1,720,974 research outputs found
Exposure to tio2 nanoparticles increases listeria monocytogenes infection of intestinal epithelial cells
Full text linkTitanium dioxide nanoparticles (TiO2 NPs) are widely used in a variety of consumer products. Cellular exposure to TiO2 NPs results in complex effects on cell physiology that could impact biological systems. We investigated the behavior of Listeria monocytogenes in intestinal epithelial cells pre-treated with either a low or high (1 and 20 μg/cm2) dose of TiO2 NPs. Our results indicate that the pre-treated cells with a low dose became more permissive to listeria infection; indeed, both adhesion and invasion were significantly increased compared to control. Increased invasion seems to be correlated to cytoskeletal alterations induced by nanoparticles, and higher bacterial survival might be due to the high levels of listeriolysin O that protects L. monocytogenes from reactive oxygen species (ROS). The potential risk of increased susceptibility to L. monocytogenes infection related to long-term intake of nanosized TiO2 at low doses should be considered
Seasonal effects on the physico-chemical characteristics of PM2.1 in Rome: a study by SEM and XPS
No full text(A) large body of epidemiological research has shown a significant statistical correlation between acute health effects and the fine fraction of urban particulate (PM2.5). There is still a wide debate over which characteristics of PM are responsible for the adverse health effects. The aim of this study was to evaluate seasonal effects on the composition and physico-chemical characteristics of PM2.1 (particulate with aerodynamic diameter < 2.1 mum) in an urban area of Rome. The role as a "carrier" of carbonaceous particles was thoroughly studied using scanning electron microscopy with an EDS X-ray attachment and photo-electron spectroscopy (XPS). Atmospheric aerosol was analysed by ion chromatography to evaluate the soluble ions collected, by an annular denuder. X-ray microanalysis data were subjected to hierarchical cluster analysis to classify the particles into groups (clusters) of similar chemical composition. We identified four clusters of particles in the PM2.1: carbonaceous particles, soil erosion particles, sulphates and metals. EDX spectra showed the presence of a surface coating containing S or sometimes S, K, Na on a variable percentage of carbonaceous particles. XPS data showed C, O, N, Si, S to be the most abundant elements with only a trace presence of Ca, Na and Fe. XPS spectra in the region of S-2p peak confirm that the sulphur compounds in the PM2.1 are constituted by SO42- anion. The trend of the abundances in weight of S and N obtained by XPS showed an evident peak in summer. A similar summer peak was seen in the abundances of carbonaceous particles with S-coating obtained by SEM/EDX. (C) 2003 Elsevier Ltd. All rights reserved
Video assisted thoracoscopy in thoracic injury: early or delayed indication ?
No full textThe aim of this study was to evaluate the diagnostic role and therapeutic effectiveness of videothoracoscopy in chest trauma. Between 1st January 1993 and 30th September 2003, 112 traumatized patients underwent a videothoracoscopy. The origin of trauma was different: 60 road accidents, 42 accidental falls, 7 knife wounds and 3 firearm wounds. Seventy-six patients presented hemothorax, 21 hemopneumothorax, 10 suspected diaphragmatic injury and 5 pericardium effusion. All patients were hemodynamically stable and conscious. In suspected diaphragmatic rupture patients, videothoracoscopy confirmed the presence of 4 lesions with diameter from 7 to 10cm. The etiopathogenetic causes in the other clinical patterns were: 20 lung lacerations, 17 apical adhesion lacerations, 11 diaphragmatic lesions, 16 wall bleedings and 38 vessel lesions. Ninety patients (80.3%) were treated with video assisted thoracic surgery. The remaining procedures were : 17 drainage tube insertions, 4 thoracotomies and 1 laparotomy. Videothoracoscopy made the use of the primary intention drainage tube obsolete in stable traumatized patients with hemothorax or hemopneumothorax. It is a safe technique that allows the diagnostic and surgical management of the lesions
Giant metastatic small bowel and mesentery localization and pleural secondary to breast cancer. Case report
No full textThe authors present a case of a patient with double metastatic abdominal and thoracic localization coming from breast cancer. Peculiarity of this case concerns both the considerable size of metastatic abdominal mass (11 centimetres of the major axis for a weight of almost half a kilogram) and the swift development of the relapses at distance, even in the presence of an original tumour at first stage. Both abdominal surgical operation of the removal of the mass and diagnostic video assisted thoracoscopy (VAT) are described
ZnO nanoparticle tracking from uptake to genotoxic damage in human colon carcinoma cells
No full textZinc Oxide (ZnO) nanoparticles are widely used both in the industry and in biomedical applications for their chemical and physical nanomaterial properties. It is therefore essential to go in depth into the cytotoxicity mechanisms and interactions between nanomaterials and cells. The aim of this work was to evaluate the dissolution of ZnO nanoparticles and their uptake, from a few minutes after treatments up to 24 h. ZnO nanoparticles routes of entry into the human colon carcinoma cells (LoVo) were followed at different times by a thorough ultrastructural investigation and semiquantitative analysis. The intracellular release of Zn2 + ions by Zinquin fluorescent dye, and phosphorylated histone H2AX (γ-H2AX) expression were evaluated. The genotoxic potential of ZnO nanoparticles was also investigated by determining the levels of 8-hydroxyl-2′-deoxyguanosine (8-oxodG). The experimental data show that ZnO nanoparticles entered LoVo cells by either passive diffusion or endocytosis or both, depending on the agglomeration state of the nanomaterial. ZnO nanoparticles coming into contact with acid pH of lysosomes altered organelles structure, resulting in the release of Zn2 + ions. The simultaneous presence of ZnO nanoparticles and Zn2 + ions in the LoVo cells determined the formation of reactive oxygen species at the mitochondrial and nuclear level, inducing severe DNA damage
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
