2,340 research outputs found
Crowd quantification with flow direction estimation : a low-cost IoT-enabled solution
Monitoring crowds in public environments is of great value for understanding human routines and managing crowd routes in indoor or outdoor environments. This type of information is crucial to improve the business strategy of an organization, and can be achieved by performing crowd quantification and flow direction estimation to generate information that can be later used by a business intelligence/analytic layer to improve sales of a specific service or targeting a new specific product. In this paper, we propose the design of an IoT Crowd sensor composed of an array of ultrasonic ping sensors that is responsible for detecting movement in specific directions. The proposed device has a built-in algorithm that is optimized to quantify and detect the human flow direction in indoor spaces
such as hallways. Results have shown an average accuracy above 86% in the five scenarios evaluated when using an array with three elements.5311-8814-F0ED | Sara Maria da Cruz Maia de Oliveira PaivaN/
The Complex Dynamic of Phase I Drug Metabolism in the Early Stages of Doxorubicin Resistance in Breast Cancer Cells
Funding: This research was partly funded by the Research Center grant ToxOmics (UIDB/00009/2020 and UIDP/0009/2020), from the Portuguese Fundação para a Ciência e a Tecnologia—FCTThe altered activity of drug metabolism enzymes (DMEs) is a hallmark of chemotherapy resistance. Cytochrome P450s (CYPs), mainly CYP3A4, and several oxidoreductases are responsible for Phase I metabolism of doxorubicin (DOX), an anthracycline widely used in breast cancer (BC) treatment. This study aimed to investigate the role of Phase I DMEs involved in the first stages of acquisition of DOX-resistance in BC cells. For this purpose, the expression of 92 DME genes and specific CYP-complex enzymes activities were assessed in either sensitive (MCF-7 parental cells; MCF-7/DOXS) or DOX-resistant (MCF-7/DOXR) cells. The DMEs genes detected to be significantly differentially expressed in MCF-7/DOXR cells (12 CYPs and eight oxidoreductases) were indicated previously to be involved in tumor progression and/or chemotherapy response. The analysis of CYP-mediated activities suggests a putative enhanced CYP3A4-dependent metabolism in MCF-7/DOXR cells. A discrepancy was observed between CYP-enzyme activities and their corresponding levels of mRNA transcripts. This is indicative that the phenotype of DMEs is not linearly correlated with transcription induction responses, confirming the multifactorial complexity of this mechanism. Our results pinpoint the potential role of specific CYPs and oxidoreductases involved in the metabolism of drugs, retinoic and arachidonic acids, in the mechanisms of chemo-resistance to DOX and carcinogenesis of BC.publishersversionpublishe
Kinetics of Expression in Cancer Drug Resistance
This research was funded by Fundação de Ciência e Tecnologia (FCT), grant number UID-BIM-00009-2020 and GHTM-UID/Multi/04413/2013. The APC was funded by Fundação de Ciência e Tecnologia (FCT), grant number UID-BIM-00009-2020.Cancer drug resistance (CDR) is a major problem in therapeutic failure. Over 90% of patients with metastatic cancer present CDR. Several mechanisms underlie CDR, including the increased expression of efflux ABC transporters and epigenetic phenomena. Nevertheless, a topic that is not usually addressed is the mechanism underlying the loss of CDR once the challenge to these cells is withdrawn. A KCR cell line (doxorubicin-resistant, expressing ABCB1) was used to induce loss of resistance by withdrawing doxorubicin in culture medium. ABCB1 activity was analysed by fluorescence microscopy and flow cytometry through substrate (DiOC2) retention assays. The expression of 1008 microRNAs was assessed before and after doxorubicin withdrawal. After 16 weeks of doxorubicin withdrawal, a decrease of ABCB1 activity and expression occurred. Moreover, we determined a signature of 23 microRNAs, 13 underexpressed and 10 overexpressed, as a tool to assess loss of resistance. Through pathway enrichment analysis, “Pathways in cancer”, “Proteoglycans in cancer” and “ECM-receptor interaction” were identified as relevant in the loss of CDR. Taken together, the data reinforce the assumption that ABCB1 plays a major role in the kinetics of CDR, and their levels of expression are in the dependence of the circuitry of cell miRNAspublishersversionpublishe
Microfluidics-based automated genotyping of Saccharomyces Cerevisiae strain by interdelta sequence typing : an interlaboratory comparasion
High-throughput molecular characterization of microbial isolates requires the application of automated microfluidic
electrophoresis. We herein evaluate the factors that affect interlaboratory reproducibility of interdelta sequence typing for
Saccharomyces cerevisiae strain delimitation, using microfluidic electrophoresis (Caliper Lab Chip
®
). This approach is
necessary for the constitution of bio-databanks, equitable sharing of genotypic data among laboratories, for biodiversity
conservation and sustainable development of genetic resources. Delta sequences are 300 bp regions flanking
retrotransposons Ty1 and Ty2 of S. cerevisiae, occurring also as separate elements dispersed throughout the genome. PCRbased interdelta sequence typing has a high discriminatory power [1], generating polymorphic banding patterns. Our
approach included 12 genetically diverse S. cerevisiae strains, two different Taq polymerases (commercial and in-house
cloned/prepared) and two different thermal cyclers. PCR amplifications were performed in two laboratories, resulting in a total
of 384 electrophoretic banding patterns (32 replicates for each strain). From the combinations between strains, Taq
polymerase, thermal cycler and laboratory, a total of 60 different groups was obtained. Data were analyzed in terms of the
fragment sizes (bp), absolute and relative concentrations of each band. Due to the lack of normality (Kolmogorov-Smirnov
and Shapiro-Wilk tests) and the homogeneity of variances (Levene's test), the ANOVA test was not applied. The nonparametric alternative, Kruskal-Wallis one-way analysis of variance was used to test the equality of the medians among the
different groups. By rejecting the null hypotheses with a p-value < 0.001, we performed multiple pairwise comparisons using
the method proposed by Conover and Iman [2], based on a t-Student distribution to search for the origins of the differences.
The data obtained revealed that both the performance of experiments in two independent laboratories and the use of different
Taq polymerases introduced significant variability between the respective replicates. The use of in-house cloned/prepared
Taq polymerase was associated with highest variability, pointing to the need for careful experimental standardization of PCRbased interdelta sequence analysis.Portuguese Science and Technology Foundation (PTDC/AGR-ALI/103392/2008)European Community´s Seventh Framework Programme (FP7/2007-2013) - grant agreement nº 23245
High-yield synthesis and catalytic response of chainlike hybrid materials of the [(MoO3)m(2,2′-bipyridine)n] family
The one-dimensional organic–inorganic hybrid material [MoO3(2,2'-bipy)] (1) (2,2'-bipy = 2,2'-bipyridine)
has been used as a starting material to prepare the bipy-deficient phases [Mo2O6(2,2'-bipy)] (2) and
[Mo3O9(2,2'-bipy)2] (3) in excellent yields. The hybrid 2 was obtained by a solid-state thermal treatment
of 1 (300 ºC, 10 min) while 3 was obtained by a hydrothermal treatment of 1 (160 ºC, 6 d). A study was
performed to compare the catalytic properties of 1–3 in the epoxidation of cis-cyclooctene at 55 ºC
with tert-butylhydroperoxide (TBHP) or aqueous H2O2 as oxidant. In all cases Cy was converted to
cyclooctene oxide (CyO) with 100% selectivity, and Cy conversions increased in the order 1 < 3 < 2,
which parallels an increase in the Mo/2,20-bipy molar ratio of the hybrid (1 < 1.5 < 2). With compound
2, CyO yields at 24 h were 96% for TBHP (cosolvent a,a,a-trifluorotoluene) and 53% for H2O2 (cosolvent
CH3CN). The catalytic reactions occurred in homogeneous phase with active species formed in situ from
1–3. All three hybrids react with aqueous H2O2 to give the catalytically active oxodiperoxo complex
[MoO(O2)2(2,2'-bipy)]. The 2 : 1 hybrid 2 was further examined for the epoxidation of other cyclic and
linear non-functionalised olefins with TBHP, namely cyclododecene, 1-octene and trans-2-octene, and
the biomass-derived olefins DL-limonene, a-pinene and methyl oleate.publishe
Hierarchical Spatial Organization of Geographical Networks
In this work we propose the use of a hirarchical extension of the
polygonality index as a means to characterize and model geographical networks:
each node is associated with the spatial position of the nodes, while the edges
of the network are defined by progressive connectivity adjacencies. Through the
analysis of such networks, while relating its topological and geometrical
properties, it is possible to obtain important indications about the
development dynamics of the networks under analysis. The potential of the
methodology is illustrated with respect to synthetic geographical networks.Comment: 3 page, 3 figures. A wokring manuscript: suggestions welcome
Evaluation of air lime and clayish earth mortars for earthen wall renders
CIAV2013 – International Conference on Vernacular Architecture, 7º ATP, VerSus, 16-20 october 2013An experimental rammed earth wall was traditionally made with local earth and characterized in terms of superficial hardness, compactness, thermal conductivity and water absorption, in exterior environmental conditions. Two mortars were made with an air lime and a mixture of three washed graduated siliceous sands, with volumetric proportions of 1:2 and 1:3 (air lime:sand). A clayish earth was characterized and applied as partial substitutions of air lime on 1:2 mortars and as partial substitutions of the finest sand on 1:3 mortars. Mortars were formulated and characterized in terms of constitution and consistency and samples of mortars applied on ceramic brick were prepared. For each volumetric proportion, mortars without earth and the ones with earth that presented the best workability were applied as renders on panels on the experimental
rammed earth wall; also prismatic samples were made. The mortar samples and the renders on the wall were characterized at 90 days of age. This paper presents and discusses some of the results obtained with the characterization of the rammed earth wall, the fresh mortars and its application on the bricks and on the wall. Differences
between the mortars are highlighted while their compatibility with traditional rammed earth wall is verified
Genotyping of Saccharomyces cerevisiae strains by interdelta sequence typing using automated microfluidics
Amplification of genomic sequences flanked by delta elements of retrotransposons TY1 and TY2 is a reliable method for characterization of Saccharomyces cerevisiae strains. The aim of this study is to evaluate the usefulness of microfluidic electrophoresis (Caliper LabChip®) to assess the factors that affect interlaboratory reproducibility of interdelta sequence typing for S. cerevisiae strain delimitation. We carried out experiments in two laboratories, using varying combinations of Taq DNA polymerases and thermal cyclers. The reproducibility of the technique is evaluated using non-parametric statistical tests and we show that the source of Taq DNA polymerase and technical differences between laboratories have the highest impact on reproducibility, whereas thermal cyclers have little impact. We also show that the comparative analysis of interdelta patterns is more reliable when fragment sizes are compared, than when absolute and relative DNA concentrations of each band are considered. Interdelta analysis based on a smaller fraction of bands with intermediate sizes between 100 and 1000 bp yield the highest reproducibility.Fundação para a Ciência e Tecnologi
Synthesis, Characterization and Catalytic application of Water Stable η3-Allyl Dicarbonyl Complexes of Molybdenum(II)
Trabalho apresentado em EuropaCat X – Catalysis across disciplines, 28 Aug - 02 Sep 2011, Glasgow, ScotlandN/
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