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A graphene-supported highly dispersed cobalt catalyst with abundant Co–Nx active sites was synthesized to boost 1O2 production from H2O2 activation, exhibiting excellent degradation efficiency towards the model organic pollutant methylene blue.

Three new phenylpropenoid glycosides (1–3), and five undescribed shikimic acid derivatives (4–8), together with six known analogues (9–14), were obtained from the dried leaves of Illicium dunnianum.

To address the problem of shutting effect of Li-S batteries, we used Ti-based MOF as precursor to obtain a conductive matrix with dual inhibitors. The target material, namely NTiPC, shown remarkable discharge capacity with 1178 mA h g

Thirty-seven diterpenoid alkaloids (DAs) with diverse structures were isolated and identified from the lateral roots of Aconitum carmichaelii Debx., comprising eight C20-DAs and twenty-nine C19-DAs. Besides the 31 known DAs identified by comparing the 1H NMR and 13C NMR data with those reported in the literature, the structures of four new compounds (1, 14, 17, and 25), and two other compounds (26 and 37) which were reported to be synthesized previously, were also elucidated based on the comprehensive analysis of their HR-ESI-MS, 1D and 2D NMR spectra, including 1H–1H COSY, HSQC and HMBC and NOESY/ROESY. Among them, compound 1 represents the first example of a C20-DA glucoside. Besides, the anti-tumor activities of all the isolated compounds against human non-small-cell lung cancer A549 and H460 cells were systematically evaluated by MTT methods. The results revealed that all of the C19-DAs possessed moderate activities against both of the two cell lines with IC50 values ranging from 7.97 to 28.42 μM, and their structure–activity relationships indicated the active sites of C-8, C-10, and C-14 positions and the nitrogen atom in the C19-DA skeleton. In addition, all of the isolated DAs, with chemical structures confirmed, were further applied for network pharmacology analysis, in order to give an insight into the possible mechanisms of their anti-tumor activities. As a result, 173 potential targets and three most important pathways related to non-small-cell lung carcinoma were finally unearthed.

Surface enhanced Raman spectroscopy (SERS) is a promising sensing technique that can provide unique chemical and structural fingerprint information, but gaining reliable SERS quantitative data with high sensitivity and stability still remains a challenge. Although using a molecule as an internal standard (IS) can improve the SERS quantitative capability, the reliability and SERS measuring conditions for signal fluctuations during calibration based on IS are yet to be explored when the embedded IS molecules and target objects are located in different environments. Herein, a 3D hotspot matrix SERS platform based on Au@4-MPy@AgNPs was constructed in water with the assistance of glycerol and the dynamic signal changes from the IS, i.e. 4-Mpy, and target molecules were monitored during the process of evaporation with high sensitivity and stability. In contrast to the traditional water-dispersed drying film system, the variation trends of IS and target molecules were consistent in the glycerol-assisted liquid film protection system. Therefore, it is reasonable to calibrate the signal fluctuation by utilizing the embedded IS based on the construction strategy of a glycerol-assisted 3D hotspot platform. This work demonstrates a rational, reliable and precise SERS quantitative technique for testing analyte concentrations in practical systems and has great application prospects in the field of analytical chemistry.

Eight previously undescribed diarylheptanoids (1–8), together with fifteen known analogues (9–23), were isolated from the rhizomes of Zingiber officinale. Their structures were unambiguously determined by comprehensive spectroscopic analyses and electronic circular dichroism (ECD) calculations. It is worth mentioning that 1–3 are the first reported structures of diaryl ether heptanoids in Z. officinale, whereas 15–17 were isolated from Zingiber for the first time. Furthermore, a gene enrichment analysis of the interacting targets indicated that diarylheptanoids were mainly associated with the anti-tumor activity by affecting DNA damage signaling pathway. The results showed that 6, 16–19 had remarkable inhibitory effects against five tumor cell lines (A549, HepG2, HeLa, MDA-MB-231, and HCT116) with IC50 values ranging from 6.69–33.46 μM, and showed down-regulating the expression of ATR (ataxia telangiectasia mutated and RAD3-related) and CHK1 (checkpoint kinase 1) levels in HCT116 and A549 cell lines. Our studies not only enrich the structural diversity of diarylheptanoids in nature, but also discover several natural compounds for anti-tumor agents.

Phytochemical investigations on the dry leaves of Illicium dunnianum have led to the isolation of 24 lignans. Illiciumlignans G–K (1–5) were five undescribed benzofuran lignans, illiciumlignan L (6) was one undescribed ditetrahydrofuran lignan, illiciumlignans M–O (7–9) were three new sesquilignans, and compounds 10, 12, 13, 15, and 18–21 were firstly isolated from the genus Illicium. Their structures were elucidated by detailed spectroscopic analyses (UV, IR, HR-ESI-MS, and NMR) and CD experiments. All isolates were evaluated by measuring their inhibitory effects on PGE2, and NO production in LPS-stimulated RAW 264.7 macrophages.

Usually, Al-Ga alloys are prepared by heating materials to hundreds of degrees for a long time, and the alloys obtained are in the solid state. Although some Ga-rich liquid Al-Ga composites have been developed lately, the mass percentage of Al is small, due to which the hydrogen generation rate and efficiency are limited. Besides, an alkaline solution is indispensable in these studies, which is also a limitation. In this paper, a semisolid Al-Ga composite has been fabricated by mixing liquid gallium and fragmented aluminium foils at room temperature, which is an effective means to generate hydrogen from pure water. With the increase in the Al proportion, the mixture changes from a liquid to a cement-like semisolid material morphologically. Furthermore, an application of the fuel cell taking advantage of the hydrogen released from the composites is given. This method does not require a high-temperature device and only requires water to produce hydrogen once the semisolid Al-Ga composite material is fabricated. Therefore, this is a new approach for making more portable and safer devices for hydrogen production.

Acute myocardial infarction (AMI) is a complication of atherosclerosis that takes place in coronary arteries. Cardiac endothelial cells play a significant role in the pathogenesis of AMI. Oxygen-glucose deprivation/reperfusion (OGD/R) is widely used as a model to simulate AMI in vitro. Recently, antidiabetic GLP-1 receptor agonists have been shown to exert pleiotropic effects that modulate cardiovascular complications. In this study, we investigated the vascular effect of lixisenatide. We show that pre-treatment of endothelial cells with lixisenatide protected them from OGD/R-induced cytotoxicity and improved their viability. Pre-treatment with lixisenatide ameliorated OGD/R-induced ROS accumulation and disturbed endothelial tube formation. At the molecular level, lixisenatide mitigated OGD/R-induced reduced eNOS expression and NO production but further promoted the expression of the anti-oxidant regulators Nrf2 and HO-1. Mechanistically, we confirmed that the PI3K/Akt pathway is essential for mediating the effects of lixisenatide, and blockage of PI3K/Akt using the inhibitor LY294002 abolished the ameliorative effect of lixisenatide on ROS production and impaired tube formation. These data indicate that lixisenatide possesses a beneficial effect on the vasculature in a model of ischemia-induced endothelial injury. We conclude that the GLP-1 receptor agonist lixisenatide has pleiotropic properties that can modulate vascular function independent of its anti-glycemic effect.

Thirty-seven diterpenoid alkaloids (DAs) with diverse structures were isolated and identified from the lateral roots of

Computational studies on Ir(III)-catalyzed intermolecular branch-selective allylic C–H amination of terminal olefins with methyl dioxazolone have been carried out to investigate the mechanism, including the origins of regioselectivity and catalytic activity difference. The result suggests that the reaction proceeds through generation of active species, alkene coordination, allylic C–H activation, decarboxylation, migratory insertion, and protodemetalation. The presence of AgNTf2 could thermodynamically promote the formation of catalytically active species [Cp*Ir(OAc)]+. Both the weaker Ir–C(internal) bond and the closer interatomic distance of N⋯C(internal) in the key allyl-Ir(V)-nitrenoid intermediate make the migratory insertion into Ir–C(internal) bond easier than into the Ir–C(terminal) bond, leading to branch-selective allylic C–H amidation. The high energy barrier for allylic C–H activation in the Co system could account for the observed sluggishness, which is mainly ascribed to the weaker coordination capacity of alkenes to the triplet Cp*Co(OAc)+ and the deficient metal⋯H interaction to assist hydrogen transfer.

Eight previously undescribed diarylheptanoids (1-8), together with fifteen known analogues (9-23), were isolated from the rhizomes of

Phytochemical investigations on the dry leaves of

A microwave assisted extraction technology was used to extract chrysophanol from rhubarb. The present study will focus on the optimum extraction conditions of chrysophanol and discuss the inhibitory effect of chrysophanol on the biofilm formation of Streptococcus suis (S. suis). A Box–Behnken design based on single-factor experiments was applied to optimize the microwave assisted extraction process and to study the factors' relationships with each other. The results showed that a microwave temperature of 56 °C, ethanol concentration of 70%, microwave power of 540 W and liquid to raw material ratio of 55 mL g−1 were the optimal conditions for the microwave method. The yield of chrysophanol was 2.54 ± 0.07% under the optimal conditions, which was in agreement with the predicted value (2.64%). Then, the chemical structure of the extracted chrysophanol was identified by LC-MS. In addition, in vitro experiments showed that chrysophanol has an inhibitory effect on S. suis (minimum inhibitory concentration was 1.98 μg mL−1) and was shown to significantly inhibit the capability of S. suis to form a biofilm using crystal violet staining. Finally, scanning electron microscopy analysis showed that the three-dimensional structure of the biofilm deposited by the S. suis community was destroyed by chrysophanol.

Lonimacranaldes A and B (1 and 2), along with one biogenetically related intermediate, lonimacranalde C (3), were isolated from the flower buds of Lonicera macranthoides. Characterized by an iridoid structure and an additional C-6 unit with an aldehyde group, compounds 1 and 2 are the first examples of hybrid iridoids possessing an unexpected 6/5/6 fused tricyclic ring system, while compound 3 serves as an important precursor for their generation. The structures of lonimacranaldes A–C (1–3) were revealed by extensive spectroscopic and X-ray diffraction analyses. A plausible biogenetic pathway for them was proposed. Compound 3 showed anti-inflammatory activities by inhibiting the production of IL-6 on LPS-induced RAW 264.7 cells with an IC50 value of 6.33 μM.

Surface-enhanced Raman spectroscopy (SERS) has been one of the most promising analytical tools. Despite many efforts in the design of SERS substrates, it remains a great challenge for creating a general flexible substrate that could in situ detect analytes on diverse objects. Herein, we report our attempt to address this issue by developing a facile and versatile method capable of generating silver/gold nanoparticles in situ on the surface of a cellulose acetate (CA) polymer in a simple, cheap, practical, and capping agent-free way. The as-prepared substrates exhibit excellent sensitivity, which enabled detection of Rhodamine 6G at concentrations as low as 10−12 M. Taking advantage of the excellent flexibility and optical transparency of the CA matrix, the highly SERS-active substrate was applied for in situ identification and detection of pesticide residues on fruits. The results indicated that tetramethylthiuram disulfide (TMTD) and thiabendazole (TBZ) can be clearly identified at concentrations as low as 18.05 ng cm−2 and 15.1 ng cm−2, respectively, which were much lower than the maximum permitted residue doses with respect to food safety.

Novel Nb-doped Bi2WO6 nanosheets have been successfully synthesized by a simple hydrothermal method. XRD, Raman spectra, XPS and SEM were adopted to analyze the structure and morphology of the samples, then the structure-dependent optical properties, photoelectric behavior and photocatalytic activities were investigated, and the structure–property relationship was also discussed. The results show that doping Nb5+ can increase the oxygen vacancies in the Bi2WO6 lattice and reduce the optical band gap of Bi2WO6. The oxygen vacancies also act as electron traps, which promote the separation of photogenerated carriers. Hence, compared with the pure Bi2WO6, the as-prepared Nb-doped Bi2WO6 nanosheets exhibit enhanced visible-light photocatalytic activity for removing contaminants in water such as rhodamine B and tetracycline.

Thermoelectric devices have great potential as a sustainable energy conversion technology to harvest waste heat and perform spot cooling with high reliability. However, most of the thermoelectric devices use toxic and expensive materials, which limits their application. These materials also require high-temperature fabrication processes, limiting their compatibility with flexible, bio-compatible substrate. Printing electronics is an exciting new technique for fabrication that has enabled a wide array of biocompatible and conformable systems. Being able to print thermoelectric devices allows them to be custom made with much lower cost for their specific application. Significant effort has been directed toward utilizing polymers and other bio-friendly materials for low-cost, lightweight, and flexible thermoelectric devices. Fortunately, many of these materials can be printed using low-temperature printing processes, enabling their fabrication on biocompatible substrates. This review aims to report the recent progress in developing high performance thermoelectric inks for various printing techniques. In addition to the usual thermoelectric performance measures, we also consider the attributes of flexibility and the processing temperatures. Finally, recent advancement of printed device structures is discussed which aims to maximize the temperature difference across the junctions.

By introducing the dye Rhodamine 6G (R6G) into a metal–organic framework (MOF), Mn-sdc-2 (H2sdc = 4,4′-stilbenedicarboxylic acid), with a pore size of 20 × 9.8 A2, the composite R6G@Mn-sdc-2 was obtained. Subsequently, the MOF Mn-sdc-1 with a smaller pore size of 7.5 × 7.5 A2 can be formed through a single-crystal to single-crystal transformation from Mn-sdc-2, thus tightly locking the dye R6G within the pores. Compared with R6G@Mn-sdc-2, R6G@Mn-sdc-1 exhibits a stronger fluorescence emission of R6G. Because the MOF Mn-sdc-1 can reversibly transform back to Mn-sdc-2 in the presence of trace water, the dye R6G can be released. This enables R6G@Mn-sdc-1 to be used as a new luminescent sensor for trace water in organic solvents by monitoring the fluorescence intensity of released R6G. The limit of detection can reach 0.035% in ethanol (v : v), which is among the most sensitive fluorescent water probes.

Shogaols, mainly [6]-shogaol (6S), [8]-shogaol (8S) and [10]-shogaol (10S), the predominant and characteristic pungent phytochemicals in ginger, are responsible for most of its beneficial effects. However, poor oral bioavailability owing to extensive glucuronidation limits their application. The present study aimed to characterize the glucuronidation pathways of 6S, 8S and 10S by using pooled human liver microsomes (HLM), human intestine microsomes (HIM) and recombinant human UDP-glucosyltransferases (UGTs). The rates of glucuronidation were determined by incubating shogaols with uridine diphosphate glucuronic acid-supplemented microsomes. Kinetic parameters were derived by appropriate model fitting. Reaction phenotyping assays, activity correlation analyses and relative activity factors were performed to identify the main UGT isoforms. As a result, one mono-4′-O-glucuronide was detected after incubating each shogaol with HLM and HIM. Enzymes kinetic analysis demonstrated that glucuronidation of shogaols consistently displayed the substrate inhibition profile, and the liver showed higher metabolic activity for shogaols (CLint = 1.37–2.87 mL min−1 mg−1) than the intestine (CLint = 0.67–0.85 mL min−1 mg−1). Besides, reaction phenotyping assays revealed that UGT2B7 displayed the highest catalytic ability (CLint = 0.47–1.17 mL min−1 mg−1) among all tested UGTs. In addition, glucuronidation of shogaols was strongly correlated with AZT glucuronidation (r = 0.886, 0.803 and 0.871 for glucuronidation of 6S, 8S and 10S, respectively; p < 0.01) in a bank of individual HLMs (n = 9). Furthermore, UGT2B7 contributed to 40.8%, 34.2% and 36.0% for the glucuronidation of 6S, 8S and 10S in HLM, respectively. Taken altogether, shogaols were efficiently metabolized through the glucuronidation pathway, and UGT2B7 was the main contributor to their glucuronidation.

Drug-induced liver injury (DILI) is a serious concern in modern medicine due to its unpredictability. Currently, biochemical serum markers are being used in DILI detection. However, these biomarker-based methods lack sensitivity and specificity. A high intracellular level of hydroxyl radicals (˙OH) has been regarded as an early indicator of DILI. Therefore, we proposed an ˙OH-responsive and hepatocyte-targeted nanoprobe via conjugation of carboxyfluorescein-labeled DNA and pegylated galactose on the surface of gold nanoparticles. The nanoprobe could bind to a hepatocyte-specific asialoglycoprotein receptor through galactose, and it could be internalized into liver cells. In the presence of high levels of ˙OH in DILI, the DNA could be cleaved to release carboxyfluorescein, leading to remarkable fluorescence enhancement for ˙OH detection. Confocal fluorescence imaging demonstrated that the nanoprobe could be successfully applied in monitoring high ˙OH levels resulting from acetaminophen or triptolide-induced liver injury, which may provide a simple but powerful protocol for the prediction of DILI.

Gabapentin (GAB) is an emerging contaminant that is frequently detected in water bodies across the globe. The present study used zebrafish as a model organism to investigate the effects of GAB on the early development of zebrafish and on its antioxidant system. Acute toxicity tests indicated that the 96 h LC50 value of GAB for zebrafish embryos was 59.9 g L−1. Further, it was observed that GAB causes malformation of embryos such as hemagglutination and pericardial edema. Compared to the control group, a significant enhancement (p < 0.05) of heartbeat rates was found at GAB concentrations exceeding 50 mg L−1, while the swimming frequency was clearly increased upon exposure to GAB at a concentration of 100 mg L−1 (p < 0.05). Additionally, the development of the zebrafish embryo was also negatively impacted after exposure to GAB as demonstrated by significantly decreased body lengths. Exposure to GAB at concentrations exceeding 50 mg L−1 significantly influenced the development of zebrafish, leading to malformation of organs and abnormal movements. Although no significant developmental effects of GAB were observed at environmentally relevant concentrations (0.1 and 10 μg L−1), further research about the antioxidant system confirmed that severe oxidant injury happened inside the organisms. catalase (CAT), lactate dehydrogenase (LDH), glutathione S-transferase (GST), glutathione (GSH) and the ability of inhibition of hydroxyl radicals (IHR) were used as biomarkers in the present study to illustrate GAB toxicity at environmentally relevant concentrations. The results showed that activities of CAT, LDH and GST as well as IHR were all elevated after GAB exposure, which proved that ROS were formed in the body as derived from GAB exposure. Among all of these biomarkers, CAT was the most sensitive one to evaluate the influence of GAB, and showed a significant increase even at a very low exposure concentration (0.1 μg L−1).

Compounds consisting of unsubstituted, monofluoro and difluoro substituted benzothiadiazole bonded to two tetraphenylethenes were successfully prepared by palladium catalyzed Suzuki-Miyaura cross-coupling reaction of their corresponding co-monomers. All compounds exhibited aggregation-induced emission characteristics when the water fraction was higher than 60% in the THF/water mixtures. The emission maximum for the three compounds was blue-shifted when the water content reached 90% compared to that in THF solution. The intensity of emission maximum of difluorinated benzothiadiazole linked with two tetraphenylethenes was 2.5 times higher in 90% water compared to those in THF solution. Surprisingly, two liquid crystal phases with two distinct emission colors were observed only for the compound containing difluorinated benzothiadiazole bonded to two tetraphenylethene. All compounds showed remarkable solvatochromic properties in selected solvents with different polarities. The powder XRD results and mechanochromism of the compounds suggested that the solid state structures can change from one form to another by grinding, fuming or annealing processes.

4-Bromo substituted [2.2]paracyclophane-1,9-diene was synthesized from the corresponding dithia[3.3]paracyclophane in three steps through benzyne Steven rearrangement, oxidation, and a thermal elimination reaction. 4-Triphenylvinylphenyl substituted [2.2]paracyclophane-1,9-diene was successfully prepared by the Suzuki–Miyaura cross-coupling reaction of 4-bromo substituted [2.2]paracyclophane-1,9-diene and 4,4,5,5-tetramethyl-2-(4-(1,2,2-triphenylvinyl)phenyl)-1,3,2-dioxaborolane using Pd(OAc)2 as a catalyst, S-Phos as a ligand and K3PO4 as a base. The structures of bromo substituted [2.2] paracyclophane-1,9-diene and triphenylvinylphenyl substituted [2.2]paracyclophane-1,9-diene were fully characterized by 1H NMR spectroscopy and X-ray crystallography. 4-Triphenylvinylphenyl substituted [2.2]paracyclophane-1,9-diene exhibited aggregation-induced emission characteristics when the water fraction was higher than 80% in the THF/water mixtures. 4-Triphenylvinylphenyl substituted [2.2]paracyclophane-1,9-diene displays much higher fluorescence when the water fraction is 90% compared to that of model compounds due to both through bond and through space conjugation. To the best for our knowledge, we are the first to synthesize triphenylvinylphenyl substituted [2.2]paracyclophane-1,9-diene with aggregation-induced emission characteristics.

A novel 7-O-7′ type mesomeric neolignan, meso-asarolignan A (1), six pairs of new neolignan enantiomers, (±)-asarolignan B–G (2a/2b, 3a/3b, 4–6, 7a/7b), along with 16 known analogues (8–23) were isolated from the rhizomes of Acorus tatarinowii. The structures of the new compounds were elucidated by extensive analysis of spectroscopic, X-ray diffraction, and computational data. Compounds 1–3 represent rare examples of naturally occurring lignans with a 7-O-7′ linkage pattern. All isolated compounds were assayed for their anti-neuroinflammatory effects on tumor necrosis factor α (TNF-α) production in an activated murine microglia cell line. Compounds 7(a/b), 14(a/b), 16, 20, and 22 reduced TNF-α levels without high cell toxicity in LPS-activated BV-2 cells.

Fe2+ can act as a catalyst to disproportionate hydrogen peroxide (H2O2) to produce extremely reactive hydroxyl radicals (˙OH) through the so-called Fenton reaction. Combining this reaction with the prominent sensitive nature of gold nanoclusters (Au NCs), we present herein a simple strategy of sensitive and rapid detection of H2O2. Compared with H2O2, the produced hydroxyl radical exhibits a much stronger oxidizing ability, and therefore could lead to a more efficient oxidation of the Au NCs and an improved sensitivity and oxidation rate. The results indicate that the detection limit for the determination of H2O2 was 0.2 μM (signal/noise = 3) and the linear range was 0.4–12 μM. Furthermore, in combination with the specific catalytic effect of glucose oxidase, the present sensing strategy can be successfully expanded to detect glucose in blood. The preliminary results are in good agreement with those provided by the hospital, which suggests the generalizability and great potential of the Au NCs/Fenton hybrid system for research and clinical diagnosis of diabetes.

Cupredoxins are electron transfer proteins with a single type 1 copper center. A metal-binding loop in the protein harbors 3 of the copper ligands. Previous research has altered the sequence and length of the loop, changing the spectroscopic properties and reduction potentials of cupredoxins. It remains elusive whether the loop is flexible enough to tolerate long sequences. In this work we extended the loop to infinity by performing circular permutation on azurin, a typical cupredoxin. The mutant protein, Az-loop was characterized by absorption spectroscopy, electron paramagnetic resonance spectroscopy, cyclic voltammetry and X-ray crystallography. The results further confirm the flexibility of the metal-binding loop.

Water treatment sludge, which is mechanically dewatered and landfilled as solid waste, is considerably generated in water plants for potable water production. Herein, a novel route to hydrothermally convert this sludge into magnetic particles (MPs) is demonstrated. The sludge comprised amorphous aggregates with a relatively high Al/Si ratio of 3.7 and low Fe content of 8.5 wt%. After hydrothermal treatment, the Al/Si ratio of the MPs was approximated to 1, which was unaffected as the NaOH concentration increased from 2 M to 4 M or 6 M. The amorphous sludge was converted to MPs in the following order: spherical sodalite with a diameter of 3–5 μm, large spherical sodalite with a diameter of 5–10 μm and crystal dendritic cancrinite. Dendritic cancrinite was generated by recrystallisation of amorphous Al/Si oxides with spherical sodalite as the intermediate. With the addition of ascorbic acid, magnetisation of the weakly magnetised sludge increased from 0.11 emu g−1 to 3.6 emu g−1 and 14.8 emu/g by raising the NaOH concentration from 2 M to 4 M and 6 M. The magnetic property was related to the magnetite generated from the reduction of ferrihydrite and hematite in the sludge by the added ascorbic acid. Dendritic cancrinite exhibited an optimal surface site concentration of 0.31 mmol g−1 and desirable adsorption capacity of tetracycline (TC) (482.6 mg g−1), which were twice those of spherical sodalite prepared with 4 M NaOH. This study not only highlights the resource recovery of wastewater treatment sludge for MP preparation but also presents a new and effective adsorbent for treatment of TC-containing wastewater.

Lonimacranaldes A and B (1 and 2), along with one biogenetically related intermediate, lonimacranalde C (3), were isolated from the flower buds of

Novel Nb-doped Bi

Double hysteresis loops induced by defect dipoles are obtained in PbZr0.52Ti0.48O3/PbZr0.8Ti0.2O3 ferroelectric bilayer thin films prepared by a sol–gel method. The migration of the defect dipoles related to the temperature and applied electric field is investigated in detail, which has a deep influence on the polarization due to the effect of the domain pinning caused by defect dipoles. Meanwhile, the electrocaloric effect based on double hysteresis loops induced by defect dipoles has been studied. The coexistence of a negative electrocaloric effect and positive electrocaloric effect has been achieved in PbZr0.52Ti0.48O3/PbZr0.8Ti0.2O3 bilayer films, ΔT = −8.4 K at 155 °C, and ΔT = 4.4 K at 45 °C. The amplifying effect of the applied electric field in the PZr0.8Ti0.2O3 layer films plays an important role in the excellent negative electrocaloric values. More interestingly, the coexistence of the negative electrocaloric and positive electrocaloric effect can be obtained by regulating the applied electric field, which is beneficial to enhancing the cooling efficiency during the cycling of the applied electric field.

This study describes the synthesis of cobalt–ceria catalysts with octahedron and nanosphere shapes via a facile and surfactant-free hydrothermal method. The morphology of the products could be controlled by adjusting the proportion of solvent. The products evolved from nanospheres to octahedra with decreasing ethylene glycol/water volume fraction ratio in the reaction system. The formation process of the nanospheres involved dissolution–recrystallization-assembly and Ostwald ripening processes. Furthermore, the sizes of the obtained ceria–cobalt nanospheres were about 30 to 150 nm; these were composed of many crystallites with sizes of approximately 7 to 9 nm. The size of the ceria–cobalt nanospheres could be controlled by changing the cobalt doping amount in the mixed water–glycol system. These synthesized catalysts were applied for NO oxidation. The catalytic performance is closely related to the oxygen vacancy and the NO adsorption ability. In the low cobalt doping amount, NO adsorption and desorption played an important role in the oxidation process. However, the adsorption and activation O2 was the key step when the NO adsorption and desorption ability was similar.

External resistance is one of the important factors that affect the performance of microbial fuel cells (MFCs). In this study, bioelectrochemical and biofilm characterization was conducted for Shewanella oneidensis MR-1 inoculated MFCs with 250 Ω, 500 Ω, 2 kΩ, 6 kΩ and 22 kΩ resistors. Overall, a smaller external resistance resulted in a higher maximum power density and more riboflavin secretion. A maximum power density of 136.8 ± 3.1 mW m−2 was achieved when MFCs were operated with a 500 Ω resistor, which was 3.7 times that with a 22 kΩ resistor. Electrochemical impedance spectra (EIS) analysis verified an increased internal resistance with a higher external resistance. Meanwhile, more biofilm mass and extracellular polymer substances (EPS) were confirmed on the MFC anode with a higher external resistance.

Arsenic contamination in groundwater has raised great concern in many countries around the world. In this study, a new activated carbon fiber (ACF) based material targeting the simultaneous removal of arsenic and natural organic matter was developed. The ACF, as a support material, was modified by doping with zirconium-based nanoparticles (NP) with chitosan as a linking polymer. The fabrication of Zr-based NP doped ACF was optimized by a L9 (3)4 orthogonal experimental design approach. The adsorption kinetics study showed that the adsorption equilibrium was established within 30 h. The adsorption increased as the solution pH was decreased; the optimal pH for adsorption was 3.0. The experimental data were better described by the Langmuir equation than the Freundlich equation; the maximum adsorption capacity of 21.7 mg As per g was achieved at pH 3.0. The adsorption was not reduced in the presence of carbonate. The presence of fluoride and phosphate had some negative effects on the adsorption. The arsenic uptake was however greatly retarded by the silicate. The fixed-bed column filtration experiment demonstrated that the sorbent had 570.4 bed volumes, to meet the maximum contaminant level of 10 µg L−1 when treating simulated arsenic contaminated water with an initial concentration of 106 µg L−1. The XPS analysis indicated that the adsorption of arsenate was mainly associated with an ion-exchange reaction between hydrogen sulfate and arsenate ions.

The porous metal–organic framework (MOF) {[Mg2(BDC)2(BPNO)]·2DMF (Mg-MOF, mother crystal; DMF = N,N-dimethylformamide) was prepared by the solvothermal reaction of 1,4-benzene dicarboxylate (H2BDC), 4,4′-dipyridyl-N,N′-dioxide (BPNO) and Mg(NO3)·6H2O in DMF/EtOH. This Mg-MOF has a unique structure with 1-dimensional (1D) channel as well as infinite metal chains, which resembles the topology of MIL-53. Desolvated Mg-MOF can be used as absorbent for selective adsorption and separation of nitrile guest molecules including acetonitrile (MeCN), acrylonitrile (ACN), allylnitrile (AN) and crotononitrile (CTN) without loss of crystallinity. Furthermore, desolvated Mg-MOF also selectively captured cis-crotononitrile into its cavity from a mixture of cis and trans isomers. The process of adsorption produced quantitatively four daughter crystals, [Mg2(BDC)2(BPNO)]·2S (2: 2A, S = MeCN; 2B, S = ACN; 2C, S = AN; 2D, S = cis-CTN), which exhibit reversible interconversion by guest-exchanges at RT in single crystal transformations. Vapor phase adsorption isotherms of MeCN, ACN, AN and CTN on the desolvated Mg-MOF are presented.

A sensitive electrochemical immunosensor for the detection of human chorionic gonadotropin (hCG) is designed based on a novel signal amplification strategy. A hierarchical nanoporous (HNP) AuAg alloy with the advantages of a large surface area, excellent structure stability, and rich pore channels is used as an hCG antibody carrier for the preparation of a highly sensitive immunosensor. The HNP-AuAg alloy with bimodal ligament/pore size distribution is fabricated by means of simple dealloying and redealloying of the AuAgAl source alloy combined with an annealing operation. Graphene sheets (GS) and ionic liquid (IL) composites have been introduced as transducing materials to modify the conductivity as well promote the electron transfer in the immunosensor. Based on the dual-amplification effects of the HNP-AuAg alloy and the IL/GS composite film, the constructed immunosensor exhibits an enhanced performance for hCG detection compared with that based on single nanoporous (NP) Au, including a lower detection limit of 0.01 ng mL−1 and wider linear range from 0.05 to 35.0 ng mL−1. Moreover, the immunosensor exhibits respectable reproducibility and stability, indicating a potential application in clinical monitoring of hCG.