The outbreak of severe acute respiratory syndrome (SARS) in 2002 affected thousands of people and an efficient diagnostic system is needed for accurate detection of SARS coronavirus (SARS CoV) to prevent or limit future outbreaks. Of the several SARS CoV structural proteins, the nucleocapsid protein has been shown to be a good diagnostic marker. In this study, an ssDNA aptamer that specifically binds to SARS CoV nucleocapsid protein was isolated from a DNA library containing 45-nuceotide random sequences in the middle of an 88mer single-stranded DNA. After twelve cycles of systematic evolution of ligands by exponential enrichment (SELEX) procedure, 15 ssDNA aptamers were identified. Enzyme-linked immunosorbent assay (ELISA) analysis was then used to identify the aptamer with the highest binding affinity to the SARS CoV nucleocapsid protein. Using this approach, an ssDNA aptamer that binds to the nucleocapsid protein with a K(d) of 4.93±0.30nM was identified. Western blot analysis further demonstrated that this ssDNA aptamer could be used to efficiently detect the SARS CoV nucleocapsid protein when compared with a nucleocapsid antibody. Therefore, we believe that the selected ssDNA aptamer may be a good alternative detection probe for the rapid and sensitive detection of SARS.

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The overexpression of cell reprogramming factors (Oct4, Sox2, Klf4, Nanog, and c-Myc) allows differentiated cells to revertto an earlier developmental stage. Differentiated cells can also be reprogrammed by directly delivering reprogramming proteins tagged with cell-penetrating peptides, which allow the proteins to pass through the cell membrane and into the cytoplasm-although this method has been an inefficient process. Here, we describe a novel technique for delivering reprogramming proteins into cells using titanium oxide (TiO2 ) nanotubes, which show no cytotoxic effects and do not affect cell proliferation. TiO2 nanotubes successfully transferred the above-mentioned reprogramming factors into differentiated somatic cells. After 3 weeks of treatment with protein-conjugated nanotubes, the somatic cells adopted an embryonic stem cell-like morphology and expressed activated Oct4-green fluorescent protein, a pluripotency biomarker. Our results indicate that TiO2 nanotubes can be used to directly deliver reprogramming factors into somatic cells to induce pluripotency.

In order to classify a web page as being benign or malicious, we designed 14 basic and 16 extended features. The basic features that we implemented were selected to represent the essential characteristics of a web page. The system heuristically combines two basic features into one extended feature in order to effectively distinguish benign and malicious pages. The support vector machine can be trained to successfully classify pages by using these features. Because more and more malicious web pages are appearing, and they change so rapidly, classifiers that are trained by old data may misclassify some new pages. To overcome this problem, we selected an adaptive support vector machine (aSVM) as a classifier. The aSVM can learn training data and can quickly learn additional training data based on the support vectors it obtained during its previous learning session. Experimental results verified that the aSVM can classify malicious web pages adaptively.