Search Results (176)

Layered graphene oxide (GO) has emerged as an ideal membrane structure for water desalination. In GO-stacked structures, the slit gaps between GO nanosheets can serve as critical pathways for molecule permeation. Exploring the permeation mechanisms of functionalized GO nanoslits is critical for improving the separation performance. Herein, molecular simulations were performed to investigate the water permeation and ion rejection for six types of ionic solutions by considering edge-amino functionalized GO (NGO) slit membranes. The NGO slit exhibits higher ion retention while maintaining reasonable water permeability. Edge amine groups can interact strongly with water molecules and immobilize ions, thus enhancing ion rejection. The thermodynamic free energy for ion passing was simulated to explain the unique ion rejection mechanism of amine-functionalized GO slits. The thermodynamic barrier for ion rejection can be considered as the delicate combination of the ion dehydration effect and the slit-generated attraction. The ion dehydration accounts for a repulsive contribution, which is the controlling portion in governing the free-energy profile. Overall, our work is important and valuable for the development and design of new-type layered GO membranes. Full article

Background/Objectives: Animal and fungal sterols and stanols exhibit remarkable structural diversity, driven by variations in the number and position of C=C bonds within the steroidal tetracyclic core and side chain, along with diverse branching patterns of the latter. Similarly to phytosterols, these metabolites produce highly complex tandem mass spectra, whose interpretation has so far been limited. To address this gap, the fragmentation behavior of selected animal/fungal sterols and stanols was studied in this paper. Methods: Higher-Collisional-energy Dissociation–High-resolution tandem mass spectrometry (HCD-HRMS/MS) of protonated/dehydrated species generated via atmospheric pressure chemical ionization (APCI) was performed on structurally diverse compounds, including lathosterol, desmosterol, zymosterol, lanosterol, ergosterol, chalinasterol, and the stanols coprostanol and cholestanol. Results: Structurally diagnostic product ions originating from the side chains were unveiled, shedding light on the intramolecular migration of positive charge from the initial ionization site at C3 to alternative stable sites across the molecular structure, which is a typical mechanism also noted in cholesterol and phytosterols. In addition, characteristic fragmentation patterns related to the steroidal backbone were found and discussed for Δ⁷, Δ^5,7 and Δ⁸-sterols, and a novel elucidation of the fragmentation behavior of 4,4-dimethyl-Δ⁸-sterols, based on lanosterol as a model compound, was achieved. The relative intensities of diagnostic product ions allowed a correlation with specific structural motifs, and “cholesterol-like” and “stigmasterol-like” fragmentations pathways were recognized. These findings were integrated with prior data on cholesterol and plant sterol fragmentation acquired under identical analytical conditions. Moreover, as a proof of its relevance for novel sterol identification, MS/MS-related information was successfully applied to the identification of a positional isomer (Δ⁷) of zymosterol in baker’s yeast extract, along with typical fungal major sterols. Conclusions: The comprehensive archive of sterol/stanol fragmentations obtained by APCI-HCD-MS/MS might prove very useful for the future characterization of novel sterol/stanol species in complex matrices. Full article

Metallic magnesium is a strategic material with applications in mobility, energy and medicine, due to its low density, biocompatibility and use as an anode in rechargeable batteries. However, industrial production methods—such as the thermal reduction of dolomite or the electrolysis of anhydrous MgCl₂—face environmental and operational challenges, including high temperatures, emissions, and dehydration of precursors like bischofite. In response, ionic liquids (ILs) have emerged as alternative electrolytes, offering low volatility, thermal stability and wide electrochemical windows that enable electrodeposition in water-free media. This study presents a systematic review of 32 peer-reviewed articles, applying the PRISMA 2020 methodology. The analysis is structured across three dimensions: (1) types of ILs employed, (2) operational parameters and (3) magnesium source materials. In addition to electrolyte composition, key factors such as temperature, viscosity control, precursor purity and cell architecture were identified as critical for achieving efficient and reproducible magnesium deposition. Furthermore, the use of elevated temperatures and co-solvent strategies has been shown to effectively mitigate viscosity-related transport limitations, enabling more uniform ion mobility and enhancing interfacial behavior. The use of alloy co-deposition strategies and multicomponent electrolyte systems also expands the technological potential of IL-based processes, especially for corrosion-resistant coatings or composite electrode materials. This review contributes by critically synthesizing current techniques, identifying knowledge gaps and proposing strategies for scalable, sustainable magnesium production. The findings position IL-based electrodeposition as a potential alternative for environmentally responsible metal recovery. Full article

Developing efficient bio-based membranes is key to sustainable wastewater treatment, especially when they can be applied across multiple separation processes for components of varying molecular weights. This study reports the development and characterization of bio-based mixed matrix membranes from carboxymethyl cellulose (CMC) modified with synthesized carboxylated graphene oxide (GOCOOH), aimed at improving performance in both pervaporation and nanofiltration for water treatment. Membrane design was optimized by adjusting the GOCOOH content, applying chemical cross-linking (by immersing in glutaraldehyde with H₂SO₄), and developing highly effective supported membranes (by the deposition of a thin selective CMC-based layer onto a porous substrate). Comprehensive characterization was performed using spectroscopic, microscopic, and thermogravimetric analyses and contact angle measurements. The optimized cross-linked supported CMC/GOCOOH (5%) membrane demonstrated significantly improved transport properties: a 2.5-fold increased permeation flux and over 99.9 wt.% water in permeate in pervaporation dehydration of isopropanol, and high rejection rates—above 98.5% for anionic dyes and over 99.8% for heavy metal ions in nanofiltration. These findings demonstrate that CMC/GOCOOH membranes are promising, sustainable materials suitable for multiple separation processes involving components of varying molecular weights, contributing to more efficient and eco-friendly wastewater treatment solutions. Full article

Mutations in the CFTR genes causing cystic fibrosis (CF) are associated with the presence of thick, viscous mucus and the formation of biofilms in the gastrointestinal tract (GI) that impair intestinal homeostasis, triggering chronic inflammation, epithelial barrier dysfunction, and changes in the composition and activity of the gut microbiota. CFTR protein modulators represent a promising approach to enhancing lower GI function in patients with CF. The aim of the review is to present the complex relationships between the presence of CFTR gene mutations and the gut microbiota dysbiosis in patients with cystic fibrosis. Mutations in the CFTR gene, the molecular basis of cystic fibrosis (CF), disrupt epithelial ion transport and profoundly alter the gastrointestinal environment. Defective chloride and bicarbonate secretion leads to dehydration of the mucosal layer, increased mucus viscosity, and the formation of biofilms that favour microbial persistence, which together promote gut microbiota dysbiosis. This dysbiotic state contributes to impaired epithelial barrier function, chronic intestinal inflammation, and abnormal immune activation, thereby reinforcing disease progression. The interplay between CFTR dysfunction and microbial imbalance appears to be bidirectional, as dysbiosis may further exacerbate epithelial stress and inflammatory signalling. Therapeutic interventions with CFTR protein modulators offer the potential to partially restore epithelial physiology, improve mucus hydration, and foster a microbial milieu more consistent with intestinal homeostasis. The aim of this review is to elucidate the complex relationships between CFTR gene mutations and gut microbiota dysbiosis in patients with cystic fibrosis, with a particular emphasis on the clinical implications of these interactions and their potential to inform novel therapeutic strategies. Full article

Drying is ubiquitous. However, its influence on surface speciation has been seldom studied. Through an in situ Attenuated Total Reflection–Infrared (ATR-IR) spectroscopy analysis of the drying of molybdate solutions on a lepidocrocite particle film, the change in surface speciation is followed. No formation polymolybdates nor precipitate are observed upon drying at pH 8. An in situ washing of the dried solid/solution interface unveils the existence of surface outer-sphere and inner-sphere complexes. Decreasing the molybdate concentration highlights a saturation effect of the surface upon drying. Moreover, the careful analysis of substrate IR bands showed non-uniform drying which is an important insight to understand dehydration chemistry. The remaining molybdate ions at the surface as inner-sphere complexes are present as binuclear monodentate complexes stabilized by sodium. Full article

Dehydration is a serious medical problem for elderly patients and young children. The most widely used diagnostics are measurements of sodium ion (Na⁺) and potassium ion (K⁺) in blood serum. Dehydration is difficult to diagnose even by trained health care professionals because the body compensates to maintain the appearance of skin. These measurements required a blood draw because specific tests are generally not available for only Na⁺ and K⁺. The blood samples are analyzed by an electrolyte panel (EP) or a basic metabolic panel (BMP). Most hospitals limit EP and BMP to one per day to control costs. More frequent measurements of Na⁺ and K⁺ are needed, especially during rehydration. We designed a dehydration contact lens that can provide the Na⁺ and K⁺ concentrations as needed or for continuous monitoring. The measurements are obtained from the fluorescent lifetime or wavelength-ratiometric intensities of the Na⁺- and K⁺-sensitive fluorophores. The dehydration contact lens does not contain electronic components and are inexpensive to prepare. Full article

Gypsum (CaSO₄·2H₂O) crystallization underpins numerous industrial processes, yet its response to chemical admixtures remains incompletely understood. This study investigates diffusion-controlled crystal growth in a coaxial test tube system to evaluate how three Sika^® ViscoCrete^® superplasticizers—430P, 111P, and 120P—affect nucleation, growth kinetics, morphology, and thermal behavior. The superplasticizers, selected for their surface-active properties, were hypothesized to influence crystallization via interfacial interactions. Ion diffusion was maintained quasi-steadily for 12 weeks, with crystal evolution tracked weekly by macro-photography; scanning electron microscopy and thermogravimetric/differential scanning were performed at the final stage. All admixtures delayed nucleation in a concentration-dependent manner. Lower dosages (0.5–1.0 wt%) yielded platy-to-prismatic morphologies and higher dehydration enthalpies, indicating more ordered lattice formation. In contrast, higher dosages (1.5–2.0 wt%) produced denser, irregular crystals and shifted dehydration to lower temperatures, suggesting structural defects or increased hydration. Among the additives, 120P showed the strongest inhibitory effect, while 111P at 0.5 wt% resulted in the most uniform crystals. These results demonstrate that ViscoCrete^® superplasticizers can modulate gypsum crystallization and thermal properties. Full article

The mechanism by which voltage-gated ion channels open and close has been the subject of intensive investigation for decades. For a large class of potassium channels and related sodium channels, the consensus has been that the gating current preceding the main ionic current is a large movement of positively charged segments of protein from voltage-sensing domains that are mechanically connected to the gate through linker sections of the protein, thus opening and closing the gate. We have pointed out that this mechanism is based on evidence that has alternate interpretations in which protons move. Very little literature considers the role of water and protons in gating, although water must be present, and there is evidence that protons can move in related channels. It is known that water has properties in confined spaces and at the surface of proteins different from those in bulk water. In addition, there is the possibility of quantum properties that are associated with mobile protons and the hydrogen bonds that must be present in the pore; these are likely to be of major importance in gating. In this review, we consider the evidence that indicates a central role for water and the mobility of protons, as well as alternate ways to interpret the evidence of the standard model in which a segment of protein moves. We discuss evidence that includes the importance of quantum effects and hydrogen bonding in confined spaces. K⁺ must be partially dehydrated as it passes the gate, and a possible mechanism for this is considered; added protons could prevent this mechanism from operating, thus closing the channel. The implications of certain mutations have been unclear, and we offer consistent interpretations for some that are of particular interest. Evidence for proton transport in response to voltage change includes a similarity in sequence to the H_v1 channel; this appears to be conserved in a number of K⁺ channels. We also consider evidence for a switch in -OH side chain orientation in certain key serines and threonines. Full article

Molasses, a by-product of raw sugar production, is widely used as a cost-effective carbon and nutrient source for industrial fermentations, including the production of baker’s yeast (Saccharomyces cerevisiae). Due to the cost and limited availability of molasses, efforts have been made to replace molasses with cheaper and more readily available substrates such as corn syrup. However, the quality of dry yeast drops following the replacement of molasses with corn syrup, despite the same amount of total sugar being provided. Our understanding of how molasses replacement affects yeast physiology, especially during the dehydration step, is limited. Here, we examined changes in gene expression of a strain of baker’s yeast during fermentation with increasing corn syrup to molasses ratios at the transcriptomic level. Our findings revealed that the limited availability of the key metal ions copper, iron, and zinc, as well as sulfur from corn syrup (i) reduced their intracellular storage, (ii) impaired the synthesis of unsaturated fatty acids and ergosterol, as evidenced by the decreasing proportions of these important membrane components with higher proportions of corn syrup, and (iii) inactivated oxidative stress response enzymes. Taken together, the molecular and metabolic changes observed suggest a potential reduction in nutrient reserves for fermentation and a possible compromise in cell viability during the drying process, which may ultimately impact the quality of the final dry yeast product. These findings emphasize the importance of precise nutrient supplementation when substituting molasses with cheaper substrates. Full article

Nafion, while a benchmark proton exchange membrane (PEM) for fuel cells, suffers from significant performance degradation at elevated temperatures and low humidity due to dehydration and diminished mechanical stability. To address these limitations, this study investigated the development and characterization of Nafion nanocomposite membranes incorporating sulfonated silica layered materials (sSLMs). The inherent lamellar structure, high surface area, and abundant sulfonic acid functionalities of sSLMs were leveraged to synergistically enhance membrane properties. Our results demonstrate that sSLM incorporation significantly improved ion exchange capacity, water uptake, and dimensional stability, leading to superior water retention and self-diffusion at higher temperatures. Critically, the nanocomposite membranes exhibited remarkably enhanced proton conductivity, particularly under demanding conditions of 120 C and low relative humidity (i.e., 20% RH), where filler-free Nafion largely ceases to conduct. Single H₂/O₂ fuel cell tests confirmed these enhancements, with the optimal sSLM-Nafion nanocomposite membrane (N-sSLM₅) achieving a two-fold power density improvement over pristine Nafion at 120 C and 20% RH (340 mW cm⁻² vs. 117 mW cm⁻² for Nafion). These findings underscore the immense potential of sSLM as a functional filler for fabricating robust and high-performance PEMs, paving the way for the next generation of fuel cells capable of operating efficiently under more challenging environmental conditions. Full article

Background/Objectives: In diabetic ketoacidosis (DKA), absolute insulin deficiency and elevation of counter-regulatory hormones may cause osmotic diuresis and water and electrolyte loss, which may lead to dehydration and renal failure. Fluids with high Na content are preferred in the DKA fluid therapy algorithm due to the association of Na with β-Hydroxybutyrate (β-HB) and the renal excretion of Na-β-HB. However, these fluids may cause hyperchloremic metabolic acidosis due to their high chloride concentration. In the literature, base-excess chloride (BE_Cl) has been suggested as a better approach for assessing the effect of chloride on acid–base status. Our aim in this study was to investigate the effect of fluids with BE_Cl values less than zero versus those with values equal to or greater than zero on the metabolic acid–base status in the first 6 h of DKA. Methods: This retrospective study included DKA cases managed in the tertiary intensive care units of five hospitals in the last 10 years. Patients were divided into two groups according to the Na-Cl difference of the administered fluids during the first 6 h of treatment: Group I [GI, fluids with Na-Cl difference = 0, chloride-rich group] and Group II [GII, fluids with Na-Cl difference > 32 mmol, chloride non-rich group]. Demographic data, blood gas analysis results, types and amounts of administered fluids, urea–creatinine values, and urine ketone levels were recorded. Results: Thirty-five patients with DKA in the ICU were included in the study (GI; 22 patients, GII; 13 patients). There was no difference between the patients in the two groups in terms of age, gender, and LOS-ICU. According to the distribution of the administered fluids, the main fluid administered in GI was 0.9% NaCl, whereas in the GII, it was bicarbonate, Isolyte-S, and 0.9% NaCl. In GI, the chloride load administered was higher; the BE_Cl level of the fluids was lower than in GII. At the end of the first 6 h, although sodium and strong ion gap values were similar, patients in GI were more acidotic due to iatrogenic hyperchloremia and, as a result, were more hypocapnic than GII. Conclusions: In conclusion, administering chloride-rich fluids in DKA may help reduce unmeasured anion acidosis. Still, risks cause iatrogenic hyperchloremic acidosis, which can hinder the expected resolution of acidosis and increase respiratory workload. Therefore, it is suggested that DKA guidelines be revised to recommend an individualized approach that avoids chloride-rich fluids and includes monitoring of metabolic parameters like Cl and BE_Cl. Full article

Cystic fibrosis (CF) is a multisystemic disease caused by a genetic defect, namely a mutation in the CFTR gene, that results in the production of an abnormal protein that regulates the flow of chloride ions through epithelial cells, leading to the dehydration of secreted mucus and changes in its biological properties. Chronic inflammation and recurrent respiratory infections progressively damage lung tissue, leading to respiratory and cardiorespiratory failure. This study aims to present a clinical case and explore the clinical changes in CF that may influence the provision of pre-hospital first aid. The study presents a case report of a 23-year-old CF patient undergoing evaluation for lung transplantation, infected with Pseudomonas aeruginosa and Staphylococcus aureus with the MSSA phenotype, and in a severe condition due to infectious exacerbation. Despite antibiotic treatment, the patient’s condition deteriorated, leading to respiratory failure and cardiac arrest. Emergency measures were taken to maintain airway patency—the patient was sedated, intubated, and connected to a ventilator. CF involves systemic complications that, during exacerbations, may require urgent interventions. Cystic fibrosis is associated with multiple systemic complications, some of which may, during exacerbations, require emergency medical interventions. Providing care to this patient group involves specific procedures addressing the consequences of the underlying disease. Due to increasing survival rates and the emergence of new phenotypes, there is a need for the continuous education of medical personnel, including emergency responders, regarding the management of genetically determined diseases. This study underscores the importance of recognizing CF’s complex nature and adapting emergency care accordingly to ensure timely and effective intervention in life-threatening situations. Full article

Gas chromatography–ion mobility spectrometry (GC-IMS) is an interesting candidate to face geographical origin declaration fraud in dehydrated apple samples. It allows the collection of the peculiar fingerprints of the analysed samples with the bi-dimensional separation of volatile molecules, based on their polarity and their dimension and shape. It represents a rapid, cost-effective, and sensitive solution for food authenticity issues. A design of experiment (DoE) led to robust sampling, taking into account different factors, such as harvesting year, the presence of peel, variety. The sample preparation was limited as it required only the milling of the dehydrated apple dices before the analysis. The GC-IMS analytical method permitted us to obtain of a 3D graph in 11 min, and the multivariate statistical analysis returned a clear separation between Italian and non-Italian (French, Chinese, Hungarian, Polish) samples, considering both unsupervised and supervised approaches. The statistical model, created employing a training set, was applied on a further test set, with a good overall performance. Thus, GC-IMS could play a relevant role as a tool to prevent/fight false origin declaration frauds and also, potentially, other kinds of food authenticity and safety frauds. Full article

Introduction: Many orally administered drugs are either unstable in the acidic environment of the stomach or cause moderate to severe side effects in the upper gastrointestinal tract (GIT). These limitations can reduce therapeutic efficacy, discourage patient compliance, worsen the disease, and even contribute to the risk of cancer development. To overcome these issues, drug release often needs to be modified and targeted to the distal parts of the GIT. This is typically achieved through the use of pH-sensitive polymer coatings or incorporation into polymeric delivery systems. With this in mind, the aim of this project was to design, develop, and characterize gellan gum-based beads for colon-specific prolonged release of mesalazine, with potential application in the chemoprevention and treatment of bowel diseases. Materials and Methods: The dehydrated capsules were characterized using Raman spectroscopy and scanning electron microscopy. The crosslinked gellan gum was additionally evaluated for cytotoxicity. Key parameters such as pH-dependent swelling behavior, drug content, encapsulation efficiency, and drug release in simulated gastrointestinal fluids were also assessed. Furthermore, the behavior of the capsules in the gastrointestinal tract was studied in a rat model to evaluate their in vivo performance. Results: Significant differences in drug release profiles were observed between formulations crosslinked solely with calcium ions and those additionally crosslinked with glutaraldehyde (GA). The incorporation of GA effectively prolonged the release of mesalazine. These findings were further supported by in vivo studies conducted on Wistar rats, where the GA-crosslinked formulation demonstrated a markedly extended release compared to the formulation prepared using only ionotropic gelation. Conclusions: The combination of ionotropic gelation and glutaraldehyde crosslinking in gellan gum-based beads appears to be a promising strategy for achieving colon-specific prolonged release of mesalazine, facilitating targeted delivery to the distal regions of the gastrointestinal tract. Full article