Biodegradable antioxidant chitosan films useful as an anti-aging skin mask.

Cosmetics, personal care and biomedical products obtained by bio-based polymers and natural bioactive compounds are a new growing market. The ecological awareness is changing consumers' demands, causing consumers to look for more sustainable options, with a reduced environmental impact. The innovation of this work was to develop a natural polymer matrix (chitosan) entrapping antioxidant actives compounds such as annatto (Bixa Orellana L.) and vitamin C with potential application as sustainable anti-aging skin mask treatment. Films of chitosan (Ch) and reacetylated chitosan (RCh), exhibiting different degrees of acetylation (DA = 13.3 and 33.9%, respectively), were produced. The formulations of active films of chitosan (BCh) and reacetylated chitosan (BRCh) were 1% (w/w) of chitosan, 1% (w/w) of annatto powder, 5% (w/w) of vitamin C and 1% (w/w) of glycerol (as plasticizer). Reacetylated chitosan films (DA = 33.9%) presented higher water affinity than chitosan films (DA = 13.3%). The elongation of RCh and BRCh increased and the resistance decreased, as compared to Ch and BCh. The antioxidants compounds (annatto and vitamin C) of BRCh films released faster than BCh films. Thus, the BRCh films showed potential application as an anti-aging skin mask.

Multiple sulfur isotope evidence for massive oceanic sulfate depletion in the aftermath of Snowball Earth.

The terminal Neoproterozoic Era (850-542 Ma) is characterized by the most pronounced positive sulfur isotope ((34)S/(32)S) excursions in Earth's history, with strong variability and maximum values averaging δ(34)S∼+38‰. These excursions have been mostly interpreted in the framework of steady-state models, in which ocean sulfate concentrations do not fluctuate (that is, sulfate input equals sulfate output). Such models imply a large pyrite burial increase together with a dramatic fluctuation in the isotope composition of marine sulfate inputs, and/or a change in microbial sulfur metabolisms. Here, using multiple sulfur isotopes ((33)S/(32)S, (34)S/(32)S and (36)S/(32)S ratios) of carbonate-associated sulfate, we demonstrate that the steady-state assumption does not hold in the aftermath of the Marinoan Snowball Earth glaciation. The data attest instead to the most impressive event of oceanic sulfate drawdown in Earth's history, driven by an increased pyrite burial, which may have contributed to the Neoproterozoic oxygenation of the oceans and atmosphere.

Influence of phase transformations on dynamical elastic modulus and anelasticity of beta Ti-Nb-Fe alloys for biomedical applications.

Recent studies in materials for biomedical applications have focused on ß-titanium alloys that are highly biocompatible, free of toxic elements and with an elastic modulus close to that of human bone (10-40 GPa). Beta Ti-xNb-3Fe (x=10, 15, 20 and 25 wt%) alloys were obtained by rapid solidification and characterized by anelastic relaxation measurements at temperatures between 140 K and 770 K, using a free-decay elastometer, as well as analysis by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The observed stabilization of the ß-phase with rising Nb content was linked to the strength of the relaxation peak around 570 K. The phase transformations detected in the anelastic relaxation spectra agreed with those observed in the DSC curves. However, the results from anelastic relaxation spectra provide more detailed information about the kinetics of phase transformations. At temperatures between 140 K and 300 K, there was an indication of a reversible transformation in the alloys studied. The elastic modulus measurements showed a hardening of the material, between 400 K and 620 K, related to the ω-phase precipitation. However, the starting temperature of ω-phase precipitation was clearly influenced by the Nb content, showing a shift to high temperature with increasing percentage of Nb. At temperatures above 620 K, a fall was observed in the dynamical elastic modulus, accompanied by a relaxation peak centered at 660 K, which was attributed to the growing α-phase arising from the ω-phase, which acts as a nucleation sites or from the decomposition of the metastable ß-phase. XRD patterns confirmed the formation of ß, α and ω phases after mechanical relaxation measurements. A predominant ß phase with dendritic morphology was observed, which became more stable with 25 wt% Nb. The lowest elastic modulus was of 65 GPa obtained in the Ti-25Nb-3Fe alloy, representing a good low value for a ß-Ti alloy with a relatively low addition of ß stabilizing elements (Nb and Fe).

A palaeobiogeographic model for biotic diversification within Amazonia over the past three million years.

Many hypotheses have been proposed to explain high species diversity in Amazonia, but few generalizations have emerged. In part, this has arisen from the scarcity of rigorous tests for mechanisms promoting speciation, and from major uncertainties about palaeogeographic events and their spatial and temporal associations with diversification. Here, we investigate the environmental history of Amazonia using a phylogenetic and biogeographic analysis of trumpeters (Aves: Psophia), which are represented by species in each of the vertebrate areas of endemism. Their relationships reveal an unforeseen 'complete' time-slice of Amazonian diversification over the past 3.0 Myr. We employ this temporally calibrated phylogeny to test competing palaeogeographic hypotheses. Our results are consistent with the establishment of the current Amazonian drainage system at approximately 3.0-2.0 Ma and predict the temporal pattern of major river formation over Plio-Pleistocene times. We propose a palaeobiogeographic model for the last 3.0 Myr of Amazonian history that has implications for understanding patterns of endemism, the temporal history of Amazonian diversification and mechanisms promoting speciation. The history of Psophia, in combination with new geological evidence, provides the strongest direct evidence supporting a role for river dynamics in Amazonian diversification, and the absence of such a role for glacial climate cycles and refugia.

Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data

The sediments from the Coari lake, a “terra firme” lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acará lake sediments have higher concentrations of Al2O3, Fe2O3, FeO, CaO, K2O, MgO, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimões river, and the Acará lake was formed by the meander abandonment of Solimões river retaining its grass dominated shore at ca. 3710 yr BP.

Os sedimentos do lago Coari, de ambiente de terra firme eesculpido nos depósitos do Plio-Pleistocenos, e o Acará, típico lago de várzea e ambos formados nos sedimentos quaternários da planície de inundação do médio Solimões, no oeste da Amazônia, Brasil, foram estudados para investigar as condições ambientais durante sua formação. Este estudo inclui dados da composição mineralógica, química, isótopos de Pb, palinologia, datações de radiocarbono e a configuração morfológica dos lagos obtida por imagens SRTM. As condições geológica e ambiental dos lagos variam e sugerem que suas evoluções refletem processos autogenéticos em condições de floresta úmida e chuvosa. Embora caulinita, quartz, muscovita, illita e esmectita sejam os principais minerais em ambos os lagos, a geoquímica indica fonte distinta, os sedimentos do lago Acará têm maior concentração de Al2O3, Fe2O3, FeO, CaO, K2O, MgO, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y e La e têm mais Pb radiogênico que os sedimentos do lago Coari. As idades de radiocarbono sugerem que há aproximadamente 10160 anos AP o lago Coari iniciou o desenvolvimento devido a avulsão do rio Solimões, enquanto o lago Acará foi formado devido ao abandono de meandro do rio Solimões e retendo o domínio das gramíneas nas suas praias há aproximadamente 3710 anos AP.

Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data.

The sediments from the Coari lake, a "terra firme" lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acará lake sediments have higher concentrations of Al(2)O(3), Fe(2)O(3), FeO, CaO, K(2)O, MgO, Na(2)O, P(2)O(5), Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimões river, and the Acará lake was formed by the meander abandonment of Solimões river retaining its grass dominated shore at ca. 3710 yr BP.

Syringohydromyelia or HTLV-I-associated myelopathy/tropical spastic paraparesis. A diagnostic challenge. Case report.

Human T-cell lymphotropic virus type I (HTLV-I) associated myelopathy/tropical spastic paraparesis (HAM/TSP) is the most common chronic myelopathy in Brazil. We present the case of a 53 year old man that fulfilled the diagnostic criteria for HAM/TSP but had at the magnetic resonance imaging (MRI) of the spinal cord evidences of syringohydromyelia at the C6-C7 and D2-D7 levels along with Chiari type I malformation. The clinical picture was more typical of HAM/TSP than of syringohydromyelia, which was probably asymptomatic. The present case clearly demonstrates that serology and neuroimaging should be always used together. We conclude that, specially in places where HTLV-I is endemic, every patient with a spastic paraparesis, even with a radiological picture suggestive of a structural spinal cord lesion, should have a screening test for HTLV-I. The clinical picture must dictate the final direction of the diagnosis.

Síndrome de Shy-Grager: relato de um caso clínico / Shy-Drager syndrome: case report

A síndrome de Shy-Drager é uma doença degenerativa do sistema nervoso central, de etiologia desconhecida, caracterizada por falência progressiva do sistema autonômico e atrofia de múltiplos sistemas. É relatado o caso de uma paciente do sexo feminino que aos 41 anos de idade foi estabelecido o diagnóstico de síndrome de Shy-Drager. Provas funcionais autônomas, exames laboratoriais e exame físico, principalmente minucioso exame neurológico, evidenciaram claramente a falência do sistema nervoso autônomo e sinais de atrofia multissistematizada. Seräo ressaltados aspectos clínicos-evolutivos que caracterizaram os 8 anos da enfermidade, de investigaçäo da funçäo autonômica e de diagnóstico diferencial - já que a doença foi confundida durante a fase inicial com outras enfermidades sistêmicas e do sistema nervoso

Sindrome de Shy-Drager: relato de um caso clinico

A sindrome de Shy-Drager e uma doenca degenerativa do sistema nervoso central, de etiologia desconhecida, caracterizada por falencia progressiva do sistema autonomo e atrofia de multiplos sistemas. E relatado o caso de uma paciente do sexo feminino que aos 41 anos de idade foi estabelecido o diagnostico de sindrome de Shy-Drager: Provas funcionais autonomas, exames laboratoriais e exame fisico, principalmente minucioso exame neurologico, evidnciaram claramente a falencia do sistema nervoso autonomo e sinais de atrofia multissistematizada. Serao ressaltados aspectos clinicos-evolutivos que caracterizaram os 8 anos da enfermidade, de investigacao da funcao autonomica e de diagnostico diferencial-ja que a doenca foi confundida durante a fase inicial com outras enfermidades sistemicas e do sistema nervoso.

Intravenous methylprednisolone in HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP).

HTLV-I (Human T-lymphotropic virus type I) associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an immunomediated myelopathy induced by the HTLV-I. Some patients, specially those from Japan, seem to have a good response to steroid treatment. However, this has not been found in other regions of the world. High dose intravenous methylprednisolone has been used with success in patients with relapses of multiple sclerosis (MS), another autoimmune disease of the central nervous system. To test the effectiveness of methylprednisolone in patients with HAM/TSP, we devised an open trial in 23 patients. We found a very limited benefit of this form of treatment in these patients. Only one patient, who had the shortest disease duration (five months) in the whole group, showed a sustained benefit. We speculate that those patients with a shorter history, with presumably less demyelination and more inflammatory lesions, would show a better response to immunosuppressive treatments.

Spastic paraparesis of obscure origin. A case-control study of HTLV-I positive and negative patients from Rio de Janeiro, Brazil.

In order to find clinical findings that could significantly discriminate between HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and HTLV-I negative spastic paraparesis of obscure origin (SPOneg) prior to serological testing, and to find risk factors significantly associated with HAM/TSP we devised a case-control study. Sixty consecutive SPO patients were studied without previous knowledge of their HTLV-I serological status. Thirty-four (56.7%) turned out to be HTLV-I positive and 26 (43.3%) HTLV-I negative. HTLV-I infected patients tended to have more commonly motor and bladder disturbances at the beginning of their illness and a disease that was still in progression at the time of the examination. Bladder dysfunction, constipation and penile impotence, and more widespread pyramidal signs, were also more frequent during the whole course of their illness. Likewise, an increased intrathecal synthesis of IgG was found more often in the HTLV-I positive group. The only risk factor for HTLV-I infection significantly associated to HAM/TSP was a prior history of sexually transmitted diseases. These results suggest that, at least in RJ, HAM/TSP might be mainly sexually acquired.