Biobased Imine Vitrimers Obtained by Photo and Thermal Curing Procedures-Promising Materials for 3D Printing.

Imine-based vitrimers were prepared from synthesized diimine-dimethacrylate monomer derived from biobased vanillin. First, a methacrylate derivative starting from vanillin was synthesized. The diimine derivative was synthesized by condensation of the aldehyde groups from two vanillin methacrylate units with the amine groups of hexamethylenediamine (HMDA). The synthesized product was used in formulations containing ethylene glycol phenyl ether methacrylate (EGPMA) as a reactive diluent for the customization of final material properties and cured by exposure to ultraviolet (UV)-light using suitable radical photoinitiators or else with temperature using a radical thermal initiator. Materials with glass transition temperatures (Tgs) ranging from 70 to 90 °C were prepared, showing good thermal stability and mechanical and thermomechanical properties. The evaluation of their vitrimeric characteristics revealed that all materials achieved a stress-relaxation factor (σ = 0.37σ0) in less than 130 s at 160 °C, with photocured materials exhibiting faster relaxation rates. The catalytic effect of phosphine oxide groups in imine metathesis has also been evidenced. All prepared materials could be mechanically recycled and completely solubilized in a two-step degradation process, putting evidence of their potential use for carbon fiber-reinforced composites (CFRCs). In addition, they demonstrated promising self-repairing abilities. Finally, as a proof of concept, it was established that these formulations could be effectively processed using a Digital Light Processing three-dimensional (3D) Printer (DLP), resulting in the fabrication of complex shapes with high resolution.

Pediatric Plexiform Fibromyxoma: A Case Report.

The plexiform fibromyxoma is a rare mesenchymal tumor in adults that generally originates in the antrum of stomach, being its occurrence in pediatric patients exceptional. It was classified as a distinct entity by World Health Organization in 2010. No recurrences and metastases have been documented in many of the reported patients to date, being the surgical treatment curative. We report the case of a 3-month-old infant who presented to the emergency department with an episode of intestinal subocclusion requiring an emergent surgery. During the surgical intervention, a mass was identified in the jejunum, causing partial occlusion of its lumen. The surgical pathology report revealed an infiltrative tumor composed of spindle-shaped cells disposed in a stroma with a plexiform pattern alternating myxoid areas. These findings and the immunohistochemical characteristics of the neoplastic cells led to classify the tumor as a plexiform fibromyxoma. A description of the immunophenotype of this tumor is made and differential diagnosis with other gastrointestinal tumors is also discussed.

Use of non-invasive scales for detecting esophageal varices in paediatric patients with portal vein thrombosis. / Utilización de escalas no invasivas en la detección de varices esofágicas en pacientes con trombosis venosa portal.

INTRODUCTION: Portal vein thrombosis (PVT) is the most frequent cause of portal hypertension in paediatric population. Baveno VI Consensus considers endoscopic variceal ligation as the second therapeutic option after meso-Rex bypass (surgical shunt). AIM: Analyse the diagnostic profitability of non-invasive scales in order to predict the risk of oesophageal varices (OV) in children with PVT. MATERIAL AND METHODS: Descriptive retrospective study where every upper gastrointestinal endoscopy (UGE) carried on patients <15 years old with non-cirrhotic PVT were included. There were divided according to the presence of OV and sex, cause, age, previous gastrointestinal bleeding or treatments, results of UGE and scales (Clinical Prediction Rule - CPR), Varices Prediction Rule - VPR), King's Variceal Prediction Score - K-VaPS) and Platelet count/Spleen diameter Ratio - PSR). Qualitative variables were expressed as absolute frequency and percentage, and quantitative variables as median and interquartile range. U Mann-Whitney and Hanley-McNeil tests were used for comparisons. RESULTS: Forty-five UGE were analysed. 80% (n=36) presented OV: median of 3 (2-3) and 33.3% (n=12) required endoscopic variceal ligation. Statistical differences were demonstrated between both groups: CPR (142.39 [132.22-166.53] vs. 122.75 [115.24-133.15]; p=0.003), VPR (9.91 [9.36-11.75] vs. 5.6 [3.34-8.39]; p=0.001), K-VaPS (117.86 [99.66-126.58] vs. 99.64 [94.88-10.18]; p=0.019), PSR (2384.62 [1902.22-3201.63] vs. 1252.5 [579.6-2144.42]; p=0.05), with and area under the curve AUROC>75%, without statistical differences between scales. CONCLUSIONS: In paediatric patients with non-cirrotic PVT non-invasive scales can be used as a tool to predict the presence of OV and raise the indication of UGE.

Analysis of the Predictive Capacity of the Clinical Variables That Indicate the Performance of Voiding Urosonography in the Study of Vesicoureteral Reflux in Children.

INTRODUCTION: Voiding urosonography (VUS) is a dynamic imaging technique which evaluates the lower urinary tract by introducing sonographic contrast into the bladder, preferably used in the diagnosis of vesicoureteral reflux (VUR). Our goals were to describe the clinical indications for performing a VUS for VUR's diagnosis and analyse its diagnostic reliability. MATERIAL AND METHODS: Cross-sectional study carried on patients under 15 years old with a VUS taken between November 2013-2020. Sex, age, indications (lower urinary tract infection-LUTI; dilatated lower urinary tract-DLUT; duplex collecting system-DCS), results (presence/absence of VUR, score and side) and complications were analysed. U Mann-Whitney and Chi-squared tests were used and 2 predictive capacity models for the indications used to detect VUR were employed (logistic binomial regression and multilayer perceptron neural network). Statistical significance p < 0.05. RESULTS: 415 VUS were completed correctly (male 51.8%, median age 7.3 (3.1-15.3) months). Indications were: LUTI (67.5%), DLUT (33.5%) and DCS (10.2%); presenting 1, 2 and 3 indications in 86.5%, 12.8% and 0.7% respectively. VUR was diagnosed in 34.7% cases. A tendency towards statistically significance was showed related to male sex (p = 0.052) and the only significative clinical indication for VUR was DCS (p = 0.007). Patients with 2 simultaneous indications had higher probability of VUR (p = 0.012). DCS presence or male sex were the only predictive variables of VUR: DCS = OR 1.89 (1.54-6.52) (p = 0.006) and male sex = OR 1.56 (1.03-2.35) (p = 0.035). CONCLUSIONS: VUS is a thriving technique, radiation free and with a low complications rate. Presence of DCS, male sex or 2 simultaneous indications for VUS increase the probability of presenting VUR.

Enuresis: clinical evolution of patients attended at specialized unit of paediatric urology.

OBJECTIVE: To analyse the clinical evolution, the therapeutic strategies and the characteristics of the patients presenting enuresis attended at our outpatient clinic. MATERIAL AND METHODS: Retrospective study of patients <14 years old(yo) diagnosed of enuresis attended at our outpatient clinic (2011-2019) and completed their follow-up (remission or aged 15). Urotherapy was offered to all patients as initial management. The therapeutic strategies were classified as: first line (desmopressin or clock alarm), second line (desmo-pressin+alarm) and third line(anticholinergics). The remission rate during follow-up, the number of consultations needed until remission and the treatments used were calculated. Statistical tests used:Kaplan-Meier, actuarial survival. Multivariate analysis:Cox regression.Statistical significance:p<0.05. RESULTS: Data were collected from 125 patients (mean age: 8.6±2.45yo). Family history of enuresis was present in 38.9%. The mean follow-up was 2.37±1.55yo and the average number of consultations was 7.54±5.06. The remission rate (RE) was 84%(n=105), with a median remission interval:2.66 years (2.34-2.991[95%CI]). The average number of treatments required for remission was 2.74±1.27. RE with urotherapy alone was 20%(n=25); RE with first line:19.3%(n=17) and second line:16.7(n=11). In the remaining patients, a RE of 78.18%(n=43) was achieved by adding an anticholinergic. Patients aged > 8.7 years at the beginning of the follow-up required less time to achieve remission (p=.025). These patients had a higher RE (hazard ratio 1.15 (1.05-1.25))(p=.004). No other variables were significant. CONCLUSION: Staged therapeutic strategies are necessary to achieve remission. Only 25% remitted with urotherapy as single treatment. RE are higher when patients are >8.7 yo once they initiate their follow up.

Polyacrylates Derived from Biobased Ethyl Lactate Solvent via SET-LRP.

The precise synthesis of polymers derived from alkyl lactate ester acrylates is reported for the first time. Kinetic experiments were conducted to demonstrate that Cu(0) wire-catalyzed single electron transfer-living radical polymerization (SET-LRP) in alcohols at 25 °C provides a green methodology for the LRP of this forgotten class of biobased monomers. The acrylic derivative of ethyl lactate (EL) solvent and homologous structures with methyl and n-butyl ester were polymerized with excellent control over molecular weight, molecular weight distribution, and chain-end functionality. Kinetics plots in conventional alcohols such as ethanol and methanol were first order in the monomer, with molecular weight increasing linearly with conversion. However, aqueous EL mixtures were found to be more suitable than pure EL to mediate the SET-LRP process. The near-quantitative monomer conversion and high bromine chain-end functionality, demonstrated by matrix-assisted laser desorption ionization time-of-flight analysis, further allowed the preparation of innovative biobased block copolymers containing rubbery poly(ethyl lactate acrylate) poly(ELA) sequences. For instance, the poly(ELA)- b-poly(glycerol acrylate) block copolymer self-assembled in water to form stable micelles with chiral lactic acid-derived block-forming micellar core as confirmed by the pyrene-probe-based fluorescence technique. Dynamic light scattering and transmission electron microscopy measurements revealed the nanosize spherical morphology for these biobased aggregates.