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Potassium ion batteries (PIBs) have drawn considerable interest because of the resource-abundance and tempting electrochemical potential of potassium. However, developing high-performance anodes for PIBs with superior reversible capacity and ultralong stability is still a huge challenge to meet the requirements of sustainable and cost-effective large area energy storage systems. To address the above-mentioned issues, we report for the first time a simple in situ growth strategy to synthesize pillared graphene nanosheets with expanded interlayer spacing as free-standing flexible electrodes for PIBs. The expanded interlayer spacing is confirmed to accelerate ion transmission by kinetics. The graphene nanosheet/NiO-500 (GS/NiO-500) composite assembled binder-free flexible anode delivers ultrahigh reversible capability (416.1 mA h g−1 at 0.1 A g−1), excellent rate performance (305.6 mA h g−1 at 1 A g−1) and superior capacity retention (82.6% over 3000 cycles at 1 A g−1). This study provides ideas for the development of fast charging potassium electrode materials and promotes the commercialization of large-scale energy storage systems.

Porous structures and heterogeneous compositions are highly desirable to achieve improved sensing performance. Herein, a SnO2/Co3O4 composite with catalytic sites and abundant oxygen vacancies has been successfully synthesized by pyrolyzation of Sn- and Co-based bimetallic organic frameworks (bMOFs). The composites demonstrate desirable p–n heterojunctions, which was confirmed by diffuse reflection ultraviolet–visible spectroscopy (DRS) and Mott–Schottky (M–S) plots. Gas-sensing experiments reveal that the response of SnO2/Co3O4 composites (Sn/Co = 2 : 1, atomic ratio) reaches 498 to 50 ppm acetone, which is about 5 times higher than that of the pure SnO2. Moreover, the composites exhibit better selectivity and stability at an operating temperature of 275 °C. This excellent performance is attributed to the synergistic effect of catalysis of Co3+ and the formation of p–n heterojunctions at the interface between Co3O4 and SnO2.

A series of Eu3+ doped Y2O3 nanophosphors have been synthesized via an ultra-fast ultrasonic-microwave method followed by thermal annealing. The emission of Y2O3:Eu3+ nanophosphors depends tremendously on the concentration of Eu3+ ions and maximum emission intensity is achieved at 612 nm (red luminescence) with a doping concentration of 3 mol%. Moreover, the Y2O3:Eu3+ nanophosphors in this work have much higher photoluminescence lifetime (1.570 ms) and quantum efficiency (80.88%) than that synthesized by other methods. The results of chromaticity coordinates indicate that the Y2O3:Eu3+ as red-emitting phosphor is promising candidate for white light-emitting diodes (LEDs).

A facile and versatile microwave-assisted and shell-confined Kirkendall diffusion strategy is used to fabricate ultrasmall hollow nanoparticles by modulating the growth and thermal conversion of metal-organic framework (MOF) nanocrystals on graphene. This method involves that the adsorption of microwave by graphene creates a high-energy environment in a short time to decompose the in situ grown MOF nanocrystals into well-dispersed uniform core-shell nanoparticles with ultrasmall size. Upon a shell-confined Kirkendall diffusion process, hollow nanoparticles of multi-metal oxides, phosphides, and sulfides with the diameter below 20 nm and shell thickness below 3 nm can be obtained for the first time. Ultrasmall hollow nanostructures such as Fe2O3 can promote much faster charge transport and expose more active sites as well as migrate the volume change stress more efficiently than the solid and large hollow counterparts, thus demonstrating remarkable lithium-ion storage performance.

The interaction between angiotensin I-converting enzyme (ACE) and the inhibitory peptide KNFL from Wakame was explored using isothermal titration calorimetry, multiple spectroscopic techniques and molecular dynamics simulations, and an inhibition model was established based on free energy binding theory. The experiments revealed that the binding of KNFL to ACE was a spontaneous exothermic process driven by enthalpy and entropy and occurred via multiple binding sites to form stable complexes. The complexes may be formed through multiple steps of inducing fit and conformational selection. The peptide KNFL had a fluorescence quenching effect on ACE and its addition not only affected the microenvironment around the ACE Trp and Tyr residues, but also increased the diameter and altered the conformation of ACE. This study should prove useful for improving our understanding of the mechanism of ACE inhibitory peptides.

This work reports the synthesis of a N-doped acicular hollow porous carbon/carbon-nanotubes (N-AHPC@H-CNTs) using acicular CaCO3 as a green template and activating agent coupled with Fe Co catalyst, polydopamine and melamine as carbon and nitrogen precursors respectively. The prepared materials were applied for CO2 capture. N-AHPC@H-CNTs were characterized by SEM, TEM, PXRD, XPS, and BET techniques, which revealed their high SSA (SBET, 561 m2·g−1), microporous surface area (351.9 m2·g−1), N content (11.60 wt%) having a ratio of Pyrrolic-N (56.63%) and a great mass of ultramicropores (d

The interactions between bovine serum albumin (BSA) and polymer (poly (METAC-co-NIPAm-co-Eu(AA)3Phen), PMNEu) containing rare earth element (Europium) were detailedly investigated by both of experi...

New experimental vapor–liquid equilibrium (VLE) data for three binary systems composed of p-cymene + (−)-β-caryophyllene, 3-carene + (−)-β-caryophyllene, and 3-carene + p-cymene and for the ternary system of (−)-β-caryophyllene + p-cymene + 3-carene were obtained using a modified Ellis equilibrium still over the temperature range from 444.44 to 528.78 K at 101.33 kPa. The compositions of these mixtures were assessed using gas chromatography. The VLE data for the binary systems passed thermodynamic consistency tests based on the Herington method and Van Ness test. The thermodynamic consistency of the ternary system was checked by a Van Ness test. The VLE data for binary systems were correlated using the Wilson, NRTL, and UNIQUAC activity coefficient models with minor deviations. The ternary VLE data were also satisfactorily correlated using the Wilson, NRTL and UNIQUAC models. By comparing the experimental values for the ternary system with the values calculated using the three models, the average absolute deviation of the equilibrium temperature and vapor–phase composition were determined to be less than 0.57 K and 0.0060, respectively. These results indicated excellent agreement of the models with experimental values.

Angiotensin-converting enzyme (ACE) inhibitory peptides derived from food protein exhibited antihypertensive effects by inhibiting ACE activity. In this work, the interaction between ACE inhibitory peptide GMKCAF (GF-6) and ACE was studied by isothermal titration calorimetry (ITC), molecular docking, ultraviolet absorption spectroscopy, fluorescence spectroscopy, and circular dichroism spectroscopy. Experimental results revealed that the binding of GF-6 to ACE was a spontaneous exothermic process driven by both enthalpy and entropy. The interaction occurred via a static quenching mechanism and involved the alteration of the conformation of ACE. In addition, ITC and molecular docking results indicated binding of GF-6 to ACE via multiple binding sites on the protein surface. This study could be deemed helpful for the better understanding of the inhibitory mechanism of ACE inhibitory peptides.

Papain was immobilized onto Ti

Angiotensin-I-converting enzyme (ACE) inhibitory peptides derived from marine organism have shown a blood pressure lowering effect with no side effects. A new affinity medium of Fe3O4@ZIF-90 immobilized ACE (Fe3O4@ZIF-90-ACE) was prepared and used in the purification of ACE inhibitory peptides from Wakame (Undaria pinnatifida) protein hydrolysate (&lt, 5 kDa). The Fe3O4@ZIF-90 nanoparticles were prepared by a one-pot synthesis and crude ACE extract from pig lung was immobilized onto it, which exhibited excellent stability and reusability. A novel ACE inhibitory peptide, KNFL (inhibitory concentration 50, IC50 = 225.87 μM) was identified by affinity purification using Fe3O4@ZIF-90-ACE combined with reverse phase-high performance liquid chromatography (RP-HPLC) and MALDI-TOF mass spectrometry. Lineweaver–Burk analysis confirmed the non-competitive inhibition pattern of KNFL, and molecular docking showed that it bound at a non-active site of ACE via hydrogen bonds. This demonstrates that affinity purification using Fe3O4@ZIF-90-ACE is a highly efficient method for separating ACE inhibitory peptides from complex protein mixtures and the purified peptide KNFL could be developed as a functional food ingredients against hypertension.

To remove the bisphenol AF (BPAF) from aqueous solution, two different types of lignin-based aromatic porous polymers (LAPP-1 and LAPP-2) were fabricated via one-pot crosslinking of lignin with 1,4-dichloroxylene and 4,4′-bis(chloromethyl)-1,1′-biphenyl, respectively. The successful synthesis of LAPPs was confirmed by FTIR and XPS, SEM, TEM and N2 adsorption-desorption analysis. Then, batch adsorption experiments were conducted to investigate adsorption properties toward BPAF. Based on the results, the adsorption processes were in accordance with the pseudo-second-order kinetic model and the Freundlich isotherm model, and the thermodynamic studies showed that the adsorption was a spontaneous and exothermic process. It is remarkable that LAPPs exhibited good adsorption performance in wide ranges of pH and ionic strength as well as in recycling process. Notably, compared to LAPP-1, LAPP-2 exhibited higher adsorption capacity for BPAF, which can be ascribed to its higher porosity and content of aromatic ring. Moreover, the comprehensive analysis of experimental and theoretical results indicated that the π-π interactions and pore adsorption may jointly drive the uptake process of BPAF. Considering the simple fabrication method employed and excellent BPAF adsorption performance, LAPPs provided new insights into the development of advanced lignin-based adsorbents for removal of BPAF from water.

In this work, a visible light-driven ternary heterojunction photocatalyst, CdS/Bi

A metal affinity-immobilized magnetic liposome (MA-IML) was prepared in this research, which was with lipid and Ni2+ content of 143.25 μg/mg and 32 μmol/mg, respectively. The antihypertensive peptides Ile-Pro-Pro (IPP) and Val-Pro-Pro (VPP) could be adsorbed onto MA-IML under specific conditions, and the adsorption kinetics was explored. The pseudo-second-order kinetics (R2 value>0.98) was more suitable to describe the adsorption process of IPP and VPP than the intraparticle diffusion model and pseudo-first-order kinetic model. The results indicated that MA-IML could be used as an adsorbent for screening antihypertensive peptides from natural products.

In the past years, considerable efforts have been devoted to the deliberate synthesis of nanosulfur in various hosts with sophisticated structures to improve the performance of lithium-sulfur batteries (LSBs) and reveal the structure-property relationship. It is taken for granted that these elaborate sulfur nanostructures are well maintained in the ultimate electrode after the traditional mixing and coating method. Herein, we, for the first time, reveal the unexpected sulfur structure deterioration in nanosulfur/graphene composites during the electrode preparation using the traditional method because of the long-term neglected dissolution-recrystallization effect of sulfur in solvents. Consequently, compared with binder-free three-dimensional graphene/sulfur electrodes, the milled graphene/sulfur electrodes exhibit much worse electrochemical performance. On the basis of this, we further propose a facile and universal graphene oxide-assisted assembly method to avoid the dissolution-recrystallization of sulfur, by which binder-free three-dimensional ethylenediamine-functionalized graphene/sulfur (3DEFGS) electrodes have been successfully prepared. The 3DEFGS electrodes with a high areal sulfur loading of ∼6 mg cm

Background Low concentration NaHCO3 (ca. 12 mM) had been demonstrated to be an excellent carbon source for industrially important green alga Chlorella vulgaris and high concentration NaHCO3 (e.g. 160 mM) had been shown to be capable of controlling protozoa and stimulating lipid accumulation of another green alga, i.e., Neochloris oleoabundans. Furthermore, little was known about the mechanisms of the effects of NaHCO3 on microalgae. Thorough studies on the effects of high NaHCO3 on C. vulgaris and their mechanisms were therefore warranted. Methods We systematically compared the cell growth, lipid production, and cell morphology of the industrially important C. vulgaris in 160 mM NaHCO3 or 160 mM NaCl media at different pH levels. These data allowed us to analyze the effects of total dissolved inorganic carbon (DIC) and individual DIC species on C. vulgaris. Cell growth of C. vulgaris at a range of concentrations at 160 mM or lower was also studied. Results Cellular lipid cell content of 494 mg g−1 and lipid productivity of 44.5 mg L−1 day−1 were obtained at 160 mM NaHCO3 and pH 9.5. High concentration NaHCO3 (e.g. 160 mM) was inhibitive to cell growth but stimulating to lipid accumulation and caused unicellular C. vulgaris to transfer to colonial cells. Increasing pH in the range of 7.5–9.5 caused increasing inhibition to cell growth in 160 mM NaCl. Whereas the optimal pH for cell growth was 8.5 for 160 mM NaHCO3 cultures. Comparative experiments with 0–160 mM NaHCO3 indicate that 10 mM was the optimal concentration and increasing NaHCO3 from 10 to 160 mM caused increasing inhibition to cell growth. Conclusions High concentration DIC was inhibitor to cell growth but stimulator to lipid accumulation of C. vulgaris. It caused unicellular C. vulgaris to transform to colonial cells. Results suggest that high concentration of a particular DIC species, i.e., dCO2, was the primary stress responsible for cell growth inhibition. Where CO3 2− was likely the DIC species responsible for lipid stimulation of C. vulgaris. Furthermore, we propose that the colony formation at high DIC conditions was employed by C. vulgaris to mitigate the stress by minimizing cell exposure to unfavorable environment.

Pyrolyze metal-organic frameworks (MOFs) is a promising method to prepare metal oxides with large specific surface and multiple active sites. The obtained metal oxides can be utilized as gas sensors. Noble metal doping is an effective way to improve the gas sensitivity of materials. In this work, SnO2 are prepared by pyrolyzation of metal organic frameworks and Ag-doped SnO2 composites are fabricated by AgNO3 reduction in a water bath at 4 °C. The gas-sensing experiment reveals that the optimum operating temperature of different mass fraction of Ag doped SnO2 samples is 250 °C which is lower than pure SnO2 (300 °C). The response of composites (7 wt% Ag–SnO2) is 157 to 10 ppm ethanol, which is about 10 times higher than pure SnO2 (14). The composites have good selectivity and stability. Such excellent performance is contributed to the increase of the gas adsorption capacity, catalytic active site and oxygen vacancy of the composites caused by the doping of Ag.

Papain was immobilized onto Ti3C2 MXene nanosheets by physical adsorption and physical adsorption combined with covalent crosslinking with glutaraldehyde. Ti3C2 MXene nanosheets were prepared by hydrofluoric acid etching method. The resulting products were well characterized by SEM, BET, XRD, FTIR, XPS. The optimized immobilization conditions are pH 6.5, immobilization time of 20 h, immobilization temperature of 10℃, and 10 mL 2 mg mL−1 papain, the amount of papain immobilized was 156 mg g−1, the activity of the immobilized papain determined was 1701 U∙g−1. The immobilized papain exhibited enhanced pH and temperature endurances, immobilized papain also showed improved storage stability (39.25 % and 65.57 % after 20 days of storage at 4 °C). papain reusability was significantly improved after immobilization and it retained more than 50 % of its initial activity after 5 repeated cycles. Interestingly, the results of immobilized enzymes demonstrated that the immobilization of enzymes on Ti3C2 MXene is feasible. Such approach could be transferred to other support systems for anchoring enzyme.

Cell density and morphology changes were tested to examine the effects of salts including NaHCO3 , NaCl, KHCO3 , and KCl at 160 mM on protozoa. It was demonstrated that ionic stress rather than osmotic stress led to protozoa cell death and NaHCO3 was shown to be the most effective inhibitor. Deformation of cells and cell shrinkage were observed when protozoan cells were exposed to polyethylene glycol (PEG) or any of the salts. However, while PEG treated cells could fully recover in both number and size, only a small portion of the salt-treated cells survive and cell size was 36-58% smaller than the regular. The disappearance of salt-treated protozoa cells was hypothetically attributed to disruption of the cytoplasmic membrane of these cells. It is further hypothesized that the PEG-treated protozoan cells carried out regulatory volume increase (RVI) after the osmotic shock but the RVI of salt-treated protozoa was hurdled to varied extents. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1418-1424, 2017.

Angiotensin I-converting enzyme (ACE) inhibitory peptide from silkworm pupa ( Bombyx mori ) was purified, modified, as well as inhibition mechanism by using molecular docking analysis. Silkworm pupa protein was hydrolyzed by neutral protease and the obtained hydrolysate was subjected to various types of chromatography to acquire peptide isolate. Then the molecular mass and amino acid sequence of the peptide was determined by MALDI-TOF/TOF MS. Subsequently, thermal and digestive stability of the peptide were explored through a high temperature processing and a simulated gastrointestinal digestion. Finally, the peptide was modified to smaller peptides and investigated their potentiate activities. Results showed that the peptide from silkworm pupa was determined to be Gly-Asn-Pro-Trp-Met (603.7 Da) with IC 50 21.70 μM. Stability testing showed that ACE inhibitory activities were not significantly changed at temperature from 40 to 80 °C as well as during in vitro gastrointestinal digestion. The inhibitory activity of four modified peptides were Trp-Trp > Gly-Asn-Pro-Trp-Trp > Asn-Pro-Trp-Trp > Pro-Trp-Trp, and the IC 50 of Trp-Trp was 10.76 μM Docking simulation revealed that the inhibitory activity was closely related to the spatial structure of peptide and zinc ions. The purified peptide and four modified peptides may be beneficial as functional food or drug for treating hypertension.

N-doped hollow porous carbon materials have attracted significant scientific interest in the field of peptide adsorption, drug delivery and catalysis. However, their facile synthesis is still a challenge due to the lack of an ideal template and effective route for high specific surface area (SSA). In this work, we report a facile approach for preparing N-doped hollow porous carbon whiskers (HPCWs) by using CaCO3 whiskers as a green template and double inner-activating agent. Two inner activators, CO2 and Ca(OH)2, are generated from the CaCO3 whisker template during the carbonization process. Among them, Ca(OH)2 was formed by H2O vapors reacting with the remaining template CaO. Attributed to the drastic synergistic effect of inner-activation (CO2 or Ca(OH)2) and outer-activation (KOH), the synthesized HPCWs exhibit ultrahigh SSA (3007 m2 g−1), the largest pore volume (2.63 cm3 g−1) and a controllable proportion of micropores (Sm/St, 60–86%). These intriguing pore structure characteristics of HPCWs endow with them rich target-oriented applications, as exemplified by their outstanding adsorption for casein hydrolysate (10 080 mg g−1), which is two orders of magnitude (102) higher than that of common porous materials. This facile and green synthesis strategy may pave a new way to prepare hollow porous carbon materials with the desired pore structure and high surface area for numerous applications.

High N-doped porous graphitic carbons (S-NPGCs) with multi-flaky shell hollow structure were prepared by using CaCO3 as a green/useful template. S-NPGCs exhibit very fast adsorption for toluene (31 times that of HKUST-1) and effectively selective enrichment of small peptides with high inhibitory activity of angiotensin converting enzymes.

Purification of small bioactive peptides from complex biological samples is a difficult task due to the interference of concentrated large biomolecules. In this study, a magnetic immobilized metal affinity chromatography matrix modified by poly (ethylene glycol) methyl ether (IMACM@mPEG) was prepared and applied for the rapid purification of angiotensin I-converting enzyme (ACE) inhibitory peptides from casein hydrolysate. The proposed IMACM@mPEG considerably reduced the non-specific adsorption of large proteins and exhibited improved purification efficiency towards ACE inhibitory peptides. A novel peptide with moderate ACE inhibitory activity (IC50 value of 274 ± 5 μM) was identified as LLYQEPVLGPVR. Lineweaver-Burk plot confirmed the non-competitive inhibition pattern of LLYQEPVLGPVR. The purified peptide was digested after simulated gastrointestinal digestion and produced shorter peptides which contributed to enhanced ACE inhibitory activity. These results indicated that the IMACM@mPEG is an effective method for the prepurification of ACE inhibitory peptide and the purified peptide LLYQEPVLGPVR may have potential as nutraceutical ingredient in functional foods for hypertension treatments.

In the paper, a novel BiOI/MoS2 (BMS) heterojunction was prepared by a facile hydrothermal method. BiOI nanoplates grew in-situ on the surface of exfoliated MoS2 nanosheets, followed by anisotropic growth and self-assembly, forming a hierarchical flower-like heterostructure finally. Experimental results illustrated that MoS2 as well as the BiOI amounts play a vital role in influencing the morphology and photocatalytic activity of BMS heterojunctions. Among the obtained photocatalysts, BMS-8 displayed the strongest photocatalytic performance under visible light irradiation towards the degradation of rhodamine B (RhB) and disinfection of Pseudomonas aeruginosa (P. aeruginosa). The highly enhanced photocatalytic activity can be attributed to the synergistic effect and formation of a type II heterostructure between BiOI and MoS2, boosting the catalytic active sites, enhancing visible light harvesting, and promoting the efficient separation of photoinduced charge carriers. Moreover, BMS-8 composite showed a good stability in photocatalytic reaction, which favored a long-term use. The active species trapping experiments validated the dominating role of photogenerated holes (h+) and ⋅O2− radicals in the photocatalytic process for BMS-8 heterojunction. It is anticipated that this work can promote further interest in constructing novel heterostructures with controllable morphology and highly efficient photocatalytic activity for potential environmental purification and energy conversion.

In this work, a visible light–driven ternary heterojunction photocatalyst, CdS/Bi2WO6/ZnO, was synthesized using hydrothermal, ultrasonic dispersion, and deposition precipitation methods. The results show that photocatalysts with flower-like heterostructures were obtained, which could efficiently separate electron–hole pairs, and the photocatalytic activity was thereby significantly enhanced. Furthermore, CdS/Bi2WO6/ZnO and polyvinylidene fluoride (PVDF) were used to fabricate hybrid membranes via a phase-conversion method. The samples were characterized using SEM, TEM, EDX, XRD, DRS, XPS, PL, and N2 adsorption–desorption isotherms, and the transient photocurrent response. The photocatalytic activity of the hybrid membrane was evaluated, and 92.58% of the nitrite was converted into non-toxic substances within 4 h under simulated sunlight irradiation. This result indicated that the photocatalyst exhibited a good photocatalytic activity after immobilization. The possible mechanism was elucidated by studying the product during the photocatalytic degradation, and the effects of different pH values, electron scavengers, and hole scavengers on the photocatalytic performance were further investigated.

Carapax Trionycis (the shell of the turtle Pelodiscus sinensis) was hydrolyzed by six different commercial proteases. The hydrolysate prepared from papain showed stronger inhibitory activity against angiotensin I-converting enzyme (ACE) than other extracts. Two noncompetitive ACE inhibitory peptides were purified successively by ultrafiltration, gel filtration chromatography, ion exchange column chromatography, and high-performance liquid chromatography (HPLC). The amino acid sequences of them were identified as KRER and LHMFK, with IC50 values of 324.1 and 75.6 μM, respectively, confirming that Carapax Trionycis is a potential source of active peptides possessing ACE inhibitory activities. Besides, both enzyme kinetics and isothermal titration calorimetry (ITC) assay showed that LHMFK could form more stable complex with ACE than KRER, which is in accordance with the better inhibitory activity of LHMFK.

In this study, angiotensin converting enzyme (ACE) inhibitory peptides from lizard fish protein hydrolysate with neutral protease were purified through magnetic affinity separation. Magnetic agarose microsphere was prepared by reverse-phase microemulsion method, and its surface was modified with epoxy groups to immobilize ACE as a magnetic affinity medium (MAM-ACE) and then mixed with lizard fish ultrafiltration hydrolysate (

Lizard fish (Saurida elongata) muscle protein was hydrolyzed by neutral protease to obtain the hydrolysate with angiotensin-I converting enzyme (ACE) inhibitory activity. A novel ACE inhibitory peptide was successfully purified from Lizard fish protein hydrolysate (LFPH) by ultrafiltration, size exclusion chromatography, and high-performance liquid chromatography (HPLC). The amino acid sequence of the purified peptide was identified as Arg-Val-Cys-Leu-Pro (RVCLP) and in vitro ACE inhibitory activity assay revealed an IC50 value of 175 µM. Our study suggests that peptide from lizard fish hydrolysate may be beneficial as antihypertensive compounds for use as functional food ingredients or pharmaceuticals against hypertension.

High N-doped porous graphitic carbons (S-NPGCs) with multi-flaky shell hollow structure were prepared by using CaCO