56 research outputs found
Meccanica quantistica e "lensing" gravitazionale
La deflessione della luce in un campo gravitazionale è una delle prove sperimentali più rilevanti della relatività generale. In questo contesto si discutono alcuni effetti della meccanica quantistica sulla propagazione dei fotoni in uno spazio-tempo curvo. In particolare si presentano le correzioni quantistiche del Modello Standard delle particelle elementari alla diffusione del fotone da una sorgente gravitazionale
The spine in Paget’s disease
Paget’s disease (PD) is a chronic metabolically active bone disease, characterized by a disturbance in bone modelling and remodelling due to an increase in osteoblastic and osteoclastic activity. The vertebra is the second most commonly affected site. This article reviews the various spinal pathomechanisms and osseous dynamics involved in producing the varied imaging appearances and their clinical relevance. Advanced imaging of osseous, articular and bone marrow manifestations of PD in all the vertebral components are presented. Pagetic changes often result in clinical symptoms including back pain, spinal stenosis and neural dysfunction. Various pathological complications due to PD involvement result in these clinical symptoms. Recognition of the imaging manifestations of spinal PD and the potential complications that cause the clinical symptoms enables accurate assessment of patients prior to appropriate management
Ultrasound diagnosis of renal infarction: Case report and review of the Literature
Renal infarction secondary to thromboembolism is usually a sequela of cardiac disease,the heart being the source of systemic arterial emboli in up to 94% of cases; the three major causes are: atrial fibrillation, myocardial infarction and rheumatic mitral stenosis.Renal infarction is often confused with other conditions due to similar presenting symptoms. This leads to delay in initiating treatment and significantly decreases thechances of renal salvage.We report a sonographic diagnosis in 39-year-old man, with risk factors for thrombosis, withouta prior history of thromboembolism
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