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Surface functionalization of piezoelectric greatly determines its piezo-catalytic activity and selectivity in that functional group affect specific reactants’ surface adsorption and activation abilities. Herein, we propose chemical functionalization on the surface of nano-scaled BaTiO3 piezoelectric via a one-pot hydrothermal process using polyethylene glycol as surfactant, and evaluate its piezo-catalytic activity and selectivity by degrading model antibiotic and dye reactants under ultrasonic vibrations. Acetate or/and oxalic unidentate ligands on the surface of BaTiO3 nanobelts can be formed by controlling precursor and hydrothermal parameters. Particularly, oxalic acid functionalized BaTiO3 nanobelts presented a high piezo-catalytic rate constant of 0.068 min−1 for Rhodamine B solution and maintained >87% degradation efficiency within 30 min under the condition of ultrasonic bath with 40 kHz and 100 W, which was mainly ascribed to piezo-sensitization effect. This work provides references for the preparation of chemical functionalized catalysts and also contributes to the development of novel catalysts for special applications.

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) influence the nitrate (NO3−) reduction and its final fate in the environment. However, it is unclear how denitrifying and DNRA bacterial communities respond to different environment conditions. Here, we investigated the effects of fertilization and sampling time (April, July and November) on the abundances of nitrogen (N) cycling genes in processes of denitrification and DNRA at different soil depths (0–20, 20–40 and 40–60 cm) based on a long-term fertilization experiment station (initiated in 1987). The abundances of genes involved in NO3− reduction process were determined using quantitative PCR (qPCR) analysis method. Sampling time showed a stronger effect on the abundances of denitrifying and DNRA genes than fertilization. And the effect of fertilization on the abundances of genes involved in NO3− reduction process was decreased with soil depths. Compared with no fertilizer (CK), the application of mineral N fertilizer (N2 and N4) reduced the abundances of denitrification and DNRA genes at 0–20 cm soil depth, regardless of sampling time. However, the application of organic manure combined with mineral N fertilizer (M2N2) clearly increased the abundance of specific denitrifying genes, including napA (NO3− to NO2−) and nosZ (N2O to N2) genes compared with N2 and N4 treatments at 0–20 and 20–40 cm soil depths. Although the abundance of nrfA gene was the highest, the abundance of norB gene was the most sensitive to environmental variation among all the tested N cycling genes. Ratio of NO3− to ammonium (NO3−/NH4+) was significantly correlated with all the denitrifying and DNRA genes. In general, long-term application of organic manure combined with mineral N fertilizer has a potential to mitigate the NO3− leaching and N2O production, and NO3−/NH4+ ratio is an important factor driving the dynamics of bacterial communities involved in the NO3− reduction process.

The coexistence of blowout and lost circulation in multi-pressure fractured reservoirs has always been a huge challenge to the oil industry. Although the use of high-density kill fluids can ensure the safety of well control, the problem of lost circulation in low pressure layer is still troublesome. Gel is widely used as a temporary plugging system, but the conventional gel plugging system will float when used in combination with high-density kill fluid, resulting in failure of temporary plugging. In this paper, a novel high-density bromide-based nanocomposite gel (HDGEL) was developed, the gel formation mechanism was explored, and its performance was evaluated in the laboratory. The gel is weighted by sodium bromide (NaBr), and cross-linked by covalent bonds, density 1.2–1.5 g/cm3 adjustable, and its temperature resistance can reach 160 °C. Rheological tests show that the gel solution has low initial viscosity and easy to pump. The gelation time can be adjusted from 8 to 12 h, which can be directly broken by the drill or regular jetting nozzle and then flowed back. It can be used in combination with high-density kill fluid to ensure temporary plugging effect. In the fractures with tip sizes (0.014 cm), the maximum bearing pressure of HDGEL is 17.52 MPa, and the regained-permeability recovery can reach 86.81% without the use of gel breaker. This paper introduces a new gel system for multi-pressure reservoirs that can be used in combination with high-density kill fluid and makes recommendations for its engineering application.

In this work, a simple and efficient dispersive solid-phase microextraction (DSPME) method based on magnetic dummy molecularly imprinted polymer nanoparticles (MMIPs) was developed for the extraction of five phthalate monoesters (mPAEs) from human urine samples. The MMIPs synthesized by sol–gel reaction and surface imprinting were analyzed by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometry, and thermogravimetric analysis. The obtained results demonstrate that the MMIPs prepared herein are characterized by high selectivity, good adsorption capacity (124.5 mg/g), excellent reusability (over five sorption–desorption cycles), and fast adsorption rates (about 30 min to equilibrium) with respect to five mPAEs. In addition, the MMIPs can be easily separated from the sample solutions due to their good magnetic susceptibility (34.0 emu/g). Using MMIPs as sorbent material in DSPME, five mPAEs in three human urine samples were extracted, and then analyzed by high-performance liquid chromatography (HPLC). Based on the obtained results, this method shows good linearity in the range of 1–100 mg/L for monomethyl phthalate, monoethyl phthalate, and monobutyl phthalate, in the range of 1–80 mg/L for monobenzyl phthalate, and in the range of 1–50 mg/L for monoethylhexyl phthalate. Moreover, good recovery (80.0%–101.0%) of all five mPAEs was observed at three spiked level with relative standard deviations of 0.6–6.6%. Overall, the results reported herein indicate that the prepared MMIPs can be used as sorbent material for the dispersive solid-phase microextraction of phthalate monoesters in human urine samples.

In utero exposure to phthalates may have adverse effects on pregnant women and their offsprings. Therefore, the exposure level of these substances among individuals, particularly among sensitive population, is of concern. The objective of the present study is to characterize urinary concentrations of phthalate metabolites at multiple time points during pregnancy in Chinese women. A total of 3455 pregnant women were included from Ma'anshan Birth Cohort in China. Spot urine samples in the morning (8:00–10:00) and questionnaires were obtained at three separate visits (approximately in 10, 26, and 34 gestational weeks). Seven phthalate metabolites from urine samples were analyzed, including monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), mono benzyl phthalate (MBzP), mono-2-ethylhexyl phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). Geometric means of concentrations were ranged from 0.05 to 41.0 ng/mL for all the metabolites mentioned above. No individual exposure level was above the 95th percentiles for all the seven phthalates. On the three separate visits, 0.5%, 0.9% and 1.2% of the participants had coexposure to above the 75th percentiles for all metabolites. Taken these visits together, a total of 29 urine samples had concentrations above the 95th percentiles, while 3.0%–5.6% of urine levels were above 75th percentiles for at least one specific phthalate metabolite. We observed moderate intraclass correlation coefficients (ICCs) ranging from 0.44 to 0.56 for MBzP, MEHP and MEP, and lower ICCs, from 0.28 to 0.32, for MMP, MBP, MEOHP and MEHHP. Sampling season was associated with concentrations of all phthalate metabolites, showing heavier exposure was more likely to occur during summer. In summary, phthalate exposure is prevalent in Chinese pregnant women. However, throughout pregnancy coexposure to multiple phthalates at the upper percentile of exposure is infrequent. Mild to moderate temporal stability indicates that a single measurement in spot urine collected in the morning (8:00–10:00) seems not enough to describe throughout pregnancy phthalate exposure. Urinary levels vary by sampling seasons, which should be taken into consideration in future analyses. Keywords: Phthalate metabolites, Pregnant women, Birth cohort, Repeated measure analysis, China

A multiferroic BiFeO3 (BFO) catalyst was fabricated through a mild one-pot hydrothermal process with a bath-ultrasound assisted dissolution of Fe(NO3)3·9H2O for 30 min. X-ray photoemission spectroscopy revealed that the BFO (BFO-u) catalyst with US assisted dissolution of Fe(NO3)3·9H2O in the synthetic process exhibited high Fe2+ and OH− levels, which could be explained to be Fe3+ + H2O → ) ) ) Fe2+ + H+ + •OH. As a result, BFO-u catalyst activated potassium peroxymonosulfate (PMS) efficiently for degrading tetracycline hydrochloride. In particular, visible-light assisted activation of PMS over BFO-u catalyst exhibited the highest degradation rate constant, at 0.352 min−1. Species-trapping experiments revealed that the presence of PMS promoted the generation of •OH, •O2− and 1O2 that all participated in degrading TCH, in which 1O2 was primarily contributed to the degradation. Also, BFO-u catalyst was stable and recyclable and thus suitable for practical applications.

An acridinium ester (AE) alkaline solution can react with Mn(II) to generate a strong chemiluminescence (CL) centered at 435 nm. The effects of reaction conditions such as pH and Mn(II) concentration on CL intensity were examined. In order to explore the CL mechanism, the effect of oxygen on the CL reaction was examined and an X-ray photoelectron spectroscopy study of the reaction precipitate was carried out. The results indicated that oxygen participated in the CL reaction and Mn(IV) was the primary product in the system. A possible mechanism was proposed that involved two pathways: (1) dissolved oxygen was reduced to reactive oxygen radicals by Mn(II), these reactive intermediates then reacted with AE to produce excited state acridone; (2) Mn(II) could reduce AE to partly reduced AE, which then reacted with oxygen to form excited state acridone. The reactions of other metal ions with AE were also tested, and only Mn(II) was shown to trigger strong CL emission of AE, which indicated that the system had good selectivity for Mn(II). Copyright © 2014 John Wiley & Sons, Ltd.

The separations of single-wall carbon nanotubes on length by sepharose gel were investigated in this work. The solutions of sodium dodecyl sulfate and sodium deoxycholate were applied as the eluent in sequence. SEM and Raman were used to characterize the length of nanotube bundles. The results show that the longer nanotubes were eluted out first, and then the shorter tubes were followed by the sodium dodecyl sulfate. However, the separated order was totally reversed by the sodium deoxycholate. By this method, the process generated nanotube fractions not only were narrower in length distributions, but also could control the separation orders by changing the eluents. Moreover, the separation principle was also discussed.

Background. Herbicides are commonly ingested for self-harm, but relatively little has been published on poisoning with herbicides other than paraquat and glyphosate. We report here a case series of patients with acute exposure to a combination herbicide (brand name Tiller Gold or Whip Super) containing the selective phenoxy herbicide fenoxaprop-P-ethyl, the sulfonylurea herbicide ethoxysulfuron and the safener isoxadifen ethyl. Method. Clinical data on all patients presenting with Tiller Gold or Whip Super poisoning to two General Hospitals in Sri Lanka from 2002-2008 were collected prospectively until discharge. Results. Eighty-six patients with a history of Tiller Gold or Whip Super ingestion were included. The main clinical features were an epigastric burning sensation and vomiting; however, most of those who vomited had received gastric lavage or forced emesis. Eight patients had a reduced level of consciousness on admission (Glasgow coma scale 9-14) that resolved without intervention over several hours. Only symptomatic and supportive care was required. The median hospital stay was 1 day (IQR: 1-2) and the case fatality was zero (95% confidence interval: 0-4.2%). This low case fatality compared favorably with the case fatality of other common herbicides in our cohort: paraquat > 40%, propanil > 10%, 4-chloro-2-methylphenoxyacetic acid > 5%, and glyphosate > 2%. Conclusion. This combination herbicide product appears to be safe in patients with acute self-poisoning, particularly in comparison with other herbicides, and causing few clinical features.

An HPLC-DAD-ESI-MS/MS method was developed for analysis of iridoid glucosides (IGs) from Hedyotis diffusa Willd. The optimized separation condition was achieved with the Complex Sample Analysis Software System (CSASS) software, under which the whole analytes were achieved complete resolution especially for some isomeric IGs. Based on the UV and fragmentations, eleven IGs were detected. According to the fragmentation patterns of the three standard IGs, especially those of the isomeric standards, seven IGs including three pairs of isomers were unambiguous/tentatively identified. For the isomeric IGs with methyl ester or carboxyl group at C-4, the extents of the losses of CH3OH and/or H2O from their molecular and/or the aglycone adducts are useful for the differentiation of the stereoisomers in positive ion (PI) mode, which depends on the stereochemistry of the hydroxyl group on the cyclopentanoid unit.

The optical activation of Si nanowires (SiNWs) by the coating of Er3+ doped binary silicon–aluminum oxides (Si–Al oxides) films derived from sol–gel solutions is reported. Continuous and crack-free Si–Al oxide film could be successfully coated onto an Si substrate where the SiNWs were grown. The strong Er3+ luminescence of 1.534 μm from the SiNWs was observed at a high Er concentration (5 at.%). These results suggest that the Al–Si oxide film makes it possible to realize a strong Er3+ luminescence by excluding concentration quenching while at the same time improving the quality of film.

A method has been developed for the analysis of seven metabolites of phthalates in human urine by high performance liquid chromatography-tandem mass spectrometry ( HPLC-MS/MS). The urine samples were hydrolyzed with glucuronidase followed by purification with solid-phase extraction (SPE) cartridges. Both 0. 1% formic acid in water (v/v) and 0.1% formic acid in acetonitrile were used as the mobile phases in a gradient mode. The chromatographic separation was achieved on a phenyl column. Mass detection was then conducted by electrospray ionization in negative ion mode and multiple reaction monitoring mode. The components were quantified by stable isotope-labelled (13C-) phthalate monoester internal standards. The calibration curves of the seven phthalates metabolites showed good linear relationships in the range of 0.2-200.0 µg/L (r > 0.999 76). The recoveries at three levels were from 88.8% to 108.9% with relative standard deviations no more than 17.05%. The limits of detection of the method were 13.43-80.2 ng/L. The limits of quantification were 44.77-267.37 ng/L. This method was successfully applied to the determination of metabolism of phthalates in human urine with efficiency, increased accuracy and high sensitivity.

NPB and arachidic acid (AA) are introduced to the ITO surface through Langmuir–Blodgett (LB) technique to modify the hydrophilic surface to hydrophobic surface. The π–A isotherms and AFM images of NPB–arachidic acid with different mol concentration show that they can form stable and condensed LB films, and the compactness are increased with the increasing of the NPB molecular concentration. The surface morphologies of the composite films were investigated by atomic force microscopy (AFM). The surface properties of the film are characterized by contact angle and cyclic voltammetry.

Layered double hydroxides (LDHs) containing carboxylate anions are often contaminated with carbonate or other anions arising from atmospheric carbon dioxide or precursor salts, respectively. If the structure of the layered host is to be exploited in order to control features such as the stereochemistry of reactions of intercalated guest species or the kinetics of their ion-exchange, or if the structure of the host–guest assembly is to be compared with molecular dynamics simulations it is essential to prepare materials containing the target anion only. In this paper, we show that LDHs containing citrate, oxalate, tartrate and malate ions free from other anions may be obtained by a simple procedure involving dissolution of a magnesium–aluminium, nickel–aluminium or zinc–aluminium carbonate-containing LDH precursor by addition of the appropriate carboxylic acid followed by precipitation of the product by addition of the mixture to a basic solution. In contrast to other synthetic procedures for LDHs, the reaction does not need to be carried out under nitrogen in order to prevent co-intercalation of carbonate ions.

Immobilized penicillin G acylase (PGA) has been assembled in the interlayer galleries of a layered double hydroxide (LDH) by a three-step process. Glutamate-pillared LDH was first prepared by a novel process involving dissolution of an LDH-carbonate precursor in aqueous glutamic acid, followed by precipitation of the product by addition of base. This method avoids the problem of competitive intercalation by nitrate ions observed with conventional methods involving precipitation of LDHs from solutions of metal nitrate salts. The glutamate ions are strongly held in the interlayer region of the LDH by virtue of the electrostatic interaction between their carboxylate groups and the cationic layers, and act as carriers for the introduction and retention of free amino groups in the interlayer galleries. Subsequent reaction of the amino groups of the immobilized glutamate ions with a glutaraldehyde linker followed by addition of PGA affords the immobilized enzyme (IME). The intermediate and final materials, which can be termed bioinorganic nanocomposites, have been characterized by FT-IR spectra, powder X-ray diffraction (XRD) and thermal analysis. The activity, thermal stability, pH stability and operational stability of the IME have been assayed. After 10 recycles, carried out in succession in a discontinuous reactor, the IME displayed 90% activity retention, with the expressed activity remaining above 430 U/g.

A new type of support, calcined layered double hydroxides (CLDH), has been used to immobilize penicillin G acylase. The effect of varying the composition of the layered double hydroxide precursor and the calcination temperature on the activity of the immobilized enzyme has been studied. The activity of the immobilized enzyme decreased with increasing Mg/Al molar ratio of the CLDH. Mg/Al-CLDH had a higher affinity for the enzyme than Zn/Al-CLDH, but a lower percentage expressed activity. The activity of the immobilized enzyme was a maximum when the calcination temperature was between 450 and 550°C. The amount of enzyme adsorbed by the support shows a close correlation with its surface area. Immobilization of the enzyme on the support increases the acid resistance of the former.

New kinds of Pd-coordinating azo-based liquid crystalline polysilsesquioxanes, Pd-H-FBA and Pd-C-FBA, have been synthesized first by hydrosilylation reactions of a vinyl-terminated mesomorphic azo compound with ladder-like homopolyhydrosilsesquioxane (H-T) and copolymethylhydrosilsesquioxane (MH-T) to produce fishbone-like, azo-based liquid crystalline polysilsesquioxanes H-FBA and C-FBA, respectively, followed by a further ortho -palladation reaction with palladium chloride. The mesomorphic properties have been investigated by DSC, optical polarizing microscopy and temperature-variable X-ray diffraction. It is found that their clearing temperatures, Tcl, are much higher and the mesophase ranges, Delta T,are much wider than those of the corresponding comb-like polymers with a single main chain by more than 100 C. This indicates that the double main chain structures of the title polymers have a positive effect on mesomorphic properties. The influence of the contents of Pd2 ions on the liquid crystallinity ...

A novel ionic crosslinking sodium alginate (SA)/carboxymethylated bacterial cellulose (CM-BC) composite with a semi-interpenetrating polymer network (semi-IPN) structure was developed in this study. The composite was prepared through the blending of an SA gel with CM-BC then crosslinking by Ca2+ followed by a freeze-drying process. Scanning electron microscopy showed the composite matrix organized in a three-dimensional network of CM-BC interpenetrated against SA molecular chains with a quantity of calcium alginate microspheres upon the surface. The swelling ratios of the composite were enhanced by 183, 198, and 212% with the supplementation of CM-BC weight fractions of 25, 50, and 75%, respectively; the swelling ratios changed with changing pH. The tensile modulus, tensile strength, and elongation at break of SA were enhanced by 165, 152, and 188%, respectively, with the addition of 50 wt % CM-BC. This study demonstrated that the semi-IPN structure dramatically changed the swelling and mechanical properties of the composite, and the semi-IPN will be a promising candidate for biomedical applications such as wound dressings and skin tissue engineering. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39848.

The thickness of HfO2 ultrathin films was determined by grazing incidence x-ray reflectivity (GIXRR) with simulation. Two samples were prepared by atomic layer deposition, and the Si substrate of one sample was treated by HF acid (1:20) to erase the native oxide layer, while the other was not. According to the GIXRR, the films consisted of two contamination layers, an interface layer, a HfO2 layer and a native oxide layer (except for the acid-treated sample) from top to bottom. As a result, the HfO2 thickness of the two samples was 1.23 nm and 1.25 nm respectively, and the thicknesses of the interface layers between the HfO2 and the Si substrate were 0.1 nm and 0.95 nm respectively. The chemical states of the film were investigated by ultrasonification and x-ray photoemission spectroscopy (XPS), and the thickness was verified by transmission electron microscopy (TEM). All these phenomena proved that GIXRR is a powerful and effective piece of technology for characterizing HfO2 ultrathin film.

Fragmentation pathways of five iridoid glycosides have been studied by using electrospray ionization multi-stage tandem mass spectrometry (ESI-MSn). The first-stage MS data of the five iridoid glycosides were compared. The MS spectra showed that the adduct ions of iridoid glycosides and the formate anion were diagnostic ions to distinguish iridoid glycosides with a carboxyl group at the C-4 position or an ester group at the C-4 position. The MS fragmentation pathways of the five iridoid glycosides were also studied. Analyzing the product ion spectra of iridoid glycosides, some neutral losses were observed, such as H2O, CO2 and glucose residues, which were very useful for the identification of the functional groups in the structures of iridoid glycosides. Furthermore, specific loss of one molecule of methyl 3-oxopropanoate or 3-oxopropanic acid was firstly discussed, which corresponded to the isomerization of the hemiacetal group in the structure of iridoid aglycone. According to the fragmentation mechanisms and HPLC/MSn data, the structures of five iridoid glycosides in a crude extract of Gardenia jasminoisdes fruit have been identified. Three compounds were compared with standards and the other two were identified as shanzhiside and genipin gentibioside by their MSn data without standard compounds. In order to further validate the veracity of the deduction, genipin gentiobioside was isolated from the extract of Gardenia jasminoisdes fruit using Purification Factory and was further identified by C- and H-NMR. Copyright (c) 2007 John Wiley & Sons, Ltd.

RP-HPLC is the main method for the analysis of alkaloids. However, peak tailing is a problem that commonly occurs in the separation of alkaloids. In order to overcome this, three kinds of RP columns were compared for the analysis of protoberberine alkaloids in Coptidis Rhizoma and Phellodendri Cortex in this work. XTerra MS C18 column was the best one which gave the best symmetry factor under the same conditions. With this column, a good separation of the crude extracts of C. Rhizoma and P. Cortex was achieved using 0.1% v/v formic acid buffer and methanol as mobile phase. At the same time, the crude extracts of C. Rhizoma and P. Cortex were analyzed by the LC-ESI-MSn and LC-atmospheric pressure chemical ionization (APCI)-MSn methods. In the analysis of HPLC-ESI/MSn, structures of five protoberberine alkaloids were elucidated, compared to authentic standards, and data from the literature. At the same time, the structure of a novel compound was elucidated. In the HPLC-APCI/ MSn analysis, there was an interesting phenomenon that the relative abundance of the ions M+ and [M + 2]+ was different for different alkaloids. The possible fragmentation pathways of protoberberine alkaloids in APCI/MS analysis were studied for the first time in the present work.