352 research outputs found
First report on cyanotoxin (Mc-lr) removal from surface water by multi-soil-layering (msl) eco-technology: Preliminary results
Cyanobacteria blooms occur frequently in freshwaters around the world. Some can produce and release toxic compounds called cyanotoxins, which represent a danger to both the environment and human health. Microcystin-LR (MC-LR) is the most toxic variant reported all over the world. Conventional water treatment methods are expensive and require specialized personnel and equipment. Recently, a multi-soil-layering (MSL) system, a natural and low-cost technology, has been introduced as an attractive cost-effective, and environmentally friendly technology that is likely to be an alternative to conventional wastewater treatment methods. This study aims to evaluate, for the first time, the efficiency of MSL eco-technology to remove MC-LR on a laboratory scale using local materials. To this end, an MSL pilot plant was designed to treat distilled water contaminated with MC-LR. The pilot was composed of an alternation of permeable layers (pozzolan) and soil mixture layers (local sandy soil, sawdust, charcoal, and metallic iron on a dry weight ratio of 70, 10, 10, and 10%, respectively) arranged in a brick-layer-like pattern. MSL pilot was continuously fed with synthetic water containing distilled water contaminated with increasing concentrations of MC-LR (0.18–10 µg/L) at a hydraulic loading rate (HLR) of 200 L m−2 day−1. The early results showed MC-LR removal of above 99%. Based on these preliminary results, the multi-soil-layering eco-technology could be considered as a promising solution to treat water contaminated by MC-LR in order to produce quality water for irrigation or recreational activities. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 823860
Novel Collective Effects in Integrated Photonics
Superradiance, the enhanced collective emission of energy from a coherent
ensemble of quantum systems, has been typically studied in atomic ensembles. In
this work we study theoretically the enhanced emission of energy from coherent
ensembles of harmonic oscillators. We show that it should be possible to
observe harmonic oscillator superradiance for the first time in waveguide
arrays in integrated photonics. Furthermore, we describe how pairwise
correlations within the ensemble can be measured with this architecture. These
pairwise correlations are an integral part of the phenomenon of superradiance
and have never been observed in experiments to date.Comment: 7 pages, 3 figure
Noise induced transitions in semiclassical cosmology
A semiclassical cosmological model is considered which consists of a closed
Friedmann-Robertson-Walker in the presence of a cosmological constant, which
mimics the effect of an inflaton field, and a massless, non-conformally coupled
quantum scalar field. We show that the back-reaction of the quantum field,
which consists basically of a non local term due to gravitational particle
creation and a noise term induced by the quantum fluctuations of the field, are
able to drive the cosmological scale factor over the barrier of the classical
potential so that if the universe starts near zero scale factor (initial
singularity) it can make the transition to an exponentially expanding de Sitter
phase. We compute the probability of this transition and it turns out to be
comparable with the probability that the universe tunnels from "nothing" into
an inflationary stage in quantum cosmology. This suggests that in the presence
of matter fields the back-reaction on the spacetime should not be neglected in
quantum cosmology.Comment: LaTex, 33.tex pages, no figure
Synthesis and evaluation of the antitumor potential of new aminated or methoxylated di(hetero)arylthioethers in the thieno[3,2-b]pyridine series
Synthesis and evaluation of the antitumor potential of new aminated or methoxylated di(hetero)arylthioethers in the thieno[3,2-b]pyridine séries. In 1st Symposium on Medicinal Chemistry. Braga
Several thienopyridines have already been described as inhibitors of cell proliferation using
human tumor cells[1,2], highlighting the interest of studying their antitumorpotential. ln this work,
we present the synthesis of di(hetero)arylthioethers 1a-fby SNAr of the 7-chloro thieno[3,2-
b]pyridine with amino or methoxy thiophenols in good to high yields, like presented in the scheme.Foundation for the Science and Technology (FCT- Portugal) for financial support through
the NMR Portuguese network (Bruker 400 Avance 111-Univ Minho). To FCT and FEDERCOMPETE/
QREN/EU for financial support through the research unities PEst-C/QUI/UI686/2011
and PEst-OE/AGR/UI0690/20 11 , the research project PTDC/QUI-QUI/111 060/2009 and the postOoctoral
grant attributed to R.C.C. (SFRH/BPD/68344/2010) also financed by POPH and FSE
Virtual screening of thieno[3,2-b]pyridine arylthioether (hetero)aryltriazole derivatives as potential tyrosine kinase VEGFR2 inhibitors.
Recently we presented a series of thieno[3,2-d]pyrimidinc ether I ,3-diaryl ureas with potent
VEGFR2 inhibit ion activity. The binding mode was analyzed and the compounds showed a
type-11 tyrosine kinase inhibition mode, with the thienopyrimidine moiety forming a
Hydrogen Bond (H-bond) with CYS919 residue and the urea moiety forming a H-bonds with key residues G LU885 and ASP I 046 of the kinase domain.
In this study, the potential of changing the more widely used urea moiety to a triazole moiety now in thieno[3,2-b)pyridine a rylthioethers, was analyzed. A number of 3D thieno[3.2-b ]pyrid ine arylthioethers (hetero )aryltriazole derivatives (Figure I) were designed and then molecular docking studies, using AutoDock4, were performed against a VEGFR2 crystal
Synthesis of new N-[3-(thieno[3,2-b]pyridine-7-ylthio)phenyl]benzamides as potential inhibitors the tyrosine kinase domain of VEGFR2
Angiogenesis, the growth of new vessels from preexisting vasculature, is a critical step in tumor
progression [1]. The tyrosine kinase Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) is
a crucial mediator in angiogenesis since the VEGF, excreted by the tumor cells, binds to it
activating several signaling pathways involved in cell survival and proliferation [2]. Recently
thienopyridine derivatives showed to be promising inhibitors of the tyrosine kinase domain of
VEGFR2 [3,4]. In this work new N-[3-(thieno[3,2-b]pyridine-7-ylthio)phenyl]benzamides were
prepared as potential VEGFR2 inhibitors suggested by rational design, as presented below.FCT -Portugal for financial support through the NMR Portuguese network (Bruker 400 Avance 111-Univ
Minho). FCT and FEDER -COMPETE-QREN-EU for financial support through the research unities PEstC/
QUI/UI686/2011, PEst-OE/AGR/UI0690/2011, the research project PTDC/QUI-QUI/111 060/2009 and the
post-Doctoral grant A.B.(SFRH/BPD/36753/2007) also financed by POPH and FSE
The fraction of cancer attributable to ways of life, infections, occupation, and environmental agents in Brazil in 2020
Many human cancers develop as a result of exposure to risk factors related to the environment and ways of life. The aim of this study was to estimate attributable fractions of 25 types of cancers resulting from exposure to modifiable risk factors in Brazil. The prevalence of exposure to selected risk factors among adults was obtained from population-based surveys conducted from 2000 to 2008. Risk estimates were based on data drawn from metaanalyses or large, high quality studies. Population-attributable fractions (PAF) for a combination of risk factors, as well as the number of preventable deaths and cancer cases, were calculated for 2020. The known preventable risk factors studied will account for 34% of cancer cases among men and 35% among women in 2020, and for 46% and 39% deaths, respectively. The highest attributable fractions were estimated for tobacco smoking, infections, low consumption of fruits and vegetables, excess weight, reproductive factors, and physical inactivity. This is the first study to systematically estimate the fraction of cancer attributable to potentially modifiable risk factors in Brazil. Strategies for primary prevention of tobacco smoking and control of infection and the promotion of a healthy diet and physical activity should be the main priorities in policies for cancer prevention in the country. \ua9 2016 Azevedo e Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
New di(hetero)arylethers and di(hetero)arylamines in the thieno[3,2-b]pyridine series: Synthesis, growth inhibitory activity on human tumor cell lines and non-tumor cells, effects on cell cycle and on programmed cell death
New fluorinated and methoxylated di(hetero)arylethers and di(hetero)arylamines were prepared functionalizing the 7-position of the thieno[3,2-blpyridine, using copper (C-O) or palladium (C N) catalyzed couplings, respectively, of the 7-bromothieno[3,2-blpyridine, also prepared, with ortho, meta and para fluoro or methoxy phenols and anilines. The compounds obtained were evaluated for their growth inhibitory activity on the human tumor cell lines MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HCI15 (colon carcinoma), HepG2 (hepatocellular carcinoma) and HeLa (cervical carcinoma). The most active compounds, a di(hetero)arylether with a methoxy group in the meta position relative to the ether function and two di(hetero)arylamines with a methoxy group either in the ortho or in the meta position relative to the NH, were further tested at their GI(50) concentrations on NCI-H460 cells causing pronounced alterations in the cell cycle profile and a strong and significant increase in the programmed death of these cells. The fluorinated and the other methoxylated compounds did not show important activity, presenting high GI(50) values in all the cell lines tested. Furthermore, the hepatotoxicity of the compounds was assessed using porcine liver primary cells (PLP2), established by some of us. Results showed that one of the most active compounds was not toxic to the non-tumor cells at their GI(50) concentrations showing to be the most promising as antitumoral.The authors would like to thank to the Foundation for the Science and Technology (PCT Portugal) for financial support through the NMR Portuguese network (Bruker 400 Avance III-Univ Minho); to FCT and FEDER-COMPETE/QREN/EU for financial support through the research unities PEst-C/QUI/UI686/2011 and PEst-OE/AGR/UI0690/2011, the research project PTDC/QUI-QUI/111060/2009 and the post-Doctoral grants attributed to R.C.C. (SFRH/BPD/68344/2010) and R.T.L. (SRH/BPD/68787/2010). IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education and is partially supported by FCT
- …