Structurally Adjustable Eugenyl-Based Quaternary Phosphonium Cation Degradable Antibacterial Nanomaterials via RAFT.

This study contributed to improving our understanding of how disinfectants, applied to control biofouling of reverse osmosis (RO) membranes, result in membrane performance degradation. We investigated changes in physicochemical properties and permeation performance of a RO membrane with fully aromatic polyamide (PA) active layer. Membrane samples were exposed to varying concentrations of monochloramine, bromide, and iodide in both synthetic and natural seawater. Elemental analysis of the membrane active layer by Rutherford backscattering spectrometry (RBS) revealed the incorporation of bromine and iodine into the polyamide. The kinetics of polyamide bromination were first order with respect to the concentration of the secondary oxidizing agent Br2 for the conditions investigated. Halogenated membranes were characterized after treatment with a reducing agent and heavy ion probes to reveal the occurrence of irreversible ring halogenation and an increase in carboxylic groups, the latter produced as a result of amide bond cleavage. Finally, permeation experiments revealed increases in both water permeability and salt passage as a result of oxidative damage.

Change in AC conduction mechanism together with conversion of submicron to nanoparticles in polyaniline and its poly(vinyl pyrrolidone) blends on heating-induced water elimination

Water plays an important role in the physicochemical and mechanical properties of Nafion (poly tetrafluorosulfonic acid) and cellulosic materials. Due to the strong influence of hydration on the properties of these materials, the mechanism and molecular-level understanding of hydration processes are the subject of ongoing interest in food, environmental and energy science. Nafion is a sulfonated tetrafluoroethylene polymer that represents a prototypical polymer electrolyte membrane (PEM) material. PEMs are often composed of a hydrophobic backbone with a strongly hydrophilic region (e.g., sulfonic acid moieties), which are directly attached to the backbone or through a pendant group. The application of Nafion in fuel cells as PEMs necessitate that the hydration properties of the membrane play an important role for maintaining high proton conductivity and mechanical properties. Cellulose on the other hand is one of the most abundant and low-cost renewable biopolymers with unique hydration properties. The hydration of cellulose impacts its biodegradability, recyclability and tunable physicochemical properties for various applications employing composite materials, pharmaceutical delivery systems, paper production, fibers and biofuel production. One of the challenges in the development and valorization of cellulose-based materials relates to its insolubility in aqueous media and conventional solvents. Therefore, evaluation of the hydration properties of Nafion and cellulose materials is required in order to characterize their physicochemical properties. Studies of the hydration properties of these materials include dielectric, spectroscopic techniques (NMR and IR), dynamic vapor sorption, differential scanning calorimetry (DSC), viscometry and computer simulations to determine the structural, kinetic and thermodynamic properties associated with such hydration processes. DSC is a sensitive and versatile thermal analysis method for the study of hydration phenomena, thermal behavior and thermodynamic state of water in hydrated macromolecular systems. The aim of this mini-review is to provide an overview of recent DSC studies relevant to aspects of hydration phenomena for Nafion and cellulose. This overview will contribute to an improved understanding of the hydration properties of Nafion and cellulose materials for applications that involve hydration phenomena.

Fermentation is a crucial technology to improve the nutritional and functional properties of food materials. In this study, edible grass was processed by spontaneous fermentation. Changes in physicochemical properties, metabolites, and antioxidant activity of edible grass were investigated by colorimetric method and chromatography mass spectrometry-based non-targeted metabolomics approach during fermentation. The highest total polyphenol and total flavonoid contents, and free radical scavenging abilities were observed on the 17th day of fermentation. The maximum activity of superoxide dismutase was maintained stable in the fermentation time range of 7–70 days. In total, 16 differential metabolites were identified with fermentation duration up to 124 days. Fermented edible grass exerted protection from H2O2-induced cytotoxicity on HepG2 cells, regulating by the reduction in reactive oxygen species level and the increase in antioxidant enzyme activities. Overall, this study confirms that fermented edible grass obtained by spontaneous fermentation presented favorable nutritional and functional quality, and is expected to be a kind of food with antioxidant function.

In this work, physico-chemical, lipolytic, free amino acids, and volatile flavor compounds changes that occur during the processing of Laowo ham were observed. Moisture content, water activity, trimethylamine- nitrogen (TMA-N), and luminosity value (L*) decreased significantly (p < .05) from 74.74%, 0.90, 22.33 mg/kg, and 51.92 to 55.66%, 0.74, 10.40 mg/kg a, nd 39.88, respectively. Chloride content, pH, thiobarbituric acid (TBARS) value, peroxide value (POV), nitrite residue, and yellowness value (b*) increased significantly (p < .05) from 0.17%, 5.69, 0.06 mg/100 g, 0.03 g/100 g, 0.52 mg/kg, and 2.29 to 9.26%, 6.10, 0.33 mg/100 g,0.10 g/100 g, 1.00 mg/kg, and 5.13, respectively. Eleven kinds of free fatty acids were identified. The content of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) increased during processing. The total amount of free amino acids increased significantly (p < .05) from 4.94 mg/g to 87.89 mg/g. About 115 volatile compounds were identified.In the final products, alcohols and hydrocarbons became the dominant volatile compounds. Practical applications Laowo ham is one of the most popular dry-cured hams in southwest China’s Yunnan province. At present, there are few studies on the changes in physicochemical properties and volatile flavor compounds in Laowo ham during processing, and the mechanism of flavor formation is still unknown. Therefore, the aim of the present study was to investigate the changes in physicochemical properties and flavor in Laowo ham during the production. These results contribute to a more accurate understanding of the quality changes in Laowo ham during processing and help to improve the product quality and optimize the duration of processing in the future.

Changes in various physicochemical properties (P (n)) of noncyclic alkanes can be roughly classified as linear and nonlinear changes. In our previous study, the NPOH equation was proposed to express nonlinear changes in the properties of organic homologues. Until now, there has been no general equation to express nonlinear changes in the properties of noncyclic alkanes involving linear and branched alkane isomers. This work, on the basis of NPOH equation, proposes a general equation to express nonlinear changes in the physicochemical properties of noncyclic alkanes, including a total of 12 properties, boiling point, critical temperature, critical pressure, acentric factor, heat capacity, liquid viscosity, and flash point, named as the "NPNA equation", as follows: ln(P (n)) = a + b(n - 1) + c(S CNE) + d (ΔAOEI) + f(ΔAIMPI), where a, b, c, and f are coefficients, and P (n) represents the property of the alkane with n carbon atom number. n, S CNE, ΔAOEI, and ΔAIMPI are number of carbon atoms, sum of carbon number effects, average odd-even index difference, and average inner molecular polarizability index difference, respectively. The obtained results show that various nonlinear changes in the properties of noncyclic alkanes can be expressed by the NPNA equation. Nonlinear and linear change properties of noncyclic alkanes can be correlated with four parameters, n, S CNE, ΔAOEI, and ΔAIMPI. The NPNA equation has the advantages of uniform expression, usage of fewer parameters, and high estimation accuracy. Furthermore, using the above four parameters, a quantitative correlation equation can be established between any two properties of noncyclic alkanes. Employing the obtained equations as model equations, the property data of noncyclic alkanes, involving 142 critical temperatures, 142 critical pressures, 115 acentric factors, 116 flash points, 174 heat capacities, 142 critical volumes, and 155 gas enthalpies of formation, a total of 986 values, were predicted, which have not be experimentally measured. NPNA equation not only can provide a simple and convenient estimation or prediction method for the properties of noncyclic alkanes but also can provide new perspectives for studying quantitative structure-property relationships of branched organic compounds.

It is important to determine the stability constant (Km:n defined by Eq. 1) of cyclodextrin (CyD) complexes with great accuracy, because this parameter is useful for the estimation of changes in physicochemical and biopharmaceutical properties of the guest molecule included in the CyD cavity: $$ Kc = \frac{{[complex]}} {{[CyD]_m \cdot[guest]_n }} $$ (1) where [complex], [CyD] and [guest] are molar concentrations of the complex and free CyD and guest molecules, respectively, and m and n are binding mole numbers of CyD and guest in the complex, respectively. There are many methods for determination of the stability constant of CyD complexes, using various techniques such as solubility, potentiometry, kinetic and spectroscopic methods [1]. All these methods are based principally on titrating certain physical or chemical properties of the guest with CyD, and analyzing the CyD concentration dependencies by means of Benesi-Hildebrand equation, Lineweaver-Burk equation or their modified forms. Therefore, the change in physicochemical property of the guest molecule has to be measured as a function of CyD concentration. In this study, we developed a simple and reliable method for the determination of stability constant of CyD complexes by analyzing permeation rate of the guest in the presence of CyD through a cellophane membrane.

Silk fibroin nanoprecipitation by organic desolvation in semi-batch and microfluidic formats provides promising bottom-up routes for manufacturing narrow polydispersity, spherical silk nanoparticles. The translation of silk nanoparticle production to pilot, clinical, and industrial scales can be aided through insight into the property drifts incited by nanoprecipitation scale-up and the identification of critical process parameters to maintain throughout scaling. Here, we report the reproducibility of silk nanoprecipitation on volumetric scale-up in low-shear, semi-batch systems and estimate the reproducibility of chip parallelization for volumetric scale-up in a high shear, staggered herringbone micromixer. We showed that silk precursor feeds processed in an unstirred semi-batch system (mixing time > 120 s) displayed significant changes in the nanoparticle physicochemical and crystalline properties following a 12-fold increase in volumetric scale between 1.8 and 21.9 mL while the physicochemical properties stayed constant following a further 6-fold increase in scale to 138 mL. The nanoparticle physicochemical properties showed greater reproducibility after a 6-fold volumetric scale-up when using lower mixing times of greater similarity (8.4 s and 29.4 s) with active stirring at 400 rpm, indicating that the bulk mixing time and average shear rate should be maintained during volumetric scale-up. Conversely, microfluidic manufacture showed high between-batch repeatability and between-chip reproducibility across four participants and microfluidic chips, thereby strengthening chip parallelization as a production strategy for silk nanoparticles at pilot, clinical, and industrial scales.

Effect of zinc-biochar composite aging on its physicochemical and ecotoxicological properties

A biological functional hybrid scaffold based on decellularized extracellular matrix/gelatin/chitosan with high biocompatibility and antibacterial activity for skin tissue engineering

\n Rosmarinus officinalis L. (rosemary) comprise polyphenolic compounds, principally phenolic acids and diterpenes which possess excellent antioxidant and antimicrobial properties. However, deriving maximum benefits from this material is limited by several drawbacks; including low solubility, bioavailability, and stability among others issues. Encapsulation of plant extracts in different materials is a credible way to improve their physicochemical properties and circumvent these challenges. Encapsulation in proliposomes is particularly interesting, having further advantages of incorporating multiple components of varying polarity with relatively higher stability compared to liquid formulations. Hence, this study aims at preparing proliposomes of rosemary polyphenols with a view to encapsulating bioactive compounds of varying polarity, thus enhancing the scope of their applicability. Polyphenolrich extract from dried and milled rosemary leaves was obtained by dynamic maceration, filtered, concentrated and freeze-dried. Following preliminary studies, liposomal compositions (using hydrogenated soyphosphatidylcholine and cholesterol) encapsulating rosemary polyphenols (caffeic, rosmarinic and carnosic acids, and carnosol as markers) were prepared by a modified solvent replacement method. The compositions were dried in a lab-scale spray dryer at flow rate of 4.0 g/min and temperature of 100 °C, using lactose as the drying aid to obtain proliposomes. The proliposome formulations were optimized by experimental design, using the Central Composite Design, and validated by correlating experimental values of critical quality attributes with the predicted. Spray dried proliposomes (SDP) were characterized by moisture content, water activity, retention and total content of marker polyphenols, density and flow properties, crystallinity, morphology, infrared spectroscopy, and redispersibility - including vesicle size and zeta potential on hydration. The spray drying performance was characterized by determination of the powder recovery. The optimal SDP and lyophilized extract (LE) were evaluated for antioxidant (DPPH&amp;middot; method) and antimicrobial (antibacterial and antifungal) properties. Stability study was carried out to evaluate the effect of relative humidity and temperature on SDP and LE. Storage samples were similarly analysed for changes in physicochemical properties. Results of experimental runs showed that SDP exhibited polyphenol retention, ranging from 62.0 - 100.0% w/w; showing dependence on composition variables and polyphenol lipophilicity. SDP recovery ranged from 20.1 to 45.8 %, with moisture content and water activity of 1.7±0.14 - 2.5±0.23 %w/w and 0.30±0.004 - 0.47±0.003, respectively. Composition variables influenced proliposome properties with optimal combinations being 4.26% w/w, 4.48% w/w, and 7.55% w/w for lipid concentration, LE concentration, and drying aid:(lipid+extract) ratio, respectively on wet basis. Results showed concurrence between predicted and experimental values except carnosol retention, being 22 % lower. Optimal SDP showed high antioxidant activity with IC50 of 9.2±0.2 µg/mL, superior to results obtained for LE (10.8 µg/mL) and Butylated Hydroxytoluene, a synthetic antioxidant (12.5 µg/mL). MIC and MFC against Candida albicans (ATCC1023) were 312.5 &amp;mu;g/mL and 1,250 &amp;mu;g/mL, respectively; lower than values obtained for bacteria strains used. The product stability was more affected by storage humidity (compared to temperature), indicating need for waterproof packaging. SDP is shown as a veritable tool to encapsulate hydrophilic and lipophilic rosemary polyphenols generating a product with improved physicochemical and biological properties.\n

Layered double hydroxide-galactose as an excellent nanocarrier for targeted delivery of curcumin to hepatocellular carcinoma cells

Hydrogen-Bonding-Induced H-Aggregation of Charge-Transfer Complexes for Ultra-Efficient Second Near-Infrared Region Photothermal Conversion

Common enzymes used in starch modification include α-amylase, β-amylase, glucoamylase, isoamylase, and pullulanase. Botanical sources of starch are widely used in grains, beans, and tubers. The modification of starch is used to change the lack of native starch properties and make the desired physicochemical properties. Besides, starch modification can produce resistant starch (RS), which is essential for health concerns. The review aims to provide information on the enzymatic modification of starch and its effect on changes in the physicochemical properties of various botanical starch sources. Changes in physicochemical properties in modified starch include granular morphology, crystalline type, paste properties, swelling power, and solubility.

The present study investigated the dynamics changes in physicochemical properties and non-volatile metabolites during Bulang pickled tea fermentation. A combination of artificial sensory evaluation, chemical-physical analysis, ultra performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS), and multivariate statistical analysis were employed to examine the differences among four fermentation stages of Bulang pickled tea. The bitterness, astringency, sweetness after taste, sourness and fermentation taste tended to increase with fermentation. The highest lactic acid bacteria, aerobic bacteria, total titratable acidity, total soluble sugar, total polyphenols, and total flavonoids were recorded at the second month of fermentation, while fungi, total free amino acids, total antioxidant capacity and hydroxyl free radical scavenging capacity increased with fermentation. Mantel test demonstrated significant associations between lactic acid bacteria /fungal communities and taste characteristics. UPLC-QTOF-MS analysis led to the identification of 35 differential non-volatile metabolites, predominantly comprising heterocyclic compounds, organic acids with their derivatives, and flavonoids. Nine non-volatile metabolites are related to antioxidant activity, and morin, malvidin and 7-methylxanthine exhibit relatively strong antioxidant activity. This study provides comprehensive insights into the non-volatile metabolites and antioxidant function of Bulang pickled tea.