Pressure-Induced Phase Transformations of Quasi-2D Sr3Hf2O7

We present an abinitio study of the quasi-2D layered perovskite Sr3Hf2O7 compound, performed within the framework of the density functional theory and lattice dynamics analysis. At high temperatures, this compound takes a I4/mmm centrosymmetric structure (S.G. n. 139); as the temperature is lowered, the symmetry is broken into other intermediate polymorphs before reaching the ground-state structure, which is the Cmc21 ferroelectric phase (S.G. n. 36). One of these intermediate polymorphs is the Ccce structural phase (S.G. n. 68). Additionally, we have probed the C2/c system (S.G n. 15), which was obtained by following the atomic displacements corresponding to the eigenvectors of the imaginary frequency mode localized at the Γ-point of the Ccce phase. By observing the enthalpies at low pressures, we found that the Cmc21 phase is thermodynamically the most stable. Our results show that the I4/mmm and C2/c phases never stabilize in the 0-20 GPa range of pressure values. On the other hand, the Ccce phase becomes energetically more stable at around 17 GPa, surpassing the Cmc21 structure. By considering the effect of entropy and the constant-volume free energies, we observe that the Cmc21 polymorph is energetically the most stable phase at low temperature; however, at 350 K, the Ccce system becomes the most stable. By probing the volume-dependent free energies at 19 GPa, we see that Ccce is always the most stable phase between the two structures and also throughout the studied temperature range. When analyzing the phonon dispersion frequencies, we conclude that the Ccce system becomes dynamically stable only around 19-20 GPa and that the Cmc21 phase is metastable up to 30 GPa.

Runs of homozygosity provide a genome landscape picture of inbreeding and genetic history of European autochthonous and commercial pig breeds

ROHs are long stretches of DNA homozygous at each polymorphic position. The proportion of genome covered by ROHs and their length are indicators of the level and origin of inbreeding. Frequent common ROHs within the same population define ROH islands and indicate hotspots of selection. In this work, we investigated ROHs in a total of 1131 pigs from 20 European local pig breeds and in three cosmopolitan breeds, genotyped with the GGP Porcine HD Genomic Profiler. plink software was used to identify ROHs. Size classes and genomic inbreeding parameters were evaluated. ROH islands were defined by evaluating different thresholds of homozygous SNP frequency. A functional overview of breed-specific ROH islands was obtained via over-representation analyses of GO biological processes. Mora Romagnola and Turopolje breeds had the largest proportions of genome covered with ROH (~1003 and ~955 Mb respectively), whereas Nero Siciliano and Sarda breeds had the lowest proportions (~207 and 247 Mb respectively). The highest proportion of long ROH (>16 Mb) was in Apulo-Calabrese, Mora Romagnola and Casertana. The largest number of ROH islands was identified in the Italian Landrace (n = 32), Cinta Senese (n = 26) and Lithuanian White Old Type (n = 22) breeds. Several ROH islands were in regions encompassing genes known to affect morphological traits. Comparative ROH structure analysis among breeds indicated the similar genetic structure of local breeds across Europe. This study contributed to understanding of the genetic history of the investigated pig breeds and provided information to manage these pig genetic resources.

Targeted nanostructured lipid carriers for doxorubicin oral delivery

The treatment with anticancer drugs remains a challenge, as available drugs still entail the risk of deleterious off-target effects. The present study describes folic acid conjugated nanostructured lipid carriers (NLCs) as an effective doxorubicin delivery approach targeted to breast cancer cells. Two distinct NLCs formulations were designed and optimized leading to an encapsulation efficiency over than 65%. Cytotoxic and targeting potential of NLCs were studied in vitro, using MDA-MB-231 cell line. Results showed an enhanced cellular uptake of conjugated NLCs. In vitro release studies, mimicking the path in the body after oral administration, show that all formulations would reach the tumor microenvironment bearing 50% of the encapsulated doxorubicin. Moreover, NLCs demonstrated storage stability at 25 °C for at least 42 days. Overall, results revealed that the developed NLCs enable the possibility of oral administration and are a promising approach for the targeted delivery of doxorubicin to breast cancer cells.

Crystal mosaicity determined by a novel layer deconvolution Williamson–Hall method

An improvement to the classical Williamson–Hall method is developed to study several samples of AlGaN and α-MoO₃.

Multiple reflection optimization package for X-ray diffraction

New software for the simulation and fitting of 2θ–ω scans of symmetric and asymmetric reflections based on the dynamical theory of X-ray diffraction is presented.

Evolution of two-step magnetic transition on nanogranular Gd5Si1.3Ge2.7 thin film

A multi-functional Gd₅Si_1.3Ge_2.7 thin film deposited by pulsed laser ablation in the form of an ensemble of nanoparticles was studied for 18 thermal cycles via electron transport measurements together with structural and magnetic characterization. A general negative thermal dependency of the resistivity (ρ) is observed, which contrasts with the metallic-like behavior observed in bulk Gd₅Si _x Ge_4-x compounds. This general trend is interrupted by a two-step, positive-slope transition in ρ(T) throughout the [150, 250] K interval, corresponding to two consecutive magnetic transitions: a fully coupled magnetostructural followed by a magnetic order on heating. An avalanche-like behavior is unveiled by the ∂ρ/∂T(T) curves and is explained based on the severe strains induced cyclically by the magnetostructural transition, leading to a cycling evolution of the transition onset temperature ([Formula: see text]/∂n ∼ 1.6 K/cycle, n being the number of cycles). Such behavior is equivalent to the action of a pressure of 0.56 kBar being formed and building up at every thermal cycle due to the large volume induced change across the magnetostructural transition. Moreover the thermal hysteresis, detected in both ρ and magnetization versus temperature curves, evolves significantly along the cycles, decreasing as n increases. This picture corroborates the thermal activation energy enhancement-estimated via an exponential fitting of the ∂ρ/∂T(T) in the avalanche regime. This work demonstrates the importance of using a short-range order technique, to probe both magnetic and magnetostructural transitions and their evolution with thermal cycles.

Pathogen effects on milk yield and composition in chronic subclinical mastitis in dairy cows

This study aimed to evaluate the effects of chronic subclinical mastitis (CSM) on milk production and component yields in dairy cows. A total of six herds located in the Midwest area of São Paulo State, Brazil were selected. Herds were visited once every 2 weeks to measure milk yield and to collect milk samples from lactating Holstein cows. Milk samples were collected at two stages (1 and 2), and each stage comprised three milk samplings. In stage 1, a total of 117 of 647 cows were diagnosed with CSM based on at least two of three repeated somatic cell counts (SCC) > 2000,000 cells/mL and positive bacterial milk culture results (BC). Cows with CSM were selected for the second stage. In stage 2, selected cows had quarter sampling aseptically collected for BC analyses prior to milking, and quarter milk yield was measured. Milk components (total protein, fat, lactose, and total solids) were measured using mid-infrared spectroscopy. Mammary quarters were considered healthy if all three repeated SCC results were ≤ 200,000 cells/mL and no bacterial growth was detected on BC. All quarters with positive bacterial growth were classified as having (non-chronic) subclinical mastitis when only one of three SCC results were > 200,000 cells/mL, and CSM when at least two of three SCC results were > 200,000 cells/mL. The effects of CSM by type of pathogen on milk and components yield were assessed using a linear mixed model. Mammary quarters with CSM caused by major pathogens had milk loss of 1.1 kg/quarter milking in comparison to healthy quarters. Milk losses were 0.8 and 1.3 kg/quarter milking when CSM was caused by Staphylococcus aureus or environmental streptococci, respectively. In addition, healthy quarters produced more milk components than quarters with CSM caused by major pathogens. Minor pathogens causing CSM (non-aureus staphylococci and Corynebacterium spp.) had no effect on milk yield. Quarters with CSM had lower milk and component yields when compared with healthy quarters. Milk losses varied according to the type of pathogen and were higher when associated with major pathogens such as S. aureus and environmental streptococci compared with healthy quarters.

Local inhomogeneous state in multiferroic SmCrO3

Rare-earth orthochromites with distorted perovskite structure (e.g. RCrO₃, R = Sm, Gd) have been under strong debate with respect to the origin of their ferroelectric order. Of particular interest is the question of whether such orthochromites are, in fact, magnetically driven improper ferroelectrics, as many rare-earth manganites or orthoferrites. Here we show, by studying at the atomic scale the rare-earth SmCrO₃ system that a distortion of the Sm local environment emerges within the paramagnetic phase, near room temperature. Our Electric Field Gradient measurements combined with first-principles calculations show that the emergent phase cannot be simply ascribed to the Pna2₁ structure as reported for GdCrO₃ or SmCrO₃. Instead a local inhomogeneous state, where regular non-polar and polar distorted environments coexist, develops at low temperatures.

Spatial-temporal variation in litterfall in seasonally dry tropical forests in Northeastern Brazil

The production of litterfall is essential for nutrient cycling in terrestrial ecosystems. From November 2009 to October 2011, analyzed the monthly litterfall production in two areas of Caatinga, a type of Seasonally Dry Tropical Forest located in the Cariri Paraibano, in the semiarid region of the Paraíba, Northeastern Brazil. One of the areas, Private Natural Heritage Reserve (RPPN) Fazenda Almas, is legally protected, and the other, Fazenda Moreiras, does not. The aims were to evaluate the effects of precipitation, evapotranspiration and vegetation structure on the temporal and spatial dynamics of litterfall production. Eight sampling points were randomly chosen at each site, and two 1 m2 collectors were installed 50 m apart from each other. The collected material was sorted, dried and weighed. Additionally, the characteristics (density, species richness, height and mean basal area) of the tree-shrub stratum in plots with a 10 m radius surrounding each collector. Total litterfall production was 4,500 kg ha-1 yr-1 for Fazenda Almas and 3,300 kg ha-1 yr-1 for Fazenda Moreiras; these values were within the expected range for Seasonally Dry Tropical Forests. The inter- and intra-annual variation in litterfall production was positively correlated with precipitation and evapotranspiration rates, and four months after the highest precipitation rates, there was a marked decrease in litterfall occurred during the dry season. Furthermore, the contributions of the material fractions were distinct with the leaf fraction representing for more than 60% of the litterfall, and the vegetation structure explained 75% of the variation in litterfall production. Therefore, climatic factors and vegetation structure affect the temporal and spatial dynamics of litterfall production and consequently influence nutrient dynamics in the semiarid region of Brazil.

Magnetoliposomes containing magnesium ferrite nanoparticles as nanocarriers for the model drug curcumin

Magnesium ferrite nanoparticles, with diameters around 25 nm, were synthesized by coprecipitation method. The magnetic properties indicate a superparamagnetic behaviour, with a maximum magnetization of 16.2 emu g-1, a coercive field of 22.1 Oe and a blocking temperature of 183.2 K. These MgFe2O4 nanoparticles were used to produce aqueous and solid magnetoliposomes, with sizes below 130 nm. The potential drug curcumin was successfully incorporated in these nanosystems, with high encapsulation efficiencies (above 89%). Interaction by fusion between both types of drug-loaded magnetoliposomes (with or without PEGylation) and models of biological membranes was demonstrated, using FRET or fluorescence quenching assays. These results point to future applications of magnetoliposomes containing MgFe2O4 nanoparticles in cancer therapy, allowing combined magnetic hyperthermia and chemotherapy.

Effects of strength training with blood flow restriction on torque, muscle activation and local muscular endurance in healthy subjects

The present study aimed to analyse the effects of six weeks of strength training (ST), with and without blood flow restriction (BFR), on torque, muscle activation, and local muscular endurance (LME) of the knee extensors. Thirty-seven healthy young individuals were divided into four groups: high intensity (HI), low intensity with BFR (LI+BFR), high intensity and low intensity + BFR (COMB), and low intensity (LI). Torque, muscle activation and LME were evaluated before the test and at the 2nd, 4th and 6th weeks after exercise. All groups had increased torque, muscle activation and LME (p<0.05) after the intervention, but the effect size and magnitude were greater in the HI, LI+BFR and COMB groups. In conclusion, the groups with BFR (LI+BFR and COMB) produced magnitudes of muscle activation, torque and LME similar to those of the HI group.

Magnetoliposomes as carriers for promising antitumor thieno[3,2-b]pyridin-7-arylamines: photophysical and biological studies

Magnetoliposomes containing MnFe₂O₄ nanoparticles were used as nanocarriers for new potent antitumor thieno[3,2-b]pyridin-7-arylamines, inhibiting the growth of human tumor cells.

Pain reduction and improvement of function following ultrasound-guided intra-articular injections of triamcinolone hexacetonide and hyaluronic acid in hip osteoarthritis

The scientific literature has shown positive results regarding intra-articular injections of hyaluronic acid in osteoarthritic joints. When injecting in the hip joint, the guidance of ultrasound can provide higher injection accuracy and repeatability. However, due to the methodological limitations in the current available literature, its recommendation in the current practice is still controversial. This study shows that ultrasound-guided intra-articular injections of triamcinolone hexacetonide and hyaluronic acid can improve pain, function and quality of life in patients with symptomatic and radiographic hip osteoarthritis. In addition, the administration of triamcinolone hexacetonide and hyaluronic acid to the hip joint in these patients can delay the need for interventional surgery.

Tuning the magnetic properties of multisegmented Ni/Cu electrodeposited nanowires with controllable Ni lengths

The fabrication of segmented Ni/Cu nanowires (NWs), with tunable structural and magnetic properties, is reported. A potentiostatic electrodeposition method with a single electrolytic bath has been used to fabricate multisegmented Ni/Cu NWs inside a highly hexagonally ordered anodic nanoporous alumina membrane, with diameters of 50 nm and Ni segment lengths (L Ni) tuned from 10 nm up to 140 nm. The x-ray diffraction results evidenced a strong dependence of the Ni NWs crystallographic face-centered-cubic (fcc) texture along the [220] direction on the aspect ratio of the NWs. The magnetic behavior of the multisegmented Ni/Cu NW arrays, as a function of the magnetic field and temperature, is also studied and correlated with their structural and morphological properties. Micromagnetic simulations, together with the experimental results, showed a dominant antiferromagnetic coupling between Ni segments along the wire length for small low aspect-ratio magnetic segments. When increasing the Ni segments' length, the magnetic interactions between these along the wire became stronger, favouring a ferromagnetic coupling. The Curie temperature of the NWs was also found to strongly depend on the Ni magnetic segment length. Particularly the Curie temperature was found to be reduced 75 K for the 20 nm Ni segments, following the finite-size scaling relation with ξ 0 = 8.1 Å and γ = 0.48. These results emphasize the advantages of using a template assisted method to electrodeposit multilayer NWs, as it allows an easy tailor of the respective morphological, chemical, structural and magnetic properties.

Qualitative and Quantitative Determination and Resistance Patterns of Salmonella from Poultry Carcasses

Poultry products are important in the transmission of zoonotic pathogens, mainly Salmonella. This genus causes millions of foodborne diseases worldwide every year. Cross-contamination by food sources in human cases of salmonellosis and the increase in resistant strains have become important issues. A qualitative and quantitative Salmonella detection method was utilized in a poultry slaughterhouse in São Paulo State, Brazil. We collected 33 samples from different batches of carcasses. Each sample was analyzed at three process points: postbleeding, postdefeathering, and postchilling. A fourth point, retail simulation, was added to simulate retail market storage at 5°C for 72 h. The qualitative methods revealed 100% (33 samples) contamination at postbleeding, 39% (13 samples) contamination at postdefeathering, 58% (19 samples) contamination at postchilling, and 30% (10 samples) contamination at the retail simulation. The quantitative results, determined by the most-probable-number (MPN) technique, ranged from <0.03 to >2,400 MPN/g. We identified 23 Salmonella serovars; the most prevalent were Mbandaka, Senftenberg, and Enteritidis. Resistance to nalidixic acid was significantly more common (P < 0.05) than resistance to other antimicrobial agents. Five multidrug-resistant strains were identified. This study contributes important epidemiological data and demonstrates the need to improve sanitary conditions in slaughterhouses.

Tuning the Stoichiometry of Ag2S Thin Films for Resistive Switching Applications

In this work silver-rich and sulfur-rich silver sulfide (Ag2S) thin films were fabricated using a diversified set of experimental methods, namely ion beam deposition and atmosphere- and solution-based sulfurizations. The composition of the Ag2S thin films was studied using X-ray diffraction, Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. We found that it strongly depends on the fabrication conditions, such as sulfurization time and temperature. These conditions, in turn, affect the electrical characteristics of the thin films, namely the resistivity and resistive switching. We were able to control the Ag2S stoichiometry and infer its dependence on the fabrication parameters for all the followed methods.

Cell cycle kinetics, apoptosis rates and gene expressions of MDR-1, TP53, BCL-2 and BAX in transmissible venereal tumour cells and their association with therapy response

Transmissible venereal tumour (TVT) generally presents different degrees of aggressiveness, which makes them unresponsive to conventional treatment protocols. This implies a progressive alteration of their biological profile. This study aimed to evaluate the cytotoxicity, cell survival, apoptosis and cell cycle alterations in TVT cell cultures subjected to treatment with vincristine. Similarly, it assessed possible implications of MDR-1, TP53, BCL-2, and BAX gene expressions in eight TVT primary cultures for both resistance to chemotherapy and biological behaviour. When comparing TVT cells receiving vincristine to those untreated, a statistical difference related to increased cytotoxicity and decreased survival rates, and alterations in G1 and S cell cycle phases were found but without detectable differences in apoptosis. Increased MDR-1 gene expression was observed after treatment. The groups did not differ statistically in relation to the TP53, BAX and BCL-2 genes. Although preliminary, the findings suggest that such augmented expression is related to tumour malignancy and chemotherapy resistance.

Magnetoliposomes based on manganese ferrite nanoparticles as nanocarriers for antitumor drugs

Aqueous and solid magnetoliposomes containing MnFe₂O₄ nanoparticles were prepared and evaluated as nanocarriers for a new antitumor drug.

Isolation and Characterization of Madariaga Virus from a Horse in Paraíba State, Brazil

Madariaga virus (MADV), the new species designation for the South American isolates of eastern equine encephalitis virus (EEEV), is genetically divergent and substantially different in ecology and pathogenesis from North American EEEV strains. We isolated and characterized a MADV isolate obtained from a horse in Brazil. Our results support previous phylogenetic studies showing there are three genetically distinct MADV lineages. The MADV isolate from Paraíba State belongs to the South American lineage III and is closely related to Peruvian, Colombian and Venezuelan isolates.

Modeling the Growth Kinetics of Anodic TiO2 Nanotubes

The fundamental understanding of the barrier layer (δ(b)) growth in TiO2 nanotubes (NTs) is here established and compared with the classical metal oxidation theory from Mott and Cabrera. The role of δ(b) in the anodization of TiO2 NTs under different applied potentials and times was analyzed using scanning transmission electron microscopy (STEM). Contrary to the well-known case of anodic aluminum oxide, we found that δ(b) of TiO2 NTs progressively grows over time due to the nonsteady anodization regime. We then establish a relation between the phenomenological growth of the barrier layer with time and applied voltage, δ(b)(V,t) using the high-field Mott and Cabrera conduction theory. The developed model was found to be in excellent agreement with the experimental data from both STEM and anodization curves. On the basis of these results, the relationship between δ(b) and the anodization time and potential can now be quantitatively understood.

Magnetic liposomes based on nickel ferrite nanoparticles for biomedical applications

Aqueous and dry magnetoliposomes containing NiFe₂O₄ nanoparticles were prepared using a new method and fusion with model membranes was demonstrated.

Tailoring the Ti surface via electropolishing nanopatterning as a route to obtain highly ordered TiO2 nanotubes

Highly ordered TiO2 nanotubes (NTs) were synthesized by the electrochemical anodization of Ti foils subjected to electropolishing (EP) pre-treatment. We found that the Ti surface roughness plays an important role in the onset of pore nucleation in enhancing the local focusing effect of the electrical field. Additionally, EP induces the formation of dimple structures on the metal surface, which can work as a pre-pattern prior to anodization. These shallow ripples lead to a preferentially ordered pore nucleation, offering an organizational improvement of the anodic oxide NTs. We found that, depending on the EP applied potential, the roughness and the spatial period of the ripple-like structures varies from 8-2 nm and from 122-30 nm, respectively. Such tuning allowed us to focus on the influence of the initial Ti pre-surface topography features on the NTs' length, organization, and hexagonal arrangement quality, as well as diameter and density. Our results show that an EP under 10 V is the most suitable to obtain a small Ti surface roughness, the largest NT length (40% enhancement), and the effective improvement of the ordered hexagonal NTs' arrays over larger areas. Furthermore, the NTs' dimensions (pore diameters and density) were also found to depend on the initial Ti surface topography. The use of optimized EP allows us to obtain highly hexagonal self-ordered samples at a reduced time and cost.

The effect of coolants on the performance of magnetic micro-refrigerators

Magnetic refrigeration is an alternative cooling technique with envisaged technological applications on micro- and opto-electronic devices. Here, we present a magnetic micro-refrigerator cooling device with embedded micro-channels and based on the magnetocaloric effect. We studied the influence of the coolant fluid in the refrigeration process by numerically simulating the heat transfer processes using the finite element method. This allowed us to calculate the cooling power of the device. Our results show that gallium is the most efficient coolant fluid and, when used with Gd5Si2Ge2, a maximum power of 11.2 W/mm3 at a working frequency of -5 kHz can be reached. However, for operation frequencies around 50 Hz, water is the most efficient fluid with a cooling power of 0.137 W/mm3.

Hyperfine local probe study of alkaline-earth manganites SrMnO₃ and BaMnO₃

We report perturbed angular correlation measurements with (111m)Cd/(111)Cd and (111)In/(111)Cd probes, at the ISOLDE-CERN facility, in the manganite compounds BaMnO3, with the 6H and 15R polymorphs, and SrMnO3, with the 4H polymorph. The electric field gradient (EFG) is measured, and found approximately constant in a large temperature range for all the compounds. The EFG is also calculated from first principles with density functional theory, and compared with experimental results by considering diluted substitutional Cd impurities. Based on the results, we assign as sites for the probes the Ba (for BaMnO3-6H, 15R) and Sr (for SrMnO3-4H) sites, apart from fractions of undetermined origin in the case of BaMnO3-6H. We predict the hyperfine parameters in the recently synthesized multiferroic manganite Sr(0.5)Ba(0.5)MnO3, and its variation with the structure and electric polarization, which is found to be very small.

Paramagnetism and antiferromagnetic interactions in single-phase Fe-implanted ZnO

As the intrinsic origin of the high-temperature ferromagnetism often observed in wide-gap dilute magnetic semiconductors becomes increasingly debated, there is a growing need for comprehensive studies on the single-phase region of the phase diagram of these materials. Here we report on the magnetic and structural properties of Fe-doped ZnO prepared by ion implantation of ZnO single crystals. A detailed structural characterization shows that the Fe impurities substitute for Zn in ZnO in a wurtzite Zn(1-x)Fe(x)O phase which is coherent with the ZnO host. In addition, the density of beam-induced defects is progressively decreased by thermal annealing up to 900 ° C, from highly disordered after implantation to highly crystalline upon subsequent annealing. Based on a detailed analysis of the magnetometry data, we demonstrate that isolated Fe impurities occupying Zn-substitutional sites behave as localized paramagnetic moments down to 2 K, irrespective of the Fe concentration and the density of beam-induced defects. With increasing local concentration of Zn-substitutional Fe, strong nearest-cation-neighbor antiferromagnetic interactions favor the antiparallel alignment of the Fe moments.

Jahn-Teller distortion relaxation across the LaMnO3+Δ phase diagram

The evolution of the local Jahn-Teller distortion across the LaMnO3+Δ phase diagram was obtained using the perturbed angular correlation local probe technique. We found that upon doping, the local distortion decreases continuously with increasing doping and that no fully Jahn-Teller distorted Mn(3+)O6 octahedra are observed within the orthorhombic insulating phase. A local single-phase scenario is established for the orbital disordered orthorhombic crystallographic structure. We also show that the continuous weakening of the Jahn-Teller distortions is not limited to a single-phase environment and occurs in a similar manner within an undistorted rhombohedric matrix upon lowering the temperature.

Evaluation of sperm DNA peroxidation in fertile and subfertile dogs

Oxidative stress (OS) has been recognized as one of the most important causes of male infertility. The antioxidant activities of seminal plasma and epididymal fluid are not enough to prevent OS, which can damage sperm membranes and DNA, so antioxidant supplementation has been used as a treatment of male infertility. The aim of this experiment was to evaluate the DNA peroxidation before and after antioxidant supplementation with vitamin C and E in dogs with and without fertility problems. A total of eleven dogs were used and were divided in two groups: fertile group (G1), dogs with normal spermiogram (n = 5); subfertile group (G2): dogs with low sperm count (<20 × 10(6) sptz/ml) and/or more than 30% of total sperm pathology (n = 6). Both groups received 500 mg/day of vitamin C and 500 mg/day of vitamin E for 60 days. A semen sample was collected before (M1) and after (M2) oral supplementation. Samples were analysed for DNA peroxidation by measuring the 8-hydroxy-2'-deoxyguanosine concentration. No significant difference was observed between groups at either time. Oral supplementation with 500 mg/day of vitamin C and 500 mg/day of vitamin E did not change the DNA peroxidation in fertile and subfertile dogs.

164 RAPID IDENTIFICATION OF BACTERIA IN BOVINE SEMEN BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY

Frozen bovine semen used in the IVF process can be a potential source of microorganisms that can prevent or disturb embryo development and cause issues with the sanitary certification for bovine embryo commercialization and export. Therefore, the aim of this work is to introduce a novel tool for the fast identification of the pathogens on the frozen semen based on the mass spectra of their ribosomal proteins analysed by matrix-assisted desorption/ionization-mass spectrometry (MALDI-MS). Thirty bovine semen samples, which were aliquots of commercial sealed straws used daily in the commercial IVF routine at In vitro Brasil Ltd. (Mogi Mirim, SP, Brazil), were used for this work. Fifty microlitres of semen were incubated in 10 mL of brain heart infusion broth (BHI) for 24 h at 37°C. If turbidity was observed, the bacterial cultures were submitted to bacterial extraction and mass spectrometric analysis according to Barreiro et al. (2010). The mass spectra were obtained using an AUTOFLEX MALDI TOF/TOF and were analysed with the database library MALDI Biotyper 3.0 software (Bruker Daltonik, Germany) at default settings. For each sample, the result was given by means of a log score with a maximum value of 3.0. In this study, only scores higher than 2.0 were considered, which provide confident species identification. The bacteria identified were Citrobacter freundii (2 samples), Stenotrophomonas maltophilia (4 samples), Enterobacter cloacae (6 samples) complex, Candida parapsilosis (2 samples), and Enterococcus mundtii (2 samples). Note that all the identified bacteria consistently match with the most common contaminants reported in literature for bovine frozen semen (Bielanskia et al. 2003). The capability of the technique to identify the bacteria without the ribosomal extraction (i.e. of bacteria pellets diluted in water and acetonitrile) was successful for the pellet of S. maltophilia, C. freundii, and E. cloacae complex with scores higher than 2.3, indicating a very high probability of the identification of the bacterial genus and the species. This can be explained by considering the capability of the mass spectrometric matrix to lyse the membrane of the bacteria and directly extract and then ionize the ribosomal proteins. In order to exclude the presence of a mixing of bacteria in the pellet, the colonies were properly isolated. The results matched with the ones obtained before the isolation. In order to confirm the MALDI-MS identification, the isolated bacteria from the bovine semen were also submitted to sequencing of region 16SrRNA. In conclusion, MALDI-MS technique was successfully applied for the identification of pathogens in the bovine semen. Experiments to evaluate the presence of microorganisms in media used for in vitro maturation, IVF, and in vitro culture of the bovine oocytes and embryos using this strategy are underway. This robust and fast approach is able to detect early contamination and allows prevention of economic losses and sanitary excellence in the bovine IVF process.

Influence of the rest pulse duration in pulsed electrodeposition of Fe nanowires

Highly uniform iron nanowires were synthesized in porous anodic alumina, through a pulsed electrodeposition method. The effect of the rest pulse duration in the deposition quality was systematically investigated, being the best duration found at 0.6 s with 91.9% of pores filled. A methodology of surface response design of experiment was conducted to find the optimum predicted value for the rest pulse duration, by controlling the following experimental parameters/variables: current density, electrolyte concentration and temperature. The influence of the rest pulse in the grain size of the iron nanowires was also studied trough X-ray diffraction patterns. A numerical simulation of the concentration evolution along a nanopore was performed, allowing to achieve a deeper understanding of the importance of the rest pulse in the NW electrodeposition.

Probing the quality of Ni filled nanoporous alumina templates by magnetic techniques

Pulsed electrodeposition prepared porous alumina templates with Ni nanowires pore filling ranged from 1 to 100%, depending on the alumina barrier-layer thickness, were probed by continuous wave ferromagnetic resonance at room temperature. For completely filled samples, a single resonance peak was observed in the whole range of angles between the applied magnetic field and normal to the sample plane. Its position was described by Kittel formula that takes into account shape anisotropy of individual Ni wires and dipolar interactions between them. For the samples with lower pore filling the effective anisotropy field decreased and the resonance linewidth in the perpendicular configuration increased. Also a quite intense second peak was observed at lower fields for these samples. These changes are associated with reduction of pore filling percentage that can lead to decrease of dipolar interactions between nanowires and to appearance of magnetic inhomogeneities inside wires.

Tunning pore filling of anodic alumina templates by accurate control of the bottom barrier layer thickness

The role of the alumina barrier layer thickness (δ(b)) on the growth of Ni nanowires (NWs) in porous anodic alumina (PAA) has been revealed. By varying the final anodization voltage to form dendrites at the bottom of the nanoporous structure, we are able to optimize δ(b) (in the 2-16 nm range), allowing us to obtain a Ni pore filling percentage (f(p)) of almost 100% for δ(b) = 10 nm. However, deviations from this optimal δ(b)-value led to a strong decrease of f(p). Moreover, an increase of the electrodeposition efficiency (EE) and NW homogeneity was also verified for δ(b) up to 10 nm. Such increase in nominal δ(b) leads to a consistent growth rate in all pores and consequently a complete and uniform nanopore filling. On the other hand, the decrease in electrodeposition efficiency visible for δ(b) > 10 nm is related with hydrogen evolution and dielectric breakdown of the insulator layer due to the required high deposition voltages. Non-uniform NW growth is then visible, with the consequent decrease in f(p). The control of the pore filling and length homogeneity of the fabricated 1D metallic nanostructures, combined with the ability to adjust the pore dimensions of PAA, can bring novel approaches for the fabrication of nano-objects and thus exciting new applications.

Designing novel hybrid materials by one-pot co-condensation: from hydrophobic mesoporous silica nanoparticles to superamphiphobic cotton textiles

This work reports the synthesis and characterization of mesoporous silica nanoparticles (MSNs) functionalized with tridecafluorooctyltriethoxysilane (F13) and their in situ incorporation onto cotton textiles. The hybrid MSNs and the functional textiles were prepared by a one-pot co-condensation methodology between tetraethylorthosilicate (TEOS) and F13, with hexadecyltrimethylammonium chloride (CTAC) as the template and triethanolamine as the base. The influence of the F13 to TEOS molar ratio (1:10, 1:5 and 1:3) on the nanoparticle morphology, porosity, degree of functionalization, and hydro/oleophobic properties is discussed. The hybrid nanosilicas presented high colloidal stability and were spherical and monodispersed with average particle size of ∼45 nm. They also showed high surface areas, large pore volumes, and a wormhole-type mesoporous structure. The increase in the organosilane proportion during the co-condensation process led to a more radially branched wormhole-like mesoporosity, a decrease in the surface area, pore volume, and amount of surface silanol groups, and an enrichment of the surface with fluorocarbon moieties. These changes imparted hydrophobic and oleophobic properties to the materials, especially to that containing the highest F13 loading. Cotton textiles were coated with the F13-MSNs through an efficient and less time-consuming route. The combination between surface roughness and mesoporosity imparted by the MSNs, and the low surface energy provided by the organosilane resulted in superhydrophobic functional textiles. Moreover, the textile with the highest loading of fluorocarbon groups was superamphiphobic.

Propolis immunomodulatory action in vivo on Toll-like receptors 2 and 4 expression and on pro-inflammatory cytokines production in mice

Propolis is a bee product and its immunomodulatory action has been the subject of intense investigation lately. The recent discovery and characterization of the family of Toll-like receptors (TLR) have triggered a great deal of interest in the field of innate immunity due to their crucial role in microbial recognition and development of the adaptive immune response. This work aimed to evaluate propolis's effect on TLR-2 and TLR-4 expression and on the production of pro-inflammatory cytokines (IL-1beta and IL-6). Male BALB/c mice were treated with propolis (200 mg/kg) for three consecutive days, and TLR-2 and TLR-4 expression as well as IL-1beta and IL-6 production were assessed in peritoneal macrophages and spleen cells. Basal IL-1beta production and TLR-2 and TLR-4 expression were increased in peritoneal macrophages of propolis-treated mice. TLR-2 and TLR-4 expression and IL-1beta and IL-6 production were also upregulated in the spleen cells of propolis-treated mice. One may conclude that propolis activated the initial steps of the immune response by upregulating TLRs expression and the production of pro-inflammatory cytokines in mice, modulating the mechanisms of the innate immunity.

Polar properties and phase sequence in Eu(0.8)Y(0.2)MnO(3)

In this work, we have studied in detail the temperature dependence of the electric polarization of Eu(0.8)Y(0.2)MnO(3) aimed at clarifying the controversial issues concerning the ferroelectric nature of the lower temperature magnetic phases and hence its multiferroic character. The existence of a spontaneous polarization in 30 K < T < 22 K, provides clear evidence for the ferroelectric character of the re-entrant non-collinear spiral-antiferromagnetic phase, stable in that temperature range. Contrary to results published in previous works, our experimental data clearly show that the weak-ferromagnetic, canted antiferromagnetic phase stable below 20 K is not intrinsically ferroelectric. The misinterpretation, regarding the polar character of the lower temperature magnetic phases, stems from the existence of an induced polarization occurring below 30 K. The mechanisms associated with polar and magnetic properties, and their correlation with both spin and lattice structures are also discussed.

Detection of enterotoxin genes of Staphylococcus SP isolated from nasal cavities and hands of food handlers

Food handlers, an important factor in food quality, may contain bacteria that are able to cause foodborne disease. The present study aimed to research coagulase-negative (CNS) and -positive staphylococci (CPS) in 82 food handlers, analyzing nasal and hand swabs, with identification of 62 CNS (75.6%) and 20 CPS strains (24.4%). Staphylococcal enterotoxins genes were investigated by PCR. In 20 CPS strains, 19 were positive for one or more genes. The percentage of CNS presenting genes for enterotoxins was high (46.8%). Despite of the staphylococcal species, the most common gene was sea (35.4%), followed by seh and sej (29.2%). The detection of new staphylococcal enterotoxins (SEs) genes showed a higher pathogenic potential in this genus. The presence of these gene points out the importance of CNS not only as contaminant bacteria but also as a pathogen.

Influence of grain size dispersion on the magnetic properties of nanogranular BaTiO3-CoFe2O4 thin films

Thin film nanogranular composites of cobalt ferrite (CoFe2O4) dispersed in a barium titanate (BaTiO3) matrix were deposited by laser ablation with different cobalt ferrite concentrations (x). Their structural and magnetic properties were characterized. The films were polycrystalline and composed by a mixture of tetragonal-BaTiO3 and CoFe2O4 with the cubic spinel structure. A slight (111) barium titanate phase orientation and (311) CoFe2O4 phase orientation were observed. The lattice parameter of the CoFe2O4 was always smaller than the bulk value indicating that the cobalt ferrite was under compressive stress. From atomic force microscopy a broad distribution of grain sizes was observed in the nanocomposites, with a significant amount of smaller grains (<40 nm) from the CoFe2O4 phase. The magnetic measurements show an increase of the magnetic moment from the low concentration region where the magnetic grains are more isolated and their magnetic interaction is small, towards the bulk value for higher CoFe2O4 content in the films. A corresponding decrease of coercive field with increasing cobalt ferrite concentration was also observed, due to the higher inter-particle magnetic interaction (and reduced stress) of the agglomerated grains.

New phase transition in the Pr1-xCaxMnO3 system: evidence for electrical polarization in charge ordered manganites

In this Letter a detailed study of the electric field gradient (EFG) across the Pr(1-x)Ca(x)MnO(3) phase diagram and its temperature dependence is given. Clearly, distinct EFG behavior for samples outside or inside the charge order (CO) region are observed. The EFG temperature dependence evidences a new phase transition occurring over the broad CO region of the phase diagram. This transition is discontinuous and occurs at temperatures between the charge ordering and the Néel temperatures. The prominent features observed in the EFG are associated with polar atomic vibrations which eventually lead to a spontaneous local electric polarization below CO transition.

Weaning from non-invasive positive pressure ventilation: experience with progressive periods of withdraw

BACKGROUND

In recent years non-invasive ventilation (NIV) as become a valuable therapeutic option in exacerbations of patients with chronic pulmonary obstructive disease. Although widely used there is a paucity of information on weaning from NIV.

OBJECTIVES

We aimed to describe the performance of a weaning protocol based on progressive periods of NIV withdraw.

METHODS

During a one year period we performed NIV in 78 patients with acute exacerbation of chronic respiratory failure. Weaning was considered in patients with 24 hours without acidosis and respiratory rate less than 25 cycles per minute. Weaning was performed as following: during the first 24 hours in each 3 hours, one hour without NIV (except during night period), in the second day in each 3 hours, two hours without NIV (except during night period) and in the third day NIV was used during the night period.

RESULTS

Sixty five patients began the weaning protocol. Mean NIV time was 120,9 hours (17 to 192 hours). No adverse effects were recorded in patients who began the weaning protocol. All patients completed the weaning protocol with no re-institution of NIV or invasive ventilation during hospitalization.

CONCLUSIONS

We report an excellent weaning success rate of NIV in patients with acute severe exacerbation of CRF. Although our weaning protocol required 72 hours, our results suggest that strategies based on periods with and with-out NIV are effective. Weather similar less time consuming weaning strategies are effective, merits investigation.

Observation of a Griffiths-like phase in the magnetocaloric compound Tb5Si2Ge2

The onset of a Griffiths-like phase has been observed in Tb5Si2Ge2 (TC=110 K) by means of magnetic susceptibility and small-angle neutron scattering experiments. We show the growth of a ferromagnetic cluster system characterized by an inverse susceptibility exponent lower than unity at TC<T<TG approximately 200 K. We suggest that the Griffiths-like state is originated by local disorder within the crystallographic structure, stabilized and enhanced by competing intralayer and interlayer magnetic interactions. Both factors thus promote segregation of nanometric regions with ferromagnetic interactions.

Extensive antigenic and genetic variation among foot-and-mouth disease type A viruses isolated from the 1994 and 1995 foci in São Paulo, Brazil

Nine foot-and-mouth disease virus (FMDV) type A isolates recovered from the field FMD foci in São Paulo State, Brazil, during 1994 and 1995 (a period preceding the last reported focus of FMD in 1996 in this state) were compared among themselves and with the reference vaccine strain A(24)Cruzeiro. The techniques used were sandwich ELISA, virus neutralization (VN), polyacrylamide gel electrophoresis (PAGE) of the structural polypeptides and direct sequencing of the VP1-coding region (1D gene). Results of VN were recorded as serological relationships "R" and those from ELISA were expressed as percentage of the homologous reaction "r". ELISA and VN gave comparable results (correlation coefficient, 0.936) allowing assignment of these field viruses to four groups which were distinct from the A(24)Cruzeiro strain. PAGE and 1D nucleotide sequencing were also able to distinguish between these viruses. The high level of genetic and antigenic variation found when comparing the A(24)Cruzeiro vaccine strain and type A strains recovered from the last identified foci of FMD came from a formerly endemic area where vaccination with polyvalent vaccines (O(1)Campos, A(24)Cruzeiro and C(3)Indaial) had been extensively applied. The similarity between the results of the serological and genetic analyses suggest that the antigenic differences found are mainly located in the 1D protein.

Angiotensin-converting enzyme inhibitors in heart failure: physicians' prescribing behavior

BACKGROUND

Several studies document an underuse of angiotensin-converting enzyme inhibitors (ACEIs) in heart failure (HF) patients, despite their proven efficacy and good tolerability. Also, there is some evidence that the doses used in clinical practice are far lower than those used in clinical trials.

METHODS AND RESULTS

To identify patterns of ACEI use in HF patients this study examined data collected on admission day regarding demographic, clinical, and medical care characteristics of 355 patients hospitalized because of decompensated HF who were treated with and without ACEIs. Additionally, measures of in-hospital outcome were compared among the two groups. Fifty-eight point six percent of patients were receiving ACEIs at admission and 80.6% were treated with ACEIs during hospitalization. The average ACEI does was low. No differences were observed in age and measures of severity of HF between ACEI-prescribed and nonprescribed patients. Patterns that could explain ACEI underuse included female sex, lower systolic blood pressure, worse renal function, left ventricular diastolic dysfunction, use of alternate drugs (eg, spironolactone), and overall less intense medical management. Patterns associated with the use of lower doses of ACEIs included older age, higher New York Heart Association functional class, and lower systolic blood pressure. In-hospital death rates were significantly higher for patients not treated with ACEIs.

CONCLUSIONS

This study suggests that many patients eligible for ACEI treatment were deprived of the advantages of these drugs because of erroneous clinical strategies. Nevertheless, the patterns of ACEI use were similar to those reported by other studies. Clinical trials conducted to determine the risk/benefit ratio of ACEI use in patients with renal dysfunction and the utility of ACEIs in diastolic HF, as well as programs to educate care providers on proper use of ACEIs in HF patients, are strongly recommended.

Liquid-phase blocking sandwich enzyme-linked immunosorbent assay for detection of antibodies against foot-and-mouth disease virus in water buffalo sera

OBJECTIVE

To develop and apply the liquid-phase blocking sandwich ELISA (BLOCKING-ELISA) for the quantification of antibodies against foot-and-mouth disease virus (FMDV) strains O1 Campos, A24 Cruzeiro, and C3 Indaial. DESIGN--Antibody quantification.

SAMPLE POPULATION

158 water buffalo from various premises of Sao Paulo State-Brazil. The sera were collected either from systemically vaccinated or nonvaccinated animals.

PROCEDURE

The basic reagents of BLOCKING-ELISA (capture and detector antibodies, virus antigens, and conjugate) were prepared and the reaction was optimized and standardized to quantify water buffalo antibodies against FMDV. An alternative procedure based on mathematical interpolation was adopted to estimate more precisely the antibody 50% competition titers in the BLOCKING-ELISA. These titers were compared with the virus-neutralization test (VNT) titers to determine the correlation between these techniques. The percentages of agreement, cutoff points, and reproducibility also were determined.

RESULTS

The antibody titers obtained in the BLOCKING-ELISA had high positive correlation coefficients with VNT, reaching values of 0.90 for O1 Campos and C3 Indaial, and 0.82 for the A24 Cruzeiro (P < 0.0005). The cutoff points obtained by use of the copositivity and conegativity curves allowed determination of high levels of agreement between BLOCKING-ELISA and VNT antibody titers against the 3 FMDV strains analyzed.

CONCLUSIONS

The results characterized by high correlation coefficients, levels of agreement, and reproducibility indicate that the BLOCKING-ELISA may replace the conventional VNT for detection and quantification of antibodies from water buffalo sera to FMDV.