Life cycle assessment of routinely used endoscopic instruments and simple intervention to reduce our environmental impact.

OBJECTIVES: GI endoscopy units represent the third largest producers of medical waste. We aimed to determine endoscopic instrument composition and life cycle assessment (LCA) and to assess a sustainability proposal based on a mark on the instruments that identifies parts can be safely recycled or 'green mark'. DESIGN: Material composition analysis and LCA of forceps, snares and clips from four different manufacturers (A-D) were performed with four different methods. Carbon footprint from production, transportation and end of life of these instruments was calculated. In 30 consecutive procedures, we marked the contact point with the working channel. 5 cm away from that point was considered as green mark. One-week prospective study was conducted with 184 procedures evaluating 143 instruments (75 forceps, 49 snares and 19 haemoclips) to assess the efficacy of this recyclable mark. RESULTS: Composition from different manufacturers varied widely. Most common materials were high global warming potential (GWP) waste (polyethylene, polypropylene and acrylonitrile) and low GWP waste (stainless steel). Significant differences were found for the forceps (0.31-0.47 kg of CO2 equivalent (CO2-eq)) and haemoclips (0.41-0.57 kg CO2-eq) between the manufacturers. Green mark was established 131.26 cm for gastroscope and 195.32 cm for colonoscope. One-week activity produced 67.74 kg CO2-eq. Applying our sustainability intervention, we could reduce up to 27.44% (18.26 kg CO2-eq). This allows the recycling of 61.7% of the instrument total weight (4.69 kg). CONCLUSION: Knowledge of carbon footprint is crucial to select the most sustainable alternatives because there are large variations between brands. A mark to identify recyclable parts could reduce our environmental impact significantly.

Classification Predictive Model for Air Leak Detection in Endoworm Enteroscopy System.

Current enteroscopy techniques present complications that are intended to be improved with the development of a new semi-automatic device called Endoworm. It consists of two different types of inflatable cavities. For its correct operation, it is essential to detect in real time if the inflatable cavities are malfunctioning (presence of air leakage). Two classification predictive models were obtained, one for each cavity typology, which must discern between the "Right" or "Leak" states. The cavity pressure signals were digitally processed, from which a set of features were extracted and selected. The predictive models were obtained from the features, and a prior classification of the signals between the two possible states was used as input to different supervised machine learning algorithms. The accuracy obtained from the classification predictive model for cavities of the balloon-type was 99.62%, while that of the bellows-type was 100%, representing an encouraging result. Once the models are validated with data generated in animal model tests and subsequently in exploratory clinical tests, their incorporation in the software device will ensure patient safety during small bowel exploration.

Engineered Highly Porous Polyvinyl Alcohol Hydrogels with Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Graphene Nanosheets for Musculoskeletal Tissue Engineering: Morphology, Water Sorption, Thermal, Mechanical, Electrical Properties, and Biocompatibility.

Electroactive composite materials are very promising for musculoskeletal tissue engineering because they can be applied in combination with electrostimulation. In this context, novel graphene-based poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/polyvinyl alcohol (PHBV/PVA) semi-interpenetrated networks (semi-IPN) hydrogels were engineered with low amounts of graphene (G) nanosheets dispersed within the polymer matrix to endow them with electroactive properties. The nanohybrid hydrogels, obtained by applying a hybrid solvent casting-freeze-drying method, show an interconnected porous structure and a high water-absorption capacity (swelling degree > 1200%). The thermal characterization indicates that the structure presents microphase separation, with PHBV microdomains located between the PVA network. The PHBV chains located in the microdomains are able to crystallize; even more after the addition of G nanosheets, which act as a nucleating agent. Thermogravimetric analysis indicates that the degradation profile of the semi-IPN is located between those of the neat components, with an improved thermal stability at high temperatures (>450 °C) after the addition of G nanosheets. The mechanical (complex modulus) and electrical properties (surface conductivity) significantly increase in the nanohybrid hydrogels with 0.2% of G nanosheets. Nevertheless, when the amount of G nanoparticles increases fourfold (0.8%), the mechanical properties diminish and the electrical conductivity does not increase proportionally, suggesting the presence of G aggregates. The biological assessment (C2C12 murine myoblasts) indicates a good biocompatibility and proliferative behavior. These results reveal a new conductive and biocompatible semi-IPN with remarkable values of electrical conductivity and ability to induce myoblast proliferation, indicating its great potential for musculoskeletal tissue engineering.

Active methods in electricity and magnetism courses: Influence of degree, academic level and gender on student performance.

The performance of first-year students in electromagnetism (E&M) courses of different engineering degrees at a Spanish public university was measured using the Brief Electricity and Magnetism Assessment (BEMA), a standard research-based instrument to assess students' understanding after attending introductory courses in electricity and magnetism. In all cases, Flipped classroom (FC) built on information and communications technology was used. The objective of this paper is to analyse if the gain in the BEMA pre and post-test results is influenced by several factors such as the degree, the students' academic grade, and gender. Moreover, as some studies have shown that the students' retention of the concepts was significantly stronger in active learning than in traditional approaches, a third BEMA test was performed by the students to analyse the long-term retention gain dependence on the same factors. Students from different engineering degree programs were asked to complete two BEMA tests during the course and a third one after a few months. ANOVA tests were used to analyse the existence of significant differences in gain between student degree programs, student academic level and student gender. Results have shown no differences in the BEMA performance by degree program, but significant differences were found by academic level and gender. Retention did not depend on the degree course but on the academic level. Mean gain value by academic level, and gender was obtained and concluded that the best students presented the best gain results and that gain depends on the students' gender: males outperformed females in the BEMA tests, although there were no significant differences in the course grades. It is thus necessary to understand these differences and to implement measures in daily teaching work to improve women's performance.

Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Hospitalized Patients in Peru.

There is a knowledge gap in the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) causing bloodstream infections (BSIs) in Peru. Through a surveillance study in 13 hospitals of 10 Peruvian regions (2017-2019), we assessed the proportion of MRSA among S. aureus BSIs as well as the molecular typing of the isolates. A total of 166 S. aureus isolates were collected, and 36.1% of them were MRSA. Of note, MRSA isolates with phenotypic and genetic characteristics of the hospital-associated Chilean-Cordobes clone (multidrug-resistant SCCmec I, non-Panton-Valentine leukocidin [PVL] producers) were most commonly found (70%), five isolates with genetic characteristics of community-associated MRSA (CA-MRSA)-SCCmec IV, PVL-producer-(8.3%) were seen in three separate regions. These results demonstrate that hospital-associated MRSA is the most frequent MRSA found in patients with BSIs in Peru. They also show the emergence of S. aureus with genetic characteristics of CA-MRSA. Further studies are needed to evaluate the extension of CA-MRSA dissemination in Peru.

Pro-Myogenic Environment Promoted by the Synergistic Effect of Conductive Polymer Nanocomposites Combined with Extracellular Zinc Ions.

A new strategy based on the combination of electrically conductive polymer nanocomposites and extracellular Zn2+ ions as a myogenic factor was developed to assess its ability to synergically stimulate myogenic cell response. The conductive nanocomposite was prepared with a polymeric matrix and a small amount of graphene (G) nanosheets (0.7% wt/wt) as conductive filler to produce an electrically conductive surface. The nanocomposites' surface electrical conductivity presented values in the range of human skeletal muscle tissue. The biological evaluation of the cell environment created by the combination of the conductive surface and extracellular Zn2+ ions showed no cytotoxicity and good cell adhesion (murine C2C12 myoblasts). Amazingly, the combined strategy, cell-material interface with conductive properties and Zn bioactive ions, was found to have a pronounced synergistic effect on myoblast proliferation and the early stages of differentiation. The ratio of differentiated myoblasts cultured on the conductive nanocomposites with extracellular Zn2+ ions added in the differentiation medium (serum-deprived medium) was enhanced by more than 170% over that of non-conductive surfaces (only the polymeric matrix), and more than 120% over both conductive substrates (without extracellular Zn2+ ions) and non-conductive substrates with extracellular Zn2+. This synergistic effect was also found to increase myotube density, myotube area and diameter, and multinucleated myotube formation. MyoD-1 gene expression was also enhanced, indicating the positive effect in the early stages of myogenic differentiation. These results demonstrate the great potential of this combined strategy, which stands outs for its simplicity and robustness, for skeletal muscle tissue engineering applications.

Analysis of the 'Endoworm' prototype's ability to grip the bowel in in vitro and ex vivo models.

Access to the small bowel by means of an enteroscope is difficult, even using current devices such as single-balloon or double-balloon enteroscopes. Exploration time and patient discomfort are the main drawbacks. The prototype 'Endoworm' analysed in this paper is based on a pneumatic translation system that, gripping the bowel, enables the endoscope to move forward while the bowel slides back over its most proximal part. The grip capacity is related to the pressure inside the balloon, which depends on the insufflate volume of air. Different materials were used as in vitro and ex vivo models: rigid polymethyl methacrylate, flexible silicone, polyester urethane and ex vivo pig small bowel. On measuring the pressure-volume relationship, we found that it depended on the elastic properties of the lumen and that the frictional force depended on the air pressure inside the balloons and the lumen's elastic properties. In the presence of a lubricant, the grip on the simulated intestinal lumens was drastically reduced, as was the influence of the lumen's properties. This paper focuses on the Endoworm's ability to grip the bowel, which is crucial to achieving effective endoscope forward advance and bowel folding.

Data set on the effectiveness of flip teaching on engineering students' performance in the physics lab compared to Traditional Methodology.

This paper shows the data of the Flip Teaching and Traditional Methodology on the laboratory practice in two subjects, Physics and Electricity, of a technical degree. The laboratory and final grades of these subjects were shown in four consecutive years. The characteristics of all four years were quite similar, except that the Traditional teaching Methodology (TM) was used in two, while Flip Teaching methodology (FT) was applied in the other two. For further discussion, please refer to the scientific article entitled "Effectiveness of flip teaching on engineering students' performance in the physics lab" [1]. Additional segmentation data in three levels are presented in this data in brief paper.

Morphology, Crystallinity, and Molecular Weight of Poly(ε-caprolactone)/Graphene Oxide Hybrids.

A study was carried out to determine the effects of graphene oxide (GO) filler on the properties of poly(ε-caprolactone) (PCL) films. A series of nanocomposites were prepared, incorporating different graphene oxide filler contents (0.1, 0.2, and 0.5 wt%) by the solution mixing method, and an in-depth study was made of the morphological changes, crystallization, infrared absorbance, molecular weight, thermal properties, and biocompatibility as a function of GO content to determine their suitability for use in biomedical applications. The infrared absorbance showed the existence of intermolecular hydrogen bonds between the PCL's carbonyl groups and the GO's hydrogen-donating groups, which is in line with the apparent reduction in molecular weight at higher GO contents, indicated by the results of the gel permeation chromatography (GPC), and the thermal property analysis. Polarized optical microscopy (POM) showed that GO acts as a nucleating point for PCL crystals, increasing crystallinity and crystallization temperature. The biological properties of the composites studied indicate that adding only 0.1 wt% of GO can improve cellular viability and that the composite shows promise for use in biomedical applications.

Endoworm: A new semi-autonomous enteroscopy device.

Using enteroscopes with therapeutic capacity to explore the small intestine entails certain limitations, including long exploration times, patient discomfort, the need for sedation, a high percentage of incomplete explorations and a long learning curve. This article describes the advances and setbacks encountered in designing the new Endoworm enteroscopy system, a semi-autonomous device consisting of a control unit and three cavities that inflate and deflate in such a way that the bowel retracts over the endoscope. The system can be adapted to any commercial enteroscope. Endoworm was tested in different intestine models: a polymethyl methacrylate rigid tube, an in vitro polyester urethane model, an ex vivo pig model and an in vivo animal model. The general behavior of the prototype was evaluated by experienced medical personnel. The mean distance covered through the lumen was measured in each cycle. The system was found to have excellent performance in the rigid tube and in the in vitro model. The ex vivo tests showed that the behavior depended largely on the mechanical properties of the lumen, while the in vivo experiments suggest that the device will require further modifications to improve its performance.

Physical characterization of polycaprolactone scaffolds.

Films and sponges were prepared from a solution of Poly(epsilon-caprolactone) (PCL) in tetrahydrofuran (THF). The porosity, crystallinity, and mechanical properties of the samples were studied. Porosity of around 15% was obtained for the films produced by evaporation of THF at room temperature. A much more porous structure (50-70%) was found for the sponges obtained by cooling the solution at -30 degrees C and subsequently eliminating the solvent by freeze drying. The porosity of the samples was also observed by scanning electron microscopy (SEM). The crystallinity of the samples was studied by the calorimetric technique (DSC) before and after the compression scans. The mechanical properties of the different samples were determined by compression test, and were compared to those corresponding to the PCL in bulk. The compression scans did not affect the crystallinity of the samples. The variations observed in the results of the different scans were attributed to the differences in porosities and crystallinity.