Incorporation of a tungsten Fischer-type metal carbene covalently bound to functionalized SBA-15

A metal Fischer carbene [(CO)₅WC(φ)OCH₂CH₃] was covalently linked for the first time to the silanol groups of the mesoporous channels of SBA15 by following two different synthetic anchoring routes. The first one goes through the reaction of the SBA15 mesoporous silica walls functionalized by aminopropyltriethoxysilane (APTES) with a tungsten carbene Wφ, while in the second approach a precursor synthesized by reacting APTES with the carbene Wφ is then anchored via a direct bond to the silanol groups in the interior pore channels of SBA-15.

This tethering is helpful to prevent the decomposition of the metallic complex. XRD, N₂ adsorption–desorption, and TEM analysis provide strong evidence that the mesoporous support structure retains its long-range ordering after the grafting process, despite a significant reduction of its specific surface area, pore-volume and pore-size. The chemical bonding of the tungsten carbene to the silanol groups of SBA-15 materials was studied with solid-state NMR spectroscopy. Both ¹³C MAS NMR and ²⁹Si CP MAS NMR spectra confirm the covalent linking of the carbene to the silica-pore system.     

N-Stearoyl-phosphatidylserine: Synthesis and role in divalent-cation-induced aggregation and fusion

N-Acylphosphatidylserines have been isolated from intact and injured tissues, but the participation of such acidic phospholipids in membrane aggregation and fusion has not been demonstrated. We have synthesized N-stearoylphosphatidylserine (NSPS) and examined divalent-cation-induced aggregation of NSPS-liposomes, which leads to membrane destabilization and fusion. The purified lipid was characterized by its chromatographic and spectroscopic (infrared and ¹H nuclear magnetic resonance) properties and by its chemical degradation pattern. Aggregation of unilamellar NSPS-liposomes was studied as a function of calcium and magnesium concentration. The ability of calcium and magnesium to induce vesicle aggregation is higher for phosphatidylserine (PS)-liposomes (threshold concentration 1.5 mM for calcium and 4.6 mM for magnesium) than for NSPS-liposomes (threshold concentration 2.8 mM for calcium and 6.6 mM for magnesium). The irreversibility of the aggregation reactions after adding EDTA suggests that vesicle fusion might occur in the presence of calcium and magnesium. Preliminary studies, based on mixing of both lipid and internal aqueous contents, show that fusion rather than aggregation of NSPS-liposomes occurs in the presence of calcium ions. The tendency of NSPS-liposomes to aggregate at higher cation concentrations than PS-liposomes suggests that N-acylation of phosphatidylserine protects the membrane against degenerative damage caused by aggregation and fusion.     

Design,Synthesis, and Biological Evaluation of Unconventional Aminopyrimidine,Aminopurine, and Amino‐1,3,5‐triazine Methyloxynucleosides

Herein we describe a class of unconventional nucleosides (methyloxynucleosides) that combine unconventional nucleobases such as substituted aminopyrimidines, aminopurines, or aminotriazines with unusual sugars in their structures. The allitollyl or altritollyl derivatives were pursued as ribonucleoside mimics, whereas the tetrahydrofuran analogues were pursued as their dideoxynucleoside analogues. The compounds showed poor, if any, activity against a broad range of RNA and DNA viruses, including human immunodeficiency virus (HIV). This inactivity may be due to lack of an efficient metabolic conversion into their corresponding 5′‐triphosphates and poor affinity for their target enzymes (DNA/RNA polymerases). Several compounds showed cytostatic activity against proliferating human CD4⁺ T‐lymphocyte CEM cells and against several other tumor cell lines, including murine leukemia L1210 and human prostate PC3, kidney CAKI‐1, and cervical carcinoma HeLa cells. A few compounds were inhibitory to Moloney murine sarcoma virus (MSV) in C3H/3T3 cell cultures, with the 2,6‐diaminotri‐O‐benzyl‐D ‐allitolyl‐ and ‐D ‐altritolyl pyrimidine analogues being the most potent among them. This series of unconventional nucleosides may represent a novel family of potential antiproliferative agents.     

Commercial Supported Gold Nanoparticles Catalyzed Alkyne Hydroamination and Indole Synthesis

Commercial gold nanoparticles supported on titanium dioxide (TiO₂) were found to be a highly efficient catalyst for alkyne hydroamination. Terminal alkynes could easily undergo intermolecular hydroamination with low catalyst loadings (0.2 mol% Au) under solvent‐free conditions. Indoles were efficiently synthesized using microwave heating through intramolecular hydroamination.

     

New anionic surface‐active agent derived from wool proteins for hair treatment

An anionic surface‐active agent derived from wool proteins was developed as an alternative to the anionic surfactants extensively used in shampoo formulations. The physicochemical properties of this new surface‐active agent prepared form wool proteins and its application for human hair treatments were studied. This new product could be considered a new mild anionic surface‐active agent, as evidenced by the results found by the evaluation of its physicochemical properties. The new wool anionic surface‐active agent was shown to be very substantive to hair, coating the fiber surface, giving rise to a significant improvement in the mechanical properties of the hair fibers, and providing a certain damage‐prevention effect on the hair. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Microwave-assisted polyol synthesis of sub-micrometer Y2O3 and Yb-Y2O3 particles for laser source application

Sub-micrometer powder (100–150 nm diameter) of Yb-doped yttrium oxide was obtained, for the first time, by microwave-assisted polyol (diethylene glycol, DEG) method. This method is based on fast and homogeneous increase of temperature, due to the microwave heating, and on addition of the hydrolysing agent (water) at high temperature. This promotes a fast nucleation followed by a controlled growth of nuclei. Different procedures were used to process the as-synthesized powders. In some cases washing by ultrapure water was used to dissolve nitrate and DEG by-products, this treatment allowed the use of a lower calcination temperature (150–200 °C less) to obtain the crystalline phase. Analysis of the calcined powder showed different levels of structures: from nanocrystal (10–15 nm), to primary particles (100–150 nm), to micrometer soft aggregates (2–4 μm). The microwave-assisted polyol method resulted an easy way to dope yttria with the desired amount of Yb³⁺. This work was carried out in order to prepare particles to be used as rare-earth doped Y₂O₃ and YAG polycrystalline transparent ceramic for laser source applications.     

Modification of the fat composition of the Iberian pig using Bacillus licheniformis and Bacillus subtilis

The aim of this work was to study the influence of a diet with probiotic bacteria on the lipid composition of different tissues from Iberian pigs. Cholesterol and fatty acid profiles were measured in liver, subcutaneous fat, and Serratus ventralis muscle samples. Feeding Iberian pigs a mixture of probiotic microorganisms for 45 days prior to slaughter affected the tissue composition. The feeds of the control and probiotic groups were identical except for the added Bacillus licheniformis and Bacillus subtilis (1.28 × 10⁹ cfu/kg feed) in the feed of the probiotic group. The diet with probiotics significantly affected the fatty acid profile of liver, subcutaneous fat and Serratus ventralis muscle samples, but no significant differences were found for the cholesterol content. The livers of the probiotic group contained lower levels of n‐6 fatty acids and higher levels of n‐3 fatty acids. The subcutaneous fat contained lower levels of n‐6 fatty acids. Serratus ventralis muscles from the probiotic group contained a significantly higher percentage of oleic acid than those of the control group. Practical applications: This study deals with the effect of the addition of probiotic bacteria to the diet of pigs on both the cholesterol and fatty acid content. B. subtilis and B. licheniformis can be used in pig feed (Regulation EC no. 2148/2004), but there are no studies about their effects on fresh meat or other tissues, particularly regarding the fat composition. Thus, it is interesting to study how feeding these microorganisms affects the different tissues. Including these microorganisms in the basic diet could serve as a strategy to modify the fat composition and to obtain healthier products from pigs.     

New Blended Cement from Polishing and Glazing Ceramic Sludge

Waste generated in ceramic tiles manufacturing is not usually recycled inside the productive plant, but rather disposed to landfill. This paper deals with ceramic residues from polishing and glazing processes, as constituents for innovative blended cements. New binders made up of 75% CEM I 52.5 R and 25% residues were chemically, physically, and mechanically characterized with reference to EN 197-1 requirements and the results compared with ordinary Portland cement. Mechanical strength development and microstructure of the relevant mortar have been investigated up to 90 days of curing, and the behavior of polishing and glazing residues as cement constituents is reported.