Bactericidal efficacy of gold nanoparticles conjugated with ampicillin, streptomycin and kanamycin were evaluated. Gold nanoparticles (Gnps) were conjugated with the antibiotics during the synthesis of nanoparticles utilizing the combined reducing property of antibiotics and sodium borohydride. The conjugation of nanoparticles was confirmed by dynamic light scattering (DLS) and electron microscopic (EM) studies. Such Gnps conjugated antibiotics showed greater bactericidal activity in standard agar well diffusion assay. The minimal inhibitory concentration (MIC) values of all the three antibiotics along with their Gnps conjugated forms were determined in three bacterial strains,Escherichia coli DH5α,Micrococcus luteusandStaphylococcus aureus. Among them, streptomycin and kanamycin showed significant reduction in MIC values in their Gnps conjugated form whereas; Gnps conjugated ampicillin showed slight decrement in the MIC value compared to its free form. On the other hand, all of them showed more heat stability in their Gnps conjugated forms. Thus, our findings indicated that Gnps conjugated antibiotics are more efficient and might have significant therapeutic implications.

No abstract

Abstract. Over the past few years, virtualization has been employed to environments ranging from densely populated cloud computing clusters to home desktop computers. Security researchers embraced virtual machine monitors (VMMs) as a new mechanism to guarantee deep isolation of untrusted software components. Unfortunately, their widespread adoption promoted VMMs as a prime target for attackers. In this paper, we present HyperCheck, a hardware-assisted tampering detection framework designed to protect the integrity of VMMs and, for some classes of attacks, the underlying operating system (OS). HyperCheck leverages the CPU System Management Mode (SMM), present in x86 systems, to securely generate and transmit the full state of the protected machine to an external server. Using HyperCheck, we were able to ferret-out rootkits that targeted the integrity of both the Xen hypervisor and traditional OSes. Moreover, HyperCheck is robust against attacks that aim to disable or block its operation. Our experimental results show that HyperCheck can produce and communicate a scan of the state of the protected software in less than 40ms.

No abstract

Guanosine 5'-monophosphate, (5'-GMP), is a self-assembling natural nucleotide that has unique potential to form ordered supramolecular structures. We herein describe an intriguing property of Na2(5'-GMP) to form blue emitting chiral carbon dots (G-dots) that exhibit excitation dependent down-conversion and up-conversion fluorescence signature and self-assemble to form fluorescent hydrogels.