Functionalized-radiolabeled hydroxyapatite/tenorite nanoparticles as theranostic agents for osteosarcoma

Hydroxyapatite (HA) nanoparticles (NPs) doped with different radioisotopes for use as theranostic systems play an important role in scientific research nowadays due to their ability to simultaneously act in the treatment and diagnosis of various types of cancers. In this work, we describe the synthesis and characterization of a hydroxyapatite/tenorite nanocomposite functionalized with folic acid, representing a nanotheranostic material with potential for application as an agent in positron emission tomography imaging systems and to act specifically in the treatment and diagnosis of osteosarcoma. ⁶⁴Cu and ³²P were produced by nuclear activation in the TRIGA reactor at CDTN. The obtained samples were characterized by XRD with Rietveld refinement, XAFS, SEM, BET, TGA, FTIR, CHN, ICP-AES, XPS and gamma spectroscopy. We investigated how CuO grows in HA NPs, the stability of the interactions between CuO and HA constituents and the interactions between folic acid and the surface of the HA NPs. The results indicate the formation of a second phase (tenorite) besides hydroxyapatite, and that the interactions between the two phases are stable, resulting in a nanocomposite. Furthermore, the activation of ⁶⁴Cu and ³²P inside the HA matrix, through the exposition to a neutron flux, produces a theranostic material of interest for biological tests.     

A novel transfer learning approach for the classification of histological images of colorectal cancer

Colorectal cancer (CRC) is the second most diagnosed cancer in the United States. It is identified by histopathological evaluations of microscopic images of the cancerous region, relying on a subjective interpretation. The Colorectal Histology dataset used in this study contains 5000 images, made available by the University Medical Center Mannheim. This approach proposes the automatic identification of eight types of tissues found in CRC histopathological evaluation. We apply Transfer Learning from architectures of Convolutional Neural Networks (CNNs). We modify the structures of CNNs to extract features from the images and input them to well-known machine learning methods: Naive Bayes, Multilayer Perceptron, k-Nearest Neighbors, Random Forest, and Support Vector Machine (SVM). We evaluated 108 extractor–classifier combinations. The one that achieved the best results is DenseNet169 with SVM (RBF), reaching an Accuracy of 92.083% and F1-Score of 92.117%. Therefore, our approach is capable of distinguishing tissues found in CRC histopathological evaluation.

     

Compressive auto-indexing in femtosecond nanocrystallography

Ultrafast nanocrystallography has the potential to revolutionize biology by enabling structural elucidation of proteins for which it is possible to grow crystals with 10 or fewer unit cells on the side. The success of nanocrystallography depends on robust orientation-determination procedures that allow us to average diffraction data from multiple nanocrystals to produce a three-dimensional (3D) diffraction data volume with a high signal-to-noise ratio. Such a 3D diffraction volume can then be phased using standard crystallographic techniques. “Indexing” algorithms used in crystallography enable orientation determination of diffraction data from a single crystal when a relatively large number of reflections are recorded. Here we show that it is possible to obtain the exact lattice geometry from a smaller number of measurements than standard approaches using a basis pursuit solver.     

Hydrologic Modelling Calibration for Operational Flood Forecasting

Runoff prediction in flood forecasting depends on the use of hydrological simulation models and on the input of accurate precipitation forecasts. Reliability of predictions thus obtained hinges on proper calibration of the model. Moreover, when the model is intended to be used systematically in operational forecasting of streamflows, the calibration process must take into account the variation of the model parameters over time, namely in response to changing weather and hydrological conditions in the basin. The goal of the study was to build a process to adjust, on a daily basis, the simulation model parameters to the current hydrological conditions of the river basin, in order for the model to be run operationally for prediction of the streamflow for the next 10-days period, and, thereby, to forecast the occurrence of flood events. Towards this end, hydrological simulations using the HEC-HMS model were performed, using a 3 h period time step. The present communication focuses on the hydrological model calibration and verification processes and on the evaluation of forecasts’ accuracy. The procedure was applied to a part of the largest (full) Portuguese river basin, the Mondego river basin, corresponding to the Aguieira dam section watershed, which comprises an area of 3070 km². Four wet periods, associated with the occurrence of flooding, were selected for the calibration and verification of the model, by adjustment of the model parameters. The results of the study aim to define the optimal calibration parameters values to model the observed streamflow for various hydro-meteorological states, thus enabling adequate prediction of flow in flooding situations and proper application of the model in operational flood forecasting.     

Monitoring Methodology of Interventions for Riverbanks Stabilization: Assessment of Technical Solutions Performance

The success of the river rehabilitation process depends not only on the intervention project but also on the attention given to the monitoring and evaluation of the implemented measures. In spite of the recent efforts on the quantification and sharing of interventions’ results, there are still very few written records documenting that information. The present work proposes a monitoring methodology for riverbanks’ stabilization interventions by comparing the results obtained by monitoring the implemented technical solutions with the corresponding theoretical time-expected performance. For this purpose, two case studies located in the south of Portugal were analysed. For each of those case studies, the dominant factors that influenced the temporal evolution of the observed outcomes were assessed. It was possible to verify that, depending on the implemented technical solution type and on the specific characteristics of the intervention site, monitoring actions can be fundamental to achieve the expected technical and ecological efficiency, namely when bioengineering technical solutions are involved. This work led to the development of a database structure that will gather information on the application of the proposed methodology over time and that shall be improved with the analysis of the behaviour of other riverbanks’ stabilization interventions. The development of this database will surely contribute to enable choosing and applying the most adequate riverbank protection solutions.     

Curupira tefeensis (Olacaceae) — A Rich Source of Very Long Chain Fatty Acids

The fatty acid composition of the seed oil of Curupira tefeensis was analysed by capillary GC of their methyl esters. The gaschromatographic assignments were ensured by corresponding mass spectra. The oil is composed to more than 62% of very long chain fatty acids (>C18). Erucic acid is found to be the main component (35%). The position of the double bonds of the monounsaturated fatty acids (MUFAME) was verified after derivatization with dimethyl disulfide and subsequent GC/MS analysis. All identified MUFAME belong to the (n-9-)type. The UV-spectroscopical data show that approx. 1.2% conjugated acetylenic fatty acids occur in the oil. Furthermore IR- and NMR-spectroscopical investigations and the basic analyses of the seed were carried out.     

Ecofriendly modification of acetosolv lignin from oil palm biomass for improvement of PMMA thermo‐oxidative properties

The environmentally friendly esterification of acetosolv lignin (AL), obtained from pressed oil palm mesocarp fibers, is described, for the improvement of thermo‐oxidative properties of poly(methyl methacrylate) (PMMA) films. Acetylation of AL was performed in ecofriendly conditions using acetic anhydride in the absence of catalysts. Acetylated acetosolv lignin (AAL) was successfully obtained in only 12 min with a solvent‐free and catalyst‐free microwave‐assisted procedure. Lignins were characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), confirming the efficacy of the methodology employed. AL and AAL as fillers in different concentrations (1% and 5%) were added to PMMA films. The thermal and mechanical properties of the lignin‐incorporated films were analyzed by TGA, DSC, and dynamic mechanical analysis (DMA). The films incorporated with lignin and acetylated lignin presented initial degradation temperature (T_onset) and onset oxidative temperature (OOT) values higher than pure PMMA films, contributing thus to an enhancement of thermo‐oxidative stability of PMMA. The DMA analyses showed that incorporation of AL or AAL increased the storage modulus (E′) of PMMA films, but did not affect their glass‐transition temperatures (T_g). The results indicate the potential use of oil palm mesocarp lignin to enhance the thermo‐oxidative properties of PMMA without compromising its mechanical response. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45498.     

奥斯卡·尼迈耶——拉戈阿住宅与卡诺阿斯住宅

本文旨在分析巴西建筑师奥斯卡·尼迈耶在1942年与1953年所建造的两幢自宅,归纳在其空间构成、结构以及体验上的异同,重点在于分析这两幢住宅与各自所处的环境关系。文章结论系于尼迈耶如何将柯布西耶的设计理念与巴西的环境相结合。在第一幢住宅中,他严格地遵守柯布所设定的原则,而其后则在卡诺阿斯住宅的自由形体中作出种种发展与修改。在第二幢住宅中,建筑与自然紧密联系,并可以在可视性与可达性上通过空间句法分析证明。同时也可认为拉戈阿住宅功能被明确区分为室内与室外两个独立部分,而卡诺阿斯住宅则作为一个完整的整体体系。全部的研究基于柯布西耶理念背景以及巴西自由形式运动。     

Contributing to Understand the Crosstalk between Brain and Periphery in Methylmercury Intoxication: Neurotoxicity and Extracellular Vesicles

Human exposure to methylmercury (MeHg) is currently high in regions such as the Amazon. Understanding the molecular changes associated with MeHg-induced neurotoxicity and the crosstalk with the periphery is essential to support early diagnoses. This work aimed to evaluate cellular and molecular changes associated with behavioral alterations in MeHg acute exposure and the possible changes in extracellular vesicles (EVs) number and S100β content. Adults male Wistar rats were orally treated with 5 mg/kg for four days. Behavioral performance, molecular and histological changes in the cerebellum, and plasma EVs were assessed. MeHg-intoxicated animals performed significantly worse in behavioral tests. MeHg increased the number of GFAP+ cells and GFAP and S100β mRNA expression in the cerebellum but no change in NeuN+ or IBA-1+ cells number was detected. The number of exosomes isolated from plasma were decreased by the metal. S100B mRNA was detected in circulating plasma EVs cargo in MeHg exposure. Though preliminary, our results suggest astrocytic reactivity is displaying a protective role once there was no neuronal death. Interestingly, the reduction in exosomes number could be a new mechanism associated with MeHg-induced neurotoxicity and plasma EVs could represent a source of future biomarkers in MeHg intoxication.