556 research outputs found

    Lmit and shakedown analysis based on solid shell models

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    The paper treats the formulation of the shakedown problem and, as special case, of the limit analysis problem, using solid shell models and ES-FEM discratization technology. In this proposal the Discrete shear gap method is applied to alleviate the shear locking phenomenon

    Assessing the impact of suppressing Southern Ocean SST variability in a coupled climate model

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    The Southern Ocean exerts a strong influence on global climate, regulating the storage and transport of heat, freshwater and carbon throughout the world's oceans. While the majority of previous studies focus on how wind changes influence Southern Ocean circulation patterns, here we set out to explore potential feedbacks from the ocean to the atmosphere. To isolate the role of oceanic variability on Southern Hemisphere climate, we perform coupled climate model experiments in which Southern Ocean variability is suppressed by restoring sea surface temperatures (SST) over 40 degrees-65 degrees S to the model's monthly mean climatology. We find that suppressing Southern Ocean SST variability does not impact the Southern Annular Mode, suggesting air-sea feedbacks do not play an important role in the persistence of the Southern Annular Mode in our model. Suppressing Southern Ocean SST variability does lead to robust mean-state changes in SST and sea ice. Changes in mixed layer processes and convection associated with the SST restoring lead to SST warming and a sea ice decline in southern high latitudes, and SST cooling in midlatitudes. These results highlight the impact non-linear processes can have on a model's mean state, and the need to consider these when performing simulations of the Southern Ocean

    Using Artificial Intelligence for the Diagnosis of Prostate Cancer: The Paper of Yuichiro Oishi et al. Is a Step Forward on the Way of Precision Medicine

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    Yuichiro Oishi et al. presented an interesting study reporting the ability of Artifi- cial Intelligence (AI) to diagnose and locate prostate cancer from multiparametric MRI (mpMRI) [1]. The authors evaluated the diagnostic performance of their AI with a ROC analysis; interestingly the area under the ROC curve was 0.985, while the sensitivity and the specificity were 0.875 and 0.961 (p < 0.01), respectively. Figure 1 of the paper shows that the regions of the prostate labeled by AI as prostate cancer correspond strictly to the cancer areas identified at pathological examination of the gland. These good results justified the strong conclusions of the paper: “diagnostic partition using the superpixel method and SVM-computed likelihood maps enables automated diagnosis of prostate cancer location and shape in mpMRI” [1]. Many aspects of this paper deserve to be emphasized. During the last two decades, numerous attempts to use radiomics for the diagnosis of cancer have been made [2]. So far, the dimensions of the dataset have always been a major limiting factor for the AI training and consequently for its diagnostic performance. The AI-based computer-aided diagnosis used in this study interestingly reached a good result with only a small number of patients, apparently overcoming the need for a large dataset. The authors achieved this result by sampling all the peripheral zone pixels for training the Support Vector Machine. Using this strategy, the dataset which resulted was very large despite the small number of patients included in the study. Because of the previous consideration, the strategy proposed by Yuichiro Oishi et al. will probably be crucial in the development of future diagnostic tools

    Regional Clima the Modeling of the Mediterranean and the Iberian Peninsula Climate Variability

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    La región Mediterránea se caracteriza por una fuerte interacción entre mar y atmósfera y por sistemas dominantes de alta y baja presión que resultan en un clima complejo y fuertemente estacional. Las proyecciones para el clima futuro obtenidas forzando el clima con concentraciones crecientes de gases a efecto invernadero muestran como esta región sea un “hotspot” del cambio climático proyectado por el siglo 21. La vulnerabilidad del clima Mediterráneo al cambio climático en curso, y el importante papel que la interacción océano-atmósfera juega en esta región, ha motivado coordinar un esfuerzo común en la realización de simulaciones regionales acopladas regionales. Este esfuerzo común se ha formalizado en el marco del proyecto Med-CORDEX, cuyos objetivos primarios son mejorar el conocimiento de la variabilidad climática y de la tendencia en el clima del pasado y proporcionar proyecciones para el clima futuro con mayor precisión y exactitud. Parte de este trabajo de tesis ha sido desarrollado como contribución al proyecto Med-CORDEX. En este trabajo de tesis se analiza un ensamble de modelos regionales climáticos (RCMs) para estudiar la variabilidad climática de la región mediterránea y de la Península Ibérica (IP). A pesar de que de la IP sea una región relativamente pequeña, su clima, que está influenciado tanto por el oceano Atlántico como por el mar Mediterráneo, presenta una gran variedad climática. Puesto que la variabilidad climática de la IP y de la región Mediterránea están conectadas, un estudio integrado de las dos regiones resulta ser un marco excelente para investigar los mecanismos físicos responsables de la variabilidad climática observada en estas regiones. Aunque los proyectos de investigación que han producido los ensembles de RCM han realizado simulaciones para el clima actual y el clima futuro, este manuscrito solo presenta los resultados obtenidos para las del clima actual. El primer paso ha sido un enfoque en la variabilidad climática de la cuenca mediterránea y en particular en la asociada con el intercambio de calor entre el océano y la atmósfera. Este flujo de calor a la interfaz mar-aire afecta a muchos procesos que controlan el clima del Mediterráneo como, por ejemplo, la formación de aguas profundas, principal motor de la circulación termohalina. Combinando modelos y observaciones, se ha podido asociar los primeros dos modos de variabilidad del flujo de calor a la interfaz mar-aire con algunos patrones de variabilidad atmosférica de gran escala. Además, calculando el balance calor entre mar y atmósfera, hemos identificado los mecanismos físicos que conectan la variabilidad de los flujos de calor con los patrones de variabilidad atmosférica. Tras valorar la variabilidad de los flujos de calor en la cuenca Mediterránea, se ha estudiado la variabilidad de la IP usando un ensemble de RCM formado por 4 modelos. En particular, se han investigado el estado medio de parámetros básicos atmosféricos y la variabilidad interanual de los extremos de temperatura y precipitación. También se ha valorado la distribución espacial de los eventos extremos y, comparando los cuatro RCMs, se han identificado las regiones con alta y baja variabilidad interna

    Pulmonary recurrence from prostate cancer and biochemical remission after metastasis directed therapy. A case report.

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    We report a case of a 69-years-old man who presented with a solitary 1 cm nodule in the lower lobe of the left lung almost 3 years after radical prostatectomy for pT3aN0M0, Gleason score 4+3 disease, without evidence of osseous or lymphatic spread. Surgical resection of the pulmonary lobe confirmed the metastatic nature of the lesion, with subsequent reduction of serum PSA to undetectable levels. After 2 years from the metastasis resection, serum PSA is still undetectable, without the necessity of additional treatments. Solitary pulmonary metastases from prostate cancer (Pca) are rare in clinical practice, with only 29 previous cases described besides the one that we present

    Bone fragility: conceptual framework, therapeutic implications, and COVID-19-related issues

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    Bone fragility is the susceptibility to fracture even for common loads because of structural, architectural, or material alterations of bone tissue that result in poor bone strength. In osteoporosis, quantitative and qualitative changes in density, geometry, and micro-architecture modify the internal stress state predisposing to fragility fractures. Bone fragility substantially depends on the structural behavior related to the size and shape of the bone characterized by different responses in the load–deformation curve and on the material behavior that reflects the intrinsic material properties of the bone itself, such as yield and fatigue. From a clinical perspective, the measurement of bone density by DXA remains the gold standard for defining the risk of fragility fracture in all population groups. However, non-quantitative parameters, such as macro-architecture, geometry, tissue material properties, and microcracks accumulation can modify the bone’s mechanical strength. This review provides an overview of the role of different contributors to bone fragility and how these factors might be influenced by the use of anti-osteoporotic drugs and by the COVID-19 pandemi

    Rehabilitation of Neuromuscular Diseases During COVID-19: Pitfalls and Opportunities

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    The outbreak of COVID-19 caused by SARS-CoV-2 has spread worldwide with a huge impact on the healthcare system. Compared to the previous coronaviruses-related pandemics, COVID-19 is more transmissible with potential systemic involvement and peculiar neurological manifestations, such as Guillan-Barrè syndrome up to critical illness myopathy, occurring in the intensive care setting. In this clinical scenario, people living with a neuromuscular disease (NMD) represent a vulnerable category with a high risk of a severe course of COVID-19. Moreover, in the NMD population, the management of respiratory and muscular impairments after SARS-CoV-2 infection might be troubling in terms of both pharmacological and rehabilitative approaches. To date, rehabilitation is still an unmet need in this population with several implications on NMD progression with and without SARS-CoV-2 infection. In particular, rehabilitation intervention for patients with NMD after COVID-19 are lacking. Therefore, in the current paper, we analyze the critical issues of COVID-19 on NMDs patients and propose a home-based rehabilitation program targeted for this population after mild to moderate SARS-CoV-2 infection

    Selective arterial embolization for a high-flow priapism following perineal trauma in a young gymnast

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    Introduction. High-flow priapism is a rare condition in children, usually due to a perineal trauma. Materials and methods. We present a case of traumatic highflow priapism investigated by Doppler ultrasound and managed by angiography and selective embolization of a branch of the internal pudendal artery. Results. A 13-year-old gymnast underwent perineal trauma during training and developed a high-flow priapism. The first ultrasound (immediately after the trauma) showed the presence of an inhomogeneous area of 3 x 2 cm associated with an anechoic vascularized area (pseudoaneurysm) in the right corpus cavernosum. On the left side there was a similar finding, but of smaller size. After 3 weeks the pseudoaneurysm on the left was completely obliterated while the right one was still present. Angiography and superselective catheterization of a branch of the left pudendal artery and its embolization with microspheres and with metal microcoils were performed. After the procedure, ultrasound showed that the right pseudoaneurysm was completely obliterated and there were no more branches reaching it. The cavernous arteries were both pervious. Conclusions. Selective arterial embolization is a safe treatment that can also be used in pediatric patients

    Muscle Regeneration and Function in Sports: A Focus on Vitamin D

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    Muscle is one of the main targets for the biological effects of vitamin D. This hormone modulates several functions of skeletal muscles, from development to tissue repair after injury, through genomic and non-genomic mechanisms. Vitamin D deficiency and supplementation seem to significantly affect muscle strength in different populations, including athletes, although optimal serum 25(OH)D3 level for sport performance has not been defined so far. Additionally, vitamin D de- ficiency results in myopathy characterized by fast-twitch fiber atrophy, fatty infiltration, and fibrosis. However, less is known about regenerative effects of vitamin D supplementation after sport-related muscle injuries. Vitamin D receptor (VDR) is particularly expressed in the embryonic mesoderm during intrauterine life and in satellite cells at all stages of life for recovery of the skeletal muscle after injury. Vitamin D supplementation enhances muscle differentiation, growth, and regeneration by increasing the expression of myogenic factors in satellite cells. The objective of this narrative review is to describe the role of vitamin D in sport-related muscle injury and tissue regeneration

    It's not always varicocele: A strange case of Zinner syndrome

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    A 42-year-old man presented with a huge varicocele. The patient was completely asymptomatic and he did not complain of dysuria, perineal discomfort, or ejaculatory pain. During the visit, the mass mimicked a varicocele and during the Valsalva maneuver a reflux was documented by colour Doppler ultrasound and an abdominal ultrasound revealed an agenesis of the right kidney and a 4.5-cm diameter intra-prostatic cyst. An abdominal and pelvis magnetic resonance imaging was then performed, which confirmed the right renal agenesis, with an epididymal enlargement in the body and tail. This is a unique case of Zinner syndrome in which the patient presented with a paratesticular mass mimicking a varicocele. \ua9 2015 Canadian Urological Association
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