Synthesis of Poly(vinylcatechols).

5-Vinyl-1,3-benzodioxole, 28, 3,4-dimethoxystyrene, 29, 2,3-dimethoxystyrene, 30, 6-vinyl-1,4-benzodioxane, 31, and 4-vinyl-1,3-benzodioxole, 32 were synthesized and evaluated as poly(vinylcatechol) precursors. Four methods for preparing these monomers were explored. Dehydration of (alpha)-phenethyl alcohols was the best general procedure. Molecular weights as high as 95,000 in the case of poly(2,3-dimethoxystyrene) were achieved in the presence of free radical initiators. The kinetics of free radical polymerization of 2,3-dimethoxystyrene, 30, was studied dilatometrically and the overall rate of the reaction was found to be R(,p) + 2.53 x 10(\u27-2) mol/L min. Radical copolymerizations of monomers 30 and 31 with styrene and methyl methacrylate were examined. The reactivity ratios of monomer 30 (M(,1)) with comonomers (M(,2)) were r(,1) = 0.69, r(,2) = 0.92 and r(,1) = 0.92, r(,2) = 0.23 respectively. Q and e values of 30 were calculated to be Q(,1) = 1.89, e(,1) = -1.48 in the styrene system and Q(,1) = 1.91, e(,1) = -0.83 in the methyl methacrylate system. The copolymerization parameters of monomer 31 were r(,1) = 1.09, r(,2) = 0.96; Q(,1) = 1.33, e(,1) = -1.00 in the first system, and r(,1) = 0.45, r(,2) = 1.05; Q(,1) = 0.45, e(,1) = -0.47 for the second system. Polystyrene grafts onto poly(vinylcatechol) precursors were also prepared. Poly(vinylcatechol) precursors were further characterized by DTA and TGA techniques; they were found to be thermally stable and decompose only at a temperature range of 360-550(DEGREES)C. Chloromethylation of poly 31 only with chloromethyl ethyl ether and subsequent quaternization were successful. Lithiation of poly 28, poly 30, and poly 31 was studied. Bromination of each poly(vinylcatechol) precursor was thoroughly examined. Phthalimidomethylation, followed by hydrazinolysis of poly 29, poly 30, poly 31 and poly 32 afforded aminomethylated polymers. Sulfonation of poly 29, poly 30, and poly 31 with chlorosulfonic acid was possible and could produce water soluble polymers. Conditions for deblocking the protecting groups to liberate the catechol functions were established. Boron trichloride in the presence of dodecyl mercaptan was found to be the most effective cleaving reagent. Subsequent oxidation of poly(3- and 4-vinylcatechols) with ceric ammonium nitrate generated poly(benzoquinones). Redox potentials of the oxidation of catechol and poly(3-vinylcatechol) were estimated. At 23(DEGREES)C, the midpotentials were found to be 764 and 707 mV respectively. At 35(DEGREES)C, while one midpoint potential, 290 mV, was observed for the polymeric catechol, two midpoint potentials, 432 and 870 mV were detected for the catechol. (Abstract shortened with permission of author.)

Covalent Functionalizations of Poly(vinyl chloride) in Tune with Applications: An Update

Poly(vinyl chloride), PVC, stands as one of the best polymer candidates as far as polymeric materials are strongly sought for in our today's life. Functionalization of poly(vinyl chloride) (PVC) remains an appropriate way to fashion materials for specific applications. Molecules of different functionalities and sizes, up to macromolecules, were affixed to PVC matrix. Graft polymerization led to functionalized PVC with several properties for different applications. Some covalently modified PVCs, mainly with heteroatom-containing and cyclic molecules, proved to be biologically active and efficient scaffolds for enzyme/protein immobilization. Suitable functionalizations of PVC even ensured the effectiveness of the polymers as separative, ion-selective electrode, and fuel cell membranes. Some modifying agents incorporated in PVC made the polymeric materials convenient and reliable for solar cells design. Reactions of PVC with metal chelating molecules engendered PVC-metal complexes that were efficient polymer-supported catalysts for Heck, Sonogashira, and Suzuki-Miyaura coupling reactions. Heavy metal sorbents were also made by tailored functionalization of PVC. Modifications of PVC with allotropic carbon nanoparticles, including fullerene C60, carbon nanotubes, and graphene and their applications in the nanocomposites making are herein discussed. The newly emerged “click chemistry†and “living controlled radical polymerization, LCRP†were exploited in the functionalization of poly(vinyl chloride)

Kyste paratubaire tordu: à propos d’un cas rare de diagnostique difficile

Les kystes para tubaires sont des lésions fréquentes, et peuvent être responsables de complications à type de torsion d’annexe qui est rarissime et difficile à diagnostiquer. Cette pathologie est souvent confondue à une torsion ovarienne, la prise en charge dans les deux cas nécessite une intervention chirurgicale en urgence afin de tenter de conserver l’annexe. Nous rapportons un cas rare d’une jeune patiente opérée d’un kyste para tubaire bénin tordue de diagnostic difficile.Key words: Kysteparatubaire, torsion d´annexe, salpingectomi

Carcinome épidermoïde du sein: à propos de 3cas et revue de la littérature

Les carcinomes épidermoides du sein sont rares. Ils sont d’origine métaplasiques. Leur histogénèse est controversée. La présentation clinique et mammographique n’est pas spécifique, l’aspect kystisé des lésions et la présence de nécrose sont recherchés à l’échographie mammaire. Le diagnostic est histologique. Ce cancer est réputé être peu lymphophile et non hormonodépendant. Le traitement rejoint celui des carcinomes infiltrants canalaires et repose sur la chirurgie, la radiothérapie et la chimiothérapie. Le pronostic est péjoratif. Nous rapportons trois cas de carcinome épidermoide du sein colligés au service de Gynécologie obstétrique II au CHU Hassan II de Fès et une revue de la littérature.Pan African Medical Journal 2012; 12:3

RNF8 ubiquitylation of XRN2 facilitates R-loop resolution and restrains genomic instability in BRCA1 mutant cells

Breast cancer linked with BRCA1/2 mutations commonly recur and resist current therapies, including PARP inhibitors. Given the lack of effective targeted therapies for BRCA1-mutant cancers, we sought to identify novel targets to selectively kill these cancers. Here, we report that loss of RNF8 significantly protects Brca1-mutant mice against mammary tumorigenesis. RNF8 deficiency in human BRCA1-mutant breast cancer cells was found to promote R-loop accumulation and replication fork instability, leading to increased DNA damage, senescence, and synthetic lethality. Mechanistically, RNF8 interacts with XRN2, which is crucial for transcription termination and R-loop resolution. We report that RNF8 ubiquitylates XRN2 to facilitate its recruitment to R-loop-prone genomic loci and that RNF8 deficiency in BRCA1-mutant breast cancer cells decreases XRN2 occupancy at R-loop-prone sites, thereby promoting R-loop accumulation, transcription-replication collisions, excessive genomic instability, and cancer cell death. Collectively, our work identifies a synthetic lethal interaction between RNF8 and BRCA1, which is mediated by a pathological accumulation of R-loops

The Effect of Different Vegetable Oils on Cedar Wood Surface Energy: Theoretical and Experimental Fungal Adhesion

Despite having been used for ages to preserve wood against several effects (biological attack and moisture effects) that cause its degradation, the effect of vegetable oils on the cedar wood physicochemical properties is poorly known. Thus, in this study, the hydrophobicity, electron-acceptor (γ+), and electron-donor (γ−) properties of cedar wood before and after treatment with vegetable oils have been determined using contact angle measurement. The cedar wood has kept its hydrophobic character after treatment with the different vegetable oils. It has become more hydrophobic quantitatively with values of surface energy ranged from −25.84 to −43.45 mJ/m2 and more electron donors compared to the untreated sample. Moreover, the adhesion of four fungal strains (Penicillium commune (PDLd”), Thielavia hyalocarpa, Penicillium commune (PDLd10), and Aspergillus niger) on untreated and treated cedar wood was examined theoretically and experimentally. For untreated wood, the experimental adhesion showed a positive relationship with the results obtained by the extended Derjaguin–Landau–Verwey–Overbeek (XDLVO) approach which found that all fungal strains could adhere strongly to the cedar wood material. In contrast, this relationship was not always positive after treatment. The Environmental Scanning Electron Microscopy (ESEM) has shown that P. commune (PDLd10) and A. niger were found unable to adhere to the wood surface after treatment with sunflower and rapeseed oils. In addition, the results showed that the four fungal strains’ adhesion was decreased with olive and linseed oils treatment except that of P. commune (PDLd10) treated with linseed oil

Adaptive Traffic Signal Control : Exploring Reward Definition For Reinforcement Learning

International audienceAs mobility grow in urban cities, traffic congestion become more frequent and troublesome. traffic signal is one way to decrease traffic congestion in urban areas but needs to be adjusted in order to take into account the stochasticity of traffic. Reinforcement learning (RL) has been the object of investigation of many recent papers as a promising approach to control such a stochastic environment. The goal of this paper is to analyze the feasibility of RL, particularly the use of Q-learning algorithm for adaptive traffic signal control in different traffic dynamics. A RL control was developed for an isolated multi-phase intersection using a microscopic traffic simulator known as Paramics. The novelty of this work consists of its methodology which uses a new generalized state space with different known reward definitions. The results of this study demonstrate the advantage of using RL over fixed signal plan, and yet exhibit different outcomes depending on the reward definitions and different traffic dynamics being considered