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A scaling law for the osmotic pressure of quasi-two-dimensional polymer melts as a function of concentration is obtained, which shows fractal characteristics. Structural properties such as the chains' contour length and their inner-monomer pair distribution function display fractal scaling properties as well. These predictions are confirmed with mesoscale numerical simulations. The chains are swollen and highly entangled, yet Flory's exponent is always ν = 1/2. The melt can be considered a fluid of "blobs" whose size becomes renormalized in terms of the contour's length while the fractal dimension df increases monotonically between 5/4 and 2, as the monomer concentration is increased. The semidilute scaling of the pressure is recovered when df = 1. Our results agree with recent experiments and with numerical reports on quasi-2d melts. This work provides a new paradigm to study and interpret thermodynamic and structural data in low-dimensional polymer melts, namely as fractal macromolecular objects. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are conducted to systematically investigate the insertion of spherical nanoparticles (NPs) in polymer brushes as a function of their size, strength of their interaction with the polymers, polymer grafting density, and polymer chain length. For attractive interactions between the NPs and the polymers, the depth of NPs' penetration in the brush results from a competition between the enthalpic gain due to the favorable polymer–NP interaction and the effect of osmotic pressure resulting from displaced polymers by the NP's volume. A large number of simulations show that the average depth of the NPs increases by increasing the strength of the interaction strength. However, it decreases by increasing the NPs' diameter or increasing the polymer grafting density. While the NPs' effect on the polymer density is local, their effect on their conformations is long-ranged and extends laterally over length scales larger than the NP's size. This effect is manifested by the emergence of laterally damped oscillations in the normal component of the chains' radius of gyration. Interestingly, we found that for high enough interaction strength, two NPs dimerize in the polymer brush. The dimer is parallel to the substrate if the NPs' depth in the brush is shallow. However, the dimer is perpendicular to the substrate if the NPs' are deep in the brush. These results imply that polymer brushes can be used as a tool to localize and self-assemble NPs in polymer brushes. [ABSTRACT FROM AUTHOR]

Short nanopores find extensive applications, capitalizing on their high throughput and detection resolution. Ionic behaviors through long nanopores are mainly determined by charged inner-pore walls. When pore lengths decrease to sub-200 nm, charged exterior surfaces provide considerable modulation to ion current. We find that the charge status of inner-pore walls affects the modulation of ion current from charged exterior surfaces. For 50-nm-long nanopores with neutral inner-pore walls, the charged exterior surfaces on the voltage (surfaceV) and ground (surfaceG) sides enhance and inhibit the ion transport by forming ion enrichment and depletion zones inside nanopores, respectively. For nanopores with both charged inner-pore and exterior surfaces, continuous electric double layers enhance the ion transport through nanopores significantly. The charged surfaceV results in higher ion current by simultaneously weakening the ion depletion at pore entrances and enhancing the intra-pore ion enrichment. The charged surfaceG expedites the exit of ions from nanopores, resulting in a decrease in ion enrichment at pore exits. Through adjustment in the width of charged-ring regions near pore boundaries, the effective charged width of the charged exterior is explored at ∼20 nm. Our results may provide a theoretical guide for further optimizing the performance of nanopore-based applications, such as seawater desalination, biosensing, and osmotic energy conversion. [ABSTRACT FROM AUTHOR]

Maintenance of water homeostasis is a fundamental cellular process required by all living organisms. Here, we use the single-celled green alga Chlamydomonas reinhardtii to establish a foundational understanding of osmotic-stress signaling pathways through transcriptomics, phosphoproteomics, and functional genomics approaches. Comparison of pathways identified through these analyses with yeast and Arabidopsis allows us to infer their evolutionary conservation and divergence across these lineages. 76 genes, acting across diverse cellular compartments, were found to be important for osmotic-stress tolerance in Chlamydomonas through their functions in cytoskeletal organization, potassium transport, vesicle trafficking, mitogen-activated protein kinase and chloroplast signaling. We show that homologs for five of these genes have conserved functions in stress tolerance in Arabidopsis and reveal a novel PROFILIN-dependent stage of acclimation affecting the actin cytoskeleton that ensures tissue integrity upon osmotic stress. This study highlights the conservation of the stress response in algae and land plants, and establishes Chlamydomonas as a unicellular plant model system to dissect the osmotic stress signaling pathway.

We present a derivation of the screening length for a solution containing a charge-regulated macroion, e.g. protein, with its counterions. We show that it can be obtained directly from the second derivatives of the total free energy by taking recourse to the "uncertainty relation" of the Legendre transform, which connects the Hessians or the local curvatures of the free energy as a function of density and its Legendre transform, i.e., osmotic pressure, as a function of chemical potentials. Based on the Fowler–Guggenheim–Frumkin model of charge regulation, we then analyze the "screening resonance" and the "overscreening" of the screening properties of the charge-regulated macroion solution. [ABSTRACT FROM AUTHOR]

Light-driven diffusioosmosis is a membrane-free method for manipulating colloidal ensembles at solid–liquid interfaces based on photo-sensitive molecules inducing fluid flows along solid surfaces. In this study, we present our findings on porous colloids settled at a solid wall in an aqueous solution comprising a photo-sensitive azobenzene-containing cationic surfactant and a cyanine-based dye, capable of ionically binding to each other. The surfactant acts as an activation agent for diffusioosmotic flow. When exposed to modulated light, it undergoes photo-isomerization from a hydrophobic trans-state to a more hydrophilic cis-state, creating a concentration gradient near the irradiated area of the wall. The resulting osmotic pressure gradient sets the flow in motion. Porous colloids actively participate in flow generation by readily incorporating the surfactant molecules in the trans-state and releasing them in the cis-state, creating a constant source of diffusioosmotic flow. Under UV illumination, an excess of cis-isomers near the porous colloids elicits long-range repulsive interactions, tenfold the diameter of a particle. The dye acts as a sensor for the surfactant filling or emptying the pores of the colloids. It forms a complex with the trans-isomer and diffuses into the pores, where photoisomerization to cis-state destroys the complex and causes both the dye and the surfactant to leave the pores, altering the luminescence brightness within the colloids. We demonstrated that the presence of the dye affects cis-trans isomer ratios of the surfactant at photo-stationary states, thereby influencing the process of diffusioosmosis. This process enables the manipulation of colloidal particles and remote control of the interaction potential between them, facilitating the formation of well-ordered surface aggregates. [ABSTRACT FROM AUTHOR]

Charge-stabilized colloidal suspensions display a rich variety of microstructural and thermodynamic properties, which are determined by electro-steric interactions between all ionic species. The large size asymmetry between molecular-scale microions and colloidal macroions allows the microion degrees of freedom to be integrated out, leading to an effective one-component model of microion-dressed colloidal quasi-particles. For highly charged colloids with strong macroion–microion correlations, nonlinear effects can be incorporated into effective interactions by means of charge renormalization methods. Here, we compare and partially extend several practical mean-field methods of calculating renormalized colloidal interaction parameters, including effective charges and screening constants, as functions of concentration and ionic strength. Within the one-component description, we compute structural and thermodynamic properties from the effective interactions and assess the accuracy of the different methods by comparing predictions with elaborate primitive-model simulations [P. Linse, J. Chem. Phys. 113, 4359 (2000)]. We also compare various prescriptions for the osmotic pressure of suspensions in Donnan equilibrium with a salt ion reservoir and analyze instances where the macroion effective charge becomes larger than the bare one. The methods assessed include single-center cell, jellium, and multi-center mean-field theories. The strengths and weaknesses of the various methods are critically assessed, with the aim of guiding optimal and accurate implementations. [ABSTRACT FROM AUTHOR]

In recent years, ionic microgels have garnered much attention due to their unique properties, especially their stimulus-sensitive swelling behavior. The tunable response of these soft, permeable, compressible, charged colloidal particles is increasingly attractive for applications in medicine and biotechnologies, such as controlled drug delivery, tissue engineering, and biosensing. The ability to model and predict variation of the osmotic pressure of a single microgel with respect to changes in particle properties and environmental conditions proves vital to such applications. In this work, we apply both nonlinear Poisson–Boltzmann theory and molecular dynamics simulation to ionic microgels (macroions) in the cell model to compute density profiles of microions (counterions, coions), single-microgel osmotic pressure, and equilibrium swelling ratios of spherical microgels whose fixed charge is confined to the macroion surface. The basis of our approach is an exact theorem that relates the electrostatic component of the osmotic pressure to the microion density profiles. Close agreement between theory and simulation serves as a consistency check to validate our approach. We predict that surface-charged microgels progressively deswell with increasing microgel concentration, starting well below close packing, and with increasing salt concentration, in qualitative agreement with experiments. Comparison with previous results for microgels with fixed charge uniformly distributed over their volume demonstrates that surface-charged microgels deswell more rapidly than volume-charged microgels. We conclude that swelling behavior of ionic microgels in solution is sensitive to the distribution of fixed charge within the polymer-network gel and strongly depends on bulk concentrations of both microgels and salt ions. [ABSTRACT FROM AUTHOR]

Phospholipid bilayers are dynamic cellular components that undergo constant changes in their topology, facilitating a broad diversity of physiological functions including endo- and exocytosis, cell division, and intracellular trafficking. These shape transformations consume energy, supplied invariably by the activity of proteins. Here, we show that cycles of oppositely directed osmotic stresses─unassisted by any protein activity─can induce well-defined remodeling of giant unilamellar vesicles, minimally recapitulating the phenomenologies of surface area homeostasis and macropinocytosis. We find that a stress cycle consisting of deflationary hypertonic stress followed by an inflationary hypotonic one prompts an elaborate sequence of membrane shape changes ultimately transporting molecular cargo from the outside into the intravesicular milieu. The initial osmotic deflation produces microscopic spherical invaginations. During the subsequent inflation, the first subpopulation contributes area to the swelling membrane, thereby providing a means for surface area regulation and tensional homeostasis. The second subpopulation vesiculates into the lumens of the mother vesicles, producing pinocytic vesicles. Remarkably, the gradients of solute concentrations between the GUV and the daughter pinocytic vesicles create cascades of water current, inducing pulsatory transient poration that enable solute exchange between the buds and the GUV interior. This results in an efficient water-flux-mediated delivery of molecular cargo across the membrane boundary. Our findings suggest a primitive physical mechanism for communication and transport across protocellular compartments driven only by osmotic stresses. They also suggest plausible physical routes for intravesicular, and possibly intracellular, delivery of ions, solutes, and molecular cargo stimulated simply by cycles of osmotic currents of water.

We report a method to predict equilibrium concentration profiles of hard ellipses in nonuniform fields, including multiphase equilibria of fluid, nematic, and crystal phases. Our model is based on a balance of osmotic pressure and field mediated forces by employing the local density approximation. Implementation of this model requires development of accurate equations of state for each phase as a function of hard ellipse aspect ratio in the range k = 1–9. The predicted density profiles display overall good agreement with Monte Carlo simulations for hard ellipse aspect ratios k = 2, 4, and 6 in gravitational and electric fields with fluid–nematic, fluid–crystal, and fluid–nematic–crystal multiphase equilibria. The profiles of local order parameters for positional and orientational order display good agreement with values expected for bulk homogeneous hard ellipses in the same density ranges. Small discrepancies between predictions and simulations are observed at crystal–nematic and crystal–fluid interfaces due to limitations of the local density approximation, finite system sizes, and uniform periodic boundary conditions. The ability of the model to capture multiphase equilibria of hard ellipses in nonuniform fields as a function of particle aspect ratio provides a basis to control anisotropic particle microstructure on interfacial energy landscapes in diverse materials and applications. [ABSTRACT FROM AUTHOR]

Genome-scale metabolic models (GEMs) can facilitate metabolism-focused multi-omics integrative analysis. Since Yeast8, the yeast-GEM of Saccharomyces cerevisiae, published in 2019, has been continuously updated by the community. This has increased the quality and scope of the model, culminating now in Yeast9. To evaluate its predictive performance, we generated 163 condition-specific GEMs constrained by single-cell transcriptomics from osmotic pressure or reference conditions. Comparative flux analysis showed that yeast adapting to high osmotic pressure benefits from upregulating fluxes through central carbon metabolism. Furthermore, combining Yeast9 with proteomics revealed metabolic rewiring underlying its preference for nitrogen sources. Lastly, we created strain-specific GEMs (ssGEMs) constrained by transcriptomics for 1229 mutant strains. Well able to predict the strains' growth rates, fluxomics from those large-scale ssGEMs outperformed transcriptomics in predicting functional categories for all studied genes in machine learning models. Based on those findings we anticipate that Yeast9 will continue to empower systems biology studies of yeast metabolism. Synopsis: Yeast9 is the latest release of the community-consensus genome-scale model of Saccharomyces cerevisiae metabolism. Among others, Yeast9 has corrected mass & charge balancing; curated gene associations and is annotated with Gibbs free energies. When used to analyse 163 single-cell transcriptomes, Yeast9 reveals a high osmotic adaptation mechanism. Yeast9 is able to elucidate the organism's nitrogen source preference and its metabolic rewiring under nitrogen limitation. When constraint with transcriptomics from 1229 mutants, Yeast9 can predict fluxes that inform machine learning-based gene function prediction. Yeast9 is the latest release of the community-consensus genome-scale model of Saccharomyces cerevisiae metabolism. [ABSTRACT FROM AUTHOR]

Most albumin in blood plasma is thought to be monomeric with some 5% covalently dimerized. However, many reports in the recent biophysics literature find that albumin is reversibly dimerized or even oligomerized. We review data on this from X‐ray crystallography and diverse biophysical techniques. The number‐average molecular weight of albumin would be increased by dimerization, affecting size‐dependent filtration processes of albumin such as at the glycocalyx of the capillary endothelium and the podocyte slit‐diaphragm of the renal glomerulus. If correct, and depending on characteristics of the process, such as Kd, reversible dimerization of albumin in plasma would have major implications for normal physiology and medicine. We present quantitative models of the impact of dimerization on albumin molecular forms, on the number‐average molecular weight of albumin, and estimate the effect on the colloid osmotic pressure of albumin. Dimerization reduces colloid osmotic pressure as total albumin concentration increases below that expected in the absence of dimerization. Current models of albumin filtration by the renal glomerulus would need revision to account for the dynamic size of albumin molecules filtered. More robust biophysical data are needed to give a definitive answer to the questions posed and we suggest possible approaches to this. What is the central question of this study?Is there reversible dimerization of albumin in blood plasma? Albumin in blood plasma is generally considered monomeric apart from a small proportion of covalent dimer, but recent reports suggest it may actually be reversibly dimerized: is this physiologically significant?What is the main finding and its importance?There is some evidence that fatty acid‐free albumin dimerizes but less for native albumin. Dimerization, if proven, requires revision of the current molecular concepts underlying observed colloid osmotic pressures of plasma and renal ultrafiltration of albumin. Biophysical evidence for dimerization in plasma is currently weak. [ABSTRACT FROM AUTHOR]

This study investigates the intricate interplay of hydraulic coupling, creep damage, and permeability evolution mechanisms in phyllite, focusing on their relevance to tunnel engineering design and long-term stability in soft rock formations. To achieve this, conventional triaxial tests were conducted on saturated phyllite specimens under creep-seepage acoustic emission conditions. The results were systematically analyzed to unveil the inherent characteristics of creep deformation, seepage rate evolution, and damage progression in phyllite when subjected to stress–seepage coupling. Furthermore, a permeability model for representative volume element (RVE) was developed based on meso-mechanics principles, considering the distinctive attributes of low-permeability non-Darcy's flow in rock. Consequently, a novel relationship between effective damage and permeability was established. We determined that seepage pressure induces three key effects on the creep damage mechanism of phyllite samples: (1) It adds to the existing stress through the superposition of osmotic pressure and axial load, (2) it induces tensile expansion stress because of pore water pressure, and (3) it softens the fracture surfaces to some extent. More importantly, this study validates the relationship between effective damage and permeability through the fitting of creep and damage parameters, which were obtained from the test results, and it reveals a square relationship between subsequent damage and permeability under stress conditions. The findings of this study provide a robust theoretical foundation for comprehending the evolution of damage and permeability characteristics during the creep process of rock under seepage conditions. We obtained essential insights and quantitative analyses for comprehending the damage mechanisms in rock creep under hydraulic coupling, which has significant implications for tunnel engineering and long-term rock stability assessments in soft rock environments. Highlights: Model developed for RVE element based on meso-mechanics to consider low-permeability non-Darcy seepage in rock. Relationships between effective damage and permeability analyzed. Creep damage mechanism of phyllite under stress–seepage coupling investigated. Evolution law of damage and permeability properties of phyllite under seepage condition clarified. [ABSTRACT FROM AUTHOR]

Red blood cells (RBCs) carry oxygen and make up 40–45% of blood by volume in large vessels down to 10% or less in smaller capillaries. Because of their finite size and large volume fraction, they are heterogeneously distributed throughout the body. This is partially because RBCs are distributed or partitioned nonuniformly at diverging vessel bifurcations where blood flows from one vessel into two. Despite its increased recognition as an important player in the microvasculature, few studies have explored how the endothelial surface layer (ESL; a vessel wall coating) may affect partitioning and RBC dynamics at diverging vessel bifurcations. Here, we use a mathematical and computational model to consider how altering ESL properties, as can occur in pathological scenarios, change RBC partitioning, deformation, and penetration of the ESL. The two-dimensional finite element model considers pairs of cells, represented by interconnected viscoelastic elements, passing through an ESL-lined diverging vessel bifurcation. The properties of the ESL include the hydraulic resistivity and an osmotic pressure difference modeling how easily fluid flows through the ESL and how easily the ESL is structurally compressed, respectively. We find that cell–cell interaction leads to more uniform partitioning and greatly enhances the effects of ESL properties, especially for deformation and penetration. This includes the trend that increased hydraulic resistivity leads to more uniform partitioning, increased deformation, and decreased penetration. It also includes the trend that decreased osmotic pressure increases penetration. [ABSTRACT FROM AUTHOR]

Summary: Diurnal floret opening time (DFOT) is a pivotal trait for successful fertilization and hybrid breeding in rice. However, the molecular mechanism underlying this trait is poorly understood in rice.In this study, we combined the cytological, genetic and molecular studies to demonstrate that jasmonic acid (JA) regulates DFOT in rice through modulating the turgor and osmotic pressure of the lodicules.We show that lodicules undergo dramatic morphologic changes, accompanied by changes in water and sugar contents during the process of floret opening. Consistently, a large set of genes associated with cell osmolality and cell wall remodeling exhibits distinct expression profiles at different time points in our time‐course transcriptomes of lodicules. Notably, a group of JA biosynthesis and signaling genes is continuously upregulated, accompanied by a gradual increase in JA accumulation as floret opening approaching. Furthermore, we demonstrate that the JA biosynthesis gene OsAOS1 is required for endogenous JA biosynthesis in lodicules and promoting rice DFOT. Moreover, OsMYC2, a master regulator of JA signaling, regulates rice DFOT by directly activating OsAOS1, OsSWEET4, OsPIP2;2 and OsXTH9.Collectively, our findings establish a core regulatory network mediated by JA for modulating rice DFOT and provide effective gene targets for the genetic improvement of DFOT in rice. [ABSTRACT FROM AUTHOR]

• The DREAM scheme improves solid-state NMR analysis of whole cells. • Spectral editing of carbon-13 polysaccharide signals present in the cell wall can be achieved. • Spectral editing is tuned by the choice of the carbon-13 carrier frequency. • The method is demonstrated on Neurospora crassa and Aspergillus fumigatus. Most bacterial, plant and fungal cells possess at their surface a protective layer called the cell wall, conferring strength, plasticity and rigidity to withstand the osmotic pressure. This molecular barrier is crucial for pathogenic microorganisms, as it protects the cell from the local environment and often constitutes the first structural component encountered in the host-pathogen interaction. In pathogenic molds and yeasts, the cell wall constitutes the main target for the development of clinically-relevant antifungal drugs. In the past decade, solid-state NMR has emerged as a powerful analytical technique to investigate the molecular organization of microbial cell walls in the context of intact cells. 13C NMR chemical shift is an exquisite source of information to identify the polysaccharides present in the cell wall, and two-dimensional 13C–13C correlation experiments provide an efficient tool to rapidly access the polysaccharide composition in whole cells. Here we investigate the use of the adiabatic DREAM (for dipolar recoupling enhancement through amplitude modulation) recoupling scheme to improve solid-state NMR analysis of polysaccharides in intact cells. We demonstrate the advantages of two-dimensional 13C–13C experiments using the DREAM recoupling scheme. We report the spectral editing of polysaccharide signals by varying the radio-frequency carrier position. We provide practical considerations for the implementation of DREAM experiments to characterize polysaccharides in whole cells. We demonstrate the approach on intact fungal cells of Neurospora crassa and Aspergillus fumigatus , a model and a pathogenic filamentous fungus, respectively. The approach could be envisioned to efficiently reduce the spectral crowding of more complex cell surfaces, such as cell wall and peptidoglycan in bacteria. [ABSTRACT FROM AUTHOR]

Under complex geological circumstances, the deep part of ultrahigh-performance concrete (UHPC) experiences high stress, high temperature, and high permeability, resulting in the rapid corrosion and damage of concrete structures. This paper evaluates the chloride ion transport performance of UHPC under the simultaneous impact of load, temperature, and osmotic pressure by measuring the chloride ion concentration distribution and employing X-ray diffraction. The results show that the chloride concentration and penetration depth increase with load, temperature, osmotic pressure, and water-binder ratio. The factors with the most significant influence on the chloride ion transport performance of UHPC in descending order are osmotic pressure, load, temperature, water–cement ratio, and fiber content. As the load, temperature, osmotic pressure, and water-binder ratio increase, the content of Ca(OH)2 decreases, while the content of the generated Friedel's salt increases. Moreover, the content of Ca(OH)2 in pure UHPC is lower than UHPC mixed with fiber, and the content of generated Friedel's salt is markedly higher than in UHPC mixed with fiber. A chloride ion transport diffusion-convection theoretical model is established and proven to be valid. [ABSTRACT FROM AUTHOR]

Mysterious craters, with anomalously high concentrations of methane, have formed in the Yamal and Taymyr peninsulas of Siberia since 2014. While thawing permafrost owing to climate warming promotes methane releases, it is unknown how such release might be associated with explosion and crater formation. A significant volume of surface ice‐melt water can migrate downward driven by osmotic pressure associated with a cryopeg, a lens of salty water below. Overpressure reached at depth may lead to the cracking of the soil and subsequent decomposition of methane hydrates, with implications for the climate. Plain Language Summary: We show how osmosis drives explosions and methane release in Siberian permafrost. We anticipate that as well as being of direct relevance to permafrost researchers, this work will be of interest to a large number of people involved in climate change research, because the mechanism we uncover of osmotic pumping leading to permafrost explosions has potentially grave consequences involving the release of methane presently locked up in hydrates. Key Points: Surface ice‐melt water can migrate downward driven by the osmotic pressure associated with a cryopeg, a lens of salty water belowOverpressure can cause the frozen soil to crack resulting in mechanical explosion [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) is a significant public health issue characterized by high mortality rates and long-term complications. This commentary examines the controversial role of the use of albumin in the fluid management of patients with severe TBI. Despite its physiological benefits, the clinical use of albumin remains controversial due to the fact that various studies have yielded mixed results. Serum albumin is important for maintaining normovolemia, primarily through its contribution to colloid osmotic pressure, which helps to retain fluid in the circulatory system. This review highlights the existing evidence, examines inconsistencies in guideline recommendations, and suggests future research directions to clarify the efficacy and safety of the use of albumin in maintaining normovolemia in patients with TBI. The review also discusses the potential benefits of small-volume resuscitation strategies for the management of acute kidney injury in TBI patients, drawing parallels with the management of septic acute kidney injury. The need for further well-designed randomized controlled trials and ethical considerations in studies regarding the use of hyperoncotic albumin in TBI management is emphasized. [ABSTRACT FROM AUTHOR]

To explore the influence of the working face excavation rate on the rock deformation mechanism and seepage characteristics, deformation and seepage tests of sandstone under different loading and unloading stress paths, such as constant axial pressure unloading confining pressure and loading axial pressure unloading confining pressure, were carried out. Particle Flow Code in 3 Dimensions (PFC3D) and Python were used to realize fluid-solid coupling, and numerical simulation calculations were performed along the test path to analyze the influence of the unloading rate on the fine-scale deformation mechanism and permeability characteristics of sandstone, and the relationship between crack type and permeability was obtained. A sandstone fracture mechanics model is established to analyze the stress concentration degree at the end of the branch crack of the test path. The results show that the rate of confining pressure unloading is inversely proportional to the strain. Additionally, permeability correlates with the principal stress difference in an exponential manner. Interestingly, the sensitivity of permeability to stress shows an inverse trend with the unloading rate of confining pressure. Furthermore, there exists a linear relationship between permeability and the number of cracks. During the unloading process, tensile cracks predominate, and the propagation of shear cracks lags behind that of tensile cracks. The proportion of tensile cracks decreases with the increase of the unloading rate when the axial pressure is unchanged but increases when axial pressure is added, resulting in axial compression deformation and expansion deformation along the unloading direction. These research outcomes offer theoretical insights for the prudent selection of mining rates, and they hold significant implications for mitigating water inrush disasters in deep mining operations. [ABSTRACT FROM AUTHOR]

Invasive alien species drive extensive ecological changes and cause unexpected risks worldwide. Perceptive germination requirements and the growth function of invasive species are crucial for understanding their invasion and subsequent dissemination in various environmental conditions. Therefore, the germination response of invasive Conyza bonariensis, Parthenium hysterophorus, and Bidens pilosa of Asteraceae family were examined under alternating temperature regimes and some environmental factors. The prevailing germination ability occurs highest at moderate-temperature regimes at 20/30°C attained by 94.83% (C. bonariensis) and at 20/25 SS by 96.28% (P. hysterophorus) and high-temperature regimes at 25/30°C reached 92.94% (B. pilosa) respectively. The half germination percentage (G50) was -0.406 MPa and 2878.35 ppm (B. pilosa), -0.579 MPa and 2490.9 ppm (C. bonariensis), and—0.32 MPa and 2490.8 ppm (P. hysterophorus) affected by osmotic pressure and salt stress (NaCl) respectively. The highest growth plasticity characteristics were identified in total dry mass attained at 0.968 (C. bonariensis), 0.985 (B. pilosa) and 0.957 (P. hysterophorus) respectively. The relative growth, net assimilation and plasticity index appeared higher in both B. pilosa, and C. bonariensis than P. hysterophorus in the invaded area. In conclusion, germination and growth traits are precisely functional factors that correlate to invasion success under stressed conditions, and zones, and also lead to successful control plans for invasive species and ecological protection. [ABSTRACT FROM AUTHOR]

Glaesserella parasuis is the pathogen that causes Glässer's disease in pigs, which is characterized by fibrinous polyserositis, arthritis and meningitis. Research on ribosomal protein L32 in microorganisms has mainly focused on regulating gene transcription and translation, but its effect on bacterial virulence is unclear. The role of L32 gene in G. parasuis is not clear, and in order to study the function of L32 gene, a suicide plasmid-mediated natural transformation method was used to construct a L32 gene deletion mutant. We found that although L32 was shown to be non-essential for cell proliferation, the growth curve of ΔL32 is clearly different compared with that of ZJ1208. ΔL32 produced more outer membrane vesicles (OMVs) with a variety of irregular shapes, but produced similar biofilm to the parental strain. ΔL32 is more sensitive to osmotic pressure, oxidation pressure and heat shock stress. Meanwhile, ΔL32 is significantly more susceptible to antimicrobials such as spectinomycin, apramycin, sulfafurazole, but not to other antibiotics used in this study. In the mouse challenge experiment, the mortality of mice infected with the mutant strain decreased by 40% compared to those infected with the wild-type strain, indicating that L32 is a virulence-associated factor which contributes to bacterial fitness in host environments. The above results show that L32 is important for the growth, stress resistance and virulence of G. parasuis, and this study also confirms for the first time that L32 plays an important role in antibiotic resistance against aminoglycosides and sulfonamides. [ABSTRACT FROM AUTHOR]

Here we report on light-triggered generation of local flow utilizing a bio-compatible non-ionic photo-active surfactant. The mechanism is based on diffusioosmotic phenomenon, where the gradient of relative concentration with respect to different chemical species near a surface leads to an osmotic pressure gradient driving liquid flow along the surface. The application of a photo-responsive surfactant allows for easy and reversible changes in concentration gradient by positioning a light source at the desired place. Along with the so-inscribed concentration gradient one can change reversible the direction and strength of the flow even in a closed system. The phenomenology of light-driven diffusioosmotic flow (LDDO) can be used in a rather flexible way: colloids can be gathered or dispersed and bio-compatibility extends the range of colloid types also to living microorganisms such as soil bacterium Pseudomonas putida. We show that DO flow can be considered a versatile method to set hydrodynamic conditions along the sample for investigating the motility of living cells. Further advantages of employing LDDO are the flexibility of flow generation in a reversible way and with spatiotemporal control, without the need to either change the channel geometry by loading a different device, or the periphery of pumps and connectors. [ABSTRACT FROM AUTHOR]

Understanding the mechanism towards interaction of water with polymer composite is of significance in the arena of solid-state device application, biomaterial science etc. A systematic research work is presented on the swelling behaviour and its influence towards the ionic conduction of poly [ethylene oxide] (PEO) -salt films. The influence of salts (viz. NH4I and KBr termed as PSN- & PSK-series) on the diffusion trait of polymer is analysed using non-Fickian python programming. The presence of ions and its polarizability behaviour influences the aqueous equilibration, number density of bounded and free water molecules along with the extent of cross linkage. The contribution of osmotic pressure tends to balance the dynamic non-covalent interactions thereby enhancing the diffusion driven ionic conduction (10–3 S.cm−1) process of PSK-films. Non Fickian diffusion is also found to accelerate the ionic conduction of PSK-series to 10–2 S.cm−1. The dielectric relaxation and long-term endurance (18500 h) establish the stability and applicability of such functionalized films as ionic electrolytes, membranes etc. [ABSTRACT FROM AUTHOR]

The surface pre-reacted glass ionomer (S-PRG) filler is a type of bioactive functional glass that releases six different ions. This study examined the effects of the S-PRG filler eluate on Streptococcus mutans in the presence of sucrose. In a solution containing S. mutans, the concentrations of BO33−, Al3+, Sr2+, and F− were significantly higher in the presence of the S-PRG filler eluate than in its absence (p < 0.001). The concentrations of these ions further increased in the presence of sucrose. Additionally, the S-PRG filler eluate significantly reduced glucan formation by S. mutans (p < 0.001) and significantly increased the pH of the bacterial suspension (p < 0.001). Bioinformatic analyses revealed that the S-PRG filler eluate downregulated genes involved in purine biosynthesis (purC, purF, purL, purM, and purN) and upregulated genes involved in osmotic pressure (opuAa and opuAb). At a low pH (5.0), the S-PRG filler eluate completely inhibited the growth of S. mutans in the presence of sucrose and significantly increased the osmotic pressure of the bacterial suspension compared with the control (p < 0.001). These findings suggest that ions released from the S-PRG filler induce gene expression changes and exert an inhibitory effect on S. mutans in the presence of sucrose. [ABSTRACT FROM AUTHOR]

Salt weathering is a common deterioration phenomenon that affects outdoor cultural properties, and it is important to precisely predict the heat, moisture, and salt transfer in porous materials to suppress salt weathering. Osmosis and osmotic pressure were considered in the field of soil research, especially in clay research, but not in the field of outdoor cultural properties and building materials, which are the main target of salt weathering. Osmosis in clay is supposed to be caused by its surface charge. However, it has been suggested that sandstones and bricks that constitute cultural properties and buildings also have surface charge as clay. Thus, osmosis and osmotic pressure can occur in building materials, which may lead to materials degradation. In this study, we derive basic equations, based on nonequilibrium thermodynamics, for the simultaneous heat, dry air, water vapor, liquid water, cation, and anion transfer in building materials by considering osmosis. This equation was compared with existing model for heat and moisture transfer equations as well as models that considered the salt transfer. Based on the previous research for osmosis in clay, we summarized conditions under which osmosis occurs in building materials and presented an outlook for modeling the physical properties of materials related to osmosis. [ABSTRACT FROM AUTHOR]

Osmotic water alters the physicochemical properties and internal structures of limestone. This issue is particularly critical in tunnel construction across mountainous regions with aquifers, where pressurized groundwater can destabilize the limestone-based surrounding rock. Thus, systematic research into the physicochemical properties and pore structure changes in the limestone under pressurized water is essential. Additionally, it is essential to develop an interpretable mathematical model to accurately depict how pressurized osmotic water weakens limestone. In this research, a specialized device was designed to simulate the process of osmotic laminar flow within limestone. Then, four main tests were conducted: mass loss, acoustic emission (AE), mercury intrusion porosimetry (MIP), and fluorescence analysis. Experimental results gained from tests led to the development of a "Particle-pore throat-water film" model. Proposed model explains water-induced physicochemical and pore changes in limestone under osmotic pressure and reveals evolutionary mechanisms as pressure increases. Based on experimental results and model, we found that osmotic pressure not only alters limestone composition but also affects pore throats larger than 0.1 µm. Furthermore, osmotic pressure expands pore throats, enhancing pore structure uniformity, interconnectivity, and permeability. These effects are observed at a threshold of 7.5 MPa, where cohesive forces within the mineral lattice are surpassed, leading to the breakdown of erosion-resistant layer and a significant increase in hydrochemical erosion. [ABSTRACT FROM AUTHOR]

The glomerular filtration rate (GFR) is the outcome of glomerular hemodynamics, influenced by a series of parameters: renal plasma flow, resistances of afferent arterioles and efferent arterioles (EAs), hydrostatic pressures in the glomerular capillary and Bowman's capsule, and plasma colloid osmotic pressure in the glomerular capillary. Although mathematical models have been proposed to predict the GFR at both the single-nephron level and the two-kidney system level using these parameters, mathematical equations governing glomerular filtration have not been well-established because of two major problems. First, the twokidney system-level models are simply extended from the equations at the single-nephron level, which is inappropriate in epistemology and methodology. Second, the role of EAs in maintaining the normal GFR is underappreciated. In this article, these two problems are concretely elaborated, which collectively shows the need for a shift in epistemology toward a more holistic and evolving way of thinking, as reflected in the concept of the complex adaptive system (CAS). Then, we illustrate eight fundamental mathematical equations and four hypotheses governing glomerular hemodynamics at both the single-nephron and two-kidney levels as the theoretical foundation of glomerular hemodynamics. This illustration takes two steps. The first step is to modify the existing equations in the literature and establish a new equation within the conventional paradigm of epistemology. The second step is to formulate four hypotheses through logical reasoning from the perspective of the CAS (beyond the conventional paradigm). Finally, we apply the new equation and hypotheses to comprehensively analyze glomerular hemodynamics under different conditions and predict the GFR. By doing so, some concrete issues are eliminated. Unresolved issues are discussed from the perspective of the CAS and a desinger's view. In summary, this article advances the theoretical study of glomerular dynamics by 1) clarifying the necessity of shifting to the CAS paradigm; 2) adding new knowledge/insights into the significant role of EAs in maintaining the normal GFR; 3) bridging the significant gap between research findings and physiology education; and 4) establishing a new and advanced foundation for physiology education. [ABSTRACT FROM AUTHOR]

Stachydrine, also known as proline betaine, is a prominent constituent of traditional Chinese herb Leonurus japonicus, renowned for its significant pharmacological effects. Widely distributed in plants like Leonurus and Citrus aurantium, as well as various bacteria, stachydrine serves pivotal physiological functions across animal, plant, and bacterial kingdoms. This review aims to summarizes diverse roles and mechanisms of stachydrine in addressing cardiovascular and cerebrovascular diseases, neuroprotection, anticancer activity, uterine regulation, anti-inflammatory response, obesity management, and respiratory ailments. Notably, stachydrine exhibits cardioprotective effects via multiple pathways encompassing anti-inflammatory, antioxidant, antiapoptotic, and modulation of calcium handling functions. Furthermore, its anti-cancer properties inhibit proliferation and migration of numerous cancer cell types. With a bi-directional regulatory effect on uterine function, stachydrine holds promise for obstetrics and gynecology-related disorders. In plants, stachydrine serves as a secondary metabolite, contributing to osmotic pressure regulation, nitrogen fixation, pest resistance, and stress response. Similarly, in bacteria, it plays a crucial osmoprotective role, facilitating adaptation to high osmotic pressure environments. This review also addresses ongoing research on the anabolic metabolism of stachydrine. While the biosynthetic pathway remains incompletely understood, the metabolic pathway is well-established. A deeper understanding of stachydrine biosynthesis holds significance for elucidating its mechanism of action, advancing the study of plant secondary metabolism, enhancing drug quality control, and fostering new drug development endeavors. [ABSTRACT FROM AUTHOR]

Reflectin is a cationic, block copolymeric protein that mediates the dynamic fine-tuning of color and brightness of light reflected from nanostructured Bragg reflectors in iridocyte skin cells of squids. In vivo, the neuronally activated phosphorylation of reflectin triggers its assembly, driving osmotic dehydration of the membrane-bounded Bragg lamellae containing the protein to simultaneously shrink the lamellar thickness and spacing while increasing their refractive index contrast, thus tuning the wavelength and increasing the brightness of reflectance. In vitro, we show that the reduction in repulsive net charge of the purified, recombinant reflectin—either (for the first time) by generalized anionic screening with salt or by pH titration—drives a finely tuned, precisely calibrated increase in the size of the resulting multimeric assemblies. The calculated effects of phosphorylation in vivo are consistent with these effects observed in vitro. The precise proportionality between the assembly size and charge neutralization is enabled by the demonstrated rapid dynamic arrest of multimer growth by a continual, equilibrium tuning of the balance between the protein's Coulombic repulsion and short-range interactive forces. The resulting stability of reflectin assemblies with time ensures a reciprocally precise control of the particle number concentration, encoding a precise calibration between the extent of neuronal signaling, osmotic pressure, and the resulting optical changes. The charge regulation of reflectin assembly precisely fine-tunes a colligative property-based nanostructured biological machine. A physical mechanism is proposed. [ABSTRACT FROM AUTHOR]

Injectable hydrogels have emerged as versatile materials with potential applications in various fields, including biomedicine, lubrication, adhesion, surface coatings, and tissue engineering. However, the critical aspect of spreading and wetting on various substrates, which is essential for obtaining significant interfacial properties, has not been adequately addressed. This work presents an approach to prepare hydrogel coatings on kinds of substrates through the superspreading of polyelectrolyte complex solution during its liquid‐liquid phase inversion process. Due to the low interfacial tension, the solution spreads and wets various surfaces underwater driven by osmotic pressure, improving the contact area and interface integration. Combined with the simultaneous sol‐gel transition through electrostatic interaction, it forms a stable and homogeneous hydrogel coating. The hydrogel coating possesses control thickness (4–8 µm), improved hydrophilicity (CA decrease from 102° to 10°), interfacial toughness (increase from 70 to 455 J m−2), and lubrication performance (coefficients of friction decrease from 0.712 to 0.112). The work provides an excellent opportunity to investigate the spreadability and wettability in a water/water/solid three‐phase system and develop functional hydrogel coatings for various applications. [ABSTRACT FROM AUTHOR]

[Display omitted] Microcapsules with osmotically-inflated elastic shells exhibit an ultrafast release of encapsulants while mechanically stimulating the microenvironments, akin to popping balloons. To prepare elastic shells with uniform thickness and size, monodisperse water-in-oil-in-water (W/O/W) double-emulsion drops are produced in a capillary microfluidic device. The polydimethylsiloxane (PDMS)-containing oil phase is thermally cured to create the elastic shell. The elastic shells are inflated by pumping water into the lumen in hypotonic conditions. The inflated microcapsules produced undergo mechanical compression, and their release properties are studied. By controlling the osmotic pressure difference, Microballoons are inflated into a diameter of 200 μm – 316 μm and shell thickness of 7.8 μm – 0.7 µm, respectively. The inflated shell pops due to mechanical failure when subjected to mechanical stress above a certain threshold, resembling a balloon. During popping, the stretched shell rapidly retracts to the original uninflated state, resulting in an ultrafast release of encapsulants from the lumen within a millisecond. This process converts elastic potential energy stored in the shell into mechanical energy with substantial power. The microballoons mechanically stimulate the local environment, leading to the direct and rapid release of encapsulants. This has the potential to improve absorption efficiency. [ABSTRACT FROM AUTHOR]

Introduction: Cytotoxic cerebral edema is a serious complication associated with cerebral ischemic stroke and is widely treated using the hypertonic dehydrant. Here, we propose, for the first time, the decrease of intracellular osmosis as a treatment strategy for alleviating cytotoxic cerebral edema. Methods: We established a fluorescence resonance energy transfer-based intermediate filament tension probe for the study and in situ evaluation of osmotic gradients, which were examined in real-time in living cells from primary cultures as well as cell lines. The MCAO rat model was used to confirm our therapy of cerebral edema. Results: Depolymerization of microfilaments/microtubules and the production of NLRP3 inflammasome resulted in an abundance of protein nanoparticles (PNs) in the glutamate-induced swelling of astrocytes. PNs induced changes in membrane potential and intracellular second messengers, thereby contributing to hyper-osmosis and the resultant astrocyte swelling via the activation of voltage-dependent nonselective ion channels. Therefore, multiple inhibitors of PNs, sodium and chloride ion channels were screened as compound combinations, based on a decrease in cell osmosis and astrocyte swelling, which was followed by further confirmation of the effectiveness of the compound combination against alleviated cerebral edema after ischemia. Discussion: The present study proposes new pathological mechanisms underlying "electrophysiology-biochemical signal-osmotic tension," which are responsible for cascade regulation in cerebral edema. It also explores various compound combinations as a potential treatment strategy for cerebral edema, which act by multi-targeting intracellular PNs and voltage-dependent nonselective ion flux to reduce astrocyte osmosis. [ABSTRACT FROM AUTHOR]

Food‐related stresses such as heating and freezing may influence the biofilm formation ability of bacteria. This study aimed to investigate the main and interactive effects of food‐related stresses on the biofilm formation potential of Salmonella strains isolated from meat. Salmonella enteritidis, Salmonella typhi, and Salmonella typhimurium were subjected to osmotic, acid, heat, cold, and freezing stresses. The colorimetric microtiter plate method was used to measure the biofilm formation ability as a response to the stresses. Among the main effects, freezing time had the most significant effect on the biofilm formation responses of three Salmonella serovars. Freezing reduced the biofilm formation ability of Salmonella typhimurium and Salmonella enteritidis but increased that of Salmonella typhi (p < 0.05). Among the interaction effects, the most significant effect on the biofilm formation response of Salmonella typhi was the interaction between pH and heat, which had a negative effect on the biofilm formation response. In contrast, the interaction between osmotic pressure and cold stresses was the most significant interactive effect on the biofilm formation responses of Salmonella enteritidis and Salmonella typhimurium, which had an increasing effect. This study concluded that the food‐related stresses could change the biofilm formation capacity of Salmonella serotypes, and each serotype might show different biofilm formation abilities in response to different stresses. [ABSTRACT FROM AUTHOR]

This study introduces draw solutions for application in forward osmosis (FO) processes, combining mono propylene glycol propyl ether (PGPE) with the cellulose derivative hydroxypropyl cellulose (HPC). A total of 16 unique single‐solute and ternary organic draw solutions were prepared and evaluated, leading to the selection of three promising solutions for further investigation. Notably, eight of the initial organic draw solutions demonstrated osmotic pressures exceeding 2.4 MPa. The dynamic viscosities of all draw solutions exhibited a significant reduction with increasing temperature. Among the investigated solutions, the 0.25HPC‐3.75PGPE demonstrated the most favorable FO performance, achieving average experimental water fluxes of 11.062 and 9.852 Lm−2 h−1 (LMH) against a 1 g/L NaCl brackish feed solution across two FO runs. Practitioner Points: Hydroxypropyl cellulose (HPC, MW ~100,000) was mixed with propylene glycol propyl ether (PGPE) as draw solutes for FO processes.Seven combinations of HPC and PGPE produced osmolalities greater than 1000 mOsm/kg.0.5HPC‐7.5PGPE ternary draw solution achieved experimental water fluxes of 11.062 and 9.852 LMH against 1 g/L NaCl brackish feed solution.Leveraging the LCSTs of these ternary organic solutions holds promise for improved separation and regeneration processes. [ABSTRACT FROM AUTHOR]

The present study investigates the multiphasic nature of the mechanical behavior of human dermis. Motivated by experimental observations and by consideration of its composition, a quadriphasic model of the dermis is proposed, distinguishing solid matrix components, interstitial fluid and charged constituents moving within the fluid, i.e., anions and cations. Compression and tensile experiments with and without change of osmolarity of the bath are performed to characterize the chemo-mechanical coupling in the dermis. Model parameters are determined through inverse analysis. The computations predict a dominant role of the permeability in the determination of the temporal evolution of the mechanical response of the tissue. In line with the previous studies on other tissues, the analysis shows that an ideal model based on Donnan's equilibrium overestimates the osmotic pressure in skin for the case of very dilute solutions. The quadriphasic model is applied to predict changes in dermal cell environment and therefore alterations in what is called the "mechanome," associated with skin stretch. The simulations indicate that skin deformation causes a variation in several local variables, including in particular the electric field associated with a deformation-induced non-homogeneous distribution of fixed charges. [ABSTRACT FROM AUTHOR]

• Ultrasound-assisted puncture and drainage is micro-invasion and precise. • Osmotic pressure gradient can form space-occupying tumor bed cysts. • Puncture and drainage is a novel method for space-occupying tumor bed cysts. To investigate the causes of space-occupying tumor bed cysts formed early after glioma resection by measuring the osmotic pressure gradient between cystic fluid, serum, and cerebrospinal fluid (CSF) and propose a new method of bedside ultrasound-assisted puncture and drainage (UAP&D) under local anesthesia for treatment. Bedside UAP&D under local anesthesia was performed through a burr hole on the skull flap. Following a successful puncture, cystic fluid was collected, while blood and CSF were obtained through vein and lumbar puncture, respectively. The osmotic pressure of all fluids collected was measured. The appearance, biochemical composition, and results of microbial culture of cystic fluid and CSF were analyzed. Within 24 h after UAP&D, a CT examination and Glasgow coma scale (GCS) were assessed. The osmotic pressure of cystic fluid was higher than that of serum and CSF. White blood cell count and protein concentration were higher in the cystic fluid compared to the CSF. Conversely, the concentration of chloride ions and glucose were lower. CT scan confirmed the correct placement of the cysts' drainage tube and that the cysts' volume decreased significantly with continued drainage. Accompanied by a reduction in the volume of cysts, there were significant improvements in GCS score within 24 h after UAP&D. All drainage tubes were removed within 2–5 days, and no puncture tract hemorrhage or infection was observed. The osmotic pressure gradient between cystic fluid, serum, and CSF caused the formation of early post-operative space-occupying tumor bed cysts for glioma. UAP&D aligns with the concept that micro-invasive neurosurgery is an effective treatment method for such cysts. [ABSTRACT FROM AUTHOR]

In order to elucidate the response mechanisms of Gleditsia sinensis Lam. with different phosphorus (P) efficiencies to low P stress, this study set up low P treatment (0.01 mmol·L−1, LP) and normal P treatment (1.00 mmol·L−1, NP). The experimental materials included low P-tolerant G. sinensis families F10 and F13, and low P-sensitive G. sinensis families F21 and F29. This study aimed to investigate the effects of low P stress on the agronomic traits, nutrient content, and physiological indices of G. sinensis seedlings with different P efficiencies. The results showed that the agronomic traits, such as plant height, stem diameter, and so on, of the low P-tolerant family, were significantly higher than those of the low P-sensitive family under low P stress. Low P stress significantly increased the total root length, total root surface area, total root projected area, total root volume, and main root diameter of the tolerant family. The tolerant family exhibited significantly higher net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, and transpiration rate compared to the sensitive family. Low P stress significantly increased the activities of protective enzymes, acid phosphatase activity, and malondialdehyde content in the low P-tolerant family. The tolerant family exhibited higher P absorption efficiency and P utilization efficiency compared to the sensitive family. Low P stress significantly increased the P utilization efficiency of the tolerant family. In summary, compared to the sensitive family, the low P-tolerant G. sinensis family has stronger reactive oxygen species scavenging ability and can accumulate more osmotic regulatory substances to maintain cell osmotic potential and better protect cells; this improves P utilization efficiency and nutrient content, thereby alleviating the harm caused by low P stress and maintaining normal growth and metabolism. [ABSTRACT FROM AUTHOR]

Sinonovacula constricta is one of the four traditional cultured shellfish in China. The salinity in the aquaculture water body is easily affected by tides, seasonal rainfall, and high temperatures, and often fluctuates to different degrees. This affects the physiological activities of S. constricta and causes a series of changes in the structure of the osmoregulation organs, osmotic pressure, ion transport, and free amino acid (FAA) content in the body to adapt to the changes in environmental salinity. Aquatic animals can regulate cell volume and maintain osmotic pressure balance through FAAs. This mechanism has been proven in aquatic animals, such as Meretrix lusoria, Crassostrea gigas, Haliotis discus hannai, Penaeus vannamei, and Portunus trituberculatus. The common FAAs that regulate osmotic pressure in bivalves mainly include Ala, Gly, Pro, and Tau. Whether FAAs play an osmoregulation role in S. constricta, whether their involvement in osmoregulation is similar to that in other shellfish, and what the metabolic pathway is of main FAAs deserve further study. This study explored the changes of osmotic pressure and FAAs in the gill, foot, and hemolymph of S. constricta after salinity stress and analyzed the sequence characteristics, tissue expression, and mRNA expression characteristics after salinity stress and RNA interference (RNAi) of the Sc-CARNS gene, and the changes of alanine and carnosine contents. The osmotic pressure and FAA contents in the gills, foot, and hemolymph of S. constricta under different salinities (5, 20, and 35) were measured by freezing point osmometer and automatic amino acid analyzer. At the same time, the expression of the Sc-CARNS gene in the foot under different salinities (5, 20, and 35) was analyzed by RT-qPCR and RNAi technology. The content of alanine was determined with the shellfish alanine ELISA kit. The content of carnosine was determined by phthalaldehyde colorimetry. The results showed that the osmotic pressure in the gills, foot, and hemolymph of S. constricta significantly decreased within 1–72 h under low salt stress (P < 0.05), while under high salt stress, the osmotic pressure in the gills, foot, and hemolymph reached a steady state within 24 h, which was consistent with the osmotic pressure of external seawater. Compared with the control group, the osmotic pressure in the gills, foot, and hemolymph decreased by 66.7%, 69.7%, and 71.6%, respectively, when the salinity was low. The wet weight of tissues was then increased by 68.3%, 67.5%, and 70.2%, respectively. At the same stress time, the osmotic pressure of each group of S. constricta was salinity 35 > salinity 20 > salinity 5. Under normal salinity, the FAAs with the highest content in the gills, foot, and hemolymph of S. constricta were Gly, Arg, and Gly, respectively. After salinity stress, the content of total free amino acids in all tissues increased significantly with the increase of salinity. The main FAAs with the largest content change in the gills, foot, and hemolymph, respectively, were Ala, Gly, Glu, and Pro; Ala, Gly, Arg, and Tua; and Ala, Ser, Thr, and Gly. Ala was the most variable FAA in all tissues. According to the transcriptome results of S. constricta after salinity stress, it was speculated that Sc-CARNS is related to osmotic regulation. The expression of Sc-CARNS was the highest in the muscle type tissues of S. constricta, followed by the gills, and was the lowest in the hepatopancreas. After low salt stress, the expression of the Sc-CARNS gene mRNA in S. constricta increased at first and then decreased with the stress time, and was significantly higher than that in the control group after 4 h of stress (P < 0.01), and reached the peak at 24 h. The content of alanine decreased significantly with time, and the content of carnosine increased significantly with time (P < 0.05). After high salt stress, the expression of Sc-CARNS decreased, and there was no significant change compared with the control group. The content of alanine first increased, then decreased, and then increased after 8 h, and was not lower than that of the control group. The content of carnosine showed a decreasing trend after 24 h. After RNAi, the expression level of Sc-CARNS mRNA in the interference group decreased first and then increased with the interference time under normal salinity. At 24 and 48 h, the expression level of Sc-CARNS mRNA was significantly lower than that of negative control (P < 0.05), and the interference efficiency was 24% and 69%, respectively. The interference efficiency at 48 h was the highest. In the interference group, the content of alanine first increased and then decreased, and the content of carnosine first decreased and then increased, reaching the maximum at 48 h. Under low salt stress, the expression of Sc-CARNS mRNA increased, the content of alanine decreased, and the content of carnosine increased after interference for 0–24 h. After interference for 24 h and 96 h, the mRNA expression of Sc-CARNS and the contents of alanine and carnosine did not change significantly in control group and diethyl pyrocarbonate treated water. The expression level of Sc-CARNS mRNA in the interference group first decreased and then increased with the interference time, the content of alanine first increased and then decreased with time, and the content of carnosine first decreased and then increased. At 48 h, the expression of Sc-CARNS mRNA and the content of carnosine were significantly decreased, and the content of alanine was significantly increased. The results showed that S. constricta has a variable osmotic pressure. Ala as a FAA in vivo contributed the most to osmotic regulation. Moreover, carnosine synthetase was the key enzyme for converting alanine to carnosine. This study revealed the key mechanism of osmotic pressure regulation under low salt stress and provided a basis for revealing the unique salinity tolerance mechanism of Solenida shellfish.

We study the interaction between heterogeneously charged surfaces in an electrolyte solution by employing classical Density Functional Theory (cDFT) and Monte Carlo simulations. We observe a consistent behavior between cDFT and Monte Carlo simulations regarding force curves and two-dimensional density profiles. Armed with the validated cDFT, we explore the system's behavior under parameters that are challenging to simulate directly. Our findings include the impacts of domain size, domain charge, domain charge configuration, and bulk electrolyte concentration on the osmotic pressure. Remarkably, the force curve is more sensitive to the domain size for an asymmetric configuration than a symmetry configuration; the bulk concentration weakly influences the force curve independent of the system configurations. [ABSTRACT FROM AUTHOR]

• Anaerobic sludge activity was severely inhibited at a salinity of 16 g/L. • High salinity reduced species diversity, with Patescibacteria and Proteobacteria being the dominant phyla under high osmotic stress. • Addition of betaine promotes bacterial secretion of extracellular polymers in response to high osmotic pressure. • The relative abundance of Desulfobacterota and Spirochaetota was significantly increased by the addition of betaine. In this study, the effects of different salinity gradients and addition of compatible solutes on anaerobic treated effluent water qualities, sludge characteristics and microbial communities were investigated. The increase in salinity resulted in a decrease in particle size of the granular sludge, which was concentrated in the range of 0.5-1.0 mm. The content of EPS (extracellular polymeric substances) in the granular sludge gradually increased with increasing salinity and the addition of betaine (a typical compatible solute). Meanwhile, the microbial community structure was significantly affected by salinity, with high salinity reducing the diversity of bacteria. At higher salinity, Patescibacteria and Proteobacteria gradually became the dominant phylum, with relative abundance increasing to 13.53% and 12.16% at 20 g/L salinity. Desulfobacterota and its subordinate Desulfovibrio , which secrete EPS in large quantities, dominated significantly after betaine addition.Their relative abundance reached 13.65% and 7.86% at phylum level and genus level. The effect of these changes on the treated effluent was shown as the average chemical oxygen demand (COD) removal rate decreased from 82.10% to 79.71%, 78.01%, 68.51% and 64.55% when the salinity gradually increased from 2 g/L to 6, 10, 16 and 20 g/L. At the salinity of 20 g/L, average COD removal increased to 71.65% by the addition of 2 mmol/L betaine. The gradient elevated salinity and the exogenous addition of betaine played an important role in achieving stability of the anaerobic system in a highly saline environment, which provided a feasible strategy for anaerobic treatment of organic saline wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Artificial colloidal motors capable of converting various external energy into mechanical motion, have emerged as attractive photosensitizer (PS) nanocarriers with good deliverability for photodynamic therapy. However, photoactivated 3O 2 -to-1O 2 transformation as the most crucial energy transfer of the photodynamic process itself is still challenging to convert into autonomous transport. Herein, we report on PS-loaded thiophane-containing semiconducting conjugated polymer (SCP)-based polymer colloidal motors with asymmetric geometry for photodynamic-regulated propulsion in the liquid. The asymmetrical presence of the SCP phases within the colloidal motors would lead to significant differences in the 3O 2 -to-1O 2 transformation and 1O 2 release manners between asymmetrical polymer phases, spontaneously creating asymmetrical osmotic pressure gradients across the nanoparticles for powering the self-propelled motion under photodynamic regulation. This photoactivated energy-converting behavior can be also combined with the photothermal conversion of the SCP phases to create two energy gradients exerting diffusiophoretic/thermophoretic force on the colloidal motors for achieving multimode synergistic propulsion. This unique motile feature endows the light-driven PS nanocarriers with good permeability against various physiological barriers in the tumor microenvironment for enhancing antitumor efficacy, showing great potential in phototherapy. [ABSTRACT FROM AUTHOR]

Glass fiber reinforced phenolic composites (GFRP) are an advanced composite material with good processability, fatigue resistance, corrosion resistance and stability, and are widely used in the production of structural parts for aircraft and ships. Our research described in this article explores the performance changes of GFRP in different aging media with prolonged aging time using GFRP with different fiber/matrix ratios. The research results indicated that aging time had the most significant impact on the various properties of the composite materials among all variables. With the extension of aging time, the bending strength of our composite materials decreased significantly, with a maximum decrease of 33%. The water absorption rate gradually increased and tended to stabilize, but the thermal decomposition temperature remained at 300 °C, and the mass residual rate remained stable at around 61% with little change. As the content of GF was increased, the aging of the composite gradually slowed down, and the rate of decline in its bending strength gradually decreased. In addition, the influence of different aging media on the performance was also studied, and it was found that the presence of NaCl in artificial seawater could cause changes in the osmotic pressure at the interface of the composite materials and the sea water, thus exacerbating interface damage and affecting the material's performance. [ABSTRACT FROM AUTHOR]

Factors affecting the swelling of cellulosic fibers are considered in this review. Emphasis is placed on aqueous systems and papermaking fibers, but the review also considers cellulose solvent systems, nanocellulose research, and the behavior of cellulosic hydrogels. The topic of swelling of cellulosic fibers ranges from effects of humid air, continuing through water immersion, and extends to hydrogels and the dissolution of cellulose, as well as some of its derivatives. The degree of swelling of cellulose fibers can be understood as involving a balance between forces of expansion (especially osmotic pressure) vs. various restraining forces, some of which involve the detailed structure of layers within the fibril structure of the fibers. The review also considers hornification and its effects related to swelling. The expansive forces are highly dependent on ionizable groups, pH, and the ionic strength of solution. The restraining forces depend on the nature of lignin, cellulose, and their detailed structural arrangements.

Rhizome rot is a destructive soil-borne disease of Polygonatum kingianum and adversely affects the yield and sustenance of the plant. Understanding how the causal fungus Fusarium oxysporum infects P. kingianum may suggest effective control measures against rhizome rot. In germinating conidia of infectious F. oxysporum, expression of the zinc finger transcription factor gene Zfp1, consisting of two C2H2 motifs, was up-regulated. To characterize the critical role of ZFP1, we generated independent deletion mutants (zfp1) and complemented one mutant with a transgenic copy of ZFP1 (zfp1 tZFP1). Mycelial growth and conidial production of zfp1 were slower than those of wild type (ZFP1) and zfp1 tZFP1. Additionally, a reduced inhibition of growth suggested zfp1 was less sensitive to conditions promoting cell wall and osmotic stresses than ZFP1 and zfp1 tZFP1. Furthermore pathogenicity tests suggested a critical role for growth of zfp1 in infected leaves and rhizomes of P. kingianum. Thus ZFP1 is important for mycelial growth, conidiation, osmoregulation, and pathogenicity in P. kingianum. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Human serum albumin (HSA) is the most abundant protein in plasma, playing crucial roles in regulating osmotic pressure and maintaining protein homeostasis. It is widely applied in the clinical treatment of various diseases. HSA can be purified from plasma or produced using recombinant DNA technology. Due to the improved efficiency and reduced costs, a growing body of research has focused on enhancing albumin production through bacterial strain overexpression. However, there have been few studies on the effect of albumin on the characteristics of the overexpressing‐strain itself, particularly stress resistance. In this study, we utilized Lactiplantibacillus plantarum (L. plantarum) AR113 as the expression host and successfully constructed the albumin overexpression strain AR113‐pLLY01 through gene editing technology. The successful expression of albumin was achieved and subsequently compared with the wild‐type strain AR113‐pIB184.The results demonstrated that the survival rate of AR113‐pLLY01 was also significantly better than that of AR113‐pIB184 after lyophilization. In addition, AR113‐pLLY01 exhibited a significantly better protective effect than AR113‐pIB184 at pH 3, indicating that albumin possesses a certain tolerance to acidic stress. At bile salt concentrations higher than 0.03%, both strains showed limited growth, but at a concentration of 0.02%, AR113‐pLLY01 had a significant protective effect.This study suggest that albumin can improve strain tolerance, which has significant implications for future applications. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Introduction: Biphasic insulin secretion is an intrinsic characteristic of the pancreatic islet and has clinical relevance due to the loss of first-phase in patients with Type 2 diabetes. As it has long been shown that first-phase insulin secretion only occurs in response to rapid changes in glucose, we tested the hypothesis that islet response to an increase in glucose is a combination of metabolism plus an osmotic effect where hypertonicity is driving first-phase insulin secretion. Methods: Experiments were performed using perifusion analysis of rat, mouse, and human islets. Insulin secretion rate (ISR) and other parameters associated with its regulation were measured in response to combinations of D-glucose and membrane-impermeable carbohydrates (L-glucose or mannitol) designed to dissect the effect of hypertonicity from that of glucose metabolism. Results: Remarkably, the appearance of first-phase responses was wholly dependent on changes in tonicity: no first-phase in NAD(P)H, cytosolic calcium, cAMP secretion rate (cAMP SR), or ISR was observed when increased D-glucose concentration was counterbalanced by decreases in membraneimpermeable carbohydrates. When D-glucose was greater than 8 mM, rapid increases in L-glucose without any change in D-glucose resulted in first-phase responses in all measured parameters that were kinetically similar to D-glucose. First-phase ISR was completely abolished by H89 (a non-specific inhibitor of protein kinases) without affecting first-phase calcium response. Defining firstphase ISR as the difference between glucose-stimulated ISR with and without a change in hypertonicity, the peak of first-phase ISR occurred after second-phase ISR had reached steady state, consistent with the well-established glucosedependency of mechanisms that potentiate glucose-stimulated ISR. Discussion: The data collected in this study suggests a new model of glucosestimulated biphasic ISR where first-phase ISR derives from (and after) a transitory amplification of second-phase ISR and driven by hypertonicity-induced rise in H89- inhibitable kinases likely driven by first-phase responses in cAMP, calcium, or a combination of both. [ABSTRACT FROM AUTHOR]

Acrylamide is an important chemical in great global demand for the synthesis of polyacrylamide. A facile and benign approach of concentrating high osmotic acrylamide aqueous solution at a low temperature is needed to replace the current energy-intensive and cost-expensive thermal flash evaporation process. For the first time, a multi-stage forward osmosis (FO) process has been developed to concentrate acrylamide solution from 200 g/L to 600 g/L. Thin-film composite (TFC) membrane was fabricated and used for the multi-stage FO process. Acrylamide feed solution (FS) with various concentrations was systematically characterized in terms of viscosity and osmotic pressure (OP). Draw solutes including NaCl and MgCl2 were tested, and their reverse salt fluxes were measured with the quantification of their accumulative contents in the resultant concentrated acrylamide solution. Different operation modes including AL-FS (active layer facing FS) and AL-DS (active layer facing DS) were explored to optimize the system efficiency of the FO concentration process. Both single- and multi-stage FO operations were investigated, and their performances were quantified to assess the efficiency of the concentration of acrylamide solution. The results demonstrate that the multi-stage FO operation could dramatically improve the system efficiency for the concentration of acrylamide solution better than the single-stage FO process, and the draw concentration renewal at Stages II, III, and IV led to a water flux increase of 18.56%, 17.52%, and 18.43%, respectively. Moreover, the accumulated MgCl2 in the final 600 g/L acrylamide solution was below 3.7 g/L, less than 0.62 wt% impurity in the product of acrylamide. Our work provides a practical insight into the viability and optimization of a multi-stage FO process for concentrating high osmotic chemicals. [ABSTRACT FROM AUTHOR]

Transient receptor potential (TRP) melastatin member 8 (TRPM8) is a non-selective cation channel that can be activated by low temperatures (8–26 °C), cooling agents (including menthol analogs such as menthol, icilin, and WS-12), voltage, and extracellular osmotic pressure changes. TRPM8 expression has been identified in the digestive system by several research teams, demonstrating its significant involvement in tissue function and pathologies of the digestive system. Specifically, studies have implicated TRPM8 in various physiological and pathological processes of the esophagus, stomach, colorectal region, liver, and pancreas. This paper aims to comprehensively outline the distinct role of TRPM8 in different organs of the digestive system, offering insights for future mechanistic investigations of TRPM8. Additionally, it presents potential therapeutic targets for treating conditions such as digestive tract inflammation, tumors, sensory and functional disorders, and other related diseases. Furthermore, this paper addresses the limitations of existing studies and highlights the research prospects associated with TRPM8. [ABSTRACT FROM AUTHOR]