Efficient removal of estrogenic activity during oxidative treatment of waters containing steroid estrogens

The discharge of synthetic and natural steroid estrogens from municipal wastewaters to the aquatic environment has received increased attention because of their potential reproductive effects on fish. Using 17alpha-ethinylestradiol (EE2) as a representative steroid estrogen, several oxidants applied in wastewater treatment (chlorine, bromine, ozone, hydroxyl radical, chlorine dioxide, and ferrate) were shown to selectively and rapidly transform EE2. For typically applied oxidant doses, these transformations occur in the time range of seconds to minutes. The resulting initial transformation products of EE2 exhibit a substantially lower in vitro estrogenic activity (< 13% of EE2). For selected structural derivatives of EE2, a quantitative structure-activity relationship was established between substituents changed on the phenolic moiety and the relative in vitro estrogenic activity. In addition, the initial EE2 transformation products that still exhibit residual estrogenic activity are quickly further transformed by most of the tested oxidants. Therefore, oxidative wastewater treatment may serve as a powerful tool to remove estrogenic activity induced by steroid estrogens.     

Zur Warmfestigkeit austenitischer Ventilstähle mit hohem Stickstoffgehalt

On the hot strength of austenitic valve steels with a high nitrogen content Exhaust valves are made of CrMnNi steels with about 1 wt% of (C + N) and additions of W, Mo and Nb. Remelting under pressure allows to raise N and do without C. After solution annealing the formation of discontinuous N‐perlite during aging is suppressed by ∼ 1 wt% of Nb whereby the creep strength is increased. The size and distribution of continuously precipitated nitrides in N‐steels are finer than those of carbides and nitrides in (C + N)‐steels. Thus the creep strength of the former is superior at 700 °C. However, at 800 °C σ‐phase leads to a breakdown of creep strength. The reason is seen in a lower stability of N‐austenite as compared to (C + N)‐austenite, which shows a higher concentration of free electrons and more short range atomic ordering.     

Bioanalytical assessment of the formation of disinfection byproducts in a drinking water treatment plant

Disinfection of drinking water is the most successful measure to reduce water-borne diseases and protect health. However, disinfection byproducts (DBPs) formed from the reaction of disinfectants such as chlorine and monochloramine with organic matter may cause bladder cancer and other adverse health effects. In this study the formation of DBPs through a full-scale water treatment plant serving a metropolitan area in Australia was assessed using in vitro bioanalytical tools, as well as through quantification of halogen-specific adsorbable organic halogens (AOXs), characterization of organic matter, and analytical quantification of selected regulated and emerging DBPs. The water treatment train consisted of coagulation, sand filtration, chlorination, addition of lime and fluoride, storage, and chloramination. Nonspecific toxicity peaked midway through the treatment train after the chlorination and storage steps. The dissolved organic matter concentration decreased after the coagulation step and then essentially remained constant during the treatment train. Concentrations of AOXs increased upon initial chlorination and continued to increase through the plant, probably due to increased chlorine contact time. Most of the quantified DBPs followed a trend similar to that of AOXs, with maximum concentrations observed in the final treated water after chloramination. The mostly chlorinated and brominated DBPs formed during treatment also caused reactive toxicity to increase after chlorination. Both genotoxicity with and without metabolic activation and the induction of the oxidative stress response pathway showed the same pattern as the nonspecific toxicity, with a maximum activity midway through the treatment train. Although measured effects cannot be directly translated to adverse health outcomes, this study demonstrates the applicability of bioanalytical tools to investigate DBP formation in a drinking water treatment plant, despite bioassays and sample preparation not yet being optimized for volatile DBPs. As such, the bioassays are useful as monitoring tools as they provide sensitive responses even at low DBP levels.     

Down-regulation of hepatic and renal 11 beta-hydroxysteroid dehydrogenase in rats with liver cirrhosis

Twenty-four crossbred primiparous sows were used to investigate the influence of insulin administration after weaning on the intrafollicular insulin-like growth factor i (IGF-I) system. Sows received 0.4 i.u. insulin kg-1 bodyweight or an equivalent volume of saline for 3 days (n = 5 insulin; n = 4 saline) or 5 days (n = 5 insulin; n = 6 saline) after weaning or served as untreated controls on day 1 (n = 4). The number and diameters of ovarian follicles were recorded, and fluid was aspirated from the 20 largest follicles for determination of oestradiol and IGF-I by radioimmunoassay and of insulin-like growth factor-binding proteins (IGFBPs) by western ligand blotting. The walls of the follicles were collected for mRNA analysis by RNase protection assay or granulosa cells were collected for estimation of apoptosis by flow cytometry. Insulin treatment resulted in smaller diameters of all follicles (P < 0.05) and tended (P < 0.07) to increase the number of follicles available on day 5 compared with saline-treated animals (19.8 versus 17.8). The concentration of oestradiol in follicular fluid from large (7-10 mm) follicles on days 3 and 5 was reduced (treatment by size class interaction; P < 0.05) by insulin treatment. Insulin also reduced intrafollicular concentrations of IGF-I at days 3 and 5 after weaning (treatment by day interaction; P < 0.02) while the amounts of IGFBP-3 and IGFBPs of molecular mass 30 and 22 kDa decreased from day 3 to day 5 in saline-treated animals only (treatment by day interaction; P < 0.05). Gene expression for IGF-I increased in saline-treated animals but decreased fourfold in insulin-treated sows from day 3 to day 5 (treatment by day interaction; P < 0.002). Gene expression for IGFBP-d decreased (P < 0.04) from day 3 to day 5, while expression of IGFBP-2 was unaffected by treatment or day. Overall, insulin influenced the IGF-I system in a manner consistent with slowing follicular growth and possibly allowed more follicles to become available for ovulation.     

Recombinant human natural autoantibodies against GPIIb/IIIa inhibit binding of autoantibodies from patients with AITP

Autoimmune thrombocytopenic purpura (AITP) is caused by autoantibodies predominantly against platelet membrane glycoproteins (GP) IIb/IIIa and GPIb/IX. Naturally occurring autoantibodies have been described against a variety of autoantigens; it has been suggested that perturbation of their regulation may be associated with autoimmune diseases. Using a combinatorial Fab phagemid library from an individual immunized with human RhD+ red blood cells, we evaluated the presence of natural anti-GPIIb/IIIa autoantibodies as well as their relation to AITP-associated anti-GPIIb/IIIa autoantibodies. Selection on native GPIIb/IIIa and characterization of positive clones by inhibition studies against murine monoclonal anti-GPIIb/IIIa antibodies and by DNA analysis revealed the presence of two distinct recombinant anti-GPIIb/IIIa autoantibodies, which partially inhibited binding of affinity-purified platelet-associated autoantibodies from 8/12 AITP patients. Our results demonstrated that GPIIb/IIIa-specific Fab directed against conformational epitopes within the GPIIb/IIIa complex may be cloned from the genome of an individual immunized with RhD+ red blood cells, who was not affected by AITP. The partial inhibition of binding of platelet-associated autoantibodies from AITP patients to GPIIb/IIIa by the recombinant anti-GPIIb/IIIa phage clones suggests recognition of closely related antigenic epitopes. These phage clones may represent down-regulated, potentially pathological autoantibodies and could be used as new tools for investigation of AITP.     

Rapid exposure assessment of PSII herbicides in surface water using a novel chlorophyll a fluorescence imaging assay

Recently a new Maxi-Imaging-PAM (Max-I-PAM) instrument for phytotoxicity assessment via chlorophyll fluorescence imaging was introduced. This new instrument allows rapid detection of the effects of PS II inhibiting herbicides which are high use agricultural chemicals frequently detected in surface waters in Australia and elsewhere. Several studies have applied the new instrument for detection of phytotoxicants in water using microalgae suspensions; however, these use preliminary protocols and to date no validated method is available for high throughput testing of environmental samples in 96-well plates. Here we developed and applied a new protocol allowing dose-response assessment of four samples within 2 h (8 dilutions in duplicate). The technique was found to be sensitive, with a detection limit of 2.3 ng l(-1) for the herbicide diuron when testing solid phase extracts (SPE) of 1000 ml water samples, and reproducible both between experiments (coefficient of variation (CV)=0.30) and within the 96-well plate (CV=0.06). Relative potencies were determined for four reference PS II impacting herbicides (diuron>hexazinone>atrazine>simazine). Extracts from 1000 ml environmental samples and diuron spiked ultrapure water as well as passive sampler extracts were evaluated and good agreement was found between diuron equivalent concentrations calculated from bioassay results (DEQ(IPAM)) and DEQ(CHEM) values calculated from LCMS chemical analysis of the four reference compounds in the same samples. Overall, the technique provides a valuable bioanalytical tool for rapid and inexpensive effects-based assessment of PS II impacting herbicides in environmental mixtures.     

Hydrogen-oxygen utilization systems

A Hydrogen-energy system embracing production, delivery and utilization or end-use means, can alternatively take on one of two basic configurations: (1) hydrogen (only) or (2) hydrogen + oxygen. The former, which would be analagous to today's natural gas system, implies air-using utilization devices in which the oxygen required for sustaining the using-point energy conversion by way of heat-release or electricity-generation, is extracted from the atmosphere.The second alternative would be represented by a “twin-pipe” delivery system in which both elemental constituents of the basic water-splitting production process are delivered to the utilization sectors. This hydrogen + oxygen alternative configuration offers significant, but not very well-known benefits attributable to hydrogen-oxygen utilization systems, the subject of this paper. The thesis offered is that such systems and end-use devices provide the potential for major gains in energy conversion efficiency, capital costs, operating flexibility, and in environmental impact.However, today concensus seems to favor the “hydrogen only” option in which the oxygen concomitant to hydrogen production is vented to the atmosphere, or at best assumed to be a cheap bulk industrial credit byproduct.If hydrogen-oxygen utilization systems are eventually judged by the ultimate consumer to offer the benefits postulated, production and delivery means supportive of hydrogen + oxygen distribution may be forthcoming. Since this predicates fundamental and large-scale changes in the production and delivery sector so far as physical makeup is concerned, advanced energy system planners are urged to give early heed to the potential and ramifications of hydrogen-oxygen utilization systems, and to voice their judgment.     

Development and Application of a Stainless CrNbMoC Tool Steel

Steels with 15 mass% Cr, 2 mass% Mo and varying contents of C, V, Nb and Ti were investigated by thermodynamic calculations to find a stainless grade promising a wear resistance equal to that of the standard cold work tool steel X153CrMoV12. It was shown that Nb is most suited to form MC carbides for wear resistance thus reducing the content of M₇C₃, which in turn raised the Cr content dissolved in the matrix to a passivating level. Small melts in the vicinity of steel X140CrNbMoTi15‐5‐2 confirmed this concept in respect to hardenability, wear resistance and corrosion resistance. Industrial manufacturing and application of the new grade RN15X® will be discussed.     

Effect of microencapsulation on survival of Lactobacillus plantarum in simulated gastrointestinal conditions, refrigeration, and yogurt

In the present research the survival of free and microencapsulated cells of a new strain of Lactobacillus plantarum BL011 under stress conditions was tested in sodium alginate or pectin, coated with sodium alginate or chitosan. Results for the simulated gastrointestinal medium (SGT) showed no change in viability of cells in relation to the control. However, the simulated gastric medium (GM) drastically reduced the viability under the tested conditions, with no significant differences between free and immobilized cells. Under refrigerated storage viability of immobilized cells were greatly enhanced compared to the free microorganisms, and the treatments showing the lowest loss of viability were those of 4% (w/v) pectin, 3% (w/v) sodium alginate coated with chitosan and a mixture of 2% (w/v) sodium alginate and 2% (w/v) pectin, respectively. Loss of viability of immobilized L. plantarum in 3% alginate coated with chitosan in yogurt was of 0.55 log cycles during 38 days of storage. The results of this study suggest the efficiency of immobilization techniques to increase the survival of lactobacilli in yogurt under refrigerated storage.