50 research outputs found
Self-Assembling Peptide Detergents Stabilize Isolated Photosystem Ion a Dry Surface for an Extended Time
We used a class of designed peptide detergents to stabilize photosystem I (PS-I) upon extended drying under N(2) on a gold-coated-Ni-NTA glass surface. PS-I is a chlorophyll-containing membrane protein complex that is the primary reducer of ferredoxin and the electron acceptor of plastocyanin. We isolated the complex from the thylakoids of spinach chloroplasts using a chemical detergent. The chlorophyll molecules associated with the PS-I complex provide an intrinsic steady-state emission spectrum between 650 and 800 nm at −196.15 °C that reflects the organization of the pigment-protein interactions. In the absence of detergents, a large blue shift of the fluorescence maxima from approximately 735 nm to approximately 685 nm indicates a disruption in light-harvesting subunit organization, thus revealing chlorophyll−protein interactions. The commonly used membrane protein-stabilizing detergents, N-dodecyl-β-D-maltoside and N-octyl-β-D-glucoside, only partially stabilized the approximately 735-nm complex with approximately 685-nm spectroscopic shift. However, prior to drying, addition of the peptide detergent acetyl- AAAAAAK at increasing concentration significantly stabilized the PS-I complex. Moreover, in the presence of acetyl- AAAAAAK, the PS-I complex is stable in a dried form at room temperature for at least 3 wk. Another peptide detergent, acetyl-VVVVVVD, also stabilized the complex but to a lesser extent. These observations suggest that the peptide detergents may effectively stabilize membrane proteins in the solid-state. These designed peptide detergents may facilitate the study of diverse types of membrane proteins
Alzheimer's disease: Clinical practice guideline
El Grupo de Trabajo de Neurología de la Conducta y Neurociencias Cognitivas de la Sociedad Neurológica Argentina publicó en 2006 la primera Guía de práctica clínica sobre la enfermedad de Alzheimer para su aplicación en nuestro medio y, eventualmente, en el resto de los países hispanoparlantes del Cono Sur. La Guía que hoy publicamos, mediante la revisión y actualización del estado actual del conocimiento sobre la enfermedad de Alzheimer y su manejo clínico y neurológico, provee a los profesionales los estándares surgidos de la medicina basada en la evidencia para una adecuada implementación de las conductas diagnósticas y terapéuticas a su alcance en nuestro medio.In 2006, the Argentine Neurological Society Research Group on Behavioral Neurology and Cognitive Neurosciences published the first Clinical Practice Guideline on Alzheimer's Disease to be consulted in Argentina and eventually in other countries in Latin America. The present Guideline is a review of the state of the art concerning the 2010 knowledge on the management of this disease. It provides physicians with the usual standards provided by evidence based medicine in order to reach the most adequate diagnostic and therapeutic measures at hand in our countries.Fil: Allegri, Ricardo Francisco. Sociedad Neurológica Argentina; Argentina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia. Instituto de Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Neurociencias; ArgentinaFil: Arizaga, Raúl Luciano. Sociedad Neurológica Argentina; ArgentinaFil: Bavec, Claudia V.. Sociedad Neurológica Argentina; ArgentinaFil: Colli, Liliana P.. Sociedad Neurológica Argentina; ArgentinaFil: Demey, Ignacio. Sociedad Neurológica Argentina; ArgentinaFil: Fernández, María C.. Sociedad Neurológica Argentina; ArgentinaFil: Frontera, Silvina A.. Sociedad Neurológica Argentina; ArgentinaFil: Garau, María L.. Sociedad Neurológica Argentina; ArgentinaFil: Jiménez, Julio J.. Sociedad Neurológica Argentina; ArgentinaFil: Golimstok, Angel. Sociedad Neurológica Argentina; ArgentinaFil: Kremer, Janus. Sociedad Neurológica Argentina; ArgentinaFil: Labos, Edith. Sociedad Neurológica Argentina; ArgentinaFil: Mangone, Carlos Antonio. Sociedad Neurológica Argentina; ArgentinaFil: Ollari, Juan A.. Sociedad Neurológica Argentina; ArgentinaFil: Rojas, Zenón Galeno. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; Argentina. Sociedad Neurológica Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salmini, Omar. Sociedad Neurológica Argentina; ArgentinaFil: Ure, Jorge A.. Sociedad Neurológica Argentina; ArgentinaFil: Zuin, Daniel R.. Sociedad Neurológica Argentina; Argentin
Quaternary glacial history of the Mediterranean mountains
Glacial and periglacial landforms are widespread in the mountains of the Mediterranean region. The evidence for glacial and periglacial activity has been studied for over 120 years and it is possible to identify three phases of development in this area of research. First, a pioneer phase characterized by initial descriptive observations of glacial landforms; second, a mapping phase whereby the detailed distribution of glacial landforms and sediments have been depicted on geomorphological maps; and, third, an advanced phase characterized by detailed understanding of the geochronology of glacial sequences using radiometric dating alongside detailed sedimentological and stratigraphical analyses. It is only relatively recently that studies of glaciated mountain terrains in the Mediterranean region have reached an advanced phase and it is now clear from radiometric dating programmes that the Mediterranean mountains have been glaciated during multiple glacial cycles. The most extensive phases of glaciation appear to have occurred during the Middle Pleistocene. This represents a major shift from earlier work whereby many glacial sequences were assumed to have formed during the last cold stage. Glacial and periglacial deposits from multiple Quaternary cold stages constitute a valuable palaeoclimatic record. This is especially so in the Mediterranean mountains, since mountain glaciers in this latitudinal zone would have been particularly sensitive to changes in the global climate system. © 2006 Edward Arnold (Publishers) Ltd
Liraglutide modulates GABAergic signaling in rat hippocampal CA3 pyramidal neurons predominantly by presynaptic mechanism
Effect of planting density on green ear yield of maize cultivars bred in different periods
Tocopherols and polyphenols in pumpkin seed oil are moderately affected by industrially relevant roasting conditions
Traditionally, pumpkin seed oil is obtained by pressing the seeds after a roasting pretreatment, at temperatures up to 150 °C. However, the appropriate temperatures and roasting times are under discussion. In this study, oils from seeds roasted at different temperatures (60–150 °C) are compared with oil from non‐roasted seeds. At higher roasting temperatures, lower roasting times are required to release the oil. Both, for tocopherols and phenolic compounds, no decreasing trend with the increasing roasting temperature are observed. In contrast, the oil from non‐roasted seeds have relatively low levels of tocopherols and phenolics and lacked the typical aroma. Levels of polyaromatic hydrocarbons (PAHs) are very low, ranging from not detected in oil from non‐roasted seeds to 13.8 μg kg−1 in the oil from seeds roasted at 150 °C. Therefore, the choice between the studied roasting conditions may depend rather on sensory evaluations than on the content of antioxidants or of PAHs. Practical Applications: The process of the production of virgin pumpkin oil is based on a thermal treatment of the ground seeds, favoring the separation of the lipid fraction, and giving a typical aroma of the roasted oil. Results of this research provide important information regarding the influence of roasting conditions on the quality and safety of the oil. Roasting pumpkin seeds increased the tocopherol and phenols content in the pumpkin oil, with no significant formation of PAHs. The information will be valuable and important for not only for the pumpkin oil production, but also for all the seeds submitted to a roasting treatment before extraction11912CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP406856/2013-32014/21252-
Progesterone receptors coupled to G-proteins in the plasma membrane of the fungus Rhizopus nigricans
Stratigraphic and morphologic evidence of the Holocene evolution of the Italian and Slovenian Waters (Northern Adriatic)
Il settore pi\uf9 settentrionale del Mare Adriatico, data la bassa pendenza del suo fondale, \ue8 un\u2019area
particolarmente sensibile alle variazioni del livello marino che, durante il Quaternario recente, hanno causato
importanti cambiamenti paleoambientali. Questa zona, situata tra l\u2019Istria, il Carso e la Pianura Veneto-
Friulana, \ue8 suddivisa tra le acque territoriali italiane, slovene e croate e, nel passato, tale frammentazione
amministrativa ha fortemente limitato gli studi. Nel maggio 2012 un team di ricercatori italiani e sloveni ha
effettuato il rilevamento della piattaforma slovena e italiana a bordo della nave oceanografica \u201cUrania\u201d.
Durante la crociera, denominata NAD2012, sono state acquisite circa 400 NM di profili sismo acustici
CHIRP-sonar e, nelle acque italiane, sono stati effettuati 10 carotaggi a gravit\ue0. I nuovi dati hanno consentito
di osservare in continuit\ue0 la transizione stratigrafica tra la pianura alluvionale friulana e la costa rocciosa
dell\u2019Istria. L\u2019assetto generale del Nord Adriatico era stato recentemente ricostruito grazie ai dati geofisici,
batimetrici e stratigrafici raccolti durante altre crociere effettuate per la realizzazione della Carta Geologica
dei Mari Italiani [Trincardi et al., 2011].
Nella piattaforma slovena lo studio delle morfologie del fondale \ue8 stato consentito da un DEM di
altissima risoluzione prodotto negli ultimi anni dalla societ\ue0 Harpha Sea tramite rilievi batimetrici
multibeam. Il DEM ha inoltre consentito la precisa pianificazione dei profili geofisici acquisiti durante la
crociera NAD2012.
L\u2019area tra Monfalcone e Pirano \ue8 caratterizzata da depositi marini olocenici fini, con uno spessore
massimo di 25 m presso Pirano che si assottiglia verso la costa friulana. Questo corpo sigilla la pianura
alluvionale che caratterizzava la zona fino a circa 9,5 ka cal BP [Covelli et al., 2006], quando l\u2019innalzamento
eustatico ha portato l\u2019Adriatico a sommergere il Golfo di Trieste. Lungo la costa orientale l\u2019antica pianura \ue8
contraddistinta da un complesso di dossi fluviali, con una direzione ENE-WSW, alimentati dalle valli che
drenano il Carso e l\u2019Istria. Invece, dalla piattaforma italiana fino alla baia di Capodistria, il DEM evidenzia
un percorso meandriforme inciso, parzialmente sepolto dal delta olocenico dell\u2019Isonzo e che corrisponde ad
un probabile percorso tardoglaciale di questo fiume. Anche al largo di Chioggia si riconosce un esteso
sistema idrografico inciso di et\ue0 post-LGM, successivamente riempito da depositi estuarini e lagunari,
probabilmente formato dal Po.
Bibliografia
Covelli, S., Fontolan, G., Faganeli, J., Ogrinc, N., (2006). Anthropogenic markers in the Holocene
stratigraphic sequence of the Gulf of Trieste (northern Adriatic Sea). Marine Geology, 230, 29-51.
Trincardi, F., Argnani, A., Correggiari, A.M., (2011). Note illustrative della Carta Geologica dei Mari
Italiani alla scala 1:250.000 \u2013 Foglio NL 33-7 Venezia. S.EL.CA., Firenze, 151 pp