Co-surfactant of ethoxylated sorbitan ester and sorbitan monooleate for enhanced flushing of tetrachloroethylene

This work evaluated the flushing efficiency of tetrachloroethylene (PCE) using the co-surfactant of non-ionic ethoxylated sorbitan ester (Tween) and oilphilic sorbitan monooleate (Span 80), which formed more hydrophobic micelles than Tween alone. The flushing efficiency was evaluated with laboratory columns filled with silica and aquifer sand. Results from column flushing were also compared to those of batch solubility experiments to study the removal mechanism by the co-surfactant solution. Compared to Tween 80 alone, the molar solubilization ratio and the affinity between the micelles and PCE increased 84% and 90%, respectively, by the co-surfactant solution of Tween 80 and Span 80 mixed at a 4:1 ratio. Flushing with 1% Tween 80 solution yielded a steady PCE recovery of 7% for both silica and aquifer sand in each pore volume (PV). Flushing with co-surfactant of 1% Tween 80 + Span 80 (4:1) further increased PCE recovery to 10% for silica sand and 13% for aquifer sand per PV. A comparison of results from column flushing and batch solubility tests indicated that the primary flushing mechanism of PCE using the co-surfactant solution of Tween 80 + Span 80 (4:1) was micellar solubilization.     

Royal jelly inhibited N-acetylation and metabolism of 2-aminofluorene in human liver tumor cells (J5)

The present study was carried out to evaluate the question of whether or not royal jelly affects N-acetylation and metabolism of 2-aminofluorene (2-AF) in the human liver tumor cell line (J 5). N-acetylation and metabolism of 2-AF in intact J5 cells was determined by using high performance liquid chromatography for the amounts of acetylated and nonacetylated 2-AF and profile of 2-AF metabolism. The results indicated that royal jelly displayed a dose-dependent inhibition of N-acetylation of 2-AF in J5 cells. Royal jelly also decreased the profile of 2-AF metabolites in J5 cells. This report is the first demonstration which showed that royal jelly affects N-acetylation of 2-AF in human liver tumor cells (J5).     

Effects of carrying handles,postures, materials and distances on carrying capability

This study recruited 14 industrial workers to examine the effects of carrying handles, postures, materials and distances on maximum acceptable weights of carrying (MAWC), and resulting heart rate and body rating of perceived exertion (RPE) for a 20 min intensive carrying task. This study showed that MAWC of carrying with bar handles, carrying with hands-and-body posture, solid materials and 4?m distance were significantly higher than that of carrying with groove handles, carrying with hands posture, liquid materials and 8?m distance, respectively. The resulting heart rates while carrying MAWCs of groove handles, hands-and-body carrying posture, solid materials and 4?m distance were lower than the resulting heart rates while carrying MAWCs of bar handles, hands carrying posture, liquid materials and 8?m distance, respectively. Most pair levels of independent variables resulted in similar body's RPEs except for the pair levels of carrying distance.     

Electroactive polyamide modified carbon paste electrode for the determination of ascorbic acid

Construction electroactive polyamide (EPA) with aniline-pentamer-based in the main chain has been modified on the surface of carbon paste electrode (CPE) for detecting ascorbic acid (AA). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy studies confirm the well-defined molecular structure of the oligoaniline and EPA. Further, the in situ chemical oxidation of EPA was monitored by UV-Visible absorption spectrum. The electroactivity of the EPA was evaluated by performing electrochemical cyclic voltammetry study. The sensing response studies have revealed that this EPA-modified CPE electrode can detect AA in the range of 0.05–0.7 mM with detection limit of 0.005 mM and sensitivity of 1.5 × 10^–5 AmM^–1. Besides, this EPA-modified CPE electrode shows a minimal relative standard deviation of 1.73%.     

Analysis of the health risk of exposure to breast milk mercury in infants in Taiwan

The aim of this study was to assess the total concentration and health risk to infants of breast milk mercury in urban mothers and mothers married to fishermen in relation to fish intake in Taiwan. A total of sixty-eight healthy mothers were recruited for the study. The breast milk mercury geometric mean concentration was 2.02 microgl(-1) (n=56, range: 0.24-9.45 microgl(-1)) for the city group and 2.04 microgl(-1) (n=12, range: 0.26-8.62 microgl(-1)) for the fishermen's group. Of the three sources of mercury exposure (i.e., ingestion (breast milk), inhalation (ambient air), and dermal exposure (shower)), breast-feeding was found to be the largest (96.3-99.6% of the total). From a Monte Carlo simulation, in which methyl mercury accounted for about 50% of total mercury, the hazard quotient (exposure estimate/oral minimal risk level or target organ toxicity dose) exceeded 1.0 for 12.9% of urban babies and 18.8% of fishermen's babies (chronic oral minimal risk level and target organ toxicity dose: 3 x 10(-4)mgkg(-1)d(-1)). The calculated mercury exposure was 3.02 x 10(-1) microgkg(-1)d(-1) for a 3.49 kg urban baby boy and 3.06 x 10(-1) microgkg(-1)d(-1) for a 3.44 kg urban baby girl. These results suggest the life style of mothers (eating raw fish and shellfish such as used in "Sashimi" and "Sushi," and vitamin supplementation) may influence the mercury concentration in breast milk.     

Advanced superhydrophobic electroactive fluorinated polyimide and its application in anticorrosion coating

A novel superhydrophobicelectroactive fluorinated polyimide (HEFPI) was first synthesized from aniline trimer and 4,4′-(Hexafluoroisopropylidene) diphthalic anhydride. The HEFPI could be fabricated as superhydrophobicfilm by replicated the surface of the Xanthosomasagittifolium leaves. The water contact angle of HEFPI film reaches as high as 157 ° and the superhydrophobic property of HEFPI could coat on cold-rolled steel (CRS) to prevent the metal corrosion. Electroactivity of EFPI was evaluated by performing electrochemical cyclic voltammetry study. Besides, redox catalytic capabilities of aniline trimer units existed in HEFPI main chain may induce the formation of passive metal oxide layers on the CRS electrode. The synergistic effects (hydrophobic property and passive metal oxide layers) make the HEFPI coating has great potential for advanced anticorrosion material.     

Protein tyrosine dephosphorylation during copper-induced cell death in rice roots

Early signalling events that control the process of heavy metal-induced cell death are largely unknown in plants. In mammals protein tyrosine phosphorylation plays an important role in the activation of programmed cell death. We thus examined the involvement of tyrosine phosphorylation in Cu-induced rice cell death. This investigation demonstrates that Cu induces cell death and DNA fragmentation in rice root cells. In the presence of Cu, the level of phosphotyrosine accumulation declined in the band of 45 kDa, p45. To analyze the role of tyrosine dephosphorylation for the regulation of Cu-induced cell death more precisely, we increased levels of tyrosine phosphorylation using the protein tyrosine phosphatase inhibitor, sodium orthovanadate (Na(3)VO(4)). Treatment of rice roots with Na(3)VO(4) blocked Cu-induced cell death and protein tyrosine dephosphorylation. In addition, the antioxidant GSH and the calcium chelator EGTA significantly abolished Cu-induced cell death and protein tyrosine dephosphorylation. These results provide evidence that dephosphorylation of a tyrosine-phosphorylated protein, p45, is an important step in the Cu-triggered signalling transduction pathway.     

Model Development and Calibration of a Saltwater Intrusion Model in Southern California1

Abstract: A nine‐layered confined‐unconfined flow and transport model is developed for the Alamitos saltwater intrusion barrier in Southern California. The conceptual model is based on the geological structure of the coastal aquifer system. The key parameters in the flow and transport models are calibrated using a two‐phase procedure which matches the types of data available for calibration. Because of the abundance of point measurements of hydraulic conductivity, the heterogeneous and random hydraulic conductivity field for each of the five aquifers is estimated by the geostatiscal method of natural‐neighbor‐kriging in Phase 1. In Phase 2, the longitudinal and transverse dispersivities in the transport model are estimated by a traditional inverse procedure that minimizes the least‐squares error for concentration (LSE‐CON). The minimum LSE‐CON is achieved near 15.2 and 1.52 m for the longitudinal and transverse dispersivities, respectively. Additional simulations with increasing transport parameter complexity did not yield significant improvements in LSE‐CON. Also, tracking least‐squares error for head while parametrically varying the transport parameters revealed there is a negligible interaction between predicted head and transport parameters.