WHO; Bill & Melinda Gates Foundation.

This systematic review demonstrated that viruses are strongly associated with AECOPD, with the highest detection rates of viruses being in Europe. The geographical epidemiology of viruses may have important therapeutic implications for management of AECOPD.

Vinyl ester resins (VERs) are high-performance unsaturated resins derived by the addition reaction of various epoxide resins with α-β unsaturated carboxylic acids. These resins have always been classified under unsaturated polyester resins. However, VERs have remarkable corrosion resistance and superior physical properties as compared with these conventional polyester resins, which make VERs a class of their own and hallmark of today's resin industries. Hence, there is a need to review the available literature on this important class of thermosetting resins separately. In this article, an attempt is made to review the state of the art of VERs, including synthesis, characterization, curing, thermal, chemical, oxidative properties, and applications. The main focus is on the latest developments in this area.

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Organic chemistryOrganic chemistry Z 0200 Azido Polymers-Energetic Binders for Solid Rocket Propellants -[88 refs.]. -(GAUR, B.; LOCHAB, B.; CHOUDHARY, V.; VARMA, I. K.; J. Macromol. Sci., Polym. Rev. C43 (2003) 4, 505-545; Cent. Polym. Sci. Eng., Indian Inst. Technol. Delhi, New Delhi 110 016, India; Eng.) -Lindner 20-263

Multifunctional bio-based epoxy resin (PEMPAE) was synthesized by reacting Diels-Alder adduct of gum rosin and maleic anhydride (MPA) with pentaerythritol to get the esterified product (PEMPA) which was further epoxidized using epichlorohydrin and potassium hydroxide. This paper includes the synthesis of bio-based imidoamine curing agent (IAEDK) by reacting diamino diphenyl ether (DDE) with dimaleopimaryl ketone (DMPK), a dehydrodecarboxylated derivative of MPA. The synthesized products were characterized by Fourier transform infrared Spectroscopy (FTIR), proton and 13 C nuclear magnetic resonance spectroscopy ( 1 H-NMR and 13 C-NMR). Curing dynamics of rosin-based epoxy cured with rosinbased imidoamine crosslinker were evaluated using differential scanning calorimetry (DSC) and were compared with resin cured with synthesized DMPK and commercial DDE curing agents. The mechanical properties and thermal stability of the cured epoxy samples were evaluated using a universal testing machine (UTM) and thermogravimetric analyzer (TGA), respectively. The chemical resistance of the samples was determined in terms of % weight loss when immersed in NaOH, HCl and NaCl solutions. The morphological changes were also evaluated via scanning electron microscopy (SEM). Results revealed that rosin-based epoxy cured with imidoamine curing agent gave preeminent properties over the commercial one. The studies suggested that curing properties were greatly affected by the molecular topology and kind of curing agent used.