SQLite Optimization with Phase Change Memory for Mobile Applications

ABSTRACT Given its pervasive use in smart mobile platforms, there is a compelling need to optimize the performance of sluggish SQLite databases. Popular mobile applications such as messenger, email and social network services rely on SQLite for their data management need. Those mobile applications tend to execute relatively short transactions in the autocommit mode for transactional consistency in databases. This often has adverse effect on the flash memory storage in mobile devices because the small random updates cause high write amplification and high write latency. In order to address this problem, we propose a new optimization strategy, called per-page logging (PPL), for mobile data management, and have implemented the key functions in SQLite/PPL. The hardware component of SQLite/PPL includes phase change memory (PCM) with a byte-addressable, persistent memory abstraction. By capturing an update in a physiological log record and adding it to the PCM log sector, SQLite/PPL can replace a multitude of successive page writes made to the same logical page with much smaller log writes done to PCM much more efficiently. We have observed that SQLite/PPL would potentially improve the performance of mobile applications by an order of magnitude while supporting transactional atomicity and durability

Au–Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen

Background Blood prostate-specific antigen (PSA) levels are widely used as diagnostic biomarkers for prostate cancer. Lateral-flow immunoassay (LFIA)-based PSA detection can overcome the limitations associated with other methods. LFIAbased PSA detection in clinical samples enables prognosis and early diagnosis owing to the use of high-performance signal reporters. Results Here, a semiquantitative LFIA platform for PSA detection in blood was developed using Au–Ag nanoparticles (NPs) assembled on silica NPs (SiO2@Au–Ag NPs) that served as signal reporters. Synthesized SiO2@Au–Ag NPs exhibited a high absorbance at a wide wavelength range (400–800 nm), with a high scattering on nitrocellulose membrane test strips. In LFIA, the color intensity of the test line on the test strip differed depending on the PSA concentration (0.30–10.00 ng/mL), and bands for the test line on the test strip could be used as a standard. When clinical samples were assessed using this LFIA, a visual test line with particular color intensity observed on the test strip enabled the early diagnosis and prognosis of patients with prostate cancer based on PSA detection. In addition, the relative standard deviation of reproducibility was 1.41%, indicating high reproducibility, and the signal reporter showed good stability for 10 days. Conclusion These characteristics of the signal reporter demonstrated the reliability of the LFIA platform for PSA detection, suggesting potential applications in clinical sample analysis.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF2020R1F1A1072702). This study was also supported by the WTU Joint Research Grant of Konkuk University in 2017 (2017-A019-0334)