An accelerating cosmology without dark energy

The negative pressure accompanying gravitationally-induced particle creation can lead to a cold dark matter (CDM) dominated, accelerating Universe (Lima et al. 1996 [1]) without requiring the presence of dark energy or a cosmological constant. In a recent study, Lima et al. 2008 [2] (LSS) demonstrated that particle creation driven cosmological models are capable of accounting for the SNIa observations [3] of the recent transition from a decelerating to an accelerating Universe, without the need for Dark Energy. Here we consider a class of such models where the particle creation rate is assumed to be of the form Gamma = beta H + gamma H(0), where H is the Hubble parameter and H(0) is its present value. The evolution of such models is tested at low redshift by the latest SNe Ia data provided by the Union compilation [4] and at high redshift using the value of z(eq), the redshift of the epoch of matter - radiation equality, inferred from the WMAP constraints on the early Integrated Sachs-Wolfe (ISW) effect [5]. Since the contributions of baryons and radiation were ignored in the work of LSS, we include them in our study of this class of models. The parameters of these more realistic models with continuous creation of CDM are constrained at widely-separated epochs (z(eq) approximate to 3000 and z approximate to 0) in the evolution of the Universe. The comparison of the parameter values, {beta, gamma}, determined at these different epochs reveals a tension between the values favored by the high redshift CMB constraint on z(eq) from the ISW and those which follow from the low redshift SNIa data, posing a potential challenge to this class of models. While for beta = 0 this conflict is only at less than or similar to 2 sigma, it worsens as beta increases from zero.

Transepithelial transport of glucose and mRNA of glucose transporters in the small intestine of rats with iron-deficiency anemia

Objective: To evaluate the transepithelial transport of sodium, glucose, potassium, and water and the mRNA level of the sodium-glucose cotransporter (SGLT1) and the facilitated sugar transporter (GLUT2) in the small intestine of iron-deficient rats. Methods: After 6 wk of receiving diets with low or normal iron content, rats (Wistar-EPM) were subjected to two experiments: 1) evaluation of the transepithelial transport of sodium, glucose, potassium, and water by an ""in vivo"" experimental model of intestinal perfusion and 2) determination of relative SGLT1 and GLUT2 mRNA levels in the proximal, intermediate, and distal portions of the small intestine by the northern blotting technique. Results: Hemoglobin and hepatic iron levels were statistically lower in the anemic rats. The mean transepithelial transports of sodium (-33.0 mu Eq . min(-1) . cm(-1)), glucose (426.0 mu M . min(-1) . cm(-1)), and water (0.4 mu L . min(-1) . cm(-1)) in the small intestine of the anemic rats were significantly lower than in the control group (349.1 mu Eq . min(-1) cm(-1), 842.6 mu M . min(-1) . cm(-1), and 4.3 mu l . min(-1) cm(-1), respectively, P < 0.05). The transepithelial transport of potassium was similar for both groups. The relative SGLT1 mRNA levels of the anemic rats in the intermediate (1.796 +/- 0.659 AU) and distal (1.901 +/- 0.766 AU) segments were significantly higher than the values for the control rats (intermediate 1.262 +/- 0.450 AU, distal 1.244 +/- 0.407 AU). No significant difference was observed for the relative SLGT1 mRNA levels in the proximal segment or for the GLUT2 mRNA levels in all segments. Conclusion: Iron deficiency decreases the absorption of glucose, sodium, and water and increases SGLT1 mRNA in the intermediate and distal segments of the small intestine of rats. (C) 2011 Elsevier Inc. All rights reserved.

Pinguino In-bearing polymetallic vein deposit, Deseado Massif, Patagonia, Argentina: characteristics of mineralization and ore-forming fluids

The Pinguino deposit, located in the low sulfidation epithermal metallogenetical province of the Deseado Massif, Patagonia, Argentina, represents a distinct deposit type in the region. It evolved through two different mineralization events: an early In-bearing polymetallic event that introduced In, Zn, Pb, Ag, Cd, Au, As, Cu, Sn, W and Bi represented by complex sulfide mineralogy, and a late Ag-Au quartz-rich vein type that crosscut and overprints the early polymetallic mineralization. The indium-bearing polymetallic mineralization developed in three stages: an early Cu-Au-In-As-Sn-W-Bi stage (Ps(1)), a Zn-Pb-Ag-In-Cd-Sb stage (Ps(2)) and a late Zn-In-Cd (Ps(3)). Indium concentrations in the polymetallic veins show a wide range (3.4 to 1,184 ppm In). The highest indium values (up to 1,184 ppm) relate to the Ps(2) mineralization stage, and are associated with Fe-rich sphalerites, although significant In enrichment (up to 159 ppm) is also present in the Ps(1) paragenesis associated with Sn-minerals (ferrokesterite and cassiterite). The hydrothermal alteration associated with the polymetallic mineralization is characterized by advanced argillic alteration within the immediate vein zone, and sericitic alteration enveloping the vein zone. Fluid inclusion studies indicate homogenisation temperatures of 308.2-327A degrees C for Ps(1) and 255-312.4A degrees C for Ps(2), and low to moderate salinities (2 to 5 eq.wt.% NaCl and 4 to 9 eq.wt.% NaCl, respectively). delta(34)S values of sulfide minerals (+0.76aEuro degrees to +3.61aEuro degrees) indicate a possible magmatic source for the sulfur in the polymetallic mineralization while Pb isotope ratios for the sulfides and magmatic rocks ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb ratios of 17.379 to 18.502; 15.588 to 15.730 and 38.234 to 38.756, respectively) are consistent with the possibility that the Pb reservoirs for both had the same crustal source. Spatial relationships, hydrothermal alteration styles, S and Pb isotopic data suggest a probable genetic relation between the polymetallic mineralization and dioritic intrusions that could have been the source of metals and hydrothermal fluids. Mineralization paragenesis, alteration mineralogy, geochemical signatures, fluid inclusion data and isotopic data, confirm that the In-bearing polymetallic mineralization from Pinguino deposit is a distinct type, in comparison with the well-known epithermal low sulfidation mineralization from the Deseado Massif.

PokerMapper: : mapping executive functions, poker playing ability and responsible gambling in online environments

Research objectives Poker and responsible gambling both entail the use of the executive functions (EF), which are higher-level cognitive abilities. The main objective of this work was to assess if online poker players of different ability show different performances in their EF and if so, which functions are the most discriminating ones. The secondary objective was to assess if the EF performance can predict the quality of gambling, according to the Gambling Related Cognition Scale (GRCS), the South Oaks Gambling Screen (SOGS) and the Problem Gambling Severity Index (PGSI). Sample and methods The study design consisted of two stages: 46 Italian active players (41m, 5f; age 32±7,1ys; education 14,8±3ys) fulfilled the PGSI in a secure IT web system and uploaded their own hand history files, which were anonymized and then evaluated by two poker experts. 36 of these players (31m, 5f; age 33±7,3ys; education 15±3ys) accepted to take part in the second stage: the administration of an extensive neuropsychological test battery by a blinded trained professional. To answer the main research question we collected all final and intermediate scores of the EF tests on each player together with the scoring on the playing ability. To answer the secondary research question, we referred to GRCS, PGSI and SOGS scores.  We determined which variables that are good predictors of the playing ability score using statistical techniques able to deal with many regressors and few observations (LASSO, best subset algorithms and CART). In this context information criteria and cross-validation errors play a key role for the selection of the relevant regressors, while significance testing and goodness-of-fit measures can lead to wrong conclusions.   Preliminary findings We found significant predictors of the poker ability score in various tests. In particular, there are good predictors 1) in some Wisconsin Card Sorting Test items that measure flexibility in choosing strategy of problem-solving, strategic planning, modulating impulsive responding, goal setting and self-monitoring, 2) in those Cognitive Estimates Test variables related to deductive reasoning, problem solving, development of an appropriate strategy and self-monitoring, 3) in the Emotional Quotient Inventory Short (EQ-i:S) Stress Management score, composed by the Stress Tolerance and Impulse Control scores, and in the Interpersonal score (Empathy, Social Responsibility, Interpersonal Relationship). As for the quality of gambling, some EQ-i:S scales scores provide the best predictors: General Mood for the PGSI; Intrapersonal (Self-Regard; Emotional Self-Awareness, Assertiveness, Independence, Self-Actualization) and Adaptability  (Reality Testing, Flexibility, Problem Solving) for the SOGS, Adaptability for the GRCS. Implications for the field Through PokerMapper we gathered knowledge and evaluated the feasibility of the construction of short tasks/card games in online poker environments for profiling users’ executive functions. These card games will be part of an IT system able to dynamically profile EF and provide players with a feedback on their expected performance and ability to gamble responsibly in that particular moment. The implementation of such system in existing gambling platforms could lead to an effective proactive tool for supporting responsible gambling. 

A inteligência emocional e a leitura: um estudo com crianças do 1º Ciclo do Ensino Básico

Os estudos acerca da inteligência emocional têm explorado as repercussões e a importância deste constructo no quotidiano dos individuo. Os estudos na infância, em particular, têm-se debruçado sobre estratégias e métodos que permitam o desenvolvimento de competências associadas a este domínio. No processo de leitura, nomeadamente de histórias, existe toda uma descodificação de narrativas, papeis e emoções que não se traduzem apenas no aumento de conhecimentos mas igualmente em aprendizagens que podem ser transpostas para a vida real. Os estudos entre a inteligência emocional e a leitura são muito escassos, assim esta investigação objetiva verificar se existe relação entre a inteligência emocional e a leitura Neste estudo participaram 138 crianças com idades compreendidas entre os oito e os 11 anos de idade e que frequentavam o 3º e 4º ano de escolaridade em dois estabelecimentos de ensino público da Região Autónoma da Madeira (RAM). Foram aplicados um Questionário acerca da Leitura, o Emotional Quotient-inventory: youth version (EQ-i: YV (short form)) e o Test of Emotional Comprehension (TEC- versão computorizada). Os resultados obtidos sugerem que a Inteligência emocional está relacionada com a leitura, no sentido que as crianças que gostam de ler e que têm hábitos de leitura, apresentaram valores mais elevados nos instrumentos administrados. Observou-se ainda que os resultados são diferentes consoante os tipos de livros, a influência de outros indivíduos e até mesmo as razões da escolha de um determinado livro.

A influência das variáveis socioemocionais e do autoconceito nos anos de transição 2º e 3º Ciclo do Ensino Básico: um estudo exploratório na RAM

Nos últimos anos tem havido um aumento da investigação em torno das transições escolares. Assim, consideramos que as variáveis socioemocionais e o autoconceito podem influenciar de forma positiva e/ou negativa este processo de transição. No mesmo sentido as expetativas criadas pelos alunos nos anos de transição podem condicionar a adaptação ao novo ciclo de estudos. Se soubermos antecipadamente o que carateriza estes alunos, poderemos intervir adequadamente no sentido de potencializar o seu sucesso escolar. Centramos então o nosso estudo numa amostra de alunos do 2º e 3º ciclo do ensino básico de uma escola situada na zona rural da ilha da Madeira onde foram aplicados testes de inteligência emocional, autoconceito e de expetativas na transição de ano, nomeadamente, o PACS - Avaliação de Competências Sociais; EQ-i: YV - Inteligência Emocional; PCIS - Inteligência Social; PHCSCS 2 - Piers-Harris Children’s Self-Concept Scale 2 e o Questionário de Expetativas dos Alunos nos anos de Transição. Os resultados apontam para que quer no 2º, quer no 3º ciclo a inteligência emocional esteja direta e positivamente associada ao autoconceito. No 2º ciclo, existe uma relação positiva entre a competência social e o autoconceito bem como entre a competência social e a inteligência emocional, existindo diferenças entre os géneros, nas diferentes dimensões da inteligência emocional, sendo que as raparigas registam índices mais elevados nos domínios intrapessoal, interpessoal e inteligência geral no 2º ciclo, enquanto no 3º ciclo são os rapazes que nas dimensões do humor geral e na escala total registam os índices mais elevados. Por último, no 2º ciclo as raparigas manifestam um autoconceito superior aos rapazes, no aspeto comportamental, intelectual e na satisfação-felicidade, enquanto no 3º ciclo apenas se verificam maiores níveis de ansiedade no género masculino. As correlações relativamente às expetativas também são apresentadas.

Aspetos desenvolvimentais da inteligência emocional em jovens institucionalizados: estudo de caso

Nos últimos anos o interesse acerca do construto de inteligência emocional e das competências sociais tem aumentado. Este facto é explicado pela proliferação de vários estudos, que tem demonstrado a importância das competências socioemocionais na vida dos indivíduos. Os estudos, que incidem nas faixas etárias da infância e da adolescência, têm descrito a influência das competências sociemocionais em aspetos como o sucesso escolar, a adaptação social, bem-estar e ajuste psicológico. O processo de institucionalização envolve grandes mudanças na estrutura emocional e social de crianças e jovens. Neste âmbito é importante conhecer como é e como ocorre o desenvolvimento sociemocional destes jovens e qual o impacto da institucionalização nas suas competências socioemocionais. O estudo deu continuidade a uma investigação que tinha-se iniciado no ano de 2007, de forma a acompanhar o desenvolvimento dos indivíduos. A amostra incidiu sobre 20 utentes de uma instituição, com regime de internamento integral da Região Autónoma da Madeira. Foram aplicados os seguintes instrumentos: Matrizes Progressivas de Raven (CPM-SPM), Inventário de Quociente Emocional de Bar-On: versão para jovens (EQ-i:YV), Prova Cognitiva de Inteligência Social (PCIS) e Prova de Avaliação da Competência Social (PACS). Os resultados apontam para um destaque das competências como a adaptabilidade flexibilidade, resolução de problemas e de aspetos relacionados com a resolução de situações sociais. Verificou-se igualmente uma redução das competências sociemocionais ao longo do tempo, particularmente no que concerne à perceção dos jovens acerca das suas competências intrapessoais, a motivação e autoconfiança para a para a resolução de situações sociais e as competências sociais em termos de liderança.

Estratégias de obtenção do corante do jambo vermelho (Syzygium malaccense) e avaliação de sua funcionalidade

The food industry is interested in natural products. Anthocyanins are phenolic antioxidants of great importance with health-relevant applications. Several studies have linked the intake of fruits and vegetables with reduced risk of chronic degenerative diseases because of its antioxidant properties. This study aimed to compare different strategies for obtaining natural pigments from red jambo (Syzygium malaccence) and analyze its functional potential. Two different strategies were studied: (1) solid-liquid extraction (SLE) in reactor with controlled parameters, (2) powder obtention. The investigation of the functional potential was conducted taking into account the total phenolic content (TPC), the antioxidant activity (AA), the total anthocyanins concentration (TA) and α-amylase and α-glucosidase inhibition. The best extracts obtained by SLE showed TPC of 174.15 mg GAE/100g, AA of 3.56 μmol Trolox eq/g and TA of 133.59 mg cyd-3-glu/100 g. The best results for the second strategy were TPC of 1024.22 mg GAE/100 g, AA of 29.03 μmol Trolox eq/g and TA of 1193.41 mg cyd-3- glu/100 g. It was observed moderate amylase inhibition (26.30%) and high glucosidase inhibitory activity (97.47%). Skin extracts showed, in general, superior results when compared to whole red jambo, with superior values for dehydrated products. Based on our result, red jambo can be considered as a rich source of phenolic antioxidants, as well on amylase and glucosidase inhibitors

Estudo das características físico-químicas e funcionalidade de bagaços de frutas tropicais desidratados em leito de jorro

Fruits are rich sources of bioactive compounds, including phenolic compounds. Tropical fruit cultivation is an important productive segment in Brazilian Northeast. Its industrialization generates solid wastes as co-products, with potential environmental impact. Considering the recognized bioactive content of fruit and its derivatives, this research has the objective of investigating acerola (Malpighia glabra L.), cajá-umbu (Spondia ssp), jambolan (Syzygium cumini) and pitanga (Eugenia uniflora) dried wastes obtained by spouted bed drier. It was analyzed the physical-chemical composition, solubility and microphotographic aspect of these dried wastes. Besides this, it was also evaluated the bioactive content, antioxidant activity and inhibitory activity against aamylase and a-glycosidase enzymes of water and ethanol (70%, 80% e 100% v/v) extracts prepared from fruit dried wastes, as well as their possible correlations. The dried fruit wastes showed high phenolic (606.04 to 3074.6 mg GAE eq/100 g sample), anthocyanin (478.7 mg/100 g for jambolan) and ascorbic acid (2748.03 mg/100 g for acerola) contents, as well as high antioxidant DPPH activity (14.27 a 36.30 mg Trolox eq/g sample). The extracts exhibited moderate to high a-amylase inhibition (23.97% a 76.58%) and high α-glycosidase inhibition, which 99.32% peak was reached for ethanol 70% pitanga extracts. It was also observed great positive correlation between phenolic content and DPPH activity (0.97 for acerola), anthocyanin (0.95 for jambolan) and α- glycosidase inhibition (0.98 for acerola). The α-glycosidase inhibition also correlated well with the antioxidant activity for all fruit extracts. The results show that these dried fruit wastes are valuable material for further applications as functional ingredients

Secagem do resíduo de acerola (Malphigia emarginata D.C.): estudo do processo e avaliação do impacto sobre o produto final

Brazil, one of the largest agricultural producers in the world, has managed in recent years to significantly improve its production. However, in response to this advance in the agro-industrial sector, the generation of agro-industrial residues has also increased. New technological alternatives have to be implemented in order to bring economic and rational use of this material and drying is one of the possible choices. Considering the great importance that bioactive compounds present for food science and technology, this research aims to evaluate the air-drying process of acerola residue in a tray convective drier under controlled temperature (60, 70 e 80ºC), air velocity (4.0, 5.0 e 6.0 m/s) and material width (0.5, 0.62 e 0.75 cm) by applying an experimental planning 23 + 3. Based on that, the impact on physical-chemical characteristics, color, bioactive compounds concentration and antioxidant activity of dried acerola waste was evaluated, having the in natura and freeze dried waste as control groups. Dried acerola residue presented natural pigments, mainly carotenoids (143.68 - 68.29 mg/g) and anthocyanins (290.92 - 90.11 mg/100 g), which explain the red and yellow instrumental color parameters observed. The acerola residue powder is also rich in phenolic compounds (3261.11 -2692.60 mgGAEeq/100g), proanthocyanidins (61.33-58.46 eq/100g), ascorbic acid (389.44 739.29 mg/100 g) and DPPH antioxidant activity (20.91 24.72 μg Trolox eq/g). Results show decreased concentration of phenolic compounds, anthocyanins, carotenoids, proanthocyanidins and ascorbic acid caused by the air-drying process. However, even after the observed drying losses, the acerola residue powder can be considered a high value food ingredient, considering the high bioactive compounds concentration found in the final product, as well as the colorimetric characterization and microbiological stability of the dried powder

Jambolão (Syzygium cumini) desidratado por liofilização e secagem em leito de jorro: avaliação do impacto do processo de secagem e caracterização do potencial funcional do produto final

Tropical fruits have been extensively studied due to their functional potential attributed to the presence of natural bioactive compounds. The exotic fruit jambolan (Syzygium cumini) has been reported for its appreciable amount of phenolic compounds, especially anthocyanins and antioxidant capacity. Nevertheless, there are hardly any derived jambolan products in the Brazilian market. In addition to that, considerable volumes of fruit are lost due to their high perishability. Dried fruits have become an important fruit market segment due to its weight and volume reduction and decreased transportation and storage costs. Thus, this study evaluated the jambolan pulp submitted to spouted bed drying (JLJ) and lyophilization (JLI), besides assessing the drying impact on the final product. In order to achieve this, the process performance was calculated and compared, as well the physicochemical and bioactive characteristics (moisture, water activity (aw), solubility, hygroscopicity, density, color, structure through images obtained by scanning electron microscopy (SEM), concentration of bioactive (total phenolic compounds (TPC), anthocyanins, proanthocyanidins and ascorbic acid) and antioxidant activity. The results showed drying efficiency higher than 60% for both products and that JLJ group showed higher moisture and water activity when compared to the JLI group (p<0.05). The two types of drying were able to produce stable final product in the microbiological point of view, given that both showed aw < 0.6. The final products exhibited high solubility (73.7 to 81.6%) and low hygroscopicity (9.8 to 11.6%), desirable characteristics for dehydrated foods. Despite the losses caused by drying, the dried jambolan pulp by both methods showed high TPC (468.6 to 534.0 mg GAE/100g dm), anthocyanins (from 491.9 to 673.4 mg. eq. cyanidin-3-glicoside/100g dm), proanthocyanidins (66.9 to 76.6 mg QTE/g dm) and ascorbic acid (156.4 to 186.8 mg/100 g dm). Taken together, the results of this study reveal spouted dried and freeze dried jambolan pulp as bioactive-rich natural products with suitable physicochemical and functional characteristics to be used as food ingredients. The data also demonstrate the drying techniques as rational strategies for the exploitation of the exotic fruit jambolan

Suco desidratado de caju (Anacardium occidentale L.) por atomização: caracterização físico-química, bioativa e estudo da vida de prateleira do produto

Despite the relatively organized cashew (Anacardium occidentale L.) productive chain and the number of cashew derivatives found in the market, it is estimated that over 90% of the cashew peduncle is wasted. A possible strategy for a better commercial exploitation of this agroindustrial commodity would be the production of spray dried cashew pulp. Thus, this paper approaches the yellow cashew pulp spray drying process and the final product evaluation. Based on that, the shelf life of the spray dried cashew pulp packed in different packaging was evaluated. Drying was conducted in two drying temperatures (140 °C to 150 °C) and two concentrations of Arabic gum (AG, 15% and 25%), which summed four experimental groups. The drying performance was evaluated as well as the physicochemical characteristics (moisture, water activity, total soluble solids, pH, density, solubility, particle diameter, hygroscopicity, degree of caking, color, scanning electronic microscopy and X-ray diffraction), composition (protein, ash, fat and sugars) and bioactive and functional value (total phenolic compounds, carotenoids, ascorbic acid and antioxidant activity) of the final products. Results showed spray drying efficiency higher than 65% for all experiments, mainly for the C4 group (150 °C and 25% AG) which reached efficiency of 93.4%. It was also observed high solubility (94.7% to 97.9%) and the groups with lower hygroscopicity (5.8% and 6.5%) were those with the highest proportion of drying coadjuvant. The particle diameters ranged between 14.7 μm and 30.2 μm and increased with the proportion of AG. When comparing the product before and after spray drying, the drying impact was evident. However, despite the observed losses, dried yellow cashew showed high phenolic concentration (from 235.9 to 380.4 mg GAE eq / 100 g DM), carotenoids between 0.22 and 0.49 mg/100 g DM and remarkable ascorbic acid levels (852.4 to 1346.2 mg/100 g DM), in addition to antioxidant activity ranging from 12.9 to 16.4 μmol TE/ g DM. The shelf life study revealed decreased phenolic content over time associated to a slight water activity increase. Overall, our results unveil the technological and bioactive potential of dried yellow cashew as a functional ingredient to be used in food formulations or as a ready-to-use product. The technological approach presented here can serve as an efficient strategy for a rational use of the cashew apple, avoiding its current underutilization

Cerâmicas avançadas no processo de retificação cilíndrica externa de mergulho utilizando a técnica da mínima quantidade de lubrificação (MQL) com rebolos diamantados

Nas últimas duas décadas, as cerâmicas avançadas têm sido exaustivamente utilizadas em aplicações na indústria devido às suas propriedades de elevada resistência ao desgaste e dureza. Entretanto, ainda se tem um alto custo agregado ao acabamento da peça. Esse acabamento geralmente é feito pelo processo de retificação, único processo economicamente viável que produz superfícies de elevada qualidade e precisão geométrica. Nesse contexto, as empresas vêm buscando a otimização no processo de retificação como, por exemplo, a redução do fluxo de fluido de corte utilizado, o que também visa atender exigências mundiais de preservação ambiental. Desta forma, este projeto pretendeu explorar a técnica da Mínima Quantidade de Lubrificação (MQL) na retificação cilíndrica externa de mergulho em cerâmicas com rebolos diamantados. Foram utilizados dois métodos de refrigeração: o convencional e o MQL, com três avanços de corte para cada caso. Foram usados um bocal convencional e um bocal para o MQL, tendo este um uniformizador de saída do jato. Foram analisadas como variáveis de saída: a emissão acústica, relação G, aspecto da superfície via microscopia eletrônica de varredura (MEV), rugosidade e circularidade. Assim, embora a refrigeração convencional ainda apresente os melhores resultados em comparação com a refrigeração com MQL, esta última pode atender os requisitos necessários para diversas aplicações, em especial quando utilizadas baixas espessuras equivalentes de corte (h eq). Além disso, a técnica de MQL possui a vantagem de gerar um menor impacto ambiental em comparação com a lubrificação convencional, devido ao uso mínimo de fluido de corte cujo descarte é cada vez mais regulamentado e custoso.

Efeitos hemodinâmicos e renais da injeção de doses elevadas de clonidina no espaço peridural do cão

JUSTIFICATIVA E OBJETIVOS: Não existem estudos que relatem as repercussões renais determinadas pela injeção de doses elevadas de clonidina no espaço peridural. O objetivo do estudo foi avaliar os efeitos hemodinâmicos e renais determinados pela injeção de doses elevadas de clonidina no espaço peridural do cão. MÉTODO: Vinte animais anestesiados com tiopental sódico e fentanil foram distribuídos aleatoriamente e de forma duplamente encoberta em dois grupos: Grupo 1 ou placebo (n = 10), que recebeu 0,2 mL.kg-1 de solução fisiológica, e Grupo 2 ou clonidina (n = 10), que recebeu 0,2 mL.kg-1 de uma solução contendo 50 µg.mL-1 de clonidina, no espaço peridural. Foram avaliados os seguintes parâmetros hemodinâmicos: freqüência cardíaca (FC): bat.min-1; pressão arterial média (PAM): mmHg; pressão da artéria pulmonar ocluida (PAOP): mmHg; débito cardíaco (DC): L.min-1; volume sistólico (VS): mL; também, os seguintes parâmetros da função renal foram avaliados: fluxo sangüíneo renal (FSR): mL.min-1; resistência vascular renal (RVR): mmHg.mL-1.min; volume urinário minuto (VUM): mL.min-1; depuração de creatinina (D Cr): mL.min-1; depuração de para-aminohipurato (D PAH): mL.min-1; fração de filtração (FF); depuração de sódio (D Na): mL.min-1; depuração de potássio (D K): mL.min-1; excreção fracionária de sódio (EF Na): %; excreção urinária de sódio (U NaV): µEq.min-1; excreção urinária de potássio (U K V): µEq.min-1. O experimento consistiu em três momentos de 20 minutos cada. Os dados foram coletados aos 10 minutos de cada momento e a diurese, no início e no final de cada momento. Ao término de M1, a clonidina ou a solução fisiológica foi administrada no espaço peridural. Após período de 20 minutos iniciou-se M2 e, em seguida, M3. RESULTADOS: A clonidina na dose de 10 µg.kg-1 no espaço peridural do cão promoveu alterações significativas, com diminuições da freqüência cardíaca e do débito cardíaco e aumento da relação depuração de para-aminohipurato de sódio/débito cardíaco. CONCLUSÕES: Nas condições realizadas e nas doses empregadas, pode-se concluir que a clonidina não promoveu alteração da função renal, mas diminuiu valores hemodinâmicos (freqüência e débito cardíaco).

Involvement of central alpha(1)-adrenoceptors on renal responses to central moxonidine and alpha-methylnoradrenaline

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)