1,721,049 research outputs found
Endoscopic procurement of tympano-ossicular allografts : impact on donation and transplantation
No full textAbstract: Since the technique of tympano-ossicular allograft tympanoplasty was founded in the 1960s by Marquet, en bloc allografts have been procured using the Schuknecht bone plug technique. The technique was used in many centers around the world but the rise of infectious diseases that can potentially be transmitted from donor to recipient, like HIV and Creutzfeldt-Jakob disease, led to the downfall of the use of tympano-ossicular allografts in many countries. In many centers in the Antwerp region, the technique withstood these challenges. Technological progression and the shift towards the use of a tympanomeatal allograft with separate incus, enabled the introduction of an endoscopic procurement technique. We have shown that it is feasible to procure tympano-ossicular allografts of good quality via transmeatal approach using a 30\ub0 nasal endoscope. When comparing this new procurement technique to the traditional transcranial technique, the endoscopic technique is much more time efficient (the end product is retrieved immediately rather than being dissected in a separate step), it is safer (contact with the dura mater during procurement is avoided, eliminating the already low risk of transmission of Creutzfeldt-Jakob disease) and it is less invasive, which has significantly increased the donor volume and has made the procurement more acceptable for donor relatives and cooperating hospitals. On the other side it is more difficult to learn and the long term percentage of good quality allografts is lower. However, the increase in donor volume outweighs the decrease in percentage of good quality allografts. This aspect together with the other mentioned advantages have argumented our decision to fully replace the transcranial bone plug technique by the endoscopic procurement technique. After switching to the new technique, the clinical outcome of the tympano-ossicular allografts was reported. In a first step we compared in a prospective, randomized audit the results of transcranially versus endoscopically procured allografts. No statistically relevant difference was observed in a small group of patients with regards to the graft take rate three months after surgery. In a second step, the graft take rate was analyzed retrospectively on a bigger group of patients. The graft take rate at three months was shown to be similar to the graft take rate as reported in literature. Finally, literature showed that the formaldehyde solution used for tympano-ossicular allograft preservation is efficient in inactivating viruses like HIV, HBV, HCV and coronaviruses. These results, combined with other safety measures, make tympano-ossicular allografts a very safe reconstruction material
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
Molecular imaging for early response assessment of neo-adjuvant chemotherapy and drugs targeting the PI3K/Akt/mTOR pathway in HER-2 amplified breast cancer
No full textAbstract: Neoadjuvant chemotherapy (NACT) is a well-established, safe, and effective treatment for breast cancer, offering benefits like increased rates of breast-conserving surgery and early evaluation of therapy effectiveness. Combining NACT with the anti-HER-2 antibody trastuzumab improves survival in patients with HER-2 overexpressing breast cancer. However, only a minority of these patients respond to trastuzumab, with relapse often linked to drug resistance through the PI3K/Akt/mTOR pathway. This resistance suggests that combining trastuzumab with PI3K inhibitors might improve outcomes. Early identification of non-responders could allow for timely modification of treatment strategies, but currently, there are no clinical biomarkers to predict or monitor response to PI3K/Akt/mTOR-targeted drugs. Imaging modalities like PET scans, which assess tumor glucose metabolism using [18F]FDG, provide a comprehensive view of the tumor burden. However, it's unclear if [18F]FDG PET effectively indicates cell kill. An alternative tracer, [18F]FLT, which focuses on cell proliferation, might offer a better indication of response, although its efficacy in HER-2 positive breast cancer remains uncertain. In comparative studies of [18F]FDG and [18F]FLT uptake in HER-2 overexpressing breast cancer cell lines treated with trastuzumab and PI3K/Akt/mTOR inhibitors, [18F]FDG uptake reductions were not evident before cell kill, while [18F]FLT PET showed earlier response reflections. Nonetheless, [18F]FLT uptake had temporary increases, or metabolic flares, potentially affecting assessment accuracy. Further studies on HER-2 overexpressing tumor xenografts treated with PI3K/Akt/mTOR inhibitors confirmed that [18F]FDG uptake correlated with tumor volume, validating [18F]FDG PET as an early response biomarker. However, treatment responses might be underestimated due to early metabolic flares. A clinical study evaluated the role of [18F]FDG PET as a biomarker of response to combined chemotherapy and targeted therapies in HER-2 overexpressing breast cancer. The study found that tumor metabolic response after six weeks of NACT, assessed with [18F]FDG, was an early predictor of response. The metabolic flare seen in preclinical data was not observed clinically, likely due to the timing of the PET scan. In summary, the timing of PET scans is critical for accurate assessment. Scanning too early can result in false positives due to metabolic flares, while delayed scanning can hinder the effectiveness of tailored therapies. Properly timed [18F]FDG PET scans are essential for predicting treatment response in HER-2 overexpressing breast cancer
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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