Search

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Non-repaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p = 0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p = 0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTA-Angelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.

OBJETIVO: Determinar a prevalência da doença celíaca e descrever as alterações histológicas, manifestações clínicas e condições associadas de um grupo de familiares de primeiro grau de celíacos na cidade de Recife (PE), Nordeste do Brasil. MÉTODO: O estudo foi realizado em ambulatórios de gastropediatria da cidade de Recife. Foram incluídos no estudo 174 familiares de primeiro grau submetidos à pesquisa do anticorpo antitransglutaminase IgA. Os familiares com sorologia positiva foram convidados a realizar biópsia do intestino delgado (classificadas segundo Marsh) e avaliação do peso, estatura, manifestações clínicas e condições associadas à doença celíaca. Foram utilizados os testes do qui-quadrado e de Fisher para avaliar as diferenças, considerando-se significativo o valor de p < 0,05. RESULTADOS: O anticorpo antitransglutaminase IgA foi positivo em 20,1% (34/174) dos familiares (IC95% 14,6-26,5). Não se observou diferença na positividade da sorologia quanto ao grau de parentesco, nem quanto ao sexo. Vinte e dois pacientes submeteram-se a biópsia. Treze apresentaram alterações histológicas grau III de Marsh; sete, grau I; e dois, grau zero, conferindo uma prevalência presumível de 11,5%. Todos os pacientes, exceto um, eram sintomáticos; o único paciente sem sintomas tinha baixa estatura. CONCLUSÃO: A prevalência de doença celíaca nesse grupo de familiares foi elevada. Todos os novos casos identificados tinham sintomas ou condições associadas. Nesse grupo, houve uma frequência elevada de indivíduos com sorologia positiva, sintomatologia sugestiva de doença celíaca e sem evidência de atrofia vilositária na mucosa intestinal. OBJECTIVE: To determine the prevalence of celiac disease and to describe the histological alterations, clinical manifestations, and conditions associated with a group of first-degree relatives of celiac disease patients in the municipality of Recife, Northeast Brazil. METHOD: The study was conducted in outpatient clinics of pediatric gastroenterology located in Recife. We included in the study 174 first-degree relatives who were screened for the anti-transglutaminase IgA antibody. Those relatives who had positive serological tests were invited to undergo a small intestine biopsy (classified according to Marsh). They were also evaluated regarding weight, height, clinical symptoms and conditions associated with celiac disease. The chi-square test and Fisher's exact test were used to assess the differences with a significance level of p < 0.05. RESULTS: The anti-transglutaminase IgA antibody was positive for 20.1% (34/174) of the relatives (95%CI 14.6-26.5). There was no difference in terms of positive serological tests regarding either degree of kinship or sex. Twenty-two patients underwent biopsy. Thirteen had histological alterations classified as Marsh stage 3; seven had stage 1; and two had stage zero, with a probable prevalence of 11.5%. All patients, except for one, had symptoms; the only patient with no symptoms was short. CONCLUSION: Celiac disease prevalence in this group of relatives was high. All new cases identified were symptomatic or had associated conditions. In this group, there was a high frequency of individuals with positive serological tests, symptoms suggestive of celiac disease, and no evidence of villous atrophy in the intestinal mucosa.

A large number of geologic environments are composed of different layers of contrasting grain sizes. An accurate description of the locations of these stratigraphic units is necessary for defining flow-field boundaries. In groundwater contamination problems, preferential pathways are controlled by the hydraulic properties of these units. This work presents and applies a Bayesian Kriging technique to a subsurface characterization problem. Expertise guesses with given uncertainties are included in the estimation procedure. This technique assures that observation data (hard data) prevail in areas close to observation points, whereas in areas without observations the guesses (soft data) have greater influence. Maps of the estimates and the associated uncertainties are shown to be key tools in reflecting the quantity and quality of the available data. The Simple and Universal Kriging become subsets of this procedure. Key words : Kriging, subsurface characterization, conditional simulation, geostatistics.

Carbonic anhydrase VI is a secreted enzyme that catalyzes the hydration of carbon hydroxide in saliva and other body fluids. This enzyme has been implicated in taste and gastrointestinal dysfunctions, tooth erosion, and caries. The purpose of this study was to analyze the allele and genotype distribution of three polymorphisms in the coding sequences of (CA6) gene and check for possible associations with salivary buffer capacity, number of decayed, missing, and filled teeth in deciduous and permanent teeth (dmft/DMFT, Decayed/Missing/Filled Teeth), plaque index (PI), and the plaque pH variation (DeltapH) in children aged 7-9 years. Two hundred and forty-five children from both genders, residents in area with fluoridated water (Piracicaba, São Paulo, Brazil) were divided into two groups: caries free and with caries. The clinical examinations were conducted by a single previously calibrated examiner (kappa=0.91) in an outdoor setting using a mirror and a probe, according to WHO criteria index (dmft/DMFT). Approximately 2 h after the first daily meal, the buffer capacity (BC) and the plaque pH were analyzed by means of a pH meter and an ion selective electrode. Plaque pH was measured immediately and 5 min after a mouth rinse with a 10% sucrose solution. The data were submitted to chi(2), Student's, and Mann-Whitney tests (alpha=0.05). The PI and DeltapH of the upper and lower teeth were significantly higher in the carious group than control (P0.05). There was no difference between the groups in relation to BC. There was no association between the alleles and genotypes distributions for polymorphisms in the CA6 gene exons 2 and 3 and caries experience (P0.05). There was a positive association between buffer capacity and the rs2274327 (C/T) polymorphism. The allele T and genotype TT were significantly less frequent in individuals with the highest buffer capacity (P=0.023 and 0.045, respectively). This finding encourages future studies relating CA6 gene polymorphisms and their association with malfunctions, such as taste and gastrointestinal alterations, or the differential effect of chemical modulators on the protein products originated from the distinct genotypes of the CA6 gene.

Zwitterionic peptides with trypanocidal activity are promising lead compounds for the treatment of African Sleeping Sickness, and have motivated research into the design of compounds capable of disrupting the protozoan membrane. In this study, we use the Langmuir monolayer technique to investigate the surface properties of an antiparasitic peptide, namely S-(2,4-dinitrophenyl)glutathione di-2-propyl ester, and its interaction with a model membrane comprising a phospholipid monolayer. The drug formed stable Langmuir monolayers, whose main feature was a phase transition accompanied by a negative surface elasticity. This was attributed to aggregation upon compression due to intermolecular bond associations of the molecules, inferred from surface pressure and surface potential isotherms, Brewster angle microscopy (BAM) images, infrared spectroscopy and dynamic elasticity measurements. When co-spread with dipalmitoyl phosphatidyl choline (DPPC), the drug affected both the surface pressure and the monolayer morphology, even at high surface pressures and with low amounts of the drug. The results were interpreted by assuming a repulsive, cooperative interaction between the drug and DPPC molecules. Such repulsive interaction and the large changes in fluidity arising from drug aggregation may be related to the disruption of the membrane, which is key for the parasite killing property.

This paper illustrates the importance of sensitivity analysis in the design of clay barriers. Theoretical modelling simulations are performed using the finite element method in which realistic scenarios for unsaturated flow are conceived. Results show that the adjoint operator technique can be an efficient component to evaluate the impact of the thickness of the clay barriers as well as in the values of hydraulic conductivity values on pressure head distribution and integrated travel time.

In this work we report the interaction effects of the local anesthetic dibucaine (DBC) with lipid patches in model membranes by Atomic Force Microscopy (AFM). Supported lipid bilayers (egg phosphatidylcholine, EPC and dimyristoylphosphatidylcholine, DMPC) were prepared by fusion of unilamellar vesicles on mica and imaged in aqueous media. The AFM images show irregularly distributed and sized EPC patches on mica. On the other hand DMPC formation presents extensive bilayer regions on top of which multibilayer patches are formed. In the presence of DBC we observed a progressive disruption of these patches, but for DMPC bilayers this process occurred more slowly than for EPC. In both cases, phase images show the formation of small structures on the bilayer surface suggesting an effect on the elastic properties of the bilayers when DBC is present. Dynamic surface tension and dilatational surface elasticity measurements of EPC and DMPC monolayers in the presence of DBC by the pendant drop technique were also performed, in order to elucidate these results. The curve of lipid monolayer elasticity versus DBC concentration, for both EPC and DMPC cases, shows a maximum for the surface elasticity modulus at the same concentration where we observed the disruption of the bilayer by AFM. Our results suggest that changes in the local curvature of the bilayer induced by DBC could explain the anesthetic action in membranes.

We report a methodology to obtain thin films of cucurbit[6]uril, starting from ammoniacal solutions. This technique is very useful for the obtention of modified electrodes or other substrates for sensor purposes. Cucurbit[6]uril is insoluble in most media, and film formation was impossible until now.

This in vitro study evaluated the combined effects of a 10.6 microm CO2 laser, fluoridated dentifrice, and mouthrinse on the reduction of lesion progression in carious human enamel.Slabs of previously demineralized dental enamel were assigned to nine groups, either treated with/without a CO2 laser, with/without fluoridated dentifrice, and with/without fluoridated mouthrinse. After a pH-cycling regime, fluoride concentrations were determined in the demin- and remineralizing solutions. A qualitative polarized light analysis was performed on enamel, and enamel mineral loss was determined by cross-sectional microhardness testing.All treatments were able to decrease mineral loss, and the inhibition of demineralization progression ranged from 48% to 60%.The 10.6 microm CO2 laser irradiation alone or combined with fluoridated products reduced demineralization progression in enamel. However, there was no significant additional demineralization inhibitory effect with the use of the combined laser-fluoride treatments.CO2 lasers have proven to be efficient in reducing subsurface enamel demineralization. Its association with a high frequent fluoride therapy may enhance this protective effect.

The electronic state spectroscopy of acetone (CH3)2CO has been investigated using high-resolution VUV photoabsorption spectroscopy in the energy range 3.7-10.8 eV. New vibronic structure has been observed, notably in the low energy absorption band assigned to the 1(1)A(1) --1(1)A2 (ny --pi*) transition. The local absorption maximum at 7.85 eV has been tentatively attributed to the 4(1)A1 (pi --pi*) transition. Six Rydberg series converging to the lowest ionisation energy (9.708 eV) have been assigned as well as a newly-resolved ns Rydberg series converging to the first ionic excited state (12.590 eV). Rydberg orbitals of each series have been classified according to the magnitude of the quantum defect (delta) and are extended to higher quantum numbers than in the previous analyses.

7 pags., 2 figs. -- Radiation damage inbiomolecular systems 19–22 June 2007, The Royal College of Surgeons, Dublin, Ireland, Acetone in human breath has been established as a biomarker for diabetes. The application of UV spectroscopy for the study of biomedical compounds has been developed over recent years but is often limited by the lack of absolute data for calibration of the instrumentation. By measuring high resolution absolute VUV photoabsorption cross sections of acetone, we are able to provide calibration values at several wavelengths with special attention to 4.661 eV (266 nm). Results are compared with recent published data [C Wang, A Mbi, Meas. Sci. Technol., 2007, 18, 2731-2741]. The acetone spectrum is here revisited from a recent contribution [Nobre M, et al, Phys Chem Chem Phys, 2008 (in press)] where the absolute cross sectional values are obtained in the 3.7-10.8 eV energy region. Future medical units working in close link with synchrotron radiation facilities can make use of the VUV spectra wavelength region to trace acetone in diabetic patients. © 2008 IOP Publishing Ltd., MN, AF and DA acknowledge the support from the EU network RADAM and RA the Portuguese Foundation for Science and Technology (FCT-MCTES) for a post-graduate scholarship. PLV acknowledges the visiting research fellow position at CEMOS, The Open University, UK, and together with NJM, the support from the British Council for the Portuguese-UK joint collaboration. The authors wish to acknowledge the beam time at the ISA synchrotron facility, University of Aarhus, Denmark, I3 Integrated Activity on Synchrotron and Free Electron Laser Science (IA-SFS), contract number RII3-CT-2004-506008, under the Research Infrastructure Action of the FP6 EC programme Structuring the European Research Area. Some of this work forms part of the ESF network programme EIPAM and EU/ESF RADAM COST Action-P9.

The interaction between chitosan and Langmuir and Langmuir-Blodgett (LB) films of dimyristoyl phosphatidic acid (DMPA) is investigated, with the films serving as simplified cell membrane models. At the air-water interface, chitosan modulates the structural properties of DMPA monolayers, causing expansion and decreasing the monolayer elasticity. As the surface pressure increased, some chitosan molecules remained at the interface, but others were expelled. Chitosan could be transferred onto solid supports alongside DMPA using the LB technique, as confirmed by infrared spectroscopy and quartz crystal microbalance measurements. The analysis of sum-frequency vibration spectroscopy data for the LB films combined with surface potential measurements for the monolayers pointed to chitosan inducing the ordering of the DMPA alkyl chains. Furthermore, the morphology of DMPA LB films, studied with atomic force microscopy, was affected significantly by the incorporation of chitosan, with the mixed chitosan-DMPA films displaying considerably higher thickness and roughness, in addition to chitosan aggregates. Because chitosan affected DMPA films even at pressures characteristic of cell membranes, we believe this study may help elucidate the role of chitosan in biological systems.

In this paper we employed phospholipid Langmuir monolayers as membrane models to probe interactions with chitosan. Using a combination of surface pressure--area and surface potential--area isotherms and rheological measurements with the pendent drop technique, we observed that chitosan interacts with phospholipid molecules at the air-water interface. We propose a model in which chitosan interacts with the phospholipids mainly through electrostatic interactions, but also including H-bonding and hydrophobic forces, depending on the phospholipid packing density. At large areas per molecule, chitosan in the subphase adsorbs onto the monolayer, expanding it. At small areas per molecule, chitosan is located in the subsurface. Indeed, a mixed chitosan-phospholipid monolayer can be transferred onto solid supports, even at high surface pressures. The effects of chitosan on the viscoelastic properties of phospholipid monolayers may be taken as evidence for the ability of chitosan to disrupt cell membranes.

An adaptation of the Drivers-Pressure-State-Impact-Response methodology is presented in this work. The differential DPSIR (DeltaDPSIR) was developed to evaluate impacts on the coastal environment and as a tool for integrated ecosystem management. The aim of the DeltaDPSIR is to provide scientifically-based information required by managers and decision-makers to evaluate previously adopted policies, as well as future response scenarios. The innovation of the present approach is to provide an explicit link between ecological and economic information related to the use and management of a coastal ecosystem within a specific timeframe. The application of DeltaDPSIR is illustrated through an analysis of developments in a Southwest European coastal lagoon between 1985 and 1995. The value of economic activities dependent on the lagoon suffered a significant reduction (ca. -60%) over that period, mainly due to a decrease in bivalve production. During that decade the pressures from the catchment area were managed (ca. 176 million Euros), mainly through the building of waste water treatment plants. Notwithstanding this, the ecosystem state worsened with respect to abnormal clam mortalities due to a parasite infection and to benthic eutrophication symptoms in specific problematic areas. The negative economic impacts during the decade were estimated between -565 and -315 million Euros, of which 9-49% represent the cost of environmental externalities. Evaluation of these past events indicates that future management actions should focus on reducing the limitation on local clam seeds, which should result in positive impacts to both the local socio-economy and biodiversity.

With the aim of contributing to the comprehension of the changes that have recently been observed in Portuguese EFL school curriculum, this paper is a critical analysis of curricular factors that contribute to the challenges today’s EFL teachers face in schools. The data analysed comprise the documents published by national educational authorities (EFL learning outcomes) as well as the teachers’ examination test required to enter the EFL teaching profession. The educational principles underlying these documents, as well as the teaching practices they support and encourage, are compared to the principles and the methodological recommendations of previous, more progressive, Portuguese EFL syllabi. The methodological trends identified on the current EFL teaching panorama are also contrasted with the principles of the language teachers education programs taught at Portuguese universities.

In this work we present equilibrium and dynamic surface tension together with dilational elasticity data for dodecyltrimethylammonium bromide in the presence of lambda-carrageenan, a sulfated polysaccharide extracted from algae. The critical aggregation concentration and (CAC) and critical micellar concentration CMC of the mixed system were determined and shown to have a direct influence on the elasticity modulus. The behavior of the adsorption kinetics was shown to be dependent on the surfactant to polyelectrolyte charge ratio or excess species in the bulk solution.

Laser and fluoride treatments have been shown to inhibit enamel demineralization in the laboratory. However, the intra-oral effects of this association have not been tested. This study assessed in situ the effect of a Transversely Excited Atmospheric CO2 laser (λ = 9.6 μm) and the use of pressure fluoridated dentifrice on enamel demineralization. During two 14-day phases, 17 volunteers wore palatal appliances containing human enamel slabs assigned to treatment groups, as follows: (1) non-fluoride dentifrice, (2) CO2 laser irradiation plus non-fluoride dentifrice, (3) fluoride dentifrice, and (4) CO2 laser irradiation plus fluoride dentifrice. A 20% sucrose solution was dripped onto the slabs 8 times per day. The specimens treated with laser and/or fluoridated dentifrice presented a significantly lower mineral loss when compared with those from the non-fluoride dentifrice group. The results suggested that CO2 laser treatment of enamel inhibits demineralization in the human mouth, being more effective when associated with fluoride.

Gram-negative bacteria possess a double membrane system, with the external leaflet of the outer membrane composed of lipopolysaccharides (LPS) that act as the first barrier to drugs. The importance of studying the permeability of LPS barrier comes from its correlation with strain susceptibility. In this study, we extracted LPS from two isogenic Salmonella sp strains, that contains alterations in the lipid A portion regulated by the phoPQ-system. Interaction between phoP- (LPS with no modification) or phoPc (palmitoylation of the 3-hydroxyl group in the 3-OH-myristyl residue, addition of 4-aminoarabinose to the 4' phosphate group and addition of a 2-hydroxy group to the myristate residue at the position 3') LPS and novobiocin was evaluated by using Langmuir monolayers. Novobiocin was chosen due to its size (612 Da), large enough to permeate cells throughout the LPS, and not through the porin channels. MIC of novobiocin for phoP- was 14 μg mL-1 and for phoPc, 40 μg mL-1. p-A isotherms indicated that phoP- occupies a limiting area of 150A2, while for phoPc this value is 175A2. However, addition of Mg2+ promotes condensation of 20A2 for phoP-, and 70A2 for phoPc. Epifluorescence microscopy reveals phoP- has fluid-like morphology .In contrast, phoPc displays circular-shaped domains that increase in size and number with the compression. The addition of novobiocin to the subphase promoted slight changes in phoP- morphology. However, for phoPc monolayer, changes in morphology were observed for higher concentrations of novobiocin at which domains started to aggregate generating structures like a "pearl necklace". Structural organization was evaluated by GIXD, and data corroborates the one obtained by epifluorescence, in which novobiocin interaction promotes liquid-crystalline phase formation. Electron density profile probed that novobiocin interacts with phoP- hydrophobic portion, but much higher concentration is needed to permeate phoPc.

A eutrophication assessment method was developed as part of the National Estuarine Eutrophication Assessment (NEEA) Program. The program is designed to improve monitoring and assessment of eutrophication in the estuaries and coastal bays of the United States with the intent to guide management plans and develop analytical and research models and tools for managers. These tools will help guide and improve management success for estuaries and coastal resources. The assessment method, a Pressure-State-Response approach, uses a simple model to determine Pressure and statistical criteria for indicator variables (where applicable) to determine State. The Response determination is mostly heuristic, although research models are being developed to improve that component. The three components are determined individually and then combined into a single rating. Application to several systems in the European Union (E.U.), specifically in Portugal, shows that the method is transferable, and thus is useful for development of management measures in both the Unites States and E.U. This approach identifies and quantifies the key anthropogenic nutrient input sources to estuaries so that management measures can target inputs for maximum effect. Because nitrogen is often the limiting nutrient in estuarine systems, examples of source identification and quantification for nitrogen have been developed for 11 coastal watersheds on the U.S. east coast using the WATERSN model. In general, estuaries in the Northeastern United States receive most of their nitrogen from human sewage, followed by atmospheric deposition. This is in contrast to some watersheds in the Mid-Atlantic (Chesapeake Bay) and South Atlantic (Pamlico Sound), which receive most of their nitrogen from agricultural runoff. Source identification is important for implementing effective management measures that should be monitored for success using assessment methods, as described herein. For instance, these results suggest that Northeastern estuaries would likely benefit most from improved sewage treatment, where as the Mid and South Atlantic systems would benefit most from agricultural runoff reductions.

O alargamento da União Europeia de quinze a vinte e cinco Estados membros suscita numerosas interrogações sobre a coerência e a viabilidade de um tal projecto. Contudo, há quem considere que os media poderão assumir um papel importante nesta matéria, favorecendo a construção de uma sociedade civil e de uma identidade europeias vigorosas. A fragmentação da paisagem mediática europeia e a dimensão norte-americana dos media transnacionais provocam porém um certo cepticismo…

Poly(ethylene oxide) (PEO)/methanol can be used as solvent medium for the Pd-catalyzed Suzuki cross-coupling reaction under mild conditions. After the end of the reaction the product is extracted with heptane and the polar phase can be reused several times without any change in the activity. Pure biaryl products are obtained from the nonpolar phase in excellent isolated yields (>90%). The same catalyst-containing polar phase was used to coupling different aryl halides furnishing the biaryl products in good to high isolated yields.

The Ria Formosa is a shallow mesotidal lagoon on the south coast of Portugal, with natural biogeochemical cycles essentially regulated by tidal exchanges at the seawater boundaries and at the sediment interface. Existing data on nutrients in the water column and the sediment, together with chlorophyll a and oxygen saturation in the water column, are compared using different models for assessing eutrophication. The European Environmental Agency criteria are based on the comparison of nutrient concentrations which indicate that the situation in the Ria Formosa is ‘‘poor’’ to ‘‘bad’’. In contrast, the United States Estuarine Eutrophication Assessment is based on symptoms, including high chlorophyll a and low oxygen saturation, which indicate that the Ria Formosa is near pristine. Despite these contradictions, a preliminary assessment by Driving forces, Pressures, State, Impact, Reponses (DPSIR) of eutrophication demonstrate the potential for episodic eutrophic conditions from treated and untreated domestic effluent as well as from non-point source agricultural run off. Sediments are also an important source of nutrients in the lagoon, but their contribution to potential eutrophic conditions is unknown. r 2003 Elsevier Ltd. All rights reserved.

The increase of Gram-negative bacteria super-resistant to antibiotics is a major problem in medicine. These bacteria possess a double membrane system, with the external leaflet of the outer membrane composed of lipopolyssaccharides (LPS) that act as the first barrier to drugs. Thus, bacteria's susceptibility to lipophilic antibiotics is highly correlated with the permeability of this LPS barrier. In this study, we extracted LPS from two isogenic Salmonella sp strains, using the method of Galanos. These strains contain alterations in the lipid A portion of their LPS regulated by the PhoPQ-system. These modifications include palmitoylation of the 3-hydroxyl group in the 3-OH-myristyl residue, addition of 4-aminoarabinose to the 4' phosphate group and addition of a 2-hydroxy group to the myristate residue at the position 3'. Langmuir monolayers were formed of both LPS and compression isotherms indicated that PhoP- (LPS from the strain with no modifications) occupies a limiting area of 150A2, while for PhoPc (LPS from the strain with the modifications cited above) this value is 175A2. These are in agreement with previous report for other Salmonella sp LPS. Epifluorescence microscopy reveals PhoP- has a very homogeneous, fluid-like, morphology throughout the compression without discrete domain formation. In contrast, PhoPc displays circular-shaped domains that increase in size and number with the compression. The addition of novobiocin (0.4 μg mL-1) to the subphase promoted slight changes in PhoP- morphology, suggesting that this monolayer was already fluid enough to incorporate this antibiotic. For PhoPc monolayer, changes in morphology were observed only for high concentrations (2.5x) of novobiocin at which the domains started to aggregate generating structures like a “pearl necklace”.

Pulchellin, a type-2 Ribosome Inactivating Protein (RIP), whose action mechanism proposed would be initiate by B-chain binding on glycoconjugate onto the cell surface (lectinic chain). Into the cell, the A-chain (toxic chain) binding in ER lipids and stopping protein synthesis at ribosome inducing cell death. Was showed that Puchelin isoforms have different toxicity and were separated subgroups PI, PII, PIII, PIV based: toxicity, secondary structure, specificity for sugar binding. PII and PIV subgroups present structural identity above 70%, however PII is five-fold more toxic than PIV (Castilho, et al. FEBS journal, 2008). The present studies show results of interaction between model membranes and the two isoforms (PII and PIV) using Langmuir monolayers (LM) and giant unilamellar vesicles (GUVs). PII and PIV bond to LM-DPPC in the same extension, but when monolayers contented 5% of GalCer, PII remained strongly interacting with the mixed monolayer and PIV seems to be inhibited by the presence of the glycolipids. In GUVs-POPC, both PII and PIV destroyed the vesicles, however, in GUVs-POPC+5%GalCer, only PII induced vesicles decreased in their surface around 30% and some invaginations could be observed. After 20 minutes, small vesicles were observed inside of the GUV structure. For PIV, instead of invaginations, only fluctuations on the GUV surface were verified. Increasing PIV concentration the GUVs were destruction. In view of the results, one can conclude that the key for understanding differences in pulchellin isoforms toxicity is the interaction between B-chain lectinic and the glycosyl residues on cell surface.Supported by Brazilian Agencies: FAPESP, CNPq

We have previously reported that zona pellucida (ZP) removal and cationic lipid-based transfection (lipofection) of 1-cell stage bovine embryos with siRNA or DNA did not affect development to the blastocyst (BL) stage (Bertolini et al. 2006 Reprod. Fertil. Dev. 18, 168–169). Moreover, approximately half of green fluorescent protein (GFP)-transfected embryos showed various levels of fluorescence at the BL stage, which was also recently confirmed by others (O’Meara et al. 2010 Reprod. Fertil. Dev. 22, 224). The objective of this study was to evaluate the effect of the timing of ZP removal on the efficiency of lipofection in Day 8 bovine IVF-derived blastocyst stage embryos. In vitro-derived (IVP) embryos, produced based on (Bertolini et al. 2004 Reproduction 128, 341–354), were allocated to one of three experimental groups: (a) G-1, ZP removal on Day 1 of development, in embryos at the 1-cell stage (7 days before transfection); (b) G-2, ZP removal performed on Day 7 BL (24 h before transfection); and (c) G-3, naturally hatched Day 8 BL. On Day 8 of development, zona-free BL from G1, G2, and G3 were transfected by the incubation in 5 μL Lipofectamine 2000 (Invitrogen, Carlsbad, CA, USA) and 12 μg DNA (pEGFP, Clontech Laboratories, Mountain View, CA, USA) in 100 μL Opti-MEM I (Invitrogen), at 39°C for 30 to 60 min. Transfected embryos were cultured for 24 h, when qualitative and quantitative assessments of the transfection efficiency were done by fluorescence microscopy. Positively-transfected BL were DNA-stained for the estimation of the total GFP-positive cells and total cell numbers (ANOVA and Tukey’s test, P

a Department of Biological Engineering, University of Minho, Campus Gualtar, 4710-057 Braga, Portugal b Biodiversity and Conservation Biology, University of the Western Cape, Bellville 7535, South Africa c Israel Oceanographic and Limnological Research, National Centre for Mariculture, P.O. Box 1212, Eilat 88112, Israel d Department of Botany, University of Cape Town, Rondebosch 7701, South Africa

The reliability of flow and transport models depends on the understanding of the characteristics and impacts of spatial structures of subsurface formations. Preferential pathways are controlled by the geometries of these units. In subsurface characterization, it is the current practice to use both interpolation and extrapolation using a series of observations from well logs. Classical techniques, such as weighted interpolation and least-squares polynomial, are not recommended because they assume independence of sample data. Geostatistics methods bring a new horizon for reservoir engineering studies. Spatial dependence or autocorrelation of data exist, given the fact that neighbouring points tend to present similarities. In addition to this fact, reservoir heterogeneities are caused by usually known geologic processes such as deposition, sediment diagenesis and fracturing. Thus geologic data and models should also be helpful in characterizing spatial variability of flow properties. This work applies a Bayesian Kriging technique which includes an expertise guess with a given uncertainty in the estimation procedure. This technique assures that observation data (hard data) prevail in areas close to field measurements, whereas in areas without observations the expert’s experience (soft data) have greater influence. Maps of the estimates and the associated uncertainties are shown to be key tools in reflecting the quantity and quality of the available. Simple Kriging and Universal Kriging become subsets of this procedure.

The mixing of unfamiliar sows usually results in fighting which can have adverse consequences for both welfare and production. It has been suggested that aggression may be moderated by both the presence of a boar and by allowing sows access to feeding stalls (Arey and Edwards, 1998). The objective of this experiment was to investigate these effects on the behaviour of newly weaned sows mixed into two loose-housing systems.In the first system (dynamic), 24 Large White x Landrace mixed parity sows were introduced 4 days post weaning to a dynamic group of 22 sows and 2 boars with a replacement rate of 2 sows per week. Observations were carried out on the 2 newly introduced sows each week. The straw-bedded pen provided 4.5 m2 space per animal. The sows were floor fed 3 kg/sow at 08.00 each day.

© 2015 Biophysical Society. Small hydrophilic antibiotics traverse the outer membrane of Gram-negative bacteria through porin channels. Large lipophilic agents traverse the outer membrane through its bilayer, containing a majority of lipopolysaccharides in its outer leaflet. Genes controlled by the two-component regulatory system PhoPQ modify lipopolysaccharides. We isolate lipopolysaccharides from isogenic mutants of Salmonella sp., one lacking the modification, the other fully modified. These lipopolysaccharides were reconstituted as monolayers at the air-water interface, and their properties, as well as their interaction with a large lipophilic drug, novobiocin, was studied. X-ray reflectivity showed that the drug penetrated the monolayer of the unmodified lipopolysaccharides reaching the hydrophobic region, but was prevented from this penetration into the modified lipopolysaccharides. Results correlate with behavior of bacterial cells, which become resistant to antibiotics after PhoPQ-regulated modifications. Grazing incidence x-ray diffraction showed that novobiocin produced a striking increase in crystalline coherence length, and the size of the near-crystalline domains.

RESUMO: Aproximadamente 75% das doenças em vacas leiteiras acontecem no primeiro mês após o parto e esses problemas têm sua origem associada ao sistema imune e ao consumo de alimentos duas a três semanas antes do parto. Doenças relacionadas ao trato reprodutivo como, por exemplo, retenção de placenta pode afetar a eficiência reprodutiva assim como a produção de leite. Os efeitos das doenças nos processos fisiológicos dos animais se transformam em impactos econômicos passíveis de serem mensurados. Objetivou-se avaliar o impacto econômico da retenção de placenta em um rebanho composto de 900 vacas em lactação. O diagnóstico de retenção de placenta foi definido como presença da placenta 24 horas após o parto. Foi utilizado um banco de dados no estudo, do qual foram extraídas as seguintes informações: ano de parição, época de parição, ordem de lactação, presença da placenta 24 horas após o parto, e número de doses de sêmen por gestação. Para cálculo do impacto econômico foram considerados os custos diretos (tratamento, mão de obra, redução da produção de leite e descarte de leite durante o período de tratamento) e indiretos (aumento do período de serviço, aumento do número de doses de sêmen e aumento do risco de descarte). Os valores médios relacionados aos custos foram obtidos junto ao veterinário responsável pela propriedade com referência ao ano de 2009 para que os cálculos fossem realizados. O custo total por ocorrência de retenção de placenta em vacas primíparas no período de chuva e seca foi de US$51,8 e em vacas multíparas foi de US$70,6 e US$87,9 nas épocas de seca e de chuvas, respectivamente. A retenção de placenta apresentou custo para a propriedade no período avaliado de US$8.878,0 ou 19.666 litros de leite. A retenção de placenta apresentou impacto econômico importante na propriedade leiteira nas condições avaliadas. ABSTRACT: Approximately 75% of diseases in dairy cows occur in the first month after parturition and these problems have their origin associated with the immune system and food consumption two to three weeks before parturition. Diseases related to the reproductive tract, such as retained placenta, can affect reproductive efficiency as well as milk production. The effects of diseases on the physiological processes of animals become economic impacts that can be measured. The objective of this study was to evaluate the economic impact of retained placenta on a herd of 900 lactating cows. The diagnosis of placental retention was defined as presence of the placenta 24 hours postpartum. A database was used in the study, from which the following information was extracted: placenta presence 24 hours after calving, year of calving, calving season, and number of semen doses per gestation. In order to calculate the economic impact, the direct costs (treatment, labor, reduction of milk production and milk discharge during the treatment period) and indirect costs (increase in the service period, increase in the number of semen doses and increase of the risk of disposal). The average values related to the costs were obtained from the veterinarian responsible for the property with reference to the year 2009 for the calculations to be carried out. The total cost per occurrence of placenta retention in primiparous cows in the rainy and dry season was US$51.8 and in multiparous cows was US$70.6 and US$87.9 in times of drought and rain, respectively. Retention of placenta presented a cost for the property in the evaluated period of US$8,878.0 or 19,666 liters of milk. Retention of placenta presented a significant economic impact on milk production under the conditions evaluated.

The action of a synthetic antimicrobial peptide analog of Plantaricin 149 (Pln149a) against Saccharomyces 24 ^ cerevisiae and its interaction with biomembrane model systems were investigated. Pln149a was shown to 25 inhibit S. cerevisiae growth by more than 80% in YPD medium, causing morphological changes in the yeast 26 wall and remaining active and resistant to the yeast proteases even after 24 h of incubation. Different 27 membrane model systems and carbohydrates were employed to better describe the Pln149a interaction with 28 cellular components using circular dichroism and fluorescence spectroscopies, adsorption kinetics and 29 surface elasticity in Langmuir monolayers. These assays showed that Pln149a does not interact with either 30 mono/polysaccharides or zwitterionic LUVs, but is strongly adsorbed to and incorporated into negatively 31 charged surfaces, causing a conformational change in its secondary structure from random-coil to helix upon 32 adsorption. From the concurrent analysis of Pln149a adsorption kinetics and dilatational surface elasticity 33 data, we determined that 2.5 μM is the critical concentration at which Pln149a will disrupt a negative DPPG 34 monolayer. Furthermore, Pln149a exhibited a carpet-like mechanism of action, in which the peptide initially 35 binds to the membrane, covering its surface and acquiring a helical structure that remains associated to the 36 negatively charged phospholipids. After this electrostatic interaction, another peptide region causes a strain 37 in the membrane, promoting its disruption. Fil: Lopes, José Luiz S.. Universidade de Sao Paulo; Brasil Fil: Nobre, Thatyane M.. Universidade de Sao Paulo; Brasil Fil: Siano, Alvaro Sebastían. Universidad Nacional del Litoral; Argentina Fil: Humpola, Verónica. Universidad Nacional del Litoral; Argentina Fil: Bossolan, Nelma R.S.. Universidade de Sao Paulo; Brasil Fil: Zaniquelli, Maria. E.D.. Universidade de Sao Paulo; Brasil Fil: Tonarelli, Georgina Guadalupe. Universidad Nacional del Litoral; Argentina Fil: Beltramini, Leila M.. Universidade de Sao Paulo; Brasil

Design criteria for GaAs on crystalline silicon tandem solar cells under spectral conditions at different locations are presented. Such double-junction solar cells have the potential for realizing commercial PV modules with 1-Sun efficiencies of 30%.

The N-terminus of the human dihydroorotate dehydrogenase (HsDHODH) has been described as important for the enzyme attachment in the inner mitochondrial membrane and possibly to regulate enzymatic activity. In this study, we synthesized the peptide acetyl-GDERFYAEHLMPTLQGLLDPESAHRL AVRFTSLGamide, comprising the residues 33-66 of HsDHODH N-terminal conserved microdomain. Langmuir monolayers and circular dichroism (CD) were employed to investigate the interactions between the peptide and membrane model, as micelles and monolayers of the lipids phosphatidylcholine (PC), 3-phosphatidylethanolamine (PE) and cardiolipin (CL). These lipids represent the major constituents of inner mitochondrial membranes. According to CD data, the peptide adopted a random structure in water, whereas it acquired α-helical structures in the presence of micelles. The π-A isotherms and polarization- modulated infrared reflection-absorption spectroscopy on monolayers showed that the peptide interacted with all lipids, but in different ways. In DPPC monolayers, the peptide penetrated into the hydrophobic region. The strongest initial interaction occurred with DPPE, but the peptide was expelled from this monolayer at high surface pressures. In CL, the peptide could induce a partial dissolution of the monolayer, leading to shorter areas at the monolayer collapse. These results corroborate the literature, where the HsDHODH microdomain is anchored into the inner mitochondrial membrane. Moreover, the existence of distinct conformations and interactions with the different membrane lipids indicates that the access to the enzyme active site may be controlled not only by conformational changes occurring at the microdomain of the protein, but also by some lipid-protein synergetic mechanism, where the HsDHODH peptide would be able to recognize lipid domains in the membrane.

Peptides with trypanocidal activity are promising compounds for the treatment of African Sleeping Sickness, which have motivated the research into the ability of these compounds to disrupt the protozoan membrane. In this present study, we used the Langmuir monolayer technique to investigate the surface properties of an antiparasitic and zwitterionic peptide, namely S-(2,4-dinitrophenyl) glutathione di-2-propyl ester, and its interaction with a model membrane comprising a phospholipid monolayer, dipalmitoyl phosphatidyl choline (DPPC). The peptide formed a stable Langmuir monolayer, whose main feature of its surface pressure-area isotherm was the presence of a phase transition accompanied by a negative surface compressional modulus, which was attributed to the aggregation upon compression due to intermolecular bond associations of the molecules. This was inferred from surface pressure and surface potential isotherms, Brewster angle microscopy (BAM) images, Polarization modulation-infrared reflection-adsorption spectroscopy (PM-IRRAS), and dynamic elasticity measurements by the pendant drop technique. When co-spread with dipalmitoyl phosphatidyl choline (DPPC), the drug affected both the surface pressure and the monolayer morphology, even at high surface pressures and with low amounts of the drug. The results were interpreted by assuming a repulsive, cooperative interaction between the drug and DPPC molecules. Such repulsive interaction and the large changes in fluidity arising from drug aggregation may be related to the disruption of the membrane, which is key for the parasite killing property.

O desenvolvimento de novas técnicas analíticas e metodologias capazes de identificar e quantificar os componentes de amostras complexas, como aquelas relacionadas a problemas ambientais, é uma tendência atual. Os objetivos deste trabalho foram: fazer uso da técnica de fluorescência de raios X, com equipamento portátil, para identificação dos elementos químicos existentes na água e a medida da sua concentração no local de amostragem; implementar no Laboratório de Física Nuclear Aplicada da Universidade Estadual de Londrina, a metodologia de quantificação de metais em amostras aquosas, através de medidas de amostras in natura e pré-concentradas em filtros de membrana usando a técnica de Fluorescência de Raios-X com Dispersão em Energia (EDXRF) e otimizar a metodologia de pré-concentração e adaptá-la para utilização em campo. As análises foram realizadas em laboratório e in situ, com água in natura e amostras pré-concentradas em membranas. O trabalho consistiu na utilização de um tubo de raios X portátil (alvo de Ag, filtro de Ag de 50 ?m, 4 W) para excitar a amostra e um detector de Si-PIN (resolução de 221 eV para a energia de 5,9 keV e janela de Be de 25 ?m) com a eletrônica padrão para aquisição e avaliação do espectro. As amostras foram filtradas em membranas para retenção do material particulado em suspensão. Após isso, o procedimento de pré-concentração otimizado, utilizando a precipitação com APDC foi aplicado nas amostras com posterior filtragem em membranas. Ambos os filtros foram analisados para obtenção dos metais não dissolvidos e dissolvidos. A metodologia foi validada através da análise dos materiais de referência certificados SRM1640 e SRM1643e preparados nas mesmas condições das amostras. Foram analisadas amostras de vários pontos da cidade de Londrina, PR, sendo possível identificar e quantificar Ca, Ti, Mn, Fe, Cu, Zn e Pb. A performance e robustez do equipamento foram muito boas e os resultados satisfatórios para medidas in situ empregando equipamento portátil. Considerando as medidas em membranas, os limites de detecção do sistema estão abaixo dos valores máximos permitidos, satisfazendo a legislação nacional e internacional para corpos de água doce. Além disso, o limite de quantificação, que é da ordem de 0,01 mg L-1 para a maioria dos elementos, torna viável a aplicação da metodologia para análises em água. A EDXRF portátil mostrou-se uma ferramenta muito útil para análises ambientais, por ser uma técnica de análise rápida, eficiente e conveniente, com potencial para substituir métodos laboratoriais demorados e com custo elevado. Development of new analytical techniques and methodologies capable to identify and quantify the composition of complex samples, as the ones related to environmental problems, is an actual tendency. The objectives of this work were: to use X-ray fluorescence technique, with portable equipment, to identify and quantify the chemical elements present in the water and its concentration measurement in the sampling place; implement in the Applied Nuclear Physics Laboratoty of State University of Londrina, the metal quantification methodology for aqueous samples, through the in natura measurement and preconcentrated in membranes samples using Energy Dispersive X-Ray Fluorescence (EDXRF) technique, to optimize the preconcentration methodology and to adapt it for field use. The analyses were realized at laboratory and in situ, measuring in natura water and preconcentrated samples in membranes. It was employed a portable X-ray tube (Ag target, 50 ?m Ag filter, 4 W) to excite the samples and a Si-PIN detector (221 eV resolution for 5.9 KeV energy and 25 ?m Be window) with standard electronics for acquisition and evaluation of the spectra. The samples were filtered for suspended particulate matter retention. After this, the optimized preconcentration procedure, with APDC precipitation, was applied. Both filters were analyzes for non-dissolved and dissolved metal analysis. The standard reference materials SRM1640 and SRM1643e, prepared in the same conditions of the samples, were analyzed for methodology validation. Samples from several points at Londrina city, Paraná State, Brazil, were analyzed. It was possible to identify and quantify Ca, Ti, Mn, Fe, Cu, Zn and Pb. The equipment performance and robustness were very good and the results satisfactory for in situ analysis employing a portable system. Considering membrane measurements, the system detection limits are below the maximum values established by national and international legislation for drinking water. Besides this, the quantification limit, that is around 0.01 mg L-1 for the majority of the elements, makes viable the methodology application for water analysis. Portable EDXRF has shown to be an useful tool for environmental analysis, as it is a fast, efficient and convenient technique, with potential to substitute high cost and time consuming laboratory methods.