10 research outputs found

    Synthesis of new pseudo‐C‐nucleosides containing pyrazole rings in their structure

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    Synthetic approaches to new 4-(furanos-4-C-yl)-1H-pyrazole and 3-(furanos-4-C-yl)-1H-pyrazole derivatives are described, including its pyrazole-5-carboxylate derivative, which is a pyrazofurin analogue. Preparation of related 5-acetoxy-1-acetyl-1H-pyrazole, 5-acetoxy-1H-pyrazole-1-carboxylate, and 4,5-dihydro-1-phenyl-1H-pyrazol-5-one derivatives is also reported. The formation of the pyrazole rings was accomplished either by reaction of enones and of 1,3-diketones with N-nucleophiles or by ring closure of a diazoketone.info:eu-repo/semantics/publishedVersio

    Synthesis of phenylseleno sugars from epoxides and of α,ÎČ-unsaturated carbonyl derivatives for the study of their insecticidal activity

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    This work reports the synthesis of sugar epoxides and their derivatives obtained by reaction with the dianion of phenyl selenoacetic acid. Approaches to the introduction of α,ÎČ-unsaturated carbonyl units in pyranoid systems were investigated. Preparation of a protected D-glycero-hex-3-enepyranosid-2-ulose and of a D-erythro-hex-2-enono-1,5-lactone is described. Some of the synthesized compounds possess insecticidal activity against fruit flies, house flies, and white flies.Treaty of Windsor Programme, British Council, MinistĂ©rio da CiĂȘncia e do Ensino Superiorinfo:eu-repo/semantics/publishedVersio

    Definition of an Artificial Reef Unit through Hydrodynamic and Structural (CFD and FEM) Models—Application to the Ares-Betanzos Estuary

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    [Abstract] The application of hydrodynamics to the definition of artificial reefs is of great interest since the positioning of the artificial reef modules on the sea floor alters the water velocity field, causing an appropriate circulation of nutrients and promoting a habitat for settling desired species. Nevertheless, the designs must be subjected to a structural calculation that will condition the constructive process to be applied. The present research proposes a methodology to determine the geometry of an artificial reef in terms of hydrodynamic and structural criteria. The solution proposed was analyzed through Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM). Using concrete as base material for artificial reefs, four different dosages were proposed with different proportions of cement and water, leading to different mechanical properties, which determine different constructive strategies, such as dwell time in the mold. From the hydrodynamic point of view, it was found that the solution proposed provides a proper replacement of nutrients. From the structural point of view, it was found that the solution proposed does not need steel reinforcements in concrete, which improves the sustainability of the artificial reef. The four different concrete dosages will condition the constructive strategy through the dwelling time in the mold and, for any established production, the necessary number of molds (formworks).Xunta de Galicia; CN-10MMA003C

    Facile synthesis of oxo-/thioxopyrimidines and tetrazoles C–C linked to sugars as novel non-toxic antioxidant acetylcholinesterase inhibitors

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    Microwave-assisted synthesis of oxo-/thioxopyrimidines and tetrazoles linked to furanoses with D-xylo and D-ribo configuration, and to a D-galacto pyranose is reported and compared to conventional methods. Reaction of dialdofuranoses and dialdopyranoses with a b-keto ester and urea or thiourea under micro wave irradiation at 300 W gave in 10 min the target molecules containing the 2-oxo- or 2-thioxo-pyrimidine ring in high yield. The tetrazole-derived compounds were obtained in two steps by reaction of the formyl group with hydroxylamine hydrochloride, copper sulfate, triethylamine and dicyclohexylcarbodiimide to give an intermediate nitrile, which was then treated with sodium azide. The use of microwave irradiation in the latter step also resulted in a considerably shorter reaction time (10 min) compared to hours under conventional heating to obtain a complete starting materials conversion. Acetylcholinesterase inhibition ranged from 20% to 80% for compounds concentration of 100 lg/mL, demonstrating the potential of this family of compounds for the control of Alzheimer’s disease symptoms. Most of the compounds showed antioxidant activity in the b-carotene/linoleic acid assay, some of them exhibiting IC50 values in the same order of magnitude as those of gallic acid. The bioactive compounds did not show cytotoxic effects to human lymphocytes using the MTT method adapted for non-adherent cells, nor geno toxicity determined by the short-term in vitro chromosomal aberration assay.info:eu-repo/semantics/publishedVersio

    Growth performance, body composition, and digestive functionality of senegalese sole (solea senegalensis kaup, 1858) juveniles fed diets including microalgae freeze-dried biomass

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    Senegalese sole is one of the most promising fish species cultivated in the Southern European countries. This study was aimed at assessing the effects of microalgae biomass added to diets for Senegalese sole juveniles on fish growing and condition status. Three isoproteic (52%) and isolipidic (10%) were formulated containing 15% Tisochrysis lutea (TISO), Nannochloropsis gaditana (NAN), or Scenedesmus almeriensis (SCE) biomass, respectively. An experimental microalgae-free diet (CT) and a commercial diet (COM) were used as controls. Fish were fed at 3% of their body weight for 85 days. Final body weight of fish fed microalgae-supplemented diets did not differ from group fed CT diet. Fish-fed CT, TISO, NAN, and SCE showed higher growth performance and nutrient utilization figures than specimen-fed COM diet. The highest carcass lipid content was found in COM group (141 g kg−1 ), and no differences were observed in tein content. .....

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort

    Transverse momentum spectra of charged particles in proton–proton collisions at √s=900 GeV with ALICE at the LHC

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    The inclusive charged particle transverse momentum distribution is measured in proton–proton collisions at s=900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (|η|<0.8) over the transverse momentum range 0.15<pT<10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for |η|<0.8 is 〈pT〉INEL=0.483±0.001 (stat.)±0.007 (syst.) GeV/c and 〈pT〉NSD=0.489±0.001 (stat.)±0.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger 〈pT〉 than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET
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