High survival of frozen cells irradiated with gamma radiation

Cell storage in liquid nitrogen (LN) offers the most secure method of cell preservation even if cryopreserved cells are exposed to natural background of ionising radiation (IR). A lot of experiments have demonstrated that IR can induce damages in living cells, but only a little information regarding the response of cryopreserved cells is available. To investigate the effect of IR on frozen and unfrozen cells, peripheral blood mononuclear cells were directly irradiated at room temperature, then immediately frozen, or frozen and then irradiated in LN with different doses of gamma rays. After thawing, cells were incubated and death fraction was evaluated at different time points. Interestingly, the percentages of dead cells induced by IR gradually increased with both dose radiation and incubation time and were significantly lower for cells irradiated at -196°C than those irradiated at room temperature.     

Finite Element Modeling to Predict Cure-Induced Microcracking in Three-Dimensional Woven Composites

Realistic finite element models of 3D woven composites are constructed utilizing micro-scale numerical modeling to accurately represent the geometry of as-woven textile fabrics. The models are used to predict microcracking of carbon fiber / epoxy composites during resin curing. Numerical predictions of the stress concentration areas correlate well with the observations of microcracking obtained by micro-computed tomography.     

Increasing the antibacterial effect of lysozyme by immobilization on multi-walled carbon nanotubes

We report a facile strategy to obtain multiwalled carbon nanotubes (MWCNTs) functionalized with covalently bonded lysozyme. The functionalization procedure has been investigated by means of several techniques, including thermogravimetry, Raman spectroscopy, transmission electron microscopy, and cyclic voltammetry. A functionalization of about 1 lysozyme molecule every 4000 carbon atoms is obtained. The modified lysozyme-CNTs nanocomposite shows a significant increase of the antibacterial activity towards the Gram-positive S. aureus if compared with lysozyme in solution.     

A thermal treatment to increase the antioxidant capacity of natural phenols: catechin, resveratrol and grape extract cases

In this work, the critical role of temperature (the values assayed were 22, 37 and 60 °C), the chemical characteristics of the medium (ethanol, methanol and water) and the reaction time on the antiradical capacity of phenolic systems was studied. An initial increase and a following decrease in antiradical activity were observed for catechin and resveratrol solutions in all solvents assayed. The maximum antioxidant activity was higher and occurred in a shorter time as the storage temperature was increased or the solvent polarity was decreased. The maximum values of the latter variable in the catechin and resveratrol cases (reaching an antiradical activity value higher than 50% in comparison with the initial one) were detected when oxidation was carried out in ethanol at 60 °C after 6 and 24 h of storage, respectively. Such variations were due to different reaction pathways. In fact, oxidative polymerization and oxidative formation of hydroxyl groups were found to be responsible for the enhancements of antiradical activity in catechin and resveratrol, respectively. A similar trend with variations of temperature in the different media was also observed in the grape extract case. The evolution of antiradical activity was followed by high-performance liquid chromatography analysis, which pointed to the phenol polymerization of the monophenols detected (catechin, gallic acid, epicatechin and quercetin) as mainly responsible for such variations.     

Optical absorption spectrum of rotated trilayer graphene

Using ab initio calculations we have studied the optical linear response of different configurations of twisted trilayer graphene systems. We have found that when one of the outer layers is rotated the system shows an angle-dependent optical spectrum as its twisted bilayer counterpart; however, in this case there are two absorption peaks located in the visible range of the spectrum and one more in the intermediate infrared range for large relative rotation angles. When two layers are rotated the spectrum exhibits only two absorption peaks in the visible range revealing information about the two relative rotation angles between the layers in the structure. All these absorption peaks in the visible range shift to the intermediate infrared range for small angles.     

Real Time PCR for the detection and discrimination of cereal contamination in gluten free foods

Real-time PCR methods, using melting curve analysis for product identification, were established for the specific discrimination of wheat, rye, barley and oats in food samples. Specific primers targeting cereal prolamin genes were chosen for the amplification. The lengths of the amplicons varied between 104 and 181 base pairs and the melting point between 81.2 and 85.0 °C. The specificity of the wheat PCR was shown for spring and autumn wheat but also for durum wheat, spelt wheat and kamut. The methods were applied for final food products and for detection of toxic cereal contamination in oat samples. The results of the analysis were compared with those obtained with an established enzyme immuno assay for gluten analysis. The PCR methods give a good correlation with the protein assay and are rapid and sensitive. The PCR methods can thus be used as confirmatory methods in food analysis of gluten-free and naturally gluten-free foods.     

An Adaptive Questionnaire generation using <Emphasis Type="Italic">learning from fuzzy</Emphasis> and <Emphasis Type="Italic">post clustering</Emphasis> of customers responses: an Experience with Communication Products

A central problem in marketing is the clear understanding of consumer’s choice or preferences. Designing questionnaires and then analyzing the answers of probable customers can achieve this. The traditional approach in the marketing analysis has been the designing of non-adaptive questionnaires, questionnaires that are predetermined and not at all influenced by respondent’s answers. The aim of this paper is to design a questionnaire that is influenced by respondent’s answer through implementation of soft computing and approximate reasoning methodologies. The learning of particular pattern on respondent’s fuzzy responses has also been envisaged in the post-survey (Post-conjoint) and further better clustering of choices and segregation is accomplished. The module of learning and finer clustering from respondent’s choice pattern could be a major pre-requisite for construction of adaptive questionnaires. Further extensions of the soft computing methods for product recommender system have also been mentioned for the design of adaptive questionnaire.