1,721,098 research outputs found
The four subunits of rabbit skeletal muscle lactate dehydrogenase do not exert their catalytic action additively
No full textOligomeric enzymes containing multiple active sites are usually considered to perform their catalytic action at higher rates when compared with their monomeric counterparts. This implies, in turn, that the activity performed by different holoenzyme subunits features additivity. Nevertheless, the extent of this additivity occurring in holoenzymes is far from being adequately understood. To tackle this point, we used tetrameric rabbit lactate dehydrogenase (rbLDH) as a model system to assay the reduction of pyruvate catalysed by this enzyme at the expense of beta-NADH under pre-steady-state conditions. In particular, we observed the kinetics of reactions triggered by concentrations of beta-NADH equimolar to 1, 2, 3, or all 4 subunits of the rbLDH holoenzyme, in the presence of an excess of pyruvate. Surprisingly, when the concentration of the limiting reactant exceeded that of a single holoenzyme subunit, we observed a sharp slowdown of the enzyme conformational rearrangements associated to the generation and the release of L-lactate. Furthermore, using a model to interpret the complex kinetics observed under the highest concentration of the limiting reactant, we estimated the diversity of the rates describing the action of the different rbLDH subunits
Effects of a new packaging on the shelf-life of almond cookies
No full textTo prolong the shelf-life of almond cookies the AA have proceeded to the packaging of the product (with and without sugar in surface) in polistyrene/poliethylene settled with flexible film in air and modified atmosphere. During the conservation period (50 days) physical-chemical, micro-biological, and sensorial controls have been carried out. The analysis of the Principal Components has underlined the difference between samples with and on the basis of the first 2 PC positively correlated with the sensorial parameters and negatively with the rheological softness. According to discriminant analysis the 62% of samples were correctly classified
Le forme della conoscenza: test diagnostici preliminari e verifiche a restauro in corso d’opera / Forms of Knowledge: Preliminary diagnostic testing and investigations during the restoration process
No full textIl restauro persegue l’obiettivo di preservare il carattere autentico dell’architettura storica e le sue stratificazioni, rendere distinguibili le aggiunte e proporre un uso compatibile. Questa posizione culturale ha sostenuto l’intervento condotto sui resti dell’ex chiesa Madre a Santa Margherita di Belice in Sicilia, distrutta da un terremoto nel 1968, che oggi ospita il Museo della Memoria. Esclusa l’iniziale proposta di ripristino delle parti crollate, il progetto di restauro è stato indirizzato verso la conservazione critica del frammento autentico, la reintegrazione della fabbrica lacunosa e la ridefinizione dell’involucro architettonico con componenti strutturali dal carattere potenzialmente reversibile. Una campagna scientifica di test diagnostici ha guidato il consolidamento delle finiture a stucco, e le parti reintegrate sono state realizzate con materiali e tecniche attuali. La nuova copertura consente alla luce di entrare all’interno della ex chiesa attraversando uno schermo di listelli lignei che, idealmente, ripropone la forma della volta crollata. Il volume restituisce un quadro completo delle riflessioni e delle fasi operative legate alla definizione del progetto di restauro, agli approfondimenti scientifici, alla proposta di riuso e al cantiere d’intervento.The aim of restoration is to preserve the authenticity of historic architecture and its stratifications, making the additions clearly distinct and proposing a compatible use. This cultural position is behind the intervention carried out on the remains of the former Mother Church in Santa Margherita di Belice in Sicily, destroyed by an earthquake in 1968, which today houses the Remembrance Museum. After ruling out the first idea of rebuilding the parts that had collapsed, the restoration project steered towards the critical conservation of the genuine fragments, the reintegration of the incomplete structure and the redefinition of the architectural envelope with new potentially reversible structural components. A scientific campaign of diagnostic investigations guided the consolidation of stucco finishes, and the reintegrated parts were realized with current materials and techniques. The new roof lets the light enter the former church through a screen of wooden slats that recreate ideally the shape of the collapsed vault. This book presents all the thoughts and the main aspects of the operational phases related to the restoration project, the scientific insights, the reuse proposal and the intervention site.La restauración persigue el objetivo de preservar el carácter auténtico de la arquitectura histórica y sus estratificaciones, haciendo que las adiciones sean distinguibles y propongan un uso compatible. Esta posición cultural apoyó la intervención llevada a cabo en los restos de la antigua Iglesia Madre en Santa Margherita di Belice en Sicilia, destruida por un terremoto en 1968, que hoy alberga el Museo de la Memoria. Excluyendo la propuesta inicial para restaurar las partes colapsadas, el proyecto de restauración se dirigió hacia la conservación crítica del fragmento auténtico, la reintegración de la fábrica incompleta y la redefinición de la envoltura arquitectónica con componentes estructurales de carácter potencialmente reversible. Una campaña científica de pruebas de diagnóstico ha guiado la consolidación de los acabados de estuco y las partes reintegradas se han realizado con los materiales y las técnicas actuales. El nuevo techo permite que la luz entre a la antigua iglesia a través de una pantalla de listones de madera que, idealmente, vuelve a proponer la forma de la bóveda colapsada. El volumen ofrece una imagen completa de las reflexiones y fases operativas relacionadas con la definición del proyecto de restauración, los conocimientos científicos, la propuesta de reutilización y el sitio de intervención
Indagini diagnostiche nella ex Chiesa Madre di Santa Margherita di Belice
No full textIl testo descrive l’applicazione sperimentale di una nuova metodologia analitica diagnostica basata sullo svolgimento sinergico delle indagini diagnostiche non distruttive. La ricerca si pone l'obiettivo di caratterizzare lo stato di conservazione delle superfici nella ex Chiesa Madre di Santa Margherita di Belice attraverso l'elaborazione della diagnosi che risulti specifica per la redazione del progetto di conservazione e la direzione del relativo cantiere d’intervento. L'applicazione scientifica è svolta nell'ambito della sperimentazione della nuova Metodologia T.R.U.E. e del relativo software
La distribuzione degli amminoacidi liberi quale criterio per accertare l’origine geografica delle arance bionde e pigmentate
No full textIl presente lavoro si prefigge l’obiettivo di individuare dei marker in grado di distinguere l’origine geografica delle arance siciliane e calabresi, che insieme costituiscono oltre il 90% dell’intera produzione italiana. La distribuzione degli acidi idrossicinnamici nei succhi si è rivelata efficace per discriminare l’origine geografica delle varietà a polpa rossa, ma è inidonea per discriminare quelle a polpa bionda. Quale criterio diagnostico è stata analizzata e discussa la distribuzione degli amminoacidi liberi nei succhi. Pertanto, nel corso dell’annata arancicola 2007-2008, sono stati prelevati presso diverse aziende agrumicole siciliane e calabresi 70 differenti campioni di arance di varietà bionde e pigmentate. Sono stati determinati 19 amminoacidi con la metodologia
HPLC con rivelatore a fluorescenza, previa derivatizzazione. Gli amminoacidi sono stati quantificati mediante calibrazione esterna ed espressi in mmol/L, e i dati sperimentali sono stati elaborati con trattamenti statistici descrittivi e multivariati. Il contenuto di arginina nei succhi può essere considerato un marker di varietà e di origine geografica, ma anche altri amminoacidi (acido aspartico, asparagina, serina, glicina e prolina) contribuiscono a discriminare nettamente le varietà bionde siciliane da quelle calabresi
Analisi, storia e restauro del Castello di Burgio (Palermo)
No full textIl contributo presenta le fasi di ricerca svolte per il rilevamento, l'indagine conoscitiva, l'analisi delle forme di degrado e dissesto del bene architettonico, e propone le tecniche di restauro e la strategia per il riuso.The article exposes the research phases carried out for the survey, the cognitive investigation, the analysis of the forms of decay and instability of the ancient castle, and proposes the restoration techniques and the strategy for reuse
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Reply: “Indications, outcomes, and complications of neoumbilical reconstruction: A systematic review”
No full textGeographical origin assessment of orange juices by comparison of free aminoacids distribution
No full textScientific research nowadays makes considerable efforts for the setting of methods for the assessment of the geographical origin of food products. Very few studies have focused on orange juices, aiming at differentiating the origin of samples coming from very far areas of the world, while no research has attempted to find suitable markers able to ascertain the geographical origin of orange juices produced in neighbouring regions, such as those of south Italy, where more than 90% of the entire Italian production is concentrated. Past studies showed that the distribution of hydroxycinnamic acids in juices is effective for the origin assessment of blood orange varieties, but unsuitable for blonde ones. In the present, we have assessed and discussed the distribution of free aminoacids in orange juices. Seventy samples of the blood and blonde varieties were collected from different citrus farms located in Sicily and Calabria throughout the season 2007-2008. Nineteen aminoacids were determined, subject to prior derivatization, by HPLC with fluorimetric detector. Aminoacids were quantified by external calibration and expressed as mmol L-1 and experimental data were elaborated by statistical analysis. The total free aminoacid content, as well as the level of proline, arginine, aspartic acid, asparagine, serine and glycine can be considered as a markers of geographic origin, contributing to sharply discriminate blonde Sicilian orange varieties from Calabrian ones
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