The influence of different co-catalysts in Pt-based ternary and quaternary electro-catalysts on the electro-oxidation of methanol and ethanol in acid media

One of the key objectives in fuel cell technology is to reduce Pt loading by the improvement of its catalytic activity towards alcohol oxidation. Here, a sol-gel based method was used to prepare ternary and quaternary carbon supported nanoparticles by combining Pt-Ru with Mo, Ta, Pb, Rh or Ir, which were used as electro-catalysts for the methanol and ethanol oxidation reactions in acid medium. Structural characterization performed by XRD measurements revealed that crystalline structures with crystallites ranging from 2.8 to 4.1 nm in size and with different alloy degrees were produced. Tantalum and lead deposited as a heterogeneous mixture of oxides with different valences resulting in materials with complex structures. The catalysts activities were evaluated by cyclic voltammetry and by Tafel plots and the results showed that the activity towards methanol oxidation was highly dependent of the alloy degree, while for ethanol the presence of a metal capable to promote the break of C-C bond, such as Rh, was necessary for a good performance. Additionally, the catalysts containing of TaOx or PbOx resulted in the best materials due to different effects: the hi-functional mechanism promoted by TaOx and a better dispersion of the catalysts constituents promoted by PbOx. (C) 2012 Elsevier B.V. All rights reserved.

Carboxypeptidases A1 and A2 from the perfusate of rat mesenteric arterial bed differentially process angiotensin peptides

Here we report the isolation of carboxypeptidases A1 and A2 (CPA1 and CPA2) from the rat mesenteric arterial bed perfusate, which were found to be identical with their pancreatic counterparts. Angiotensin (Ang) I, Ang II, Ang-(1-9) and Ang-(1-12) were differentially processed by these enzymes, worthy mentioning the peculiar CPA1-catalyzed conversion of Ang II to Ang-(1-7) and the CPA2-mediated formation of Ang I from Ang-(1-12). We detected gene transcripts for CPA1 and CPA2 in mesentery and other extrapancreatic tissues, indicating that these CPAs might play a role in the renin-angiotensin system in addition to their functions as digestive enzymes. (C) 2011 Elsevier Inc. All rights reserved.

Detection of DENV-4 genotype I from mosquitoes collected in the city of Manaus, Brazil

Background Dengue epidemics have been reported in Brazil since 1981. In Manaus, a large city in the Amazon region, dengue is endemic with all four-virus serotypes (DENV-1, -2, -3, and -4) simultaneously causing human disease. In 2008, during a surveillance of dengue virus in mosquitoes in the district of Tancredo Neves in Manaus, 260 mosquitoes of Aedes genus were captured, identified and grouped into pools of 10 mosquitoes. Findings RNA extracts of mosquito pools were tested by a RT-Hemi-Nested-PCR for detection of flaviviruses. One amplicon of 222 bp, compatible with dengue virus serotype 4, was obtained from a pool of Aedes aegypti. The nucleotide sequence of the amplicon indicated that the mosquitoes were infected with DENV-4 of genotype I. This virus of Asian origin has been described in Manaus in 2008 infecting acute febrile illness patients. Conclusion This is the first report of dengue virus serotype 4 genotype I infecting Aedes aegypti in the Americas.

Tidal perturbations of the rotation of the moon: the creep tide approach

In this communication we report results from the application to the study of the rotation of the Moon of the creeping tide theory just proposed (Ferraz-Mello, Cel. Mech. Dyn. Astron., submitted. ArXiv astro-ph 1204.3957). The choice of the Moon for the first application of this new theory is motivated by the fact that the Moon is one of the best observed celestial bodies and the comparison of the theoretical predictions of the theory with observations i may validate the theory or point out the need of further improvements. Particularly, the tidal perturbations of the rotation of the Moon - the physical libration of the Moon - have been detected in the Lunar Laser Ranging measurements (Williams et al. JGR 106, 27933, 2001). The major difficulty in this application comes from the fact that tidal torques in a planet-satellite system are very sensitive to the distance between the two-bodies, which is strongly affected by Solar perturbations. In the case of the Moon, the main solar perturbations - the Evection and the Variation - are more important than most of the Keplerian oscillations, being smaller only than the first Keplerian harmonic (equation of the centre). Besides, two of the three components of the Moon's libration in longitude whose tidal contributions were determined by LLR are related to these perturbations. The results may allow us to determine the main parameter of a possible Moon's creeping tide. The preliminary results point to a relaxation factor (gamma) 2 to 4 times smaller than the one predicted from the often cited values of thr Moon's quality factor Q (between 30 and 40), and points to larger Q values.

The role of Nox2-derived ROS in the development of cognitive impairment after sepsis

BACKGROUND: Sepsis- associated encephalopathy (SAE) is an early and common feature of severe infections. Oxidative stress is one of the mechanisms associated with the pathophysiology of SAE. The goal of this study was to investigate the involvement of NADPH oxidase in neuroinflammation and in the long-term cognitive impairment of sepsis survivors. METHODS: Sepsis was induced in WT and gp91phox knockout mice (gp91phox-/-) by cecal ligation and puncture (CLP) to induce fecal peritonitis. We measured oxidative stress, Nox2 and Nox4 gene expression and neuroinflammation in the hippocampus at six hours, twenty-four hours and five days post-sepsis. Mice were also treated with apocynin, a NADPH oxidase inhibitor. Behavioral outcomes were evaluated 15 days after sepsis with the inhibitory avoidance test and the Morris water maze in control and apocynin-treated WT mice. RESULTS: Acute oxidative damage to the hippocampus was identified by increased 4-HNE expression in parallel with an increase in Nox2 gene expression after sepsis. Pharmacological inhibition of Nox2 with apocynin completely inhibited hippocampal oxidative stress in septic animals. Pharmacologic inhibition or the absence of Nox2 in gp91phox-/- mice prevented glial cell activation, one of the central mechanisms associated with SAE. Finally, treatment with apocynin and inhibition of hippocampal oxidative stress in the acute phase of sepsis prevented the development of long-term cognitive impairment. CONCLUSIONS: Our results demonstrate that Nox2 is the main source of reactive oxygen species (ROS) involved in the oxidative damage to the hippocampus in SAE and that Nox2-derived ROS are determining factors for cognitive impairments after sepsis. These findings highlight the importance of Nox2-derived ROS as a central mechanism in the development of neuroinflammation associated with SAE.

The Making of a Shiite Bourgeoisie in Lebanon Political Mobilisation, Economic Resources and Formation of a Social Group

The thesis analyses the making of the Shiite middle- and upper/entrepreneurial-class in Lebanon from the 1960s till the present day. The trajectory explores the historical, political and social (internal and external) factors that brought a sub-proletariat to mobilise and become an entrepreneurial bourgeoisie in the span of less than three generations. This work proposes the main theoretical hypothesis to unpack and reveal the trajectory of a very recent social class that through education, diaspora, political and social mobilisation evolved in a few years into a very peculiar bourgeoisie: whereas Christian-Maronite middle class practically produced political formations and benefited from them and from Maronite’s state supremacy (National Pact, 1943) reinforcing the community’s status quo, Shiites built their own bourgeoisie from within, and mobilised their “cadres” (Boltanski) not just to benefit from their renovated presence at the state level, but to oppose to it. The general Social Movement Theory (SMT), as well as a vast amount of the literature on (middle) class formation are therefore largely contradicted, opening up new territories for discussion on how to build a bourgeoisie without the state’s support (Social Mobilisation Theory, Resource Mobilisation Theory) and if, eventually, the middle class always produces democratic movements (the emergence of a social group out of backwardness and isolation into near dominance of a political order). The middle/upper class described here is at once an economic class related to the control of multiple forms of capital, and produced by local, national, and transnational networks related to flows of services, money, and education, and a culturally constructed social location and identity structured by economic as well as other forms of capital in relation to other groups in Lebanon.

Inflammatory Biomarkers in Patients with Posttraumatic Stress Disorder Caused by Myocardial Infarction and the Role of Depressive Symptoms

Inflammation might link posttraumatic stress disorder (PTSD) with an increased risk of cardiovascular events. We explored the association between PTSD and inflammatory biomarkers related to cardiovascular morbidity and the role of co-morbid depressive symptoms in this relationship.

Cold ischemia contributes to the development of chronic rejection and mitochondrial injury after cardiac transplantation

Chronic rejection (CR) remains an unsolved hurdle for long-term heart transplant survival. The effect of cold ischemia (CI) on progression of CR and the mechanisms resulting in functional deficit were investigated by studying gene expression, mitochondrial function, and enzymatic activity. Allogeneic (Lew F344) and syngeneic (Lew Lew) heart transplantations were performed with or without 10 h of CI. After evaluation of myocardial contraction, hearts were excised at 2, 10, 40, and 60 days for investigation of vasculopathy, gene expression, enzymatic activities, and mitochondrial respiration. Gene expression studies identified a gene cluster coding for subunits of the mitochondrial electron transport chain regulated in response to CI and CR. Myocardial performance, mitochondrial function, and mitochondrial marker enzyme activities declined in all allografts with time after transplantation. These declines were more rapid and severe in CI allografts (CR-CI) and correlated well with progression of vasculopathy and fibrosis. Mitochondria related gene expression and mitochondrial function are substantially compromised with the progression of CR and show that CI impacts on progression, gene profile, and mitochondrial function of CR. Monitoring mitochondrial function and enzyme activity might allow for earlier detection of CR and cardiac allograft dysfunction.

Multicentre evaluation of a new point-of-care test for the determination of NT-proBNP in whole blood

BACKGROUND: The Roche CARDIAC proBNP point-of-care (POC) test is the first test intended for the quantitative determination of N-terminal pro-brain natriuretic peptide (NT-proBNP) in whole blood as an aid in the diagnosis of suspected congestive heart failure, in the monitoring of patients with compensated left-ventricular dysfunction and in the risk stratification of patients with acute coronary syndromes. METHODS: A multicentre evaluation was carried out to assess the analytical performance of the POC NT-proBNP test at seven different sites. RESULTS: The majority of all coefficients of variation (CVs) obtained for within-series imprecision using native blood samples was below 10% for both 52 samples measured ten times and for 674 samples measured in duplicate. Using quality control material, the majority of CV values for day-to-day imprecision were below 14% for the low control level and below 13% for the high control level. In method comparisons for four lots of the POC NT-proBNP test with the laboratory reference method (Elecsys proBNP), the slope ranged from 0.93 to 1.10 and the intercept ranged from 1.8 to 6.9. The bias found between venous and arterial blood with the POC NT-proBNP method was < or =5%. All four lots of the POC NT-proBNP test investigated showed excellent agreement, with mean differences of between -5% and +4%. No significant interference was observed with lipaemic blood (triglyceride concentrations up to 6.3 mmol/L), icteric blood (bilirubin concentrations up to 582 micromol/L), haemolytic blood (haemoglobin concentrations up to 62 mg/L), biotin (up to 10 mg/L), rheumatoid factor (up to 42 IU/mL), or with 50 out of 52 standard or cardiological drugs in therapeutic concentrations. With bisoprolol and BNP, somewhat higher bias in the low NT-proBNP concentration range (<175 ng/L) was found. Haematocrit values between 28% and 58% had no influence on the test result. Interference may be caused by human anti-mouse antibodies (HAMA) types 1 and 2. No significant influence on the results with POC NT-proBNP was found using volumes of 140-165 muL. High NT-proBNP concentrations above the measuring range of the POC NT-proBNP test did not lead to false low results due to a potential high-dose hook effect. CONCLUSIONS: The POC NT-proBNP test showed good analytical performance and excellent agreement with the laboratory method. The POC NT-proBNP assay is therefore suitable in the POC setting.

Exploring the periodicity of cardiovascular events in Switzerland: Variation in deaths and hospitalizations across seasons, day of the week and hour of the day

Purpose The purpose of this study is to explore the periodical patterns of events and deaths related to cardiovascular disease (CVD), acute myocardial infarction (AMI) and stroke in Swiss adults (≥18years). Methods Mortality data for period 1969–2007 (N=869,863 CVD events) and hospitalization data for period 1997–2008 (N=959,990 CVD events) were used. The annual, weekly and circadian distribution of CVD-related deaths and events were assessed. Multivariate analysis was conducted using multinomial logistic regression adjusting for age, gender and calendar year and considering deaths from respiratory diseases, accidents or other causes as competitive events. Results CVD deaths and hospitalizations occurred less frequently in the summer months. Similar patterns were found for AMI and stroke. No significant weekly variation for CVD deaths was found. Stratification by age and gender showed subjects aged <65years to present a higher probability of dying on Mondays and Saturday, only for men. This finding was confirmed after multivariate adjustment. Finally, a circadian variation in CVD mortality was observed, with a first peak in the morning (8–12am) and a smaller second peak in the late afternoon (2–6pm). This pattern persisted after multivariate adjustment and was more pronounced for AMI than for stroke. Conclusion There is a periodicity of hospitalizations and deaths related to CVD, AMI and stroke in Switzerland. This pattern changes slightly according to the age and sex of the subjects. Although the underlying mechanisms are not fully identified, preventive measures should take into account these aspects to develop better strategies of prevention and management of CVD.

The ABCs of membrane transporters in health and disease (SLC series): introduction

The field of transport biology has steadily grown over the past decade and is now recognized as playing an important role in manifestation and treatment of disease. The SLC (solute carrier) gene series has grown to now include 52 families and 395 transporter genes in the human genome. A list of these genes can be found at the HUGO Gene Nomenclature Committee (HGNC) website (see www.genenames.org/genefamilies/SLC). This special issue features mini-reviews for each of these SLC families written by the experts in each field. The existing online resource for solute carriers, the Bioparadigms SLC Tables (www.bioparadigms.org), has been updated and significantly extended with additional information and cross-links to other relevant databases, and the nomenclature used in this database has been validated and approved by the HGNC. In addition, the Bioparadigms SLC Tables functionality has been improved to allow easier access by the scientific community. This introduction includes: an overview of all known SLC and "non-SLC" transporter genes; a list of transporters of water soluble vitamins; a summary of recent progress in the structure determination of transporters (including GLUT1/SLC2A1); roles of transporters in human diseases and roles in drug approval and pharmaceutical perspectives.

High proportion of healthcare-associated urinary tract infection in the absence of prior exposure to urinary catheter: a cross-sectional study

Exposure to urinary catheters is considered the most important risk factor for healthcare-associated urinary tract infection (UTI) and is associated with significant morbidity and substantial extra-costs. In this study, we assessed the impact of urinary catheterisation (UC) on symptomatic healthcare-associated UTI among hospitalized patients.