design indications. Full article

Drugs and drug candidate compounds commonly suffer from poor solubility and permeability. One promising strategy to mediate these drawbacks is use of novel solvents, such as deep eutectic compositions. The present research aims to determine the applicability of this approach for therapeutic metal complexes on the example of [Cu(Fur)₂(Phen)] (Fur = furoate-anion, Phen = 1,10-phenantroline) and [Cu(Fur)₂(Neoc)(H₂O)] (Fur = furoate-anion, Neoc = 2,9-dimetyl-1,10-phenanthroline) with molar weight of appx. 500 Da. Interaction of the metal complexes with the deep eutectic solvent (DES) reline was studied using electron paramagnetic resonance (EPR). Minimal inhibitory concentrations of the complexes dissolved in DES and dimethyl sulfoxide (DMSO) were determined and found to be equivalent in both solvents. That is, use of reline as a solvent did not alter the functional properties of the metal complexes. Changes in the transdermal permeation of the complexes in DMSO and DES were assessed using a Franz diffusion cell. It was discovered that depending on the structure of the complex, the permeability might either increase (from 15 to 30%) or decrease (from 13 to 8%) with changes in the solvent, and this can be used to develop dosing strategies. Therapeutic eutectogels were successfully produced by impregnating SiO₂ nanoparticles with the metal complex solution in DES, facilitating convenient topical application. Full article

Large-scale storage solutions play a critical role in the ongoing energy transition, with Underground Hydrogen Storage (UHS) emerging as a possible option. UHS can benefit from existing natural gas storage expertise; however, key differences in hydrogen’s behavior compared to CH₄ must be characterized at the pore scale to optimize the design and the management of these systems. This work investigates two-phase (gas–water) flow behavior using microfluidic devices mimicking reservoir rocks’ pore structure. Microfluidic tests provide a systematic side-by-side comparison of H₂–water and CH₄–water displacement under the same pore-network geometries, wettability, and flow conditions, focusing on the drainage phase. While all experiments fall within the transitional flow regime between capillary and viscous fingering, clear quantitative differences between H₂ and CH₄ emerge. Indeed, the results show that hydrogen’s lower viscosity enhances capillary fingering and snap-off events, while methane exhibits more stable viscous-dominated behavior. Both gases show rapid breakthrough; however, H₂’s flow instability—especially at low capillary numbers (Ca)—leads to spontaneous water imbibition, suggesting stronger capillary forces. Relative permeability endpoints are evaluated when steady state conditions are reached: they show dependence on Ca, not just saturation, aligning with recent scaling laws. Despite H₂ showing a different displacement regime, closer to capillary fingering, H₂ mobility remains comparable to CH₄. These findings highlight differences in flow behavior between H₂ and CH₄, emphasizing the need for tailored strategies for UHS to manage trapping and optimize recovery. Full article

To address the problem of serious gas channeling during CO₂ flooding in low-permeability reservoirs, which leads to poor oil recovery, this study developed a CO₂-resistant gel using a novel CO₂-responsive polymer (ADA) for gas channel control. The ADA polymer was synthesized via free-radical copolymerization of acrylamide (AM), dimethylaminopropyl methacrylamide (DMAPMA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), which introduced protonatable tertiary-amine groups and sulfonate moieties into the polymer backbone. Comprehensive characterizations confirmed the designed structure and adequate thermal stability of the ADA polymer. Rheological tests demonstrated that the ADA polymer solution exhibits significant CO₂-triggered viscosity enhancement and excellent shear resistance. When crosslinked with phenolic resin, the resulting ADA gel showed outstanding CO₂ tolerance under simulated reservoir conditions (110 °C, 10 MPa). After 600 s of CO₂ exposure, the ADA gel retained over 99% of its initial viscosity, whereas a conventional HPAM-based industrial gel degraded to 61% of its original viscosity. The CO₂-resistance mechanism involves protonation of tertiary amines to form quaternary ammonium salts, which electrostatically interact with sulfonate groups, creating a reinforced dual-crosslinked network that effectively protects the gel from H⁺ ion attack. Core flooding experiments confirmed its ability to enhance oil recovery by plugging high-permeability channels and diverting flow, achieving a final recovery of up to 48.5% in heterogeneous cores. This work provides a novel gel system for improving sweep efficiency and storage security during CO₂ flooding in low-permeability reservoirs. Full article

Class III reservoirs in the Daqing Oilfield are characterized by low permeability and strong heterogeneity, posing significant challenges to enhanced oil recovery (EOR). To improve the recovery efficiency of these reservoirs, the viscosifying ability, stability, shear resistance, and profile-control performance of fifteen polymer solutions were experimentally evaluated, and the two most compatible formulations were selected for the Daqing Class III reservoirs. Subsequently, a three-dimensional physical model equipped with real-time saturation monitoring was employed to compare the EOR performance of the selected polymers. The results indicate that a 1500 mg L⁻¹ polymer solution with a molecular weight (Mw) of 16 × 10⁶ Da and a 1200 mg L⁻¹ polymer solution with an Mw of 19 × 10⁶ Da exhibit the best compatibility with the target formation. After injecting the 1500 mg L⁻¹ (Mw = 16 × 10⁶ Da) polymer solution, the ultimate recovery reached 53.38%, with displacement efficiencies of 64.34% and 58.16% and sweep efficiencies of 92.26% and 80.35% in the high- and low-permeability layers, respectively. Injection of the 1200 mg L⁻¹ (Mw = 19 × 10⁶ Da) polymer solution yielded an overall recovery of 47.71%, corresponding to displacement efficiencies of 60.34% and 54.16% and sweep efficiencies of 88.52% and 76.38%. Consequently, the 1500 mg L⁻¹ (Mw = 16 × 10⁶ Da) polymer solution delivers the highest recovery increment in Class III reservoirs. These findings provide valuable guidance for the efficient polymer-flooding development of Class III reservoirs in Daqing and analogous formations worldwide. Full article