102,176 research outputs found
Equilibrium and growth forms of sucrose crystals in the {h0l} zone. II. Growth kinetics of the {101} d-form
No full textThe aim of the work is to assess the steady growth morphology of the zone of sucrose crystals by measuring the growth rates of its individual faces. Experimental results on the kinetics of (101)-d form are presented and discussed in this paper. The novelty consists in the shape of growth isotherms, which, at the moment, can be interpreted only qualitatively. Some possible parametrs determining this shape are considered throughout
Equilibrium and growth forms of sucrose crystals in the {h0l} zone. 1. Theoretical treatment of {101}-d form
No full textObserved (h0l) growth forms of the sucrose crystal are compared with calculated ones, on the basis of attachment energy plots. Agreement is found for all forms only if a modification of character of the ( 101)-d face is taken into considation. Calculation of equilibrium and growth forms have been carried out using two potential foe dispersion and bond energy respectively. The same method is applied for studying the spiral growth shape on the (101) face and its field of validity is discussed: a low driving force values, the attachment energy at the steps is the relevant energy, determining the shape of spirals on (101) face of sucrose
La stampa di traduzione nel collezionismo inglese tra la fine del Settecento e gli inizi dell’Ottocento. Il caso di Francesco Bartolozzi: un italiano a Londra nel fondo Douce
No full textLo scopo del contributo è quello di fornire un resoconto parziale su alcune stampe di traduzione del vasto repertorio cartaceo di Francesco Bartolozzi, volendo integrare le ricerche fin qui condotte nei campi fondamentali della letteratura artistica, del disegno riproduttivo e del collezionismo; tali stampe risultano più rappresentative di altre nel lascito di Douce per le loro implicazioni storico-critiche, in un momento importante della Storia dell'arte, del gusto e del collezionismo inglese che, verso la seconda metà del Settecento e gli inizi dell'Ottocento, testimonia il grande interesse per l'Italia e la sua arte e vede il formarsi delle grandi collezioni di Old Masters, come prodotto culturale sulla scia dell'esperienza del Grand Tou
Sucrose crystal growth kinetics in the presence of some peculiar impurities
No full textThe effect of some impurities on the growth rate of the single faces of sucrose crystals together with its morphology variation, is studied. The kinetic data are qualitatively explained on the grounds of the direct interaction between the impurities and the structure of the different faces of sucrose crystals
Sostanze coloranti nel cristallo di saccarosio
No full textCristalli di saccarosio ottenuti in presenza di varie sostanze coloranti sia in laboratorio che in scala pilota hanno mostrato l'importanza decisiva della velocità di crescita per l'inclusione di queste nelle loro facce (110), (111), (011), (11-1): quanto più è rapida la crescita, tanto maggiore la colorazione acquisita dai relativi settori
La colorazione dei cristalli di zucchero in funzione di alcuni parametri della cristallizzazione industriale. Sucrose crystals colour as a function of some industrial crystallization parametrs
No full textSulla base dei risultati raggiunti in una precedente ricerca, che aveva individuato nella cinetica di accrescimento la principale causa di inglobamento di sostanze coloranti nei cristalli di saccarosio, gli Autori proseguono la sperimentazione allo scopo di poter trasferire le loro conclusioni alla pratica della cristallizzazione industriale
Hodgkin lymphoma presenting with spinal cord compression: A systematic review and clinical analysis
No full textQuantitation of the roles played by the main determinants of meal glucose tolerance in patients with type 1 diabetes on insulin pump therapy
No full textThe relative roles of each component of the glucose (G)/insulin (I) system in determining after meal hyperglycemia in type 1 diabetes (T1DM) are still under debate. Metabolic Control Analysis (MCA) quantifies the control exerted by each component of a system on a variable of interest, by computing the relevant coefficients of control (CCs), which are systemic properties. We applied MCA to a mixed meal test (MMT) to quantify the CCs of the main components of the G/I system on G concentration. 7 T1DM patients (age: 41±5 yrs; BMI: 24.3±0.6 kg.m-2; HbA1c: 7.9±0.2%) on insulin pump therapy and continuous glucose monitoring (CGM) participated in 2 separate studies:1. A standard euglycemic insulin (240 pmol.min-1.m-2 BSA) clamp (duration: 120 min, M value: 1209±169 μmol.min-1.m-2 BSA) including CGM; 2. A standardized MMT (292 Kcal; 38.9 g complex CHO, 8.9 g lipids, 14 g proteins) with plasma I/G monitoring and CGM. With our modeling strategy, data from the clamp and from the MMT are sufficient to build an in silico replica (“virtual patient”) of the G/I system of each patient (CGM included), which behaves as the real patient during the MMT. Virtual patients were used to compute the CCs of plasma G and G measured by CGM.
During the MMT, plasma glucose and insulin peaked at (time ) and at (time ), respectively, and leveled at and at time 300’. The CCs exerted by some primary components of the G/I system on plasma G are summarized in the Table. Size of s.c. insulin depot had the highest CCs (p<0.01 or less vs other CCs). The CCs of meal insulin bolus peaked at 300’ (p<0.01 vs CCs at 30’-60’). The CCs of CHO transit time across the gut, including also absorption, was relevant in the first half and became negligible in the second half of the meal (p<0.01 CCs 180-300’ vs CCs 30’-120’). The CCs of CGM measured G were parallel, but not superimposable to CCs of plasma G, with some statistically significant difference (p<0.03-0.01) in CCs exerted by gut CHO transit time. Conclusions. In patients with T1DM on insulin pump therapy, after a mixed meal: 1. the most relevant factor of after meal G may be the size of subcutaneous insulin depot; 2. Pre-meal insulin bolus may be much more influential in the last 3 than in the initial 2 hours. These findings may have important implications for the development and the refinement of closed loop control of insulin delivery systems
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