Construction of Cs2AgBiCl6/COF Heterojunction for Boosted Photocatalytic Thioester Oxidation.

Lead-free halide perovskites as a new kind of potential candidate for photocatalytic organic synthesis have attracted much attention recently. The rational heterojunction construction is regarded as an efficient strategy to delicately regulate their catalytic performances. Herein, a semi-conductive covalent organic framework (COF) nanosheet, C4N, is employed as the functional component to construct Cs2AgBiCl6/C4N (CABC/C4N) heterojunction. It is found that the C4N nanosheets with rich surface functional groups can serve as heterogeneous nucleation sites to manipulate the growth of CABC nanocrystals and afford close contact between each other, therefore facilitate the transfer and spatial separation of photogenerated charge carriers, as verified by in situ X-ray photoelectronic spectroscopy and Kelvin probe force microscopy. Moreover, the oxygen affinity of C4N endows the heterojunctions with outstanding aerobic reactivity, thus improving the photocatalytic performance largely. The optimal CABC/C4N heterojunction delivers a thioanisole conversion efficiency of 100% after 6 h, which is 2.2 and 7.7-fold of that of CABC and C4N. This work provides a new ideal for the design and application of lead-free perovskite heterojunction photocatalysts for organic reactions.

Secure Outsourced SIFT: Accurate and Efficient Privacy-Preserving Image SIFT Feature Extraction.

Cloud computing has become an important IT infrastructure in the big data era; more and more users are motivated to outsource the storage and computation tasks to the cloud server for convenient services. However, privacy has become the biggest concern, and tasks are expected to be processed in a privacy-preserving manner. This paper proposes a secure SIFT feature extraction scheme with better integrity, accuracy and efficiency than the existing methods. SIFT includes lots of complex steps, including the construction of DoG scale space, extremum detection, extremum location adjustment, rejecting of extremum point with low contrast, eliminating of the edge response, orientation assignment, and descriptor generation. These complex steps need to be disassembled into elementary operations such as addition, multiplication, comparison for secure implementation. We adopt a serial of secret-sharing protocols for better accuracy and efficiency. In addition, we design a secure absolute value comparison protocol to support absolute value comparison operations in the secure SIFT feature extraction. The SIFT feature extraction steps are completely implemented in the ciphertext domain. And the communications between the clouds are appropriately packed to reduce the communication rounds. We carefully analyzed the accuracy and efficiency of our scheme. The experimental results show that our scheme outperforms the existing state-of-the-art.

Controllable synthesis of hollow COFs for boosting photocatalytic hydrogen generation.

COF-LZU1 with a cubic hollow structure was fabricated through a hard template approach by using water solvable NaCl as a template. The precisely prepared COF-LZU1 hollow cube displays an enhanced H2 evolution rate (651 µmol h-1 g-1), which is approximately 1.8 times greater than that of pristine COF-LZU1 (361 µmol h-1 g-1).

Astragalus IV Undermines Multi-Drug Resistance and Glycolysis of MDA-MB-231/ADR Cell Line by Depressing hsa_circ_0001982-miR-206/miR-613 Axis.

BACKGROUND: Allowing for the power of astragalus in improving cancer patients' response to chemotherapy, we endeavored to clarify if hsa_circ_0001982-centered miRNA axes participated in the impact of astragaloside IV on multi-drug resistance (MDR) of triple-negative breast cancer (TNBC). METHODS: TNBC patients were recruited into an Astragalus detoxification decoction (ADD) treatment group (N=62) and a non-ADD treatment group (N=78), according to whether they consumed ADD after chemotherapy or not. Furthermore, drug resistance of the MDA-MB-231/ADR cell line in response to gemcitabine (GEM), adriamycin (ADM), oxaliplatin (OXA), and cisplatin (DDP) was evaluated, and glycolytic potential of MDA-MB-231/ADR cells was determined after astragaloside IV treatment or si-hsa_circ_0001982/miR-206 inhibitor/miR-613 inhibitor transfection. RESULTS: TNBC patients receiving ADD adjuvant therapy after chemotherapy, with decreased serum level of hsa_circ_0001982 and increased serum level of miR-206/miR-613 as relative to non-ADD treatment group (P<0.05), were less likely to relapse than TNBC population not undergoing ADD treatment (P<0.05). In addition, GEM/ADM/OXA/DDP-resistance and glycolysis of MDA-MB-231/ADR cell line were debilitated after exposure to astragaloside IV or transfection by si-hsa_circ_0001982 (P<0.05). Nonetheless, miR-206/miR-613 inhibitor transfection reversed inhibitory effects of si-hsa_circ_0001982 and astragaloside IV on glycolysis and MDR of MDA-MB-231/ADR cell line (P<0.05). CONCLUSION: Astragaloside IV undermined MDR and glycolysis of MDA-MB-231/ADR cell line by blocking hsa_circ_0001982-miR-206/miR-613 axis.

Hsa_circ_0000199 facilitates chemo-tolerance of triple-negative breast cancer by interfering with miR-206/613-led PI3K/Akt/mTOR signaling.

Increasing attentions have been paid to the role of circRNAs in the etiology of triple-negative breast cancer (TNBC), and we strived to figure out the association of circRNA AKT3/miRNA axis with TNBC chemo-resistance. Altogether 207 BC patients were divided into TNBC group (n=83) and non-TNBC group (n=124), and MCF-10A, MDA-MB-231, MDA-MB-468, SK-BR-3 and MCF-7 cell lines were prepared in advance. Expressions of AKT3-derived circRNAs and relevant miRNAs in the TNBC tissues and cell lines were determined by employing real-time polymerase chain reaction (PCR). It was indicated that hsa_circ_0000199 expression was higher in TNBC tissues than in non-TNBC tissues, and high hsa_circ_0000199 expression was predictive of large tumor size, advanced TNM grade, high Ki-67 level and poor 3-year survival of TNBC patients (all P<0.05). Furthermore, miR-613 and miR-206 were sponged and negatively regulated by hsa_circ_0000199 (P<0.001), and PI3K/Akt/mTOR signaling was depressed by si-hsa_circ_0000199 in TNBC cell lines (P<0.01). Ultimately, miR-206/miR-613 inhibitor reversed impacts of si-hsa_circ_0000199 on PI3K/Akt/mTOR signaling, proliferation, migration, invasion, chemo-sensitivity and autophagy of TNBC cells (all P<0.01). Conclusively, silencing of hsa_circ_0000199 enhanced TNBC chemo-sensitivity by promoting miR-206/miR-613 expression and deactivating PI3K/Akt/mTOR signaling, which was conducive to improving chemotherapeutic efficacy of TNBC patients.

Oxygen doped g-C3 N4 with nitrogen vacancy for enhanced photocatalytic hydrogen evolution.

Generally, bulk graphic carbon nitride (g-C3 N4 ) suffers from fast photogenerated charge carrier combination, inferior light absorption and insufficient active sites. Herein, we developed a defect engineering approach which can simultaneously realize O dopant and N defects in the g-C3 N4 framework via an acid-assisted thermal treatment route. The modified g-C3 N4 demonstrated greatly enhanced photocatalytic H2 activity with a H2 evolution rate of 2.20 mmol ⋅ g-1 ⋅ h-1 , which is more than three times higher than that of bulk g-C3 N4 . The mechanism of the enhanced activity was investigated and proposed that the introduction of O dopants and N defects in the g-C3 N4 could optimize the electron structure, up-shift the conduction band, increase the surface area, and thus achieve more efficient separation of photogenerated carriers, stronger reduction ability and abundant active sites for photocatalytic H2 evolution. Thus, defect engineering has been demonstrated to be a prospective strategy to modify the performance of g-C3 N4 for future photocatalytic energy generation.

Cantharidin Inhibits the Growth of Triple-Negative Breast Cancer Cells by Suppressing Autophagy and Inducing Apoptosis in Vitro and in Vivo.

BACKGROUND/AIMS: Cantharidin, a type of terpenoid secreted by the blister beetle Mylabris phalerata (Pallas), has attracted great attention in cancer therapy because of its potential anti-cancer activities. Here, we report the effects on apoptosis and autophagy in human triple-negative breast cancer (TNBC) cell lines after treatment with cantharidin and attempt to elucidate the underlying mechanisms. METHODS: MDA-MB-231 and MDA-MB-468 cells were treated with cantharidin and cell proliferation was examined using CCK-8 and clone formation assays. The expression of apoptosis- and autophagy-associated proteins was detected by western blotting. Cells were infected with lentivirus carrying the Beclin-1 gene, and MDA-MB-231-beclin1 (MB231-Bec) and MDA-MB-468-beclin-1(MB468-Bec) cells stably expressing Beclin-1 were established. Autophagic vacuoles in cells were observed with LC3 staining using fluorescence microscopy, and apoptotic cells were detected via flow cytometry. Tumor growth was assessed by subcutaneous inoculation of TNBC cells into BALB/c nude mice. RESULTS: Cantharidin inhibited the proliferation of MDA-MB-231 and MDA-MB-468 cells, and induced cell apoptosis. Cantharidin additionally inhibited the conversion of LC3 I to LC3 II and autophagosome formation by suppressing the expression of Beclin-1. Furthermore, overexpression of Beclin-1 in TNBC cells attenuated the cytotoxicity of cantharidin. In vivo, cantharidin inhibited the growth of MDA-MB-231 and MDA-MB-468 xenografts in nude mice by suppressing autophagy and inducing apoptosis, and Beclin-1 overexpression in TNBC cells reduced the efficacy of cantharidin. CONCLUSIONS: Cantharidin inhibits autophagy by suppressing Beclin-1 expression and inducing apoptosis of TNBC cells in vitro and in vivo, thereby representing a potential strategy for the treatment of TNBC.

Two new taxoids from Taxus chinensis.

Two new taxoids, 2,20-O-diacetyltaxumairol N (1) and 14beta-hydroxy-10-deacetyl-2-O-debenzoylbacatin III (2), were isolated from the needles and stems of Taxus chinensis. Their structures were determined on the basis of extensive 1D- and 2D-NMR-spectral analysis. Compound 1 showed weak cytotoxicity activity against T-24 (IC50 = 34 microg/ml) and QGY-7701 (IC50 = 22 microg/ml) cancer lines. Compound 2 showed no obvious cytotoxicity activity against T-24 (IC50 > 100 microg/ml) and QGY-7701 (IC50 > 100 microg/ml) cancer lines.