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Purpose: To analyze the functions of the stomatognathic system in children with or without molar-incisor hypomineralization (MIH). Methods: For this cross-sectional study, 72 children aged 6–12 years were recruited and divided in two groups: with MIH (G1) and without MIH (G2). T-SCAN was used to verify the distribution of occlusal contacts, gnathodynamometer to measure maximum molar bite force, and Iowa Oral Pressure Instrument (IOPI) to assess the strength of facial expression muscles. The t test and paired t test (p ≤ 0.05) were used for statistical comparisons. Results: The molars affected by MIH exhibited lower distribution of occlusal forces (p < 0.001) and lower maximum molar bite force (p < 0.05) compared to the molars in the control group. However, there was no difference between the MIH-affected sides compared to the unaffected side, nor between the molars affected by MIH and their antagonists (p > 0.05). There were no differences in the forces of the facial expression muscles between the groups. Conclusions: These findings suggest that MIH significantly impacts occlusal force distribution and bite force, but not facial expression musculature. [ABSTRACT FROM AUTHOR]

Large-scale flank collapses are one of the main hazards associated with the evolution of volcanic islands. Precisely dating such events is critical to evaluate the frequency of destabilization episodes and further assess the triggering mechanism(s) associated with internal and/or external factors, such as volcano dynamics, regional tectonics, and global paleoclimatic changes. Here, we constrain the age of a pumice-rich pyroclastic deposit exposed on the eastern flank of Flores Island (Azores), which we interpret as a co-blast deposit generated by a major flank collapse that destroyed the whole western flank of the former volcanic edifice. Twelve single-grain 40Ar/39Ar analyses, performed on 250–500 µm anorthoclase feldspars (mean K/Ca close to 5) with our high-sensitivity multi-collector NGX mass spectrometer, provide a robust weighted mean age of 1.32 ± 0.01 Ma for this eruption. This new age is consistent with previous K/Ar data bracketing the flank collapse between 1.30 ± 0.04 and 1.18 ± 0.09 Ma, and indicates that this event occurred at the end of the main construction phase of the volcano. The explosion produced pumice-rich layers preceded by a lahar as attested by a polygenetic mudflow deposit underlying the dated deposit. From the geochemistry of lavas erupted just before and after the collapse, we speculate upon the possible role of magmatic processes on flank destabilization. We propose a first hypothesis where differentiation in a shallow magma reservoir could have favored edifice inflation, ground shaking, and flank failure, triggering a decompression-induced violent eruption. Overall, our study shows that high-sensitivity mass spectrometers have now reached analytical performances allowing to measure precisely and accurately ages on relatively small and moderately K-rich single feldspars, which is of the utmost importance for dating heterogeneous blasts and tephra deposits that may have been induced by large-scale flank collapses during the late Quaternary. [ABSTRACT FROM AUTHOR]

Aim: The objective of this study was to investigate whether dental hypersensitivity and dental fear were linked to the presence and severity of MIH. Methods: For this cross-sectional study, 1830 students between the ages of 6 and 12 years were recruited from four randomly selected schools. The Children's Fear Survey Schedule-Dental Subscale questionnaire was used to assess dental anxiety and fear. The children's self-reported dental hypersensitivity resulting from MIH was evaluated using the Wong-Baker Facial Scale and the Visual Analog Scale (VAS). Results: MIH was correlated with tooth hypersensitivity, particularly in severe cases. Dental fear was present in 17.4% of the children with MIH, but it was not associated with dental hypersensitivity, gender, or age. Conclusion: No association was found between dental fear and dental hypersensitivity in children with MIH. [ABSTRACT FROM AUTHOR]

MgO-doped partially stabilized zirconia (xMgPSZ, with x = 8 or 10 mol%) materials sintered at 1700°C, were characterized with respect to structure, microstructure, thermal expansion and electrical performance. The monoclinic (M) phase content is almost vestigial in 10MgPSZ, unlike in 8MgPSZ. Combined powder XRD and customized thermal expansion data analysis, allowed a separation between M and tetragonal (T) particles, outside or imbedded in cubic grains. Combination of thermal expansion and impedance spectroscopy data provided novel insights on the totally distinct roles of fine and dispersed T or M particles within the PSZ cubic matrix grains. [ABSTRACT FROM AUTHOR]

Stall flutter is turning into a more likely condition to be encountered as the demand for increasingly more flexible wings grows for HALE-like aircraft. Due to the various nonlinearities involved that can lead to complex motion, the characterization of the dynamical behavior in the post-flutter condition becomes important. The dynamics of a pitch–plunge idealized HALE typical section with aerodynamic, structural and kinematic nonlinearities in the stall flutter regime was investigated using an aeroelastic state-space formulation which includes a modified Beddoes-Leishman dynamic stall model. The results reveal that period-doubling was possible without stall, but chaos arose at discontinuity-induced bifurcations due to dynamic stall. A parametric study has been conducted to assess the influence of key parameters in the development of bifurcations and chaos. [ABSTRACT FROM AUTHOR]

Santa Maria is the oldest island in the Azores, formerly belonging to the Eurasia plate and currently the only one sitting on the Nubia Plate, thus sharing a geodynamic evolution with the Azores Triple Junction. It is therefore important to evaluate the effects of active tectonics on the evolution of Santa Maria, for example on its vertical movements. We present new stratigraphic, geomorphologic, structural and geochronological data from Santa Maria which shed further light on how a volcanic ocean island evolves in a tectonically active setting. Santa Maria island started with a first shield volcano (Old Volcanic Complex) that emerged ca. 6.0 Ma ago and was active until ca. 5.3 Ma. The short time span between the first and second shield volcanoes (ca. 0.3 Ma) and the preservation of only the western flank of this first shield volcano indicate an initial flank collapse at ca. 5 Ma. The collapse scar was covered by an eastwards dipping sedimentary complex (Intermediate Sedimentary Complex), with a likely tsunami deposit at the base. A second shield volcano (Young Volcanic Complex) rapidly grew on these sediments from 4.8 to 3.8 Ma, and the island subsided by more than 100 m. At 3.7 Ma, a second flank collapse occurred, as inferred from the missing summit and eastern flank. Volcanism then resumed (3.6 to 2.8 Ma), giving rise to Strombolian cones lying unconformably on the collapse scar and conformable parasitic cones on the unaffected flank. Submarine lavas occurring at up to 200 m altitude with a youngest age of 3.0 Ma indicate major uplift of the island since, at most, that time. Here we interpret uplift as the result of rift flank uplift on the southern shoulder of the nearby Terceira Rift in the last ca. 1.5 Ma. [ABSTRACT FROM AUTHOR]

Preclinical imaging studies offer a unique access to the rat brain, allowing investigations that go beyond what is possible in human studies. Unfortunately, these techniques still suffer from a lack of dedicated and standardized neuroimaging tools, namely brain templates and descriptive atlases. Here, we present two rat brain MRI templates and their associated gray matter, white matter and cerebrospinal fluid probability maps, generated from ex vivo T 2 * -weighted images (90 µm isotropic resolution) and in vivo T2-weighted images (150 µm isotropic resolution). In association with these templates, we also provide both anatomical and functional 3D brain atlases, respectively derived from the merging of the Waxholm and Tohoku atlases, and analysis of resting-state functional MRI data. Finally, we propose a complete set of preclinical MRI reference resources, compatible with common neuroimaging software, for the investigation of rat brain structures and functions. Magnetic resonance imaging (MRI) is widely used to study the rat brain. Here, the authors provide standardized MRI brain templates and descriptive atlases for the rat, incorporating both structural and functional MRI data, along with associated resources. [ABSTRACT FROM AUTHOR]

In the last decades, the Volterra series theory has been used to construct reduced-order models of nonlinear systems in engineering and applied sciences. For the particular case of weakly nonlinear aerodynamic and aeroelastic systems, the Volterra series theory has been tested as an alternative to the high computing costs of CFD methods. The Volterra series model determination depends on identifying the kernels associated with the respective convolution integrals. The Volterra kernels identification has been tried in many ways, but the majority of them addresses only the direct kernels of single-input, single-output nonlinear systems. However, multiple-input, multiple-output relations are the most typical case for many dynamic systems. In this case, the so-called Volterra cross-kernels represent the internal couplings between multiple inputs. Not many generalizations of the single-input kernel identification methods to multi-input Volterra kernels are available in the literature. This work proposes a methodology for the identification of Volterra direct kernels and cross-kernels, which is based on time-delay neural networks and the relationship between the kernels functions and the internal parameters of the network. Expressions to derive the pth-order Volterra direct kernels and cross-kernels from the internal parameters of a trained time-delay neural network are derived. The method is checked with a two-degree-of-freedom, two-input, one-output nonlinear system to demonstrate its capabilities. The application to a mildly nonlinear unsteady aerodynamic loading due to pitching and heaving motions of an airfoil is also evaluated. The Volterra direct kernels and cross-kernels of up to third order are successfully identified using training datasets computed with CFD simulations of the Euler equations. Comparisons between CFD simulations and Volterra model predictions are presented, thereby ensuring the potential of the method to systematically extract kernels from neural networks. [ABSTRACT FROM AUTHOR]

Summary: The association of genetic polymorphisms with low bone mineral density in elite athletes have not been considered previously. The present study found that bone mass phenotypes in elite and pre-elite dancers are related to genetic variants at the Wnt/β-catenin and ER pathways.Introduction: Some athletes (e.g. gymnasts, dancers, swimmers) are at increased risk for low bone mineral density (BMD) which, if untreated, can lead to osteoporosis. To investigate the association of genetic polymorphisms in the oestrogen receptor (ER) and the Wnt/β-catenin signalling pathways with low BMD in elite and pre-elite dancers (impact sport athletes).Methods: The study included three phases: (1) 151 elite and pre-elite dancers were screened for the presence of low BMD and traditional osteoporosis risk factors (low body weight, menstrual disturbances, low energy availability); (2) a genetic association study was conducted in 151 elite and pre-elite dancers and age- and sex- controls; (3) serum sclerostin was measured in 101 pre-elite dancers and age- and sex-matched controls within a 3-year period.Results: Eighty dancers revealed low BMD: 56.3% had at least one traditional osteoporosis risk factor, whereas 28.6% did not display any risk factor (37.2% revealed traditional osteoporosis risk factors, but had normal BMD). Body weight, menstrual disturbances and energy availability did not fully predict bone mass acquisition. Instead, genetic polymorphisms in the ER and Wnt/β-catenin pathways were found to be risk factors for low BMD in elite dancers. Sclerostin was significantly increased in dancers compared to controls during the 3-year follow-up (p < 0.05).Conclusions: Elite and pre-elite dancers demonstrate high prevalence of low BMD, which is likely related to genetic variants at the Wnt/β-catenin and ER pathways and not to factors usually associated with BMD in athletes (body weight, menstrual disturbances, energy deficiency). [ABSTRACT FROM AUTHOR]

3,4-Methylenedioxymethamphetamine (MDMA or “ecstasy”) is a widespread drug of abuse with known neurotoxic properties. The present study aimed to evaluate the differential toxic effects of MDMA in adolescent and aged Wistar rats, using doses pharmacologically comparable to humans. Adolescent (post-natal day 40) (3 × 5 mg/kg, 2 h apart) and aged (mean 20 months old) (2 × 5 mg/kg, 2 h apart) rats received MDMA intraperitoneally. Animals were killed 7 days later, and the frontal cortex, hippocampus, striatum and cerebellum brain areas were dissected, and heart, liver and kidneys were collected. MDMA caused hyperthermia in both treated groups, but aged rats had a more dramatic temperature elevation. MDMA promoted serotonergic neurotoxicity only in the hippocampus of aged, but not in the adolescents’ brain, and did not change the levels of dopamine or serotonin metabolite in the striatum of both groups. Differential responses according to age were also seen regarding brain p-Tau levels, a hallmark of a degenerative brain, since only aged animals had significant increases. MDMA evoked brain oxidative stress in the hippocampus and striatum of aged, and in the hippocampus, frontal cortex, and striatum brain areas of adolescents according to protein carbonylation, but only decreased GSH levels in the hippocampus of aged animals. The brain maturational stage seems crucial for MDMA-evoked serotonergic neurotoxicity. Aged animals were more susceptible to MDMA-induced tissue damage in the heart and kidneys, and both ages had an increase in liver fibrotic tissue content. In conclusion, age is a determinant factor for the toxic events promoted by “ecstasy”. This work demonstrated special susceptibility of aged hippocampus to MDMA neurotoxicity, as well as impressive damage to the heart and kidney tissue following “ecstasy”. [ABSTRACT FROM AUTHOR]

Summary: According to existing literature, bone health in ballet dancers is controversial. We have verified that, compared to controls, young female and male vocational ballet dancers have lower bone mineral density (BMD) at both impact and non-impact sites, whereas female professional ballet dancers have lower BMD only at non-impact sites. Introduction: The aims of this study were to (a) assess bone mineral density (BMD) in vocational (VBD) and professional (PBD) ballet dancers and (b) investigate its association with body mass (BM), fat mass (FM), lean mass (LM), maturation and menarche. Methods: The total of 152 VBD (13 ± 2.3 years; 112 girls, 40 boys) and 96 controls (14 ± 2.1 years; 56 girls, 40 boys) and 184 PBD (28 ± 8.5 years; 129 females, 55 males) and 160 controls (27 ± 9.5 years; 110 female, 50 males) were assessed at the lumbar spine (LS), femoral neck (FN), forearm and total body by dual-energy X-ray absorptiometry. Maturation and menarche were assessed via questionnaires. Results: VBD revealed lower unadjusted BMD at all anatomical sites compared to controls ( p < 0.001); following adjustments for Tanner stage and gynaecological age, female VBD showed similar BMD values at impact sites. However, no factors were found to explain the lower adjusted BMD values in VBD (female and male) at the forearm (non-impact site), nor for the lower adjusted BMD values in male VBD at the FN. Compared to controls, female PBD showed higher unadjusted and adjusted BMD for potential associated factors at the FN (impact site) ( p < 0.001) and lower adjusted at the forearm ( p < 0.001). Male PBD did not reveal lower BMD than controls at any site. Conclusions: Both females and males VBD have lower BMD at impact and non-impact sites compared to control, whereas this is only the case at non-impact site in female PBD. Maturation seems to explain the lower BMD at impact sites in female VBD. [ABSTRACT FROM AUTHOR]

MgO-doped partially stabilized zirconia is a complex ceramic electrolyte in which all properties, phase composition, and microstructure are strongly influenced by thermal history besides chemical composition. The electrochemical performance of this ceramic used in oxygen sensors for molten steel is reviewed here. A wide collection of data on electrical properties obtained at various temperatures (up to 1600 °C) and oxygen partial pressures (from 1 atm to values below 10 atm) is considered. New aspects are brought to evidence after proper handling of published data on undoped zirconia and MgO-doped materials. The close temperature dependencies of the lower limits of the ionic domains of all these materials suggest the relevance of acceptor-type contaminations on the performance of nominally pure materials. High ionic mobility in the tetragonal phase with respect to the cubic phase is also likely, based on published data. Dopants like YO originate wider ionic domains but are not equally effective with respect to thermal shock resistance. The unique characteristics of MgO-doped zirconia are due to the coexistence of distinct phases, including large populations of finely dispersed monoclinic and/or tetragonal phases within cubic matrix grains. An overview of key features (materials and design) involved in the performance of oxygen sensors for molten steel is also provided. Graphical abstract: Typical microstructure of Mg-PSZ with multiple phases and interfaces [ABSTRACT FROM AUTHOR]

Unravelling the complete genetic predisposition to high blood pressure (BP) has proven to be challenging. This puzzle and the fact that coding regions of the genome account for less than 2% of the entire human DNA support the hypothesis that genetic mechanism besides coding genes are likely to contribute to BP regulation. Non-coding RNAs (ncRNAs) are emerging as key players of transcription regulation in both health and disease states. They control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct involvement with BP regulation is highly probable. Here, we review the literature about ncRNAs associated with human BP and essential hypertension, highlighting investigations, methodology and difficulties arising in the field. The most investigated ncRNAs so far are microRNAs (miRNAs), small ncRNAs that modulate gene expression by posttranscriptional mechanisms. We discuss studies that have examined miRNAs associated with BP in biological fluids, such as blood and urine, and tissues, such as vascular smooth muscle cells and the kidney. Furthermore, we review the interaction between miRNA binding sites and single nucleotide polymorphisms in genes associated with BP. In conclusion, there is a clear need for more human and functional studies to help elucidate the multifaceted roles of ncRNAs, in particular mid- and long ncRNAs in BP regulation. [ABSTRACT FROM AUTHOR]

The production, accumulation and aggregation of amyloid beta (Aβ) peptides in Alzheimer's disease (AD) are influenced by different modulators. Among these are iron and iron-related proteins, given their ability to modulate the expression of the amyloid precursor protein and to drive Aβ aggregation. Herein, we describe that lipocalin 2 (LCN2), a mammalian acute-phase protein involved in iron homeostasis, is highly produced in response to Aβ1-42 by choroid plexus epithelial cells and astrocytes, but not by microglia or neurons. Although Aβ1-42 stimulation decreases the dehydrogenase activity and survival of wild-type astrocytes, astrocytes lacking the expression of Lcn2 are not affected. This protection results from a lower expression of the proapoptotic gene Bim and a decreased inflammatory response. Altogether, these findings show that Aβ toxicity to astrocytes requires LCN2, which represents a novel mechanism to target when addressing AD. [ABSTRACT FROM AUTHOR]

Interest in astroglial cells is rising due to recent findings supporting dynamic neuron-astrocyte interactions. There is increasing evidence of astrocytic dysfunction in several brain disorders such as depression, schizophrenia or bipolar disorder; importantly these pathologies are characterized by the involvement of the prefrontal cortex and by significant cognitive impairments. Here, to model astrocyte pathology, we injected animals with the astrocyte specific toxin L-α-aminoadipate (L-AA) in the medial prefrontal cortex (mPFC); a behavioral and structural characterization two and six days after the injection was performed. Behavioral data shows that the astrocyte pathology in the mPFC affects the attentional set-shifting, the working memory and the reversal learning functions. Histological analysis of brain sections of the L-AA-injected animals revealed a pronounced loss of astrocytes in the targeted region. Interestingly, analysis of neurons in the lesion sites showed a progressive neuronal loss that was accompanied with dendritic atrophy in the surviving neurons. These results suggest that the L-AA-induced astrocytic loss in the mPFC triggers subsequent neuronal damage leading to cognitive impairment in tasks depending on the integrity of this brain region. These findings are of relevance to better understand the pathophysiological mechanisms underlying disorders that involve astrocytic loss/dysfunction in the PFC. [ABSTRACT FROM AUTHOR]

The implantation of argon in tetrahedral amorphous carbon (ta-C), deposited by the filtered cathodic vacuum arc technique and concurrently bombarded with argon ions (Ar), is investigated in this study. The ta-C films were prepared with a 5-ms DC-pulsed arc, a current of 190 A, and a frequency of 3 Hz, and they were deposited on a ground substrate holder. The argon atoms were implanted into the film by simultaneously bombarding the films with a beam of Ar in the 0-180 eV energy range. The concentration of argon, determined by Rutherford backscattering spectroscopy, was investigated as a function of the Ar energy. Raman scattering spectroscopy was used to investigate the structure of the films. The stress of the films depends on the Ar energy and reduces significantly as a function of the annealing temperature. A study of argon effusion, ranging from room temperature up to 1000 °C, shows that the argon atoms evolve from the films at different temperatures depending on the Ar energy. Scanning electron microscopy revealed the formation of bubbles after argon effusion. It was observed that the structural transformations that promote the relaxation of the carbon matrix and the argon effusion are different from each other. [ABSTRACT FROM AUTHOR]

Abstract: Background: The prevalence of atrial fibrillation increases substantially with age. As atrial fibrillation carries a higher risk of thromboembolic events, several scores have been developed to estimate thromboembolic and bleeding risk in order to help with the prophylactic decision. Objective: To determine thromboembolic and bleeding risk of elderly with atrial fibrillation according to CHADS2, CHA2DS2-VASc and HASBLED and its repercussions on thromboembolic prophylaxis. Methods: Retrospective, observational study including 142 consecutively hospitalized patients over 65 years old, with non-valvular atrial fibrillation/flutter. CHADS2 and CHA2DS2-VASc were applied and compared and HASBLED score was used to estimate haemorrhagic risk. The adequacy of prescribed antithrombotic therapy was evaluated. Long-term follow-up of thromboembolic and haemorrhagic events was carried out. Results: None of the elderly patients were allocated to the low-risk category according to CHADS2 and CHA2DS2-VASc risk stratification. CHADS2 classified 32 (22.5%) patients at moderate risk, while CHA2DS2-VASc score classified all patients at high risk. Applying the HASBLED score, 57 (40.1%) had high haemorrhagic risk. Although by CHA2DS2-VASc all patients had a formal indication for anticoagulation, only 77 (54.2%) were anticoagulated. Age was found to be a common criteria for withholding oral anticoagulation. The thromboembolic event rate was 2.6% for anticoagulated patients and 11.5% for not anticoagulated ones, while major haemorrhages occurred in 6.5% anticoagulated and 1.5% not anticoagulated patients. Conclusions: All elderly with atrial fibrillation had high thromboembolic risk, better predicted by CHA2DS2-VASc. Anticoagulation, the only factor that can alter prognosis, was underused despite the evidence of the scores. Paradoxically, age alone was frequently considered a contra-indication for anticoagulation. [Copyright &y& Elsevier]

The Cryptococcus neoformans species complex contains the most important agents of fungal meningoencephalitis. Therapeutic choices are limited and issues related to toxicity and resistance to antifungals have been described. The present study evaluated the inhibitory effect of the antifolate combinations sulfamethoxazole-trimethoprim (SMX/TMP) and sulfadiazine-pyrimethamine (SDZ/PYR) against planktonic cells and biofilms of C. neoformans and C. gattii. The influence of the antifolate combinations on the amphotericin minimum inhibitory concentration (MIC) of planktonic cells was also investigated. In addition, the effect of these combinations on the cellular ergosterol content of planktonic cells was studied. Strains of C. neoformans ( n = 15) and C. gattii ( n = 15) obtained from environmental or clinical sources were evaluated by the broth microdilution method. SMX/TMP and SDZ/PYR showed antifungal activity against free living cells and sessile cells of Cryptococcus spp. Moreover, planktonic cells showed increased susceptibility to amphotericin B after pre-incubation with sub-inhibitory concentrations of SMX/TMP or SDZ/PYR. The drug combinations SMX/TMP and SDZ/PYR were able to prevent the biofilm formation and showed inhibitory effect against mature biofilms of both species. Additionally, the study showed that antifolate drugs reduced the ergosterol content in C. neoformans and C. gattii planktonic cells. Our results highlight the antifungal potential of antifolate drugs. [ABSTRACT FROM AUTHOR]

Although several studies have demonstrated an association between the 7-repeat (7R) allele in the 48-bp variable number of tandem repeats (VNTRs) in the exon 3 at dopamine receptor D4 (DRD4) gene and attention-deficit/hyperactivity disorder (ADHD), others failed to replicate this finding. In this study, a total of 786 individuals with ADHD were genotyped for DRD4 exon 3 VNTR. All 7R homozygous subjects were selected for VNTR re-sequencing. Subjects homozygous for the 4R allele were selected paired by age, ancestry and disorder subtypes in order to have a sample as homogeneous as possible with 7R/7R individuals. Using these criteria, 103 individuals (66 with ADHD and 37 control individuals) were further investigated. An excess of rare variants were observed in the 7R alleles of ADHD patient when compared with controls (P=0.031). This difference was not observed in 4R allele. Furthermore, nucleotide changes that predict synonymous and non-synonymous substitutions were more common in the 7R sample (P=0.008 for total substitutions and P=0.043 for non-synonymous substitutions). In silico prediction of structural/functional alterations caused by these variants have also been observed. Our findings suggest that not only repeat length but also DNA sequence should be assessed to better understand the role of DRD4 exon 3 VNTR in ADHD genetic susceptibility. [ABSTRACT FROM AUTHOR]

Neospora caninum is a protozoan parasite that causes the most important reproductive problems in cattle worldwide. The objective of this study was to evaluate the possibility of vertical transmission of N. caninum in zebus breed beef cows ( Bos indicus) submitted for slaughter at an abattoir in the northern region of the State of Paraná, southern Brazil. One hundred and fifty-nine cows were evaluated: 83 pregnant (in different stages of gestation) and 76 non-pregnant. Serum determination of N. caninum was evaluated by indirect ELISA (Idexx). Blood (with EDTA) from pregnant cows and tissue samples (brain and heart) from their fetuses were collected and used for PCR analyses. Antibodies against N. caninum were observed in 14.6% (12/83) of pregnant and in 15.8% (12/76) of non-pregnant cows. Antibodies against the parasites were detected in one fetus (1.4%). The PCR analyses revealed that 6.0% (5/83) of cows and 4.8% (4/83) of fetuses evaluated were positive to specific N. caninum primers. These positive fetuses were between 4 and 6 months of age. Thus, considering PCR and serology as an indicative of vertical transmission in fetuses, 4.8% of fetuses were infected by N. caninum during gestation. [ABSTRACT FROM AUTHOR]

The mechanisms underlying the initiation/onset of, and the recovery from, depression are still largely unknown; views that neurogenesis in the hippocampus may be important for the pathogenesis and amelioration of depressive symptoms have gained currency over the years although the original evidence has been challenged. In this study, an unpredictable chronic mild stress protocol was used to induce a depressive-like phenotype in rats. In the last 2 weeks of stress exposure, animals were treated with the antidepressants fluoxetine, imipramine, CP 156,526 or SSR 1494515, alone or combined with methylazoxymethanol, a cytostatic agent used to arrest neurogenesis. We found that antidepressants retain their therapeutic efficacy in reducing both measured indices of depression-like behavior (learned helplessness and anhedonia), even when neurogenesis is blocked. Instead, our experiments suggest re-establishment of neuronal plasticity (dendritic remodeling and synaptic contacts) in the hippocampus and prefrontal cortex, rather than neurogenesis, as the basis for the restoration of behavioral homeostasis by antidepressants.Molecular Psychiatry (2009) 14, 764–773; doi:10.1038/mp.2008.119; published online 4 November 2008 [ABSTRACT FROM AUTHOR]

Erectile dysfunction (ED) is a highly prevalent disease affecting millions of men worldwide with a tendency for widespread increase. ED is now considered an early manifestation of atherosclerosis and, consequently, a precursor of systemic vascular disease. Atherosclerosis and ED share potentially modifiable risk factors, as smoking or high-fat food intake, but it is unclear how regular consumption of anti-oxidant rich drinks, which exhibit recognised anti-atherosclerotic features, affects ED progression. The objective of this study was to evaluate the modulating effects of chronic consumption of catechin-rich beverages on the vascular structure of the rat corpus cavernosum, and how this could contribute to delay or prevention of the onset of ED. Male Wistar rats aged 12 months were treated with green tea (GT) or a green tea extract solution (GTE) as the only liquid source for 6 months. Consumption of GT and GTE led to decreased plasma androgen levels without any significant change in plasma lipid levels. A reduction in corpus cavernosum intracellular storage of lipids, associated with decreased expression of vascular endothelial growth factor (VEGF) and its receptor VEGFR2 in endothelial cells, was observed. Taken together, these results suggest diminished atherosclerotic progression in cavernous tissue. However, functional studies will be necessary to elucidate if catechin-rich beverages are useful compounds in the prevention of deleterious vascular events associated with ED. It was also demonstrated that regular consumption of catechins reduces atherosclerotic progression and mortality due to cardiovascular disease. The results reported here suggest diminished atherosclerotic progression in cavernous tissue in aged rats following chronic ingestion of catechin-rich beverages. [ABSTRACT FROM AUTHOR]

Two examples were selected to emphasize the potential of grain boundary engineering in the performance design of heterogeneous ceramics. Gadolinium-doped ceria-based powders were co-fired with additions of silica, and silica and lanthanum oxide, to test the silica scavenging role of lanthanum. The formation of one ionic conducting secondary phase, instead of an insulating phase, was attempted. The structural, microstructural, and electrical characterization of these samples confirmed the formation of one apatite-type lanthanum silicate-based phase and a significant enhancement of the grain boundary conductivity of these materials. One second approach addressed the formation of one mixed conductor, with electronically conductive grain boundaries, surrounding the grains of one lanthanum gallate-based electrolyte (core-shell type microstructure). Fe-doped grain boundaries were formed by selective Fe-diffusion (thermally assisted) from lanthanum ferrite screen printed layers. Combined microstructural and electrical characterization showed that the adopted solution was also effective. [ABSTRACT FROM AUTHOR]

The present study investigates possible associations between the 5-HTT control region polymorphism (5-HTTLPR) with adult ADHD, including subtypes, severity, temperament profile and comorbidities. The polymorphic site was genotyped in 312 adult patients with ADHD and 236 controls, all of them Brazilians of European descent. The interviews followed the DSM-IV criteria, using the K-SADS-E for ADHD and oppositional defiant disorder, SCID-I and MINI for comorbidities and the TCI for temperament dimensions. The 5-HTTLPR polymorphism was not associated with ADHD. Carriers of the S allele presented slightly higher inattention and novelty seeking scores, and a higher frequency of drug dependence. These differences do not persist after correction for multiple comparisons. These results suggest that the 5-HTTLPR polymorphism does not have a direct role in the predisposition to adult ADHD. There is suggestive evidence for a small effect in some behavioral phenotypes related to ADHD. [ABSTRACT FROM AUTHOR]

The aim of the present study is to test for possible associations between the C-1291G polymorphism in the alpha2A-adrenergic receptor gene (ADRA2A) with tobacco smoking and alcohol dependence. The genotype and allele frequencies were compared in three groups of European-derived Brazilian males: individuals with co-occurrence of tobacco smoking and alcohol dependence ( N = 110), with tobacco smoking ( N = 121) and controls ( N = 114). The frequency of the G allele was higher in the group with both conditions, intermediate among subjects with smoking, and lower among controls (χ2 = 8.00; p = 0.02). The χ2 partitioning did not reveal significant differences between the sample with the two conditions and the sample of smokers (χ2 = 0.82; p = 0.36). Combining both groups, the difference to the non-smoking controls is higher than the one observed in the three-groups analysis (χ2 = 7.18; p = 0.007). The results suggest a role for the ADRA2A C-1291G polymorphism, notably the G allele, in the predisposition to tobacco smoking. The influence of the ADRA2A gene in nicotine and other substance dependencies should be more extensively assessed in future studies. [ABSTRACT FROM AUTHOR]

Several modifications of the faradaic efficiency and electromagnetic field (EMF) methods, taking electrode polarisation resistance into account, were considered based on the analysis of ion transport numbers and p-type electronic conductivity of $$ {\left( {{\text{La}}_{{0.9}} {\text{Sr}}_{{0.1}} } \right)}_{{0.98}} {\text{Ga}}_{{0.8}} {\text{Mg}}_{{0.2}} {\text{O}}_{{3 - \delta }} $$ ceramics at 973–1,223 K. In air, the activation energies for p-type electronic and oxygen ionic transport are 115 ± 9 and 71 ± 5 kJ/mol, respectively. The oxygen ion transference numbers vary in the range 0.992–0.999, increasing when oxygen pressure or temperature decreases. The apparent electronic contribution to the total conductivity, estimated from the classical faradaic efficiency and EMF techniques was considerably higher than true transference numbers due to a non-negligible role of interfacial exchange processes. The modified measurement routes give reliable and similar results when p(O2) values at the electrodes are high enough, whilst decreasing the oxygen pressure leads to a systematic error for all techniques associated with measurements of concentration cell EMF. This effect, presumably due to diffusion polarisation, increases with decreasing temperature. The most reliable results in the studied p(O2) range were provided by the modified faradaic efficiency method. [ABSTRACT FROM AUTHOR]

The T allele of the C825T polymorphism in the G-protein β3 subunit gene (GNB3) is related to the increase of signal transduction by the G-protein. G-proteins are intermediary paths in signal transduction from receptors involved in mood regulation and substance dependence. We studied the C825T polymorphism in individuals with (i) alcohol and nicotine dependence ( n = 109), (ii) nicotine dependence only ( n = 117) and (iii) non-dependent controls ( n = 108). We also tested for possible associations with psychiatric comorbidities among alcohol-dependent individuals. No differences were detected for allele and genotype frequencies in individuals with or without dependencies. Alcohol-dependent individuals with the heterozygous genotype presented more frequently major depressive disorder (χ2 = 12.34; p = 0.002). These findings, taken together with other studies suggesting an influence of the C825T polymorphism in major depressive disorder, support the hypothesis of the involvement of G-proteins in mood regulation. [ABSTRACT FROM AUTHOR]

The electrocatalytic activity of composite anodes, comprising metallic platinum and nanocrystalline Pt-modified Ce0.45Zr0.45La0.10O2-δ and Ce0.9Sm0.1O2-δ , was evaluated for the oxidation of dry methane in a solid oxide fuel cell (SOFC) – type reactor with yttria-stabilized zirconia solid electrolyte. At 923–1073 K, the total combustion is dominant, whilst above 1100 K the composite anodes exhibit significant catalytic activity towards the partial oxidation of methane (POM). At 1223 K and for a O2:CH4 ratio equal to 0.5, stoichiometric for the POM reaction, CO selectivity and CH4 conversion over Ce0.9Sm0.1O2-δ /Pt achieves 55% and 41%, respectively. Under these conditions, Ce0.45Zr0.45La0.10O2-δ /Pt anodes possess higher catalytic activity for partial oxidation, associated with the lower lattice oxygen mobility and instability of the Ce0.45Zr0.45La0.10O2-δ cubic fluorite structure, and provide 54% conversion efficiency with 73% selectivity to carbon monoxide. Further increase in CH4 conversion and CO selectivity can be achieved by packing the reactor with an additional catalyst, such as Pt-promoted Ce0.45Zr0.45La0.10O2-δ or LaNiO3-δ / Al2O3 . [ABSTRACT FROM AUTHOR]

Effects of mechanical activation of precursors in order to obtain CaTi0.8Fe0.2O3-δ are reported. Mixtures of CaCO3, TiO2 and Fe2O3 were dry-grinded in Teflon or zirconia containers using planetary ball-mills at different rotations (200, 300 and 500 rpm) and for various periods of time. The perovskite is not formed just by milling and a subsequent heat treatment at 800–1,000 °C was necessary. This still represents a significant advantage over the classical ceramic route as a result of the improved reaction kinetics due to the smaller grain size (<100 nm) of the activated powders and a modification of the thermodynamic initial state. Dense ceramic samples showing a bimodal submicrometric grain-size distribution (100–200 and 250–500 nm) were obtained after sintering the activated powders at 1,150 °C TEM revealed homogeneous samples, free from inhomogeneities such as core-shell grains typically observed in ceramics obtained from non-activated precursors sintered at 1,320–1,350 °C. [ABSTRACT FROM AUTHOR]

Patients in end-stage renal disease (ESRD) present reduced quality of life (QOL) and impaired sexual function. Previous studies have mostly addressed male sexual dysfunction. This was a cross-sectional controlled study that applied a general and the World Health Organization Quality of Life-bref© questionnaires to assess demographic, marital, and sexual conditions, and QOL in 86 healthy women aged 18 or more years (Group 1), and 38 female ESRD patients on dialysis for at least 2 months (Group 2). The effect of several explanatory variables upon QOL components was estimated. Quality of life was lower in Group 2 – overall, and on physical and environment domains. To undergo dialysis and to be poorly educated negatively affected the QOL. Yet age, a stable marital relationship or being sexually active had no effect. Female patients undergoing chronic dialysis had lower QOL and were significantly more sexually dysfunctional than comparable healthy women. Decline in sexual function had no effect on the QOL.International Journal of Impotence Research (2006) 18, 539–543. doi:10.1038/sj.ijir.3901470; published online 23 March 2006 [ABSTRACT FROM AUTHOR]

Yttria-stabilized zirconia (YSZ)-based composite electrolytes were produced by mixture and firing of the base electrolyte, namely with silica, and silica and lanthanum oxide, to study the impact of presence and formation of new phases on the electrical performance of the composite materials. Combined information obtained from structural, microstructural, and electrical characterization confirmed the formation of an apatite-type solid solution based on La9.33Si6O26. The effectiveness of lanthanum oxide addition to remove silica by reaction was demonstrated. However, the conductivity of the composite electrolytes is lower than that of YSZ, probably due to lanthanum zirconate formation in-between the ceramic grains and/or relatively poor transport properties of the formed lanthanum silicate phase. The adopted procedure can be extended to other systems and combinations of properties based on predictable phase interactions. [ABSTRACT FROM AUTHOR]

In the past ten years a series of developments in the field of materials with dominant oxygen ion conduction introduced a variety of new systems. The most relevant aspect is a shift from ionic transport mechanisms based on the motion of oxygen vacancies, to mechanisms based on mobile oxygen interstitials. In parallel, structures identified with dominant oxygen ion conduction moved from the relatively simple fluorite related ones to more complex materials, namely with the apatite-type and related structures, including coexistence of ionic and covalent bonding. This shift is understood as a major development, opening a wide range of alternative solutions for further exploitation. [ABSTRACT FROM AUTHOR]

Mixed-conducting SrFe0.7Al0.3O3-d (SFA) exhibits substantial catalytic activity towards partial oxidation of methane and can thus be considered as a component of monolithic ceramic reactors for synthesis gas generation, where the dense membrane and porous catalyst at the permeate-side surface are made of similar compositions. Surface modification of SFA powder and membranes with Pt has no essential effect on the performance of a model reactor, suggesting that the catalytic behavior of SFA is mainly determined by the surface states of iron and oxygen ions in the catalyst. The Mössbauer spectroscopy shows that reduction of SrFe0.7Al0.3O3-d, having cubic perovskite lattice in air, leads to the co-existence of perovskite- and brownmillerite-like domains, whilst the concentrations of metallic Fe and even Fe2+ under typical operation conditions are lower than the detection limits. The amount of vacancy-ordered phase increases with decreasing oxygen content, the estimations of which were confirmed by coulometric titration data. The catalytic activity of ferrite-based materials may thus be associated with lattice instability characteristic of morphotropic phase transformations. [ABSTRACT FROM AUTHOR]

The unfolding due to imperfections of a gluing bifurcation occurring in a periodically forced Taylor-Couette system is analyzed numerically. In the absence of imperfections, a temporal glide-reflection Z2 symmetry exists, and two global bifurcations occur within a small region of parameter space: a heteroclinic bifurcation between two saddle two-tori and a gluing bifurcation of three-tori. As the imperfection parameter increase, these two global bifurcations collide, and all the global bifurcations become local (fold and Hopf bifurcations). This severely restricts the range of validity of the theoretical picture in the neighborhood of the gluing bifurcation considered, and has significant implications for the interpretation of experimental results. [ABSTRACT FROM AUTHOR]

Perovskite-related phases derived from SrFeO3-δ are among known mixed conductors with highest oxygen permeability and are thus of interest as the ceramic membrane materials for oxygen separation and partial oxidation of light hydrocarbons. Dense ceramics of SrFe1-xAlxO3-δ (x=0.1–0.5) were prepared via the glycine-nitrate process. The cubic solid solution formation was found to occur in the concentration range x=0–0.35. Increasing aluminum content leads to decreasing thermal expansion coefficients (TECs), relative fraction of Fe4+ under oxidizing conditions, and also the total conductivity, predominantly p-type electronic at oxygen pressures close to atmospheric. The TECs vary in the range (13.5–16.4)×10−6 K−1 at 373–923 K and increase up to (18.6–31.9)×10−6 K−1 at 923–1273 K. The oxygen permeation fluxes decrease moderately with aluminum additions. The Mössbauer spectroscopy data and p(O2) dependencies of electrical properties indicate a small-polaron mechanism of electronic transport in SrFe1-xAlxO3-δ. Reducing oxygen partial pressure results in transition from dominant p- to n-type electronic conduction. The low-p(O2) stability limit of SrFe1-xAlxO3-δ perovskites lies between that of LaFeO3-δ and Fe/Fe1-γO boundary. [ABSTRACT FROM AUTHOR]

In order to reveal the role of grain boundaries on the ionic and electronic conduction processes, the transport properties of Gd2−xGaxTi2O7−δ (x=0.10–0.14) pyrochlore ceramics, pure and with SiO2 additions, were studied at 700–950 °C by impedance spectroscopy and faradaic efficiency measurements. The oxygen ion transference numbers of “pure” materials in air vary in the range of 0.95–0.97, increasing when temperature decreases. For silica-containing ceramics having, as expected, highly resistive grain boundaries, the ion transference numbers were considerably lower, 0.76–0.88, and increase with temperature. This behavior suggests that grain boundaries in these oxygen ion-conducting ceramics have a larger limiting effect on ionic transport than on electronic conduction. Increasing boundary resistivity may increase the relative role of electronic conductivity in solid oxide electrolytes, thus preventing their potential use in electrochemical cells at low temperatures. Also, the presence of even small electronic contributions to the total conductivity may lead to significant errors in the grain-boundary resistance values estimated from impedance spectroscopy data. The evaluation of the grain boundary exact contribution should be based on a clear knowledge of the magnitude of transference numbers. [ABSTRACT FROM AUTHOR]

NASICON dense ceramics were obtained from solid state reaction between SiO2, Na3PO4·12H2O and two different types of zirconia: monoclinic ZrO2 and the yttria-doped tetragonal phase (ZrO2)0.97(Y2O3)0.03. Higher temperatures were needed to obtain dense samples of the yttrium free composition (1265 °C). The electrical conductivity, at room temperature, of the yttria-doped samples sintered at 1230 °C (0.20 S/m) is significantly higher than the value obtained with the material prepared from pure ZrO2. The impedance spectra show that the differences in conductivity are predominantly due to the higher grain boundary resistance of the undoped ceramics, probably due to formation of monoclinic zirconia and glassy phases along the grain boundary. Further improvement of the electrical conductivity could be achieved after optimization of the grain size and density of grain boundaries. A maximum conductivity value of about 0.27 S/m at room temperature was obtained with the yttria-doped samples sintered at 1220 °C for 40 h. Yttria-doped and undoped ceramics were tested as Na+ potentiometric sensors. The detection limit of the yttria-doped sample (10−4 mol/l) was one order of magnitude lower than the obtained with the undoped material. [ABSTRACT FROM AUTHOR]

Modifications of the e.m.f. and faradaic efficiency techniques, taking into account electrode polarization in the measuring cells, in combination with the use of electrodes having sufficiently high polarization resistances enable a precise determination of minor electronic contributions to the conductivity of solid electrolytes. These methods were used to determine the p-type conductivity of compositions based on La(Sr)Ga(Mg)O3-δ (LSGM) and Ce(Gd)O2-δ (CGO) at 900–1270 K. The oxygen ion transference numbers of these materials under oxygen/air gradient vary in the range 0.999–0.970, increasing with decreasing temperature. Substitution of 2 % gadolinium in Ce0.80Gd0.20O2-δ with praseodymium was found to increase the electron-hole conduction by 2.5 – 4 times. At temperatures above 700 K, both the partial oxygen ionic and p-type electronic conductivities of LaGaO3-based phases are higher than those in CGO. The electron-hole transport in LSGM tends to increase with the magnesium concentration, while the activation energy is essentially independent of composition. Electronic conduction in CGO and LSGM electrolytes was also found to be influenced by the ceramic microstructure. [ABSTRACT FROM AUTHOR]

This paper is focused on the comparative analysis of data on electronic and ionic conduction in gadolinia-doped ceria (CGO) ceramics as well as on the electrochemical properties of various oxide electrodes in contact with ceria-based solid electrolytes. Properties of electrode materials, having thermal expansion compatible with that of doped ceria, are briefly reviewed. At temperatures below 1000 K, Ce0.90Gd0.10O2−δ (CGO10) was found to possess a better stability at reduced oxygen pressures than Ce0.80Gd0.20O2−δ (CGO20). Incorporation of small amounts of praseodymium oxide into Ce0.80Gd0.20O2−δ leads to a slight improvement of the stability of CGO20 at intermediate temperatures, but the difference between electrolytic domain boundaries of the Pr-doped material and CGO10 is insignificant. Since interaction of ceria-based ceramis with electrode materials, such as lanthanum-strontium manganites, may result in the formation of low-conductive layers at the electrode/electrolyte interface, optimization of electrode fabrication conditions is needed. A good electrochemical activity in contact with CGO20 electrolyte was pointed out for electrodes of perovskite-type La0.8Sr0.2Fe0.8Co0.2O3−δ and LaFe0.5Ni0.5O3−δ, and LaCoO3−δ/La2Zr2O7 composites; surface modification of the electrode layers with praseodymium oxide results in considerable decrease of cathodic overpotentials. Using highly-dispersed ceria for the activation of SOFC anodes significantly improves the fuel cell performance. [ABSTRACT FROM AUTHOR]

A combination of dc and ac results was used to study the electrode processes of LaCoO3+La2Zr2O7 cathodes deposited onto a GCO electrolyte, in air and in the range 600–800 °C. Steady state polarisation results showed that the overpotential values are very dependent on the electrode microstructures, which might be optimised by changes in the deposition and/or firing conditions of the electrodes. Tafel plots suggest different mechanisms under low and relatively high cathodic polarisation, with a transition at about −0.2 V at 700 °C. The transition tends to be displaced towards higher cathodic overpotentials with decreasing temperatures. The exchange current density is higher in the high polarisation regime (high values of |η|) than under low polarisation, and the exchange coefficient is lower in the range of high |η| The changes in pseudocapacitance and electrode resistance extracted from ac results also indicate a change in the regime. [ABSTRACT FROM AUTHOR]

Systems which admit waves via Hopf bifurcations and even systems that do not undergo a Hopf bifurcation but which support weakly damped waves may, when parametrically excited, respond quasiperiodically. The bifurcations are from a limit cycle (the time-periodic basic flow) to a torus, i.e. Naimark—Sacker bifurcations. Floquet analysis detects such bifurcations, but does not unambiguously determine the second frequency following such a bifurcation. Here we present a technique to unambiguously determine the frequencies of such quasiperiodic flows using only results from Floquet theory and the uniqueness of the self-rotation number (the generalization of the rotation number for continuous systems). The robustness of the technique is illustrated in a parametrically excited Taylor—Couette flow, even in cases where the bifurcating solutions are subject to catastrophic jumps in their spatial/temporal structure. [ABSTRACT FROM AUTHOR]

Zirconia-based oxygen sensors are used in many applications and in research. However, the measurement of oxygen partial pressures with these devices is not necessarily correct. Reasons for deviation between sensor reading and nominal composition of the gas mixture are reviewed in this work. The sensor electrochemical permeability is introduced as a starting point. The impact of this oxygen leak on the composition of the surrounding atmosphere is evaluated from mass balances to all species in the system. This procedure shows that even the use of mixtures like CO+CO2 to establish a given oxygen partial pressure has a limited range of applicability. This is due to the small buffer behavior of some of these mixtures. The gas phase transport of oxygen away from the sensor electrode is also studied. High concentration overpotentials are expected to develop under the circumstances where the buffer behavior of the gas mixture is small. In fact, high concentrations of the CO/CO2 couple are required both to optimize the gas-mixture buffer effect and the oxygen transport in the gas phase. The latter instead of consisting exclusively of simple diffusion of free oxygen molecules might also involve combined diffusion and counter diffusion of both carbon oxides as oxygen carriers. [ABSTRACT FROM AUTHOR]

Oxygen ion conduction in La0.9Sr0.1Ga1−xMxO3−δ (M=Cr, Fe; x=0 – 0.20), LaGa1−xMxO3−δ (M=Co, Ni; x=0.20 – 0.60), LaGa1−x−yCoxMgyO3−δ (x=0.35 – 0.60; y=0.10 – 0.25) and LaGa0.85−xMg0.15(Nb0.33Mg0.66)xO3−δ (x=0 – 0.20) is reported. At temperatures below 1200 K the ionic conductivity of La(Ga,M)O3−δ (M=Co, Ni) increases with increasing oxygen nonstoichiometry, but is lower than for La(Ga,Mg)O3−δ and (La,Sr)GaO3−δ. Co-doping with Nb and Mg was found to result in decreasing ionic transport in La(Ga,Nb,Mg)O3−δ due to blocking of oxygen sites by Nb5+. Small additions of Fe to the B-site of La0.9Sr0.1GaO3−δ increase the ionic conductivity, whereas substitution of Cr for Ga has the opposite effect. Incorporation of transition metal cations into the Ga site leads to a higher p-type electronic conductivity in all studied perovskites. [ABSTRACT FROM AUTHOR]

The basic relationships required to analyse permeability data of fluorite-based solid electrolytes are rewritten in order to account for an overpotential term related to slow surface exchange. Results of a gadolinia doped ceria solid electrolyte suggest that surface exchange might limit the permeability especially at low Po2 and temperature. However, the analysis of the data with different relationships leads to somewhat different estimates of the electron and hole conductivity and overpotential values. [ABSTRACT FROM AUTHOR]

Oxygen sensors based on YSZ (yttria stabilized zirconia) are best known for high temperature measurements. The protection of such oxygen sensors with dense electrochemical filters is an effective way to increase their life time in aggressive industrial atmospheres. This work reports on the performance of sensors protected by composite or single phase mixed conducting filters. The first group includes materials based on GCO (Gd2O3 doped CeO2)+LC (LaCoO3), and on YSZ+LCM (La(Mn,Co)O3). Sensors protected with GCO+LC composites showed the best performance amongst the composite filters already evaluated. Electroded single phase GCO filters were also tested to check on the role of surface reaction kinetics on the overall oxygen transport process across the filter. The fastest sensor responses to a sudden decrease in oxygen partial pressure were obtained with deposited electrodes either on both surfaces of the filter or on the filter cathode side. These preliminary results suggest that the cathodic process is more relevant than the anodic one in determining the filter permeability (and protected sensor performance), which fulfils the logical requirement of electrode free surfaces in contact with the furnace atmosphere. [ABSTRACT FROM AUTHOR]