First-principles Analysis of Photo-current in Graphene PN Junctions

We report a first principles investigation of photocurrent generation by graphene PN junctions. The junctions are formed by either chemically doping with nitrogen and boron atoms, or by controlling gate voltages. Non-equilibrium Green's function (NEGF) formalism combined with density functional theory (DFT) is applied to calculate the photo-response function. The graphene PN junctions show a broad band photo-response including the terahertz range. The dependence of the response on the angle between the light polarization vector and the PN interface is determined. Its variation against photon energy $E_{ph}$ is calculated in the visible range. The essential properties of chemically doped and gate-controlled PN junctions are similar, but the former shows fingerprints of dopant distribution.Comment: 7 pages, 6 figure

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The Role of Cell Autophagy in Cancer and Its Application in Drug Discovery

Autophagy is a vital basic phenomenon that widely exists in eukaryotic cells. As one type of programmed cell death, autophagy has gained much more attention in the past few years. Recent studies suggest that the alterations in autophagy are associated with the genesis and development of cancers. It can affect cell apoptosis, angiogenesis, and treatment of tumor. Others’ and our studies have found that some herbal medicines can induce autophagic cell death in cancer cell models. As herbal medicines are very important recourses for drug discovery and lead compounds of anticancer drugs, we have summarized the role of autophagy in inhibitive effect of natural products in cancer cell growth and metastasis. Finally, we present summary and critical comments on problems in current autophagy study and its future prospect

Liver Cancer Treatment by Chinese Medicines and their Active Compounds

Recent studies have indicated that traditional Chinese medicines (CMs) and their active compounds play an important role in liver cancer treatment by preventing tumor formation, inhibiting tumor growth, metastasis and recurrence as well as improving the quality of life and reducing side effects of radiotherapy and chemotherapy. Mechanism studies have proved the advantage of multicomponent, multitarget and multipathway combinational regulation by CMs in liver cancer treatment. This chapter emphatically introduces the molecular mechanisms underlying liver cancer treatment by CMs. In addition, we also put forward discussion on existing obstacles and prospect of the future development on liver cancer treatment using CMs, in terms of providing a comprehensive understanding of action of CMs in liver cancer treatment

IRE1 phosphatase PP2Ce regulates adaptive ER stress response in the postpartum mammary gland.

We recently reported that the PPM1l gene encodes an endoplasmic reticulum (ER) membrane targeted protein phosphatase (named PP2Ce) with highly specific activity towards Inositol-requiring protein-1 (IRE1) and regulates the functional outcome of ER stress. In the present report, we found that the PP2Ce protein is highly expressed in lactating epithelium of the mammary gland. Loss of PP2Ce in vivo impairs physiological unfolded protein response (UPR) and induces stress kinase activation, resulting in loss of milk production and induction of epithelial apoptosis in the lactating mammary gland. This study provides the first in vivo evidence that PP2Ce is an essential regulator of normal lactation, possibly involving IRE1 signaling and ER stress regulation in mammary epithelium