Search Results (8,831)

Amphiphilic dendrimers represent a promising class of nanoscale building blocks for functional materials, yet their conformational behavior, solvation, and interfacial activity remain incompletely understood. In this work, we employ atomistic molecular dynamics simulations to investigate G2–G4 carbosilane dendrimers functionalized with ethylene glycol terminal groups of two lengths—R1 (one ethylene glycol unit) and R3 (three units)—in water, toluene, and at fluid interfaces (water–toluene and water–air). Both types of dendrimers adopt compact, nearly spherical conformations in water but swell significantly (~83% in volume for G4) in toluene, a good solvent for the hydrophobic core. At the water–toluene interface, the dendrimers remain fully solvated in the toluene phase and show no surface activity. In contrast, at the water–air interface, they adsorb and adopt a mildly anisotropic, biconvex conformation, with a modest deformation. The total number of hydrogen bonds is reduced by ~50% compared to bulk water. Notably, the R3 dendrimers form more hydrogen bonds overall due to their higher oxygen content, which may contribute to the enhanced stability of their monolayers observed experimentally. These results demonstrate how dendrimer generation as well as terminal group length and hydrophilicity finely tune dendrimer conformation, hydration, and interfacial behavior, which are key factors for applications in nanocarriers, interfacial engineering, and self-assembled materials. The validated simulation protocol provides a robust foundation for future studies of multi-dendrimer systems and monolayer formation. Full article

Adiabatic demagnetization refrigeration (ADR)is regaining relevance for refrigeration to temperatures below 1 K as global helium-3 supply is increasingly strained. While ADR at these temperatures is long established with paramagnetic hydrated salts, more recently, frustrated rare-earth oxides were found to offer higher entropy densities and practical advantages, since they do not degrade under heating or evacuation. We report structural, magnetic, and thermodynamic properties of the rare-earth borates Ba${}_3$XB${}_9$O${}_{18}$ and Ba${}_3$XB${}_3$O${}_9$ with X = (Yb, Gd). Except for Ba${}_3$GdB${}_9$O${}_{18}$, which orders at 108 mK, the three other materials remain paramagnetic down to their lowest measured temperatures. ADR performance starting at 2 K in a field of 5 T is analyzed and compared to literature. Full article

Electrospun polymeric nanofibers have emerged as promising materials for wound management owing to their high surface area, efficient exudate absorption and gas exchange, and extracellular-matrix-like architecture. This study investigates the fabrication of nanofiber dressings from poly(vinyl alcohol) (PVA) and hyaluronic acid (HA), prepared by fully aqueous electrospinning (without organic solvents) for potential wound-care applications. HA incorporation is expected to influence hydration and matrix interactions, properties that have been associated with modulation of wound healing in previous studies. However, the high solubility of PVA-based NFs in aqueous environments limits their use in biological applications. To address this issue, PVA/HA nanofibers were chemically crosslinked through a solid-state esterification process at 150 °C using biocompatible citric acid (CA). The electrospinning parameters were optimized to obtain PVA/HA fibers with diameters ranging from 130 to 200 nm, which were assembled to form mats with different porosity and intersection density. FTIR confirmed the formation of ester bonds, while DSC analysis showed an increase in Tg from 41 °C to about 55 °C and a slight decrease in Tm after crosslinking. Swelling and degradation analyses demonstrated a significant enhancement in hydrolytic stability, as the weight loss of the nanofiber mats decreased from ~90% in the non-crosslinked samples to less than 10% after 2 h of crosslinking. Dynamic mechanical analysis (DMA) showed an increase in Young’s modulus from ~70 MPa to 230 MPa after crosslinking. Overall, the results demonstrate the stabilizing effect of citric-acid crosslinking on PVA/HA nanofibers and support their potential use in wound dressings under physiological conditions. Full article

As a cutting-edge technology in the field of cement-based materials, early carbonation curing enables industrial carbon sequestration and functional modification, and the optimization of process parameters is the key to advancing the development of this technology. This paper reviews the mechanism of action and influencing factors of early carbonation curing (including moisture content, carbon dioxide concentration, pre-hydration degree, etc.), its effects on the mechanical properties and durability of materials, as well as the resulting changes in microstructure. Meanwhile, this review also covers content such as the hydration–carbonation coupling mechanism, mentions the relevant conditions of carbonation products and microstructure, analyzes the performance enhancement of the interfacial transition zone (ITZ), and provides relevant support for the low-carbon development of cement-based materials by combining the application practice of prefabricated components and the comparison of technical routes. Although early carbonation can significantly improve material properties and optimize microstructure, current research still has shortcomings: the exploration of mineral carbonation–hydration activity, microstructure evolution law, and product combination mechanism is relatively insufficient, and the understanding of carbonation–hydration coupling kinetics is still not in-depth enough, all of which are areas requiring further research in the future. Full article

This study compares the mechanisms of organic (Hydroxypropyl Methyl Cellulose, HPMC) and inorganic (bentonite) thickeners in regulating the bleeding behavior and surface homogeneity of cement pastes. In situ low-field nuclear magnetic resonance (LF-NMR) was employed to monitor water migration, while X-ray diffraction (XRD), scanning electron microscopy (SEM), and carbonation tests were conducted to evaluate the property disparities between the top surface and bottom layers. Results indicate fundamentally different working modes: HPMC reduces bleeding by swelling to block capillary channels, exhibiting a saturation threshold at 0.2% dosage. Beyond this point, as the primary transport channels are effectively sealed, additional HPMC merely densifies the polymer “plugs” without further suppressing the bleeding rate. XRD and SEM analyses reveal that despite the reduction in total bleeding, HPMC-modified pastes still exhibit significant stratification; the top layer retains a loose, granular morphology with higher carbonation susceptibility compared to the dense bottom layer. In contrast, bentonite mitigates bleeding through a volume-filling mechanism and thixotropic structuring, demonstrating a continuous, dosage-dependent efficacy up to 1.2%. At a 0.6% dosage, bentonite effectively eliminates microstructural disparities, yielding a top surface with a dense matrix and hydration product distribution nearly identical to the bottom layer. These findings demonstrate that the specific inorganic thickener (bentonite) utilized in this work is more effective in restoring surface homogeneity and enhancing carbonation resistance than the evaluated organic polymer (HPMC). Full article

Galactomannans are a typical reserve polysaccharide in the endosperm of leguminous seeds; they turn the endosperm hard when dry and gelatinous and swollen when hydrated. Although galactomannans of several species have been biochemically characterized, little is known about their deposition within the endosperm. This study aimed to clarify how polysaccharides, galactomanans according to the literature, are produced and stored in the endosperm of Caesalpinia pulcherrima seeds by describing its structural and ultrastructural features throughout development. Samples of seeds at different developmental stages were collected and processed for study under light and electron microscopy. During development, the endosperm of C. pulcherrima undergoes substantial anatomical modifications associated with cellular cycles of polysaccharide release that gradually accumulates in the intercellular spaces. Endosperm cells exhibit an active Golgi apparatus with intense polysaccharide production, confirming their secretory function. In the mature endosperm, polysaccharides are stored in periplasmic and intercellular spaces rather than in thickened cell walls, as previously reported for other Leguminosae. By showing that galactomannans accumulate in periplasmic and intercellular spaces rather than in cell walls, our findings expand current understanding of endosperm diversity in Leguminosae and provide a foundation for future comparative studies on galactomannan synthesis and deposition across the family. Full article

Gel-based depots are increasingly recognized as platforms to extend the intratissue residence of local anesthetics (LAs) while reducing systemic exposure. Hydrogels, organogels, and emerging bigels represent three distinct architectures defined by their continuous phases and drug–matrix interactions. Hydrogels provide hydrated polymer networks with predictable injectability, tunable degradation, and diffusion- or stimulus-responsive release, enabling sustained analgesia in perineural, peri-incisional, intra-articular, and implant-adjacent settings. Organogels, formed by supramolecular assembly of low-molecular-weight gelators in lipids or semi-polar solvents, strongly solubilize lipophilic LA bases and enhance barrier partitioning, making them suitable for dermal, transdermal, and mucosal applications in outpatient or chronic pain care. Bigels integrate aqueous and lipid domains within biphasic matrices, improving rheology, spreadability, and dual-solubilization capacity, although their use in LA delivery remains at the formulation stage, with no validated in vivo pharmacology. This narrative review synthesizes the design principles, release mechanisms, and translational evidence across these platforms, highlighting domain-specific advantages and barriers related to mechanical robustness, sterilization, reproducibility, and regulatory feasibility. We propose a platform-level framework in which depot selection is aligned with LA chemistry, anatomical context, and clinical objectives to guide the development of workflow-compatible next-generation LA depots. Full article

Depressurization combined with thermal stimulation based on injection-production well patterns is considered promising for gas hydrate development. Nevertheless, its direct application to Shenhu challenging hydrates may be problematic due to the presence of low reservoir permeability and permeable boundaries. The present study proposes to improve the development potential of Shenhu hydrate by reservoir reconstruction, including boundary sealing and reservoir fracturing, and numerically investigates the production performance. The results showed that water intrusion, hot loss, and gas leakage can be effectively addressed by boundary sealing. Nevertheless, it cannot enhance productivity as thermal decomposition gas accumulated around the injection well. Conversely, reservoir fracturing can significantly improve extraction efficiency as substantial amounts of hydrates dissociate along the fractures, and the gas can be well recovered through the fractures. However, reservoir fracturing was not conducive to water control and energy utilization as it induced more severe water flooding and gas leakage. Under the synergistic effect of the two, there was no methane leakage, and the gas production rate increased with increasing fracture conductivity, while the gas-to-water ratio and energy ratio presented the opposite trend. To obtain a favorable production performance, a fracture with a conductivity of 1–10 D·cm was recommended. Therefore, the combination of boundary sealing and reservoir fracturing makes it feasible for safe and efficient extraction of offshore challenging hydrate under the injection-production mode. Full article

Low-temperature plasma treatments were applied to barley seeds using a dielectric barrier-stabilized corona discharge operated in ambient air enriched with oxygen or nitrogen to quantify surface chemical modifications and seed wettability. X-ray photoelectron spectroscopy showed that oxygen-enriched plasma produced the strongest oxidation, increasing surface oxygen from 9 ± 5 at% (control) to 24 ± 5 at%, while reducing carbon from 88 ± 5 at% to 76 ± 5 at%. Nitrogen-enriched plasma induced more moderate changes (O: 13 ± 5 at%, C: 85 ± 5 at%) but resulted in clear nitrogen incorporation, with an enhanced N 1s amine/amide component at ~400.8 eV. The hydroxyl O 1s contribution increased from 70% (control) to 82% (oxygen) and 90% (nitrogen), indicating substantial surface hydroxylation. SEM-EDX showed only minor micrometer-scale composition changes and no detectable morphological damage. Raman and ATR-FTIR spectra confirmed that polysaccharide, protein, and lipid structures remained intact, with intensity variations reflecting increased hydrophilicity. Water imbibition kinetics fitted with the Peleg model demonstrated faster initial hydration after plasma exposure, with 1/k₁ increasing from 20.25 ± 1.90 h⁻¹ (control) to 36.70 ± 6.56 h⁻¹ (oxygen) and 38.87 ± 7.57 h⁻¹ (nitrogen), while 1/k₂ remained nearly unchanged. Full article

Understanding the atomic-level behavior of photocatalysts under hydrated conditions is essential for improving hydrogen production efficiency. In this work, density functional theory calculations and classical all-atom molecular dynamics simulations were performed to investigate the intra- and intermolecular interactions of rod- and cluster-shaped cadmium sulfide in the presence of implicit and explicit water, respectively. The density functional theory optimized geometries, reduced density gradient, noncovalent interaction, critical point, and molecular electrostatic potential maps were examined using the LC-ωPBE functional with the LANL2DZ basis set and the IEFPCM implicit solvation model, while explicit hydration was modeled via classical all-atom molecular dynamics simulations by obtaining molecular snapshots and radial distribution functions. Density functional theory results revealed that rod-shaped cadmium sulfide exhibits stronger directional bonding and higher electronic localization compared to cluster-shaped cadmium sulfide, while classical all-atom molecular dynamics simulations showed that water molecules preferentially interact with surface S atoms of cadmium sulfide sites. This atomistic insight clarifies how morphology and hydration jointly modulate cadmium sulfide electronic structure and reactivity, providing guidance for the rational design of efficient cadmium sulfide-based photocatalysts for solar-driven water splitting. Full article

Skin hydration is a key indicator of skin health and stratum corneum (SC) integrity, yet its relationship with multi-dimensional physiological parameters remains incompletely understood. This study aimed to investigate the association between facial skin hydration and key physiological parameters and explored the lipidomic differences between individuals with high and low hydration levels. We enrolled 60 healthy Chinese women (aged 30–55), divided into a low-hydration (LH, n = 11) group and a high-hydration (HH, n = 19) group based on Corneometer measurements. An integrated methodology was employed, including confocal Raman spectroscopy, multiphoton laser tomography, biophysical instruments, and untargeted lipidomics. Our results demonstrated a positive correlation between skin hydration and SC thickness, ceramides, and lactate levels. However, no significant correlation was identified in relation to wrinkles, color, or elasticity. The lipidomic analysis revealed eighty-three significantly upregulated lipids (VIP > 1.0, p < 0.05) in LH skin, among which ten lipids, including nine ceramides, exhibited strong negative correlations with hydration (|r| > 0.8, p < 0.05). These lipids were predominantly associated with sphingolipid and triacylglycerol metabolic pathways. Together, our findings suggest that low-hydration skin is characterized by systemic lipidomic dysregulation, rather than a deficiency of individual lipids. These findings represent novel insights into the mechanisms underlying skin hydration and identify potential therapeutic targets for addressing skin dryness and aging. Full article

Background/Objectives: Successful and sustained breastfeeding depends on maternal, psychological, metabolic and obstetric factors including hydration status, body composition, gestational age at delivery and mode of delivery, which are rarely assessed together in routine postpartum care. Bioelectrical impedance analysis (BIA) provides a non-invasive assessment of hydration and tissue composition, yet its potential to support lactation outcomes remains insufficiently studied. This study aimed to evaluate the relationship between postpartum body composition, hydration status assessed with BIA, and breastfeeding duration. Methods: A total of 122 women in the early postpartum period after term singleton deliveries were enrolled, of whom 50 completed the full protocol, including a 7-month follow-up. BIA and anthropometric measurements were performed on postpartum days 2 and 3. Breastfeeding duration was assessed at 7 months via telephone interview and categorized as <6 months or ≥6 months. Two indices (PLBI and sPLBI) were calculated to describe BMI change from pre-pregnancy to 7 months postpartum. Results: Breastfeeding for ≥6 months was significantly associated with marital status, mode of delivery, lower BMI on postpartum day 2, and a positive change in the overhydration index (ΔOH). Women in this group exhibited significantly lower PLBI and sPLBI values, indicating more effective postpartum weight recovery and a greater return toward pre-pregnancy BMI. Hydration parameters derived from BIA differentiated between shorter and longer breastfeeding duration. Conclusions: Positive postpartum hydration balance (ΔOH ≥ 0) and efficient metabolic recovery, reflected by lower PLBI and sPLBI values, may support longer breastfeeding. BIA-based assessment of hydration and body composition could help identify women at higher risk of early breastfeeding cessation. Further longitudinal research is warranted to confirm the clinical utility of BIA in postpartum care and its potential role in early lactation support. Full article

The importance of proper hydration for work performance in hot climates is well known, as opposed to its role in cold climates. Workers’ water requirements may be high in both cold and hot environments, and the effects of dehydration can be a serious problem in either case. The National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) recommend that workers drink small amounts (150–250 mL at once) of chilled water (especially in hot environments) or warm beverages (especially in cold environments) every 15–20 min (before they become thirsty) to stay well hydrated. However, individual hydration plans are now more preferred, as no single recommendation is suitable for everyone. Workers should stay hydrated before, during, and after work. The article presents the importance of adequate hydration of workers as well as some recommendations for fluid intake in the workplace. Full article

Volume electron microscopy (Volume-EM) has transformed structural cell biology by enabling nanometre-resolution imaging across cellular and tissue scales. Serial-section TEM, Serial Block-Face Scanning Electron Microscopy (SBF-SEM), Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) and multi-beam SEM now routinely generate terabyte-scale volumes that capture organelles, synapses and neural circuits in three dimensions, while cryogenic Volume-EM extends this landscape by preserving vitrified, fully hydrated specimens in a near-native state. Together, these room-temperature and cryogenic modalities define a continuum of approaches that trade off volume, resolution, throughput and structural fidelity, and increasingly interface with correlative light microscopy and cryo-electron tomography. In parallel, advances in computation have turned Volume-EM into a data-intensive discipline. Multistage preprocessing pipelines for alignment, denoising, stitching and intensity normalisation feed into automated segmentation frameworks that combine convolutional neural networks, affinity-based supervoxel agglomeration, flood-filling networks and, more recently, diffusion-based generative restoration. Weakly supervised and self-supervised learning, multi-task objectives and human-AI co-training mitigate the scarcity of dense ground truth, while distributed storage and streaming inference architectures support segmentation and proofreading at the terascale and beyond. Open resources such as COSEM, MICRONS, OpenOrganelle and EMPIAR provide benchmark datasets, interoperable file formats and reference workflows that anchor method development and cross-laboratory comparison. In this review, we first outline the physical principles and imaging modes of conventional and cryogenic Volume-EM, then describe current best practices in data acquisition and preprocessing, and finally survey the emerging ecosystem of AI-driven segmentation and analysis. We highlight how cryo-Volume-EM expands the field towards native-state structural biology, and how multimodal integration with light microscopy, cryo-electron tomography (cryo-ET) and spatial omics is pushing Volume-EM from descriptive imaging towards predictive, mechanistic, cross-scale models of cell physiology, disease ultrastructure and neural circuit function. Full article

Magnetoliposomes are hybrid nanostructures that integrate superparamagnetic ultrasmall carbon-coated ferrite nanodots (MNCDs) within liposomes (Lipo) composed of egg yolk-derived phospholipids and stabilized with an environmentally benign potato peel extract (PPE), enabling enhanced magnetic resonance imaging (MRI) and optical imaging. The hydrothermally synthesized MNCDs were entrapped in liposomes prepared by thin-film hydration, and physicochemical properties were established at each stage of engineering. These magnetoresponsive vesicles (MNCDs+Lipo@PPE) serve as a triple-mode medical imaging contrast for T1 & T2-weighted MRI, while simultaneously enabling optical tracking of liposome degradation under an external magnetic field. They exhibited long-term enhanced fluorescence intensity and colloidal stability over 30 days, with hydrodynamic diameters ranging from 190 to 331 nm and an improved surface charge following PPE coating. In vitro cytotoxicity assays (MTT and Live/Dead staining) demonstrated over 87% cell viability for MNCDs+Lipo@PPE up to 2.7 mM concentration in A549 cells, indicating considerable toxicity. This multimodality engineering facilitates precise image-guided anticancer doxorubicin delivery and magnetic-responsive controlled release. The theoretical model shows that the release profile follows the Korsmeyer-Peppas profile. The externally applied magnetic field enhances the release by 1.4-fold. To demonstrate the anticancer efficiency in vitro with minimum off-target cytotoxicity, MTT and live/dead cell assay were performed against A549 cells. The reported study is a validated demonstration of magnetic-responsive nanocarrier systems for anticancer therapy and multimodal MRI and optical imaging-based diagnosis. Full article