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[Display omitted] • A series of pyrimidine-based energetic molecules were obtained within three steps. • Theoretical calculations were adopted to predict energy and stability parameters. • Compound 5 can act as a heat-resistant and insensitive explosive. • Compound 10 exhibits superior comprehensive properties for a high-energy material. The current rise in performance prediction techniques for energetic compounds provides the possibility of prejudging the effectiveness of derived patterns. In this work, 2,4-diamino-6-chloropyrimidine was used as the precursor, and the three possible derived pathways were systematically explored (guest oxidant, nitration, and N-oxidation). Theoretical calculations were adopted to predict the energy and stability parameters of possible products. The calculations indicated that constructing bridged-ring energetic molecules with N-oxide and nitro group is an effective way to balance energy and safety. Based on this protocol, we synthesized a series of pyrimidine-based energetic molecules within three steps and tested and analyzed their physicochemical properties, verifying the consistency between experimental results and theoretical predictions. This work provides a research model for determining the feasibility and effectiveness of the derivative pathway based on a specific energetic compound precursor and can offer guidance for the directed and large-scale synthesis of high-energy and low-sensitivity explosive molecules. [ABSTRACT FROM AUTHOR]

The first trinitromethyl-substituted pyrimidine derivative was synthesized by direct nitration of its 2-methylpyrimidine precursor. It has a high density (1.85 g cm−3) and excellent detonation performances (v D = 8600 m s−1, P = 32.8 GPa) that may find useful applications in the field of high energy density materials. [Display omitted] • The first trinitromethyl-substituted pyrimidine derivative was synthesized. • A mild and efficient synthetic method has been developed. • The prepared energetic compound demonstrates its potentials as a high energy density material. The first trinitromethyl-substituted pyrimidine derivative (3) was synthesized by direct nitration of its 2-methylpyrimidine precursor, and its structure was thoroughly characterized by FTIR, NMR, elemental analysis, and single-crystal X-ray diffraction. Compound 3 has a high density (1.85 g cm−3) and excellent detonation performances (v D = 8600 m s−1, P = 32.8 GPa), which highlights its great potential as high-energy density material. Furthermore, this work provides a mild and efficient method for the synthesis of trinitromethyl-substituted pyrimidine derivatives, which might have potential application in the design and synthesis of other trinitromethyl-based heterocyclic compounds. [ABSTRACT FROM AUTHOR]

The role of serum tumor markers (STMs) in the modern management of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) mutations in lung cancer remains poorly described. In this study, we investigated whether STMs could be a valuable noninvasive tool to predict EGFR mutations and ALK positivity in non-small-cell lung cancer (NSCLC) patients. We retrospectively reviewed and included 1089 NSCLC patients who underwent EGFR or ALK mutation testing and STMs measurement prior to treatment. The differences in several clinical characteristics and STMs between the subgroups were analyzed. Multivariate logistic regression analysis was performed to identify predictors of EGFR mutations and ALK positivity. EGFR mutations were found more frequently in females (63.11%), never-smokers (59.69%), and those with lung adenocarcinoma (ADC) (53.87%). Negative carbohydrate antigen (CA) 125, ferritin (FERR), squamous cell carcinoma antigen (SCC), and soluble fragment of cytokeratin 19 (CYFRA 21-1) levels were significantly associated with EGFR mutations (p < 0.05). Multivariate analysis demonstrated that ADC, never-smoker status, and negative CA 125 and SCC results were predictors of EGFR mutations (p < 0.05). The receiver operating characteristic (ROC) curve yielded an area under the curve (AUC) of 0.715 (95% confidence interval [CI]: 0.673–0.758) for the combination of the four factors. Positive ALK expression was found more frequently in younger patients (median age: 49 years), females (8.40%), never-smokers (8.82%), and those negative for carcinoembryonic antigen (CEA) (8.02%). Multivariate analysis demonstrated that younger age and never-smoker status were the only independent predictors of ALK positivity (p < 0.05). The ROC curve yielded an AUC of 0.760 (95% CI: 0.677–0.844) for the combination of these two factors. STMs are associated with mutant EGFR status and could be integrated with other clinical factors to enhance the ability to distinguish EGFR mutation status among NSCLC patients. For ALK-positive patients, younger age and never-smoker status could predict the mutation status, whereas STMs could not. • ADC, never-smoker status, and negative CA 125 SCC levels can predict EGFR mutation status in NSCLC patients (AUC, 0.715). • Younger age and never-smoker status are independent predictors of ALK positivity (AUC, 0.760). [ABSTRACT FROM AUTHOR]

The development of halogen-free nitramine-based green solid propellants has attracted a significant interest due to their application in rapidly developing aerospace technologies. However, relatively low burn rates, and generation of high pressure in the combustion chamber limit applications of such propellants. The alleviation of these problems could be achieved by using suitable combustion catalysts. Herein, a new energetic nitrogen-rich open framework compound 1 was prepared and evaluated as an efficient Pb-free combustion catalyst for HMX-nitrocellulose-nitroglycerin solid composite propellant formulation. Compound 1 was synthesized by a straightforward one-step process, its structure was comprehensively characterized by x-ray crystallography, and it was found to be thermostable (decomposition at 289 °C), insensitive to mechanical impact and friction (60 J, 360 N), and showed high hydrolytic stability. A propellant formulation containing 3.0 wt.% of 1 exhibited 45% increase in its burning rate (under 6.0 MPa) versus catalyst-free reference propellant. In the pressure range of 3–10 MPa, the pressure exponent was calculated to be 0.32, which is more than two times lower than of the reference propellant. These impressive properties of catalyst 1 suggest that it has a great potential to be further used in the development of future highly energetic green solid propellants. [ABSTRACT FROM AUTHOR]

The development of hypergolic materials has aroused great interest since their significant application in bipropellant systems. In this work, five energetic complexes (1–5) were developed to demonstrate hypergolic performance with the green oxidizer hydrogen peroxide. The compounds were comprehensively characterized. The decomposition temperatures of these compounds were in the range from 228.8 to 295.5 °C. The highest thermal stability was observed in compound 5. The density of these compounds were in the range from 1.389 to 1.502 g∙cm−3 which was higher than most of the known hypergolic materials. Furthermore, the hypergolic performance of these materials were evaluated with 90% H 2 O 2 by an "oxidizer-to-fuel" standard droplet test. For the examined hypergolic combinations, the shortest ignition delay time was only 3 ms which was observed in compound 2. This ultra-short ignition delay time was shorter than that of most hypergolic combinations and attributed to synergy between different components in the energetic complexes. The copper ion metal center was the key promoting factor affecting hypergolic performance of the target compounds. The organic ligand acted as an energetic fuel while the NO 3 − counter ions further improved the hypergolic performance. Integrating these components into one complex and demonstrating their hypergolic performance with hydrogen peroxide as the oxidizer was successfully achieved. The hypergolic phenomenon observed in this work between energetic complexes and hydrogen peroxide may lead to a new approach for the development of green hybrid propulsion systems. [ABSTRACT FROM AUTHOR]