1,720,957 research outputs found
Nephrogenic remnants: Occasional ultrasound diagnosis and follow-up
Full text linkNephrogenic remnants (NRs) are nodular collections of undifferentiated renal blastema cells in the postnatal kidney that are recognized as putative precursor lesions of Wilms tumor (WT). NRs may remain stationary, undergo regression, or proliferate. In the last case, there is a high risk for the development of a WT. During infancy, they are most frequently of microscopic size, to be found only at autopsy in approximately 1% of infant kidneys. Approximately 1 out of 100 microscopic lesions persist and grow developing lesions large enough to be seen by ultrasound in the first months of life. We report on a case of NRs in a six year old child, as incidental finding during abdominal ultrasound performed for other purposes. In consideration of the potential evolution in WT, after a period of close surveillance of 14 months, the lesion was resected. Histological examination revealed the presence of NRs, no neoplastic lesions were found. Currently the patient is 16 years old, in good health, and there have been no signs of recurrence
Lung ultrasound in bronchiolitis: Comparison with chest X-ray
No full textThe diagnosis of bronchiolitis is based mainly on the patient's medical history and physical examination. However, in severe cases, a further evaluation including chest X-ray (CXR) may be necessary. At present, lung ultrasound (LUS) is not included in the diagnostic work-up of bronchiolitis. This study aimed to compare the diagnostic accuracy of LUS and CXR in children with bronchiolitis, and to evaluate the correlation between clinical and ultrasound findings. Only patients with a diagnosis of bronchiolitis, who had undergone a CXR, were enrolled in the study. Fifty-two infants underwent LUS and CXR. LUS was also performed in 52 infants without clinical signs of bronchiolitis. LUS was positive for the diagnosis of bronchiolitis in 47/52 patients, whereas CXR was positive in 38/52. All patients with normal LUS examination had a normal CXR, whereas nine patients with normal CXR had abnormal LUS. In these patients, the clinical course was consistent with bronchiolitis. We found that LUS is a simple and reliable tool for the diagnosis and follow-up of bronchiolitis. It is more reliable than CXR, can be easily repeated at the patient's bedside, and carries no risk of irradiation. In some patients with bronchiolitis, LUS is able to identify lung abnormalities not revealed by CXR. Furthermore, there is a good correlation between clinical and ultrasound findings. Given the short time needed to get a US report, this technique could become the routine imaging modality for patients with bronchiolitis. © 2011 Springer-Verlag
Usefulness of lung ultrasound in a newborn with pulmonary atelectasis
No full textThe use of ultrasound for the evaluation of the lung is relatively recent. We describe the case of a newborn with pulmonary atelectasis and shift of the mediastinum underlining both advantages and limits of lung ultrasound (LUS). The baby, 1 month of age, was admitted to our hospital for tachypnoea, vomiting and poor weight gain. Chest X-ray (CXR) showed displacement of the heart to the right, suggesting the presence of atelectasis of the right lung. LUS confirmed the displacement of the mediastinum to the right and atelectasis of the right lung, clearly visible as a consolidation with the presence of air bronchograms. The computed tomography image showed that the lung parenchyma displayed in the right hemithorax could be attributed to the hyperexpanded left lung. However, once this information was acquired, and compared to the ultrasound picture, we were able to monitor the patient by LUS until normalization, thus avoiding further exposure to ionizing radiation. Our case, in accordance with the recent Literature, indicates that LUS can be adopted as a simple and non-invasive method for evaluating children with lung disease. It is easy to perform at bedside, allows a close follow-up and avoids the use of ionizing radiation
Lung ultrasound characteristics of community-acquired pneumonia in hospitalized children
No full textBackground The diagnosis of community-acquired pneumonia (CAP) is based mainly on the patient's medical history and physical examination. However, in severe cases a further evaluation including chest X-ray (CXR) may be necessary. At present, lung ultrasound (LUS) is not included in the diagnostic work-up of pneumonia. Aim To describe the ultrasonographic appearance of CAP at presentation and during the follow-up. Methods A total of 102 patients with clinical signs and symptoms suggesting pneumonia, who underwent a clinically driven CXR, were evaluated by LUS on the same day. LUS signs of pneumonia included subpleural lung consolidation, B-lines, pleural line abnormalities, and pleural effusion. The diagnostic gold standard was the ex-post diagnosis of pneumonia made by two independent experienced pediatricians on the basis of clinical presentation, CXR and clinical course following British Thoracic Guidelines recommendations. Results A final diagnosis of pneumonia was confirmed in 89/102 patients. LUS was positive for the diagnosis of pneumonia in 88/89 patients, whereas CXR was positive in 81/89. Only one patient with normal LUS examination had an abnormal CXR, whereas 8 patients with normal CXR had an abnormal LUS. LUS was able to detect pleural effusion resulting from complicated pneumonia in 16 cases, whereas CXR detected pleural effusion in 3 cases. Conclusions LUS is a simple and reliable imaging tool, not inferior to CXR in identifying pleuro-pulmonary alterations in children with suspected pneumonia. During the course of the disease, LUS allows a radiation-free follow-up of these abnormalities. Pediatr Pulmonol. 2013; 48:280-287. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc
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
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