Ricerc@Sapienza

Background. Multidrug resistance is an established and growing worldwide public health problem, since few therapeutic options remain available. MRSA is the leading Gram-positive organism which has spread both in
the community and healthcare environment. Gram-negative bacteria, either fermenter (enterobacteriaceae) or nonfermenter, pose a major challenge to the healthcare providers because they can express a wide
multidrug resistance.

An isolation technique, which does not require conventional circulators, is proposed for the realization of a simple and low-cost aperture-coupled circularly polarized antenna for application to full-duplex devices. The approach is based on the use of slotlines loops to provide surface current cancellation in specific regions of the antenna structure, leading to improved axial ratio and isolation between the ports in excess of 50 dB.

In this article the scientific activity carried out on stemarane diterpenes and diterpenoids, isolated over the world from various natural sources, was reviewed. The structure elucidation of stemarane diterpenes and diterpenoids was reported, in addition to their biogenesis and biosynthesis. Stemarane diterpenes and diterpenoids biotransformations and biological activity was also taken into account. Finally the work leading to the synthesis and enantiosynthesis of stemarane diterpenes and diterpenoids was described.