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Potentilla kleiniana belongs to the family Rosaceae, which distributes in Central Asia, East Asia and Southeast Asia. In China, this plant is mainly found in east, south and southwest provinces. P. kleiniana has been prescribed for the treatment of various diseases in the field of traditional Chinese medicine, such as cough, fever, tuberculosis, mastitis, rheumatoid arthritis. Our previous study found that P. kleiniana had a certain cytotoxicity on tumor cells. The purpose of this paper was to investigate the chemical constituents of P. kleiniana and their cytotoxicity on tumor cells. The 60% ethanol extract of P. kleiniana were isolated by D-101 macroporous adsorptive resins, silica gel, Sephadex LH-20, Toyopearl HW-40F, semi-preparative high performance liquid chromatography and other methods, and their chemical structures were elucidated on the basis of physicochemical properties, NMR and HR-ESI-MS analysis. Meanwhile, all these compounds were evaluated for cytotoxicity against human cervical cancer cell line Hela. The results were as follows: (1) Thirteen lignans were isolated and identified as (+)-pionresinol (1), (+)-8-hydroxypinoresinol (2), (+)-syringaresinol (3), (+)-medioresinol (4), (+)-pionresinol-4-O-β-D-glucopyranoside (5), (+)-8′-hydroxypinoresinol-4-O-β-D-glucopyranoside (6), (+)-8′-hydroxypinoresinol-4′-O-β-D-glucopyranoside (7), (+)-pinoresinol-8′-O-β-D-glucopyranoside (8), schilignan F (9), (+)-pionresinol-4, 4′-O-bisglucopyranoside (10), (+)-lariciresinol-4′-O-β-D-glucopyranoside (11), neoolivil-4-O-β-D-glucopyranoside (12), 3,3′-bis［3,4-dihydro-4-hydroxy-6-methoxy-2H-1-benzopyran］(13). Among them, compounds 1-4, 7, 8, 10, 12, 13 were isolated from genus Potentilla for the first time, and compounds 5, 6, 9, 11 were isolated from P. kleiniana for the first time. (2) Cytotoxicity studies showed that compounds 1, 3 and 4 display certain inhibitory activities against Hela cells with IC50 values of (69.94 ± 1.89), (66.25 ± 2.11), (59.81 ± 1.73) μmol·L-1, respectively. Therefore, the study enriches the chemical constituents of P. kleiniana, and provides a material basis for the development of anti-cervical cancer drugs.

Domain boundaries in perovskite oxides often exhibit abundant physical properties and phenomena. Here, epitaxial LaTiO3 thin films on (100) SrTiO3 substrates are prepared by pulsed-laser deposition. X-ray diffraction and transmission electron microscopy investigations reveal that the epitaxial LaTiO3 thin films have good crystallinity but a high density of domain boundaries. Atomic-scale scanning transmission electron microscopy observations reveal that two types of domain boundaries are formed in the LaTiO3 thin films. The type I domain boundaries are formed on the {100} crystal planes, while the type II domain boundaries on the {110} crystal planes. Electron energy-loss spectroscopy analyses suggest that the valence states of Ti ions at the type I domain boundaries are +3, while those at the type II domain boundaries are +4. First-principles calculations reveal that the bandgap decreases at both domain boundaries compared to the bulk. The carrier concentration at the type I domain boundaries is significantly higher than that of the bulk, while the carrier concentration at the type II domain boundaries is lower. These findings suggest that domain boundaries play an important role in tailoring the electrical properties of the LaTiO3 thin films, thereby promoting the potential applications and property modulation of related materials and devices. [ABSTRACT FROM AUTHOR]

For planar and rigid π-conjugated molecular systems, electrostatic and inductive interactions are pivotal in governing molecular packing structures and electron polarization energies. These electrostatic interactions typically exhibit an anisotropic nature within π-conjugated systems. In this study, we utilize the atoms in molecules (AIM) theory in conjunction with linear response theory to decompose molecular polarizability into distributed atomic polarizability tensors. On the basis of atomic polarizability tensors, we extended an anisotropic polarizable model into the AMOEBA polarizable force field. Both anisotropic and isotropic polarizable models in combination with various density functional theory (DFT)-derived atomic multipoles were applied to optimize the experimental crystals of naphthalene and anthracene. Furthermore, these two types of electrostatic models, coupled with the evolutionary algorithm USPEX program, are utilized to predict the crystal structures of oligoacenes. Our findings demonstrate that the anisotropic polarizable model exhibits superior performance in crystal refinement and crystal structure prediction. This enriched anisotropic polarizable model is seamlessly integrated into the AMOEBA polarizable force field and readily applicable within our modified Tinker program. [ABSTRACT FROM AUTHOR]

Staining of foods by toxic mycotoxins is a general severe problem in the world. To explore simple methods for effective monitoring of mycotoxin-stained foods has extraordinary significance. Herein, we designed and prepared a covalent organic framework (COF)-derived fluorescent composite (DhBd-PT-COF-FITC) by anchoring a continually utilized fluorescent tag, fluorescein isothiocyanate (FITC), in the nanopore channel of a two-dimensional imine COF (DhBd-PT-COF) to detect a major existent mycotoxin of moldy sugar cane3-nitropropionic acid (3-NPA), which is closely related to toxicosis events of humans. Tying FITC molecules into the pore channels of DhBd-PT-COF can not only enhance the fluorescence intensity of FITC by relying on the confinement effect of DhBd-PT-COF but also retain inherent pH-responsive characteristics. As a result, DhBd-PT-COF-FITC showed the selective and sensitive response to 3-NPA. The detection limit of DhBd-PT-COF-FITC toward 3-NPA is achieved to be ultralow as 12.5 nM. More attractively, facile recovery of DhBd-PT-COF-FITC can be obtained via simple alkaline treatment. The prepared sensor has also been used to detect 3-NPA in actual sugar cane samples with satisfying recovery. Our work not only exhibits fascinating performance of COF-derived fluorescent composites toward 3-NPA monitoring but also offers a prospective approach to develop various specific materials for other targets. [ABSTRACT FROM AUTHOR]