Hydrophilic Sites Research Articles

Effects of dextran molecular weight on starch retrogradation and technological properties of Chinese steamed bread: Based on the rubber/glass transition

From the perspective of rubber/glass transition, this study clarified that the impact of dextran on retarding hardening behavior and slowing starch retrogradation of Chinese Steamed Bread (CSB) depended on its molecular weight and concentration level. Guggenheim-Anderson-de Boer (GAB) model was fitted to explore critical behavior changes in rubber/glass transition of CSB. Incorporation of high molecular weight dextran enhanced the elasticity of dough and porosity of CSB, reduced the aging and hardening degree of CSB at appropriate addition levels. CSB hardness showed a growing tendency during storage, while macromolecular dextran reduced the hardness and retrogradation degree by 22.87 % and 67.53 %. Dextran with high molecular weights lowered the glass transition temperature (Tg) and improved the moisture sorption and molecular mobility of CSB under various relative humidity (RHs) conditions by providing hydrophilic sites or intermolecular space to bind water molecules. Meanwhile, it reinforced the binding between denatured gluten and gelatinized starch. Both of them devoted to starch retrogradation inhibition and stable quality maintenance of CSB. CSB is suggested to maintain stable quality at room temperature with RHs ≤33 % to prevent rubber/glass transition. This work provided theoretical guidance for fractionation application of dextran to regulate the quality and extend the shelf-life of flour products.

Different wettability surfaces composited by polydopamine-based SiO2/TiO2 coatings for efficient water collection and anti-corrosion application

Designing hybrid surfaces with superhydrophilic and superhydrophobic properties represents a promising approach for fog collection. Inspired by the adhesive properties of mussel proteins, a polydopamine (PDA) film was firmly attached to a brass surface through a combination of chemical etching and spontaneous dopamine polymerization. By harnessing the exceptional characteristics of PDA as a "double-sided adhesive," a hybrid surface with mixed wettability was created using a facile and cost-effective method involving SiO2 and TiO2 nanoparticles (NPs). The TiO2 NPs served as the hydrophilic sites for water capture, while the SiO2 NPs acted as the hydrophobic region to induce water droplet rolling. The resulting hybrid surface exhibited a significant improvement in water collection rate, measuring approximately 1.182 g/cm2/h, which was 1.84 times higher than that of the bare brass surface. This demonstrated a remarkable enhancement in fog collection capacity. Moreover, the hybrid surface demonstrated commendable corrosion resistance and remarkable durability, indicating its great potential for widespread application in practical scenarios.

Preparation of poly(divinylbenzene-co-methyl acrylate) adsorbent with tunable surface hydrophilicity for atrazine removal

To efficiently remove atrazine, it is crucial to facilitate synergistic adsorption effect between aromatic structure and hydrophilic adsorption sites through tuning surface hydrophilicity. Herein, we reported a polymer adsorbent which was synthesized by copolymerizing divinylbenzene (DVB) and methyl acrylate (MA) with different monomer ratio, and subsequently hydrolyzing the copolymer to obtain carboxyl group on its surface. The surface hydrophilicity could be easily adjusted by changing the ratio of monomer and the optimal feeding ratio was 4:1 (VDVB:VMA) in terms of porosity (specific surface area 712.92 m2/g) and hydrophilicity regarding atrazine adsorption. The adsorption process followed the Langmuir isotherm with a maximum adsorption capacity of 75.75 mg/g. The mixed surface reaction and film diffusion model revealed that the adsorption procedure is dramatically controlled by film diffusion. Atrazine molecules diffusive and bound with porous adsorbent via strong hydrogen bonding between N (triazine and amine) and carboxyl groups introduced by copolymerization. Furthermore, high porosity caused by aromatic crosslinked network provided sufficient adsorption sites through π-stacking interaction. This work not only supplies a highly efficient adsorbent for atrazine removal but also enables a platform for preparation of polymers with tunable porosity and surface hydrophilicity.

Preparing high-performance microspheres based on the chitosan-assisted dispersion of reduced graphene oxide in aqueous solution for bilirubin removal

The removal of excess bilirubin from blood is of great clinical importance. Reduced graphene oxide (rGO) is often used to efficiently remove bilirubin. However, thin rGO pieces tend to aggregate in the aqueous phase because they are hydrophobic. In this context, we propose an effective strategy based on the chitosan-assisted (CS-assisted) dispersion of rGO to produce high-performance bilirubin-adsorbing microspheres. CS possesses a hydrophobic CH structure, which offers strong hydrophobic interactions with rGO that assist its dispersion, and the large number of hydrophilic sites of CS increases the hydrophilicity of rGO. CS serves as a dispersant in a surfactant-like manner to achieve a homogeneous and stable CS/rGO dispersion by simply and gently stirring CS and rGO in a LiOH/KOH/urea/H2O system. Subsequently, CS/rGO hybrid microspheres were prepared by emulsification. CS ensures blood compatibility as a base material, and the entrapped rGO contributes to mechanical strength and a high adsorption capacity. The CS/rGO microspheres exhibited a high bilirubin adsorption capacity (215.56 mg/g), which is significantly higher than those of the rGO and CS microspheres. The determined mass-transfer factors revealed that the rich pores of the CS/rGO microspheres promote mass transfer during bilirubin adsorption (equilibrium is almost achieved within 30 min). The CS/rGO microspheres are promising candidates for bilirubin removal owing to a combination of high strength, blood compatibility, and high adsorption capacity.

Recycling of waste plastic combustion soot and diesel oil mixing to prepare a new collector to improve the performance of low-rank coal flotation

Clean utilization of soot pollution and low-rank coal has received extensive attention worldwide. In this study, soot from plastic combustion was mixed with diesel oil as a new collector (SPC-DO) to enhance the low-rank coal flotation. The flotation results showed that SPC-DO improved the flotation of low-rank coal more effectively than diesel oil, with a higher yield of fine coal and lower ash content. In addition, the results of the scanning electron microscope, contact angle, X-ray photoelectron spectrometer, and Fourier transform infrared spectroscopy measurements showed that the soot from plastic combustion has superhydrophobicity, and the oxygen-containing functional groups on its surface can interact with the hydroxyl groups on the low-rank coal surface to form hydrogen bonds, which in turn cover the hydrophilic sites. When applying SPC-DO as the collector, the soot from plastic combustion not only increased the hydrophobic sites on the LRC surface but also enhanced the adsorption effect of diesel oil on the low-rank coal surface.

Chitosan Incorporated with Titanium (IV) Oxide Membrane for Direct Methanol Fuel Cell Application

The direct methanol fuel cell (DMFC), a type of promoted polymer electrolyte membrane fuel cell (PEMFC), has received tremendous attention in the past two decades because of its potential as a promising technology for clean and efficient power generation in the twenty-first century. Over the past four decades, the dominancy of perfluorinated proton exchange membranes (PEM) such as Nafion is prolonging in the current PEM technology due to its chemical stability, high proton conductivity and high mechanical strength in the low operating temperatures. However, the Nafion membrane also has several weaknesses, such as high methanol permeability, high manufacturing cost, and dehydration with low proton conductivity at elevated temperatures > 100°C. This study fabricated a novel composite membrane by blending the pristine chitosan (CS) and titanium oxide (TiO2) at various loadings, 0.5, 1.0, 1.5 and 2.0 wt% to obtain high performance in DMFC. SEM and FTIR analysis showed that the grafting of (O-Ti-O) successfully incorporated into the CS polymer matrix. Water and methanol uptake of CS/TiO2 composite membrane decreased with increase of TiO2 loadings, but proton conductivity value increased. The CS/TiO2 membrane with 1.5wt.%TiO2 loading exhibited highest proton conductivity (0.41mScm-1) and lowest methanol permeability (17.18E-08cm2/s) characteristics among other membranes this due to the hydrophilic TiO2 raised the membrane hydrophilic character by increasing the number of hydrophilic sites, such as OH-, COO- and O-. The results obtained from the study can be used to conclude that chitosan membrane with TiO2 filler is a promising high performance PEM candidate for DMFC applications.

Construction of hydrophilic-hydrophobic domains in Bi2O3/nitrogen-doped carbon electrode to boost CO2-to-formate conversion

Bi has drawn attention in catalyzing the electrochemical CO2-to-formate conversion due to promising selectivity and low cost, but the process suffers from low activity. Herein, we introduce nitrogen-doped carbon (NC) support with hydrophobicity modification to enhance the activity of a binder-free Bi2O3 electrode. Formate partial current on the NC supported Bi2O3 electrode almost doubles compared to Bi2O3 on unmodified support. Furthermore, the hydrophobicity modification with polytetrafluoroethylene (PTFE) significantly extends the stability of NC supported Bi2O3 by diminishing flooding. It also maintains >90% formate selectivity at a broad potential range from −0.87 to −1.27 V (vs. RHE) and shows a formate partial current density of −100 mA cm−2 at −1.37 V (vs. RHE) in 0.5 M KHCO3. The improvement is attributed to the synergetic effects of the hydrophilic active sites and the hydrophobic PTFE modified NC support. The unique structure promotes the reactants transport and thus maximizes the active site utilization at the triple-phase interface. This facile microenvironment regulation can be extended to other applications involving gaseous-aqueous phases.

Synergistic effect of surfactants and nanoparticles on the wettability of coal: An experimental and simulation study

Injecting surfactants into coal seams is an effective means to improve coal wettability. Previous studies have shown that nanofluids provided excellent drag reduction and wetting. Therefore, this manuscript investigates the synergies of AOS (Sodium alpha-olefin sulfonate)-modified SiO2 nanofluid on the wettability of coal. Contact angle experiments were performed to examine the effects of deionized water on the wettability of coal treated with different solutions. The results demonstrated that 0.01 wt% nanofluid containing with 0.2 wt% AOS as the significantly increased the wettability. At the micro level, molecular dynamics simulations were employed to analyze the relative concentration distribution and MSD (mean square displacement) of water molecules in different systems. The simulation outcomes revealed that water molecules formed the thickest adsorption layer, and the diffusion range was more expansive, in the H2O/AOS-modified SiO2/Coal system. This was attributed to the amphiphilic structure of AOS-modified SiO2, which bent and folded on the coal surface, where hydrophobic sites were masked and hydrophilic sites were increased. Therefore, water molecules were attracted to the coal, the potential for collision was increased, and the wettability of the coal was enhanced. These findings provide a crucial foundation for modifying nanoparticles with surfactants and using them in coal seam water injection.

Simultaneous adsorption of fulvic acid and organic contaminants by KOH activated mesoporous biochar with large surface area

Returning carbon materials from biomass to soil is a potential technology to retard organic contaminants or dissolved organic matter (DOM) in soil by adsorption, as well as to store carbon in soil for carbon sequestration. However, DOM was widely reported to inhibit adsorption of organic contaminants on carbon materials by competition and by enhancing contaminants' solubility. In this study, a KOH activated carbon material (KAC), pyrolyzed from bamboo chips, with high surface area (3108 m2/g), micropores volumes (0.964 cm3/g), mesopores volumes (1.284 cm3/g), was observed that it can adsorb fulvic acid (FA) and organic contaminants (e.g., nitrobenzene, phenols, and anilines) simultaneously with weak competition and high adsorption capacity. With 50 mg TOC/L FA, for example, the average competition suppressing rate (ΔKf/Kf-m) of organic contaminants on KAC was lower than 5%, the adsorption for organic contaminants and FA were higher than 1100 mg/g and 90 mg TOC/g, respectively. The weak competition on KAC could be attributed to the low micropore blockage (<35%) and the weak adsorption sites competition on mesopores of KAC, as well as the minimal solubility enhancement of organic contaminants by FA because most FA is adsorbed on KAC but is not dissolved in the solution. In addition, adsorption of organic contaminants with high hydrogen-bonding donor ability (αm) and adsorption affinity was less suppressed by FA because of the heterogeneous nature of hydrophilic sites on KAC's surface. Therefore, KAC could be a potential carbon material to be produced to implement to soil for carbon storage and simultaneous retarding organic contaminants and DOM.

Atomically isolated Sb(CN)3 on sp2-c-COFs with balanced hydrophilic and oleophilic sites for photocatalytic C-H activation.

Activation of carbon-hydrogen (C-H) bonds is of utmost importance for the synthesis of vital molecules. Toward achieving efficient photocatalytic C-H activation, our investigation revealed that incorporating hydrophilic C≡N-Sb(CN)3 sites into hydrophobic sp2 carbon-conjugated covalent organic frameworks (sp2-c-COFs) had a dual effect: It simultaneously enhanced charge separation and improved generation of polar reactive oxygen species. Detailed spectroscopy measurements and simulations showed that C≡N-Sb(CN)3 primarily functioned as water capture sites, which were not directly involved in photocatalysis. However, the potent interaction between water molecules and the Sb(CN)3-modified framework notably enhanced charge dynamics in hydrophobic sp2-c-COFs. The reactive species ·O2- and ·OH (ad) subsequently combined with benzyl radical, leading to the formation of benzaldehyde, benzyl alcohol, and lastly benzyl benzoate. Notably, the Sb(CN)3-modified sp2-c-COFs exhibited a 54-fold improvement in reaction rate as compared to pristine sp2-c-COFs, which achieved a remarkable 68% conversion rate for toluene and an 80% selectivity for benzyl benzoate.

Discovery of water-soluble semicarbazide-containing sulfonamide derivatives possessing favorable anti-glaucoma effect in vivo and drug-like properties

In order to obtain topical and non-irritating anti-glaucoma drugs, novel semicarbazide-containing sulfonamide derivatives were designed and synthetized by sugar tail method in this study. The hydrophilic monosaccharides were expected to form interaction with the hydrophilic site of hCA II meanwhile the linker semicarbazides are used to further enhance water solubility, and more importantly, regulate the pH values of the target compounds in aqueous solution. First, all target compounds were synthesized and evaluated for their CA inhibitory activities. The results showed our target compounds demonstrated comparable activity to the positive control drug acetazolamide. The best derivative 11d exhibits an IC50 value of 14 nM for hCA II and 2086-fold selectivity over CA I. Subsequently, physicochemical properties study showed that the target compounds displayed very good water solubility (up to 3 %) and neutral pH value in solutions. Meanwhile, the artificial membrane permeability assay was performed to verify that the target compound could also pass through the membrane structure despite their strong water solubility. In the glaucomatous rabbit eye model, the applied topically representative compounds showed strongly lowered intraocular pressure (IOP), as 1 % or 2 % water solutions. Subsequent drug-like evaluation showed our target compounds possessed low hemolysis effect and low cytotoxicity toward human corneal epithelial cell line. Also, it was not found that these target compounds had significant inhibition of hERG and CYP. In addition, these novel analogs also displayed good liver microsomal metabolic stability and plasma stability. Finally, docking studies provided the rational binding modes of representative compounds in complex with hCA II. Taken together, these results suggested that compound 11d may be a promising hCA II inhibitor deserving further development.

Incorporating Au nanoparticles into metal-organic framework for low humidity sensors

Locating high active metal species into idea support surface to form spatially integrated nanostructure is essential for the adsorption and excitation process of water molecules. In this work, we proposed a spatial confinement strategy through incorporating Au nanoparticles into metal-organic framework (MOF) to realize low humidity sensing detection. We found the porous nature of MOF-303 morphology can provide confined room to induce Au species accumulation around the high active hydrophilic pocket (composed by three μ2-OH groups and two N(H)). In-situ Raman results further indicate the spatially-close Au species and hydrophilic pocket sites could synergistically promote chemical adsorption of water molecules and proton transfer processes. The as-fabricated Au@MOF-303 humidity sensor exhibits ultra-high response at low humidity condition (4345 Hz to 3.39 % RH), low humidity hysteresis (0.18 % RH), excellent repeatability and selectivity. Furthermore, the Au@MOF-303 sensor enables real-time monitoring of breathing signals attached to the surgical mask and the proximity of the fingertips.

Directional drying of a colloidal dispersion: quantitative description with water potential measurements using water clusters in a poly(dimethylsiloxane) microfluidic chip.

We have developed a poly(dimethylsiloxane) (PDMS) microfluidic chip to study the directional drying of a colloidal dispersion confined in a channel. Our measurements on a dispersion of silica nanoparticles once again revealed the phenomenology commonly observed for such systems: the formation of a porous solid with linear growth in the channel at short times, slowing down at longer times as the evaporation rate decreases. The growth of the solid is also accompanied by mechanical stresses that are released by the delamination of the solid from the channel walls and the formation of cracks. In addition to these observations, we report original measurements using hydrophilic filler in the PDMS formulation used (Sylgard-184). When the PDMS matrix is in contact with water, water molecules pool around these hydrophilic sites, resulting in the formation of microscopic water clusters whose size depends on the water potential ψ. In our work, we have used these water clusters to estimate the water potential profile in the channel as the porous solid grows. Using a transport model that also takes into account solid delamination in the channel, we then linked these water potential measurements to the hydraulic permeability of the porous solid. These measurements finally enabled us to show that the slowdown in the evaporation rate is due to the invasion of the porous solid by air/water nanomenisci at a critical capillary pressure ψcap.

Understanding the mechanisms of green tea EGCG against amyloid β oligomer neurotoxicity through computational studies.

Oligomeric species of amyloid β peptide (Aβ) are pivotal in Alzheimer's disease (AD) pathogenesis, making them valuable therapeutic targets. Currently, there is no cure or preventive therapy available for AD, with only a few therapeutics offering temporary alleviation of symptoms. Natural products (NPs) are now considered promising anti-amyloid agents. Green tea catechins have garnered considerable attention due to their ability to remodel the toxic amyloid β peptide oligomers (AβOs) into non-toxic assemblies. Nevertheless, the precise molecular mechanism underlying their effects on AβOs remains unclear. In this study, we employ a combination of binding site prediction, molecular docking, and dynamics simulations to gain mechanistic insights into the binding of the potent anti-amyloid epigallocatechin-3-gallate (EGCG) and the less effective catechin, epicatechin (EC), on the structure of pore-forming Aβ tetramers (PDB ID 6RHY). This recently elucidated structure represents AβO(1-42) with two faces of the hydrophobic β-sheet core and hydrophilic edges. Our simulations revealed three potential druggable binding sites within the AβO: two in hydrophilic edges and one in the β-sheet core. Although both catechins bind via hydrogen bond (H-bond) and aromatic interactions to the three potential binding sites, EGCG interacted with key residues more efficiently than EC. We propose that EGCG may remodel AβOs preventing pore formation by binding to the hydrophilic edge binding sites. Additionally, EGCG interacts with key residues in the oligomer's β-sheet core binding site, crucial for fibrillar aggregation. A better understanding of how anti-amyloid compounds remodelling AβOs could be valuable for the development of new therapeutic strategies targeting Aβ in AD. Further experimental validation using point mutations involving key residues could be useful to define whether the establishment of these interactions is crucial for the EGCG remodelling effect.

Хімічні властивості та характеристики поверхневої активності гумінової кислоти з бурого вугілля

The article is devoted to the study of some specific physicochemical properties of humic acids, which are attracting increasing attention due to their potential applications. The unique structural composition, which includes both hydrophilic and hydrophobic sites, makes these materials a versatile agent in various technological processes. It has been shown that humic acid solutions have the properties of surfactants and can serve as a natural alternative to surfactants. The paper presents the results of studies of a sample of humic acid obtained from lignite. Infrared spectroscopy has revealed signs of the aromatic structure of humic acid, the presence of phenolic and other functional groups, such as hydroxyl and nitrile. The presence of carboxylic acids, esters, and complex esters was established. The complex and heterogeneous nature of humic acids has been confirmed, which makes them promising for use as surfactants. No clear evidence of the presence of -NH₂ groups was found in the IR spectrum. This suggests that lignite humic acids generally correspond to the structural formula reported in the literature. The potentiometric titration of the lignite humic acid sample made it possible to determine the dissociation constants of functional groups. The obtained values are close to the calculated dissociation constants of carboxyl groups for the model molecule of lignite humic acid. The analysis of the calculated properties of humic acid based on various structural models showed that lignite is a promising raw material for the production of humic acids with certain surface-active properties. Compared to other structures, humic acid from lignite is more hydrophobic and less soluble in water, which indicates the prospects of its use as a surfactant with better interaction with the oil phase. Keywords: humic acids, lignite, surfactant, infrared spectroscopy, composition, functional groupsб structural model. Corresponding author: Bannikov L.P., e-mail: ukhinbannikov@gmail.com

Uncharacteristic Adsorption Breakthrough Behavior of a Core–Shell Copper Hydroxysulfate Metal–Organic Framework Against Gaseous Formaldehyde

AbstractCore–Shell structured microspheres with a packed nano‐platelet copper hydroxysulfate (CHS) core and an octahedral crystalized metal–organic framework‐199 (CHS@M199) shell are synthesized and tested as adsorbent for gaseous formaldehyde (FA). CHS@M199 outperforms reference materials (e.g., activated carbon (AC), CHS, and M199) with adsorption capacity (Q) of 8.13 mg g−1 and partition coefficient (PC) of 0.263 mol kg−1 Pa−1 against 10 Pa FA at 10% breakthrough (BT) level with the aid of large surface area and copper sites for coordinating with carbonyl group. Contrary to general expectations, CHS@M199 exhibits a unique adsorption behavior in that BT volume increases systematically with the rise in FA inlet partial pressure (e.g., 5–10 Pa). The 10% BT capacity of CHS@M199 decreases noticeably (8.13 to 2.08 mg g−1) with increasing relative humidity (0.016 to 10%), reflecting water‐FA competition for hydrophilic adsorption sites. Although FA adsorption on CHS@M199 diminishes with elevated RH levels, such reduction intensifies when simulating ambient conditions (through stepwise addition of competing components: O2, CO2, and H2O). The FA adsorption on CHS@M199 is well described by both pseudo‐first‐order (PFO) and pseudo‐second‐order (PSO) kinetics. Polymerization may play a pivotal role in the adsorption of FA on CHS@M199, as Qi‐LeVan isotherm best fits the experimental data.

Ionically crosslinked cellulose nanocrystals by metal nitrates for the preparation of stable emulsions with tunable interface properties

Biologically extracted cellulose nanocrystals (CNCs) are rod-like and amphiphilic materials with surface-exposed (hydrophilic sites) and hidden (hydrophobic sites) hydroxyl groups. These physicochemical characteristics make CNCs suitable for use as emulsifying agents to stabilize emulsions. Stable oil-in-water emulsions, using sulfated (i.e., –SO3-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{SO}}}_{3}^{-}$$\\end{document}) CNCs that were ionically crosslinked with alkaline-earth (i.e., Mg2+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{Mg}}}^{2+}$$\\end{document}) or transition-d-block (i.e., Zn2+\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${{\ ext{Zn}}}^{2+}$$\\end{document}) metal cations, were developed without the use of any synthetic surfactants or prior functionalization of pure CNCs with hydrophobic molecules. Various emulsion surface properties such as interfacial tension, surface charge, surface chemistry, as well as rheology were characterized. Ionically crosslinked CNCs (iCNCs) adsorbed at the interface of an oil and water and fortified the emulsion droplets (5–30 µm) against coalescence by lowering the interfacial tension from 65 mN/m (i.e., pure CNC mixture with oil) to 25 mN/m (i.e., iCNC mixture with oil) and reducing zeta potential with surface charge values (–30 mV to –10 mV), ideal to maintain droplet layer assembly at the water–oil interface. This study provided an alternative approach to achieve particle-stabilized and surfactant-free emulsions by using divalent metal nitrates to develop “clean” emulsion-based technologies for applications in many industries from agriculture to food to pharmaceuticals.

Sterols in Inflammatory Diseases: Implications and Clinical Utility.

The characteristic steroid skeleton, with its 4-ringed 17-carbon structure, is one of the most recognizable organic compounds in biochemistry. In the presence of a hydroxyl ion bound to the third carbon, this structure is defined as a "sterol" (chemical formula: C17H28O). The hydroxyl group provides a hydrophilic site for the otherwise hydrophobic molecule, yielding an amphipathic lipid, which is a vital property for cellular function. It is crucial to remark that the term "steroid" describes a larger group of compounds that often retain the hydroxyl group but are primarily characterized by methyl groups, double bonds in the rings, and an aliphatic side-chain extending from the 17th carbon. In addition to serving various structural roles in the cellular membrane, sterols and steroids contribute to cellular and systemic functions as messengers, hormones, and regulators of several critical metabolic pathways.Sterol nomenclature is often confusing, partly due to structural complexity and partly due to the sheer number of different compounds that fall under the definition. Fortunately, the foremost sterols of interest in biochemistry are much fewer, and therefore, these lipids have been defined and studied vigorously. With the renaissance of lipid research during the 1990s and 2000s, many different metabolites of sterols, and more specifically phytosterols, were found to be associated with various diseases and conditions, including cardiovascular disease, hypercholesterolemia, cancer, obesity, inflammation, diabetes, and inborn errors of metabolism; thus, it is evident that the ever-evolving research in this field has been, and will continue to be, exceedingly productive.With respect to inflammation and inflammatory diseases, plant-based sterols (i.e., phytosterols) have gained considerable fame due to their anti-inflammatory and cholesterol-lowering effects demonstrated by experimental and clinical research. Besides, the exceptional pharmacological benefits of these sterols, which operate as antioxidant, antidiabetic, and anti-atherosclerotic agents, have been the subject of various investigations. While the underlying mechanisms necessitate further research, the possible function of phytosterols in improving health outcomes is an important topic to explore.In this regard, the current review aims to offer comprehensive information on the therapeutic potential of plant-based sterols in the context of human health, with a focus on preclinical effects, bioavailability, and clinical use.

Dual positive charging sites for MIL-101 enhanced adsorption of toluene under high humidity conditions: Experimental and theoretical studies

Highly efficient capture of volatile organic compounds (VOCs) under humid conditions is a significant yet formidable task for metal–organic frameworks (MOFs). Based on the material simulation technique, we proposed implanting a significantly positive-density ligand (DABA) to modify MIL-101 and constructing dual positive-charging centers to improve MIL-101 competitive adsorption of benzene VOCs over H2O vapors both thermodynamically and kinetically. The introduction of DABA containing two –NH2 groups with electrostatically positive charges into MIL-101 resulted in the formation of an open tetrahedral cage with a dual positive charging center. This facilitated strong N-H…π interactions with toluene molecules, leading them to accumulate firmly in MOF pores, and thus dramatically enhanced its adsorption capacity from 17 to 31 toluene molecules per unit cell compared to pristine MIL-101. Moreover, the open tetrahedral cage in D-MIL-101 preferentially captured toluene and occupied the strongest adsorption sites first, thus effectively preventing H2O entry into MOF pores to contact with hydrophilic metal sites. This realized high water resistance and toluene adsorption uptake under high humidity conditions. Results showed that D-MIL-101 had a high specific surface area of 2558 m2/g and a new microporous structure of 9.5 Å size. It presented higher toluene uptake of 4.69 mmol/g at lower vapor pressure of P/P0 = 0.013 and 298 K temperature, as well as 3.3 folds higher working capacity of toluene compared to pristine MIL-101 under 80 % RH. This study presents a novel approach for constructing hydrophobic MOFs using new positive charging ligands and delves deeper into the competitive adsorption of VOCs/H2O in MOF composites for large-scale applications.

Synchronously improved permeability, selectivity and fouling resistance of Fe-N-C functionalized ceramic catalytic membrane for effective water treatment: The critical role of Fe

Constructing catalytic membrane simultaneously displaying high permeability, selectivity and antifouling performance in water treatment remains challenging. Herein, the surface and pore channels of the ceramic membrane were co-functionalized with nitrogen doped carbon supported Fe catalyst (CN-F), and the Fe content was varied to investigate its effect on performance of CN-F coupled with peroxymonosulfate (PMS) activation (CN-F/PMS) for water treatment. Results confirmed the introduced Fe (in Fe-N coordination form) greatly enhanced the permeability, selectivity and fouling resistance of CN-F. Optimal CN-F3/PMS achieved 96.5% removal and 52.1% mineralization of sulfamethoxazole in short retention duration (2.7 min), whose performance was 5.4 and 6.7 times higher than that of nitrogen doped carbon functionalized ceramic catalytic membrane (CN/PMS) and CN-F3 filtration alone, respectively. CN-F3/PMS also efficiently inhibited fouling on both surface and pores with 2.8 and 2.4 times lower flux loss than that of CN/PMS and CN-F3 filtration alone, respectively. Moreover, CN-F3/PMS displayed superior performance in long-term treatment of real coking wastewater. The outstanding performance of CN-F was mainly attributed to the dual role of supported Fe, which served as hydrophilic site for enhanced water permeation and major active site for PMS adsorption and reduction into reactive species (mainly high-valent Fe(IV)=O species) towards pollutant elimination.