Optical properties and charge-transfer excitations in edge-functionalized all-graphene nanojunctions

We investigate the optical properties of edge-functionalized graphene nanosystems, focusing on the formation of junctions and charge transfer excitons. We consider a class of graphene structures which combine the main electronic features of graphene with the wide tunability of large polycyclic aromatic hydrocarbons. By investigating prototypical ribbon-like systems, we show that, upon convenient choice of functional groups, low energy excitations with remarkable charge transfer character and large oscillator strength are obtained. These properties can be further modulated through an appropriate width variation, thus spanning a wide range in the low-energy region of the UV-Vis spectra. Our results are relevant in view of designing all-graphene optoelectronic nanodevices, which take advantage of the versatility of molecular functionalization, together with the stability and the electronic properties of graphene nanostructures.Comment: J. Phys. Chem. Lett. (2011), in pres

ESTUDO SOBRE A INADIMPLÊNCIA EM CONTRATOS DO PRONAF NO BRASIL

O estudo analisa a inadimplência em contratos do Pronaf no Brasil, à luz de dados obtidos junto ao Ministério da Fazenda. As informações da pesquisa, desenvolvida pelo Departamento de Ciências Sociais Agrárias da UFPel, evidenciam que as maiores taxas de inadimplência encontram-se nos estados do nordeste brasileiro e junto às famílias assentadas em projetos de reforma agrária e em programas de crédito fundiário. Palavras-chave: Agricultura familiar. Inadimplência. Financiamento público

Effect of stocking density and use of environmental enrichment materials on the welfare and the performance of pigs in the growth and finishing phases

Aim of study: To evaluate the effects of stocking density and the use of environmental enrichment (EE) objects on the welfare and the performance of pigs in the growing and finishing phases.Area of study: The southern region of Brazil.Material and methods: A total of 240 pigs, 120 immunocastrated males and 120 females, with an initial weight of 22.38 ± 2.38 kg and mean age of 65 days, were submitted to two stocking densities conditions (0.85 and 1.28 m²pig) with and without EE for 117 days. The experimental design was a 2×2×2 factorial (two categories, two densities, and two EE conditions), with six replicates. Performance variables and behavior were evaluated.Main results: For stocking density, there was a significant difference in the finishing phase from 148 to 161 days of age for the final weight (FW), average daily weight gain (ADWG), and feed conversion rate (FCR). For the EE factor, there was no difference in any of the phases or in the overall period. In the overall period, the higher availability of space improved the results of FW (140.56 kg vs 136.63 kg), ADWG (1.005 kg vs 0.974 kg), and FCR (2.05 vs 2.10). There was no effect of EE, stocking densities, or their interaction on the frequency of different behaviors of the pigs in the growth and finishing phases.Research highlights: There was no effect of interactions between enriched environments, stocking densities, and sex for animal performance and behavioral frequencies; however, differences between the factors were observed separately. The higher availability of space improved the results of FW, ADWG, and FCR

Contribuições para caracterização do agricultor familiar de feijão no estado do Rio Grande do Sul.

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Sustained PGC-1α2 or PGC-1α3 expression induces astrocyte dysfunction and degeneration

Funding Information: This work is funded by FEDER through the Lisbon Regional Operational Program Lisbon 2020 and by National Funds through Foundation for Science and Technology under the LISBOA-01-0145-FEDER-030104 ; PTDC/MEDFSL/030104/2017 project, and by the Swedish Research Council. Publisher Copyright: © 2023 The AuthorsPeroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) transcriptional coactivators are key regulators of energy metabolism-related genes and are expressed in energy-demanding tissues. There are several PGC-1α variants with different biological functions in different tissues. The brain is one of the tissues where the role of PGC-1α isoforms remains less explored. Here, we used a toxin-based mouse model of Parkinson's disease (PD) and observed that the expression levels of variants PGC-1α2 and PGC-1α3 in the nigrostriatal pathway increases at the onset of dopaminergic cell degeneration. This increase occurs concomitant with an increase in glial fibrillary acidic protein levels. Since PGC-1α coactivators regulate cellular adaptive responses, we hypothesized that they could be involved in the modulation of astrogliosis induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Therefore, we analysed the transcriptome of astrocytes transduced with expression vectors encoding PGC-1α1 to 1α4 by massively parallel sequencing (RNA-seq) and identified the main cellular pathways controlled by these isoforms. Interestingly, in reactive astrocytes the inflammatory and antioxidant responses, adhesion, migration, and viability were altered by PGC-1α2 and PGC-1α3, showing that sustained expression of these isoforms induces astrocyte dysfunction and degeneration. This work highlights PGC-1α isoforms as modulators of astrocyte reactivity and as potential therapeutic targets for the treatment of PD and other neurodegenerative disorders.publishersversionpublishe

Clinical and laboratory findings in sheep experimentally poisoned by Palicourea marcgravii and the use of magnesium chloride with possible therapeutic effect on poisoning.

This study aimed to examine the efficacy of magnesium chloride therapy in sheep experimentally poisoned by Palicourea marcgravii and describe the clinical and laboratory findings that may aid in early ante mortem diagnosis of this poisoning. P. marcgravii is an important plant within a group of 22 species in Brazil that cause ?sudden death.? Its toxic component is sodium monofluoroacetate. It was observed that a time for evolution of poisoning was longer in our study compared to other studies that used the same dose of P. marcgravii in sheep. However, all animals that were poisoned and subsequently treated with magnesium chloride died. The sheep presented characteristic clinical signs before death in addition to other signs that have not been previously described for this type of poisoning, such as abdominal breathing, coughing, head pressing, and nystagmus. This is the first evaluation of hematological parameters of sheep poisoned by P. marcgravii. Leukocytosis with neutrophilia, hyperfibrinogenemia, and hyperglycemia, associated with hypophosphatemia and elevated levels of serum aspartato aminotransferase (AST), glutamate dehydrogenase (GLDH), urea, creatinine, creatine kinase (CK) and lactate dehydrogenase (LDH), were observed. Additionally, changes were noted in necropsy, such as engorged jugular, large vessel congestion, pulmonary edema. Histological examination revealed vacuolar hydropic degeneration in the distal twisted uriniferous tubules in the kidneys, similar to those reported in previous studies on P. marcgravii poisoning

Assay strategies for the discovery and validation of therapeutics targeting <i>Brugia pahangi</i> Hsp90

The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target

Neglected area of meiobenthos: bibliometric analysis in the status of research on hyporheic meiofauna.

Studies on freshwater meiofauna are still enigmatic. This field of research is relatively neglected because this topic is not as increasing as the others, creating a gap in this area. The deficit of knowledge and surveys impose a barrier to new research and the increase of scientific interest in this area. This paper briefly reviews what exists in freshwater meiofauna worldwide, focusing on increasing knowledge on this topic and making this little-known area of meiofauna a common study field in science. The methodology involved a bibliographic survey from the Web of Science (WOS) bibliographic database. The search was performed by document title, keywords, and abstract, highlighting meiofauna (or meiobenthos) and hyporheic zone (or hyporheos). The results showed 28 documents on hyporheic meiofauna worldwide, mainly concentrated in Germany. The few articles highlighted that the lack of research on the hyporheic meiofauna community, its ecology, taxonomy, and biology is evident. It is hoped that this bibliometric review can be used as an alert about this area of meiofauna that is so important but at the same time is neglected, having a very exclusive group of authors and works, being of extreme importance different directions of research that involves hyporheic meiofauna to a better understanding of this fauna importance, ecosystemic services, and ecology