1,721,367 research outputs found
Inherited extensive speckled lentiginous nevus with ichthyosis: report of a previously undescribed association
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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
Clinical features of 36 cases of amelanotic melanomas and considerations about the relationship between histologic subtypes and diagnostic delay
No full textAmelanotic melanomas (AM) are a difficult diagnostic challenge for clinicians. Objective To consider the clinical presentation of AM, the histologic subtypes involved, the relationship with the diagnostic delay and the possible involvement in overall prognosis. Patients/Methods Patients who were observed in our department to be affected by cutaneous melanomas were recorded. Sex, age, the clinical features, the site of presentation, the suspected diagnosis, the clinical course, the histological type, the Clark level and the Breslow thickness were recorded. AM were divided in three main clinical types: an erythematous macule or patch on sun-exposed skin, a dermal plaque or nodule without a particular epidermal change, an exophytic nodule. Only pure AM were considered.Histological subtypes considered were superficial spreading melanoma, nodular melanoma, and lentigo maligna melanoma. Diagnostic delay considered from when the patients first noticed the lesion on the site where the melanoma was diagnosed and when the physician or the patient first proposed the removal was recorded. The chi-squared test was used for statistical evaluation with P < 0.05 as level of significance. Results Thirty-six cases of AM out of a total of 500 melanomas (7.2%) were collected. The most frequent morphology of clinical presentation was the papulo-nodular form, followed by the plaque form. Mean Breslow thickness of AM was 1.72 mm compared to 0.61 mm of pigmented cases. Nodular histotype was highly represented in AM (30.5% of cases) with respect to pigmented nodular melanomas (2.9%). The diagnostic delay did not differ between amelanotic and pigmented melanomas, nor between nodular AM and nodular pigmented melanomas. Conclusion The great prevalence of clinical and histological nodular cases, the higher mean Breslow thickness (considered as the most important factor of prognosis) of AM compared with a not significant greater diagnostic delay may point out that a good percentage of AM have an intrinsic faster speed of growth with a worse prognosis irrespectively of the diagnostic performance. The importance of educational campaign for patient and physicians is stressed
Melanoma of the glans penis
No full textThe authors describe the case of a 64-year old man who presented with an asymptomatic brown macula on his glans penis that had appeared about 18 months earlier. Dermoscopy analysis demonstrated a prominent, wide and irregular pigment network, which stopped abruptly at the periphery of the lesion. A diagnostic biopsy showed the characteristics of a melanoma in situ. The patient was referred for partial surgical excision of the glans. No recurrence or metastasis occurred during the two years after the operation. Melanoma in situ of the penis is very rare in dermatologic literature. Early diagnosis is of paramount importance because its prognosis is very poor. Early systematic use of dermoscopy may be useful for the differential diagnosis of pigmented mucosal lesions, which include mucosal melanosis and other benign melanoses of genitalia
Psoriasiform id reaction in tinea corporis
No full textA case of tinea corporis due to Microsporum canis followed by a scattered psoriasiform eruption is reported. The nature, clinical features and pathogenesis of the dermatophytid are discussed
A new approach for reduced order modeling of mechanical systems using vibration measurements
No full textThis study investigates the possibilities of obtaining reduced order mass-damping-stiffness models of mechanical systems using state space realizations identified via dynamic tests. It is shown that even when the system is insufficiently instrumented with sensors and actuators, it is still possible to create physically meaningful reduced order mass-damping-stiffness models that incorporate measured and unmeasured degrees of freedom. It is further discussed that certain assumptions, such as having a diagonal mass matrix or having classical damping in the system, allow one to develop alternative reduced order representations with different physical interpretations. The theoretical presentation is supplemented by a numerical example that illustrates the applications of the formulations developed herein
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