Impact of different crystalline forms of nTiO2 on metabolism and arsenic toxicity in Limnoperna fortunei

Arsenic (As) is a ubiquitous contaminant in the environment and it is known to induce oxidative stress in aquatic organisms. In an attempt to remove As from water, some studies have suggested the titanium dioxide nanomaterial (nTiO2) as a promising alternative. However, it has been observed that nTiO2 can induce toxicity alone or in combination with metals, and this toxicity is dependent on its crystalline form of nanomaterial (mainly rutile as nTiO2R and anatase as nTiO2A, respectively). Considering that both (nTiO2 and As) can occur together, the objective of this study was to evaluate if co-exposure to rutile and anatase may influence accumulation, metabolisation, and toxicity of arsenite (As+3) in the golden mussel Limnoperna fortunei after 48 h of co-exposure to nTiO2 (1 mg/L) and As (50 μg/L). Accumulation and chemical speciation of As in organisms were determined. Also, biochemical analyses, such as the activity of the enzymes glutathione S-transferase omega (GSTΩ), catalase (CAT) and glutathione S-transferase (GST), as well as lipid peroxidation (LPO) were investigated. Results showed that co-exposure to nTiO2A + As changed accumulation pattern of metalloid in gills and digestive gland. Both crystalline forms of nTiO2 affected the metabolisation capacity favoring the accumulation of more toxic As compounds and nTiO2A alone or in combination with As showed induce oxidative stress in gills of L. fortunei. In this way, it has a high potential risk of the co-exposure of these contaminants to aquatic organisms, and it also needs to consider the nanomaterial (nTiO2) properties and their application in the environmental remediation, carefully and judiciously

Genotoxic effect of dimethylarsinic acid and the influence of co-exposure to titanium nanodioxide (nTiO2) in Laeonereis culveri (Annelida, Polychaeta)

Few data are available about the effect of dimethylated forms (DMA) on aquatic organisms. As rarely a contaminant occurs alone, studies evaluating the combined effect of different contaminants in aquatic organisms are needed. In fact, the presence of nanomaterials, such as titaniumdioxide nanoparticles (nTiO2), in the aquatic environment is now a reality due to its intensive production and use. So, this study evaluated the toxicological effects of DMA in an acute exposure condition and considered the potential influence of nTiO2 on the effects induced by DMA in the polychaete, Laeonereis culveri. The animals were exposed over 48 h to DMA (50 and 500 μg/l) alone or in combination with nTiO2 (1 mg/l). Biochemical parameters such as concentration of reactive oxygen species (ROS), glutathione-S-transferase (GST) activity, levels of reduced glutathione levels (GSH) and macromolecular (lipid and DNA) damage were evaluated, as well the DNA repair system. In addition, the accumulation of total As and the chemical speciation of the metalloid in the organisms was determined. The results showed that: (1) only the group exposed to 500 μg of DMA/l accumulated As and when co-exposed to nTiO2, this accumulation was not observed. (2) The levels of ROS increased in the group exposed to 50 μg/l ofDMA alone and the effectwas reversedwhen this groupwas co-exposed to nTiO2 (3) None of the treatments showed altered GST activity or GSH levels. (4) All groups that received nTiO2 (alone or in combination with DMA) showed lipid peroxidation. (5) The exposure to DMA (both concentrations) alone or in combination with nTiO2 induced DNA damage in L. culveri. These results showed that DMA exhibits a genotoxic effect and that co-exposure to nTiO2 had an influence on its toxicity. So the occurrence of both contaminants simultaneously can represent a threat to aquatic biota

Toxicity evaluation of nanocrystalline silver-impregnated coated dressing on the life cycle of worm Caenorhabditis elegans

In recent times, however, due to the emergence of bacterial strains with resistance to conventional antibiotics, silver has again gained attention as an alternative for developing new efficient bactericides, including the use of silver nanoparticles (AgNPs). However, the improper disposal of these items after use may cause toxicological effects on organisms in the environment. To evaluate the potential environmental hazard of nanosilver-coated dressings, the nematode Caenorhabditis elegans was chosen as a test organism. The assays were conducted in 24-well plates that contain four different sizes of coated dressing to obtain different concentrations. L1 and L4 C. elegans larval stages were exposed to these nanosilver concentrations. Dressing cutouts were arranged between two layers of agar for 3 days and Escherichia coli (OP 50 strain) was added as food source for the worms. After the exposure period, growth, reproduction, fertility, silver concentration in the medium and the concentration of reactive oxygen species (ROS) in the worms were evaluated. Scanning and transmission electron microscopy analyses were performed on the coated dressings, as well as analyses of zeta potential, ionic release and antibacterial power in two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus). It was verified the antibacterial power of the coated dressing, in both bacteria strains tested. Characterization of the coated dressing indicated heterogeneous nanoparticles, as well as distinct zeta potentials for the medium in water and saline medium (0.9% NaCl). L1 larval worms exposed to nanosilver-coated dressing showed a high ROS concentration and reductions in growth, fertility and reproduction. Worms exposed to the coated dressing during the L4 stage showed almost no response. Overall, the obtained results indicate the potential environmental hazard of nanosilver-coated dressings.Fil: Ayech, Alinne. Universidade Federal do Rio Grande; BrasilFil: Josende, M. E.. Universidade Federal do Rio Grande; BrasilFil: Ventura Lima, J.. Universidade Federal do Rio Grande; BrasilFil: Ruas, Caroline Pires. Universidade Federal do Rio Grande; BrasilFil: Gelesky, M. A.. Universidade Federal do Rio Grande; BrasilFil: Ale, Analía. 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; ArgentinaFil: 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; ArgentinaFil: Galdopórpora, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Duarte, Miriam. Universidade Federal do Rio Grande; BrasilFil: Halicki, Priscila Cristina Bartolomeu. Universidade Federal do Rio Grande; BrasilFil: Ramos, Daniela Fernandes. Universidade Federal do Rio Grande; BrasilFil: Carvalho, L. M.. Universidade Federal de Santa Maria; BrasilFil: Leal, Gabriela Camera. Universidade Federal de Santa Maria; BrasilFil: Monserrat, José María. Universidade Federal do Rio Grande; Brasi

Ohio History 2014

https://kent-islandora.s3.us-east-2.amazonaws.com/node/10128/OH-v121-thumb.jpgOHIO HISTORY Contents for Volume 121, 2014 Time Not Ripe: Black Women’s Quest for Citizenship and the Battle for Full Inclusion at Ohio State University Tyran Kai Steward ...... 4 “The Most Free of the Free States”: Politics, Slavery, Race, and Regional Identity in Early Ohio, 1790–1820 John Craig Hammond ...... 35 James A. Shedd to Dr. David Jordon: A Documentary Perspective on the Dayton Mob of 1841 Hans C. Rasmussen ...... 58 The Ohio Constitution of 1803, Jefferson’s Danbury Letter, and Religion in Education David Scott ...... 73 Memories of Work and the Definition of Community: The Making of Italian Americans in the Mahoning Valley Donna M. DeBlasio and Martha I. Pallante ...... 89 Germans, Jubilee Singers, and Axe Men: James A. Garfield and the Original Front-Porch Campaign for the Presidency Jeffrey Normand Bourdon ...... 112 &nbsp; Book Reviews ......&nbsp;130 On the cover: Niles Fire Brick workers, ca. 1896.</p