Water in a Polymeric Electrolyte Membrane: Sorption/Desorption and Freezing phenomena

Nafion is a perfluorosulfonated polymer, widely used in Proton Exchange Membrane Fuel Cells. This polymer adopts a complex structural organisation resulting from the microsegregation between hydrophobic backbones and hydrophilic sulfonic acid groups. Upon hydration appear water-filled channels and cavities, in which are released the acidic protons to form a solution of hydronium ions in water embedded in the polymer matrix. Below 273 K, a phenomenon of water sorption/desorption occurs, whose origin is still an open question. Performing neutron diffraction, we monitored the quantity of ice formed during the sorption/desorption as a function of temperature down to 180 K. Upon cooling, we observe that ice forms outside of the membrane and crystallises in the hexagonal Ih form. Simultaneously, the membrane shrinks and dehydrate, leading to an increase of the hydronium ions concentration inside the matrix. Reversibly, the ice melts and the membrane re-hydrate upon heating. A model of solution, whose freezing point varies with the hydronium concentration, is proposed to calculate the quantity of ice formed as a function of temperature. The quantitative agreement between the model and experimental data explains the smooth and reversible behavior observed during the sorption or desorption of water, pointing out the origin of the phenomena. The proposed picture reconciles both confinement and entropic effects. Other examples of water filled electrolyte nano-structures are eventually discussed, in the context of clarifying the conditions for water transport at low temperature

Operative and nonoperative management for renal trauma. Comparison of outcomes. A systematic review and meta-analysis

INTRODUCTION: Preservation of kidney and renal function is the goal of nonoperative management (NOM) of renal trauma (RT). The advantages of NOM for minor blunt RT have already been clearly described, but its value for major blunt and penetrating RT is still under debate. We present a systematic review and meta-analysis on NOM for RT, which was compared with the operative management (OM) with respect to mortality, morbidity, and length of hospital stay (LOS). METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement was followed for this study. A systematic search was performed on Embase, Medline, Cochrane, and PubMed for studies published up to December 2015, without language restrictions, which compared NOM versus OM for renal injuries. RESULTS: Twenty nonrandomized retrospective cohort studies comprising 13,824 patients with blunt (2,998) or penetrating (10,826) RT were identified. When all RT were considered (American Association for the Surgery of Trauma grades 1-5), NOM was associated with lower mortality and morbidity rates compared to OM (8.3% vs 17.1%, odds ratio [OR] 0.471; 95% confidence interval [CI] 0.404-0.548; P<0.001 and 2% vs 53.3%, OR 0.0484; 95% CI 0.0279-0.0839, P<0.001). Likewise, NOM represented the gold standard treatment resulting in a lower mortality rate compared to OM even when only high-grade RT was considered (9.1% vs 17.9%, OR 0.332; 95% CI 0.155-0.708; P=0.004), be they blunt (4.1% vs 8.1%, OR 0.275; 95% CI 0.0957-0.788; P=0.016) or penetrating (9.1% vs 18.1%, OR 0.468; 95% CI 0.398-0.0552; P<0.001). CONCLUSION: Our meta-analysis demonstrated that NOM for RT is the treatment of choice not only for AAST grades 1 and 2, but also for higher grade blunt and penetrating RT

Scanning probe oxidation of SiC, fabrication possibilities and kinetics considerations

The following article appeared in Applied Physics Letters 103.16 (2013): 163109 and may be found at http://scitation.aip.org/content/aip/journal/apl/103/16/10.1063/1.4825265We report the outcome of atomic force microscopy local anodic oxidation experiments on 6H-SiC in air. Oxide thickness can be easily tuned by varying applied voltage and pulse duration. The height and the aspect ratio of single dots produced by single DC pulses are remarkably higher than what was reported previously, with self limiting heights exceeding 100 nm. We propose that the diminished density and the change in chemical composition of the oxide grown on SiC with respect to oxide grown under similar condition on Si cause a drop in the activation energy of oxanions diffusion within the newly formed oxide layer.This work was entirely supported by the Italian Institute of Technology (IIT

Hollow viscus injuries. Predictors of outcome and role of diagnostic delay

INTRODUCTION: Hollow viscus injuries (HVIs) are uncommon but potentially catastrophic conditions with high mortality and morbidity rates. The aim of this study was to analyze our 16-year experience with patients undergoing surgery for blunt or penetrating bowel trauma to identify prognostic factors with particular attention to the influence of diagnostic delay on outcome. METHODS: From our multicenter trauma registry, we selected 169 consecutive patients with an HVI, enrolled from 2000 to 2016. Preoperative, intraoperative, and postoperative data were analyzed to assess determinants of mortality, morbidity, and length of stay by univariate and multivariate analysis models. RESULTS: Overall mortality and morbidity rates were 15.9% and 36.1%, respectively. The mean length of hospital stay was 23±7 days. Morbidity was independently related to an increase of white blood cells (P=0.01), and to delay of treatment >6 hours (P=0.033), while Injury Severity Score (ISS) (P=0.01), presence of shock (P=0.01), and a low diastolic arterial pressure registered at emergency room admission (P=0.02) significantly affected postoperative mortality. CONCLUSION: There is evidence that patients with clinical signs of shock, low diastolic pressure at admission, and high ISS are at increased risk of postoperative mortality. Leukocytosis and delayed treatment (>6 hours) were independent predictors of postoperative morbidity. More effort should be made to increase the preoperative detection rate of HVI and reduce the delay of treatment

Simple and effective graphene laser processing for neuron patterning application

Astraightforward fabrication technique to obtain patterned substrates promoting ordered neuron growth is presented. Chemical vapor deposition (CVD) single layer graphene (SLG) was machined by means of single pulse UV laser ablation technique at the lowest effective laser fluence in order to minimize laser damage effects. Patterned substrates were then coated with poly-D-lysine by means of a simple immersion in solution. Primary embryonic hippocampal neurons were cultured on our substrate, demonstrating an ordered interconnected neuron pattern mimicking the pattern design. Surprisingly, the functionalization is more effective on the SLG, resulting in notably higher alignment for neuron adhesion and growth. Therefore the proposed technique should be considered a valuable candidate to realize a new generation of highly specialized biosensor

A review of the continuous professional development system for pharmacists

Funding Information: The authors would like to acknowledge the work developed by the Council for Qualification & Admission: Ana Cabral, Carla Gomes, Francisco Batel Marques, Hugo Valente, Isabel Cunha, Laura Ribeiro, Luíza Granadeiro, Nuno Barros, Paula Campos, Paulo Cruz, Perpétua Gomes, Ricardo Lima, Rui Pinto, Liliana Ribeiro, Diana Costa, and the invaluable support of Fernanda Silva. The authors would like to acknowledge the support of the President of the Portuguese Pharmaceutical Society, Ana Paula Martins, and the National Board. Funding Information: This work was supported by the Portuguese Pharmaceutical Society. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Publisher Copyright: © 2021, The Author(s).Background: The Portuguese Pharmaceutical Society (PPS) implemented a system of Continuous Professional Development (CPD) for pharmacists in 2004. This system has evolved throughout the years, and currently all active pharmacists in Portugal are required to participate in the CPD program. Each CPD cycle takes 5 years. In each cycle, pharmacists must collect 15 CPD points, through participation in educational activities. The PPS accreditation process is managed via an online platform, where education/training providers, as well as pharmacists themselves, can submit educational activities for accreditation. Pharmacists may access their CPD status and assess their development at any point. The objective of this study was to analyze and review the educational activities submitted by providers over a 11-year period (2009–2019). Methods: Data from activities were retrieved from the PPS CPD online platform. All educational activities were labeled according to the area of pharmaceutical professional focus, type of promoter, and activity type. Results: During the study 3685 activities were analyzed. Over the last decade, submitted activities for accreditation increased in 52.6%. A significantly high proportion (98.9%) of these activities has been accredited. Promoters of activities were mostly pharmacies sectoral associations (29.6%), consultancy/training companies (19.6%), the PPS (18.5%), pharmaceutical industry (17.7%) and wholesalers’ consortia (9.0%). Academia represented only 2.3% of the total amount of educational activities. The most frequent topics were related to “pharmacology & pharmacotherapy” (9.9%), followed by “counselling” (9.8%) and “management & administration” (7.2%). The most accredited type of activities was face-to-face (68.9%) and e-learning trainings (13.1%). Conclusions: This study shows increasing interest in submitting CPD activities for accreditation between 2009 and 2019, but it also demonstrates that Academia could play a more interventive role in the lifelong learning education of Portuguese pharmacists.publishersversionpublishe

Differences between computed tomoghaphy and surgical findings in acute complicated diverticulitis

Summary Background/Objective: A preoperative reliable classification system between clinical and computed tomography (CT) findings to better plan surgery in acute complicated diverticulitis (ACD) is lacking. We studied the inter-observer agreement of CT scan data and their concordance with the preoperative clinical findings and the adherence with the intraoperative status using a new classification of diverticular disease (CDD). Methods: 152 patients operated on for acute complicated diverticulitis (ACD) were retrospectively enrolled. All patients were studied with CT scan within 24 h before surgery and CT images were blinded reanalyzed by 2 couples of radiologists (A/B). Kappa value evaluated the inter-observer agreement between radiologists and the concordance between CDD, preoperative clinical findings and findings at operation. Univariate and multivariate analysis were used to evaluate the predicting values of CT classification and CDD stage at surgery on postoperative outcomes. Results: Overall inter-observer agreement for the CDD was high, with a kappa value of 0.905 (95% CI Z 0.850e0.960) for observers A and B, while the concordance between radiologica

Formation and microscopic investigation of iron oxide aligned nanowires into polymeric nanocomposite films

We present a microscopic investigation of nanocomposite films of iron oxide (g-Fe2O3) magnetic nanowires (NWs) aligned into polymers, formed upon evaporation of solutions of acrylate polymer/magnetic nanoparticles under magnetic field (MF). The field causes the assembly of the g-Fe2O3 nanoparticles along the direction of the MF lines, resulting in magnetic NWs embedded throughout the entire volume of the polymer film. The scanning electron microscopy and the trans- mission electron microscopy studies show that the cylindrical-shaped NWs have � 15-lm average length and are isotropically distributed throughout the film. The study with the MF microscopy tech- nique not only proves that the composed NWs are magnetic but also makes possible the magnetic study of each individual NW in a nondestructive way. In this way it becomes possible for the localized study of the magnetic properties alteration after the binding of various molecules onto individual NWs, opening up the way of using these films in sensor devices applied in various fields ranging from biology to environmental purposes. Microsc. Res. Tech. 73:952-958, 2010. V C 2010 Wiley-Liss, Inc

China: el gigante ha despertado

“China es un gigante dormido. Dejadlo dormir porque, cuando despierte, el mundo se sacudirá” dijo Napoleón Bonaparte en 1816. Dos siglos después, el gigante ya ha despertado. Actualmente, la República Popular China es la segunda economía del mundo y ha logrado, sin dejar de lado su lugar como potencia regional en Asia, extender su poderío por los cinco continentes. De manera pacífica, y con el softpower como su mayor estrategia, ha sabido ganarse un lugar en la agenda política y económica de cada país con el cual ha iniciado vínculos diplomáticos. En el presente trabajo se analizará el camino recorrido por el gigante asiático en el siglo XX y su transición hacia el siglo XXI. Su sistema político, su relación con los países vecinos, Estados Unidos y Europa; y su política exterior para África, la región latinoamericana y la República Argentina serán los ejes centrales.‘China is a sleeping giant. Let her sleep, for when she wakes she will shake the world’ said Napoleon in 1816. Two centuries later, the giant has awakened. Currently the People's Republic of China is the second largest economy in the world and, without neglecting its place as a regional power in Asia, has extended its power to the five continents. Peacefully, and using the soft power as its main strategy, it has succeeded in gaining a place in the political and economic agenda of each country with which it has initiated diplomatic ties. In the present work the path traveled by the Asian giant in the 20th century and its transition towards the 21st century will be analyzed. The focus will be in its political system, its relationship with the neighboring countries, United States and Europe; and its foreign policy towards Africa, Latin American region and Argentina.Universidad Católica de Santa F

Nanochains Formation of Superparamagnetic Nanoparticles

We present simulations on the aggregation of nanometer sized polydispersed superparamagnetic particles under the application of an external magnetic field. We make use of a Monte Carlo method, using a cluster-moving approach, as previously used in literature for ferrofluids. van der Waals attraction and magnetic anisotropy are taken into account in the simulations. Chains elongated in the field direction are formed. The results are in good agreement with recent experimental results on nanochains made of iron oxide nanoparticles into polymer matrix, obtained with the application of a magnetic field during film deposition. The magnetization anisotropy of the nanocomposite film under dc magnetic field can be predicted within this simple model