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Bacillus subtilis is a spore forming bacterium that takes up both inorganic As(III) and As(V). Incubating the bacteria with Fe(III) causes iron uptake (up to ∼0.5% w/w), and some of the iron attaches to the cell membrane as hydrous ferric oxide (HFO) with additional HFO as a separate phase. Remarkably, 30% of the Bacillus subtilis cells remain viable after treatment by 8 mM Fe(III). At pH 3, upon metalation, As(III) binding capacity becomes ∼0, while that for As(V) increases more than three times, offering an unusual high selectivity for As(V) against As(III). At pH 10 both arsenic forms are sorbed, the As(V) sorption capacity of the ferrated Bacillus subtilis is at least of 11 times higher than that of the native bacteria. At pH 8 (close to pH of most natural water), the arsenic binding capacity per mole iron for the ferrated bacteria is greater than those reported for any iron containing sorbent. A sensitive arsenic speciation approach is thus developed based on the binding of inorganic arsenic species by the ferrated bacteria and its unusual high selectivity toward As(V) at low pH.

In the past decade, the lab-on-valve (LOV) system, as the third-generation of the flow-injection analysis technique, has exhibited powerful capability in instrument miniaturization and on-line sample pretreatment. This review presents and discusses the state of the art in the progress of the LOV system in the determination of metal species in two parts: • miniaturization of analytical instrumentations; and, • sample-processing front-ends. As a miniaturized analytical set-up, LOV incorporates detection techniques for the determination of metal species (e.g., spectrophotometry, electrochemical detection and atomic spectrometry). However, coupling LOV sample pretreatment with atomic or mass spectrometric detectors provides high-sensitivity determination or speciation of metal species. We also discuss future perspectives of the LOV system in metal determination and/or speciation.

A novel adsorbent-silica gel bound dithizone (H 2 Dz-SG) was prepared and used as solid-phase extraction of copper from complex matrix. The H 2 Dz-SG is investigated by means of FT-IR spectra and the SEM images, demonstrating the bonding of dithizone. The H 2 Dz-SG quantitatively adsorb copper ions, and the retained copper is afterwards collected by elution of 10% (v/v) nitric acid. An on-line flow injection solid-phase extraction procedure was developed for trace copper separation and preconcentration with detection by flame atomic spectrometry. By loading 5.4 mL of sample solution, a liner range of 0.5–120 μg L −1 , an enrichment factor of 42.6, a detection limit of 0.2 μg L −1 and a precision of 1.7% RSD at the 40 μg L −1 level ( n = 11) were obtained, along with a sampling frequency of 47 h −1 . The dynamic sorption capacity of H 2 Dz-SG to Cu 2+ was 0.76 mg g −1 . The accuracy of the proposed procedure was evaluated by determination of copper in reference water sample. The potential applications of the procedure for extraction of trace copper were successfully accomplished in water samples (tap, rain, snow, sea and river). The spiking recoveries within 91–107% are achieved.

A novel method for arsenic speciation is developed by interfacing solid phase preconcentration-liquid chromatography (LC) separation-gradient hydride generation (GHG)-quartz flame atomic absorption spectrometry (QFAAS). A MnO2 mini-column is used to preconcentrate the arsenic species of As(III), As(V), MMA and DMA, during which process, As(III) is converted to As(V)viaoxidation by MnO2, while other species remain unchanged. The recovery of As(V) (i.e., the total amount of arsenate and arsenite in the original sample), MMA and DMA from the MnO2 mini-column is facilitated by tetramethylammonium hydroxide (TMAH). After LC separation with C30 columns, arsenic species in the eluate are subject to gradient hydride generation with detection by QFAAS. On the other hand, cellulose fibre selectively adsorbs the chelating complex between As(III) and ammonium pyrrolidine dithiocarbamate (APDC). After elution with HNO3, As(III) in the original sample is quantified by graphite furnace atomic absorption spectrometry (GFAAS), and the amount of As(V) is obtained by subtraction. A sample volume of 2.0 mL derives enrichment factors of 14.0–19.2 for the arsenic species. By injecting 20 μL of eluate into the LC system (the eluate of As(III)-PDC complex is injected into the GFAAS), detection limits of 0.019, 0.33, 0.39, 0.62 μg L−1 are obtained for As(III), As(V), MMA and DMA respectively. RSDs of less than 4.2% are achieved at the level of 2 μg L−1 for As(V), MMA, DMA and 1 μg L−1 for As(III). The procedure is evaluated by speciating arsenic in snow water and Hijiki samples.

Eggshell membranes (ESMs) provide a unique, disulfide bond-rich surface. Thioglycolate reduction was used to generate thiol (-SH) groups on the ESM surface by S-S bond cleavage. The thiol-bearing ESMs (TESMs) were characterized by scanning electron microscopy and Raman spectroscopy. The fibrous network structure of the ESM is retained in the TESMs. TESMs adsorb both Se(IV) and Se(VI) but by different mechanisms: Se(VI) is retained reversibly, possibly via ionic interactions, while Se(IV) is reduced to Se(0) and deposited. We thus demonstrate speciation of selenium species, by using samples (a) as such and after prior oxidation to Se(VI), (b) preconcentration on a TESM microcolumn, (c) elution by 0.5 M HNO(3) that only elutes Se(VI) and (d) detection by graphite furnace atomic absorption spectrometry (GFAAS). The Se(IV) amount is determined by difference. For a 1.0 mL sample, the enrichment factor was 17.2, the S/N = 3 detection limit was 0.06 μg L(-1) and the precision was 3.3% at 0.50 μg L(-1). The linear range was 0.25-2.50 μg L(-1). The procedure was validated by analyzing selenium in certified reference materials of human hair (GBW 09101) and rice (GBW 10010). We further demonstrate utility by speciation of inorganic selenium in a series of water samples.

Carbon nanotubes (CNTs) were loaded onto the surface of silica gel (SG) beads, and the CNTs/SG composite was used as a novel adsorbent for the preconcentration of trace silver in a flow system by adsorbing nascent Ag2O in solution. This treatment of the material significantly improved the mechanical strength and capability of preconcentration of CNTs. With NaOH as precipitating reagent, the nascent Ag2O in the solution was readily retained on the surface of the CNTs/SG composite and recovered afterward by elution with nitric acid (10%, V/V). The eluate was finally introduced into a flame atomic absorption spectrometer for quantification. By loading 5.4 mL of sample solution, a liner range of 1–120 μg L−1, an enrichment factor of 34.5, a detection limit of 0.35 μg L−1 and a precision of 0.5% RSD at 40 μg L−1 level (n = 7) were obtained, along with a sampling frequency of 47 h−1. The enrichment factor, the detection limit and the precision of this procedure are obviously superior to those achieved by using wither pure CNTs or pure silica gel as adsorbents. The procedure was applied for the determination of silver in water samples, and satisfactory spiking recoveries were obtained in the range of 96%–108%.

In this study, the nickel alloying and austempering effects on corrosion behavior of ductile irons were investigated. The microstructure of austempered ductile iron (ADI) was analyzed by XRD, and the polarization corrosion tests were conducted using 3.5 wt.% NaCl solution. The results showed Ni-alloyed as-cast has less nodule counts than the unalloyed one; therefore, the former is more corrosion resistant than the latter. For the ADI, the nickel addition increases the retained austenite content, resulting in having better corrosion inhibition than the unalloyed ADI. Comparatively, the order of corrosion resistance in 3.5 wt.% NaCl solution is as follows: 4%Ni–ADI > ADI > 4%Ni–DI > DI.

Cationic hyperbranched BPEI was immobilized on the surface of MWNTs via electrostatic interactions between the positively charged protonated amines within the polymer and the carboxyl groups on the chemically oxidized MWNT surface. The functionalized BPEI-MWNTs were characterized by FT-IR, TGA, TEM and surface charge analysis, and it was used as a bio-sorbent for the adsorption of proteins. CD spectra showed no conformational change of BSA during the adsorption/desorption process. A dynamic adsorption capacity of 167 mg · g⁻¹ for BSA was achieved. With a sample volume of 2.0 mL, an enrichment factor of 10 was obtained along with an adsorption efficiency of 100%, a recovery of 100%, a sampling frequency of 10 h⁻¹ and a RSD of 2.6% at 25 µg · mL⁻¹ BSA.

Arsenic speciation was performed based on liquid chromatographic separation followed by gradient hydride generation (GHG) and quartz atomizer atomic absorption spectrometric detection. The arsenic species, i.e., arsenate (As(V)), arsenite (As(III)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and trimethylarsine oxide (TMAO), were separated on C30-5 columns, and the concept of gradient hydride generation facilitates high conversion efficiency of the arsenic species into corresponding hydrides. The use of 2% L-cysteine in the GHG process gives rise to further improvements on the hydride generation efficiency of 13% to 32% for the arsenic species. The hydrides were separated in a unique design of gas–liquid separator, which not only ensures a complete separation but minimizes the dispersion of hydrides when delivering into the atomizer, resulting in a maximum of 13-fold improvement on the sensitivity of As(V) compared to previous studies. A separation process was finished within 800 s by injecting 100 µL sample solution, achieving detection limits of 0.9, 1.4, 1.4, 1.6, 1.5 µg/L, respectively, for As(V), As(III), MMA, DMA and TMAO. Precisions of less than 3% and 6% RSD were obtained for the five arsenic species at 100 µg/L and 20 µg/L, respectively. Three arsenic species, i.e., As(V), DMA and TMAO, were identified in Hijiki samples by this procedure.

Fermentation of enzymatic hydrolysate of waste newspaper was investigated for cellulosic ethanol production in this study. Various nonionic and ionic surfactants were applied for waste newspaper pretreatment to increase the enzymatic digestibility. The surfactant-pretreated newspaper was enzymatically digested in 0.05 M sodium citrate buffer (pH 4.8) with varying solid content, filter paper unit loading (FPU/g newspaper), and ratio of filter paper unit/beta-glucosidase unit (FPU/CBU). Newspaper pretreated with the anionic surfactant sodium dodecyl sulphate (SDS) demonstrated the highest sugar yield. The addition of Tween-80 in the enzymatic hydrolysis process enhanced the enzymatic digestibility of newspaper pretreated with all of the surfactants. Enzymatic hydrolysis of SDS-pretreated newspaper with 15% solid content, 15 FPU/g newspaper, and FPU/CBU of 1:4 resulted in a newspaper hydrolysate conditioning 29.07 g/L glucose and 4.08 g/L xylose after 72 h of incubation at 50 degrees C. The fermentation of the enzymatic hydrolysate with Saccharomyces cerevisiae, Pichia stipitis, and their co-culture produced 14.29, 13.45, and 14.03 g/L of ethanol, respectively. Their corresponding ethanol yields were 0.43, 0.41, and 0.42 g/g.

This study analyzes sustainability of fresh fruit certifications using consumers' willingness-to-pay measures of 12 different kinds of fruits. Consumers tended to pay higher prices for fruit certifications when retail prices of fruits were relatively high. If certified fruits were purchased for gifts, purchasing quantities tended to be larger for fruits of high retail prices like wax apples, Indian jujubes, and grapes. If certified fruits were purchased for household consumption, low-priced fruits like guava, honeydew, cantaloupe, pineapples, grapefruits, and papaya tended to be purchased in large quantities. Fresh fruit certifications can be sustainable if marketing strategies are well targeted to customers.

The separation and speciation of inorganic arsenic(III) and arsenic(V) are facilitated by employing a novel sequential injection system incorporating two mini-columns followed by detection with hydride generation atomic fluorescence spectrometry. An octadecyl immobilized silica mini-column is used for selective retention of the complex between As(III) and APDC, while the sorption of As(V) is readily accomplished by a 717 anion exchange resin mini-column. The retained As(III)-PDC complex and As(V) are effectively eluted with a 3.0 mol L(-1) hydrochloric acid solution as stripping reagent, which well facilitates the ensuing hydride generation process via reaction with tetrahydroborate. With a sampling volume of 1.0 mL and an eluent volume of 100 microL for both species, linear ranges of 0.05-1.5 microg L(-1) for As(III) and 0.1-1.5 microg L(-1) for As(V) are obtained, along with enrichment factors of 7.0 and 8.2, respectively. Precisions of 2.8% for As(III) and 2.9% for As(V) are derived at the concentration level of 1.0 microg L(-1). The practical applicability of the procedure has been demonstrated by analyzing a certified reference material of riverine water (SLRS-4), in addition to spiking recovery in a lake water sample matrix.

Live HeLa cells immobilized on Sephadex G-50 beads were used as a medium for the preconcentration and speciation of inorganic arsenic. The sorption of arsenic species by live HeLa cells involves both surface uptake and bioaccumulation within the cells. At pH 3.0, the cells accumulate arsenate with high specificity over arsenite: 83.0 +/- 1.3% of the arsenate was sorbed while the retention of arsenite was negligible at 2.1 +/- 0.6%. The speciation of inorganic arsenic could thus be performed by direct determination of arsenate followed by quantifying total inorganic arsenic after conversion of arsenite to arsenate. We formed a disposable live cell preconcentration microcolumn with the live HeLa cells immobilized on Sephadex G-50 beads. After the sample was passed through the column for sorption to occur, the cells and any retained arsenate were stripped with 2 M HNO(3). The arsenic in the 30 microL eluate was directly measured by graphite furnace atomic absorption spectrometry. A new microcolumn was used for each sample. With a sample volume of 450 muL, a S/N = 3 limit of detection (LOD) of 0.05 microg/L and a linear range of 0.15-2.5 microg/L were attained; the relative standard deviation (RSD) was 1.7% at 1.25 microg/L. The procedure was validated by arsenic speciation in certified reference river water.

Lanthanum hydroxide precipitate is for the first time coated onto cellulose fibre and serves as a novel sorption medium for separation and speciation of inorganic selenium. A micro-column packed with precipitate-layer-coated cellulose fibre is incorporated into a sequential injection system for selenite retention from a neutral aqueous solution, which is afterwards stripped with a NaBH(4)-NaOH solution as eluent. The hydride generation is actuated by merging the eluate and hydrochloric acid downstream, followed by the detection with atomic fluorescence spectrometry. Total inorganic selenium is derived by pre-reduction of selenate and speciation is estimated by difference. The coated precipitate layer can be used for 150 runs for selenium sorption, offering a clear advantage over the conventional precipitation protocols where a large amount of precipitate is dissolved into a small volume of eluent which might interfere with the detection. With a sample volume of 1.0 mL, an enrichment factor of 9.7 and a detection limit of 9 ng L(-1) are obtained in a linear range of 0.05-2.5 microg L(-1). A sampling frequency of 24 h(-1) is achieved along with a R.S.D. of 1.7% at 0.5 microg L(-1) Se(IV). The procedure is validated by analyzing selenium in a reference material GBW 10010 (rice) and a human hair sample. It is further demonstrated by speciation of inorganic selenium in surface water samples by pre-reduction of selenate.

Since it commenced in the 1970s, flow-based analysis has gone through three generations. The first generation (i.e. flow injection) provided revolutionary changes in conventional sample processing in terms of automation and economy. As the second generation, sequential injection offered great freedom in the design of the flow manifold in addition to further downscaling sample consumption. The recently proposed lab-on-valve brings to flow-based analysis the third generation, which significantly facilitates integration of various analytical units in the valve and provides great potential for miniaturization of the entire instrumentation. A literature search clearly demonstrated that flow-based analytical protocols have been widely employed in bio-assays. They provide an especially versatile, powerful platform for on-line DNA assays, including DNA quantification, purification, separation, sequencing, hybridization studies and damage investigations. The present review discusses up-to-date developments in these fields and sets out future perspectives.

A procedure for chromium preconcentration and speciation with a dual mini-column sequential injection system coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed. At pH 6, the sample solution was firstly aspirated to flow through a Chlorella vulgaris cell mini-column on which the Cr(III) was retained. The effluent was afterwards directed to flow through a 717 anion exchange resin mini-column accompanied by the retention of Cr(VI). Thereafter, Cr(III) and Cr(VI) were eluted by 0.04 mol L − 1 and 1.0 mol L − 1 nitric acid, respectively, and the eluates were quantified with ETAAS. Chemical and flow variables governing the performance of the system were investigated. By using a sampling volume of 600 µL, sorption efficiencies of 99.7% for Cr(III) and 99% for Cr(VI) were achieved along with enrichment factors of 10.5 for Cr(III) and 11.6 for Cr(VI), within linear ranges of 0.1–2.5 µg L − 1 for Cr(III) and 0.12–2.0 µg L − 1 for Cr(VI). Detection limits of 0.02 µg L − 1 for Cr(III) and 0.03 µg L − 1 for Cr(VI) along with RSD values of 1.9% for Cr(III) and 2.5% for Cr(VI) (1.0 µg L − 1 , n = 11) were obtained. The procedure was validated by analyzing a certified reference material of GBW08608 and further demonstrated by chromium speciation in river and tap water samples.

Egg-shell membrane (ESM) is a unique cell surface with various functional groups, providing the potential for bio-sorption of metal species. We have demonstrated the selective retention of chromium(VI)via a reductive sorption process, while Cr(III) is virtually not retained. This includes adsorption of Cr(VI) onto the ESM surface while charge transfer on the ESM results in the reduction of Cr(VI) to Cr(III) through transient, unstable species of Cr(V) and Cr(IV). A novel procedure for chromium speciation was thus developed in a sequential injection system with detection by electrothermal atomic absorption spectrometry. The procedure includes the separation and preconcentration of Cr(VI) on ESM at pH 2 and its subsequent detection after elution, followed by conversion of Cr(III) to Cr(VI) and total chromium analysis, Cr(III) finally being obtained by subtraction. With a sampling volume of 1000 µl, an enrichment factor of 13.3 was achieved. A linear range of 0.05–1.25 µg l−1 for Cr(VI), along with a detection limit of 0.01 µg l−1 and a precision of 3.2% at the level of 0.5 µg l−1, were obtained. Chromium speciation was performed by using a certified reference material of riverine water (GBW08608) and cave water.

The dominant role played by flow injection/sequential injection (FI/SI, including lab-on-valve, LOV) in automatic on-line sample pretreatments coupling to various detection techniques is amply demonstrated by the large number of publications it has given rise to. Among these, its hyphenation with hydride/vapor generation atomic fluorescence spectrometry (HG/VG-AFS) has become one of the most attractive sub-branches during the last years, attributed not only to the high sensitivity of this technique, but also to the superb separation capability of hydride/vapor forming elements from complex sample matrices. In addition, it also provides potentials for the speciation of the elements of interest. It is worth mentioning that quite a few novel developments of sample pretreatment have emerged recently, which attracted extensive attentions from the related fields of research. The aim of this mini-review is thus to illustrate the state-of-the-art progress of implementing flow injection/sequential injection and miniaturized lab-on-valve systems for on-line hydride/vapor generation separation and preconcentration of vapor forming elements followed with detection by atomic fluorescence spectrometry, within the period from 2004 up to now. Future perspectives in this field are also discussed.

The cell-sorption of paramagnetic ions of Mn 2+ and Cr 3+ onto a Chlorella vulgaris (C. vulgaris) cell-immobilized micro-column was significantly improved in the presence of an external magnetic field generated in a finite solenoid, by placing the micro-column in the center of the solenoid in a sequential injection system. Magnetic field creates an opposite drift velocity on the hydrated paramagnetic ions against the flow of the sample zone, retards the moving velocity of the metal ions and provides extra contacting time with the cells on the micro-column and offers more chances for the paramagnetic ions to interact with the various functional groups or binding sites on the cell surface, which significantly facilitates cell-sorption of the paramagnetic ions. The sorption efficiencies of Mn 2+ and Cr 3+ at the 20 μg L −1 level were improved from 45 to 80% and 60 to 90%, respectively, in a magnetic field of 240 mT. The system was applied for the separation/preconcentration of ultra-trace level of manganese. The presence of an external magnetic field significantly alleviated the interfering effects from coexisting metal ions. Within a liner range of 0.025–0.5 μg L −1 and a sampling volume of 500 μL, an enrichment factor of 21.2, a limit of detection of 0.008 μg L −1 , along with a sampling frequency of 20 h −1 was attained, achieving a precision of 2.1% R.S.D. (0.2 μg L −1 ). Manganese contents in a certified reference material of riverine water and a snow water were analyzed.

During the last 30 years, flow injection analysis has gone through three generations, that is, the first generation in 1970s, supplemented by sequential injection in the 1990s as the second generation, and the recently emerged lab‐on‐valve system as the third generation, which holds clear advantages for instrumental miniaturization. The three generations have revolutionized the concept of sample pretreatment by facilitating on‐line operation and coupling with various detection techniques, among which its hyphenation with electrothermal atomic absorption spectrometry (ETAAS) has been one of the most attractive research field offering vast potentials and versatilities in the quantification of ultra‐trace metal species in complex matrices. In the present mini‐review, the state‐of‐the‐art developments for flow injection on‐line sample pretreatment coupled to ETAAS for trace metal analysis since 2003 were summarized, with special emphasis on the exploitations of the lab‐on‐valve system.

In the study, 4% cobalt and nickel elements were added to ductile iron (DI) to investigate the effects of the alloying elements on both its microstructure and its mechanical properties. The results show that 4% cobalt alloyed ductile iron (4% Co-DI) not only increases the nodule count and ferrite content in the microstructure, but also improves the mechanical properties such as yield strength, tensile strength, impact toughness and fracture toughness ( K IC ) as compared to unalloyed DI. In contrast, with 4% nickel addition, there is a decreased nodule count and increased pearlite content in the matrix. However, this material (4% Ni-DI) has the highest hardness and strength but the lowest ductility and toughness among all the ductile irons. In the case of microstructure, all kinds of iron have a sufficient nodularity up to 90% and the sequence of the nodule count is 4% Co-DI (150 nodules/mm 2 ) > DI (106 nodules/mm 2 ) > 4% Ni-DI (85 nodules/mm 2 ). Moreover, it appears that cobalt plays an important role in stabilizing the ferrite phase, whereas 4% nickel accelerates the formation of pearlite in ductile iron.

The screening of suitable sorption medium is the key for highly selective solid phase extraction (SPE) of heavy metals. Herein, we demonstrate a universal protocol for producing selective SPE adsorbent through an evolutional approach based on phage display peptide library. By choosing chromium(III) as the model target, immobilized Cr(III) resins are first prepared using Ni-NTA affinity resins for the interaction with NEB heptapeptide phage library. After three rounds of positive biopanning against target Cr(III) and negative biopanning against foreign metal species, Cr(III) binding phages with high selectivity are obtained. The binding affinity and selectivity are further assessed with ELISA. The phages bearing peptide (YKASLIT) is finally chosen and immobilized on cytopore beads for Cr(III) preconcentration. The retained Cr(III) is efficiently recovered by 0.10 mol L(-1) HNO3 and quantified with ICP-MS. By loading 4000 μL of sample solution at pH 7.0 for 2 h and stripping with 400 μL of 0.10 mol L(-1) HNO3, a linear range of 0.05-0.50 μg L(-1) is achieved along with an enrichment factor of 7.1. The limit of detection is derived to be 15 ng L(-1) (3σ, n = 7) with a RSD of 3.6% (0.25 μg L(-1), n = 7). The procedure is validated by analyzing chromium content in a certified reference material GBW08608 (simulate water). In addition, chromium speciation in real water samples is demonstrated. Cr(VI) is first converted into Cr(III), and the latter subjected to the sorption onto the Cr(III) binding phage, followed by elution and quantification of the total chromium amount, and finally speciation is achieved by difference.

In the present study, octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS) functionalized carbon dots (CDs/POSS) are prepared by a one-pot approach with glycerol as carbon source and solvent medium. OA-POSS serves as a passivation agent, and it is obtained via hydrolytic condensation of 3-aminopropyltriethoxysilane (APTES). During the functionalization process, the amino groups on OA-POSS combine with carboxylic groups on the bare CDs via formation of amide bond to construct organic-inorganic hybrid carbon dots. The obtained CDs/POSS are well dispersed in aqueous medium with a diameter of ca. 3.6 nm. It is demonstrated that CDs/POSS provide favorable photoluminescent property with a quantum yield of 24.0%. They also exhibit resistance to photobleaching and excellent photoluminescence stability in the presence of biological sample matrix (characterized by heavy metals and organic molecules), which facilitate cell imaging in biological systems. Both the photoluminescent emission wavelength and the fluorescence intensity depend closely on the excitation wavelength, and thus, it provides a potential for multicolor imaging as demonstrated with HeLa cells and MCF-7 cells.

Acetone is a predominant volatile organic compound (VOC) in the exhaled breath and a promising biomarker for diabetes and ketoacidosis. A non-thermal micro-plasma generated in a planar dielectric barrier discharge (DBD) is used as a radiation source for the excitation of gaseous acetone followed by its quantification with optical emission spectrometry (OES). Gaseous acetone can be directly sampled, while liquid acetone is evaporated by heated tungsten coil and then introduced into the DBD micro-plasma by a helium carrier flow for performing optical emission and detection at a 519 nm emission line. In the present study, the exhaled breath is collected and transferred into aqueous medium for sampling. With a sampling volume of 7 μL in a micro-drop, a linear range of 40–1600 mg L−1 is obtained along with a detection limit of 44 ng and a precision of 5.7% RSD. The present system is successfully applied to the determination of breath acetone for both diabetic patients and healthy volunteers.

In this study, austempered ductile iron (ADI) substrate containing acicular ferrite and high-carbon austenite in the microstructure is made by austempering treatment at 360. Cathodic arc evaporation (CAE) coating technique was used to coat DLC, TiN and TiAlN films on ADI for surface modification. The results showed that the three coatings could be successfully coated onto ADI through CAE process without altering the unique microstructure of ADI. The structures of the coatings were identified by XRD, Raman and TEM, respectively. After HRC indentation testing, it was found that nodular graphite was the initial site of cracking for the coatings and then peeled. Surface roughness of all coated specimens was increased because the droplets generated on the substrate surface during the CAE process. Coated ADI had better wearability performance than uncoated ADI due to higher surface hardness. Coated specimens exhibited higher corrosion resistance than uncoated ones when they were immersed in separate solutions of both 3.5 wt. % NaCl and 10 vol. % HCl. In particular, TiAlN had the best corrosion resistance among the coated specimens.

Because of its low cost, high tensile strength, fatigue resistance, and wear resistance, austempered ductile iron (ADI) has been utilized in a wide variety of mechanical applications. However, in opposition to the versatility of the above-mentioned mechanical properties, the shortcomings of ADI are its surface hardness (Hv: 396) and corrosion resistance. And, because its relatively low austempering temperature falls in the range of Ms–450 °C (Ms: the martensite start temperature), ADI cannot be case hardened using traditional high temperature heat treatment. This study explored the effects of TiN and TiAlN coatings on ADI, with respect to surface hardness and corrosion resistance. The process employed for coating TiN/TiAlN onto ADI involved variable target current low temperature cathodic arc deposition (CAD). The coating characteristics and corrosion resistance of TiN/TiAlN-coated ADI were analyzed for further understanding of the feasibility of the low temperature CAD coating process. The analysis showed that TiN and TiAlN films could successfully be coated onto ADI through CAD technology without altering the unique microstructure of ADI. Utilizing a variety of target currents in the coating process yielded an acceptable level of adhesion while raising the surface hardness of ADI by a factor of 2–4 (Hv: 396 versus 1356–1910). It was observed that as target current increased, the surface roughness of the specimens also increased. TiN/TiAlN-coated ADI specimens exhibited higher corrosion resistance than uncoated ones when both were immersed in separate solutions of both 3.5 wt% NaCl and 10 vol.% HCl. Conclusively, the application of TiN and TiAlN films to ADI through the coating process of low temperature CAD is a viable surface modification for ADI applications that require increased surface hardness and corrosion resistance.

A novel bactericidal material comprising rod-shaped core–shell–shell Au–Ag–Au nanorods is constructed as a nanoheater in the near-infrared (NIR) region. The outer Au shell melts under laser irradiation and results in exposure of the inner Ag shell, facilitating the controlled release of the antibacterial Ag shell/layer or Ag + . This results in the Au–Ag–Au nanorods having a favorable bactericidal ability as it combines the features of physical photothermal ablation sterilization of the outer Au shell and the antibacterial effect of the inner Ag shell or Ag + to the surrounding bacteria. The sterilizing ability of Au–Ag–Au nanorods is investigated with Escherichia coli O157:H7 as a model bacterial strain. Under low-power NIR laser irradiation (785 nm, 50 mW cm −2 ), the Au–Ag–Au nanoheater exhibits a higher photothermal conversion efficiency (with a solution temperature of 44 °C) with respect to that for the Au–Ag nanorods (39 °C). Meanwhile, a much improved stability with respect to Au–Ag nanorods is observed, i.e., 16 successive days of monitoring reveal virtually no change in the ultraviolet–visible spectrum of Au–Ag–Au nanorods, while a significant drop in absorption along with a 92 nm red shift of Localized Surface Plasmon Resonance is recorded for the Au–Ag nanorods. This brings an increasing bactericidal efficiency and long-term stability for the Au–Ag–Au nanorods. At a dosage of 10 μg ml −1 , a killing rate of 100% is reached for the E. coli O157:H7 cells under 20 min of irradiation. The use of Au–Ag–Au nanorods avoids the abuse of broad-spectrum antibiotics and reduces the damage of tissues by alleviating the toxicity of silver under controlled release and by the use of low-power laser irradiation. These features could make the bimetallic core–shell–shell nanorods a favorable nanoheater for in vivo biomedical applications.

Carboxylic graphene oxide (GO-COOH) is decorated with akaganeite (β-FeOOH) to produce a β-FeOOH@GO-COOH nanocomposite. The nanocomposite acts as an efficient adsorption medium for the uptake of arsenite and arsenate within a wide range of pH 3-10, providing high adsorption capacities of 77.5mgg(-1) for As(III) and 45.7mgg(-1) for As(V), respectively. Adsorption efficiencies of 100% and 97% are achieved for 5 successive operation cycles for the removal of 100μgL(-1) As(V) and As(III) in 5 fresh portions of aqueous solution (1.0mL for each) with 3mg nanocomposite. After 20 successive adsorption cycles, removal efficiency of >80% is still maintained for both arsenate and arsenite. Further, a removal efficiency of >90% is obtained for 1000μgL(-1) As(V) with 3mg β-FeOOH@GO-COOH for 5 successive adsorption cycles, and the presence of 2000-fold SO4(2-), NO3(-), Cl(-) and Mg(2+) pose no interfering effect. β-FeOOH@GO-COOH also provides a promising medium for the preconcentration of ultra-trace inorganic arsenic. 1mg of nanocomposite is used to adsorb 0.1-3.00μgL(-1) As(V) in 4.0mL solution, and the retained arsenate is recovered by 400μL of NaOH (2molL(-1), containing 2.0% NaBH4), followed by detection with atomic fluorescence spectrometry. A detection limit of 29ngL(-1) is obtained for arsenate. This procedure is validated by analyzing arsenic in a certified reference material (GBW 09101b) and further applied for arsenic determination in water samples.

In order to solve the problem that wetland herbaceous plants tend to die during winter in subtropics areas, selection and purification potential evaluation experiments were carried out by introducing into the constructed wetlands 16 species of woody wetland plants. Cluster analysis was performed by including the morphological characteristics, physiological characteristics, as well as nitrogen and phosphorus accumulation of the woody wetland plants. The results indicated that there were significant differences among the tested woody plants in their survival rate, height increase, root length increase and vigor, Chlorophyll content, Superoxide dismutase, Malonaldehyde, Proline, Peroxidase, biomass, average concentration and accumulation of nitrogen and phosphorus. Based on the established evaluation system, the tested plants were clustered into 3 groups. The plants in the 1st group possessing high purification potentials are Nerium oleander and Hibiscus syriacus. Those in the 2nd group possessing moderate purification potentials are Trachycarpus fortune, Llex latifolia Thunb., Gardenia jasminoides, Serissa foetida and Ilex crenatacv Convexa. And those in the 3rd group with low purification potentials are Jasminum udiflorum, Hedera helix, Ligustrum vicaryi, Ligustrum lucidum, Buxus sempervives, Murraya paniculata, Osmanthus fragrans, Mahoniafortune and Photinia serrulata.

Considerable analytical methods have been developed for arsenic speciation in the last 5 years, the details of these new arsenic speciation procedures are thus summarized in present mini review. The performances of various sample pretreatment techniques including solid phase extraction, liquid–liquid extraction, hydride generation, liquid chromatography and capillary electrophoresis, which offer effective preconcentration/separation and eventually contribute greatly to excellent sensitivity and selectivity in arsenic speciation when coupling with suitable detection mode, are discussed and compared thoroughly. High-performance liquid chromatography coupling with inductively coupled plasma mass spectrometry and hydride generation atomic spectrometry are proved to be the most powerful hyphenated methodologies for arsenic speciation in environmental and biological matrices.

The Steenrod problem asks: given a G-module, when does there exist a Moore space realizing the module? By using the equivariant Postnikov Tower, it is shown that a ZG-module is ZG-realizable if and only if it is ZHrealizable for all p-Sylow subgroups H, for all primes pl GI. Let G be a finite group. Let M be a finitely generated ZG-module. We say that M is a Steenrod representation if there exists a Moore space X with G-action such that the homology of X is isomorphic to M as a ZG-module. Recall that a Moore space is a topological space whose reduced homology vanishes in all dimensions except one. Without loss of generality, M will be assumed 2-free [1] from now on. In this paper, the following statement will be proved: M is a Steenrod representation as a ZG-module if and only if M is a Steenrod representation as a 7H-module for all p-Sylow subgroups H of G, for all primes pII GIC. This statement is inspired by papers by J. Arnold [1, 2] and P. Vogel [18]. Arnold [2] showed that if G is cyclic, then every finitely generated ZG-module is a Steenrod representation. And Vogel showed that if for any ZG-module M, we can always find a G-Moore space X realizes M, then G has only cyclic Sylow subgroups. Let us first consider a Moore space X whose homology is isomorphic to M as a 2-module. Let G(X) denote the space of self homotopy equivalences of X and let BG(X) [9] denote the classifying space of the H-space G(X) for a certain fibration defined by Dold and Lashof [10]; see also Stasheff [15]. Since a homotopy equivalence of X induces an automorphism on M, there is a map G(X) -* Aut(M). And the map G(X) -* Aut(M) induces another map a : BG(X) -' BAut(M). On the other hand, since M is a ZG-module, there is a map G -* Aut(M) (= GL(n, 2) if M = Zn), which induces .p : BG -) BAut(M). Following Cooke's theory [9], as pointed out in [12], M is a Steenrod representation as a ZG-module if and only if the lifting f exists in

To investigate the correlation of three-dimensional (3D) ultrasound features with prognostic factors in invasive ductal carcinoma. Surgical resection specimens of 85 invasive ductal carcinomas of 85 women who had undergone 3D ultrasound were included. Morphology features and vascularization perfusion on 3D ultrasound were evaluated. Pathologic prognostic factors, including tumour size, histological grade, lymph node status, oestrogen and progesterone receptor status (ER, PR), c-erbB-2 and p53 expression, and microvessel density (MVD) were determined. Correlations of 3D ultrasound features and prognostic factors were analysed. The retraction pattern in the coronal plane had a significant value as an independent predictor of a small tumour size (P = 0.014), a lower histological grade (P = 0.009) and positive ER or PR expression status (P = 0.001, 0.044). The retraction pattern with a hyperechoic ring only existed in low-grade and ER-positive tumours. The presence of the hyperechoic ring strengthened the ability of the retraction pattern to predict a good prognosis of breast cancer. The increased intra-tumour vascularization index (VI, the mean tumour vascularity) reflected a higher histological grade (P = 0.025) and had a positive correlation with MVD (r = 0.530, P = 0.001). The retraction pattern and histogram indices of VI provided by 3D ultrasound may be useful in predicting prognostic information about breast cancer. • Three-dimensional ultrasound can potentially provide prognostic evaluation of breast cancer. • The retraction pattern and hyperechoic ring in the coronal plane suggest good prognosis. • The increased intra-tumour vascularization index reflects a higher histological grade. • The intra-tumour vascularization index is positively correlated with microvessel density.

Dielectric barrier discharge (DBD) at atmospheric pressure provides an efficient radiation source for the excitation of bromine and it is used for the first time for optical emission spectrometric (OES) detection of bromide and bromate. A portable DBD–OES system is developed for screening potential pollution from bromide and bromate in environmental waters. Bromide is on-line oxidized to bromine for in-situ generation of volatile bromine. Meanwhile, a helium stream carries bromine into the DBD micro-plasma for its excitation at a discharging voltage of 3.7 kV and optical emission spectrometric detection with a QE65000 charge-coupled device (CCD) spectrometer in the near-infrared spectral region. Similarly, the quantification of bromate is performed by its pre-reduction into bromide and then oxidized to bromine. The spectral characteristics and configuration of the DBD micro-plasma excitation source in addition to the oxidation vapor generation of bromine have been thoroughly investigated. With a sampling volume of 1 mL, a linear range of 0.05–10.0 mg L −1 is obtained with a detection limit of 0.014 mg L −1 by measuring the emission at 827 nm. A precision of 2.3% is achieved at 3 mg L −1 bromide. The system is validated by bromine detection in certified reference material of laver (GBW10023) at mg L −1 level, giving rise to satisfactory agreement. In addition, it is further demonstrated by screening trace bromide and bromate as well as spiking recoveries in a series of environmental water samples.

Egg-shell membrane (ESM) is a promising adsorbent for heavy metal uptake. However, carboxylic groups on ESM surface barrier arsenic adsorption. Herein, ESM is modified by esterification and the methyl esterified egg-shell membrane (MESM) possesses positive charge within pH 1-9. As a novel green sorbent material, MESM exhibits 200-fold improvement on sorption capacity of arsenate with respect to bare ESM. It presents an ultra-high selectivity of 256:1 toward arsenate against arsenite. At pH 6, 100% sorption efficiency is achieved for 2 μg L(-1) As(V) by 10 mg MESM, while virtually no adsorption of As(III) is observed. This provides great potential for selective sorption of arsenate in the presence of arsenite. By loading 4.0 mL sample within 0.05-5.00 μg L(-1) As(V) followed by elution with 300 μL HCl (1.5 mol L(-1)), a detection limit of 15 ng L(-1) is obtained along with a RSD of 3.5% at 0.5 μg L(-1). Total inorganic arsenic is achieved by converting As(III) to As(V) and following the same sorption process. This procedure is applied for arsenate determination and inorganic arsenic speciation in Hijiki and water samples. The results are confirmed by graphite furnace atomic absorption spectrometry and spiking recovery.

Drug resistance is a major hurdle to the success of chemotherapy. The permeability glycoprotein (P-gp) is an important factor dictating drug access to the cells, as it controls the efflux of chemotherapeutic agents against the concentration gradient. Pmd1, a P-gp-like protein, was recently isolated as a doxorubicin resistance gene in fission yeast. Although the null mutant of pmd1 (Δ pmd1) exhibited sensitivity to doxorubicin, it showed an unexpectedly high resistance to the drug at relatively high concentrations. The data presented here suggest that this is due to the presence of cooperative processes that can complement and counteract drug cytotoxicity in the absence of Pmd1. One such factor, Rav1, is an essential factor in controlling the assembly of the pH-regulating transporter vacuolar-ATPase (V-ATPase) in fission yeast. The simultaneous disruption of Pmd1 and Rav1 resulted in a prominent accumulation of doxorubicin in the cytoplasm of cells, accompanied by a decline in cell viability. With concurrent treatment of pharmacological inhibitors in human cervical cancer cells, P-gp and V-ATPase were further shown to act synergistically to sensitize cells to doxorubicin also in the human cells. Furthermore, a novel Cornichon-like protein SPAC2C4.05 (herein named as Cor1) was demonstrated for the first time to be involved in the interaction with P-gp and V-ATPase to counteract doxorubicin-dependent cytotoxicity. Therefore this study identified a molecular cooperation between multiple membrane transporter proteins that confers chemoresistance to cells against the chemical insult of doxorubicin. Interestingly, this network exhibited differential effects to doxorubicin as compared with its close epimeric analog epirubicin, suggestive of the intricacy of the drug response regulated by this synergistic interaction. A model is discussed on how the versatility of this network can differentiate closely related chemical drug structures yet allow for the robustness to counteract a vast range of drugs.

The detection of mercury in biological systems and its imaging is of highly importance. In this work, a ratiometric fluorescence sensor is developed based on fluorescence resonance energy transfer (FRET) with N-acetyl-L-cysteine functionalized quantum dots (NAC-QDs) as donor and Rhodamine 6G derivative-mercury conjugate (R6G-D-Hg) as acceptor. Mercury annihilates the fluorescence of NAC-QDs at 508 nm and meanwhile interacts with R6G derivative to form a fluorescent conjugate giving rise to emission at 554 nm. Resonance energy transfer from NAC-QDs to R6G-D-Hg is triggered by mercury resulting in concentration-dependent variation of fluorescence ratio F508/F554. A linear calibration of F508/F554 versus mercury concentration is obtained within 5-250 μg L(-1), along with a detection limit of 0.75 μg L(-1) and a RSD of 3.2% (175 μg L(-1)). The sensor generates colorimetric images for mercury within 0-250 μg L(-1), facilitating visual detection of mercury with a distinguishing ability of 50 μg L(-1). This feature is further demonstrated by colorimetric imaging of intracellular mercury. On the other hand, the NAC-QDs/R6G-D FRET sensing system is characterized by a combination of high sensitivity and selectivity. The present study provides an approach for further development of ratiometric sensors dedicated to selective in vitro or in vivo sensing some species of biologically interest.

Multi-wall carbon nanotubes (MWNTs) are modified with branched cationic polyethyleneimine (BPEI). The MWNTs-BPEI nanocomposites serve as a novel adsorbent and exhibit favorable selectivity toward adsorption of As(V). Appropriate amount of MWNTs-BPEI suspension containing ca. 5 mg of the composites is used to pack a mini-column for on-line solid phase extraction preconcentration of inorganic arsenic in a sequential injection system, following detection by hydride generation atomic fluorescence spectrometry. At pH 5.8, an sorption efficiency of 80% is achieved for As(V) at 10 μg L(-1), resulting in a sorption capacity of 26.18 mg g(-1). Meanwhile, the sorption efficiency for As(III) is5%. The retained As(V) is readily recovered by 100 μL NH4HCO3 (0.6%, m/v). With a sample volume of 2.0 mL, an enrichment factor of 16.3 for As(V) is obtained along with a detection limit of 14 ng L(-1) within a linear range of 0.05-1.50 μg L(-1). A RSD of 3.6% is derived at 0.5 μg L(-1). Total amount of arsenic is obtained by converting As(III) to As(V) and following the same procedure. The speciation of inorganic arsenic is realized by difference. This procedure is validated by analyzing a certified reference material of human hair (GBW09101), achieving satisfactory agreements between the certified and the obtained values. Speciation of As(V) and As(III) is also performed in snow water and rain water samples.

The potential of selective cell-sorption for separation/preconcentration of ultra-trace heavy metals was exploited by surface engineering of Saccharomyces cerevisiae cells. The general idea is to display the cadmium-binding peptide on the cell surface in order to enhance the covalent interaction between cadmium and the yeast cells. By immobilizing the surface-engineered yeast cells onto cytopore(®) microcarrier beads for cadmium adsorption, we demonstrated that with respect to the native yeast 600-fold and 25-1000-fold improvements were observed respectively for the tolerance of ionic strength and the tolerant capability toward various metal cations after surface engineering. Based on these observations, a novel procedure for selective cadmium preconcentration was developed with detection by graphite furnace atomic absorption spectrometry (GFAAS), employing the engineered S. cerevisiae cell-loaded cytopore(®) beads as a renewable sorption medium incorporated into a sequential injection lab-on-valve system. The cadmium retained on the yeast cell surface was eluted with a small amount of nitric acid and quantified with GFAAS. Within a range of 5-100 ng L(-1) and a sample volume of 1 mL, an enrichment factor of 30 was achieved along with a detection limit of 1.1 ng L(-1), a sampling frequency of 20 h(-1) and a precision of 3.3% RSD at 50 ng L(-1). The procedure was validated by analyzing cadmium in certified reference materials and a series of environmental water samples.

The selective culture method and PCR-DGGE technology were applied to analyze the number and the biodiversity of microorganism species in cells with plant intercropping models and without plants in different seasons in a wetland system constructed for treatment of municipal sewage. The results showed that the numbers of microorganisms were considerably larger in the cells with plant intercropping models than those without plants, while the number of microorganisms was apparently larger in summer than that in winter in all treatments. Along the three-sequenced treatment cells with plant intercropping models a "low-high-low" changing trend in the numbers of microorganisms in summer. The UPGMA cluster analysis showed that the treatments in the same season were clustered in the same branch except for a few samples in winter and the biodiversity index was consistently higher in summer than that in winter. Five different sequences (DF1-DF5) were obtained through BLAST analysis and retrieval. The closest known origin groups were located as Escherichia coli, Citrobacter sp., Proteus sp., Klebsiella oxytoca, and Burkholderia sp. respectively. The BLASTX comparison test showed that DF1 closely related to the activities of the Mycobacterium bacillus and the Bacillus amyloliquefaciens, DF2 functioned as a conservative potential ATP binding protein, DF3 related to the activities of the Bacillus cereus spore, DF4 was involved in catabolism metabolism of microorganism and DF5 played an important role in decomposition of organic matters.

To evaluate the efficacy of an ultrasound-based quantitative method to diagnose liver fibrosis using a rat model. Ultrasonography was performed on the livers of 90 Sprague-Dawley rats with or without thioacetamide-induced fibrosis. The liver capsule thickness and 13 texture parameters of gray level co-occurrence matrix were extracted from the standard sonograms. After sacrifice, severity of liver fibrosis (S0-S4 classification) was diagnosed by histopathology. Analysis of variance and correlation statistical tests were used to analyze the differences between groups and determine the relationships between each of the 14 quantitative ultrasound index points and the histological results, respectively. Discriminant analysis models were developed for quantitative diagnosis of liver fibrosis, and the leave-one-case-out method was used to verify the efficiency of models. All 14 indices were significantly correlated with the histological stages of fibrosis (P less than 0.05). The accuracy of the discriminant model for S0, S1, S2, S3 and S4 was 83.3%, 84.2%, 70.0%, 50.0% and 88.2%, respectively. In addition, 73.3% of cross-validated rats were accurately classified. Grouping S0 as no fibrosis, S1 as mild fibrosis, S2 with S3 as moderate to severe fibrosis and S4 as early cirrhosis increased the accuracy of the discriminant model for these four groups (respectively, 91.7%, 84.2%, 69.0% and 88.2%) and allowed for 78.9% of cross-validated rats to be correctly identified. Ultrasonography combined with texture analysis was a novel and accurate method to diagnose liver fibrosis in a rat model; further studies may provide insights into its applicability for quantitating liver fibrosis in other animal models or in clinic.

Fluorescence resonance energy transfer (FRET) between two quantum dots of different sizes causes fluorescence quenching. Hereby a binding site pre-blocking approach is proposed to avoid this effect. Pre-binding of glucose on the donor occupies the binding sites and thus blocks resonance energy transfer between the two quantum dots, protecting the fluorescence from being quenched. A glucose assay is developed based on this approach. The glucose content is correlated with the fluorescence difference in the absence and in the presence of glucose. In practice, Green QDs–Con A conjugates are used as donors and Red QDs–NH 2 -glu conjugates as acceptors to form FRET system. The inhibition of fluorescence quenching is then measured in the presence of glucose. A linear calibration graph is achieved within 0.1–2.0 mmol L −1 , along with a detection limit of 0.03 mmol L −1 and a RSD of 2.1% (1.0 mmol L −1 ). 91–105% of glucose in serum and urine samples is recovered. It is worth mentioning that the present glucose assay approach also generates a fluorescence chromatic difference imaging, and the color display clearly identifies the glucose contents by visual detection with a distinguishing ability of ca. 0.5 mmol L −1 . The present approach can potentially be used for the clinical determination of glucose in biological samples which can be further developed into a glucose sensor.

A procedure for the separation and preconcentration of bismuth was developed in a sequential injection system by employing bamboo carbon as sorbent. The detection was facilitated by both hydride generation atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry. With a sample volume of 1 mL, a detection limit of 13 ng x L(-1) was obtained, along with a precision of 0.9% (0.3 microg x L(-1), n = 9) with detection by HG-AFS, and a detection limit of 10 ng x L(-1) along with a precision of 2.8% (0.3 microg x L(-1), n = 5) was achieved with detection by ICP-MS. The present system was validated by analyzing a certified reference material of river sediment (CRM 320), and spiking recovery of bismuth in human whole blood was performed with hydride generation atomic fluorescence spectrometry. No significant difference was identified in the results of bismuth detection in blood samples by hyphenating the present solid phase extraction system with detection by hydride generation atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry.

We constructed a combinant landscape constructed wetland for sewage treatment based on landscape plants in this study. The results are summerized as follows: the system uses model as: A(biological pretreatment pond)-B(biochemistry pond)- C(subsurface flow wetland)-D(surface flow wetland)-E(the third level vertical-flow wetland)-F(second-level vertical-flow wetland) -G(landscape surface flow wetland)-H(biology pond), this combination craft sewage treatment is performed effectively, and the system outcome water quality achieves the first-level A standard. In this system, through plant's screening, we found out the nearly 30 plants fitted the system with high compatibility, strong purification, high landscape value and high economic value, which were Mainly: Cannaindica, Iris ensata, Acoruscalamus, Iris tectorum, Iris germanica, Thalia dealbata, Cyperus alternifolius, Juncus effusus, Pontederia cordata, Phragmites austral is, Pennisetum purpureum, Paulownia tomentosa, Ipomoea aquatica, Zephyranthes candida, Liriope spicata, Lolium perenn, Oenanthe clecumbens, Trifolium, Reineckiacarnea, Cuphea ignea, Salix babylonica, Fatsia japonica, Lucidum Ait, Cuphea ignea, Lythrum salicaria, Metasequoia glyptosto boides, Eichhornia crassipes, Salvinia natans, Nelumbo nucifera, Nymphaea tetragona, Nymphoides peltatm.

In order to establish an evaluation system for selection of winter wetland plants possessing high wastewater purification potentials in subtropics areas, designed sewage treatment experiments were carried out by introducing into the constructed wetlands 25 species of winter wetland plants. Cluster analysis was performed by including harmful environment-resistant enzyme and substrate enzyme activities into the commonly applied plant screening and assessment indexes system. The obtained results indicated that there were significant differences among the tested winter plants in their root length and vigor, leaf malonaldehyde (MDA), biomass, average nitrogen and phosphorus concentration and uptake, and urease and phosphoric acid enzyme activities in the root areas. Based on the established evaluation system, the tested plants were clustered into 3 groups. The plants in the 1st group possessing high purification potentials are Oenanthe javanica, Brassicacapestris, Juncus effusu, Saxifragaceae, Iris pseudoacorus, Osmanthus fragrans and Iris ensata; those in the 2nd group possessing moderate purification potentials are Brassica oleracea var acephala, Calendula officinalis, Aucuba japonica, Ligustrum lucidu, Beta vulgaris, Rhododendron simsii and Ilex latifolia; and those in the 3rd group with low purification potentials are Brassica oleracea var acephala, Calistephus chinensis, Rosa chinensis, Antirrhinums, Liriope palatyphylla, Zephyranthes candida, Fatshedera lizei, Petunia hybrida, Ilex quihoui, Dianthus caryophyllus and Loropetalum chinensis.

Cationic hyperbranched BPEI was immobilized on the surface of MWNTs via electrostatic interactions between the positively charged protonated amines within the polymer and the carboxyl groups on the chemically oxidized MWNT surface. The functionalized BPEI-MWNTs were characterized by FT-IR, TGA, TEM and surface charge analysis, and it was used as a bio-sorbent for the adsorption of proteins. CD spectra showed no conformational change of BSA during the adsorption/desorption process. A dynamic adsorption capacity of 167 mg · g⁻¹ for BSA was achieved. With a sample volume of 2.0 mL, an enrichment factor of 10 was obtained along with an adsorption efficiency of 100%, a recovery of 100%, a sampling frequency of 10 h⁻¹ and a RSD of 2.6% at 25 µg · mL⁻¹ BSA.