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The present study describes the application of sodium dodecyl sulfate micellar electrokinetic chromatography (SDS MEKC) for the fast analysis of TNT biotransformation products in the aqueous phase of anaerobic sludge cultures. SDS MEKC was performed using a Hewlett-Packard HP 3D CE capillary electrophoresis system with photodiode array detection. In a single sample injection the SDS MEKC method detected 2,4,6-trinitrotoluene (TNT), 2-hydroxylamino-4,6-dinitrotoluene (2-HADNT), 4-hydroxylamino-2,6-dinitrotoluene (4-HADNT), 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-diaminonitrotoluene (2,4-DANT), 2,6-diaminonitrotoluene (2,6-DANT), and 2,4,6-triaminotoluene (TAT). Analyte peaks were verified using visible/ultraviolet photodiode array spectra from commercial standards and periodic analyses using electrospray ionization liquid chromatography mass spectrometry (ES-LC-MS). A time course study constructed from the SDS MEKC data provided supporting evidence for the stepwise red...

Charge stripping experiments indicate that in the reaction M+ → M2 + e− the doublycharged transition-metal ions M2+ (M = Fe, Co, Ni) are formed in excited states. Introduction of one or two C5H5 ligands drastically reduces the Qmin values of the reaction M(C5H5)+x → M(C5H5)2+)x + e− (x = 1, 2) by at least 3.5 eV. The experimental findings support existing molecular orbital concepts of metallocene compounds.

Recently we demonstrated that hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a trimer of methylene nitramine (CH2=N-NO2) undergoes spontaneous decomposition following an initial microbial attack using a mixed microbial culture at pH 7 in the presence of glucose as carbon source. The present study describes whether the second cyclic nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), a more strained tetramer of CH2=N-NO2, degrades similarly using sludge of the same source. Part of HMX biotransformed to give products that are tentatively identified as the nitroso derivatives octahydro-1-nitroso-3,5,7-trinitro-1,3,5,7-tetrazocine (mNs-HMX) and octahydro-1,3-dinitroso-5,7-dinitro-1,3,5,7-tetrazocine and its isomer octahydro-1,5-dinitroso-3,7-dinitro-1,3,5,7-tetrazocine (dNs-HMX). Another fraction of HMX biotransformed, apparently via ring cleavage, to produce products that are tentatively identified as methylenedinitramine (O2NNHCH2-NHNO2) and bis(hydroxymethyl)nitramine ((HOCH2)2NNO2). None of the above intermediates accumulated indefinitely; they disappeared to predominantly form nitrous oxide (N2O) and formaldehyde (HCHO). Formaldehyde biotransformed further to eventually produce carbon dioxide (14CO2). Nitrous oxide persisted in HMX microcosms containing glucose but denitrified rapidly to nitrogen in the absence of glucose. The presence of nitrous oxide was accompanied by the presence of appreciable amounts of hydrogen sulfide, a known inhibitor of denitrification.

The cyclic nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) were examined in field and microcosm soil samples to determine their patterns of degradation and environmental fates. A number of analytical techniques, including solid-phase microextraction with on-fiber derivatization, gas chromatography-mass spectrometry, gas chromatography with electron-capture detection, liquid chromatography-mass spectrometry, and micellar electrokinetic chromatography were required for the analyses. Two different classes of intermediates were detected, both of which lead ultimately to the formation of nitrous oxide (N2O) and carbon dioxide (CO2). The first class was identified as the nitroso derivatives formed by the sequential reduction of -NO2 functional groups. The second class of intermediates, which was favored at higher humidities and in the presence of anaerobic sludge amendments, consisted of ring cleavage products including bis-(hydroxymethyl)-nitramine and methylenedinitramine. Rye-grass (Lolium perenne) present in field samples was found to extract and accumulate HMX from soil without further degradation. In all cases (excepting the plant samples), the indigenous microbes or amended domestic anaerobic sludge consortia degraded the cyclic nitramine explosives eventually to produce N2O and CO2.

The nitroaromatic explosive 2,4,6-trinitrotoluene (TNT) is a reactive molecule that biotransforms readily under both aerobic and anaerobic conditions to give aminodinitrotoluenes. The resulting amines biotransform to give several other products, including azo, azoxy, acetyl and phenolic derivatives, leaving the aromatic ring intact. Although some Meisenheimer complexes, initiated by hydride ion attack on the ring, can be formed during TNT biodegradation, little or no mineralization is encountered during bacterial treatment. Also, although the ligninolytic physiological phase and manganese peroxidase system of fungi can cause some TNT mineralization in liquid cultures, little to no mineralization is observed in soil. Therefore, despite more than two decades of intensive research to biodegrade TNT, no biomineralization-based technologies have been successful to date. The non-aromatic cyclic nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) lack the electronic stability enjoyed by TNT or its transformed products. Predictably, a successful enzymatic change on one of the N–NO2 or C–H bonds of the cyclic nitramine would lead to a ring cleavage because the inner C–N bonds in RDX become very weak (

We have previously shown that thymic CD34 1 cells have a very limited myeloid differentia- tion capacity and differentiate in vitro mostly into CD1a 1 -derived but not CD14 1 -derived dendritic cells (DC). Herein we characterized the human neo- natal thymic DC extracted from the organ in rela- tionship with the DC generated from CD34 1 cells in situ. We show that in vivo thymic DC express E cad- herin, CLA, CD4, CD38, CD40, CD44, and granu- locyte-macrophage colony-stimulating factor-R (GM- CSF-R; CD116) but no CD1a. According to their morphology, functions, and surface staining they could be separated into two distinct subpopulations: mature HLA-DR hi , mostly interleukin-3-R (CD123)- negative cells, associated with thymocytes, some apoptotic, and expressed myeloid and activation markers but no lymphoid markers. In contrast, immature HLA-DR 1 CD123 hi CD36 1 cells with monocytoid morphology lacked activation and my- eloid antigens but expressed lymphoid antigens. The latter express pTa mRNA, which is also found in CD34 1 thymocytes and in blood CD123 hi DC further linking this subset to lymphoid DC. How- ever, the DC generated from CD34 1 thymic pro- genitors under standard conditions were pTa-neg- ative. Thymic lymphoid DC showed similar pheno- type and cytokine production profile as blood/ tonsillar lymphoid DC but responded to GM-CSF, and at variance with them produced no or little type I interferon upon infection with viruses and did not induce a strict polarization of naive T cells into TH2 cells. Their function in the thymus re- mains therefore to be elucidated. J. Leukoc. Biol. 68: 836-844; 2000.

The biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in liquid cultures with municipal anaerobic sludge showed that at least two degradation routes were involved in the disappearance of the cyclic nitramine. In one route, RDX was reduced to give the familiar nitroso derivatives hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX). In the second route, two novel metabolites, methylenedinitramine [(O 2 NNH) 2 CH 2 ] and bis(hydroxymethyl)nitramine [(HOCH 2 ) 2 NNO 2 ], formed and were presumed to be ring cleavage products produced by enzymatic hydrolysis of the inner C—N bonds of RDX. None of the above metabolites accumulated in the system, and they disappeared to produce nitrous oxide (N 2 O) as a nitrogen-containing end product and formaldehyde (HCHO), methanol (MeOH), and formic acid (HCOOH) that in turn disappeared to produce CH 4 and CO 2 as carbon-containing end products.

The biotransformation of 2,4,6-trinitrotoluene (TNT) (175 μM) by Phanerochaete chrysosporium with molasses and citric acid at pH 4.5 was studied. In less than 2 weeks, TNT disappeared completely, but mineralization (liberated 14 CO 2 ) did not exceed 1%. A time study revealed the presence of several intermediates, marked by the initial formation of two monohydroxylaminodinitrotoluenes (2- and 4-HADNT) followed by their successive transformation to several other products, including monoaminodinitrotoluenes (ADNT). A group of nine acylated intermediates were also detected. They included 2- N -acetylamido-4,6-dinitrotoluene and its p isomer, 2-formylamido-4,6-dinitrotoluene and its p isomer (as acylated ADNT), 4- N -acetylamino-2-amino-6-nitrotoluene and 4- N -formylamido-2-amino-6-nitrotoluene (as acetylated DANT), 4- N -acetylhydroxy-2,6-dinitrotoluene and 4- N -acetoxy-2,6-dinitrotoluene (as acetylated HADNT), and finally 4- N -acetylamido-2-hydroxylamino-6-nitrotoluene. Furthermore, a fraction of HADNTs were found to rearrange to their corresponding phenolamines (Bamberger rearrangement), while another group dimerized to azoxytoluenes which in turn transformed to azo compounds and eventually to the corresponding hydrazo derivatives. After 30 days, all of these metabolites, except traces of 4-ADNT and the hydrazo derivatives, disappeared, but mineralization did not exceed 10% even after the incubation period was increased to 120 days. The biotransformation of TNT was accompanied by the appearance of manganese peroxidase (MnP) and lignin-dependent peroxidase (LiP) activities. MnP activity was observed almost immediately after TNT disappearance, which was the period marked by the appearance of the initial metabolites (HADNT and ADNT), whereas the LiP activity was observed after 8 days of incubation, corresponding to the appearance of the acyl derivatives. Both MnP and LiP activities reached their maximum levels (100 and 10 U/liter, respectively) within 10 to 15 days after inoculation.

The dependence of the protonation of neutral ammonia on the axial kinetic energy of protonated reactant ions has been studied in the gas phase, using various protonated carbonyl compounds, inside the collision cell of a tandem quadrupole mass spectrometric system. The hypothesis of two different and non-competitive reaction channels has been proposed. The first is characterized by a very low (peaked at ±0.05 eVcm) and well-defined axial kinetic energy of the reactant ion, while the second is more energy demanding (estimated threshold at ±0.2 eVcm) and expressed by a collisionally induced dissociation-like energy curve. Fourier transform mass spectrometric experiments have shown that ammonium ion can be generated by direct proton exchange and fragmentation of the adduct ion obtained.

L’Équipe de rétablissement des oiseaux de proie du Québec (EROP) a été fondée en 2004, à la suite de la fusion des équipes de rétablissement du faucon pèlerin (Falco peregrinus), du pygargue à tête blanche (Haliaeetus leucocephalus) et de l’aigle royal (Aquila chrysaetos). À ces espèces d’intérêt pour l’EROP s’est ajouté récemment le hibou des marais (Asio flammeus). À l’aide des plans de rétablissement de chacune des espèces, l’EROP veille à la mise en oeuvre de mesures de conservation (p. ex. acquisition de connaissances, sensibilisation, protection) visant à redresser la situation des populations d’oiseaux de proie en situation précaire au Québec. Cet article présente le mandat, le mode de fonctionnement et les principales réalisations de l’EROP au cours de la dernière décennie., The Québec raptor recovery team (EROP) was established in 2004 following the merger of the peregrine falcon (Falcoperegrinus), bald eagle (Haliaeetus leucocephalus) and golden eagle (Aquilachrysaetos) recovery teams. Recently, the short-eared owl (Asioflammeus) has also been added to the list of species covered by EROP. The team aims to foster conservation measures (e.g., data collection, public awareness and protection) to improve the population status of endangered birds of prey, and achieves this through the publication of species recovery plans. This article outlines the mission, and the working and main achievements of EROP over the past decade.