1,720,988 research outputs found
Francavilla A, Di Leo A, Wu SQ, Ove P, Van Thiel D, Sciascia C, Starzl TE.
No full textDuring regeneration of rat livers following 70% hepatectomy, insulin binding sites on hepatocyte plasma membranes are increased after 24-48 hours, glucagon binding sites are reduced on days 2-8, and the resultant insulin/glucagon binding ratio is markedly increased. An apparent paradox was the finding of a depression of the activity of an insulin associated enzyme, glucokinase, at a time when the number of insulin binding sites was increased
Ultrasensitive magnetic nanomechanical biosensors for simultaneous detection of multiple cardiovascular disease biomarkers in a single blood drop
No full textCardiovascular disease (CVD) is the number one cause of death, and the early prevention of CVD is considered the most useful and cost-effective intervention strategy, highlighting the critical need for frequent and long-term monitoring cardiac abnormalities. However, traditional blood test methods often require considerable volumes of blood (>10 mL), which could burden physical health, especially for individuals in poor health. Here, we report a novel magnetic nanomechanical sensor (MNS) capable of simultaneously detecting multiple CVD biomarkers (brain natriuretic peptide (BNP), cardiac troponin I (cTnI) and creatine kinase MB (CK-MB)) in a single drop of blood (<1 mu L). Relying on the force-sensitive microcantilevers and robust magnetic force, MNS can directly detect blood samples with a detection sensitivity for BNP as low as 0.1 pg/mL. Moreover, we improved the MNS sensitivity by reducing nonspecific adsorption and focusing the force on specific locations on the sensor surface. The effectiveness of the MNS was demonstrated through the detection of samples from clinical CVD patients and healthy individuals. Given its ultrasensitive, trace-sample requirement, and ability to monitor multiple biomarkers, the MNS holds significant potential for frequent and long-term monitoring-not only for CVD but also for the prevention and management of other chronic diseases
High Efficiency Production of Functional Small Extracellular Vesicles through Cellular Self-Motivation
No full textIn stem cell therapies, small extracellular vesicles (sEVs) are extremely limited in application due to their limited production. Here, we propose a new concept of "cellular self-stimulation" and develop a cost-effective method for the preparation of sEVs, which enables the conversion of cellular traction to self-generated stimulation through piezoionic hydrogels and enhances the ability of cells to secrete sEVs by more than an order of magnitude. The traction of the adherent cells leads to deformation of the piezoionic substrate, which in turn translates into a millivolt-level electrical signal acting on the cell itself, stimulating the cell to produce more sEVs. These sEVs remain biologically intact and have shown excellent efficacy in in vitro and in vivo assays, confirming the superior therapeutic potential of high concentrations of sEVs. This provides a strong impetus for the development and dissemination of stem cell therapies
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Regenerating rat liver: correlations between estrogen receptor localization and deoxyribonucleic acid synthesis.
No full textEstrogen receptor activity was quantitated in the cytosol and nucleus of normal rat liver and in regenerating rat liver at several time intervals after 75% hepatectomy. Cytosolic estradiol binding in regenerating liver decreases at 12, 24, and 48 h after hepatectomy and at 48 h is 30% of that in normal rat liver. Nuclear estrogen binding 48 h after surgery is elevated fivefold over normal values. No alterations in affinity of the receptor for estrogen have been observed. Specificity studies indicate that the estrogen receptors from both normal and regenerating liver were similar and are highly specific for estrogens. These changes in cellular distribution of receptors parallel increases in nuclear deoxyribonucleic acid synthesis and mitotic indices in the liver
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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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