Membrane Structure Research Articles

Fabrication of green xylose-based nanofiltration membrane with enhanced performance and chlorine resistance

Nanofiltration technology has been widely used in drinking water purification due to its excellent permeance and selectivity properties, especially in small molecular solute separation. However, using oxidizing agents in the pretreatment process for fouling control threatens the nanofiltration membrane structure, leading to the deterioration of the separation performance. Herein, we fabricate a polyester nanofiltration membrane utilizing xylose as an aqueous monomer in the interfacial polymerization process. Due to abundant hydroxyl groups and low reactivity of xylose monomers, the polyester membrane possessed a hydrophilic and thin separation layer, which led to high water permeance with the optimal value of 28.7 L·m−2·h−1·bar−1. Possessing highly cross-linking structures and negatively charged surfaces, the fabricated polyester membranes showed an excellent Na2SO4 rejection of up to 95.4 %. In addition, the low electron-donating property of polyester membranes ensured their chemical stability toward active chlorine. This endows relatively stable performance of the polyester membrane after chlorine resistance tests in a wide pH range. This study presents a feasible approach employing green monomers for fabricating nanofiltration membranes with outstanding separation performance and robust chlorine resistance.

Carboxymethyl chitosan/polyvinyl alcohol hydrogel films by incorporating MSNs as ε-PL carrier with pH-responsive controlled release and antibacterial properties

A hydrogel film with pH-responsive release and excellent antibacterial properties was developed by utilizing mesoporous silica nanoparticles (MSNs) as carriers for ε-PL. Carboxymethyl chitosan (CMCS) is grafted onto aminated-MSNs through amine-bond reaction mediated, which is subsequently bound to polyvinyl alcohol (PVA) by esterification reaction. The addition of MSNs and optimization of CMCS proportion improved the dispersion stability of CMCS/PVA, resulting in a TSI value of 0.6 for 1.6CMCS/0.8PVA@MSNs-ε-PL, which is significantly lower than other groups. The proportion increase of CMCS improved the thermal stability and water oxygen barrier capacities of the 1.6CMCS/0.8PVA@MSNs-ε-PL by enhancing cross-linking with MSNs. The 1.6CMCS/0.8PVA@MSNs-ε-PL exhibited pH-responsive release behavior, with the extent of release increasing proportionally with higher pH levels. The 1.6CMCS/0.8PVA@MSNs-ε-PL exhibited significant antibacterial activity against Pseudomonas azotoformans MN10 in vitro, attributed to the ε-PL's ability to damage the bacterial membrane structure. Hence, the 1.6CMCS/0.8PVA@MSNs-ε-PL exhibits significant potential in food preservation.

Fabrication and Characterization of Dome-Shaped Actuator Membrane for Peristaltic Valveless Electromagnetic Micropump

This paper discusses the method of fabrication and characterization of a peristaltic micropump with a dome-shaped electromagnetic (EM) actuator membrane by pouring Polydimethylsiloxane (PDMS) on top of the glass master mould. The peristaltic micropumps have three membranes separated by a spacer of 2 mm. The structure of the mould consists of three pillar-shaped glasses that have a dome-like structure at the top. The border on the edge of the mould functions as a barrier to prevent the spill of the PDMS. When the PDMS is poured on top of the glass mould, a thin membrane will be formed and it will automatically overflow to form a chamber and spacer. The fabricated membrane structures were characterized using Scanning Electron Microscopy (SEM), while the mechanical and electrica properties were analysed by observing the deformation of the membrane. The SEM images show that a hanging PDMS membrane with a thickness of 77.5 µm was established. The permanent magnet connected to the lever and attached to the membrane will interact with the magnetic field generated by the EM coil. The measurement results show that a coil of 275 turns carrying a current of 600 mA produces a magnetic field of 11 mT causing a membrane deflection of 1.5 mm. The resulting dome-shaped membrane will have its potential application for the use as the actuator for the EM peristaltic micropumps.

The Influence of Water Deficit on Dehydrin Content in Callus Culture Cells of Scots Pine

Under a water deficit, the protective proteins known as dehydrins (DHNs) prevent nonspecific interactions in protein and membrane structures and their damage, in addition to playing an antioxidant role. The DHNs of a widespread xerophytic species Scots pine (Pinus sylvestris L.) have been poorly studied, and their role in resistance to water deficits has not been revealed. In this paper, we have expanded the list of DHNs that accumulate in the cells of Scots pine under the conditions of water deficits and revealed their relationship with the effects of water deficits. In this investigation, callus cultures of branches and buds of Scots pine were used. A weak water deficit was created by adding polyethylene glycol to the culture medium. Under the conditions of a water deficit, the activity of catalase and peroxidase enzymes increased in the callus cultures. A moderate decrease in the total water content was correlated with a decrease in the growth rate of the callus cultures, as well as with an increase in the activity of lipid peroxidation. The accumulation of Mr 72, 38, and 27 kDa DHNs occurred in the callus cultures of buds, and the accumulation of Mr 72 and 27 kDa DHNs positively correlated with the lipid peroxidation activity. An increase in the content of DHNs was observed in cultures that differed in origin, growth indicators, and biochemical parameters, indicating the universality of this reaction. Thus, previously undescribed DHNs were identified, the accumulation of which is caused by water deficiency and is associated with manifestations of oxidative stress in the kidney cells of Scots pine.

A review of antioxidant strategies to improve reproduction in aging male broiler breeders.

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Specific iron binding to natural sphingomyelin membrane induced by non-specific co-solutes

HypothesisSphingomyelin (SPM), a crucial phospholipid in the myelin sheath, plays a vital role in insulating nerve fibers. We hypothesize that iron ions selectively bind to the phosphatidylcholine (PC) template within the SPM membrane under near-physiological conditions, resulting in disruptions to membrane organization. These interactions could potentially contribute to the degradation of the myelin sheath, thereby playing a role in the development of neurodegenerative diseases. ExperimentsWe utilized synchrotron-based X-ray spectroscopy and diffraction techniques to study the interaction of iron ions with a bovine spinal-cord SPM monolayer (ML) at the liquid-vapor interface under physiological conditions. The SPM ML serves as a model system, representing localized patches of lipids within a more complex membrane structure. The experiments assessed iron binding to the SPM membrane both in the presence of salts and with additional evaluation of the effects of various ion species on membrane behavior. Grazing incidence X-ray diffraction was employed to analyze the impact of iron binding on the structural integrity of the SPM membrane. FindingsOur results demonstrate that iron ions in dilute solution selectively bind to the PC template of the SPM membrane exclusively at near-physiological salt concentrations (e.g., NaCl, KCl, KI, or CaCl2) and are pH-dependent. In-significant binding was detected in the absence of these salts or at near-neutral pH with salts. The surface adsorption of iron ions is correlated with salt concentration, reaching saturation at physiological levels. In contrast, multivalent ions such as La3+ and Ca2+ do not bind to SPM under similar conditions. Notably, iron binding to the SPM membrane disrupts its in-plane organization, suggesting that these interactions may compromise membrane integrity and contribute to myelin sheath damage associated with neurological disorders.

Encapsulation of lemongrass essential oil by bilayer liposomes based on pectin, gum Arabic, and carrageenan: Characterization and application in chicken meat preservation

The volatile characteristics of lemongrass essential oil (LO) have seriously hindered its further application, and encapsulation it with multilayer modified liposomes may be an effective strategy to improve this dilemma. This study selected chitosan (CH) and three anionic polymers, pectin (P) / gum arabic (GA) / carrageenan (C), as the first and second coating polymers to modify nano liposomes (NL) by layer-by-layer electrostatic deposition, obtaining three bilayer liposomes, P-CH-NL, GA-CH-NL, and C-CH-NL as high-quality stabilized carriers of LO. The bilayer liposomes showed a dense membrane structure ranging from 110 to 150 nm uniformly, with good antioxidant properties. All bilayer liposomes had good stability during 28-day storage at 4 °C, while C-CH-NL performed relatively better inferred by smaller changes of size, PDI and Zeta potential. The total volatile base nitrogen (TVB-N) values of fresh chicken meat and a total number of bacterial colonies (TBC) experiments showed that GA-CH-NL and C-CH-NL could better retard the increase of volatile salt base nitrogen. All bilayer liposomes could delay the time for the total bacterial count to exceed 6 log CFU/g (from 7 days to 10 / 12 days). Therefore, the bilayer liposomes P-CH-NL, GA-CH-NL, and C-CH-NL may be promising natural preservatives for food products.

First report of toxigenic Amphidoma languida (Amphidomataceae, Dinophyceae) from the Pacific, with reference to intracellular ultrastructure and azaspiracid compounds

SUMMARYMorphology, phylogeny and azaspiracid (AZA) production of a strain of Amphidoma languida isolated from the subtropical Mexican Pacific were examined. Scanning electron microscopy showed the thecal plate arrangement of Am. languida from Mexico as Po, cp, X, 6′, 6′′, 6C, 5S, 6′′′, 2′′′′, with the prominent apical pore complex, the ventral pore on the anterior of the 1′ plate near the suture to the 6′ plate, and the antapical pore on the 2′′′′ plate, which are congruent with those of Am. languida reported from the Atlantic. The ventral depression was occasionally observed on the anterior end of Sa plate. Cells had a dinokaryotic nucleus positioned in the posterior part of the cell and parietal yellowish chloroplasts with a spherical pyrenoid in the episome. Transmission electron microscopy showed crystalline vesicles and tubular cytoplasmic invaginations in the pyrenoid, which resembled those reported from the most related non‐toxigenic species Amphidoma fulgens. The intracellular components, different from Am. fulgens, were oil droplets and lipid‐associated membranous structures. AZA‐2 was detected from the strain by liquid chromatography‐tandem mass spectrometry with a cell quota of 30.9 fg cell−1. Three other AZA‐related compounds were also detected. This is the first report of AZA‐producing Am. languida in the Pacific Ocean.

Enhanced anti-fouling and selective performance of GO-modified nanofiltration membranes for lithium extraction from salt lake brine

Nanofiltration (NF) is a promising method in lithium extraction from salt lake brine with a high Mg2+/Li+ mass ratio. However, membrane fouling challenges its applicability and productivity. This study incorporated graphene oxide (GO) into the polyamide (PA) selective layer of NF membranes to enhance anti-fouling properties and improve lithium extraction from brine. Membrane structure analyses revealed that 0.002 wt% and 0.01 wt% GO facilitated the interfacial polymerization reaction. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) results indicated that the PA selective layers in the GO-0.002 % and GO-0.01 % membranes were denser, smoother, and thinner. In contrast, the addition of 0.05 wt% GO resulted in the Turing structures on the membrane surface. Adsorption kinetics indicated pollutant adhesion in the following order: GO-0.05 % > GO-0 % > GO-0.002 % > GO-0.01 %, which was attributed to calcium-carboxyl complexation, as directly measured by AFM and consistent with carboxyl density. The GO-0.002 % and GO-0.01 % NF membranes demonstrated excellent anti-fouling properties in brines, with lower initial fouling rates and higher flux recovery after cleaning, underscoring the significant role of calcium-carboxyl complexation in membrane fouling. The retention of Mg2+ increased to 95 %, while that of Li+ decreased to below −28 % for GO-0.002 % and GO-0.01 % membranes, indicating promising potential for Mg and Li separation. This study provides valuable insights into developing NF membranes with high Mg/Li selectivity and anti-fouling capabilities for lithium extraction from salt lake brine.

Effect of Oral Zinc Supplementation on Phase Angle and Bioelectrical Impedance Vector Analysis in Duchenne Muscular Dystrophy: A Non-Randomized Clinical Trial.

Zinc plays a crucial role in cell structure and functionality. Neurodegenerative Duchenne muscular dystrophy (DMD) alters muscle membrane structure, leading to a loss of muscle mass and strength. The objective of this study was to evaluate the changes in phase angle (PA) and bioelectrical impedance vector analysis (BIVA) results in patients with DMD after oral zinc supplementation. This clinical trial included 33 boys aged 5.6 to 24.5 years diagnosed with DMD. They were divided into three groups according to age (G1, G2, and G3) and supplemented with oral zinc. The mean serum zinc concentration was 74 μg/dL, and 29% of patients had concentrations below the reference value. The baseline values (mean (standard deviation)) of the bioelectrical impedance parameters PA, resistance (R), and reactance (Xc) were 2.59° (0.84°), 924.36 (212.31) Ω, and 39.64 (8.41) Ω, respectively. An increase in R and a decrease in PA and lean mass proportional to age were observed, along with a negative correlation (r = -0.614; p < 0.001) between age and PA. The average cell mass in G1 was greater than that in G3 (p = 0.012). There were no significant differences in serum zinc levels or bioelectrical impedance parameters before and after zinc supplementation. We conclude that this population is at risk of zinc deficiency and the proposed dosage of zinc supplementation was not sufficient to alter serum zinc levels, PA and BIVA results.

Static and dynamic analysis of a hyperelastic toroidal air-spring structure

The present work proposes a novel toroidal air-spring model consisting of two cylindrical elastomeric membranes unlike conventional convoluted air-spring with one rubber bellow. The membranes are attached with two annular plates at top and bottom in circumferential direction, forming a closed space in between. With internally pressurizing the setup, the inflated bellow in the shape of a toroidal air-spring structure is formed. The static and dynamic analysis of the air-spring model is performed under transverse loading on top plate. The static analysis is carried out by compressing the air-spring to different suspension heights, assuming adiabatic compression of the enclosed air. The conditions for impending wrinkling, its prevention measures by choosing suitable design parameters, and the effect using cord-reinforced membranes are explored. The dynamic study under harmonic forcing is performed using the method of assumed modes coupled with a perturbation technique to solve the Eigenvalue problem of the discretized membrane structure. The radial asymmetric perturbations are included in the formulation to explore the symmetry breaking during dynamic study. The Eigen frequencies of the structure are obtained for different inflation pressures of the air-spring. Interestingly, a frequency veering phenomenon is observed between a few Eigen modes associated with closely spaced natural frequencies, where the possibility of mode swapping exists. The forced vibration analysis around a few Eigen frequencies shows beating like responses. The stiffness of the proposed air-spring is found to be linear under both static and dynamic conditions, which is inline with the stiffness nature of the convectional convoluted air-springs.

Three-dimensional reconstruction of insect chemosensory sensillum

The olfactory system is involved in food and mate recognition in insects. However, 3D structures of chemosensory sensilla in insects are unexplored yet. Here, the internal structures of an olfactory sensillum on the antenna of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae), one of the most important rice pests, are examined and imaged using focused ion beam scanning electron microscopy. Based on these images, a 3D structure is reconstructed in this study. We find that the trichoid olfactory sensillum possesses a multiporous wall encircling a lumen with one sensory cell. Besides, there are three accessory cells (ACs) and a glia cell with different cell contents surrounding the sensory cell. The abundant tubular membrane structures in the tormogen cell suggest its role in secreting proteins like odorant binding proteins into the receptor lymph, while three auxiliary cells with simpler cellular content closely enfold the sensory cell, probably to prevent leaking of the receptor lymph into the surrounding epidermis. In the sensory cell, the microtubules and two tandem basal bodies at the base of the microtubules are also reconstructed. They are considered as a propulsive engine to ensure dendrite vibration or spinning in the receptor lymph, so that the proteins and odorant molecules move faster in the receptor lymph, which improves recognition of environmental odors and enables the insect to immediately respond to this information.

Dopamine hydrochloride and L-arginine Co-functionalized halloysite nanotubes for modification of polyethersulfone ultrafiltration membrane with improved separation performance

In recent years, a range of high-performance ultrafiltration membranes have been developed, but maintaining high retention without sacrificing high throughput remains a serious challenge. In this paper, functionalized halloysite nanotubes is constructed by copolymerization and by a one-step reaction of L-arginine and dopamine hydrochloride using halloysite nanotubes as carriers. Subsequently, modified polyethersulfone membranes are prepared by blending them as additives through non-solvent-induced phase transition separation. As the synthesized nanofillers is rich in functional groups, negative electronegativity, and unique structures, the study focuses on adding nanofillers’ effect on the membrane structure and physicochemical properties. The addition of appropriate nanofillers enhances the membrane surface wettability and negative electronegativity, and the enlarged internal pores and the dense layer that remains flat and homogeneous effectively promote the flux of small molecules, the retention of large molecules, and the cyclic stability of the membrane. The prepared polyethersulfone membranes demonstrate exceptional cycle stability, high separation efficiency (almost 100 % for Congo red), and significantly improved permeation performance (initial permeate flux up to 316.5 L m-2h−1). The results demonstrate the high potential of the modified prepared polyethersulfone membranes for pertinent environmental separation processes.

RESEARCH OF GANODERMA LUCIDUM EXTRACTS’ ANTIOXIDATIVE AND MEMBRANE STABILLIZING PROPERTIES IN VITRO CONDITION

The using of bioactive compounds received from natural raw as nutriceutics is aknowledged as well as strengthening, immunomodulatory, adaptogenic agents and in order to reduce the risk of emergence of various diseases. Ganoderma Lucidum or Reishi mushroom is known on east during centuries and has been used in different aims. Modern researches of Reishi mushroom show its high antioxidative potential. Our experiments have shown that extracts made from micelium and fruiting body of ganoderma reduce the intensity of lipoperoxidation in membranes and increase the resistance in vitro conditions.Micelium extract inhibited the level of products of lipoperoxidation up to 37,6% at concentration 10 mkg, 21,1% at 20 mkg, 14,9% at 50 mkg. At influence the same concentrations of ascorbic acid means of level of lipid peroxidation amount 74,3%, 60,4% and 36,4% - respectively, for vitamin E - Е-70,2%, 65,3%, 53,5% and 38%respectively. Antioxidative effect of fruit body’s extract significantly have shown at 10-50 mkg – level of LPO decreased on 80% from origin level, the increasing of concentration from 50 to 100 mkg leaded to practically total inhibition of formation LPO products. At concentrations lower than 10 mkg antioxidative effect of the testing agents didn’t differ significantly. The experiments revealed that the mycelium extracts' antioxidant properties exceed the well-known antioxidant agents such as vitamins E and C, while the extract of the fruit body has a substantially similar effect of ascorbic acid and alpha-tocopherolResults of study have shown that extracts of ganoderma possess pronounced property to stabilize the structure of cell membrane. Severity of membrane stabilizing effect of extracts depended on concentration. In concentration 0-200 mkg in samples incubated in the presence of mycelium and fruit body extracts the hemolysis decreased on 19,8% and 25% at 10 mkg, on 27% and 37% at 20 mkg, on 55% and 57,2% at 50 mkg, on 63% and 68% at 100 mkg, on 69% and 65% at 200 mkg respectively, whereas at the introducing in samples the ascorbic acid in analogical concentrations the hemolysis have descended on 10%, 14,5%, 25%, 40% and 44%, and at the cariing in α-tocopherol the hemolysis lowered on 5%, 22%, 32%, 40%, 45% and 50% respectively.The researches of total polyphenols and flavonoids in extracts showed, that in extracts abscent compounds, which are related to flavonoids, whereas have found the existence of another polyphenolic compounds.

Fabrication and application of highly permeable ceramic membranes: Membrane-forming mechanism, pore structure, separation performance and fouling mechanism analyses

High separation efficiency and satisfactory economic benefits are of great importance for ceramic membranes in the field of water treatment. Herein, microfiltration ceramic membrane with high permeability and selectivity was prepared in one-step (dip-coating and sintering) by sacrificial-interlayer method. The membrane-forming mechanism, effect of temperature on the morphology and pore structure, separation performance, fouling mechanism, and regeneration performance of the ceramic membranes were systematically investigated. The results show that membrane-forming mechanism of the membranes largely depends on film-coating filtration. The membrane with a mixture of nanocellulose crystals and graphene oxide as sacrificial interlayer (C1G1) and sintered at 1100–1300 °C possessed smooth surface. The open porosity and average pore size increased, and the pore size distribution became broader as the temperature increased. Moreover, the sacrificial-interlayer membrane sintered at 1300 °C (mA4S-C1G1) possessed suitable porosity (53.4%) and average pore size (200 nm), high permeance (4828 L·m−2·h−1·bar−1), which was larger than that of the membrane without sacrificial interlayer, manifesting that C1G1 could prevent the penetration of membrane-forming particles into support. The final fouling mechanism of mA4S-C1G1 was cake filtration, although complete pore blocking, standard pore blocking, intermediate pore blocking also involved in the initial stage. In addition, the oil rejection rate (∼97%) and steady-state feed flux (810–1154 L·m−2·h−1) of mA4S-C1G1 was high, and it also possessed good regeneration performance.

Alkoxy-functionalized covalent organic Framework membranes for efficient molecular sieving with high water permeance

The presence of various trace water-soluble organic pollutants, such as dyes, poses significant potential risks to human health and ecosystems. Membrane technology presents a promising and sustainable approach for their removal from aqueous environments. However, the amorphous structure of most commercial membranes makes it challenging to achieve effective separation with high water flux. Here, we present a novel series of hydrophilic COF membranes with different alkoxy sidechain lengths for the first time. These alkoxy sidechain functional COF membranes exhibit efficient rejection of water-soluble organic dyes, including rose bengal (> 50 %), congo red (> 98 %), brilliant blue R250 (> 99 %), and alcian blue (> 99 %). Moreover, these membranes demonstrate a high water flux exceeding 291.8 L m-2h−1 bar−1 and exceptional long-term operational stability lasting at least 2880 min. The superior performance of COF membranes is attributed to their optimal pore size, excellent hydrophilicity, and high crystallinity. This finding offers a promising approach for effectively eliminating water-soluble organic pollutants, thereby ensuring the safety and sustainability of the water supply.

Multi-omics analysis reveals the mechanisms by which C6-HSL enhances the resistance of typical functional bacteria in activated sludge to low-temperature stress

Signaling molecules, particularly acyl-homoserine lactones (AHLs), can enhance microbial activity under low-temperature stress. However, the specific mechanisms underlying this effect remain unclear. This study identified a typical activated sludge functional bacterium that is sensitive to low temperatures and regulated by hexanoyl-L-homoserine lactone (C6-HSL), a representative of AHLs. It elucidates how C6-HSL modulates the bacterium's resistance to low-temperature stress. Experimental results indicated that C6-HSL significantly increased the levels of adenosine triphosphate (ATP), superoxide dismutase (SOD), peroxidase (POD) and glutathione peroxidase (GSH-Px) in strain LB-001 under low-temperature stress, while also decreasing the levels of reactive oxygen species (ROS). Additionally, C6-HSL markedly repaired the damage to cell membrane structure caused by low-temperature stress. At the genetic level, C6-HSL upregulated the expression of 20 key genes related to energy metabolism, antioxidation, and fatty acid synthesis. At the metabolic level, C6-HSL increased the levels of metabolites related to energy metabolism and antioxidation, boosted the content of unsaturated fatty acids, and reduced the content of saturated fatty acids. This study utilized C6-HSL and low-temperature induction in conjunction with 16S microbial diversity sequencing, genomics, transcriptomics, and metabolomics. These methods were employed to elucidate the molecular mechanisms by which exogenous C6-HSL regulates the resistance of activated sludge microbial communities to low-temperature stress. This research lays the foundation for the application of AHLs and cell communication in wastewater biological treatment, fostering deeper exploration and further innovation in related academic research.

Magnetomechanical Behaviors of Hard-Magnetic Elastomer Membranes Placed in Uniform Magnetic Field.

This paper aims to develop a theoretical model for a viscoelastic hard-magnetic elastomer membrane (HMEM) actuated by pressure and uniform magnetic field. The HMEM is initially a flat, circular film with a fixed boundary. The HMEM undergoes nonlinear large deformations in the transverse direction. The viscoelastic behaviors are characterized by using a rheological model composed of a spring in parallel with a Maxwell unit. The governing equations for magneto-visco-hyperelastic membrane under the axisymmetric large deformation are constructed. The Zeeman energy, which is related to the magnetization of the HMEM and the magnetic flux density, is employed. The governing equations are solved by the shooting method and the improved Euler method. Several numerical examples are implemented by varying the magnitude of the pre-stretch, pressure, and applied magnetic field. Under different magnetic fields, field variables such as latitudinal stress exhibit distinct curves in the radial direction. It is observed that these varying curves intersect at a point. The position of the intersection point is independent of the applied magnetic field and only controlled by pressure and pre-stretch. On the left side of the intersection point, the field variables increase as magnetic field strength increases. However, on the other side, this trend is reversed. During viscoelastic evolution, one can find that the magnetic field can be used to modulate the instability behaviors of the HMEM. These findings may provide valuable insights into the design of the hard-magnetic elastomer membrane structures and actuators.

A protocol for detecting the cytoplasm-exposed mitochondrial DNA

Mitochondria, being semi-autonomous organelles, possess a double membrane structure and harbor their own DNA, known as mtDNA. In situations of stress, mtDNA is released from the mitochondrial membrane and enters the cytoplasm. The mtDNA released into the cytoplasm plays a dual role in promoting both the initiation and escalation of intracellular reactive oxygen species (ROS), the activation of inflammatory pathways, and the death of cells. Consequently, the identification of intracytoplasmic mtDNA fragments holds immense significance in the realm of scientific investigation. In this paper, we delineate the experimental methodologies presently employed for quantifying intracytoplasmic mtDNA fragments.

Hydrothermally rearranged cellulose membranes for controlled size sieving

Biodegradable polymers are important for reducing pollution and promoting sustainability as they break down more easily than traditional petroleum-based polymers. One such polymer is regenerated cellulose (RC), which is widely used in water purification and pharmaceuticals due to its chemical resistance and hydrophilicity. Since its direct use of cellulose is limited by its insolubility, derivatives like cellulose acetate (CA) are first converted through a regeneration process back into RC to make use of its functional properties. During this process, however, the membrane structure may be compromised, impairing its separation performance. Here we show that simply soaking CA membranes in hot water before regeneration significantly improves the structural integrity of RC membranes, retaining the sieving properties. The pretreatment causes planar shrinkage without disrupting the general characteristics of cellulose, allowing for sole adjustment of pore size. This straightforward approach enables precise tuning of membrane pore properties to suit specific application, such as adjusting pore size for efficient sieving of materials with particular molecular masses, all while maintaining high water permeance. Our findings suggest that hydrothermal processing has the potential to enhance the filtration performance of RC membranes and broaden their range of applications.