440 research outputs found
Avaliação experimental da vulnerabilidade sísmica de edifícios existentes e de técnicas de reforço
Uma vasta campanha de ensaios foi realizada sobre estruturas de betão armado representativas da prática de projecto e construção até finais dos anos 70 nos países do sul da Europa. Dois pórticos de 4 pisos à escala real foram projectados, construídos e testados para intensidades crescentes da acção sísmica. Os principais objectivos desta série de ensaios foram a avaliação da capacidade original destes edifícios, com e sem alvenaria, e ainda a validação experimental da eficiência de várias técnicas de reparação e reforço. Com esta comunicação pretende-se apresentar e comentar os resultados mais relevantes da campanha de ensaios realizada no âmbito do projecto ICONS
Analysis of thylakoid membrane protein complexes from maize by Blue-Native Gel Electrophoresis and Tandem Mass Spectrometry
Avaliação e reforço sísmico de estruturas de betão armado
Apresenta-se um programa experimental que incluiu o ensaio em escala real de dois pórticos de betão armado representativos da construção no sul da Europa com 40/50 anos, com necessi-dade de reabilitação sísmica. São feitas algumas considerações sobre o comportamento experi-mental das estruturas, que foram ensaiadas sem qualquer intervenção, posteriormente reparadas e novamente ensaiadas considerando diferentes técnicas de reforço sísmico
Salivary Amylase Induction by Tannin-Enriched Diets as a Possible Countermeasure Against Tannins
Tannins are characterized by protein-binding affinity. They have astringent/bitter properties that act as deterrents, affecting diet selection. Two groups of salivary proteins, proline-rich proteins and histatins, are effective precipitators of tannin, decreasing levels of available tannins. The possibility of other salivary proteins having a co-adjuvant role on host defense mechanisms against tannins is unknown. In this work, we characterized and compared the protein profile of mice whole saliva from animals fed on three experimental diets: tannin-free diet, diet with the incorporation of 5% hydrolyzable tannins (tannic acid), or diet with 5% condensed tannins (quebracho). Protein analysis was performed by one-dimensional gel electrophoresis combined with Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry to allow the dynamic study of interactions between diet and saliva. Since abundant salivary proteins obscure the purification and identification of medium and low expressed salivary proteins, we used centrifugation to obtain saliva samples free from proteins that precipitate after tannin binding. Data from Peptide Mass Fingerprinting allowed us to identify ten different proteins, some of them showing more than one isoform. Tannin-enriched diets were observed to change the salivary protein profile. One isoform of α-amylase was overexpressed with both types of tannins. Aldehyde reductase was only identified in saliva of the quebracho group. Additionally, a hypertrophy of parotid salivary gland acini was observed by histology, along with a decrease in body mass in the first 4 days of the experimental period
Comparison of Electrophoretic Protein Profiles from Sheep and Goat Parotid Saliva
Saliva provides a medium for short-term adaptation to changes in diet composition, namely, the presence of plant secondary metabolites. Salivary proteins have biological functions that have particular influence on oral homeostasis, taste, and digestive function. Some salivary proteins, such as proline-rich proteins, are present in browsers but absent in grazers. Despite the significance of salivary proteins, their expression patterns in many herbivores are unknown. We investigated the sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile of parotid salivary proteins from two domesticated species, one a grazer, the sheep, Ovis aries, and the other a mixed feeder, the goat, Capra hircus, both fed on the same conventional diet. With 12.5% polyacrylamide linear gels, we observed uniform patterns of salivary proteins within the two species. In the goat profile, 21 major bands were observed, and 19 in the sheep profile. Each band was subjected to peptide mass fingerprinting for purposes of identification, allowing for 16 successful protein identifications. Marked differences were observed between the species in the region of 25–35 kDa molecular weights: one band was present in significantly different intensities; three bands were present only in goats; and one band was present only in sheep. This is the first report of a comparison of the protein salivary composition of sheep and goats and suggests that future research should be conducted to reveal a physiological function for salivary proteins related to the differences in feeding behavior of these species
A lapa do Bugio
A jazida pré-histórica do Bugio constitui uma das mais importantes grutas
sepulcrais da faixa estremenha. Encontrava-se intacta à data das primeiras
escavações, realizadas em 1957 e 1958. Vicissitudes várias que motivaram a
dissolução da primeira equipa e favoreceram diversas depredações, entretanto
realizadas, impediram que, antes do recomeço dos trabalhos, em 1966, mesmo
dos materiais recuperados, se pudessem extrair todas as informações neles
potencialmente contidas. Foi possível, a partir do estudo exaustivo do espólio conservado no Museu
de Sesimbra e no recolhido nas escavações de 1966, estabelecer a seguinte
sucessão cronológica-cultural:
Primeira ocupação - corresponde talvez à ocupação mais importante,
integrável no Neolítico recente-final estremenho. Estreitas analogias com o
"horizonte dolménico" identificado na vizinha Lapa do Fumo e datado pelo
rádio-carbono de 3090 ± 160 a. C. (SERRÃO,1978). A datação realizada no
Bugio deu 2800 ± 45 a.C.
Segunda ocupação- corresponde muito provavelmente a momento inicial
(ou pleno) do Calcolítico, definido pela presença de raros produtos, como o
recipiente de osso recolhido na sep. 7 e "ídolos" de calcário, de osso e marfim.
Terceira ocupação - Calcolítico final, campaniforme - representada pelos
Grupos de Palmela e Inciso. Trata-se da ocupação menos importante,
excessivamente valorizada em trabalhos anteriores, talvez pela grande dispersão
de fragmentos cerâmicos que não ultrapassam, contudo, nove recipientes (alguns
deles representados por apenas um fragmento): taças em calote - (I), de bordo
espessado - (I), de tipo Palmela - (I), caçoilas acampanadas - (2), e vasos
campaniformes - (2), além de dois recipientes de tipologia mal definida.Le gisement préhistorique de Bugio est l 'une des plus importantes grottes
sépulcrales du littoral de l'Estrémadure. Elle a été trouvée intacte lors des
premières fouilles, réalisées en 1957 et 1958. Diverses vicissitudes, qui devaient
aboutir à la dissolution de la première équipe de fouilleurs et favoriser le pillage
du site, empêchèrent la difusion de toute information avant la reprise des travaux
en 1966, même sur le matériel récupéré.
A partir de l' étude exhaustive du mobilier conservé au Musée de Sesimbra
et de celui qui a été découvert en 1966, on a pu établir les niveaux chronologiques
suivants: Première occupation, peut-être la plus importante, s'intégrant dans le
Néolithique récent et final de l'Estrémadure, présentant d' étroites analogies avec
"l'horizon dolménique" identifié sur le site voisin de Lapa do Fumo, daté de
3090 ± 160 a.C. par radio-carbone (SERRÃO, 1978). La datation obtenue à
Bugio est de 2800 ± 45 a.C..
Seconde occupation, correspondant très probablement à la phase initiale ou
médiane du Chalcolithique, définie par de rares productions, comme le récipient
en os recueilli dans la sépulture 7 et les "idoles" en calcaire, en os et en ivoire.
Troisième occupation (Chalcolithique final, Campaniforme) représentée
par les Groupes de Palmela et incisé. Il s'agit d'une occupation moins importante,
surévaluée dans les travaux antérieurs, peut-être en raison de la grande dispersion
des fragments de céramiques qui ne correspondaient, cependant, qu'à neuf
récipients: coupes en calotte (1 ), coupes au bord épais (1), coupes de type de
Palmela (1), casseroles en forme de cloche (2), vases campaniformes (2) et deux
récipients à la typologie mal définie
Liquid chromatography–diode array detection–electrospray ionisation mass spectrometry/nuclear magnetic resonance analyses of the anti-hyperglycemic flavonoid extract of Genista tenera Structure elucidation of a flavonoid-C-glycoside
The anti-hyperglycemic flavonoid extract obtained from Genista tenera was first studied by liquid chromatography (LC)–diode array detection (DAD) which showed the presence of two major compounds. One of them was identified as genistein-7-O-glucoside. Luteolin-7-O-glucoside was detected as a minor constituent, while luteolin-7,3′-di-O-glucoside and rutin were found in trace amounts. LC–DAD–ESI–MS and NMR were used to confirm the structure of these compounds and allowed the elucidation of the structure of the unknown major compound, which is the flavonoid 5,7,4′-trihydroxyisoflavone-8-C-glucoside.info:eu-repo/semantics/publishedVersio
Desempenho e características construtivas de um protótipo de dosador pneumático para sementes de arroz
Development of the heavy ion beam probing diagnostic and new results in the plasma electric potential investigations
Melatonin in maturation media fails to improve oocyte maturation, embryo development rates and DNA damage of bovine embryos
- …