NADPH-Cytochrome P450 Oxidoreductase: Extraction of the Full-Length Protein and Methyl-TROSY NMR of the Soluble Mutants

NADPH-cytochrome p450 oxidoreductase (CYPOR) is a membrane-bound protein in living cells. CYPOR delivers electrons to cytochrome p450 proteins (CYPs) to catalyze metabolism of drugs and synthesis of steroids. Extraction and solubilization of CYPOR from the membrane is typically done with the TritonX-100 detergent. The amount of the solubilized protein by this detergent, however, remains relatively low to structurally analyze CYPOR with NMR spectroscopy. The goal of the first project in this thesis was to optimize the amount of the extracted CYPOR from the E. coli membrane using various detergents and additives. To this aim, non-ionic detergents with variable hydrophobicity (TritonX-100, X-114, and X-405) and binding strength to the extracted protein (TritonX-100, TWEEN20, and Brij35) were evaluated. Besides, the combinations of TritonX-100 with CHAPS or polyamine and alkylamine additives were assessed. None of these detergents and additives extracted more of CYPOR than the typical amount extracted by TritonX-100. Thus, it was concluded that this detergent extracts all of the available and functional CYPOR. The remaining protein is probably in an unusual and aggregated form. Understanding the details of CYPOR dynamics can be achieved by solution NMR spectroscopy. The initial step towards this goal requires NMR signal assignments of crucial residues in the protein. In this contribution, NMR analysis was performed on the soluble form of CYPOR lacking its N-terminal hydrophobic anchor (Δ56). Two dual cysteine mutants of this form of the protein (Q157C/Q517C and Q157C/N271C) were reacted with 13C-methyl-methanethiosulfonate (13C-MMTS). The resulting residue, which is 13C -methylthiocysteine (13C-MTC) gave strong signals in the 1H-13C HSQC and 1H-13C HMQC spectra of the mutants. The new assignment of MTC-271 at 2.46 ppm 1H, 25.42 ppm 13C was established besides the existing assignments of MTC-157 and MTC-517. The NMR spectra of the two mutants were highly resolved, and they lacked the middle peak. This peak was previously reported in the 1H-13C HMQC spectra of several Δ56 CYPOR mutants. It was concluded that this unspecific peak is due to sample preparation rather than the NMR technique

On Neural Architectures for Astronomical Time-series Classification with Application to Variable Stars

Despite the utility of neural networks (NNs) for astronomical time-series classification, the proliferation of learning architectures applied to diverse datasets has thus far hampered a direct intercomparison of different approaches. Here we perform the first comprehensive study of variants of NN-based learning and inference for astronomical time-series, aiming to provide the community with an overview on relative performance and, hopefully, a set of best-in-class choices for practical implementations. In both supervised and self-supervised contexts, we study the effects of different time-series-compatible layer choices, namely the dilated temporal convolutional neural network (dTCNs), Long-Short Term Memory (LSTM) NNs, Gated Recurrent Units (GRUs) and temporal convolutional NNs (tCNNs). We also study the efficacy and performance of encoder-decoder (i.e., autoencoder) networks compared to direct classification networks, different pathways to include auxiliary (non-time-series) metadata, and different approaches to incorporate multi-passband data (i.e., multiple time-series per source). Performance---applied to a sample of 17,604 variable stars from the MACHO survey across 10 imbalanced classes---is measured in training convergence time, classification accuracy, reconstruction error, and generated latent variables. We find that networks with Recurrent NN (RNNs) generally outperform dTCNs and, in many scenarios, yield to similar accuracy as tCNNs. In learning time and memory requirements, convolution-based layers are more performant. We conclude by discussing the advantages and limitations of deep architectures for variable star classification, with a particular eye towards next-generation surveys such as LSST, WFIRST and ZTF2.Comment: Submitted to ApJ

Responsabilidade social corporativa: uma comparação transcultural entre a Alemanha e Portugal

Esta Dissertação aborda questões de adoção e comunicação de políticas e estratégias de comunicação de Responsabilidade Social Corporativa. Com base numa revisão de literatura na área, pretendeu-se comparar estilos de comunicação corporativa nos mercados alemão e português, partindo-se de uma análise das diferenças culturais entre estes dois países. A comparação dos parâmetros culturais importantes num contexto de tomada de decisão empresarial foi realizada, através das ferramentas Hofstede Insights e GLOBE Framework. Estas ferramentas permitem explorar particularidades culturais nos diferentes países e averiguar o seu impacto nas ações que as empresas desencadeiam para fazer face às mudanças climáticas e garantir a sua sustentabilidade. Foram analisadas as páginas web corporativas de três empresas alemãs, com forte presença no mercado português. A utilização da plataforma Sketch Engine permitiu extrair keywords e realizar uma análise micro e macroestrutural comparativa da comunicação de Responsabilidade Social Corporativa nos seus websites locais. As empresas escolhidas foram a Bosch, a C&A e o Lidl, três empresas alemãs que possuem websites adaptados ao mercado português e atuam nos setores da tecnologia, moda e retalho, respetivamente.This Dissertation approaches the adoption and communication of Corporate Social Responsibility guidelines and communication strategies. Starting with a literature review, this paper aims to compare corporate communication styles in the Portuguese and German market. For this comparison, an analysis of cultural differences between these two countries was carried out. In order to compare cultural dimensions, which are important in the context of corporate decision making, two platforms were used: Hofstede Insights and GLOBE Framework. These tools allowed me to explore different particularities in these countries and assess their impact in the company’s efforts towards sustainability. An analysis of the corporate webpages of three German companies with strong presence in Portugal was carried out. Sketch Engine was used to extract keywords. The keywords retrieved contributed to the analysis of the webpages in micro and macrostructural levels. The companies chosen for this linguistic analysis were Bosch, C&A and Lidl. These are three German companies belonging to the technology, fashion and retail industries, respectively.Mestrado em Línguas e Relações Empresariai

Triple-Modal Imaging of Magnetically-Targeted Nanocapsules in Solid Tumours In Vivo

Triple-modal imaging magnetic nanocapsules, encapsulating hydrophobic superparamagnetic iron oxide nanoparticles, are formulated and used to magnetically target solid tumours after intravenous administration in tumour-bearing mice. The engineered magnetic polymeric nanocapsules m-NCs are ~200 nm in size with negative Zeta potential and shown to be spherical in shape. The loading efficiency of superparamagnetic iron oxide nanoparticles in the m-NC was ~100%. Up to ~3- and ~2.2-fold increase in tumour uptake at 1 and 24 h was achieved, when a static magnetic field was applied to the tumour for 1 hour. m-NCs, with multiple imaging probes (e.g. indocyanine green, superparamagnetic iron oxide nanoparticles and indium-111), were capable of triple-modal imaging (fluorescence/magnetic resonance/nuclear imaging) in vivo. Using triple-modal imaging is to overcome the intrinsic limitations of single modality imaging and provides complementary information on the spatial distribution of the nanocarrier within the tumour. The significant findings of this study could open up new research perspectives in using novel magnetically-responsive nanomaterials in magnetic-drug targeting combined with multi-modal imaging

Fresh Frozen Plasma in Hereditary Angioedema Crisis: To Give or Not To Give?

Objectives: Fresh frozen plasma (FFP) has been used in angioedema crises, however there is a risk of aggravating the symptoms as well as transmitting infections. In this report, the authors emphasize the dangers of this therapy. Materials and methods: A 25-year-old woman with hereditary angioedema (HAE) was treated with FFP after which her symptoms escalated. Results: Administration of purified C1-inhibitor (C1-INH) resulted in relief of her symptoms. Conclusions: FFP is to be avoided in a HAE crisis. Newer therapies for angioedema are preferred

Quasar and galaxy classification using Gaia EDR3 and CatWise2020

In this work, we assess the combined use of Gaia photometry and astrometry with infrared data from CatWISE in improving the identification of extragalactic sources compared to the classification obtained using Gaia data. We evaluate different input feature configurations and prior functions, with the aim of presenting a classification methodology integrating prior knowledge stemming from realistic class distributions in the universe. In our work, we compare different classifiers, namely Gaussian Mixture Models (GMMs), XGBoost and CatBoost, and classify sources into three classes - star, quasar, and galaxy, with the target quasar and galaxy class labels obtained from SDSS16 and the star label from Gaia EDR3. In our approach, we adjust the posterior probabilities to reflect the intrinsic distribution of extragalactic sources in the universe via a prior function. We introduce two priors, a global prior reflecting the overall rarity of quasars and galaxies, and a mixed prior that incorporates in addition the distribution of the these sources as a function of Galactic latitude and magnitude. Our best classification performances, in terms of completeness and purity of the galaxy and quasar classes, are achieved using the mixed prior for sources at high latitudes and in the magnitude range G = 18.5 to 19.5. We apply our identified best-performing classifier to three application datasets from Gaia DR3, and find that the global prior is more conservative in what it considers to be a quasar or a galaxy compared to the mixed prior. In particular, when applied to the pure quasar and galaxy candidates samples, we attain a purity of 97% for quasars and 99.9% for galaxies using the global prior, and purities of 96% and 99% respectively using the mixed prior. We conclude our work by discussing the importance of applying adjusted priors portraying realistic class distributions in the universe.Comment: 21 pages, 23 figures, Accepted for publication in A&

Evaluation of triclosan exposures on secretion of pro-inflammatory cytokines from human immune cells

Triclosan (TCS) is widely used in personal hygiene products, such as mouthwash and toothpaste, and is found in human tissues. Interleukin (IL)-1 beta (IL-1β), IL-6, tumor necrosis factor alpha (TNFα), and interferon gamma (IFNγ) are pro-inflammatory cytokines and inappropriately elevated levels of each have been associated with pathologies including rheumatoid arthritis and certain cancers. Here we examine effects of TCS on the secretion of the pro-inflammatory cytokines from human immune cell preparations. TCS at concentrations between 0.05–5 μM consistently increased the secretion of IL-1β, IL-6, and TNFα within 24 h of exposure and the increases often maintained out to 6 days of exposure. TCS also induced increases in IFNγ secretion, however the increases were most consistent after 48 h of exposure rather than within 24 h. Additionally, a role for both p44/42 and p38 MAPK in TCS-stimulated increases in IL-1β was seen in cells from some donors