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As a new structural motif, an interesting 3D energetic metal – framework of silver ions and 3,4-diaminofurazan, [Ag+(daf)NO3−]n, is successfully synthesized and the structure is determined by single-crystal X-ray diffraction. The effects of hydrogen bond, coordination bond, adsorption and filling interactions make this compound have a high density (2.694 g·cm−3 at 293 K). The calculated detonation velocity and the sensitivities are all comparable with trinitrotoluene (TNT). The onset decomposition temperature is equal to hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), state-of-the-art explosive. This framework provides a potential superiority of E-MOFs for energetic materials. [ABSTRACT FROM AUTHOR]

We detected PD-L1 and intra-tumoral CD8+ T lymphocytes (CD8+ TIL) in 19 patients with esophageal carcinosarcoma (ECS). The median follow-up period of these patients was 43 months, and the three- and five-year survival rates were 78.9 and 63.2%, respectively. No statistically significant correlation was observed between PD-L1 and CD8+ TIL in sarcomatous components(SC) (r = −0.262, p = 0.279) and epithelial carcinomatous (EC) (r = 0.055, p = 0.824). This study examined the immunological markers in ECS for the first time. PD-L1 is highly expressed in the SC and is associated with a poorer prognosis. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulation has been used to investigate the new explosive 5,5ʹ-dinitramino-3,3ʹ-bi[1,2,4-triazolate] carbohydrazide salt (CBNT) and its polymer-bonded explosives (PBXs) with polymethyl methacrylate (PMMA), polyisobutylene (PIB), cellulose acetate butyrate (CAB) and polyurethane (Estane 5703). The binding energy, isotropic mechanical properties (tensile modulus, bulk modulus, shear modulus, and Poisson's ratio) and moldability are reported for CBNT and its based PBXs. Moreover, the detonation parameters (detonation velocity, detonation pressure, detonation temperature, and detonation heat) of CBNT and CBNT-based PBXs are calculated using EXPLO5. The binding energy between each of the crystalline surfaces and each polymer is different, of which the descending order is CBNT/CAB > CBNT/Estane5703 > CBNT/PMMA > CBNT/PIB. The obtained mechanical properties results indicate that the mechanical properties of the CBNT can be effectively improved by adding a tiny amount of polymer binders and the ability of different polymer binders improving the plasticity and moldability of CBNT in the descending order of Estane 5703 > CAB > PMMA > PIB. The calculated detonation performances show that when 5% binders are added, the detonation velocity and detonation pressure of PBXs are lower than those of pure CBNT, of which the detonation velocity is higher than 8500 m/s and the detonation pressure is higher than 26 GPa. Due to the high enthalpy of formation, the detonation temperature and detonation heat of CBNT/CAB are larger than those of pure CBNT. [ABSTRACT FROM AUTHOR]

Dihydroxylammonium 5,5ʹ-bistetrazole-1,1ʹ-diolate (TKX-50) is an energetic ionic salt with excellent properties of low mechanical sensitivity, environment-friendliness, and low toxicity. It meets the requirement of high insensitivity for military high-energy explosives. However, the poor crystal habit of TKX-50 in most solvents, as well as its poor adhesive ability with conventional binders, has limited its application. In the present work, we report a novel strategy to improve the morphology and surface property of TKX-50 using an environmentally friendly anionic polyelectrolyte, carboxymethylcellulose sodium (CMC), by the anti-solvent method. The scanning electron microscope analysis indicates that the morphology of TKX-50 was greatly altered in the presence of CMC, resulting in TKX-50 granules with low aspect ratios. Molecular dynamics simulation was conducted to explore the mechanism of such morphological change. It was found that the combined action of ethanol and CMC promoted the growth of (110) and (011), while the (020) still dominated the crystal growth, resulting in the low aspect ratio of TKX-50. The effects of CMC coating on the particle size of TKX-50 and the interaction between CMC and TKX-50 were investigated with the focused beam reflectance measurement and particle video microscope. Further characterization suggested that the highest coating efficiency (R) could be obtained at the CMC content of 4% with which granular TKX-50 crystals were produced. The non-isothermal kinetic study revealed that the CMC coating also improved the thermal stability of TKX-50. Our work has provided a novel method to improve the properties of TKX-50 for its practical application. [ABSTRACT FROM AUTHOR]

The pressure characteristics and safety performance of dihydroxylammonium 5,5ʹ-bistetrazole-1,1ʹ-diolate (TKX-50) decomposition were studied in confined space by using the accelerating rate calorimeter (ARC). The effects of the heating rate and the sample amount on the safety performance were investigated. The experiment results revealed that high heating rate was harmful to the safety performance of TKX-50. The decomposition mechanism did not change when using different amounts of sample in the range between 47.5 and 72.5 mg. After ignition, TKX-50 exhibited better safe performance than RDX and HMX. [ABSTRACT FROM AUTHOR]

The crystal morphology of Hexanitrohexaazaisowurtzitane (HNIW) in vacuum and ethyl acetate was investigated by attachment energy (AE) model through molecular dynamics (MD). The simulated solvent-affected outcome agrees well with the experimental crystal habit cultivated from ethyl acetate. The influence of model size on the modified AE was discussed, and a reasonable model size was obtained. The model size can be broadened to calculate the morphology of other compounds. The radial distribution function (RDF) analyses and diffusion coefficient analyses were performed to explore the adsorption and diffusion behaviors of ethyl acetate molecules on HNIW surfaces. The simulation results can provide some guidance for the further crystallization process of HNIW. [ABSTRACT FROM AUTHOR]

The dissolution and thermochemical properties of dihydroxylammonium 5,5ʹ-bistetrazole-1,1ʹ-diolate (TKX-50) and its intermedium disodium 5,5ʹ-bistetrazole-1,1ʹ-diolate ([Na2(H2O)4]BTO) in water at 298.15 K were studied using a C-80 Calvet microcalorimeter. Empirical formulae for the calculation of the molar enthalpies of dissolution (ΔdissH), relative partial molar enthalpies (ΔdissHpartial), and relative apparent molar enthalpies (ΔdissHapparent) were deduced by the experimental results of the dissolution processes of TKX-50 and [Na2(H2O)4]BTO in water. Finally, the corresponding kinetic equations describing the dissolution processes weredα/dt = 10−2.95(1 − α)0.64for the dissolution of TKX-50 in water anddα/dt = 10−2.76(1 − α)1.07for the dissolution of [Na2(H2O)4]BTO in water. [ABSTRACT FROM AUTHOR]