bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibacterial Effects of Six Endodontic Sealers
Authors: Poggio Claudio , Lombardini Marco , Colombo Marco , Dagna Alberto , Saino Enrica , Arciola Carla Renata , Visai Livia 
Published: November 2011

Purpose The objective of this study was to perform an in vitro evaluation of the antibacterial properties of 6 endodontic sealers (Endomethasone C, Argoseal, Bioseal Normal, Acroseal, AH Plus, Sicura Seal). Methods The agar diffusion test (well and paper disc methods) with Enterococcus faecalis, Staphylococcus aureus and Streptococcus mutans was used. For the well method, Petri dishes were inoculated with bacterial suspensions. Each well was completely filled with freshly mixed endodontic sealer. For the paper disc method, sterile paper discs were immersed in freshly mixed sealers and put on agar plates. Diameters of halos formed around the sealers were measured after 24 h and 48 h. Statistical analysis: The effects of well method and of paper disc method were analyzed by 1-way ANOVA. Results Endomethasone C, Argoseal and Bioseal showed the largest inhibition halos for all the tested microorganisms, while Sicura Seal and AH Plus showed low antibacterial effects. Moreover, the comparison of well method and paper disc methods showed significant statistical differences (P<0,01) for all sealers and indicated a dose-dependent antimicrobial effect.
Photoactivated Disinfection (PAD) in Endodontics: an in vitro Microbiological Evaluation
Authors: Poggio Claudio , Arciola Carla Renata , Dagna Alberto , Florindi Filippo , Chiesa Marco , Saino Enrica , Imbriani Marcello , Visai Livia 
Published: November 2011

Purpose The objective of the present study was the in vitro evaluation by MTT test of the antimicrobial effect of photoactivated disinfection (PAD) and, comparatively, of a conventional 5.25% NaOCl irrigating solution. Methods Enterococcus faecalis, Streptococcus mutans and Streptococcus sanguis strains were selected for the test. Freshly extracted single-rooted human teeth were endodontically treated, inoculated with bacterial strains and then divided into different groups, each of them treated with PAD, with PAD plus 0.5% NaOCl solution, with TBO, with PAD for longer time and with 5% NaOCl solution (positive control). Results The results were significantly different among the various groups, and for Enterococcus faecalis, Streptococcus mutans and Streptococcus sanguis. PAD applied for a longer time (in respect to manufacturer's instructions) or PAD associated to 5% NaOCl showed the significantly higher antibacterial effects.
Biofilm Growth on Implants: Bacteria Prefer Plasma Coats
Authors: Wagner Christof , Aytac Sara , Hänsch G. Maria 
Published: November 2011

Purpose Bacterial biofilm formation on prostheses or devices used for osteosynthesis is increasingly recognized as cause of persistent infections, an entity known as implant-associated posttraumatic osteomyelitis. Biofilm formation is a very complex, multistep process with adhesion as the first and decisive step. The most prevalent pathogens found are staphylococci species, especially S. aureus, presumably due to a preference to non-biological materials, such as metal. Adherence is influenced by several factors, including the microenvironment, in which blood proteins from serum or plasma might influence adhesion and maybe biofilm formation. The aim of the present study was to test and to compare adherence of S. aureus and P. aeruginosa to different biological and non-biological surfaces in vitro. The question was addressed if coating of the surface by plasma or serum proteins influences bacterial adherence. Methods Adherence of radiolabeled bacteria to different surfaces in the presence or absence or serum/plasma proteins was measured over time. Results When testing adherence of S. aureus to plastic, titanium or to monolayers of epithelial cells (A549) or fibroblasts (Colo800) a clear-cut preference for non-biological surfaces, especially for titanium was seen. Using P. aeruginosa species a similar pattern without a significant difference was revealed. When mimicking the in vivo situation by pre-coating of titanium with human serum or plasma adherence was increased, especially when titanium was coated (“opsonized”) by plasma. Conclusions Bacterial adherence to surfaces is determined by a variety of factors such as temperature, the presence of nutrients, the absence of host defense systems and the configuration of the covered surface. In vivo, adherence to non-biological surfaces is also influenced by the microenvironment, especially plasma proteins, promoting biofilm formation.
Análisis numérico de la convección natural en recintos cerrados con distinto factor de forma
Authors: Lizardi A , Hernández A , Terrés H , López R , Morales JR , Lara A 
Published: November 2011

En este trabajo se utilizó el análisis numérico, aplicando el programa de simulación para ingeniería ANSYS, para establecer la distribución de temperaturas, densidad y velocidades vertical y horizontal en una cavidad cerrada con relación geométrica alto/ancho (H/E) del sistema de 0.5, 1 y 2, temperatura constante en la pared vertical izquierda y derecha de 50 y 20 °C, respectivamente, y condición de frontera adiabática en las paredes horizontales. Lo anterior para un número de Prandtl de 4.83 y Rayleigh de 5.84x107. Al comparar los resultados entre el sistema con H/E = 2 y H/E = 1, se encontró que el valor máximo positivo de la velocidad vertical se incrementó un 26.29 %, el de la velocidad horizontal disminuyó 72.75 % y la temperatura en la zona central de la cavidad disminuyó un 2.46 %. Por otro lado, al comparar los resultados del sistema H/E = 0.5 y H/E = 1, se encontró que el valor máximo positivo de la velocidad vertical aumentó un 7.24 %, el de la velocidad horizontal se incrementó 34.08 % y la temperatura de la zona central del sistema disminuyó un 3.70 %. Palabras claves: Convección natural; Cavidad cerrada; ANSYS DOI: http://dx.doi.org/10.5377/nexo.v24i1.589 Nexo, Vol. 24, No. 1, pp. 3-10, 2011
Nuevas aportaciones a la gestión informatizada de derrames de hidrocarburos: su aplicación a "zonas refugio"
Authors: Bergueiro JR , Moreno S , Hernández L , Cavilla JM , Gómez JJ , González J 
Published: November 2011

El objeto del presente trabajo es el de describir la mayor parte de los procedimientos a seguir para decidir si es aconsejable trasladar un petrolero siniestrado a una “zona refugio”. Para tomar esta decisión se deberán considerar diferentes procedimientos, con la finalidad de objetivizar al máximo dicha decisión. Es de gran importancia conocer muy bien las características y las infraestructuras de las diferentes zonas costeras que pueden ser consideradas posibles “zonas refugio”. En base a todo lo anterior, se ha desarrollado un programa formado por varios módulos que permiten obtener datos de gran importancia, entre los que se incluyen las matrices de valores ambientales e infraestructurales, y que permite el cálculo de determinados factores determinantes para las actuaciones de traslado y preparación del petrolero (tiempo de traslado del petrolero, tiempo de atraque y conexión a los sistemas de bombeo, tiempo de vaciado de los hidrocarburos a los depósitos de almacenamiento, trasvase a otro petrolero, etc.). Además, dicho programa permite estimar los costes de limpieza y restauración, así como las pérdidas en el sector turístico. Palabras claves: Hidrocarburos; Zona refugio; Derrames de hidrocarburos DOI: http://dx.doi.org/10.5377/nexo.v24i1.590 Nexo, Vol. 24, No. 1, pp. 11-19, 2011
Estudio de la cinética de adsorción de Cu y Hg a partir de soluciones binarias usando quitosano
Authors: Matus I , Paniagua L , Benavente M 
Published: November 2011

En este trabajo se estudió la cinética de adsorción de Cu(II) y Hg(II) en quitosano a partir de una solución binaria, a diferentes concentraciones iniciales de los iones metálicos, tamaño de partículas del adsorbente y velocidad de agitación. El quitosano fue extraído por métodos químicos de caparazón de camarón. Soluciones de 1 L de Cu(II) y Hg(II) fueron puestas en contacto con 2 g de quitosano y se agitaron por un período de 8 h. Al final del proceso, las muestras fueron analizadas en un espectrómetro de absorción atómica. Los datos experimentales fueron evaluados aplicando los modelos cinéticos de pseudo-primer orden y pseudo-segundo orden. Los resultados del proceso de adsorción de los iones metálicos Cu(II) y Hg(II) con quitosano, mostraron que en la mayoría de los casos, ambos iones fueron eficazmente adsorbidos por la quitosano, obteniéndose un porcentaje de adsorción entre 44-100 % para Cu(II) y entre 95-100 % para el Hg(II). Para ambos iones, los resultados mostraron que a bajas concentraciones el proceso de adsorción se ajusta mejor al modelo de pseudo-primer orden y a concentraciones altas el modelo que mejor se ajusta a los datos experimentales es el modelo de pseudo-segundo orden; es decir, el paso limitante en la velocidad es la reacción de adsorción y no la transferencia de masa. Palabras claves: Caparazón de camarón; Cinética de adsorción; Modelos cinéticos; Solución binaria; Quitosano DOI: http://dx.doi.org/10.5377/nexo.v24i1.591 Nexo, Vol. 24, No. 1, pp. 20-32, 2011
Estudio de la fermentación láctica para la extracción de quitina a partir de desechos de crustáceos
Authors: Marcia E , Malespín J , Sánchez M , Benavente M 
Published: November 2011

La extracción de quitina a partir de desechos de crustáceos involucró la fermentación acido láctica para la desproteinización y desmineralización del caparazón de camarón, haciendo uso de suero de leche y sacarosa, como sustrato y fuente de carbono. El proceso de fermentación se llevo a cabo en un reactor vertical de vidrio Pyrex de 4 L por un período de 2 y 3 semanas a temperatura ambiente. Los resultados mostraron que aunque hubo una buena desproteinización y desmineralización, todavía el producto contenía restos de proteínas y pigmentos. Por ello, se hizo necesario aplicar un procedimiento químico con hidróxido de sodio e hipoclorito de sodio, para remover completamente las proteínas y los pigmentos de la estructura del caparazón. Al final del proceso se obtuvo una recuperación del 85 %. La comparación de los espectros FT-IR de la quitina producida con una muestra de quitina comercial, mostró un porcentaje de correlación del 93-95 %, lo que indica que la quitina obtenida utilizando el método combinado, tiene un alto grado de pureza. Palabras claves: Caparazón de camarón; Quitina; Reactor vertical; Sacarosa; Suero de leche DOI: http://dx.doi.org/10.5377/nexo.v24i1.592 Nexo, Vol. 24, No. 1, pp. 33-42, 2011
Salar de Surire un ecosistema altoandino en peligro, frente a escenario del cambio climático
Authors: Garcés I 
Published: November 2011

Este trabajo realiza un análisis al salar de Surire desde el punto de vista de la biodiversidad y sus implicancias producto del cambio climático. Como resultado se predice que los próximos años serán secos y la temperatura podría ir en aumento, lo cual afectará notablemente a la flora y fauna del altiplano. El salar de Surire es un cuerpo salino ubicado en el altiplano andino chileno, en un entorno geológico de características volcánicas. La climatología actual de aridez no permite una acumulación de agua superficial de gran extensión, y por lo tanto es posible diferenciar tres tipos principales de aguas: los aportes de drenaje, las acumulaciones de agua en la aureola pantanosa externa o “bofedales”, y las aguas del interior del cuerpo salino (surgencias termales y salmueras). Estas condiciones hidrológicas afectan factores abióticos, como anaerobiosis de suelos, disposición de nutrientes y salinidad, factores determinantes del desarrollo de la flora y fauna. Palabras claves: Salar de Surire; Biodiversidad andina; Cambio climático; Ecosistema andino DOI: http://dx.doi.org/10.5377/nexo.v24i1.593 Nexo, Vol. 24, No. 1, pp. 43-49, 2011
Simulación y experimentación de laminación plana de placas de aluminio 6063
Authors: Robert T , Vázquez O , López E 
Published: November 2011

Se generó una metodología experimental para el entendimiento teórico-práctico de los conceptos del proceso de laminación plana en frío. Se laminaron placas de aluminio de aproximadamente 100 mm de longitud y 9 mm de espesor, a diferentes anchos: 10 y 30 mm. Se seleccionó una razón de reducción constante de 0.3 mm para cada paso de laminación, hasta lograr una reducción superior al 80 % en espesor. Se implementó un modelo matemático en el paquete comercial Abaqus® con el fin de obtener un mayor entendimiento sobre la influencia de las variables del proceso (fuerza aplicada y dimensiones de las probetas) en los campos de esfuerzos y deformaciones que, experimentalmente, no se pueden observar. Se encontró, mediante la simulación matemática, que se produce un endurecimiento superficial en las placas y que la deformación obtenida es heterogénea, lo cual se corrobora físicamente. Palabras claves: Laminación plana; Aluminio 6063-Al; Sistema de adquisición de datos; Simulación DOI: http://dx.doi.org/10.5377/nexo.v24i1.594 Nexo, Vol. 24, No. 1, pp. 50-60, 2011
The red queen and her king: Cooperation at all levels of life
Authors: Weiss Kenneth M. , Buchanan Anne V. , Lambert Brian W. 
Published: November 2011

AbstractThe Red Queen in “Through the Looking Glass” is often used as a metaphor for the relentless, unremitting competitive struggle by which Darwin described life. That imagery fits comfortably in our culture, with its emphasis on competition and inequity, but less so for nature herself. Life is manifestly much more about cooperation, at all levels and through a variety of ubiquitous mechanisms, than it is about competition. Most organisms of most species are nowhere near the proverbial Malthusian edge of survival, such that selection will detect the tiniest difference in their performance and enhance its genetic basis. Cooperation through interaction of multiple entities is inherent in many fundamental aspects of life, and its importance is not widely enough appreciated. Here we discuss a set of principles by which this works. We illustrate the points with a computer simulation of a topic of interest to anthropology, the development of the head. In a sense, our culture has its metaphors reversed. The red royal family is a more accurate symbol for the true nature of life, human or otherwise. Yrbk Phys Anthropol 54:3–18, 2011. © 2011 Wiley Periodicals, Inc.
GIS and paleoanthropology: Incorporating new approaches from the geospatial sciences in the analysis of primate and human evolution
Authors: Anemone R.L. , Conroy G.C. , Emerson C.W. 
Published: November 2011

AbstractThe incorporation of research tools and analytical approaches from the geospatial sciences is a welcome trend for the study of primate and human evolution. The use of remote sensing (RS) imagery and geographic information systems (GIS) allows vertebrate paleontologists, paleoanthropologists, and functional morphologists to study fossil localities, landscapes, and individual specimens in new and innovative ways that recognize and analyze the spatial nature of much paleoanthropological data. Whether one is interested in locating and mapping fossiliferous rock units in the field, creating a searchable and georeferenced database to catalog fossil localities and specimens, or studying the functional morphology of fossil teeth, bones, or artifacts, the new geospatial sciences provide an essential element in modern paleoanthropological inquiry. In this article we review recent successful applications of RS and GIS within paleoanthropology and related fields and argue for the importance of these methods for the study of human evolution in the twenty first century. We argue that the time has come for inclusion of geospatial specialists in all interdisciplinary field research in paleoanthropology, and suggest some promising areas of development and application of the methods of geospatial science to the science of human evolution. Yrbk Phys Anthropol 54:19–46, 2011. © 2011 Wiley Periodicals, Inc.
The roles of the immune system in Women's reproduction: Evolutionary constraints and life history trade‐offs
Authors: Abrams Elizabeth T. , Miller Elizabeth M. 
Published: November 2011

AbstractLife history theory posits that, as long as survival is assured, finite resources are available for reproduction, maintenance, and growth/storage. To maximize lifetime reproductive success, resources are subject to trade‐offs both within individuals and between current and future investment. For women, reproducing is costly and time‐consuming; the bulk of available resources must be allocated to reproduction at the expense of more flexible systems like immune function. When reproducing women contract infectious diseases, the resources required for immune activation can fundamentally shift the patterns of resource allocation. Adding to the complexity of the reproductive‐immune trade‐offs in women are the pleiotropic effects of many immune factors, which were modified to serve key roles in mammalian reproduction. In this review, we explore the complex intersections between immune function and female reproduction to situate proximate immunological processes within a life history framework. After a brief overview of the immune system, we discuss some important physiological roles of immune factors in women's reproduction and the conflicts that may arise when these factors must play dual roles. We then discuss the influence of reproductive‐immune trade‐offs on the patterning of lifetime reproductive success: (1) the effect of immune activation/infectious disease on the timing of life history events; (2) the role of the immune system, immune activation, and infectious disease on resource allocation within individual reproductive events, particularly pregnancy; and (3) the role of the immune system in shaping the offspring's patterns of future life history trade‐offs. We close with a discussion of future directions in reproductive immunology for anthropologists. Yrbk Phys Anthropol 54:134–154, 2011. © 2011 Wiley Periodicals, Inc.
Brief communication: Enamel thickness and durophagy in mangabeys revisited
Authors: McGraw W. Scott , Pampush James D. , Daegling David J. 
Published: November 2011

AbstractThe documentation of enamel thickness variation across primates is important because enamel thickness has both taxonomic and functional relevance. The Old World monkeys commonly referred to as mangabeys have figured prominently in investigations of feeding ecology and enamel thickness. In this article, we report enamel thickness values for four mangabey taxa (Cercocebus atys, Cercocebus torquatus, Lophocebus aterrimus, and Lophocebus albigena), offer revised interpretation of the significance of thick enamel in papionin evolution, and place our new data in a broader comparative framework. Our data indicate that all mangabeys have thick enamel and that the values obtained for Cercocebus and Lophocebus equal or exceed those published for most extant non‐human primates. In addition, new field data combined with a current reading of the dietary literature indicate that hard foods make up a portion of the diet of every mangabey species sampled to date. Clarification on the relationship between diet and enamel thickness among mangabeys is important not only because of recognition that mangabeys are not a natural group but also because of recent arguments that explain thick enamel as an evolved response to the seasonal consumption of hard foods. Am J Phys Anthropol 147:326–333, 2012. © 2011 Wiley Periodicals, Inc.
Spatial and temporal ecological diversity amongst eocene primates of france: Evidence from teeth
Authors: Ramdarshan Anusha , Merceron Gildas , Marivaux Laurent 
Published: November 2011

AbstractDiet is of paramount importance in the life of a primate. It is also highly variable, as potential food sources vary in spatial distribution and availability over time. The fossil record, due to its fragmentary nature, offers few possibilities to assess the dietary range of a given primate across its spatial and temporal distribution. Here we focus on three taxa, Leptadapis magnus (Adapidae, Adapiformes), Necrolemur cf. antiquus (Microchoeridae, Omomyiformes), and Pseudoloris parvulus (Microchoeridae, Omomyiformes). These taxa occur at different localities of the Late Eocene in the south of France ranging from MP16 (Robiac, Lavergne; 39 Ma), MP17a (La Bouffie, Euzet, Fons 4; 38 Ma) to MP17b (Perrière; 37 Ma). Diets of fossil taxa are assessed here by dental microwear analysis using a comparative database of 11 species of living strepsirhines. On the whole, leaves were a preferred food for the large‐bodied Leptadapis (4–5 kg). However, the diet of this taxon varied from a mix of leaves and fruit at La Bouffie, a closed tropical rain forest environment, to a strictly leaf‐eating one in the more open environment of Perrière. Based on body mass (200–350 g) and dental microwear patterns, Necrolemur had a mainly fruit‐based diet, perhaps supplemented by insects. However, the comparison of the different localities reveals the dietary range of this small‐bodied omomyiform which seems to vary between insects and a much softer diet. Pseudoloris had a diet strictly based on insects. Contrary to Leptadapis or Necrolemur, its diet seems to have been confined to insects whatever the locality considered. Am J Phys Anthropol 147:201–216, 2012. © 2011 Wiley Periodicals, Inc.
Descriptive epidemiology of selected heritable birth defects in Texas
Authors: Moffitt Karen B. , Abiri Oseni O. , Scheuerle Angela E. , Langlois Peter H. 
Published: November 2011

AbstractBACKGROUND Few population‐based studies exist on descriptive epidemiologic characteristics of rare heritable birth defects. The number of birth defect cases in the Texas Birth Defects Registry (one of the largest active birth defects surveillance systems in the world) enabled us to examine six different heritable disorders (aqueductal stenosis, infantile polycystic kidney disease, achondroplasia, thanatophoric dwarfism, chondrodysplasia/dwarfism not otherwise specified (NOS), and osteogenesis imperfecta) for a variety of descriptive demographic variables. METHODS The Texas Birth Defects Registry was used to identify infants or fetuses with heritable birth defects. Crude prevalence rates were calculated and Poisson regression was used to test the association of each demographic variable (e.g., maternal age) with each of the selected genetic birth defects. RESULTS White non‐Hispanics exhibited higher rates of achondroplasia and osteogenesis imperfecta than other race/ethnic groups. Lower maternal education level and to a lesser extent, paternal education level, was associated with higher rates of several disorders. The birth prevalence rate for achondroplasia decreased from 1999 through 2006. CONCLUSION The use of a large birth defects registry provides a sufficient count of cases to perform some basic epidemiologic analysis on selected rare heritable birth defects. Birth Defects Research (Part A) 2011. © 2011 Wiley Periodicals, Inc.