Computational design of chemical nanosensors: Transition metal doped single-walled carbon nanotubes

We present a general approach to the computational design of nanostructured chemical sensors. The scheme is based on identification and calculation of microscopic descriptors (design parameters) which are used as input to a thermodynamic model to obtain the relevant macroscopic properties. In particular, we consider the functionalization of a (6,6) metallic armchair single-walled carbon nanotube (SWNT) by nine different 3d transition metal (TM) atoms occupying three types of vacancies. For six gas molecules (N_{2}, O_{2}, H_{2}O, CO, NH_{3}, H_{2}S) we calculate the binding energy and change in conductance due to adsorption on each of the 27 TM sites. For a given type of TM functionalization, this allows us to obtain the equilibrium coverage and change in conductance as a function of the partial pressure of the "target" molecule in a background of atmospheric air. Specifically, we show how Ni and Cu doped metallic (6,6) SWNTs may work as effective multifunctional sensors for both CO and NH_{3}. In this way, the scheme presented allows one to obtain macroscopic device characteristics and performance data for nanoscale (in this case SWNT) based devices.Comment: Chapter 7 in "Chemical Sensors: Simulation and Modeling", Ghenadii Korotcenkov (ed.), 47 pages, 22 figures, 10 table

Susceptibility of different life stages of Blattella germanica (Blattodea: Blattellidae) and Periplaneta fuliginosa (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Fil: Gutierrez, Alejandra Concepción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: García, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Alzogaray, Raul Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación de Plagas e Insecticidas; ArgentinaFil: Urrutia, María I.. Universidad Nacional de La Plata; ArgentinaFil: Lopez Lastra, Claudia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentina. Universidad Nacional de La Plata; Argentin

Susceptibility of different life stages of <i>Blattella germanica</i> (Blattodea: Blattellidae) and <i>Periplaneta fuliginosa</i> (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Centro de Estudios Parasitológicos y de Vectore

Susceptibility of different life stages of <i>Blattella germanica</i> (Blattodea: Blattellidae) and <i>Periplaneta fuliginosa</i> (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Centro de Estudios Parasitológicos y de Vectore

Susceptibility of different life stages of <i>Blattella germanica</i> (Blattodea: Blattellidae) and <i>Periplaneta fuliginosa</i> (Blattodea: Blattidae) to entomopathogenic fungi

The susceptibility of nymphs and adults of the German cockroach, Blattella germanica Linnaeus (Blattodea: Blattellidae) and the smokybrown cockroach, Periplaneta fuliginosa Serville (Blattodea: Blattidae) to Argentinian isolates of the entomopathogenic fungi Metarhizium anisopliae (Metschn.) Sorokin (CEP 085) and Beauveria bassiana (Bals.-Criv.) Vuill. (CEP 077) was evaluated. Fungi were tested by using two different methods: bait and direct contact. Mortality was monitored daily for twenty days to obtain LT50. M. anisopliae produced 60 and 93% mortality in nymphs and adults of B. germanica, respectively, when conidia were applied by direct contact. The LT50 for adults was 3.8 days, and 8.6 days for nymphs. Direct contact of B. bassiana produced 80% mortality on adults of B. germanica with a LT50 of 4.9 days, and for nymphs 40 % mortality in 10 days. When B. germanica was exposed to bait, the level of mortality was significant in adults. Nymphs of P. fuliginosa were treated with bait with M. anisopliae and B. bassiana and they caused 50% mortality with a LT50 of 22 days, and LT50 of 27 days respectively. Nymphs and adults of P. fuliginosa treated by direct contact and adults treated with bait showed that mortality level was not significantly different as compared to the control. Results showed differences in susceptibility between the two species of cockroaches and between nymphs and adults of the same species. In addition, different responses to the fungal species with the two methods that were used in the bioassays have been demonstrated. This is the first report of susceptibility of P. fuliginosa to entomopathogenic fungi. This study demonstrates the potential of fungi as biocontrol agents against this pest.Centro de Estudios Parasitológicos y de Vectore

Pressure-induced changes in Cr3+-doped elpasolites and LiCaAlF6: interpretation of macroscopic data

In the research of pressure effects on Cr3+-doped insulating lattices, it is crucial to understand the dependence of the 10Dq parameter on the sample volume, V. This problem is explored in the present work through ab initio calculations on Cr3+-doped K2NaScF6, Cs2NaYCl6, and Cs2NaYBr6 elpasolite lattices as a function of pressure in the 0?5 GPa range. From the calculated values of the lattice parameter and the Cr3+?X? (X=F, Cl, and Br) distance, R, it is found that R varies with the cell volume, vc, as v(1/3?)c where ? lies around 2.6. These results allow one to understand quantitatively the 10Dq dependence on V?m/3 for LiCaAlF 6:Cr3+ where the measured exponent m=2.3 is seemingly anomalous when compared to the values found for ruby (m=4.5) or NiO (m=5).The support by the Spanish Ministerio de Ciencia y Tecnología under Project No. FIS2009-07083 is acknowledged

Protective Effect of L‐Arginine Against Ibuprofen‐induced Gastric Injury in Rats

This study has been designed to confirm the protective effect of different single oral doses of L‐arginine in the presence of equimolar doses of ibuprofen, and to compare the results with those obtained after treatment with ibuprofen alone. Different parameters were assessed in rats: gastric damage (mm2 and score), ratio of lesionated stomachs/total stomachs evaluated, and presence of haemorrhage. Six hours after dosing, oral administration of ibuprofen (0·3, 0·6 and 1·2 mmol kg −1) produced a progressive dose‐dependent increase in damage to the gastric mucosa. All treatments with equimolar doses of L‐arginine considerably reduced lesions (mm2 and score) and the same tendency was observed with the other parameters examined. We also evaluated the gastroprotective effect of L‐arginine against anti‐ulcer reference drugs, ranitidine and roxatidine (two antisecretory agents) and misoprostol (a cytoprotective drug). The degree of inhibition of damage provided by L‐arginine was similar to those obtained with the other drugs. Thus, we conclude that the simultaneous administration of equimolar doses of ibuprofen and L‐arginine offers significant protection compared with gastrolesive doses of ibuprofen alone, with an important decrease in the lesionated areas and improvement of the vascular state. The extent of this protective action is comparable with that observed with anti‐ulcer reference drugs

(−)-Methyl-Oleocanthal, a New Oleocanthal Metabolite Reduces LPS-Induced Inflammatory and Oxidative Response: Molecular Signaling Pathways and Histones Epigenetic Modulation

The antioxidant and anti-inflammatory responses of (−)-methyl-oleocanthal (met-OLE), a new metabolite of the extra virgin olive oil (EVOO) phenolic oleocanthal (OLE), were explored in lipopolysaccharide (LPS)-induced murine peritoneal macrophages. Possible signaling pathways and epigenetic modulation of histones were studied. Met-OLE inhibited LPS-induced intracellular reactive oxygen species (ROS) and nitrite (NO) production and decreased the overexpression of the pro-inflammatory enzymes COX-2, mPGES-1 and iNOS in murine macrophages. In addition, met-OLE was able to significantly decrease the activation of p38, JNK, and ERK mitogen-activated protein kinases (MAPKs) and blocked canonical and non-canonical inflammasome signaling pathways. On the contrary, met-OLE upregulated haem oxigenase 1 (HO-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) expression in treated cells. Finally, met-OLE pretreated spleen cells counteracted LPS induction, preventing H3K18 acetylation or H3K9 and H3K27 demethylation. Overall, these results provide novel mechanistic insights into the beneficial effects of met-OLE regarding the regulation of the immune–inflammatory response through epigenetic changes in histone markers. This revealing evidence suggests that the methylated metabolite of OLE may contribute significantly to the beneficial effects that are associated with the secoiridoid-related compound and the usual consumption of EVOO.España Ministerio de Economía y Competitividad grant number AG-2017-89342-PJunta de Andalucía funded by CTS-259, FQM-18

Analysis of laccase-like enzymes secreted by fungi isolated from a cave in northern Spain

[EN] Laccases belong to a family of multicopper enzymes able to oxidize a broad spectrum of organic compounds. Despite the well-known property of laccases to carry out bleaching and degradation of industrial dyes and polyphenolic compounds, their industrial use is often limited by the high cost, low efficiency, or instability of these enzymes. To look for new microorganisms which produce laccases that are potentially suitable for industrial applications, we have isolated several fungal strains from a cave in northern Spain. Their phenotypic analysis on agar plates supplemented with ABTS (2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) disclosed two laccase-positive strains. Further genotyping revealed that they belonged to the Gliomastix murorum and Conidiobolus thromboides species. The secretion of G. murorum and C. thromboides laccase-like enzymes was then confirmed by zymography. Further identification of these polypeptides by mass-spectroscopy revealed the nature of the laccases and made it possible to predict their functional domains and other features. In addition, plate assays revealed that the laccases secreted by both G. murorum and C. thromboides were capable of degrading industrial dyes (Congo Red, Indigo, and Eriochrome Black T). Homology modeling and substrate docking predicted the putative structure of the currently uncrystallized G. murorum enzyme as well as its amino acid residues potentially involved in interactions with these dyes. In summary, new biochemical and structural insights into decolorization mediated by G. murorum laccase as well as identification of laccase-like oxidase in C. thromboides point to a promising future for these enzymes in biotechnology.AIOTEK, Grant/Award Number: SPE12UN84; Basque Foundation for Science; Basque Government, Grant/Award Number: PRE-2013-1-90

Encuentro internacional de reflexión y participación Al Otro La'o de la raya: Memoria

Este libro recoge las reflexiones compartidas, así como las propuestas y recomendaciones en torno a los desafíos que plantean las fronteras (la "raya") trazadas a lo largo de la Comarca del Pacífico organizadas según los siguientes ejes temáticos: identidades afrodescendientes en las regiones de frontera; territorialidad, territorios ancestrales y propuestas binacionales; identidad colectiva y memoria compartida; y, finalmente, los caminos de la tradición oral y la memoria