Artykuły w czasopismach: „-dinitrotoluene (DNT)”

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Nishino, Shirley F., George C. Paoli i Jim C. Spain. "Aerobic Degradation of Dinitrotoluenes and Pathway for Bacterial Degradation of 2,6-Dinitrotoluene". Applied and Environmental Microbiology 66, nr 5 (1.05.2000): 2139–47. http://dx.doi.org/10.1128/aem.66.5.2139-2147.2000.

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ABSTRACT An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. We report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway.Burkholderia cepacia strain JS850 andHydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon and nitrogen. The initial steps in the pathway for degradation of 2,6-DNT were determined by simultaneous induction, enzyme assays, and identification of metabolites through mass spectroscopy and nuclear magnetic resonance. 2,6-DNT was converted to 3-methyl-4-nitrocatechol by a dioxygenation reaction accompanied by the release of nitrite. 3-Methyl-4-nitrocatechol was the substrate for extradiol ring cleavage yielding 2-hydroxy-5-nitro-6-oxohepta-2,4-dienoic acid, which was converted to 2-hydroxy-5-nitropenta-2,4-dienoic acid. 2,4-DNT-degrading strains also converted 2,6-DNT to 3-methyl-4-nitrocatechol but did not metabolize the 3-methyl-4-nitrocatechol. Although 2,6-DNT prevented the degradation of 2,4-DNT by 2,4-DNT-degrading strains, the effect was not the result of inhibition of 2,4-DNT dioxygenase by 2,6-DNT or of 4-methyl-5-nitrocatechol monooxygenase by 3-methyl-4-nitrocatechol.

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Monti, Mariela R., Andrea M. Smania, Georgina Fabro, María E. Alvarez i Carlos E. Argaraña. "Engineering Pseudomonas fluorescens for Biodegradation of 2,4-Dinitrotoluene". Applied and Environmental Microbiology 71, nr 12 (grudzień 2005): 8864–72. http://dx.doi.org/10.1128/aem.71.12.8864-8872.2005.

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ABSTRACT Using the genes encoding the 2,4-dinitrotoluene degradation pathway enzymes, the nonpathogenic psychrotolerant rhizobacterium Pseudomonas fluorescens ATCC 17400 was genetically modified for degradation of this priority pollutant. First, a recombinant strain designated MP was constructed by conjugative transfer from Burkholderia sp. strain DNT of the pJS1 megaplasmid, which contains the dnt genes for 2,4-dinitrotoluene degradation. This strain was able to grow on 2,4-dinitrotoluene as the sole source of carbon, nitrogen, and energy at levels equivalent to those of Burkholderia sp. strain DNT. Nevertheless, loss of the 2,4-dinitrotoluene degradative phenotype was observed for strains carrying pJS1. The introduction of dnt genes into the P.fluorescens ATCC 17400 chromosome, using a suicide chromosomal integration Tn5-based delivery plasmid system, generated a degrading strain that was stable for a long time, which was designated RE. This strain was able to use 2,4-dinitrotoluene as a sole nitrogen source and to completely degrade this compound as a cosubstrate. Furthermore, P. fluorescens RE, but not Burkholderia sp. strain DNT, was capable of degrading 2,4-dinitrotoluene at temperatures as low as 10°C. Finally, the presence of P. fluorescens RE in soils containing levels of 2,4-dinitrotoluene lethal to plants significantly decreased the toxic effects of this nitro compound on Arabidopsis thaliana growth. Using synthetic medium culture, P. fluorescens RE was found to be nontoxic for A.thaliana and Nicotiana tabacum, whereas under these conditions Burkholderia sp. strain DNT inhibited A.thaliana seed germination and was lethal to plants. These features reinforce the advantageous environmental robustness of P. fluorescens RE compared with Burkholderia sp. strain DNT.

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Aburto-Medina, Arturo, Esmaeil Shahsavari, Mohamed Taha, Andrew Bates, Leon Van Ieperen i Andrew S. Ball. "The Impacts of Different Biological Treatments on the Transformation of Explosives Waste Contaminated Sludge". Molecules 26, nr 16 (9.08.2021): 4814. http://dx.doi.org/10.3390/molecules26164814.

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The dinitrotoluene isomers 2,4 and 2,6-dinitrotoluene (DNT) represent highly toxic, mutagenic, and carcinogenic compounds used in explosive manufacturing and in commercial production of polyurethane foam. Bioremediation, the use of microbes to degrade residual DNT in industry wastewaters, represents a promising, low cost and environmentally friendly alternative technology to landfilling. In the present study, the effect of different bioremediation strategies on the degradation of DNT in a microcosm-based study was evaluated. Biostimulation of the indigenous microbial community with sulphur phosphate (2.3 g/kg sludge) enhanced DNT transformation (82% transformation, from 300 g/L at Day 0 to 55 g/L in week 6) compared to natural attenuation over the same period at 25 °C. The indigenous microbial activity was found to be capable of transforming the contaminant, with around 70% transformation of DNT occurring over the microcosm study. 16S rDNA sequence analysis revealed that while the original bacterial community was dominated by Gammaproteobacteria (30%), the addition of sulphur phosphate significantly increased the abundance of Betaproteobacteria by the end of the biostimulation treatment, with the bacterial community dominated by Burkholderia (46%) followed by Rhodanobacter, Acidovorax and Pseudomonas. In summary, the results suggest biostimulation as a treatment choice for the remediation of dinitrotoluenes and explosives waste.

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Jeżewska, Anna, i Dorota Kondej. "Dinitrotoluene. Determination in workplace air". Podstawy i Metody Oceny Środowiska Pracy XXXVII, nr 1 (30.03.2021): 77–87. http://dx.doi.org/10.5604/01.3001.0014.8152.

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Dinitrotoluene (DNT) is a yellow, crystalline solid with a characteristic odor. It may consist of 6 isomers, but only two (2,4-DNT and 2,6-DNT) are of industrial importance. DNT can cause cancer. The aim of this study was to develop a method for the determination mixture of DNT isomers in workplace air, which will allow to determine its concentration at the level of 0.033 mg/m3. The method consists in stopping the mixture of dinitrotoluene isomers contained in the air on the glass fiber and the silica gel, extraction with methanol and chromatographic analysis of the obtained solution. The tests were carried out using a liquid chromatograph (HPLC) 1200 series from Agilent Technologies with a diode array detector (DAD). The method was validated in accordance with the requirements of the European Standard No. EN 482. The method allows the determination mixture of DNT isomers in the working environment air in the concentration range: 0.033 ÷ 0.66 mg/m3. The described method enables determination mixture of DNT isomers in the workplace air in the presence of: toluene-2,4-diamine, toluene-2,6-diamine, toluene-2,4-diyl diisocyanate, toluene-2,6-diyl diisocyanate and toluene. The method for determining dinitrotoluene has been recorded in the form of an analytical procedure (see Appendix). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

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Johnson, Glenn R., Rakesh K. Jain i Jim C. Spain. "Origins of the 2,4-Dinitrotoluene Pathway". Journal of Bacteriology 184, nr 15 (1.08.2002): 4219–32. http://dx.doi.org/10.1128/jb.184.15.4219-4232.2002.

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ABSTRACT The degradation of synthetic compounds requires bacteria to recruit and adapt enzymes from pathways for naturally occurring compounds. Previous work defined the steps in 2,4-dinitrotoluene (2,4-DNT) metabolism through the ring fission reaction. The results presented here characterize subsequent steps in the pathway that yield the central metabolic intermediates pyruvate and propionyl coenzyme A (CoA). The genes encoding the degradative pathway were identified within a 27-kb region of DNA cloned from Burkholderia cepacia R34, a strain that grows using 2,4-DNT as a sole carbon, energy, and nitrogen source. Genes for the lower pathway in 2,4-DNT degradation were found downstream from dntD, the gene encoding the extradiol ring fission enzyme of the pathway. The region includes genes encoding a CoA-dependent methylmalonate semialdehyde dehydrogenase (dntE), a putative NADH-dependent dehydrogenase (ORF13), and a bifunctional isomerase/hydrolase (dntG). Results from analysis of the gene sequence, reverse transcriptase PCR, and enzyme assays indicated that dntD dntE ORF13 dntG composes an operon that encodes the lower pathway. Additional genes that were uncovered encode the 2,4-DNT dioxygenase (dntAaAbAcAd), methylnitrocatechol monooxygenase (dntB), a putative LysR-type transcriptional (ORF12) regulator, an intradiol ring cleavage enzyme (ORF3), a maleylacetate reductase (ORF10), a complete ABC transport complex (ORF5 to ORF8), a putative methyl-accepting chemoreceptor protein (ORF11), and remnants from two transposable elements. Some of the additional gene products might play as-yet-undefined roles in 2,4-DNT degradation; others appear to remain from recruitment of the neighboring genes. The presence of the transposon remnants and vestigial genes suggests that the pathway for 2,4-DNT degradation evolved relatively recently because the extraneous elements have not been eliminated from the region.

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Quakenbush, A. B., i B. T. Pennington. "The Olin Dinitrotoluene (DNT) Process". Journal of Cellular Plastics 29, nr 5 (wrzesień 1993): 463. http://dx.doi.org/10.1177/0021955x9302900572.

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Jang, Hyun-Sook, Hyun-Seok Cho, David Uhrig i Mu-Ping Nieh. "Insight into the interactions between pyrene and polystyrene for efficient quenching nitroaromatic explosives". Journal of Materials Chemistry C 5, nr 47 (2017): 12466–73. http://dx.doi.org/10.1039/c7tc04288d.

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Polystyrene enhances the quenching efficiency of pyrene excimer fluorescence in the presence of 2,4-dinitrotoluene (2,4-DNT)viathe photoinduced electron transfer (PET) from the electron-rich Py/PS to the electron-deficient 2,4-DNT.

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Lent, Emily May, Lee C. B. Crouse, Michael J. Quinn i Shannon M. Wallace. "Comparison of the Repeated Dose Toxicity of Isomers of Dinitrotoluene". International Journal of Toxicology 31, nr 2 (marzec 2012): 143–57. http://dx.doi.org/10.1177/1091581811434645.

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Dinitrotoluene (DNT) is a nitroaromatic explosive used in propellant mixtures and in the production of plastics. Isomers of DNT were administered daily via oral gavage to male Sprague-Dawley rats for 14 days to determine the subacute toxicity of individual isomers of DNT. The 3,5-DNT isomer was the most toxic isomer, inducing weight loss and mortality within 3 days. Cyanosis and anemia were observed for all isomers. Exposure to 2,4-, 2,6-, and 3,5-DNT resulted in decreased testes mass and degenerative histopathological changes. Increased splenic mass was observed for 2,4-, 2,6-, and 2,5-DNT. Extramedullary hematopoiesis of the spleen was noted for all isomers, while lymphoid hyperplasia of the spleen was noted for all isomers except 2,5-DNT. Increased liver mass was observed for 2,3-DNT and 3,4-DNT. Hepatocellular lesions were observed for 2,6-DNT and 2,4-DNT. Neurotoxic effects were noted for 3,4-DNT, 2,4-DNT, and 3,5-DNT.

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Prante, Marc, Christian Ude, Miriam Große, Lukas Raddatz, Ulrich Krings, Gernot John, Shimshon Belkin i Thomas Scheper. "A Portable Biosensor for 2,4-Dinitrotoluene Vapors". Sensors 18, nr 12 (3.12.2018): 4247. http://dx.doi.org/10.3390/s18124247.

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Buried explosive material, e.g., landmines, represent a severe issue for human safety all over the world. Most explosives consist of environmentally hazardous chemicals like 2,4,6-trinitrotoluene (TNT), carcinogenic 2,4-dinitrotoluene (2,4-DNT) and related compounds. Vapors leaking from buried landmines offer a detection marker for landmines, presenting an option to detect landmines without relying on metal detection. 2,4-Dinitrotoluene (DNT), an impurity and byproduct of common TNT synthesis, is a feasible detection marker since it is extremely volatile. We report on the construction of a wireless, handy and cost effective 2,4-dinitrotoluene biosensor combining recombinant bioluminescent bacterial cells and a compact, portable optical detection device. This biosensor could serve as a potential alternative to the current detection technique. The influence of temperature, oxygen and different immobilization procedures on bioluminescence were tested. Oxygen penetration depth in agarose gels was investigated, and showed that aeration with molecular oxygen is necessary to maintain bioluminescence activity at higher cell densities. Bioluminescence was low even at high cell densities and 2,4-DNT concentrations, hence optimization of different prototypes was carried out regarding radiation surface of the gels used for immobilization. These findings were applied to sensor construction, and 50 ppb gaseous 2,4-DNT was successfully detected.

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Chakraborty, Urmila, Gaurav Bhanjana, Jost Adam, Yogendra Kumar Mishra, Gurpreet Kaur, Ganga Ram Chaudhary i Ajeet Kaushik. "A flower-like ZnO–Ag2O nanocomposite for label and mediator free direct sensing of dinitrotoluene". RSC Advances 10, nr 46 (2020): 27764–74. http://dx.doi.org/10.1039/d0ra02826f.

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Suzuki, Hiroshi, Tadashi Imamura, Akiko Koeda, Kiyoshi Morimoto, Yoshio Wakasa, Yoshihiro Takei, Rie Amemiya, Hirofumi Hatakeyama, Hiroshi Satoh i Shin-ichi Sato. "Genotoxicity studies of 2,6-dinitrotoluene (2,6-DNT)". Journal of Toxicological Sciences 36, nr 4 (2011): 499–505. http://dx.doi.org/10.2131/jts.36.499.

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Zheng, Ai Rong, i Jing Bo Xu. "Analysis of 2,6-Dinitrotoluene Toxicity to Common Carp (Cyprinus carpio)". Advanced Materials Research 433-440 (styczeń 2012): 798–804. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.798.

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2,6-dinitrotoluene (2,6-DNT) is the preferential toxicants stipulated by OECD and EPA of USA. The present study was conducted to determine the effect of 2,6-DNT chemical on acute toxicity and subacute toxicity in common carp (Cyprinus carpio). The 24h, 48h, 72h and 96h LC50 values of common carp by 2,6-DNT were 1.137±0.023mg/L, 0.830±0.024mg/L, 0.661±0.019mg/L and 0.479±0.020mg/L, respectively. The subacute experiment shows that C. carpio are rarely affected by 0.0251mg/L 2,6-DNT, but significantly affected by 0.0398, 0.0631, 0.0794mg/L 2,6-DNT in contrast to the controlled sample (p liver > kidney.

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Huang, Zhong Hua, Xue Pu, Hui Zhang, Fang Yuan i Zheng Li Liu. "Biodegradation of 2, 4-Dinitrotoluene by Pseudomonas fluorescens sp. Isolated from a Nitrobenzene Contaminated Soil". Advanced Materials Research 610-613 (grudzień 2012): 1233–36. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1233.

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A 2,4-Dinitrotoluene degrading bacterium was isolated from sludge contaminated by DNT and identiﬁed as a member of Pseudomonas fluorescens sp. based on 16S rDNA sequence. Under growth substrates limited conditions, the strain was enriched with 2,4-DNT as its sole source of carbon and energy in the groundwater environment. Results indicate the isolate grew optimally at 12(±4)°C and initial pH 7.5 in the mineral salts medium supplemented 2,4-DNT with 40mg/L, thus showing potential for the remediation of 2,4-DNT contaminated groundwater.

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Long, Yin, Xiaosong Du, Yang Wang, Jinzhu Zhao, Huiling Tai, Xianzhong Tang i Yadong Jiang. "Hydrogen-bond acidic polymers coated SAW sensors for 2,4-dinitrotoluene detection". RSC Adv. 4, nr 103 (2014): 59643–49. http://dx.doi.org/10.1039/c4ra11525b.

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Algharagholy, Laith A., Qusiy H. Al-Galiby, Amaal A. Al-Backri, Hatef Sadeghi i Ahmed A. Wabdan. "Discriminating sensing of explosive molecules using graphene–boron nitride–graphene heteronanosheets". RSC Advances 12, nr 54 (2022): 35151–57. http://dx.doi.org/10.1039/d2ra06125b.

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Graphene–boron nitride–graphene (h-NSHs) heterostructures can be used for discriminate sensing of 2,4-dinitrotoluene (DNT), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), pentaerythritol tetranitrate (PENT), and 2,4,6-trinitrotoluene (TNT) molecules.

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Zhang, Jin Hua, Hai Qing Zheng, Fang Jiang, Kai Rong Cheng, Xin Jiang, Xiang Long Li i Yi Lin. "Comparison of Removal of 2,4-DNT by Reduction Using Various Iron-Based Materials". Advanced Materials Research 391-392 (grudzień 2011): 303–7. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.303.

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The reductive degradation of 2,4-dinitrotoluene (2,4-DNT) by three kinds of iron-based materials, namely, copper-doped iron, scrap iron and iron powder, was investigated in detail. The effects of iron materials, pH and iron dosage on the removal efficiency were studied. The results indicated that copper-doped iron had the highest removal rate of 2,4-DNT. The removal rate of 2,4-DNT increased with increasing temperature. After addition of sodium sulfate, the removal rate of 2,4-DNT was enhanced. According to GC/MS analyses, 2,4-diaminotoluene was the final product of 2,4-DNT and possible reductive pathway of 2,4-DNT was proposed.

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Cheng, Jiayang, Makram T. Suidan i Albert D. Venosa. "Kinetics of anaerobic cometabolism of 2,4-dinitrotoluene with ethanol as the primary substrate". Water Science and Technology 36, nr 6-7 (1.09.1997): 271–78. http://dx.doi.org/10.2166/wst.1997.0600.

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A kinetic model that describes the anaerobic cometabolism of 2,4-dinitrtoluene (DNT) with ethanol as the primary substrate has been developed based on experimental results. The kinetic parameters were estimated using the Levenberg-Marquardt algorithm. 2,4-DNT is anaerobically biotransformed to 2,4-diaminotoluene (DAT) via 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) by the bacteria whose growth is supported by utilizing ethanol. 2,4-DNT shows inhibition to its own biotransformation. It also exhibits a very strong competitive inhibition to further biotransformation of 4-A-2-NT and 2-A-4-NT. All the aromatics in the system, 2,4-DNT, 4-A-2-NT, 2-A-4-NT, and 2,4-DAT, inhibit the conversion of ethanol. Hydrogen produced from the acetogenesis of ethanol is utilized for the transformation of the nitroaromatics. The utilization of hydrogen and acetate by methanogenic bacteria is very strongly inhibited by the presence of the nitroaromatics. Acetate exhibits strong competitive inhibition to the biodegradation of propionate.

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Wang, Jing, Guang Fei Liu, Hong Lu, Ji Ti Zhou i Lihua Li. "Enhanced Biotransformation of Dinitrotoluene by Mediator-Functionalized Polypyrrole Composites". Advanced Materials Research 610-613 (grudzień 2012): 129–32. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.129.

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The continuous dosing and discharge of water soluble redox mediators such as biologically recalcitrant compounds will result in the secondary contamination. The immobilized redox mediator prepared by incorporation of anthraquinonedisulphon-ate (AQDS) during the electropolymerization of pyrrole monomer on active carbon felt (ACF), AQDS/PPy/ACF, was used for catalyzing bioreduction of 2,4-dinitrotoluene(2,4-DNT) in this study. The results showed that the morphology of the PPy films deposits on ACF are characterized by some globular structure; AQDS/PPy/ACF exhibited good catalytic activity and stability for 2,4-DNT, the enhanced reduction rates obtained in the incubations with AQDS/PPy/ACF was about 5 times that without AQDS/PPy/ACF, the corresponding first-order reduction rate constant k reached 0.045 h-1; 2,4-DNT was reduced to be 2,4-diaminotoluene via 2-amino-4-nitrotoluene and 4-amino-2-nitrotoluene in the system.

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Jiayang, Cheng, Makram T. Suidan i Albert D. Venosa. "Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions". Water Science and Technology 34, nr 10 (1.11.1996): 25–33. http://dx.doi.org/10.2166/wst.1996.0235.

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Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

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Jakab-Nácsa, Alexandra, Viktória Hajdu, László Vanyorek, László Farkas i Béla Viskolcz. "Overview of Catalysts with MIRA21 Model in Heterogeneous Catalytic Hydrogenation of 2,4-Dinitrotoluene". Catalysts 13, nr 2 (10.02.2023): 387. http://dx.doi.org/10.3390/catal13020387.

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Although 2,4-dinitrotoluene (DNT) hydrogenation to 2,4-toluenediamine (TDA) has become less significant in basic and applied research, its industrial importance in polyurethane production is indisputable. The aim of this work is to characterize, rank, and compare the catalysts of 2,4-dinitrotoluene catalytic hydrogenation to 2,4-toluenediamine by applying the Miskolc Ranking 21 (MIRA21) model. This ranking model enables the characterization and comparison of catalysts with a mathematical model that is based on 15 essential parameters, such as catalyst performance, reaction conditions, catalyst conditions, and sustainability parameters. This systematic overview provides a comprehensive picture of the reaction, technological process, and the previous and new research results. In total, 58 catalysts from 15 research articles were selected and studied with the MIRA21 model, which covers the entire scope of DNT hydrogenation catalysts. Eight catalysts achieved the highest ranking (D1), whereas the transition metal oxide-supported platinum or palladium catalysts led the MIRA21 catalyst ranking list.

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Martin, J. L., S. D. Comfort, P. J. Shea, R. A. Drijber i T. A. Kokjohn. "Denitration of 2,4,6-trinitrotoluene byPseudomonas savastanoi". Canadian Journal of Microbiology 43, nr 5 (1.05.1997): 447–55. http://dx.doi.org/10.1139/m97-063.

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Past disposal of wastewaters containing 2,4,6-trinitrotoluene (TNT) at the former Nebraska Ordnance Plant has resulted in numerous acres of TNT-contaminated soil. Examining the microbial population of these soils revealed several TNT-tolerant Pseudomonas spp. We selected one species, P. savastanoi, to determine its ability to transform TNT. Pure culture experiments were performed in pseudomonas minimal medium containing 0.31 mM TNT (70 mg TNT∙L−1) under varied nutrient and cell density regimes. Experiments with TNT as a sole C or N source showed that P. savastanoi has the ability to denitrate TNT, as evidenced by production of 2,4-dinitrotoluene (2,4-DNT) and NO2−with time. TNT denitration and formation of 2,4-DNT were enhanced by removing NH4+and adding NO2−to the growth medium. In all experiments, 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) appeared as incidental reduction products. Glucose addition to the medium enhanced 2-ADNT and 4-ADNT production and decreased denitration of TNT. Mid-log phase cells rapidly transformed [ring-14C(U)]TNT but were unable to mineralize significant quantities of TNT, as evidenced by conversion of less than 1% of the label to14CO2. These results indicate that P. savastanoi is a TNT-tolerant pseudomonad that can promote TNT degradation through reductive denitration and nitro moiety reduction.Key words: TNT, biodegradation, transformation, reduction, nitrite.

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Rawat, Arun, Kurt A. Gust, Youping Deng, Natàlia Garcia-Reyero, Michael J. Quinn, Mark S. Johnson, Karl J. Indest, Mohamed O. Elasri i Edward J. Perkins. "From raw materials to validated system: the construction of a genomic library and microarray to interpret systemic perturbations in Northern bobwhite". Physiological Genomics 42, nr 2 (lipiec 2010): 219–35. http://dx.doi.org/10.1152/physiolgenomics.00022.2010.

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The limited availability of genomic tools and data for nonmodel species impedes computational and systems biology approaches in nonmodel organisms. Here we describe the development, functional annotation, and utilization of genomic tools for the avian wildlife species Northern bobwhite ( Colinus virginianus ) to determine the molecular impacts of exposure to 2,6-dinitrotoluene (2,6-DNT), a field contaminant of military concern. Massively parallel pyrosequencing of a normalized multitissue library of Northern bobwhite cDNAs yielded 71,384 unique transcripts that were annotated with gene ontology (GO), pathway information, and protein domain analysis. Comparative genome analyses with model organisms revealed functional homologies in 8,825 unique Northern bobwhite genes that are orthologous to 48% of Gallus gallus protein-coding genes. Pathway analysis and GO enrichment of genes differentially expressed in livers of birds exposed for 60 days (d) to 10 and 60 mg/kg/d 2,6-DNT revealed several impacts validated by RT-qPCR including: prostaglandin pathway-mediated inflammation, increased expression of a heme synthesis pathway in response to anemia, and a shift in energy metabolism toward protein catabolism via inhibition of control points for glucose and lipid metabolic pathways, PCK1 and PPARGC1, respectively. This research effort provides the first comprehensive annotated gene library for Northern bobwhite. Transcript expression analysis provided insights into the metabolic perturbations underlying several observed toxicological phenotypes in a 2,6-DNT exposure case study. Furthermore, the systemic impact of dinitrotoluenes on liver function appears conserved across species as PPAR signaling is similarly affected in fathead minnow liver tissue after exposure to 2,4-DNT.

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Hajdu, Viktória, Alexandra Jakab-Nácsa, Gábor Muránszky, István Kocserha, Béla Fiser, Tibor Ferenczi, Miklós Nagy, Béla Viskolcz i László Vanyorek. "Precious-Metal-Decorated Chromium(IV) Oxide Nanowires as Efficient Catalysts for 2,4-Toluenediamine Synthesis". International Journal of Molecular Sciences 22, nr 11 (31.05.2021): 5945. http://dx.doi.org/10.3390/ijms22115945.

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The catalytic hydrogenation of 2,4-dinitrotoluene (DNT) to 2,4-toluenediamine (TDA) is a key step in the production of polyurethanes; therefore, the development of efficient hydrogenation catalysts for industrial use is of paramount importance. In the present study, chromium(IV) oxide nanowires were decorated by palladium and platinum nanoparticles in a one-step, simple, and fast preparation method to yield highly efficient hydrogenation catalysts for immediate use. The nanoparticles were deposited onto the surface of CrO2 nanowires by using ultrasonic cavitation and ethanol as a reduction agent. Beneficially, the catalyst became catalytically active right at the end of the preparation and no further treatment was necessary. The activity of the Pd- and Pt-decorated CrO2 catalysts were compared in the hydrogenation of 2,4-dinitrotoluene (DNT). Both catalysts have shown high activity in the hydrogenation tests. The DNT conversion exceeded 98% in both cases, whereas the 2,4-toluenediamine (TDA) yields were 99.7 n/n% and 98.8 n/n%, with the Pd/CrO2 and Pt/CrO2, respectively, at 333 K and 20 bar H2 pressure. In the case of the Pt/CrO2 catalyst, 304.08 mol of TDA formed with 1 mol Pt after 1 h hydrogenation. Activation energies were also calculated to be approximately 24 kJ∙mol−1. Besides their immediate applicability, our catalysts were well dispersible in the reaction medium (methanolic solution of DNT). Moreover, because of their magnetic behavior, the catalysts were easy to handle and remove from the reaction media by using a magnetic field.

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Xiong, Jianglin, Hang Sha, Hualin Zhou, Lijuan Peng, Lingying Wu, Yinsheng Qiu, Rui Wang i Xianqin Hu. "2,4-Dinitrotoluene (DNT) Perturbs Yolk Absorption, Liver Development and Lipid Metabolism/Oxygen Transport Gene Expression in Zebrafish Embryos and Larvae". International Journal of Molecular Sciences 20, nr 15 (25.07.2019): 3632. http://dx.doi.org/10.3390/ijms20153632.

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2,4-dinitrotoluene (2,4-DNT) is a common environmental pollutant, and was classified as a group 2B human carcinogenic compound by the International Agency for Research on Cancer. This study determined the toxic effects of 2,4-DNT exposure on zebrafish at the embryo-larvae stage, in terms of organ morphogenesis and the expression pattern of selected target genes related to lipid metabolism and oxygen transportation. The results showed that the 120-h post-fertilization LC50 of 2,4-DNT was 9.59 mg/L with a 95% confidence interval of 8.89–10.44 mg/L. The larvae treated with 2,4-DNT showed toxic symptoms including smaller body, less skin pigment production, yolk malabsorption, and disordered liver development. Further studies on the expression of genes related to lipid transport and metabolism, and respiration indicated that they were significantly affected by 2,4-DNT. It is concluded that 2,4-DNT exposure perturbed liver development and yolk absorption in early-life zebrafish, and disturbed the lipid metabolism /oxygen transport gene expression.

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Leungsakul, Thammajun, Brendan G. Keenan, Hong Yin, Barth F. Smets i Thomas K. Wood. "Saturation mutagenesis of 2,4-DNT dioxygenase ofBurkholderia sp. strain DNT for enhanced dinitrotoluene degradation". Biotechnology and Bioengineering 92, nr 4 (2005): 416–26. http://dx.doi.org/10.1002/bit.20602.

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Turner, Nicholas W., Clovia I. Holdsworth, Adam McCluskey i Michael C. Bowyer. "N-2-Propenyl-(5-dimethylamino)-1-naphthalene Sulfonamide, a Novel Fluorescent Monomer for the Molecularly Imprinted Polymer-Based Detection of 2,4-Dinitrotoluene in the Gas Phase". Australian Journal of Chemistry 65, nr 10 (2012): 1405. http://dx.doi.org/10.1071/ch12155.

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Fluorescent molecularly imprinted polymers (MIP) specific for 2,4-dinitrotoluene (DNT) have been synthesised using a novel monomer N-2-propenyl-(5-dimethylamino)-1-naphthalene sulfonamide. Three formats of the polymer were produced: a traditional bulk monolith ground into particles, a flexible, but highly cross-linked plasticiser-modified free standing membrane, and a hybrid material consisting of particles embedded in a poly(acrylonitrile) phase inversed film. Within all materials, a clearly defined imprinting effect was observed upon exposure to DNT vapour at room temperature. In all cases, preferential rebinding of DNT to the molecularly imprinted materials (3–5 times) over their non-imprinted (NIP) equivalents was evident within <10 min of contact with the DNT vapour stream. Fluorographic images of the fluorescent polymers showed the DNT binding-induced quenching to be significantly higher in the MIP material than in the non-imprinted control polymer.

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Rani, Sushma, Bharti Sharma, Shivani Kapoor, Rajesh Malhotra, Rajender S. Varma i Neeraj Dilbaghi. "Construction of Silver Quantum Dot Immobilized Zn-MOF-8 Composite for Electrochemical Sensing of 2,4-Dinitrotoluene". Applied Sciences 9, nr 22 (18.11.2019): 4952. http://dx.doi.org/10.3390/app9224952.

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In the present study, we report a highly effective electrochemical sensor for detecting 2,4-dinitrotoluene (2,4-DNT). The amperometric determination of 2,4-DNT was carried out using a gold electrode modified with zinc–metal organic framework-8 and silver quantum dot (Zn-MOF-8@AgQDs) composite. The synthesized nanomaterials were characterized by using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The synthesized nanocomposite proved to be efficient in electro-catalysis thereby reducing the 2,4-DNT. The unique combination present in Zn-MOF-8@AgQDs composite offered an excellent conductivity and large surface area enabling the fabrication of a highly sensitive (−0.238 µA µM−1 cm−2), selective, rapid and stable 2,4-DNT sensor. The dynamic linear range and limit of detection (LOD) was about 0.0002 µM to 0.9 µM and 0.041 µM, respectively. A 2,4-DNT reduction was also observed during the linear sweep voltammetry (LSV) experiments with reduction peaks at −0.49 V and −0.68 V. This is an unprecedented report with metal organic framework (MOF) composite for sensing 2,4-DNT. In addition, the presence of other species such as thiourea, urea, ammonia, glucose, and ascorbic acid displayed no interference in the modified electrode suggesting its practicability in various environmental applications.

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Sponza, D. T., i H. Atalay. "Simultaneous toxicity and nutrient removals in simulated DEPHANOX (anaerobic/anoxic/oxic sequentials) process treating dinitrotoluene and trichlorotoluene". Water Science and Technology 49, nr 5-6 (1.03.2004): 237–44. http://dx.doi.org/10.2166/wst.2004.0759.

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A modified DEPHANOX process including two upflow sludge blanket reactors (USB) (anaerobic-upflow sludge blanket -UASB and anoxic-upflow anoxic sludge blanket -UANSB) and one completely stirred tank reactor (CSTR system was simulated in order to detect the simultaneous removal of dinitrotoulene (DNT), trichlorotoluene (TCT), and nutrients. The phosphorus uptake and nitrification was excessively determined in aerobic CSTR reactor. Influent DNT was transformed to toluene, NH4-N and total aromatic amines (TAA) while TCT was transformed to toluene and dichlorotoluene (DCT) under anaerobic and anoxic conditions. Increasing the volumetric loading rate of DNT and TCT from 18 mg/L.day and 0.35 g/L.day to 60 mg/l.day and 1.2 g/L.day, respectively, resulted in higher COD conversion (70-80%) rates and methane productions (250-300 ml/day) in anaerobic reactor. 90% NO3-N and 87% PO4-P were achieved in anoxic and aerobic reactors at DNT and TCT loading rates as high as 40-60 mg/L.day and 0.8-1.2 g/L.day, respectively. The TAA produced under anaerobic and anoxic conditions were ultimately removed under the aerobic stage. The UASB and anoxic UASB reactor effluents were less toxic relative to the influent when analyzed by anaerobic toxicity tests and specific methanogenic activity tests, indicating that such anaerobic/anoxic aerobic sequential treatments could be able to reduce toxic organics together with nutrient removal.

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Lee, Junqiao, i Debbie S. Silvester. "Electrochemical Detection of Explosive Compounds in an Ionic Liquid in Mixed Environments: Influence of Oxygen, Moisture, and Other Nitroaromatics on the Sensing Response". Australian Journal of Chemistry 72, nr 2 (2019): 122. http://dx.doi.org/10.1071/ch18396.

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From a security point of view, detecting and quantifying explosives in mixed environments is required to identify potentially concealed explosives. Electrochemistry offers a viable method to detect nitroaromatic explosive compounds owing to the presence of easily reducible nitro groups that give rise to a current signal. However, their reduction potentials can overlap with interfering species, making it difficult to distinguish particular compounds. We have therefore examined the effect of oxygen, moisture, and other nitroaromatic species on the cyclic voltammetry and square wave voltammetry of nitroaromatic compounds of a range of mixed environments, focussing on 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT) as model analytes, and using the hydrophobic room-temperature ionic liquid (RTIL) [P14,6,6,6][NTf2] as the solvent. Oxygen (0–20% vol.) minimally affected the current of the first reduction peak of TNT in [P14,6,6,6][NTf2], but significantly affects the current for DNT. The impact of water (0 to 86% relative humidity), however, was much more dramatic – even in the hydrophobic RTIL, water significantly affected the currents of the analyte peaks for TNT and DNT, and gave rise to additional reduction features, further contributing to the current. Additionally, the voltammetry of other related di- and tri-nitro compounds (2,6-dinitrotoluene, 1,3-dinitrobenzene, 2,4,6-trinitrotoluene, 1,3,5-trinitrobenzene, and musk xylene) was also studied to understand how different substituents on the aromatic ring may affect the reduction potentials. A 50:50 mixture of TNT and DNT revealed that both analytes could be separately identified and quantified using square wave voltammetry. Overall, this information is useful in determining the effect of other species on the current signals of electrochemical explosive sensors, and reveals that it may be necessary to dry the aprotic RTIL electrolyte when used in humid environments.

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Lee, Junqiao, Catherine E. Hay i Debbie S. Silvester. "Electrochemical Reduction of 2,4-Dinitrotoluene in Room Temperature Ionic Liquids: A Mechanistic Investigation". Australian Journal of Chemistry 71, nr 10 (2018): 818. http://dx.doi.org/10.1071/ch18315.

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The reduction mechanism of 2,4-dinitrotoluene (DNT) has been studied in eight room temperature ionic liquids (RTILs) using cyclic voltammetry (CV), square wave voltammetry (SWV), chronoamperometry, and digital simulation. Two distinctive peaks are observed in the voltammetry, corresponding to the stepwise reduction of the two nitro groups on the aromatic ring. Diffusion coefficients (D) and electron counts (n) were calculated from chronoamperometric transients, revealing an electron count of one in most RTILs, and a linear relationship between D and the inverse of viscosity. Focusing on the first reduction only, the peak appears to be chemically reversible at low concentrations. However, as the concentration increases, the current of the reverse peak diminishes, suggesting that one or more chemical steps occur after the electrochemical step. The results from digital simulation of the CVs in one of the RTILs reveal that the most likely mechanism involves a deprotonation of the methyl group of a parent DNT molecule by the electrogenerated radical anion and/or a dimerisation of two electrogenerated radical anions. Elucidation of the reduction mechanism of DNT (and other explosives) is vital if electrochemical techniques are to be employed to detect these types of compounds in the field.

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Wang, E., Dianming Sun, Huihui Li, Xiaoli Sun, Junteng Liu, Zhongjie Ren i Shouke Yan. "High efficiency organosilicon-containing polymer sensors for the detection of trinitrotoluene and dinitrotoluene". Journal of Materials Chemistry C 4, nr 28 (2016): 6756–60. http://dx.doi.org/10.1039/c6tc01892k.

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Shah, J. K., G. D. Sayles, M. T. Suidan, P. Mihopoulos i S. Kaskassian. "Anaerobic bioventing of unsaturated zone contaminated with DDT and DNT". Water Science and Technology 43, nr 2 (1.01.2001): 35–42. http://dx.doi.org/10.2166/wst.2001.0070.

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Initial degradation of highly chlorinated compounds and nitroaromatic compounds found in munition waste streams is accelerated under anaerobic conditions followed by aerobic treatment of the degradation products. The establishment of anaerobic environment in a vadose zone can be accomplished by feeding appropriate anaerobic gas mixture, i.e., “anaerobic bioventing”. The gas mixture contains an electron donor for the reduction of these compounds. Lab scale study was conducted to evaluate potential of anaerobic bioventing for the treatment of an unsaturated zone contaminated with 1,1,1-trichloro -2,2-bis(p-chlorophenyl)ethane (DDT) and 2,4-dinitrotoluene (DNT). Hydrogen was used as the electron donor. Using the soil columns innoculate with anaerobic microorganisms, it was observed that by feeding a gas mixture of 1% hydrogen, 1% carbon dioxide and nitrogen, methanogenic conditions were established and DDT was reductively dechlorinated. 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) accumulated as the intermediate product. The half life of DDT was calculated to be 8.5 months. DNT completely disappeared after six months of operation and no intermediates could be detected.

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Cui, Yue Zhi, Xiao Liang Ren, Xue Ming Dong i Yong Tao Wang. "Fluorescent Sensors for Nitroaromatic Compounds Based on the Comb-Like Polysiloxane-Acrylate". Advanced Materials Research 306-307 (sierpień 2011): 1640–44. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.1640.

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A functional polysiloxane monomer, with a double bond and a fluorophore pyrene at each end of the polysiloxane chain, respectively, was synthesized. Copolymerize this functional monomer with other acrylates in emulsion, we got a comb-like polymer in which pyrene fluorophore is at the end of each polysiloxane side-chain. This polymer shows great advantage in sensing performance for 2,4-dinitrotoluene (DNT) over its analog that was prepared just by mixing pyrene with pure polyacrate emulsion.

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Ellis, H. V., C. B. Hong, C. C. Lee, J. C. Dacre i J. P. Glennon. "Subchronic and Chronic Toxicity Studies of 2,4-Dinitrotoluene. Part I. Beagle Dogs". Journal of the American College of Toxicology 4, nr 4 (lipiec 1985): 233–42. http://dx.doi.org/10.3109/10915818509078676.

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Subchronic and chronic toxicities of 2,4-dinitrotoluene (2,4-DNT) were studied in beagle dogs. The major adverse effect of 2,4-DNT in dogs was a neuropathy, characterized by incoordination and paralysis. There were vacuolation, endothelial proliferation, and gliosis of the cerebellums of some affected dogs. These effects were seen in 1 dog given 1.5 mg/kg per day for 2 years, in all dogs given 10 mg/kg per day within 6 months, and in all dogs given 25 mg/kg per day within 2 months. There was great variation between individuals in onset and severity of adverse effects. Some dogs progressed to a complete paralysis, leading to death. Methemoglobin and its sequelae were common, but not life threatening. Heinz bodies were a useful indicator of this effect. Less important adverse effects seen included testicular degeneration and biliary tract hyperplasia. No changes were found in tumor incidence, immunoglobin E and cytogenetic assays, and other routine hematologic and clinical laboratory tests.

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Hong, C. B., H. V. Ellis, C. C. Lee, H. Sprinz, J. C. Dacre i J. P. Glennon. "Subchronic and Chronic Toxicity Studies of 2,4-Dinitrotoluene. Part III. CD-1® Mice". Journal of the American College of Toxicology 4, nr 4 (lipiec 1985): 257–69. http://dx.doi.org/10.3109/10915818509078678.

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Subchronic and chronic toxicities of 2,4-dinitrotoluene (2,4-DNT) were evaluated in CD-1® mice. 2,4-DNT was more toxic to males than to females. Male mice fed 47 mg/kg per day or 137 mg/kg per day for 13 weeks gained less weight. However, females fed 52 or 147 mg/kg per day had no adverse effects. Feeding of 413 mg/kg per day for males or 468 mg/kg per day for females lowered feed consumption, depressed body weight, and caused mild anemia and mild hepatocellular dysplasia in both sexes and mild testicular degeneration in males. Both males and females were fed an average of 14 (low dose), 95 (middle dose), or 898 mg/kg per day (high dose) for up to 24 months. In males, there was a high incidence of epithelial renal tumor and hepatocellular dysplasia in all dose groups, Incidence of testicular atrophy was increased in the middle-and high-dose males. In addition, the high dose caused toxic anemia and death. In females, the high dose was associated with toxic anemia, hepatocellular dysplasia, nonfunctional follicle with a lack of corpora lutea, an effect analogous to the testiclar atrophy in males, and death. A generalized pigmentation, probably of 2,4-DNT metabolite origin, was seen in many tissues of especially the high-dose males and females.

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Schick, Luca Aroha, Jennifer Susanne Strehse, Tobias Hartwig Bünning, Edmund Maser i Ursula Siebert. "Energetic Compounds in the Trophic Chain—A Pilot Study Examining the Exposure Risk of Common Eiders (Somateria mollissima) to TNT, Its Metabolites, and By-Products". Toxics 10, nr 11 (12.11.2022): 685. http://dx.doi.org/10.3390/toxics10110685.

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The Baltic and North Seas still contain large amounts of dumped munitions from both World Wars. The exposure of the munition shells to the seawater causes corrosion, which leads to the disintegration of shells and a leakage of energetic compounds, including the highly toxic 2,4,6-trinitrotoluene (TNT), and consequently threatening the marine environment. To evaluate the risk of accumulation of energetic compounds from conventional munitions in the marine food chain, we analyzed the presence of TNT and its metabolites 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) as well as their byproducts 1,3-dinitrobenzene (1,3-DNB) and 2,4-dinitrotoluene (2,4-DNT) in different tissues (including muscle, liver, kidney, brain, and bile) from 25 Common Eiders (Somateria mollissima) from the Danish Baltic Sea. Tissues were prepared according to approved protocols, followed by GC-MS/MS analysis. None of the aforementioned energetic compounds were detected in any of the samples. This pilot study is one of the first analyzing the presence of explosive chemicals in tissues from a free-ranging predatory species. This study highlights the need for continuous monitoring at different levels of the trophic chain to increase our knowledge on the distribution and possible accumulation of energetic compounds in the marine environment in order to provide reliable data for decision-making tools and risk assessments.

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Strehse, Jennifer Susanne, Tobias Hartwig Bünning, Jan Koschorreck, Anita Künitzer i Edmund Maser. "Long-Term Trends for Blue Mussels from the German Environmental Specimen Bank Show First Evidence of Munition Contaminants Uptake". Toxics 11, nr 4 (7.04.2023): 347. http://dx.doi.org/10.3390/toxics11040347.

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Submerged munitions are present in marine waters across the globe. They contain energetic compounds (ECs), such as TNT and metabolites thereof, which are considered carcinogenic, exhibit toxic effects in marine organisms, and may affect human health. The aim of this study was to investigate the occurrence of ECs and their trends in blue mussels from the annual collections of the German Environmental Specimen Bank sampled over the last 30 years at three different locations along the coastline of the Baltic and North Sea. Samples were analyzed by GC-MS/MS for 1,3-dinitrobenzene (1,3-DNB), 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2-ADNT), and 4-amino-2,6-dinitrotoluene (4-ADNT). The first signals indicating trace levels of 1,3-DNB were observed in samples from 1999 and 2000. ECs were also found below the limit of detection (LoD) in subsequent years. From 2012 onwards, signals just above the LoD were detected. The highest signal intensities of 2-ADNT and 4-ADNT, just below the LoQ (0.14 ng/g d.w. and 0.17 ng/g d.w., respectively), were measured in 2019 and 2020. This study clearly shows that corroding submerged munitions are gradually releasing ECs into the waters that can be detected in randomly sampled blue mussels, even though the concentrations measured are still in the non-quantifiable trace range.

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Kundu, Debasree, Chinmay Hazra i Ambalal Chaudhari. "Biodegradation of 2,4-dinitrotoluene with Rhodococcus pyridinivorans NT2: characteristics, kinetic modeling, physiological responses and metabolic pathway". RSC Advances 5, nr 49 (2015): 38818–29. http://dx.doi.org/10.1039/c5ra02450a.

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Bruening, T., C. Chronz, R. Thier, G. Weirich, H. M. Bolt i Y. Ko. "Technical dinitrotoluene (t-DNT): A potential carcinogenic and nephrotoxic hazard in humans?" Toxicology Letters 95 (lipiec 1998): 182. http://dx.doi.org/10.1016/s0378-4274(98)80727-3.

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Wang, Z. Y., Z. F. Ye i M. H. Zhang. "Bioremediation of 2,4-dinitrotoluene (2,4-DNT) in immobilized micro-organism biological filter". Journal of Applied Microbiology 110, nr 6 (27.04.2011): 1476–84. http://dx.doi.org/10.1111/j.1365-2672.2011.04997.x.

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Suen, W. C., B. E. Haigler i J. C. Spain. "2,4-Dinitrotoluene dioxygenase from Burkholderia sp. strain DNT: similarity to naphthalene dioxygenase." Journal of bacteriology 178, nr 16 (1996): 4926–34. http://dx.doi.org/10.1128/jb.178.16.4926-4934.1996.

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Zhang, Hong-Xia, i Jun-Hong Zhang. "Voltammetric detection of nitroaromatic compounds using carbon-nanomaterials-based electrodes". Canadian Journal of Chemistry 89, nr 1 (styczeń 2011): 8–12. http://dx.doi.org/10.1139/v10-064.

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The morphology of glassy carbon surfaces was investigated by the atomic force microscope (AFM) method. Multi-wall carbon nanotubes (MWCNTs) were purified and investigated with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). An electrochemical technique based on the glassy carbon electrode (GCE) or MWCNT-modified GCEs was used for the detection of nitroaromatic compounds (NACs), namely 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitrobenzene (TNB), 2,4-dinitrotoluene (2,4-DNT), and 1,3-dinitrobenzene (1,3-DNB). MWCNT-modified GCEs were more sensitive than GCEs to TNB, 2,4-DNT, and 1,3-DNB, with the detection limit down to ppb level, whereas the modified GCEs showed lower sensitivity to TNT. In varying degrees, the accumulation of nitro compounds can be promoted by MWCNT-modified GCEs in the detection process, a property which can be attributed to the large surface area and graphene-sheet structure of MWCNTs.

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Smets, Barth F., R. Guy Riefler, Urs Lendenmann i Jim C. Spain. "Kinetic analysis of simultaneous 2,4-dinitrotoluene (DNT) and 2,6-DNT biodegradation in an aerobic fluidized-bed biofilm reactor". Biotechnology and Bioengineering 63, nr 6 (20.06.1999): 642–53. http://dx.doi.org/10.1002/(sici)1097-0290(19990620)63:6<642::aid-bit2>3.0.co;2-b.

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Doppalapudi, R., D. Palaniswamy, G. Sorial i S. Maloney. "Electrochemical pilot scale study for reduction of 2,4-DNT". Water Science and Technology 47, nr 9 (1.05.2003): 173–78. http://dx.doi.org/10.2166/wst.2003.0519.

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An electrochemical pilot scale reactor was used to treat simulated munitions wastewater containing 100 mg/L of 2,4-dinitrotoluene (DNT). Experiments were conducted by using a glassy carbon (zero porosity) coated graphite cylinder as the cathode and a platinum wire as the anode. All experiments were conducted under dissolved oxygen concentration of less than 1.5 mg/L. Initially, experiments simulating batch conditions were conducted to obtain the optimum operating conditions for the reactor. During this batch-mode study, the effects of various parameters such as applied current, electrolyte concentration, and type of electrolyte on the reduction of DNT were evaluated. Results obtained showed that the rates of reduction of DNT increased with an increase in current or concentration of electrolyte. Based on the results obtained from the batch simulation experiments, continuous flow experiments were conducted at three different currents. The ionic strength of the feed solution was maintained at 0.027 M. A current of 200 mA was found to provide a stable reduction of DNT at the 80% level for a period of 14 days after which reactor cleaning is necessary for removal of solids that were formed within the reactor. End products determined for the continuous flow experiments showed 100% molar balance conversion.

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Dai, Jingjing, Michael Zambrana i Maria Fidalgo. "Amino-functionalized Fluorescent Carbon Dots for Chemical Sensing". MRS Advances 1, nr 19 (2016): 1365–70. http://dx.doi.org/10.1557/adv.2016.169.

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ABSTRACTQuantum dots have been applied in sensing with success, but their use in environmental applications has been questioned due to their heavy metal content. Carbon dots are fluorescent nanoparticles that offer a promising alternative to quantum dots for sensing, due to their low cost, benign fabrication process and negligible environmental impact. Fluorescence sensors are specially suited for detection of nitroaromatic compounds such as 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT), since they can quench the emission of excited species. When combined to Molecularly Imprinted Polymers (MIPs), the sensors become specific to the imprinted target molecules. Amino-functionalized carbon dots (CDs) with high photoluminescence were fabricated. The CDs were characterized with respect to their surface charge, surface chemistry, particle size distribution, and photoluminescence properties (PL). A molecularly imprinted polymer with template of DNT was combined with fluorescent carbon dots via a simple covalent reaction. The ability of aqueous DNT to quench amino CDs fluorescence was tested for concentrations in the range of 1mM to 50 mM. It can be concluded that the amino carbon dots can be used in fluorescent-labeled MIP systems and that they provide a feasible method for the detection of DNT, and potentially other nitroaromatic compounds, in environmental water samples.

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Johnson, Mark S., Mark W. Michie, Matthew A. Bazar i Robert M. Gogal. "Influence of Oral 2,4-Dinitrotoluene Exposure to the Northern Bobwhite (Colinus virginianus)". International Journal of Toxicology 24, nr 4 (lipiec 2005): 265–74. http://dx.doi.org/10.1080/10915810591007247.

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Military activities associated with training, munitions manufacturing, and demilitarization has resulted in soil residues of munition compounds and their breakdown products. Two isomers of dinitrotoluene (2,4- and 2,6-) are often found in soil associated with those activities at considerable concentrations. Consequently, issues regarding the effects of exposure to birds that visit these habitats require evaluation. To provide data useful to a risk assessment approach, we followed a controlled dosing regime (gavage) using 2,4-dinitrotoluene (2,4-DNT) in the Northern Bobwhite ( Colinus virginianus) for 60 days following a 14-day range-finding study and the determination of a LD50 using the up/down method. The LD50 was determined to be 55 mg/kg using corn oil as a vehicle. Individuals dosed exceeding this level were moribund or died within 60 h of exposure. Morbidity and death occurred during the 14-day range-finding study at dosing regimens of 35 and 55, but not at 15, 5, and 0.5 mg/kg-day. Compound-related morbidity/mortality occurred in the 60-day study during the first week of exposure at 25 and 15, but not at 5, 1, and 0 mg/kg-day. Overt signs of toxicity occurred with both sexes at the onset of exposure. Signs included weight loss, diarrhea, and lethargy. Dose-related changes in egg production, ovary, kidney, and brain mass, and body weight, but not feed consumption, were found. Changes in kidney mass and histological observations suggest accumulation of nitrogenous waste may be the cause of morbidity. These data suggest that oral 2,4-DNT exposures are more acutely toxic and has a different etiology than 2,4,6-trinitrotoluene in birds.

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Suen, W. C., i J. C. Spain. "Cloning and characterization of Pseudomonas sp. strain DNT genes for 2,4-dinitrotoluene degradation." Journal of Bacteriology 175, nr 6 (1993): 1831–37. http://dx.doi.org/10.1128/jb.175.6.1831-1837.1993.

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Parales, Juanito V., Rebecca E. Parales, Sol M. Resnick i David T. Gibson. "Enzyme Specificity of 2-Nitrotoluene 2,3-Dioxygenase from Pseudomonas sp. Strain JS42 Is Determined by the C-Terminal Region of the α Subunit of the Oxygenase Component". Journal of Bacteriology 180, nr 5 (1.03.1998): 1194–99. http://dx.doi.org/10.1128/jb.180.5.1194-1199.1998.

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ABSTRACT Biotransformations with recombinant Escherichia coliexpressing the genes encoding 2-nitrotoluene 2,3-dioxygenase (2NTDO) from Pseudomonas sp. strain JS42 demonstrated that 2NTDO catalyzes the dihydroxylation and/or monohydroxylation of a wide range of aromatic compounds. Extremely high nucleotide and deduced amino acid sequence identity exists between the components from 2NTDO and the corresponding components from 2,4-dinitrotoluene dioxygenase (2,4-DNTDO) from Burkholderia sp. strain DNT (formerlyPseudomonas sp. strain DNT). However, comparisons of the substrates oxidized by these dioxygenases show that they differ in substrate specificity, regiospecificity, and the enantiomeric composition of their oxidation products. Hybrid dioxygenases were constructed with the genes encoding 2NTDO and 2,4-DNTDO. Biotransformation experiments with these hybrid dioxygenases showed that the C-terminal region of the large subunit of the oxygenase component (ISPα) was responsible for the enzyme specificity differences observed between 2NTDO and 2,4-DNTDO. The small subunit of the terminal oxygenase component (ISPβ) was shown to play no role in determining the specificities of these dioxygenases.

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Erturan, Ahmet Murat, Seyfettin Sinan Gultekin i Habibe Durmaz. "Detection of 2,4-Dinitrotoluene by Metal-Graphene Hybrid Plasmonic Nanoantennas with a Golden Ratio Rectangular Resonator". Elektronika ir Elektrotechnika 29, nr 3 (27.06.2023): 33–38. http://dx.doi.org/10.5755/j02.eie.33869.

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Plasmonic nanoantenna arrays have become increasingly popular for the detection of chemical molecules, biomolecules, viruses, and agents. In this study, our objective was to detect explosive-based 2,4-dinitrotoluene (2,4-DNT) with a metal-graphene hybrid plasmonic rectangular nanoantenna with a golden ratio size formed by choosing two consecutive numbers from the Fibonacci series. The golden rectangular resonator provides nearly perfect absorption without the need for impedance matching calculations and complex optimisation algorithms. In surface enhanced infrared absorption (SEIRA) applications, the internal losses of metallic nanostructures degrade their sensing performance. To improve performance sensitivity, graphene with high electrical conductivity and electrical tunability was used. The spectral fingerprints of 2,4 DNT at 6300 nm, 6580 nm, and 7500 nm were enhanced with a metal-graphene hybrid structure. The biosensor platform introduced, by combining the graphene and nanoantennas with a golden ratio and by adjusting the Fermi energy level of graphene, can be beneficial for highly sensitive tunable biosensors for a broad spectrum to identify the molecular fingerprints of specific biomolecules.

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Barata, Patrícia D., i José V. Prata. "Fluorescent Calix[4]arene-Carbazole-Containing Polymers as Sensors for Nitroaromatic Explosives". Chemosensors 8, nr 4 (10.12.2020): 128. http://dx.doi.org/10.3390/chemosensors8040128.

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Two highly fluorescent calix[4]arene-containing phenylene-alt-ethynylene-carbazolylene polymers (Calix-PPE-CBZs) were used in the detection of explosives from the nitroaromatic compounds (NACs) family, in solution and in vapour phases. Both fluorophores exhibit high sensitivity and selectivity towards NACs detection. The quenching efficiencies in solution, assessed through static Stern-Volmer constants (KSV), follow the order picric acid (PA) >> 2,4,6-trinitrotoluene (TNT) > 2,4-dinitrotoluene > (2,4-DNT) > nitrobenzene (NB). These correlate very well with the NACs electron affinities, as evaluated from their lowest unoccupied molecular orbitals (LUMOs) energies, indicating a photo-induced electron transfer as the dominant mechanism in fluorescence quenching. Moreover, and most interesting, detection of TNT, 2,4-DNT and NB vapours via thin-films of Calix-PPE-CBZs revealed a remarkably sensitive response to these analytes, comparable to state-of-the-art chemosensors. The study also analyses and compares the current results to previous disclosed data on the detection of NACs by several calix[4]arene-based conjugated polymers and non-polymeric calix[4]arenes-carbazole conjugates, overall highlighting the superior role of calixarene and carbazole structural motifs in NACs’ detection performance. Density functional theory (DFT) calculations performed on polymer models were used to support some of the experimental findings.

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