Kewen Sun

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The chemotherapeutic approach using non-toxic natural products may be one of the strategies for the management of the cholangiocarcinoma. Here we report that in vitro treatment of human cholangiocarcinoma QBC939 cells with berberine, a naturally occurring isoquinoline alkaloid, decreased cell viability and induced cell death in a dose-dependent manner,(More)
The structural and spectral properties of (ortho and para) C8-aryl-purine adducts formed from carbon attachment by phenolic toxins were investigated through DFT calculations and UV-vis absorbance and emission studies. The global minima of both the deoxyadenosine (dA) and deoxyguanosine (dG) adducts adopted a syn conformation about the glycosidic bond due to(More)
In this paper, a gyroscopic mounting method for crystal oscillators to reduce the impact of dynamic loads on their output stability has been proposed. In order to prove the efficiency of this mounting approach, each dynamic load-induced instability has been analyzed in detail. A statistical study has been performed on the elevation angle of the(More)
Primary malignant melanoma of the esophagus (PMME) is a rare malignant neoplasm of the esophagus. In the majority of cases, the disease originates in the mucosal layer of the esophagus, which is similar to other types of esopha-geal cancer. With the development of endoscopic submucosal dissection (ESD), endoscopic resection is possible for cases in which(More)
In this paper, an improved joint time-frequency (TF) analysis method based on a reassigned smoothed pseudo Wigner-Ville distribution (RSPWVD) has been proposed in interference detection for Global Navigation Satellite System (GNSS) receivers. In the RSPWVD, the two-dimensional low-pass filtering smoothing function is introduced to eliminate the cross-terms(More)
In this paper, the efficiency of the gyroscopic mounting method is studied for a highly dynamic GNSS receiver's reference oscillator for reducing signal loss. Analyses are performed separately in two phases, atmospheric and upper atmospheric flights. Results show that the proposed mounting reduces signal loss, especially in parts of the trajectory where its(More)
  • Kewen Sun
  • 2011
After the acquisition stage of a GNSS receiver has roughly synchronized the received and the locally generated codes typically within less than a half chip period residual offset, a fine synchronization stage, named signal tracking, takes over and continuously maintains and corrects the best possible alignment between the two codes by means of closed loop(More)
Interference detection is very important for Global Navigation Satellite System (GNSS) receivers. Current work on interference detection in GNSS receivers has mainly focused on time-frequency (TF) analysis techniques, such as spectrogram and Wigner-Ville distribution (WVD), where the spectrogram approach presents the TF resolution trade-off problem, since(More)