BepiColombo mission confirms stagnation region of Venus and reveals its large extent.

The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.

Effects of Ischemic Preconditioning and Postconditioning in a Renal Ischemia-Reperfusion Injury Model: A Comparative Experimental Study in Rats.

BACKGROUND: Ischemia-reperfusion injury is an unavoidable aspect of transplantation, as well as an important cause of acute kidney injury in clinical practice. Pre- and post-ischemic conditioning are strategies that may provide organs with resistance to major ischemic events. This study evaluates the effects of ischemic preconditioning and ischemic postconditioning, either separately or in combination, after an acute ischemia-reperfusion kidney injury. METHODS: Forty Wistar rats received isoflurane anesthesia and were randomized into 5 groups: 1. the sham group underwent laparotomy; 2. the control group underwent laparotomy and 30 minutes of renal ischemia followed by reperfusion; 3. the preconditioning group underwent laparotomy, ischemic preconditioning, and 30 minutes of renal ischemia followed by reperfusion; 4. the preconditioning and postconditioning group underwent laparotomy, ischemic preconditioning, 30 minutes of renal ischemia, and ischemic postconditioning followed by reperfusion; and 5. the postconditioning group underwent laparotomy, 30 minutes of renal ischemia, and ischemic postconditioning followed by reperfusion. Serum analyses of creatinine and neutrophil gelatinase-associated lipocalin (NGAL) were performed, and renal histology was examined 24 hours later. RESULTS: Severe tubular injury and increases in creatinine were observed in all groups except the sham group. The control group and all ischemic conditioning groups were no different in the degree of renal injury and values of NGAL and creatinine after the injury. CONCLUSIONS: Ischemic preconditioning and ischemic postconditioning, together or separately, are unable to preserve kidney function or exert a protective effect against tubular cell injury after an acute ischemia-reperfusion kidney injury.

Heart rate variability in children with type 1 diabetes mellitus.

OBJECTIVE: To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior. DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review. DATA SYNTHESIS: The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals. CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group.

Heart rate variability in children with type 1 diabetes mellitus / Variabilidad de la frecuencia cardiaca en niños con diabetes mellitus tipo 1 / Variabilidade da frequência cardíaca em crianças com diabetes melito tipo 1

To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior. DATA SOURCES: The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review. DATA SYNTHESIS: The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals. CONCLUSIONS: Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group...

Reunir informaciones actuales sobre los efectos de la diabetes mellitus tipo 1 sobre el comportamiento cardiaco de niños. FUENTES DE DATOS: La búsqueda de artículos se realizó en las bases de datos PubMed, Ibecs, Medline, Cochrane, Lilacs y PEDro por medio de los descriptores del área de salud (DeCS) a continuación: "sistema nervioso autónomo", "diabetes mellitus", "niño", "diabetes mellitus tipo 1", "sistema nervioso simpático" y "sistema nervioso parasimpático" sus respectivas versiones en lengua inglesa (MeSH).Los artículos fueron publicados de enero de 2003 a febrero de 2013, implicando a niños de nueve a 12 años portadores de diabetes mellitus tipo 1. SÍNTESIS DE LOS DATOS: La búsqueda resultó en cuatro artículos que trataban la variabilidad de la frecuencia cardiaca en niños con diabetes mellitus tipo 1, demostrando que, por lo general, esos niños presentan reducción de la variabilidad de la frecuencia cardiaca global y de la actividad vagal. La práctica de actividad física promueve beneficios al organismo de niños con diabetes mellitus tipo 1. CONCLUSIONES: Niños diabéticos tipo 1 presentan modificaciones en la modulación autonómica, lo que demuestra la necesidad de atención temprana a esa población para evitar complicaciones futuras...

Reunir informações atuais acerca dos efeitos do diabetes melito tipo 1 sobre o comportamento autonômico cardíaco de crianças. FONTES DE DADOS: A busca dos artigos foi realizada nas bases de dados PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO e PEDro por meio dos seguintes descritores da área da saúde (DeCS): "sistema nervoso autônomo", "diabetes mellitus", "criança", "diabetes mellitus tipo 1", "sistema nervoso simpático" e "sistema nervoso parassimpático" e suas respectivas versões em língua inglesa (MeSH). Os artigos foram publicados de janeiro de 2003 a fevereiro de 2013, envolvendo crianças de nove a 12 anos portadoras de diabetes melito tipo 1. SÍNTESE DOS DADOS: A busca resultou em quatro artigos que abordam a variabilidade da frequência cardíaca em crianças com diabetes melito tipo 1, demonstrando que, em geral, essas crianças apresentam redução da variabilidade da frequência cardíaca global e da atividade vagal. A prática de atividade física promove benefícios no organismo de crianças com diabetes melito tipo 1. CONCLUSÕES: Crianças diabéticas tipo 1 apresentam modificações na modulação autonômica, o que demonstra a necessidade de atenção precoce a essa população para evitar complicações futuras...

Deregulation of adipokines related to target organ damage on resistant hypertension.

Resistant hypertension (RHTN) includes patients with controlled blood pressure (BP) (CRHTN) and uncontrolled BP (UCRHTN). In fact, RHTN patients are more likely to have target organ damage (TOD), and resistin, leptin and adiponectin may affect BP control in these subjects. We assessed the relationship between adipokines levels and arterial stiffness, left ventricular hypertrophy (LVH) and microalbuminuria (MA). This cross-sectional study included CRHTN (n=51) and UCRHTN (n=38) patients for evaluating body mass index, ambulatory blood pressure monitoring, plasma adiponectin, leptin and resistin concentrations, pulse wave velocity (PWV), MA and echocardiography. Leptin and resistin levels were higher in UCRHTN, whereas adiponectin levels were lower in this same subgroup. Similarly, arterial stiffness, LVH and MA were higher in UCRHTN subgroup. Adiponectin levels negatively correlated with PWV (r=-0.42, P<0.01), and MA (r=-0.48, P<0.01) only in UCRHTN. Leptin was positively correlated with PWV (r=0.37, P=0.02) in UCRHTN subgroup, whereas resistin was not correlated with TOD in both subgroups. Adiponectin is associated with arterial stiffness and renal injury in UCRHTN patients, whereas leptin is associated with arterial stiffness in the same subgroup. Taken together, our results showed that those adipokines may contribute to vascular and renal damage in UCRHTN patients.

Construction materials as a waste management solution for cellulose sludge.

Sustainable waste management system for effluents treatment sludge has been a pressing issue for pulp and paper sector. Recycling is always recommended in terms of environmental sustainability. Following an approach of waste valorisation, this work aims to demonstrate the technical viability of producing fiber-cement roof sheets incorporating cellulose primary sludge generated on paper and pulp mills. From the results obtained with preliminary studies it was possible to verify the possibility of producing fiber-cement sheets by replacing 25% of the conventional used virgin long fiber by primary effluent treatment cellulose sludge. This amount of incorporation was tested on an industrial scale. Environmental parameters related to water and waste, as well as tests for checking the quality of the final product was performed. These control parameters involved total solids in suspension, dissolved salts, chlorides, sulphates, COD, metals content. In the product, parameters like moisture, density and strength were controlled. The results showed that it is possible to replace the virgin long fibers pulp by primary sludge without impacts in final product characteristics and on the environment. This work ensures the elimination of significant waste amounts, which are nowadays sent to landfill, as well as reduces costs associated with the standard raw materials use in the fiber-cement industrial sector.

Pulp and paper plant wastes valorisation in bituminous mixes.

Nowadays, the increasing amount of wastes is a concerning reality and the environmental aspects has become a major priority. Following this worry, the purpose of this experimental study was to investigate the possibility of using pulp and paper inorganic wastes, named dregs and grits, in bituminous mixtures as aggregate replacement to reduce environmental effects of these wastes disposal. First, the wastes were chemically and physically characterized and also tested primarily taking into account the requirements for aggregates in bituminous mixtures. Then, formulations were prepared replacing aggregates with wastes in different amounts. The mechanical properties of these mixtures containing wastes were compared with reference samples based on standard methods. According to the results it was possible to verify that grits had a good performance and it might be directly tested industrially as an aggregate in road construction. On the other hand, dregs need to be treated before incorporation to guarantee stable mixes in terms of water sensitivity.

The magnetic memory of Titan's ionized atmosphere.

After 3 years and 31 close flybys of Titan by the Cassini Orbiter, Titan was finally observed in the shocked solar wind, outside of Saturn's magnetosphere. These observations revealed that Titan's flow-induced magnetosphere was populated by "fossil" fields originating from Saturn, to which the satellite was exposed before its excursion through the magnetopause. In addition, strong magnetic shear observed at the edge of Titan's induced magnetosphere suggests that reconnection may have been involved in the replacement of the fossil fields by the interplanetary magnetic field.

Bezold-Jarisch reflex in myocardial infarcted rats.

The Bezold-Jarisch reflex (BJR), produced by the administration of 5-hydroxytryptamine (5-HT, 4-16 micrograms/kg, iv), was evaluated in awake rats bearing short- (1 day) or long-term (30 days) myocardial infarction. Heart chronotropic response produced by acetylcholine was further assessed by Langendorff's isolated heart perfusion technique. Compared to the sham-operated group, infarcted rats showed either hypotension and tachycardia or bradycardia following short- or long-term myocardial infarction, respectively. Whereas the long-term myocardial infarction attenuated 5-HT-induced hypotension and bradycardia by about -25 and -80%, respectively, no significant response changes were observed in short-term infarcted rats. Impairment of BJR correlated significantly (P < 0.01) with the extent of myocardial necrosis in the 30-days infarcted group. Chronotropic responsiveness of the heart to acetylcholine in infarcted rats did not differ from the sham-operated group. Transmural antero-medio-lateral infarcted areas spanned over nearly 37% (1-day group) and 35% (30-days group) of the left ventricular circumference. These results indicate that cardioinhibitory and vasodepressor reflex responses to 5-HT are significantly impaired in chronic myocardial infarction associated with (1) marked hypertrophy of left atrium and/or of non-infarcted left ventricle, which are the main origin of vagal chemosensitive C-fibers, (2) morphological damage of this innervation due to the necrotic injury of the left ventricle, (3), possible attenuation in the vagal afferents located in the lungs and/or (4) enhancement of the chemical sensitivity of cardiac sympathetic afferents.

[Evaluation of the vagal efferent pathway in rats in the acute and chronic phases of myocardial infarction]. / Avaliação da via eferente vagal em ratos nas fases aguda e crônica do infarto do miocárdio.

PURPOSE: To investigate the sensitivity of the muscarinic receptors to acetylcholine (Ach) and to vagal stimulation in rats during the acute and the chronic phases of myocardial infarction (MI). METHODS: Male albino rats were submitted to ligature of the descending anterior branches of the left coronary artery to produce MI. Control rats (Con) were submitted to a sham surgery. The animals were studied 1-3 days (acute phase) or 30 days (chronic phase) after surgery. Under anesthesia (ketamine+xylazine) the right vagus nerve was isolated at the neck and stimulated with suprathreshold pulses (2ms, 1-64Hz). Atrial and ventricular rates were measured in the ECG recording. Dose-response curve to Ach (5-80 micrograms) was studied in the isolated hearts perfused according to the Langendorftechnique. Atrial and ventricular rates were evaluated through the surface electrogram recording. The left ventricular pressure was measured with an intraventricular balloon. RESULTS: Basal heart rate in the anesthetized animals was similar in Con and MI rats. The vagal stimulation produced a frequency dependent reduction of the heart rate. This reduction was less intense in the MI groups to stimulation rates of 32 and 64Hz. It was not observed any difference in the sensitivity of sinus and AV nodes to exogenous Ach in infarcted hearts. The reduction of the systolic pressure obtained after Ach administration to the hearts paced artificially (3.3Hz) was similar in MI and Con hearts. CONCLUSION: MI hearts were less sensitive to vagal stimulation than Con hearts. Since the in vitro effects of Ach remained unchanged after infarction, these results suggest an impairment of the cardiac neuroeffector vagal synapse. This may contribute to a less efficient control of the heart rate by the parasympathetic pathway in infarcted individuals.