Sound field control with hemi-cylindrical loudspeaker arrays

An acoustical model for the sound field generated by hemi-cylindrical loudspeaker arrays is presented and a method for beamforming with said arrays is derived. The sound field model is obtained by introducing two independent boundary conditions for the sound field of a single impinging plane wave. The model for the radiation from a single loudspeaker in the array is then obtained from the reciprocity principle. Various beam patterns are presented and the theoretically predicted sound field is evaluated as a function of frequency. The results are discussed and an experimental array prototype is presented

Editorial of Special Issue "Embolization Techniques: State of the Art and Future Perspectives"

Embolization is one of the most important applications in interventional radiology which can be mainly performed using an endovascular approach [...]

Accurate Extraction of Equivalent Circuit Parameters of Spiral Resonators for the Design of Metamaterials

Spiral resonators (SRs) are one of the most common typologies of resonant magnetic unit cell for the realization of metamaterials. The precise knowledge of their lumped electric properties (RLC parameters) is of crucial importance in the metamaterial design. Thus, an accurate and unambiguous procedure for estimating the value of the RLC lumped parameters of compact SRs is introduced. The proposed procedure relies on a rigorous approach allowing a complete characterization of SRs also in terms of Q-factor. The method is general and valid for other shapes of resonators. The estimations have been finally verified by performing measurements on fabricated SRs through a magnetic probe

A stepwise transmission/reflection multiline-based algorithm for broadband permittivity measurements of dielectric materials

Transmission/reflection (T/R) techniques for measuring dielectric material's complex permittivity are broadband but have usually problems when the length of the tested sample is a multiple of λ/2. In this paper, we apply a stepwise scheme to a multiline T/R measurement method that solve those ambiguity problems thus allowing wideband and accurate permittivity estimation

Knockout of the Glucocorticoid Receptor Impairs Reproduction in Female Zebrafish

none8The pleiotropic effects of glucocorticoids in metabolic, developmental, immune and stress response processes have been extensively investigated; conversely, their roles in reproduction are still less documented. It is well known that stress or long-lasting therapies can cause a strong increase in these hormones, negatively affecting reproduction. Moreover, the need of glucocorticoid (GC) homeostatic levels is highlighted by the reduced fertility reported in the zebrafish glucocorticoid receptor mutant (nr3c1ia30/ia30) line (hereafter named gr-/-). Starting from such evidence, in this study, we have investigated the role of glucocorticoid receptor (Gr) in the reproduction of female zebrafish. Key signals orchestrating the reproductive process at the brain, liver, and ovarian levels were analyzed using a multidisciplinary approach. An impairment of the kiss-GnRH system was observed at the central level in (gr-/-) mutants as compared to wild-type (wt) females while, in the liver, vitellogenin (vtg) mRNA transcription was not affected. Changes were instead observed in the ovary, particularly in maturing and fully grown follicles (classes III and IV), as documented by the mRNA levels of signals involved in oocyte maturation and ovulation. Follicles isolated from gr-/- females displayed a decreased level of signals involved in the acquisition of competence and maturation, causing a reduction in ovulation with respect to wt females. Fourier transform infrared imaging (FTIRI) analysis of gr-/- follicle cytoplasm showed major changes in macromolecule abundance and distribution with a clear alteration of oocyte composition. Finally, differences in the molecular structure of the zona radiata layer of gr-/- follicles are likely to contribute to the reduced fertilization rate observed in mutants.openMaradonna, Francesca; Gioacchini, Giorgia; Notarstefano, Valentina; Fontana, Camilla Maria; Citton, Filippo; Dalla Valle, Luisa; Giorgini, Elisabetta; Carnevali, OlianaMaradonna, Francesca; Gioacchini, Giorgia; Notarstefano, Valentina; Fontana, Camilla Maria; Citton, Filippo; Dalla Valle, Luisa; Giorgini, Elisabetta; Carnevali, Olian

Plasma-mediated radiofrequency ablation followed by percutaneous cementoplasty under fluoro-CT guidance: a case report

We report a case of a 81-year-old Caucasian man with colorectal carcinoma, treated by surgery in 1998, referred for palliative treatment of a refractory painful caused by osteolytic metastases of 2.5 cm in back-upper ilium spine. Plasma-mediated radiofrequency ablation was performed under conscious sedation, using Fluoroscopic Computer Tomography guidance. After completing the ablation phase of the procedure, a mixture of bone cement and Biotrace sterile barium sulfate was injected into the ablated cavity

Ablation of painful metastatic bone tumors: A systematic review

AbstractThe pain is the most common problem in patients with bone metastases. It is not related to the characteristics of the tumor (type, location, number or size of metastases). Currently, the bone metastases can be treated with chemotherapy, hormonal therapy, surgery and radiotherapy, but the drugs most used in the treatment of pain are opioids. These drugs give benefit between 8 and 12weeks and often give non-negligible toxic effects. Percutaneous techniques are varied and, when there is indication, can be used to reduce pain and dose of morphine in these patients, being safe and effective techniques already at 4weeks of treatment.The choice of a methodical of ablation compared to another depends on the type, size and location of the lesion. Moreover, the combined treatments of ablation and cementoplastic are also useful to stabilize the bone lesion.This review article analyzes techniques and effectiveness of percutaneous treatments of skeletal metastases

Ichthyosauria. Soluzioni multidisciplinari per la lettura integrata dell’Appennino emiliano a partire dal rinvenimento dell’ittiosauro di Neviano degli Arduini

The ‘Inter Amnes. Archeologia tra Enza, Parma e Baganza’ project in the framework of the Programma ‘S.F.E.R.A. Spazi e Forme dell’Emilia Romagna Antica’ of the University of Parma has promoted a series of survey campaigns on the Parma Apennines, previously never involved in surface reconnaissance. The research was conducted by a multidisciplinary team aimed at highlighting the various peculiarities of the territory from a geological, archaeological, historical, and paleontological point of view, with a view to reconstruct the evolutionary dynamics of the landscape. Among the most relevant discoveries is the discovery of ten fossil ichthyosaur caudal vertebrae from a ‘Chaotic Complex’ in the Apennines of western Emilia and found during the reconnaissance for the mapping of fossil deposits. Compared to the great majority of vertebrate remains from the units of the ‘Chaotic Complex’, usually represented by isolated or damaged skeletal elements, the specimen preserves the original relationships between the different vertebral elements. The biostratigraphic analysis of the fossil made it possible to recognize a micro-paleontological association attributable to the Aptian stage (Lower Cretaceous). Starting from the systematic palaeontological analysis, the discovery is also brought back here to its context for an integrated, diachronic, and multidisciplinary re-reading of the ancient landscapeIl progetto   Inter Amnes. Archeologia tra Enza, Parma e Baganza nella cornice del Programma S.F.E.R.A. Spazi e Forme dell’Emilia Romagna Antica dell’Università di Parma, ha promosso una serie di campagne di survey sull’Appennino parmense, in precedenza mai interessato da ricognizioni di superficie.  Le ricerche sono state condotte da un team multidisciplinare volto a mettere in luce le diverse peculiarità del territorio sotto il profilo  geologico, archeologico, storico, paleontologico, nella prospettiva di una ricostruzione delle  dinamiche evolutive del paesaggio. Tra i rinvenimenti più rilevanti si segnala la scoperta di 9 vertebre caudali fossili di Ittiosauro provenienti da un “Complesso Caotico” negli Appennini dell’Emilia occidentale ritrovate durante le perlustrazioni per la mappatura dei giacimenti fossiliferi. Rispetto alla grande maggioranza dei resti di vertebrati delle unità del "Complesso Caotico", solitamente rappresentati da elementi scheletrici isolati o danneggiati, l'esemplare conserva le relazioni originali tra i diversi elementi vertebrali. Configura quindi un modello che richiede impostazioni deposizionali relativamente a bassa energia e quindi sfida il tradizionale scenario “ad alta energia” per la genesi dei fossili del “Complesso Caotico”. La presenza sia di ittiosauri e di talattosuchi nell'Aptiano d'Italia supporta la persistenza nella Tetide occidentale della comunità di rettili pelagici di grosso corpo tipici del Giurassico medio e tardo-lungo e la prima metà del Cretaceo inferiore. Muovendo dall’analisi paleontologica sistematica il rinvenimento viene ricondotto in questa sede anche al suo contesto per una rilettura integrata, diacronica e multidisciplinare del paesaggio antico

Transcatheter Aortic Valve Implantation (TAVI) Planning with Dual-Layer Spectral CT Using Virtual Monoenergetic Image (VMI) Reconstructions and 20 mL of Contrast Media

Transcatheter aortic valve implantation (TAVI) is a less invasive alternative to surgical implantation and its implementation is progressively increasing worldwide. We routinely perform pre-procedural aortic angiography CT to assess aortic dimensions and vascular anatomy. This study aims to evaluate the image quality of CTA for TAVI planning using dual-layer spectral CT, with virtual monoenergetic image reconstructions at 40 keV. Thirty-one patients underwent a CTA protocol with the injection of 20 mL of contrast media. Image quality was assessed by measuring the mean density in Hounsfield Units (HU), the signal-to-noise ratio, and the contrast-to-noise ratio in VMI reconstructions. Additionally, a blinded subjective analysis was conducted by two observers. The results showed significant enhancement at all sampled vascular levels with a gradual decrease in HU from proximal to distal regions. Favourable subjective ratings were given for all parameters, with greater variability in the evaluation of iliac axes. A significant negative correlation (p < 0.05) was observed between BMI and CA at all vascular levels, indicating reduced contrast enhancement with increasing BMI. Spectral CT, along with reducing iodine load, allows for obtaining high-quality images without a significant increase in noise. The reduction in iodine load can have positive implications in clinical practice, improving patient safety and resource efficiency

Combined Trans-Arterial Embolization and Ablation for the Treatment of Large (>3 cm) Liver Metastases: Review of the Literature

Background: The aim of this review was to determine the state of clinical practice in the role of the combined approach of embolization and ablation in patients with secondary liver lesions greater than 3 cm who are not candidates for surgery, and to study its safety and efficacy. (2) Methods: Two reviewers conducted the literature search independently. Eight articles on the combined approach of embolization and ablation in secondary liver lesions were selected. (3) Results: The studies were published between 2009 and 2020. Two studies were prospective in design. The sample size was < 100 patients for all studies. All studies demonstrated the safety of the combined approach based on the low complication rate. Some studies lamented non-uniform systemic chemotherapy regimens and the variability in the sequence of embolization and ablation. (4) Conclusions: This review presents the combined approach of ablation and embolization in liver lesions greater than 3 cm as a safe therapeutic procedure with positive effects on patient survival. Prospective and multicentric studies are needed to further evaluate its efficacy