Green-Kubo expressions for transport coefficients from dissipative particle dynamics simulations revisited.

This article addresses the debate about the correct application of Green-Kubo expressions for transport coefficients from dissipative particle dynamics simulations. We demonstrate that the Green-Kubo expressions are valid provided that (i) the dynamic model conserves the physical property, whose transport is studied, and (ii) the fluctuations satisfy detailed balance. As a result, the traditional expressions used in molecular dynamics can also be applied to dissipative particle dynamics simulations. However, taking the calculation of the shear viscosity as a paradigmatic example, a random contribution, whose strength scales as 1/δt1/2, with δt the time-step, can cause difficulties if the stress tensor is not separated into the different contributions. We compare our expression to that of Ernst and Brito (M. H. Ernst and R. Brito, Europhys. Lett., 2006, 73, 183-189), which arises from a diametrically different perspective. We demonstrate that the two expressions are completely equivalent and find exactly the same result both analytically and numerically. We show that the differences are not due to the lack of time-reversibility but instead from a pre-averaging of the random contributions. Despite the overall validity of Green-Kubo expressions, we find that the Einstein-Helfand relations (D. C. Malaspina et al. Phys. Chem. Chem. Phys., 2023, 25, 12025-12040) do not suffer from the need to decompose the stress tensor and can readily be used with a high degree of accuracy. Consequently, Einstein-Helfand relations should be seen as the preferred method to calculate transport coefficients from dissipative particle dynamics simulations.

Transport coefficients from Einstein-Helfand relations using standard and energy-conserving dissipative particle dynamics methods.

In this article we demonstrate that contrary to general belief, the standard Einstein-Helfand (EH) formulas are valid for the evaluation of transport coefficients of systems containing dissipative and random forces provided that for these mesoscopic systems: (i) the corresponding conservation laws are satisfied, and (ii) the transition probabilities satisfy detailed balance. Dissipative particle dynamics (DPD) and energy-conserving DPD methods (DPDE), for instance, are archetypical of such mesoscopic approaches satisfying these properties. To verify this statement, we have derived a mesoscopic heat flux form for the DPDE method, suitable for the calculation of the thermal conductivity from an EH expression. We have compared EH measurements against non-equilibrium simulation values for different scenarios, including many-body potentials, and have found excellent agreement in all cases. The expressions are valid notably for systems with density- and temperature-dependent potentials, such as the recently developed generalised DPDE method (GenDPDE) [Avalos et al., Phys. Chem. Chem. Phys., 2019, 21, 24891]. We thus demonstrate that traditional EH formulas in equilibrium simulations can be widely used to obtain transport coefficients, provided that the appropriate expression for the associated flux is used.

Incidence and risk factors for acute kidney injury: a prospective, randomized, single-blind clinical trial comparing total knee arthroplasty with and without tourniquet.

PURPOSE: Identify the incidence and risk factors for acute kidney injury (AKI) following total knee arthroplasty (TKA) with and without tourniquet. MATERIAL AND METHODS: 100 patients were randomized into two groups. Postoperative AKI was defined as the postoperative creatinine level 0.3 mg/dl compared with baseline. Potential variables associated with AKI were analyzed by multivariate logistic regression model to identify the AKI risk factors in TKA patients with and without tourniquet. RESULTS: AKI rate was 22%, tourniquet use (OR = 2.66, p = 0.014), blood loss > 500 cm3 (OR = 3.99, p = 0.001), postoperative Hb < 10 g/dl (OR = 2.68, p = 0.008), blood transfusions (OR = 2.86, p = 0.012) and diabetes (OR = 2.80, p = 0.006) were associated with increased risk of postoperative AKI. CONCLUSIONS: The use of tourniquet should be indicated with caution and should not be used routinely in patients with other risk factors for the development of acute kidney dysfunction, other measures to achieve trans-surgical hemostasis should be implemented in our environment to reduce the incidence of acute kidney dysfunction related to the use of the tourniquet.

PROPÓSITO: Identificar la incidencia y factores de riesgo para lesión renal aguda (LRA) después de la artroplastia total de rodilla (ATR) con y sin uso de torniquete. MATERIAL Y MÉTODOS: Se dividieron 100 pacientes en dos grupos. Se definió la LRA como una elevación postoperatoria de la creatinina 0.3 mg/dl comparada con el nivel basal preoperatorio. Las potenciales variables asociadas con la DRA fueron analizadas con un modelo de regresión logística multivariada para identificar los factores de riesgo de DRA en pacientes sometidos a ATR con y sin torniquete. RESULTADOS: La incidencia de LRA fue de 22%. El uso de torniquete (OR = 2.66, p = 0.014), pérdida sanguínea > 500 cm3 (OR = 3.99, p = 0.001), Hb postoperatoria < 10 g/dl (OR = 2.68, p = 0.008), transfusión sanguínea (OR = 2.86, p = 0.012) y la diabetes (OR = 2.80, p = 0.006) fueron asociados a un mayor riesgo postoperatorio de LRA. CONCLUSIONES: El uso de torniquete debe estar indicado con precaución y no debe utilizarse de forma rutinaria en pacientes con otros factores de riesgo para el desarrollo de disfunción renal aguda, otras medidas para lograr la hemostasia transquirúrgica deben implementarse en nuestro entorno para reducir la incidencia de disfunción renal aguda relacionada con el uso del torniquete.

General isotropic micropolar fluid model in smoothed particle hydrodynamics.

The smoothed particle hydrodynamics (SPH) method is used in this paper to model micropolar fluids, with emphasis on their dissipation mechanisms. To this aim, a dissipation function is defined at the particle level which depends on the relative velocity between particles but also on an additional spin degree of freedom, which modifies such relative velocity as well as introduces spin-related intrinsic dissipation mechanisms, comparable to those related to the rate of deformation tensor in Newtonian fluids. This dissipation function is then incorporated within the Lagrangian formalism, leading to a set of SPH particle equations to describe the dynamics. A continuous integral SPH version of the scheme is obtained with a bottom-up derivation which guarantees the consistency of the SPH term. The model is then enriched with two additional terms based exclusively on the spin derivatives, which grant it the maximal generality as an isotropic model for micropolar fluids. Finally, numerical verification and validation tests are documented that show that SPH is capable of accurately modeling this type of dynamics.

Incidence and risk factors for acute kidney injury: a prospective, randomized, single-blind clinical trial comparing total knee arthroplasty with and without tourniquet / Incidencia y factores de riesgo para lesión renal aguda: Un ensayo clínico ciego, prospectivo y aleatorizado comparando la artroplastía total de rodilla con y sin torniquete

Abstract: Purpose: Identify the incidence and risk factors for acute kidney injury (AKI) following total knee arthroplasty (TKA) with and without tourniquet. Material and methods: 100 patients were randomized into two groups. Postoperative AKI was defined as the postoperative creatinine level ≥ 0.3 mg/dl compared with baseline. Potential variables associated with AKI were analyzed by multivariate logistic regression model to identify the AKI risk factors in TKA patients with and without tourniquet. Results: AKI rate was 22%, tourniquet use (OR = 2.66, p = 0.014), blood loss > 500 cm3 (OR = 3.99, p = 0.001), postoperative Hb < 10 g/dl (OR = 2.68, p = 0.008), blood transfusions (OR = 2.86, p = 0.012) and diabetes (OR = 2.80, p = 0.006) were associated with increased risk of postoperative AKI. Conclusions: The use of tourniquet should be indicated with caution and should not be used routinely in patients with other risk factors for the development of acute kidney dysfunction, other measures to achieve trans-surgical hemostasis should be implemented in our environment to reduce the incidence of acute kidney dysfunction related to the use of the tourniquet.

Resumen: Propósito: Identificar la incidencia y factores de riesgo para lesión renal aguda (LRA) después de la artroplastia total de rodilla (ATR) con y sin uso de torniquete. Material y métodos: Se dividieron 100 pacientes en dos grupos. Se definió la LRA como una elevación postoperatoria de la creatinina ≥ 0.3 mg/dl comparada con el nivel basal preoperatorio. Las potenciales variables asociadas con la DRA fueron analizadas con un modelo de regresión logística multivariada para identificar los factores de riesgo de DRA en pacientes sometidos a ATR con y sin torniquete. Resultados: La incidencia de LRA fue de 22%. El uso de torniquete (OR = 2.66, p = 0.014), pérdida sanguínea > 500 cm3 (OR = 3.99, p = 0.001), Hb postoperatoria < 10 g/dl (OR = 2.68, p = 0.008), transfusión sanguínea (OR = 2.86, p = 0.012) y la diabetes (OR = 2.80, p = 0.006) fueron asociados a un mayor riesgo postoperatorio de LRA. Conclusiones: El uso de torniquete debe estar indicado con precaución y no debe utilizarse de forma rutinaria en pacientes con otros factores de riesgo para el desarrollo de disfunción renal aguda, otras medidas para lograr la hemostasia transquirúrgica deben implementarse en nuestro entorno para reducir la incidencia de disfunción renal aguda relacionada con el uso del torniquete.

Tratamiento endoscópico de lesiones quísticas supratentoriales en pediatría / Endoscopic treatment of supratentorial cystic lesions in pediatrics

Introducción: La endoscopía neuroquirúrgica es una técnica mínimamente invasiva, utilizada desde principios del siglo XX para dar solución a las patologías localizadas en el sistema ventricular. En la actualidad las indicaciones de esta técnica se han ampliado notablemente. El objetivo de este trabajo consiste en presentar el tratamiento endoscópico de quistes cerebrales supratentoriales de diferentes etiologías en pediatría. Materiales y métodos: Se realizó un estudio transversal retrospectivo, desde enero de 2016 hasta diciembre de 2019, de pacientes pediátricos con lesiones quísticas supratentoriales tratados endoscópicamente en el Hospital de Niños de La Plata. Para definir el éxito se utilizó la clasificación en 5 grados de Ross et al. Resultados: Se practicaron 14 procedimientos en 12 pacientes, con edades comprendidas entre los 2 meses y los 9 años. Del total, 6 fueron quistes intraventriculares, 3 quistes de línea media, 5 quistes paraventriculares. Todos presentaban algún signo o síntoma al momento de la consulta, predominando entre ellos la alteración del estado neurológico y los vómitos. Luego de practicarse la fenestración endoscópica, presentaron una evolución clínica favorable en 12 de los 14 procedimientos y una mejoría en al menos un criterio imagenológico en 10 del total de los procedimientos.Basados en la categorización de Ross et al. se obtuvo un grado I en el 57% de los casos, lo que implica una mejoría completa permanente. La tasa de complicación global fue del 7%, presentando en solo un caso infección post endoscopia. Conclusión: La neuroendoscopía debería ser considerada como una opción de primera línea para el tratamiento en las lesiones quísticas supratentoriales. Demostró ser un método poco invasivo, con el cual se obtuvieron buenos resultados y una baja tasa de complicaciones.

Introduction: Neurosurgical endoscopy is a minimally invasive technique, used since the beginning of the 20th century to solve pathologies localized in the ventricular system. Currently the indications for this technique have been greatly expanded. The objective of this work is to present the endoscopic treatment of supratentorial brain cysts of different etiologies in pediatrics. Material and methods: We carried out a retrospective cross-sectional study, from January 2016 to December 2019, of pediatric patients with supratentorial cystic lesions treated endoscopically at the Hospital de Niños of La Plata City. To define success, we used the 5-degree classification of Ross et al. Results: 14 procedures were performed in 12 patients, aged between 2 months and 9 years. Of the total, 6 were intraventricular cysts, 3 midline cysts, 5 paraventricular cysts. All presented any signs or symptoms at the time of the consultation, prevailing among them the alteration of the neurological state and vomiting. After endoscopic fenestration was performed, they presented a favorable clinical evolution in 12 of the 14 procedures and an improvement in at least one imaging criterion in 10 of all procedures. Based on the categorization of Ross et al. we obtained a grade I in 57% of the cases, which implies a permanent complete improvement. The overall complication rate was 7%, presenting post-endoscopy infection in only one case. Conclusion: Neuroendoscopy should be considered as a first-line option for the treatment of supratentorial cystic lesions. It proved to be a non-invasive method, with which we obtained good results and a low complication rate

Lavado endoscópico con colocación de catéter trans acueducto de Silvio en paciente lactante con ventriculitis de difícil manejo / Endoscopic lavage with placement of a trans-aqueduct of Silvio catheter in a nursing patient with difficult-to-manage ventriculitis

Introducción: La ventriculitis representa una emergencia infectológica, generalmente asociada a un procedimiento neuroquirúrgico. La incidencia es desconocida debido a la variación de los criterios diagnóstico. Descripción del caso: Presentamos una paciente de sexo femenino de 6 meses de edad con antecedente de hidrocefalia post hemorrágica, con diagnóstico de ventriculitis por Enterobacter complex asociada a sistema de derivación ventrículo peritoneal (DVP) de difícil manejo. La misma realizó tratamiento combinado de antibiótico con Meropenem y Colistin endovenoso e intraventricular asociado a tratamiento endoscópico que consistió en lavados, aspiración del contenido purulento intraventricular, tercer ventriculostomía endoscópica (TVE), coagulación bilateral del plexo coroideo y acueductoplastia con colocación de catéter de derivación ventricular externa (DVE) entre el tercer y el cuarto ventrículo con el objetivo de mantener la permeabilidad de la misma y de esta manera asegurar la llegada de antibiótico intraventricular al cuarto ventrículo. Discusión: La ventriculitis se asocia a múltiples complicaciones y una elevada tasa de morbi-mortalidad. El tratamiento de las ventriculitis de difícil manejo, es aún controvertido, actualmente existe bibliografía que reporta buenos resultados del tratamiento con lavado endoscópicos asociado al tratamiento combinado endovenoso e intraventricular para lograr mayores concentraciones de antibiótico intraventricular. Conclusión: Consideramos que el tratamiento combinado es una herramienta frente a las ventriculitis por patógenos resistentes a los tratamientos convencionales. En los casos con obstrucción del acueducto de Silvio recomendamos realizar acueductoplastia y colocación de catéter multifenestrado; para mantener la permeabilidad y la llegada de antibiótico al cuarto ventrículo.

Introduction: Ventriculitis represents an infectious emergency which is normally associated with neurosurgical procedures. The incidence is unknown due to the variation of the diagnostic criteria. Case description: We present a 6-month-old female patient with a history of post-hemorrhagic hydrocephalus. The patient was diagnosed with Enterobacter complex ventriculitis difficult to manage associated with peritoneal ventricular shunt (VP). The patient received combined antibiotic treatment with Meropenem intravenous and intravenous-intraventricular Colistin associated with endoscopic treatment. This endoscopic treatment consisted of washes, aspiration of the intraventricular purulent content, third endoscopic ventriculostomy (ETV), bilateral coagulation of the choroid plexus and aqueductoplasty with external ventricular drain catheter (EDV). This EDV was placed between the third and fourth ventricle in order to maintain its permeability so as to ensure the arrival of intraventricular antibiotics to the fourth ventricle. Discussion: Ventriculitis is associated with multiple complications and a high morbidity and mortality rate. The treatment of ventriculitis that is difficult to manage is still controversial. Currently several authors show good results of endoscopic lavage treatment associated with combined intravenous/intraventricular antibiotic treatment. This leads to greater intraventricular antibiotic concentrations. Conclusion: We consider that combined treatment has been successful for ventriculitis difficult to manage. In those cases, with obstruction of the Silvio aqueduct, it is recommended to perform aqueductoplasty and placement of a multi-fenestrated catheter; to maintain patency and the arrival of antibiotics in the fourth ventricle.

Efficacy and safety of preemptive analgesia with gabapentinoids for patients undergoing arthroscopic shoulder surgery: a systematic review and meta-analysis / Eficacia y seguridad de la analgesia preventiva con gabapentinoides para pacientes sometidos a cirugía artroscópica de hombro: una revisión sistemática y metanálisis

Abstract: Objective: To assess the efficacy and safety of preemptive analgesia with gabapentinoids for patients undergoing arthroscopic shoulder surgery. Material and methods: A PRISMA-compliant systematic review and meta-analysis was conducted in PubMed, Cochrane Library and ScienceDirect databases. Randomized Controlled Trials (RCTs) comparing gabapentinoids (gabapentin and pregabalin) with placebo in patients undergoing shoulder arthroscopic surgery were retrieved. The primary endpoint was the visual analogue scale (VAS) score at 24 hours and cumulative morphine consumption at 24 hours. The secondary outcomes were complications of nausea/vomiting, sedation and dizziness. After tests for publication bias and heterogeneity among studies were performed, data were aggregated for random-effects models when necessary. Results: Five clinical studies (gabapentin group n = 4 and pregabalin group n = 1) were ultimately included in the meta-analysis. Gabapentinoids were associated with reduced pain scores at 24 hours. Similarly, gabapentinoids were associated with a reduction in cumulative morphine consumption at 24 hours. Furthermore, gabapentinoids can significantly reduce the occurrence of nausea/vomiting. There were no significant differences in the occurrence of sedation and dizziness. Conclusions: Preoperative use of gabapentinoids was able to reduce postoperative pain, total morphine consumption, and morphine-related complications following arthroscopic shoulder surgery. Further studies should determine the optimal dose and whether pregabalin is superior to gabapentin in controlling acute pain after shoulder surgery.

Resumen: Objetivo: Evaluar la eficacia y seguridad de la analgesia preventiva con gabapentinoides para pacientes sometidos a cirugía artroscópica del hombro. Material y métodos: Se llevó a cabo una revisión sistemática y metaanálisis conforme a PRISMA en las bases de datos PubMed, Cochrane Library y ScienceDirect. Se recuperaron ensayos controlados aleatorios (RCT) que comparaban los gabapentinoides (gabapentina y pregabalina) con placebo en pacientes sometidos a cirugía artroscópica del hombro. El punto final principal fue la puntuación de la escala analógica visual (VAS) a las 24 horas y el consumo acumulado de morfina a las 24 horas. Los resultados secundarios fueron complicaciones de náuseas/vómitos, sedación y mareos. Después de realizar pruebas de sesgo de publicación y heterogeneidad entre los estudios, se agregaron datos para modelos de efectos aleatorios cuando fue necesario. Resultados: En última instancia, se incluyeron en el metaanálisis cinco estudios clínicos (grupo de gabapentina n = 4 y grupo de pregabalina n = 1). Los gabapentinoides se asociaron con puntuaciones de dolor reducidas a las 24 horas. Del mismo modo, los gabapentinoides se asociaron con una reducción en el consumo acumulado de morfina a las 24 horas. Además, los gabapentinoides pueden reducir significativamente la aparición de náuseas/vómitos. No hubo diferencias significativas en la ocurrencia de sedación y mareos. Conclusiones: El uso preoperatorio de gabapentinoides fue capaz de reducir el dolor postoperatorio, el consumo total de morfina y las complicaciones relacionadas con la morfina después de la cirugía artroscópica del hombro. Otros estudios deben determinar la dosis óptima y si la pregabalina es superior a la gabapentina en el control del dolor agudo después de la cirugía de hombro.

Eficacia y seguridad de la analgesia preventiva con gabapentinoides para pacientes sometidos a cirugía artroscópica de hombro: una revisión sistemática y metanálisis.

OBJECTIVE: To assess the efficacy and safety of preemptive analgesia with gabapentinoids for patients undergoing arthroscopic shoulder surgery. MATERIAL AND METHODS: A PRISMA-compliant systematic review and meta-analysis was conducted in PubMed, Cochrane Library and ScienceDirect databases. Randomized Controlled Trials (RCTs) comparing gabapentinoids (gabapentin and pregabalin) with placebo in patients undergoing shoulder arthroscopic surgery were retrieved. The primary endpoint was the visual analogue scale (VAS) score at 24 hours and cumulative morphine consumption at 24 hours. The secondary outcomes were complications of nausea/vomiting, sedation and dizziness. After tests for publication bias and heterogeneity among studies were performed, data were aggregated for random-effects models when necessary. RESULTS: Five clinical studies (gabapentin group n = 4 and pregabalin group n = 1) were ultimately included in the meta-analysis. Gabapentinoids were associated with reduced pain scores at 24 hours. Similarly, gabapentinoids were associated with a reduction in cumulative morphine consumption at 24 hours. Furthermore, gabapentinoids can significantly reduce the occurrence of nausea/vomiting. There were no significant differences in the occurrence of sedation and dizziness. CONCLUSIONS: Preoperative use of gabapentinoids was able to reduce postoperative pain, total morphine consumption, and morphine-related complications following arthroscopic shoulder surgery. Further studies should determine the optimal dose and whether pregabalin is superior to gabapentin in controlling acute pain after shoulder surgery.

OBJETIVO: Evaluar la eficacia y seguridad de la analgesia preventiva con gabapentinoides para pacientes sometidos a cirugía artroscópica del hombro. MATERIAL Y MÉTODOS: Se llevó a cabo una revisión sistemática y metaanálisis conforme a PRISMA en las bases de datos PubMed, Cochrane Library y ScienceDirect. Se recuperaron ensayos controlados aleatorios (RCT) que comparaban los gabapentinoides (gabapentina y pregabalina) con placebo en pacientes sometidos a cirugía artroscópica del hombro. El punto final principal fue la puntuación de la escala analógica visual (VAS) a las 24 horas y el consumo acumulado de morfina a las 24 horas. Los resultados secundarios fueron complicaciones de náuseas/vómitos, sedación y mareos. Después de realizar pruebas de sesgo de publicación y heterogeneidad entre los estudios, se agregaron datos para modelos de efectos aleatorios cuando fue necesario. RESULTADOS: En última instancia, se incluyeron en el metaanálisis cinco estudios clínicos (grupo de gabapentina n = 4 y grupo de pregabalina n = 1). Los gabapentinoides se asociaron con puntuaciones de dolor reducidas a las 24 horas. Del mismo modo, los gabapentinoides se asociaron con una reducción en el consumo acumulado de morfina a las 24 horas. Además, los gabapentinoides pueden reducir significativamente la aparición de náuseas/vómitos. No hubo diferencias significativas en la ocurrencia de sedación y mareos. CONCLUSIONES: El uso preoperatorio de gabapentinoides fue capaz de reducir el dolor postoperatorio, el consumo total de morfina y las complicaciones relacionadas con la morfina después de la cirugía artroscópica del hombro. Otros estudios deben determinar la dosis óptima y si la pregabalina es superior a la gabapentina en el control del dolor agudo después de la cirugía de hombro.

Colloidal properties of sodium caseinate-stabilized nanoemulsions prepared by a combination of a high-energy homogenization and evaporative ripening methods.

Nanoemulsions stabilized by sodium caseinate (NaCas) were prepared using a combination of a high-energy homogenization and evaporative ripening methods. The effects of protein concentration and sucrose addition on physical properties were analyzed by dynamic light scattering (DLS), Turbiscan analysis, confocal laser scanning microscopy (CLSM) and small angle X-ray scattering (SAXS). Droplets sizes were smaller (~100nm in diameter) than the ones obtained by other methods (200 to 2000nm in diameter). The stability behavior was also different. These emulsions were not destabilized by creaming. As droplets were so small, gravitational forces were negligible. On the contrary, when they showed destabilization the main mechanism was flocculation. Stability of nanoemulsions increased with increasing protein concentrations. Nanoemulsions with 3 or 4wt% NaCas were slightly turbid systems that remained stable for at least two months. According to SAXS and Turbiscan results, aggregates remained in the nano range showing small tendency to aggregation. In those systems, interactive forces were weak due to the small diameter of flocs.

Environmental factors associated with Dictyocaulus viviparus and Fasciola hepatica prevalence in dairy herds from Costa Rica.

Dictyocaulosis and fasciolosis are parasitic diseases that cause considerable economic losses for owners of farm animals worldwide, with special relevance on fasciolosis because it is an emerging zoonosis. Indirect diagnosis of these diseases through analyses of bulk milk tank samples has allowed carrying out large-scale prevalence studies, while the use of geographical information systems has helped to visualize and determine those variables that affect distribution of these pathogens. This study is intended to describe the spatial distribution of Dictyocaulus viviparus and Fasciola hepatica in dairy herds from Costa Rica, as well as their associated environmental factors. Bulk milk tank samples from 526 dairy herds in the three most important dairy regions of Costa Rica were analyzed using enzyme immunoassays. Results from the farms were subjected to spatial analyses using Holdridge's life zones, relief and soil type environmental layers. Of the total bulk milk tank samples analyzed, 3.8% (n=20) and 3.6% (n=19) were positive for D. viviparus and F. hepatica, respectively. Moran's I analysis revealed the existence of potential cluster (Moran's I=1.789, z=12.726 p<0.05) for D. viviparus. Consequently, Getis-Ord General G analysis showed that the spatial distribution of positive farms in the dataset was clustered (Observed General G=0.015, variance=0.000001, z=12.823, p<0.05). No significant positive spatial autocorrelation (Moran's I=0.038, z=0.286, p>0.0.5) was observed for F. hepatica. Furthermore, a significant difference was detected in the spatial locations of both parasites (latitude p<0.05, longitude p<0.05), and about the spatial distribution of both D. viviparus negative and positive farms (latitude p<0.05, longitude p<0.05), as well as in F. hepatica negative and positive farms regarding on latitude (p<0.05), but not on longitude (p>0.05). In the case of environmental factors, significant differences were found for D. viviparus and F. hepatica with respect to types of soil, precipitation, altitudinal belts, life zones, biotemperature, and elevation.

Experiencia con el balón de Bakri en hemorragia obstétrica / Brakri balloon experience in obstetric hemorrhage

Resumen OBJETIVO: reportar la experiencia con el balón de Bakri en el control de la hemorragia obstétrica, su relación con la cantidad y concentraciones de hemoglobina antes y después de su aplicación. MATERIALES Y MÉTODOS: estudio prospectivo y observacional efec- tuado en dos unidades hospitalarias del 1 de enero al 31 de diciembre de 2016. A todas las pacientes se les aplicó el balón de Bakri por falta de respuesta a los uterotónicos. Variables de estudio: datos clínicos, cantidad de pérdida sanguínea antes y después de la aplicación del balón, cantidad de sangrado en el posparto y transcesárea, tiempo trascurrido entre el diagnóstico y la colocación, tiempo de llenado y volumen administrado, concentraciones de hemoglobina y pruebas de coagulación al ingreso a la unidad de atención, postsangrado y posterior a la aplicación, indicación de hemocomponentes, cantidad y tiempo de permanencia del balón, éxito y complicaciones. Se realizó análisis estadístico de todas estas variables. RESULTADOS: se incluyeron 20 pacientes con hemorragia posparto y transcesárea. La cantidad de sangrado después de la aplicación, tanto en los casos de posparto como transcesárea, fue menor y se obtuvo una adecuada respuesta. El tiempo medio entre el diagnóstico de la hemorragia y la colocación del balón fue de 30 minutos, tiempo medio de llenado de 5 minutos y cantidad media de llenado de 400 mL. El tiempo medio de permanencia del balón fue de 29.5 horas. En 95% de los casos se consiguió una respuesta favorable para el control de la hemorragia, sin complicaciones. CONCLUSIONES: la aplicación del balón de Bakri resultó en una medida útil, rápida y sin complicaciones para controlar la hemorragia obstétrica.

Abstract OBJECTIVE: To present the results obtained by using the Bakri Balloon to control obstetric hemorrhage. MATERIALS AND METHOD: Prospective, observational study within two inpatient medical care units from January 1 to December 31 2016. All of them were applied the Bakri Balloon because of failure to respond to uterotonic drug therapy. The following were analized: clinical data, amount of bleeding before and after the balloon, amount of postpartum or transcesarean bleeding, time between diagnosis and insertion, insufflation time and supplied volumen, hemoglobin levels and coagulation tests results initially, post-hemorrhage and post insertion, use of and amount of haemocomponents ministered, and the balloons use time, success, and complications. RESULTS: 20 patients with postpartum and transesarean hemorrhage are included. The amount of bleeding after insertion, both in postpartum and trans cesarean was reduced and there was an adequate response in hemoglobin levels. The average time between hemorrhage diagnosis and balloon insertion was thirty minutes; average insufflation time, five minutes, and average volumen supplied 400 mL. Balloon's average use time, 29.5 hours. In 95% of the cases there was a positive response for hemorrhage control, with no complications derived from use. CONCLUSIONS: The Bakri Balloon proved to be a useful, quick and complication-free therapy for controlling obstetric hemorrhage.

Flight behaviour and dispersal of Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) adults using mark-release-recapture method.

The flight ability and patterns of an insect influence its spread, and the study of its behaviour can be used to improve the strategies to control the pest. Regarding Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), one of the worst threats to palm trees worldwide, laboratory experiments have been conducted to analyze their flight potential. However, these data must be complemented with tests that allow us to know its flight behaviour and dispersal patterns under field conditions. Two mark-release-recapture experiments were conducted in areas with R. ferrugineus infestations. In the first, the effects of weevil sex, temperature, solar radiation, and relative humidity, on the take-off and flight mobility of adults were analyzed. The second experiment aimed to determine the maximum flight distance covered by adults in field. The take-off rate for R. ferrugineus males was significantly greater than for females, and was positively influenced by temperature (optimum take-off around 25°C) and solar radiation, both factors being highly correlated. Female weevil recaptures were significantly higher, especially as temperatures increased (optimum recapture around 21°C). Dispersal distances of weevil adults increased when temperatures rose, and while this insect tended to fly short distances (<500 m), it was able to cover up to 7 km. The dispersal of R. ferrugineus adults mainly occurred during the first 7 days after their release, and when relative humidity increased, their dispersal time was reduced. The results obtained will permit a more effective implementation of certain measures used to control R. ferrugineus, such as olfactory trapping or intensive surveillance around pest outbreaks.

Medición de niveles de parathormona como predictor de hipocalcemia sintomática en el post-operatorio precoz de tiroidectomía total / Parathormone levels measurement as predictor of symptomatic hypocalcemia after total thyroidectomy

Introduction: The most frequent complication after total thyroidectomy is hypocalcemia. It is difficult to predict it. The objective of this paper is determinate if measurement of parathormone 6 hours after total thyroidectomy can predict symptomatic hypocalcemia, and determinate associated factors in the development of this complication. Material and Method: Prospective case series. Patients that underwent total thyroidectomy between 2006 and 2008 in our Hospital. We registered epidemiological data, related surgery factors and measurement of parathormone 6 hours after surgery. Hypocalcemia symptoms were registered. We used statistical analysis considering significant p < 0.05. Results: We included 82 patients. Median age was 53.2 years. 79.3 percent were female. The average of parathormone 6 hours after surgery was 28.7 pg/dL. Sensibility was 100 percent, specificity 79.4 percent, positive predictive value 59.4 percent, negative predictive value 100 percent and accuracy 84.1 percent to predict symptomatic hypocalcaemia. A statistical association among levels under the normal base line of parathormone and symptomatic hypocalcemia was detected (p < 0.0001). Relative risk was 4.84. Univariated analysis showed association between hypocalcemia and pre-operative thyroid cancer diagnosis (p = 0.01), cervical dissection (p = 0.03) and level of parathormone (p = 0.002). Multivariated analysis showed that only the level of parathormone associates with hypocalcemia (p = 0.002). Conclusion: The measurement of parathormone allows identifying which patients are at risk of presenting symptomatic hypocalcemia after total thyroidectomy.

Introducción: La complicación más frecuente de la tiroidectomía total es la hipocalcemia. Su predicción es difícil. El objetivo de este trabajo es determinar si la medición de parathormona a las 6 h posterior a una tiroidectomía total es un factor que pueda predecir la aparición de hipocalcemia sintomática y determinar los factores asociados al desarrollo de esta complicación. Material y Método: Serie de casos prospectiva. Pacientes intervenidos de tiroidectomía total entre 2006 y 2008 en el Hospital FACH. Se registraron datos epidemiológicos, factores relacionados a la cirugía y la medición de parathormona a las 6 h. Se registraron los síntomas de hipocalcemia. Se utilizó estadística analítica considerando significativo p < 0,05. Resultados: Se enrolaron 82 pacientes. La edad media fue 53,2 años. El 79,3 por ciento fue de sexo femenino. El promedio de parathormona a las 6 h fue 28,7 pg/dL. Se obtuvo sensibilidad 100 por ciento, especificidad 79,4 por ciento, valor predictivo positivo 59,4 por ciento, negativo 100 por ciento y precisión 84,1 por ciento para predecir hipocalcemia. Cuando los valores de PTH estaban bajo el margen normal, el riesgo relativo de hipocalcemia sintomática fue 4,84 (p < 0,0001). El análisis univariado mostró asociación entre hipocalcemia y el diagnóstico pre operatorio de cáncer (p = 0,01), la disección cervical (p = 0,03) y el nivel de parathormona a las 6 h (p = 0,002). El análisis multivariado demostró que sólo el nivel de parathormona se asocia con hipocalcemia (p = 0,002). Conclusión: La medición de parathormona es un elemento que permite estimar de manera adecuada qué pacientes están en riesgo de presentar hipocalcemia sintomática en el post-operatorio precoz de tiroidectomía total.

Efectividad de anestesia de plexo cervical superficial preoperatorio para control de dolor postoperatorio en cirugía de tiroides / Analgesic effects of bilateral superficial cervical plexus block with Bupivacaine after thyroidectomy

Background: Bilateral superficial cervical plexus block is a simple non-invasive technique that can be used as preventive analgesia in the perioperative period of thyroidectomy. Aim: to assess the analgesic effects of the technique during the postoperative period of thyroidectomy. Material and Methods: Patients with indication of total thyroidectomy, with a low operative risk according to the American Society of Anesthesiology, were studied. All were operated with general anesthesia using Fentanyl, Propofol, Vecuronium and Isoflurane. Patients were randomly and blindly assigned to superficial cervical plexus block using Bupivacaine 0.25% or to a placebo injection. Postoperative pain, need for analgesics and patient satisfaction were assessed...

Introducción: La cirugía de la glándula tiroides es reconocida como un procedimiento que produce un dolor leve a moderado. El bloqueo bilateral de plexo cervical superficial es una técnica simple, poco invasiva, que pudiera ser beneficioso en estos pacientes como modelo de analgesia preventiva. Objetivos: Evaluar la calidad de la analgesia del postoperatorio de la cirugía de tiroides, con el uso de bloqueo bilateral del plexo cervical superficial. Material y Métodos: Se estudiaron pacientes ASA I y II propuestos para cirugía de tiroides bajo anestesia general. En todos los pacientes se hizo anestesia general balanceada con Fentanyl, Propofol, Vecuronio e Isoflurano. En forma aleatoria y ciega se asignaron los pacientes en 2 grupos: grupo A, Bupivacaína 0,25% 20 ml y grupo B placebo. Se evaluó características demográficas, dolor postoperatorio, necesidad de analgésicos de rescate, náuseas, vómitos y satisfacción del paciente...

Sobrevida en carcinoma espinocelular de mucosa oral: análisis de 161 pacientes / Survival in oral mucosa squamous cell carcinoma: analysis of 161 patients

Introduction: Oral Cancer accounts 3 percent of all human cancers. Squamous Cell Carcinoma is the most common. nowadays, in Chile and the world, oral cancer is reaching relevance because of its high incidence and low survival rates; most often is squamous cell carcinoma (SCC). Aim: We analyzed the five-year survival of 161 patients diagnosed with SCC. Also was studied relationships between survival and gender, age, location, tobacco, alcohol and treatment. Methods: Retrospective study among 1989 and 2010. The study population was mainly men gender (59 percent), average age 64 years and location of the CEC preferably in tongue (37.6 percent). 54 percent were well differentiated carcinomas and TOM, the majority corresponding to T2N0M0. Kaplan-Meier curve and Log Rank test were used for survival analysis and to compare them. We determined significant difference when p value < 0.05. Results: The overall survival at five years was 46 percent, the lowest rates were in the male gender, age group 60, floor of mouth, smokers and alcohol consumers. Conclusions: Although tobacco and alcohol are factors highly related to the presence of CEC, there was no significant difference between survival and these habits. There were differences between the survival curves for patients treated with surgery associated with radiotherapy in comparison to other treatments.

Introducción: Hoy en día, en Chile y el mundo, el cáncer oral ha tomado mayor importancia por su incidencia y bajos porcentajes de sobrevida, el más frecuente corresponde al Carcinoma Espinocelular (CEC). Objetivo: Analizar la sobrevida a cinco años de 161 pacientes de la Facultad de Odontología de la Universidad Mayor y Fundación Arturo López Pérez (FALP), diagnosticados con CEC de mucosa oral mediante biopsia. Se analizó cómo afecta a la sobrevida, el género, edad, localización, consumo de tabaco y/o alcohol y tratamiento. Material y método: Estudio retrospectivo entre los años 1989 y 2010. La población estudiada correspondía principalmente a hombres (59 por ciento), edad promedio de 64 años y ubicación del CEC preferentemente en lengua (37,6 por ciento). El 54 por ciento eran carcinomas bien diferenciados y, según TNM, la mayor parte correspondía a T2N0M0. Se utilizó para los análisis de sobrevida la curva de Kaplan-Meier y Log Rank Test para compararlas. Se determinó si existían diferencias significativas cuando el valor de p < 0,05. Resultados: La sobrevida general a los cinco años fue de 46 por ciento, las tasas más bajas fueron en el género masculino, el grupo mayores de 60 años, en piso de boca, fumadores y bebedores de alcohol. Conclusiones: A pesar que el tabaco y el alcohol son factores altamente relacionados a la presencia de CEC, no se observó diferencia significativa entre la sobrevida y estos hábitos. Hubo diferencia entre las curvas de sobrevida de pacientes tratados con cirugía asociada a radioterapia en relación a otros tratamientos.

Study of the flying ability of Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) adults using a computer-monitored flight mill.

The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae), native to tropical Asian regions, has become a serious threat to palm trees all over the world. Knowledge of its flight potential is vital to improving the preventive and curative measures currently used to manage this pest. As R. ferrugineus is a quarantine pest, it is difficult to study its flight potential in the field. A computer-monitored flight mill was adapted to analyse the flying ability of R. ferrugineus through the study of different flight parameters (number of flights, total distance flown, longest single flight, flight duration, and average and maximum speed) and the influence of the weevil's sex, age, and body size on these flight parameters. Despite significant differences in the adult body size (body weight and length) of males and females, the sex of R. ferrugineus adults did not have an influence on their flight potential. Neither adult body size nor age was found to affect the weevil's flying abilities, although there was a significantly higher percentage of individuals flying that were 8-23 days old than 1-7 days old. Compared to the longest single flight, 54% of the insects were classified as short-distance flyers (covering <100 m) and 36 and 10% were classified as medium- (100-5000 m) and long-distance (>5000 m), respectively. The results are compared with similar studies on different insect species under laboratory and field conditions.

Fine and ultrafine particle emissions from microwave popcorn.

This study characterized fine (PM2.5 ) and ultrafine particle (UFP, diameter < 100 nm) emissions from microwave popcorn and analyzed influential factors. Each pre-packed popcorn bag was cooked in a microwave oven enclosed in a stainless steel chamber for 3 min. The number concentration and size distribution of UFPs and PM2.5 mass concentration were measured inside the chamber repeatedly for five different flavors under four increasing power settings using either the foil-lined original package or a brown paper bag. UFPs and PM2.5 generated by microwaving popcorn were 150-560 and 350-800 times higher than the emissions from microwaving water, respectively. About 90% of the total particles emitted were in the ultrafine size range. The emitted PM concentrations varied significantly with flavor. Replacing the foil-lined original package with a brown paper bag significantly reduced the peak concentration by 24-87% for total particle number and 36-70% for PM2.5 . A positive relationship was observed between both UFP number and PM2.5 mass and power setting. The emission rates of microwave popcorn ranged from 1.9 × 10(10) to 8.0 × 10(10) No./min for total particle number and from 134 to 249 µg/min for PM2.5 .

Confirmation of in vitro and clinical safety assessment of behentrimonium chloride-containing leave-on body lotions using post-marketing adverse event data.

Behentrimonium chloride (BTC) is a straight-chain alkyltrimonium chloride compound commonly used as an antistatic, hair conditioning, emulsifier, or preservative agent in personal care products. Although the European Union recently restricted the use of alkyltrimonium chlorides and bromides as preservatives to ≤0.1%, these compounds have been safely used for many years at ≤5% in hundreds of cosmetic products for other uses than as a preservative. In vitro, clinical, and controlled consumer usage tests in barrier-impaired individuals were conducted to determine if whole body, leave-on skin care products containing 1-5% BTC cause dermal irritation or any other skin reaction with use. BTC-containing formulations were predicted to be non-irritants by the EpiDerm® skin irritation test and the bovine corneal opacity and permeability (BCOP)/chorioallantoic membrane vascular assay (CAMVA) ocular irritation test battery. No evidence of allergic contact dermatitis or cumulative dermal irritation was noted under the exaggerated conditions of human occlusive patch tests. No clinically assessed or self-reported adverse reactions were noted in adults or children with atopic, eczematous, and/or xerotic skin during two-week and four-week monitored home usage studies. These results were confirmed by post-marketing data for five body lotions, which showed only 0.69 undesirable effects (mostly skin irritation) reported per million shipped consumer units during 2006-2011; a value consistent with a non-irritating body lotion. No serious undesirable effects were reported during in-market use of the products. Therefore, if formulated in appropriate conditions at 1-5%, BTC will not cause dermal irritation or delayed contact sensitization when used in a whole-body, leave-on product.

Consentimiento informado: síntesis de teoría actual y recomendaciones / Recommendations and theoretical basis of the informed consent

The informed consent is the rational acceptance of a medical intervention or the choice between several alternatives, by a patient. The intervention can be for diagnostic or therapeutic purposes. The concept of autonomous decision goes beyond the fulfillment of a legal regulation about the informed consent. We must not forget the ethical grounds of the relationship between health care providers and recipients, which should be based on mutual trust. The information should be disclosed in an honest, sincere and truthful way and without conflicts of interest, to obtain a fully informed consent to proceed with the proposed interventions.

El consentimiento informado es la aceptación racional por parte de un paciente de una intervención médica o la elección entre cursos alternativos posibles. Esta intervención puede ser de orden terapéutica o diagnóstica. El concepto de decisiones autónomas va así más allá del cumplimiento de una norma jurídica sobre consentimiento informado, por lo que no debemos perder de vista el fundamento ético de esta necesaria relación entre el profesional de la salud y el paciente, en un ámbito de confianza personal, de información otorgada en forma honesta, sincera, verdadera, de manera de obtener el consentimiento de éste para un determinado tratamiento.