Bicyclic guanidine superbase carboxylate salts for cellulose dissolution.

Bicyclic guanidines are utilized in organic synthesis as base catalysts or reagents. They also offer a platform for coordination chemistry, for example in CO2 activation, and their carboxylate salts offer an efficient media for cellulose dissolution. We have studied a series of bicyclic guanidines with varying ring sizes and with varying methyl substituents with a specific aim to find hydrolytically stable acetate salts for dissolution and processing of cellulose. Different superbase synthesis pathways were tested, followed by hydrolytic stability and cellulose dissolution capacity tests. The synthesis pathways were designed to enable the scale up of the production of the superbases considering the availability of the starting molecules and the feasibility of the synthesis. As a result, we found several hydrolytically stable bicyclic guanidine structures, which can overcome many of the reoccurring problems as carboxylate salts or free bases.

Computational Investigation of Substituent Effects on the Alcohol + Carbonyl Channel of Peroxy Radical Self- and Cross-Reactions.

Organic peroxy radicals (RO2) are key intermediates in atmospheric chemistry and can undergo a large variety of both uni- and bimolecular reactions. One of the least understood reaction classes of RO2 are their self- and cross-reactions: RO2 + R'O2. In our previous work, we have investigated how RO2 + R'O2 reactions can lead to the formation of ROOR' accretion products through intersystem crossings and subsequent recombination of a triplet intermediate complex 3(RO···OR'). Accretion products can potentially have very low saturation vapor pressures, and may therefore participate in the formation of aerosol particles. In this work, we investigate the competing H-shift channel, which leads to the formation of more volatile carbonyl and alcohol products. This is one of the main, and sometimes the dominant, RO2 + R'O2 reaction channels for small RO2. We investigate how substituents (R and R' groups) affect the H-shift barriers and rates for a set of 3(RO···OR') complexes. The variation in barrier heights and rates is found to be surprisingly small, and most computed H-shift rates are fast: around 108-109 s-1. We find that the barrier height is affected by three competing factors: (1) the weakening of the breaking C-H bond due to interactions with adjacent functional groups; (2) the overall binding energy of the 3(RO···OR'), which tends to increase the barrier height; and (3) the thermodynamic stability of the reaction products. We also calculated intersystem crossing rate coefficients (ISC) for the same systems and found that most of them were of the same order of magnitude as the H-shift rates. This suggests that both studied channels are competitive for small and medium-sized RO2. However, for complex enough R or R' groups, the binding energy effect may render the H-shift channel uncompetitive with intersystem crossings (and thus ROOR' formation), as the rate of the latter, while variable, seems to be largely independent of system size. This may help explain the experimental observation that accretion product formation becomes highly effective for large and multifunctional RO2.

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Inclusion of Yucca schidigera extract in diets with different protein levels for dogs.

This study evaluated the effects of inclusion of Yucca schidigera extract (YSE) in two diets with different levels of crude protein (CP) for dogs on facal odour, nutrient digestibility, ammonia concentration in feces and hematological and serum biochemical profiles. Twenty adults Beagles were used, distributed in a randomized block design in a 2 × 4 factorial design (two diets, 25% and 34% CP, and four YSE levels: 0, 250, 500 and 750 mg/kg) with five replicates, obtained during two experimental periods. The fecal odour reduced (P < 0.05) when 500 mg/kg of YSE was used in diets with higher CP. The inclusion of YSE reduced (P < 0.05) fecal ammonia, and the inclusion of 250 and 500 mg/kg YSE reduced intestinal gas. The inclusion of 750 mg/kg YSE increased the mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT) activity and tended to increase the serum cholesterol concentration, regardless of the protein level of the diets. There was no effect on the digestibility of nutrients, fecal consistency, nitrogen balance and thickness of the intestinal wall. The inclusion of 500 mg/kg YSE is effective in reducing fecal odour in dogs receiving diets with 34% of CP. Regardless of the protein content, YSE reduces fecal ammonia, but may cause adverse effects if included at higher doses.

Functionalized graphene oxide as a nanocatalyst in dephosphorylation reactions: pursuing artificial enzymes.

The present study reports for the first time the use of a thiol-functionalized graphene oxide nanocatalyst with impressive activity (>10(5)-fold) in dephosphorylation reactions. The innovative and recyclable nanocatalyst has potential in designing artificial enzymes with targeted multifunctionalities and in detoxification of organophosphorus agents.

Increasing hospital admission rates and economic burden for colorectal cancer in Brazil, 1996-2008.

OBJECTIVE: to determine the trends in hospital admission rates for colorectal cancer (CRC) in the Brazilian Public Health System from 1996 to 2008 and to assess the economic costs. METHODS: data from the Hospital Information Systems database of the Brazilian Unified Health System were used for analysis of all admissions with a primary diagnosis of CRC between 1996 and 2008. RESULTS: there were 297 108 CRC admissions over the study period, with an annual increase from 12 821 in 1996 to 35 040 in 2008. Age-standardized admission rates increased from 8.7 to 23.56 per 100 000 for a percentage increase of 171%. The average length of stay decreased from 11.6 days in 1996 to 7.5 days in 2008. The average hospital mortality declined from 10.4% to 8.5%. Overall costs in United States dollars (US$) of CRC hospitalizations rose from US$ 16.5 million in 1996 to US$ 33.5 million in 2008; the average cost of each admission, however, decreased from US$ 1 283 to US$ 954. CONCLUSIONS: hospitalization rates for CRC in Brazil significantly increased during a 13-year period, incurring a considerable rise in the inflation-adjusted economic burden; national in-hospital mortality rates have remained relatively high.

A saúde e estresse ocupacional em médicos / The health and occupational stress in physicians

Introdução: A prática da Medicina sofreu alterações relevantes nas últimas décadas e está atualmente associadaa condições desgastantes de trabalho, como carga horária excessiva, perda de autonomia, redução de salários e exposição a situações estressantes, que aumentam a vulnerabilidade desses profissionais para adoecimento,depressão, abuso de substâncias e suicídio. Objetivos: Identificar e analisar publicações sobre o estresse ocupacional e a saúde do médico. Métodos: Os artigos foram identificados nas bases de dados MedLine, LILACS e SciElo. Foram utilizadas as palavras-chave: saúde, médicos, estresse, trabalho. O período pesquisado foi de 1999 a 2009. Resultados: As publicações identificadas associam o trabalho médico com situações geradoras de ansiedade e estresse, que podem aumentar a vulnerabilidade para a Síndrome de Burnout, principalmente em profissionais que atuam em situações de emergência, cuidados intensivos, psiquiatria e oncologia. Abordam também a relação entre estresse e saúde, destacando a adoção de estratégias de enfrentamento inadequadas como a automedicação, abuso do álcool ou outras substâncias e tabagismo. Discussão: A alta demanda emocional e física do trabalho médico está associada a altos níveis de estresse e baixa freqüência hábitos saudáveis, como alimentação adequada, prática regular de atividade física, tempo para lazer e para a convivência com a família, o que afeta não só a saúde física e mental do médico, mas a qualidade dos serviços por ele prestados. Conclusão: Pesquisas sobre estratégias de enfrentamento para o estresse em médicos brasileiros ainda são importantes e o desenvolvimento de modelos de prevenção e intervenção é necessário para diminuir a vulnerabilidade desses profissionais ao adoecimento.

Introduction: In the last decades, Medicine practice has had great changes, and this is currently associatedwith bad working conditions such as wok overload, loss of autonomy, low salary and stress situations that expose physicians to sickness, depression, substance addiction and suicide. Background: To identify and evaluate publications about occupational stress and health of physicians. Methods: The papers were selected from Medline, SciELO and LILACS, using the keywords health, physicians, stress and work. The research comprised related papers of the the period from 1999 to 2009. Results: In these papers, the physician´s work was associated with conditions resulting stress situations which can increase the risk of Burnout Syndrome in professionals who work with Emergency, Intensive Care, Psychiatry and Oncology. They also reported the relationship between stress and health, pointing out the use of inadequate coping strategies such as selfmedication, alcohol or drug addiction and smoking habits. Discussion: The physicians´ high emotional and physical working overload creates stress and can produce low frequency of healthy habits such as adequate nutrition, physical exercises, spare time and familial contact. This can affect the physicians´ physical and mental health and also damage their service quality. Conclusion: Further research on strategies coping stress addressing Brazilian physicians are still important, and models of stress prevention and intervention are needed to reduce the vulnerability of these professionals to illness.

Increasing hospital admission rates and economic burden for colorectal cancer in Brazil, 1996-2008 / Aumento de las tasas de ingresos hospitalarios por cáncer colorrectal y su carga económica en Brasil, 1996-2008

OBJECTIVE: To determine the trends in hospital admission rates for colorectal cancer (CRC) in the Brazilian Public Health System from 1996 to 2008 and to assess the economic costs. METHODS: Data from the Hospital Information Systems database of the Brazilian Unified Health System were used for analysis of all admissions with a primary diagnosis of CRC between 1996 and 2008. RESULTS: There were 297 108 CRC admissions over the study period, with an annual increase from 12 821 in 1996 to 35 040 in 2008. Age-standardized admission rates increased from 8.7 to 23.56 per 100 000 for a percentage increase of 171 percent. The average length of stay decreased from 11.6 days in 1996 to 7.5 days in 2008. The average hospital mortality declined from 10.4 percent to 8.5 percent. Overall costs in United States dollars (US$) of CRC hospitalizations rose from US$ 16.5 million in 1996 to US$ 33.5 million in 2008; the average cost of each admission, however, decreased from US$ 1 283 to US$ 954. CONCLUSIONS: Hospitalization rates for CRC in Brazil significantly increased during a 13-year period, incurring a considerable rise in the inflation-adjusted economic burden; national in-hospital mortality rates have remained relatively high.

OBJETIVO: Determinar las tendencias de las tasas de ingresos hospitalarios por cáncer colorrectal (CCR) en el sistema de salud pública brasileño de 1996 al 2008 y evaluar sus costos económicos. MÉTODOS: Se utilizó la información de la base de datos de los sistemas de información de los hospitales del Sistema Único de Salud brasileño con objeto de analizar todos los ingresos con diagnóstico primario de CCR entre 1996 y el 2008. RESULTADOS: Durante el período de estudio, se produjeron 297 108 ingresos por CCR, con un aumento anual de 12 821 en 1996 a 35 040 en el 2008. Las tasas de ingresos estandarizadas según la edad aumentaron de 8,7 a 23,56 por 100 000, con un aumento porcentual de 171 por ciento. La estancia hospitalaria media disminuyó de 11,6 días en 1996 a 7,5 días en el 2008. La mortalidad hospitalaria promedio descendió de 10,4 por ciento a 8,5 por ciento. Los costos de las hospitalizaciones por CCR aumentaron de US$16,5 millones en 1996 a US$33,5 millones en el 2008; el costo promedio de cada ingreso, sin embargo, disminuyó de US$1 283 a US$954. CONCLUSIONES: Las tasas de hospitalización por CCR en Brasil han aumentado significativamente a lo largo de un período de 13 años y han acarreado un considerable incremento de la carga económica ajustada según la inflación; las tasas nacionales de mortalidad hospitalaria se han mantenido relativamente elevadas.