Resumen: Introducción y objetivos: Los tratamientos quirúrgicos o endoscópicos desempeñan un papel fundamental en el manejo de acalasia. La probabilidad de eventos adversos en la realización de estos tratamientos es un aspecto relevante a la hora de establecer el balance riesgo beneficio; este estudio pretende establecer la asociación entre eventos adversos serios y la realización de estos procedimientos en pacientes adultos con acalasia. Materiales y métodos: Se realizó una búsqueda sistemática de ensayos clínicos aleatorizados y no aleatorizados, cohortes retrospectivas y series de casos de pacientes adultos con acalasia llevados a miotomía laparoscópica de Heller (LHM), Peroral Endoscopic Myotomy (POEM) o dilatación endoscópica con balón que reportarán eventos adversos serios en Medline, CENTRAL y EBSCO. Los eventos adversos serios se definieron como: muerte a 30 días, clasificación de Clavien y Dindo grado iii en adelante, perforación esofágica o gástrica, neumotórax, desgarro mucoso, fuga, enfisema, neumonía y dolor torácico. La metodología incluyó los lineamientos PRISMA para reporte de revisiones sistemáticas. Resultados: Se encontraron 35 estudios que reportaron información de 1,276 pacientes intervenidos con POEM, 5,492 llevados a LHM y 10,346 a dilatación endoscópica con balón, las proporciones de eventos adversos para las 3 técnicas fueron del 3.6, el 4.9 y el 3.1%, respectivamente. Discusión y conclusiones: Las 3 intervenciones terapéuticas evaluadas presentan proporciones similares de eventos adversos, los reportes de mortalidad a 30 días como desenlace fueron pocos y es notoria la falta de estandarización del reporte de eventos adversos en los estudios analizados. Abstract: Introduction and aims: Surgical or endoscopic treatments play an essential role in the management of achalasia. The probability of adverse events in the performance of said treatments is a relevant aspect, when establishing the risk-benefit balance. The present study aimed to establish the association between serious adverse events and the performance of those procedures, in adult patients with achalasia. Materials and methods: A systemic search of randomized and nonrandomized clinical trials, retrospective cohorts, and cases series on adult patients with achalasia that underwent laparoscopic Heller myotomy (LHM), peroral endoscopic myotomy (POEM), or endoscopic balloon dilation, that reported serious adverse events, was carried out on the Medline, CENTRAL, and EBSCO databases. Serious adverse events were defined as: death at 30 days, Clavien-Dindo grade iii or higher classification, esophageal or gastric perforation, pneumothorax, mucosal tear, leakage, emphysema, pneumonia, and chest pain. The methodology included the PRISMA guidelines for reporting systematic reviews. Results: Thirty-five studies were found that reported information on 1,276 patients that underwent POEM, 5,492 that underwent LHM, and 10,346 that underwent endoscopic balloon dilation. The proportions of adverse events for the 3 techniques were 3.6, 4.9, and 3.1%, respectively. Discussion and conclusions: The 3 therapeutic interventions evaluated had similar proportions of adverse events. There were few reports of death at 30 days as an outcome and the lack of standardization in reporting adverse events in the studies analyzed was prominent.

INTRODUCTION AND AIMS:Surgical or endoscopic treatments play an essential role in the management of achalasia. The probability of adverse events in the performance of said treatments is a relevant aspect, when establishing the risk-benefit balance. The present study aimed to establish the association between serious adverse events and the performance of those procedures, in adult patients with achalasia.MATERIALS AND METHODS:A systemic search of randomized and nonrandomized clinical trials, retrospective cohorts, and cases series on adult patients with achalasia that underwent laparoscopic Heller myotomy (LHM), peroral endoscopic myotomy (POEM), or endoscopic balloon dilation, that reported serious adverse events, was carried out on the Medline, CENTRAL, and EBSCO databases. Serious adverse events were defined as: death at 30 days, Clavien-Dindo grade III or higher classification, esophageal or gastric perforation, pneumothorax, mucosal tear, leakage, emphysema, pneumonia, and chest pain. The methodology included the PRISMA guidelines for reporting systematic reviews.RESULTS:Thirty-five studies were found that reported information on 1,276 patients that underwent POEM, 5,492 that underwent LHM, and 10,346 that underwent endoscopic balloon dilation. The proportions of adverse events for the three techniques were 3.6, 4.9, and 3.1%, respectively.DISCUSSION AND CONCLUSIONS:The 3 therapeutic interventions evaluated had similar proportions of adverse events. There were few reports of death at 30 days as an outcome and the lack of standardization in reporting adverse events in the studies analyzed was prominent.

El desarrollo de la psicología en Guatemala durante las últimas décadas se ha visto fortalecido por varios hitos en su historia como han sido los congresos, encuentros académicos y profesionales, colaboraciones internacionales y conferencias para nombrar algunos. Este número especial de nuestra revista da testimonio de uno de ellos. Gracias a la confianza, apoyo y mentoría de los grandes exponentes de las psicoterapias integrativas de América Latina y de la valiosa y comprometida colaboración de un comité organizador, pudo realizarse en Guatemala, de manera virtual con sólido apoyo tecnológico, el VIII Encuentro Latinoamericano de Psicoterapias Integrativas (ELAPSI). Si bien, el producto final fue de una excelente calidad académica, científica, profesional y sociocultural, también fue de inmenso valor el llegar a concretarlo. Desde el momento en que nos fue confiada la realización del mismo en el marco del VII Encuentro Latinoamericano que se llevó a cabo en Uruguay en 2018, sabíamos que estábamos abriendo brecha. Por primera vez, un ELAPSI sería realizado fuera de América del Sur, en donde históricamente se había congregado la comunidad académica y profesional de las psicoterapias integrativas. Por lo tanto, iniciar el proceso de organización implicaba no solo colocar a Guatemala en el mapa latinoamericano de la integración psicoterapéutica sino también consolidar un equipo organizador que representara las voces integrativas de las Américas particularmente de aquellos países donde hasta el momento estaban casi silenciadas. Los valores de solidaridad, apoyo, entusiasmo y compromiso se hicieron presentes para emprender una tarea que, aunque ambiciosa desde sus albores, fue apasionante.

Walking is one of the most complex tasks a human being can perform. It takes several years to develop the patterns that enable a person to walk and run. Although it is now possible to replicate these patterns in machines such as robots, actuators are needed to control the pace and compensate for the energy loss of walking. However, in small robots (in the scale of centimeters) the size and weight of the actuators could be a limiting factor for their use. To solve this problem, quasi-passive walkers have been recently proposed. These walkers consist of several coupled rigid bodies, usually forming a biped, that move on flat surfaces in the presence of a gravitational field. It is well known that these bipeds can descend on small slope planes without the need for actuators. Walking on horizontal planes requires the presence of actuators to initiate and maintain the pace, however, these actuators could be small enough to ”kick” the walker at the right point at the right time. In this work, we present a physical-mathematical model of a bipedal walker composed of five rigid bodies (two legs, two feet, and the hip) moving in a horizontal plane. The model focuses on the natural motion of the biped under certain initial conditions with the ultimate goal of determining the best position of the actuators and the actuation time to maintain the gait. This model could be used as a guide for the construction of small laboratory-scale walkers and as a teaching tool in biomedical engineering courses.

Composite materials manufactured by means of the superposition of layers and some specific morphologies, are susceptible to losing part of their resistant capacity due to the presence of delaminations between their layers. The objective of this work is to evaluate experimentally the generation and propagation of these interlaminar cracks in a carbon-epoxy composite subjected to dynamic stress under mixed fracture mode I/II, using for this purpose two different test methodologies, on the one hand the standardized MMB (Mixed-Mode Bending) and on the other hand the ADCB (Asymmetric Double Cantilever Beam), with the intention of exploring the viability of the ADCB test as a simpler alternative of execution, especially in fatigue tests, to the MMB test. For this purpose and after a previous static characterization of the material in which the critical values of the energy release rate were determined in both test methods, the energy release rate levels to be applied in the fatigue tests were defined for two GII/Gc mixed mode grades of 0.2 and 0.4(0,33 ADCB) and a ratio of stress levels to fatigue of R= Gmin/Gmax=0.1.DG-N fatigue initiation curves were obtained from these experimental data. The most relevant result of the work is that, in general, the MMB mixed mode provides different fatigue limits depending on the degree of mixed mode, whereas in the ADCB type test the fatigue limits tend to have the same value.

The automotive, aerospace and renewable energy generation industries have replaced significantly the use of traditional materials, such as steel and aluminum, by reinforced fiber composites. It has recognized that joints drilling and screwing joints damage the fibers introducing a higher concentration of stresses. That is why the application of structural adhesives, as a method of joining in reinforced composites, has increased in recent years. Delamination is the most critical failure mode of composite materials resulting in stiffness and structural strength losses. This works studies the behavior against delamination under mode I and mode II interlaminar fracture of adhesive bonded joints in carbon-epoxy composite materials, using structural adhesives of epoxy and acrylic bases. For the execution of the joints, different surface treatments have been employed: sanding, grit blasting and peel ply technique, allowing to make a fracture resistance comparision study. The double cantilever beam (DCB) and end notched flexure (ENF) tests configuration were used to determine stress-strain behavior and fracture toughness for mode I (GIC) and mode II (GIIC), respectively. Surface modifications have been evaluated by contact angle measurements and scanning electron microscopy (SEM). The experimental results are shown in the same situation. The experimental results obtained show that, even if not showing the same delamination tendency for both fracture modes, the strain energy release rate are higher for an improved of wetting properties and an increase of surface roughness.

The present work shows the results obtained after rehearsing fatigue in mode III a material composed of epoxy resin with unidirectional carbon fiber reinforcement. For the execution of the tests and has used a test device that has been previously designed and whose validity has been proven. The novelty of this work is that it is the first time that a study of fatigue to fracture is carried out according to mode III in this type of materials. In addition, this fatigue has been made in two different ways. First, it has been loaded in one direction until reaching a certain angle and returning almost to the starting point and, secondly, it has been loaded both in one direction and in the opposite. Hence the first case is called asymmetric fatigue and in the second, symmetrical fatigue. The results obtained are different since the case of loading is, in both cases, substantially different. In both cases, a statistical analysis of the results has been carried out in order to be able to compare the existing differences more properly.

The oncoprotein Smoothened (SMO), a Frizzled-class-G-protein-coupled receptor, is the central transducer of hedgehog (Hh) signaling. While canonical SMO signaling is best understood in the context of cilia, evidence suggests that SMO has other functions in cancer biology that are unrelated to canonical Hh signaling. Herein, we provided evidence that elevated levels of human SMO show a strong correlation with elevated levels of insulin-like growth factor 1 receptor (IGF1R) and reduced survival in diffuse large B-cell lymphoma (DLBCL). As an integral component of raft microdomains, SMO plays a fundamental role in maintaining the levels of IGF1R in lymphoma and breast cancer cells as well IGF1R-associated activation of protein kinase B (AKT). Silencing of SMO increases lysosomal degradation and favors a localization of IGF1R to late endosomal compartments instead of early endosomal compartments from which much of the receptor would normally recycle. In addition, loss of SMO interferes with the lipid raft localization and retention of the remaining IGF1R and AKT, thereby disrupting the primary signaling context for IGF1R/AKT. This activity of SMO is independent of its canonical signaling and represents a novel and clinically relevant contribution to signaling by the highly oncogenic IGF1R/AKT signaling axis.

Composite materials manufactured by means of the superposition of layers and some specific morphologies, are susceptible to losing part of their resistant capacity due to the presence of delaminations between their layers. The objective of this work is to evaluate experimentally the generation and propagation of these interlaminar cracks in a carbon-epoxy composite subjected to dynamic stress under mixed fracture mode I/II, using for this purpose two different test methodologies, on the one hand the standardized MMB (Mixed-Mode Bending) and on the other hand the ADCB (Asymmetric Double Cantilever Beam), with the intention of exploring the viability of the ADCB test as a simpler alternative of execution, especially in fatigue tests, to the MMB test. For this purpose and after a previous static characterization of the material in which the critical values of the energy release rate were determined in both test methods, the energy release rate levels to be applied in the fatigue tests were defined for two GII/Gc mixed mode grades of 0.2 and 0.4(0,33 ADCB) and a ratio of stress levels to fatigue of R= Gmin/Gmax=0.1.DG-N fatigue initiation curves were obtained from these experimental data. The most relevant result of the work is that, in general, the MMB mixed mode provides different fatigue limits depending on the degree of mixed mode, whereas in the ADCB type test the fatigue limits tend to have the same value.

The determination of the eventual abrupt fracture of a reinforced concrete structure is of fundamental importance to estimate and mitigate the possible damages caused by its failure; of particular importance are shear-type fractures since these usually lead to sudden failure of the structure. One way to determine the presence of shear-type micro-cracks is by parametric analysis of the acoustic emissions produced by the micro-cracks during their growth. In this analysis, a direct comparisson of the waveform allows a distinction to be made between tensile-type and shear-type events. In the present study, we performed a comparative analysis of fracture processes in two reinforced concrete walls. In one of the walls an out-of-plane force was applied leading to bending and a non-abrupt failure; in the other one diagonal forces were applied leading to an abrupt shear-type fracture. Acoustic emissions were detected throughout and we found that at least one of the parameters associated with the parametric analysis allows distinguishing between abrupt and non-abrupt failures. Our results suggest that parametric analysis of acoustic emissions could be a useful tool in the prediction of abrupt failures in reinforced concrete structures.

Despite their common origin, experiments show that acoustic and electromagnetic emissions evolve in different ways during the fracture processes of brittle materials. It is common to find peaks of acoustic activity without the presence of electromagnetic emissions and vice versa, it is possible to find high electromagnetic radiation without significant acoustic activity. As far as we know, there are currently no models that explain these discrepancies in a simple way. In this work we propose a minimal model that is able to generate the frequently observed discrepancies between acoustic and electromagnetic emissions during fracture processes of brittle materials. The model is an electrical version of the fiber bundle model where the fibers are replaced by fuses in a resistor. The resistors are placed on a Wheatstone bridge subjected to a gradually increasing voltage. A capacitor is added to generate charge and discharge processes that will generate the electromagnetic emissions, while the breaking of the fuses will generate the acoustic emissions. The model allows to follow the evolution of acoustic and electromagnetic activities and shows that, despite their common origin, the two phenomena evolve differently.

En este libro se condensan las memorias del Congreso Virtual de la Sociedad Interamericana de Psicología 2020, que se celebró (en modalidad sincrónica) entre el 21 y 23 de octubre, con el lema "Aportes de la Psicología ante la COVID-19". Cuenta con Prólogo de la Dra. Michelle Bachelet, Alta Comisionada de la ONU para los Derechos Humanos. Incluye la Introducción de los compiladores, titulada "Un hito en la historia de los congresos de la SIP". A continuación, aparecen las "Palabras del Comité Organizador", a cargo de Miguel Gallegos (Coordinador del Comité Organizador). Luego el reconocimiento a los voluntarios del Congreso Virtual de la SIP 2020 y la lista de evaluadores de los trabajos sometidos al Congreso. Después el Mensaje de Invitación, Información de las Modalidades de Presentación y Evaluación del Evento, esta última a cargo de Nelson Portillo. A continuación, se presenta la información de los Premios "Isabel Reyes Lagunes" de Investigación Psicológica en COVID-19. Finalmente, se presentan los resúmenes de trabajos presentados en el evento (que constituyen la mayor parte del libro), entre las páginas 28 y 491. Las ilustraciones de portada y contraportada se titulan "La flor de la quila", elaboradas Sady Becerra (Chile).

Abstract Background: Chromosomal abnormalities in multiple myeloma (MM) patients, identified by either conventional metaphase cytogenetics or fluorescence in situ hybridization (FISH), stratify those at high risk of relapse and poorer survival after treatment. However the prognostic value of high-risk (HR) features in regard to survival after autologous hematopoietic stem cell transplantation is unclear. In addition, recent epidemiologic studies describe difference between Hispanic and non-Hispanic whites (NHW) in incidence, age at presentation, time to initial treatment, and rate of auto-HSCT within one year of diagnosis, but the presence of cytogenetic abnormalities as a prognostic factor in Hispanic patients has not yet been described. Methods: We conducted a retrospective analysis of 367 MM patients at the University of Miami Sylvester Comprehensive Cancer center who underwent auto-HSCT between January 2014 and December 2020. Patients were classified as HR if either conventional cytogenetics or FISH demonstrated at least one of the following: 1q+, 1p-, 17p-, 13q-, t(4;14), or t(14;16). All other patients with normal chromosomal studies or with trisomies and/or hyperdiploidy were considered standard risk (SR). Survival analysis were performed using the log-rank test, with significance at p-value < 0.05. Results: Male patient comprised 58% of our patient population with 43% of patients of Hispanic ethnicity. Of the 367 patients who underwent auto-HSCT, 183 (50%) had at least one HR cytogenetic abnormality. Overall, HR patients exhibited inferior PFS (32.9m vs 50.6m, p=0.017) and OS (median not reached/NR for both, p=0.0086) compared to SR patients. When evaluating outcomes with specific HR cytogenetic abnormalities, we identified cohorts that did not exhibit survival benefit, either in overall survival (OS) or progression-free survival (PFS) after transplant compared to SR patients, in particular patients with 17p-, 13q-, or 1q+ (Table 1). Patients with 1p-, t(14;16) or t(4;14) derived partial benefit from transplant in terms of PFS but not OS. Notably, patients with 1p- exhibited significantly worse OS compared to other HR patients (38.3m vs NR, p=0.007). We next evaluated differences in outcome when stratifying across ethnicity. Of the 183 patients with HR cytogenetic abnormalities, 75 (41%) were of Hispanic ethnicity, while 58 (32%) were NHW and 46 (25%) were of African-American (AA) ethnicity. The proportion of patients with SR or each individual HR cytogenetic abnormality was mostly equivalent amongst each ethnicity with the exception of 13q- (35% of Hispanic patients, vs. 44% of NHW and 26% of AA patients). Nevertheless, we observed that Hispanic patients with either t(4;14) or 13q- had significantly worse OS and PFS than their NHW and AA counterparts, and similarly observed inferior OS in Hispanic patients with 1q+ (Table 2). Conclusion: In our single-center retrospective analysis of HR MM patients undergoing auto-HSCT, we have identified specific patient populations that derive some survival benefit from transplant as well as populations that did not derive any benefit. Additionally, we demonstrate that despite similar incidence of certain HR abnormalities when comparing across ethnicities, Hispanic patients with particular chromosomal abnormalities have inferior overall survival outcomes after transplant. Further investigation is warranted to identify patient-specific and treatment-related factors leading to inferior outcomes in this patient population. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.