1,720,953 research outputs found
Actividad trombolítica del extracto hidroalcohólico de Bougainvillea x buttiana (Var. Rosa) en modelo murino
No full textLa hemostasia es un suceso fisiológico que mantiene la sangre fluida en los vasos sanguíneos,
pero ante una lesión vascular este mecanismo tiene la finalidad de crear un coagulo; una
alteración en este proceso lleva a la formación de trombos. Y su formación está representado
por la integridad de la triada de Virchow, lo cual conduce a graves complicaciones como
infarto al miocardio, infarto cerebral, trombosis venosa y embolia pulmonar que implican
una falta de circulación que en ocasiones conduce a la muerte, siendo así las Enfermedades
Cardiovasculares (ECV), la principal causa de defunción a nivel mundial y tiene un registró
del 21% de defunciones durante el 2018. Se estima que el tromboembolismo pulmonar
corresponde el tercer lugar de morbimortalidad, luego de la enfermedad coronaria y
trombosis cerebral, responsables del 5% de mortalidad global en la población de edad
avanzada. A pesar de las diferentes alternativas quirúrgicas y tratamientos, éstos son de
elevados costos, producen efectos adversos y generan tolerancia en las administraciones
prolongadas. Y el empleo de plantas medicinales sigue siendo una alternativa para los
pacientes, en este contexto, diversos estudios científicos han comprobado diferentes
actividades farmacológicas relacionada con los extractos o compuestos presentes en la
especie Bougainvillea x buttiana (Bxb) como actividad analgésica, antidiabética,
antiinflamatoria, antioxidante y antihistamínica. En este sentido el presente trabajo evaluó la
actividad trombolítica de B. x buttiana (Var. Rosa) a partir del extracto hidroalcohólico en
un modelo murino, en el cual se realizó la determinación del efecto toxicológico agudo
obteniendo que la administración de extracto hidroalcohólico de B. x buttiana (EHABxb) no
causa toxicidad y se requiere dosis mayores a 2,000 mg/Kg de peso para inducir la letalidad.
Posteriormente al ensayo toxicológico, se analizó el ensayo exploratorio a múltiples dosis
del EHABxb mediante la vía oral e intraperitoneal y se evaluó en ratones CD1 en un modelo
de trombosis generado por FeCl3, el EHABxb mostró que la dosis es dependiente en función
del tiempo obteniendo que la DE50 se encuentra entre 50 mg/Kg vía intraperitoneal y 18
mg/Kg vía oral. Además, desde las 24 hasta las 72 horas el EHABxb mostro una disminución
significativa de la actividad trombolítica comparado con el grupo control. El cual, a las 24
horas presentó el coagulo en el modelo murino que fue incrementando en función del tiempo.
Posterior al ensayo trombolítico, se cuantificó el perfil de coagulación de cada grupo
experimental al termino de 3 días de tratamiento, donde se presentó en el FeCl3 un incremento
en los valores de fibrinógeno comparado con el EHABxb y no se mostró cambio de TP y
TPT del EHABxb en via oral e intraperitoneal comparado con los valores basales y los de
referencia; concluido lo anterior, se llevó a cabo el análisis de expresión de citocinas
mostrando que el extracto promueve una mayor actividad antinflamatoria (IL-10) de acuerdo
al balance de citocinas comparada con FeCl3, adicionalmente con la administración el
EHABxb vía intraperitoneal en la expresión de IL-6 se obtuvo una diferencia significativa
comparada con el FeCl3 y además, el extracto tuvo un comportamiento similar al de la
aspirina y heparina utilizados como punto de referencia.ABSTRACT
Hemostasis is a physiological event that keeps blood flowing in blood vessels, but in the
event of vascular injury this mechanism is intended to create a clot; an alteration in this
process leads to thrombus formation. And its formation is represented by the integrity of
Virchow's triad, which leads to serious complications such as myocardial infarction, cerebral
infarction, venous thrombosis and pulmonary embolism involving a lack of circulation that
sometimes leads to death, thus being cardiovascular diseases (CVD), the leading cause of
death worldwide and has a record of 21% of deaths during 2018. It is estimated that
pulmonary thromboembolism is the third leading cause of morbidity and mortality, after
coronary heart disease and cerebral thrombosis, responsible for 5% of overall mortality in
the elderly population. In spite of the different surgical alternatives and treatments, these are
expensive, produce adverse effects and generate tolerance in prolonged administrations. And
the use of medicinal plants remains an alternative for patients, in this context, several
scientific studies have shown different pharmacological activities related to extracts or
compounds present in the species Bougainvillea x buttiana (Bxb) as analgesic, antidiabetic,
anti-inflammatory, antioxidant and antihistamine activity. In this sense, the present work
evaluated the thrombolytic activity of B. x buttiana (Var. Rosa) from the hydroalcoholic
extract in a murine model, in which the acute toxicological effect was determined, obtaining
that the administration of hydroalcoholic extract of B. x buttiana (EHABxb) does not cause
toxicity and doses higher than 2,000 mg/kg body weight are required to induce lethality.
After the toxicological assay, the exploratory multi-dose assay of EHABxb was analyzed by
oral and intraperitoneal routes and evaluated in CD1 mice in a model of thrombosis generated
by FeCl3, EHABxb showed that the dose is time-dependent, obtaining that the DE50 is
between 50 mg/kg intraperitoneal route and 18 mg/kg oral route. Furthermore, from 24 to 72
hours EHABxb showed a significant decrease in thrombolytic activity compared to the
control group. At 24 hours, the coagulum in the murine model presented a clot that increased
as a function of time.
After the thrombolytic assay, the coagulation profile of each experimental group was
quantified at the end of 3 days of treatment, where FeCl3 showed an increase in fibrinogen
values compared to EHABxb and no change in TP and TPT of EHABxb in oral and
intraperitoneal route compared to baseline and reference values; After this, the analysis of
cytokine expression showed that the extract promoted a greater anti-inflammatory activity
(IL-10) according to the cytokine balance compared to FeCl3; additionally, with the
administration of EHABxb intraperitoneally in the expression of IL-6, a significant difference
was obtained compared to FeCl3 and the extract had a behavior similar to that of aspirin and
heparin used as a reference point
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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