Fifteen compounds were extracted and purified from the leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena. These compounds include liriodenine (1), lysicamine (2), (-)-anonaine (3), (-)-asimilobine (4), (-)-caaverine (5), (-)-N-methylasimilobine (6), (-)-nuciferine (7), (-)-nornuciferine (8), (-)-roemerine (9), 7-hydroxydehydronuciferine (10) cepharadione B (11), β-sitostenone (12), stigmasta-4,22-dien-3-one (13) and two chlorophylls: pheophytin-a (14) and aristophyll-C (15). The anti-oxidation activity of the compounds was examined by antiradical scavenging, metal chelating and ferric reducing power assays. The results have shown that these compounds have antioxidative activity. The study has also examined the antiproliferation activity of the isolated compounds against human melanoma, prostate and gastric cancer cells. The results shown that 7-hydroxydehydronuciferine (10) significantly inhibited the proliferation of melanoma, prostate and gastric cancer cells. Together, these findings suggest that leaves of Nelumbo nucifera Gaertn. cv. Rosa-plena are a good resource for obtaining the biologically active substances with antioxidant properties.

Malcode can be easily hidden in document files and go undetected by standard technology. We demonstrate this opportunity of stealthy malcode insertion in several experiments using a standard COTS Anti-Virus (AV) scanner. Furthermore, in the case of zero-day malicious exploit code, signature-based AV scanners would fail to detect such malcode even if the scanner knew where to look. We propose the use of statistical binary content analysis of files in order to detect suspicious anomalous file segments that may suggest insertion of malcode. Experiments are performed to determine whether the approach of n-gram analysis may provide useful evidence of a tainted file that would subsequently be subjected to further scrutiny. We further perform tests to determine whether known malcode can be easily distinguished from otherwise "normal" Windows executables, and whether self-encrypted files may be easy to spot. Our goal is to develop an efficient means by static content analysis of detecting suspect infected files. This approach may have value for scanning a large store of collected information, such as a database of shared documents. The preliminary experiments suggest the problem is quite hard requiring new research to detect stealthy malcode.

Abstract. By exploiting the object-oriented dynamic composability of modern document applications and formats, malcode hidden in otherwise inconspicuous documents can reach third-party applications that may harbor exploitable vulnerabilities otherwise unreachable by network-level service attacks. Such attacks can be very selective and difficult to detect compared to the typical network worm threat, owing to the complexity of these applications and data formats, as well as the multitude of document-exchange vectors. As a case study, this paper focuses on Microsoft Word documents as malcode carriers. We investigate the possibility of detecting embedded malcode in Word documents using two techniques: static content analysis using statistical models of typical document content, and run-time dynamic tests on diverse platforms. The experiments demonstrate these approaches can not only detect known malware, but also most zero-day attacks. We identify several problems with both approaches, representing both challenges in addressing the problem and opportunities for future research.

Cerium conversion coatings are a potential alternative to chromium conversion coatings for improving the corrosion resistance of magnesium alloys. This study detailed the microstructure and corrosion resistance of cerium conversion coatings on AZ31 magnesium plates treated in 0.05 kmol m À3 cerium nitrate solution, with and without 0.25 kmol m À3 hydrogen peroxide. The results indicate that the corrosion resistance of the coating was related to the microstructure of the major overlay, and to the defects of the coating. The major overlay changed from a fibrous structure to a compact layer, as hydrogen peroxide was added to a cerium nitrate solution. Meanwhile, severely-damaged areas were observed on the coating formed in the presence of hydrogen peroxide. Although the compact coating displayed better corrosion resistance than its fibrous counterpart, both coatings were locally corroded during the polarization test.