Research progress on the catalytic and thermal decomposition of ammonium dinitramide (ADN).

Ammonium dinitramide (NH4N(NO3)2, ADN) is regarded as a promising oxidizer due to its low signature and high specific impulse. Generally, ADN undergoes exothermic decomposition above 140 °C accompanied by the byproduct of ammonium nitrate (AN). The inevitable endothermic decomposition of AN decreases the overall heat release, and so there is a need to develop efficient catalysts to guide ADN decomposition along desired pathways with a lower decomposition temperature and higher heat release. A suitable catalyst should be able to withstand the harsh conditions in a thruster to achieve a stable thrust force, which poses a huge obstacle for manufacturing a stable and active catalyst. This review gives a comprehensive summary of the thermal and catalytic decomposition pathways of ADN for the first time, which is expected to deepen the understanding of its reaction mechanism and provide useful guidance for designing prospective catalysts toward efficient ADN decomposition.

CIRCESPL1 SILENCING PROTECTS AGAINST LPS-INDUCED LUNG FIBROBLAST DYSFUNCTION PARTLY BY TARGETING THE MIR-146B-3P/TRAF1 AXIS IN PNEUMONIA.

ABSTRACT: Background: Neonatal pneumonia is a common disease in the neonatal period with high mortality. The present work concentrated on the role and mechanism of circular RNA extra spindle pole bodies like 1, separase (circESPL1) in LPS-induced dysfunction of lung fibroblasts. Methods: Reverse transcription-quantitative polymerase chain reaction and Western blot assay were conducted to analyze RNA and protein expression, respectively. Cell viability, proliferation, apoptosis, and inflammation were assessed by Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Dual-luciferase reporter assay and RNA immunoprecipitation assay were conducted to verify the intermolecular interactions among circESPL1, miR-146b-3p, and TRAF1. Results: CircESPL1 expression was upregulated in the serum samples of pneumonia patients and LPS-induced lung fibroblasts. CircESPL1 silencing protected lung fibroblasts against LPS-induced dysfunction. CircESPL1 bound to microRNA-146b-3p (miR-146b-3p) in lung fibroblasts. CircESPL1 knockdown-mediated protective effects on LPS-induced lung fibroblasts were largely reversed by the silence of miR-146b-3p. miR-146b-3p directly interacted with the 3' untranslated region of TNF receptor associated factor 1 (TRAF1), and TRAF1 expression was regulated by the circESPL1/miR-146b-3p axis in lung fibroblasts. TRAF1 overexpression largely reversed miR-146b-3p accumulation-mediated protective effects on LPS-induced lung fibroblasts. Conclusion: CircESPL1 knockdown protected lung fibroblasts from LPS-induced injury partly by targeting the miR-146b-3p/TRAF1 axis.

Quality Evaluation of Traditional Chinese Medicine Mylabris Based on Heavy Metal Risk Assessment and Analysis of Pharmacological Component Contents.

As a highly representative traditional Chinese anti-tumor medicinal material, the biomass of Mylabris is collected from the wild. However, the living environments of Mylabris is differ, so Mylabris may be contaminated by heavy metal pollution depending on the environment. These environments may also affect the amount of biosynthesis of its medicinal ingredient, cantharidin, there by affecting the quality of Mylabris. In this study, we determined the heavy metal content in Mylabris from different origins by using ICP-MS, evaluated the risk posed by these heavy metals, and recommended theoretical maximum limits of heavy metals in medicinal Mylabris. The results show that the Cu content in Mylabris is substantially higher than that in Cr, As, Pb, Cd, and Hg. A quantitative risk assessment showed that Mylabris poses no noncarcinogenic risks. The results of the total carcinogenic risk value showed that origins S12 and S13 pose carcinogenic risk by Cr and As, and the rest of the origins were in the human-tolerable carcinogenic risk range. We found large differences in the cantharidin content in Mylabris from different origins. In general, the Mylabris from origins S2, S3 and S4 had a higher in vivo cantharidin content, which proved that the quality of the medicinal materials was higher here than in other production areas. Finally, we providing a reference for the quality evaluation of medicinal Mylabris materials.

Antitumor Activity of the Zinc Oxide Nanoparticles Coated with Low-Molecular-Weight Heparin and Doxorubicin Complex In Vitro and In Vivo.

Various metal oxide nanomaterials have been widely used as carriers to prepare pH-sensitive nanomedicines to respond to the acidic tumor microenvironment promoting antitumor efficiency. Herein, we used zinc oxide nanoparticles (ZnO NPs) as metal oxide nanomaterial coated with low-molecular-weight heparin (LMHP) and doxorubicin (DOX) complex (LMHP-DOX) to prepare ZnO-LD NPs for controllable pH-triggered DOX release on the targeted site. Our results indicated that the released DOX from ZnO-LD NPs was pH-sensitive. The oxygen produced by ZnO-LD NPs in H2O2 solution was observed in in vitro experiment. The ZnO-LD NPs entered into both PC-3M and 4T1 tumor cells via clathrin-mediated endocytosis and micropinocytosis pathway. The intracellular reactive oxygen species (ROS) generated by ZnO-LD NPs could significantly increase the caspase 3/7 level, leading to tumor cell apoptosis. The in vitro and in vivo antitumor activity was confirmed in PC-3M and 4T1 cell lines or tumor-bearing mice models. The in vivo and in vitro tumor images via second-order nonlinearity of ZnO-LD NPs indicated that ZnO-LD NPs could penetrate deep into the tumor tissues. Therefore, the ZnO-LD NPs developed in our study could provide an efficient approach for the preparation of pH-sensitive nano delivery systems suitable for tumor therapy and imaging.

Heavy Metal Pollution Analysis and Health Risk Assessment of Two Medicinal Insects of Mylabris.

Mylabris is the dried body of the Chinese blister beetle (Mylabris sp.), which has been used in traditional Chinese medicine and achieved significant positive effects in the treatment of cancer including liver cancer, lung cancer, and rectal cancer. However, heavy metal pollution and accumulation of Mylabris insects could pose threat to human health. This study was carried out to assess levels of different heavy metals like Cu, As, Cd, Hg, and Pb, along with soil-plant-insect system and health risks using two representative Mylabris insects from the Hasi Mountains of Gansu Province, China. The results showed that the heavy metal concentration of plants and insects followed the order Cu > Pb > As > Hg > Cd. Compared with soil and plants, the content of Cu in insects was the highest, reaching 45.65 mg/kg. Cu was the main element that caused insects to absorb and accumulate. The quantitative risk analysis implied the two Mylabris insects had carcinogenic risks, with the contribution of As providing 63% and 60.7%, respectively. This kind of carcinogenic risk that the human body could bear was not easy to cause side effects to normal people, but it was difficult and dangerous for cancer patients. Thus, the evaluation of health risk lays the foundation for pollutant risk monitoring.

PEGylated dihydromyricetin-loaded nanoliposomes coated with tea saponin inhibit bacterial oxidative respiration and energy metabolism.

The biofilms produced by the aggregation of bacterial colonies are among the major obstacles of host immune system monitoring and antimicrobial treatment. Herein, we report PEGylated dihydromyricetin-loaded liposomes coated with tea saponin grafted on chitosan (TS/CTS@DMY-lips) as an efficient cationic antibacterial agent against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which is supported by their deep penetration into bacterial biofilms and broad pH-stable release performance of dihydromyricetin (DMY). The successful construction of the drug delivery system relied on tea saponin grafted on chitosan (TS/CTS) via formatted ester bonds or amido bonds as a polyelectrolyte layer of PEGylated dihydromyricetin-loaded liposomes (DMY lips), which achieved controlled release of DMY in weak acidic and neutral physiological environments. The micromorphology of TS/CTS@DMY-lips was observed to resemble dendritic cells with an average size of 266.49 nm, and they had excellent encapsulation efficiency (41.93%), water-solubility and stability in aqueous solution. Besides, TS/CTS@DMY-lips displayed effective destruction of bacterial energy metabolism and cytoplasmic membranes, resulting in the deformation of the cell wall and leaking of cytoplasmic constituents. Compared to free DMY, DMY lips and chitosan-coated dihydromyricetin liposomes (CTS@DMY-lips), TS/CTS@DMY-lips has more thorough killing activity against E. coli and S. aureus, which is related to its excellent sustained release performance of DMY under the protection of the TS/CTS coating.

Improved localized surface plasmon resonance index sensitivity based on chemically-synthesized gold nanoparticles on indium tin oxide surfaces.

The results of this reported work indicated that gold nanoparticle arrays self-assembled on indium tin oxide (ITO) glasses can obtain broader localized surface plasmon resonance (LSPR) wavelength range and higher sensitivity than the bare quartz. The results of surface electric field calculated using finite difference time domain showed that the electric field of nanoparticles on ITO glasses is enhanced and the repulsive forces within each particle is weakened. According to the dipolar interaction mechanism, a weakened repulsive forces within each particle lead to a lower resonance frequency and a strong redshift of the LSPR spectra.

The injectable neurostimulator: an emerging therapeutic device.

Injectable neurostimulators are currently applied in clinical trials to minimize the side effects such as discomfort, risk of infection, and post-surgery trauma, which can be pronounced with conventional, bulky implantable neurostimulators. Owing to its smaller size, wireless-updatable software, and wireless power supply, the injectable neurostimulator is presumably less invasive, 'smarter', and has a longer lifetime. We discuss the concept and development of the injectable neurostimulator, persistent implementation challenges, and obstacles to be overcome in its evolution. We survey the use of new materials, technologies, and design methods for injectable electrodes, batteries, antennas, and packaging to enhance reliability and other features. These advances in the field are accompanied by progress in electrophysiology, neuroscience, neurology, clinical trials, and treatments.