1,721,031 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Medical therapy of patients contaminated with radioactive cesium or iodine
No full textFollow-up studies after the Chernobyl and Fukushima accidents have shown that137Cs and131I made up the major amount of harmful contaminants in the atmospheric dispersion and fallout. Other potential sources for such radionuclide exposure may be terrorist attacks, e.g., via contamination of drinking water reservoirs. A primary purpose of radionuclide mobilization is to minimize the radiation dose. Rapid initiation of treatment of poisoned patients is imperative after a contaminating event. Internal contamination with radioactive material can expose patients to prolonged radiation, thus leading to short-and long-term clinical consequences. After the patient’s emergency conditions are addressed, the treating physicians and assisting experts should assess the amount of radioactive material that has been internalized. This evaluation should include estimation of the radiation dose that is delivered and the specific radionuclides inside the body. These complex assessments warrant the reliance on a multidisciplinary approach that incorporates regional experts in radiation medicine and emergencies. Regional hospitals should have elaborated strategies for the handling of radiation emergencies. If radioactive cesium is a significant pollutant, Prussian blue is the approved antidote for internal detoxification. Upon risks of radioiodine exposure, prophylactic or immediate treatment with potassium iodide tablets is recommended. Chelators developed from calcium salts have been studied for gastrointestinal trapping and enhanced mobilization after strontium exposure
Variations on the Author
No full text“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
Mercury-induced autoimmunity: Drifting from micro to macro concerns on autoimmune disorders
No full textMercury (Hg) is widely recognized as a neurotoxic metal, besides it can also act as a proinflammatory agent and immunostimulant, depending on individual exposure and susceptibility. Mercury exposure may arise from internal body pathways, such as via dental amalgams, preservatives in drugs and vaccines, and seafood consumption, or even from external pathways, i.e., occupational exposure, environmental pollution, and handling of metallic items and cosmetics containing Hg. In susceptible individuals, chronic low Hg exposure may trigger local and systemic inflammation, even exacerbating the already existing autoimmune response in patients with autoimmunity. Mercury exposure can trigger dysfunction of the autoimmune responses and aggravate immunotoxic effects associated with elevated serum autoantibodies titers. The purpose of the present review is to provide a critical overview of the many issues associated with Hg exposure and autoimmunity. In addition, the paper focuses on individual susceptibility and other health effects of Hg
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
A review on coordination properties of thiol-containing chelating agents towards mercury, cadmium, and lead
No full textThe present article reviews the clinical use of thiol-based metal chelators in intoxications and overexposure with mercury (Hg), cadmium (Cd), and lead (Pb). Currently, very few commercially available pharmaceuticals can successfully reduce or prevent the toxicity of these metals. The metal chelator meso-2,3-dimercaptosuccinic acid (DMSA) is considerably less toxic than the classical agent British anti-Lewisite (BAL, 2,3-dimercaptopropanol) and is the recommended agent in poisonings with Pb and organic Hg. Its toxicity is also lower than that of DMPS (dimercaptopropane sulfonate), although DMPS is the recommended agent in acute poisonings with Hg salts. It is suggested that intracellular Cd deposits and cerebral deposits of inorganic Hg, to some extent, can be mobilized by a combination of antidotes, but clinical experience with such combinations are lacking. Alpha-lipoic acid (alpha-LA) has been suggested for toxic metal detoxification but is not considered a drug of choice in clinical practice. The molecular mechanisms and chemical equilibria of complex formation of the chelators with the metal ions Hg2+, Cd2+, and Pb2+ are reviewed since insight into these reactions can provide a basis for further development of therapeutics
Interactions between iron and manganese in neurotoxicity
No full textThe essential and naturally occurring transition metal manganese (Mn) is present in the soil, water, air, and various foods. Manganese can accumulate in the brain if the Mn intake or exposure is excessive and this can result in neurotoxic effects. Manganese is important for the proper activation of different metabolic and antioxidant enzymes. There are numerous Mn importers and exporters. However, the exact transport mechanism for Mn is not fully understood. On the other hand, iron (Fe) is another well-known essential metal, which has redox activity in addition to chemical characteristics resembling those of Mn. Existing data show that interactions occur between Fe and Mn due to certain similarities regarding their mechanisms of the absorption and the transport. It has been disclosed that Mn-specific transporters, together with Fe transporters, regulate the Mn distribution in the brain and other peripheral tissues. In PC12 cells, a significant increase of transferrin receptor (TfR) mRNA expression was linked to Mn exposure and accompanied by elevated Fe uptake. In both humans and animals, there is a strong relationship between Fe and Mn metabolism. In the present review, special attention is paid to the interaction between Mn and Fe. In particular, Fe and Mn distribution, as well as the potential molecular mechanisms of Mn-induced neurotoxicity in cases of Fe deficiency, are discussed
Arsenic toxicity: Molecular targets and therapeutic agents
No full textHigh arsenic (As) levels in food and drinking water, or under some occupational conditions, can precipitate chronic toxicity and in some cases cancer. Millions of people are exposed to unacceptable amounts of As through drinking water and food. Highly exposed individuals may develop acute, subacute, or chronic signs of poisoning, characterized by skin lesions, cardiovascular symptoms, and in some cases, multi-organ failure. Inorganic arsenite(III) and organic arsenicals with the general formula R-As2+ are bound tightly to thiol groups, particularly to vicinal dithiols such as dihydrolipoic acid (DHLA), which together with some seleno-enzymes constitute vulnerable targets for the toxic action of As. In addition, R-As2+-compounds have even higher affinity to selenol groups, e.g., in thioredoxin reductase that also possesses a thiol group vicinal to the selenol. Inhibition of this and other ROS scavenging seleno-enzymes explain the oxidative stress associated with arsenic poisoning. The development of chelating agents, such as the dithiols BAL (dimercaptopropanol), DMPS (dimercapto-propanesulfonate) and DMSA (dimercaptosuccinic acid), took advantage of the fact that As had high affinity towards vicinal dithiols. Primary prevention by reducing exposure of the millions of people exposed to unacceptable As levels should be the prioritized strategy. However, in acute and subacute and even some cases with chronic As poisonings chelation treatment with therapeutic dithiols, in particular DMPS appears promising as regards alleviation of symptoms. In acute cases, initial treatment with BAL combined with DMPS should be considered
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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