Reproducibility of Ablated Volume Measurement Is Higher with Contrast-Enhanced Ultrasound than with B-Mode Ultrasound after Benign Thyroid Nodule Radiofrequency Ablation—A Preliminary Study

The reproducibility of contrast-enhanced ultrasound (CEUS) and standard B-mode ultrasound in the assessment of radiofrequency-ablated volume of benign thyroid nodules was compared. A preliminary study was conducted on consecutive patients who underwent radiofrequency ablation (RFA) of benign thyroid nodules between 2014 and 2016, with available CEUS and B-mode post-ablation checks. CEUS and B-mode images were retrospectively evaluated by two radiologists to assess inter- and intra-observer agreement in the assessment of ablated volume (Bland-Altman test). For CEUS, the mean inter-observer difference (95% limits of agreement) was 0.219 mL (-0.372-0.809 mL); for B-mode, the mean difference was 0.880 mL (-1.655-3.414 mL). Reproducibility was significantly higher for CEUS (85%) than for B-mode (27%). Mean intra-observer differences (95% limits of agreement) were 0.013 mL (0.803-4.097 mL) for Reader 1 and 0.031 mL (0.763-3.931 mL) for Reader 2 using CEUS, while they were 0.567 mL (-2.180-4.317 mL, Reader 1) and 0.759 mL (-2.584-4.290 mL, Reader 2) for B-mode. Intra-observer reproducibility was significantly higher for CEUS (96% and 95%, for the two readers) than for B-mode (21% and 23%). In conclusion, CEUS had higher reproducibility and inter- and intra-observer agreement compared to conventional B-mode in the assessment of radiofrequency-ablated volume of benign thyroid nodules

Poly(vinylidene fluoride) membranes by phase inversion: the role the casting and coagulation conditions play in their morphology, crystalline structure and properties

Flat membranes with controlled morphology, pore dimensions, mechanical properties and crystal structure were prepared by wet and dry wet phase inversion from polyvinylidene fluoride (PVDF). The effects of several parameters such as precipitation temperature, composition of the polymer solution (concentration, type of solvent), exposure time before immersion in the coagulation bath, type of coagulant on the sequence and the extent of the two phase separation processes, i.e. liquid-liquid and liquid-solid demixing (crystallization), were studied. Using solvent/nonsolvent pairs with different mutual affinity (DMA/water, DMA/C1-C8 alcohols), different morphologies were obtained. High casting solution temperature plays important role to increase the rate of the liquid-liquid demixing on the crystallization, i.e. the type of crystallites formed (α-type) also by using a soft coagulation bath. Exposure time before immersion favours the first type of phase separation and therefore once again crystallites of α type were observed. At room temperature, using C1-C8 alcohols as nonsolvents, the presence of crystallites of α type can be related to molar volume of the coagulant. © 2007 Elsevier Ltd. All rights reserved

Polymeric membranes modified via plasma for nanofiltration of aqueous solutions containing organic compounds

Polymeric nanofiltration membranes were prepared modifying via low temperature plasma treatment flat membranes based on a modified poly(ether ether ketone) (PEEKWC). PEEKWC membranes, prepared using wet phase inversion using methanol (M2m) and 1-butanol (M2b) as internal non-solvent, were further plasma surface modified (RF 13.56 MHz) introducing amino groups on the membrane using two different pre-treatment gases, Ar (M2bpsm/Ar/NH3 and M2mpsm/Ar/NH3) and H2 (M2bpsm/H2/NH3 and M2mpsm/H2/NH3). The performances of unmodified and plasma modified membranes M2b and M2m and of a commercial nanofiltration membrane (NFTFC50) were tested in treatment of aqueous solution containing two dyes, characterized by similar molecular weight (320 g/mol) and opposite charge, methylene blue and methyl orange, positively and negatively charged, respectively. The observed rejections resulted optimized in terms of fouling for the plasma modified membranes with respect to unmodified and commercial NFTFC50 membranes. In particular, methylene blue was retained for 100% by M2mpsm/Ar/NH3 with a relative flux of 100% compared to 100% and 95% rejections and 85% and 90% relative fluxes observed for unmodified PEEKWC M2b membrane and commercial NFTFC50, respectively

New ruthenium porphyrin polymeric membranes: preparation, characterization and catalytic activity in alkenes aziridination

In recent years the study of new materials in the field of catalysis has been attracted the attention of scientific world in order to prepare catalysts more stable, selective and with the possibility of their easy recovery and recycle. In this work we investigated the preparation and characterization of new catalytic polymeric membranes based on PVDF and PDMS polymers, entrapping a series of ruthenium porphyrin. Their behaviour as catalysts for olefins aziridination was studied

New Ruthenium Porphyrin Polymeric Membranes: Preparation and Characterization

In this work, the ruthenium porphyrin complex Ru(4-(CF3)TPP)CO (1) (TPP = dianion of tetraphenylporphyrin) was entrapped into polymeric membranes during the phase inversion process to obtain new heterogeneous catalysts for aziridination reactions. In order to study the effect of the polymeric environment on the activity of the metallic complex, symmetric dense polymeric catalytic membranes were prepared using three different polymers: polyethersulphone (PES), polysulphone (PSf) and Hyflon AD60X. Different hydrophobicity/hydrophilicity characteristics, sorption properties and ability to retain the metallic complex characterized the catalytic polymeric membranes. On the basis of the good results compared to the other two polymers, Hyflon AD60X was selected to prepare asymmetric membranes with a skin layer on an open sublayer. The Hyflon AD60X membranes showed good catalytic activity in the aziridination reaction of a-methylstyrene by aryl azides and moreover they have been recycled without any loss in azide conversion and aziridine selectivity

Reproducibility of DXA-based bone strain index and the influence of body mass: an in vivo study

Objectives: Bone strain index (BSI) is a dual-energy X-ray absorptiometry (DXA)-derived index of bone strength obtained from lumbar densitometric scan. We estimated the reproducibility of BSI in healthy women with different body mass index. Methods: We enrolled postmenopausal women (mean age ± SD: 66 ± 10 years) divided into three groups (A, B and C) according to body mass index (BMI: < 25; 25–29.9; ≥ 30 kg/m2) and two groups (D and E) according to waist circumference (WC: ≤ 88; > 88 cm), each of 30 subjects. They underwent two DXA examinations with in-between repositioning, according to the International Society for Clinical Densitometry guidelines for precision estimation. Bone mineral density (BMD) and BSI were expressed as g/cm2 and absolute value, respectively. The coefficient of variation (CoV) was calculated as the ratio between root-mean-square standard deviation and mean; least significant change percentage (LSC%) as 2.77 × CoV; reproducibility as the complement to 100% LSC. Results: BSI increased proportionally to BMI and WC and significantly in group C compared to B and A (p = 0.032 and 0.006, respectively). BSI was significantly higher in E compared to D (p = 0.017), whereas no differences were observed in BMD. Although BSI reproducibility was slightly lower in group C (89%), the differences were not significant between all groups. BMD reproducibility did not significantly differ between all groups. Conclusions: BSI reproducibility was significantly lower than that of BMD and decreased proportionally to BMI and WC increase. This reduction of BSI reproducibility was more pronounced in patients with BMI ≥ 30 and WC > 88, as expected, being BSI a parameter sensible to weight

Ti(IV)-based catalytic membranes for efficient and selective oxidation of secondary amines

Abstract\u2014The incorporation of homogenous Ti(IV)/trialkanolamine catalyst in polymeric membranes provided new polymeric catalytic Ti(IV)-based membranes, stable and efficient as heterogeneous catalysts for chemoselective oxidations of secondary amines to nitrones by alkyl hydroperoxides. Polyvinylidene fluoride (PVDF)-based catalytic membranes gave the best results affording products in short reaction times, high yields and selectivity using as little as 1% of catalyst, comparable with the performances of the corresponding homogeneous system. PVDF\u2013Ti membrane could be recycled up to five runs with no loss of activit

Catalytic Polymer Membranes under Forcing Conditions : Reduction of Nitrobenzene by CO/H2O Catalyzed by Ruthenium Bis(arylimino)acenaphthene Complexes

Polymeric membranes embedding a metal complex have been previously employed as reusable catalysts under relatively mild conditions. In this paper we report the first example of a polymeric catalytic membrane employed under very forcing conditions (160 \ub0C and 50 bar CO). The reaction investigated was the reduction of nitrobenzene to aniline by CO/H2O catalyzed by ruthenium Ar-BIAN (Ar-BIAN = bis-(arylimino)acenaphthene) complexes. To better retain the complex in the membrane a modified ligand was prepared having long alkyl chains in the para positions of the aryl rings. Among several polymers tested, PEEK-WC gave best results. Attempts to embed the ligand only in the membrane and functionalize it with the metal later, analogously to the in situ generation of the active species practiced for the homogeneous system, failed and it was necessary to synthesize new complexes that could be reduced under the reaction conditions. Best results were obtained using Ru(Ar-BIAN)(CO)2Cl2 + Et3N. During the reaction the complex is transformed into a mixture of Ru3(CO)12 and a reduced form of the ligand, Ar-BIANH2. The latter was independently prepared and shown to be able to reduce nitrobenzene even in the absence of any metal. A new kind of support was designed to allow the placing of the membrane in a stirred autoclave. Using only water as solvent, no metal or ligand leaching was observed and several recycles were performed. All employed membranes were thoroughly characterized by different techniques