Biosurfactant complexed with arginine has antibiofilm activity against methicillin-resistant Staphylococcus aureus.

Aim: The present study investigated the antimicrobial effectiveness of a rhamnolipid complexed with arginine (RLMIX_Arg) against planktonic cells and biofilms of methicillin-resistant Staphylococcus aureus (MRSA). Methodology: Susceptibility testing was performed using the Clinical & Laboratory Standards Institute protocol: M07-A10, checkerboard test, biofilm in plates and catheters and flow cytometry were used. Result: RLMIX_Arg has bactericidal and synergistic activity with oxacillin. RLMIX_Arg inhibits the formation of MRSA biofilms on plates at sub-inhibitory concentrations and has antibiofilm action against MRSA in peripheral venous catheters. Catheters impregnated with RLMIX_Arg reduce the formation of MRSA biofilms. Conclusion: RLMIX_Arg exhibits potential for application in preventing infections related to methicillin-resistant S. aureus biofilms.

[Box: see text].

Antimicrobial and Anesthetic Niosomal Formulations Based on Amino Acid-Derived Surfactants.

BACKGROUND: This work proposes the development of new vesicular systems based on anesthetic compounds (lidocaine (LID) and capsaicin (CA)) and antimicrobial agents (amino acid-based surfactants from phenylalanine), with a focus on physicochemical characterization and the evaluation of antimicrobial and cytotoxic properties. METHOD: Phenylalanine surfactants were characterized via high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). Different niosomal systems based on capsaicin, lidocaine, cationic phenylalanine surfactants, and dipalmitoyl phosphatidylcholine (DPPC) were characterized in terms of size, polydispersion index (PI), zeta potential, and encapsulation efficiency using dynamic light scattering (DLS), transmitted light microscopy (TEM), and small-angle X-ray scattering (SAXS). Furthermore, the interaction of the pure compounds used to prepare the niosomal formulations with DPPC monolayers was determined using a Langmuir balance. The antibacterial activity of the vesicular systems and their biocompatibility were evaluated, and molecular docking studies were carried out to obtain information about the mechanism by which these compounds interact with bacteria. RESULTS: The stability and reduced size of the analyzed niosomal formulations demonstrate their potential in pharmaceutical applications. The nanosystems exhibit promising antimicrobial activity, marking a significant advancement in pharmaceutical delivery systems with dual therapeutic properties. The biocompatibility of some formulations underscores their viability. CONCLUSIONS: The proposed niosomal formulations could constitute an important advance in the pharmaceutical field, offering delivery systems for combined therapies thanks to the pharmacological properties of the individual components.

Cardiovascular effect of preeclampsia upon offspring development: Are (Pro) renin-renin receptor ((P)RR) and gender related?

Objectives: Preeclampsia (PE) is a complication of pregnancy that might increase progeny risk of cardiovascular and metabolic problems, mainly in males. Renin angiotensin aldosterone system is known to be involved. (Pro) renin/renin receptor ((P)RR) has been shown to participate in cardiovascular pathology. The aim of this work was to evaluate (P)RR expression and function upon cardiovascular and renal tissues from PE dams' offspring. Materials and Methods: We used offspring from normal pregnant and preeclamptic rats, evaluating body, heart, aorta and kidney weight, length, and blood pressure along 3 months after birth. Subsets of animals received handle region peptide (HRP) (0.2 mg/Kg, sc). Another group received vehicle. Animals were sacrificed at first, second, and third months of age, tissues were extracted and processed for immunoblot to detect (P)RR, PLZF, ß-catenin, DVL-1, and PKCα. (P)RR and PLZF were also measured by RT-PCR. Results: We found that offspring developed hypertension. Male descendants remained hypertensive throughout the whole experiment. Female animals tended to recover at second month and returned to normal blood pressure at third month. HRP treatment diminished hypertension in both male and female animals. Morphological evaluations showed changes in heart, aorta, and kidney weight, and HRP reverted this effect. Finally, we found that (P)RR, PLZF, and canonical WNT transduction pathway molecules were stimulated by PE, and HRP treatment abolished this increase. Conclusion: These findings suggest that PE can induce hypertension in offspring, and (P)RR seems to play an important role through the canonical WNT pathway and that gender seems to influence this response.

Antimicrobial potential of a biosurfactant gel for the prevention of mixed biofilms formed by fluconazole-resistant C. albicans and methicillin-resistant S. aureus in catheters.

Dual-species biofilms formed by Candida albicans and Staphylococcus aureus have high virulence and drug resistance. In this context, biosurfactants produced by Pseudomonas aeruginosa have been widely studied, of which a new derivative (RLmix_Arg) stands out for possible application in formulations. The objective of this study was to evaluate the antibiofilm activity of RLmix_Arg, both alone and incorporated in a gel prepared with Pluronic F-127, against dual-species biofilms of fluconazole-resistant C. albicans (FRCA) and methicillin-resistant S. aureus (MRSA) in impregnated catheters. Broth microdilution tests, MTT reduction assays of mature biofilms, impregnation of RLmix_Arg and its gel in peripheral venous catheters, durability tests and scanning electron microscopy (SEM) were performed. RLmix_Arg showed antimicrobial activity against Candida spp. and S. aureus, by reducing the cell viability of mixed biofilms of FRCA and MRSA, and preventing their formation in a peripheral venous catheter. The incorporation of this biosurfactant in the Pluronic F-127 gel considerably enhanced its antibiofilm activity. Thus, RLmix_Arg has potential application in gels for impregnation in peripheral venous catheters, helping to prevent development of dual-species biofilms of FRCA and MRSA.

Clinicopathological and Genomic Identification of Breast Cancers with No Impact on Mortality.

BACKGROUND: Implementing mammogram screening means that clinicians are seeing many breast cancers that will never develop metastases. The purpose of this study was to identify subgroups of breast cancer patients who did not present events related to long-term breast cancer mortality, taking into account diagnosis at breast screening, absence of palpability and axillary involvement, and genomic analysis with PAM50. PATIENTS AND METHODS: To identify them, a retrospective observational study was carried out selecting patients without any palpable tumor and without axillary involvement, and a genomic analysis was performed with PAM50. RESULTS: The probability of distant metastasis-free interval (DMFI) of 337 patients was 0.92 (95% CI, 0.90-0.93) at 20 years and 0.96 (95% CI, 0.92-1.00) in 95 patients (28%) with available PAM50 tests. In 22 (23.15%) luminal A tumors and in 9 (9.47%) luminal B tumors smaller than 1 cm, and in HER2 and basal type tumors, there were no metastatic events (20-year DMFI of 1.00). CONCLUSION: Patients with nonpalpable breast cancer found at screening with negative nodes are at very low risk. It is possible to identify subgroups without metastatic events by determining the intrinsic subtype and tumor size less than 1 cm. Therefore, de-escalation of treatment should be considered.

Real-world experience with pertuzumab and trastuzumab combined with chemotherapy in neoadjuvant treatment for patients with early-stage HER2-positive breast cancer: the NEOPERSUR study.

PURPOSE: HER2-targeted therapies have dramatically improved outcomes of patients with HER2-positive breast cancer (BC), as demonstrated in neoadjuvant trials. This study aims to provide real-world evidence on the use and effectiveness of combined pertuzumab, trastuzumab and chemotherapy (CT) in early-stage HER2-positive BC. METHODS: A retrospective, multicentre study was conducted on patients diagnosed with HER2-positive early BC treated with neoadjuvant pertuzumab and trastuzumab plus CT at 13 Spanish sites. The primary endpoint was pathological complete response (pCR). RESULTS: A total of 310 patients were included. Pertuzumab and trastuzumab were combined with anthracyclines and taxanes, carboplatin and docetaxel, and taxane-based CT in 77.1%, 16.5%, and 6.5% of patients, respectively. Overall, the pCR rate was 62.2%. The pCR was higher amongst patients with hormone receptor-negative tumours and with tumours expressing higher levels of Ki-67 (> 20%). After postoperative adjuvant treatment, 13.9% of patients relapsed. Those patients who did not achieve pCR, with tumours at advanced stages (III), and with node-positive disease were more likely to experience distant relapse. Median overall survival (OS) and distant disease-free survival (D-DFS) were not reached at the study end. The estimated mean OS and D-DFS times were 7.5 (95% CI 7.3-7.7) and 7.3 (95% CI 7.1-7.5) years, respectively (both were significantly longer amongst patients who achieved pCR). Grade 3-4 anti-HER2 related toxicities were reported in six (1.9%) patients. CONCLUSION: Neoadjuvant pertuzumab and trastuzumab plus CT achieve high pCR rates in real-life patients with HER2-positive early BC, showing an acceptable safety profile. Innovative adjuvant strategies are essential in patients at high risk of distant disease recurrence.

[Association between reproductive history, breast cancer subtype, and survival in premenopausal women]. / Asociación entre la historia reproductiva, el subtipo de cáncer de mama y la supervivencia de mujeres premenopáusicas.

BACKGROUND AND OBJECTIVE: Reproductive history influences breast cancer risk. We analysed its association with tumour subtype and survival in premenopausal women. PATIENTS AND METHODS: Retrospective, observational study of premenopausal women with stage I-III breast carcinoma in the last 20 years. Review of reproductive history, clinical data, and treatments in health records. RESULTS: In 661 premenopausal women (32.40% of 1377 total cases), median age was 47 years (19-53), menarche 12 (7-17), first delivery 28 (16-41) and number of deliveries 2 (0-9). One hundred and eleven (18.20%) were nulliparous. Three hundred and fifty-nine (58.80%) used natural lactation, with a median duration of 6 months. Anovulatory drugs were used by 271 (44.40%), with a median duration of 36 months. Associations were found between menarche <10 years and lower risk of luminal subtype (OR: 0.52, 95% CI: 0.28-0.94; P=.03), between menarche >11 years and lower risk of HER2 subtype (OR: 0.50, 95% CI: 0.26-0.97; P=.04) and between first birth >30 years and lower risk of triple negative subtype (OR: 0.40, 95% CI: 0.17-0.93; P=.03). The 20-year overall and disease-free survival probabilities were 0.80 (95% CI: 0.71-0.90) and 0.72 (95% CI: 0.64-0.79) respectively. Patients with ≥1 delivery had better overall survival than nulliparous patients (HR: 0.51, 95% CI: 0.27-0.96, P=.04). CONCLUSIONS: The findings suggest an association between age at menarche and age at first delivery and breast cancer subtype. Nulliparity is associated with worse survival.

Factors associated with mechanical ventilation longer than 24 h after liver transplantation in patients at risk for bleeding.

BACKGROUND: This risk analysis aimed to explore all modifiable factors associated with prolonged mechanical ventilation (lasting > 24 h) after liver transplantation, based on prospectively collected data from a clinical trial. METHODS: We evaluated 306 candidates. Ninety-three patients were excluded for low risk for transfusion (preoperative haemoglobin > 130 g.l-1), and 31 patients were excluded for anticoagulation therapy, bleeding disorders, familial polyneuropathy, or emergency status. Risk factors were initially identified with a log-binomial regression model. Relative risk was then calculated and adjusted for age, sex, and disease severity (Model for End-Stage Liver Disease [MELD] score). RESULTS: Early tracheal extubation was performed in 149 patients (84.7%), and 27 patients (15.3%) required prolonged mechanical ventilation. Reoperations were required for 6.04% of the early extubated patients and 44% of patients who underwent prolonged ventilation (p = 0.001). A MELD score > 23 was the main risk factor for prolonged ventilation. Once modifiable risk factors were adjusted for MELD score, sex, and age, three factors were significantly associated with prolonged ventilation: tranexamic acid (p = 0.007) and red blood cell (p = 0.001) infusion and the occurrence of postreperfusion syndrome (p = 0.004). The median (IQR) ICU stay was 3 (2-4) days in the early extubation group vs. 5 (3-10) days in the prolonged ventilation group (p = 0.001). The median hospital stay was also significantly shorter after early extubation, at 14 (10-24) days, vs. 25 (14-55) days in the prolonged ventilation group (p = 0.001). Eight patients in the early-extubation group (5.52%) were readmitted to the ICU, nearly all for reoperations, with no between-group differences in ICU readmissions (prolonged ventilation group, 3.7%). CONCLUSION: We conclude that bleeding and postreperfusion syndrome are the main modifiable factors associated with prolonged mechanical ventilation and length of ICU stay, suggesting that trials should explore vasopressor support strategies and other interventions prior to graft reperfusion that might prevent potential fibrinolysis. TRIAL REGISTRATION: European Clinical Trials Database (EudraCT 2018-002510-13,) and on ClinicalTrials.gov (NCT01539057).

Arginine Gemini-Based Surfactants for Antimicrobial and Antibiofilm Applications: Molecular Interactions, Skin-Related Anti-Enzymatic Activity and Cytotoxicity.

The antimicrobial and antibiofilm properties of arginine-based surfactants have been evaluated. These two biological properties depend on both the alkyl chain length and the spacer chain nature. These gemini surfactants exhibit good activity against a wide range of bacteria, including some problematic resistant microorganisms such us methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Moreover, surfactants with a C10 alkyl chain and C3 spacer inhibit the (MRSA) and Pseudomonas aeruginosa biofilm formation at concentrations as low as 8 µg/mL and are able to eradicate established biofilms of these two bacteria at 32 µg/mL. The inhibitory activities of the surfactants over key enzymes enrolled in the skin repairing processes (collagenase, elastase and hyaluronidase) were evaluated. They exhibited moderate anti-collagenase activity while the activity of hyaluronidase was boosted by the presence of these surfactants. These biological properties render these gemini arginine-based surfactants as perfect promising candidates for pharmaceutical and biological properties.

Cholinium-Based Ionic Liquids as Promising Antimicrobial Agents in Pharmaceutical Applications: Surface Activity, Antibacterial Activity and Ecotoxicological Profile.

Cholinium-based ionic liquids are compounds increasingly studied in pharmaceutics and biomedicine to enhance bioavailability in drug delivery systems and as bioactive ingredients in pharmaceutical formulations. However, their potential as antimicrobial agents has scarcely been investigated. Herein, we explored the antimicrobial activity of a series of surface-active cholinium-based ionic liquids (Chol-ILs). For this purpose, Chol-ILs with alkyl chains of 10-16 carbon atoms were synthesized and their self-assembly in aqueous medium was investigated. Subsequently, their antimicrobial activity against a panel of clinically relevant bacteria and their ability to eradicate MRSA and P. aeruginosa PAO1 biofilms was evaluated. Finally, we analyzed the ecotoxicological profile of Chol-ILs in terms of susceptibility to aerobic biodegradation and acute aquatic toxicity against D. magna and V. fisheri. Our results reveal that cholinium-based ILs with alkyl chain lengths ≥12 C show a broad spectrum of antibacterial activity. Their antimicrobial efficacy depends on their hydrophobicity, with the C14-C16 homologs being the most effective compounds. These ILs exhibit antimicrobial activity similar to that of imidazolium ILs and quaternary ammonium antiseptics. Moreover, the longer alkyl chain Chol-ILs are able to eradicate established biofilms at concentrations as low as 16-32 µg/mL. The biodegradation rate of cholinium-based ILs decreases with alkyl chain elongation. Our results reinforce the suitability of Chol-ILs as promising multifunctional compounds for application in pharmaceutical and biomedical formulation.

Phenylalanine and Tryptophan-Based Surfactants as New Antibacterial Agents: Characterization, Self-Aggregation Properties, and DPPC/Surfactants Vesicles Formulation.

Cationic surfactants based on phenylalanine (CnPC3NH3Cl) and tryptophan (CnTC3NH3Cl) were synthesized using renewable raw materials as starting compounds and a green synthetic procedure. The synthesis, acid-base equilibrium, aggregation properties, and antibacterial activity were investigated. Conductivity and fluorescence were used to establish critical micelle concentrations. Micellization of CnPC3NH3Cl and CnTC3NH3Cl occurred in the ranges of 0.42-16.2 mM and 0.29-4.6 mM, respectively. Since those surfactants have some acidic character, the apparent pKa was determined through titrations, observing increasing acidity with increasing chain length and being slightly more acidic with the phenylalanine than the tryptophan derivatives. Both families showed promising antibacterial efficacy against eight different bacterial strains. Molecular docking studies against the enzyme peptidoglycan glycosyltransferase (PDB ID:2OQO) were used to investigate the potential binding mechanism of target surfactant molecules. According to small angle X-ray scattering (SAXS) results, the surfactants incorporate into DPPC (Dipalmitoyl Phosphatidyl Choline) bilayers without strong perturbation up to high surfactant concentration. Some of the C12TC3NH3Cl/DPPC formulations (40%/60% and 20%/80% molar ratios) exhibited good antibacterial activity, while the others were not effective against the tested bacteria. The strong affinity between DPPC and surfactant molecules, as determined by the DFT (density functional theory) method, could be one of the reasons for the loss of antibacterial activity of these cationic surfactants when they are incorporated in vesicles.

Guía para la implementación de cursos en red / A guide for the implementation of network resources

Introducción: Los cambios en la educación médica superior, provocados por la pandemia del virus SARS-CoV-2, impulsaron la integración de las tecnologías de la información y la comunicación a la docencia en Cuba y el mundo. La Universidad Virtual de Salud se convirtió en un medio importante para apoyar los procesos docente-educativos, por lo que los profesores tuvieron que afrontar el reto de virtualizar sus actividades formativas. Objetivo: Validar una guía para el diseño y montaje de entornos virtuales de enseñanza aprendizaje en la educación médica de pregrado y posgrado. Métodos: Se realizó una investigación de tipo innovación tecnológica en tres etapas: diseño de la guía, implementación y validación. Se aplicó una encuesta a los participantes del entrenamiento virtual en Entornos Virtuales de Enseñanza Aprendizaje. Resultados: Se propusieron seis pasos para el diseño y la implementación de procesos formativos mediante la virtualidad: análisis de los recursos y la factibilidad; diseño del curso o adaptación de un programa existente; producción de contenidos; subida de recursos y configuración de las actividades; acción formativa; y evaluación del curso, mejora y rediseño. Conclusiones: La integración de la tecnología a la docencia en la educación superior es una realidad impulsada por la situación epidemiológica, que se seguirá desarrollando hasta que forme parte de la labor habitual del docente. Esta guía sistematiza y simplifica las acciones para facilitar el proceso inicial de virtualización. Se propone un modelo flexible y escalable para mejorar continuamente la calidad del proceso docente educativo en entornos virtuales de enseñanza aprendizaje(AU)

Introduction: Changes in higher medical education, caused by the SARS-CoV-2 virus pandemic, prompted the integration of information and communication technologies to teaching in Cuba and the world. The virtual university of health became an important means to support the teaching-educational processes; therefore, professors had to face the challenge of virtualizing their training activities. Objective: To validate a guide for designing and assembling virtual teaching-learning environments in undergraduate and postgraduate medical education. Methods: A technological innovation research was carried out in three stages: design of the guide, implementation and validation. A survey was conducted to the participants of the virtual training in virtual teaching-learning environments. Results: Six steps were proposed for the design and implementation of training processes through the virtual modality: analysis of resources and feasibility; course design or adaptation of an existing program; content production; resource uploading and activity configuration; training action; and course assessment, improvement and redesign. Conclusions: The integration of technology to higher education teaching is a reality driven by the epidemiological situation, which will continue to develop until it becomes part of the professor's regular work. This guide systematizes and simplifies actions to facilitate the initial virtualization process. A flexible and scalable model is proposed to improve continuously the quality of the educational teaching process in virtual teaching-learning environments(AU)

Zein Nanoparticles Containing Arginine-Based Surfactants: Physicochemical Characterization and Effect on the Biological Properties.

Cationic surfactants carry antimicrobial activity, based on their interaction and disruption of cell membranes. Nonetheless, their intrinsic toxicity limits their applicability. To overcome this issue, a feasible strategy consists of using solid nanoparticles to improve their delivery. The zein nanoparticles were loaded with four cationic arginine-based surfactants: one single chain Nα-lauroyl-arginine (LAM) and three Gemini surfactants Nα Nω-Bis (Nα-lauroyl-arginine) α, ω-diamide) (C3(LA)2, C6(LA)2 and C9(LA)2). Blank and loaded zein nanoparticles were characterized in terms of size, polydispersity and zeta potential. Furthermore, the antimicrobial activity against bacteria and yeasts and the hemolytic activity were investigated and compared to the surfactants in a solution. Nanoparticles were found to be monodisperse, presenting a size of between 180-341 nm, a pdI of <0.2 and a positive zeta potential of between +13 and +53 mV, remaining stable over 365 days. The nanoencapsulation maintained the antimicrobial activity as unaltered, while the extensive hemolytic activity found for the surfactants in a solution was reduced drastically. Nuclear Magnetic Ressonance (NMR), molecular docking and monolayer findings indicated that zein entraps the surfactants, interfering in the surfactant-membrane interactions. Accordingly, the nanoepcasulation of arginine surfactants improved their selectivity, while the cationic charges were free to attack and destroy bacteria and fungi; the aliphatic chains were not available to disrupt the cellular membranes.

Blood component requirements in liver transplantation: effect of 2 thromboelastometry-guided strategies for bolus fibrinogen infusion-the TROMBOFIB randomized trial.

BACKGROUND: A low plasma fibrinogen level influences blood component transfusion. Thromboelastometry provides clinical guidance for fibrinogen replacement in liver transplantation (LT). OBJECTIVES: We hypothesized that infusions of fibrinogen concentrate to reach an A10FibTem value of 11 mm during LT could reduce red blood cell (RBC) and other component and fluid requirements in comparison to standard care. METHODS: This randomized, blinded, multicenter trial in 3 hospitals enrolled 189 LT-scheduled patients allocated to an intervention target (A10FibTem, 11 mm) or a standard target (A10FibTem, 8 mm); 176 patients underwent LT with fibrinogen replacement. Data were analyzed by intention-to-treat (intervention group, 91; control group, 85). Blood was extracted, and fibrinogen kits were prepared to bring each patient's fibrinogen level to the assigned target at the start of LT, after portal vein clamping, and after graft reperfusion. The main outcome was the proportion of patients requiring RBC transfusion during LT or within 24 hours. RESULTS: The proportion of patients requiring RBCs did not differ between the groups: intervention, 74.7% (95% CI, 65.5%-83.3%); control, 72.9% (95% CI, 62.2%-82.0%); absolute difference, 1.8% (95% CI, -11.1% to 14.78%) (P = .922). Thrombotic events occurred in 4% of the patients in both groups; reoperation and retransplantation rates and mortality did not differ. Nearly 70% of the patients in both groups required fibrinogen concentrate to reach the target. Using an 11-mm A10FibTem target increased the maximum clot firmness without affecting safety. However, this change provided no clinical benefits. CONCLUSION: The similar low plasma fibrinogen concentrations could explain the lack of significant between-group outcomes.

Zein Nanoparticles Containing Arginine-Phenylalanine-Based Surfactants: Stability, Antimicrobial and Hemolytic Activity.

Although cationic surfactants have a remarkable antimicrobial activity, they present an intrinsic toxicity that discourages their usage. In this work novel zein nanoparticles loaded with arginine-phenylalanine-based surfactants are presented. The nanoparticles were loaded with two single polar head (LAM and PNHC12) and two with double amino acid polar head surfactants, arginine-phenylalanine (C12PAM, PANHC12). The formulations were characterized and their stability checked up to 365 days. Furthermore, the antimicrobial and hemolytic activities were investigated. Finally, NMR and molecular docking studies were carried out to elucidate the possible interaction mechanisms of surfactant-zein. The nanoparticles were obtained with satisfactory size, zeta potential and dispersibility. The surfactants containing arginine-phenylalanine residues were found to be more stable. The nanoencapsulation maintained the antimicrobial activities unaltered in comparison to the surfactants' solutions. These results are in agreement with the NMR and docking findings, suggesting that zein interacts with the surfactants by the aromatic rings of phenylalanine. As a result, the cationic charges and part of the aliphatic chains are freely available to attack the bacteria and fungi, while not available to disrupt the cellular membranes. This approach opens new possibilities for using cationic surfactants and benefits from their extraordinary antimicrobial responses for several applications.

Seis acciones metodológicas sencillas para el uso de la plataforma Moodle / Six simple methodological actions for the use of the Moodle platform

Para desarrollar un curso o asignatura a través de la educación a distancia utilizando la plataforma Moodle, es preciso dominar los recursos que esta ofrece; aunque sin el conocimiento del contenido, de pedagogía y una experiencia práctica de impartición tradicional de la materia, no es posible lograrlo con posibilidades de éxito. Es propósito de los autores socializar algunas acciones metodológicas sencillas, conformadas por ellos y aplicadas ya en su práctica docente, las que pueden ser útiles a los que se inician en la virtualización del proceso enseñanza aprendizaje.

To develop a course or subject through distance learning using the Moodle platform, it is necessary to master the resources that it offers; although without knowledge of the content, pedagogy and a practical experience of traditional teaching of the subject, it is not possible to achieve it with any chance of success. It is the purpose of the authors to socialize some simple methodological actions, formed by them and already applied in their teaching practice, which can be useful to those who are starting out in the virtualization of the teaching-learning process.

La pedagogía de la inclusión aplicada a la clase de Educación Física / The pedagogy of inclusion applied to the Physical Education class

La pedagogía de la inclusión persigue formar personas desde la perspectiva de su individualidad, teniendo en cuenta su interacción social. Para la escuela cubana es un reto porque requiere cambios en la forma de interactuar, investigar y ofrece oportunidades de aprendizaje considerando la diversidad de necesidades y las diferencias de contextos, como alternativa más viable para proporcionar una respuesta educativa individualizada, comprensiva y diversificada. La Educación Física es una de las materias del currículo que tiene una alta responsabilidad de educar desde la diversidad, pero para ello los docentes deben capacitarse en las exigencias educativas a satisfacer. Los autores proponen algunas acciones metodológicas ya aplicadas a fin de que constituyan experiencias compartidas entre los docentes de la especialidad en sus clases.

The pedagogy of inclusion seeks to train people from the perspective of their individuality, taking into account their social interaction. For the Cuban school it is a challenge because it requires changes in the way of interacting, investigating and offering learning opportunities considering the diversity of needs and the differences in contexts, as a more viable alternative to provide an individualized, comprehensive and diversified educational response. Physical Education is one of the subjects in the curriculum that has a high responsibility to educate from diversity, but for this, teachers must be trained in the educational demands to be met. The authors propose some methodological actions already applied so that they constitute shared experiences among the teachers of the specialty in their classes.

Cationic Surfactants Based on Arginine-Phenylalanine and Arginine-Tryptophan: Synthesis, Aggregation Behavior, Antimicrobial Activity, and Biodegradation.

Cationic surfactants have great potential as drug vehicles and for use in gene therapy (cationic vesicles made from cationic surfactants can encapsulate RNA or DNA for cellular transfer). They can also be used as antimicrobial and antifungal agents to treat human infections. In an era of increasing antimicrobial resistance, the development of new biocompatible surfactants suitable for application as antimicrobial agents is of high interest. In this work, a library of amino acid-based surfactants was synthesized, characterized and tested for antimicrobial activity. The head group architecture (number and type of amino acids, density of cationic charge, ionic character) and the hydrophobic moiety (alkyl chain length and position of the hydrophobic group) were systematically modified, and the effect on the surfactant biological and aggregation behavior was studied. Thus, the pKa values, micellization process, antimicrobial efficiency and biodegradability were evaluated. The critical micelle concentration values of the surfactants depended on their hydrophobic character, but changes in the polar head as well as the position and length of the alkyl chain also significantly affected activity against some of the tested microorganisms. Moreover, biodegradability was closely related to the hydrophobic character of the surfactant and attachment of the alkyl chain to the polar head. The structure-activity relationships established here may open perspectives for the design of effective biodegradable antimicrobial materials that can overcome emerging resistance.

Estudio comparativo de los diferentes acondicionamientos de superficie sobre las propiedades de flexión y análisis topográfico de los postes de fibra de vidrio / Comparative study of the different surface conditions on the bending properties and topographic analysis of the fiberglass posts

RESUMEN Objetivo: Evaluar las propiedades de flexión y topografía de los postes de fibra tratados superficialmente. Material y Métodos : Experimental, In vitro. Las muestras fueron divididas en dos grupos, se evaluó la flexibilidad de 40 postes de fibra de vidrio de 2 casas comerciales para cada procedimiento de acondicionamiento P1: FGM White Post DC; P2: MAQUIRA Fiber Post. Las técnicas de acondicionamiento fueron: T1: control T2: Ácido Fluorhídrico 10% 15 segundos T3: Peróxido de Hidrógeno 24% 60 segundos T4: oxido de aluminio 50 µm y se sometieron a la máquina universal de ensayos, para la prueba de flexión de 3 puntos. Se observó la superficie topográfica de los postes de fibra de vidrio utilizando un microscopio electrónico de barrido. Resultados : La deflexión (mm) se evidenció diferencia significativa comparando los grupos control y los grupos acondicionados con un valor máximo promedio de 0,59mm ±0,04 y un valor mínimo de 0,51mm ±0,06. En la fuerza máxima (N) se evidenció diferencia significativa comparando los grupos control y los grupos acondicionados, con un valor máximo de 133,68 ±11,42 N y un valor mínimo de 103,48 ±17,79 N. Conclusiones : No se encontró efectos adversos sobre las propiedades de flexión para ambos grupos de postes de fibra de vidrio después del acondicionamiento de superficie con los diferentes protocolos.

ABSTRACT Objectives: To evaluate the bending and topography properties of surface treated fiber posts. Material and Methods : Experimental, In vitro. The samples were divided into two groups, the flexibility of 40 fiberglass posts from 2 commercial houses was evaluated for each conditioning procedure P1: FGM White Post DC; P2: MAQUIRA Fiber Post. The conditioning techniques were: T1: control T2: Hydrofluoric Acid 10% 15 seconds T3: Hydrogen Peroxide 24% 60 seconds T4: aluminum oxide 50 µm and were subjected to the universal testing machine, for the bending test of 3 points. The topographic surface of the fiberglass posts was observed using a scanning electron microscope. Results : The deflection (mm) showed a significant difference comparing the control groups and the conditioned groups with an average maximum value of 0.59mm ±0.04 and a minimum value of 0.51mm ±0.06. In the maximum force (N), a significant difference was observed when comparing the control groups and the conditioned groups, with a maximum value of 133.68 ±11.42 N and a minimum value of 103.48 ±17.79 N. Conclusions : No adverse effects on bending properties were found for both groups of fiberglass posts after surface conditioning with the different protocols.

Activity of arginine-phenylalanine and arginine-tryptophan-based surfactants against Staphylococcus aureus.

Aims: This study aimed to evaluate the antibacterial effect of two new cationic surfactants based on phenylalanine-arginine (LPAM) and tryptophan-arginine (LTAM). Materials & methods: Antibacterial activity, mechanism of action and interactions with Staphylococcus aureus enzymes were measured through microbiological, flow cytometry and molecular docking assays, respectively. Results & conclusion: These compounds showed antibacterial activity in the range of 4.06-16.24 µg/ml against planktonic cells and no activity against mature biofilms, since they caused a loss of membrane integrity and increased DNA damage, as revealed by flow cytometry analysis. In silico assays revealed the existence of molecular bonds such as hydrogen bonds, mainly with DNA. Therefore, these compounds have promising pharmacological activity against MRSA strains.