On the Effect of Standard Deviation of Cationic Radii on the Transition Temperature in Fluorite-Structured Entropy-Stabilized Oxides (F-ESO).

It is confirmed that Fluorite-structured Entropy-Stabilized Oxides (F-ESO) can be obtained with multicomponent (5) equimolar systems based on cerium, zirconium, and other rare earth elements, selected according to the predictor already proposed by the authors. Indeed, in the present study, three different samples owning a standard deviation (SD in the following) of their cationic radii greater than the threshold value (i.e., SD > 0.095 with cationic radii measured in Å) needed to ensure the formation of the single-phase fluorite structure, were prepared via co-precipitation method. After a calcination step at 1500 °C for 1 h, the entropy-driven transition from multiple phases to single-phase fluorite-like structure has been actually confirmed. Thus, with the aim of defining the temperature at which such entropy-driven transition occurred, and identifying possible relation between such temperature and the actual value of SD, the phase evolution of all the prepared samples as a function of temperature (ranging from 800 °C to 1300 °C) was analyzed by in situ High Temperature X-ray Diffraction. An apparent inverse correlation between the standard deviation and the entropy-driven transition temperature has been identified, i.e., the higher the former, the lower the latter. These results, based on the conducted basic structural analysis, provide further support to the SD-based empirical predictor developed by the authors, suggesting that high values of SD could bring additional contribution to the overall entropy of the system, other than the configurational one. Thus, this SD-driven entropy contribution directly increases with the increasing of the standard deviation of the cationic radii of a given F-ESO.

Is patient satisfaction sufficient to validate endoscopic anti-reflux treatments?

Endoscopic anti-reflux treatment is emerging as a new option for gastro-esophageal reflux disease (GERD) treatment in patients with the same indications as for laparoscopic fundoplication. There are many techniques, the first of which are transoral incisionless fundoplication (TIF) and nonablative radio-frequency (STRETTA) that have been tested with comparative studies and randomized controlled trials, whereas the other more recent ones still require a deeper evaluation. The purpose of the latter is to verify whether reflux is abolished or significantly reduced after intervention, whether there is a valid high pressure zone at the gastroesophageal junction, and whether esophagitis, when present, has disappeared. Unfortunately in a certain number of cases, and especially in the more recently introduced ones, the evaluation has been based almost exclusively on subjective criteria, such as improvement in the quality of life, remission of heartburn and regurgitation, and reduction or suspension of antacid and antisecretory drug consumption. However, with the most studied techniques such as TIF and STRETTA, an improvement in symptoms better than that of laparoscopic fundoplication can often be observed, whereas the number of acid episodes and acid exposure time are similar or higher, as if the acid refluxes are better tolerated by these patients. The suspicion of a local hyposensitivity taking place after anti-reflux endoscopic intervention seems confirmed by a Bernstein test at least for STRETTA. This examination should be done for all the other techniques, both old and new, to identify the ones that reassure rather than cure. In conclusion, the evaluation of the effectiveness of the endoscopic anti-reflux techniques should not be based exclusively on subjective criteria, but should also be confirmed by objective examinations, because there might be a gap between the improvement in symptoms declared by the patient and the underlying pathophysiologic alterations of GERD.

Electron diffraction characterization of nanocrystalline materials using a Rietveld-based approach. Part I. Methodology.

Transmission electron microscopy is a powerful experimental tool, very effective for the complete characterization of nanocrystalline materials by employing a combination of imaging, spectroscopy and diffraction techniques. Electron powder diffraction (EPD) pattern fingerprinting in association with chemical information from spectroscopy can be used to deduce the identity of the crystalline phases. Furthermore, EPD has similar potential to X-ray powder diffraction (XRPD) for extracting additional information regarding material specimens, such as microstructural features and defect structures. The aim of this paper is to extend a full-pattern fitting procedure, broadly used for analysing XRPD patterns, to EPD. The interest of this approach is twofold: in the first place, the relatively short times involved with data acquisition allow one to speed up the characterization procedures. This is a particularly interesting aspect in the case of metastable structures or kinetics studies. Moreover, the reduced sampling volumes involved with electron diffraction analyses can better reveal surface alteration layers in the analysed specimen which might be completely overlooked by conventional bulk techniques. The first step forward to have an effective application of the proposed methodology concerns establishing a reliable calibration protocol to take into correct account the instrumental effects and thus separate them from those determined by the structure, microstructure and texture of the analysed samples. In this paper, the methodology for determining the instrumental broadening of the diffraction lines is demonstrated through a full quantitative analysis based on the Rietveld refinement of the EPD. In this regard, a CeO2 nanopowder reference specimen has been used. The results provide indications also on the specific features that a good calibration standard should have.

Improving the Wet-Spinning and Drawing Processes of Poly(lactide)/Poly(ethylene furanoate) and Polylactide/Poly(dodecamethylene furanoate) Fiber Blends.

This work aims to produce poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAF)s fiber blends for textile applications and evaluates their microstructural, chemical, thermal, and mechanical properties. The work focuses on two PAFs with very different alkyl chain lengths, i.e., poly(ethylene 2,5-furandicarboxylate) (PEF) and poly(dodecamethylene 2,5-furandicarboxylate) (PDoF), which were blended in solution at various concentrations (in the range 2.5-10 wt %) with PLA, wet spun, and subsequently drawn. Light optical micrographs highlight that PLA/PEF blends present large and concentrate PEF domains, whereas PLA/PDoF blends show small and homogeneously distributed PDoF domains. The blends appear to be immiscible, which is confirmed also by scanning electron microscopy (SEM), Fourier-Transform Infrared (FT-IR) spectroscopy, and differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) highlights that the addition of the PAFs improves the thermal stability of the fibers. The drawing process, which was carried out at 80 °C with a heat setting step at 95 °C and at three draw ratios, improves the mechanical properties of the fibers upon the addition of the PAFs. The results obtained in this study are promising and may serve as a basis for future investigations on these novel bio-based fiber blends, which can contribute to increase the environmental sustainability of industrial textiles.

Magnetic challenge against gastroesophageal reflux.

Almost 15 years have passed since the first paper on the possibility of using magnets to prevent gastro-esophageal reflux (GER) was published and so it is time to assess the results obtained with the first magnetic device available on the market, the Linx magnetic sphincter augmentation (MSA) and to consider what other options are forthcoming. MSA demonstrated an anti-reflux activity similar to that of Nissen fundoplication, considered the "gold standard" surgical treatment for GER disease, and caused less gas-bloating and a better ability to allow vomiting and belching. However, unlike Nissen fundoplication, this magnetic device is burdened by complications, which are roughly similar to those of the non-magnetic anti-reflux Angelchik prosthesis, that, after considerable use in the eighties, was shelved due to these complications. It is interesting to note that some of these complications show the same pathophysiological mechanism in both devices. The upcoming new magnetic devices should avoid these complications, as their anti-reflux magnetic mechanism is completely different. The experiments in animals regarding these new magnetic appliances were examined, remarking their advantages and drawbacks, but the way to apply them in surgical practice is long and difficult, although worthy, as they represent the future of magnetic surgery.

Mechanical and Functional Properties of Novel Biobased Poly(decylene-2,5-furanoate)/Carbon Nanotubes Nanocomposite Films.

The present work investigates the microstructural, thermo-mechanical, and electrical properties of a promising, but still not thoroughly studied, biobased polymer, i.e., poly(decylene furanoate) (PDeF), and its performance when multi-walled carbon nanotubes (CNTs) are added. After sample preparation by solution mixing and film casting, the microstructural investigation evidences that the fracture surface becomes smoother and more homogeneous with a small fraction of CNTs, and that the production process is suitable to achieve good disentanglement and dispersion of CNTs within the matrix, although some aggregates are still observable. CNTs act as nucleating agents for PDeF crystals, as evidenced by differential scanning calorimetry, as the crystallinity degree increases from 43.2% of neat PDeF to 55.0% with a CNT content of 2 phr, while the crystallization temperature increases from 68.4 °C of PDeF to 91.7 °C of PDeF-CNT-2. A similar trend in crystallinity is confirmed by X-ray diffraction, after detailed Rietveld analysis with a three-phase model. CNTs also remarkably improve the mechanical performance of the bioderived polymer, as the elastic modulus increases up to 123% and the stress at break up to 131%. The strain at break also increases by +71% when a small amount of 0.25 phr of CNTs are added, which is probably the consequence of a more homogeneous microstructure. The long-term mechanical performance is also improved upon CNT addition, as the creep compliance decreases considerably, which was observed for both the elastic and the viscoelastic component. Finally, the films become electrically dissipative for a CNT content of 1 phr and conductive for a CNT amount of 2 phr. This study contributes to highlight the properties of bioderived furan-based polymer PDeF and evidences the potential of CNTs as a promising nanofiller for this matrix.

New Insights in the Hydrothermal Synthesis of Rare-Earth Carbonates.

The rare-earth carbonates represent a class of materials with great research interest owing to their intrinsic properties and because they can be used as template materials for the formation of other rare earth phases, particularly of rare-earth oxides. However, most of the literature is focused on the synthesis and characterization of hydroxycarbonates. Conversely, in the present study we have synthesized both rare-earth carbonates-with the chemical formula RE2(CO3)3·2-3H2O, in which RE represents a generic rare-earth element, and a tengerite-type structure with a peculiar morphology-and rare-earth hydroxycarbonates with the chemical formula RECO3OH, by hydrothermal treatment at low temperature (120 °C), using metal nitrates and ammonium carbonates as raw materials, and without using any additive or template. We found that the nature of the rare-earth used plays a crucial role in relation to the formed phases, as predicted by the contraction law of lanthanides. In particular, the hydrothermal synthesis of rare-earth carbonates with a tengerite-type structure was obtained for the lanthanides from neodymium to erbium. A possible explanation of the different behaviors of lighter and heavier rare-earths is given.

Acute administration of capsaicin increases resting energy expenditure in young obese subjects without affecting energy intake, appetite, and circulating levels of orexigenic/anorexigenic peptides.

Although capsaicin has been reported to reduce energy intake and increase energy expenditure in an adult (normal weight or overweight) population, thus resulting in a net negative energy balance and weight loss, these beneficial effects have not been investigated in young obese subjects. We hypothesize that capsaicin acutely administered in young obese subjects exerts the same effects on energy balance and that these effects are mediated by changes in gastrointestinal peptides regulating appetite. Thus, the aim of the present study was to evaluate the acute effects of capsaicin (2 mg) or placebo on energy intake, hunger, and satiety in obese adolescents and young adults (female-male ratio: 4:6, age: 21.0 ± 5.8 years; body mass index: 41.5 ± 4.3 kg/m2) provided an ad libitum dinner. Furthermore, circulating levels of some orexigenic (ghrelin) and anorexigenic (glucagon-like peptide 1 and peptide YY) peptides were measured after a meal completely consumed (lunch), together with the evaluation of hunger and satiety and assessment of resting energy expenditure (REE) through indirect computerized calorimetry. When compared to placebo, capsaicin did not significantly change either energy intake or hunger/satiety 6 hours after its administration (dinner). No differences in circulating levels of ghrelin, glucagon-like peptide 1, and peptide YY and in hunger/satiety were found in the 3 hours immediately after food ingestion among obese subjects treated with capsaicin or placebo (lunch). By contrast, the meal significantly increased REE in the capsaicin- but not placebo-treated group (capsaicin: from 1957.2 ± 455.1 kcal/d up to 2342.3 ± 562.1 kcal/d, P < .05; placebo: from 2060.1 ± 483.4 kcal/d up to 2296.0 ± 484.5 kcal/d). The pre-post meal difference in REE after capsaicin administration was significantly higher than that observed after placebo (385.1 ± 164.4 kcal/d vs 235.9 ± 166.1 kcal/d, P < .05). In conclusion, although capsaicin does not exert hypophagic effects, these preliminary data demonstrate its ability as a metabolic activator in young obese subjects.

A New Reliable Method for Evaluating Gallbladder Dynamics: The 3-Dimensional Sonographic Examination.

OBJECTIVES: The purpose of this study was to compare conventional 2-dimensional (2D) B-mode sonography with 3-dimensional (3D) sonography for assessing gallbladder volume and contractility. METHODS: Gallbladder volume and contractility were evaluated in 32 healthy volunteers after fasting and abstinence from smoking for 8 hours and after a standardized balanced liquid meal. The gallbladder was evaluated with 2D sonography (with the use of the ellipsoid method) and with 3D sonography using a volumetric matrix probe. Both measurements were made by an operator who was skilled in sonography and an unskilled operator. The group of volunteers was subdivided into 2 subgroups including 16 participants, which represented the "2 moments" of acquisition by the techniques, particularly for the unskilled operator. RESULTS: The postprandial volumes obtained with 3D sonography were significantly lower in comparison to the volumes obtained with 2D sonography (P= .013), and there was a significant difference between the measurements made by the skilled and unskilled operators only for 2D sonography (P< .001), whereas between the 2 moments of acquisition by the 3D technique, there was no significant difference. The reproducibility of the technique for evaluation of gallbladder volumes was higher for 3D sonography than 2D sonography, particularly for the postprandial evaluation. CONCLUSIONS: The new 3D sonographic method using a volumetric matrix probe is a simple, reliable, and more reproducible technique than conventional 2D sonography, even if performed by an unskilled operator, and it allows a reliable stimulation test for a gallbladder dynamic study.

Determination of the crystal structure of nifedipine form C by synchrotron powder diffraction.

The crystal structure of the metastable form C polymorph of nifedipine [C(17)H(18)N(2)O(6), 3,5-dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate] was determined by means of direct-space techniques applied to high-resolution synchrotron powder diffraction data. The polymorph crystallizes in the space group P1 and exhibits a molecular packing significantly different from that of the stable modification, with molecules aligned in an orthogonal configuration inside the unit cell. The molecular conformation, on the other hand, remains substantially unmodified between the two polymorphs. Additionally, in situ thermal characterization of nifedipine crystallization behaviour was performed, confirming the nucleation of another metastable polymorph (form B) prior to the complete crystallization of the stable modification. A complete structural characterization of form B was not possible owing to its very limited stability interval.

Gastric electrical stimulation for gastroparesis: a goal greatly pursued, but not yet attained.

The lack of an effective medical treatment for gastroparesis has pushed the research of new techniques of gastric electrical stimulation (GES) for nearly half a century of experimentation with a large variety of electrical stimuli delivered to the gastric wall of animals and patients with gastroparesis. Three principal methods are currently available: gastric low-frequency/high-energy GES with long pulse stimulation, high-frequency/low-energy GES with short pulse stimulation and neural sequential GES. The first method aims to reset a regular slow wave rhythm, but has variable effects on contractions and requires devices with large and heavy batteries unsuitable for implantation. High-frequency/low-energy GES, although inadequate to restore a normal gastric electro-mechanical activity, improves dyspeptic symptoms, such as nausea and vomiting, giving patients a better quality of life together with a more satisfactory nutritional status and is suitable for implantation. Unfortunately, the numerous clinical studies using this type of GES, with the exception of two, were not controlled and there is a need for definitive verification of the effectiveness of this technique to justify the cost and the risks of this procedure. The last method, which is neural sequential GES, consists of a microprocessor-controlled sequential activation of a series of annular electrodes along the distal two thirds of the stomach and is able to induce propagated contractions causing forceful emptying of the gastric content. The latter method is the most promising, but has been used only in animals and needs to be tested in patients with gastroparesis before it is regarded as a solution for this disease.

Gastroesophageal reflux disease (GERD) and inflammatory bowel disease (IBD): attachment styles and parental bonding.

The attachment styles and parental bonding by 64 patients (M age = 43.2 yr., SD = 13.3) with Gastroesophageal Reflux Disease (GERD) were compared with those of 64 patients (M age = 42.2 yr., SD = 13.5) with Inflammatory Bowel Disease (IBD) and 126 Healthy participants (M age = 42.2 yr., SD = 12.1). Analysis of scores on the Attachment Style Questionnaire indicated insecure attachment in both the patient and control groups. The Parental Bonding scores indicated perceptions of Affectionless Control by parents in both patient groups. In particular, the mean Father-Protection subscale scores were significantly higher for in the GERD group than in the Healthy and IBD groups.

Numerical models for the evaluation of the contact angle from axisymmetric drop profiles: a statistical comparison.

Axisymmetric drop shape analysis (ADSA) is a well-established methodology for estimating the contact angle value and the surface tension of liquids starting from sessile drops images. It consists of an iterative procedure in which a best fit between a theoretical axisymmetric Laplacian curve and an experimental drop profile is performed. When only an evaluation of the geometric contact angle value is needed, a similar numerical approach can be adopted by using simpler algebraic models in place of a Laplace profile, thus allowing more straightforward implementations and shorter computation times. In this work the relative merits of the different methodologies are compared. Beside the standard ADSA procedure, four different mathematical models are examined, namely the circular and elliptical models, the first-order perturbative solution of the Laplace equation, and a cubic spline model. Their relative statistical performances are tested on both calculated and experimental drop profiles. For simulated drops, the actual capability of the models to predict the correct contact angle is also investigated.