Hong Kong Baptist University

About: Hong Kong Baptist University is a education organization based out in Hong Kong, China. It is known for research contribution in the topics: Population & China. The organization has 7811 authors who have published 18919 publications receiving 555274 citations. The organization is also known as: Hong Kong Baptist College & HKBU.

ADME Properties Evaluation in Drug Discovery: Prediction of Caco-2 Cell Permeability Using a Combination of NSGA-II and Boosting

Abstract: The Caco-2 cell monolayer model is a popular surrogate in predicting the in vitro human intestinal permeability of a drug due to its morphological and functional similarity with human enterocytes. A quantitative structure-property relationship (QSPR) study was carried out to predict Caco-2 cell permeability of a large data set consisting of 1272 compounds. Four different methods including multivariate linear regression (MLR), partial least-squares (PLS), support vector machine (SVM) regression and Boosting were employed to build prediction models with 30 molecular descriptors selected by nondominated sorting genetic algorithm-II (NSGA-II). The best Boosting model was obtained finally with R(2) = 0.97, RMSEF = 0.12, Q(2) = 0.83, RMSECV = 0.31 for the training set and RT(2) = 0.81, RMSET = 0.31 for the test set. A series of validation methods were used to assess the robustness and predictive ability of our model according to the OECD principles and then define its applicability domain. Compared with the reported QSAR/QSPR models about Caco-2 cell permeability, our model exhibits certain advantage in database size and prediction accuracy to some extent. Finally, we found that the polar volume, the hydrogen bond donor, the surface area and some other descriptors can influence the Caco-2 permeability to some extent. These results suggest that the proposed model is a good tool for predicting the permeability of drug candidates and to perform virtual screening in the early stage of drug development.

Entanglement as a signature of quantum chaos.

Abstract: We explore the dynamics of entanglement in classically chaotic systems by considering a multiqubit system that behaves collectively as a spin system obeying the dynamics of the quantum kicked top. In the classical limit, the kicked top exhibits both regular and chaotic dynamics depending on the strength of the chaoticity parameter kappa in the Hamiltonian. We show that the entanglement of the multiqubit system, considered for both the bipartite and the pairwise entanglement, yields a signature of quantum chaos. Whereas bipartite entanglement is enhanced in the chaotic region, pairwise entanglement is suppressed. Furthermore, we define a time-averaged entangling power and show that this entangling power changes markedly as kappa moves the system from being predominantly regular to being predominantly chaotic, thus sharply identifying the edge of chaos. When this entangling power is averaged over all states, it yields a signature of global chaos. The qualitative behavior of this global entangling power is similar to that of the classical Lyapunov exponent.

Degradation of indometacin by simulated sunlight activated CDs-loaded BiPO4 photocatalyst: Roles of oxidative species

Abstract: In this study, novel carbon dots/BiPO4 (CDBP) photocatalytic complexes were successfully synthesized via a facile hydrothermal-calcination synthesis strategy. The physicochemical properties of the synthesized samples were studied by X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (DRS), Fourier infrared spectrometer (FT-IR), Raman spectrometer, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), photoluminescence26spectra (PL), electrochemical workstation, etc. The activities of the CDBP were evaluated through the photocatalytic degradation of Indometacin(IDM) in an aqueous solution under simulated sunlight irradiation. With increasing concentrations of carbon dots (CDs), the photocatalytic activity of the CDBP initially increased, and then decreased. A CDs content of 3.0 wt% shows 12 times higher photocatalytic activity than that of pristine BiPO4. Reactive oxidative species, particularly O2 − and h+, were the two critical reactive oxidative species to mediator immediate the photocatalytic degradation of IDM. A notable sign of 5, 5-dimethyl-1-pyrrolidone-N-oxyl(DMPOX) was observed through electron spin resonance spectroscopy(EPR) with CDBP as the photocatalyst, which indicated higher oxidability than pristine BiPO4 under simulated sunlight irradiation. This enhanced photocatalytic activity might due to high-efficiency charge separation, unique up-converted PL properties, as well as the bandgap narrowing of the CDs. Moreover, the byproducts of IDM were detected by HPLC–MS/MS and GC–MS, and the probable pathways were deduced. The acute toxicity at three trophic levels initially increased slowly and then decreased rapidly as the IDM dechlorination and total organic carbon(TOC) decreased during photocatalytic degradation.