1,720,987 research outputs found
Mesenchymal stem cells: from biology to clinical use.
No full textStem cells are immature progenitor cells capable of self-renewal and multilineage differentiation through a process
of asymmetric mitosis that leads to two daughter cells, one
identical to the stem cell and one capable of differentiation
into more mature cells. Stem cells may be: 1) totipotent, i.e. early embryonic cells (1-3 days from oocyte fertilization), which can give rise to all the embryonic tissues and placenta; 2) pluripotent, i.e. embryonic cells from blastocystis (days 4-14 after oocyte fertilization), which can differentiate only into embryonic tissues belonging to the inner cell mass (ectoderm, mesoderm, and endoderm); or 3) multipotent, i.e. embryonic cells from the 14th day onwards, fetal stem cells, cord blood stem cells, and adult stem cells, which can give rise only to tissues belonging to one embryonic germ layer (ectoderm or mesoderm or endoderm).
Mesenchymal stem cells (MSC) are non-haematopoietic
cell precursors initially found in the bone marrow, but
actually present in many other tissues. MSC in culture are
adherent, proliferating, and capable of multilineage
differentiation into several tissues of mesenchymal origin,
such as bone marrow stroma, adipose tissue, bone,
cartilage, tendon, skeletal muscle, visceral mesoderm, and
endothelial cells1-5. Well known and used for bone
regeneration for many years, MSC came in the limelight at
the end of the 1990s thanks to the evidence that, despite
their adult stem cell nature, these cells are capable of
pluripotent differentiation, which may be useful for
regenerative medicine. In addition, since the beginning of
2000 it has become clear that MSC possess immune
regulatory properties that may make them useful in
autoimmune diseases
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
Group specific component and susceptibility to acquired immunodeficiency syndrome in patients with HIV infection.
No full textVariations 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
Chagas disease and transfusion medicine: a perspective from non-endemic countries
No full textIn the last decades, increasing international migration and travel from Latin America to Europe have favoured the emergence of tropical diseases outside their "historical" boundaries. Chagas disease, a zoonosis endemic in rural areas of Central and South America represents a clear example of this phenomenon. In the absence of the vector, one of the potential modes of transmission of Chagas disease in non-endemic regions is through blood and blood products. As most patients with Chagas disease are asymptomatic and unaware of their condition, in case of blood donation they can inadvertently represent a serious threat to the safety of the blood supply in non-endemic areas. Since the first cases of transfusion-transmitted Chagas disease were described in the last years, non-endemic countries began to develop ad hoc strategies to prevent and control the spread of the infection. United States, Spain, United Kingdom and France first recognised the need for Trypanosoma cruzi screening in at-risk blood donors. In this review, we trace an up-to-date perspective on Chagas disease, describing its peculiar features, from epidemiological, pathological, clinical and diagnostic points of view. Moreover, we describe the possible transmission of Chagas disease through blood or blood products and the current strategies for its control, focusing on non-endemic areas
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
Association of phlebotomy and subcutaneous bolus injection of deferoxamine for the treatment of anemic patients with iron overload
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