The MELD score in patients awaiting liver transplant: strengths and weaknesses.

Adoption of the Model for End-stage Liver Disease (MELD) to select and prioritize patients for liver transplantation represented a turning point in organ allocation. Prioritization of transplant recipients switched from time accrued on the waiting list to the principle of "sickest first". The MELD score incorporates three simple laboratory parameters (serum creatinine and bilirubin, and INR for prothrombin time) and stratifies patients according to their disease severity in an objective and continuous ranking scale. Concordance statistics have demonstrated its high accuracy in stratifying patients according to their risk of dying in the short-term (three months). Further validations of MELD as a predictor of survival at various temporal end-points have been obtained in independent patient cohorts with a broad spectrum of chronic liver disease. The MELD-based liver graft allocation policy has led to a reduction in waitlist new registrations and mortality, shorter waiting times, and an increase in transplants, without altering overall graft and patient survival rates after transplantation. MELD limitations are related either to the inter-laboratory variability of the parameters included in the score, or to the inability of the formula to predict mortality accurately in specific settings. For some conditions, such as hepatocellular carcinoma, widely accepted MELD corrections have been devised. For others, such as persistent ascites and hyponatremia, attempts to improve MELD's predicting power are currently underway, but await definite validation

Dynamics of commercial diffusion of Veneto Denominations: comparison among some case studies

openLo studio si è posto l’obiettivo di analizzare i fattori che influenzano la propagazione nel mercato locale di alcune delle sue Denominazioni minori presenti nella Regione del Veneto, con particolare riferimento a: Asolo Prosecco DOCG, Colli Euganei DOCG, Breganze DOC, Colli di Conegliano DOCG e Valdadige Terradeiforti DOC. L’approccio teorico seguito nello studio si riferisce al modello implementato dall’economista tedesco Von Thünen secondo il quale la rendita di un bene è legata alla sua localizzazione. La metodologia utilizzata ha considerato le tecniche di analisi statistica, su un campione di 561 tra bar e ristoranti, vedendo se lo sviluppo di tali Denominazioni siano legate alla distanza dal centro di produzione. I risultati della ricerca confermano la bontà dell’approccio seguito, emergendo una relazione tra gli elementi commerciali che caratterizzano le Denominazioni analizzate, la distanza e i fattori che influenzano la diffusione dei vini a Denominazione di Origine; in particolare, è stato osservato come all’aumentare della distanza si assiste ad una graduale diminuzione delle vendite. Lo studio ha permesso di comprendere i driver che favoriscono e ostacolano la diffusione dei prodotti a Denominazione consentendo quindi di suggerire l’adozione di strategie di vendita e comunicazione maggiormente efficaci

An approach for the automatic verification of blockchain protocols: the Tweetchain case study

This paper proposes a model-driven approach for the security modelling and analysis of blockchain based protocols. The modelling is built upon the definition of a UML profile, which is able to capture transaction-oriented information. The analysis is based on existing formal analysis tools. In particular, the paper considers the Tweetchain protocol, a recent proposal that leverages online social networks, i.e., Twitter, for extending blockchain to domains with small-value transactions, such as IoT. A specialized textual notation is added to the UML profile to capture features of this protocol. Furthermore, a model transformation is defined to generate a Tamarin model, from the UML models, via an intermediate well-known notation, i.e., the Alice &Bob notation. Finally, Tamarin Prover is used to verify the model of the protocol against some security properties. This work extends a previous one, where the Tamarin formal models were generated by hand. A comparison on the analysis results, both under the functional and non-functional aspects, is reported here too

FACILE FUNCTIONALIZATION OF sp2 CARBON ALLOTROPES WITH A BIOBASED JANUS MOLECULE

A simple, versatile, sustainable, not expensive method for the functionalization of sp2 carbon allotropes, both nanosized and nano-structured, without altering their bulk crystalline organization, is presented. Carbon materials available at the commercial scale were used: furnace carbon black (CB), nano-sized graphite with high surface area, and multiwalled carbon nanotubes. A bio-sourced molecule, 2-(2,5-dimethyl-1H-pyrrol-1-yl)-1,3-propanediol (serinol pyrrole), was used for the functionalization. Serinol pyrrole (SP) was obtained from serinol through a reaction with atomic efficiency of about 82%, performed in the absence of solvents or catalysts. Synthesis of serinol pyrrole was performed as well on carbon allotropes as the solid support. Adducts of serinol pyrrole with a carbon allotrope were prepared with the help of either thermal or mechanical energy. Functionalization yield was in all cases larger than 90%. With such adducts, stable dispersions in water and inNRlatex were prepared.Afew layers of graphene were isolated from the water dispersions, and NR-based composites precipitated from the latex revealed very even distribution of fine graphitic particles. Composites were prepared, based on NR, IR, andBRas the rubbers andCBand silica as the fillers, with different amounts of CB–SPadduct, and were cross-linked with a sulfur-based system without observing appreciable effect of functionalization on vulcanization kinetics. The CB–SP adduct led to appreciable reduction of the Payne effect

A new algorithm for extended nonequilibrium molecular dynamics simulations of mixed flow

In this work, we develop a new algorithm for nonequilibrium molecular dynamics of fluids under planar mixed flow, a linear combination of planar elongational flow and planar Couette flow. To date, the only way of simulating mixed flow using nonequilibrium molecular dynamics techniques was to impose onto the simulation box irreversible transformations. This would bring the simulation to an end as soon as the minimum lattice space requirements were violated. In practical terms, this meant repeating the short simulations to improve statistics and extending the box dimensions to increase the total simulation time. Our method, similar to what has already been done for pure elongational flow, allows a cuboid box to deform in time following the streamlines of the mixed flow and, after a period of time determined by the elongational field, to be mapped back and recover its initial shape. No discontinuity in physical properties is present during the mapping and the simulation can, in this way, be extended indefinitely. We also show that the most general form of mixed flow, in which the angle between the expanding (or contracting) direction and the velocity gradient axis varies, can be cast in a so-called canonical form, in which the angle assumes values that are multiples of π (when a mixed flow exists), by an appropriate choice of the field parameters

Giant leiomyoma of the gastroesophageal junction: technique and results of endoscopic full-thickness resection

Four consecutive patients with a giant leiomyoma originating from the posterior aspect of the gastroesophageal junction were treated with full-thickness endoscopic retroflex dissection. A complete removal of the lesion was obtained in all cases. No complications were observed except for some degree of air filtration causing symptomatic pneumoperitoneum in one patient. Retroflex endoscopic full-thickness resection of giant leiomyoma at the gastroesophageal junction is feasible and safe

Physiological effectors modify voltage sensing by the cyclosporin A-sensitive permeability transition pore of mitochondria.

This paper reports an investigation on the modulation of the mitochondrial permeability transition pore (MTP) by the membrane potential. Energized rat liver mitochondria loaded with a small Ca2+ pulse in sucrose medium supplemented with phosphate favor a high MTP "closed" probability because of the high membrane potential and therefore maintain a low permeability to sucrose. Upon depolarization by the addition of fully uncoupling concentrations of carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) mitochondria favor a high MTP "open" probability and rapidly undergo a process of osmotic swelling following sucrose diffusion toward the matrix. A titration with FCCP reveals that discrete subpopulations of mitochondria with different gating potentials for MTP opening may exist, since increasing concentrations of FCCP increase the fraction of mitochondria undergoing osmotic swelling. We show that physiological effectors (Ca2+, Mg2+, ADP, palmitate) modify pore opening in a mitochondrial population by shifting the fraction of mitochondria with a functionally open pore at any given membrane potential. Many inducers and inhibitors may therefore affect the pore directly through an effect on the MTP voltage sensing rather than indirectly through an effect on the membrane potential. Thus, many effectors may induce pore opening by shifting the MTP gating potential to higher levels, whereas many inhibitors may induce pore closure by shifting the MTP gating potential to lower levels

Flow cytometry for feline lymphoma: a retrospective study about pre-analytical factors possibly affecting the quality of samples

Introduction Flow cytometry (FC) is an increasingly required technique on which veterinary oncologists rely to have an accurate, fast, minimally invasive lymphoma or leukemia diagnosis. FC has been studied and applied with great results in canine oncology, whereas in feline oncology the use of this technique is still to be experienced. This is mainly due to a supposed discomfort in sampling, because of the high prevalence of intra-abdominal lymphomas. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis.Methods 97 consecutive samples of suspected feline lymphoma were retrospectively selected from the authors’ institution FC database. The referring veterinarians were recalled and interrogated about several different variables, including signalling, features of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of being finally processed for FC.Results None of the investigated variables significantly influenced the quality of the submitted samples, but the needle size, with 21G needles providing the highest cellularity (Table 1). Notably, the samples quality did not vary between peripheral and intra-abdominal lesions. Sample cellularity alone influenced the likelihood of being processed. About a half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling).Conclusions FC can be safely applied to cases of suspected feline lymphomas, even for intra-abdominal lesions. 21G needle should be preferred for sampling. This study provides the bases for the spread of this minimally invasive, fast and cost-effective technique in feline medicine

ENEAR Redshift-Distance Survey: Cosmological Constraints

We present an analysis of the ENEAR sample of peculiar velocities of field and cluster elliptical galaxies, obtained with Dn-σ distances. We use the velocity correlation function ψ1(r) to analyze the statistics of the field object\u27s velocities, while the analysis of the cluster data is based on the estimate of their rms peculiar velocity Vrms. The results are compared with predictions from cosmological models using linear theory. The statistics of the model velocity field is parameterized by the amplitude η8 = σ8Ω and by the shape parameter Γ of the cold dark matter-like power spectrum. This analysis is performed in redshift space, so as to circumvent the need to address corrections due to inhomogeneous Malmquist bias and to the redshift cutoff adopted in the sample selection. From the velocity correlation statistics, we obtain η8 = 0.51 for Γ = 0.25 at the 2 σ level for one interesting fitting parameter. This result agrees with that obtained from a similar analysis of the SFI I-band Tully-Fisher (TF) survey of field Sc galaxies. Even though less constraining, a consistent result is obtained by comparing the measured Vrms of clusters with linear theory predictions. For Γ = 0.25, we find η8 = 0.63 at 1 σ. Again, this result agrees, within the uncertainties, with that obtained from the SCI cluster sample based on TF distances. Overall, our results point toward a statistical concordance of the cosmic flows traced by spiral and early-type galaxies, with galaxy distances estimated using TF and Dn-σ distance indicators, respectively