669 research outputs found

    Wellposedness of Cauchy problem for the Fourth Order Nonlinear Schr\"odinger Equations in Multi-dimensional Spaces

    Get PDF
    We study the wellposedness of Cauchy problem for the fourth order nonlinear Schr\"odinger equations i\partial_t u=-\eps\Delta u+\Delta^2 u+P((\partial_x^\alpha u)_{\abs{\alpha}\ls 2}, (\partial_x^\alpha \bar{u})_{\abs{\alpha}\ls 2}),\quad t\in \Real, x\in\Real^n, where \eps\in\{-1,0,1\}, n\gs 2 denotes the spatial dimension and P()P(\cdot) is a polynomial excluding constant and linear terms.Comment: 28 page

    Association of the shuffling of Streptococcus pyogenes clones and the fluctuation of scarlet fever cases between 2000 and 2006 in central Taiwan

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The number of scarlet fever occurrences reported between 2000 and 2006 fluctuated considerably in central Taiwan and throughout the nation. Isolates of <it>Streptococcus pyogenes </it>were collected from scarlet fever patients in central Taiwan and were characterized by <it>emm </it>sequencing and a standardized pulsed-field gel electrophoresis (PFGE) method. National weekly report data were collected for investigating epidemiological trends.</p> <p>Results</p> <p>A total of 23 <it>emm </it>types were identified in 1,218 <it>S. pyogenes </it>isolates. The five most prevalent <it>emm </it>types were <it>emm</it>12 (50.4%), <it>emm</it>4 (23.2%), <it>emm</it>1 (16.4%), <it>emm</it>6 (3.8%) and <it>emm</it>22 (3.0%). PFGE analysis with <it>Sma</it>I suggested that, with a few exceptions, strains with a common <it>emm </it>type belonged to the same clone. There were two large <it>emm</it>12 clones, one with DNA resistant to cleavage by <it>Sma</it>I. Each prevalent <it>emm </it>clone had major PFGE strain(s) and many minor strains. Most of the minor strains emerged in the population and disappeared soon after. Even some major strains remained prevalent for only 2–3 years before declining. The large fluctuation of scarlet fever cases between 2000 and 2006 was associated with the shuffling of six prevalent <it>emm </it>clones. In 2003, the dramatic drop in scarlet fever cases in central Taiwan and throughout the whole country was associated with the occurrence of a severe acute respiratory syndrome (SARS) outbreak that occurred between late-February and mid-June in Taiwan.</p> <p>Conclusion</p> <p>The occurrences of scarlet fever in central Taiwan in 2000–2006 were primarily caused by five <it>emm </it>types, which accounted for 96.8% of the isolates collected. Most of the <it>S. pyogenes </it>strains (as defined by PFGE genotypes) emerged and lasted for only a few years. The fluctuation in the number of scarlet fever cases during the seven years can be primarily attributed to the shuffling of six prevalent <it>emm </it>clones and to the SARS outbreak in 2003.</p

    Repurposing Metformin for Lung Cancer Management

    Get PDF
    In this article, we introduced the background knowledge of lung cancer management and considered repurposing old drugs to overcome therapy bottleneck. We chose metformin to prove both its antihyperglycemia and antitumor formation effects. Based on the metformin-related AMPK-dependent pathway, we tried to explore the AMPK-independent pathway in inhibition of lung tumorigenesis by metformin. Using preclinical data mining from clinical settings with a literature review, we attempted to clarify the role of metformin in lung cancer management. Additional objective and strong evidence are needed using randomized control studies to verify the benefit of metformin in clinical practice. Furthermore, we proposed two lung cancer animal models and showed the establishment processes thoroughly. We hope that these two lung cancer animal models provide a useful platform for furthering old drug repurposing as well as new drug investigations in the future

    Modulation of nucleosome-binding activity of FACT by poly(ADP-ribosyl)ation

    Get PDF
    Chromatin-modifying factors play key roles in transcription, DNA replication and DNA repair. Post-translational modification of these proteins is largely responsible for regulating their activity. The FACT (facilitates chromatin transcription) complex, a heterodimer of hSpt16 and SSRP1, is a chromatin structure modulator whose involvement in transcription and DNA replication has been reported. Here we show that nucleosome binding activity of FACT complex is regulated by poly(ADP-ribosyl)ation. hSpt16, the large subunit of FACT, is poly(ADP-ribosyl)ated by poly(ADP-ribose) polymerase-1 (PARP-1) resulting from physical interaction between these two proteins. The level of hSpt16 poly(ADP-ribosyl)ation is elevated after genotoxic treatment and coincides with the activation of PARP-1. The enhanced hSpt16 poly(ADP-ribosyl)ation level correlates with the dissociation of FACT from chromatin in response to DNA damage. Our findings suggest that poly(ADP-ribosyl)ation of hSpt16 by PARP-1 play regulatory roles for FACT-mediated chromatin remodeling

    Fibronectin and laminin promote differentiation of human mesenchymal stem cells into insulin producing cells through activating Akt and ERK

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Islet transplantation provides a promising cure for Type 1 diabetes; however it is limited by a shortage of pancreas donors. Bone marrow-derived multipotent mesenchymal stem cells (MSCs) offer renewable cells for generating insulin-producing cells (IPCs).</p> <p>Methods</p> <p>We used a four-stage differentiation protocol, containing neuronal differentiation and IPC-conversion stages, and combined with pellet suspension culture to induce IPC differentiation.</p> <p>Results</p> <p>Here, we report adding extracellular matrix proteins (ECM) such as fibronectin (FN) or laminin (LAM) enhances pancreatic differentiation with increases in insulin and Glut2 gene expressions, proinsulin and insulin protein levels, and insulin release in response to elevated glucose concentration. Adding FN or LAM induced activation of Akt and ERK. Blocking Akt or ERK by adding LY294002 (PI3K specific inhibitor), PD98059 (MEK specific inhibitor) or knocking down Akt or ERK failed to abrogate FN or LAM-induced enhancement of IPC differentiation. Only blocking both of Akt and ERK or knocking down Akt and ERK inhibited the enhancement of IPC differentiation by adding ECM.</p> <p>Conclusions</p> <p>These data prove IPC differentiation by MSCs can be modulated by adding ECM, and these stimulatory effects were mediated through activation of Akt and ERK pathways.</p

    Relationships among Constitution, Stress, and Discomfort in the First Trimester

    Get PDF
    The purpose of this study was to explore correlations among constitution, stress, and discomfort symptoms during the first trimester of pregnancy. We adopted a descriptive and correlational research design and collected data from 261 pregnant women during their first trimester in southern Taiwan using structured questionnaires. Results showed that (1) stress was significantly and positively correlated with Yang-Xu, Yin-Xu, and Tan-Shi-Yu-Zhi constitutions, respectively; (2) Yin-Xu and Tan-Shi-Yu-Zhi constitutions had significant correlations with all symptoms of discomfort, while Yang-Xu had significant correlations with all symptoms of discomfort except for “running nose”; (3) Tan-Shi-Yu-Zhi constitution and stress were two indicators for “fatigue”; Tan-Shi-Yu-Zhi was the indicator for “nausea”; Yang-Xu and Yin-Xu were indicators for “frequent urination.” Our findings also indicate that stress level affects constitutional changes and that stress and constitutional change affect the incidence of discomfort. This research can help healthcare professionals observe these discomforts and provide individualized care for pregnant women, to nurture pregnant women into neutral-type constitution, minimize their levels of discomfort, and promote the health of the fetus and the mother

    Phyllanthus urinaria Induces Apoptosis in Human Osteosarcoma 143B Cells via Activation of Fas/FasL- and Mitochondria-Mediated Pathways

    Get PDF
    Phyllanthus urinaria (P. urinaria), in this study, was used for the treatment of human osteosarcoma cells, which is one of the tough malignancies with few therapeutic modalities. Herein, we demonstrated that P. urinaria inhibited human osteosarcoma 143B cells growth through an apoptotic extrinsic pathway to activate Fas receptor/ligand expression. Both intracellular and mitochondrial reactive oxygen species were increased to lead to alterations of mitochondrial membrane permeability and Bcl-2 family including upregulation of Bid, tBid, and Bax and downregulation of Bcl-2. P. urinaria triggered an intrinsic pathway and amplified the caspase cascade to induce apoptosis of 143B cells. However, upregulation of both intracellular and mitochondrial reactive oxygen species and the sequential membrane potential change were less pronounced in the mitochondrial respiratory-defective 143Bρ0 cells compared with the 143B cells. This study offers the evidence that mitochondria are essential for the anticancer mechanism induced by P. urinaria through both extrinsic and intrinsic pathways

    Frequency Dependent Alterations in Regional Homogeneity of Baseline Brain Activity in Schizophrenia

    Get PDF
    Low frequency oscillations are essential in cognitive function impairment in schizophrenia. While functional connectivity can reveal the synchronization between distant brain regions, the regional abnormalities in task-independent baseline brain activity are less clear, especially in specific frequency bands. Here, we used a regional homogeneity (ReHo) method combined with resting-state functional magnetic resonance imaging to investigate low frequency spontaneous neural activity in the three different frequency bands (slow-5:0.01–0.027 Hz; slow-4:0.027–0.08 Hz; and typical band: 0.01–0.08 Hz) in 69 patients with schizophrenia and 62 healthy controls. Compared with controls, schizophrenia patients exhibited decreased ReHo in the precentral gyrus, middle occipital gyrus, and posterior insula, whereas increased ReHo in the medial prefrontal cortex and anterior insula. Significant differences in ReHo between the two bands were found in fusiform gyrus and superior frontal gyrus (slow-4> slow-5), and in basal ganglia, parahippocampus, and dorsal middle prefrontal gyrus (slow-5> slow-4). Importantly, we identified significant interaction between frequency bands and groups in the inferior occipital gyrus and caudate body. This study demonstrates that ReHo changes in schizophrenia are widespread and frequency dependent

    Galaxy source counts at 7.7 μ\mum, 10 μ\mum and 15 μ\mum with the James Webb Space Telescope

    Full text link
    We present mid-infrared galaxy number counts based on the Early Release Observations obtained by the James Webb Space Telescope (JWST) at 7.7-, 10- and 15-μ\mum (F770W, F1000W and F1500W, respectively) bands of the Mid-Infrared Instrument (MIRI). Due to the superior sensitivity of JWST, the 80 percent completeness limits reach 0.32, 0.79 and 2.0 μ\muJy in F770W, F1000W and F1500W filters, respectively, i.e., \sim100 times deeper than previous space infrared telescopes such as Spitzer or AKARI. The number counts reach much deeper than the broad bump around 0.050.50.05\sim0.5 mJy due to polycyclic aromatic hydrocarbon (PAH) emissions. An extrapolation towards fainter flux from the evolutionary models in the literature agrees amazingly well with the new data, where the extrapolated faint-end of infrared luminosity functions combined with the cosmic star-formation history to higher redshifts can reproduce the deeper number counts by JWST. Our understanding of the faint infrared sources has been confirmed by the observed data due to the superb sensitivity of JWST.Comment: 6 pages, 8 figures. Accepted for publication in MNRA
    corecore