14 research outputs found
Un approccio di tipo ricorsivo per la ricostruzione del pattern completo di un sistema radiante
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NF–FF transformation with bi-polar scanning from nonuniformly spaced data
No full textAn efficient probe compensated near-field-far-field transformation technique from irregularly spaced bipolar samples is developed in this paper. The singular value decomposition method is applied to recover the uniformly distributed data, whose position is fixed by a nonredundant sampling representation of the electromagnetic field. Then an optimal sampling interpolation algorithm is used for reconstructing the plane-rectangular samples required to carry out the standard near-field-far-field transformation. This last step is required to benefit by the use of FFT algorithm. Numerical examples are reported to assess the effectiveness of the proposed technique
A nonredundant sampling technique for mapping the satellite antenna radiation intensity on the earth
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Probe compensated NF–FF transformation with cylindrical scanning from a minimum number of data
No full textError filtering in the NF–FF transformation with cylindrical scanning
No full textMeasurement techniques in the antenna near-field (NF) region have a significant role in the evaluation of far-field (FF) patterns. In fact, for electrically large antennas the required size of the conventional FF range becomes prohibitively large. Moreover, NF facilities provide a controlled and secure environment, and all weather capability. Among the NF-FF transformation techniques, that employing the cylindrical scanning (Fig. 1) is particularly attractive. In fact, at the cost of a moderate increase in the analytical and computational complication with respect to the planar scannings, it allows the reconstruction of the antenna complete radiation pattern save for the zones surrounding the spherical poles
A Systematic Review on the Role of Matrix Metalloproteinases in the Pathogenesis of Inguinal Hernias
No full textThe recurrence rate in patients who undergo surgery for abdominal wall hernias (AWHs) is high. AWHs have been hypothesized to be a disease of the extracellular matrix, which is supported by evidence showing a high incidence of AWHs in patients with connective tissue disorders. This study aimed to investigate the most recent literature studies describing the levels of several matrix metalloproteinases (MMPs) in the blood and fascia, with the objective of better clarifying the pathogenetic role of matrix metalloproteinases (MMPs) and their inhibitors in inguinal hernias (IHs). A systematic literature search was conducted using the PubMed, Scopus, and Web of Science electronic databases to identify eligible studies. The identified studies were included in the analysis, and a qualitative synthesis of the results is provided to describe the most recent findings. Seventeen studies were included. An association between MMP-2 and direct IHs has also been demonstrated. MMP-1, MMP-2, MMP-9, MMP-12, and MMP-13 levels were increased in both the serum and fascia of patients with IHs. The analysis of inhibitors showed an increase in tissue inhibitors of metalloproteinases (TIMPs), specifically TIMP-1 in IHs, particularly in direct hernias, and a reduction in TIMP-2 in the biopsy samples of the transversalis fascia. In contrast, a reduction in TIMP-1 and an increase in TIMP-2 levels have been reported only in the serum of patients with IHs. Metalloproteinases play a crucial role in the pathogenesis of IHs. The analysis of other molecules, such as TIMPs or their correlation with specific genes, is enhancing our understanding of the pathophysiology of IHs. However, more prospective studies, including comprehensive clinical and laboratory data collection, are required to confirm the relationship between the studied biomarkers and the risk of IHs
