Two-Dimensional protein map of Saccharomyces cerevisiae: Construction of a gene–protein index

This publication marks the beginning of the construction of a gene–protein index that relates proteins which are resolved on the two-dimensional protein map of Saccharomyces cerevisiae with their corresponding genes. We report the identification of 36 novel polypeptide spots on the yeast protein map. They correspond to the products of 26 genes. Together with the polypeptide spots previously identified, this raises to 41 the number of genes whose products have been identified on the protein map. The proteins identified here are concerned with four major areas of yeast cellular physiology: carbon metabolism, heat shock, amino acid biosynthesis and purine biosynthesis. Given the molecular weight and isoelectric point of the identified proteins, and the codon-usage bias of the corresponding genes, it can be estimated that 25 to 35% of all the soluble yeast proteins are detectable under the labelling and running gel conditions used in this study.     

A poly(cyclopentadithiophene) matrix suitable for electrochemically controlled DNA delivery

A conducting polymer is tested for DNA delivery trials. The conducting matrix used is successful for electrochemical delivery of DNA accumulated by covalent immobilization. The electrochemical process consists of the reduction of arylsulfonamide moieties, which occur as linker groups. The specific design of the polymer allows the electronic properties to be promoted, making available the cleavage potential in physiological media. The amount of DNA released from a modified platinum electrode is investigated by quartz crystal microbalance. The released species used to prove the system performance are long sequences of DNA strands, which are amplified by PCR after liberation and identified by electrophoresis migration.     

Seasonal and diel distributions of denitrifying and bacterial communities in a hypersaline microbial mat (Camargue, France)

Changes in spatio-temporal distribution of bacterial and denitrifying communities were qualitatively studied in a microbial mat from Camargue (France). During a diel and a seasonal cycle, patterns of 16S rRNA and nitrite reductase genes (nirS and nirK) were compared by denaturing gradient gel electrophoresis (DGGE). Statistical analysis of DGGE profiles showed a significant seasonal shift in the community structure of the nirS-containing bacteria with a winter superficial population that extended in summer, whereas the nirK-containing bacteria seemed more affected by vertical gradients rather than by month-to month-changes. Denitrifying activities remained stable during these sampling times. The bacterial community at the surface of the mat also changed according to season, but appeared stable over a day. Finally, during a diel cycle nirK populations were localized in zones with large fluctuations of environmental parameters (oxygen, pH, and sulfur levels) while nirS populations seemed more restricted to the permanent anoxic layer of the microbial mat.     

Direct Synthesis of Partially Modified 2′‐O‐Pivaloyloxymethyl RNAs by a Base‐Labile Protecting Group Strategy and their Potential for Prodrug‐Based Gene‐Silencing Applications

An original and straightforward synthesis of partially modified 2′‐O‐pivaloyloxymethyl‐substituted (PivOM‐substituted) oligoribonucleotides has been achieved. The aim of this 2′‐enzymolabile modification was to enhance nuclease stability of RNA and transmembrane transport. To make these modified RNAs easily available we developed a base‐labile protecting group strategy with standard protections for nucleobases (acyl) and phosphates (cyanoethyl), a Q‐linker and two different acetalester protection groups for 2′‐OH: propionyloxymethyl (PrOM) and PivOM. Interestingly, orthogonal deprotection conditions based on anhydrous butylamine in THF were found to remove propionyloxymethyl groups selectively, while preserving PivOM groups. Duplex stability, circular dichroism studies and nuclease resistance, as well as the ability to inhibit gene expression of modified 2′‐O‐PivOM RNA, were evaluated.     

Hybrid sol gel coating: A solution to prevent interactions between plasticized poly(vinyl chloride) and injectable drugs?

During the infusion of drugs with medical devices in plasticized poly(vinyl chloride) (PVC) release of plasticizers in the injectable solution and/or sorption of drugs on PVC may occur. Thus, patient safety and/or effectiveness of his therapy may be altered. In this study, we assessed the efficiency of a sol gel hybrid coating in preventing plasticizers' release (di‐(2‐ethylhexyl) phthalate (DEHP)) from PVC matrix and drug sorption into PVC. Remaining concentrations of drugs and plasticizer's concentration released after migration tests were assessed by liquid chromatography. Migration processes were followed by Fourier Transform Infrared – Attenuated Total Reflectance (FTIR‐ATR) spectroscopy and PVC surface changes were characterized by scanning electron microscopy (SEM). An evaluation of the mechanical properties of both uncoated and coated polymer was done. The hybrid coating protects PVC from plasticizers leaching. Sorption of drugs tested is also limited. However, the protection against plasticized PVC interactions isn't optimal, probably due to a degradation of the layer, as shown on SEM microphotographs. Furthermore improvements might provide an efficient barrier to advert risks impaired to PVC interactions, to provide patient care safety. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40145.     

New Intumescent Formulations of Fire-retardant Polypropylene—Discussion of the Free Radical Mechanism of the Formation of Carbonaceous Protective Material During the Thermo-oxidative Treatment of the Additives

The study compares five new intumescent additive mixtures and a carbonizing additive system with the ammonium polyphosphate–pentaerythritol system and additive formulations previously developed in laboratory in terms of fire retardancy of polypropylene-based formulations. The mixture of diammonium pyrophosphate and polyols produced by agrochemical industry xylitol and d-sorbitol (carbonization agent) are FR additive mixtures of interest for polyolefins. Moreover, the FR performance of the mixture of ammonium polyphosphate and polyamide-6 is reported. It is proposed that boric acid salts have to be developed as precursors for carbonization catalytic species. A thermal analysis study shows that FR performances and amounts of carbonaceous materials resulting from the thermal degradation of the additive mixtures are not related. An additional compilation of previous spectroscopic studies by the laboratory confirms that the intumescent process results from the formation of polyaromatic species and that FR systems maintain acidic species in a relatively high temperature range. An ESR study discusses the presence of π radicals in the protective coating formed using the additive systems. It provides information on the size of the carbonaceous structures in the materials and the presence of crystalline phases in the coating. Finally, the participation of free radicals in the formation of chemical bonds between the materials produced from the additives and the products of the degradation of the polymer is discussed.     

Mineralogical characteristics of electric arc furnace dusts

Reflected light microscopy can contribute important information regarding the mineralogy, mineral abundance, internal textures, sizes and shapes of particles in electric arc furnace (EAF) dusts. Scanning electron microscopy-energy dispersive spectroscopy and electron microprobe analysis are useful to determine the chemical compositions of the specific mineral grains in the dust particles. Furthermore, the mineralogical reactions that have taken place during the pyro-metallurgical treatment of EAF dusts and the mineralogy and textural character of those treated dust samples can be directly observed by reflected light microscopy. Such studies are useful in monitoring the efficiency of experimental pyrometallurgical treatment of EAF dusts which are designed to render them nonhazardous.     

New method for the purification of electrically charged polysaccharides

A new technique for the purification of pectins using protein (sodium caseinate) was developed and that could replace the process of ethanol which is currently used in industries. Commercial pectins were used as a model to verify the feasibility of the process and to define some important parameters. The results indicated that this purification technique is based primarily on the electrostatic interactions between these two polymers. The electrostatic interactions were strongly dependent on pH and salt concentration. The maximum pectin precipitation was obtained at pH 3.5. At this pH, the pectin acquires a negative charge while the protein is positively charged, promoting thus their attractions. Furthermore, the dissociation of the pectin–caseinates complex and the precipitation of caseinate at pH 4.6 were observed in the presence of salt. This method is very specific, suggesting that it could be used to purify some electrically charged polysaccharides.