Chitosan/Ag-hydroxyapatite nanocomposite beads as a potential adsorbent for the efficient removal of toxic aquatic pollutants

© 2018 Elsevier B.V. In the present study, the potential of synthesized chitosan/Ag-substituted hydroxyapatite nanocomposite beads to remove basic dye, heavy metal and microbes from aqueous solutions was investigated. Beads were prepared in different ratios via embedding of Ag-hydroxyapatite (Ag-HA) into chitosan (CS) solution. The beads were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) in order to get an insight of the functional groups and morphology. Batch adsorption studies were conducted with copper ions (Cu (II)) and rhodamine B (RhB) dye by changing several parameters such as Ag-HA to Cs ratio, contact time, solution pH and initial concentration of pollutants. The antibacterial efficiency of beads was tested under dynamic contact conditions against commonly found bacteria in water, Escherichia coli. The adsorption isotherm data were best fitted with Langmuir model. The maximum Langmuir adsorption capabilities for Cu (II) ions and rhodamine B were found to be 40.11 mg/g and 127.61 mg/g, respectively. The adsorption process could be best described by pseudo-second-order kinetic model for both rhodamine B and Cu(II). The percentage removal efficiency of Cu (II) and rhodamine B from tap water and untreated river water ranged from 86.7 to 94.4% along with 99.99% of decontamination of microbial load

Anti-asthmatic effect of Ping-Chuan Formula in asthmatic mice, and its molecular mechanism of action

Purpose: To investigate the anti-asthmatic effect of Ping-Chuan Formula (PCF) in a mouse model, and the associated molecular mechanisms.Methods: Asthma mice were induced using ovalbumin (OVA), and PCF (600 mg/kg) was administered to the mice for 4 weeks. Sections of lung tissues were examined microscopically. The expressions of interleukins (ILs), interferon (IFN)-γ, transforming growth factor (TGF)-β were assayed, while lung tissue expressions of Toll like receptor (TLR)-4, GATA binding protein (GATA)-3, Ox40 ligand (OX40L), indoleamine 2,3-dioxygenase (IDO), and forkhead box P3 (Foxp3) determined. The T box expressed in T cells (T-bet) was evaluated using western blotting. The expressions of MHC II and co-stimulators (CD 11c, CD 80 and CD 86) of dendritic cells (DCs) were determined by flow cytometry.Results: PCF decreased inflammation in lung, and also down-regulated IL-4, -6, -17 and TGF-β (p < 0.01), whereas IL-10 and IFN-γ expressions were up-regulated (p < 0.01). Moreover, PCF decreased the expressions of TLR-4, GATA-3 and OX40L in lung tissue, and promoted Foxp3, IDO and T-bet. Besides, PCF decreased the levels of MHC II and co-stimulators (CD 80 and CD 86) on the surface of DCs.Conclusion: PCF exerts anti-asthmatic effect in mice via inhibition of inflammation, and modulation of MHC II and co-stimulators on the surface of DCs. These findings suggest that PCF is a promising candidate drug for treating asthma in humans

Chitosan/Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e-HA nanocomposite beads for efficient removal of estradiol and chrysoidin from aqueous solution

© 2019 Elsevier B.V. Alumina, as a support material, was loaded together with chitosan and hydroxyapatite to form chitosan/Al2O3-HA composite beads and was used for estradiol and chrysoidin removal from aqueous solution in the present work. The physicochemical properties of the beads were studied with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectrometry (FTIR), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area analysis. FTIR spectra confirmed that the chitosan was loaded successfully on Al2O3-HA, and functional groups were immobilized onto the surface of the beads after the synthesis. The adsorption condition including pH, the amount of adsorbent, initial concentration and time were evaluated during the batch experiments. Isotherm data best matched the Langmuir model and the pseudo-second-order model best described the adsorption kinetics. The maximum adsorption capacity was found to be 39.78 mg/g and 23.26 mg/g for estradiol and chrysoidine, respectively. The adsorbed estradiol and chrysoidin were completely eluted from the composite beads with the eluent of 0.1 M H2SO4/MeOH and the regenerated material was used in several cycles without deterioration in its initial performances. This study suggests that the developed composite beads have high potential for the efficient removal estradiol and chrysoidin from aqueous solution

Taste peptides derived from Stropharia rugosoannulata fermentation mycelium and molecular docking to the taste receptor T1R1/T1R3

This study identified the peptides in the fermentation mycelia of Stropharia rugosoannulata. The molecular weight of the peptides was below 3,000 Da. Heptapeptides to decapeptides were the main peptides in the fermentation mycelia of S. rugosoannulata. More than 50% of the peptides had salty and umami taste characteristics, and the long-chain peptides (decapeptides to 24 peptides) also played an essential role in the pleasant taste characteristics of mycelium. In the salty and umami peptide of S. rugosoannulata, the distribution of non-polar hydrophobic amino acids and polar-uncharged amino acids accounted for a relatively high proportion, and the proportion of polar-uncharged amino acids further increased, with the extension of the peptide chain. P, F, I, l, V, G, S, T, and D were the amino acids with a high proportion in the peptides. The taste peptides can bind to more than 60% of the active amino acid residues in the cavity-binding domain of the T1R1/T1R3 receptors. Hydrogen bond interaction was the primary mode of interaction between the peptides and the receptor. The first and second amino acid residues (such as S, V, E, K, G, and A) at the C-terminal and N-terminal of the peptides were easy to bind to T1R1/T1R3 receptors. Asp108, Asn150, Asp147, Glu301, Asp219, Asp243, Glu70, Asp218 in T1R1, and Glu45, Glu148, Glu301, Glu48, and Ala46 in TIR3 were the key active amino acid sites of taste peptides binding to T1R1/T1R3 receptors

Experimental and numerical study on a novel dual-resonance wave energy converter with a built-in power take-off system

A new concept of point-absorber wave energy converter (WEC) with a waterproof outer-floater and a built-in power take-off (BI-PTO) mechanism, named Dual-Resonance WEC (DR-WEC), is put forward and investigated by experiments and numerical simulations. The BI-PTO mechanism includes spring, sliding-mass and damping systems, where the spring system is the most complicated and should be designed specially. A 1:10 scale model is designed. The mechanical performance of the BI-PTO system is investigated by a bench test. The results have shown that the design is feasible, and the added inertia effect of the BI-PTO has a negative influence on the power output. The average mechanical efficiency of the BI-PTO is 65.8% with maximum up to 80.0%. The motion and power responses of the DR-WEC are studied by a wave tank experiment and a linear numerical model with corrected mechanical added mass and viscosity. The viscous added mass and damping correction coefficients are obtained by a free decay test. The good agreement between the experimental measurements and numerical simulations has indicated that the present numerical model with corrections is of enough accuracy and the effects of mooring system and other degree of freedoms on the heave motion and power responses can be ignored. (C) 2018 Elsevier Ltd. All rights reserved

Separation and Identification of Umami Peptides from the Enzymatic Hydrolysate of Stropharia rugosoannulata and Their Synergistic Umami-Enhancing Effect

Umami peptides from the enzymatic hydrolysate of Stropharia rugosoannulata were separated by ultrafiltration (UF) and gel filtration chromatography (GFC) combined with sensory evaluation and electronic tongue analysis. Fraction F3, with the strongest umami intensity, were identified by reversed-phase high performance liquid chromatography-tandem mass spectrometry (RP-HPLC-MS/MS). The identified peptides were synthesized and evaluated for their taste characteristics. The results showed that eight umami peptides were identified in fraction F3, namely ELWR, RLVDR, KPDNR, AHLRF, LDWDR, LAEWR, DDWWR and EGHKGW, and all of them possessed umami characteristics and umami-enhancing effects with thresholds ranging from 0.30 to 1.33 mmol/L and from 0.53 to 2.43 mmol/L, respectively. All peptides except LDWDR showed different degrees of umami improvement in monosodium glutamate (MSG) solution, ranging from 0.18% to 61.12%. ELWR, RLVDR, KPDNR, AHLRF and EGHKGW showed good umami-enhancing effects at low concentrations. The peak concentration of RLVDR and KPDNR for synergistic umami-enhancing effect was 5 mg/mL. LDWDR, LAEWR, DDWWR and EGHKGW reached the umami peak at 4 mg/mL. The amino acid composition and the spatial structure of umami peptides could affect their taste properties. The results of this study provide a theoretical basis for the development and utilization of umami peptides from S. rugosoannulata