Effects of concurrent chemoradiotherapy with or without Endostar on the regression of retropharyngeal lymph node and prognosis of patients with locally advanced nasopharyngeal carcinoma: a retrospective study.

BACKGROUND AND PURPOSE: To investigate the effect of combining Endostar with concurrent chemoradiotherapy (ECCRT) compared to concurrent chemoradiotherapy (CCRT) on the regression rate of retropharyngeal lymph nodes (RLNs) and the relationship between regression rate of RLNs and prognosis of patients with locally advanced nasopharyngeal carcinoma (LANPC). METHODS: A total of 122 LANPC patients with RLNs metastasis were included. Metastatic RLNs were delineated both before and after treatment slice by slice on the magnetic resonance images cross-section. The regression rate of RLNs, adverse effects (AE) were evaluated. The median regression rate of RLNs was taken as the cut-off value, and the patients were furtherly divided into high regression rate (HRR) group and low regression rate (LRR) group, then survival times were evaluated. RESULTS: The median regression rates of RLNs in the ECCRT and CCRT groups were 81% and 50%, respectively (P < 0.001). There was no statistically significant difference in the incidence of grade 3/4 AEs between the two groups, except for oral mucositis (ECCRT 26.23% vs. CCRT 44.26%, P = 0.037). The 3-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS) and locoregional failure-free survival (LRFFS) rates in the HRR and LRR groups were 85.48% and 86.67% (P = 0.983), 80.65% and 68.33% (P = 0.037), 83.87% and 85% (P = 0.704), 93.55% and 81.67% (P = 0.033), respectively. CONCLUSIONS: Patients in the ECCRT group had higher regression rates of RLNs and lower incidence of severe oral mucositis. Furthermore, patients in the HRR group had a better 3-year PFS and LRFFS rate than those in the LRR group.

Theoretical Study of Alkaline-Earth Metal (Be, Mg, and Ca)-Substituted Aluminum Nitride Nanocages With High Stability and Large Nonlinear Optical Responses.

By replacing one Al or N atom of aluminum nitride nanocage Al12N12 with an alkaline-earth metal atom, two series of compounds, namely, M@Al12N11 and M@Al11N12 (M = Be, Mg, and Ca), were constructed and investigated in theory. The substituted effect of alkaline-earth metal on the geometric structure and electronic properties of Al12N12 is studied in detail by density functional theory (DFT) methods. The calculated binding energies, HOMO-LUMO gaps, and VIE values of these compounds reveal that they possess high stability, though the NBO and HOMO analyses show that they are also excess electron compounds. Due to the existence of diffuse excess electrons, these alkaline-earth metal-substituted compounds exhibit larger first hyperpolarizabilities (ß 0) than pure Al12N12 nanocage. In particular, these considered compounds exhibit satisfactory infrared (IR) (>1800 nm) and ultraviolet (UV) (˂ 250 nm) transparency. Therefore, these proposed excess electron compounds with high stability may be regarded as potential candidates for new UV and IR NLO molecules.

The behavior of the aluminum trimer when combining with different superatom clusters.

The interaction between the aluminum trimer and representative (super)halogens X (X = F, LiF2, BeF3, BF4) and (super)alkalis M (M = Li, FLi2, OLi3, NLi4) has been theoretically investigated at the MP2/6-311+(3df) level. Various geometrical structures were obtained for the resulting Al3-X and Al3-M superatom compounds, respectively. Natural bond orbital analysis reveals that the Al3 moiety exists in a cationic state in Al3-X while in an anionic state in Al3-M compounds. And the charge transfer between Al3 and (super)atoms is found to be enhanced in either polar or nonpolar solvent. The studied superatom compounds feature large bond energies, binding energies, and HOMO-LUMO gaps, which not only reflect their stability but indicate strong interactions between Al3 and (super)atoms. Although the solvent effect is not significant for the stability of Al3-X, the Al3-superalkali compounds can be better stabilized in the presence of solvent molecules. In addition, these superatom compounds exhibit aromaticity both in the gas phase and in solution.

The effects of external electric field: creating non-zero first hyperpolarizability for centrosymmetric benzene and strongly enhancing first hyperpolarizability for non-centrosymmetric edge-modified graphene ribbon H2N-(3,3)ZGNR-NO2.

How to generate a non-zero first hyperpolarizability for a centrosymmetric molecule is a challenging question. In this paper, an external (pump) electric field is used to make a centrosymmetric benzene molecule generate a non-zero value of the electric field induced first hyperpolarizability (ß (F) ). This comes from the centrosymmetry breaking of electron cloud. Two interesting rules are exhibited. (1) ß (F) is anisotropic for different directional fields (F i, i = X, Y, Z). (2) The field dependence of ß (F) is a non-monotonic function, and an optimum external electric field causes the maximum value of ß (F) . The largest first hyperpolarizability ß (F) reaches the considerable level of 3.9 × 10(5) a.u. under F Y = 330 × 10(-4) a.u. for benzene. The external electric field effects on non-centrosymmetric edge-modified graphene ribbon H2N-(3,3)ZGNR-NO2 was also studied in this work. The first hyperpolarizability reaches as much as 2.1 × 10(7) a.u. under F X = 600 × 10(-4) a.u. for H2N-(3,3)ZGNR-NO2. We show that the external electric field can not only create a non-zero first hyperpolarizability for centrosymmetric molecule, but also remarkably enhance the first hyperpolarizability for a non-centrosymmetric molecule.

Evolution of the structural and electronic properties of beryllium-doped aluminum clusters: comparison with neutral and cationic aluminum clusters.

The lowest-energy structures of the Al(n)Be (n = 1-13) clusters are obtained and compared with the corresponding Al(n+1) and Al(n+1)(+) (n = 2-13) as well as Al(n)Mg clusters at the B3LYP/aug-cc-pVDZ level. The configurations of Al(n)Be show strong resemblances to those of pure Al(n+1) clusters, and the first three-dimensional ground state in the Al(n)Be clusters occurs for Al(3)Be. Various properties of the Al(n)Be clusters are systematically investigated using the CCSD(T) method and their thermodynamic properties are also compared with those of corresponding Al(n+1)(+) clusters. The evolution of the energetic and electronic properties with the size of the clusters shows the unique stability of the 20-valence electron systems Al(6)Be and Al(7)(+), which can be understood from the spherical jellium model (SJM). However, different from Al(7)(+) with 1s(2)1p(6)1d(10)2s(2) shell occupation, the electronic-shell structure of 1s(2)1p(6)1d(6)2s(2)1d(4) for the Al(6)Be cluster demonstrates that the impurity atom makes the molecular orbital distribution of doped clusters much more complex than that of pure metal clusters.

Rare gas atomic number dependence of the hyperpolarizability for rare gas inserted fluorohydrides, HRgF (Rg = He, Ar, and Kr).

The three structures of rare gas inserted fluorohydrides HRgF (Rg = He, Ar, and Kr) with all real frequencies are obtained at the QCISD(T)/aug-cc-pVTZ level. The static first hyperpolarizabilities (beta(0)) at the QCISD/aug-cc-pVQZ level are 8 a.u. (HF), 384 a.u. (HHeF), 737 a.u. (HArF), and 465 a.u. (HKrF). The beta(0) value remarkably increases by about 50-90 times from 8 a.u. (HF) to 384-737 a.u. (HRgF) due to the inserted rare gas (Rg). The Rg atomic number dependence of beta(0) for HRgF (Rg = He, Ar, and Kr) is found at the first time. The order of beta(0) is unmonotonic to be HHeFHKrF, but not monotonic (HHeF