411 research outputs found

    Scattering from supramacromolecular structures

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    We study theoretically the scattering imprint of a number of branched supramacromolecular architectures, namely, polydisperse stars and dendrimeric, hyperbranched structures. We show that polydispersity and nature of branching highly influence the intermediate wavevector region of the scattering structure factor, thus providing insight into the morphology of different aggregates formed in polymer solutions.Comment: 20 pages, 8 figures To appear in PR

    Feature-expression heat maps – A new visual method to explore complex associations between two variable sets

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    AbstractIntroductionExisting methods such as correlation plots and cluster heat maps are insufficient in the visual exploration of multiple associations between genetics and phenotype, which is of importance to achieve a better understanding of the pathophysiology of psychiatric and other illnesses. The implementation of a combined presentation of effect size and statistical significance in a graphical method, added to the ordering of the variables based on the effect-ordered data display principle was deemed useful by the authors to facilitate in the process of recognizing meaningful patterns in these associations.Materials and methodsThe requirements, analyses and graphical presentation of the feature-expression heat map are described. The graphs display associations of two sets of ordered variables where a one-way direction is assumed. The associations are depicted as circles representing a combination of effect size (color) and statistical significance (radius).ResultsAn example dataset is presented and relation to other methods, limitations, areas of application and possible future enhancements are discussed.ConclusionThe feature-expression heat map is a useful graphical instrument to explore associations in complex biological systems where one-way direction is assumed, such as genotype-phenotype pathophysiological models

    Influence of Insulin-like Growth Factor I (IGF-I) on the survival and the in vitro development of caprine preantral follicles

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    The aim of this study was to investigate the effects of the insulin-like growth factor -I (IGF-I) on survival, activation (transition from primordial to primary follicles) and growth of caprine preantral follicles cultured in vitro. Fragments of ovarian cortex were cultured for one and seven days in the absence or presence of IGF-I (0, 50 and 100ng/ml). The non-cultured and cultured tissues were processed and analyzed by histology and transmission electron microscopy. The culture for one day in a medium with 100ng/ml of IGF-I showed 86.7% of morphologically normal follicles. These results were similar (P>0.05) to the percentage of normal follicles found in the control (96.7%). It was also found that this medium increased the percentage of follicular activation (developing follicles) with one day of culture. The oocyte and follicular diameters remained similar to the control by culturing for one day in a medium containing 100ng/ml of IGF-I. The ultrastructural analysis did not confirm the integrity of the follicular fragments in a medium containing IGF-I (100ng/ml) after one and seven days of culture. In conclusion, this study demonstrated that the addition of 100 ng/ml of IGF-I in the culture medium enables the development of preantral follicles of goats with one day of culture. However, it is not sufficient to maintain the follicular integrity and the follicular survival rate after seven days of culture.O objetivo do presente estudo foi investigar os efeitos do fator de crescimento semelhante a insulina-I (IGF-I) na sobrevivĂȘncia, ativação (transição de folĂ­culos primordiais para primĂĄrios) e crescimento de folĂ­culos prĂ©-antrais caprinos cultivados in vitro. Fragmentos de cĂłrtex ovariano foram cultivados por um e sete dias na ausĂȘncia ou presença de IGF-I (0, 50 e 100ng/mL). Os tecidos nĂŁo cultivados e cultivados foram processados e analisados por histologia e microscopia eletrĂŽnica de transmissĂŁo. O cultivo por um dia em meio com 100ng/mL de IGF-I apresentou 86,7% de folĂ­culos morfologicamente normais. Estes resultados foram semelhantes (P>0,05) ao percentual de folĂ­culos normais encontrados no controle (96,7%). Verificou-se ainda que este meio aumentou o percentual de ativação folicular (folĂ­culos em desenvolvimento) com um dia de cultivo. Os diĂąmetros ovocitĂĄrio e folicular mantiveram-se semelhantes ao controle ao cultivar por um dia em meio contendo 100ng/mL de IGF-I. As anĂĄlises ultraestruturais nĂŁo confirmaram a integridade folicular dos fragmentos em meio contendo IGF-I (100 ng/mL) apĂłs um e sete dias de cultivo. Em conclusĂŁo, esse estudo demonstrou que a adição de 100 ng/mL de IGF-I no meio de cultivo ativa o desenvolvimento de folĂ­culos prĂ©-antrais de caprinos com um dia de cultivo. Entretanto, nĂŁo Ă© suficiente para manter a integridade folicular e a taxa de sobrevivĂȘncia folicular apĂłs sete dias de cultivo

    Quantum control and the Strocchi map

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    Identifying the real and imaginary parts of wave functions with coordinates and momenta, quantum evolution may be mapped onto a classical Hamiltonian system. In addition to the symplectic form, quantum mechanics also has a positive-definite real inner product which provides a geometrical interpretation of the measurement process. Together they endow the quantum Hilbert space with the structure of a K\"{a}ller manifold. Quantum control is discussed in this setting. Quantum time-evolution corresponds to smooth Hamiltonian dynamics and measurements to jumps in the phase space. This adds additional power to quantum control, non unitarily controllable systems becoming controllable by ``measurement plus evolution''. A picture of quantum evolution as Hamiltonian dynamics in a classical-like phase-space is the appropriate setting to carry over techniques from classical to quantum control. This is illustrated by a discussion of optimal control and sliding mode techniques.Comment: 16 pages Late

    Nanomaterials for Advancing the Health Immunosensor

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    Nanotechnology has exerted a significant impact in the development of biosensors allowing more sensible analytical methods. In health applications, the main challenge of the immunoassay is to reach the suitable limit of detection, recognizing different analytes in complex samples like whole blood, serum, urine, and other biological fluids. Different nanomaterials, including metallic, silica and magnetic nanoparticles, quantum dots, carbon nanotubes, and graphene, have been applied, mainly to improve charge electron transfer, catalytic activity, amount of immobilized biomolecules, low-background current, signal-to-noise ratio that consequently increase the sensitivity of immunosensors. Given the great impact of nanotechnology, this chapter intends to discuss new aspects of nanomaterials relating to immunosensor advancement

    Evaluation of lasting effects of heat stress on sperm profile and oxidative status of ram semen and epididymal sperm

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    Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm

    OMA orthology in 2021: website overhaul, conserved isoforms, ancestral gene order and more.

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    OMA is an established resource to elucidate evolutionary relationships among genes from currently 2326 genomes covering all domains of life. OMA provides pairwise and groupwise orthologs, functional annotations, local and global gene order conservation (synteny) information, among many other functions. This update paper describes the reorganisation of the database into gene-, group- and genome-centric pages. Other new and improved features are detailed, such as reporting of the evolutionarily best conserved isoforms of alternatively spliced genes, the inferred local order of ancestral genes, phylogenetic profiling, better cross-references, fast genome mapping, semantic data sharing via RDF, as well as a special coronavirus OMA with 119 viruses from the Nidovirales order, including SARS-CoV-2, the agent of the COVID-19 pandemic. We conclude with improvements to the documentation of the resource through primers, tutorials and short videos. OMA is accessible at https://omabrowser.org
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