1,721,029 research outputs found
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
Corrigendum to: The presence of residents during orthopedic operation exerts no negative influence on outcome
Full text linkThe presence of residents during orthopedic operation exerts no negative influence on outcome
No full textBACKGROUND: Operative procedural training is a key component of orthopedic surgery residency. It is unclear how and whether residents participation in orthopedic surgical procedures impacts on post-operative outcomes. SOURCES OF DATA: A systematic search was performed to identify articles in which the presence of a resident in the operating room was certified, and was compared with interventions without the presence of residents. AREAS OF AGREEMENT: There is a likely beneficial role of residents in the operating room, and there is only a weak association between the presence of a resident and a worse outcome for orthopedic surgical patients. AREAS OF CONTROVERSY: Most of the studies were undertaken in USA, and this represents a limit from the point of view of comparison with other academic and clinical realities. GROWING POINT: The data provide support for continued and perhaps increased involvement of resident in orthopedic surgery. AREAS OF RESEARCH: To clarify the role of residents on clinically relevant outcomes in orthopedic patients, appropriately powered randomized control trials should be planned
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
Italy and COVID-19: The changing patient flow in an orthopedic trauma center emergency department
Full text linkOn 12 March 2020, the World Health Organization de clared a pandemic by Coronavirus disease (COVID-19) [1]. Despite the lockdown measures adopted to stop the spread of SARS-CoV-2, we are dangerously close to 400,000 deaths worldwide [2]
Evolution of meniscal biomechanical properties with growth: An experimental and numerical study
No full textThe menisci of the knee are complex fibro-cartilaginous tissues that play important roles in load bearing, shock absorption, joint lubrication, and stabilization. The objective of this study was to evaluate the interaction between the different meniscal tissue components (i.e., the solid matrix constituents and the fluid phase) and the mechanical response according to the developmental stage of the tissue. Menisci derived from partially and fully developed pigs were analyzed. We carried out biochemical analyses to quantify glycosaminoglycan (GAG) and DNA content according to the developmental stage. These values were related to tissue mechanical properties that were measured in vitro by performing compression and tension tests on meniscal specimens. Both compression and tension protocols consisted of multi-ramp stress–relaxation tests comprised of increasing strains followed by stress–relaxation to equilibrium. To better understand the mechanical response to different directions of mechanical stimulus and to relate it to the tissue structural composition and development, we performed numerical simulations that implemented different constitutive models (poro-elasticity, viscoelasticity, transversal isotropy, or combinations of the above) using the commercial software COMSOL Multiphysics. The numerical models also allowed us to determine several mechanical parameters that cannot be directly measured by experimental tests. The results of our investigation showed that the meniscus is a non-linear, anisotropic, non-homogeneous material: mechanical parameters increase with strain, depend on the direction of load, and vary among regions (anterior, central, and posterior). Preliminary numerical results showed the predominant role of the different tissue components depending on the mechanical stimulus. The outcomes of biochemical analyses related to mechanical properties confirmed the findings of the numerical models, suggesting a specific response of meniscal cells to the regional mechanical stimuli in the knee joint. During maturation, the increase in compressive moduli could be explained by cell differentiation from fibroblasts to metabolically active chondrocytes, as indicated by the found increase in GAG/DNA ratio. The changes of tensile mechanical response during development could be related to collagen II accumulation during growth. This study provides new information on the changes of tissue structural components during maturation and the relationship between tissue composition and mechanical response
Biomechanical issues of tissue-engineered constructs for articular cartilage regeneration: in vitro and in vivo approaches
No full textBACKGROUND: Given the limited regenerative capacity of injured articular cartilage, the absence of suitable therapeutic options has encouraged tissue-engineering approaches for its regeneration or replacement. SOURCES OF DATA: Published articles in any language identified in PubMed and Scopus electronic databases up to August 2019 about the in vitro and in vivo properties of cartilage engineered constructs. A total of 64 articles were included following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. AREAS OF AGREEMENT: Regenerated cartilage lacks the biomechanical and biological properties of native articular cartilage. AREAS OF CONTROVERSY: There are many different approaches about the development of the architecture and the composition of the scaffolds. GROWING POINTS: Novel tissue engineering strategies focus on the development of cartilaginous biomimetic materials able to repair cartilage lesions in association to cell, trophic factors and gene therapies. AREAS TIMELY FOR DEVELOPING RESEARCH: A multi-layer design and a zonal organization of the constructs may lead to achieve cartilage regeneration
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