Showing papers by "Chongqing University of Technology published in 2019"

Photocatalytic and Photo-Fenton Catalytic Degradation Activities of Z-Scheme Ag2S/BiFeO3 Heterojunction Composites under Visible-Light Irradiation

Abstract: Z-scheme Ag2S/BiFeO3 heterojunction composites were successfully prepared through a precipitation method. The morphology and microstructure characterization demonstrate that Ag2S nanoparticles (30–50 nm) are well-decorated on the surfaces of polyhedral BiFeO3 particles (500–800 nm) to form Ag2S/BiFeO3 heterojunctions. The photocatalytic and photo-Fenton catalytic activities of the as-derived Ag2S/BiFeO3 heterojunction composites were evaluated by the degradation of methyl orange (MO) under visible-light irradiation. The photocatalytic result indicates that the Ag2S/BiFeO3 composites exhibit much improved photocatalytic activities when compared with bare Ag2S and BiFeO3. The optimum composite sample was observed to be 15% Ag2S/BiFeO3 with an Ag2S mass fraction of 15%. Furthermore, the addition of H2O2 can further enhance the dye degradation efficiency, which is due to the synergistic effects of photo- and Fenton catalysis. The results of photoelectrochemical and photoluminescence measurements suggest a greater separation of the photoexcited electron/hole pairs in the Ag2S/BiFeO3 composites. According to the active species trapping experiments, the photocatalytic and photo-Fenton catalytic mechanisms of the Ag2S/BiFeO3 composites were proposed and discussed.

Niobium Incorporation into CsPbI2Br for Stable and Efficient All-Inorganic Perovskite Solar Cells.

Abstract: All-inorganic perovskites are attracting increasing attention due to their superior thermal stability than that of the traditional CH3NH3PbI3, while their inferior phase stability in ambient conditions is still an unsolved issue. Here, for the first time, we report the incorporation of niobium (Nb5+) ions into the CsPbI2Br perovskite. Results indicate that Nb5+ can effectively stabilize the photoactive α-CsPbI2Br phase by the possible substitution of Pb2+. With 0.5% Nb doping, the carbon electrode-based all-inorganic perovskite solar cells achieved a high photoconversion efficiency value of 10.42%, 15% higher than that of the control device. The Nb5+ incorporation reduces the charge recombination in the perovskite, leading to a champion Voc value of 1.27 V and a negligible hysteresis effect. This work explicates the high compatibility of all-inorganic perovskite materials and unlocks the opportunities for the use of high-valence ions for perovskite property modification.

Aptamer-Functionalized and Gold Nanoparticle Array-Decorated Magnetic Graphene Nanosheets Enable Multiplexed and Sensitive Electrochemical Detection of Rare Circulating Tumor Cells in Whole Blood

Abstract: The identification and monitoring of circulating tumor cells (CTCs) in human blood plays a pivotal role in the convenient diagnosis of different cancers. However, it remains a major challenge to monitor these CTCs because of their extremely low abundance in human blood. Here, we describe the synthesis of a new aptamer-functionalized and gold nanoparticle (AuNP) array-decorated magnetic graphene nanosheet recognition probe to capture and isolate rare CTCs from human whole blood. In addition, by employing the aptamer/electroactive species-loaded AuNP signal amplification probes, multiplexed electrochemical detection of these low levels of CTCs can be realized. The incubation of the probes with the sample solutions containing the target CTCs can lead to the efficient separation of the CTCs and result in the generation of two distinct voltammetric peaks on a screen-printed carbon electrode, whose potentials and current intensities, respectively, reflect the identity and number of CTCs for the multiplexed detection of the Ramos and CCRF-CEM cells with detection limits down to 4 and 3 cells mL-1. With the successful demonstration of the concept, further extension of the developed sensing strategy for the determination of various CTCs in human whole blood for the screening of different cancers can be envisioned in the near future.

Synergistically Toughening Polyoxymethylene by Methyl Methacrylate–Butadiene–Styrene Copolymer and Thermoplastic Polyurethane

Abstract: J. Yang, W. Yang, Prof. X. Wang College of Materials Science and Engineering Chongqing University of Technology Chongqing 400054, China E-mail: wangxuanlun@cqut.edu.cn Prof. X. Wang State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065, China M. Dong, Dr. H. Liu, Prof. Z. Guo Integrated Composites Laboratory Department of Chemical & Biomolecular, Engineering University of Tennessee Knoxville, TN 37996, USA E-mail: dmy1989melo@126.com; zguo10@utk.edu M. Dong, Dr. H. Liu Key Laboratory of Materials Processing and Mold (Zhengzhou University) Ministry of Education National Engineering Research Center for Advanced Polymer Processing Technology Zhengzhou University Zhengzhou 450002, China

Acetyl-CoA carboxylase (ACC) as a therapeutic target for metabolic syndrome and recent developments in ACC1/2 inhibitors.

Abstract: Introduction: Acetyl-CoA Carboxylase (ACC) is an essential rate-limiting enzyme in fatty acid metabolism. For many years, ACC inhibitors have gained great attention for developing therapeutics for various human diseases including microbial infections, metabolic syndrome, obesity, diabetes, and cancer. Areas covered: We present a comprehensive review and update of ACC inhibitors. We look at the current advance of ACC inhibitors in clinical studies and the implications in drug discovery. We searched ScienceDirect ( https://www.sciencedirect.com/ ), ACS ( https://pubs.acs.org/ ), Wiley ( https://onlinelibrary.wiley.com/ ), NCBI ( https://www.ncbi.nlm.nih.gov/ ) and World Health Organization ( https://www.who.int/ ). The keywords used were Acetyl-CoA Carboxylase, lipid, inhibitors and metabolic syndrome. All documents were published before June 2019. Expert opinion: The key regulatory role of ACC in fatty acid synthesis and oxidation pathways makes it an attractive target for various metabolic diseases. In particular, the combination of ACC inhibitors with other drugs is a new strategy for the treatment of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Expanding the clinical indications for ACC inhibitors will be one of the hot directions in the future. It is also worth looking forward to exploring safe and efficient inhibitors that act on the BC domain of ACC.

Dual-Mode Optical Thermometry Based on the Fluorescence Intensity Ratio Excited by a 915 nm Wavelength in LuVO4:Yb3+/Er3+@SiO2 Nanoparticles.

Abstract: The optical thermometry properties of LuVO4:Yb3+/Er3+@SiO2 nanoparticles (NPs) are studied in detail. In order to avoid the overheating effect for biological tissue caused by 980 nm radiation, 915 ...

Design for cost performance of crashworthy structures made of high strength steel

Abstract: The existing studies on thin-walled structures have focused on structural optimization mainly for enhancing crashworthiness and lightweighting, whilst relatively little attention has been paid to analysis of cost efficiency of an optimized structure. How to develop cost-effective products has always been a primary goal pursued by enterprises in different ways. To address this issue, this study aims to elucidate a systematic approach for exploring the effects of various material grades and structural dimension (e.g. wall thickness) on cost efficiency relative to the crashworthiness performance by taking the double-hat (DH) thin-walled structure as an example. First, a series of drop-weight tests for the DH structure are carried out under axial and lateral impacts. The experimental results show that different material grades and dimensions have different effects on the crashworthiness under different impact velocities. Second, the finite element (FE) models are established and validated with the experiments to analyze the effects of the three factors (wall thickness, material grade, and impact velocity) on the crashworthiness criteria. Third, the surrogate models for each crashworthiness performance indicator and cost efficiency (namely, specific energy absorption – SEA, bending moment – M b , SEA/cost and M b /cost) are constructed by using the regression technique. Finally, the combined effects of material grade and structural dimension on cost and performance are analyzed and compared respectively; and the results show that there is room to significantly reduce production cost without sacrificing the crashworthiness performance. For mass production implemented in modern automotive industry, the proposed design methodology allows to better balance performance and cost.

Facile Engineering of Indomethacin-Induced Paclitaxel Nanocrystal Aggregates as Carrier-Free Nanomedicine with Improved Synergetic Antitumor Activity.

Abstract: Carrier-free nanomedicines mainly composed of drug nanocrystals are considered as promising candidates for next-generation nanodrug formulations. However, such nanomedicines still need to be stabilized by additive surfactants, synthetic polymers, or biologically based macromolecules. Based on the strong intermolecular interactions between indomethacin (IDM, a COX-2 inhibitor) and paclitaxel (PTX, a chemotherapy drug), we herein successfully engineered a novel kind of carrier-free nanomedicines that organized as IDM-induced PTX nanocrystal aggregates via one-pot self-assembly without any nonactive excipients. In the assemblies of IDM and PTX (IDM/PTX assemblies), PTX nanocrystals were casted with amorphous IDM molecules, like a "brick-cement" architecture. In serum, these nanoassemblies could rapidly collapse into a great number of smaller nanoparticles, thus targeting the tumor site through the EPR effect. Under the assistance of IDM on immunotherapy, the IDM/PTX assemblies showed obviously improved synergetic antitumor effects of immunotherapy and chemotherapy. The self-assembly of two synergistic active substances into nanomedicines without any nonactive excipients might open an alternative avenue and give inspiration to fabricate novel carrier-free nanomedicines in many fields.

ILSR rumor spreading model with degree in complex network

Abstract: Most rumors in social networks are extremely harmful and have a significant negative impact on social welfare. Therefore, exploring the laws of rumor propagation has been one of the hot topics in current researches. Most traditional rumor spreading models are based on infectious disease transmission models, such as SIR. Since the influence of individual differences and the network structure on rumor spreading are not considered, the rumor propagation process in complex networks can only be described in a coarse-grained manner. In this paper, we consider the role of different users in rumor propagation. Based on the degree of different nodes in the network, we design a new state transition function for each node and proposed a new rumor propagation ILSR model. Firstly, we analyze the model, calculate the equilibrium point and the basic reproductive number to prove the rationality of the model. Then experiments are performed in WS networks, BA scale-free networks and a real Facebook network to investigate the relationship between various nodes with time and the impact of network structure on rumor propagation, and the experimental results show the correctness and effectiveness of the model. It provides a reference for exploring the propagation law of rumors in complex networks and guiding and controlling the propagation of rumors.