Membrane Uptake Research Articles

The preparation and evaluation of granulated chitosan-catechin tablets with excellent disintegration properties

In this study, we prepared granulated chitosan (G-CS)/catechin tablets with excellent disintegration properties. We then compared their physical properties, dissolution behavior, and pharmacokinetic profile to non-granulated chitosan (N-CS)/catechin tablets. During the tableting process, the G-CS/catechin tablets demonstrated significantly higher compatibility and superior manufacturability, as evidenced by lower ejection and detachment stress than the N-CS/catechin tablets. This resulted in more robust tablets with better physical properties. The dissolution of catechin from the G-CS/catechin tablets occurred significantly faster than from the N-CS/catechin tablets, resulting in a significantly higher 2,2′-azino-bis(3 ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity. Similarly, the primary catechin components of the tablets, epigallocatechin gallate (EGCG) and caffeine, showed faster dissolution and membrane uptake from the G-CS/catechin tablets. These indicate a more efficient tablet formulation than N-CS/catechin tablets. Furthermore, the absorption and bioavailability of EGCG and caffeine in rats were significantly higher after oral administration of the G-CS/catechin tablets than the N-CS/catechin tablets. These findings suggest that G-CS/catechin tablets, having better disintegration properties than N-CS/catechin tablets, could allow for combination with other supplements, leading to the design of highly efficient supplement combination tablets.

Hyperpolarized 129Xe MRI and spectroscopy of gas exchange abnormalities in chronic hypersensitivity pneumonitis

PurposeTo evaluate 3D gas-exchange functional imaging characteristics using 129Xe MRI in a group of study participants with chronic hypersensitivity pneumonitis (CHP) as compared with healthy control participants. MethodsIn this prospective study, 11 participants with clinical and CT findings of CHP (4M 7F, mean age 67 ± 6.1 years) as well as 41 healthy subjects (25M 16F, mean age 44 ± 18 years) were enrolled between 2017 and 2022 and underwent 129Xe MRI. Three-dimensional images of ventilation, interstitial membrane uptake, and RBC transfer were rendered into quantitative 3D maps relative to a healthy reference cohort. In addition, 129Xe spectroscopy was used to assess the RBC:membrane ratio (RBC:M), the oxygen-dependent RBC chemical shift, and cardiogenically-driven RBC oscillation amplitude. Differences between the CHP participants and healthy subjects were assessed using the two-sample t-test or Wilcoxon rank-sum test as appropriate. ResultsCHP participants demonstrated significant differences in 6 parameters (p < 0.001) including regions of reduced ventilation, increased membrane uptake, and reduced RBC transfer as compared to healthy subjects. Gas exchange abnormalities measured on spectroscopy included a reduced RBC:M, reduced RBC chemical shift, and increased RBC oscillation amplitude. ConclusionIn participants with CHP, 129Xe MRI demonstrated gas exchange abnormalities common to other fibrotic lung diseases including increased membrane uptake, deficits in RBC transfer, and reduced RBC:M. However, CHP participants also exhibited prominent ventilation abnormalities, which may be reflective of the airway-centric nature of the disease. Further, the high variability observed in the membrane uptake could suggest varying degrees of disease progression or activity.

(Energy Technology Division Graduate Student Award sponsored by BioLogic) In-Situ Diagnostic Tools and Analysis to Identify Root Causes for Voltage Losses in Anion Exchange Membrane Water Electrolyzers

Water electrolysis has been getting significant attention worldwide as a leading technology that allows for the storage of renewable energy in the form of hydrogen. Anion exchange membrane water electrolyzers (AEMWEs) have emerged in recent years as a possible low-cost and high performance alternative to traditional alkaline electrolyzers (AWEs) and proton exchange membrane electrolyzers (PEMWEs). AEMWEs can potentially offer the complimentary benefits of the two developed technologies, namely high current density, pressurized cell operation, the use of platinum group metal (PGM) free electrocatalysts, and the ability to use earth abundant cheap materials for other cell components [1-2]. AEMWEs are currently in an early research and development stage. Most of the attention has been focused on the development of new polymers, electrocatalysts and other component materials [3-4]. Such materials are generally reported to offer high performance and durability, evaluated using standard ex-situ electrochemical techniques. Integration of these materials in actual water electrolyzer system often does not translate linearly into long life and high performance, and understanding material behavior in the real operating conditions is essential for their large-scale deployment. In-situ performance evaluation and diagnostic tools help analyze the contributions from individual components at membrane electrode assembly (MEA) level [5-7]. Differentiating kinetic, ohmic, transport as well as the catalyst layer overpotential contributions may lead a way for enhancing overall device performance and degradation. For instance, high IEC, water uptake and conductivity of polymer membranes and ionomers are desirable, however, may not linearly translate in high in-situ performance. Excessive swelling of the membrane and/or ionomer may dominate, increasing the charge transfer resistance, subsequently lowering the overall device performance [8]. In this presentation, a combination of methods – electrochemical impedance spectroscopy (EIS), cyclic voltammograms (CVs), I-V scans and constant current / voltage hold – are used to evaluate device performance and separate individual voltage losses caused by each MEA component. These tools help pinpoint the shortcomings of individual components that lead to losses in cell performance or degradation, allowing for new control strategies to be developed.

Nucleobase-mediated hydrogen bonding crosslinked highly sulfonated poly(ether ether ketone) electrodialysis membranes for efficient waste acid recovery

Electrodialysis is a promising technology for waste acid recovery with the advantages of low energy consumption and high efficiency. In this work, two nucleobase-modified highly sulfonated poly(ether ether ketone) with adenine (SPEEK-50A) and thymine (SPEEK-50T) were successfully synthesized. Then, a series of blending SPEEK-50Ax/50Ty membranes with varying molar ratios of these two functionalized SPEEKs were fabricated by solution casting. The hydrogen bonding crosslinked structure of ‘A-T base pairs’, as well as the acid-base interactions between the incorporated nucleobases and SO3H groups of the polymer backbone, not only enhanced the mechanical properties and thermal stability of the blending membranes, but more importantly, it successfully addressed the over-swelling issue of highly sulfonated SPEEK membrane. The SPEEK-50Ax/50Ty membranes exhibited tensile strengths between 59.3 and 72.3 MPa, which is 2.2–2.6 times that of the pristine SPEEK membrane. And the water uptake of the blending membranes reduced from 116 % to 14.6–19.2 %, while the swelling ratio decreased from 27.1 % to 5.86–6.60 %. The proton affinity of the multiple basic N atoms in nucleobases, as well as the ‘A-T base pairs’ hydrogen bonding network and acid-base interactions between nucleobases and SO3H groups, all can serve as effective proton transport channels. Additionally, the charge repulsion effect of protonated nucleobases and the crosslinking structure is beneficial to the permselectivity. Therefore, the fabricated blending SPEEK-50Ax/50Ty membranes exhibited superior H+ flux (1.66–1.73 mmol m−2 s−1) and enhanced H+/Fe2+ permselectivity (40.3–43.2). The SPEEK-50A0.5/50T0.5 membrane demonstrated a H+ flux of 1.70 mmol m−2 s−1 and a H+/Fe2+ permselectivity of 43.2, which is 2.8 times that of the pristine SPEEK membrane, surpassing both commercially available and recently reported membranes. Therefore, the nucleobase-modified blending SPEEK-50Ax/50Ty membranes might be potential candidates for the efficient recovery of acid from pickling wastewater.

Phase-State-Dependent Silica Nanoparticle Uptake of Giant Unilamellar Vesicles.

We quantify endocytosis-like nanoparticle (NP) uptake of model membranes as a function of temperature and, therefore, phase state. As model membranes, we use giant unilamellar vesicles (GUV) consisting of 1,2-dipentadecanoyl-sn-glycero-3-phosphocholine (15:0 PC). Time-series micrographs of the vesicle shrinkage show uptake rates that are a highly nonlinear function of temperature. A global maximum appears close to the main structural phase transition at T = Tm + 3 K = 37 °C and a minor peak at the pretransition T = Tp = 22 °C. The quality of linear fits to the shrinkage, and thus uptake kinetics, reveals a deviation from the linear trend at the vesicle shrinkage peaks. Taking values for the bending modulus as a function of temperature from literature and Helfrich's model allows us to draw qualitative conclusions on the membrane tension and the adhesion of the NP to the membrane as a function of temperature. These findings provide valuable insights into the dynamic interplay between temperature, membrane phase transitions, and NP uptake, shedding light on the complex behavior of biological membranes.

The developmental pattern related to fatty acid uptake and oxidation in the yolk sac membrane and jejunum during embryogenesis in Muscovy duck

This study aimed to investigate the developmental change of body growth and gene expression related to fatty acid uptake and oxidation in the yolk sac membrane (YSM) and jejunum during embryogenesis in Muscovy ducks. The weights of embryos and yolk sac (YS) (5 embryos per replicate, n = 6) were recorded on embryonic days (E)16, E19, E22, E25, E28, E31, and the day of hatch (DOH). The fat and fatty acid contents in YSM, jejunal histology, and gene expression related to fatty acid metabolism in YSM and jejunum were determined in each sampling time. Among the nonlinear models, the maximum growth is estimated at 2.83 (E22.5), 2.67 (E22.1), and 2.60 (E21.3) g/d using logistic, Gompertz, and Von Bertalanffy models, respectively. The weight of YS, and ether extract-free YS as well as the amounts of fat and fatty acids in YS decreased (P < 0.05) linearly, whereas the villus height, crypt depth, villus height/crypt depth, and musculature thickness in jejunum increased (P < 0.05) linearly during embryogenesis. The mRNA expression of CD36, SLC27A4, and FABP1 related to fatty acid uptake as well as the mRNA and protein expressions of PPARα and CPT1 related to fatty acid oxidation increased in a quadratic manner (P < 0.05) in both YS and jejunum, and the maximum values were achieved during E25 to E28. In conclusion, the maximum growth rate of Muscovy duck embryos was estimated at 2.60 to 2.83 g/d on E21.3 to E23.5, while the accumulations of lipid and fatty acid in YS were decreased in association with the increased absorptive area of morphological structures in jejunum. The gene and protein expression involved in fatty acid metabolism displayed a similar enhancement pattern between YSM and jejunum during E25 to E28, suggesting that fatty acid utilization could be strengthened to meet the energy demand for embryonic development.

Illuminating the function of the orphan transporter, SLC22A10, in humans and other primates

SLC22A10 is an orphan transporter with unknown substrates and function. The goal of this study is to elucidate its substrate specificity and functional characteristics. In contrast to orthologs from great apes, human SLC22A10, tagged with green fluorescent protein, is not expressed on the plasma membrane. Cells expressing great ape SLC22A10 orthologs exhibit significant accumulation of estradiol-17β-glucuronide, unlike those expressing human SLC22A10. Sequence alignments reveal a proline at position 220 in humans, which is a leucine in great apes. Replacing proline with leucine in SLC22A10-P220L restores plasma membrane localization and uptake function. Neanderthal and Denisovan genomes show proline at position 220, akin to modern humans, indicating functional loss during hominin evolution. Human SLC22A10 is a unitary pseudogene due to a fixed missense mutation, P220, while in great apes, its orthologs transport sex steroid conjugates. Characterizing SLC22A10 across species sheds light on its biological role, influencing organism development and steroid homeostasis.

Liquid- liquid (Cyclohexanone: Cyclohexanol) separation using augmented tight nanofiltration membrane: A sustainable approach

Organic solvent nanofiltration (OSN) is an incipient technology in the field of organic liquid-liquid separation. The incomplete separations and complexity involved in these, forces many organic liquids to be released as effluents and the adverse effects of these on environment is enormous and irreparable. The work prominences on the complete separation of industrially significant cyclohexanone: cyclohexanol (keto-alcohol oil) and heptane: toluene mixtures. The separations of these above-mentioned organic liquid mixtures were carried out using the fabricated Lewis acid modified graphitic carbon nitride (Cu2O@g-C3N4) incorporated polyvinylidene difluoride (PVDF) composite membranes. These fabricated membranes showed a separation factor of 18.16 and flux of 1.62 Lm−2h−1 for cyclohexanone: cyclohexanol mixture and separation of heptane and toluene mixture (with heptane flux of 1.52 Lm−2h−1) showed a separation factor of 9.9. The selectivity and productivity are based on the polarity and size of the organic liquids. The role of Cu2O@g-C3N4 is influencing the pore size distribution, increased divergence from solubility parameters, polarity, solvent uptake and porosity of the composite membranes. The developed composite membranes are thus envisioned to be apt for a wide range of liquid-liquid separations due to its implicit nature.

Quantifying Regional Radiation-Induced Lung Injury in Patients Using Hyperpolarized 129Xe Gas Exchange Magnetic Resonance Imaging

PurposeRadiation-induced lung injury (RILI) has been shown to alter regional ventilation and perfusion in the lung. However, changes in regional pulmonary gas exchange have not previously been measured. MethodsTen patients receiving conventional radiation therapy (RT) for lung cancer underwent pre-RT and 3-month post-RT MRI using an established hyperpolarized-129Xe gas exchange technique to map lung function. Four patients underwent an additional 8-month post-RT MRI. The MR signal from inhaled xenon is measured in three pulmonary compartments: the lung airspaces, the alveolar membrane tissue, and the pulmonary capillaries (interacting with red blood cells, RBCs). Thoracic 1H MRI scans were acquired, and deformable registration was used to transfer 129Xe functional maps to the RT planning CT. The RT-associated changes in ventilation, membrane uptake, and RBC transfer, were computed as a function of regional lung dose (equivalent dose in 2-Gy fractions, EQD2). Pearson correlation and t-tests were used to determine statistical significance, and weighted sum of squares linear regression subsequently characterized the dose-dependence of each functional component. Pulmonary function testing (PFT) metrics forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) were also acquired at each timepoint. ResultsCompared to pre-RT baseline, 3-month post-RT ventilation decreased by an average of -0.24±0.05 %/Gy (ρ=-0.88; P<.001), membrane uptake increased by 0.69±0.14 %/Gy (ρ=0.94; P<.001), and RBC transfer decreased by -0.41±0.06 %/Gy (ρ=-0.92; P<.001). Membrane uptake maintained a strong positive correlation with regional dose at 8 months post-RT, demonstrating an increase of 0.73±0.11 %/Gy (ρ=0.92; P=.006). Changes in membrane uptake and RBC transfer appeared greater in magnitude (%/Gy) for subjects with low heterogeneity in their baseline lung function. An increase in whole-lung membrane uptake showed moderate correlation with decreases in FVC (ρ=-0.50; P=0.17) and DLCO (ρ=-0.44; P=0.23), with neither correlation reaching statistical significance. ConclusionHyperpolarized-129Xe MRI measured and quantified regional, RT-associated, dose-dependent changes in pulmonary gas exchange. This tool could enable future work to improve our understanding and management of RILI.

Preparation and Evaluation of Nafion/CeO2 Composite Electrolyte Membranes for Polymer Electrolyte Fuel Cells

Polymer electrolyte fuel cells (PEFCs) are increasingly applied to the vehicles (FCVs) toward the suppression of carbon dioxide emission. The larger FCVs requires the high power density to exceed the presumed temperature limit of 80 ℃, causing some issues of material durability and system performances. In particular, a commercial electrolyte membrane of Nafion occurs the decrease of proton conductivity at the high temperatures under an atmospheric pressure. To overcome this problem, our research group has developed a composite electrolyte membrane consisting of Nafion and Ta-TiO2 nanoparticles with a chain-like network structure. The composite electrolyte membrane improves a proton conductivity in a wide temperature range over 100 ℃ by the effect of hydrophilic surface of the oxide. In this study, the other candidate materials of CeO2, nanoparticles with highly hydrophilic surface rather than that of Ta-TiO2 was selected to try to improve the proton conductivity of the composite electrolyte membranes.The hydrophilic CeO2 nanoparticles with a chain-like network structure were prepared using flame oxide-synthesis method. The hydrophilic CeO2 nanoparticles were dispersed in a dispersion solvent in desired ratio. The dispersion was then added to 20 wt.% Nafion dispersion solution (DE2020 CS, Chemours Co.) neutralized with potassium hydroxide. The resulting dispersion was coated onto a die coater and dried using a hot air. The CeO2/Nafion composite membrane was then treated in high purified water with a sulfuric acid solution. The transmission electron microscopy (TEM) and water adsorption, and four-probe alternating current method was conducted to detect the microstructure, water uptake and proton conductivity of the composite membrane.TEM images confirmed that the CeO2 nanoparticles were highly dispersed in the composite membrane. The proton conductivity of the 3 wt.% CeO2 containing composite membrane was 2.1 times higher than that of commercial Nafion membrane (NRE211, Chemours Co.) at 80 ℃, 20% RH, and was 1.5 times higher than that at 80 ℃, 80% RH (Fig. 1). The proton conductivity of the 3 wt.% CeO2 containing composite membrane was found to be higher than that of the Nafion monolayer in each water uptake (Fig. 2), indicating that the morphology of the membrane might be changed by the adding of CeO2 oxide. Further research will be needed to examine the proton conductivity mechanism of this composite membrane, and fuel cell evaluations using this composite membrane. Figure 1

Novel chitosan-ionic liquid immobilized membranes for PEM fuel cells operating above the boiling point of water

Novel chitosan (CS) composite membranes modified with ionic liquids (ILs), namely, 1-Hexyl-3- methylimidazolium tricyanomethanide ([HMIM][TCM]), Diethylmethylammonium methanesulfonate ([DEMA][OMs]), were synthesized to be used as a polymer electrolyte membrane (PEM) in for PEM fuel cells. The ionic conductivities of the prepared membrane samples were evaluated using electrochemical impedance spectroscopy (EIS). The CS is one of the attractive choices of green and sustainable membrane materials in PEMs because of its chemical tunability and cost-effectiveness. The membranes were prepared by solution casting followed by a solvent evaporating procedure. The low proton conductivity of pristine CS biopolymer was enhanced by the incorporation of ILs in the membrane framework. Tensile testing confirmed the excellent membrane mechanical integrity. A significant enhancement in the membranes’ characteristics was observed upon the introduction of [DEMA][OMs] into its matrix. The experimental results showed enhanced proton conductivities of the prepared membranes along with enhanced flexibility. The proton conductivity of pristine CS membrane was increased from 8.4 × 10−4 to 1.25 × 10−2 S/cm and 1.1 × 10−2 S/cm when a 30 wt% [HMIM][TCM] and 100 wt% [DEMA][OMs] were added, respectively. Synergistic effects of amine and imidazolium-based ILs on the electrical, structural, water uptake, and thermal properties of CS-based biopolymer solid electrolyte membranes are reported for the first time in this work. The aforementioned characterization results demonstrate the potential of using these membranes in PEM fuel cells operating above the boiling point of water and at a lower cost. This work showed that there should be an optimization amount of the ILs content in the membrane to maintain its mechanical integrity.

Outstanding proton conductivity over wide temperature and humidity ranges and enhanced mechanical, thermal stabilities for surface-modified MIL-101-Cr-NH2/Nafion composite membranes

High-performance proton exchange membranes are of great importance for fuel cells. Here, we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2 (PCP-MCN), a kind of hybrid metal−organic framework, which exhibits a superior proton conductivity. PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes. Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated. Significant enhancement in proton conduction for PCP-MCN around 55 °C is interestingly found due to the thermal motion of the PCP molecular chains. Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains, i.e. the formation of substantial acid–base pairs (-SO3-⋅⋅⋅+H–NH-), which further improves compatibility between additive and Nafion matrix. At the same humidity and temperature condition, the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion. Proton conductivity (σ) over wide ranges of humidities (30 − 100 % RH at 25 °C) and temperatures (30 − 98 °C at 100 % RH) for prepared membranes is measured. The σ in PCP-MCN/Nafion composite membranes is remarkably enhanced, i.e. 0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98 °C and 100 % RH, because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes. The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN. In particular, when 3 wt.% PCP-MCN was added to Nafion, the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480, 1.098 W/cm2 under 40 % RH, 100 % RH at 60 °C, respectively, guaranteeing it to be a promising proton exchange membrane.

PKCα Isoform Inhibits Insulin Signaling and Aggravates Neuronal Insulin Resistance.

Overexpression of PKCα has been linked to inhibit insulin signaling disrupting IRS-1 and Akt phosphorylations in skeletal muscle. PKCα inhibits IRS-1 and Akt phosphorylations, but not required for insulin-stimulated glucose transport in skeletal muscles. Inhibition of PKCα increased whereas in some studies decreased GLUT-4 levels at the plasma membrane in skeletal muscles and adipocytes. Controversial studies have reported opposite expression pattern of PKCα expression in insulin-resistant skeletal muscles. These findings indicate that the role of PKCα on insulin signaling is controversial and could be tissue specific. Evidently, studies are required to decipher the role of PKCα in regulating insulin signaling and preferably in other cellular systems. Utilizing neuronal cells, like Neuro-2a, SHSY-5Y and insulin-resistant diabetic mice brain tissues; we have demonstrated that PKCα inhibits insulin signaling, through IRS-Akt pathway in PP2A-dependent mechanism by an AS160-independent route involving 14-3-3ζ. Inhibition and silencing of PKCα improves insulin sensitivity by increasing GLUT-4 translocation to the plasma membrane and glucose uptake. PKCα regulates GSK3 isoforms in an opposite manner in insulin-sensitive and in insulin-resistant condition. Higher activity of PKCα aggravates insulin-resistant neuronal diabetic condition through GSK3β but not GSK3α. Our results mechanistically explored the contribution of PKCα in regulating neuronal insulin resistance and diabetes, which opens up new avenues in dealing with metabolic disorders and neurodegenerative disorders.

Anion exchange membranes: The effect of reinforcement in water and electrolyte

Alkaline anion-conducting polymer-based CO2 electrolysis and water electrolysis are among two emerging renewable energy conversion technologies. Their system design and integration offer promise of lower capital cost due to utilization of low-cost catalysts, in contrast to platinum group metal catalysts required for cation-conducting polymer-based devices. However, a critical component, the polymer electrolyte membrane, remains an obstacle hampering system performance and durability. In this study, commercially-available Sustainion® membranes with and without PTFE-reinforcement were investigated to understand previously unreported origins of improved device performance when compared to alternative membrane chemistries. We report critical membrane properties, such as morphology, thermal stability, as well as temperature-, hydration-, and counter-ion dependent ion conductivity. Moveover, the changes in uptake and conductivity of membranes in supporting electrolytes of K2CO3 and KOH investigated as a function of their concentration. Presence of reinforcement and supporting electrolyte type alter the membrane's transport functionality, which could help guide device design for improved performance. The obtained results not only show how Sustainion® properties change with operating environment for CO2 and water electrolysis applications, but also provide understanding for internal and external factors controlling anion-exhcnage membrane functionality in electrochemical devices.

Chitosan-based mixed matrix composite membranes for CO2/CH4 mixed gas separation. Experimental characterization and performance validation

Membrane technology is acknowledged as one of the most efficient for biogas upgrading, separating simultaneously CH4 and CO2 in the retentate and permeate streams, respectively. The sustainability would still be improved by using renewable and environmentally friendly materials for membrane fabrication. Specifically, this study is focused on laboratory-scale mixed gas separation tests of composite membranes prepared from chitosan (CS), a hydrophilic, biodegradable and biocompatible polymer from abundant natural resources, with good adhesive and film forming properties and high affinity for CO2 due to the primary amine and hydroxyl groups functionalities in CS. To improve mechanical resistance and CO2/CH4 separation, CS was hybridized by a 5 wt% loading of non-toxic ionic [emim][acetate] liquid (IL), and variable loadings of compatible inorganic fillers, such as 3D zeolite 4A and NaETS-10, and layered AM-4 titanosilicate. The CS-based mixed matrix layer was coated on porous polyether sulfone (PES) support. The CO2 permeance and CO2/CH4 separation were measured at different feed concentrations to evaluate the membranes performance in the treatment of different streams. This separation behavior was explained by the wet thickness, water uptake, morphology and ionic resistance of the composite membrane. As such, the 5 wt% Zeolite 4A and NaETS-10-filled ILCS/PES membranes provided a good dispersion in the ILCS matrix and the mixed matrix layer a good adhesion with the porous PES support, leading to high CO2 permeances and separation factors up to 30, whereas the more hydrophilic lamellar AM-4 titanosilicate-filled ILCS layer showed cluster agglomeration in the matrix and a faster detachment of the coated layer from the PES substrate. With increasing filler loading, an increase of the permeance of both CO2 and CH4 gas components was, although selectivity decreased upon increasing AM-4 filler loading. The CO2/CH4 mixed gas separation performance was validated by a custom-built model for a wide range of feed composition, to cover such processes as natural gas sweetening, biogas upgrading and enhanced oil recovery with acceptable relative error below 10% (absolute value), except for the AM-4 titanosilicate-filled ILCS membranes, showing morphological fabrication defects.

Preparation and structural investigations of the composite containing lead oxide and graphite as reinforcements and its adsorptive and photocatalytic dye-degradation activity

Water contamination by lead (Pb+2) has attracted enormous research owing to its potential carcinogenic, mutagenic, and toxic effects. Composite membranes are highly efficient, and cost-effective adsorbents for the elimination of heavy metals from water. The present study involves the preparation, characterization, and adsorption properties of a novel (Polyvinyl chloride) PVC/PbO-graphite adsorptive composite membrane (ACM) for the effective removal of Pb+2 ions from water. Four composite membranes were fabricated using PbO-graphite as a filler (5, 10, 15, and 20 %) and PVC as a binder. The physiochemical properties such as water uptake, swelling degree, density, and porosity of the composite membrane were studied. All the mentioned properties were decreased and the adsorptive capacity of the membranes (5.54–9.01 mg/g) declined with increasing filler percentage. It was observed that an increase in the initial concentration, adsorption, time, and pH improved the removal efficiency of the membranes. Maximum adsorption was observed for 5 % filler composite at 80 ppm initial concentration of Pb+2 in 300 min time at a pH of 6. Furthermore, both Langmuir and Freundlich adsorption isotherms were applied to investigate and understand the adsorption ability of the prepared ACMs. These isotherms well explained the adsorption process with an average R2 of 0.9860 and 0.9813 respectively. But the results were best aligned with the Langmuir adsorption mechanism (average R2 = 0.9860). The ACMs were also utilized for the photodegradation of Congo red dye and the ACMs (20 %) degraded about 71 % dye within 50 min.

Transcriptom and miRNA data of PUFA-enriched stimulated murine macrophage and human endothelial cell lines

Inflammation is associated with the adaptation of macrophages and endothelial cells, and the dysregulation of these differentiation processes has been directly linked to both acute and chronic disease states. As cells in constant contact with blood, macrophages and endothelial cells are also under the direct influence of immunomodulatory dietary components such as polyunsaturated fatty acids (PUFA). RNA sequencing analyses allow us to understand the global changes in gene expression occurring during cell differentiation, including both transcriptional (transcriptome) and post-transcriptional (miRNAs) levels. We generated a comprehensive RNA sequencing dataset of parallel transcriptome and miRNA profiles of PUFA-enriched and pro-inflammatory stimulated macrophages and endothelial cells aiming to uncover the underlying molecular mechanisms. PUFA concentrations and duration of supplementation were based on dietary ranges, allowing for metabolism and plasma membrane uptake of fatty acids. The dataset may serve as a resource to study transcriptional and post-transcriptional changes associated with macrophage polarisation and endothelial dysfunction in inflammatory settings and their modulation by omega-3 and omega-6 fatty acids.

Polylactic acid/multi-wall carbon nanotubes composite fibrous membrane and their applications in oil-water separation

Because of the rising consumption of oil, the oily pollutants contained in wastewater have caused great damage to the ecological environment. Herein, we report a novel composite PLA fibrous membrane for oil-water separation. First, a series of hydrophobic polylactic acid/multi-wall carbon nanotubes (PLA/CNTs) composite fibrous membranes were fabricated via electrospinning. To modify the membranes’ crystalline structure, the as-prepared PLA/CNTs composite fibrous membranes were subsequently treated by being immersed in an acetone/ethanol mixed solution for 5 min. FTIR and XRD were applied to thoroughly investigate the crystalline modification's mechanism and effects on the oil-water separation capability of the as-prepared composite fibrous membranes. With the introduction of CNTs and the crystalline modification, a low polar, rough and porous surface was endowed to the as-prepared fibrous membranes, enhancing their hydrophobicity and oil-water selectivity. The oil uptake of the as-prepared fibrous membrane could reach 114.01 g/g. The water contact angle in the air could reach 134.2° while the water contact angle under oil can reach 157.3° Therefore, such high separation capability in the oil-water mixture will make the PLA/CNTs composite fibrous membranes promising candidates for oil-water separation applications.

Versatile Silver-Nanoparticle-Impregnated Membranes for Water Treatment: A Review.

Increased affordability, smaller footprint, and high permeability quality that meets stringent water quality standards have accelerated the uptake of membranes in water treatment. Moreover, low pressure, gravity-based microfiltration (MF) and ultrafiltration (UF) membranes eliminate the use of electricity and pumps. However, MF and UF processes remove contaminants by size exclusion, based on membrane pore size. This limits their application in the removal of smaller matter or even harmful microorganisms. There is a need to enhance the membrane properties to meet needs such as adequate disinfection, flux amelioration, and reduced membrane fouling. To achieve these, the incorporation of nanoparticles with unique properties in membranes has potential. Herein, we review recent developments in the impregnation of polymeric and ceramic microfiltration and ultrafiltration membranes with silver nanoparticles that are applied in water treatment. We critically evaluated the potential of these membranes in enhanced antifouling, increased permeability quality and flux compared to uncoated membranes. Despite the intensive research in this area, most studies have been performed at laboratory scale for short periods of time. There is a need for studies that assess the long-term stability of the nanoparticles and the impact on disinfection and antifouling performance. These challenges are addressed in this study and future directions.

Brush Border Membrane Vesicles from Rats and Gerbils Can Be Utilized to Evaluate the Intestinal Uptake of All-trans and 9-cis β-Carotene

Intestinal brush border membrane vesicles (BBMV) have previously been used to investigate the absorptive processes of a wide variety of nutrients. The first objective of this work was to develop a BBMV system to study carotenoid uptake using rat small intestine. The uptake of all-trans β-carotene by rat BBMV was linear up to 5.9 µmol/L, suggesting passive uptake at the concentrations used in this study. Both all-trans β-carotene and 9-cis β-carotene were taken up at a similar rate by the rat BBMV. The vesicle system was then utilized to investigate the uptake of retinol and β-carotene by BBMV isolated from Mongolian gerbils which had been subjected to three different vitamin A depletion and refeeding protocols. Three groups of gerbils (n = 10/group) were fed vitamin A-deficient diets for 8 wk. One group was killed at that point (marginally depleted), a second group was refed vitamin A for 5 d and a third group was further depleted of vitamin A for 5 d. Pooled BBMV from the marginally depleted group demonstrated greater uptake of all-trans β-carotene than pooled BBMV from the other two groups of gerbils while those from the group refed vitamin A for 5 d had greater uptake than the group that was depleted for 5 additional days (P < 0.01). In contrast, the uptake of retinol by BBMV was not significantly different among the three groups of gerbils. The results of the gerbil study suggest that as they become increasingly vitamin A deficient, impairment of all-trans β-carotene uptake by intestinal mucosal cells may be taking place. The BBMV system should prove valuable for the evaluation of the intestinal mucosal cell membrane uptake of carotenoids and retinoids under various nutritional conditions.