77 research outputs found
Modified theories of gravity with non-minimal curvature-matter coupling
In this contribution one examines the generalization of the theories
of gravity where one introduces a non-minimal coupling between curvature and
matter. This model has new and interesting features. %, specially concerning
the energy exchange between the matter fields and the curvature. However, as
any modified gravity theories, these may give origin to anomalies which might
turn the theory physically meaningless. In this respect, one undertakes a study
on the energy conditions and the Dolgov-Kawasaki criterion specific of this new
model.Comment: 6 pages, 1 table. Talk present by O. B. at the "Invisible Universe
International Conference", Paris, Palais de l'UNESCO June 29- July 3. To
appear in the Proceeding
Análise e caracterização energética de sistemas fotovoltaicos de baixa potência com ligação à rede eléctrica
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 201
Musschia isambertoi M. Seq., R. Jardim, M. Silva & L. Carvalho (Campanulaceae), una nueva especie del archipiélago de Madeira (Portugal)
A new species of Musschia Dumort. (Campanulaceae), endemic from Madeira Archipelago (Portugal), is described as Musschia isambertoi M. Seq., R. Jardim, M. Silva & L. Carvalho. Both vegetative and reproductive structures have been studied and are remarkably distinct from the recognized species [M. aurea (L. f.) Dumort. and M. wollastonii Lowe]. A full description and a diagnosis are included as well as line art, color drawings and pictures. Diagnostic characters are discussed and compared with those of the closely related species. The new species has a very restricted distribution occurring in two isolated populations in the Deserta Grande Island (Madeira Archipelago, Portugal). Nomenclatural aspects on the genus Musschia Dumort. are discussed and a diagnostic key for the species is also includedSe describe una nueva especie de Musschia Dumort. (Campanulaceae), endémica del archipiélago de Madeira (Portugal), Musschia isambertoi M. Seq., R. Jardim, M. Silva & L. Carvalho. La morfología de las estructuras vegetativas y florales estudiadas es claramente distinta de la de las otras dos especies conocidas, Musschia aurea (L. f) Dumort. y Musschia wollastonii Lowe. Se incluyen: una descripción y una diagnosis, ilustradas por imágenes, una lámina en blanco y negro y una en color. Se comparan y discuten los caracteres diagnósticos dentro del conjunto de especies del género. La nueva especie es endémica de la isla Deserta Grande (archipiélago de Madeira, Portugal). Se discuten aspectos nomenclaturales y se incluye una clave de las especies conocidas para Madeira
A biodiversidade terrestre e dulçaquícola dos arquipélagos da Madeira e das Selvagens
As ilhas atlânticas dos Açores, Madeira, Selvagens, Canárias e Cabo Verde constituem uma das regiões da Europa mais ricas em diversidade de fungos, plantas e animais. Desde 2004 que a inventariação detalhada da diversidade destas ilhas tem sido um dos principais objectivos dos projectos ATLÂNTICO e BIONATURA (incluídos no projecto EU INTERREG IIIB). Este livro é a mais recente contribuição destes projectos, apresentando uma lista de todos os fungos, flora e fauna terrestre conhecida, incluindo a dulçaquícola, para dois arquipélagos atlânticos (Madeira e Selvagens). A lista abrange o arquipélago da Madeira, constituído por duas ilhas de maiores dimensões (Madeira e Porto Santo) e três pequenas, cujo conjunto constitui as Desertas (Ilhéu Chão, Deserta Grande e Bugio), e ainda o arquipélago das Selvagens, formado por duas pequenas ilhas (Selvagem Grande e Selvagem Pequena) e um ilhéu (Ilhéu de Fora).ABSTRACT: The Azores, Madeira, Selvagens, Canary Islands and Cape Verde are among the richest regions in Fungi, plant and animal diversity in Europe. The main objectives of the EU INTERREG IIIB projects ATLÂNTICO and BIONATURA have been, since 2004, to carry out a detailed inventory of the terrestrial Fungi, Flora and Fauna of these archipelagos. This book, encompassing a checklist of all the known terrestrial and freshwater Fungi, Flora and Fauna of Madeira and Selvagens archipelagos is the latest contribution towards that goal. The geographic scope of this checklist includes the Madeira archipelago, composed of two large islands (Madeira and Porto Santo) and three small islands, which are globally named Desertas (Ilhéu Chão, Deserta Grande and Bugio), and the archipelago of Selvagens with two small islands (Selvagem Grande and Selvagem Pequena) and one islet (Ilhéu de Fora)
Chemical constituents of Euphorbia hyberna L. (Euphorbiaceae)
Chemical investigation of the aerial part and the roots of Euphorbia hyberna
L. subs. hyberna. resulted in the isolation and identification of four triterpenoids
(3�-O-octadecanoyllupeol (1), glut-5-en-3�-ol (2), 24-methylenecicloartan-3�-ol
(3) and cicloart-23-ene-3�,25-diol (6)) along with the phenolic compounds ellagic
acid (4) and 3,30
-di-O-methylellagic acid (7). Although these are all known
compounds, this is the first report of their isolation from this plant.
Their structures were elucidated on the basis of spectral methods, including 2D
NMR experiences, and confirmed by comparing with the literature data.info:eu-repo/semantics/publishedVersio
Jatrophane and lathyrane diterpenoids from Euphorbia hyberna L
A new diterpene tetraester, from the jatrophane family, and two new diterpene triesters, with a lathyrane skeleton, have been
isolated from the chloroform extract of the roots of Euphorbia hyberna L. The structures of these compounds have been established
by spectroscopic methods, including 2D NMR experiments.info:eu-repo/semantics/publishedVersio
Improved recovery of urinary small extracellular vesicles by differential ultracentrifugation
Extracellular vesicles (EVs) are lipid-membrane enclosed structures that are associated with several diseases, including those of genitourinary tract. Urine contains EVs derived from urinary tract cells. Owing to its non-invasive collection, urine represents a promising source of biomarkers for genitourinary disorders, including cancer. The most used method for urinary EVs separation is differential ultracentrifugation (UC), but current protocols lead to a significant loss of EVs hampering its efficiency. Moreover, UC protocols are labor-intensive, further limiting clinical application. Herein, we sought to optimize an UC protocol, reducing the time spent and improving small EVs (SEVs) yield. By testing different ultracentrifugation times at 200,000g to pellet SEVs, we found that 48 min and 60 min enabled increased SEVs recovery compared to 25 min. A step for pelleting large EVs (LEVs) was also evaluated and compared with filtering of the urine supernatant. We found that urine supernatant filtering resulted in a 1.7-fold increase on SEVs recovery, whereas washing steps resulted in a 0.5 fold-decrease on SEVs yield. Globally, the optimized UC protocol was shown to be more time efficient, recovering higher numbers of SEVs than Exoquick-TC (EXO). Furthermore, the optimized UC protocol preserved RNA quality and quantity, while reducing SEVs separation time.</p
Improved recovery of urinary small extracellular vesicles by differential ultracentrifugation
Extracellular vesicles (EVs) are lipid-membrane enclosed structures that are associated with several diseases, including those of genitourinary tract. Urine contains EVs derived from urinary tract cells. Owing to its non-invasive collection, urine represents a promising source of biomarkers for genitourinary disorders, including cancer. The most used method for urinary EVs separation is differential ultracentrifugation (UC), but current protocols lead to a significant loss of EVs hampering its efficiency. Moreover, UC protocols are labor-intensive, further limiting clinical application. Herein, we sought to optimize an UC protocol, reducing the time spent and improving small EVs (SEVs) yield. By testing different ultracentrifugation times at 200,000g to pellet SEVs, we found that 48 min and 60 min enabled increased SEVs recovery compared to 25 min. A step for pelleting large EVs (LEVs) was also evaluated and compared with filtering of the urine supernatant. We found that urine supernatant filtering resulted in a 1.7-fold increase on SEVs recovery, whereas washing steps resulted in a 0.5 fold-decrease on SEVs yield. Globally, the optimized UC protocol was shown to be more time efficient, recovering higher numbers of SEVs than Exoquick-TC (EXO). Furthermore, the optimized UC protocol preserved RNA quality and quantity, while reducing SEVs separation time.</p
Potential impact on stroke
Funding Information: The funding agency that supported the work \u201CFunda\u00E7\u00E3o para a Ci\u00EAncia e Tecnologia\u201D (FCT) with four projects: Applied Molecular Biosciences Unit-UCIBIO (UID/Multi/04378/2019), iNOVA4Health - Programme in Translational Medicine (UID/Multi/04462/2013), LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy and PTDC/MEC-NEU/28750/2017 and the PhD scholarship for NLS (PD/BD/127819/2016). Publisher Copyright: © 2024 The AuthorsRemote ischemic conditioning (RIC) is a procedure consisting of short cycles of ischemia applied in a limb that activates endogenous protection in distant organs, such as the brain. Despite the promising outcomes of RIC, the biochemical factors governing inter-organ communication remain largely unexplored, particularly in humans. A pilot study on 20 healthy humans was performed to identify potential circulating biochemical factors involved in RIC signalling. Blood was collected before and immediately, 4 and 22 h after the end of RIC. To characterize the responses triggered by RIC, a combination of biochemical and proteomic analysis, along with functional in vitro tests in human cells, were performed. RIC did not alter the levels of nitric oxide, bilirubin and cell-free mitochondrial DNA. In contrast, carboxyhaemoglobin levels increased following RIC at all time points and young subset, suggesting endogenous production of carbon monoxide that is a cytoprotective gasotransmitter. Additionally, the levels of glutathione and cysteinylglycine bound to proteins also increased after RIC, while glutathione catabolism decreased. Plasma proteomic analysis identified overall 828 proteins. Several steps of statistical analysis (Student's t-test, repeated measures ANOVA, with Holm corrected pairwise p-values <0.05 threshold and fold change higher or lower than 100 %) leaded to the identification of 9 proteins with altered circulating levels in response to RIC at 4h and 22h. All 9 proteins are from extracellular space or exosomes, being involved in inflammation, angiogenesis or metabolism control. In addition, RIC-conditioned plasma from young subjects protected microglial cell culture against inflammatory stimuli, indicating an anti-inflammatory effect of RIC. Nevertheless, other functional tests in neurons or endothelial cells had no effect. Overall, we present some evidence for RIC-induced anti-inflammatory and antioxidant responses in healthy human subjects, in particular in young subjects. This study is a first step towards the disclosure of signalling factors involved in RIC-mediated inter-organ communication.publishersversionpublishe
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