291 research outputs found

    Magnetic Interaction between Surface Engineered Rare-earth Atomic Spins

    Full text link
    We report the ab initio study of rare-earth adatoms (Gd) on an insulating surface. This surface is of interest because of previous studies by scanning tunneling microscopy showing spin excitations of transition metal adatoms. The present work is the first study of rare-earth spin-coupled adatoms, as well as the geometry effect of spin coupling, and the underlying mechanism of ferromagnetic coupling. The exchange coupling between Gd atoms on the surface is calculated to be antiferromagnetic in a linear geometry and ferromagnetic in a diagonal geometry, by considering their collinear spins and using the PBE+U exchange correlation. We also find the Gd dimers in these two geometries are similar to the nearest-neighbor (NN) and the next-NN Gd atoms in GdN bulk. We analyze how much direct exchange, superexchange, and RKKY interactions contribute to the exchange coupling for both geometries by additional first-principles calculations of related model systems

    A study on Impressiveness Management of Internet Celebrities

    Get PDF
    The issue of social media has attracted much attention in the fields of information management and marketing. Recently, the live webcast service newly introduced on social media has renewed the issues. With the increasing popularity of social media, the live webcast service provides more opportunities of higher interactivity to Internet celebrities to communicate with Internet users. With frequent interaction with Internet users, the Internet celebrities construct their self-images and build a long-term personal reputation. Therefore, how Internet celebrities enhance their self-image and personal reputation is an interesting research issue. Specifically, this study intends to investigate how Internet celebrities employ personal impressiveness management to improve their personal image and branding. The corporate reputation formation framework was employed as the theoretical perspective to investigate Internet celebrities’ personal impressiveness management through social media

    Membrane repair against H. pylori promotes cancer cell proliferation

    Get PDF
    Membrane repair is a universal response against physical and biological insults and enables cell survival. Helicobacter pylori is one of the most common human pathogens and the first formally recognized bacterial carcinogen associated with gastric cancer. However, little is known about host membrane repair in the context of H. pylori infection. Here we show that H. pylori disrupts the host plasma membrane and induces Ca2+ influx, which triggers the translocation of annexin family members A1 and A4 to the plasma membrane. This in turn activates a membrane repair response through the recruitment of lysosomal membranes and the induction of downstream signaling transduction pathways that promote cell survival and proliferation. Based on our data, we propose a new model by which H. pylori infection activates annexin A1 and A4 for membrane repair and how annexin A4 over-expression induced signaling promotes cell proliferation. Continual activation of this membrane repair response signaling cascade may cause abnormal cellular states leading to carcinogenesis. This study links H. pylori infection to membrane repair, providing insight into potential mechanisms of carcinogenesis resulting from membrane damage

    Therapeutic opportunities and challenges in targeting the orphan G protein-coupled receptor GPR35

    Get PDF
    GPR35 is a class A, rhodopsin-like G protein-coupled receptor (GPCR) first identified more than 20 years ago. In the intervening period identification of strong expression in the lower intestine and colon, as well as in a variety of immune cells including monocytes and a variety of dendritic cells, and in dorsal root ganglia, has suggested potential therapeutic opportunities in targeting this receptor in a range of conditions. GPR35 is, however, unusual in a variety of ways that challenge routes to translation. These include that although a substantial range and diversity of endogenous ligands have been suggested as agonist partners for this receptor it officially remains defined as an ‘orphan’ GPCR; that humans express two distinct protein isoform sequences whilst rodents express only a single form, and that the pharmacology of the human and rodent orthologues of GPR35 is very distinct, with variation between rat and mouse GPR35 as marked as between either of these species and the human forms. 2 Herein we provide perspectives on each of the topics above as well as suggesting ways to overcome the challenges currently hindering potential translation. These include better understanding of the extent and molecular basis for species selective GPR35 pharmacology and the production of novel mouse models in which both ‘on-target’ and ‘off-target’ effects of presumptive GPR35 ligands can be better defined as well as clear understanding in human of isoform expression profile and its significance at both tissue and individual cell level

    An Immunomodulatory Protein (Ling Zhi-8) from a Ganoderma lucidum

    Get PDF
    The purpose of this study was to investigate the effect of an immunomodulatory protein (Ling Zhi-8, LZ-8) on wound healing in rat liver tissues after monopolar electrosurgery. Animals were sacrificed for evaluations at 0, 3, 7, and 28 days postoperatively. It was found that the wound with the LZ-8 treatment significantly increases wound healing. Western blot analysis clearly indicated that the expression of NF-κB was decreased at 3, 7, and 28 days when liver tissues were treated with LZ-8. Moreover, caspase-3 activity of the liver tissue also significantly decreases at 7 and 28 days, respectively. DAPI staining and TUNEL assays revealed that only a minimal dispersion of NF-κB was found on the liver tissue treated with LZ-8 at day 7 as compared with day 3 and tissues without LZ-8 treatment. Similarly, apoptosis was decreased on liver tissues treated with LZ-8 at 7 days when compared to the control (monopolar electrosurgery) tissues. Therefore, the analytical results demonstrated that LZ-8 induced acceleration of wound healing in rat liver tissues after monopolar electrosurgery

    Urban-Rural Disparity of Generics Prescription in Taiwan: The Example of Dihydropyridine Derivatives

    Get PDF
    The aim of the current study was to investigate the urban-rural disparity of prescribing generics, which were usually cheaper than branded drugs, within the universal health insurance system in Taiwan. Data sources were the cohort datasets of National Health Insurance Research Database with claims data in 2010. The generic prescribing ratios of dihydropyridine (DHP) derivatives (the proportion of DHP prescribed as generics to all prescribed DHP) of medical facilities were examined against the urbanization levels of the clinic location. Among the total 21,606,914 defined daily doses of DHP, 35.7% belonged to generics. The aggregate generic prescribing ratio rose from 6.7% at academic medical centers to 15.3% at regional hospitals, 29.4% at community hospital, and 66.1% at physician clinics. Among physician clinics, the generic prescribing ratio in urban areas was 63.9 ± 41.0% (mean ± standard deviation), lower than that in suburban (69.6 ± 38.7%) and in rural (74.1% ± 35.3%). After adjusting the related factors in the linear regression model, generic prescribing ratios of suburban and rural clinics were significantly higher than those of urban clinics (β=0.043 and 0.077; P=0.024 and 0.008, resp.). The generic prescribing ratio of the most popular antihypertensive agents at a clinic was reversely associated with the urbanization level

    Major Functional Transcriptome of an Inferred Center Regulator of an ER(−) Breast Cancer Model System

    Get PDF
    We aimed to find clinically relevant gene activities ruled by the signal transducer and activator of transcription 3 (STAT3) proteins in an ER(−) breast cancer population via network approach. STAT3 is negatively associated with both lymph nodal category and stage. MYC is a component of STAT3 network. MYC and STAT3 may co-regulate gene expressions for Warburg effect, stem cell like phenotype, cell proliferation and angiogenesis. We identified a STAT3 network in silico showing its ability in predicting its target gene expressions primarily for specific tumor subtype, tumor progression, treatment options and prognostic features. The aberrant expressions of MYC and STAT3 are enriched in triple negatives (TN). They promote histological grade, vascularity, metastasis and tumor anti-apoptotic activities. VEGFA, STAT3, FOXM1 and METAP2 are druggable targets. High levels of METAP2, MMP7, IGF2 and IGF2R are unfavorable prognostic factors. STAT3 is an inferred center regulator at early cancer development predominantly in TN

    Aspartate β-Hydroxylase Expression Promotes a Malignant Pancreatic Cellular Phenotype

    Get PDF
    Pancreatic cancer (PC) is one of the leading causes of cancer related deaths due to aggressive progression and metastatic spread. Aspartate β-hydroxylase (ASPH), a cell surface protein that catalyzes the hydroxylation of epidermal growth factor (EGF)-like repeats in Notch receptors and ligands, is highly overexpressed in PC. ASPH upregulation confers a malignant phenotype characterized by enhanced cell proliferation, migration, invasion and colony formation in vitro as well as PC tumor growth in vivo. The transforming properties of ASPH depend on enzymatic activity. ASPH links PC growth factor signaling cascades to Notch activation. A small molecule inhibitor of β-hydroxylase activity was developed and found to reduce PC growth by downregulating the Notch signaling pathway. These findings demonstrate the critical involvement of ASPH in PC growth and progression, provide new insight into the molecular mechanisms leading to tumor development and growth and have important therapeutic implications

    Receptor selectivity between the G proteins Gα12 and Gα13 is defined by a single leucine-to-isoleucine variation

    Get PDF
    Despite recent advances in structural definition of GPCR–G protein complexes, the basis of receptor selectivity between G proteins remains unclear. The Gα12 and Gα13 subtypes together form the least studied group of heterotrimeric G proteins. G protein–coupled receptor 35 (GPR35) has been suggested to couple efficiently to Gα13 but weakly to Gα12. Using combinations of cells genome-edited to not express G proteins and bioluminescence resonance energy transfer–based sensors, we confirmed marked selectivity of GPR35 for Gα13. Incorporating Gα12/Gα13 chimeras and individual residue swap mutations into these sensors defined that selectivity between Gα13 and Gα12 was imbued largely by a single leucine-to-isoleucine variation at position G.H5.23. Indeed, leucine could not be substituted by other amino acids in Gα13 without almost complete loss of GPR35 coupling. The critical importance of leucine at G.H5.23 for GPR35–G protein interaction was further demonstrated by introduction of this leucine into Gαq, resulting in the gain of coupling to GPR35. These studies demonstrate that Gα13 is markedly the most effective G protein for interaction with GPR35 and that selection between Gα13 and Gα12 is dictated largely by a single conservative amino acid variation.—Mackenzie, A. E., Quon, T., Lin, L.-C., Hauser, A. S., Jenkins, L., Inoue, A., Tobin, A. B., Gloriam, D. E., Hudson, B. D., Milligan, G. Receptor selectivity between the G proteins Gα12 and Gα13 is defined by a single leucine-to-isoleucine variation
    corecore