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Chromium (Cr), Nickel (Ni), and zinc (Zn) removal from landfill leachate using mesocosm-scale vertical flow wetlands, the effect of recirculation, and the ability of macrophytes to retain metals were evaluated. Wetlands were filled with coarse sand and light expanded clay aggregates and planted with Typha domingensis or Canna indica. Wetlands were operated using intermittent loading, with and without recirculation. Raw leachate was diluted and spiked with metals to reach the following concentrations: 0.2 mg L-1 Cr , 0.2 mg L-1 Ni, and0.2 mg L-1 Zn and 1.0 mg L-1 Cr, 1.0 mg L-1 Ni, and 1.0 mg L-1 Zn. Wetlands planted with T. domingensis presented higher metal removal than those planted with C. indica. Recirculation enhanced metal removal efficiencies significantly, being for T. domingensis/C. indica: 60/54, 49/47, 61/47% for Cr, Ni, and Zn at 0.2 mg L-1, and 80/71, 76/62, 73/59% for Cr, Ni, and Zn at 1.0 mg L-1, respectively. Metals were efficiently retained by macrophytes. Plant biomass and metal concentrations in roots were significantly higher than in shoots. Scanning electron microscopy and X-ray microanalysis showed that metals were absorbed by internal root tissues. A hybrid wetland planted with T. domingensis may be implemented to improve not only metal but also chemical oxygen demand and total nitrogen removals.

14 pages, 8 figures, 4 tables.-- This is an open access article distributed under the Creative Commons Attribution License, High molecular weight (Mw) collagen hydrolysates have been demonstrated to produce a higher synthesis of collagen type I mRNA. Mw determination is a key factor maximizing the effect of collagen hydrolysates on collagen type I synthesis by fibroblasts. This work aimed to achieve a high average Mw in Blue Shark Collagen Hydrolysate, studying different hydrolysis parameters by GPC-LS analysis and testing its effect on mRNA Type I collagen expression. Analysis revealed differences in blue shark collagen hydrolysates Mw depending on hydrolysis conditions. Papain leads to obtaining a significantly higher Mw hydrolysate than Alcalase at different times of hydrolysis and at different enzyme/substrate ratios. Besides, the time of the hydrolysis factor is more determinant than the enzyme/substrate ratio factor for obtaining a higher or lower hydrolysate Mw when using Papain as the enzyme. Contrary, Alcalase hydrolysates resulted in similar Mw with no significant differences between different conditions of hydrolysis assayed. Blue shark collagen hydrolysate showing the highest Mw showed neither cytotoxic nor proliferation effect on fibroblast cell culture. Besides, it exhibited an increasing effect on both mRNA expression and pro-collagen I production, This research was funded by the project BlueHuman, EU_EAPA_151/2016 and Xunta de Galicia (Grupos de Potencial Crecimiento, IN607B2021/11)

Commercially available grades of poly(lactic acid) (PLA) and acrylonitrile-butadiene-styrene (ABS) were printed in different shapes using an additive manufacturing (AM) printer based on material extrusion (ME). It is known that the quality of a 3D printed sample is closely connected to the rheological properties of the polymer matrix. However, some printing parameters, such as the feed rate and the print speed, might not be determined only by equipment design as usually reported in the literature. Instead, the thermal and rheological properties of the polymers should be carefully considered. The focus of many studies has relied on optimizing the specific properties of an ME printer through the adjustment of the printing parameters. Still, few researchers have shown how the rheological behaviour of a material can affect its final properties. Therefore, this paper would like to answer satisfactorily some recurring questions with clear practical importance, which is related to the fact that some materials have better print quality than others do and about the feasible margins for increasing the print speed according to the characteristics of a polymeric material. Thus, in this work, rheological characterization of the resins was conducted and it was detected that the processing condition for a specific thermoplastic is highly dependent on its rheological behaviour. A method of mass flow conservation was presented for determination and consideration of the rheological characteristics when selecting an appropriate process parameter for the additive manufacturing system. It was found that even a small recovery strain resulting from the characteristic morphology of ABS could provide lower layers’ roughness and good printing quality to the 3D printed samples. Thus, the main goal of this work was to evaluate the importance of the rheological properties of common thermoplastics used in extrusion-based process on the controlling of a 3D printer and on the final printing quality.

During limb formation in vertebrates with free digits, the interdigital mesoderm is eliminated by a massive degeneration process that involves apoptosis and cell senescence. The degradation process is preceded by intense DNA damage in zones located close to methylated DNA, accompanied by the activation of the DNA repair response. In this study, we show that trimethylated histone 3 (H3K4me3, H3K9me3, and H3K27me3) overlaps with zones positive for 5mC in the nuclei of interdigital cells. This pattern contrasts with the widespread distribution of acetylated histones (H3K9ac and H4ac) and the histone variant H3.3 throughout the nucleoplasm. Consistent with the intense labeling of acetylated histones, the histone deacetylase genes Hdac1, Hdac2, Hdac3, and Hdac8, and at a more reduced level, Hdac10, are expressed in the interdigits. Furthermore, local treatments with the histone deacetylase inhibitor trichostatin A, which promotes an open chromatin state, induces massive cell death and transcriptional changes reminiscent of, but preceding, the physiological process of interdigit remodeling. Together, these findings suggest that the epigenetic profile of the interdigital mesoderm contributes to the sensitivity to DNA damage that precedes apoptosis during tissue regression.

Purpose To investigate whether plasma rich in growth factors (PRGF) eye drops maintain their biological potential after a freeze drying process. The addition of a lyoprotectant like trehalose was also evaluated. Methods Blood from three healthy donors was collected to obtain eye drops by PRGF technology. The resultant eye drops were divided in four groups: PRGF, freeze-dried PRGF (PRGF lyo), and PRGF lyophilized mixed with 2,5% trehalose (PRGF lyo+2.5T) or 5% trehalose (PRGF lyof+5T). Chemical and biological characteristics were evaluated. Photorefractive keratectomy was performed on C57BL/6 mice which were divided in three treatment groups: control, PRGF, and PRGF lyo. Corneal wound healing and haze formation were evaluated macroscopically. Eyes were collected at 1, 2, 3, and 7 days after surgery, and were processed for histologic studies. Results The pH values of PRGF samples increased significantly after the lyophilization process. Osmolarity levels increased significantly in PRGF samples mixed with trehalose in comparison with PRGF samples without protectants. The freeze drying process maintained growth factors levels as well as the biological properties of PRGF eye drops even without the use of lyoprotectants. PRGF lyo treatment significantly decreased the re-epithelialization time and haze formation in photorefractive keratectomy-treated corneas regarding PRGF and control groups. Furthermore, the PRGF lyo group significantly decreased the number of smooth muscle actin-positive cells in comparison with the control group at each time of the study and at days 2 and 3 in the PRGF group. Conclusions The freeze drying process preserves the protein and growth factor content as well as the biological properties of PRGF eye drops, even without the use of protectants. Freeze-dried PRGF eye drops accelerate corneal tissue regeneration after photorefractive keratectomy in comparison with the control group. Translational Relevance Our study shows the feasibility to preserve the biological capability of PRGF eye drops as freeze-dried formulation, avoiding the addition of protectants., Resumen (Foreign Language Abstract) Objetivo Investigar si el colirio de plasma rico en factores de crecimiento (PRGF) mantiene su potencial biológico después de un proceso de liofilización. También se evaluó la adición de un lioprotector como la trehalosa. Métodos Se recogió sangre de tres donantes sanos para obtener colirio mediante la tecnología PRGF. El colirio resultante se dividió en cuatro grupos: PRGF, PRGF liofilizado (PRGF lyo) y PRGF liofilizado mezclado con trehalosa al 2,5% (PRGF lyo + 2.5T) o trehalosa al 5% (PRGF lyof + 5T). Se evaluaron las características químicas y biológicas de cada uno de los colirios. Se realizó una queratectomía fotorrefractiva (PRK) en ratones C57BL/6 que se dividieron en tres grupos de tratamiento: Control, PRGF y PRGF lyo. La curación de la herida corneal y la formación de “haze” se evaluaron macroscópicamente. Los ojos se recolectaron en los días 1, 2, 3 y 7 después de la cirugía, y se procesaron para la realización de estudios histológicos. Resultados Los valores de pH de las muestras de PRGF aumentaron significativamente después del proceso de liofilización. Los niveles de osmolaridad aumentaron significativamente en las muestras de PRGF mezcladas con trehalosa en comparación con las muestras de PRGF sin protectores. El proceso de liofilización mantuvo los niveles de factores de crecimiento, así como las propiedades biológicas de los colirios de PRGF, incluso sin el uso de lioprotectores. El tratamiento con PRGF lyo redujo significativamente el tiempo de reepitelización y la formación de “haze” en las córneas tratadas con PRK con respecto al grupo de control y PRGF. Además, el grupo PRGF lyo redujo significativamente el número de células SMA positivas en comparación con el grupo control en cada tiempo de estudio y en los días 2 y 3 con respecto al grupo de PRGF. Conclusiones el proceso de liofilización conserva el contenido de proteínas y factores de crecimiento, así como las propiedades biológicas del colirio de PRGF, incluso sin el uso de protectores. El colirio de PRGF liofilizado acelera la regeneración del tejido corneal después de la PRK en comparación con el grupo de control. Relevancia Traslacional nuestro estudio muestra la viabilidad de preservar la capacidad biológica del colirio de PRGF como formulación liofilizada evitando la adición de protectores.

Two constructed wetlands for treating industrial and sewage effluents (CW1 and CW2) and two natural wetlands (NW1 and NW2), located in Argentina, were studied. The aims of the study were (1) to assess the accumulation and distribution pattern of P in the surface sediments of both natural and constructed wetlands, and (2) to evaluate P long-term retention in sediment. In the sediment of all study sites, inorganic P fractions were dominant. Similar incoming water composition was determined between NW2 and CW1 and between NW1 and CW2. Water composition governed P concentration and distribution in sediment, being mainly P bound to CaCO3 in CW1 and NW2 and bound to Fe(OOH) in NW1 and CW2. According to water and sediment characteristics, the four wetlands will continue removing P from water. Studied wetlands are efficient and sustainable in terms of P retention. Fil: Di Luca, Gisela Alfonsina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Mufarrege, María de Las Mercedes. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Sánchez, Germán Hugo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Caffaratti, Sandra Ester. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina

Wastewater from a fertilizer manufacturing plant requires improvement prior to its environmental disposal. Ammonium is the critical contaminant to be removed. The aim of this study was to evaluate the feasibility of using free water surface wetlands (FWSWs), horizontal subsurface flow wetlands (HSSFWs), and their combination in hybrid wetlands (HWs) for the final treatment of wastewater with high ammonium concentration from a fertilizer manufacturing plant. Substrates and macrophytes were evaluated in microcosm experiments during three months. There were no significant differences in contaminant removal among HSSFWs with LECA or FWSWs planted with Typha domingensis or Canna indica. In a second stage, two configurations of pilot-scale HWs were constructed at the manufacturing facilities. Configuration A: HSSFW(A1)-FWSW(A2) and Configuration B: FWSW(B1)-HSSFW(B2) were evaluated during 12 months. There were no significant differences in contaminant removal (%) between the two configurations of HWs for COD (A: 74.5 ± 12.2/B: 81.5 ± 9.4), ammonium (A: 59.5 ± 17.5/B: 57.9 ± 21.4), nitrite (A: 79.8 ± 24.2/B: 80.6 ± 16.8) and dissolved inorganic nitrogen (DIN) (A: 59.4 ± 17.3/B: 50.3 ± 24.4). However, nitrate concentration (9.83 ± 3.11 mg N L−1) was significantly lower after Configuration A than after Configuration B (18.8 ± 5.2 mg N L−1). Comparing FWSWs and HSSFWs, they did not present significant differences in ammonium removal, while FWSWs presented the highest DIN removal. T. domingensis and C. indica in HSSFWs and T. domingensis in FWSWs tolerated wastewater conditions. T. domingensis presented the highest productivity. In further research, FWSWs in series planted with T. domingensis should be studied. Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Caffaratti, Sandra Ester. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Mufarrege, María de Las Mercedes. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Di Luca, Gisela Alfonsina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina

Melatonin exerts oncostatic actions and sensitizes tumor cells to chemotherapeutics or radiation. In our study, we investigated the effects of docetaxel, vinorelbine, and radiation on human breast fibroblasts and its modulation by melatonin. Docetaxel or vinorelbine inhibits proliferation and stimulates the differentiation of breast preadipocytes, by increasing C/EBP&alpha, and PPAR&gamma, expression and by downregulating tumor necrosis factor &alpha, (TNF&alpha, ), interleukin 6 (IL-6), and IL-11 expression. Radiation inhibits both proliferation and differentiation through the downregulation of C/EBP&alpha, and by stimulating TNF&alpha, expression. In addition, docetaxel and radiation decrease aromatase activity and expression by decreasing aromatase promoter II and cyclooxygenases 1 and 2 (COX-1 and COX-2) expression. Melatonin potentiates the stimulatory effect of docetaxel and vinorelbine on differentiation and their inhibitory effects on aromatase activity and expression, by increasing the stimulatory effect on C/EBP&alpha, expression and the downregulation of antiadipogenic cytokines and COX expression. Melatonin also counteracts the inhibitory effect of radiation on differentiation of preadipocytes, by increasing C/EBP&alpha, expression and by decreasing TNF&alpha, expression. Melatonin also potentiates the inhibitory effect exerted by radiation on aromatase activity and expression by increasing the downregulation of promoter II, and COX-1 and COX-2 expression. Our findings suggest that melatonin modulates regulatory effects induced by chemotherapeutic drugs or radiation on preadipocytes, which makes it a promising adjuvant for chemotherapy and radiotherapy sensibilization.

The removal efficiency and tolerance of Typha domingensis to Cr(VI) in treatments with and without organic matter (OM) addition were evaluated in microcosm-scale wetlands. Studied Cr(VI) concentrations were 15 mg L−1, 30 mg L−1, and 100 mg L−1, in treatments with and without OM addition, arranged in triplicate. Controls (without neither metal nor OM addition—without metal with OM addition) were disposed. Cr(VI) was removed efficiently from water in all treatments. OM addition enhanced significantly Cr(VI) and total Cr removals from water. In the treatments with OM addition, significantly higher Cr concentrations were found in sediment than the treatments without OM addition. Plants of the treatments without OM addition showed significantly higher Cr concentrations in tissues but lower biomass increase than the treatments with OM addition. The highest Cr concentrations in tissues were observed in submerged parts of leaves, followed by roots. According to SEM analysis, in the 100 mg L−1 treatments, the highest Cr accumulation was observed in the epidermis of old leaves. Although Cr(VI) produced changes in root morphology, the OM addition favored the plant growth. In T. domingensis, root morphological plasticity is an important mechanism to improve metal tolerance and Cr uptake in wetland systems minimizing the environmental impact. Fil: Mufarrege, María de Las Mercedes. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Di Luca, Gisela Alfonsina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Caffaratti, Sandra Ester. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina

A missense C1858T single nucleotide polymorphism within PTPN22 is a strong genetic risk factor for the development of multiple autoimmune diseases. PTPN22 encodes a protein tyrosine phosphatase that negatively regulates immuno-receptor proximal Src and Syk family kinases. Notably, PTPN22 negatively regulates kinases downstream of T-cell receptor (TCR) and LFA-1, thereby setting thresholds for T-cell activation. Alterations to the quality of TCR and LFA-1 engagement at the immune synapse and the regulation of downstream signals can have profound effects on the type of effector T-cell response induced. Here we describe how IFNγ+ Th1 responses are potentiated in Ptpn22−/− T-cells and in T-cells from mice expressing Ptpn22R619W (the mouse orthologue of the human genetic variant) as they age, or following repeated immune challenge, and explore the mechanisms contributing to the expansion of Th1 cells. Specifically, we uncover two LFA-1-ICAM dependent mechanisms; one T-cell intrinsic, and one T-cell extrinsic. Firstly, we found that in vitro anti-CD3/LFA-1 induced Th1 responses were enhanced in Ptpn22−/− T-cells compared to WT, whereas anti-CD3/anti-CD28 induced IFNy responses were similar. These data were associated with an enhanced ability of Ptpn22−/− T-cells to engage ICAM-1 at the immune synapse when incubated on planar lipid bilayers, and to form conjugates with dendritic cells. Secondly, we observed a T-cell extrinsic mechanism whereby repeated stimulation of WT OT-II T-cells with LPS and OVA323-339 pulsed Ptpn22−/− bone marrow derived dendritic cells (BMDCs) was sufficient to enhance Th1 cell development compared to WT BMDCs. Furthermore, this response could be reversed by LFA-1 blockade. Our data point to two related but distinct mechanisms by which PTPN22 regulates LFA-1 dependent signals to enhance Th1 development, highlighting how perturbations to PTPN22 function over time to regulate the balance of the immune response., Highlights • PTPN22R620W is one of the strongest risk factors for multiple autoimmune diseases. • In Ptpn22−/− and Ptpn22R619W mice IFNy+ Th1 cells preferentially and significantly expand with age or following immune challenge. • PTPN22 negatively regulates IFNγ+ Th1 cells by T-cell and dendritic cell LFA-1-ICAM-1 dependent mechanisms. • PTPN22 negatively regulates LFA-1 induced Th1 cells enhancing T-cell LFA-1 clustering and immune synapse formation. • Repeated stimulation of T-cells with Ptpn22−/− BMDC enhances Th1 responses.

Eichhornia crassipes is a macrophyte widely used in phytoremediation, demonstrating a high ability to remove metals from water. The aim of this work was to evaluate its enzymatic detoxification strategies and metal accumulation when it is exposed to different Zn concentrations (0, 2, 4, 6, and 9 ppm) for periods of 24, 48, and 72 h. Zn concentration in roots was significantly higher than in aerial parts. Independently of the treatment, in the first 48 h, concentrations of photosynthetic pigments were not affected. However, a significant increase (between 19 and 34%) in Chl-b concentrations for all treatments was observed at 72 h. Carotenoid concentration was not affected during the first 48 h, while at 72 h, there was a significant increase regarding the control (between 11 and 24%) for all treatments. Malondialdehyde concentration in aerial parts and roots was not affected during the experiment. Nonetheless, a significant increase in the enzymatic activity of the antioxidant system was observed. Results suggest that Zn could have potential antioxidant properties, which may result in the activation of different antioxidant enzymes involved in the protection against metal stress. Fil: González, César Iván. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina Fil: Benavides, Maria Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Biológica; Argentina Fil: Campagnoli, Marcelo Abel. Universidad Nacional del Litoral. Instituto de Química Aplicada del Litoral. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Química Aplicada del Litoral.; Argentina

The values of delta C-13 in benthic foraminifera have been measured in a gas-hydrate-bearing sediment core collected from an area of active methane venting on the Vestnesa Ridge (West Svalbard continental margin) to reconstruct the local history of methane emissions over the past 23.500 yrs BP. The chronostratigraphic framework of the core has been derived from AMS C-14 dates and biostratigraphic analysis. While foraminifera from some intervals have delta C-13 within the normal marine range (0 to-1%.), five intervals are characterized by a much lower delta C-13, as low as -17.4%.. These intervals are interpreted to record the incorporation of C-13-depleted carbon in the presence of methane emissions at the seafloor during biomineralization of the carbonate foraminiferal tests and subsequent secondary mineralization. Methane emission events (MEE) occur from the Last Glacial Maximum (LGM) to the Holocene, with the most prominent one, in terms of delta C-13 depletion, predating the Bolling-Allerod Interstadial (GI-1 in the Greenland ice core record). The lack of correlation between the values of delta C-13 and delta O-18, however, appears to preclude warming of bottom waters as the principal control on methane release. Rather, it seems likely that methane release is a consequence of episodicity in the supply of gas to the hydrate system and in the processes that enable methane gas to migrate through the hydrate stability field to the seabed, or of other geological processes still under debate. (C) 2014 Elsevier B.V. All rights reserved.

The effects of different concentrations of P and N, added separately or combined, on the Cr(III) accumulation capacity of P. stratiotes were studied. Plants and pond water with the addition of contaminant(s) were placed in plastic aquaria. Cr concentration was 5 mg L-1, while P and N concentrations were 5 mg L-1 or 10 mg L-1. Nutrient addition significantly favoured Cr removal and enhanced Cr translocation to leaves. In Cr treatments a high detritus formation from loss of root biomass was observed probably due to its toxicity. Cr was mainly accumulated in the detrital fraction, whereas P and N were retained fundamentally in leaves. A toxic effect was observed in the Cr+P10 and Cr+N10 treatments. These results could be applied to enhance Cr removal efficiency of constructed wetlands using P. stratiotes, where nutrient enrichment could be attained by treating sewage together with the industrial effluents. Fil: Di Luca, Gisela Alfonsina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Hadad, Hernán Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina Fil: Mufarrege, María de Las Mercedes. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

The aim of this work was to study the influence of nutrients on the tolerance, removal efficiency and accumulation of high concentration of Cr(III) by Typha domingensis. This species was exposed to the following Cr(III) treatments, arranged in triplicate: 200 mg L−1 Cr; 600 mg L−1 Cr; 200 mg L−1 Cr + 50 mg L−1 P + 50 mg L−1 N; 600 mg L−1 Cr + 50 mg L−1 P + 50 mg L−1 N; without metal or nutrient additions (control 1); 50 mg L−1 P + 50 mg L−1 N, without metal addition (control 2). In order to simulate extreme events, the concentrations studied were higher than the concentrations commonly found in constructed wetlands. Cr and nutrient concentrations in water decreased in all treatments along time. Nutrient addition did not affect Cr removal for the two concentrations studied. In tissues, the highest Cr concentrations were observed in roots in all treatments. The mass balance showed that sediment showed the highest accumulation of Cr. Metals caused growth inhibition and a decrease in chlorophyll concentration. Despite these sublethal effects, T. domingensis demonstrated that it could accumulate Cr. These results confirm the high tolerance of this species ensuring the survival plant and wetland efficiency in time. Fil: Mufarrege, María de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Di Luca, Gisela Alfonsina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Sánchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

A free water surface wetland was built in 2002 to treat wastewater from a tool factory containing metals (Cr, Ni, Zn and Fe), nutrients and organic matter. Until 2006, the last reported period, the wetland retained metals and stored them primarily in the bottom sediment and in the biomass of macrophytes secondarily. The aim of this work was to study metal retention and distribution in the sediment of a constructed wetland for industrial wastewater treatment. Total concentrations and fractions (exchangeable, carbonate-bound, Fe–Mn oxides-bound, organic matter-bound and residual) of metals in sediment were analyzed in this treatment wetland, in order to estimate the fate of metals over time. Metal concentrations were significantly higher in the inlet than in the outlet sediment; concentrations in the latter remained without significant differences throughout the testing period. Metal concentrations and redox potential decreased with depth within the sediment. The lowest metal concentrations and pH and the highest redox values were attained in spring, in agreement with the period of maximum macrophyte growth. Ni and Zn were mainly stored associated with the carbonate fraction; Cr was mainly associated with the Fe–Mn oxides fraction, while Fe was mainly associated with the residual fraction, probably as pyrite. The incoming wastewater composition containing high pH, carbonate, calcium and Fe concentrations favored the observed association in the surface sediment. It would be expected that sediment will continue retaining metals in fractions that will not release them into the water while the chemical and environmental conditions remain unchanged.

The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L−1 of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work. Fil: Maine, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Hadad, Hernán Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Sánchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Caffaratti, Sandra Ester. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina

This contribution summarizes the nutrient and metal removal of a free water surface constructed wetland, compares it with the previous small-scale prototype and discusses the observed differences. Several locally available macrophyte species were transplanted into the wetland. Eichhornia crassipes (water hyacinth) showed a fast growth and it soon became dominant, attaining 80% cover of the wetland surface. Typha domingensis (cattail) and Panicum elephantipes (elephant panicgrass) developed as accompanying species attaining 14 and 4% cover. The wetland removed 86% of Cr and 67% of Ni. Zn concentrations were below 50 μg l−1 in most samplings. The FeS precipitation probably caused the high retention of Fe (95%). The outcoming water was anoxic in most samplings. Phosphate and ammonium were not retained within the wetland while 70% and 60% of the incoming nitrate and nitrite were removed. Large denitrification losses are suggested. Cr, Ni and Zn were retained by the macrophytes in the larger wetland and in sediment in the small-scale one. Differences in the retention mechanism of the two wetlands are discussed.

The synthesis, characterization, and electrochemical study of the Zn(II)–Al(III) and Zn(II)–Cr(III) Layered Double Hydroxides (LDHs) containing 2-thiopenecarboxylate as the interlayer anions are described. The LDHs were prepared by the constant pH coprecipitation technique followed by hydrothermal treatment for 72 h. The materials were analyzed by PXRD, FT-IR, 13 C CP-MAS, EDX, TEM, and CV. The presence of the organic heterocyclic anions was confirmed by FT-IR and the related solid-state 13 C NMR data strongly suggested that these were dimerised during coprecipitation. Accordingly, the basal spacing found by the X-ray technique was ∼15.3 A, a distance coincident with the formation of bilayers of the intercalated anions. The structural organization of all the new materials was greatly enhanced by hydrothermal treatment, as shown by PXRD. The improved organization of the bilayered structures had a strong influence in the electrochemical behaviour of clay-modified electrodes produced with these materials, such as the diminished resistance to the ionic flow through the LDHs films.

An on-line method for the determination of airborne organophosphate esters based on dynamic sonication-assisted solvent extraction and large-volume injection (LVI) gas chromatography with nitrogen-phosphorous detection is introduced. The LVI is performed with a programmed-temperature vaporizer. The entire extracted fraction of 800 microl (hexane-methyl-tert.-butyl ether, 7:3, v/v) is introduced directly into the GC system without any clean-up step following extraction. The extraction and analysis step were completed in less than 15 min. The limit of detection of the investigated organophosphate esters was established to be in the range of 5-32 pg/filter. The correlation coefficients (r2) were investigated in the linear range study of the entire system and established to be approximately 0.9900 for all the investigated organophosphates esters. Applications of the method was demonstrated with the extraction of air samples collected onto glass fiber filters from different indoor environments. Six organophosphate esters were found at the levels 0.4-138 ng/m3.

The competition between 2'-deoxyguanosine (dG) and water has been quantitatively evaluated for the allylic carbocation derived from tamoxifen and for the stabilized diarylmethyl cation (bis-(4-methoxyphenyl)methyl). Both systems were examined by the competition kinetics method, in which the products were quantitatively analyzed after the SN1 solvolysis of the corresponding acetate esters in aqueous solutions containing the nucleoside. The principal product of the reaction of both cations with dG is the adduct at the NH2 group, a characteristic of delocalized carbocations. The tamoxifen cation was also examined by laser flash photolysis, with absolute rate constants for the reaction with dG and water being obtained and converted into rate constant ratios. The principal result of this study is that there is a three orders of magnitude difference in the reactivity of these cations towards the neutral form of dG and its conjugate base. Under acidic conditions where the reaction occurs with neutral dG, the guanine–water selectivity is low. Even at relatively high concentrations of dG, the majority of the product is alcohol derived from the water reaction. At pH 10 to 11, in contrast, dG is present as the anion and this is highly competitive. Yields of adduct as high as 90% can be attained. A consequence of the large difference in reactivities is that at neutral pH the majority of the reaction of the cation with dG is actually occurring via the small amount of conjugate base present. A further feature of the results is that the NH2 adduct is the predominant stable product from the anion. To explain the high rate constant for the reaction forming this product, a mechanism is proposed whereby one of the protons of the NH2 group is transferred to N1 as the N2-cation bond is forming.Key words: guanine, DNA adduct, carbocation, tamoxifen.

The effect of exposure of Eichhornia crassipes to Cr (III) was assessed by measuring changes in photosynthetic pigments, malondialdehyde, superoxide dismutase, glutathione reductase, catalase, and guaiacol peroxidase activities, as well as Cr concentration in tissues. Cr concentration in roots was significantly higher than in aerial parts and increased with Cr concentration in water. Photosynthetic pigments increased significantly, whereas the activities of antioxidant enzymes varied differently in plant tissues. Low Cr concentrations induced a rapid response of E. crassipes during short-term exposure, implying that the antioxidant system conferred redox homeostasis. Results showed that Cr (III) was more toxic at the two highest concentrations and long-term exposure, while it was not harmful but beneficial at the two lowest concentrations and short-term exposure. This work concludes that E. crassipes was able to grow under Cr (III) stress by protecting itself with an increase in the activity of its antioxidant system. Fil: González, César Iván. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Benavides, Maria Patricia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The tamoxifen carbocation (Ph(Ar)C=CPh-CH+-CH3, Ar = 4-Me2NCH2CH2OC6H4) is generated from acetate and sulfate precursors by SN1 ionization in water. The cation exists in (E) and (Z) forms which equilibrate before reaction. The major products are the α-hydroxytamoxifens Ph(Ar)C=CPh-CHOH-CH3, both (E) 64% and (Z) 29%, with the ratio independent of the configuration of the starting ester. Two minor products with a total yield of 7% account for the rest of the products. These have been characterized as indenes derived from intramolecular cyclization, a 4.5% yield of the indene derived from cyclization into the Ar ring with 2.5% due to cyclization into the phenyl ring. Experiments in acid solutions (0.01-0.1 M HCl) starting with pure (E)- or (Z)-α-hydroxytamoxifen reveal that the two alcohols equilibrate. This occurs by H+-catalyzed formation of the carbocation followed by water capture. Occurring about 10-fold slower than this isomerization is an irreversible process resulting in the two indenes. This cyclization will result in the destruction of the α-hydroxytamoxifens upon exposure to acidic conditions and also makes the direct observation of the tamoxifen carbocation under super-acid conditions difficult, if not impossible. The indenes do form in low yield whenever the tamoxifen carbocation is generated from an SN1 precursor. Thus these products could serve as markers for the formation of the tamoxifen carbocation in cellular systems or in in vivo experiments.Key words: carbocation, indene, allylic cation, isomerization.

The structure and the rheology of systems resulting from heating at 80°C isoelectric solutions of bovine serum albumin (BSA) in the concentration range 10–200mg/ml were studied. Small-angle neutron scattering measurements view the systems as being formed of large aggregates of micrometric size with a close packed arrangement of denatured protein molecules. No indication of a fractal structure stands out. The viscoelastic behaviour is linear up to about 5% strain, except in the BSA concentration range 30–90mg/ml where the linearity limit is below 1% strain. The viscoelastic response was analysed in the linear domain, or as close as possible to it, by combining the results of dynamic and creep recovery measurements. The dependence on concentration of the steady state viscosity, of the steady state compliance, and of the average retardation time shows a marked change around a concentration C0∼50mg/ml, corresponding probably to a percolation threshold.

The aim of this work was to study the accumulation and fractionation of P in the inlet and outlet sediment of a constructed wetland for the wastewater treatment of a metallurgic plant in Argentina. It was important to predict whether P could be released into the water again by changing environmental conditions or retained over time. P-fractionation was performed using a sequential extraction method. Sediment cores were sliced at depths of: 0-3; 3-7 and 7-10 cm. Sediment showed high pH values and anoxic conditions. In the inlet area, P was principally bound to the carbonate fraction, whereas in the outlet area, it was mainly bound in the residual fraction. This behavior was justified by the effluent composition, which is rich in Ca2+ and Fe 3+ and presents high values of pH and conductivity. These conditions favor CaCO3 and Fe(OOH)n precipitation and the subsequent sorption of P to their surface. The sediment active layer involved in the exchange reactions was the superficial one (0-3 cm). The wetland is highly efficient in P retention. P was retained by sediment in fractions that will not release it to the water while chemical and environmental conditions of the system are maintained. Fil: Di Luca, Gisela Alfonsina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Mufarrege, María de Las Mercedes. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina Fil: Maine, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina

The syntheses of four novel sulfur-containing nitrate esters are reported, together with data for guanylyl cyclase activation and tissue relaxation.

A free water surface wetland was built to treat wastewater containing metals (Cr, Ni and Zn) and nutrients from a tool factory in Santo Tomé, Santa Fe, Argentina. Eichhornia crassipes became dominant and covered about 80% of the surface throughout the first year, and decreased progressively until its disappearance. When water depth was lowered Typha domingensis steadily increased plant cover and attained 30% of the surface by the end of the study. While E. crassipes was dominant, the wetland retained 62% of the incoming Cr and 48% of the Ni. NO3- and NO2-, were also removed (65% and 78%, respectively), while dissolved inorganic phosphate (i-Pdiss) and NH4+ were not removed. Zn was below 50 μg l−1 in both the influent and effluent. Metal concentration in the sediments did not increase and retention was mediated through macrophytes uptake. During the period of E. crassipes decline the wetland retained 49% of the incoming Cr, 45% of Ni, 58% NO3-, 94% NO2-, 58% NH4+ and 47% i-Pdiss. Cr, Ni and Zn in the bottom sediment increased in the inlet but not in the outlet. Since T. domingensis became dominant, retention was 58% Cr, 48% Ni and 64% i-Pdiss, while 79% NO3-, 84% NO2- and 13% NH4+ were removed. Metals in the bottom sediment increased in the inlet. In spite of the significant growth of E. crassipes at the beginning, T. domingensis remained after most of the transplanted macrophytes had disappeared. Macrophyte disappearance could be related to the overall toxicity of several environmental constrains as high pH and conductivity, metal concentration, and sulphide presence. Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Suñe, Noemi Liliana. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bonetto, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; Argentina

This study was aimed at determining the spatial and temporal variation of P distribution in sediment of an artificial wetland for sewage and industrial wastewater treatment, and the fraction that is potentially involved in the P exchange processes. Influent, effluent, macrophytes and sediment at the inlet, middle and outlet areas were sampled over 24 months. The P-fractionation in sediment was performed following the EDTA method. Eichhornia crassipes and Typha domingensis removed P efficiently when cover was high, but E. crassipes caused anoxic conditions. The increase in cover of T. domingensis may contribute to attain oxic conditions and to improve P removal. When macrophytes are not present or when cover is low, sediment seems to increase removal efficiency. A significant increase in the concentration of the fraction of Fe(OOH) approximately P and mainly that of CaCO(3) approximately P can be observed at the inlet. High pH, Ca(2+) and CO(3)(-)(2) concentrations in the influent suggest that P co-precipitates together with CaCO(3). Therefore, it seems that CaCO(3) approximately P represents the main precipitating mechanism. However, mineralization of organic matter maintained the sediment at a pH range lower than the high values prevailing in the influent. CO(3)(-)(2) could undergo partial dissolution and the released i-P(diss) could be readsorbed onto the Fe(OOH) approximately P fraction. Since the environment for P retention (high pH, Fe, Ca and ionic concentrations) is largely provided by the influent, the wetland may be expected to continue retaining P as far as the composition of the influent is maintained and there are available adsorption sites in the sediment.

Earlier work (Paul, T., et al. (2000) Biochemistry 39, 4129-4135) has demonstrated that the water soluble positively charged peroxyl radical, (H(2)N)(2)(+)CC(CH(3))(2)OO(*) ((+)AOO(*)), caused direct strand scission of the Escherichia coli plasmid supercoiled DNA, pBR 322, with ca. 50% scission occurring at a (+)AOO(*)/base pair (bp) ratio of 0.2. There was no measurable direct scission with a negatively charged peroxyl ((-)BOO(*)) at (-)BOO(*)/bp = 24, nor with a neutral peroxyl (COO(*)) at COO(*)/bp = 5. Base modification (BM) of the same DNA by the same peroxyls has now been investigated using four base excision repair (BER) glycosylases. At (+)AOO(*)/bp = 0.04, there is 10% direct strand scission, and the Fpg protein recognized an additional 25% BM, while endonuclease (Endo) IV recognized an additional 20% BM and the other two BER enzymes did not give statistically significant BMs. None of the BER enzymes showed BMs in the DNA treated with -BOO(*). However, Fpg and Endo IV showed that at COO(*)/bp = 3.4 there was a BM comparable to that observed at (+)AOO(*)/bp = 0.04. Thus, COO(*) radicals are only ca. 1.2% as reactive toward the DNA's bases as (+)AOO(*). These results underline the importance of Coulombic forces in DNA reactions. It is also proposed that (+)AOO(*) has a higher intrinsic reactivity in H-atom abstractions and electron transfer processes than (-)BOO(*) or COO(*) radicals.

This paper explores the use of C18 solid-phase extraction membranes for sampling very low concentrations of nitroaromatic compounds in the atmosphere. After sampling, analytes trapped in the membrane are desorbed on-line directly by a chromatographic mobile phase. The analytes are then separated onto a porous graphitic carbon (PGC) HPLC column. Finally, they are analyzed by an LC-MS/MS detector equipped with an atmospheric pressure chemical ionization (APCI) interface. The method was validated by controlled exposure of the membranes to standard gaseous mixtures of 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (2,4-DNT). The developed method was fully characterized, and no breakthrough was observed when sampling volumes up to 9.2 m3. Analyses of membranes following medium- and long-term storage demonstrated that samples could be stored on the C18 membranes without degradation or losses. In addition, the results obtained with this technique were compared with those obtained by a gas chromatographic method in which analytes were collected on Tenax TA and thermally desorbed. The developed method allows sampling at flow rates of 15 L/min and has method detection limits in the femtogram/liter range, with a relative standard deviation lower than 10%. An additional advantage of this method is that it separates most of the TNT and DNT isomers, as demonstrated by applying the method to the analysis of headspace over military-grade TNT explosives.

A new system for extracting solid samples based on dynamic sonication-assisted solvent extraction (DSASE) is described. The technique is highly efficient with respect to both time and solvent consumption. In tests reported here, organophosphate esters were extracted from air sampling filters in 3 min with an extraction volume of 600 microL of solvent. Furthermore, it was possible to replace a previously used chlorinated solvent with a halogen-free solvent mixture. The sample was placed in a cartridge through which fresh solvent was pumped continuously. A restrictor connected to the outlet of the cartridge allowed the system to be used at a temperature of 70 degrees C without reaching the boiling point of the solvent. Both spiked and non-spiked native samples were used for the evaluation, which clearly revealed a stronger analyte-matrix interaction in native samples. The DSASE technique was shown to recover larger amounts of organophosphate esters from native samples, compared to a static method. DSASE was applied to air samples collected in a lecture hall and from above a computer monitor.

at least one new peak compared to the product from the matching normal tissue. Statistical Analysis: The Kaplan-Meier method was used for estimating recurrence-free survival. Cox proportional hazard analysis was used to evaluate the association between MSI status and other clinicopathological factors for predicting recurrent distant metastasis. The P value less than 0.05 was considered to be statistically significant. Results: Stage II and III patients with MSI-L and/or EMAST had a shorter recurrence-free survival than patients with high levels of MSI (MSI-H) (P=0.0084) or with highly stable microsatellites (H-MSS) (P=0.0415) by Kaplan-Meier analysis. MSI-L and/or EMAST are independent predictors of recurrent distant metastasis in primary stage II and III CRCs by Cox proportional hazard analysis (Hazard Ratio: 1.83, 95%CI: 1.06-3.15, P=0.0301). Compatible with other studies, the present study also showed that MSI-H is associated with proximal location and exhibited lowest risk for recurrent distant metastasis. Conclusions: Our results showed that MSI-L/EMAST is a predictive factor of stage II/III primary CRC for recurrent distant metastasis. Because MSI-L/EMAST CRC is different from MSI-H and H-MSS CRC, we proposed to define MSI-L/EMAST as one group and named this group of CRC moderate MSI (MSI-M).

The syntheses of four novel sulfur-containing nitrate esters are reported, together with data for guanylyl cyclase activation and tissue relaxation.

tert-Butyl thionitrate decomposes rapidly in neutral aqueous solution to yield nitric oxide, sulfonyl and sulfinyl species, but does not activate soluble guanylyl cyclase.

9,10-Dihydroxy-9,10-diphenyl-9,10-dihydroanthracene, 2,5-diarylhydroquinones, and 9-hydroxy-9-(1-propynyl)fluorene and its 2,7-dihalo-analogs were found to form inclusion complexes with various alcohols. By using the complexation, ethanol was extracted from aqueous solution of various concentration.