Compositional synthesis of modular systems

Innovations in Systems and Software Engineering - In contrast to the breakthroughs in reactive synthesis of monolithic systems, distributed synthesis is not yet practical. Compositional approaches...     

Bimodal X‐ray and Infrared Imaging of an Organometallic Derivative of Praziquantel in Schistosoma mansoni

An organometallic derivative of praziquantel was studied directly in worms by using inductively coupled plasma‐mass spectrometry (ICP‐MS) for quantification and synchrotron‐based imaging. X‐ray fluorescence (XRF) and IR absorption spectromicroscopy were used for the first time in combination to directly locate this organometallic drug candidate in schistosomes. The detection of both CO (IR) and Cr (XRF) signatures proved that the Cr(CO)₃ core remained intact in the worms. Images showed a preferential accumulation at the worm's tegument, consistent with a possible targeting of the calcium channel but not excluding other biological targets inside the worm.     

Efficacy of waterborne polyurethane to prevent the enzymatic attack on paper‐based materials

The chemical and biological deterioration of paper‐based materials is mainly due to the degradation of its main component, the cellulose. However, paper also contains small amounts of organic and inorganic additives which might influence its biodegradability. To protect the paper‐based materials against various degradative agents, coating treatments with polymeric materials might be developed. In this study, the protective effect of commercial waterborne polyurethanes (WPU) against an enzymatic attack was investigated. Uncoated and coated samples with WPU of newsprint were subjected to degradation by enzymatic complexes (cellulosomes) produced by Clostridium cellulolyticum for different incubation times and then characterized using several analytical techniques (energy dispersive X‐ray fluorescence, scanning electron microscopy, nuclear magnetic resonance, Raman and infrared spectroscopy) with the aim to assess if waterborne polyurethanes can be used in paper conservation, looking at their efficacy against the biodegradation induced by enzymes. The selected waterborne polyurethanes showed a high effectiveness in the protection of paper‐based materials when they were submitted to the enzymatic attack. Indeed, their presence delayed the destruction of the cellulose matrix and the release of both soluble sugars and paper additives. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Role of Oxidative Stress in Refractory Epilepsy: Evidence in Patients and Experimental Models

Oxidative stress, a state of imbalance in the production of reactive oxygen species and nitrogen, is induced by a wide variety of factors. This biochemical state is associated with systemic diseases, and diseases affecting the central nervous system. Epilepsy is a chronic neurological disorder with refractoriness to drug therapy at about 30%. Currently, experimental evidence supports the involvement of oxidative stress in seizures, in the process of their generation, and in the mechanisms associated with refractoriness to drug therapy. Hence, the aim of this review is to present information in order to facilitate the handling of this evidence and determine the therapeutic impact of the biochemical status for this pathology.     

Aberrant Early in Life Stimulation of the Stress-Response System Affects Emotional Contagion and Oxytocin Regulation in Adult Male Mice

Results over the last decades have provided evidence suggesting that HPA axis dysfunction is a major risk factor predisposing to the development of psychopathological behaviour. This susceptibility can be programmed during developmental windows of marked neuroplasticity, allowing early-life adversity to convey vulnerability to mental illness later in life. Besides genetic predisposition, also environmental factors play a pivotal role in this process, through embodiment of the mother’s emotions, or via nutrients and hormones transferred through the placenta and the maternal milk. The aim of the current translational study was to mimic a severe stress condition by exposing female CD-1 mouse dams to abnormal levels of corticosterone (80 µg/mL) in the drinking water either during the last week of pregnancy (PreCORT) or the first one of lactation (PostCORT), compared to an Animal Facility Rearing (AFR) control group. When tested as adults, male mice from PostCORT offspring and somewhat less the PreCORT mice exhibited a markedly increased corticosterone response to acute restraint stress, compared to perinatal AFR controls. Aberrant persistence of adolescence-typical increased interest towards novel social stimuli and somewhat deficient emotional contagion also characterised profiles in both perinatal-CORT groups. Intranasal oxytocin (0 or 20.0 µg/kg) generally managed to reduce the stress response and restore a regular behavioural phenotype. Alterations in density of glucocorticoid and mineralocorticoid receptors, oxytocin and µ- and κ-opioid receptors were found. Changes differed as a function of brain areas and the specific age window of perinatal aberrant stimulation of the HPA axis. Present results provided experimental evidence in a translational mouse model that precocious adversity represents a risk factor predisposing to the development of psychopathological behaviour.     

Stabilization of meat suspensions by organogelation: A rheological approach

The stabilization of suspensions is a relevant issue in several industrial applications and particularly in the food area. Water‐based systems are widely studied and they are commonly stabilized by the addition of hydrocolloids (such as polysaccharides or proteins) whereas for oil‐based products less information is available. In this paper, oil‐based meat suspensions are investigated, and the addition of organogelators is proposed as a potential solution to the stability problems currently observed in some practical applications. Investigated suspensions are obtained by grinding a meat phase with vegetable oil blends, thus yielding products typically used in the traditional southern Italian diet as spreadable spicy sauces or as oil‐based dressings for pizzas. The effects of proposed additives were investigated by destabilizing the modified suspensions (by centrifugation) and comparing their rheological characteristics and oil loss to those of the unmodified systems (i.e., without addition of stabilizers). It was observed that both additives exert a stabilizing action, even if one of them (monoglycerides of fatty acids) is more effective than the other, even at a very low concentration. The adopted rheological approach has proved very useful to determine the type and amount of the proper organogelator to be used as an oil suspension stabilizer.     

Stabilizing effect of saccharides on bovine plasma protein: a calorimetric study

Bovine plasma proteins provide the needed amino acids for the growth and development of an organism. With the purpose of preserving the native structure, related with the protein functional properties, the oligosaccharide inulin was used as protective agent and was compared with glucose and sucrose, during freeze-drying. In the present study, the thermal stability of protein was investigated as a function of type of saccharide in a concentration range of 5-15% (w/v), and at different pHs. The effect of these variables on phase transition, thermal stability and miscibility was assessed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results of thermal protein properties (denaturation temperature and enthalpy), demonstrated that endothermic transition shifted to higher temperatures, being the stabilizing effect: inulin>glucose>sucrose. The thermal behavior suggests compatibility or interactions between the components of blends. In this way, the micrographs showed a homogeneous distribution of the different phases, corroborating the miscibility in the matrix. The unfolding process was irreversible and could be adequately described by a two-state model.     

Assessment of linear semiconductor amplifiers for upgrading WDM-PONs with wavelength reuse

In this work we have assessed the capacity of a linear semiconductor optical amplifier to compensate the fiber and component losses present in a wavelength division multiplexing passive optical network (WDM-PON) evolution from fiber-to-the-building (FTTB) to fiber-to-the-home access. The evaluation measurements confirm that the presence of a semiconductor optical amplifier placed at the entry of a group of optical network units that share the same wavelength channel can raise the loss budget that the link can tolerate in the fiber, compensating for the losses of a passive splitter up to a 1:16 division rate, allowing the upgrade of existing WDM-PON FTTB structures to make the fiber reach the final user's home.     

Graphene‐Based Nafion Nanocomposite Membranes: Enhanced Proton Transport and Water Retention by Novel Organo‐functionalized Graphene Oxide Nanosheets

Novel nanostructured organo‐modified layered materials based on graphene oxide carrying various hydrophilic functional groups (‐NH₂, ‐OH, ‐SO₃H) are prepared and tested as nanofillers for the creation of innovative graphene‐based Nafion nanocomposites. The hybrid membranes are characterized by a combination of analytical techniques, which show that highly homogeneous exfoliated nanocomposites are created. The pulsed field gradient NMR technique is used to measure the water self‐diffusion coefficients. Remarkable behavior at temperatures up to 140 °C is observed for some composite membranes, thereby verifying the exceptional water retention property of these materials. Dynamic mechanical analysis shows that hybrid membranes are much stiffer and can withstand higher temperatures than pure Nafion.