Increase In Water Permeability Research Articles

Establishment of the deuterium oxide dilution method as a new possibility for determining the transendothelial water permeability

Increase in transendothelial water permeability is an essential etiological factor in a variety of diseases like edema and shock. Despite the high clinical relevance, there has been no precise method to detect transendothelial water flow until now. The deuterium oxide (D2O) dilution method, already established for measuring transepithelial water transport, was used to precisely determine the transendothelial water permeability. It detected appropriate transendothelial water flow induced by different hydrostatic forces. This was shown in four different endothelial cell types. The general experimental setup was verified by gravimetry and absorbance spectroscopy. Determination of transendothelial electrical resistance (TEER) and immunocytochemical staining for proteins of the cell-cell contacts were performed to ensure that no damage to the endothelium occurred because of the measurements. Furthermore, endothelial barrier function was modulated. Measurement of transendothelial water flux was verified by measuring the TEER, the apparent permeability coefficient and the electrical capacity. The barrier-promoting substances cyclic adenosine monophosphate and iloprost reduced TEER and electrical capacity and increased permeability. This was accompanied by a reduced transendothelial water flux. In contrast, the barrier-damaging substances thrombin, histamine and bradykinin reduced TEER and electrical capacity, but increased permeability. Here, an increased water flow was shown. This newly established in vitro method for direct measurement of transendothelial water permeability was verified as a highly precise technique in various assays. The use of patient-specific endothelial cells enables individualized precision medicine in the context of basic edema research, for example regarding the development of barrier-protective pharmaceuticals.

Differential Effects of Soy Isoflavones on the Biophysical Properties of Model Membranes.

The effects that the main soy isoflavones, genistein and daidzein, have upon the biophysical properties of a model lipid bilayer composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or DOPC with cholesterol (4 to 1 mol ratio) have been investigated by transbilayer water permeability, differential scanning calorimetry, and confocal Raman microspectroscopy. Genistein is found to increase water permeability, decrease phase transition temperature, reduce enthalpy of transition, and induce packing disorder in the DOPC membrane with an increasing concentration. On the contrary, daidzein decreases water permeability and shows negligible impact on thermodynamic parameters and packing disorder at comparable concentrations. For a cholesterol-containing DOPC bilayer, both genistein and daidzein exhibit an overall less pronounced effect on transbilayer water permeability. Their respective differential abilities to modify the physical and structural properties of biomembranes with varying lipid compositions signify a complex and sensitive nature to isoflavone interactions, which depends on the initial state of bilayer packing and the differences in the molecular structures of these soy isoflavones, and provide insights in understanding the interactions of these molecules with cellular membranes.

The role of sheet-like TiO2 in polyamide reverse osmosis membrane for enhanced removal of endocrine disrupting chemicals

Thin film composite (TFC) reverse osmosis (RO) membrane shows good promise for treating wastewater containing endocrine disrupting chemical (EDC) pollutants. The incorporation of functional materials with exceptional structural and physico-chemical properties offers opportunities for the membranes preparation with enhanced permselectivity and better antifouling properties. The present study aims to improve the EDC removal efficiency of TFC RO membrane using two-dimensional titania nanosheets (TNS). RO membrane was prepared by incorporating TNS in the dense layer of polyamide (PA) layer to form thin film nanocomposite (TFN) membrane. The TNS loading was varied and the influences on membrane morphology, surface hydrophilicity, surface charge, as well as water permeability and rejection of EDC were investigated. The results revealed that the inclusion of TNS in the membrane resulted in the increase of water permeability and EDC rejection. When treating the mixture of bisphenol A (BPA) and caffeine at 100 ppm feed concentration, the TFN membrane incorporated with 0.05% TNS achieved water permeability of 1.45 L/m2·h·bar, which was 38.6% higher than that of unmodified TFC membrane, while maintaining satisfactory rejection of >97%. The enhancement of water permeability for TFN membrane can be attributed to their hydrophilic surface and unique nanochannel structure created by the nanoscale interlayer spacing via staking of TiO2 nanosheets. Furthermore, the 0.05TFN membrane exhibited excellent fouling resistance towards BPA and caffeine pollutants with almost 100% flux recovery for three cycles of operations.

Construction of PDA-PEI/ZIF-L@PE tight ultra-filtration (TUF) membranes on porous polyethylene (PE) substrates for efficient dye/salt separation

Tight ultra-filtration (TUF) membranes were constructed by in situ growing zinc imidazole frameworks micro-crystalline leaves (ZIF-L) in polyethylene imine (PEI) and polydopamine (PDA) deposit layers on porous polyethylene (PE) substrates. The effects of preparation conditions on the surface physical and chemical structures as well as on the dye/salt separation performance of the formed TUF membranes were systematically investigated. By inserting selective water permeation channels and increasing contacting surface areas, in situ-grown ZIF-L arrays tightly cross-linked in the coating matrix greatly increased water permeation without trading off dye/salt retention selectivity. The morphology of the included ZIF-L particles could be varied by adjusting the ligand/Zn molar ratio (α) in the preparation processes. Optimized PDA-PEI/ZIF-L@PE TUF membranes containing ZIF-L of cross-cross block morphology showed very high pure water permeability of 180 ± 20 L·m−2·h−1·bar−1 (LMHB) and retention selectivity (SCR/Na2SO4 and SMB/Na2SO4) of 267 and 43, respectively, as well as excellent stability and anti-fouling properties.

Long-term stability of cellulose membranes in spent deep eutectic solvent used in the recovery of lignin from lignocellulosic biomass

Deep eutectic solvents (DESs) are a novel class of solvents that can be used to fractionate biomass compounds. However, their sustainability depends strongly on their recyclability. In previous research, it was seen that membrane filtration with commercial cellulose membranes (RC70PP and Ultracel 5 kDa) might be a solution for purification of spent deep eutectic solvent (DES) that has been used in lignin extraction (Choline Chloride: Lactic Acid 1:10 molar ratio) from woody biomass. This DES is, however, very acidic (pH 1.3), which can have detrimental effects on the longevity of the membrane. In a previous study, the time that the membranes were exposed to the spent DES was relatively short. This study aims to increase knowledge of how cellulose membranes withstand spent DES over longer time periods of up to 8 weeks. The results show that cellulose membranes are quite stable under exposure to spent DES in terms of pure water flux and PEG retention for up to 4 weeks. After 8 weeks, the RC70PP membrane demonstrated an increase in pure water permeability of 45% and a noticeable decrease in PEG retention. Surface characterization revealed, however, that the chemical structure of the cellulose membranes changed already after 2 weeks of exposure prior to any changes in pure water permeability were observed. Experimentally revealed esterification of cellulose membrane by Lactic Acid of DES led to more negative charge of the exposed samples compared to their references. This esterification was accompanied by hydrolysis that removed amorphous parts and increased the crystallinity of the membrane.

Enhancing natural gas dehumidification with Pebax/Silica mixed matrix membrane: a comprehensive study

ABSTRACT In this study, a new polymer membrane was developed for natural gas dehumidification using the combination of hydrophilic silica nanoparticles in the Pebax polymer matrix. The membranes were characterized using various analytical methods including FTIR, XRD, SEM, and TGA. The results indicated that adding nanoparticles increased the porosity and thermal stability of the membranes. Also, the enhancement of copolymer hydrophilicity was confirmed by reducing contact angles. The study found that increasing the nanoparticle content from 0 w% to 3 w% at 15 bar pressure resulted in a 33% increase in water permeability and a 12% increase in methane permeability. Adding of silica also increased the H2O/CH4 selectivity from 24.17 to 27.34. Moreover, at higher temperatures (from 25 to 55°C), the permeability of H2O and CH4 reached 171.3 and 10.71 bar, respectively. The findings of this study show that the inclusion of hydrophilic silica nanoparticles in the Pebax matrix can enhance the efficiency of membranes for natural gas dehumidification. Additionally, the study highlights the significance of temperature in the design and implementation of such membranes.

Research of deformation processes of Amu-Bukhara canal and increase of water permeability

Research of deformation processes of Amu-Bukhara canal and increase of water permeability

Effects of pollution of saline soils with oil and oil products on soil physical properties

In the article, pollution of saline soils with oil and oil products, physical and water-physical properties depending on the level of salinity are studied. As a result of the research, it is scientifically based that the increase in the level of contamination of the soil is subject to the decrease in water permeability, and the decrease in the level of pollution is subject to the law of the increase in water permeability. In the article, weakly, moderately, strongly and very strongly contaminated soils with oil were studied. According to the results, it was determined that the water permeability of the soil was observed in 25, 45, 45, 37, 5, 3, 2 minutes, and it carried 75, 26, 44, 45, 540, 1050, 1200 ml of water, respectively, for 90 minutes. The amount of water transfer compared to the control soil for 90 minutes was less in 1%, 2%, 5% contaminated soils, and very high in 15%, 25% and 37.5% contaminated soils. The increase in the level of pollution is explained by the deterioration of water permeability and moisture retention. Also, due to the fact that oil is a viscous organic pollutant, the changes of 0.25, 0.5, 1, 3, 5, 7, 10 mm microaggregates, which are important for soil fertility, as a result of pollution, and changes in the amount of these microaggregates were also determined. It was found that the soils around the South Mirshodi oil field were previously contaminated and the amount of microaggregates smaller than 0.25 mm, 0.25 mm, 1 mm, 2 mm and 3 mm in the irrigated soils increased as the distance from the source of contamination increased. This is explained by the decrease in the concentration of oil in the soil. The amount of 5 mm, 7 mm and 10 mm aggregates has decreased. A similar situation was observed around the Kumkurgan oil base. The effect of petroleum hydrocarbons is more noticeable in microaggregates with a diameter of 10 mm.

The agrophysical properties effects in syderation used short-row sowing on soil

In short-term cotton-crop rotation fields agrophysical features was achieved improvement by sowing pure rape, peas + rape, peas + rape + chick peas are 22–32 tons of biomass per hectare of land is sown in the fall. In particular, when peas + rape, peas + rape + chick peas are used as siderites, macroaggregates in the topsoil increase by 7.87–8.73% and in the subsoil by 3.35–3.50%, when water-resistant aggregates are planted with gooseberry (55.82%) and pea when mixed with rapeseed and peas (56.7%), and increased soil fertility. As a result, the decrease in soil volume had a significant effect on the increase in water permeability and soil moisture more than 2%. The highest moisture content was observed in the mixture of peas + rape + chick peas as a siderite, and when rapeseed was used in its pure form. Sideration has resulted in an increase in organic humus in the soil and an optimal retention of moisture.

Improved flux and anti-fouling performance of a photocatalytic ZnO membrane on porous stainless steel substrate for microalgae harvesting

Photocatalytic self-cleansing ZnO membranes were developed and used for pre-concentrating microalgae solution prior to harvesting. The inorganic membranes were fabricated via two different methods: (i) direct deposition of ZnO onto a porous stainless steel substrate and (ii) post-growth oxidation of a deposited metallic Zn layer. Systematic surface characterisation revealed a thin layer of homogeneous, crystalline ZnO on the porous membrane. Direct ZnO deposition resulted in a thicker layer with higher UV light absorption capability compared with the post-growth oxidization method. The ZnO coating made the membrane surface highly hydrophilic, resulting in two-fold increase in water permeance compared to the base stainless steel substrate. The high hydrophilicity of the ZnO-coated membrane also led to an increase in the permeate flux of the microalgae solution by up to 100%, making it suitable for microalgae pre-concentration. Upon UV light irradiation, the ZnO membrane demonstrated self-cleansing capability due to the photocatalytic activity of the ZnO coating layer. After 30 min of UV irradiation, the ZnO membrane could achieve 60% permeance recovery after complete fouling. No recovery was observed with the base stainless steel membrane, which was used as the control.

Illuminating plant water dynamics: the role of light in leaf hydraulic regulation.

Light intensity and quality influence photosynthesis directly but also have an indirect effect by increasing stomatal apertures and enhancing gas exchange. Consequently, in areas such as the upper canopy, a high water demand for transpiration and temperature regulation is created. This paper explores how light intensity and the natural high Blue-Light (BL) : Red-Light (RL) ratio in these areas, is important for controlling leaf hydraulic conductance (Kleaf ) by BL signal transduction, increasing water permeability in cells surrounding the vascular tissue, in supporting the enormous water demands. Conversely, shaded inner-canopy areas receive less radiation, have lower water and cooling demands, and exhibit reduced Kleaf due to diminished intensity and BL induction. Intriguingly, shaded leaves display higher water-use efficiency (compared with upper-canopy) due to decreased transpiration and cooling requirements while the presence of RL supports photosynthesis.

Comparison of 2D and 3D materials on membrane modification for improved pressure retarded osmosis (PRO) process

Pressure retarded osmosis (PRO) is a sustainable process that convert Gibbs free energy to osmotic energy by mixing two solutions of different salinities. The main challenges in the design of PRO membranes are obtaining a membrane with high water permeability and low salt permeability but also very high mechanical strength because the PRO process involves high pressure on the draw solution. Commercially available RO membranes with potential utility in a PRO system exhibit a high salt rejection rate but low water permeability and mechanical stability. Surface modification is a promising strategy for tuning the fundamental properties of the membranes (e.g. hydrophilicity, surface charge and thickness) that can improve the filtration performance of the membranes. The coating layer can also improve the mechanical stability of the membranes. Therefore, in this work, various types of modification materials were applied to the commercial available RO membranes to enhance their performance.With the assistance of hydrophilic materials (e.g. polydopamine – PDA), filtration performance of the membranes can be increased through membrane modification by 2D materials with high charge intensities (e.g. polyelectrolytes and graphene oxides) and by 3D mesoporous materials (e.g. zeolites), which increases the thickness of the membrane that can be beneficial in mechanically reinforcing the membrane. In this work, we modified commercial RO membrane with PDA, polyelectrolytes, graphene oxide and zeolites (ZSM-5). Improved filtration performance (increased water permeability and maintained salt permeability) of the modified membrane was observed. Tensile tests showed enhanced mechanical strength of the modified membranes, especially following 3D zeolites modification (up to 35 % of higher tensile strain was reported). Interestingly, a lower concentration of PDA (2 mg/mL) and zeolites resulted in higher mechanical strength of the modified membranes. Such results were likely due to a more homogenous coating layer when a low modifier concentration was applied. The thin and uniform layer can better absorb energy when membranes are under high pressure.

Effect of temperature on organic fouling and cleaning efficiency of nanofiltration membranes for loch water treatment

We investigated the effect of solution temperature on organic fouling and cleaning of polypiperazine nanofiltration (NF) membranes. Fouling experiments were conducted in the temperature range 5 °C ≤ T ≤ 15 °C, characteristic of surface waters in northern latitudes, such as Scottish lochs. Results of laboratory-scale fouling experiments using alginate, a polysaccharide constituent of extracellular polymeric substances, showed a moderate increase in flux loss at 15 °C (41 %) compared to 5 °C (36 %). Analysis of the fouling experiments using a series-resistance model showed that the greater extent of fouling with rising temperature stems from a monotonic increase in water permeance with T. Interfacial property characterisation provided further insight into the effect of temperature on fouling determinants such as membrane hydrophobicity, nanoscale roughness, surface charge, and surface forces. No T-dependence of surface roughness was found. Similarly, we found that water contact angle is invariant within the temperature range investigated, suggesting that the observed fouling behaviour is not due to modulation of hydrophobic interactions. Conversely, colloidal-probe force spectroscopy (CPFS) measurements showed that adhesion forces become stronger with rising temperature. Further analysis showed that repulsive forces – which oppose colloidal particle deposition – become weaker with rising temperature, consistent with fouling trends. Determination of the membrane zeta potential showed that surface charge is invariant over the range of temperatures investigated, suggesting that repulsive forces have a non-electrostatic (likely steric) origin. Additionally, we assessed the effect of temperature on physical and chemical cleaning efficiency, comparing cleaning at the same temperature as the fouling experiments (5 °C ≤ T ≤ 15 °C) with cleaning at 30 °C. We observed that physical cleaning, consisting of water circulation over the fouled membrane surface, is insufficient to remove the foulant layers. On the other hand, chemical cleaning is able to restore 95 % of the original membrane permeance at 10 °C, but only 74 % at 5 °C.

Effects of multi‐walled carbon nanotubes on structures and properties of heat‐resistant poly(m‐phenylene isophthalamide)‐based hollow fiber ultrafiltration membranes

AbstractThis study is the first attempt to fabricate a heat‐resistant hollow fiber ultrafiltration membrane using poly(m‐phenylene isophthalamide) (PMIA) polymer material, which has rarely been used as conventional polymeric membrane materials. Multi‐walled carbon nanotubes (MWCNTs) are incorporated as reinforcing agents. The PMIA polymer synthesized for this study exhibited an inherent viscosity of 1.6 dL/g, confirming its suitability for membrane fabrication, and successful synthesis was verified through Fourier‐transform infrared analysis. To enhance the dispersibility of MWCNTs during dope solution preparation and their interaction with the PMIA matrix, MWCNTs were acid‐treated and surface characteristics of the acid‐treated MWCNTs were confirmed through x‐ray photoelectron spectroscopy analysis. Scanning electron microscope analysis revealed that the introduction of MWCNTs resulted in thicker PMIA hollow fiber ultrafiltration membranes with symmetrical finger‐like and sponge‐like pore structures. Interestingly, unlike the typical polymer composite systems containing MWCNTs, which often show a dependence on MWCNT content, the mechanical properties of the PMIA/MWCNT membranes in this study seem to exhibit high variability and are not contingent on the MWCNT content. Additionally, filtration performance studies demonstrated that the introduction of MWCNTs substantially increased water permeability, particularly at 1.0 wt% MWCNT content, resulting in a remarkable 130% enhancement compared to pristine PMIA membrane. Simultaneously, even with a small quantity of MWCNTs, the rejection performance of the PMIA/MWCNT membrane witnessed significant improvement due to the reduction in average pore size, effectively overcoming the commonly observed trade‐off phenomenon. In summary, this study clearly showed the effects and changes on the structure and properties of a heat‐resistant PMIA‐based hollow fiber ultrafiltration membranes due to the introduction of MWCNTs.Highlights Heat‐resistant poly(m‐phenylene isophthalamide)‐based hollow fiber ultrafiltration membranes Introduction of multi‐walled carbon nanotubes (MWCNTs) into PMIA membrane as a reinforcing agent Unique structural changes of PMIA membrane originated from the MWCNTs Enhanced tensile strength of PMIA/MWCNT membranes Simultaneous improvement of filtration performance due to MWCNTs

Enhancing stormwater treatment through ultrafiltration: Impact of cleaning chemicals and backwash duration on membrane efficiency

Abstract The effect of chemical cleaning and regular backwashing on the efficiency of an ultrafiltration membrane fouled during stormwater treatment was studied. Increasing backwash time from 30 to 60 s resulted in an increase in productivity by 20%. However, the productivity was highest when a backwash time of 45 s was used (3% higher than using 60 s). Chemical cleaning was carried out using an alkaline solution (NaOH with or without NaOCl) followed by acid washing with HCl. The addition of NaOCl to the cleaning chemical did not significantly increase the efficiency of chemical cleaning, and the average pure water permeability increase was 97 ± 13 LMH bar−1 after chemical cleaning with NaOH followed by HCl and 117 ± 15 LMH bar−1 after chemical cleaning with NaOH + NaOCl followed by HCl, on average. In addition, reversibility after chemical cleaning was 96 ± 67%, on average. The result from scanning electron microscopy showed that at the end of the experiments, inorganic foulants existed in both the inner layer (feed side) and the outer layer (permeate side) of the membrane.

Polymeric hollow fiber (HF) mixed matrix membranes (MMMs): Mutual effect of graphene oxide (GO) and polyvinylpyrrolidone (PVP) on nano-structuration

Hollow fiber (HF) membranes were fabricated using polysulfone (PSF) and 1.0 wt% graphene oxide (GO) synthesized through Hummer's method. The dry-wet spinning process was employed for their preparation. The structure and properties of both unmodified PSF HF membranes and those modified with GO were characterized. This encompassed analyses using scanning electron microscopy, attenuated total reflection Fourier Transform Infrared spectroscopy, thermo-gravimetric analysis, water contact angle (WCA) measurements, as well as evaluations of water permeability and mechanical attributes. The outcomes highlighted favorable mechanical and thermal characteristics. Moreover, the GO-modified PSF HF membranes exhibited larger surface pore sizes, along with an approximate 10% reduction in WCA and a fourfold increase in water permeability compared to the raw PSF HF membranes. Additionally, the influence of varying wt% of the pore-forming agent Polyvinylpyrrolidone (PVP) on the GO-modified PSF HF membranes was investigated. While no evidence suggests that GO can replace PVP, it is plausible to infer that this two-dimensional material complements the pore-forming agent's role by stabilizing the polymer-lean phase. This contributes to the creation of larger pores via phase separation mechanisms.

Polyelectrolyte multilayers modification of nanofiltration membranes to improve selective separation of mono- and multivalent cations in seawater brine

Nowadays, brine produced in the Reverse Osmosis (RO) seawater desalination plants is a significant and largely untapped source of critical minerals and metals, which is usually discharged into the seas as wastewater. As a front face stage in the brine mining process, nanofiltration (NF) membranes can be used to separate brine stream into monovalent and multivalent ion-rich streams. Since high separation factors are required in seawater RO brine, polyelectrolyte multilayers with Layer-by-Layer (LbL) technique were used in this study to modify commercial polyamide NF membranes and improve their performance. Two common polyelectrolytes, poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS) were coated onto two poly-piperazine polyamide NF membranes (NF270 and Desal-5 DL). The effects of the bilayers number and the outer layer charge on membranes’ performance were studied using two crossflow filtration setups with two different membrane sizes to find the membrane with the higher monovalent/multivalent separation factor. Desal-5 DL membrane coated with 5.5 bilayers provided the highest selectivity factors for mono/multivalent cations (> 21), the highest average rejection of multivalent cations group (about 95.7%) for short-term experiments. Another interesting result was the increase in water permeance of the Desal-5 DL membrane after it was coated with 5.5 bLs (indicating more than 20% improvement in pure water permeance). In addition, the stability test with brines at 20 bar showed that this membrane was stable over an extended period of filtration (22 hours) with an even higher selectivity factor of 34 and multivalent cations rejection of 97.7% on average.

Designing a multifunctional TFC membrane with improved permeability and anti-biofouling performance using zwitterionic, quaternary ammonium, and fluorinated materials

A novel copolymer architecture integrating anti-fouling, bactericidal, and fouling-release functions has been developed for thin-film composite (TFC) membranes to effectively address biofouling concerns. The approach involves growing three functional polymers from membrane surface in sequence. The first polymer has low surface energy, the second has bactericidal properties, and the third has a strong hydration capacity. The presence of the multifunctional layer significantly increased water permeability, which is due to the swelling property of the functional polymer. The extended Derjauguin-Landau-Verway-Overbeek (XDLVO) theory analysis shows that the introduction of the multifunctional copolymer architecture increased membrane-foulant total interaction energy (ΔGTOT) from 22.6 to 35.6 mJ/m2, indicating promising anti-adhesive properties. These properties have been confirmed by an 86 % decrease in E. coli adsorption during static bacteria assay. In addition, the fluoropolymer in modified membrane enhances its self-cleaning ability, which has been verified in static fouling-release assays where the TFC membrane can release attached cells under gentle agitation. Our long-term biofouling experiments further confirmed the superior multi-defense properties of the modified TFC membrane. Comparatively, the multifunctional membrane significantly reduced flux decline by 58 % and TOC biomass by 69 % during the dynamic biofouling process, and notably enhanced flux recovery of ∼97 % after cleaning. Our new copolymer architecture highlights the potential to enhance the efficiency and longevity of TFC membranes in a variety of applications.

Prediction Model for Tight Gas Wells with Time-Dependent Mechanism and Stress Sensitivity Effect.

In the production process of tight gas wells, reservoir fluid distribution and gas-water relative permeability vary with time. However, traditional models fail to handle the time-dependent mechanism and stress sensitivity effect in the reservoir, leading to significant errors in the dynamic analysis results. To address this issue, this article presents a prediction model for fractured well production in tight gas reservoirs. It is based on a three-dimensional embedded discrete fracture model (EDFM), which considers the influences of the time-dependent mechanism and stress-dependent reservoir permeability. Transient flow equations are treated by using the finite volume method to obtain the solution of the model. The accuracy and reliability of the model are verified by comparison with the results of the commercial simulator Eclipse and the field application. Based on the model's solution, this study emphasizes the analysis of the impact of the time-dependent mechanism and reservoir stress sensitivity on gas well productivity. Simulation results show that the time-dependent relative permeability curve can decrease the level of irreducible water saturation and promote the migration of irreducible water, resulting in an increase in water permeability and a decrease in gas permeability. This effect will reduce the period of stable gas production and increase the level of water production. Besides, reservoir stress sensitivity will reduce daily water production and accelerate gas well decline. It is necessary to control the production pressure difference reasonably during the production process to effectively reduce the negative impact of stress sensitivity effects. The results indicate that when the relative permeability curve and the reservoir permeability are constant, the real gas production capacity of the reservoir will be strengthened. The application of field case studies shows that the theoretical model exhibits stronger adaptability, achieves better fitting results, and can guide the compilation and adjustment of development plans for water-bearing tight gas reservoirs. These findings provide insights into understanding the effects of the time-dependent mechanism on gas production rates in tight gas reservoirs. Furthermore, this study offers useful guidance for the prediction of field-scale gas production.

Cell membrane dysfunction in postharvest spinach leaves increases water permeability through parallel pathways involving the lipid bilayer and aquaporins

Leafy greens, such as spinach, are susceptible to postharvest deterioration. Understanding factors underlying freshness loss, particularly related to cell membrane function and water permeability, is crucial for improving postharvest handling and preservation techniques. This study aimed to investigate changes in membrane water permeability in spinach mesophyll cells during storage and to identify the factors that affect these changes. We examined three properties of the cell membrane: lipid peroxidation, which triggers cell membrane deterioration; membrane rupture strength, reflecting the viscosity and fluidity of the cell membrane; and the expression of four aquaporin (AQP) genes: SoPIP1;1, SoPIP1;2, SoPIP2;1, and SoδTIP. To analyze their relationship with membrane water permeability, we conducted a protoplast shrinking assay under a hyperosmotic challenge. Our findings revealed that lipid peroxidation increased and membrane rupture strength weakened in response to varying oxygen concentrations during storage, correlating with an increase in membrane water permeability. Interestingly, the expression of SoAQPs markedly decreased during storage, regardless of the oxygen concentration. These observations suggest that membrane peroxidation and embrittlement promote packing imperfections in the lipid bilayer and induce AQPs to adopt an open conformational state, thereby contributing to the overall increase in membrane water permeability, even when the expression of SoAQPs decreases.