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This paper describes a new label-free fluorescent aptasensor for the detection of aflatoxin B1 (AFB1) based upon exonuclease I (Exo I) and SYBR Gold, in which SYBR Gold, aptamer, AFB1, and Exo I were used. Specific combinations of aptamer and AFB1 occurred in the presence of AFB1 and consequently altered the spatial structure of the aptamer, thereby preventing its digestion by Exo I. When SYBR Gold was added, intense fluorescence was observed. Additionally, a good linear relationship was observed under optimized conditions between the fluorescence intensities and the AFB1 concentrations (R2 = 0.993). The established aptamer sensor was highly sensitive and exhibited a low limit of detection of 1.82 ng mL-1, with superior specificity for AFB1. It was also used in the quantification of AFB1 levels in soybean sauce samples and demonstrated satisfactory recoveries in the scope of 94.8-108.9%. The proposed sensor is highly sensitive, low cost, and capable of rapid detection and can thus be used to determine mycotoxin levels in a wide range of feeds and food products in a high-throughput and quantitative means.

Background: Chronic stress promotes cancer growth. Antidepressant fluoxetine (FLX) is usually prescribed for cancer patients with comorbid depression. FLX displays inhibition on cancer cell proliferation, however, the in vivo activity has not been investigated.Methods: We explored the antitumor effect of FLX in subcutaneous transplanted lung cancer cells in a tumor-bearing mouse model. Fifty-six C57BL/6 mice were randomly divided into group A (blank control), group B (tumor-bearing control), group C (tumor-bearing + FLX), group D (CUMS control), group E (CUMS + FLX), group F (tumor-bearing + CUMS), and group G (tumor-bearing + CUMS + FLX). 5-HT, tryptophane (Trp), kynurenine, IFN-γ, TNF-α, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-17A levels were measured by ELISA. T helper (Th), cytotoxic T (Tc) and regulatory T cells (Tregs) subtype were measured by flow cytometry. The antitumor effects of FLX were evaluated by tumor weight. The expression of kynurenine pathway related genes TDO, IDO1, IDO2, and apoptosis-related genes caspase1, 3, 4, 5, 7, 12 in tumor tissues were measured by western blotting and qRT-PCR. A549 cells were exposed with FLX (15 μmol/L) and its effect on cell proliferation, migration, and clonal formation were detected. Kynurenine pathway and apoptosis related gene expression were also measured.Results:In vivo, chronic stress promoted tumor growth in C57BL/6 mice. FLX administration not only significantly reversed chronic unpredictable mild stress (CUMS)-induced reduction of 5-HT and Trp, increment of kynurenine, but increased CD4+ Th and CD8+ Tc cells, and reduced CD25+ FOXP3+ Tregs. FLX promoted Th to differentiate into Th1 cells and increased IL-2 and IFN-γ, meanwhile inhibited Th differentiate into Th2 and Th17 cells and decreased the concentrations of IL-4, IL-6, IL-10, and IL-17A. Chronic stress obviously up-regulated IDO1 and IDO2 expression, down-regulated caspase 4, 7, and 12 expression, meanwhile FLX administration reversed this regulation. However, there was no significant change in TDO, caspase 1, 3, 5. Similarly, in vitro, FLX administration significantly inhibited the proliferation, migration, and clonal formation of A549 cells and induced cell apoptosis. FLX administration down-regulated the expression of IDO1, IDO2, and up-regulated caspase 4, 5, and 7.Conclusion: Fluoxetine administration could inhibit tumor growth. The inhibition might be via suppressing kynurenine pathway and enhancing cellular immunity.

Owing to poor aqueous solubility and low delivery efficiency, most of anti-cancer chemodrugs depend on various smart drug delivery platforms to enhance the treatment efficacy. Herein, a stimuli-responsive supramolecular drug delivery system (SDDS) is developed based on polymeric cyclodextrins (PCD) which crosslinked by stimuli-cleavable drug dimers via host-guest interaction. PEGylated PCD was precisely controlled synthesized by ring-opening polymerization and azide-alkyne click chemistry, and two doxorubicins (DOX) were linked with a disulfide bond to form a drug dimer (ss-DOX). They then co-assembled into supramolecular micelles. Drug dimers were utilized as cross-linkers to stabilize the micelles. The drug loading efficiency was very high that could be up to 98%. The size and morphology were measured by DLS and TEM. Owing to the disulfide bonds of drug dimers, these supramolecular micelles were dissociated by treating with dithiothreitol (DTT). In the meanwhile, the free DOXs were recovered and released from cavities of cyclodextrins because of dynamic equilibrium and hydrophilicity changes. The release profile was studied under mimic physiological conditions. Furthermore, in vitro cytotoxicity study showed excellent anti-cancer efficacy of reduced-responsive supramolecular polymeric micelles. Therefore, it can be served as a safe and stimuli-responsive SDDS for cancer therapy.

In this experimental research, a label-free sensing strategy is developed and employed to detect adenosine triphosphate with utilization of aptamers, including exonuclease I and SYBR Gold. The conformation of aptamers bonding to the specific target molecule (ATP) is transformed into an antiparallel G-quadruplex structure from a random coil. Afterwards, considering the unfolded aptamers are the preferred substrates for exonuclease I, the addition of exonuclease I is used so as to digest unfolded aptamers in the mixture in a selective manner. In the follow-up study, in order to strengthen the fluorescence intensity, SYBR Gold is applied as a fluorescent probe. The aptasensor presents the features of high selectivity against adenosine triphosphate and the low detecting limit of concentrations (39.2 nM). In order to verify the validation of experimental procedures and the practical application of the aptasensor, the detection of adenosine triphosphate for human serum samples is performed with satisfactory success. The recovery result with the range of 93.8%–108.1% is desirable and suggests that the designed approach is applicable. The outcomes of the cellular adenosine triphosphate assay manifest that the level of adenosine triphosphate concentrations in cell extracts can be monitored without the interference of other substances in the cells. Subject to its advantageous benefits (cost-effective, easiness, rapidity, and extraordinary selectivity), the designed approach has a promising implication for adenosine triphosphate detection in the research domain of bioanalytical science and biology.

The release of uranyl from uranium tailing sites is a widely concerned environmental issue, with limited investigations on the effect of coexistence of various colloids. Gibbsite colloids extensively exist, together with ubiquitous humic substances, in uranium polluted waters at tailing sites, due to high concentration of dissolved Al in acid mine drainage. In this context, we investigated the co-transport of U(VI), gibbsite colloids and humic acid (HA) as a function of pH and ionic strength at a U(VI) concentration (5.0 × 10−5 M) relevant within mine tailings and related waste. It was found that, owing to electrostatic attraction, gibbsite colloids and HA associated with each other and transported simultaneously regardless of U(VI) presence. Besides the impact of pH and ionic strength, whether gibbsite colloids facilitated U(VI) transport depended on HA concentration. Gibbsite colloids impeded U(VI) transport at relatively low HA concentration (≤5 mg L−1), because associated colloids loaded with U(VI) were positively charged which favored colloid retention on negatively charged quartz sand in the column. U(VI) together with gibbsite colloids and low concentration HA was completely blocked at natural pH and/or high ionic strength. At relatively high HA concentration (20 mg L−1), however, the associated colloids showed negative zeta potential which facilitated U(VI) transport because of repulsion between negatively charged colloids and quartz sand. Meanwhile, high concentration of HA dramatically accelerated the transport of gibbsite colloids. These results implied that gibbsite colloids might imped U(VI) migration at uranium tailing sites unless the aquifers are enriched with abundant humic substances.

Tannic acid/graphene oxide (TA/GO) composites were prepared in the present research, and their properties and sorption performance were evaluated by corresponding characterization methods and bath sorption experiments, respectively. The applications of TA/GO to remove U(VI) from aqueous solution were investigated with the maximum adsorption capacity of 87.8 mg&middot, g&minus, 1 at low pH (pH = 3.6 &plusmn, 0.03). The sorption of U(VI) ions on TA/GO followed the Langmuir model because of the complexation of oxygen-containing functional groups on the surface of TA/GO composites and uranium ions. TA/GO manifested excellent selective adsorption toward uranium ions with other metal ions (Cs+, Sr2+, Co2+). Furthermore, TA/GO as an effective adsorbent was reused to remove a large amount of U(VI) ions from aqueous solution. Therefore, TA/GO is an ideal material to remove highly toxic U(VI) ions from wastewater.

Four asymmetric alkyl-substituted DAPhens (N,N’-Dimethyl-N,N’-Dialkyl-2,9-Diamide-1,10-Phenanthrolines) were synthesized and investigated as selective ligands for UO22+. The results confirm that the ligands have higher affinity for uranyl comparing to the symmetric analogues with the same 1,10-phenanthroline core moiety. The slope analysis indicated the formation of 1:1 (metal/ligand) extracting complex, which was identified in the organic phase as [UO2(DAPhen-4)(NO3)]+ complex ion by electrospray ionization mass spectrometry (ESI-MS). The superior affinity of the ligands for UO22+ over Th4+ and Eu3+ in solvent extraction was consistent with the stability constants of their complexes in acetonitrile obtained by UV–Vis spectroscopic titrations. The observed better affinity of the asymmetric alkyl-substituted DAPhens could originate from the less steric hindrance of methyl in the terminal groups, which was confirmed by the relatively mild distortion of the ligand structure in the uranyl complex according to the crystal and molecular structure of the solid-state complex [UO2(DAPhen-1)(NO3)](NO3)·(CH3OH) as characterized by single crystal X-ray diffraction.

The photosynthetic CO2 fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) forms dead-end inhibited complexes while binding multiple sugar phosphates, including its substrate ribulose 1,5-bisphosphate. Rubisco can be rescued from this inhibited form by molecular chaperones belonging to the ATPases associated with diverse cellular activities (AAA+ proteins) termed Rubisco activases (Rcas). The mechanism of green-type Rca found in higher plants has proved elusive, in part because until recently higher-plant Rubiscos could not be expressed recombinantly. Identifying the interaction sites between Rubisco and Rca is critical to formulate mechanistic hypotheses. Toward that end here we purify and characterize a suite of 33 Arabidopsis Rubisco mutants for their ability to be activated by Rca. Mutation of 17 surface-exposed large subunit residues did not yield variants that were perturbed in their interaction with Rca. In contrast, we find that Rca activity is highly sensitive to truncations and mutations in the conserved N terminus of the Rubisco large subunit. Large subunits lacking residues 1-4 are functional Rubiscos but cannot be activated. Both T5A and T7A substitutions result in functional carboxylases that are poorly activated by Rca, indicating the side chains of these residues form a critical interaction with the chaperone. Many other AAA+ proteins function by threading macromolecules through a central pore of a disc-shaped hexamer. Our results are consistent with a model in which Rca transiently threads the Rubisco large subunit N terminus through the axial pore of the AAA+ hexamer. Ministry of Education (MOE) National Research Foundation (NRF) Published version This work was funded by Grant MOE2016-T2-2-088 from the Ministry of Education of Singapore and Grant NRF2017-NRF-ISF002-2667 from the National Research Foundation of Singapore (to O. M.-C.).

While cytochrome P450 (CYP)-mediated biosynthesis of arachidonic acid (AA) epoxides promotes tumor growth by driving angiogenesis, cancer cell intrinsic functions of CYPs are less understood. CYP-derived AA epoxides, called epoxyeicosatrienoic acids (EETs), also promote the growth of tumor epithelia. In cancer cells, CYP AA epoxygenase enzymes are associated with STAT3 and mTOR signaling, but also localize in mitochondria, where they promote the electron transport chain (ETC). Recently, the diabetes drug metformin was found to inhibit CYP AA epoxygenase activity, allowing the design of more potent biguanides to target tumor growth. Biguanide inhibition of EET synthesis suppresses STAT3 and mTOR pathways, as well as the ETC. Convergence of biguanide activity and eicosanoid biology in cancer has shown a new pathway to attack cancer metabolism and provides hope for improved treatments that target this vulnerability. Inhibition of EET-mediated cancer metabolism and angiogenesis therefore provides a dual approach for targeted cancer therapeutics.

This paper describes an aptamer/gold nanoparticle-based assay for ochratoxin A (OTA) detection. This assay is based on the use of an aptamer labeled with carboxyfluorescein (FAM) at its 5′-end and gold nanoparticles (AuNPs) that act as quenchers of fluorescence. When OTA is absent in the system, the fluorescently labeled aptamers are adsorbed on the surface of AuNPs. The fluorescence signal of the fluorescein-labeled OTA aptamer generated is quenched by the fluorescence resonance energy transfer effect of AuNPs. When OTA is present in the system, the fluorescently labeled aptamer binds to OTA and forms a folded structure, which can resist the adsorption of AuNPs. Thus, the fluorescent signal can be retained. The detection limit of this sensing platform is 5 nM, and the linear detection range is 10–1000 nM (R2 = 0.994). The procedure was validated by the quantitation of OTA in spiked ginger powder samples and were found to be free of interference by the sample matrix. The recoveries and the relative standard deviation varied from 89.0% to 117.8% and from 1.9% to 6.3%, respectively.

This study aimed to establish a detection platform for ochratoxin A (OTA), a common mycotoxin contaminant of various food products. The detection platform is based on signal amplification by Exonuclease III (Exo III) and fluorescence quenching by gold nanoparticles (AuNPs). The aptamer recognizes and binds to OTA, thus leading to the formation of duplex DNA between the complimentary DNA (cDNA) strand and the signal probe. Exo III then digests the duplex DNA from the 3′ blunt terminus of the signal probe to liberate the fluorophore and release cDNA. The released cDNA then hybridizes with other signal probes to initiate a new cleavage reaction. Through this cyclic hybridization–hydrolysis process, an OTA molecule can trigger the cleavage of a large quantity of signal probes. Upon the addition of AuNPs, the fluorophore cannot be adsorbed and quenched, thus notably amplifying fluorescence. The designed aptasensor is highly selective for OTA with a low limit of detection (4.82 nM). The feasibility of the detection procedure and the applicability of the aptasensor were validated through the detection of OTA in spiked red wine without interference from the sample matrix. Results indicated that the aptasensor could be used to verify the effectiveness of mycotoxin-control strategies.

Iron oxide coatings occur commonly in the environment and affect significantly the fate of heavy metals. However, U(VI) transport in water saturated iron oxide-coating porous media has been seldom investigated. In this study, the adsorption and retardation of U(VI) on iron oxide-coated sand were comparatively investigated over a wide range of experimental conditions by batch and column experiments combined with modelling. The presence of iron oxide coatings significantly enhanced U(VI) adsorption which could be described by a two-site surface complexation model. The breakthrough curves of U(VI) in iron oxide coated quartz sand column show a two-plateau profile, which could not be directly reproduced by the commonly used two-site kinetic model. More sites for U(VI) have to be considered, implying that the heterogeneity of surface sites might be more significant in the non-equilibrium transport system than that in the equilibrium adsorption system. In addition, the presence of salicylic acid (SA) facilitated the transport of U(VI) at acidic pH, due to the competition between surface complexation of U(VI) and the complexation of U(VI) with SA in aqueous phase. Overall, this study provides a comprehensive understanding of the migration behavior of U(VI) in water saturated iron oxide-coated sand system.

Although there have been a lot of studies on the adsorption of trivalent actinides on clay minerals, the gaps between surface complexation model (SCM) for the description and prediction of macroscopic adsorption and the coordination structures and configurations of the surface complexes are still not completely bridged. Aiming at a multi-scale description of Am(III) adsorption on bentonite, density functional theory (DFT) calculations and surface complexation modeling were carried out. The results showed that the SCM considering cation exchange reactions and the formation of surface complexes, i.e., ≡SSOAm2+, ≡SSOAm(OH)+ and ≡SSOAm(OH)2 could reproduce all batch experimental data for Am(III) adsorption on Gaomiaozi bentonite, a potential buffer material for China's Beishan high-level radioactive waste repository. The stoichiometric coefficients of 1 in the SCM are deduced, while the surface complexes at the sites of ≡Al(OH)2 on (010) surface and those of ≡AlO(OH) on (110) surface are bidentate according to DFT calculations. The detailed calculations of electronic structures indicated that both covalent bond and electrostatic interaction account for Am(III) coordinating with the surface hydroxyl groups. In addition, it was found that the structures and energy properties of Am(III) complexes on (010) surface are similar to those on (110) surface. Hydrogen bonds between binding waters of Am(III) and the surface hydroxyl groups are formed in all cases, contributing to additional stability of Am(III) surface complexes. Overall, this study provides an improved understanding of Am(III) adsorption on the edge surfaces of bentonite/montmorillonite.

Although various colloids co-exist in the environment, studies on the interaction between different kinds of inorganic colloids and their combined effects on radionuclide transport have scarcely been reported. In the present paper, the influence of colloidal gibbsite, a representative metal hydroxide in groundwater, on the transport of Na-bentonite colloids and their combined effects on U(VI) transport in saturated particulate granite columns were investigated. It was found that in the presence of the colloids, whether single Na-bentonite or the mixture of Na-bentonite and gibbsite, fewer pore volumes were needed for U(VI) breakthrough, indicating a colloid-facilitated U(VI) transport due to high binding affinity of uranyl for the colloids compared to granite. Meanwhile, the breakthrough curves of U(VI) were gradually flattened and the plateau of the curve for Na-bentonite was decreased as the concentration ratio of gibbsite to Na-bentonite increased from 1:10 to 1:6. Consequently, total recoveries of U(VI) and Na-bentonite decreased with more gibbsite in the mixed colloids. The inhibition effect of gibbsite colloids was ascribed to electrostatic interactions between positively charged surfaces of gibbsite colloids and negatively charged surfaces of bentonite colloids and granite granules. The electrostatic attraction between oppositely charged colloids led to an increase of mean size in the mixed suspension which declined colloid transport and the transport of colloid associated U(VI) as well. When the gibbsite-to-bentonite ratio was increased up to 1:5, the recoveries were obviously lower than those of single U(VI) and Na-bentonite transport. The results imply that positively charged materials may be further investigated as additives to decrease the loss of buffer material by groundwater erosion and the migration of radionuclide associated on bentonite colloids.

Ochratoxin A (OTA), is one of the most commonly found mycotoxins in food. It is primarily produced by Aspergillus ochraceus and Penicillium verrucosum. OTA can causes serious damages to liver and kidney, increases the teratogenicity, and has been considered as a potential carcinogen (group 2 B). In this study, we demonstrated a new detection system for the detection of OTA using fluorescence biosensing according to an anti-OTA aptamer and fluorescence quencher using single-walled carbon nanohorns (SWCNHs). In the presence of OTA, the OTA-specific aptamer underwent the conformation change from a random coil to an antiparallel G-quadruplex. The latter one was resistant to being adsorbed onto SWCNHs, leading to the pertection of the fluorescence of SYBR Gold. As a result, the remained fluorescent intensities correlated with the concentrations of OTA. The detection limit of OTA was 2.3 ng/ml, meanwhile the linear detection range was 5–500 ng/ml, with a satisfactory linear correlation (R2 = 0.992) of the fluorescence intensity and the logarithm of OTA concentrations. The aptasensor was subjected to quantify the concentration of OTA in red wine samples. As a result, this label-free aptasensor was suitable for the test of OTA in food samples.

A label-free sensing strategy employing aptamers, SYBR Gold, and exonuclease I (Exo I) for ochratoxin A (OTA) detection was designed. In the presence of target molecules (OTA), the conformation of the aptamer specific for OTA is switched from a random coil to an antiparallel G-quadruplex. Subsequently, Exo I is added into the mixture to digest the unfolded aptamers selectively, which are the preferred substrates of Exo I. Following the addition of SYBR Gold as probe, a strong fluorescence intensity is obtained. This aptasensor shows high selectivity toward OTA with a low limit of detection (16.5 nM). The validity of the procedure and applicability of the aptasensor are successfully assessed through the detection of OTA in spiked red wine and beer without interference from the sample matrix. Utilization of the proposed biosensor for quantitative determination of mycotoxins in food samples indicates its usefulness as a tool for verifying the effectiveness of mycotoxin control strategies.

Through a nature-inspired layer-by-layer assembly process, we developed a unique multifunctional tissue scaffold that consists of porous polyurethane substrate and nanoscale chitosan/graphene oxide hybrid coating. Alternative layers of drug-laden chitosan and graphene oxide nanosheets were held together through strong electrostatic interaction, giving rise to a robust multilayer architecture with control over structural element orientation and chemical composition at nanoscale. Combined pH-controlled co-delivery of multiple therapeutic agents and photothermal therapy has been achieved by our scaffold system. The new platform technology can be generalized to produce other tissue scaffold systems and may enable potential multimodal therapeutic applications such as bone cancer managements.

Based on Aggregation-Induced Emission (AIE), the development of a label-free, simple and sensitive fluorometric aptasensor for adenosine triphosphate (ATP) detection is described. With ATP present, the aptamers will combine with ATP and the conformation of the aptamer will switch from a random coil to an antiparallel G-quadruplex, which impedes the digestion by exonuclease I (Exo I). Addition of 4,4 -(1E,1E)-2,2-(anthracene-9,10-diyl) bis (ethene-2,1-diyl) bis (N,N, N-trimethyl-benzenaminium iodide) (DSAI) into the solution will cause aggregation of DSAI on the surface of the aptamer/ATP complex and consequently give rise to strong emission. Additionally, a good linear relationship was observed under optimized conditions between the fluorescence intensities and the logarithm of ATP concentrations (R2 = 0.9908). The established aptamer sensor was highly sensitive and exhibited a low limit of detection of 32.8 nM, with superior specificity for ATP. It was also used in the quantification of ATP levels in human serum samples and demonstrated satisfactory recoveries in the scope of 93.2%–107.6%. The cellular ATP assay results indicated that the developed method can be used for monitoring ATP concentrations in cell extracts without the interference of other substances in the cells. This method offers several advantages such as simplicity, rapidity, low cost and excellent selectivity, which make it hold great potential for the detection of ATP in bioanalytical and biological studies.

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage devices because of their high energy density of 2600 Wh kg-1. Efficient immobilization and fast conversion of soluble lithium polysulfide intermediates (LiPSs) are crucial to the electrochemical performance of Li-S batteries. Herein, we report a novel strategy to simultaneously achieve large capacity, high rate capability, and long cycle life by utilizing mesoporous niobium nitride microspheres/N-doped graphene nanosheets (NbN@NG) hybrids as multifunctional host materials for sulfur cathodes. The mesoporous NbN microspheres chemically immobilize LiPSs via Nb-S chemical bonding and catalytically promote conversion of LiPSs into insoluble Li2S resulting in enhanced redox reaction kinetics. Moreover, the highly conductive NbN and N-doped graphene nanosheets provide rapid electron transport and consequently, the S/NbN@NG cathode demonstrates a large capacity of 948 mAh g-1 at 1 C (1 C = 1650 mA g-1), high rate capability of 739 mAh g-1 at 5 C, and excellent cycle stability with a capacity decay of 0.09% per cycle for over 400 cycles. The results described here provide insights into the design of multifunctional host materials for high-performance Li-S batteries.

A time efficient and cost-effective laser-based surface texturing technique combining nanosecond laser ablation and chemical immersion treatment was developed for steel alloy to achieve enhanced corrosion resistance in marine atmospheric environment. Three different surface patterns were created by nanosecond laser ablation and the laser patterned samples were subsequently immersed in 1H,1H,2H,2H-perfluorooctyl silane (FOTS) solution to tune surface chemistry. Dual-scale surface structure was formulated on the laser-chemical treated surface, as confirmed by the scanning electron microscopy (SEM) and confocal laser scanning microscope analyses. X-ray photoelectron spectroscopy (XPS) analysis was conducted to validate that desired surface chemistry was achieved on the laser-chemical treated surface. The effect of surface pattern on several key surface functionalities, including surface wettability, corrosion resistance and chemical stability was systematically presented in this work. Firstly, it was demonstrated via wettability measurements that the laser-chemical treated surface achieved superhydrophobicity with a water contact angle of 158.9°. Secondly, electrochemical and NaCl deliquescence tests were conducted to determine the corrosion resistance of the laser-chemical treated surfaces in marine atmospheric environments. It was confirmed that the laser-chemical treated surface can prevent marine atmospheric corrosion induced by salt deliquescence. Furthermore, it was revealed by electrochemical test that the laser-chemical treated superhydrophobic surface exhibited distinctly better anti-corrosion performance. The experimental results showed that the corrosion rate for the laser-chemical treated surface with microgroove pattern is approximately 5.4% of the corrosion rate for the untreated surface, indicating significant improvement of corrosion resistance for the laser-chemical treated surface. Thirdly, the high water contact angle of 151.0° sustained on the laser-chemical treated surface after electrochemical tests helped confirm the improvement of its chemical stability in corrosion medium. These experimental findings clearly demonstrate the developed nanosecond laser-chemical treatment method can be very effective for fabrication of stable superhydrophobic metal surface as a barrier to marine atmospheric corrosion with enhanced corrosion resistance.

Sm-Nd analyses of seven scheelite samples from scheelite-quartz veins in the Honghuaerji scheelite deposit produce a well-defined linear array on an isochron diagram with a mean square weighted deviation (MSWD) of 0.87 corresponding to an age of 178.4 ± 2.9 Ma with eNd(t) = + 1.50. This age is interpreted to represent the age of scheelite mineralization. The scheelite Sm-Nd age is in good agreement with U–Pb ages obtained from a mineralization-related granite (179.4 ~ 178.6 Ma), indicating that there is no apparent age gap between granite crystallization and ore formation. Rare earth element (REE) abundances in the scheelite were determined by in situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and the scheelite samples contain elevated REE concentrations with total ΣREE + Y contents in the range of 3339 to 6321 ppm. The chondrite-normalized REE distribution patterns of all scheelites are middle REE (MREE)-enriched, with strong negative Eu-anomalies (Eu/Eu* = 0.09 ~ 0.23). The REE characteristics of the Honghuaerji scheelite suggest that REE 3 + substituted into the Ca site along with Na and Nb (dominated by Na), whereas Eu is predominantly present as Eu 2 + in the scheelite and may have crystallized from relatively reduced fluids. All sulfur isotope data (δ 34 S) for sulfide separates range from + 2.0 to + 3.8‰, with an average of 3.2‰. Measured 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios vary from 18.243 to 18.451, 15.494 to 15.574, and 37.933 to 38.340, respectively. On the basis of common Sr-Nd-Pb-Hf isotopic characteristics between the scheelite and the host granite and the positive initial Nd isotope ratios (+ 1.46 − + 1.52), low 87 Sr/ 86 Sr ratios (0.704983–0.705297) in the scheelites, it is inferred that the hydrothermal fluids responsible for tungsten mineralization at Honghuaerji were of magmatic origin with a mantle-derived signature. Based on the regional geology, tectonic evolution, and geochemical evidence, the Honghuaerji granite is thought to have been derived from the partial melting of thickened lower crust produced during post-collisional orogenic events associated with the closure of the Mongol-Okhotsk Ocean.

Introduction: Cancer cell-intrinsic CYP monooxygenases promote tumor progression. In ER+HER2-, breast cancer cells, CYP3A4 promotes tumor growth, in part, through epoxyeicosatrienoic acid (EET) biosynthesis (1). The biguanide diabetes drug metformin is currently being studied in breast cancer clinical trials. We have discovered that metformin binds to the active site heme of CYP3A4, thereby inhibiting EET biosynthesis (1). Structure-based design led to the discovery of the 100-fold more potent metformin analog N1-hexyl-N5-benzyl-biguanide (HBB). HBB specifically inhibits CYP3A4 arachidonic acid (AA) epoxygenase activity in breast cancer cells, suppresses the growth of breast cancer cell lines (IC50=3-30 uM), and inhibits growth of the MCF-7 ER+ mammary tumor model, similar to CYP3A4 gene silencing. Although CYP3A4 synthesizes EETs, how EETs may promote tumor growth is unknown. Recently, we found that HBB inhibits nuclear transit of estrogen receptor alpha (ERα) and 70kD FITC-dextran, but the mechanism was unknown (2). Metformin was discovered to inhibit nuclear pore complex (NPC) function, but the mechanism was also unknown (3). We therefore hypothesized that CYP-derived EETs function as second messengers that regulate nuclear translocation of ERα in breast cancer by promoting permeability of the NPC. This hypothesis implies that biguanide drugs suppress nuclear translocation of the ERα through inhibition of CYP-derived EETs that serve as second messengers to open the NPC. Methods: Breast cancer cells were serum-starved for 16 hours and then treated with metformin, HBB, the (±)-14,15-EET regioisomer, or EET agonists, for varying times (30 min to 6 hours). Cells were fixed, permeabilized, and incubated with antibodies specific for ERα. After incubation with fluorescent secondary antibodies and Hoechst 33342 dye, cell images were acquired with a confocal microscope and the nuclear ERα fluorescence signal was quantified relative to the Hoechst signal. Quantitative PCR was used to measure the expression of ERα regulated genes. Results: (±) 14,15-EET (5 uM) treatment for 1 hour increased nuclear ERα by 66 ± 26% (n=9, p=0.031) in MCF-7 cells and 77 ± 24% (n=7, p=0.015) in ZR-75 cells. Treatment with EET agonists C22 (5 uM) and EET-A (5 uM) for 1 hour increased nuclear ERα by 32 ± 13% (n=7, p=0.047) and 39 ± 14% (n=7, p=0.02) in MCF-7 cells. Metformin (5 mM) treatment for 6 hours reduced nuclear ERα in MCF-7 by 35 ± 4.9 % (mean ± SEM, n=8, p=0.003). HBB (20 uM) treatment for 2 hours reduced the expression of three ERα regulated genes in MCF-7 cells: estrogen receptor alpha (ESR1) was reduced by 15 ± 1.7% (n=3, p=0.001), progesterone receptor (PGR) by 21 ± 0.6% (n=3, p=0.02) and L-type amino acid transporter 1 (SLC7A5) by 14 ± 0.2% (n=3, p=0.002). Conclusion: CYP epoxygenase activity in ER+HER2- breast cancer cells produces EETs, which function as second messengers that promote nuclear transit of ERα. Metformin and HBB inhibit nuclear ERα translocation, in part, through inhibition of CYP3A4 AA epoxygenase activity and this inhibition reduces ERα mediated gene expression, providing a novel mechanism for ERα regulation. 1. Cell Chem Biol. 2017 Oct 19; 24(10) 1259 - 1275. 2. Abstract of 109th AACR meeting (#LB-023), April 2019 3. Cell. 2016 Dec 15;167(7):1705-1718 Citation Format: Zhijun Guo, Jianxun Lei, Shaoping Wu, Julissa Molina-Vega, Paloma Cervantes, Aline R. Rom'Mand, Dylan C. Castillejo Mijangos, John R. Falck, Carol Lange, Jinhua Wang, David A. Potter. Metformin inhibits nuclear localization of estrogen receptor alpha in breast cancer cells, in part, by inhibition of CYP-mediated epoxyeicosatrienoic acid (EET) biosynthesis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4372.

A novel label-free fluorescence aptasensor used for the detection of ochratoxin A (OTA) is presented in this study. When aggregated on the surface of DNA aptamer, aggregation-induced emission (AIE) fluorescence probe presents turn-on fluorescence property. The method proposed in this article was based on an AIE probe, 4, 4-(1E,1E)-2, 2-(anthracene-9, 10-diyl) bis (ethene-2, 1-diyl) bis (N, N, N-trimethylbenzenaminium iodide) (DSAI). With OTA present, the aptamer will combine with OTA and the conformation of the aptamer will switch to an antiparallel G-quadruplex from the initial random coil, which obstructs its digestion by Exo I. After the solution is added with DSAI, DSAI will aggregate on the surface of the aptamer/OTA complex and produces a strong emission. In the range of 5 to 500 ng · ml-1 OTA concentrations, the fluorescence increases with a linear logarithm relationship. The detection limit is 1.9 ng · ml-1. This method was used to detect OTA in spiked real samples, with recoveries and RSDs in the range of 92.2% to 106.3%, and 2.7% to 5.2%, respectively.

International audience; Humic acid (HA) in the environment may exist in either dissolved or fixed forms. However, laboratory studies usually take only the former into account. Here we synthesized a hybrid of HA and aluminum hydroxide (Al(OH)(3)) to mimic fixed HA, compared the effects of fixed and dissolved HA on Eu(III)/Yb(III) adsorption on Al(OH)(3), and analyzed the adsorption mechanisms using time resolved laser induced fluorescence spectroscopy (TRLFS), X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS). It was found that dissolved HA affected significantly Eu(III)/Yb(III) adsorption on Al(OH)(3), whereas fixed HA showed little apparent effect on the adsorption. The spectra of TRLFS, XPS and EXAFS for Eu(III)/Yb(III) adsorption on Al(OH)(3) in the presence of dissolved/fixed HA could be reproduced by those for Yb(III)/Eu(III) adsorption in the absence of HA and those for Yb(III)/Eu(III) binding to dissolved HA, respectively. Spectroscopic analyses indicated that the different effects of fixed and dissolved HA on Eu(III)/Yb(III) adsorption were due to different surface speciation with the same surface species, which could be interpreted by the decrease of available sites on fixed HA as compared to those on dissolved HA. This study implied that the effects of HA on the adsorption of Eu (III)/Yb(III) as well as other trivalent lanthanides/actinides in the environment might be overestimated if the differences between dissolved and fixed HA were not considered.

This study describes an aptamer based assay for the mycotoxin ochratoxin A (OTA). The method is based on the use of an OTA-specific aptamer, exonuclease (Exo) III, SYBR Gold as a fluorescent probe, and a complementary strand that specifically combines with the aptamer. In the presence of OTA, the aptamer and OTA hybridize, thereby resulting in the formation of ssDNA, which is not digested by Exo III. Intense fluorescence is observed after addition of SYBR Gold (best measured at excitation/emission wavelengths of 495/540 nm). Fluorescence increases linearly with the log of the OTA concentration in the range from 8 to 1000 ng·mL−1. The detection limit is 4.7 ng·mL−1. The assay was applied to the determination of OTA in diluted [2%(v/v)] red wine, and recoveries and RSDs ranged between 93.5% and 113.8%, and between 3.2% and 5.7%, respectively.

Silver nanoparticle-incorporated TiO2 nanotubes (Ag/TiO2-NTs) were successfully synthesized by anodization and immersion in a silver nitrate solution followed by ultraviolet light radiation. The obtained Ag/TiO2-NT samples were characterized by SEM, TEM and EDS, and the results show that the silver nanoparticles adhere strongly to the inner walls of the nanotubes along the entire length. The antibacterial ability to Escherichia coli and Staphylococcus aureus was also evaluated, and indicated that the incorporation of Ag was effective to restrain the growth of the testing bacteria.

This study aims to investigate and model the adsorption of Eu(III) on bentonite in the presence of phosphate. Binary (phosphate/bentonite) and ternary (Eu(III)/phosphate/bentonite) systems were studied as a function of contact time, pH, solid-to-liquid ratio and Eu(III)/phosphate concentration by using a batch experimental method. The adsorption of phosphate on bentonite slightly increased in the pH range of 2.5–6.5, and decreased in the pH range of 6.5–9.4. This adsorption can be quantitatively interpreted by a model considering the formation of three monodentate surface complexes. In the ternary system, a synergistic adsorption was observed in the presence of both phosphate and Eu(III). In addition to the two sub-models describing Eu(III) and phosphate adsorption, the formation of ternary surface complexes had to be considered in order to explain the synergistic effect experimentally observed. The experimental data could be quantitatively explained when Eu(III) ( SOEuH2PO4+ and SOEuHPO4) or phosphate ( SPO4Eu+) are the bridged atoms. Complementary experiments carried out by X-ray photoelectron spectroscopy suggested that the second case is the most probable. The proposed model can be used in order to predict Eu(III) adsorption on buffer/backfilling material in the presence of phosphate.

The authors describe an aptamer based assay for the food mycotoxin ochratoxin A (OTA). It is based on the use of exonuclease III (Exo III) which assists in signal amplification, and of single-walled carbon nanohorns (SWCNHs) which act as quenchers of fluorescence. The detection scheme employs a hairpin probe (HP) and a signal probe (SP) labeled with carboxyfluorescein (FAM) at its 5'-end. The fluorescence of intact SPs (best measured at excitation/emission wavelengths of 495/518 nm) is quenched by SWCNHs. The HP contains the OTA-specific aptamer sequence and is partially complementary to the SP. After addition of OTA, the aptamer binds OTA and thus exposes a single-stranded sequence that can hybridize with the SP. Exo III digests the SP to liberate the free fluorophore labels. The damaged SPs no longer are adsorbed by the SWCNHs so that fluorescence is no longer quenched. The method has a detection range that is linear from 10 nM to 1000 nM (with a correlation coefficient of 0.997). The limit of detection (LOD), calculated on the basis of a signal to noise ratio of 3, is 4.2 nM. The procedure was validated by the quantitation of OTA in spiked real samples and were found to be free of interference by the sample matrix. Recoveries ranged from 93.8 to 113.0% in beer and from 92.0 to115.9% in red wine. Graphical abstract After adding ochratoxin A (OTA), the aptamer region in hairpin probe (HP) combined with OTA and thus exposed a single-stranded sequence to hybridize with signal probe (SP). Exonuclease III (Exo III) digested SP to liberate the free fluorophore (FAM).

Oxidation debris (OD) and graphene oxide (GO) before and after OD removal were characterized by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, mass spectroscopy, X-ray diffraction, transmission electron microscopy and potentiometric titration, respectively. OD removal decreased GO absorption intensity in UV/Vis spectra, caused changes in peak position and absorption intensity in FTIR spectra, and resulted in the decrease of I D / I G in Raman spectra. OD was amorphous and had higher content of acidic groups than purified GO. OD contributed 10–25% of overall surface charge density to unpurified GO in spite of small amount (ca. 1% mass). OD removal decreased significantly GO dispersibility in aqueous solution, but increased obviously the electrical conductivity of reduced graphene oxide (rGO) and the apparent density of compacted rGO. The removal of OD was necessary because of its striking effects on both GO spectroscopic and macroscopic properties. Batch desorption in NaOH solution was recommended for OD removal from as-prepared graphite oxide because of slow OD desorption kinetics.

Batch experiments were conducted to elucidate the adsorption of a widely used salicylic acid (SA) and copper(II) on oxidized multi-walled carbon nanotubes (MWCNTs) as a function of pH and concentration. X-ray photoelectron spectroscopy and potentiometric titration were performed to study the concentration at the surface oxygen-containing functional groups of them. π–π Bond's sites were evaluated by the Dubinin–Ashtakhov model. Data analysis indicated that the adsorption mechanism was mainly due to chemical interaction among copper(II) and SA and the surface functional groups of them. The adsorbed SA on them leads to the modification of their surfaces and partial complexation of copper with the SA adsorbed on them and thus had a positive effect on the adsorption of copper. Copper was also shown to increase SA adsorption from pH 3 to 7. The surface complex model was used to describe the surface charge density, as well as adsorption equilibrium. The copper removal was due to adsorption of surface–metal complexes, while the SA uptake resulted from the formation of surface–organic complexes. Furthermore, when they coexisted in the system, it appeared that the surface/metal/organic chemical complexes were the main forms.

Graphene oxide (GO) is one of the most important carbon nano-materials. In this paper, GO was synthesized from flake graphite and characterized by transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The sorption of Th(IV) on GO was investigated as a function of contact time, solid-to-liquid ratio, pH, ionic strength, and in the presence of fulvic acid (FA) and humic acid (HA) by batch experiments. The sorption percentage of Th(IV) on GO decreased with increasing ionic strength and decreasing solid-to-liquid ratio. The sorption edge of Th(IV) in the presence of FA/HA is much lower than that in the absence of FA/HA. Furthermore, the sorption processes of Th(IV) can be described by a pseudo-second order rate model. Based on the Langmuir model, the maximum sorption capacities (Csmax) of Th(IV) were about 5.80 × 10−4 mol/L. From thermodynamic investigation, sorption of Th(IV) on GO is spontaneous and endothermic in nature. The rapid sorption rate and high sorption capacity suggest that GO is a promising adsorbent for Th(IV).

Although soft tissue replacement has been clinically successful in many cases, the corresponding procedure has many limitations including the lack of resilience and mechanical integrity, significant donor-site morbidity, volume loss with time, and fibrous capsular contracture. These disadvantages can be alleviated by utilizing bio-absorbable scaffolds with high resilience and large strain, which are capable of stimulating natural tissue regeneration. Hence, the chemically crosslinked tridimensional scaffolds obtained by incorporating water-based polyurethane (PU) (which was synthesized from polytetramethylene ether glycol, isophorone diisocyanate, and 2,2-bis(hydroxymethyl) butyric acid) into a bioactive extracellular matrix consisting of small intestinal submucosa (SIS) have been tested in this study to develop a new approach for soft tissue engineering. After characterizing the structure and properties of the produced PU/SIS composites, the strength, Young’s modulus, and resilience of wet PU/SIS samples were compared with those of crosslinked PU. In addition, the fabricated specimens were investigated using human umbilical vein endothelial cells to evaluate their ability to enhance cell attachment and proliferation. As a result, the synthesized PU/SIS samples exhibited high resilience and were capable of enhancing cell viability with no evidence of cytotoxicity. Subcutaneous implantation in animals and the subsequent testing conducted after 2, 4, and 8 weeks indicated that sound implant integration and vascularization occurred inside the PU/SIS composites, while the presence of SIS promoted cell infiltration, angiogenesis, and ultimately tissue regeneration. The obtained results revealed that the produced PU/SIS composites were characterized by high bioactivity and resilience, and, therefore, could be used for soft tissue engineering applications. Statement of Significance Hybrid composites containing synthetic polymers with high mechanical strength and naturally derived components, which create a bio-mimetic environment, are one of the most promising biomaterials. Although synthetic polymer/ECM composites have been previously used for soft tissue repair, their resilience properties were not investigated in sufficient detail, while the development of elastic composites composed of synthetic polymers and ECMs in nontoxic aqueous solutions remains a rather challenging task. In this study, porous PU/SIS composites were fabricated in a non-toxic manner; the obtained materials exhibited sufficient mechanical support, which promote cell growth, angiogenesis, and tissue regeneration. The described method can be adapted for the development of scaffolds with various acellular matrices and subsequently used during the restoration of particular types of tissue.

Introduction: Cancer cell-intrinsic CYP monooxygenases promote tumor progression. In ER+ breast cancer cells, CYP3A4 is required for tumor growth and localizes to mitochondria where it promotes electron transport chain and respiration, while suppressing autophagy, in part, through epoxyeicosatrienoic acid (EET) biosynthesis (1). The diabetes drug metformin inhibited CYP3A4-mediated EET biosynthesis and depleted cancer cell-intrinsic EETs. Metformin bound to the active site heme of CYP3A4 in a co-crystal structure, establishing CYP3A4 as a biguanide target. Structure-based design led to discovery of N1-hexyl-N5-benzyl-biguanide (HBB), which bound to the CYP3A4 heme with higher affinity than metformin. HBB potently and specifically inhibited CYP3A4 arachidonic acid epoxygenase activity, reduced oxygen consumption rates and suppressed growth of breast cancer cell lines (IC50=3-30 μM) and an established ER+ mammary tumor model. HBB inhibited activation of mTOR and suppressed S6Kinase phosphorylation. HBB also suppressed intratumoral mTOR. Recently, nuclear transit of RagC has been shown to promote mTORC1 function, a process sensitive to metformin (2), which inhibits the nuclear pore complex (NPC). Therefore, we hypothesized that HBB as a more potent biguanide may inhibit mTOR through reduction of nuclear RagC by regulating NPC. HBB may also regulate the localization of other nuclear proteins such as estrogen receptor alpha (ERα). Method: ER+HER2- breast cancer cells (MCF-7 and T47D) were seeded on chamber slides and treated with vehicle or HBB for varied periods of time. Cells were fixed, permeabilized, and incubated with specific antibodies against RagC and ERα. After incubation with fluorescence tagged secondary antibody, slides were stained with DAPI and analyzed by confocal microscopy. Levels of nuclear proteins of interest were normalized against DAPI staining. Results: CYP3A4 shRNA knockdown reduced nuclear RagC in MCF-7 cells by 61.2±12.3 % (n=3, p Conclusion: These data suggest that the biguanide sensitive enzyme CYP3A4 may play a role in nuclear localization of ERα and RagC, which work in tandem to promote the growth of ER+HER2- breast cancer cells. 1. Cell Chemical Biology. 2017 Oct 19; 24(10) 1259 – 1275. 2. Cell. 2016 Dec 15;167(7):1705-1718 Citation Format: Zhijun Guo, Shaoping Wu, Julissa Molina-Vega, Rafael Castillo, Jaime Barrera, Veronica Johnson, Carol Lange, David Potter. CYP monooxygenases regulate nuclear localization of ERá and mTORC1 component RagC in ER+HER2- breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-023.

The influence of the type of fermentation method on phenolics, antioxidant capacity, and volatiles in blackberry wine was studied. Dry blackberry wines made by traditional fermentation (TF) and carbonic maceration fermentation (CMF) were analyzed for total polyphenols, flavanols, flavonoids, anthocyanins, proanthocyanidin, and antioxidant capacity. High-performance liquid chromatography was used for analysis of nonflavonoid phenolics (gallic, benzoic, salicylic, syringic, caffeic, coumaric, and ferulic) and flavonoids (catechin, quercetin, and rutin). Volatiles were detected by gas chromatography-mass spectrometry. The results showed that CMF fermentation afforded higher antioxidant activity and phenolic content, especially individual polyphenolics. The total level of phenolics in the CMF wine was substantially higher than in traditional wines: 2953 mg of gallic acid equivalents (GAE)/L for CMF wine vs. 1647 mg of GAE/L for traditional wine. A total of 53 kinds of volatile compounds were detected. Of thes...

Ochratoxin A (OTA), a toxin produced by Aspergillus ochraceus and Penicillium verrucosum, is one of the most abundant food-contaminating mycotoxins worldwide. OTA mainly exerts nephrotoxicity, immunotoxicity, mutagenicity, carcinogenicity, teratogenicity, and neurotoxicity. This paper describes a simple and sensitive aptamer/single-walled carbon nanohorn (SWCNH)-based assay for OTA detection. SWCNHs can protect DNA from DNase I cleavage. However, aptamers can be detached from the surface of SWCNHs through specific target binding, exposing them to enzymatic cleavage and releases the target for a new cycle. Cycling of targets leads to significant signal amplification and low limit of detection (LOD), resulting in a nearly 20-fold reduction in LOD for OTA assay compared with non-target recycling under the same experimental parameters. This technique responded specifically to OTA without interference from other analogues (Ochratoxin B, Ochratoxin C, warfarin, and N-acetyl-l-phenylalanine). Moreover, the application of this technique in real sample has been verified using red wine samples spiked with a series of OTA concentrations. This aptasensor offers a great practical importance in food safety and can be widely extended for detection of other toxins by replacing the sequence of the recognition aptamer.

Pt–Au nanoparticles supported on carbon aerogel, namely 2:1 has been synthesized by the microwave-assisted polyol process. The structure of Pt–Au nanoparticles is characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical property of Pt–Au catalysts for methanol oxidation is evaluated by cyclic voltammetry (CV). The results show that Au-modified Pt catalysts exhibit a high methanol tolerance and improved electrochemical catalytic activity, suggesting that carbon aerogel supported Pt–Au catalysts are better catalysts for the electrochemical oxidation of methanol than conventional Pt catalysts.

In this study, based on ion-current rectification in the conically shaped nanochannel embedded in polyethylene terephthalate (PET) membrane, we have selectively discriminated three small biomolecules. Because three positive biomolecules (Hoechst 33342, Propidium and Bupivacaine) have different hydrophobicities, their interactions with inside wall of the conical nanochannel are different and their binding affinities can be derived from Langmuir absorption model. Therefore, we can successfully discriminate these small biomolecules. The highest binding constant was obtained for the small molecule with highest hydrophobicity. Another interesting result is that the detection limit for the small molecule with the highest binding constant shifts to submicromole.

Systematic experiments have been carried out to study the performance of the novel sodium titanate (Na 2 Ti 3 O 7 ) nanotube/Nafion ® composite membrane (5 wt% Na 2 Ti 3 O 7 ) in a single direct methanol fuel cell (DMFC) at different operating temperatures, methanol concentrations, air flow rates, methanol flow rates, and cathode humidification temperatures. The experimental results showed that the composite membrane outperform pure Nafion ® membranes with the same thickness, Nafion ® 112, under all the operating conditions. Furthermore, under some operating conditions, the new composite membranes even outperform Nafion ® 117, a much thicker membrane. These experimental results have proved that the new composite membrane is superior to pure Nafion ® membrane in DMFCs and the addition of Na 2 Ti 3 O 7 nanotubes into Nafion ® is an effective way to improve membrane performances.

Wines made from 3 spine grape (Vitis davidii Foex) genotypes—Junzi 1# (JZ 1#), Junzi 2# (JZ 2#), and Liantang (LT)—and Cherokee rose (Rosa laevigata Michx., CR) were evaluated for their phenolics composition and antioxidant activities by several assays, including 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS scavenging capacity, cupric ion reducing antioxidant capacity, and metal-chelating capacity). The results showed that CR wine had higher contents of total phenolics, total flavonoids, and oligomeric proanthocyanidins than the 3 spine grape genotype wines and Cabernet Sauvignon (CS) wine. Among the 3 varieties of spine grape wines, JZ 1# had higher contents than the 2 other genotypes. Moreover, the total monomeric anthocyanins in JZ 1# was about 4.5-fold higher than those in CS wine and CR wine. A significance analysis demonstrated that the antioxidant capacity (as measured by the ABTS scavenging capacity and cupric ion reducing antioxidant capacity) of CR wine was significantly higher than that of the control and spine grape wines. With respect to metal-chelating capacity, the CR wine was the strongest amongst all the wine samples tested, followed by JZ 1#. This indicates that CR and JZ 1# wines can potentially be considered as wild fruit wines with abundant phenolic compounds and antioxidant activities. Practical Application: Spine grape (Vitis davidii Foex) and Cherokee rose (Rosa laevigata Michx.) are 2 species of important wild plants in South China. However, they have not yet been effectively developed and utilized. Recently, some researchers attempted to convert their juice to wine. We anticipate that this research will provide sufficient experimental evidence for their good antioxidant activity and potential for further development and utilization.

Nanometer-sized lead barium titanate (Pb1−xBaxTiO3, PBxT) powders were prepared by a non-aqueous sol–gel process using lead acetate, barium acetate, and titanium isopropoxide as precursors and ethylene glycol as the solvent. In this procedure, Ti-isopropoxide was chelated with acetylacetone. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis/differential thermal analysis (TGA/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) specific surface area analysis. The results indicate that perovskite PBxT phases were obtained by heat treatment at 450 °C for 5 h, and a pure perovskite was examined at 600 °C. The average particle sizes of perovskite PBxT powders calcined at 600 °C were approximately about 40–80 nm, and BET analysis showed that the surface areas of the powders obtained at 600 °C were approximately 6–16 m2/g. In addition, the phase transition from the tetragonal ferroelectric phase to the cubic paraelectric phase occurred in a range of approximately 0.6

A Pt supported on carbon aerogel catalyst has been synthesized by the microwave-assisted polyol process. The Pt supported on carbon aerogel catalyst was characterized by high resolution transmission electron microscopy and X-ray diffraction. The results show a uniform dispersion of spherical Pt nanoparticles 2·5–3·0 nm in diameter. Cyclic voltammetry and chronoamperometry were used to evaluate the electrocatalytic activity of the Pt/carbon aerogel catalyst for methanol oxidation at room temperature. The Pt/carbon aerogel catalyst shows higher electrochemical catalytic activity and stability for methanol oxidation than a commercial Pt/C catalyst of the same Pt loading.

The acid-base chemistry of Beishan (Gansu, China) granite (BS03, 600 m) was studied by potentiometric titration, and the adsorption of Eu(III) on the granite was investigated using a batch technique. It was found that the pHPZNPC of the granite is 9.4 at I = 0.1 M NaCl and decreases to 9.0 at I = 0.4 M NaCl. The profile of parallel titration curves of the granite at variable ionic strengths is roughly comparable to that of montmorillonite under similar conditions. The distribution coefficient ( K d) of Eu(III) on the granite varies with pH, ionic strength and Eu(III) concentration. The K d values of Eu(III) decrease significantly with increasing ionic strength in the low pH range, whereas the effect of ionic strength on the K d values is very weak in the high pH range. The experimental results of Eu(III) adsorption on the granite as a function of pH, ionic strength and Eu(III) concentration were quantitatively interpreted by a model with a cation exchange reaction of Eu3+ on the granite and two inner-sphere surface complexation reactions of Eu(III) on the surface hydroxyl sites. The adsorption of Eu(III) on the granite at I = 0.1 M was predicted by the proposed model, which was compared with the results of Am(III) adsorption on the granite under similar conditions reported by other groups.

Eu(III) adsorption on rutile was investigated as a function of contact time, pH, ionic strength and Eu(III) concentration by using a batch experimental method. The effects of carbonate, sulfate, and phosphate were also studied. It was found that the kinetics of Eu(III) adsorption on rutile could be described by a pseudo-second-order model. The adsorption of Eu(III) on rutile is strongly pH-dependent, but relatively insensitive to ionic strength. A double layer model (DLM) with two inner-sphere Eu(III) surface complexes was applied to quantitatively interpret the adsorption of Eu(III) on rutile. There were no apparent effects of carbonate and sulfate on Eu(III) adsorption, whereas the presence of phosphate promoted Eu(III) adsorption on rutile. The surface complexes of Eu(III) on rutile were evidenced by X-ray photoelectron spectroscopy (XPS).

A novel electrocatalyst structure of carbon nanotubes (CNT) coated with thin SnO2 and Pt (Pt/(CNT@SnO2)) is reported. The CNT@SnO2 composites with a thin shell (about 2 nm) are prepared by a simple chemical-solution method. The Pt/(CNT@SnO2) catalyst is prepared by first microwave heating H2PtCl6 in NaOH ethylene glycol solution and then depositing Pt nanoparticles onto CNT@SnO2 composites. High-resolution transmission electron microscopy and X-ray diffraction show that crystalline SnO2 of about 2 nm thickness is coated uniformly on the surface of the CNTs. Pt nanoparticles of about 3.2 nm in diameter are homogenously dispersed on the SnO2 surface. Electrochemical studies were carried out using cyclic voltammetry and chronoamperometry. The results showed that Pt/(CNT@SnO2) catalysts have much higher catalytic activity and CO-tolerance for ethanol electro-oxidation than that of Pt/CNT.

Carbon-supported PtAuSn/C nanoparticle catalyst was synthesized by a microwave-assisted polyol process. The process is a quick process that only requires a few minutes to complete. The catalyst thus obtained was characterized by transmission electron microscopy and X-ray diffraction analysis. The electrochemical performance of the catalyst, for the ethanol oxidation reaction, was also investigated. The results indicated that the PtAuSn/C catalyst was uniformly dispersed on carbon and was in the nano-size range. The electrochemical measurements indicated that PtAuSn/C nanoparticle catalyst synthesized by the microwave-assisted polyol method demonstrated a significantly higher electrochemically active area and higher catalytic activity than Pt/C for the ethanol oxidation reaction.

U(VI) sorption on kaolinite was studied as functions of contact time, pH, U(VI) concentration, solid-to-liquid ratio (m/V) by using a batch experimental method. The effects of sulfate and phosphate on U(VI) sorption were also investigated. It was found that the sorption kinetics of U(VI) can be described by a pseudo-second-order model. Potentiometric titrations at variable ionic strengths indicated that the titration curves of kaolinite were not sensitive to ionic strength, and that the pH of the zero net proton charge (pHPZNPC) was at 6.9. The sorption of U(VI) on kaolinite increased with pH up to 6.5 and reached a plateau at pH >6.5. The presence of phosphate strongly increased U(VI) sorption especially at pH

The mechanisms by which cancer cell-intrinsic CYP monooxygenases promote tumor progression are largely unknown. CYP3A4 was unexpectedly associated with breast cancer mitochondria and synthesized arachidonic acid (AA)-derived epoxyeicosatrienoic acids (EETs), which promoted the electron transport chain/respiration and inhibited AMPKα. CYP3A4 knockdown activated AMPKα, promoted autophagy, and prevented mammary tumor formation. The diabetes drug metformin inhibited CYP3A4-mediated EET biosynthesis and depleted cancer cell-intrinsic EETs. Metformin bound to the active site heme of CYP3A4 in a co-crystal structure, establishing CYP3A4 as a biguanide target. Structure-based design led to discovery of N1-hexyl-N5-benzyl-biguanide (HBB), which bound to the CYP3A4 heme with higher affinity than metformin. HBB potently and specifically inhibited CYP3A4 AA epoxygenase activity. HBB also inhibited growth of established ER+ mammary tumors and suppressed intratumoral mTOR. CYP3A4 AA epoxygenase inhibition by biguanides thus demonstrates convergence between eicosanoid activity in mitochondria and biguanide action in cancer, opening a new avenue for cancer drug discovery.

A sequential injection analysis (SIA) system is described for the determination of phenoxybenzamine hydrochloride and metoclopramide using spectrophotometer as detector. The method is based on the detection of an unstable red intermediate compound resulting from the reaction of phenoxybenzamine hydrochloride or metoclopramide with the diazotizating product of p-phenylenediamine with sodium nitrite in hydrochloric acid medium. The sampling frequency is 69 h−1 and 75 h−1 for phenoxybenzamine hydrochloride and metoclopramide, respectively. The linear range is 10–400 μg/mL for phenoxybenzamine hydrochloride with a detection limit of 0.081 μg/mL and 20–250 μg/mL for metoclopramide with a detection limit of 0.034 μg/mL. The RSD is 1.01 and 0.45% for phenoxybenzamine hydrochloride and metoclopramide, respectively. The proposed methods were used to determine phenoxybenzamine hydrochloride and metoclopramide in pharmaceuticals. The results are compared with those obtained by pharmacopoeia method.

U(VI) sorption on goethite was investigated as functions of pH, solid-to-liquid ratio (m/V), ionic strength and U(VI) concentration by a batch experimental method. Effects of phosphate, carbonate and fulvic acid (FA) on U(VI) sorption were examined. It was found that the sorption of U(VI) increases from 0% to 100% over the pH range of 2.5-4.5 and keeps constant in the high pH range. The sorption of U(VI) on goethite is insensitive to ionic strength. Different surface complexes in the framework of double-layer model were examined for fitting the sorption of U(VI) on goethite. A model with two mononuclear inner-sphere surface complexes, identical with triple bond SOUO(2)(+) and identical with triple bond SOUO(2)OH, was found capable of reproducing the pH sorption edges, the sorption isotherms and the sorption data with variable m/V in this study. The proposed model can also interpret the pH sorption edge collected at P(CO2)=10(-3.58) atm without considering any ternary surface complexes of carbonate. Moreover, it was found that the presence of phosphate at relatively high concentration (6 x 10(-4) mol/L) promotes U(VI) sorption. The presence of FA of 20 mg/L has little effect on the sorption of U(VI) on goethite.