Pancreatic neuroendocrine tumors: Are tumors smaller than 2 cm truly indolent?

BACKGROUND: Pancreatic neuroendocrine tumors (PNETs) are relatively rare but rank as the second most common pancreatic neoplasm. They can be functional, causing early metabolic disturbances due to hormone secretion, or non-functional and diagnosed later based on tumor size-related symptoms. Recent diagnoses of PNETs under 2 cm in size have sparked debates about their management; some practitioners advocate for surgical removal and others suggest observation due to the tumors' lower potential for malignancy. However, it is unclear whether managing these small tumors expectantly is truly safe. AIM: To evaluate poor prognostic factors in PNETs based on tumor size (> 2 cm or < 2 cm) in surgically treated patients. METHODS: This cohort study included 64 patients with PNETs who underwent surgical resection between 2006 and 2019 at a high-complexity reference hospital in Medellín, Colombia. To assess patient survival, quarterly follow-ups were conducted during the first year after surgery, followed by semi-annual consultations at the hospital's hepatobiliary surgery department. Qualitative variables were described using absolute and relative frequencies, and quantitative variables were expressed using measures of central tendency and their corresponding measures of dispersion. RESULTS: The presence of lymph node involvement, neural involvement, and lymphovascular invasion were all associated with an increased risk of mortality, with hazard ratios of 5.68 (95%CI: 1.26-25.61, P = 0.024), 6.44 (95%CI: 1.43-28.93, P = 0.015), and 24.87 (95%CI: 2.98-207.19, P = 0.003), respectively. Neural involvement and lymphovascular invasion were present in tumors smaller than 2 cm in diameter and those larger than 2 cm in diameter. The recurrence rates between the two tumor groups were furthermore similar: 18.2% for tumors smaller than 2 cm and 21.4% for tumors larger than 2 cm. Patient survival was additionally comparable between the two tumor groups. CONCLUSION: Tumor size does not dictate prognosis; lymph node and lymphovascular involvement affect mortality, which highlights that histopathological factors-rather than tumor size-may play a role in management.

Urinary Cysteinyl Leukotrienes as Biomarkers of Endothelial Activation, Inflammation and Oxidative Stress and Their Relationship with Organ Dysfunction in Human Septic Shock.

Cysteinyl leukotrienes (CysLT) are potent vascular leakage-promoting agents but have been scarcely explored in human septic shock (SS). We evaluated CysLT at admission and during hospitalization and their correlation with endothelial dysfunction, inflammation, oxidative stress, the renin-angiotensin-aldosterone system, and cardiac, renal, respiratory, and hepatic parameters in SS patients. Blood and spot-urine samples were collected at days 1-2 (admission), 3-4, and 5-8 in SS patients (n = 13) and at a single time point in controls (n = 22). Urinary CysLT (u-CysLT) and isoprostanes, plasma, and urinary angiotensinogen, serum myeloperoxidase, and IL-10 were quantified by ELISA. Serum intercellular-adhesion molecule-1, vascular cell-adhesion molecule-1, E-selectin, tumor necrosis factor-α, IL-1ß, and IL-6 were measured by multiplex immunoassays. Routine markers were evaluated using automated analyzers. At admission, SS patients had increased u-CysLT, endothelial activation, inflammation, oxidative stress, and plasma and urinary angiotensinogen, as well as cardiac, respiratory, hepatic, and renal injury/dysfunction. There were no changes in u-CysLT during hospitalization. Both correlation and multivariate analyses showed positive relationships of u-CysLT with endothelial activation, inflammation, oxidative stress, proteinuria, and hepatic injury/dysfunction markers. These results suggest that u-CysLT may be potential non-invasive biomarkers for monitoring the pathophysiological mechanisms underlying SS, as well as putative therapeutic targets.

Sex Differences and Predictors of In-Hospital Mortality among Patients with COVID-19: Results from the ANCOHVID Multicentre Study.

Spain is one of the countries most affected by the COVID-19 pandemic. Although risk factors for severe disease are published, sex differences have been widely neglected. In this multicentre study, we aimed to identify predictors of in-hospital mortality in men and women hospitalised with COVID-19. An observational longitudinal study was conducted in the cohort of patients admitted to four hospitals in Andalusia, Spain, from 1 March 2020 to 15 April 2020. Sociodemographic and clinical data were collected from hospital records. The Kaplan-Meier method was used to estimate 30-day survival and multiple Cox regression models were applied. All analyses were stratified by sex. A total of 968 patients were included (54.8% men, median age 67.0 years). In-hospital mortality reached 19.1% in men and 16.0% in women. Factors independently associated with an increased hazard of death were advanced age, higher CURB-65 score and not receiving azithromycin treatment, in both sexes; active cancer and autoimmune disease, in men; cardiovascular disease and chronic lung disease, in women. Disease outcomes and predictors of death differed between sexes. In-hospital mortality was higher in men, but the long-term effects of COVID-19 merit further research. The sex-differential impact of the pandemic should be addressed in public health policies.

Sequelae, persistent symptomatology and outcomes after COVID-19 hospitalization: the ANCOHVID multicentre 6-month follow-up study.

BACKGROUND: Long-term effects of COVID-19, also called Long COVID, affect more than 10% of patients. The most severe cases (i.e. those requiring hospitalization) present a higher frequency of sequelae, but detailed information on these effects is still lacking. The objective of this study is to identify and quantify the frequency and outcomes associated with the presence of sequelae or persistent symptomatology (SPS) during the 6 months after discharge for COVID-19. METHODS: Retrospective observational 6-month follow-up study conducted in four hospitals of Spain. A cohort of all 969 patients who were hospitalized with PCR-confirmed SARS-CoV-2 from March 1 to April 15, 2020, was included. We collected all the SPS during the 6 months after discharge reported by patients during follow-up from primary care records. Cluster analyses were performed to validate the measures. The main outcome measures were return to the Emergency Services, hospital readmission and post-discharge death. Surviving patients' outcomes were collected through clinical histories and primary care reports. Multiple logistic regression models were applied. RESULTS: The 797 (82.2%) patients who survived constituted the sample followed, while the rest died from COVID-19. The mean age was 63.0 years, 53.7% of them were men and 509 (63.9%) reported some sequelae during the first 6 months after discharge. These sequelae were very diverse, but the most frequent were respiratory (42.0%), systemic (36.1%), neurological (20.8%), mental health (12.2%) and infectious (7.9%) SPS, with some differences by sex. Women presented higher frequencies of headache and mental health SPS, among others. A total of 160 (20.1%) patients returned to the Emergency Services, 35 (4.4%) required hospital readmission and 8 (1.0%) died during follow-up. The main factors independently associated with the return to Emergency Services were persistent fever, dermatological SPS, arrythmia or palpitations, thoracic pain and pneumonia. CONCLUSIONS: COVID-19 cases requiring hospitalization during the first wave of the pandemic developed a significant range of mid- to long-term SPS. A detailed list of symptoms and outcomes is provided in this multicentre study. Identification of possible factors associated with these SPS could be useful to optimize preventive follow-up strategies in primary care for the coming months of the pandemic.

Mindfulness-based mobile app reduces anxiety and increases self-compassion in healthcare students: A randomised controlled trial.

OBJECTIVE: To compare the effect of a mindfulness-based mobile application versus an in-person mindfulness-based training program in terms of reducing anxiety and increasing empathy, self-compassion, and mindfulness in a population of healthcare students. METHODS: The authors conducted a single-blind, randomised controlled trial with three parallel groups. Participants were allocated to the mobile app, the in-person mindfulness-based program (IMBP), or a control group. Assessments at baseline and postintervention (8 weeks) included measures of anxiety, empathy, self-compassion, and mindfulness. RESULTS: Of 168 students randomised, 84 were analysed on an intention-to-treat basis (app: n = 31; IMBP: n = 23; control: n = 30). The mobile app group showed a large effect size for reductions in trait anxiety compared with controls (g = 0.85, p = 0.003), and a medium, nonsignificant effect compared with the IMBP group (g = 0.52, p = 0.152). Participants from both interventions experienced a significant increase in self-compassion and mindfulness compared with controls. Levels of empathy remained unchanged for the 3 arms. CONCLUSIONS: A mobile app can be as effective as an IMBP in reducing anxiety and increasing self-compassion and mindfulness among healthcare students.

Resección hepática en metástasis de cáncer colorrectal, análisis de supervivencia de una cohorte de pacientes en el Hospital Pablo Tobón Uribe / Hepatic resection of metastases in colorectal cancer, survival analysis in a cohort of patients at Pablo Tobón Uribe Hospital, Medellín, Colombia

Introducción. La resección hepática sigue siendo la única opción de tratamiento con intención curativa y con posibilidad de supervivencia a largo plazo. El objetivo del estudio fue evaluar los resultados de la resección hepática en un grupo de pacientes. Métodos. Se llevó a cabo un estudio descriptivo retrospectivo de una serie consecutiva de 97 hepatectomías por metástasis de cáncer colorrectal, en el período comprendido entre el 15 de junio de 2005 y el 30 diciembre de 2015, en el Hospital Pablo Tobón Uribe de Medellín. Se hizo análisis bivariado de los factores asociados a la supervivencia. Resultados. De 370 hepatectomías, se practicaron 97 resecciones hepáticas en 93 pacientes por metástasis de cáncer colorrectal. El promedio de edad fue de 58 años, y el 50,5 % fueron resecciones hepáticas mayores. La mediana del volumen de sangrado intraoperatorio fue de 200 ml (rango intercuartílico, RIQ: 100 a 400 ml) y la mediana del tiempo quirúrgico fue de 150 minutos (RIQ: 120 a 180 minutos). La estancia hospitalaria tuvo una mediana de 3 días (RIQ: 2 a 4 días). Solo se trasladó a la unidad de cuidados intensivos el 25,9 % de los pacientes; se presentaron complicaciones en 21,5 % de los pacientes. La mortalidad perioperatoria a 90 días fue de 2,06 %. Se cumplió con el protocolo quirúrgico de recuperación rápida (Fast Track Surgery) en 54,8 % de los pacientes. La supervivencia global a cinco años fue de 34,5 % y, a 100 meses, de 23 %. Debido a que no se encontró significancia estadística con ninguna de las variables en el análisis bivariado para supervivencia, no se hizo un análisis multivariado. Conclusiones. La resección hepática en pacientes con metástasis de cáncer colorrectal se puede practicar en nuestro medio de manera segura, con morbilidad, mortalidad y resultado oncológico comparables a los de otras series del mundo

Introduction. Hepatic resection remains the only treatment option with curative intent and long-term survival in colorectal liver metastasis. The aim of this study is to evaluate the outcomes of hepatic resection in this group of patients. Methods. A retrospective descriptive study of a consecutive series of 97 hepatectomies due to colorectal cancer metastases in the period between June 2005 and December 2015 at the Pablo Tobón Uribe Hospital in Medellín. Bivariate analysis was performed on factors associated with survival. Results. Of a total of 370 hepatectomies, 97 liver resections were performed in 93 patients due to colorectal cancer metastases. The mean age was 58 years, 50.5% were major liver resections. The median intraoperative bleeding was 200 ml (RIQ 100-400 ml) and the median surgical time was 150 minutes (RIQ 120-180 min). The hospital stay had a median of 3 days (RIQ 2-4 days). Only 25.9% of the patients were transferred to the intensive care unit. Complications occurred in 21.5% of patients. Perioperative mortality at 90 days was 2.06%. A fast track protocol was performed in 54.8% of the patients. The 5-year actuarial survival was 34.5% and at 100 months it was 23%. Because no statistical significance was found with any of the variables in the bivariate analysis for survival, no multivariate analysis was performed. Conclusions. Liver resection in patients with colorectal cancer metastases can safely be performed in our setting, with morbidity, mortality and cancer outcomes comparable to the other series in the world

Definición de nanomateriales para Colombia / Definition of Nanomateriais for Colombia / Definição de nanomateriais para a Colômbia

Debido a la creciente producción y uso de nanomateriales para actividades de investigación y desarrollo en Colombia, es necesario establecer una definición del término nanomaterial que facilite la toma de decisiones en torno a iniciativas de carácter regulatorio y de normatividad. Se presenta la definición de nanomateriales para Colombia que ha adoptado el Consejo Nacional Asesor de Nanociencia y Nanotecnología adscrito a la Red Colombiana de Nanociencia y Nanotecnología.

Due to the increasing production and use of nanomaterials in research and development activities in Colombia, it is necessary to define the nanomaterial term in order to facilitate decision-making process regarding initiatives with a regulatory or normative character. This article presents the nanomaterials definition that has been adopted by the National Advisory Council for Nanoscience and Nanotechnology, a Colombian Network of Nanoscience and Nanotechnology.

Dada a crescente produção e utilização de nanomateriais para a pesquisa e desenvolvimiento na Colombia, é urgente estabelecer uma definição do termo de nanomaterial para facilitar a tomada de decisão sobre iniciativas na regulamentação e as leis. É apresentada uma definição de nanomateriais para a Colombia que aprovou o Conselho Consultivo Nacional de Nanociência e Nanotecnologia ligado à Rede Colombiana de Nanociência e Nanotecnologia.

Determination of lead in biomass and products of the pyrolysis process by direct solid or liquid sample analysis using HR-CS GF AAS.

A method has been developed for the determination of lead in biomass, bio-oil, pyrolysis aqueous phase, and biomass ashes by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) and direct solid or liquid sample analysis. All measurements were performed without chemical modifier and calibration could be carried out using aqueous standard solutions. A pyrolysis temperature of 800°C and an atomization temperature of 2200°C were applied. The limits of detection and quantification were, respectively, 0.5 µg kg(-1) and 2 µg kg(-1) using the analytical line at 217.001 nm and 6 µg kg(-1) and 19 µg kg(-1) at 283.306 nm. The precision, expressed as relative standard deviation, was between 3% and 10%, which is suitable for direct analysis. The lead concentrations found for the solid samples varied between 0.28 and 1.4 mg kg(-1) for biomass and between 0.25 and 2.3 mg kg(-1) for ashes, these values were much higher than those found for bio-oil (2.2-16.8 µg kg(-1)) and pyrolysis aqueous phase (3.2-18.5 µg kg(-1)). After the determination of lead in the samples, it was possible to estimate the relative distribution of this element in the fractions of the pyrolysis products, and it was observed that most of the lead present in the biomass was eliminated to the environment during the pyrolysis process, with a significant portion retained in the ashes.

Análisis de la mortalidad posoperatoria temprana en una cohorte de 132 pacientes sometidos a cirugía de Whipple en Medellín / Analysis of the early postoperative mortality in 132 patients that underwent the Whipple procedure at a hospital in Medellin, Colombia

Introducción. La pancreaticoduodenectomía es una cirugía compleja con alta morbilidad y una mortalidad que ha venido disminuyendo en las últimas décadas. El objetivo del estudio fue determinar los factores asociados a la mortalidad posoperatoria temprana de los pacientes sometidos a cirugía de Whipple. Materiales y métodos. De la base de datos prospectiva de la Unidad de Cirugía Hepatobiliar y Pancreática, se incluyeron todos los pacientes en quienes se practicó la cirugía de Whipple en el Hospital Pablo Tobón Uribe de Medellín, en el periodo comprendido entre junio de 2004 y junio de 2013. Se hizo el análisis bivariado y multivariado de los factores asociados a la mortalidad posoperatoria temprana, definida como la muerte durante los primeros 30 días del periodo posoperatorio. Resultados. Se practicaron 132 cirugías de Whipple. Como factores asociados a mortalidad posoperatoria a 30 días, con significancia estadística en el análisis bivariado, se encontraron: sangrado operatorio (p=0,014), pH intraoperatorio (p=0,006), amilasa en el drenaje en el primer día posoperatorio (p=0,012) y cuarto día posperatorio (p=0,023), y proteína C reactiva al quinto día posoperatorio (p=0,036). En el análisis multivariado se encontró el sangrado mayor de 300 ml, bicarbonato de menos de 22,2 mEq/L en el día 1 posoperatorio, pH intraoperatorio menor de 7,34 y amilasa en el drenaje en el primer día posoperatorio menor de 2.500 U/ml, como los factores asociados a mortalidad temprana, aunque sin lograr significancia estadística. Discusión. El seguimiento y análisis riguroso de la evolución de los pacientes sometidos a pancreaticoduodenectomía, permite establecer que en nuestro medio se pueden conseguir resultados comparables a los de otras series en centros especializados del mundo e identificar factores asociados a la mortalidad posoperatoria para detectar aspectos en los cuales la calidad de la atención médica puede ser mejorada.

Introduction: Pancreaticoduodenectomy is a complex operation with high morbidity and mortality rates, which have been declining in recent decades . The objective of the study was to determine factors associated with early postoperative mortality in patients undergoing the Whipple procedure. Materials and Methods: A descriptive study of a consecutive series of patients who underwent Whipple surgery at Pablo Tobon Uribe Hospital, Medellin, Colombia, in the period from June 2004 to June 2013 was performed, with bivariate and multivariate analysis of factors associated with early postoperative mortality (defined as death during the first 30 days postoperatively). Results: The 132 Whipple procedure was performed during the study time, period. The factors associated with postoperative 30-day mortality with statistical significance in the bivariate analysis were: operative bleeding (p = 0.014 ), intraoperative pH (p = 0.006 ), amylase value in the drainage in the first postoperative day (p = 0.012 ) and fourth postoperative day (p = 0.023 ) , and C reactive protein ( CRP ) on the fifth postoperative day (p = 0.036 ) . Multivariate analysis showed intraoperative bleeding of more than 300 ml, bicarbonate levels less than 22.2 mmol/L on postoperative day 1, intraoperative pH less than 7.34, and amylase value in the drainage on postoperative day 1 less than 2500 U / ml, as the factors associated with early mortality, although not achieving statistical significance. Discussion: Rigorous monitoring and outcome analysis of patients undergoing pancreaticoduodenectomy in our environment can get comparable results to those of other series in specialized centers around the world and identifying factors associated with postoperative mortality serve to detect points where quality of care can be improved .

Sequential determination of Cd and Cr in biomass samples and their ashes using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis.

High-resolution continuum source graphite furnace atomic absorption spectrometry, because of the use of only one radiation source for all elements, offers the possibility of sequential determination of two or more elements from the same sample aliquot if their volatilities are significantly different. Cd and Cr were determined sequentially in samples of biomass and biomass ashes employing direct solid sample analysis. The use of a chemical modifier was found to be not necessary, and calibration could be carried out using aqueous standard solutions. A pyrolysis temperature of 400°C and an atomization temperature of 1500°C were used for the determination of Cd; no losses of Cr were observed at this temperature. After the atomization of Cd the wavelength was changed and Cr atomized at 2600°C. The limits of detection (LOD) and quantification (LOQ) were 1.1 µg kg(-1) and 3.7 µg kg(-1), respectively, for Cd and 21 µg kg(-1) and 70 µg kg(-1), respectively, for Cr using the most sensitive line at 357.869 nm, or 90 µg kg(-1) and 300 µg kg(-1), respectively, using the less sensitive line at 428.972 nm. The precision, expressed as relative standard deviation was around 10%, which is typical for direct solid sample analysis. The values found for Cd in biomass samples were between <1.1 µg kg(-1) and 789 µg kg(-1), whereas those for Cr were between 7.9 mg kg(-1) and 89 mg kg(-1); the values found in the ashes were significantly lower for Cd, between <1.1 µg kg(-1) and 6.3 µg kg(-1), whereas the trend was not so clear for Cr, where the values were between 3.4 mg kg(-1) and 28 mg kg(-1).

Evaluación y seguimiento de los pacientes sometidos a operación de Whipple o duodenopancreatectomía cefálica en un hospital de IV nivel de Medellín / Evaluation and follow-up of patients undergoing the Whipple procedure (cepahalic pancreatoduodenectomy) at a level IV of care hospital in Medellín Colombia

Objetivo. Evaluar las indicaciones, resultados y supervivencia de los pacientes sometidos a duodenopancreatectomía cefálica en el Hospital Pablo Tobón Uribe de Medellín. Pacientes y métodos. Se incluyeron todos los pacientes sometidos a duodenopancreatectomía cefálica (operación de Whipple), desde abril de 2004 hasta abril de 2011. La información se obtuvo de la base de datos prospectiva de la Unidad de Cirugía Hepato-Biliar y Pancreática del Hospital Pablo Tobón Uribe. Resultados. Se operaron 68 pacientes, con una edad promedio de 59 años (rango, 16-82) y 50 % eran hombres. La principal indicación de la cirugía fue neoplasia maligna (97 %), con la siguiente distribución: adenocarcinoma pancreático, 25 pacientes (36,7 %); carcinoma ampular, 23 (33,8 %); colangiocarcinoma distal, 8 (11,7 %) cáncer de duodeno, 4 (5,8 %), y 8 (11,7 %) tuvieron otras indicaciones. El sangrado operatorio en promedio fue de 455 ml (rango, 200 a 2.000 ml); 5,8 % de los pacientes sangraron 1.000 ml o más; en 35,2 % de los casos se requirió transfusión de glóbulos rojos, con un rango entre 1 y 8 unidades; 5,8 % de los pacientes requirió cinco o más unidades de glóbulos rojos. El rango de estancia en la unidad de cuidados intensivos fue 1 a 20 días, con un promedio de 2 días; 45,5 % de los pacientes estuvo en la unidad de cuidados intensivos un solo día. Se presentaron complicaciones en el 33,8 % de los pacientes, y las más comunes fueron atonía gástrica, infección distante al sitio operatorio, infección del sitio operatorio y sangrado posoperatorio. La mortalidad posoperatoria a 30 días fue de 14,7 % en toda la serie; al hacer un análisis del último grupo de 25 pacientes, la cifra bajó a 8 %, con una supervivencia actuarial de toda la serie de pacientes de 54,4 %. Conclusión. En nuestro hospital, la duodenopancreatectomía cefálica sigue teniendo alta mortalidad en comparación con algunos centros de referencia en el mundo, aunque es evidente que ha mejorado en los últimos años; las cifras de morbilidad están acordes a las reportadas en diferentes series mundiales de excelencia.

Introduction: Objective: To evaluate the indications, results and survival of patients undergoing pancreatoduodenectomy at Hospital Pablo Tobon Uribe of Medellin. Materials and methods: We collected all patients that underwent pancreatoduodenectomy (Whipple operation), from April 2004 to April 2011. The information was obtained from a prospective database from the Hepato-Biliary and Pancreatic Unit of Hospital Pablo Tobón Uribe. Results: 68 patients were operated in total, with an average age of 59 years (16-82), 50% were men; the main indication for surgery was malignant disease (97%), with the following distribution: 25 patients with pancreatic adenocarcinoma ( 36.7%), 23 patients with ampullary carcinoma (33.8%), 8 with distal cholangiocarcinoma (11.7%), 4 patients with duodenal cancer (5.8%) and 11.7% with other indications. Average bleeding at surgery was 455 ml (200-2000ml), 5.8% of patients bled 1000 ml or more, 35.2% of cases required transfusion of red blood cells, with a range of 1-8 units, 5.8% of patients required 5 or more units of red cells. The range of ICU stay was 1-20 days, with an average of 2 days, 45.5% of these patients just stayed one day. Complications occurred in 33.8% of patients, the most common was gastric atony, distant infection and postoperative bleeding. Postoperative mortality at 30 days was 14.7% in the whole series, with an analysis of the last group of 25 patients, the number dropped to 8%, with an actuarial survival of the entire series of 54.4%. Conclusions: In our hospital, pancreatoduodenectomy mortality is still high compared to some reference centers in the world, but clearly has improved in recent years, morbidity results are consistent with those reported in centers of excellence around the world.

Síntesis y caratterización de un cuadrado supraolecular a partir del auto-ensaamblaje del complejo [1,2-bis(difenilfosfino)etano] bistrifluorometanosulfonato paladio (ii) y 4,4'-bipiridina / Synhesis and chaaracterization of asupramolecular square from the self-assembly between the complex [1,2-bis(diphenylphosphino) ethane] bistrifluoromethanesulfonate palladium (ii) and 4,4'-bipyridine / Síntese e cracteerização de um quadrado supramolecular a partir da automontagem do complexo [1,2-bis(difenilfosfino)etano] bistrifluorometanosulfonato paládio (ii) e 4,4'-bipiridina

Por primera vez se desarrolló la síntesis y caracterización (IR, UV, RMN-¹H, 31P, 19F) de un nuevo cuadrado supramolecular [3] mediante el auto-ensamblaje del complejo [Pd(CF3SO3)2(Dppe)] [1] y el ligando orgánico 4,4'-Bipiridina [2]. Se evidenció la obtención de [3] en mezcla con otra especie supramolecular [4], asignada como un macrociclo triangular. Las estructuras de [3] y [4] se elucidaron con base en los desplazamientos químicos, la proporcionalidad entre sus integrales y en los patrones de acoplamiento de las señales en los espectros RMN-¹H y COSY ¹H-¹H. Mediante la relación entre las integrales de las señales correspondientes a las especies supramoleculares coexistentes en los espectros RMN-¹H y 31P se determinó la composición de la mezcla al final de la reacción conteniendo 70 % de [3] y 30 % de [4].

For the first time we synthesized and characterized (IR, UV, NMR ¹H, 31P, 19F), a new supramolecular square [3] by the self-assembly of complex [Pd(CF3SO3)2(dppe)] [1] and the organic ligand 4,4'-Bipyridine [2]. There was evidence that [3] was obtained together with another supramolecular species [4], assigned to a triangular macrocycle. Structures [3] and [4] were elucidated based on chemical shifts, the proportionality between their integrals and the coupling patterns of the ¹H NMR and the COSY spectra. Based on signal intensities corresponding to the two supramolecular species we determined the composition of the mixture to be 70 % of [3] and 30 % of [4].

Pela primeira vez, foi desenvolvida a síntese e caracterização (IR, UV, RMN ¹H, 31P, 19F) de um novo quadrado supramolecular [3] através da automontagem do complexo [Pd(CF3SO3)2 (dppe)] [1] e o ligante orgânico 4,4'-bipiridina [2]. Foi evidenciada a obtenção de [3] em combinação com outra espécie supramolecular [4], atribuído como um macrociclo triangular. As estruturas de [3] e de [4] foram elucidadas com base nos deslocamentos químicos, a proporcionalidade entre os seus integrais e nos padrões de acoplamento dos sinais nos espectros de RMN-¹H e COSY ¹H-¹H. Através da relação entre as integrais dos sinais correspondentes ás espécies supramolecular coexistentes nos espectros de RMN-¹H e 31P, determinou-se a composição da mistura no final da reação contendo 70 % de [3] e 30 % de [4].

Síntesis de fuleeroles a partir de un derivado bromado de c60 / Sythesis of fulllerols from a c60 bromofullerene / Sítese de fúleroois desde um derivado bromado do c60

Se sintetizaron dos Mleroles por hidrólisis básica del compuesto C60Br24 a60°C, con 22 horas de reacción, en presencia de oxígeno atmosférico y utilizando relaciones molares de KOH/C60Br24 de 109 y 184. La geometría inicial no se mantiene al sustituir los átomos de bromo, y los fulleroles obtenidos son de naturaleza aniónica y poseen una estructura compleja que incluye grupos hidroxilo y grupos hemicetal. Se encontró que el tratamiento ácido o el intercambio iónico con resina mixta tipo H+/OH- ocasionan la aparición de grupos carbonilos dentro de su estructura. Los productos se caracterizaron por análisis elemental, espectroscopia infrarroja, UV-Vis, 1H-RMN, MALDI-TOF, TGA y DSC.

Two fullerols were synthesized by means of basic hydrolysis of the compound C60Br24 at 60°C after 22 hours of reaction in presence of atmospheric oxygen, using KOH/ C60Br24 molar ratios of 109 and 184. The initial geometry does not hold upon substitution of Bromine atoms and the obtained fullerols have anionic nature and showed complex structures including hydroxyl groups and hemiketal groups. It was determined that the acid treatment or the ionic exchange with mixed type H+/OH- resin caused the appearance of carbonyl groups in the structure. Products were characterized by elemental analysis, infrared spectroscopy, UV-Vis, MALDI-TOF, 1H-NMR, TGA and DSC.

Sintetizaram-se fulleróis por hidrolise básica do composto C60Br24 a 60°C, com 22 horas de reação, em presença de oxigênio e utilizando relações molares de KOH/ C60Br24 de 109 e 184. A geometria inicial do fullereno bromado não é mantida ao substituir os átomos de bromo. Os fulleróis obtidos são de natureza aniônica e têm uma estrutura complexa que inclui grupos hidroxila e grupos hemicetal. Observou-se que o tratamento ácido ou o intercâmbio iônico com resina tipo H+/OH-, ocasionam a aparição de grupos carbonilas na sua estrutura. Os produtos foram caracterizados por análise elementar, espectroscopia infravermelha, UV-Vis, RMN de 1H, MALDI-TOF, TGA e DSC.

Brasileiros comem cada vez mais e com pior qualidade / Brazilian people eat more and with worst quality

As mudanças nos hábitos alimentares, com a substituição crescente das tradicionais refeições por "fast food, não só fizeram explodir a obesidade no país como aumentaram os riscos de cáries dentárias. Paradoxalmente, cresce a incidência no Brasil de certas deficiências nutricionais