2,037 research outputs found
Characterization of elastic, thermo-responsive, self-healable supramolecular hydrogel made of self-assembly peptides and guar gum
Self-assembling peptides (SAPs) show great promise in regenerative medicine and beyond. Yet, their low mechanical rigidity and limited processability hinder many of their potential applications. In this work we describe the reinforcement of a synthetic biomimetic and β-sheet rich FAQRVPP-LDLK12 SAP by its integration with a naturally occurring polysaccharide - guar gum - to produce a shapeable and thermo-responsive composite hydrogel. Extensive characterization was performed via rheological measurements, CD spectroscopy, FT-IR spectroscopy, and AFM analyses. Composite hydrogels show preserved nanostructured morphology and cross-β structure aggregation typical of SAPs, improved mechanical properties (peaking at 1:1 weight ratio with G′~60 kPa) with self-healing and stress-relaxation propensities: they also exhibit reversible repeatable gel-sol transitions in response to thermal stimuli. Thanks to the dynamic properties of guar gum, stretchability was extended far beyond 5% strain of standard SAPs and processability allowed for the production of knotted threads and long (>10 cm) flexible sheets. Composite hydrogels of guar gum and SAPs may be added to the growing library of biomimetic SAP hydrogels used in 3D-printing, wound healing, suturing and beyond. Keywords: Self-assembling peptides, Guar gum, Supramolecular hydrogels, Self-healing, Thermal responsive, Nanofiber
Early Arrival of New World Species Enriching the Biological Assemblage of the Santi Quattro Coronati Complex (Rome, Italy)
This paper reports the archaeobotanical and archaeozoological data from a disposal pit, whose use started after the partial closure of a staircase, and from a mortar surface within a former porch in the Santi Quattro Coronati complex in Rome, Italy. The two contexts were in use in the Early Modern Age, when the complex served as a cardinal seat. The element that distinguishes the Santi Quattro Coronati from other contemporaneous contexts is the presence of New World species, until now only hypothesized based on a letter sent by the first resident bishop in Santo Domingo to Lorenzo Pucci, then cardinal with the titulus of the Santi Quattro Coronati. Pumpkin seeds (Cucurbita pepo and C. maxima/moschata) were found in the pit, while a pelvis of guinea pig (Cavia porcellus) was found in a former
porch. Numerous archaeobotanical remains preserved by mummification, identified mostly as food, and many archaeozoological specimens were found in the pit. Based on the data, it is hypothesized that the pit was used mainly as a deposit for table waste. The results as a whole help towards the investigation of the eating customs and daily habits of a Renaissance high-status clerical community
Sviluppo di un framework di algoritmi per l'analisi del segnale di pressione nel cilindro
Descrizione di una serie di algoritmi, realizzati nel linguaggio di programmazione Python, atti all'analisi di dati provenienti dall'analisi al banco di motori a combustione interna; richiami dei principali parametri calcolati negli algoritmi e descrizione del linguaggio di programmazione
A New Polysaccharide Carrier Isolated from Camelina Cake: Structural Characterization, Rheological Behavior, and Its Influence on Purple Corn Cob Extract’s Bioaccessibility
A polysaccharide fraction obtained from camelina cake (CCP), selected as a carrier to encapsulate purple corn cob extract (MCE), was investigated. A wide population of carbohydrate polymers (with a polydispersivity index of 3.26 ± 0.07 and an average molecular weight of about 139.749 × 103 ± 4.392 × 103 g/mol) with a gel-like behavior and a thixotropic feature characterized the fraction. MCE-CCP combinations (50-50 and 25-75, w/w), selected based on CCP encapsulation efficiency, were tested for their stability and MCE polyphenols' bioaccessibility during digestion (monitored using an in vitro static procedure). During the oral and gastric phases of the digestion process, CCP gradually swelled and totally released MCE polyphenols. MCE-CCP50 had the fastest release. Moreover, anthocyanins were still detectable during the duodenal phase, in both MCE-CCP ingredients. Furthermore, CCP (5 mg/mL) exerted in vitro potential hypocholesterolemic activity via bile salts binding during digestion
Wave run-up prediction and observation in a micro-tidal beach
Abstract. Extreme weather events bear a significant impact on coastal
human activities and on the related economy. Forecasting and hindcasting the
action of sea storms on piers, coastal structures and beaches is an important
tool to mitigate their effects. To this end, with particular regard to low
coasts and beaches, we have developed a computational model chain
based partly on open-access models and partly on an ad-hoc-developed
numerical calculator to evaluate beach wave run-up levels and flooding. The
offshore wave simulations are carried out with a version of the WaveWatch III
model, implemented by CCMMMA (Campania Centre for Marine and Atmospheric
Monitoring and Modelling – University of Naples Parthenope), validated
with remote-sensing data. The waves thus computed are in turn used as initial
conditions for the run-up calculations, carried out with various empirical
formulations; the results were finally validated by a set of specially
conceived video-camera-based experiments on a micro-tidal beach located on
the Ligurian Sea. Statistical parameters are provided on the agreement
between the computed and observed values. It appears that, while the system
is a useful tool to properly simulate beach flooding during a storm,
empirical run-up formulas, when used in a coastal vulnerability context, have
to be carefully chosen, applied and managed, particularly on gravel beaches
Endoscopic Submucosal Dissection of Gastric Neoplastic Lesions. An Italian, Multicenter Study
Endoscopic submucosal dissection (ESD) allows removing neoplastic lesions on gastric
mucosa, including early gastric cancer (EGC) and dysplasia. Data on ESD from Western countries
are still scanty. We report results of ESD procedures performed in Italy. Data of consecutive patients
who underwent ESD for gastric neoplastic removal were analyzed. The en bloc resection rate and
the R0 resection rates for all neoplastic lesions were calculated, as well as the curative rate (i.e., no
need for surgical treatment) for EGC. The incidence of complications, the one‐month mortality, and
the recurrence rate at one‐year follow‐up were computed. A total of 296 patients with 299 gastric
lesions (80 EGC) were treated. The en bloc resection was successful for 292 (97.6%) and the R0 was
achieved in 266 (89%) out of all lesions. In the EGC group, the ESD was eventually curative in 72.5%
(58/80) following procedure. A complication occurred in 30 (10.1%) patients. Endoscopic treatment
was successful in all 3 perforations, whereas it failed in 2 out of 27 bleeding patients who were
treated with radiological embolization (1 case) or surgery (1 case). No procedure‐related deaths at
one‐month follow‐up were observed. Lesion recurrence occurred in 16 (6.2%) patients (6 EGC and
10 dysplasia). In conclusion, the rate of both en bloc and R0 gastric lesions removal was very high in
Italy. However, the curative rate for EGC needs to be improved. Complications were acceptably low
and amenable at endoscopy
Robotic Heller-Dor myotomy: 10-year monocentric experience compared with POEM
Achalasia is a rare motility disorder caused by an incomplete relaxation of the lower esophageal sphincter and loss of esophageal peristalsis. As a consequence, the bolus swallowing is hindered and the patients complain dysphagia, regurgitation, chest pain, respiratory symptoms and weight loss. Achalasia’s treatment has been varied over time, from therapies aiming to relax the lower sphincter of the esophagus, including drugs andBotox injection or mechanical dilatations, to surgical myotomy. Robotic or laparoscopic Heller-Dor procedure is considered the gold standard surgical treatment for symptomatic achalasia as it is proved to be effective and safe. As an alternative, Per-Oral Endoscopic Myotomy (POEM) was applied over the past decade, aiming to combine the same results of mini-invasive procedure to the advantages of endoscopic approach. In this study, we are going to compare the medium-long term results of mini-invasive Heller-Dor procedure, routinely performed in our Department, with those of POEM reported in literature
Growth Differentiation Factor 15 in Severe Aortic Valve Stenosis: Relationship with Left Ventricular Remodeling and Frailty
Background: Frailty is an important outcome predictor in patients with aortic stenosis who are candidates for transcatheter or surgical aortic valve replacement (AVR). Growth/differentiation factor 15 (GDF15) is a cytokine playing a role in the pathophysiology of ventricular remodeling. We assessed its potential role as an independent soluble biomarker of frailty in these patients. Methods: We studied 62 patients (age, mean 79 years, 95% confidence interval (CI) 77-81; 54.8% female) with severe aortic valve stenosis and candidates for AVR. We systematically assessed pre-intervention GDF15 levels for their relationship with frailty (Katz score) and echocardiographic parameters of left ventricular dysfunction/remodeling. Fifteen hypertensive patients with left ventricular (LV) hypertrophy served as controls. Results: Patients with aortic valve stenosis featured higher GDF15 levels than controls (1773, 95% CI 1574-1971 pg/mL vs. 775, 95% CI 600-950 pg/mL, respectively, p < 0.0001). Subjects in the upper GDF15 tertile were older (p = 0.004), with a more advanced NYHA functional class (p = 0.04) and a higher prevalence of impaired renal function (p = 0.004). Such patients also showed a higher frailty score (p = 0.04) and higher indices of LV dysfunction, including reduced global longitudinal strain (p = 0.01) and a higher left ventricular mass (p = 0.001). GDF15 was significantly related to the Katz score, and predicted (OR 1.05; 95% CI 0.9-1.1; p = 0.03) a low (<5) Katz score, independent of the relationship with LV mass, age, renal function or indices of LV dysfunction. Conclusions: GDF15 is increased in patients with severe aortic stenosis and appears to be a soluble correlate of patients' frailty, independent of indices of left ventricular dysfunction
Endoscopic submucosal dissection of gastric neoplastic lesions: An Italian, multicenter study
Endoscopic submucosal dissection (ESD) allows removing neoplastic lesions on gastric mucosa, including early gastric cancer (EGC) and dysplasia. Data on ESD from Western countries are still scanty. We report results of ESD procedures performed in Italy. Data of consecutive patients who underwent ESD for gastric neoplastic removal were analyzed. The en bloc resection rate and the R0 resection rates for all neoplastic lesions were calculated, as well as the curative rate (i.e., no need for surgical treatment) for EGC. The incidence of complications, the one-month mortality, and the recurrence rate at one-year follow-up were computed. A total of 296 patients with 299 gastric lesions (80 EGC) were treated. The en bloc resection was successful for 292 (97.6%) and the R0 was achieved in 266 (89%) out of all lesions. In the EGC group, the ESD was eventually curative in 72.5% (58/80) following procedure. A complication occurred in 30 (10.1%) patients. Endoscopic treatment was successful in all 3 perforations, whereas it failed in 2 out of 27 bleeding patients who were treated with radiological embolization (1 case) or surgery (1 case). No procedure-related deaths at one-month follow-up were observed. Lesion recurrence occurred in 16 (6.2%) patients (6 EGC and 10 dysplasia). In conclusion, the rate of both en bloc and R0 gastric lesions removal was very high in Italy. However, the curative rate for EGC needs to be improved. Complications were acceptably low and amenable at endoscopy
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