3,136 research outputs found
Tooth development in the Early Devonian sarcopterygian Powichthys and the evolution of the crown osteichthyan dentition
Upsurge of deep venous thrombosis in patients affected by COVID-19: Preliminary data and possible explanations
Innate effector cells in angiogenesis and lymphangiogenesis
Angiogenesis and lymphangiogenesis are distinct and complex processes requiring a finely tuned balance between stimulatory and inhibitory signals. During adulthood, angiogenesis and lymphangiogenesis are activated at sites of tumor growth, tissue injury and remodeling, and chronic inflammation. Vascular endothelial growth factors (VEGFs), angiopoietin (ANGPTs) and a multitude of additional signaling molecules play distinct roles in the modulation of angiogenesis/lymphangiogenesis. VEGFs and ANGPTs activate specific tyrosine kinase receptor (e.g., VEGFR1, VEGFR-2, VEGFR-3 and TIE2 respectively), expressed on blood endothelial cells (angiogenesis) and lymphatic endothelial cells (lymphangiogenesis). Although tumor cells produce VEGFs and other proangiogenic mediators, tissue resident (e.g., macrophages, mast cells) and circulating immune cells (e.g., basophils, neutrophils, monocytes, eosinophils) are an important source of angiogenic/lymphangiogenic mediators in inflammation and in tumor microenvironment and at site of chronic inflammation. Certain immune cells can also release anti-angiogenic factors. Mast cells, basophils, neutrophils and presumably other immune cells are not only a source of angiogenic/lymphangiogenic molecules, but also their target. Cells of the immune system need consideration as major players and possible targets for therapeutic manipulation of angiogenesis/lymphangiogenesis in chronic inflammatory disorders and tumors
Endovascular Treatment of a Ruptured Pararenal Abdominal Aortic Aneurysm in a Patient With Coronavirus Disease-2019: Suggestions and Case Report
The aim of this report is to discuss emergent repair for complex aortic diseases in patients affected by novel coronavirus pneumonia (coronavirus disease-2019 [COVID-19]), describing a case of ruptured pararenal aortic aneurysm. An eighty-year-old man with COVID-19 was admitted for ruptured aneurysm of the pararenal aorta and hemorrhagic shock. Endovascular repair was chosen, and a proximal extension of the previous abdominal endograft was performed with parallel stents in the right renal artery and the superior mesenteric artery. Endovascular treatment and early anticoagulation are the key for success for vascular emergencies in patients with COVID-19, despite the risk of late endoleak
Tra scienza e paesaggio: formare al pensiero ecologico nella scuola dell’infanzia
A partire dal XX secolo, l’intervento sulla natura da parte dell’uomo e il suo desiderio di dominarla e controllarla hanno condizionato le relazioni tra gli esseri viventi, mettendo da parte tutte quelle disposizioni ecologiche che hanno permesso la sopravvivenza delle specie per secoli. La nascita della scienza moderna ha segnato la fine della concezione della natura quale madre benevola e nutrice, lasciando spazio a un riduzionismo meccanicista che l’ha manipolata come materia inerte e frazionata, riducendone la capacità di rigenerarsi e di rinnovarsi. Una scienza improntata alla sottomissione che, in poco tempo, è stata causa del depauperamento di terre fertili e dell’estinzione di migliaia di organismi viventi. Da qui, l’importanza di un’educazione ambientale che parta dall’infanzia, coinvolgendo bambine e bambini affinché imparino, attraverso il rapporto con la natura, ad avere rispetto e cura verso il mondo che li ospita; ad entrarci in relazione in un’ottica di scambio e protezione così da divenire ricettivi rispetto a una visione sistemica orientata alla sostenibilità . Nello specifico il ruolo del paesaggio nella didattica outdoor è, nell’emergenza del tempo attuale, una risorsa fondamentale ancora tutta da esplorare in termini cognitivi, emozionali nonché occasione di riflessione sul nostro patrimonio culturale. Infatti, il contatto con le bellezze della natura, all’insegna della condivisione, basandosi sull’apprendere dall’esperienza facilita, soprattutto nei più piccoli, lo sviluppo di sensoriale e socio relazionale. In questa prospettiva diventa necessario riflettere sul ruolo che le istituzioni educative hanno nel formare a un pensiero ecologico: nuove conoscenza e competenze, valori e sensibilità , atti a progettare nuovi modi di costruire il futuro insieme alle altre specie viventi da cui dipende la sopravvivenza del genere umano
Xray Tomographic Microscopic Studies a Resin Embedded Paint Sample from a Mechanical Failing Area in the Floor Tiles of The Art of Painting by Johannes Vermeer (1632-1675)
Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 - August 5, 201
Artichoke biorefinery: From food to advanced technological applications
A sequential extraction process has been designed for valorizing globe artichoke plant residues and waste (heads, leaves, stalks, and roots left in the field) by means of green extraction techniques according to a biorefinery approach. We investigated two cascading extractions based on microwave-assisted extractions (MAE) and green solvents (water and ethanol) that have been optimized for varying temperature, solvent and extraction time. In the first step, phenols were extracted with yields that ranged between 6.94 mg g−1 dw (in leaves) and 3.28 mg g−1 dw (in roots), and a phenols productivity of 175.74 kg Ha−1. In the second step, inulin was extracted with impressive yields (42% dw), higher than other conventional inulin sources, corresponding to an inulin productivity of 4883.58 kg Ha−1. The remaining residues were found to be valuable feedstocks both for bioenergy production and green manure (back to the field), closing the loop according to the Circular Economy paradigm
A tilted grating interferometer for full vector field differential x-ray phase contrast tomography
We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information. The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferometer are oriented at a tilt angle with respect to the sample rotation axis. In such a configuration, the differential phase images from opposing tomography projections can be combined to yield both components of the gradient vector. We show how the refractive index distribution as well as its x, y, and z gradient components can be reconstructed directly from the recorded projection data. The method can equally well be applied at conventional x-ray tube sources, to analyzer based x-ray imaging or neutron imaging. It is demonstrated with measurements of an x-ray phantom and a rat brain using synchrotron radiation
Regridding reconstruction algorithm for real-time tomographic imaging
Sub-second temporal-resolution tomographic microscopy is becoming a reality at third-generation synchrotron sources. Efficient data handling and post-processing is, however, difficult when the data rates are close to 10 GB s-1. This bottleneck still hinders exploitation of the full potential inherent in the ultrafast acquisition speed. In this paper the fast reconstruction algorithm gridrec, highly optimized for conventional CPU technology, is presented. It is shown that gridrec is a valuable alternative to standard filtered back-projection routines, despite being based on the Fourier transform method. In fact, the regridding procedure used for resampling the Fourier space from polar to Cartesian coordinates couples excellent performance with negligible accuracy degradation. The stronger dependence of the observed signal-to-noise ratio for gridrec reconstructions on the number of angular views makes the presented algorithm even superior to filtered back-projection when the tomographic problem is well sampled. Gridrec not only guarantees high-quality results but it provides up to 20-fold performance increase, making real-time monitoring of the sub-second acquisition process a reality
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