Biomonitoramento ativo de metais traço e efeito biológico em mexilhões transplantados para área de influência de efluente de indústria de beneficiamento de aço - Fase I

Preliminary results from an environmental monitoring program of an industrial submarine outflow are presented. Introduced mussels technique with Perna perna was applied. Two evaluations were carried out; one thirty days after the transplant and, another one, sixty days after the first one. Trace metal bioaccumulation and the associated cellular damage were determined. In the first evaluation, in the beginning of the industrial activity, concentrations significantly higher of some metals in mussels of the area of the emissary in comparison with the control site had been registered. In the second evaluation higher concentrations were recorded only for Cd, Zn and Ni at submarine outflow zone. Despite this, the recorded concentrations remained in the range considered normal for the studied species and below of the maximum level accepted by law for human consumption. The Neutral Red Assay, the biomarker applied, evidenced no cellular damage.Preliminary results from an environmental monitoring program of an industrial submarine outflow are presented. Introduced mussels technique with Perna perna was applied. Two evaluations were carried out; one thirty days after the transplant and, another one, sixty days after the first one. Trace metal bioaccumulation and the associated cellular damage were determined. In the first evaluation, in the beginning of the industrial activity, concentrations significantly higher of some metals in mussels of the area of the emissary in comparison with the control site had been registered. In the second evaluation higher concentrations were recorded only for Cd, Zn and Ni at submarine outflow zone. Despite this, the recorded concentrations remained in the range considered normal for the studied species and below of the maximum level accepted by law for human consumption. The Neutral Red Assay, the biomarker applied, evidenced no cellular damage

RESULTADOS PRELIMINARES DA DISTRIBUIÇÃO DE FÓSFORO E SUAS FORMAS NOS SEDIMENTOS DA PLATAFORMA CONTINENTAL DO ESTADO DE SANTA CATARINA

Distribuition of phosphorus in marine sediments have been recognized as a useful tool for the knowledgement of its geochemical cicle, that have been undergoing chances by human actions. Marine sediments represents the major reservoir of this constituint, where processes take place and control its disponibility to water column. Differents forms of phosphorus were determined by sequencial extrations in 27 samples of bottom sediment collected in the inner shelf off Santa Catarina. The aim of this study was to investigate the distribuition of phosphorus in the sequencial extrated frations and the relationship with sediment facies. The highest total phosphorus concentrations have been related to fine grained sediments. Although, there were some differences between samples with similar sedimentar patterns. Iron plus aluminium phosphate has been showed high concentrations in the neigborhood of river mounths, declining off shore. Calcium phosphate was the predominant form in most samples.O estudo de fósforo em sedimentos marinhos tem sido utilizado como importante ferramenta para compreensão do ciclo geoquímico deste nutriente, o qual vem sendo alterado pela ação antropogênica. Os sedimentos marinhos representam o depósito final deste constituinte e, dependendo dos processos de interação química que ali ocorrem, podem ser responsáveis por sua maior ou menor disponibilidade para a coluna d’água. Neste estudo foram determinadas as diferentes formas de fósforo, através do método de extração sequencial (modificado de SILVEIRA, 1993), em 27 amostras de sedimentos superficiais coletados na plataforma interna do litoral centro-norte catarinense. O objetivo era verificar a distribuição de fósforo e suas formas de acordo com as fácies sedimentares encontradas na área de estudo. As concentrações de fósforo total variaram entre 1,27 a 18,77 µmol/g, com as mais elevadas estando associadas aos sedimentos finos, embora tenham ocorrido diferenças entre fácies com características granolumétricas similares. O fosfato de ferro + alumínio apresentou concentrações mais altas próximo as desembocaduras dos rios diminuindo com o aumento da distância da linha de costa, indicando o aporte continental. A forma predominante na maioria das amostras foi o fosfato de cálcio que apresentou uma relação direta com a profundidade

Nanoscale Assembly of Functional Peptides with Divergent Programming Elements

Self-assembling peptides are being applied both in the biomedical area and as building blocks in nanotechnology. Their applications are closely linked to their modes of self-assembly, which determine the functional nanostructures that they form. This work brings together two structural elements that direct nanoscale self-association in divergent directions: proline as a β-breaker and the β-structure-associated diphenylalanine motif, into a single tripeptide sequence. Amino acid chirality was found to resolve the tension inherent to these conflicting self-assembly instructions. Stereoconfiguration determined the ability of each of the eight possible Pro-Phe-Phe stereoisomers to self-associate into diverse nanostructures, including nanoparticles, nanotapes, or fibrils, which yielded hydrogels with gel-to-sol transition at a physiologically relevant temperature. Three single-crystal structures and all-atom molecular dynamics simulations elucidated the ability of each peptide to establish key interactions to form long-range assemblies (i,e., stacks leading to gelling fibrils), medium-range assemblies (i.e., stacks yielding nanotapes), or short-range assemblies (i.e., dimers or trimers that further associated into nanoparticles). Importantly, diphenylalanine is known to serve as a binding site for pathological amyloids, potentially allowing these heterochiral systems to influence the fibrillization of other biologically relevant peptides. To probe this hypothesis, all eight Pro-Phe-Phe stereoisomers were tested in vitro on the Alzheimer's disease-associated Aβ(1-42) peptide. Indeed, one nonfibril-forming stereoisomer effectively inhibited Aβ fibrillization through multivalent binding between diphenylalanine motifs. This work thus defined heterochirality as a useful feature to strategically develop future therapeutics to interfere with pathological processes, with the additional value of resistance to protease-mediated degradation and biocompatibility

Heterochirality and Halogenation Control Phe-Phe Hierarchical Assembly

Diphenylalanine is an amyloidogenic building block that can form a versatile array of supramolecular materials. Its shortcomings, however, include the uncontrolled hierarchical assembly into microtubes of heterogeneous size distribution and well-known cytotoxicity. This study rationalized heterochirality as a successful strategy to address both of these pitfalls and it provided an unprotected heterochiral dipeptide that self-organized into a homogeneous and optically clear hydrogel with excellent ability to sustain fibroblast cell proliferation and viability. Substitution of one l-amino acid with its d-enantiomer preserved the ability of the dipeptide to self-organize into nanotubes, as shown by single-crystal XRD analysis, whereby the pattern of electrostatic and hydrogen bonding interactions of the backbone was unaltered. The effect of heterochirality was manifested in subtle changes in the positioning of the aromatic side chains, which resulted in weaker intermolecular interactions between nanotubes. As a result, d-Phe-l-Phe self-organized into homogeneous nanofibrils with a diameter of 4 nm, corresponding to two layers of peptides around a water channel, and yielded a transparent hydrogel. In contrast with homochiral Phe-Phe stereoisomer, it formed stable hydrogels thermoreversibly. d-Phe-l-Phe displayed no amyloid toxicity in cell cultures with fibroblast cells proliferating in high numbers and viability on this biomaterial, marking it as a preferred substrate over tissue-culture plastic. Halogenation also enabled the tailoring of d-Phe-l-Phe self-organization. Fluorination allowed analogous supramolecular packing as confirmed by XRD, thus nanotube formation, and gave intermediate levels of bundling. In contrast, iodination was the most effective strategy to augment the stability of the resulting hydrogel, although at the expense of optical transparency and biocompatibility. Interestingly, iodine presence hindered the supramolecular packing into nanotubes, resulting instead into amphipathic layers of stacked peptides without the occurrence of halogen bonding. By unravelling fine details to control these materials at the meso- A nd macro-scale, this study significantly advanced our understanding of these systems

Do borrão às aguadas: os engenheiros militares e a representação da Capitania de São Paulo

A análise do papel dos engenheiros militares perpassa as discussões sobre regiões específicas, mesmo quando eles, aparentemente, estão ausentes delas. Sua presença ou ausência sempre foi sinônimo de interesse e de projeto colonizador mais ou menos dirigido. Este ensaio tem como objeto de estudo a cartografia dos engenheiros militares atuantes na Capitania de São Paulo, território comumente visto como economicamente periférico e mais autônomo face aos desígnios da Coroa portuguesa. Com foco no corpus cartográfico de alguns profissionais que aqui atuaram, trata indiretamente da multifacetada atuação desses engenheiros, bem como do processo de feitura das cartas geográficas, corográficas e topográficas, do borrão às aguadas. Investigar a cartografia de alguns desses profissionais permite não apenas explorar a riqueza de suas biografias, como, também, acompanhar o processo de produção técnica dos mapas e os desígnios políticos envolvidos no devassamento e representação das terras descobertas no Novo Mundo.Analyzing the role of military engineers means venturing into discussions about specific regions, even those from which they are apparently absent. Their presence or absence has always been synonymous with interest and a more or less directed colonization project. This essay examines the maps produced by the military engineers working in the Captaincy of São Paulo, a territory often looked upon as one of little economic import and a rather autonomous area in light of the plans of the Portuguese Crown. By focusing on the cartographic corpus bequeathed by certain professionals serving in this region, we deal indirectly with the multifaceted role of these engineers as well as with the process of making geographic, chorographic and topographic charts - all the way from the sketch to watercolored maps. Perusing the charts constructed by some of these professionals enabled us not only to delve into the rich details of their biographies but also to observe the technical mapmaking process and to unravel the political designs behind the exploration and representation of the lands discovered in the New World

A coleção fotográfica V-8

This article is about the historical photos of Campinas city and its characters, shot\ud by photographer Aristides Pedro da Silva, known as V-8. The study relates the paths taken by\ud the photographer, the collections sources and composition, the circulation of the images in\ud Campinas and the collections purchase by Unicamp/Centro de Memória (Memory Centre),\ud in addition to its organisation and preservation

NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

Dependence of diffusion in Escherichia coli cytoplasm on protein size, environmental conditions and cell growth.

Inside prokaryotic cells, passive translational diffusion typically limits the rates with which cytoplasmic proteins can reach their locations. Diffusion is thus fundamental to most cellular processes, but the understanding of protein mobility in the highly crowded and non-homogeneous environment of a bacterial cell is still limited. Here we investigated the mobility of a large set of proteins in the cytoplasm of Escherichia coli, by employing fluorescence correlation spectroscopy (FCS) combined with simulations and theoretical modeling. We conclude that cytoplasmic protein mobility could be well described by Brownian diffusion in the confined geometry of the bacterial cell and at the high viscosity imposed by macromolecular crowding. We observed similar size dependence of protein diffusion for the majority of tested proteins, whether native or foreign to E. coli. For the faster-diffusing proteins, this size dependence is well consistent with the Stokes-Einstein relation once taking into account the specific dumbbell shape of protein fusions. Pronounced subdiffusion and hindered mobility are only observed for proteins with extensive interactions within the cytoplasm. Finally, while protein diffusion becomes markedly faster in actively growing cells, at high temperature, or upon treatment with rifampicin, and slower at high osmolarity, all of these perturbations affect proteins of different sizes in the same proportions, which could thus be described as changes of a well-defined cytoplasmic viscosity. © 2022, Bellotto et al

Self-Assembling l-d-l -Tripeptides Dance the Twist

Minimalistic peptides composed of d - and l -amino acids are attractive building blocks for functional supramolecular materials, including catalysts. d -Amino acids have long been known to promote turn conformations in peptides, yet unexpected twists continue to emerge on their effects on self-assembly. The combination of single-crystal X-ray diffraction and full-atom molecular dynamics have finally unraveled fine details of how l-d-l -tripeptides visit different conformations in solution and establish key interactions in supramolecular structures