1. |
- Monteiro, Fátima Liliana, et al.
(author)
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The histone H2A isoform Hist2h2ac is a novel regulator of proliferation and epithelial-mesenchymal transition in mammary epithelial and in breast cancer cells.
- 2019
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In: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 396, s. 42-52
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Journal article (peer-reviewed)abstract
- Proliferation and differentiation are controlled through chromatin remodelling. Therefore, there is an enormous biological significance and clinical value in understanding how specific signalling pathways are affected by histone replacement in the nucleosome. In this work, mass spectrometry was used to screen HC11 mammary epithelial cells for changes in histone levels throughout cell differentiation. The canonical histone isoform Histone H2A type 2-C (Hist2h2ac) was found only in undifferentiated/proliferating cells. Hist2h2ac mRNA was induced by EGF, specifically in the CD24+/CD29hi/DC44hi cell subpopulation. Hist2h2ac mRNA was increased by MEK(1/2) or PI3-K activation in HC11 and EpH4 mammary epithelial cells, and in MC4-L2 and T47-D breast cancer cells. Hist2h2ac silencing inhibited EGF-induced Zeb-1 expression and E-cadherin down-regulation, and this effect was reverted by Hist2h2ac re-expression. Notably, silencing of Hist2h2ac increased EGFR, ERBB2, and ERK(1/2) activation but did not allow EGF-induced proliferation. HIST2H2AC was expressed in all breast cancer molecular subtypes and found altered in 17% breast cancers, being 16.8% of the cases related to HIST2H2AC gene amplification and/or mRNA upregulation. In summary, this is the first study that identifies a canonical histone isoform -Hist2h2ac-downstream of the EGFR pathway, regulating oncogenic signalling and thereby contributing to deregulation of target genes.
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2. |
- Vicente, Guiomar, et al.
(author)
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Sistema Inovador de Construção Metálica : FRAMEUP
- 2015
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Conference paper (peer-reviewed)abstract
- The methodology developed under the project FRAMEUP includes the construction of residential buildings from the top to the base, whose compartments are prefabricated modules. The construction begins with the execution of the roof, on the ground level, which is later on lifted, allowing from beneath the construction of the lower floors, while it protects them from the weather. The construction ends with the execution of the ground floor. It is adopted a framed structure with tubular sections for which the beam-to-column connections are developed and the columns-splices designed to facilitate and the use of this constructive methodology.
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3. |
- Andrade, Pedro, et al.
(author)
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Innovative system for the construction and management of student resisdences : Frameup system
- 2016
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In: IABSE CONGRESS, STOCKHOLM, 2016. - CH - 8093 Zürich, Switzerland : International Association for Bridge and Structural Engineering. - 9783857481444 ; , s. 1364-1370
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Conference paper (peer-reviewed)abstract
- Sweden has a strong demand on the construction of student accommodations and consequently significant efforts have been taken to increase and streamline construction methods. In addition, the fluctuation on the number of students admitted at each year, in each university, lead to periods of house shortage or, in opposition to that, to eventual surplus on the housing market. For these reasons urges finding a fast execution process in construction to fulfil the market needs, together with a housing mechanism of control which balances the students’ needs with the housing availability. In this sense, the Frameup system arises as a solution to solve both problems by combining a modular construction with an innovative execution process.The FRAMEUP buildings uses a steel frame in combination with prefabricated 3D modules - fully equipped and suitable for student accommodations – which are assembled by starting from the roof to the 1st floor. The existence of the lifting system permits the erection of the building, promoting each time the building is lifted, a clearance of one-floor-height, at ground level, for the assembly of a new floor. The procedure is repeated several times, according to the number of floors, until the 1st floor of the building, the last floor of the execution sequence, is assembled.Alongside with its advantage on the fast execution, the Frameup system allows to efficiently increase or decrease the number of the floors and consequently its exchangeability with other buildings of same nature. Thus, assuming a net of FRAMEUP buildings at each university, its exchangeability system would create the necessary conditions so that the number of floors at each campus would follow the fluctuations of the students’ population among the different universities on different periods of time, so to suppress the needs for housing or to avoid the surplus on construction.
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4. |
- Andrade, Pedro, et al.
(author)
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On global and local buckling response of structural angle sandwich panels
- 2022
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In: Thin-walled structures. - : Elsevier. - 0263-8231 .- 1879-3223. ; 180
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Journal article (peer-reviewed)abstract
- Having in mind the topic of industrialised construction and the benefits of modular construction, sandwich panels are investigated to be utilised as load-bearing wall elements. To assess its full potential, the present paper tackles the linear elastic buckling response of axially loaded angle sandwich panels, by means of numerical and analytical calculations, as the upper bound of its load bearing capacity. The failures modes are obtained and framed for concentrically loaded angle panels with fixed and pin-ended supports. A parametric study of the angle panel comprising a series of finite element models is undertaken where responses are compared with analytical calculations based on the theory of sandwich panels. Boundaries for local and global buckling are identified and framed.
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5. |
- Andrade, Pedro, et al.
(author)
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Structural assessment of a column splice with opened slotted holes : Finger Connection
- 2017
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In: ce/papers. - : Ernst & Sohn Verlag. - 2509-7075. ; 1:2-3, s. 514-521
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Journal article (peer-reviewed)abstract
- This paper introduces a novel joint based on a friction connection designed for column-splices. The jointwas developed within the scope of modular construction to improve the fast assembly of prefabricatedframes and to accommodate eventual misalignments. Gaps at the connection are considered on the jointhorizontal and vertical axis to accommodate misalignments whether they are rotations and/ordisplacements and so to allow for the easy fit of the columns. The efficiency of the joint resistance basedon different connection gaps subjected to uniform compression is assessed.
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6. |
- de Jesus, Abílio M.P., et al.
(author)
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A comparison of the fatigue behavior between S355 and S690 steel grades
- 2012
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In: Journal of constructional steel research. - : Elsevier BV. - 0143-974X .- 1873-5983. ; 79, s. 140-150
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Journal article (peer-reviewed)abstract
- The use of higher strength steels allows the design of lighter, slenderer and simpler structures. Nevertheless, the increase of the yield strength of the steels does not correspond to a proportional increase of fatigue resistance, which makes the application of high strength steels on structures prone to fatigue, a major concern of the design. This paper presents a comparison of the fatigue behavior between the S355 mild steel and the S690 high strength steel grades, supported by an experimental program of fatigue tests of smooth specimens, performed under strain control, and fatigue crack propagation tests. Besides the cyclic elastoplastic characterization, the fatigue tests of smooth small size specimens allow the assessment of the fatigue crack initiation behavior of the materials. Results show that the S690 steel grade presents a higher resistance to fatigue crack initiation than the S355 steel. However, the resistance to fatigue crack propagation is lower for the S690 steel grade, which justifies an inverse dependence between static strength and fatigue life, for applications where fatigue crack propagation is the governing phenomenon. Consequently, the design of structural details with the S690 steel should avoid sharp notches that significantly reduce the fatigue crack initiation process.
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7. |
- Matos, Rui, et al.
(author)
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Cyclic performance of single and group micropiles on loose sand
- 2015
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In: Front Matter. - Reston, VA : American Society of Civil Engineers (ASCE). - 9780784479087 ; , s. 1751-1763
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Conference paper (peer-reviewed)abstract
- An increase in the height of new generation of wind towers is foreseen in order to improve their performance. This will imply larger shallow foundations, which represent a substantial percentage of the overall budget. Consequently, it is of interest to develop alternative foundation solutions, with a smaller environmental impact, in particular in terms of the required volume of excavation and reinforced concrete. The proposed improvement consists in the use of micropiles placed along the foundation perimeter as a way to increase the overturning resistance of the system as well as the foundation behavior. The main focus of this paper is the characterization of the behavior of single and groups of micropiles, tested under controlled conditions. An extensive set of experimental tests were conducted on single and 2x2 groups of micropiles under monotonic or cyclic loading installed in loose sand. The effect of the cyclic loading on the behavior of the micropiles was assessed as well as the effect of the grouting on the improvement of the micropile resistance and stiffness and also on the improvement of the soil mechanical properties. The assembly and procedure of the tests are described and the corresponding resistance and stiffness are presented and compared
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8. |
- Miranda, Jezid, et al.
(author)
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Metabolic profiling and targeted lipidomics reveals a disturbed lipid profile in mothers and fetuses with intrauterine growth restriction
- 2018
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1
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Journal article (peer-reviewed)abstract
- Fetal growth may be impaired by poor placental function or maternal conditions, each of which can influence the transfer of nutrients and oxygen from the mother to the developing fetus. Large-scale studies of metabolites (metabolomics) are key to understand cellular metabolism and pathophysiology of human conditions. Herein, maternal and cord blood plasma samples were used for NMR-based metabolic fingerprinting and profiling, including analysis of the enrichment of circulating lipid classes and subclasses, as well as the number of sub-fraction particles and their size. Changes in phosphatidylcholines and glycoproteins were prominent in growth-restricted fetuses indicating significant alterations in their abundance and biophysical properties. Lipoprotein profiles showed significantly lower plasma concentrations of cholesterol-intermediate density lipoprotein (IDL), triglycerides-IDL and high-density lipoprotein (HDL) in mothers of growth-restricted fetuses compared to controls (p < 0.05). In contrast, growth-restricted fetuses had significantly higher plasma concentrations of cholesterol and triglycerides transporting lipoproteins [LDL, IDL, and VLDL, (p < 0.005; all)], as well as increased VLDL particle types (large, medium and small). Significant changes in plasma concentrations of formate, histidine, isoleucine and citrate in growth-restricted fetuses were also observed. Comprehensive metabolic profiling reveals that both, mother and fetuses of pregnancies complicated with fetal growth restriction have a substantial disruption in lipid metabolism.
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