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Background: Nonalcoholic fatty liver disease (NAFLD) is a chronic disease with an increasing incidence, which can further develop into liver fibrosis and hepatocellular carcinoma at the end stage. Alantolactone (Ala), a sesquiterpene lactone isolated from Asteraceae, has shown anti-inflammatory effects in different models. However, the therapeutic effect of Ala on NAFLD is not clear. Methods: C57BL/6 mice were fed a high-fat diet (HFD) to induce NAFLD. After 16 weeks, Ala was administered by gavage to observe its effect on NAFLD. RNA sequencing of liver tissues was performed to investigate the mechanism. In vitro, mouse cell line AML-12 was pretreated with Ala to resist palmitic acid (PA)-induced inflammation, oxidative stress and fibrosis. Results: Ala significantly inhibited inflammation, fibrosis and oxidative stress in HFD-induced mice, as well as PA-induced AML-12 cells. Mechanistic studies showed that the effect of Ala was related to the induction of Nrf2 and the inhibition of NF-κB. Taken together, these findings suggested that Ala exerted a liver protective effect on NAFLD by blocking inflammation and oxidative stress. Conclusions: The study found that Ala exerted a liver protective effect on NAFLD by blocking inflammation and oxidative stress, suggesting that Ala is an effective therapy for NAFLD. [ABSTRACT FROM AUTHOR]

Magnetoelectric materials, which encompass coupled magnetic and electric polarizabilities within a single phase, hold great promises for magnetic controlled electronic components or electric-field controlled spintronics. However, the realization of ideal magnetoelectric materials remains tough due to the inborn competion between ferroelectricity and magnetism in both levels of symmetry and electronic structure. Herein, we introduce a methodology for constructing single phase paramagnetic ferroelectric molecule [TMCM][FeCl4], which shows low-magnetic-field magnetoelectricity at room temperature. By applying a low magnetic field (≤1 kOe), the halogen Cl‧‧‧Cl distance and the volume of [FeCl4]− anions could be manipulated. This structural change causes a characteristic magnetostriction hysteresis, resulting in a substantial deformation of ~10−4 along the a-axis under an in-plane magnetic field of 2 kOe. The magnetostrictive effect is further qualitatively simulated by density functional theory calculations. Furthermore, this mechanical deformation significantly dampens the ferroelectric polarization by directly influencing the overall dipole configuration. As a result, it induces a remarkable α31 component (~89 mV Oe−1 cm−1) of the magnetoelectric tensor. And the magnetoelectric coupling, characterized by the change of polarization, reaches ~12% under 40 kOe magnetic field. Our results exemplify a design methodology that enables the creation of room-temperature magnetoelectrics by leveraging the potent effects of magnetostriction. The authors report a molecular ferroelectric (TMCM)[FeCl4], which shows strong magnetostrictive and magnetoelectric effects at room temperature. The spin-lattice coupling of FeCl4 and flexible structure of organic cations are responsible for these effects. [ABSTRACT FROM AUTHOR]

CdZnTe (CZT) is an II–VI compound semiconductor with a zinc blende structure and has a wide range of applications in nuclear radiation detectors. As the device size becomes nanoscale, the displacement damage caused by high-energy proton irradiation in space environment has become one of the main factors affecting the electrical properties of components. In this paper, Monte Carlo software Geant4 is used to simulate the types and proportions of physical processes generated by different particles incident on CZT crystals, the proportion and depth distribution of NIEL of particles with different energy/angle. The results show that the type, energy and angle of incident particles will affect the proportion of energy deposition and the distribution of energy deposition with depth during irradiation. The physical effects are different under different irradiation conditions. The simulation results have reference value for studying the displacement damage law of CZT irradiated by particles under different conditions and the stability of CZT detector in radiation environment. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO)-based memristors offer the promise of low cost, eco-friendliness, and mechanical flexibility, making them attractive candidates for outstanding flexible electronic devices. However, their resistive transitions often display abrupt change rather than bidirectional progressive tuning, which largely limits their applications for biological synapse emulation and neuromorphic computing. Here, a memristor with a novel layered structure of GO/pyridinium/GO is presented with tunable bidirectional feature. The inserted organic pyridinium intercalation succeeds in serving as a satisfactory buffer layer to intrinsically control the formation of conductive filaments during device operation, leading to progressive conductance regulation. Thus, the essential synaptic behaviors including analog memory characteristics, excitatory postsynaptic current, paired pulse facilitation, prepulse inhibition, spike-timing-dependent plasticity, and spike-rate-dependent plasticity are replicated. The emulation of brainlike "learning-forgetting-relearning" process is also implemented. Additionally, the instant responses of the memristor can be stimulated by low operational voltages and short pulse widths. This study paves one way for GO-based memristors to actuate appealing features such as bidirectional tuning and fast speed switching that are desirable for the development of bio-inspired neuromorphic systems. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) in the context of oral submucous fibrosis (OSF) has a high incidence owing to undefined pathogenesis. Identifying key genes and exploring the underlying molecular mechanisms involved in the conversion of OSF into OSCC are in urgent need. Differentially expressed genes (DEGs) between OSCC and OSF were dug from GEO databases and a total of 170 DEGs were acquired. Functional association of DEGs were analyzed by GO and KEGG. Protein–protein interactions (PPIs) analysis was carried out and candidate biomarkers were identified by Gene co-expression analysis and Cox analyses. Hub genes were confirmed by qRT-PCR in tissues and cell lines, of which we found that IRF4 mRNA was successively up-regulated from Normal to OSF and then to OSCC and associated with immune infiltrating levels. In addition, Immunohistochemical (IHC) and Immunofluorescence (IF) assays were conducted to validate the consistent upregulation of IRF4 and the oncogene role of IRF4 in OSF and OSCC at translation level. IRF4 may be indicative biomarker in transformation of OSF into OSCC. High IRF4 expression contribute to increased immune infiltration of OSCC and may provide a novel diagnostic marker for OSCC patients translated from OSF. [ABSTRACT FROM AUTHOR]

A novel nitrite electrochemical biosensor is constructed by glassy carbon electrodes (GC) coated by chloroperoxidase (CPO) -Au nanoparticles-MoS2 nanoflowers in the presence of ionic liquid, 1-ethyl-3-methylimidazolium bromide (EMB-IL). Au-MoS2 nanoflowers modified nanocomposites are synthesized using sodium carboxymethyl cellulose as reducing agent and stabilizer. The EMB-IL can effectively promote direct electron transfer between CPO and electrode surface without redox mediator. Herein, the surface concentration of CPO on the electrode surface is 1.36 × 10–10 mol cm−2, and the electron transfer coefficient and the rate constant of CPO at electrode surface are 0.87 and 2.03 s−1, respectively. The proposed nitrite electrochemical biosensor shows a wide linear range, low detection limit, and high sensitivity. The biosensor was applied to the determination of nitrite in pickled cabbage with a good accuracy and recovery. [ABSTRACT FROM AUTHOR]

Halloysite nanotube (HNT) is a natural bio-compatible and stable nanomaterial available in abundance at low-cost. In this work, HNT was modified by two strategies to make it suitable for supporting immobilization of chloroperoxidase (CPO). Firstly, Fe3O4 nanoparticles were deposited on HNT, so magnetic separation can be used instead of centrifugation. Then, the magnetic HNT was modified by 3-aminopropyltriethoxysilane (APTES), which can provide amine group on surface of HNT and meanwhile inhibit the agglomeration of magnetic HNT. Then, HNT-Fe3O4 -APTES was linked with branched polyethyleneimine (PEI) to provide more amino for binding with enzyme. The so-prepared CPO@HNT-Fe3O4-APTES-PEI showed enhanced enzyme loading, reusability, improved thermal stability and tolerance to organic solvents than free CPO. For example, after 10 repeated uses, CPO@HNT- Fe3O4-APTES-PEI can maintain 92.20% of its original activity compared with 65.12% of activity of CPO@HNT-APTES-PEI and 45.69% of activity of CPO@HNT. The kinetic parameters indicated the affinity and specificity of immobilized enzyme to substrate was increased. CPO@HNT-Fe3O4-APTES-PEI was very efficient when it was applied in the degradation of pesticides mesotrione in wastewater. The degradation efficiency can reach 90% within 20 min at range of 5–40 μmol·L−1. These results ensure the potential practical application of this bio-materials in wastewater treatment. [ABSTRACT FROM AUTHOR]

A multitude of industrial processes are catalyzed by two or more enzymes working together in a cascade way. However, designing efficient enzymatic cascade reactions is still a challenge. In this work, a TiO2 thin film with mesoporous pores was prepared and used as carrier for co-immobilization of chloroperoxidase (CPO) and glucose peroxidase (GOx). By adjusting the dosage of hexadecyltrimethylammonium bromide (CTAB) and the ratio of the two enzymes, CPO and GOx were well distributed and positional orientated to their own appropriate pores to form an ordered "occupation" based on a "feet in right shoes" effect. Moreover, when the pore size was controlled around 12 nm, the enzymes aggregation was inhibited so as to avoid the decrease of activity of enzyme; The catalytic performance of TiO2–GOx and CPO composites was evaluated by the application of decolorization of Orange G dye in a cascaded manner. The oxidant H2O2 needed by CPO is generated in situ through glucose oxidation by GOx. Upon co-immobilization of CPO and GOx on the same carrier, a large increase in the initial catalytic efficiency was detected when compared to an equimolar mixture of the free enzymes, which was four times greater. Moreover, the affinity of the enzyme toward substrate binding was improved according to the kinetic assay. The thermal stability of TiO2–GOx and CPO composites were greatly improved than free enzymes. The TiO2–GOx and CPO composites can be easily separated from the reaction media which facilitate its recycle use. [ABSTRACT FROM AUTHOR]

Chloroperoxidase (CPO) was immobilized on graphene oxide (GO) nanosheets via site-specific interactions of concanavalin (ConA) with saccharide groups on the CPO surface to make GO-ConA-CPO nano-architectonics. Enzymatic oxidative decolorization of malachite green was used to investigate the catalytic performance of GO-ConA-CPO. The GO-ConA-CPO showed high activity (based on the decolorization efficiency), i.e., 93.68% in 15 min. Moreover, GO-ConA-CPO showed better thermostability and remained higher activity against pH change and high concentrations of oxidant HO compared with GO-CPO and the free enzyme. When incubated at 60 °C for 1.5 h, 63.02% of the activity of GO-ConA-CPO and 35.75% of GO-CPO remained compared with that at 25 °C, while free CPO remained only 8.46% in the same condition. The tolerance of GO-ConA-CPO to HO improved from 2.5 to 6 mmol L, and the suitable pH range enlarged from 2.5-3.0 to 2.0-4.5. After 8 cycles, the GO-ConA-CPO can keep 52% activity of that in the first run. The enzymatic kinetic constants indicated that introducing CPO into GO-ConA-CPO bioarchitecture improved the diffusion of reactants and products. [ABSTRACT FROM AUTHOR]

Norfloxacin is often found in wastewater treatment plants, groundwater, and even drinking water causing environmental concerns because of its potential undesirable effects on human health or aquatic ecosystems. However, conventional treatments cannot deal with norfloxacin efficiently. This work proposes an efficiently enzymatic degradation of norfloxacin by chloroperoxidase (CPO). 82.18% degradation efficiency of norfloxacin was achieved after 25 min reaction time at pH 5.0 with an enzyme concentration of 1.5 × 10 mol L. HPLC-MS was used to determine the intermediates or final products. The product analysis and determination of the chemical oxygen demand indicated if the enzymatic degradation by CPO was carried out before the usually existing bioremediation techniques (usually activated sludge) in sewage treatment plant, the effluent containing norfloxacin can be decontaminated more efficiently and thoroughly than that only by activated sludge treatment. The eco-toxicity tests using a green algae, Chlorella pyrenoidosa, indicated that the toxicity of degraded products of norfloxacin was lower than the parent norfloxacin molecule. CPO-catalyzed degradation of norfloxacin is a promising alternative for treating effluent containing norfloxacin. Graphical abstract: [ABSTRACT FROM AUTHOR]

Objectives: To degrade enzymatically bisphenol A (BPA) that causes serious environmental concerns and is difficult to be degraded by chemical or physical methods. Results: BPA (150 mg l) was completely degraded by chloroperoxidase (CPO)/HO within 7 min at room temperature, atmospheric pressure with the enzyme at 6 μg CPO ml. The degradation products were identified by HPLC-MS, which suggested involvement of multiple steps. Enzymatic treatment followed by existing bioremediation technologies (activated sludge) enhanced removal of COD from 9 to 54 %. Using an ecotoxicity evaluation with Chlorella pyrenoidosa, the degradation products had a lower toxicity than BPA. Conclusion: BPA can be degraded rapidly and efficiently under mild conditions with chloroperoxidase at 6 μg ml. The degradation products had a lower toxicity than BPA. [ABSTRACT FROM AUTHOR]

The effect of M2+ (Zn2+, Cu2+, Cd2+, Mn2+, Pb2+) and M3+ (Cr3+, La3+, Fe3+, Ce3+, Y3+, Al3+) metal ions on the activity and thermal stability of chloroperoxidase (CPO) was investigated in this work. It was found that the lower concentration of metal ions was favorable to CPO activity whereas the higher concentration reversed the results. CPO activity could be increased to 116.4-127.1 % in the presence of a trace amount of these M2+/M3+ metal ions at a concentration range of 0-25 μmol L-1 after 2 h of incubation at 25 °C. The activating effect of M is better than that of M2+, and Cr3+ was mostly efficient. The thermal stability of the enzyme was also improved significantly. Only 30.3 % of CPO activity was retained at 50 °C whereas 82.6 % of CPO activity was maintained in the presence of Cr3+ after 2 h of incubation at the same temperature. The activation of CPO by metal ions at their low concentration was studied through intrinsic fluorescence, circular dichroism (CD), and UV-Vis spectra assay. A favorable environment around the active site was achieved in the presence of metal ions. Intrinsic fluorescence and CD spectra indicated that the α-helix structure of CPO was strengthened in metal ion-contained media. More exposure of the heme ring was achieved for easy access of the substrate, which was suggested by UV-Vis spectrum analysis. This strategy for enhancing CPO activity is very simple and useful. It will be favorable to the practical application of this enzyme. [ABSTRACT FROM AUTHOR]

The mean activity coefficients for CsCl in N-methylformamide or urea ( w) + HO (1 − w) systems were determined in this work by potentiometry, using ion-selective electrodes at 298.15 K. The value of mass fraction w was varied between 0.00 and 0.40 in five unit-steps and the molality of CsCl was between 0.0020 and 1.4009 mol·kg. The experimental data have been correlated with the Pitzer, modified Pitzer and the extended Debye-Hückel equations. The resulting values of the mean activity coefficients, the osmotic coefficients and the standard Gibbs energy of transfer, together with the Pitzer ion-interaction parameters ( β, β and C), extended Debye-Hückel parameters ( a, c and d), and modified Pitzer parameters ( b, B, C) are reported for the investigated systems. [ABSTRACT FROM AUTHOR]

Chloroperoxidase (CPO) is thought to be the most versatile heme-containing enzyme with enormous applications in organic synthesis, biotransformation, pharmaceutical production, and detoxification of environmental pollutants. Any improvement in the stability of this enzyme will greatly enhance its application in the mentioned areas. In the present study, the effects of three polysaccharides (soluble starch, β-cyclodextrin, and dextrin) on the stability of CPO at elevated temperatures (20, 30, 35, 40, and 50 °C) or in aqueous-organic solvents media (methanol, dioxane, DMSO, and DMF) were investigated. An improved catalytic performance of CPO was observed in the presence of a small amount of the three polysaccharides, where dextrin provided the most effective promotion. The changes of enzyme structure and microenvironment around heme in the presence of additives were studied by fluorescence, circular dichroism, and UV-vis spectra analyses, as well as kinetic parameters measurement. A catalytically favorable structure of CPO was induced, including the strengthening of the α-helix structure and more exposure of heme for easy access of the substrate, resulting in an increase of catalytic turnover frequency ( k) and the improvement of affinity and selectivity of CPO to substrate. The results revealed that the introduction of trace soluble starch, β-cyclodextrin, and dextrin (<10 μmol/L) in reaction media was an effective strategy for the enhancement of the thermodynamic and the operational stability of the enzyme, which are promising in view of the industrial applications of this versatile biological catalyst. [ABSTRACT FROM AUTHOR]

The chlorination and oxidation activity of chloroperoxidase (CPO) was enhanced 32 and 20% by chitosan, and oxidation activity 24% by thioglycolic acid, respectively. The pH optimum of chlorination reaction shifted 3 units to a less acidic environment by chitosan (from 2.75 to 5.75). The kinetic parameters indicated both the affinity and specificity of CPO to substrate were improved. [ABSTRACT FROM AUTHOR]