Search

One of the membrane-based technique for harvesting salinity gradient energy is Reverse Electrodialysis (RED). Most of the studies in literature are based on utilizing river and seawater by mimicking them with NaCl solutions. However, real solutions contain many different ions; this study deals with the impact of Mg2+ ion on power density (Pd). Investigations have been carried out using six solutions of NaCl and MgCl2 prepared in varying compositions from 0 % to 100 %. Increasing Mg2+ concentration resulted in a remarkable decrease of Pd and open circuit voltage (OCV), and in a significant increase in stack resistance Rstack. Electrochemical impedance test (EIS) and ion chromatography analysis helped to clarify reasons for loss of power. In particular, it was found out that dominant negative contribution is due to increasing Cation Exchange Membrane (CEM) resistance in the presence of Mg2+.

Learning objectives Background Imaging findings OR Procedure details Conclusion Personal Information References, Learning objectives: To review the pathological basis of pigmented villonodular synovitis and bursitis. To describe the radiological manifestations of pigmented villonodular synovitis and bursitis using conventional radiography (CR), ultrasonography (US) and magnetic...

OBIETTIVI DIDATTICI: Rivedere le basi patologiche della “Sinovite Villonodulare Pigmentosa” (PVNS) e della “Borsite Villonodulare Pigmentosa” (PVNB). Descriverne le caratteristiche alla radiografia convenzionale (RX), all’ecografia (US) ed alla risonanza magnetica (RM). INTRODUZIONE: La PVNS è un raro disordine proliferativo della sinovia articolare che si manifesta in forma diffusa o focale; può insorgere anche nelle borse peri-articolari (PVNB). Entrambe le forme interessano principalmente i giovani adulti e si manifestano con sintomi aspecifici che mimano altre patologie, anche di natura traumatica, ritardando spesso la diagnosi corretta. DESCRIZIONE: Il quadro RX può essere normale o rivelare una massa di significato aspecifico nei tessuti molli. L’US può evidenziare versamento articolare, noduli iperecogeni o un ispessimento della sinovia. La RM dimostra l’estensione della patologia (particolarmente nei casi di coinvolgimento bursale) e la caratteristica ipointensità di segnale sia nelle sequenze T1 che T2-pesate. Inoltre, le sequenze gradient-echo mostrano un segno patognomonico di questa patologia che è rappresentato dall’artefatto di “blooming”, causato dalla suscettibilità magnetica dovuto ai depositi di emosiderina intracellulare. CONCLUSIONI: Per la diagnosi e per il corretto trattamento dei pazienti con PVNS e/o PVNB l’imaging, in particolare la RM, ha un ruolo fondamentale nell’identificare la sede e dimostrare l’estensione della patologia. Inoltre, la presenza di depositi di emosiderina nei noduli aumenta la confidenza diagnostica della RM.

INTRODUCTION: Pigmented villonodular synovitis (PVNS) represents an uncommon benign proliferative disorder that may involve the synovium of the joint diffusely or focally, or that may occur extraarticularly in a bursa (pigmented villonodular bursitis [PVNB]) or tendon sheath (pigmented villonodular tenosynovitis [PVNTS]). The knee, followed by the hip, is the most common location for PVNS or PVNB, whereas PVNTS occurs most often in the hand and foot. It primarily involves young adults, the peak age being between the second and fourth decade of life and appears with non-specific symptoms which mimic other pathologies, including traumatic knee injuries, thus often delaying the correct diagnosis. REPORT/DISCUSSION: A 17 year old female presented with swelling and mild degree of pain in her left knee for three months. No history of trauma or any other significant illness was present. Routine laboratory investigations were normal. X-ray was normal. MRI of the knee was performed and it showed a joint effusion with non-specific synovial proliferation and two focal nodular formations at the insertion of medial head of gastrocnemius muscle in the medial gastrocnemius bursa. Those two nodular formations had low signal intensity on all pulse sequences and bloom artifacts on the FGRE-sequence. T1 weighted fat-saturated gadolinium enhanced MR image showed a low marginal contrast-enhancement of the two nodular formations, and high contrast-enhancement of the synovial proliferation. Biopsy from the two lobulated nodules revealed synovial nodules which contained haemosiderin pigment. Imaging characteristics of PVNS and PVNB are almost the same: radiographically visible calcifications are rare; CT scans show the lesions as high attenuating because of the haemosiderin content; MRI findings are prominent low signal intensity (seen with T2-weighting) and "blooming" artifacts from the hemosiderin deposits (seen with gradient-echo sequences) that are nearly pathognomonic. In addition, MR imaging is optimal for evaluating lesion extent. This information is crucial to guide treatment and to achieve complete surgical resection.

Solid oxides protonic conductors are prepared by doping the pure matrix compounds with cationic species. Barium cerate and barium zirconate are perovskite-like compounds, characterized by a network of corner-sharing MeO6 octahedra (Me=Ce, Zr). Barium lies in the cavities between octahedra. Insertion of trivalent species in the octahedral site involves the formation of charge- compensating oxygen vacancies, that can be filled by hydroxyls coming from dissociative water absorption. Then, proton delocalization among structural oxygens ensures conductivity. The most effective conductors are obtained by yttrium doping that, on the other hand, enters only in limited amounts in both BaZrO3 and BaCeO3, thus involving limited carrier concentration. Perovskites are affected by different drawbacks: barium cerate compounds are very sensitive to the acidic components present in the environment and in particular to CO2 that induces decomposition in barium carbonate and cerium oxide; barium zirconate, notwithstanding a very high bulk conductivity, is biased by high grain boundary resistivity. A possible alternative to perovskite-like compounds is constituted by fergusonite-type lanthanum niobate and lanthanum tantalate compounds, characterized by a tetrahedral coordination of Nb and Ta. These oxides present a very high chemical stability but very low carrier concentration, usually induced by Ca-doping the lanthanum site [1]. Among the different trivalent dopants, it was demonstrated by X-ray absorption spectroscopy that indium is able to enter in any composition in the perovskite network, thus providing a very high carrier concentration, even if with lower proton mobility. This property of indium was ascribed to its electronic structure and in particular to the low Pearson hardness, allowing this cation to fit in a hosting matrix with the least structural strain [2]. A preliminar attempt of exploiting indium for enhancing the carrier concentration of lanthanum niobate was carried out. The solid state synthesis involved amounts of the reactant simple oxides suitable to force indium doping of the niobium site. X-ray diffraction do not show significant amounts of secondary oxide phases.

ObjectivesSurvival of patients with cervical cancer is strongly associated with the local extent of the primary disease. The aim of the study was to develop an integrated diagnostic algorithm, including ultrasonography (USG), magnetic resonance imaging (MRI), and examination under anesthesia, to define the local extent of disease in patients with newly diagnosed cervical cancer.MethodsPatients with biopsy proven cervical cancer who underwent primary surgery from January 2013 to December 2018 in four participating centers were recruited. Patients who underwent USG, MRI, and examination under anesthesia prior to surgery were included in the study. Those for whom complete data were not available were excluded. Data regarding tumor size, parametrial invasion, and vaginal involvement obtained by USG, MRI, and examination under anesthesia were retrieved and compared with final histology. Specificity and sensitivity of the three methods were calculated for each parameter and the methods were compared with each other. An integrated pre-surgical algorithm was constructed considering the accuracy of each diagnostic method for each parameter.ResultsA total of 79 consecutive patients were included in the study. Median age was 53 years (range 28–87) and median body mass index was 24.6 kg/m2 (range 16–43). Fifty-five (69.6%) patients had squamous carcinoma, 18 (22.8%) patients had adenocarcinoma, and six (7.6%) patients had other histological subtypes. A statistically significant difference among the three methods was found for detecting tumor size (p=0.002 for tumors >2 cm and p=0.006 for tumors >4 cm) and vaginal involvement (p=0.01). There was no difference in detection of parametrial invasion between USG, MRI, and examination under anesthesia (p=0.26). Furthermore, regarding tumor size assessment, USG was found to be the significantly better method (p2 cm and p=0.02 for tumors >4 cm). Examination under anesthesia was the most accurate method for detection of vaginal involvement (p=0.01). Examination under anesthesia and MRI had higher accuracy than USG for identification of parametrial invasion. Application of the algorithm provided the correct definition of local extent of disease in 77.2% of patients (p=0.04). USG was the most accurate method to determine tumor size, while examination under anesthesia was found to be more accurate in prediction of vaginal involvement.ConclusionOur integrated diagnostic algorithm allows a higher accuracy in defining the local extent of disease and may be used as a tool to determine the therapeutic approach in women with cervical cancer.

La1-xBa1+xGaO4-0 (LBG) compounds, based on unconnected GaO4 moieties, were recently proposed as proton conductors. Protonic defects in the lattice are inserted through self-doping with Ba2+, to create oxygen vacancies subsequently filled by hydroxyl ions. We present a combined structural analysis on self-doped LBG using X-ray diffraction (XRD) and X-ray absorption (EXAFS): these results unravel the finer structural details on the short-range and long-range scales, and they are correlated with the dynamical properties of protonic conduction coming from vibrational spectroscopy. The structure of the GaO4 groups is independent of the oxide composition. On hydration, an array of short intertetrahedral hydrogen bonds is formed, producing a contraction of the a axis. On the basis of thermogravimetric analysis, EXAFS, XRD and infrared spectroscopy (IR) results, we propose that the stiffness of the GaO4 tetrahedra hinders the intratetrahedral proton transfer, while the noticeable fraction of protons involved in strong hydrogen bonds limit the proton reorientational freedom.

Lanthanum barium gallate proton conductors are based on disconnected GaO4 groups. The insertion of hydroxyls in the LaBaGaO4 network proceeds through self-doping with Ba2+, consequent O2- vacancy formation to fulfill charge neutrality. With a structural investigation on self-doped LaBaGaO4 oxides using synchrotron XRD and EXAFS on the Ga K-edge, we find that: (a) the GaO4 tetrahedra retain their size throughout the whole series; (b) the GaO4 tetrahedra rotate as rigid bodies on hydration, leading to the formation of a network of shorter O-O configurations that are stabilized by hydrogen bonds; (c) contraction of the lattice occurs along the a unit cell axis, as a consequence of an overall structural rearrangement of the hydrated solid.

Bronchial artery embolisation (BAE) is an accepted method of controlling haemoptysis in patients with cystic fibrosis. However, anomalous origin of the bronchial arteries, documented in anatomical and angiographic studies, makes the procedure more difficult and increases the number of recurrences. Clinical records and films from three patients affected by cystic fibrosis with haemoptysis, in which the origin of the bleeding vessels was considered anomalous, out of a total of seven patients who underwent BAE, were reviewed. In two patients the source of bleeding was identified from, respectively, the left and the right internal mammary artery and in one from the left thyrocervical trunk. All the vessels considered to be the possible source of haemoptysis were embolised; immediate control of haemoptysis after embolisation was achieved in all patients, but minor haemoptysis recurred in two patients who were conservatively treated. In haemoptysis in patients with cystic fibrosis the possibility of anomalous origin of the bronchial arteries should be considered. This frequency may be higher than in other pulmonary diseases that cause haemoptysis, so a search for anomalous bronchial arteries is mandatory to achieve accurate embolisation and reduce the rate of recurrence.