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La terapia nutrizionale è uno dei cardini della terapia conservativa dell'Insufficienza Renale Cronica (IRC). È in grado di contrastare segni, sintomi e complicanze dell'insufficienza renale, di procrastinare l'inizio della dialisi e di mantenere lo stato nutrizionale. La dieta deve essere ridotta in proteine perché molte delle tossine e dei cataboliti ritenuti derivano dalle proteine esogene, e perché la restrizione proteica rappresenta una condizione necessaria, anche se non sufficiente, per la contestuale riduzione dell'apporto di sodio e fosforo che contribuisce agli effetti terapeutici. Altra caratteristica fondamentale della terapia dietetica è l'adeguatezza energetica. I due casi descritti rappresentano quello che spesso accade nella pratica clinica nel paziente con IRC cui viene prescritta una dieta ipoproteica, e sottolineano l'importanza del counselling dietetico per la sicurezza e l'efficacia della terapia nutrizionale nel paziente renale con o senza diabete mellito.

La nutrizione è considerata dalla legislazione sanitaria corrente parte integrante della prevenzione e terapia clinica, e quindi del processo assistenziale. In questa ottica il servizio di ristorazione di un ospedale rappresenta un potente ausilio terapeutico ed educazionale. Il servizio di ristorazione della nostra Azienda Ospedaliera-Universitaria Pisana si basa sul Dietetico, una raccolta di diete standardizzate a composizione bromatologica definita, nel quale vengono indicate anche le finalità e le caratteristiche dei pazienti a cui si rivolge. Questo articolo riporta la nostra esperienza in questo settore, con particolare riguardo alle diete speciali per i pazienti nefropatici. Le diete speciali, come la dieta ipoproteica (0.6 g/kg p.c./die) ipofosforica, la dieta ipoproteica (0.7 g/kg p.c./ die) vegetariana e la dieta fortemente ipoproteica (0.3 g/kg p.c./die) ipofosforica sono prescritte dal medico, elaborate dal dietista e formulate per il singolo paziente. Sin dalla sua preparazione la dieta speciale ipoproteica presenta diversi punti critici (elaborazione-confezionamento e distribuzione della dieta, mancata personaliz-zazione, prodotti artificiali aproteici). Allo scopo di migliorare il servizio dietetico abbiamo rilevato l'effettivo consumo e la gradevolezza dei pasti speciali ipoproteici distribuiti durante la degenza mediante la compilazione di due schede consegnate ai pazienti nel corso della degenza. Nel complesso i risultati indicano una buona accettazione delle diete da parte dei pazienti, ma con un ridotto consumo in particolare riguardante il pane aproteico.

Mind wandering (MW), a shift of attention away from external tasks toward internally generated thoughts, has been frequently associated with costs in reading comprehension (RC), although with some contrasting results and many reported potential intervening factors. The aim of the meta-analysis was to evaluate the relationship between MW and RC, considering the role of participants' and text's characteristics, as well as methodological issues in the measurement of the two constructs. From a set of 25 selected full texts (73 correlation coefficients), pooled correlation (r = -0.21) revealed a negative significant relationship. Using trait-based questionnaires to assess MW compared with online probes resulted in an average significant change of 0.30 in the correlation between MW and RC, leading to a null correlation. A significant effect of age was also found, with more negative correlations with increasing age. None of the other moderating variables considered (i.e., language, text type, text length, RC assessment, text difficulty, text interest, and working memory) resulted in a significant effect. From the present meta-analysis, we might suggest that MW and RC are partially overlapping and vary, within a swing effect, in relation to a set of shared factors, such as working memory, interest, and text length. There might also be side-specific factors that drive the movement of primarily one side of the swing, and future research should further consider the role of individual differences in RC. Implications for research and educational settings are discussed., (© 2022. The Author(s).)

The effect of Zr addition on the melting temperature of the CoCrFeMnNi High Entropy Alloy (HEA), known as the "Cantor's Alloy", is investigated, together with its micro-structure, mechanical properties and thermomechanical recrystallization process. The base and Zr-modified alloys are obtained by vacuum induction melting of mechanically pre-alloyed powders. Raw materials are then cold rolled and annealed. recrystallization occurred during the heat treatment of the cold-rolled HEA. The alloys are characterized by X-ray diffraction, electron microscopy, thermal analyses, mechanical spectroscopy and indentation measures. The main advantages of Zr addition are: (1) a fast vacuum induction melting process; (2) the lower melting temperature, due to Zr eutectics formation with all the Cantor's alloy elements; (3) the good chemical alloy homogeneity; and (4) the mechanical properties improvement of re-crystallized grains with a coherent structure. The crystallographic lattice of both alloys results in FCC. The Zr-modified HEA presents a higher recrystallization temperature and smaller grain size after recrystallization with respect to the Cantor's alloy, with precipitation of a coherent second phase, which enhances the alloy hardness and strength.

Background: Post-transplant lymphoproliferative disorder (PTLD) is a severe complication of solid organ transplantation that can be classified into two major subtypes, namely, early lesions and non-early lesions, based on histopathological findings. In the vast majority of cases, proliferating cells are B lymphocytes and, most frequently, proliferation is induced by Epstein-Barr virus (EBV) infection., Methods: The aim of our study was to evaluate the natural history of EBV infection and its possible evolution toward PTLD in a pediatric cohort of patients who received a renal transplant between January 2000 and December 2013. A total of 304 patients were evaluated for this study, of whom 103 tested seronegative for EBV at transplantation., Results: Following transplantation, 50 of the 103 seronegative patients (48.5%) developed a first EBV infection, based on the results of PCR assays for EBV DNA, with 19 of these patients ultimately reverting to the negative state (<3000 copies/ml). Among the 201 seropositive patients only 40 (19.9%) presented a reactivation of EBV. Non-early lesions PTLD was diagnosed in ten patients, and early lesions PTLD was diagnosed in five patients. In all cases a positive EBV viral load had been detected at some stage of the follow-up. Having a maximum peak of EBV viral load above the median value observed in the whole cohort (59,909.5 copies/ml) was a significant and independent predictor of non-early lesions PTLD and all PTLD onset., Conclusions: A high PCR EBV viral load is correlated with the probability of developing PTLD. The definition of a reliable marker is essential to identify patients more at risk of PTLD and to personalize the clinical approach to the single patient.

The assessment of pulmonary congestion in maintenance hemodialysis (MHD) patients is challenging. Bioelectrical impedance analysis (BIA) can estimate body water compartments. Natriuretic peptides are markers of hemodynamic stress, neurohormonal activation and extracellular volume overload. Lung ultrasound (LUS) has been proposed for the non-invasive estimation of extravascular lung water through B-lines assessment. Up to now, no study evaluated the correlation between B-lines, segmental thoracic BIA, and natriuretic peptides in MHD patients. The aims of this study were: (1) To validate LUS as a tool for an effective and timely evaluation of pulmonary congestion in MHD patients, in comparison with segmental thoracic BIA, and with natriuretic peptides; (2) To compare a comprehensive whole chest ultrasound scanning with a simplified and timely scanning scheme limited to the lateral chest regions.Thirty-one MHD adult patients were examined. LUS, total body and thoracic BIA, and natriuretic peptides were performed immediately before and after a mid-week dialysis session. The number of B-lines assessed by LUS was compared with total body and thoracic impedance data and with natriuretic peptides.Pre-HD B-lines ranged 0-147 (mean 31) and decreased significantly post-HD (mean 16, P < 0.001). A significant correlation was found between the number of B-lines and extra-cellular water index (ECWI, r = 0.45, P < 0.001), with thoracic impedance (r = 0.30, P < 0.05), and with BNP (r = 0.57, P < 0.01). The dynamic changes in B-lines correlated better with thoracic impedance than with total body impedance, and correlated with extra-cellular but not with intra-cellular water index. The correlation between B-lines and ECWI was similar when LUS was limited to the lateral chest regions or performed on the whole chest. Multivariate analysis showed that only segmental thoracic impedance was an independent predictor of residual pulmonary congestion.The dynamic changes in B-lines after hemodialysis are correlated to the changes in total body and extra-cellular water, and particularly to lung fluids removal. B-line assessment in MHD patients is highly feasible with a simplified and timely scanning scheme limited to the lateral chest regions. These premises make B-lines a promising biomarker for a bedside assessment of pulmonary congestion in MHD patients.

Background: Ultraviolet (UV) absorbance of spent dialysate has been proposed as a method for monitoring hemodialysis efficiency. The contribution of the various uremic toxins to UV absorption, however, needs clarifying., Methods: Urea, creatinine and uric acid were measured in blood and dialysate before and during dialysis in 22 maintenance hemodialysis patients. Absorbance was measured in dialysate., Results: High-performance liquid chromatography (HPLC) analyses of dialysate revealed uric acid as the predominant peak. Spent dialysate absorbance decreased, during dialysis, similarly to serum and dialysate urea, creatinine and uric acid. Dialysate urea correlated closely with absorbance, though urea did not contribute to absorbance, which was determined mostly by uric acid. Uric acid and urea removals were very similar. The spectrophotometric Kt/V correlated with spKt/V urea, with slight but significant differences between the two measurements., Conclusions: UV absorbance is determined mostly by uric acid. Absorbance measurements seem suitable as a method for monitoring dialysis efficiency.

The ability to control cell-surface interactions in order to achieve binding of specific cell types is a major challenge for microfluidic immunoaffinity cell capture systems. In the majority of existing systems, the functionalized capture surface is constructed of solid materials, where flow stagnation at the solid-liquid interface is detrimental to the convection of cells to the surface. We study the use of ultra-high porosity (99%) nanoporous micro-posts in microfluidic channels for enhancing interception efficiency of particles in flow. We show using both modelling and experiment that nanoporous posts improve particle interception compared to solid posts through two distinct mechanisms: the increase of direct interception, and the reduction of near-surface hydrodynamic resistance. We provide initial validation that the improvement of interception efficiency also results in an increase in capture efficiency when comparing nanoporous vertically aligned carbon nanotube (VACNT) post arrays with solid PDMS post arrays of the same geometry. Using both bacteria (∼1 μm) and cancer cell lines (∼15 μm) as model systems, we found capture efficiency increases by 6-fold and 4-fold respectively. The combined model and experimental platform presents a new generation of nanoporous microfluidic devices for cell isolation.

When a renal mass is suspected, conventional ultrasound and color Doppler imaging are often used for initial assessment. Ultrasound screening has many advantages over contrast-enhanced CT and MRI, such as accessibility, low costs, and no need for intravenous iodine contrast administration or ionizing radiation. Sonography is very helpful to distinguish cystic from solid lesions and to monitor the growth and structural pattern of cysts. Detection of small renal carcinoma of less than 3 cm in diameter is limited, however, and small tumors are detected by conventional ultrasound only in 67-79% of cases. In fact, small renal malignancies may have an echogenicity similar to the normal renal parenchyma. In these cases it is very hard to distinguish the tumor, particularly when there is no evident disarrangement of the normal renal contours and no extension into the central renal complex. Renal cell carcinoma can also be hypo- or hyperechoic and indistinguishable from renal adenoma/oncocytoma or angiomyolipomas, which are commonly described as hyperechoic masses. In other words, the pattern and ultrasound characteristics of renal masses often overlap between benign and malignant tumors. A diagnosis of a malignant cystic lesion requires evidence of multiple, thickened internal septa, calcifications, vascularity, and parietal nodularity. When a solid lesion does not show the typical appearance of a simple cyst (a round anechoic lesion with a smooth well-defined wall, without internal debris, and showing increased through-transmission), further evaluation with contrast-enhanced CT or MRI is necessary. Contrast-enhanced ultrasound (CEUS) improves the sensitivity for detection of small renal masses. Compared to CT, CEUS is able to better visualize the number of septa, the septum and wall thickness, the presence of a solid component, and enhancement in some cases, resulting in upgrading of the Bosniak classification and affecting treatment planning.

Secondary hyperparathyroidism (SHPT) is a common complication in patients with chronic kidney disease. In SHPT, the biology of parathyroid cells changes significantly toward diffuse nodular hyperplasia. Currently, diagnosis of SHPT is based on intact parathyroid hormone serum levels and parameters of mineral metabolism. The morphologic diagnosis of SHPT relies on high-resolution ultrasonography with color Doppler imaging. This report describes a maintenance hemodialysis patient with severe SHPT treated using conventional therapy (phosphate binders and oral/intravenous vitamin D or analogues) and the subsequent addition of a calcimimetic. The role of color Doppler ultrasonography in the diagnosis, clinical follow-up, and assessment of therapeutic response of SHPT is discussed. This case suggests that the availability of calcimimetics has changed the natural history of clinical SHPT and may change the therapeutic utility of parathyroidectomy. Use of color Doppler ultrasonography further supports these therapeutic advances, allowing evaluation of the morphologic and vascular changes in hyperplastic parathyroid glands and aiding clinical, pharmacologic, and surgical strategies., (Copyright © 2011 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

A simplified model of the microwave-assisted combustion synthesis of Ni and Al metal powders to form the NiAl intermetallic on titanium and steel substrates is presented. The simulation couples an electro-thermal model with a chemical model, accounting for local heat generation due to the highly exothermic nature of the reactions between the powders. Numerical results, validated by experimental values, show that the capability of microwaves to convey energy, and not heat, can be used to alter the temperature profiles during and after the combustion synthesis, leading to unique intermetallic microstructures. This phenomenon is ascribed to the extended existence of high temperature liquid intermetallic phases, which react with the metallic substrates at the interface. Moreover, microwave heating selectivity allows to maintain the bulk of the substrate metallic materials to a much lower temperature, compared to combustion synthesis in conventionally heated furnaces, thus reducing possible unwanted transformations like phase change or oxidation.

Background: This study prospectively assessed 2-[F18]-fluoro-2-deoxy-D-glucose-positron emission tomography (18F-FDG-PET)/CT (PET/CT) in oral squamous cell carcinoma., Methods: Twenty-three patients completed preoperative TNM staging (CT, MR, whole-body fusion imaging PET/CT). In patients who underwent surgical therapy (19 of 23), TNM staging based on PET/CT scan was compared with pTNM., Results: PET/CT correctly staged 16 of 19 primary tumors (accuracy 84.2%, sensitivity 84.2%, positive predictive value 100%) and correctly ruled out bone invasion in 3 patients with false-positive results according to CT and/or MR. PET/CT incorrectly identified neck involvement in 5 of 15 patients (3 false positives, 2 false negatives) who underwent neck dissection (accuracy 66.7%, specificity 76.9%, negative predictive value 83.3%). False-negative cases showed a nodal size not exceeding 10 mm. One patient with a bronchial synchronous primary tumor was identified., Conclusion: PET/CT scan showed good accuracy in determining the extension and/or depth of invasion of the primary tumor. Nevertheless, PET/CT was not accurate to rule out nodal metastases., ((c) 2008 Wiley Periodicals, Inc. Head Neck, 2008.)

The application of thin-film Luneburg lenses to integrated optical circuits will require accurate control of their focal length to permit the necessary alignment between the various circuit elements. Of particular interest is the design of lenses for application to a silicon-based integrated optical rf spectrum analyzer. This study analyzes the sensitivity of the focal length of Luneburg lenses to thickness variation at the lens center resulting from fabrication process tolerances. It is shown that this sensitivity can be minimized by properly selecting the refractive index of the waveguide material, using a larger focal length and employing a longer optical wavelength.