Continuous Electrochemical Reduction of CO to Formate: Comparative Study of the Influence of the Electrode Configuration with Sn and Bi-Based Electrocatalysts.

Climate change has become one of the most important challenges in the 21st century, and the electroreduction of CO to value-added products has gained increasing importance in recent years. In this context, formic acid or formate are interesting products because they could be used as raw materials in several industries as well as promising fuels in fuel cells. Despite the great number of studies published in the field of the electrocatalytic reduction of CO to formic acid/formate working with electrocatalysts of different nature and electrode configurations, few of them are focused on the comparison of different electrocatalyst materials and electrode configurations.

Prioritization of sediment management alternatives using stochastic multicriteria acceptability analysis.

Decision-making for sediment management is a complex task that requires the consideration of temporal and spatial impacts of several remedial alternatives as well as the associated economic, social and political impact. Multicriteria decision analysis (MCDA) is becoming increasingly recognized as an important environmental management tool that can be used to support the selection of suitable remediation alternatives and prioritization of management units in space and time. This paper proposes an MCDA framework for prioritizing sediment management alternatives.

Development of models for predicting toxicity from sediment chemistry by partial least squares-discriminant analysis and counter-propagation artificial neural networks.

There is strong interest in developing tools to link chemical concentrations of contaminants to the potential for observing sediment toxicity that can be used in initial screening-level sediment quality assessments. This paper presents new approaches for predicting toxicity in sediments, based on 10-day survival tests with marine amphipods, from sediment chemistry, by means of the application of Partial Least Squares-Discriminant Analysis (PLS-DA) and Counter-propagation Artificial Neural Networks (CP-ANNs) to large historical databases of chemical and toxicity data. The exploration of the internal structure of the developed models revealed inherent limitations of predicting toxicity from common chemical analyses of bulk contaminant concentrations.

A multicriteria-based methodology for site prioritisation in sediment management.

Decision-making for sediment management is a complex task that incorporates the selections of areas for remediation and the assessment of options for any mitigation required. The application of Multicriteria Analysis (MCA) to rank different areas, according to their need for sediment management, provides a great opportunity for prioritisation, a first step in an integrated methodology that finally aims to assess and select suitable alternatives for managing the identified priority sites. This paper develops a methodology that starts with the delimitation of management units within areas of study, followed by the application of MCA methods that allows ranking of these management units, according to their need for remediation.

Assessment of Self-Organizing Map artificial neural networks for the classification of sediment quality.

The application of mathematical tools in initial steps of sediment quality assessment frameworks can be useful to provide an integrated interpretation of multiple measured variables. This study reveals that the Self-Organizing Map (SOM) artificial neural network can be an effective tool for the integration of multiple physical, chemical and ecotoxicological variables in order to classify different sites under study according to their similar sediment quality. Sediment samples from 40 sites of 3 estuaries of Cantabria (Spain) were classified with respect to 13 physical, chemical and toxicological variables using the SOM.

Tempol improves renal hemodynamics and pressure natriuresis in hyperthyroid rats.

Hyperthyroidism in rats is associated with increased oxidative stress. These animals also show abnormal renal hemodynamics and an attenuated pressure-diuresis-natriuresis (PDN) response. We analyzed the role of oxidative stress as a mediator of these alterations by examining acute effects of tempol, a superoxide dismutase mimetic.

Sediment quality assessment and dredged material management in Spain: Part II, analysis of action levels for dredged material management and application to the Bay of Cádiz.

When sediments are removed from aquatic bottoms, they turn into dredged material that must be managed, taking into account its environmental impact. In Part II of this 2-part paper addressing sediment quality assessment and dredged material management in Spain, legislation and criteria used to regulate dredged material disposal at sea in different European countries are reviewed, as are action levels (ALs) derived by different countries used to evaluate management of dredged sediments from Cádiz Bay located on the South Atlantic coast of Spain. Comparison of ALs established for dredged material disposal by different countries reveals orders of magnitude differences in the values established for the same chemical.

Sediment quality assessment and dredged material management in Spain: Part I, application of sediment quality guidelines in the Bay of Santander.

Sediments are an essential component of aquatic ecosystems that must be assessed and managed properly. The use of quantitative environmental quality standards derived from consideration of sediment quality guidelines (SQGs) can be effective as part of a tiered risk assessment approach. In Part I of this 2-part paper addressing sediment quality assessment and dredged material management in Spain, different SQG methods are used to evaluate sediment quality in the Bay of Santander, located in the Cantabric Sea along the northern coast of Spain, and to guide development of empirically derived SQGs for marine sediments.

Toxicity bioassays in core sediments from the Bay of Santander, northern Spain.

The use of Vibrio fischeri as luminescence bacteria is particularly effective in evaluating contaminated sediment. In this study, the ecotoxicity of five core sediments from the Bay of Santander, northern Spain, utilising V. fischeri as marine bacterium, was carried out.

Chronic nitric oxide blockade modulates renal Na-K-2Cl cotransporters.

Objective: The Na-K-2Cl cotransporter (NKCC2 isoform) of the thick ascending limb of Henle's loop (TAL) plays an important role in renal sodium handling, and the vascular isoform (NKCC1) participates in the response to vasoconstrictors. Both isoforms appear to be regulated by nitric oxide. This study aimed to analyze the effect of chronic nitric oxide deficiency on tubular and vascular Na-K-2Cl cotransporters in kidney and their potential role in the development of N-nitro-L-arginine-methyl ester (L-NAME) hypertension.

Effects of chronic treatment with 7-nitroindazole in hyperthyroid rats.

This study analyzed the contribution of neuronal nitric oxide synthase (nNOS) to the hemodynamic manifestations of hyperthyroidism. The effects on hyperthyroid rats of the chronic administration of 7-nitroindazole (7-NI), an inhibitor of nNOS, were studied. Six groups of male Wistar rats were used: control, 7-NI (30 mg.

Vascular and renal function in experimental thyroid disorders.

This review focuses on the effects of thyroid hormones in vascular and renal systems. Special emphasis is given to the mechanisms by which thyroid hormones affect the regulation of body fluids, vascular resistance and, ultimately, blood pressure. Vascular function is markedly affected by thyroid hormones that produce changes in vascular reactivity and endothelial function in hyper- and hypothyroidism.

[Role of nitric oxide in the NKCC2 hyperactivity of Dahl "salt-sensitive" rats].

Renal NaCl reabsorption is increased in Dahl "salt-sensitive" (DS) rats, due to an increased activity of the Na-K-Cl cotransporter NKCC2. On the other hand, nitric oxide (NO) is an inhibitor of NKCC2 and a deficient nitric oxide synthase (NOS) seems to play an important role in salt-sensitivity of DS rats. Here, we investigated the hypothesis that NKCC2 hyperactivity in DS rats is due to a deficient NOS, via the interactions cyclic GMP (cGMP)/cyclic AMP (cAMP) at the level of the thick ascending Henle's loop (TAL).

The hemostatic agent ethamsylate promotes platelet/leukocyte aggregate formation in a model of vascular injury.

The hemostatic agent ethamsylate enhances membrane expression of P-selectin in human platelets, but whether this promotes platelet-leukocyte aggregate formation is unknown. Here we investigated this point by flow cytometry determination of human platelet-leukocyte aggregates under basal conditions and after whole-blood perfusion through a damaged rabbit aorta segment. Actions of ethamsylate on adhesive molecules of platelets and leukocytes were investigated in parallel.

Inhibition by reproterol of cAMP PDE in intact mastocytoma P-815 cells.

In vitro studies in rat mastocytes and human monocytes suggested that reproterol (a selective beta(2)-adrenoceptor agonist with a theophylline moiety) exerts anti-inflammatory actions through inhibition of cyclic AMP (cAMP) PDE activity. Thus, reproterol was tested for its ability to inhibit cAMP PDE in cultured mouse mastocytoma P-815 cells. cAMP PDE activity was measured in intact cells by spectrofluorometry using the fluorescent substrate 2'-O-anthraniloyl cAMP.

Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate.

The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into the rat peritoneal cavity.

Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants.

Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity.

The hemostatic agent ethamsylate enhances P-selectin membrane expression in human platelets and cultured endothelial cells.

Ethamsylate possesses antihemorrhagic properties, but whether or not it directly activates blood platelets is unclear. Here we investigated the platelet activation potential of ethamsylate, by measuring membrane P-selectin expression with flow cytometry in human whole blood and also by immunofluorescence imaging of isolated human platelets. Moreover, we measured membrane P-selectin expression in the SV40-transformed aortic rat endothelial cell line (SVAREC) and 14C-ethamsylate membrane binding and/or uptake in platelets and endothelial cells.

5-HT2A receptor antagonist properties of cyamemazine in rat and guinea pig smooth muscle.

5-HT(2A) receptor antagonism seems to explain the low incidence of extrapyramidal side effects with atypical neuroleptics. Whether the neuroleptic cyamemazine, which at low doses is also devoid of extrapyramidal side effects, possesses 5-HT(2A) receptor antagonist properties is unknown. Cyamemazine was tested for its ability to antagonize 5-HT(2A)-mediated responses in isolated rat aorta and guinea pig trachea and to displace [3H]ketanserin specifically bound to rat brain membranes.

Renal Na-K-Cl cotransporter NKCC2 in Dahl salt-sensitive rats.

Background: Dahl salt-sensitive (DS) rats are characterized by enhanced NaCl reabsorption in the loop of Henle, but the responsible ion transport protein is unknown.

Objective: To investigate renal Na-K-Cl cotransporter NKCC2 function and expression in DS rats under a low-salt diet.

Methods: NKCC2 functioning was assessed in vitro by measuring bumetanide-sensitive rubidium uptake and cytosolic chloride concentration in isolated medullary thick ascending limb (mTAL) tubules, and in vivo by measuring the salidiuretic action of orally given bumetanide.

Rat NKCC2/NKCC1 cotransporter selectivity for loop diuretic drugs.

It is generally assumed that bumetanide possesses some selectivity for the renal Na-K-Cl cotransporter NKCC2, although the results are scarce in the literature and comparisons were done with extra-renal NKCC1 at its basal, almost silent state. Here we investigated NKCC2/NKCC1 selectivity of loop diuretic drugs (bumetanide, piretanide and furosemide) as a function of the NKCC1 activated state (NKCC1 was activated by hypertonic media). NKCC2 activity was measured in isolated rat medullary thick ascending limb (mTAL) and NKCC1 in rat thymocytes and erythrocytes.

5-HT3- and 5-HT2C-antagonist properties of cyamemazine: significance for its clinical anxiolytic activity.

Rationale: Cyamemazine is a neuroleptic compound which possesses anxiolytic properties in humans. On the other hand, 5-HT3- and 5-HT2C-receptors have been implicated in anxiety disorders and a previous binding study has shown that cyamemazine possesses high affinity for both serotonin receptor types.

Objective: The present study was undertaken to establish whether cyamemazine antagonizes 5-HT3- and/or 5-HT2C-mediated responses, and whether it compares with reference compounds.