1,721,080 research outputs found
Carbonization of polymer precursors substrates to direct human iPSC-derived neurons differentiation and maturation
Full text linkIn this work, precursor polymers were processed by electrospinning and photolithography. Polyacrilonitrile (PAN) fibers were obtained by electrospinning, while SU-8 high-resolution micro-patterns on silicon wafers were produced by photolithography. The substrates were subjected to thermal stabilization and pyrolysis to obtain carbon structures. iPSCs-derived Neural Stem Cells (NSCs) were cultured on the carbonized materials to analyze their adhesion and differentiation into neurons on the designed scaffolds. Results show that NSCs recognized the substrates and differentiated into neurons on both scaffold typologies. In order to evaluate differences among substrates used, neuronal marker expression analysis was performed
Establishment and characterization of Cri Du Chat neuronal stem cells: a novel promising resource to study the syndrome
No full textThe Cri Du Chat (CdC) Syndrome is a rare chromosome disease condition resulting from variable size deletion occurring on the short arm of one of the chromosomes 5. This disorder, which affects one in 50,000 births, is responsible for developmental retardation, the mechanism of which has remained unexplained. TERT, SEMA5 A, CTNND2, TPPP, mapped in chromosome 5 short arm, are known to be expressed in the brain, and to play a role in the development of the nervous system, oligodentrocytes and in the regulation of glutamatergic and dopaminergic synaptic transmission. It is critical to understand how their haploinsufficiency might affect the development and presentation of the disease. In the absence of an animal model and of significant accessible, human tissue, human pluripotent stem cells (iPSC) directly reprogrammed from patient somatic cells open a new area of disease modeling as they can virtually be differentiated into any cell type. Our study reports, for the first time, the generation of neuronal stem cells (NSCs) from CdC-iPSCs line and in addition, subsequent differentiation into a heterogeneous population of neurons. Gene expression of the mentioned and single copy deleted genes was also evaluated by comparing their expression level in iPSC, NSCs and neuron lines. The present research represents the first and the most innovative approach, to create an in vitro CdC neuronal model to have a new translational framework to study the pathologic processes
Omenn Syndrome due to RAG1 Mutation Presenting With Nonimmune Hydrops Fetalis in Two Siblings
No full textOmenn syndrome (OS) is a rare variant of severe combined immunodeficiency characterized by susceptibility to severe opportunistic infections and peculiar manifestations, such as protein-losing erythroderma, alopecia, hepatosplenomegaly, lymphadenopathies, and severe diarrhea. The typical form of the disease is caused by hypomorphic mutation of the recombination-activating genes (RAG1 and RAG2), which are critical in initiating the molecular processes leading to lymphocyte and immunoglobulin receptor formation. Affected patients lack B cells, whereas autoreactive oligoclonal T cells infiltrate the skin, gut, spleen, and liver. In the absence of hematopoietic stem cell transplantation, patients with OS usually succumb early in life because of opportunistic infections. The incidence of OS is estimated to be <1 per 1 000 000; however, the actual frequency is difficult to ascertain. We report 2 siblings affected by OS due to a homozygous frameshift mutation (NM_000448.3:c.519delT, p.E174Sfs*26) in the RAG1 gene presenting with nonimmune hydrops fetalis (NIHF). To the best of our knowledge, this is the first reported association between OS and NIHF. NIHF specifically refers to the presence of ≥2 abnormal fluid collections in the fetus, without red blood cell alloimmunization. A broad spectrum of pathologies is associated with NIHF; however, in ∼20% of the cases, the primary cause remains unclear. Understanding the etiology of NIHF is essential for guiding clinical management, determining prognosis, and informing parents regarding recurrence risk. Our case contributes to expanding the spectrum of OS presentation and highlights the importance of a complete immunologic and genetic workup in otherwise unexplained cases of NIHF
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
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