Enhanced Electrostatic Safety and Thermal Compatibility of Special Powders Based on Surface Modification.

Electrostatic accumulation is associated with almost all powder-conveying processes which could bring about electrostatic discharges. In most cases of industrial accidents, electrostatic discharge is proven to be the primary source of ignition and explosion. Herein, a surface modification process of polyaniline (PANI) is proposed to construct highly exothermic special powders, namely, HMX@PANI energetic composites, with low charge accumulation for improving powder electrostatic safety. Pure HMX are encapsulated within the PANI-conductive polymer layer through simple hydrogen bonding. Simulation results demonstrate that the forming process of HMX/aniline structure is a spontaneously thermodynamical process. The resultant inclusion complex exhibits excellent thermal stability, remarkable compatibility and intensive heat release. Importantly, PANI possesses superior electrostatic mobility characteristics because of the π-conjugated ligand, which can significantly reduce the accumulated charges on the surface of energetic powders. Moreover, the modified explosive has a narrower energy gap, which will improve the electron transition by reducing the energy barrier. The electrostatic accumulation test demonstrates that HMX@PANI composites possess a trace electrostatic accumulation of 34 nC/kg, which is two orders of magnitude lower than that of pure HMX (-6600 nC/kg) and might indicate a higher electrostatic safety. In conclusion, this surface modification process shows great promise for potential applications and could be extensively used in the establishment of high electrostatic safety for special powders.

Theoretical design of new insensitive high energy metal complexes based on the double fused-ring insensitive ligands strategy.

CONTEXT: In this work, 24 new nitrogen-rich fused-ring energetic metal complexes were designed based on the double fused-ring insensitive ligands strategy. First, 7-nitro-3-(1H-tetrazol-5-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine and 6-amino-3-(4H,8H-bis([1,2,5]oxadiazolo)[3,4-b:3',4'-e]pyrazin-4-yl)-1,2,4,5-tetrazine-1,5-dioxide were linked together by coordinating with metals cobalt and copper. Then, three energetic groups (NH2, NO2, and C(NO2)3) were introduced into the system to modify the structure and adjust the performance. Then, their structures and properties were investigated theoretically; the effects of different metals and small energetic groups were studied also. Finally, 9 compounds which have both higher energy and lower sensitivity than the famous high energy compound compound 1,3,5,7-tetranitro-1,3,5,7-tetrazocine were selected out. In addition, it was found that copper, NO2, and C(NO2)3 could increase the energy while cobalt and NH2 would be helpful for reducing the sensitivity. METHODS: Calculations were performed at the TPSS/6-31G(d) level by using the Gaussian 09 software.

TCF21 inhibits tumor-associated angiogenesis and suppresses the growth of cholangiocarcinoma by targeting PI3K/Akt and ERK signaling.

Tumor-associated angiogenesis plays a critical role in the pathogenesis of cholangiocarcinoma (CCA). In this study, we examined the biological effects and molecular mechanisms of transcription factor 21 (TCF21) on CCA-associated angiogenesis. TCF21 expression was compared between 15 pairs of peritumor normal tissues and CCA tissues and also between normal bile duct epithelial cells and two CCA cell lines (QBC-939 and TFK-1) using real-time PCR and Western blot. With the use of both CCA cell lines as the model system, we stably expressed TCF21 by lentiviral transduction (Lv-TCF21). In vivo, we monitored xenograft growth from different CCA cells, measured tumor-associated angiogenesis by histological analysis, and determined the expressions and circulatory levels of VEGFA and PDGF-BB by immunohistochemistry and ELISA, respectively. In vitro, we assessed the effects of conditioned medium collected from different CCA cells on the viability, migration, and tube formation of endothelial cells and explored the significance of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), as well as ERK1/2 signaling in this process. TCF21 was significantly downregulated in CCA tissues or cell lines. Ectopic expression of TCF21 in CCA cells inhibited xenograft growth or tumor-associated angiogenesis in vivo and targeted the expression and secretion of proangiogenic factors, VEGFA and PDGF-BB. In vitro, the conditioned medium collected from Lv-TCF21 CCA cells significantly reduced the viability, migration, and tube formation of endothelial cells. On the molecular level, the targeting of PI3K/Akt and ERK1/2 signaling mediated the anti-angiogenic activity of TCF21. TCF21 presents growth-inhibitory and anti-angiogenic activities, and thus the elevation of TCF21 expression may provide therapeutic benefits for CCA. NEW & NOTEWORTHY Transcription factor 21 (TCF21) is downregulated in cholangiocarcinoma (CCA) tissues or cells. TCF21 inhibits the growth of xenografts derived from CCA cells. TCF21 suppresses in vivo tumor-associated angiogenesis. TCF21 targets expression and production of proangiogenic factors from CCA cells. The targeting of phosphatidylinositol 3-kinase/protein kinase B and ERK1/2 signaling mediates the anti-angiogenesis of TCF21.

Triple-Stimuli-Responsive Smart Nanocontainers Enhanced Self-Healing Anticorrosion Coatings for Protection of Aluminum Alloy.

Novel acid/alkali/corrosion potential triple-stimuli-responsive smart nanocontainers (TSR-SNs) were successfully assembled to regulate the release of an encapsulated corrosion inhibitor, benzotriazole (BTA), by installing specially structured bistable pseudorotaxanes as supramolecular nanovalves onto orifices of mesoporous silica nanoparticles. In normal conditions, BTA molecules were sealed in the mesopores. Upon any stimulus of acid, alkali, or corrosion potential, BTA molecules were quickly released because of the open states of the supramolecular nanovalves. TSR-SNs as smart nanocontainers were added into the SiO2-ZrO2 sol-gel coating to fabricate a stimuli-feedback, corrosion-compensating self-healing anticorrosion coating (SF-SHAC). Compared with the conventional pH-responsive smart nanocontainers synthesized for the SHAC, TSR-SNs not only respond to the pH changes occurring on corrosive microregions but also, and more importantly, feel the corrosion potential of aluminum alloys and give quick feedback. This design avoids wasting smart nanocontainers because of the local-dependent, gradient pH stimulus intensities and obviously enhances the response sensitivity of the SF-SHAC. Electrochemical impedance spectroscopy and salt spray tests prove the excellent physical barrier of the SF-SHAC. Through scanning vibrating electrode technique measurements, the SF-SHAC doped with TSR-SNs demonstrates inhibiting rates for corrosive microcathodic/anodic current densities that are faster than other control SHACs. The new incorporated corrosion potential-responsive function ensures the efficient working efficiency of TSR-SNs and makes full use of the preloaded corrosion inhibitors as repair factors.

A Facile Method to Construct MXene/CuO Nanocomposite with Enhanced Catalytic Activity of CuO on Thermal Decomposition of Ammonium Perchlorate.

In this work, a mixing-calcination method was developed to facilely construct MXene/CuO nanocomposite. CuO and MXene were first dispersed in ethanol with sufficient mixing. After solvent evaporation, the dried mixture was calcinated under argon to produce a MXene/CuO nanocomposite. As characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and X-ray photoelectron spectra (XPS), CuO nanoparticles (60⁻100 nm) were uniformly distributed on the surface and edge of MXene nanosheets. Furthermore, as evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), the high-temperature decomposition (HTD) temperature decrease of ammonium perchlorate (AP) upon addition of 1 wt% CuO (hybridized with 1 wt% MXene) was comparable with that of 2 wt% CuO alone, suggesting an enhanced catalytic activity of CuO on thermal decomposition of AP upon hybridization with MXene nanosheets. This strategy could be further applied to construct other MXene/transition metal oxide (MXene/TMO) composites with improved performance for various applications.

Constructing Sheet-On-Sheet Structured Graphitic Carbon Nitride/Reduced Graphene Oxide/Layered MnO2 Ternary Nanocomposite with Outstanding Catalytic Properties on Thermal Decomposition of Ammonium Perchlorate.

We unprecedentedly report that layered MnO2 nanosheets were in situ formed onto the surface of covalently bonded graphitic carbon nitride/reduced graphene oxide nanocomposite (g-C3N4/rGO), forming sheet-on-sheet structured two dimension (2D) graphitic carbon nitride/reduced graphene oxide/layered MnO2 ternary nanocomposite (g-C3N4/rGO/MnO2) with outstanding catalytic properties on thermal decomposition of ammonium perchlorate (AP). The covalently bonded g-C3N4/rGO was firstly prepared by the calcination of graphene oxide-guanidine hydrochloride precursor (GO-GndCl), following by its dispersion into the KMnO4 aqueous solution to construct the g-C3N4/rGO/MnO2 ternary nanocomposite. FT-IR, XRD, Raman as well as the XPS results clearly demonstrated the chemical interaction between g-C3N4, rGO and MnO2. TEM and element mapping indicated that layered g-C3N4/rGO was covered with thin MnO2 nanosheets. Furthermore, the obtained g-C3N4/rGO/MnO2 nanocomposite exhibited promising catalytic capacity on thermal decomposition of AP. Upon addition of 2 wt % g-C3N4/rGO/MnO2 ternary nanocomposite as catalyst, the thermal decomposition temperature of AP was largely decreased up by 142.5 °C, which was higher than that of pure g-C3N4, g-C3N4/rGO and MnO2, respectively, demonstrating the synergistic catalysis of the as-prepared nanocomposite.

Direct Growth of CuO Nanorods on Graphitic Carbon Nitride with Synergistic Effect on Thermal Decomposition of Ammonium Perchlorate.

Novel graphitic carbon nitride/CuO (g-C3N4/CuO) nanocomposite was synthesized through a facile precipitation method. Due to the strong ion-dipole interaction between copper ions and nitrogen atoms of g-C3N4, CuO nanorods (length 200-300 nm, diameter 5-10 nm) were directly grown on g-C3N4, forming a g-C3N4/CuO nanocomposite, which was confirmed via X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and X-ray photoelectron spectroscopy (XPS). Finally, thermal decomposition of ammonium perchlorate (AP) in the absence and presence of the prepared g-C3N4/CuO nanocomposite was examined by differential thermal analysis (DTA), and thermal gravimetric analysis (TGA). The g-C3N4/CuO nanocomposite showed promising catalytic effects for the thermal decomposition of AP. Upon addition of 2 wt % nanocomposite with the best catalytic performance (g-C3N4/20 wt % CuO), the decomposition temperature of AP was decreased by up to 105.5 °C and only one decomposition step was found instead of the two steps commonly reported in other examples, demonstrating the synergistic catalytic activity of the as-synthesized nanocomposite. This study demonstrated a successful example regarding the direct growth of metal oxide on g-C3N4 by ion-dipole interaction between metallic ions, and the lone pair electrons on nitrogen atoms, which could provide a novel strategy for the preparation of g-C3N4-based nanocomposite.

Efficacy and safety of chemotherapy with or without targeted therapy in biliary tract cancer: A meta-analysis of 7 randomized controlled trials.

The systematic treatment based on gemcitabine plus cisplatin is recommended as the current standard chemotherapy for unresectable or metastatic biliary tract cancers. However, the exact benefits from the recognized regime are still dismal. We thus elicit this study in an attempt to analyze whether targeted therapy coupled with various chemotherapy could produce improvement of survival benefits. The clinical trials were searched electronically from databases till July 2016 published in English and Chinese. Nine hundred and sixty-four patients from 7 trials were identified in our analysis. The overall analysis achieved a significantly higher overall response rate (ORR) among the patients treated with targeted drugs plus chemotherapy than chemotherapy alone (OR=1.87; 95% CI: 1.37-2.57; P=0.000), but failed in the overall progression-free survival (PFS) [mean difference (MD)=0.63; 95% CI:-0.45-1.72; P=0.26] and overall survival (OS) (MD=-0.67; 95% CI:-2.54-1.20; P=0.49). In the sub analysis, better ORR was obtained with the addition of EGFR (OR=1.75; 95% CI: 1.20-2.56; P=0.004) and VEGFR (OR=2.5; 95% CI: 1.28-4.87; P=0.007) targeted therapy. Furthermore, the sub analysis of EGFR target showed an significant improvement on PFS (MD=1.36; 95% CI: 0.29-2.43; P=0.01). No significant differences were observed in the incidences of neutropenia (OR=1.37; 95% CI: 0.89-2.12), thrombocytopenia (OR=1.40; 95% CI: 0.83-2.39), anemia (OR=1.21; 95% CI: 0.62-2.38), peripheral neuropathy (OR=1.52; 95% CI: 0.81-2.88), increased AST/ALT (OR=1.40; 95% CI: 0.82-2.39) as well as fatigue (OR=1.65; 95% CI: 0.96-2.84) in either of the treatment groups. In conclusion, better ORR associated with chemotherapy combined with targeted therapy (both targeting EGFR and VEGF) is found in the present meta-analysis without the cost of increased unacceptable toxicities, but regretfully not for the OS. The sub-analysis of targeting EGFR instead of VEGF obtains a superior PFS. Otherwise, there is no statistically significant difference in the overall PFS between the combination regime and chemotherapy alone. Given the paucity of favorable data, we need further studies to characterize optimal targeted agents to confirm the potential value to biliary tract cancer.

Efficacy and Safety of Chemotherapy with or without Targeted Therapy in Biliary Tract Cancer: A Meta-analysis of 7 Randomized Controlled Trials / 华中科技大学学报（医学）（英德文版）

The systematic treatment based on gemcitabine plus cisplatin is recommended as the current standard chemotherapy for unresectable or metastatic biliary tract cancers.However,the exact benefits from the recognized regime are still dismal.We thus elicit this study in an attempt to analyze whether targeted therapy coupled with various chemotherapy could produce improvement of survival benefits.The clinical trials were searched electronically from databases till July 2016 published in English and Chinese.Nine hundred and sixty-four patients from 7 trials were identified in our analysis.The overall analysis achieved a significantly higher overall response rate (ORR) among the patients treated with targeted drugs plus chemotherapy than chemotherapy alone (OR=1.87;95％ CI:1.37-2.57;P=0.000),but failed in the overall progression-free survival (PFS) [mean difference (MD)=0.63;95％ CI:-0.45-1.72;P=0.26] and overall survival (OS) (MD=-0.67;95％ CI:-2.54-1.20;P=0.49).In the sub analysis,better ORR was obtained with the addition of EGFR (OR=1.75;95％ CI:1.20-2.56;P=0.004) and VEGFR (OR=2.5;95％ CI:1.28-4.87;P=0.007) targeted therapy.Furthermore,the sub analysis of EGFR target showed an significant improvement on PFS (MD=l.36;95％ CI:0.29-2.43;P=0.01).No significant differences were observed in the incidences ofneutropenia (OR=1.37;95％ CI:0.89-2.12),thrombocytopenia (OR=l.40;95％ CI:0.83-2.39),anemia (OR=l.21;95％ CI:0.62-2.38),peripheral neuropathy (OR=1.52;95％ CI:0.81-2.88),increased AST/ALT (OR=l.40;95％ CI:0.82-2.39) as well as fatigue (OR=1.65;95％ CI:0.96-2.84) in either of the treatment groups.In conclusion,better ORR associated with chemotherapy combined with targeted therapy (both targeting EGFR and VEGF) is found in the present mcta-analysis without the cost of increased unacceptable toxicities,but regretfully not for the OS.The sub-analysis of targeting EGFR instead of VEGF obtains a superior PFS.Otherwise,there is no statistically significant difference in the overall PFS between the combination regime and chemotherapy alone.Given the paucity of favorable data,we need further studies to characterize optimal targeted agents to confirm the potential value to biliary tract cancer.

[Study on thermal decompositon properties of hexafluoropropane clean gaseous fire-extinguishing agent].

The thermal decomposition properties of hexafluoropropane clean gaseous fire-extinguishing agent were studied in tubular reactor from 500 to 750 degrees C and the decomposed gas was characterized by gas chromatography(GC), Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Hydrogen fluoride was detected after the decomposed gas was analyzed by pH testing, while pentafluoropropylene was found by GC-MS. The results showed that hydrogen fluoride eliminated from hexafluoropropane was the main reaction, while pentafluoropropylene was the primary product during hexafluoropropane decomposition under high temperature. GC and FTIR results indicated that the reaction temperatures had significant effects on the thermal decomposition of hexafluoropropane. Haxafluropropane was steady at 500 degrees C, whereas started to decompose weakly at 600 degrees C. The degree of the thermal decomposition of hexafluoropropane was enhanced with the temperature increase. And hexafluoropropane underwent intense decompositon at 750 degrees C. FTIR can be used as a new method to study extinguishing mechanism of fluorine-containing fire extinguishing agent online.