Pyrolysis and Physicochemical, Thermokinetic and Thermodynamic Analyses of Ceiba aesculifolia (Kunth) Britt and Baker Waste to Evaluate Its Bioenergy Potential.

Ceiba aesculifolia is an important species in Mexico that generates significant amounts of biomass waste during its exploitation, which can be utilized to produce energy. This study presents the characterization of this waste based on chemical (proximal and elemental) and thermal analyses (TGA-DTG) at different heating rates (ß = 10-30 °C/min (283-303 K/min)) in the presence of nitrogen and in a temperature range of 25-900 °C. Kinetic parameters were calculated and analyzed as well. Activation energy (Ea) and the pre-exponential factor (A) were determined using the Friedman (132.03 kJ/mol, 8.11E + 10 s -1), FWO (121.65 kJ/mol, 4.30E + 09), KAS (118.14 kJ/mol, 2.41E + 09), and Kissinger (155.85 kJ/mol, 3.47E + 11) kinetic methods. Variation in the reaction order, n (0.3937-0.6141), was obtained by Avrami's theory. We also calculated the thermodynamic parameters (ΔH, ΔG, ΔS) for each kinetic method applied. The results for Ea, A, n, ΔH, ΔG, and ΔS show that this biomass waste is apt for use in pyrolysis. Moreover, the moisture (<10%), ash (<2%), volatile material (>80%), and HHV (>19%) contents of C. aesculifolia allowed us to predict acceptable performance in generating energy and fuels. Finally, infrared spectroscopy analysis (FT-IR) allowed us to identify important functional groups, including one that belongs to the family of the aliphatic hydrocarbons.

Chemical and Energetic Characterization of the Wood of Prosopis laevigata: Chemical and Thermogravimetric Methods.

Diverse methodologies exist to determine the chemical composition, proximate analysis, and calorific value of biomass. Researchers select and apply a specific methodology according to the lignocellulosic material they study and the budgetary resources available. In this project, we determined the primary chemical constitution and proximate analysis of Prosopis laevigata (Humb. & Bonpl.) Jonhst wood using a traditional chemical method and a novel procedure based on the deconvolution of the DTG signal produced by TGA. The highest calorific value was verified using a calorimetric pump based on mathematical models. We also conducted elemental analysis and a microanalysis of ash, and applied Fourier transform infrared spectroscopic analysis (FT-IR). The means of the results obtained by the chemical method and TGA-DTG, respectively, were: hemicelluloses 7.36%-(8.72%), cellulose 48.28%-(46.08%), lignin 30.57%-(32.44%), extractables 13.53%-(12.72%), moisture 2.03%-(4.96%), ash 1.77%-(1.90%), volatile matter 75.16%-(74.14%), and fixed carbon 23.05%-(18.93%). The procedure with the calorimetric pump generated a calorific value above 20.16 MJ/kg. The range generated by the various models was 18.23-21.07 MJ/kg. The results of the elemental analysis were: carbon 46.4%, hydrogen 6.79%, oxygen 46.43%, nitrogen 0.3%, and sulfur 0.5%. The microanalysis of ash identified 18 elements. The most abundant ones were potassium ˃ calcium ˃ sodium. Based on the infrared spectrum (FT-IR) of Prosopis laevigata wood, we detected the following functional groups: OH, C-H, C=O, CH2, CH3, C-O-C, C-OH, and C4-OH. Our conclusion is that the TGA-DTG method made it possible to obtain results in less time with no need for the numerous reagents that chemical procedures require. The calorific value of P. laevigata wood is higher than the standards. Finally, according to our results, proximate analysis provides the best model for calculating calorific value.

La atención a la diversidad cultural: esencialidades para la formación de los profesores de medicina

La diversidad cultural es el resultado de un proceso que se conforma en el marco de las relaciones sociales, económicas y culturales. Se hace imprescindible que los profesores universitarios estén preparados para atender la diversidad cultural de sus estudiantes, teniendo en cuenta las particularidades de su cultura nacional y la de otros grupos de diferentes procedencias que coexisten en un mismo escenario educativo. La diversidad cultural es un reto de la comunidad educativa y debe estar contemplada en la formación permanente de los profesores de las universidades médicas fundamentalmente por sus contextos, los ambientes socioeconómicos y los problemas de salud, sobre todo por las enfermedades crónicas no trasmisibles debido a su alta prevalencia y su repercusión en el individuo y su familia, en los que influyen los factores de riesgo y las determinantes sociales, condicionados por sus orígenes, creencias, vivencias y representaciones que matizan los contextos interculturales actuales a nivel mundial.

Cultural diversity is the result of a process that is formed within the framework of social, economic and cultural relations. It is essential that university professors are prepared to address the cultural diversity of their students, taking into account the particularities of their national culture and that of other groups of different origins that coexist in the same educational setting. Cultural diversity is a challenge for the educational community and must be considered in the ongoing training of professors at medical universities, fundamentally due to their contexts, socioeconomic environments and health problems, especially chronic non-communicable diseases due to their high prevalence and its impact on the individual and his or her family, influenced by risk factors and social determinants, conditioned by their origins, beliefs, experiences and representations that color current intercultural contexts worldwide.

Techno-functional aspects of kombucha analogs formulated from mulberry coproducts.

This study investigated the techno-functional conditions for producing fermented beverages using the kombucha artisanal consortium (kAC) while implementing sustainable strategies. According to the circular economy principles, the study focused on mulberry coproducts (MC) generated as agro-industrial waste during mulberry fruit production. The presence of target microorganisms in the beverage and biofilm was recorded to determine the MC content necessary for establishing kAC. Additionally, the physicochemical characteristics, carbohydrate and polyphenol profiles were analyzed to understand their impact on antioxidant activity and sensory responses in the soft drink. Notably, a concentration of 0.25% MC was found to yield fermented soft drinks rich in probiotic populations and displaying nutraceutical qualities that enhance antioxidant activity and sensory acceptability. This study offers valuable technical guidance for repurposing mulberry pruning coproducts in the creation of novel products.

Revisión sistemática de las aplicaciones y límites de la impresión 3D en la cirugía de raquis / Systematic review of the utility and limits of 3D printing in spine surgery

Objetivo: El objetivo principal de este estudio ha sido demostrar por qué la impresión aditiva permite hacer más visibles y entendibles los procesos patológicos quirúrgicos complejos que afectan al raquis, aumentando la precisión, la seguridad y la fiabilidad del procedimiento quirúrgico.MetodologíaSe realizó una revisión sistemática de los trabajos publicados en los últimos 10 años, sobre la cirugía de raquis asistida por impresión 3D, de acuerdo con la declaración PRISMA 2020. Con las palabras clave «printing 3D» y «spine surgery» se hicieron búsquedas en las bases de datos Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar y Opengrey, que se completó con la búsqueda manual a través de la lista de referencias bibliográficas de los artículos que fueron seleccionados siguiendo los criterios de inclusión y exclusión definidos.ResultadosDel análisis de los 38 estudios seleccionados resultó que la impresión 3D es útil en la planificación quirúrgica, en la enseñanza médica, en la relación médico-paciente, así como en el diseño de plantillas de navegación e implantes de raquis y, en investigación, ofreciendo un magnífico apoyo al proceder quirúrgico.ConclusionesEl uso de biomodelos impresos de forma tridimensional permite: hacer más visibles y entendibles los procesos patológicos quirúrgicos complejos que afectan al raquis; aumentar la exactitud, precisión y seguridad del procedimiento quirúrgico; y abrir la posibilidad de poner en práctica tratamientos personalizados, fundamentalmente en la cirugía tumoral. (AU)

Objective: The main objective of this study has been to demonstrate why additive printing allows to make complex surgical pathological processes that affect the spine more visible and understandable, increasing precision, safety and reliability of the surgical procedure.MethodsA systematic review of the articles published in the last 10 years on 3D printing-assisted spinal surgery was carried out, in accordance with PRISMA 2020 declaration. Keywords «3D printing» and «spine surgery» were searched in Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar and Opengrey databases, which was completed with a manual search through the list of bibliographic references of the articles that were selected following the defined inclusion and exclusion criteria.ResultsFrom the analysis of the 38 selected studies, it results that 3D printing is useful in surgical planning, medical teaching, doctor–patient relationship, design of navigation templates and spinal implants, and research, optimizing the surgical process by focusing on the patient, offering magnificent support during the surgical procedure.ConclusionsThe use of three-dimensional printing biomodels allows: making complex surgical pathological processes that affect the spine more visible and understandable; increase the accuracy, precision and safety of the surgical procedure, and open up the possibility of implementing personalized treatments, mainly in tumor surgery. (AU)

Systematic review of the utility and limits of 3D printing in spine surgery.

OBJECTIVE: The main objective of this study has been to demonstrate why additive printing allows to make complex surgical pathological processes that affect the spine more visible and understandable, increasing precision, safety and reliability of the surgical procedure. METHODS: A systematic review of the articles published in the last 10 years on 3D printing-assisted spinal surgery was carried out, in accordance with PRISMA 2020 declaration. Keywords "3D printing" and "spine surgery" were searched in Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar and Opengrey databases, which was completed with a manual search through the list of bibliographic references of the articles that were selected following the defined inclusion and exclusion criteria. RESULTS: From the analysis of the 38 selected studies, it results that 3D printing is useful in surgical planning, medical teaching, doctor-patient relationship, design of navigation templates and spinal implants, and research, optimizing the surgical process by focusing on the patient, offering magnificent support during the surgical procedure. CONCLUSIONS: The use of three-dimensional printing biomodels allows: making complex surgical pathological processes that affect the spine more visible and understandable; increase the accuracy, precision and safety of the surgical procedure, and open up the possibility of implementing personalized treatments, mainly in tumor surgery.

Dimensión comunicacional de las habilidades de aprender a aprender en estudiantes de Medicina

Fundamento: la comunicación es esencial en el proceso de formación y desarrollo de las habilidades de aprender a aprender en estudiantes de Medicina. Objetivo: caracterizar la dimensión comunicacional de las habilidades de aprender a aprender en estudiantes de Medicina. Métodos: se realizó una investigación descriptiva con un diseño mixto del tipo explicativo secuencial, en la Universidad de Ciencias Médicas de Cienfuegos en enero-marzo de 2022. Se utilizaron métodos teóricos: análisis-síntesis e histórico-lógico; empíricos: cuestionario, observaciones a actividades docentes y grupos focales; y matemático-estadísticos para el análisis de los datos, y el software Atla.ti para el análisis cualitativo de la información. Resultados: se constató que el 65,5 % de los estudiantes afirman que utilizan la comunicación asertiva, mientras que el 43,9 % expresan los mensajes verbales y extraverbales de forma asequible a las otras personas. En los grupos focales los estudiantes aceptaron tener insuficiencias en la formación de las habilidades y presentar limitaciones en sus indicadores, lo que se corresponde con la información obtenida en las observaciones a las actividades docentes. Conclusiones: se caracterizó la dimensión comunicacional de las habilidades de aprender a aprender en estudiantes de Medicina con un nivel medio de comunicación asertiva e insuficiencias en la expresión de mensajes verbales y extraverbales de forma asequible a las otras personas.

Background: communication is essential in the process of training and development of learning-to-learn skills in medical students. Objective: to characterize the communication dimension of the skills of learning to learn in medical students. Methods: a descriptive research with a mixed design of the sequential explanatory type was carried out at Cienfuegos University of Medical Sciences from January to March 2022. Theoretical methods were used: analysis-synthesis and historical-logical; empirical ones: questionnaire, observations of teaching activities and focal groups; and mathematical-statistical for the analysis of the data, and the Atla.ti software for the qualitative analysis of the information. Results: it was found that 65.5% of the students affirm that they use assertive communication, while 43.9% express verbal and extraverbal messages in a way that is accessible to other people. In the focal groups, the students accepted that they had deficiencies in the training of skills and had limitations in their indicators, which corresponds to the information obtained in the observations of teaching activities. Conclusions: the communication dimension of skills learning-to-learn was characterized in medical students with a medium level of assertive communication and insufficiencies in the expression of verbal and extraverbal messages in a way that is accessible to other people.

Caracterización de la autonomía como indicador clave en las habilidades de aprender a aprender en estudiantes de medicina

Fundamento: la autonomía permite a los estudiantes pensar por sí mismos, con sentido crítico e independencia, tener en cuenta diferentes puntos de vista y actuar en correspondencia con ellos. Constituye un indicador necesario en el estudio de las habilidades de aprender a aprender. Objetivo: caracterizar la autonomía como indicador de las habilidades de aprender a aprender en estudiantes de medicina. Métodos: se empleó un diseño mixto de investigación del tipo explicativo secuencial. La investigación se realizó de octubre de 2021 a marzo de 2022 en la Universidad de Ciencias Médicas de Cienfuegos. La muestra no probabilística, intencionada, quedó constituida por 255 estudiantes del primer año de la carrera de Medicina. Para la recolección de información se utilizó el cuestionario que evalúa el nivel de formación de las habilidades de aprender a aprender, observaciones a actividades docentes y grupos focales. Resultados: la autonomía está presente en el 45,4 % de los estudiantes, según cuestionario. En los grupos focales algunos estudiantes reconocen presentar insuficiencias en algunos indicadores de la autonomía, lo que se corresponde con los datos obtenidos en las observaciones a las actividades docentes. Conclusiones: la autonomía como indicador clave de las habilidades de aprender a aprender en los estudiantes del primer año de la Universidad de Ciencias Médicas de Cienfuegos se caracterizó por una baja expresión en los procesos de aprendizaje de los estudiantes de medicina.

Background: autonomy allows students to think for themselves, critically and independently, take into account different points of view and act accordingly. It constitutes a necessary indicator in the study of learning-to-learn skills. Objective: to characterize autonomy as an indicator of learning-to-learn skills in medical students. Methods: a mixed research design of the sequential explanatory type was used. The research was carried out from October 2021 to March 2022 at the Cienfuegos University of Medical Sciences. The intentional, non-probabilistic sample was made up of 255 Medicine first-year students. The questionnaire that evaluates the learning to learn skills training level, observations of teaching activities and focus groups were used to collect information. Results: autonomy is present in 45.4% of the students, according to the questionnaire. In the focus groups, some students acknowledge presenting deficiencies in some autonomy indicators, which corresponds to the data obtained in the observations of teaching activities. Conclusions: autonomy as a learning to learn skills key indicator in the Cienfuegos Medical Sciences University first-year students, was characterized by a low expression in the medical students' learning processes.

Superación profesional pedagógica y formación de la habilidad búsqueda de la información / Pedagogical professional improvement and the ability formación to search for information

RESUMEN El actual desarrollo de la ciencia y la técnica constituye un reto para las universidades médicas, como centros de formación en pos de garantizar un egresado capaz de gestionar el conocimiento necesario para cumplimentar su encargo social. Se precisa de una adecuada habilidad para la búsqueda de la información, la cual permita una apropiada gestión del conocimiento y mejores resultados docentes; pero el claustro profesoral debe planificar acciones estratégicas con vistas a alcanzar la formación de esta habilidad de investigación. Se sugieren acciones para trabajar en la formación de la habilidad antes mencionada, sobre la base de talleres que aborden las esencialidades para su operacionalización a través de contenidos que se imparten; y tributen a la ejecución de investigaciones estudiantiles. La búsqueda de información no solo brinda herramientas para el desarrollo de las investigaciones, sino también constituye un instrumento para fomentar las habilidades lógicas del pensamiento, con elevado impacto cuando el estudiante, de forma independiente, enfrenta tareas de mayor envergadura, por lo que se sugiere desarrollar un sistema de talleres para la preparación profesoral.

ABSTARCT The current development of science and technology constitutes a challenge for medical universities, as training centers in order to guarantee a graduate capable of managing the necessary knowledge to fulfill their social mission. An adequate ability to search for information is required, which allows for proper knowledge management and better teaching results; but the teaching staff must plan strategic actions with a view to achieving the formation of this research skill. Actions are suggested to work on the formation of the aforementioned skill, based on workshops that address the essentials for its operationalization through the contents that are taught; and tax the execution of student research. The search for information not only provides tools for the development of research, but also constitutes an instrument to promote logical thinking skills, with a high impact when the student, independently, faces larger tasks, for which it is suggested develop a system of workshops for teacher preparation.

Spinal health in 40 patients in the initial stage of laboural life. Morfogeometric, biological and environmental study.

INTRODUCTION: Assuming that spinal shape is a genetic expression, its analysis and acquired factors could assess their respective contribution to early spine deterioration. MATERIAL AND METHODS: A geometric morphometric analysis was retrospectively performed on sagittal lumbar MRI of young patients with back pain to identify lumbar spine shape changes. Using Geometric Morphometrics, findings were analyzed with anthropometric, radiological, and clinical variables. RESULTS: 80 cases under 26 years of age were collected, 55 men (mean age 22.81) and 25 women (mean age 23.24). MRI abnormalities were reported in 57.5%: single altered disc (N=17), root compromises (N=8), and transition anomalies (35%).In the non-normal MRI subgroup, shape variation included: increased lordosis, enlarged vertebral body, canal stenosis, and lumbarization of S1. In non-Spanish origin patients, lumbar straightening and segmental deformities were prevalent. Morphometrics findings showed that lumbosacral transition anomalies are frequently underreported. CONCLUSIONS: Genetic factors could be the main determinants of abnormality in MRIs under 26 years. The primary markers are transitional abnormalities, segmental deformities, and canal stenosis. In foreign populations, shape changes could suggest spine overload at an early age.

Peripheral odontogenic keratocyst: Clinicopathological and immunohistochemical characterization.

OBJECTIVE: The aim of this study is to present and discuss the salient clinicopathological features, differential diagnosis and epithelial immunohistochemical profile of three additional cases of peripheral odontogenic keratocyst (POKC) and to present a review of the literature. POKC is a locally aggressive odontogenic lesion. The peripheral variant of the odontogenic keratocyst is rare and more frequently located in anterior gingiva. MATERIAL AND METHODS: We present the clinicopathological features of 3 new cases of POKC (2 women and 1 man; age range: 14-74 years). Immunohistochemical study included CK7, CK14, CK19 and Ki-67, and a systematic review of the literature was performed in PubMed, Scopus and Web of Science databases. RESULTS: All cases were located in the anterior gingiva (2 in maxilla and 1 mandible), and none corresponded to Gorlin-Goltz syndrome. High expression of CK14 was seen in all cases, with CK19 and CK7 been only focally positive. The expression of Ki-67 was located in the basal and parabasal cells in all cases. CONCLUSIONS: POKC is a rare gingival lesion that seems to originate from remnants of dental lamina or from the basal cells of the gingival epithelium and present a similar histopathology as compared to intraosseous OKC.

Estado de la enseñanza del diagnóstico de afecciones pulpares y periapicales centrada en el método clínico / Status of the pulp and periapical disorders diagnosis teaching focused on the clinical method

RESUMEN Fundamento: la enseñanza del diagnóstico de las afecciones pulpares y periapicales se enmarca como un contenido esencial del proceso de enseñanza-aprendizaje en la asignatura de Operatoria Clínica, para cumplir las funciones principales declaradas en el perfil profesional del modelo de formación del estomatólogo general en Cuba. Objetivo: determinar el estado actual de la enseñanza del diagnóstico de afecciones pulpares y periapicales en la asignatura de Operatoria Clínica de la carrera de Estomatología. Métodos: investigación observacional, descriptiva y de corte transversal realizada en la Universidad de Ciencias Médicas de Cienfuegos sobre una población conformada por 8 docentes y los 37 estudiantes de tercer año del curso 2017-2018. Se utilizó una guía para observar de forma directa cómo se realiza la enseñanza del diagnóstico de las afecciones pulpares y periapicales y se aplicó una encuesta a profesores y estudiantes con preguntas cerradas. Resultados: se evidenció como fortaleza que predomina la educación en el trabajo como forma organizativa y existen referencias de la enseñanza del método clínico en la carrera de medicina. Se constataron limitaciones en el claustro respecto a las categorías docentes, científicas y años de experiencia; limitado aprovechamiento de la caracterización de los estudiantes y sus resultados así como deficiente aplicación de las acciones esenciales correspondientes a la etapa diagnóstica del método clínico y prevalencia del papel autoritario del docente. Conclusiones: aún existen limitaciones en la enseñanza actual del diagnóstico de las afecciones pulpares y periapicales en la población objeto de estudio.

ABSTRACT Background: the teaching of the pulp and periapical diseases diagnosis is defined as an essential content of the teaching-learning process in the Clinical Operative subject, to fulfill the main functions declared in the professional profile of the general stomatologist training model in Cuba. Objective: to determine the current state of pulp and periapical disorders teaching diagnosis in the Stomatology career Clinical Operative subject. Methods: observational, descriptive and cross-sectional research carried out at the Cienfuegos University of Medical Sciences on a population of 8 teachers and 37 third-year students of the 2017-2018 academic year. A guide was used to directly observe how the teaching of the diagnosis of pulp and periapical diseases is carried out and a survey was applied to teachers and students with closed questions. Results: it was evidenced as a strength that education at work predominates as an organizational form and there are references to the clinical method teaching in the medical career. Limitations were found in the faculty with respect to the teaching and scientific categories and years of experience; limited use of the students characterization and their results as well as deficient application of the essential actions corresponding to the diagnostic stage of the clinical method and prevalence of the teacher authoritarian role. Conclusions: still limitations in the diagnosis of pulp and periapical diseases current teaching of the population under study.

Desde lo curricular a lo investigativo, una mirada a la COVID-19 / From the curricular to the investigative, a look at COVID-19

RESUMEN La enfermedad provocada por el coronavirus (SARS-CoV-2), causante de la COVID-19, ha generado un movimiento hacia una revisión de todo el enfoque de las ciencias médicas y a profundizar en todos los mecanismos inherentes a la respuesta inmune asociados a esta enfermedad. Se pone en evidencia el necesario pensamiento clínico epidemiológico declarado en el plan de estudio de la carrera de Medicina; la formación investigativa desde los primeros años. La asignatura Sangre-Sistema Inmune incluye en su contenido un gran número de problemas de salud por desequilibrio en la respuesta inmune, lo que constituye una clara justificación para redimensionar el proceso de formación científica. El objetivo de este trabajo es valorar la significación de la asignatura para la interpretación de las desviaciones de la respuesta inmune y emitir sugerencias para potenciar el trabajo investigativo en ella.

ABSTRACT The disease caused by the coronavirus (SARS-CoV-2), which causes COVID-19, has generated a movement towards a review of the entire approach of medical sciences and to delve into all the mechanisms inherent to the immune response associated with this disease. The necessary clinical epidemiological thinking declared in the study plan of the Medicine career is evidenced; research training from the early years. The subject Blood-Immune System includes in its content a large number of health problems due to imbalance in the immune response, which constitutes a clear justification for resizing the scientific training process. The objective of this work is to assess the significance of the subject for the interpretation of the deviations of the immune response and to make suggestions to enhance the research work in it.

Habilidades investigativas en estudiantes del ciclo clínico de la carrera de Estomatología / Research skills in students of the clinical cycle of Stomatology pre-graduate studies

RESUMEN Introducción: las habilidades investigativas se insertan en la formación del profesional de estomatología como una de las dimensiones claves del proceso de formación. Objetivo: evaluar la percepción de los estudiantes acerca del estado actual de desarrollo de las habilidades investigativas en el ciclo clínico de la carrera de Estomatología de la Universidad de Ciencias Médicas de Matanzas. Materiales y métodos: se realizó una investigación descriptiva, de corte transversal, en la que participaron 68 estudiantes de tercer a quinto año, durante la culminación del curso 2018-2019. Fueron seleccionados a través de un muestreo intencional. Se empleó un cuestionario de percepción del dominio de las habilidades relacionadas con el manejo de la información científica, el diseño y ejecución de investigaciones, y el análisis de situación de salud bucal. Resultados: los estudiantes reconocieron tener dominio de la habilidad para el manejo de la información científica y para el análisis de situación de salud bucal. Las acciones menos dominadas fueron la recopilación de información y el diseño de un perfil de proyecto de investigación. La Jornada Científica Estudiantil y el trabajo de curso fueron las vías más empleadas para la divulgación científica. Predominaron los obstáculos externos, seguidos de obstáculos asociados al propio dominio de la habilidad para el diseño y la ejecución de la investigación científica. Conclusión: los estudiantes del ciclo clínico de la carrera de Estomatología reconocen poseer un adecuado dominio de las habilidades investigativas, lo cual contribuye de modo satisfactorio a la formación profesional. No obstante, resulta necesario promover acciones educativas que tributen a las operaciones menos dominadas y estimulen la inserción estudiantil en proyectos de investigación para la sistematización de estas habilidades (AU).

ABSTRACT Introduction: research skills are inserted in the training of the stomatology professional as one of the key dimensions of the training process. Objective: to evaluate the perception of students about the current state of development of research skills in the clinical cycle of the pre-graduate studies of Stomatology of the University of Medical Sciences of Matanzas. Materials and methods: a descriptive, cross-sectional research was carried out, involving 68 third to fifth year students, during the co a descriptive, cross-sectional research was carried out, involving 68 third to fifth year students, during the completion of the 2018-2019 course. They were chosen through intentional sampling. A perception questionnaire was used for the mastering skills related to the management of scientific information, the design and execution of research, and oral health situation analysis. Results: the students recognized to master the ability of handling scientific information and oral health situation analysis. Less mastered actions were the collection of information and the design of a research project profile. The Student Science Day and the course work were the most widely used ways for scientific dissemination. External difficulties predominated, followed by difficulties associated with the own mastery of the ability to design and execute scientific research. Conclusion: the students in the clinical cycle of the pre-grade studies of Stomatology recognize having an adequate mastery of research skills, which contributes satisfactorily to professional training. However, it is necessary to promote educational actions that contribute to the less dominated operations and stimulate the insertion of students in research projects for the systematization of these skills (AU).

Embolismo pulmonar diferido de material de refuerzo vertebral. Consideraciones clínicas y médico-legales a propósito de un caso / Delayed pulmonary embolism from vertebral reinforcement material. Clinical and medico-legal considerations of a case

La vertebroplastia y la cifoplastia son procedimientos de punción percutáneos que precisan de la inyección de cemento en el soma de una vértebra fracturada, con el fin de refuerzo y alivio del dolor. Con ocasión de un caso de cifoplastia del soma de L2 que desarrolló una infrecuente embolización diferida de cemento a la arteria pulmonar, se revisa la literatura y analizan los principales problemas médico-legales de estas complicaciones. Se subraya la necesidad de un consentimiento informado detallando la frecuencia y riesgos de estas complicaciones, así como un adecuado control radiológico postoperatorio, no solo local, sino torácico. Igualmente, se enfatiza la posibilidad de repetir el estudio radiológico local y torácico, ante cualquier cambio de la morfología de la fuga local o desaparición de la fuga local, ante la posibilidad de migraciones tardías. (AU)

Vertebroplasty and kyphoplasty are percutaneous puncture procedures that require the injection of cement into the soma of a fractured vertebra for reinforcement and pain relief.As the result of a case of kyphoplasty of the soma of L2 that developed a rare, delayed embolization of cement to the pulmonary artery, we undertook a literature review, and the main medico-legal problems of these complications were analysed.The need for informed consent is stressed, detailing the frequency and risks of these complications, as well as adequate postoperative local and chest X-ray control. Likewise, the possibility is highlighted of repeat local and chest X-rays in the event of any change in the morphology of local leakage or disappearance of local leakage in the event of late migration. (AU)

Chemical composition of Luffa aegyptiaca Mill., Agave durangensis Gentry and Pennisetum sp.

The particleboard industry faces problems of wood shortage, which has led to the use of non-wood lignocellulosic materials. Furthermore, there is also interest in looking for materials that improve their physical and mechanical properties. The species Luffa aegyptiaca Mill. (fruit), Agave durangensis Gentry (bagasse) and Pennisetum sp. (plant, leaves and stem) could be used in the elaboration of wood-based particleboards. The aim of this study is to determine the feasibility of using these materials to produce particleboards in accordance with their chemical composition. Five materials were studied, A. durangensis (bagasse), L. aegyptiaca (fruit) and Pennisetum sp. (whole plant, leaves and stem). Extractives, holocellulose, Runkel lignin and ash content was determined. The pH of the fibers was also measured and a microanalysis of the ash was performed. ANOVA and Kruskal-Wallis tests were carried out, in addition Tukey and Dunn tests for group comparison were performed. Pennisetum sp. leaves presented the highest total extractives and ash content, while L. aegyptiaca fruit and A. durangensis bagasse had the highest both content of holocellulose and Runkel lignin respectively. The lowest pH was presented by the L. aegyptiaca fruit, while the highest was from the Pennisetum sp. stem. The element with the greatest presence in the five materials was potassium, except in A. durangensis bagasse showing calcium. L. aegyptiaca fruit has better characteristics to be used in particleboards with greater mechanical resistance because of its higher holocellulose content. However, Pennisetum sp. (plant, leaves and stem) could be used to make particleboards with high resistance to water absorption.