1,423 research outputs found
Characterization of PM2.5 Mass Concentration in the Onshore of Sanya, China
Numbers of real-time data (E-BAM) of PM2.5 were collected in the period from Jan 8th 2012 to Jan 1st 2013 at the laboratory of Tropical Ocean University (Sanya, China). The average mass concentration was 19.7 μg/m³. The highest 40.5 μg/m³ in October compared to the lowest 14.1 μg/m³ in July. From a seasonal perspective, the average PM2.5 mass concentration in fall and winter are relatively higher than that in both spring and summer. On the basis of satellite map of fire points and backward trajectories of the air masses, we primarily deduced that the PM2.5 in Sanya may be caused by the biomass burning and industrial pollutants from the area of Pearl River Delta of China and the Indo-China peninsula (e.g. Vietnam, Laos)
Cloning, Identification, and Characterization of the rpoS-Like Sigma Factor rpoX from Vibrio alginolyticus
Vibrio alginolyticus ZJ-51 displays phase variation between opaque/rugose colonies (Op) and translucent/smooth colonies (Tr). These colony variants show great differences in biofilm formation and motility. In this study, a gene encoding for an rpoS-like sigma factor, rpoX, has been cloned and characterized. The absence of rpoX did not affect colony switching rate but did decrease biofilm formation in both the Op and the Tr variants. When challenged with hydrogen peroxide, the ΔrpoX in the Op background showed a slightly higher survival rate compared with the wild type, whereas survival was decreased in the Tr background. Deletion of rpoX in the Tr background resulted in a higher ability to resist ethanol challenges and to survive hyperosmolarity challenges, and in the Op background the opposite phenotype was observed. This indicates that the rpoX gene is involved in biofilm formation and stress response but the effects are controlled by colony phase variation in V. alginolyticus
Hawkeye: Change-targeted Testing for Android Apps based on Deep Reinforcement Learning
Android Apps are frequently updated to keep up with changing user, hardware,
and business demands. Ensuring the correctness of App updates through extensive
testing is crucial to avoid potential bugs reaching the end user. Existing
Android testing tools generate GUI events focussing on improving the test
coverage of the entire App rather than prioritising updates and its impacted
elements. Recent research has proposed change-focused testing but relies on
random exploration to exercise the updates and impacted GUI elements that is
ineffective and slow for large complex Apps with a huge input exploration
space. We propose directed testing of App updates with Hawkeye that is able to
prioritise executing GUI actions associated with code changes based on deep
reinforcement learning from historical exploration data. Our empirical
evaluation compares Hawkeye with state-of-the-art model-based and reinforcement
learning-based testing tools FastBot2 and ARES using 10 popular open-source and
1 commercial App. We find that Hawkeye is able to generate GUI event sequences
targeting changed functions more reliably than FastBot2 and ARES for the open
source Apps and the large commercial App. Hawkeye achieves comparable
performance on smaller open source Apps with a more tractable exploration
space. The industrial deployment of Hawkeye in the development pipeline also
shows that Hawkeye is ideal to perform smoke testing for merge requests of a
complicated commercial App
N′-(3,4-Dihydroxybenzylidene)acetohydrazide
In the title compound, C9H10N2O3, the Schiff base molecule is approximately planar, the dihedral angle between the benzene ring and the acetohydrazide group (r.m.s. deviation = 0.034 Å) being 8.81 (7)°. An intramolecular O—H⋯O hydrogen bond is observed. In the crystal, molecules are linked into a three-dimensional network by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds
(E)-Methyl N′-(2-furylmethylene)hydrazinecarboxylate
The title compound, C7H8N2O3, crystallizes with two independent but essentially identical molecules in the asymmetric unit. Each molecule adopts a trans configuration with respect to the C=N bond. The hydrazinecarboxylate group is twisted from the furan ring by 7.78 (13)° in one molecule and by 7.01 (17)° in the other. In the crystal structure, molecules are linked into chains running along [010] by bifurcated N—H⋯(N,O) and N—H⋯O hydrogen bonds. In addition, weak C—H⋯O interactions and an O⋯C short contact [2.896 (3) Å] are observed
Isocorydine Inhibits Cell Proliferation in Hepatocellular Carcinoma Cell Lines by Inducing G2/M Cell Cycle Arrest and Apoptosis
The treatment of human hepatocellular carcinoma (HCC) cell lines with (+)-isocorydine, which was isolated and purified from Papaveraceae sp. plants, resulted in a growth inhibitory effect caused by the induction of G2/M phase cell cycle arrest and apoptosis. We report that isocorydine induces G2/M phase arrest by increasing cyclin B1 and p-CDK1 expression levels, which was caused by decreasing the expression and inhibiting the activation of Cdc25C. The phosphorylation levels of Chk1 and Chk2 were increased after ICD treatment. Furthermore, G2/M arrest induced by ICD can be disrupted by Chk1 siRNA but not by Chk2 siRNA. In addition, isocorydine treatment led to a decrease in the percentage of CD133+ PLC/PRF/5 cells. Interestingly, isocorydine treatment dramatically decreased the tumorigenicity of SMMC-7721 and Huh7 cells. These findings indicate that isocorydine might be a potential therapeutic drug for the chemotherapeutic treatment of HCC
- …