A low-bandgap dimeric porphyrin molecule for 10% efficiency solar cells with small photon energy loss

Dimeric porphyrin molecules have great potential as donor materials for high performance bulk heterojunction organic solar cells (OSCs). Recently reported dimeric porphyrins bridged by ethynylenes showed power conversion efficiencies (PCEs) of more than 8%. In this study, we design and synthesize a new conjugated dimeric D-A porphyrin ZnP2BT-RH, in which the two porphyrin units are linked by an electron accepting benzothiadiazole (BT) unit. The introduction of the BT unit enhances the electron delocalization, resulting in a lower highest occupied molecular orbital (HOMO) energy level and an increased molar extinction coefficient in the near-infrared (NIR) region. The bulk heterojunction solar cells with ZnP2BT-RH as the donor material exhibit a high PCE of up to 10% with a low energy loss (Eloss) of only 0.56 eV. The 10% PCE is the highest for porphyrin-based OSCs with a conventional structure, and this Eloss is also the smallest among those reported for small molecule-based OSCs with a PCE higher than 10% to date

Do Non-Executive Employees Matter in Curbing Corporate Financial Fraud

Exploiting staggered enactment of employee stock ownership plans (ESOPs) as a quasi-natural shock, we use a difference-in-differences (DiD) approach to investigate whether and how ESOPs mitigate corporate financial fraud in China. We find ESOPs significantly reduce corporate financial fraud. This is because of stock ownership of non-executives rather than executives. The underlying mechanisms are heightened internal monitoring and external monitoring through which ESOPs curb executives’ opportunistic behaviour. Our results are robust to parallel trend test, placebo test, PSM approach, instrument variable test, and considering omitted variable concern, partial observability problem, model specification, stock market crash, and industry effect. Our additional analyses indicate that the effect of ESOPs on corporate financial fraud is more pronounced when firms with weaker corporate governance, poorer information environment, less powerful executives and higher-intensity and broader-based plans. Collectively, our results indicate that ESOPs play a role, as an alternative corporate governance mechanism, in mitigating financial fraud

Tryptophan-induced pathogenesis of breast cancer

Background: The pathogenesis of breast cancer remains unclear.Aims: To investigate the pathogenesis of breast cancer through targeted metabolomics of amino acids  components in serum of patients with breast cancer.Methods: Patients with breast cancers were enrolled in our hospital between year January 1st, 2013 and  December 31st, 2014. Targeted analysis of amino acids was performed using ESI-QTOF-MS instrument. In vitro experiment was performed to determine the influence of tryptophan towards interleukin-10 (IL-10)  secretion by CD4>+ T cell.Results: Targeted metabolomics of amino acids showed that the level of tryptophan significantly  (p<0.05) increased in patients with breast cancer. Furthermore, the biological function of tryptophan was determined through determining the influence of tryptophan towards IL-10 secretion using in vitro method. The addition of tryptophan (100 uM) in the cell medium can significantly inhibited the secretion of IL-10 by CD4+ T cells, as indicated by the mRNA level and protein concentration.Conclusion: The inhibition of IL-10 secretion by CD4+ T cells is a potential pathogenesis of breast cancer.Keywords: breast cancer, interleukin-10 (IL-10), pathogenesis, T cel

Time-dependent magnetohydrodynamic self-similar extragalactic jets

Extragalactic jets are visualized as dynamic erruptive events modelled by time-dependent magnetohydrodynamic (MHD) equations. The jet structure comes through the temporally self-similar solutions in two-dimensional axisymmetric spherical geometry. The two-dimensional magnetic field is solved in the finite plasma pressure regime, or finite $\beta$ regime, and it is described by an equation where plasma pressure plays the role of an eigenvalue. This allows a structure of magnetic lobes in space, among which the polar axis lobe is strongly peaked in intensity and collimated in angular spread comparing to the others. For this reason, the polar lobe overwhelmes the other lobes, and a jet structure arises in the polar direction naturally. Furthermore, within each magnetic lobe in space, there are small secondary regions with closed two-dimensional field lines embedded along this primary lobe. In these embedded magnetic toroids, plasma pressure and mass density are much higher accordingly. These are termed as secondary plasmoids. The magnetic field lines in these secondary plasmoids circle in alternating sequence such that adjacent plasmoids have opposite field lines. In particular, along the polar primary lobe, such periodic plasmoid structure happens to be compatible with radio observations where islands of high radio intensities are mapped