5 research outputs found
Security Issues in mGovernment
E-government is one of the most rapidly evolving service domains in the contemporary information society. Many governments have already developed and provided e-government services to businesses and citizens. Nowadays
actors in the government domain attempt to take the next step and exploit the latest wireless technologies in order to provide ubiquitous services for mobile
users. However, this approach involves some hidden risks mainly due to the inherent insecurity of the air medium and the vulnerabilities of the wireless systems.
Thus, in this paper we investigate the security gaps and considerations
which should be taken into account for an m-government system. Finally, we
provide a list of security guidelines and policies, which the users of the system
should be aware of and follow in order to avoid security attacks
Comprehensive Analysis of Secondary Metabolites in Usnea longissima (Lichenized Ascomycetes, Parmeliaceae) Using UPLC-ESI-QTOF-MS/MS and Pro-Apoptotic Activity of Barbatic Acid
International audienceConsidering the importance of ultra-performance liquid chromatography-electrospray ionization-quadrupole time of flight-tandem mass spectrometry (UPLC-ESI-QTOF-MS/MS) hyphenated techniques for analysis of secondary metabolites from crude extracts, the present study was aimed at identification of secondary metabolites in acetone extract of the lichen Usnea longissima. From our study, 19 compounds were tentatively identified through comparison of exact molecular masses from their MS/MS spectra, mass fragmentation studies and comparison with literature data. In addition, potent cytotoxic activity of U. longissima extract prompted us to isolate four compounds, 18R-hydroxy-dihydroalloprotolichesterinic acid (19), neuropogolic acid (20), barbatic acid (21), and usnic acid (22) from this extract which were adequately identified through mass spectrometry and NMR spectroscopy. All four compounds displayed cytotoxic activity. Barbatic acid (21) manifested doxorubicin equivalent activity against A549 lung cancer cell line with IC of 1.78 µM and strong G0/G1 accumulation of cells. Poly ADP-ribose polymerase (PARP) cleavage confirmed that it induced cytotoxic activity via apoptosis. Finally, our work has discerned the depside, barbatic acid (21) from crude extract as a candidate anti-cancer molecule, which induces cell death by stepping up apoptosis