Production of poly (3-hydroxybutyrate) and extracellular polymeric substances from glycerol by the acidophile Acidiphilium cryptum.

Acidiphilium cryptum is an acidophilic, heterotrophic, and metallotolerant bacteria able to use dissolved oxygen or Fe(III) as an electron sink. The ability of this extremophile to accumulate poly(3-hydroxybutyrate) (PHB) and secrete extracellular polymeric substances (EPS) has also been reported. Hence, the aim of this work is to characterize the production of PHB and EPS by the wild strain DSM2389 using glycerol in shaken flasks and bioreactor. Results showed that maximum PHB accumulation (37-42% w/w) was obtained using glycerol concentrations of 9 and 15 g L-1, where maximum dry cell weight titers reached 3.6 and 3.9 g L-1, respectively. The culture in the bioreactor showed that PHB accumulation takes place under oxygen limitation, while the redox potential of the culture medium could be used for online monitoring of the PHB production. Recovered EPS was analyzed by Fourier-transform infrared spectroscopy and subjected to gas chromatography-mass spectrometry after cleavage and derivatization steps. These analyses showed the presence of sugars which were identified as mannose, rhamnose and glucose, in a proportion near to 3.2:2.3:1, respectively. Since glycerol had not been used in previous works, these findings suggest the potential of A. cryptum to produce biopolymers from this compound at a large scale with a low risk of microbial contamination due to the low pH of the fermentation process.

Virtual Clinical Simulation for Training Amongst Undergraduate Medical Students: A Pilot Randomised Trial (VIRTUE-Pilot).

BACKGROUND: Clinical virtual simulators are promising new technologies that might facilitate teaching clinical skills. OBJECTIVE: This study aimed to assess whether a virtual reality simulator might facilitate learning and improve adherence to current clinical guidelines. METHODOLOGY: A double-masked randomised trial was undertaken among fourth-year medical students at Universidad Andres Bello, Chile. Participants were randomised to a clinical virtual simulator (Body Interact®, Body Interact Inc., Austin, TX) or a small-group discussion session on the management of myocardial infarction. Main outcomes included performance in an objective structured clinical examination (OSCE) and adherence to clinical recommendations. Analyses were undertaken under the intention to treat principle by an independent statistician. RESULTS: Fifty students volunteered to participate. Most were female (30 students, 58.8%) and had a mean age of 23.0±2.7 years. Thirty-two participants (62.8%) had used virtual reality platforms before. Students allocated to the simulator showed better OSCE scores (mean difference: 2.8 points; 95% confidence interval (CI): -3.2 to +8.7 points, p=0.14) and were faster to implement diagnostic and therapeutic interventions, but not in a statistically significant way. DISCUSSION: Academic performance was slightly improved by the use the simulator, although the overall effect was smaller than expected. CONCLUSION:  This study examined the influence of a clinical virtual simulator on the academic performance and guideline adherence of undergraduate medical students, with small group discussions as a point of comparison. The findings revealed that there were no statistically significant distinctions between the two methods, potentially attributed to the selection of the comparator and the relatively brief intervention period.

SERS study on the aggregation mechanisms resulting from the orientation of dipyridinic derivatives on gold nanoparticles.

In this work, was studied the adsorption and orientation of three dipyridinic derivatives 9,10-bis-((E)-2-(pyridin-4-yl)vinyl)anthracene (DPAC), 1,4-bis-((E)-2-(pyridin-4-yl)vinyl)naphthalene (DPNA-T) and 2,6-bis-((E)-2-(pyridin-4-yl)vinyl)naphthalene (DPNA-L) on gold nanoparticles, using Surface Enhanced Raman Scattering (SERS). Systematic modification in the shapes of the bifunctional systems (Cross-shape, T-shape and Linear-shape) shows changes significant in the preferential orientation of these analytes on the nanostructured gold surface. Additional data from UV-vis measurements and TEM images are in agreement with the Reaction Limited Colloid Aggregation (RLCA) mechanisms for DPAC and DPNA-T and Diffusion Limited Colloid Aggregation (DLCA) mechanisms for DPNA-L, showing that for the same analyte concentration, the aggregation mechanism depends on the molecular shape. These results allow us to rationalize the fundamental aspects involved in the development of devices based on plasmonic resonance with potential applications in the field of molecular electronics.

[Salbutamol improves diaphragmatic contractility in chronic airway obstruction]. / El salbutamol mejora la contractilidad diafragmática en la obstrucción crónica de la vía aérea.

INTRODUCTION: Chronic airflow obstruction in conditions such as chronic obstructive pulmonary disease is associated with respiratory muscle dysfunction. Our aim was to study the effects of salbutamol-a beta-adrenergic agonist known to improve muscle strength in physiologic and pathologic conditions-on diaphragm contractility in an animal model of chronic airway obstruction achieved by tracheal banding. MATERIALS AND METHODS: Twenty-four Sprague-Dawley rats were randomized into a control group and 3 tracheal banding groups, 1 that received acute salbutamol treatment, 1 that received chronic salbutamol treatment, and 1 that received nothing. Arterial blood gases, acid-base balance, and in vitro diaphragmatic contractility were evaluated by measuring peak twitch tension, contraction time, contraction velocity, half-relaxation time, relaxation velocity, and force-frequency curves. RESULTS: The 3 study groups had significantly reduced arterial pH and increased PaCO2 and bicarbonate levels compared to the control group (P<.05). The untreated tracheal banding group had significantly reduced peak twitch tension and contraction velocity, and a significantly lower force-frequency curve in comparison with the other groups (P<.05). The chronic treatment group had a higher relaxation velocity than the untreated study group (P<.05). The mean (SE) peak twitch tension values were 6.46 (0.90)N/cm(2) for the control group, 3.28 (0.55)N/cm(2) for the untreated tracheal banding group, 6.18 (0.71)N/cm(2) for the acute treatment group, and 7.09 (0.59)N/cm(2) for the chronic treatment group. CONCLUSIONS: Diaphragmatic dysfunction associated with chronic airflow obstruction improves with both the acute and chronic administration of salbutamol. The mechanisms involved in respiratory muscle dysfunction warrant further study.

Estrés laboral en los intensivistas de Uruguay / Work stress among intensivists in Uruguay / Estresse ocupacional em médicos intensivistas no Uruguai

Resumen: Introducción: el estrés laboral (EL) se genera por experiencias en el ambiente laboral y por el relacionamiento con otros individuos. En la medicina intensiva, el desarrollo de los factores de estrés se ha vinculado principalmente a la relación del médico con el paciente en estado crítico, su familia, el equipo de trabajo así como con la realización de maniobras invasivas. El presente estudio tiene como objetivo conocer el nivel de estrés, así como determinar los factores asociados al desarrollo de estrés laboral. Metodología: en 2018 se realizó una encuesta a los intensivistas. Los niveles de estrés se midieron con el Inventario de Estrés para Profesionales de la Salud de Wolfgang y la Escala de Síntomas de Estrés. Resultados: se analizaron 96 respuestas de médicos intensivistas. La experiencia de estos en medicina intensiva es de 11 (6-22,75) años. La carga laboral semanal en UCI es de 48 (36-60) horas, correspondiendo a trabajo nocturno 24 (12-24) horas. El nivel de estrés total fue de 53 (44-65) puntos. Al discriminar de acuerdo al nivel de severidad encontramos que 5% presenta estrés mínimo, 63% estrés moderado y 32% estrés severo. Una carga laboral semanal mayor de 40 horas se asoció con el desarrollo de EL severo. Asimismo se evidenciaron mayores puntajes de EL en los intensivistas más jóvenes. Conclusiones: los médicos intensivistas presentan frecuentemente niveles elevados de estrés. Identificamos factores asociados al desarrollo del mismo. Es fundamental diseñar estrategias tendientes a reducir el impacto del EL en la UCI.

Abstract: Introduction: Work Stress (WS) is generated by interactions and experiences with other people in the work environment. In the Intensive Care Unit (ICU), the physician´s relationship with critical patients, and with their families, the work team and performing invasive procedures, have been identified as stress development factors. This study aims to explore stress levels, and to define the factors associated to work stress. Methods: in 2018, an online survey was sent to physicians working in the ICU. Stress levels were assessed using Wolfgang's Health Professionals Stress Inventory (HPSI) and the Stress Symptom Scale. Results: 96 responses by intensive care physicians were analysed. Average work experience was 11 (6-22.75) years. Intensivists workload is 48 hours a week at the ICU (36-60), 24 (12-24) of which were night shift hours. The total stress level was 53 (44-65) points. Stress levels found were: 5% minimal, 63% moderate and 32% high. A weekly workload greater than 40 hours was associated to the development of severe WS. Higher WS scores were seen in younger physicians. Conclusions: physicians working in the ICU frequently showed high levels of WS. This study identified the factors associated to its development. A recommendation is made to design strategies and policies that reduce the impact of WS on ICU physicians.

Resumo: Introdução: o estresse ocupacional (EO) é gerado por experiências no ambiente de trabalho e pelo relacionamento com outras pessoas. Na Medicina Intensiva, o desenvolvimento dos fatores de estresse tem estado vinculado principalmente à relação do médico com o paciente crítico, sua família, a equipe de trabalho, bem como a realização de manobras invasivas. O objetivo deste estudo é conhecer o nível de estresse, bem como determinar os fatores associados ao desenvolvimento do estresse ocupacional. Metodologia: em 2018, foi realizada uma pesquisa com médicos intensivistas. Os níveis de estresse foram medidos com o Inventário de Estresse de Profissionais da Saúde de Wolfgang e o Inventário de Sintomas de Estresse. Resultados: foram analisadas 96 respostas de médicos intensivistas. A experiência dos entrevistados como intensivistas é de 11 (6 a 22,75) anos. A carga horária semanal de trabalho em UTI é de 48 (36-60) horas, correspondendo a 24 (12-24) horas de trabalho noturno. O nível de estresse total foi de 53 (44-65) pontos. Ao discriminar de acordo com o nível de gravidade, encontramos que 5% apresentam estresse mínimo, 63% estresse moderado e 32% estresse severo. Uma carga de trabalho semanal superior a 40 horas foi associada ao desenvolvimento de EO grave. Da mesma forma, maiores escores de EO foram observados nos intensivistas mais jovens. Conclusões: os médicos intensivistas frequentemente apresentam altos níveis de estresse. Identificamos fatores associados ao seu desenvolvimento. É fundamental traçar estratégias para reduzir o impacto do EO na UTI.

Neumonitis lúpica con derrame pleural refractario: Pneumonitis lupica with pleural effusion refractory

RESUMEN: El Lupus Eritematoso Sistémico suele afectar el aparato respiratorio, en un 70% de los casos, siendo la pleuritis la manifestación más frecuente, con o sin derrame pleural. Es en general unilateral, autolimitado y con buena respuesta al tratamiento. Presentamos el caso de una pacientes que debuta con lupus eritematoso sistémico con extenso compromiso respiratorio que interpretamos como una neumonitis lúpica asociado a derrame pleural bilateral refractario al tratamiento corticoideo e inmunosupresor intenso.

ABSTRACT Systemic Lupus Erythematosus usually affects the respiratory system, 70% of cases, pleurisy being the most common manifestation, with or without pleural effusion. It is unilateral, self-limited and generally good response to treatment. We present the case of patients with Systemic Lupus Erythematosus debut with extensive respiratory compromise interpret as a lupus pneumonitis associated with bilateral pleural effusion refractory to corticosteroid and immunosuppressive therapy intense.