The structural and electronic properties of (001) surface of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with first-principles calculations.

CONTEXT: 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is a typical insensitive energetic material. It can be used in explosive formulations, such as PBX-9502 and LX-17-0. TATB is an intriguing and unusual explosive for another reason: it crystallizes into a wide array of planar hydrogen bonds, forming a graphite-like layered structure. Therefore, TATB is one of the important research objects, and its surface structure needs to be deeply understood. In this research work, the electronic and energetic properties of TATB (001) surface are explored. METHODS: In this paper, the structural, electronic, energetic properties and impact sensitivity of TATB (001) surface structure at 0 and -3 GPa along with x-axis were calculated in this study using the first-principles calculations. The calculations in this paper are performed in the CASTEP code, which is based on the density functional theory with the first-principles calculation method using the plan-wave pseudopotential approach. The exchange-correlation interaction was adopted by the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional. The DFT-D method with the Grimme correction accurately models van der Waals interactions. To model the surface structures of TATB, the planar slab method was employed. We constructed TATB (001) periodic slabs including three layers with a 15-Å vacuum layer.

Peripheral Tumor Location Predicts a Favorable Prognosis in Patients with Resected Small Cell Lung Cancer.

Background: Small cell lung cancer (SCLC) is an aggressive malignancy. Surgical resection is currently only recommended for clinical stage I patients who have been carefully staged. The clinical outcomes of patients with resected SCLCs vary because the disease is highly heterogeneous, suggesting that selected patients could be considered for surgical resection depending on their clinical and/or molecular characteristics. Methods: We collected data on a retrospective cohort of 119 limited-stage SCLC patients who underwent lobectomy with mediastinal lymph node dissection from March 2013 to March 2020 at Harbin Medical University Cancer Hospital. Correlations were derived using Fisher's exact test. Models of 2-year and 3-year survival were evaluated by deriving the area under receiver operating characteristic curves. Kaplan-Meier and Cox regression analyses were used to evaluate significant differences between the survival curves and hazard ratios. Results: The median disease-free survival (DFS) was 35.9 months (range 0.9-105.3 months), and the median overall survival (OS) was 45.2 months (range 4.8-105.3 months). Univariate analysis showed that TNM stage was significantly correlated with DFS and OS. The 2-year disease-free rates of patients with stage I, II, and III disease were 76.4%, 50.5%, and 36.1%, respectively, and the 3-year OS rates were 75.9%, 57.7%, and 34.4%, respectively. In pN + patients, multiple (or multiple-station) lymph node involvement significantly increased recurrence and reduced survival compared with patients with single or single-station metastases. Patients with peripheral SCLCs evidenced significantly better DFS and OS than did patients with central tumors. Multivariate analysis showed that TNM stage and tumor location were independently prognostic in Chinese patients with resected limited-stage SCLC. A combination of TNM stage and tumor location was helpful for prognosis. Conclusions: TNM stage and tumor location were independently prognostic in Chinese patients with resected SCLCs. Patient stratification by tumor location should inform the therapeutic strategy. The role of surgical resection for limited-stage SCLC patients must be reevaluated, as this may be appropriate for some patients.

Clinical outcomes of patients taking first-generation EGFR-TKIs may predict the benefits afforded by osimertinib in EGFR T790M-mutant NSCLC patients.

BACKGROUND: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are widely used to treat patients with EGFR-mutated non-small cell lung cancers (NSCLCs). The association between the clinical outcomes of patients on first-line EGFR-TKIs and the efficacy of osimertinib as second-line treatment has not been previously assessed. This is our topic here. PATIENTS AND METHODS: We retrospectively analysed 67 patients with EGFR mutations on osimertinib after treatment with first-generation EGFR-TKIs. We evaluated patient characteristics, the EGFR T790M allele frequency in plasma samples and clinical outcomes. RESULTS: When osimertinib was given as second-line treatment, the median progression-free survival (PFS) was 6.0 months, and the response rate and disease control rate were 32.8% and 91.0%, respectively. Correlation analysis showed that the female sex and isolated (not multiple) progression on first-line EGFR-TKIs were correlated with a superior response to osimertinib. Kaplan-Meier analysis showed that patients exhibiting a partial response, isolated progression, and longer PFS on first-line EGFR-TKIs experienced prolonged PFS on osimertinib. Univariate analysis indicated that the treatment response, PFS and progression when on first-line EGFR-TKIs affected the PFS on osimertinib. Multivariate analysis showed that progression when on first-line EGFR-TKIs was independently prognostic of a response to osimertinib. The median PFS of patients with isolated progressive disease PD alone who were receiving brain radiotherapy was significantly longer than that of patients with isolated progressive disease alone who did not receive brain radiotherapy as well as patients exhibiting multiple progression. A low frequency of the EGFR T790M allele in plasma tended to predict an inferior efficacy of osimertinib and shorter PFS. CONCLUSION: We found that patients who benefited from first-line EGFR-TKIs may experience prolonged PFS and a higher response rate when subsequently given osimertinib. A low plasma frequency of the EGFR T790M allele may predict poor osimertinib efficacy and shorter PFS.

Clinical Characteristics Correlate With Outcomes of Immunotherapy in Advanced Non-Small Cell Lung Cancer.

Considering the existing indicators are not sufficient to predict the patient's response to immune checkpoint inhibitors (ICIs), we conducted this study to evaluate the efficacy and safety of ICIs in advanced non-small cell lung cancer (NSCLC) patients, and to determine prognostic factors of ICIs. In this study, 61 patients diagnosed with advanced NSCLC who underwent ICIs were recruited. The univariate analysis revealed the number of metastatic sites, immune-related adverse events (irAEs) (≥ G2) and best response were significantly associated with both progression-free survival (PFS) and overall survival (OS). Peripheral blood biomarkers, including post-treatment neutrophil-to-lymphocyte ratio (NLR) and CEA levels were also associated with PFS, but not OS. The irAEs (≥ G2), best response and age were confirmed as independent predictors of a prolonged survival by multivariate analysis. The development of irAEs ≥ G2 correlated with a survival benefit in patients with advanced NSCLC (median PFS: 7.1 months vs. 4.6 months, P = 0.013). Thus, we concluded that identifying predictors of benefit from ICIs treatment will help to further extend patient survival in advanced NSCLC.