1,721,000 research outputs found
Nano-imaging of environmental dust in human lung tissue by soft and hard X-ray fluorescence microscopy
Full text linkIt is well recognized that a large number of pulmonary diseases are induced by the effects of inhaled particulates. Anthracosis is defined as an asymptomatic, mild form of pneumoconiosis caused by the accumulation of “black carbon” in the lungs due to repeated exposure to air pollution or inhalation of smoke or coal dust particles. Since the human population is progressively exposed to an increasing number and doses of anthropogenic micro and nano particles/compounds, there is a pressing urgency to explore toxicological impact arising from these exposures and the molecular mechanisms driving the body defense or possible related diseases. The toxicity mechanisms are clearly related to chemical composition and physical and surface properties of materials. A combination of synchrotron radiation-based (SR-based) nano X-ray fluorescence (XRF) imaging and soft X-ray microscopy was used to chemically characterize environmental particulates (anthracosis) in lung tissues from urban subjects with the aim of better understanding the complex nature of related lungs' deposits. High-resolution XRF analyses performed at ESRF and Elettra synchrotrons allowed discriminating single particles in the heterogeneous aggregates found in the lung tissue. The small particles have variable composition resulting from the different combinations of Ti with O, K and Si, Al and Si, or Zn and Fe with O. Interestingly, simultaneous absorption and phase contrast images showed the particulate morphology and allowed to predict the presence of very dense nanoparticles or high concentration of heavy elements
Gene expression of ABC proteins in hepatocellular carcinoma, perineoplastic tissue and liver diseases
No full textBACKGROUND: The development of hepatocellular carcinoma (HCC) is a frequent event during the natural history of cirrhosis. Effective treatment is, however, hampered by drug resistance related to the expression of multidrug resistance (MDR) proteins belonging to the ABC family transporters. Studying expression of genes coding for these proteins may help to explain the potential sensitivity of HCC to chemotherapy.
MATERIAL AND METHODS:The expression of MRP1, MRP2, MRP3, MDR1, and MDR3 was investigated by quantitative RT-PCR analyses in paraffin-embedded tissues obtained from 9 cases of HCC, 16 cases of cirrhosis, 10 cases of chronic extrahepatic cholestasis, and 16 cases of normal liver. In HCC cases, gene expression was assessed both in neoplastic and perineoplastic tissue after microscopically assisted microdissection.
RESULTS: MRP1 was significantly and similarly overexpressed in HCC and perineoplastic tissue. MRP2 and MDR1 were also increased in HCC, but the level of expression did not correlate with that of perineoplastic tissue. The level of expression was either reduced or normal in cirrhotic liver and during chronic cholestasis. Expression of MDR3 was unchanged in all conditions investigated.
CONCLUSIONS: The genetic expression of multi-drug resistance proteins, in particular MRP1, MRP2, and MDR1, is increased during HCC. In the case of MRP1, the extent of expression is similar in neoplastic and perineoplastic tissue, but this is not the case for MRP2 and MDR1. The assessment of ABC protein expression pattern may provide important information for the diagnosis and treatment of HCC
Recent achievements in reproductive medicine applications at the TwinMic soft spectromicroscopy beamline of Elettra
No full textWe present here two reproductive medicine studies at the TwinMic soft spectromicroscopy beamline of Elettra Synchrotron (Trieste, Italy), which can open new opportunities for more direct clinical applications. In particular we demonstrate the TwinMic imaging capabilities for monitoring ovarian tissue preservation and follicles quality and to investigate of chemical changes in sperm undergoing oxidative stress conditions and iron toxicity
The human Multidrug Resistance-associated Protein MRP1 mediates ATP-dependent transport of unconjugated bilirubin
No full textREASSESSMENT OF THE UNBOUND CONCENTRATIONS OF UNCONJUGATED BILIRUBIN IN RELATION TO NEUROTOXICITY IN VITRO.
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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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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