Charge-transfer excited states in the donor/acceptor interface from large-scale GW calculations

Predicting the charge-transfer (CT) excited states across the donor/acceptor (D/A) interface is essential for understanding the charge photogeneration process in an organic solar cell.Here, we present a fragment-based GW implementation that can be applied to a D/A interface structure and thus enables accurate determination of the CT states.The implementation is based on the fragmentation approximation of the polarization function and the combined GW and Coulomb-hole plus screened exchange approximations for self-energies.The fragmentbased GW is demonstrated by application to the pentacene/C60 interface structure containing more than 2000 atoms.The CT excitation energies were estimated from the quasiparticle energies and electron–hole screened Coulomb interactions; the computed energies are in reasonable agreement with experimental estimates from the external quantum efficiency measurements.We highlight the impact of the induced polarization effects on the electron–hole energetics.The proposed fragment-based GW method offers a first-principles tool to compute the quasiparticle energies and electronic excitation energies of organic materials

Utility of vessel-sealing systems in thyroid surgery.

The LigaSure TM vessel-sealing system (VSS) represents a new approach to intraoperative ligation. This clinical study retrospectively examined the utility of the VSS in thyroid surgery. In this study, we analyzed 56 consecutive patients who underwent thyroid surgery. Characteristics such as operative duration, the volume of intraoperative hemorrhage, and postoperative course were analyzed and compared between thyroid surgery using the VSS or conventional handtie methods. The present results indicate no significant differences in operative duration, volume of intraoperative hemorrhage, postoperative course, or duration of postoperative drainage between surgeries using the VSS or conventional methods. However, the postoperative hospital stay was found to be significantly shorter (p&#60;0.05) with the VSS. No serious postoperative complications were encountered, and no significant differences were observed in the frequency of postoperative complications between methods. The VSS may simplify procedures for thyroid surgery, and hemostasis is effective for both thyroid vessels and thyroid parenchyma. However, further evaluation is warranted to adequately determine the relative merits of the VSS compared to conventional handtie methods.</p

The distribution and number of Leu-7 (CD57) positive cells in lung tissue from patients with pulmonary fibrosis.

Leu-7 positive lymphocytes, including natural killer cells, play an important role in the immune system's surveillance function to prevent the development of cancer. The incidence of lung cancer is significantly high in patients with end-stage pulmonary fibrosis. We hypothesized that the number of Leu-7 positive cells may be decreased in areas of severe pulmonary fibrosis. To demonstrate this, Leu-7 positive cells were immunohistochemically stained in 41 lung specimens obtained from patients with idiopathic pulmonary fibrosis and pulmonary fibrosis associated with collagen vascular disorders. The number of Leu-7 positive cells was evaluated according to the pathological findings. In pathologically normal lung, Leu-7 positive cells were mostly found within the capillaries of the septa and rarely in the alveolar space or the stroma. The number of Leu-7 positive cells was 0.69 +/- 0.15 in areas of advanced fibrosis (n = 41), 2.39 +/- 0.60 in areas that had newly developeing fibrosis (n = 41), 1.14 +/- 0.57 in bronchiolitis obliterans organizing pneumonia (n = 9), and 1.35 +/- 0.87 in diffuse alveolar damage (DAD) (n = 11). The number of Leu-7 positive cells in areas of newly developing fibrosis (2.39 +/- 0.60) was significantly higher than that in areas of established fibrosis (0.69 +/- 0.15, P &#60; 0.05). Our present study demonstrates a significant decrease in the number of Leu-7 positive cells in areas of advanced fibrosis. This evidence may partly explain the high incidence of lung cancer associated with pulmonary fibrosis.</p

Myofibroblasts proliferation of idiopathic and collagen vascular disorders associated nonspecific interstitial pneumonia.

Nonspecific interstitial pneumonia (NSIP) has been recognized as a separate histological classification of interstitial lung disease. Similar features are found not only in idiopathic NSIP, but also in NSIP associated with collagen vascular disorder (CVD-NSIP). We examined the clinical symptoms, laboratory findings, and prognosis of 13 cases of idiopathic NSIP and 11 cases of CVD-NSIP. Immunohistochemical staining was performed using the streptavidin/biotin/peroxidase method with anti-alpha-smooth muscle actin antibody. No differences in the distribution of clinical features, laboratory findings, and prognosis were observed between idiopathic NSIP and CVD-NSIP. In immunohistochemical staining of the fibrosing areas, myofibroblasts were observed in 7 of 13 idiopathic NSIP cases, but in 10 of 11 CVD-NSIP cases. With regards to intra-alveolar organization, myofibroblasts were observed in all 10 CVD-NSIP cases, but they were observed in only 2 of 9 idiopathic NSIP cases. We found a significantly higher myofibroblast proliferation in the intra-alveolar organization of CVD-NSIP compared to idiopathic NSIP. Clinically, idiopathic NSIP and CVD-NSIP are similar, but are pathologically different.</p

Role of p53 mutation in the effect of boron neutron capture therapy on oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Boron neutron capture therapy (BNCT) is a selective radiotherapy, being effective for the treatment of even advanced malignancies in head and neck regions as well as brain tumors and skin melanomas. To clarify the role of p53 gene, the effect of BNCT on oral squamous cell carcinoma (SCC) cells showing either wild- (SAS/neo) or mutant-type (SAS/mp53) p53 was examined.</p> <p>Methods</p> <p>Cells were exposed to neutron beams in the presence of boronophenylalanine (BPA) at Kyoto University Research Reactor. Treated cells were monitored for modulations in colony formation, proliferation, cell cycle, and expression of cell cycle-associated proteins.</p> <p>Results</p> <p>When SAS/neo and SAS/mp53 cells were subjected to BNCT, more suppressive effects on colony formation and cell viability were observed in SAS/neo compared with SAS/mp53 cells. Cell cycle arrest at the G1 checkpoint was observed in SAS/neo, but not in SAS/mp53. Apoptotic cells increased from 6 h after BNCT in SAS/neo and 48 h in SAS/mp53 cells. The expression of p21 was induced in SAS/neo only, but G2 arrest-associated proteins including Wee1, cdc2, and cyclin B1 were altered in both cell lines.</p> <p>Conclusion</p> <p>These results indicate that oral SCC cells with mutant-type are more resistant to BNCT than those with wild-type p53, and that the lack of G1 arrest and related apoptosis may contribute to the resistance. At a physical dose affecting the cell cycle, BNCT inhibits oral SCC cells in p53-dependent and -independent manners.</p