1,721,036 research outputs found
Molecular and cellular aspects of induced thymus development in recombinase‐deficient mice
No full textThymus development and microenvironment organization require stage- and site-specific cross-talk between thymocyte and stroma. In this study we have used recombinase-activating gene-deficient (RAG-2(-/-)) mice to analyze regulated gene expression both in thymocytes and stromal cells following injection of anti-CD3 monoclonal antibodies as inducer of thymus development. We show that IFN-γ, TNF-α and lymphotactin are transcriptionally regulated in thymocytes, whereas cytoskeletal keratin 14, IL-1α and TNF-α are regulated in the stroma, quantitatively reproducing the variations associated with β selection of thymocytes. In addition, RAG-2(-/-) thymus development is associated with entry of epithelial cells into the cell cycle. The histochemical evidence that expanded RAG-2(-/-) thymus becomes undistinguishable from wild-type cortex further suggests that cross-talk phenomena occurring during β selection of thymocyte are reproduced in this system
Inizio precoce dell’ipotermia terapeutica dopo arresto cardiaco e correlazione con sopravvivenza e outcome neurologico : report italiano
No full text
[The sigh in ARDS (acute respiratory distress syndrome)]
No full textWe studied 10 consecutive, sedated and paralyzed patients with Acute Respiratory Distress Syndrome (ARDS). The entire study lasted 4 hours, divided in 3 periods: 2 hours of recommended ventilation [lung protective strategy, LPS, i.e., ventilation with low tidal volume (< 8 mL/kg), limiting the plateau at 35 cm H2O, together with high positive end-expiratory pressure (PEEP)], 1 hour of sigh (LPS with 3 consecutive sighs/min at 45 cm H2O plateau pressure), and 1 hour of LPS. Total minute ventilation, PEEP, FiO2 and mean airway pressure were kept constant. The introduction of sighs induced a consistent recruitment and PaO2 improvement, and a decrease in venous admixture and PaCO2. Interrupting sighs and resuming LPS led to a progressive derecruitment, and all the physiological variables returned to baseline. Derecruitment was higher in patients with higher PaCO2 and lower VA/Q ratio. We conclude that: 1) LPS alone does not provide full lung recruitment and best oxygenation in ARDS; 2) application of sigh may provide pressure enough to recruit and volume enough to prevent reabsorption atelectasis
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
Recombinase-deficient T cell development by selective accumulation of CD3 into lipid rafts
No full textThe pre-T cell receptor (pre-TCR) promotes development of thymocyte with productive rearrangement at T cell receptor β chain locus by signaling in a ligand-independent fashion. The TCR β chain associates with the invariant pre-T α (pTα) chain, which bears specific charged residues in the extracellular portion mediating pre-TCR self-oligomerization. In recombinase-deficient thymocyte, calnexin (CNX) associated with CD3 chains is inefficiently retained in the endoplasmic reticulum and weakly expressed in the plasma membrane. Deliberate cross-linking of CNX/CD3 complexes mimics pre-TCR signaling. Here we show that analogously to pTα chain, surface CNX is palmitoylated and that CD3 prominently accumulated into lipid rafts upon cross-linking. Mutant CNX isoforms devoid of ER retention determined pre-TCR-like signaling and simulated β selection only when stably translocating CD3 to lipid rafts. Inclusion of palmitoylated cytoplasmic tail from pTα chain in recombinant CNX strikingly improved pre-TCR-like signaling efficiency of CNX/CD3 into rafts. This study indicates that lipid rafts in the plasma membrane represent proficient microdomains for initiation of pre-TCR signaling and supports the view that β selection by oligomerized pre-TCR is implemented by pTα cytoplasmic tail
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