Caracterización de algunos nuevos complejos de Fe (II) en alto spin, con tioureas substituidas como ligantes

El estudio de nuevos complejos de Fe (Il) en alto spin con tioureas, utilizando X = ClO4 o BF4 como aniones, muestra que sólo hay complejos de fórmula [FeL6 X 2] cuando L = tiourea, N-metiltiourea, N-etiltiourea, N-N'-di-n-propiltiourea o N,N'-diciclohexiltiourea. Cuando el ligante es N,N'dimetiltiourea (DMTU) o N ,N'-dietiltiourea (DETU) se observa la formación de complejos de fórmula [Fe (DMTU)n (BF4)2] (n = 4, 5 ó 7), [Fe (DMTU)n (ClO4 } 2 ) (n = 4 ó 6) y [Fe (DETUJn X2 ](n = 4 ó 6). En la caracterización de estos complejos, mediante espectroscopia IR, electrónica y Mossbauer, se encontraron complejos tetraédricos ([FeL4 X2 ]), octaédricos ( [FeL 6 X2 ]) y [Fe (DMTU)6 • (BF4}2 • DMTU]) y pentacoordinados ([Fe (DMTU)5 (BF4)2 ))

Interpretación de los espectros Mössbauer y electrónicos de un complejo pentacoordinado de Fe (II) en alto spin

En este trabajo se ha calculado el desdoblamiento de los orbitales 3d y de los términos del Fe (II) libre, en un campo cristalino de una pirámide de base cuadrada distorsionada, para poder interpretar los espectros Mossbauer y electrónicos del complejo [Fe (N,N'-dimetiltiourea)5 ] ( BF4 )2. Dichos espectros son explicados satisfactoriamente considerando que el átomo metálico se encuentra sobre el plano basal, de manera que el orden de energía de los orbitales 3d es dxy < dxz, dyz < dz2 < dx2 y2

Zoonotic parasites in dog feces in Bahía Blanca city

[En Comunicaciones breves de la Revista Argentina de Zoonosis y Enfermedades Infecciosas Emergentes] Existe una gran cantidad de agentes infecciosos transmisibles entre el perro doméstico (Canis lupus familiaris) y el hombre. Entre estos se encuentran enteroparásitos, algunos de los cuales representan un riesgo para la salud pública aún en países desarrollados. La ciudad de Bahía Blanca, en Argentina, tiene una población de 301.531 habitantes distribuidos en 126.639 hogares. Asimismo, existen 83 centros de atención veterinaria (1 veterinaria cada 1.526 hogares) y aproximadamente 68.000 perros (18.000 sin dueño y 50.000 con dueño)2 a razón de (2.25 perros cada 10 habitantes). De acuerdo a la Organización Mundial de la Salud, la población canina de esta ciudad se encontraría1,25 veces (125%) por encima del límite máximo recomendado (1 perro cada 10 habitantes), lo cual genera preocupación desde el punto de vista de la salud pública y bienestar animal. Por lo tanto, el objetivo de este estudio fue estimar la prevalencia de diferentes parásitos de importancia zoonótica en la ciudad de Bahía Blanca bajo las hipótesis de que (1) la prevalencia de parasitosis entéricas se distribuye de forma heterogénea en barrios de la ciudad; (2) la calidad de vida en cada barrio se correlaciona de forma positiva con la cantidad de centros de atención veterinaria en el mismo; (3) la prevalencia parasitaria a nivel de barrio se asocia a la calidad de vida en el mismo.Fil: la Sala, Luciano Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahia Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Catedra de Parasitologia Clinica; ArgentinaFil: Costamagna, Sixto R.. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Catedra de Parasitologia Clinica; ArgentinaFil: Leiboff, Anastasia. Universidad Nacional del Sur. Departamento de Biologia, Bioquimica y Farmacia. Catedra de Parasitologia Clinica; Argentin

Melting of Partially Fluorinated Graphene: From Detachment of Fluorine Atoms to Large Defects and Random Coils

The melting of fluorographene is very unusual and depends strongly on the degree of fluorination. For temperatures below 1000 K, fully fluorinated graphene (FFG) is thermo-mechanically more stable than graphene but at T$_m\approx$2800 K FFG transits to random coils which is almost twice lower than the melting temperature of graphene, i.e. 5300 K. For fluorinated graphene (PFG) up to 30 % ripples causes detachment of individual F-atoms around 2000 K while for 40-60 % fluorination, large defects are formed beyond 1500 K and beyond 60% of fluorination F-atoms remain bonded to graphene until melting. The results agree with recent experiments on the dependence of the reversibility of the fluorination process on the percentage of fluorination.Comment: 16 pages, 6 figure

Enteroscopic Balloon Dilation of Multiple Ileal Strictures in Suspected Crohn's Disease

AbstractWith the advent of small bowel enteroscopy, the limits to the endoscopic access to the small bowel have been further exceeded, allowing histology sampling and therapeutical maneuvers. This conquest is of crucial meaning in small bowel inflammatory diseases. In this setting, enteroscopy may lead to a definite diagnosis, overcoming the limits of the anatomic disease location and of other (radiological and endoscopic imaging) techniques. Furthermore, enteroscopy permits strictures visualization and dilation, reducing or postponing the need for surgery. In this article the authors demonstrate the technique of hydrostatic balloon dilation of small bowel strictures suggestive of Crohn's disease in a patient suffering from persistent obscure gastrointestinal bleeding. This article is part of an expert video encyclopedia

Damage and contour quality in rock excavations for quarrying and tunnelling: assessment for properties and solutions for stability

This is the author accepted manuscript.Excavations in rock masses determine the creation of temporary or final exposed surfaces. Features of these surfaces are depending on both geostructural pattern of the rock mass and adopted excavation method: among the others, roughness, quality of the contour and induced damage inside the rock left in place. These aspects are important as they are requirements expected during the excavation and construction procedures, such those involving dam sidewalls, quarry benches, tunnel profile, slope scaling. This methodological paper describes a list of the possible cases, with a particular emphasis on quarrying and tunneling. By following current modes for profile surveying, the damages are reported, in order to obtain suitable indices for induced damage. Finally the proper techniques for excavation are commented on the basis of real case histories of tunnels and quarries in order to reach the primary objectives of damage reduction and stability/productivity goals

Local factors have a greater influence on the abundance of alfalfa weevil and its larval parasitoids than landscape complexity in heterogeneous landscapes

Context The alfalfa weevil Hypera postica Gyllenhal (Coleoptera: Curculionidae) is one of the most destructive pests of alfalfa worldwide. Both local and landscape-scale factors can significantly infuence crop pests, natural enemies, and the efectiveness of biological control services, but the relative infuence of these factors is unclear. Objectives We investigated the infuence of the local variables and surrounding landscape composition and configuration on the abundance of alfalfa weevil, and on the abundance and parasitism rates of its larval parasitoids, Bathyplectes spp. Methods We sampled 65 commercial alfalfa fields along the Ebro Basin, Spain, over a period of 3 years, recording the field characteristics and landscape structure at three buffer radii of 250, 500 and 1000 m from the center of each field. Results The abundance of weevil larvae was positively associated with the field perimeter and with the uncut alfalfa surrounding the pipes of the sprinkler irrigation system, but only one configuration variable was positively correlated: the alfalfa edge density. No local characteristics or landscape structures were associated with the abundance of adult weevils. The abundance of Bathyplectes spp. adults was positively associated to local factors such as the densities of alfalfa weevils and aphids. Few landscape structure variables, such as alfalfa edge density and Simpson’s Diversity Index, had explanatory value only at 250 m buffer radius. The rate of larval parasitism was affected by local variables, such as alfalfa weevil abundance and field age. Conclusion Our results provide, for the first time in the Mediterranean region and Europe, evidence of the relative importance of landscape structure and local factors on the abundance of the alfalfa weevil and its larval parasitoids, Bathyplectes spp. The strongest infuences were based on local characteristics.Springer Nature; Spanish Government; Universitat de Lleida; Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/publishedVersio