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Background Results Conclusion Saponins from Sapindus mukorossi Gaertn. are natural surfactants with excellent foaming ability, biodegradability, and safety. However, their applications in food have been rarely reported. The aim of this work was therefore to investigate the synergistic antibacterial roles of a combination of sapindoside A and B (SAB), which are major components of Sapindus saponins, in altering the properties and fatty acids (FAs) in the membrane of Micrococcus luteus, which has been identified as an opportunistic pathogen.Microscopy showed that SAB destroyed the integrity of the cell membrane and internal structures and led to the leakage of the cell content. Further analysis indicated that the ratio of saturated FAs to unsaturated FAs was increased significantly, and the membrane fluidity, permeability, and integrity changed substantially. Although sapindoside A and B exerted similar synergistic effects on fatty acid composition and membrane fluidity, sapindoside A had a greater impact on membrane permeability and integrity, consistent with density functional theory.The activity of M. luteus was inhibited more effectively by SAB than sapindoside A or B alone. It attacked cell membrane FAs, resulting in changing membrane fluidity, permeability, and integrity, eventually causing leakage of the cell contents, and ultimately cell death. This helped to provide evidence for the use of SAB as a natural antibacterial detergent additive in the food industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The cell membrane remodeling mediated by cyclopropane fatty acid synthase (CfaS) plays a crucial role in microbial physiological processes resisting various environmental stressors, including acid. Herein, we found a relatively high proportion (24.8%-28.3%) of cyclopropane fatty acid (CFA) Cy-19:0 in the cell membrane of a newly isolated extreme acidophile, Acidithiobacillus caldus CCTCC AB 2019256, under extreme acid stress. Overexpression of the CfaS encoding gene cfaS2 in Escherichia coli conferred enhanced acid resistance. GC–MS analysis revealed a 3.52-fold increase in the relative proportion of Cy-19:0 in the cell membrane of the overexpression strain compared to the control. Correspondingly, membrane fluidity, permeability and cell surface hydrophobicity were reduced to varying degrees. Additionally, HPLC analysis indicated that the overexpression strain had 1.54-, 1.42-, 1.85-, 1.20- and 1.05-fold higher levels of intracellular glutamic acid, arginine, aspartic acid, methionine and alanine, respectively, compared to the control. Overall, our findings shed light on the role of CfaS derived from extreme acidophile in bacterial defense against environmental acid stress, potentially facilitating its application in the design and development of industrial microbial chassis cells for organic acid production. [ABSTRACT FROM AUTHOR]

The cytoarchitecture of the striatum is remarkably homogeneous, in contrast to the regional variation in striatal functions. Whether differences in the intrinsic membrane properties of striatal neurons contribute to regional heterogeneity has not been addressed systematically. We made recordings throughout the young adult mouse striatum under identical conditions, with synaptic input blocked, from four major striatal neuron types, namely, the two subtypes of spiny projection neurons (SPNs), cholinergic interneurons (ChIs), and fastspiking GABAergic interneurons (FSIs), sampling at least 100 cells per cell type. Regional variation manifested across all cell types. All cell types in the nucleus accumbens (NAc) shell had higher input impedance and increased excitability. Cells in the NAc core were differentiated from the caudate-putamen (CPu) for both SPN subtypes by smaller action potentials and increased excitability. Similarity between the two SPN subtypes showed regional variation, differing more in the NAc than in the CPu. So, in the Str, both the intrinsic properties of interneurons and projection neurons are regionally heterogeneous, with the greatest difference between the NAc and CPu; greater excitability of NAc shell neurons may make the region more susceptible to activity-dependent plasticity. [ABSTRACT FROM AUTHOR]

This study investigates how temperature and forward osmosis (FO) membrane properties, such as water permeability (A), solute permeability (B), and structural parameter (S), affect the specific energy consumption (SEC) of forward osmosis-reverse osmosis system. The results show that further SEC reduction beyond the water permeability of 3 LMH bar-1 is limited owing to high concentration polarization (CP). Increasing S by 10-fold increases FO recovery by 177.6%, causing SEC decreases by 33.6%. However, membrane with smaller S also increases external CP. To reduce SEC, future work should emphasize mixing strategies to reduce external CP. Furthermore, increasing the temperature from 10 to 40 °C can reduce SEC by 14.3%, highlighting the energy-saving potential of temperature-elevated systems. The factorial design indicates that at a lower temperature, increasing A and decreasing S have a more significant impact on reducing SEC. This underlines the importance of developing advanced FO membranes, particularly for lower-temperature processes. [ABSTRACT FROM AUTHOR]

The cytoarchitecture of the striatum is remarkably homogeneous, in contrast to the regional variation in striatal functions. Whether differences in the intrinsic membrane properties of striatal neurons contribute to regional heterogeneity has not been addressed systematically. We made recordings throughout the young adult mouse striatum under identical conditions, with synaptic input blocked, from four major striatal neuron types, namely, the two subtypes of spiny projection neurons (SPNs), cholinergic interneurons (ChIs), and fast-spiking GABAergic interneurons (FSIs), sampling at least 100 cells per cell type. Regional variation manifested across all cell types. All cell types in the nucleus accumbens (NAc) shell had higher input impedance and increased excitability. Cells in the NAc core were differentiated from the caudate-putamen (CPu) for both SPN subtypes by smaller action potentials and increased excitability. Similarity between the two SPN subtypes showed regional variation, differing more in the NAc than in the CPu. So, in the Str, both the intrinsic properties of interneurons and projection neurons are regionally heterogeneous, with the greatest difference between the NAc and CPu; greater excitability of NAc shell neurons may make the region more susceptible to activity-dependent plasticity.

Solubility parameters are effective factors for controlling membrane preparation based on hydrophilic/hydrophobic polymers. Hansen solubility parameters (HSPs) of a polysulfone/polyethylene glycol (PSU/PEG) in increasing PEG molecular weights and binary coagulation bath of solvent/non-solvent mixtures are investigated. The results revealed that with increased PEG molecular weight in the casting solution, the relative energy difference (RED) of the solution increases, and subsequently its instability increases too. On the other hand, by increasing the solvent in the coagulation bath, RED decreases. Findings demonstrated that by increasing PEG molecular weight to 15,000 g /mol and increasing solvent to 60 wt% in the coagulation bath, an interconnected sponge-like structure with maximum mean pore size (120 nm) was achieved. With increased PEG molecular weight, membrane morphology tended toward to a sponge-like structure due to delayed demixing in the phase inversion stage. Furthermore, pure water permeability and rejection capability of membranes exhibited that with increasing RED of casting solution and reducing RED of coagulation bath, the highest permeability (2199 L/m2h and the lowest rejection capability (33%) of the membrane were attained. This study confirmed that, for the PSU/PEG system, by controlling the solubility parameters, RED value of casting solution and coagulation bath, membrane characteristics can be controlled. [ABSTRACT FROM AUTHOR]

Lipid biosensors are molecular tools used both in vivo and in vitro applications, capable of selectively detecting specific types of lipids in biological membranes. However, despite their extensive use, there is a lack of systematic characterization of their binding properties in various membrane conditions. The purpose of this study was to investigate the impact of membrane properties, such as fluidity and membrane charge, on the sensitivity of two lipid biosensors, LactC2 and P4M, to their target lipids, phosphatidylserine (PS) or phosphatidylinositol 4-phosphate (PI4P), respectively. Dual-color fluorescence cross-correlation spectroscopy, employed in this study, provided a useful technique to investigate interactions of these recombinant fluorescent biosensors with liposomes of varying compositions. The results of the study demonstrate that the binding of the LactC2 biosensor to low levels of PS in the membrane is highly supported by the presence of anionic lipids or membrane fluidity. However, at high PS levels, the presence of anionic lipids does not further enhance binding of LactC2. In contrast, neither membrane charge, nor membrane fluidity significantly affect the binding affinity of P4M to PI4P. These findings provide valuable insights into the role of membrane properties on the binding properties of lipid biosensors. • Fluorescence cross-correlation reveals binding properties of lipid biosensors. • Lipid biosensors binding responses might be affected by bulk membrane properties. • LactC2 sensitivity to PS is influenced by membrane charge and fluidity. • P4M is not susceptible to various membrane conditions when recognizing PI4P. [ABSTRACT FROM AUTHOR]

Adipokines are peptide hormones produced by the adipose tissue involved in several biological functions. Among adipokines, adiponectin (ADPN) has antidiabetic and anti-inflammatory properties. It can also modulate food intake at central and peripheral levels, acting on hypothalamus and facilitating gastric relaxation. ADPN exerts its action interacting with two distinct membrane receptors and triggering some well-defined signaling cascades. The ceramidase activity of ADPN receptor has been reported in many tissues: it converts ceramide into sphingosine. In turn, sphingosine kinase (SK) phosphorylates it into sphingosine-1 phosphate (S1P), a crucial mediator of many cellular processes including contractility. Using a multidisciplinary approach that combined biochemical, electrophysiological and morphological investigations, we explored for the first time the possible role of S1P metabolism in mediating ADPN effects on the murine gastric fundus muscle layer. By using a specific pharmacological inhibitor of SK2, we showed that ADPN affects smooth muscle cell membrane properties and contractile machinery via SK2 activation in gastric fundus, adding a piece of knowledge to the action mechanisms of this hormone. These findings help to identify ADPN and its receptors as new therapeutic targets or as possible prognostic markers for diseases with altered energy balance and for pathologies with fat mass content alterations. [ABSTRACT FROM AUTHOR]

[Display omitted] Two-dimensional (2D) nanomaterials, such as graphene nanosheets (GNs) and graphene oxide nanosheets (GOs), could adhere onto or insert into a biological membrane, leading to a change in membrane properties and biological activities. Consequently, GN and GO become potential candidates for mediating interleaflet phospholipid transfer. In this work, molecular dynamics (MD) simulations were employed to investigate the effects of GN and GO on lipid flip-flop behavior and the underlying molecular mechanisms. Of great interest is that GN and GO work in opposite directions. The inserted GN can induce the formation of an ordered nanodomain, which dramatically elevates the free energy barrier of flipping phospholipids from one leaflet to the other, thus leading to a decreased lipid flip-flop rate. In contrast, the embedded GO can catalyze the transport of phospholipids between membrane leaflets by facilitating the formation of water pores. These results suggest that GN may work as an inhibitor of the interleaflet lipid translocation, while GO may play the role of scramblases. These findings are expected to expand promising biomedical applications of 2D nanomaterials. [ABSTRACT FROM AUTHOR]

Comparative analysis of evolutionarily conserved neuronal circuits between phylogenetically distant mammals highlights the relevant mechanisms and specific adaptations to information processing. The medial nucleus of the trapezoid body (MNTB) is a conserved mammalian auditory brainstem nucleus relevant for temporal processing. While MNTB neurons have been extensively investigated, a comparative analysis of phylogenetically distant mammals and the spike generation is missing. To understand the suprathreshold precision and firing rate, we examined the membrane, voltage-gated ion channel and synaptic properties in Phyllostomus discolor (bat) and in Meriones unguiculatus (rodent) of either sex. Between the two species, the membrane properties of MNTB neurons were similar at rest with only minor differences, while larger dendrotoxin (DTX)- sensitive potassium currents were found in gerbils. Calyx of Held-mediated EPSCs were smaller and frequency dependence of short-term plasticity (STP) less pronounced in bats. Simulating synaptic train stimulations in dynamic clamp revealed that MNTB neurons fired with decreasing success rate near conductance threshold and at increasing stimulation frequency. Driven by STP-dependent conductance decrease, the latency of evoked action potentials increased during train stimulations. The spike generator showed a temporal adaptation at the beginning of train stimulations that can be explained by sodium current inactivation. Compared with gerbils, the spike generator of bats sustained higher frequency input-output functions and upheld the same temporal precision. Our data mechanistically support that MNTB input-output functions in bats are suited to sustain precise high-frequency rates, while for gerbils, temporal precision appears more relevant and an adaptation to high output-rates can be spared. [ABSTRACT FROM AUTHOR]

Introduction and aim. The obesity is one of the greatest public health problems in developing countries and it is a triggering factor for diabetes associated with insulin resistance. The importance of cell membrane lipids as essential regulators of insulin resistance, since changes in the dynamic properties of the cell membrane (e.g., membrane fluidity), could be one of the events by which obesity affects insulin sensitivity. Thus, the insulin resistance may not only be a cause but also a consequence of lipid disorders such as dyslipidemia and/or cell membrane phospholipid composition change. The modification of plasma membrane lipid composition can change membrane biophysical properties and thus influencing protein-lipid interactions, enzymatic activity and regulation of surface receptors. Alterations in the lipid composition modify the fluidity of plasma membranes and the expression of membrane functions, such as receptor binding and enzyme activities. This review summarizes the current knowledge on the effects of the modulation of plasma membrane lipid composition and membrane fluidity in the functionality of membrane proteins involved in insulin activity, including the insulin receptor, glucose transport and Na+/K+ ATPase and, in turn, the key features of the metabolic syndrome. Material and methods. References for that article were found through PubMed and Google Scholar, using terms: "obesity", "insulin resistance" and "membrane properties". The research was limited to abstracts and available full-text articles. Analysis of the literature. There is a strong relationship between dietary lipids, membrane lipid profiles and insulin resistance. The changes in the dynamic properties of the cell membrane (e.g., membrane fluidity), could be one of the events by which obesity affects insulin sensitivity. The modification of plasma membrane lipid composition can change membrane biophysical properties and thus influencing protein-lipid interactions, enzymatic activity, and regulation of surface receptors. Modifications of membrane phospholipid composition could have a role in the insulin action by altering membrane fluidity and, as a consequence, the insulin signaling pathway. Conclusion. As conclusion the membrane-lipid therapy approach can be used to treat important pathologies such as obesity and many others diseases such as: cancer, cardiovascular pathologies, neurodegenerative processes, obesity, metabolic disorders, inflammation, and infectious and autoimmune diseases. This pharmacological strategy aims to regulate cell functions by influencing lipid organization and membrane fluidity, inducing a concomitant modulation of membrane protein localization and activity which might serve to reverse the pathological state. Through this review we suggest an in-depth analysis of the membrane lipid therapy field, especially its molecular bases and its relevance to the development of innovative therapeutic approaches. [ABSTRACT FROM AUTHOR]

Our unique multiplexed imaging assays employing FRET biosensors have previously detected that γ-secretase processes APP C99 primarily in late endosomes and lysosomes in live/intact neurons. Moreover we have shown that Aβ peptides are enriched in the same subcellular loci. Given that γ-secretase is integrated into the membrane bilayer and functionally links to lipid membrane properties in vitro, it is presumable that γ-secretase function correlates with endosome and lysosome membrane properties in live/intact cells. In the present study, we show using unique live-cell imaging and biochemical assays that the endo-lysosomal membrane in primary neurons is more disordered and, as a result, more permeable than in CHO cells. Interestingly, γ-secretase processivity is decreased in primary neurons, resulting in the predominant production of long Aβ42 instead of short Aβ38. In contrast, CHO cells favor Aβ38 over the Aβ42 generation. Our findings are consistent with the previous in vitro studies, demonstrating the functional interaction between lipid membrane properties and γ-secretase and provide further evidence that γ-secretase acts in late endosomes and lysosomes in live/intact cells. [ABSTRACT FROM AUTHOR]

Stress-associated changes in the mechanical properties at the single-cell level of Escherichia coli (E. coli) cultures in bioreactors are still poorly investigated. In our study, we compared peptide-producing and non-producing BL21(DE3) cells in a fed-batch cultivation with tightly controlled process parameters. The cell growth, peptide content, and cell lysis were analysed, and changes in the mechanical properties were investigated using atomic force microscopy. Recombinant-tagged somatostatin-28 was expressed as soluble up to 197 ± 11 mg g−1. The length of both cultivated strains increased throughout the cultivation by up to 17.6%, with nearly constant diameters. The peptide-producing cells were significantly softer than the non-producers throughout the cultivation, and respective Young's moduli decreased by up to 57% over time. A minimum Young's modulus of 1.6 MPa was observed after 23 h of the fed-batch. Furthermore, an analysis of the viscoelastic properties revealed that peptide-producing BL21(DE3) appeared more fluid-like and softer than the non-producing reference. For the first time, we provide evidence that the physical properties (i.e., the mechanical properties) on the single-cell level are significantly influenced by the metabolic burden imposed by the recombinant peptide expression and C-limitation in bioreactors. [ABSTRACT FROM AUTHOR]

Malaria remains a major world public health problem, contributing to poverty and inequality. It is urgent to find new efficacious tools with few adverse effects. Malaria has selected red blood cell (RBC) alterations linked to resistance against infection, and understanding the protective mechanisms involved may be useful for developing host-directed tools to control Plasmodium infection. Pyruvate kinase deficiency has been associated with resistance to malaria. Pyruvate kinase-deficient RBCs display an increased concentration of 2,3-diphosphoglycerate (2,3-DPG). We recently showed that 2,3-DPG impacts in vitro intraerythrocytic parasite growth, induces a shift of the metabolic profile of infected cells (iRBCs), making it closer to that of noninfected ones (niRBCs), and decreases the number of parasite progenies that invade new RBCs. As an increase of 2,3-DPG content may also have an adverse effect on RBC membrane and, consequently, on the parasite invasion, in this study, we explored modifications of the RBC morphology, biomechanical properties, and RBC membrane on Plasmodium falciparum in vitro cultures treated with 2,3-DPG, using atomic force microscopy (AFM)-based force spectroscopy and other experimental approaches. The presence of infection by P. falciparum significantly increased the rigidity of parasitized cells and influenced the morphology of RBCs, as parasitized cells showed a decrease of the area-to-volume ratio. The extracellular addition of 2,3-DPG also slightly affected the stiffness of niRBCs, making it more similar to that of infected cells. It also changed the niRBC height, making the cells appear more elongated. Moreover, 2,3-DPG treatment influenced the cell surface charge, becoming more negative in treated RBCs than in untreated ones. The results indicate that treatment with 2,3-DPG has only a mild effect on RBCs in comparison with the effect of the presence of the parasite on the host cell. 2,3-DPG is an endogenous host metabolite, which may, in the future, originate a new antimalarial tool with few adverse effects on noninfected cells. [ABSTRACT FROM AUTHOR]

The cell membrane remodeling mediated by cyclopropane fatty acid synthase (CfaS) plays a crucial role in microbial physiological processes resisting various environmental stressors, including acid. Herein, we found a relatively high proportion (24.8%-28.3%) of cyclopropane fatty acid (CFA) Cy-19:0 in the cell membrane of a newly isolated extreme acidophile, Acidithiobacillus caldus CCTCC AB 2019256, under extreme acid stress. Overexpression of the CfaS encoding gene cfaS2 in Escherichia coli conferred enhanced acid resistance. GC-MS analysis revealed a 3.52-fold increase in the relative proportion of Cy-19:0 in the cell membrane of the overexpression strain compared to the control. Correspondingly, membrane fluidity, permeability and cell surface hydrophobicity were reduced to varying degrees. Additionally, HPLC analysis indicated that the overexpression strain had 1.54-, 1.42-, 1.85-, 1.20- and 1.05-fold higher levels of intracellular glutamic acid, arginine, aspartic acid, methionine and alanine, respectively, compared to the control. Overall, our findings shed light on the role of CfaS derived from extreme acidophile in bacterial defense against environmental acid stress, potentially facilitating its application in the design and development of industrial microbial chassis cells for organic acid production., Competing Interests: Declarations Conflict of interest The authors declare no competing interests. Ethical approval This article does not contain any studies with human participants or animals performed by any of the authors., (© 2024. The Author(s), under exclusive licence to Springer Nature Japan KK.)

Adipokines are peptide hormones produced by the adipose tissue involved in several biological functions. Among adipokines, adiponectin (ADPN) has antidiabetic and anti-inflammatory properties. It can also modulate food intake at central and peripheral levels, acting on hypothalamus and facilitating gastric relaxation. ADPN exerts its action interacting with two distinct membrane receptors and triggering some well-defined signaling cascades. The ceramidase activity of ADPN receptor has been reported in many tissues: it converts ceramide into sphingosine. In turn, sphingosine kinase (SK) phosphorylates it into sphingosine-1 phosphate (S1P), a crucial mediator of many cellular processes including contractility. Using a multidisciplinary approach that combined biochemical, electrophysiological and morphological investigations, we explored for the first time the possible role of S1P metabolism in mediating ADPN effects on the murine gastric fundus muscle layer. By using a specific pharmacological inhibitor of SK2, we showed that ADPN affects smooth muscle cell membrane properties and contractile machinery via SK2 activation in gastric fundus, adding a piece of knowledge to the action mechanisms of this hormone. These findings help to identify ADPN and its receptors as new therapeutic targets or as possible prognostic markers for diseases with altered energy balance and for pathologies with fat mass content alterations.

Several studies have reported differences in the morphological characteristics of motoneurons and the contractile properties of motor units of male and female rats. However, differences in spinal motoneuron activity between the sexes are not well understood. This study investigates the electrophysiological properties of spinal α‐motoneurons in male and female Wistar rats under pentobarbital anaesthesia. Fast and slow types of tibial motoneurons were recorded intracellularly in 15 male and 15 female rats, and the measured parameters were compared statistically using two‐way ANOVA and Tukey post hoc tests. The membrane properties, action potential parameters and firing characteristics were not different between sexes, though significant differences were observed in the properties of fast and slow motoneuron types within both sex groups. We conclude that the sex‐related differences observed in motor performance between male and female rats are largely due to differences in muscle mass, the proportion of muscle fibre types and the related motor unit contractile properties, while the mechanisms of motor control dependent on the electrophysiological activity of motoneurons are similar between the sexes. These findings are significant, as they indicate that results of experiments investigating electrophysiological properties can be reliably compared between sexes. [ABSTRACT FROM AUTHOR]

The selective separation of metal species from various sources is highly desirable in applications such as hydrometallurgy, water treatment, and energy production but also challenging. Monovalent cation exchange membranes (CEMs) show a great potential to selectively separate one metal ion over others of the same or different valences from various effluents in electrodialysis. Selectivity among metal cations is influenced by both the inherent properties of membranes and the design and operating conditions of the electrodialysis process. The research progress and recent advances in membrane development and the implication of the electrodialysis systems on counter-ion selectivity are extensively reviewed in this work, focusing on both structure–property relationships of CEM materials and influences of process conditions and mass transport characteristics of target ions. Key membrane properties, such as charge density, water uptake, and polymer morphology, and strategies for enhancing ion selectivity are discussed. The implications of the boundary layer at the membrane surface are elucidated, where differences in the mass transport of ions at interfaces can be exploited to manipulate the transport ratio of competing counter-ions. Based on the progress, possible future R&D directions are also proposed.

Passive samplers are key tools to sample hydrophilic micropollutants in water. Two main approaches address the influence of hydrodynamics: (1) determining site-specific sampling rate (R S) by characterizing k w , the mass transfer coefficient of the water-boundary layer (WBL), and (2) reducing WBL impact using a diffusive material to control the uptake. The first requires calibration data and the second has only been achieved using fragile diffusive material. This study assesses the transfer of hydrophilic contaminants through polytetrafluoroethylene (PTFE; 30 µm thick), a new membrane material with lower sorption than commonly used polyethersulfone (PES). Combined for the first time in a Chemcatcher-like configuration, we calibrated the modified samplers for 44 micropollutants to provide R S – k w relationships for in-situ R S determination (approach 1). Micropollutants accumulated over 2000 times more on the sorbent than on PTFE. PTFE-based R S (0.027 to 0.300 L day-1) were 2.5 higher than previously reported with PES. Membrane property measurements (porosity, tortuosity) indicated that accumulation is primarily controlled by the membrane. Extrapolation indicated that using thicker PTFE membranes (≥ 100 µm) would shift uptake control entirely to the membrane in river conditions (approach 2). This finding could enable R S prediction based on contaminants properties, thus representing a significant advancement in passive sampling. [Display omitted] • First use of PTFE membranes in Chemcatcher-like samplers. • PTFE membranes accumulate micropollutants 2000 times less than sorbent. • R S with PTFE membranes are 2.5 times higher than with PES membranes. • Thick PTFE membranes enable R S prediction without calibration experiments. [ABSTRACT FROM AUTHOR]

Summary: A bipolar membrane fuel cell (BPMFC) is a novel hydrogen/oxygen (H2/O2) fuel cell consisting of two‐layer membranes. The design of BPMFC is still in an early stage, and it requires profound research to explore its functions, working operations, and improve its performance. This review article systematically described the previous manipulations made in developing BPMFC in terms of process design and electrolyte materials. These two criteria are the most important in the design of BPMFC. Several modifications and manipulations were made, and the improvements observed over the years are also presented in this study in terms of electrochemical performance and properties. For instance, modifications and rearrangements of BPMFC components, new electrolyte materials, and different membrane layer integration techniques have been proposed. Different effects on BPMFC properties and performance were discovered when modifications were made. Some of the BPMFC managed to perform without any issues, whereas some encountered water management issues, lack of cell stability, and degradation of power output. To date, the optimal reported power density of the BPMFC was about 327 mW/cm2 and it managed to operate successfully for 40 h without showing any signs of degradation. In this regard, the commercialization of BPMFC for fuel cell performance is recommended as it displays a high potential for improving electrochemical cell performance and ensuring high cell durability. [ABSTRACT FROM AUTHOR]

Our unique multiplexed imaging assays employing FRET biosensors have previously detected that γ-secretase processes APP C99 primarily in late endosomes and lysosomes in live/intact neurons. Moreover we have shown that Aβ peptides are enriched in the same subcellular loci. Given that γ-secretase is integrated into the membrane bilayer and functionally links to lipid membrane properties in vitro, it is presumable that γ-secretase function correlates with endosome and lysosome membrane properties in live/intact cells. In the present study, we show using unique live-cell imaging and biochemical assays that the endo-lysosomal membrane in primary neurons is more disordered and, as a result, more permeable than in CHO cells. Interestingly, γ-secretase processivity is decreased in primary neurons, resulting in the predominant production of long Aβ42 instead of short Aβ38. In contrast, CHO cells favor Aβ38 over the Aβ42 generation. Our findings are consistent with the previous in vitro studies, demonstrating the functional interaction between lipid membrane properties and γ-secretase and provide further evidence that γ-secretase acts in late endosomes and lysosomes in live/intact cells.

Freezing is widely used for bacterial cell preservation. However, resistance to freezing can greatly vary depending on bacterial species or growth conditions. Our study aims at identifying cellular markers of cryoresistance based on the comparison of three lactic acid bacteria (LAB) exhibiting different tolerance to freezing: Carnobacterium maltaromaticum CNCM I-3298, Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842, and Lactobacillus delbrueckii subsp. bulgaricus CFL1. A thorough characterization of their cytoplasmic membrane properties was carried out by measuring their fatty acid composition, membrane fluidity, and lipid phase transition upon cooling from 50 to −50 °C. Vitrification temperatures of the intra- and extra-cellular compartments were also quantified by differential scanning calorimetry. Additionally, the cell biochemical characterization was carried out using a recently developed Fourier transform infrared (FTIR) micro-spectroscopic approach allowing the analysis of live bacteria in an aqueous environment. The multivariate analysis of the FTIR spectra of fresh and thawed cells enabled the discrimination of the three bacteria according to their lipid, protein, and cell wall peptidoglycan components. It also revealed freezing-induced modifications of these three cellular components and an increase in bacteria heterogeneity for the two strains of L. bulgaricus, the freeze-sensitive bacteria. No cellular damage was observed for C. maltaromaticum, the freeze-resistant bacteria. Comparison of the results obtained from the different analytical methods confirmed previously reported cryoresistance markers and suggested new ones, such as changes in the absorbance of specific infrared spectral bands. FTIR microspectroscopy could be used as a rapid and non-invasive technique to evaluate the freeze-sensitivity of LAB. [ABSTRACT FROM AUTHOR]

Achieving the distinctive complex behaviors of adult mammals requires the development of a great variety of specialized neural circuits. Although the development of these circuits begins during the embryonic stage, they remain immature at birth, requiring a postnatal maturation process to achieve these complex tasks. Understanding how the neuronal membrane properties and circuits change during development is the first step to understand their transition into efficient ones. Thus, using whole cell patch clamp recordings, we have studied the changes in the electrophysiological properties of layer V pyramidal neurons of the rat primary motor cortex during postnatal development. Among all the parameters studied, only the voltage threshold was established at birth and, although some of the changes occurred mainly during the second postnatal week, other properties such as membrane potential, capacitance, duration of the post-hyperpolarization phase or the maximum firing rate were not defined until the beginning of adulthood. Those modifications lead to a decrease in neuronal excitability and to an increase in the working range in young adult neurons, allowing more sensitive and accurate responses. This maturation process, that involves an increase in neuronal size and changes in ionic conductances, seems to be influenced by the neuronal type and by the task that neurons perform as inferred from the comparison with other pyramidal and motor neuron populations. [ABSTRACT FROM AUTHOR]

Achieving the distinctive complex behaviors of adult mammals requires the development of a great variety of specialized neural circuits. Although the development of these circuits begins during the embryonic stage, they remain immature at birth, requiring a postnatal maturation process to achieve these complex tasks. Understanding how the neuronal membrane properties and circuits change during development is the first step to understand their transition into efficient ones. Thus, using whole cell patch clamp recordings, we have studied the changes in the electrophysiological properties of layer V pyramidal neurons of the rat primary motor cortex during postnatal development. Among all the parameters studied, only the voltage threshold was established at birth and, although some of the changes occurred mainly during the second postnatal week, other properties such as membrane potential, capacitance, duration of the post-hyperpolarization phase or the maximum firing rate were not defined until the beginning of adulthood. Those modifications lead to a decrease in neuronal excitability and to an increase in the working range in young adult neurons, allowing more sensitive and accurate responses. This maturation process, that involves an increase in neuronal size and changes in ionic conductances, seems to be influenced by the neuronal type and by the task that neurons perform as inferred from the comparison with other pyramidal and motor neuron populations.

Detailed characterization of new Pseudomonas strains that degrade toxic pollutants is required and utterly necessary before their potential use in environmental microbiology and biotechnology applications. Therefore, phenol degradation by Pseudomonas putida KB3 under suboptimal temperatures, pH, and salinity was examined in this study. Parallelly, adaptive mechanisms of bacteria to stressful growth conditions concerning changes in cell membrane properties during phenol exposure as well as the expression level of genes encoding catechol 2,3-dioxygenase (xylE) and cyclopropane fatty acid synthase (cfaB) were determined. It was found that high salinity and the low temperature had the most significant effect on the growth of bacteria and the rate of phenol utilization. Degradation of phenol (300 mg L−1) proceeded 12-fold and seven-fold longer at 10 °C and 5% NaCl compared to the optimal conditions. The ability of bacteria to degrade phenol was coupled with a relatively high activity of catechol 2,3-dioxygenase. The only factor that inhibited enzyme activity by approximately 80% compared to the control sample was salinity. Fatty acid methyl ester (FAMEs) profiling, membrane permeability measurements, and hydrophobicity tests indicated severe alterations in bacteria membrane properties during phenol degradation in suboptimal growth conditions. The highest values of pH, salinity, and temperature led to a decrease in membrane permeability. FAME analysis showed fatty acid saturation indices and cyclopropane fatty acid participation at high temperature and salinity. Genetic data showed that suboptimal growth conditions primarily resulted in down-regulation of xylE and cfaB gene expression.

The concentration gradient battery (CGB) has numerous advantages, such as zero pollution emissions and the use of non-toxic electrolytes, making it a promising candidate for integrating renewable energy into the power grid. The use of high-performance membranes is a necessary condition for the application of CGB, but the specific membrane characteristics that contribute to desired CGB performance have not been clearly defined. In this study, five commercial membranes were employed to investigate the relationship among membrane permeation of water and salt, stack resistance, and battery performance. The results highlighted the pivotal roles of membrane permeability and resistivity in determining the CGB performance. Among the membrane tested, Selemion, notable for its low permeability and resistivity, was found to effectively break the trade-off between current and voltage efficiency. This superior performance is attributed to its distinctive membrane properties of low water volume fraction and high fixed charge density. This study further suggested that strategies aimed at controlling membrane swelling and increasing fixed charge density hold great promise in enhancing the membrane performance in CGB application. This research provides insights into membrane selection and customization for CGB and serves as a reference for other membrane processes focused on energy conversion. [Display omitted] • Membrane properties important for a concentration gradient battery were analyzed • Membranes with low resistivity and permeability are more suitable for CGBs • Selemion achieves relatively high current and voltage efficiencies at the same time • Selemion possesses both low water volume fraction and high fixed charge density [ABSTRACT FROM AUTHOR]

Ethanol is a toxic factor that damages membranes, disturbs metabolism, and may kill the cell. Tetragenococcus halophilus, considered as the cell factory during the manufacture of traditional fermented foods, encounters ethanol stress, which may affect the viability and fermentative performance of cells. In order to improve the ethanol tolerance of T. halophilus, a strategy based on cross protection was proposed in the current study. The results indicated that cross protection induced by heat preadaptation (45°C for 1.5 h) could significantly improve the stress tolerance (7.24-fold increase in survival) of T. halophilus upon exposure to ethanol (10% for 2.5 h). Based on this result, a combined analysis of physiological approaches and TMT-labeled proteomic technology was employed to investigate the protective mechanism of cross protection in T. halophilus. Physiological analysis showed that the heat preadapted cells exhibited a better surface phenotype, higher membrane integrity, and higher amounts of unsaturated fatty acids compared to unadapted cells. Proteomic analysis showed that a total of 163 proteins were differentially expressed in response to heat preadaptation. KEGG enrichment analysis showed that energy metabolism, membrane transport, peptidoglycan biosynthesis, and genetic information processing were the most abundant metabolic pathways after heat preadaptation. Three proteins (GpmA, AtpB, and TpiA) involved in energy metabolism and four proteins (ManM, OpuC, YidC, and HPr) related to membrane transport were up-regulated after heat preadaptation. In all, the results of this study may help understand the protective mechanisms of preadaptation and contribute to the improvement of the stress resistance of T. halophilus during industrial processes.

Ethanol is a toxic factor that damages membranes, disturbs metabolism, and may kill the cell. Tetragenococcus halophilus , considered as the cell factory during the manufacture of traditional fermented foods, encounters ethanol stress, which may affect the viability and fermentative performance of cells. In order to improve the ethanol tolerance of T. halophilus , a strategy based on cross protection was proposed in the current study. The results indicated that cross protection induced by heat preadaptation (45°C for 1.5 h) could significantly improve the stress tolerance (7.24-fold increase in survival) of T. halophilus upon exposure to ethanol (10% for 2.5 h). Based on this result, a combined analysis of physiological approaches and TMT-labeled proteomic technology was employed to investigate the protective mechanism of cross protection in T. halophilus. Physiological analysis showed that the heat preadapted cells exhibited a better surface phenotype, higher membrane integrity, and higher amounts of unsaturated fatty acids compared to unadapted cells. Proteomic analysis showed that a total of 163 proteins were differentially expressed in response to heat preadaptation. KEGG enrichment analysis showed that energy metabolism, membrane transport, peptidoglycan biosynthesis, and genetic information processing were the most abundant metabolic pathways after heat preadaptation. Three proteins (GpmA, AtpB, and TpiA) involved in energy metabolism and four proteins (ManM, OpuC, YidC, and HPr) related to membrane transport were up-regulated after heat preadaptation. In all, the results of this study may help understand the protective mechanisms of preadaptation and contribute to the improvement of the stress resistance of T. halophilus during industrial processes. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae is an important unicellular yeast species within the biotechnological and the food and beverage industries. A significant application of this species is the production of ethanol, where concentrations are limited by cellular toxicity, often at the level of the cell membrane. Here, we characterize 61 S. cerevisiae strains for ethanol tolerance and further analyze five representatives with various ethanol tolerances. The most tolerant strain, AJ4, was dominant in coculture at 0 and 10% ethanol. Unexpectedly, although it does not have the highest noninhibitory concentration or MIC, MY29 was the dominant strain in coculture at 6% ethanol, which may be linked to differences in its basal lipidome. Although relatively few lipidomic differences were observed between strains, a significantly higher phosphatidylethanolamine concentration was observed in the least tolerant strain, MY26, at 0 and 6% ethanol compared to the other strains that became more similar at 10%, indicating potential involvement of this lipid with ethanol sensitivity. Our findings reveal that AJ4 is best able to adapt its membrane to become more fluid in the presence of ethanol and that lipid extracts from AJ4 also form the most permeable membranes. Furthermore, MY26 is least able to modulate fluidity in response to ethanol, and membranes formed from extracted lipids are least leaky at physiological ethanol concentrations. Overall, these results reveal a potential mechanism of ethanol tolerance and suggest a limited set of membrane compositions that diverse yeast species use to achieve this. [ABSTRACT FROM AUTHOR]

Donnan dialysis separations of nitrate, bicarbonate and sulfate ions at different concentrations were studied; aiming to test the anions transport in membrane diffusion-controlled regime, boundary layer diffusion-controlled regime, and the transition region. Differences in the transport rates were correlated to differences between the properties of a homogeneous (Selemion AMV) and a heterogeneous (Ralex AM(H)-PES) anion-exchange membranes. As expected, under boundary layer diffusion control conditions, the separation of the three anions was similar with both membrane types, supporting the potential applicability of heterogeneous membranes for water treatment by Donnan dialysis. The transition region was obtained at a lower concentrations range with the heterogeneous membrane. Under membrane diffusion-controlled conditions, superior transport of all three anions were observed with the homogeneous ion-exchange membrane, suggesting that this membrane type is better for Donnan dialysis separation at higher concentrations. [ABSTRACT FROM AUTHOR]

Sodium hypochlorite (NaClO) is a commonly applied cleaning agent for ultrafiltration membranes in water and wastewater treatment. Long-term exposure to NaClO might change the properties and performance of polymeric membranes, and ultimately shorten membrane lifespan. Active species in NaClO solution vary with solution pH, and the aging effects can change depending on the membrane material. In this study, the aging of polyvinylidene fluoride (PVDF) and polyethersulfone (PES) membranes by NaClO at pH 3–11 was investigated by examining variations in chemical composition, surface charge, surface morphology, mechanical strength, permeability, and retention ability. Polyvinyl pyrrolidone (PVP), which was blended in both membranes, was oxidized and dislodged due to NaClO aging at all investigated pH values, but the oxidation products and dislodgement ratio of PVP varied with solution pH. For the PVDF membrane, NaClO aging at pH 3–11 caused a moderate increase in permeability and decreased retention due to the oxidation and release of PVP. The tensile strength decreased only at pH 11 because of the defluorination of PVDF molecules. For the PES membrane, NaClO aging at all investigated pH resulted in chain scission of PES molecules, which was favored at pH 7 and 9, potentially due to the formation of free radicals. Therefore, a decrease in tensile strength and retention ability, as well as an increase in permeability, occurred in the PES membrane for NaClO aging at pH 3–11. Overall, the results can provide a basis for selecting chemical cleaning conditions for PVDF and PES membranes. [Display omitted] [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) is a thermally driven separation process where a hydrophobic and microporous membrane separates nonvolatile compounds. Because of its advantages, this process appears as an efficient way to recover water from industrial effluents. However, the commercial membranes used in the MD process still have operational troubles with complex industrial wastewater and against harsh operational conditions. Fouling, wetting, and low time of operation compromise the membrane function and make the total consolidation of MD technology difficult beyond the traditional application (desalination). Membrane modification can be key to mitigating these operational problems, allowing MD's expansion to complex separations. In this context, herein the main technologies to modify the membranes for MD applications of the last five years are comprehensively summarized. Three kinds of postfabrication modifications are focused on: electrospinning, coating, and plasma, including polymeric and ceramic membranes. A critical analysis of each technique is developed, discussing their potentialities and the properties achieved through them. This review enables the understanding of the operational problems of MD technology and leads to finding feasible alternatives to their mitigation. It also clarifies the evolution in membrane modification, discusses the development directions, and points out the future challenges of modifications. [ABSTRACT FROM AUTHOR]

In the evolving landscape of water treatment, membrane technology has ascended to an instrumental role, underscored by its unmatched efficacy and ubiquity. Diverse synthesis and modification techniques are employed to fabricate state-of-the-art liquid separation membranes. Click reactions, distinguished by their rapid kinetics, minimal byproduct generation, and simple reaction condition, emerge as a potent paradigm for devising eco-functional materials. While the metal-free thiol-ene click reaction is acknowledged as a viable approach for membrane material innovation, a systematic elucidation of its applicability in liquid separation membrane development remains conspicuously absent. This review elucidates the pre-functionalization strategies of substrate materials tailored for thiol-ene reactions, notably highlighting thiolation and introducing unsaturated moieties. The consequential implications of thiol-ene reactions on membrane properties-including trade-off effect, surface wettability, and antifouling property-are discussed. The application of thiol-ene reaction in fabricating various liquid separation membranes for different water treatment processes, including wastewater treatment, oil/water separation, and ion separation, are reviewed. Finally, the prospects of thiol-ene reaction in designing novel liquid separation membrane, including pre-functionalization, products prediction, and solute-solute separation membrane, are proposed. This review endeavors to furnish invaluable insights, paving the way for expanding the horizons of thiol-ene reaction application in liquid separation membrane fabrication., (© 2024 Wiley‐VCH GmbH.)

The mammalian olfactory bulb (OB) has a vast population of dopamine (DA) neurons, whose function is to increase odor discrimination through mostly inhibitory synaptic mechanisms. However, it is not well understood whether there is more than one neuronal type of OB DA neuron, how these neurons respond to different stimuli, and the ionic mechanisms behind those responses. In this study, we used a transgenic rat line (hTH-GFP) to identify fluorescent OB DA neurons for recording via whole-cell electrophysiology. These neurons were grouped based on their localization in the glomerular layer (“Top” vs. “Bottom”) with these largest and smallest neurons grouped by neuronal area (“Large” vs. “Small,” in μm2). We found that some membrane properties could be distinguished based on a neuron’s area, but not by its glomerular localization. All OB DA neurons produced a single action potential when receiving a sufficiently depolarizing stimulus, while some could also spike multiple times when receiving weaker stimuli, an activity that was more likely in Large than Small neurons. This single spiking activity is likely driven by the Na+ current, which showed a sensitivity to inactivation by depolarization and a relatively long time constant for the removal of inactivation. These recordings showed that Small neurons were more sensitive to inactivation of Na+ current at membrane potentials of −70 and −60 mV than Large neurons. The hyperpolarization-activated H-current (identified by voltage sags) was more pronounced in Small than Large DA neurons across hyperpolarized membrane potentials. Lastly, to mimic a more physiological stimulus, these neurons received ramp stimuli of various durations and current amplitudes. When stimulated with weaker/shallow ramps, the neurons needed less current to begin and end firing and they produced more action potentials at a slower frequency. These spiking properties were further analyzed between the four groups of neurons, and these analyses support the difference in spiking induced with current step stimuli. Thus, there may be more than one type of OB DA neuron, and these neurons’ activities may support a possible role of being high-pass filters in the OB by allowing the transmission of stronger odor signals while inhibiting weaker ones.

Abstract Background Adult mesenchymal stem cells (MSCs) are an important resource for tissue growth, repair, and regeneration. To utilize MSCs more effectively, a clear understanding of how they react to environmental cues is essential. Currently, relatively little is known about how the composition of the plasma membranes affects stem cell phenotype and properties. The presence of lipid molecules, including cholesterol in particular, in the plasma membrane plays a crucial role in regulating a variety of physiological processes in cells. In this study, we examined the effects of perturbations in cholesterol/caveolin-1 (CAV-1)/caveolae homeostasis on the membrane properties and adhesive characteristics of MSCs. Findings from this study will contribute to the understanding of how cholesterol/CAV-1/caveolae regulates aspects of the cell membrane important to cell adhesion, substrate sensing, and microenvironment interaction. Methods We generated five experimental MSC groups: 1) untreated MSCs; 2) cholesterol-depleted MSCs; 3) cholesterol-supplemented MSCs; 4) MSCs transfected with control, nonspecific small interfering (si)RNA; and 5) MSCs transfected with CAV-1 siRNA. Each cell group was analyzed for perturbation of cholesterol status and CAV-1 expression by performing Amplex Red cholesterol assay, filipin fluorescence staining, and real-time polymerase chain reaction (PCR). The membrane fluidity in the five experimental cell groups were measured using pyrene fluorescence probe staining followed by FACS analysis. Cell adhesion to collagen and fibronectin as well as cell surface integrin expression were examined. Results Cholesterol supplementation to MSCs increased membrane cholesterol, and resulted in decreased membrane fluidity and localization of elevated numbers of caveolae and CAV-1 to the cell membrane. These cells showed increased expression of α1, α4, and β1 integrins, and exhibited higher adhesion rates to fibronectin and collagen. Conversely, knockdown of CAV-1 expression or cholesterol depletion on MSCs caused a parallel decrease in caveolae content and an increase in membrane fluidity due to decreased delivery of cholesterol to the cell membrane. Cells with depleted CAV-1 expression showed decreased cell surface integrin expression and slower adhesion to different substrates. Conclusions Our results demonstrate that perturbations in cholesterol/CAV-1 levels significantly affect the membrane properties of MSCs. These findings suggest that modification of membrane cholesterol and/or CAV-1 and caveolae may be used to manipulate the biological activities of MSCs.

In this study, attapulgite clay was extracted from North Western desert of Borg El-Arab, Egypt. The pristine clay was purified and treated before further use. The mineralogical composition of pristine clay was investigated by TEM, SEM, XRD and EDX analyses. Moreover, the pristine clay was organically modified with hexadecyl trimethyl ammonium chloride before incorporating into PVA-HES membranes. The modification of clay was also verified by FTIR, SEM and XRD analyses. Meanwhile, PVA-hydroxyethyl starch (PVA-HES/modified attapulgite clay) composite hydrogel membranes were fabricated by solution-casting method, where citric acid was utilized as cross-linker for formation of cross-linked membranes. The influence of addition of Egyptian modified attapulgite clay in ratios (0, 1.0, 3.0, 5.0, 7.0 and 10 wt%) on properties of PVA-HES composite membranes was studied in detail. Results revealed that the incorporation of modified attapulgite clay into membranes increased significantly the swelling ability and mechanical stability of composed hydrogel membranes. Also, the increase in clay contents in membranes showed antimicrobial activity against tested six pathogen strains and adequate hemolytic behavior, compared to clay-free membranes. These findings are referring to the capability of using of PVA-HES–attapulgite composite membrane as a good candidate for the purpose of super-absorbent dermal wound dressings. [ABSTRACT FROM AUTHOR]

Low-temperature direct ammonia fuel cells (DAFCs) are considered as an ideal power source for transportation due to their high energy density, easy storage and transportation, and reasonable cost. However, the alkaline electrolyte membranes suitable for DAFCs needs further research and development to achieve high power density output. Here, we conducted a pioneering study on the application of polybenzimidazole (PBI) based ion-solvating membrane (ISM) in DAFCs. The potential effect of ammonia crossover on the membrane properties during the operation of PBI ISMs based DAFCs was revealed through the treatment of poly(2,2'-(1,4-naphthylene)-5,5′-bibenzimidazole) (NPBI) and poly(2,2'-(meta -phenylene)-5,5′-bibenzimidazole) (m-PBI) ISMs with ammonia-alkali solution. More importantly, the performance of DAFCs based on PBI ISMs was reported for the first time, and the NPBI ISM based DAFC exhibited an exceptional peak power density (PPD) of 80 mW/cm2 at 80 °C, outperforming other alkaline ion membranes under identical testing conditions. Further optimization of operating conditions indicated that the performance of NPBI ISM-based DAFCs was highly dependent on concentration of KOH. This work provides a new direction and guidance for the development of alkaline polyelectrolyte membranes suitable for high performance low-temperature DAFCs. [Display omitted] • The NPBI ISM based DAFC exhibited an excellent peak power density (PPD) of 80 mW/cm2. • The potential impact of ammonia crossover on the membrane properties during the operation of PBI ISMs based DAFCs was revealed. • The effects of KOH and NH 3 concentration in anolyte on the performance of NPBI ISM based DAFC were demonstrated. [ABSTRACT FROM AUTHOR]

Microbial fuel cells (MFC) are an emerging technology for wastewater treatment that utilizes the metabolism of microorganisms to generate electricity from the organic matter present in water directly. The principle of MFC is the same as hydrogen fuel cell and has three main components (i.e., anode, cathode, and proton exchange membrane). The membrane separates the anode and cathode chambers and keeps the anaerobic and aerobic conditions in the two chambers, respectively. This review paper describes the state-of-the-art membrane materials particularly suited for MFC and discusses the recent development to obtain robust, sustainable, and cost-effective membranes. Nafion 117, Flemion, and Hyflon are the typical commercially available membranes used in MFC. Use of non-fluorinated polymeric membrane materials such as sulfonated silicon dioxide (S-SiO2) in sulfonated polystyrene ethylene butylene polystyrene (SSEBS), sulfonated polyether ether ketone (SPEEK) and graphene oxide sulfonated polyether ether ketone (GO/SPEEK) membranes showed promising output and proved to be an alternative material to Nafion 117. There are many challenges to selecting a suitable membrane for a scaled-up MFC system so that the technology become technically and economically viable.

To improve membrane fouling management, the NaClO-assisted backwash has been developed to improve permeability maintenance and reduce the need for intensive chemical cleanings. This study is aimed to focus on the efficiency of NaClO-assisted backwash in real UF pilot scale and with periodic classic backwash (CB) and air backwash (AB). The impacts on hydraulic filtration performance, physicochemical properties of membrane material under different addition frequencies of NaClO, and the performance of chlorinated CB and AB will be discussed. In result, 10 mg Cl2 L−1 NaClO addition in backwash water is confirmed to greatly improve the overall filtration performance and backwash cleaning efficiency. One condition stands out from the other due to better control of irreversible fouling, less NaClO consumption in 10 years prediction, sustainable and adaptable filtration performance, and less potential damage on the physicochemical properties of the membrane. Additionally, it can be inferred from this experiment that frequent contact with NaClO induced some degradation on the PES-made UF membrane surface properties. To retain the best state of UF membrane on anti-fouling and qualified production, the optimized condition with more frequent NaClO contact was not suggested for long-term filtration.

Some adipokines known to regulate food intake at a central level can also affect gastrointestinal motor responses. These are recognized to be peripheral signals able to influence feeding behavior as well. In this view, it has been recently observed that adiponectin (ADPN), which seems to have a role in sending satiety signals at the central nervous system level, actually affects the mechanical responses in gastric strips from mice. However, at present, there are no data in the literature about the electrophysiological effects of ADPN on gastric smooth muscle. To this aim, we achieved experiments on smooth muscle cells (SMCs) of gastric fundus to find out a possible action on SMC excitability and on membrane phenomena leading to the mechanical response. Experiments were made inserting a microelectrode in a single cell of a muscle strip of the gastric fundus excised from adult female mice. We found that ADPN was able to hyperpolarize the resting membrane potential, to enhance the delayed rectifier K+ currents and to reduce the voltage-dependent Ca2+ currents. Our overall results suggest an inhibitory action of ADPN on gastric SMC excitation–contraction coupling. In conclusion, the depressant action of ADPN on the gastric SMC excitability, here reported for the first time, together with its well-known involvement in metabolism, might lead us to consider a possible contribution of ADPN also as a peripheral signal in the hunger–satiety cycle and thus in feeding behavior.