Integrated mass spectrometry approach to profile proanthocyanidins occurring in food supplements: Analysis of Potentilla erecta L. rhizomes

Potentilla erecta (L.) is known for the high concentration of proanthocyanidin oligomers (PAs) in its underground parts. The use of its preparations as food supplements and the lack of chemical–analytical studies concerning with an efficient chromatographic separation procedure for these compounds led us to develop a strategy to profile PAs occurring in this species.     

New generation of loxP‐mutated deletion cassettes for the genetic manipulation of yeast natural isolates

In this work, we developed molecular tools used in standard laboratory yeast strains, such as the cre–loxP system, so that they can be used with natural and industrial prototrophic yeast species. We constructed a new generation of dominant cassettes, with mutated loxP sites (loxLE and lox2272) and selectable drug markers, to create heterothallic strains and auxotrophic mutants without incurring in the risk of generating chromosomal rearrangements. We have shown that our newly developed loxLE–hphNT1–loxRE and lox2272–natNT2–lox2272 gene‐disruption cassettes can be present in the yeast genome together with the widely used loxP–marker gene–loxP cassettes without any recombination between the lox sequences. Moreover, we also developed a new phleomycin‐resistant Cre‐expressing vector (to excise multiple markers simultaneously) and two new standard loxP deletion cassettes containing hygromicin B and cloNAT as selecatable markers. To validate these cassettes, we created heterothallic auxotrophic S. cerevisiae strains, without the risk of incurring gross chromosomal rearrangements, and we showed an example of a fitness study of intraspecific hybrids deriving from parents with different adaptations to carbon‐limited resources. Copyright © 2010 John Wiley & Sons, Ltd.     

Crosslinking and grafting ethylene vinyl acetate copolymer with accelerated electrons in the presence of polyfunctional monomers

In this study, we have studied the effects of polyfunctional monomers (PFMs) on physical properties of ethylene vinyl acetate (EVA) copolymer crosslinked with electron beam (EB) or peroxides. The PFMs used were triallylcyanurate, triallylisocyanurate, trimethylolpropane trimethacrylate, zinc diacrylate, and ethylene glycol dimethacrylate. Using PFMs has led to (1) optimum cure time t ₉₀ decrease from 19′25″ to 17′30″–18′45″, (2) scorch time increase from 2′ to maximum 3′45″, (3) increasing the crosslink density of peroxide or EB-cured systems by increasing the efficiency of productive radical reactions. The most efficient PFM for EVA copolymer blends has been triallylisocyanurate. Tensile strength and tear strength of samples crosslinked with EB for all irradiation doses are significantly better than those obtained for samples crosslinked with peroxides (differences up to 190%). The results show that EB irradiation gave the best results     

Immunochemical or fluorescent labeling of vesicular subcellular fractions for microscopy imaging

We describe a procedure for the labeling of membranous vesicular purified subcellular fractions, to image them, typically by confocal laser scanning microscopy. Being intracellular organelles, these fractions, once purified cannot be attached to glass slides as for cells. Fractions are labeled “in batch” without prior embedding or freezing. Each labeling step performed by passages of resuspension/centrifugation is followed by washings. Then samples are dispersed on the glass slides. Mammalian retinal rod outer segment disks, intact brain stem myelin vesicles, and brain synaptosomes were chosen, as these subcellular fractions can be purified by well established procedures. These fractions were immunolabeled with specific antibodies. Moreover, by the earlier procedure, we show that the mitochondrial vital membrane potential probe MitoTracker Deep Red 633 stains myelin vesicles and rod disks before fixation, consistently with our previous reports of a respiring capacity of these membranes. Therefore, the technique seems adequate to become an instrument to study the structure and the function of these and other subcellular fractions. Microsc. Res. Tech. 73:1086–1090, 2010. © 2010 Wiley‐Liss, Inc.     

Organometallic Pt(II) containing polymer as silver protection against sulfide tarnishing

In this work, the use of a film of an organometallic polymer, namely Pt‐DEBP, has been tested for the selective capture of sulfides with the aim of protecting silver object. Ag foils were exposed to different environmental conditions in the presence of Pt‐DEBP films. Scanning electron microscopy, energy dispersive spectrometry, and colorimetric studies allowed to assess that the polymeric layer selectively captures H₂S, preventing the tarnishing of the silver substrate over a period at least of 2 months, without any manipulation of the sample. This approach open new perspectives for the prevention of aging effects on silver objects of artistic interest, for which cleaning or coating procedures should be avoid. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

13C NMR study of presence of uron structures in amino adhesives and relation with wood‐based panels performance

The chemical structure of amino adhesives produced by the strongly acid process was investigated by ¹³C Nuclear Magnetic Resonance spectroscopy. This technique allowed the identification of functional groups and its quantitative determination. Concentration of cyclic polymeric structures (urons) was shown to be related with adhesive performance and with particleboard physico‐mechanical properties and formaldehyde content. Higher urons concentration presented lower viscosity and reactivity. Particleboards produced with resins with lower urons concentration presented lower formaldehyde content, but also lower internal bond strength. Wood‐based panels produced fulfilled E1 class requirements for formaldehyde emissions, indicating that strongly acid process is an alternative to the conventional alkaline–acid process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4500–4507, 2013     

Risk of human fatality in building fires: A decision tool using Bayesian networks

The Netherlands is the most densely populated country of the European Union, which makes space very expensive. This leads to increasing complexity of the cities’ layout and other public spaces, together with a large number of people involved. Authorities would like to know whether new and innovative building designs ensure an appropriate level of safety of people in case of fire, before the accident happens, and to be prepared for the so-called “low probability–high consequences” accidents. Therefore, they need a tool to help them estimate the extent of a fire in a building, given any combination of possible conditions and any unexpected course of events during an emergency. This paper discusses the possibility of using Bayesian belief nets for this task. Using this approach, the people in charge can take decisions at different stages of the design process of a building regarding the location, the structure, the loading of the building, the types of fire protection systems inside the building, as well as the characteristics of the fire brigade that fights the possible fire. In the current study, usefulness of the approach is investigated using a small example. This will show the feasibility of the approach for the Netherlands situation and give authorities involved confidence that building a large comprehensive model would fulfil their needs for a support tool in the planning process. The effort to gather real data therefore was restricted as demonstration of fitness for purpose was the primary objective.     

Experiences in building a Grid-based platform to serve Earth observation training activities

Earth observation data processing and storing can be done nowadays only using distributed systems. Experiments dealing with a large amount of data are possible within the timeframe of a lesson and can give trainees the freedom to innovate. Following these trends and ideas, we have built a proof-of-the-concept platform, named GiSHEO, for Earth observation educational tasks. It uses Grid computing technologies to analyze and store remote sensing data, and combines them with eLearning facilities. This paper provides an overview of the GiSHEO's platform architecture and of its technical and innovative solutions.