16 research outputs found
Germline MSH2 and MLH1 mutational spectrum in HNPCC families from Poland and the Baltic States.
Peer reviewe
Acetalization of glycerol with acetone over mesoporous cellular foams (MCF) modified with niobium and tantalum
Trabajo presentado en el 8th International Symposium on Group Five Compounds, celebrado en Málaga (España) del 24 al 27 de junio de 2014.Peer Reviewe
Real-Time Raman monitoring and control of the catalytic acetalization of glycerol with acetone over modified mesoporous cellular foams
The acetalization of glycerol with acetone over modified mesoporous cellular foam materials has been widely investigated using in situ Raman spectroscopy during reaction. Mesoporous cellular foams (MCFs) modified by niobium or tantalum and (3-mercaptopropyl)trimethoxysilane (MP) followed by H2O2 treatment were used as catalysts in the acetalization of glycerol with acetone. The influence of the type of catalyst, which determines the solid texture and number of Brønsted acid sites, and different reaction parameters, such as reaction time, reaction temperature, glycerol/acetone ratio, and catalyst amount on acetalization reaction, were investigated. The results obtained in the characterization of the catalysts show that the materials obtained differ in the number of Brønsted acidic sites. Raman spectroscopy provides noninvasive insight during acetalization of glycerol with acetone in the presence of acid heterogeneous catalysts. The progress of the acetalization reaction was monitored following the variation in intensity of characteristic Raman bands and using chemometric analyses. The results obtained by real-time Raman monitoring confirm the mechanism proposed for the reaction, which proceeds via the formation of the 3-(2-hydroxypropan-2-yloxy)propane-1,2-diol intermediate, whose presence is confirmed by Raman spectroscopy. Under optimal reaction conditions, the 5-membered ring ketal 2,2-dimethyl-1,3-dioxolane-4-yl methanol (solketal) was obtained with the highest selectivity (99%). Raman monitoring enables real-time control of the reaction, thus enabling the optimization of reaction conditions for a more efficient reaction. Raman monitoring illustrates the reversibility of the reaction upon evaporation of acetone, even under reflux.The authors acknowledge funding from Spanish Ministry Project CTQ2011-13343-E. National Science Centre in Poland is acknowledged for financial support (Projects 2011/01/B/ ST5/00847, 2011/03/N/ST5/04772, and 2013/08/T/ST5/ 00010). K.S. thanks the Adam Mickiewicz Foundation in Poznan for scholarship in 2013.Peer Reviewe
Real-Time Raman Monitoring and Control of the Catalytic Acetalization of Glycerol with Acetone over Modified Mesoporous Cellular Foams
The acetalization of glycerol with
acetone over modified mesoporous
cellular foam materials has been widely investigated using in situ
Raman spectroscopy during reaction. Mesoporous cellular foams (MCFs)
modified by niobium or tantalum and (3-mercaptopropyl)trimethoxysilane
(MP) followed by H<sub>2</sub>O<sub>2</sub> treatment were used as
catalysts in the acetalization of glycerol with acetone. The influence
of the type of catalyst, which determines the solid texture and number
of Brønsted acid sites, and different reaction parameters, such
as reaction time, reaction temperature, glycerol/acetone ratio, and
catalyst amount on acetalization reaction, were investigated. The
results obtained in the characterization of the catalysts show that
the materials obtained differ in the number of Brønsted acidic
sites. Raman spectroscopy provides noninvasive insight during acetalization
of glycerol with acetone in the presence of acid heterogeneous catalysts.
The progress of the acetalization reaction was monitored following
the variation in intensity of characteristic Raman bands and using
chemometric analyses. The results obtained by real-time Raman monitoring
confirm the mechanism proposed for the reaction, which proceeds via
the formation of the 3-(2-hydroxypropan-2-yloxy)propane-1,2-diol
intermediate, whose presence is confirmed by Raman spectroscopy. Under
optimal reaction conditions, the 5-membered ring ketal 2,2-dimethyl-1,3-dioxolane-4-yl
methanol (solketal) was obtained with the highest selectivity (99%).
Raman monitoring enables real-time control of the reaction, thus enabling
the optimization of reaction conditions for a more efficient reaction.
Raman monitoring illustrates the reversibility of the reaction upon
evaporation of acetone, even under reflux
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Ventromedial prefrontal area 14 provides opposing regulation of threat and reward-elicited responses in the common marmoset.
The ventromedial prefrontal cortex (vmPFC) is a key brain structure implicated in mood and anxiety disorders, based primarily on evidence from correlational neuroimaging studies. Composed of a number of brain regions with distinct architecture and connectivity, dissecting its functional heterogeneity will provide key insights into the symptomatology of these disorders. Focusing on area 14, lying on the medial and orbital surfaces of the gyrus rectus, this study addresses a key question of causality. Do changes in area 14 activity induce changes in threat- and reward-elicited responses within the nonhuman primate, the common marmoset, similar to that seen in mood and anxiety disorders? Area 14 overactivation was found to induce heightened responsivity to uncertain, low-imminence threat while blunting cardiovascular and behavioral anticipatory arousal to high-value food reward. Conversely, inactivation enhanced the arousal to high-value reward cues while dampening the acquisition of cardiovascular and behavioral responses to a Pavlovian threat cue. Basal cardiovascular activity, including heart rate variability and sympathovagal balance, which are dysfunctional in mood and anxiety disorders, are insensitive to alterations in area 14 activity as is the extinction of conditioned threat responses. The distinct pattern of dysregulation compared to neighboring region area 25 highlights the heterogeneity of function within vmPFC and reveals how the effects of area 14 overactivation on positive and negative reactivity mirror symptoms of anhedonia and anxiety that are so often comorbid in mood disorders
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Differential Effects of the Inactivation of Anterior and Posterior Orbitofrontal Cortex on Affective Responses to Proximal and Distal Threat, and Reward Anticipation in the Common Marmoset.
Structural and functional abnormalities of the orbitofrontal cortex (OFC) have been implicated in affective disorders that manifest anxiety-related symptoms. However, research into the functions of primate OFC has predominantly focused on reward-oriented rather than threat-oriented responses. To redress this imbalance, the present study performed a comprehensive analysis of the independent role of 2 distinct subregions of the central OFC (anterior area 11; aOFC and posterior area 13; pOFC) in the processing of distal and proximal threat. Temporary inactivation of both aOFC and pOFC heightened responses to distal threat in the form of an unknown human, but not to proximal threat assessed in a discriminative Pavlovian conditioning task. Inactivation of the aOFC, however, did unexpectedly blunt conditioned threat responses, although the effect was not valence-specific, as conditioned appetitive responses were similarly blunted and appeared restricted to a discriminative version of the task (when both CS- and CS+ are present within a session). Inactivation of the pOFC did not affect conditioned responses to either proximal threat or reward and basal cardiovascular activity was unaffected by manipulations of activity in either subregion. The results highlight the contribution of aOFC and pOFC to regulation of responses to more distal uncertain but not proximal, certain threat and reveal their opposing contribution to that of the immediately adjacent medial OFC, area 14