PAHs in franciscana dolphins from the Southwestern Atlantic Ocean: Concentration and maternal transfer assessments.

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds ubiquitous in the environment and known for their toxic, mutagenic, and carcinogenic effects. These compounds can bioaccumulate in the biota and be transferred through trophic webs. The franciscana dolphin (Pontoporia blainvillei), as top predators, can be an environmental sentinels. Thus, this study aimed to provide data about PAHs concentration in their hepatic tissue collected on the coast of Espírito Santo (Franciscana Management Area, FMA Ia), Rio de Janeiro (FMA IIa), and São Paulo states (FMA IIb), in Southeastern Brazil. PAHs were detected in 86 % of franciscana dolphins (n = 50). The highest ∑PAHsTotal median concentration was reported in FMA Ia followed by FMA IIb and FMA IIa (1055.6; 523.9, and 72.1 ng.g-1 lipid weight, respectively). Phenanthrene was detected in one fetus and two neonates, showing maternal transfer of PAHs in these dolphins. Evaluating PAHs with potential toxic effects is of utmost importance for the conservation of a threatened species.

Spatial trends of trace elements bioaccumulation in the most endangered dolphin from the Southwestern Atlantic Ocean: The franciscana (Pontoporia blainvillei).

Trace elements bioaccumulation patterns can be an important tool to assess differences among cetaceans' populations. In this work, their use as potential chemical markers to differentiate franciscanas (Pontoporia blainvillei) populations was evaluated. Franciscanas were collected from three states in southeastern Brazil, which comprise three different Franciscana Management Areas (FMAs): Espírito Santo (FMA Ia), southern Rio de Janeiro (FMA IIa), and central São Paulo (FMA IIb). The concentrations of As, Cd, Cu, Fe, Hg, Mn and Zn were determined in the muscle, liver and kidney of the animals. Cadmium was the most valuable chemical marker to differentiate stocks, separating at least FMA IIa from the others. The higher Cd levels in FMA IIa, along with dietary information, indicate that the predominant consumption of cephalopods by this population is the main reason for the differences found. Additionally, environmental characteristics of the areas should also be considered as divergent sources of trace elements. Our findings suggest that non-essential trace elements, such as Cd, can be successful markers to differentiate populations. The Mn concentrations in FMA Ia raised concern and must be carefully monitored, as well as other elements that compose the iron ore tailings that have impacted the Espírito Santo coastal area. Additionally, this is the first study to report trace element concentration in the franciscanas from FMA IIa (southern Rio de Janeiro). Trace element concentrations found in franciscanas may represent different contamination levels in their preys and environments, which might pose specific threats to distinct populations. Therefore, our findings are important to characterize and differentiate franciscana populations and to guide precise management and conservation actions for the distinct stocks of this endangered species.

Temporal trends of trace elements bioaccumulation by a vulnerable cetacean (Pontoporia blainvillei) before and after one of the largest mining disasters worldwide.

One of the largest environmental disasters worldwide occurred on November 5th, 2015, when the Fundão dam collapsed in Mariana (Minas Gerais State, Southeast Brazil). The tailing mud flooded the Doce River basin and reached the sea in the coast of Espírito Santo State (ES), Southeast Brazil. This coastal region is the habitat of the most isolated population of franciscana dolphins (Pontoporia blainvillei), with the lowest populational census and lowest genetic diversity in Franciscana Management Area Ia (FMA Ia) - 18° 25'S and 21° 17'S. This study aimed to assess the bioaccumulation of trace-elements (As, Cd, Cu, Fe, Hg, Mn, and Zn) in muscle, liver and kidney of franciscana dolphins collected near the Doce River's mouth before (n = 32) and after (n = 19) the tailing mud reached the sea. The Generalized Additive Model (GAM) showed increasing temporal trends of Hg and Zn in muscle and liver after the dam failure, probably related to higher concentrations and bioavailability in the water column and sediments from the Doce River. Declining trends were found for As and Cu muscular and hepatic concentrations and Fe concentrations in kidney due to their lower bioavailability after the disaster, caused by association with tailings mud trapped in the riverbanks and suspended particulate material. Additionally, higher As and Hg concentrations found in the first period of sampling may be due to historical contamination by mining activities. The full extent of the impacts caused by the Fundão dam failure is still unknown. However, due to their rapid increase and remobilization process, toxic effects can be induced in the biota by these elements. Elements' bioaccumulation in this study contributes to the knowledge of franciscana dolphins from FMA Ia. Considering the conservation concern regarding this franciscana population and its scarce knowledge, the impact of this disaster can be alarming for species conservation.

Variation of age and total length in Sotalia guianensis (Van Bénéden, 1864) (Cetacea, Delphinidae), on the coast of Espírito Santo state, Brazil / Variação etária e de comprimento total de Sotalia guianensis (Van Bénéden, 1864) (Cetacea, Delphinidae), no Litoral do Espírito Santo, Brasil

Abstract Variations of age and total length of Sotalia guianensis from the state of Espírito Santo, Brazil, were evaluated. Specimens were found stranded. Age and total length of 44 Guiana dolphins were assessed based on tooth analysis. Age varied between 0.5 year and 33 years (mean = 8.23 years). Most specimens were between zero and 6 years old (47%). Total length varied from 119 cm to 198 cm, with mean of 172.52 cm. Asymptotic length was reached at 185 cm and approximately 5-6 years of age. Mean total length and age were higher than in other regions of the distribution range of the species. Nevertheless, more studies have to be carried out to evaluate the morphological variations in S. guianensis populations in the study area and Brazil.

Resumo Foram avaliadas variações de comprimento total e etárias de Sotalia guianensis provenientes do estado do Espírito Santo. Os espécimes foram encontrados encalhados. Idade e comprimento total de 44 S. guianensis foram avaliados com base na análise dentária. A idade variou entre 0,5 e 33 anos (média = 8,23 anos). A maioria dos exemplares tinha entre zero e seis anos de idade (47%). O comprimento total variou de 119 a 198 centímetros, com média de 172,52 centímetros. O comprimento assintótico foi atingido com 185 cm, aproximadamente entre 5-6 anos de idade. O comprimento total médio e a idade foram maiores que outras regiões de distribuição da espécie. No entanto, mais estudos devem ser realizados para avaliar as variações morfológicas em populações de S. guianensis na região e no Brasil.

Implants composed of digoxin and poly(ε-caprolactone): development, characterization, anti-proliferative and anti-angiogenic activities.

Drug delivery systems could be applied to locally treat cervical cancer, thus preventing the drawbacks of conventional therapy. In this study, anti-proliferative and anti-angiogenic effects of digoxin incorporated into poly(ε-caprolactone) implants were evaluated, aiming at the local treatment of cervical cancer. Implants were characterized, and the in vitro release profile of digoxin was demonstrated. Anti-proliferative and anti-angiogenic activities of digoxin were investigated by using chorioallantoic membrane and human cervix carcinoma (HeLa) cells, respectively. The chemical structure of digoxin and the semi-crystalline nature of poly(ε-caprolactone) were preserved after designing implants. The hydrophobicity of drug and polymer as well as the semi-crystalline structure provided a controlled diffusion of digoxin from implants. Digoxin released from implantable devices exhibited anti-proliferative activity against HeLa cells. The anti-angiogenic effect was also shown. Finally, implants composed of digoxin and poly(ε-caprolactone) could be applied as a therapeutic alternative to treat the early stage of cervical cancer, once they were able to locally control the release of this anti-angiogenic and anti-proliferative drug, minimizing its systemic side effects and toxicity.

Variation of age and total length in Sotalia guianensis (Van Bénéden, 1864) (Cetacea, Delphinidae), on the coast of Espírito Santo state, Brazil.

Variations of age and total length of Sotalia guianensis from the state of Espírito Santo, Brazil, were evaluated. Specimens were found stranded. Age and total length of 44 Guiana dolphins were assessed based on tooth analysis. Age varied between 0.5 year and 33 years (mean = 8.23 years). Most specimens were between zero and 6 years old (47%). Total length varied from 119 cm to 198 cm, with mean of 172.52 cm. Asymptotic length was reached at 185 cm and approximately 5-6 years of age. Mean total length and age were higher than in other regions of the distribution range of the species. Nevertheless, more studies have to be carried out to evaluate the morphological variations in S. guianensis populations in the study area and Brazil.

Isolation and characterization of yeasts capable of efficient utilization of hemicellulosic hydrolyzate as the carbon source.

Few yeasts have shown the potential to efficiently utilize hemicellulosic hydrolyzate as the carbon source. In this study, microorganisms isolated from the Manaus region in Amazonas, Brazil, were characterized based on their utilization of the pentoses, xylose, and arabinose. The yeasts that showed a potential to assimilate these sugars were selected for the better utilization of lignocellulosic biomass. Two hundred and thirty seven colonies of unicellular microorganisms grown on hemicellulosic hydrolyzate, xylose, arabinose, and yeast nitrogen base selective medium were analyzed. Of these, 231 colonies were subjected to sugar assimilation tests. One hundred and twenty five of these were shown to utilize hydrolyzed hemicellulose, xylose, or arabinose as the carbon source for growth. The colonies that showed the best growth (N = 57) were selected, and their internal transcribed spacer-5.8S rDNA was sequenced. The sequenced strains formed four distinct groups in the phylogenetic tree, and showed a high percentage of similarity with Meyerozyma caribbica, Meyerozyma guilliermondii, Trichosporon mycotoxinivorans, Trichosporon loubieri, Pichia kudriavzevii, Candida lignohabitans, and Candida ethanolica. The discovery of these xylose-fermenting yeasts could attract widespread interest, as these can be used in the cost-effective production of liquid fuel from lignocellulosic materials.

Crescimento e desenvolvimento de boto-cinza (Sotalia guianensis) do litoral do Espírito Santo / Growth and development of estuarine dolphin (Sotalia guianensis) from Espírito Santo coast

Estudou-se o desenvolvimento do boto-cinza (Sotalia guianensis) do litoral do Espírito Santo e verificou-se se a análise das radiografias da aleta peitoral pode ser utilizada para tal. Trinta e sete botos passaram pela determinação do comprimento total (CT), análise do grau de fusionamento das vértebras e radiografia das aletas peitorais. O CT ao nascimento foi de 103,3cm e o de animais maduros fisicamente 187,5cm. Observou-se correlação entre o CT, as epífises distais do rádio e da ulna e correlação entre o grau de fusionamento vertebral e a epífise distal do rádio. Concluiu-se que a análise radiográfica das aletas peitorais é uma boa maneira de avaliar o grau de maturação física do boto.

The aim of this study is to analyze the development of the estuarine dolphin from the coast of Espírito Santo and verify that the analysis of X-rays of pectoral fin can be used for such. Thirty-seven Sotalia guianensis were used, determining the TL, examination of the degree of fusion of the vertebrae and X-ray of pectoral fins. At birth the TL is 103.3cm and in physically mature animals the TL is 187.5cm. The TL showed a significant correlation with the epiphyses of the distal radius and ulna and the degree of spinal fusion showed significant correlation with distal radius. It can be concluded that the X-ray analysis of the pectoral fins is a good way of assessing the physical maturation of these animals and can be used in routine procedures.

Changes in perfusion-weighted magnetic resonance imaging after carotid angioplasty with stent.

Carotid artery stenosis due to arteriosclerosis increases the risk of cerebral ischemia via embolic phenomena or reduced blood flow. The changes in cerebral perfusion that may occur after treatment are not clearly understood. This study evaluated the changes in cerebral microcirculation following carotid angioplasty with stenting (CAS) under cerebral protection with filters using ultrafast gradient echo (GRE) perfusion weighted imaging (PWI) with magnetic resonance imaging (MRI). Prospectively, 21 cervical carotid stenosis patients, mean age 69.95 years, underwent MRI 12 h before and 72 h after CAS. PWI parameters were collected for statistical analysis: cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP). Statistical analysis was applied to absolute parameters and to values normalized against those from the contralateral parenchyma. The main finding of this study was improved hemodynamics for the normalized data after CAS, shown by reduced MTT (p<0.001) and TTP (p=0.019) in the territory fed by the middle cerebral artery ipsilateral to the CAS. Absolute data showed increased blood volume in the cerebral hemispheres after CAS, which was more accentuated on the stent side (p=0.016) than the contralateral side (p=0.029). Early improvements in cerebral perfusion, mainly seen in the normalized data, were clearly demonstrated in the timing parameters - TTP & MTT - after CAS.

Bilateral agenesis of the internal carotid artery associated with basilar artery aneurysm treated via the endovascular route. A case report.

Bilateral agenesis of the internal carotid artery is a rare anomaly of embryonic development frequently associated with intracranial aneurysm. We describe a case involving an aneurysm that burst in the third middle of the basilar artery and exhibited a bilateral agenesis of the internal carotid artery. The aneurysm was treated via an endovascular route using detachable coils.

Characterization and treatment of artisanal gold mine tailings.

The solid waste generated by artisanal gold mining, with high mercury and gold contents, can be found in several areas in the South America. The present study focused on the tailings of an artisanal gold mine area located in the Brazilian northeastern. Samples of the mine tailings were taken and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron activation, X-ray fluorescence, induced coupled plasma-mass spectrometry, among others analytical methods. The results indicate that the material is composed mainly by quartz and goethite, the characteristic size of the particles (d(50)) is about 150 microm, and the density is close of that of quartz. The main constituents are silicon, iron, and aluminum. The tailings gold content is of about 1.8 mg/kg and the mercury content is of about 10 mg/kg. A remarkable feature of this solid waste is that the gold and mercury are both concentrated in both the fine and the coarse particles, but not in particles of intermediary size. Leaching studies indicated that the tailings are stable in weak organic acids, but soluble in alkaline and aired cyanide solutions, in which 89% of gold and 100% of mercury are extracted in 24 h. Electroleaching experiments, performed using sodium chloride as electrolyte, indicated that mercury and gold are extracted simultaneously and the recovery of both metals can be as high as 70% in 4 h. In addition, chromium, nickel, and lead are found in relatively large amounts in the solution, which indicate an effectively action of the electroleaching method to clean up solid wastes contaminated with metals.

Scaling relations in food webs.

In the last three decades, researchers have tried to identify universal patterns in the structure of food webs. It was recently proposed that the exponent eta characterizing the efficiency of the transport of energy in large and small food webs might have a universal value (eta = 1.13). In this work we establish lower and upper bounds for this exponent in a general spanning tree with a fixed number of trophic species and levels. When the number of species is large, the lower and upper bounds are equal to 1, implying that the result eta = 1.13 is due to finite-size effects and that the value of this exponent depends on the size of the web. We also evaluate analytically and numerically the exponent eta for hierarchical and random networks. In all cases the exponent eta depends on the number of trophic species K, and when K is large we have that eta-->1. Moreover, this result holds for any fixed number M of trophic levels.

A periodic density functional theory study of cumene formation catalyzed by H-mordenite.

A periodic density functional theory study of the alkylation of benzene with propene in proton-exchanged mordenite has been achieved. The two different reaction routes that are usually proposed for this reaction, namely the direct and the step-by-step reaction pathways, have been investigated. The explicit consideration of the zeolite catalyst framework allows a better level of description of the interactions between the catalyst framework and the reaction than what is obtained with the cluster approach method. The direct reaction route is found to be the preferred one. It is observed that the cluster approach method, which does not describe the zeolite framework, is unable to qualitatively described the trend in activation energies. This is owing to the greater stabilization of larger transition state by the mordenite zeolite framework compared with smaller ones.

Assembly and functional analysis of tight junction in a colon adenocarcinoma cell line: effect of glucose depletion.

We describe morphologic and biochemical changes in the colonic epithelial HCT-116 cell line following depletion of glucose from the culture medium. Cultured cells under permissive differentiation conditions (inosine-supplemented glucose-free medium) exhibited, after confluence, an enterocytic differentiation, in contrast to cells grown under standard culture conditions, where they remain in an undifferentiated state. The differentiated phenotype was characterized by the presence of a monolayer of polarized cells displaying an apical tight junction, and by the presence of alkaline phosphatase, a well known brush border marker. We demonstrated that the formed tight junctions were functional using the following criteria: a) labeling of the junctions with antibodies recognizing the tight juntion proteins occludin and ZO-1, as observed by immunofluorescence and immunoblotting analysis; b) characteristic organization of the tight junction strands, as observed in freeze-fracture replicas; c) increase ofthe transepithelial resistance across the monolayer; d) not permeation of the ruthenium red stain across the tight junction, and e) presence of the hyperphosphorylated form of occludin.

Stability of chiral domains produced by adsorption of tartaric acid isomers on the Cu(110) surface: a periodic density functional theory study.

In the present work the interaction of different bitartrate isomers on the Cu(110) surface has been investigated systematically by using the Vienna Ab-initio Simulation Package (VASP), which performs periodical density functional theory (DFT) calculations. Among all bitartrate isomers the R,R-configuration is the most stable under the (3 1, 1 2) domain on the Cu surface. Its optical isomer, the S,S-bitartrate, is 10 kJ mol(-)(1) less stable in the same domain. This energy difference is sufficient to produce the distinct chiral assemblies observed after the adsorption of each optical isomer on the Cu surface. The calculations also showed that these domains are not formed due to intermolecular H-bonds, in contrast with the previous proposal by Raval et al.(Nature 2000, 23, 376). In fact, there is a formation of optimal intramolecular H-bonds in the chemisorption structures. A favorable packing orientation is also needed for the respective chiral domains. For instance, the S,S-configuration suffers from a destabilizing packing energy of 21 kJ mol(-)(1) under the same domain, due to a short contact between the H atoms of the hydroxy groups. These intramolecular H-bonds cause also some distortions on the bitartrate molecule, which appear to be dependent on the relative position of the alpha-hydroxy groups. The stability of the extended asymmetric domains, when the surface is modified by a chiral additive, might have important consequences for understanding and optimizing the properties of enantioselective heterogeneous catalysts.

Stability of Zn(II) cations in chabazite studied by periodical density functional theory.

The location of the Zn(2+) cation in Zn-exchanged chabazite has been studied by the periodical density functional method. Chabazite was chosen as a zeolite model, because it contains three different types of rings commonly found in the zeolite structures: four-, six-, and eight-membered rings. Two aluminum atoms have been employed to substitute the silicon atoms in the same D6R unit cell of the zeolite framework. This leads to different arrangements for the Brønsted site pair and the Zn(II) cation. The two Brønsted sites are found to be more stable when placed in the small ring (4T ring) than in the other rings. This suggests that the most reactive Brønsted sites are located in the large rings. Two Brønsted sites are most stable when the O(H)-Al-O-Si-O(H)-Al sequence is followed in the same ring instead of being located in two different rings. This resembles the aluminum distribution in the small four-membered ring and agrees with bond order conservation rules. The cation stability is markedly influenced by the distortions of the framework. Other factors that also contribute to the stabilization are the aluminum content near the cation and the stability of the original Brønsted sites. The Zn(2+) cation is more stable in the large rings than in the small ones, the six-membered one being the most stable configuration. In the small rings, the cation is, therefore, more reactive. Two different probe molecules have been used to study the interaction with the Zn(II) cation: water and methane. These probe molecules can extract the active center from its original position. For the water molecule, this effect is large and leads to a high framework relaxation. The value of the binding energy of this molecule to the active sites is influenced by these framework relaxations as well as by the cationic position environment. For weakly interacting methane, these effects are significantly less.