Water-soluble organic carbon (WSOC) makes up a large mass fraction of the organic carbon in the aerosol and can influence important cloud processes in the atmosphere. The capacity of WSOC to form metallic complexes with transition metals is well known; however, its influence on the aerosol of urban areas in the Amazon region is not very well known. In this study, we investigated the relationship between WSOC, black carbon (BC), levoglucosan (LEV) and transition metals (Fe, Cu and Mn) present in the PM2.5 (particles with a diameter smaller than 2.5 µm) of an urban environment during the dry season in the central Amazon. Oxalic acid (C2) was used to identify the influence of transition metals on WSOC. The mean mass concentration value of the PM2.5 was 14.72 μg m-3 (2.11-31.68 μg m-3). The WSOC made up 58.34% of the PM2.5 mass, followed by BC (20.28%), and LEV (2.62%). The WSOC showed significant correlation with the transition metals analyzed (> 0.56), especially Mn with C2 (linear coefficient (R2) = 0.74). A multiple linear regression with WSOC, BC and LEV showed a strong linear correlation between them (R2 = 0.86), indicating the influence of biomass burning and vehicle traffic on the organic aerosol.

Abstract Background: GlobalSurg is an international group of researchers whose purpose is to conduct and disseminate robust collaborative, international and multicenter studies. Objective: To expose the necessary strategies and the barriers crossed in conducting massive multicenter studies in surgery. Method: During the second semester of 2020, the study Surg-Week Prospective International Cohort Study was carried out. Surg-Week has been the largest international study in the field of surgery to date, with 141,582 patients included. A total of 4975 mini-teams, of between 1 and 5 members, collected data from 116 countries on all continents. Results: The creation of an official website for the study, reports with relevant information via email or groups via WhatsApp, formation of a Dissemination Committee of the protocol, delivery of webinars on recent team publications, appointment of leaders at the national and international level, and outreach through partnerships, were the strategies used for the development of the research. However, the barriers turned out to involve different aspects. Conclusions: Collaborative work allows establishing networks between different professionals with the goal of improving the quality of management, health policies and care of our patients in a timely manner of constant change.

Resumen Antecedentes: GlobalSurg es un grupo internacional de investigadores que tiene como propósito la conducción y la diseminación de robustos estudios colaborativos, internacionales y multicéntricos. Objetivo: Exponer las estrategias necesarias y las barreras encontradas en la conducción de estudios multicéntricos masivos en cirugía. Método: Durante el segundo semestre del año 2020 se llevó a cabo el estudio Surg-Week Prospective International Cohort Study, hasta la fecha el estudio internacional más grande en el campo de la cirugía, con 141,582 pacientes incluidos. Un total de 4975 miniequipos, de uno a cinco integrantes, recopilaron datos de 116 países de todos los continentes. Resultados: La creación de un sitio web oficial del estudio, reportes con información relevante vía e-mail o grupos vía WhatsApp, conformación de un comité de diseminación del protocolo, dictado de webinars sobre publicaciones recientes del equipo, designación de líderes nacionales e internacionales, y la divulgación por medio de sociedades, fueron las estrategias utilizadas para el desarrollo de la investigación. Sin embargo, las barreras detectadas para llevar a cabo el estudio multicéntrico fueron variadas. Conclusiones: Los trabajos colaborativos permiten establecer redes entre diferentes profesionales con el fin de mejorar la calidad de la gestión, las políticas sanitarias y la atención a los pacientes en tiempos de constante cambio.

Abstract Aim: This study aimed to verify and compare the effects of 10 weeks of combined exercise training on the heart rate variability of normotensive (NT) and hypertensive (HT) postmenopausal women. Methods: This is a quasi-experimental controlled clinical trial. Therefore, 14 HT and 12 NT postmenopausal women completed 10 weeks of combined exercise training. The exercise protocol consisted of 45 min of exercise, performed 3 times a week, consisting of 5 min of warm-up, 20 min of resistance exercise, and 20 min of aerobic exercise. Heart rate variability assessments were performed before and after the end of physical training. Results: Heart rate variability was assessed pre- and post-training periods. Mean RR (δNT = 95 ± 88; δHT = 38 ± 127), SDNN (δNT = 9 ± 13; δHT = 3 ± 14), RMSSD (δNT = 10 ± 12; δHT = 2 ± 18), SD1 (δNT = 7 ± 8; δHT = 1 ± 13), and SD2 (δNT = 10 ± 18; δHT = 4 ± 17) showed improvements after the intervention (time effects p < 0.05). No parameters presented group or interaction effects (p ≥ 0.05). Conclusion: In summary, 10 weeks of combined exercise training improved heart rate variability parameters similarly in both NT and HT postmenopausal women. Therefore, combined exercise training may be used to improve autonomic modulation of the heart rate of postmenopausal women, regardless of the presence of hypertension.

OBJETIVO: A Mielopatia Cervical Espondilótica (MCE) é uma disfunção da medula espinhal relacionada à degeneração típica do envelhecimento. No estudo de imagem podemos obter a medida do Índice de Torg, para estimar a estenose cervical. Objetivamos, assim, medir o Índice de Torg através de radiografia e ressonância magnética (RM), possibilitando verificar possíveis discrepâncias entre os métodos de medida. MÉTODOS: Realizada mensuração do Índice de Torg na radiografia e na RM da coluna cervical, sendo obtido através da relação entre a superfície posterior do corpo vertebral e o ponto mais próximo à linha laminar correspondente, dividido pelo diâmetro sagital do corpo vertebral. RESULTADOS: Participaram 29 pacientes, sendo 10 mulheres e 19 homens, com médias de idade 48,1 ± 11 anos, de peso 68,7 ± 5 Kg e de altura 1,68 ± 0,6 m. Houve diferença significativa entre o Índice de Torg calculado através de radiografia e RM, sendo menores os índices observados na RM (radiografia: 0,73 ± 0,17 vs. RM: 0,48 ± 0,14, p< 0,05). No entanto, ambas as aferições traduzem o mesmo resultado: estenose cervical absoluta (Índice de Torg < 0,8). CONCLUSÕES: Nossos resultados corroboram relatos de outros autores que acreditam que o Índice de Torg medido através da radiografia, como preconizado, minimiza a real estenose do canal cervical. Sugerimos em nosso estudo que a RM permite melhor estimativa do grau de estenose do canal, muito embora nossos resultados em relação ao grau de estenose cervical tenham sido semelhantes estatisticamente.

OBJECTIVE: Cervical spondylotic myelopathy (SCM) is a dysfunction related to spinal cord degeneration typical of aging. In the imaging studies can achieve a measure of the Torg index to estimate cervical stenosis. We aim therefore to measure the Torg index in X-rays and Magnetic Resonance (MR), to investigate possible discrepancies between the methods of measurement. METHODS: The Torg Index was measured on radiographs and MR of the cervical spine, obtained by determining the relationship between the posterior surface of the vertebral body and the nearest point to the corresponding laminar line, divided by the sagittal diameter of vertebral body. RESULTS: A total 29 patients has participated, 10 women and 19 men, with mean age of 48.1 ± 11 years, weight 68.7 ± 5kg and height 1.68 ± 0.6m. There were significant differences between the Torg Index calculated by radiography and MR, and lower rates observed on MR (radiography: 0.73 ± 0.17 vs. RM: 0.48 ± 0.14, p <0.05). However, both measurements reflect the same result: absolute cervical stenosis (Torg index < 0.8). CONCLUSIONS: Our results confirm reports by other authors who believe that the Torg Index measured by radiography, as recommended, minimizes the actual cervical canal stenosis. Our study suggests that MRI allows better estimate of the degree of stenosis, although our results regarding the degree of cervical stenosis were statistically similar.

OBJETIVO: La Mielopatía Cervical Espondilótica (MCE) es un trastorno relacionado con la degeneración de la médula espinal, típica del envejecimiento. En el estudio de imagen se puede obtener la medida del Índice de Torg para estimar la estenosis cervical. Nuestro objetivo es, por tanto, medir el índice de Torg mediante rayos-X y resonancia magnética (RM), posibilitando verificar posibles discrepancias entre los métodos de medición. MÉTODOS: Se realiza la medición del Índice de Torg en la radiografía y en la resonancia magnética de la columna cervical, siendo obtenido mediante la determinación de la relación entre la superficie posterior del cuerpo vertebral y el punto más cercano a la línea de la lámina correspondiente, dividido por el diámetro sagital del cuerpo vertebral. RESULTADOS: Participó un total de pacientes 29, siendo 10 mujeres y 19 hombres, edad promedio de 48,1 ± 11 años, peso 68,7 ± 5 Kg y altura de 1,68 ± 0,6 m. No hubo diferencias significativas entre el Índice de Torg calculado por la radiografía y el de la resonancia magnética, siendo menores los índices observados en la RM (radiografía: 0,73 ± 0,17 vs RM: 0,48 ± 0,14, p <0,05). Sin embargo, ambas mediciones reflejan el mismo resultado: estenosis cervical absoluta (Índice de Torg <0,8). CONCLUSIONES: Nuestros resultados confirman los informes de otros autores quienes creen que el Índice de Torg medido por radiografía, como se recomienda, minimiza la estenosis real del canal cervical. En nuestro estudio se sugiere que la RM permite hacer una mejor estimativa del grado de estenosis del canal, aunque nuestros resultados, sobre el grado de estenosis cervical, fueron estadísticamente similares.

A analgesia preemptiva inibe a progressão da dor causada por lesão cirúrgica. Para analisar o efeito da lidocaína na diminuição da dor pós-operatória, submetemos ratos Wistar a compressão cirúrgica do nervo ciático e observamos diferenças em alguns padrões de comportamento entre o grupo tratado com lidocaína pré-operatória e o grupo não-tratado com o anestésico local. O grupo 1 não foi operado (controle); o grupo 2, submetido a ligadura do nervo ciático sem lidocaína, apresentou significativo aumento do tempo de coçar-se com um pico no 14º pós-operatório (p=0.0005) e redução na latência para os estímulos térmicos nocivo (p=0.003) e não-nocivo (p=0.004); o grupo 3, operado com a droga preemptiva, demonstrou significativo decréscimo no tempo de coçar-se (p=0.004) e maiores tempos de latência quando comparados aos do grupo 2. O uso preemptivo da lidocaína 2% pode, potencialmente, reduzir a dor neuropática pós-operatória associada à compressão do nervo ciático.

Preemptive analgesia inhibits the progression of pain caused by surgical lesions. To analyze the effect of lidocaine on postoperative pain relief, we performed compression of the right sciatic nerve in Wistar rats and observed the differences on behavior between the group that received lidocaine and the group that was not treated with the local anesthetics pre-operatively. Group 1 was not operated (control); group 2 underwent the sciatic nerve ligature without lidocaine; group 3, underwent surgery with previous local infiltration of lidocaine. Group 2 showed significantly longer scratching times with a peak on day 14 post-operative (p=0.0005) and reduction in the latency to both noxious (p=0.003) and non-noxious (p=0.004) thermal stimulus. Group 3 presented significantly shorter scratching times (p=0.004) and longer latency times when compared to Group 2. Preemptive use of lidocaine 2% can potentially reduce the postoperative neuropathic pain associated with sciatic nerve compression.