762 research outputs found

    Turbulent properties of internal waves in the South China Sea

    Get PDF
    Author Posting. © The Oceanography Society, 2011. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 24 no. 4 (2011): 78–87, doi:10.5670/oceanog.2011.96.Luzon Strait and South China Sea waters are among the most energetic internal wave environments in the global ocean. Strong tides and stratification in Luzon Strait give rise to internal waves that propagate west into the South China Sea. The energy carried by the waves is dissipated via turbulent processes. Here, we present and contrast the relatively few direct observations of turbulent dissipation in South China Sea internal waves. Frictional processes active in the bottom boundary layer dissipate some of the energy along China's continental shelf. It appears that more energy is lost in Taiwanese waters of the Dongsha Plateau, where the waves reach their maximum amplitudes, and where the bottom topography abruptly shoals from 3,000 m in the deep basin to 1,000 m and shallower on the plateau. There, energy dissipation by turbulence reaches 1 W m–2, on par with the conversion rates of Luzon Strait.Support for this work was provided by the US Office of Naval Research and the National Science Council of Taiwan

    Copy number gain of granulin-epithelin precursor (GEP) at chromosome 17q21 associates with overexpression in human liver cancer

    Get PDF
    Background: Granulin-epithelin precursor (GEP), a secretory growth factor, demonstrated overexpression in various human cancers, however, mechanism remain elusive. Primary liver cancer, hepatocellular carcinoma (HCC), ranks the second in cancer-related death globally. GEP controlled growth, invasion, metastasis and chemo-resistance in liver cancer. Noted that GEP gene locates at 17q21 and the region has been frequently reported to be amplified in subset of HCC. The study aims to investigate if copy number gain would associate with GEP overexpression. Methods: Quantitative Microsatellite Analysis (QuMA) was used to quantify the GEP DNA copy number, and fluorescent in situ hybridization (FISH) was performed to consolidate the amplification status. GEP gene copy number, mRNA expression level and clinico-pathological features were analyzed. Results: GEP DNA copy number determined by QuMA corroborated well with the FISH data, and the gene copy number correlated with the expression levels (n = 60, r = 0.331, P = 0.010). Gain of GEP copy number was observed in 20% (12/60) HCC and associated with hepatitis B virus infection status (P = 0.015). In HCC with increased GEP copy number, tight association between GEP DNA and mRNA levels were observed (n = 12, r = 0.664, P = 0.019). Conclusions: Gain of the GEP gene copy number was observed in 20% HCC and the frequency comparable to literatures reported on the chromosome region 17q. Increased gene copy number contributed to GEP overexpression in subset of HCC. © Yung et al; licensee BioMed Central.published_or_final_versio

    T Cell Integrin Overexpression as a Model of Murine Autoimmunity

    Get PDF
    Integrin adhesion molecules have important adhesion and signaling functions. They also play a central role in the pathogenesis of many autoimmune diseases. Over the past few years we have described a T cell adoptive transfer model to investigate the role of T cell integrin adhesion molecules in the development of autoimmunity. This report summarizes the methods we used in establishing this murine model. By treating murine CD4+ T cells with DNA hypomethylating agents and by transfection we were able to test the in vitro effects of integrin overexpression on T cell autoreactive proliferation, cytotoxicity, adhesion and trafficking. Furthermore, we showed that the ability to induce in vivo autoimmunity may be unique to the integrin lymphocyte function associated antigen-1 (LFA-1)

    Bacterial toxin inhibitors based on multivalent scaffolds.

    Get PDF
    Protein toxins released by certain intestinal bacteria are the cause of many diarrhoeal diseases including cholera and travellers' diarrhoea. The toxins enter their target cells by first binding to specific glycolipids in the cell membrane. Inhibition of these protein-carbohydrate interactions has the potential to prevent the toxins from reaching their site of action, and thus avoid the ensuing diarrhoea. Simple oligosaccharides typically have low affinities for the protein toxins, therefore inhibitor design has focussed on exploiting the principles of multivalency: multiple weak interactions acting in concert can enhance the overall binding interaction. The major classes of multivalent inhibitors investigated to date will be discussed; these include glycopolymers, glycodendrimers, tailored glycoclusters and inhibitors exploiting templated assembly

    Gemcitabine-based versus fluoropyrimidine-based chemotherapy with or without platinum in unresectable biliary tract cancer: a retrospective study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>There is no standard palliative chemotherapy regimen in biliary tract cancers (BTC). Fluoropyrimidine or gemcitabine, with or without platinum, are most frequently used. We conducted this study to clarify the efficacy of palliative chemotherapy in BTC.</p> <p>Methods</p> <p>Patients with unresectable BTC treated with palliative chemotherapy between Oct 2001 and Aug 2006 at Seoul National University Hospital were reviewed retrospectively. Histologically confirmed cases of intrahepatic cholangiocarcinoma, gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater carcinoma were enrolled. We analyzed the efficacy of regimens: gemcitabine (G) <it>versus </it>fluoropyrimidine (F) and with or without platinum (P).</p> <p>Results</p> <p>A total of 243 patients were enrolled. 159 patients (65%) were male and the median age of the patients was 60 years (range 26–81). Intrahepatic cholangiocarcinoma, gallbladder cancer, extrahepatic bile duct cancer, and ampulla of Vater carcinoma were 92, 72, 58, and 21 cases, respectively. The median progression free survival (PFS) was 4.3 months (95% CI, 3.7–4.9) and median overall survival (OS) was 8.7 months (95% CI, 7.4–10.0). Ninety-nine patients received G-based chemotherapy (94 GP, 5 G alone), and 144 patients received F-based chemotherapy (83 FP, 61 F alone). The response rate (RR), disease control rate (DCR), PFS and OS of G-based chemotherapy <it>versus </it>F-based chemotherapy were 16.7% <it>vs</it>. 19.5% (P = 0.591), 52.8% <it>vs</it>. 58.9% (P = 0.372), 4.0 months <it>vs</it>. 4.3 months (P = 0.816), and 7.8 months <it>vs</it>. 9.1 months (P = 0.848), respectively. Sixty-six patients received F or G without P, and 177 patients received F or G with P. The RR, DCR, PFS and OS of chemotherapy without P <it>versus </it>chemotherapy including P were 12.7% <it>vs</it>. 20.6% (P = 0.169), 46.0% <it>vs</it>. 60.6% (P = 0.049), 3.3 months <it>vs</it>. 4.4 months (P = 0.887), and 10.6 months <it>vs</it>. 8.1 months (P = 0.257), respectively.</p> <p>Conclusion</p> <p>In unresectable BTC, F-based and G-based chemotherapy showed similar efficacy in terms of RR, DCR, PFS and OS. The benefit of adding P to F or G was not significant except for DCR. Further prospective studies which define the efficacy of various chemotherapeutic regimens in BTC are warranted.</p

    NELF Potentiates Gene Transcription in the Drosophila Embryo

    Get PDF
    A hallmark of genes that are subject to developmental regulation of transcriptional elongation is association of the negative elongation factor NELF with the paused RNA polymerase complex. Here we use a combination of biochemical and genetic experiments to investigate the in vivo function of NELF in the Drosophila embryo. NELF associates with different gene promoter regions in correlation with the association of RNA polymerase II (Pol II) and the initial activation of gene expression during the early stages of embryogenesis. Genetic experiments reveal that maternally provided NELF is required for the activation, rather than the repression of reporter genes that emulate the expression of key developmental control genes. Furthermore, the relative requirement for NELF is dictated by attributes of the flanking cis-regulatory information. We propose that NELF-associated paused Pol II complexes provide a platform for high fidelity integration of the combinatorial spatial and temporal information that is central to the regulation of gene expression during animal development

    Modified FOLFOX-6 chemotherapy in advanced gastric cancer: Results of phase II study and comprehensive analysis of polymorphisms as a predictive and prognostic marker

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to evaluate the efficacy and toxicity of infusional 5-fluorouracil (5-FU), folinic acid and oxaliplatin (modified FOLFOX-6) in patients with advanced gastric cancer (AGC), as first-line palliative combination chemotherapy. We also analyzed the predictive or prognostic value of germline polymorphisms of candidate genes associated with 5-FU and oxaliplatin.</p> <p>Methods</p> <p>Seventy-three patients were administered a 2 hour infusion of oxaliplatin (100 mg/m<sup>2</sup>) and folinic acid (100 mg/m<sup>2</sup>) followed by a 46 hour continuous infusion of 5-FU (2,400 mg/m<sup>2</sup>). Genomic DNA from the patients' peripheral blood mononuclear cells was extracted. Ten polymorphisms within five genes were investigated including TS, GSTP, ERCC, XPD and XRCC.</p> <p>Results</p> <p>The overall response rate (RR) was 43.8%. Median time to progression (TTP) and overall survival (OS) were 6.0 months and 12.6 months, respectively. Toxicities were generally tolerable and manageable. The RR was significantly higher in patients with a 6-bp deletion homozygote (-6 bp/-6 bp) in TS-3'UTR (55.0% <it>vs</it>. 30.3% in +6 bp/+6 bp or +6 bp/-6 bp, <it>p </it>= 0.034), and C/A or A/A in XPD156 (52.0% <it>vs</it>. 26.1% in C/C, <it>p </it>= 0.038). The -6 bp/-6 bp in TS-3'UTR was significantly associated with a prolonged TTP and OS. In a multivariate analysis, the 6-bp deletion in TS-3'UTR was identified as an independent prognostic marker of TTP (hazard ratio = 0.561, <it>p </it>= 0.032).</p> <p>Conclusion</p> <p>Modified FOLFOX-6 chemotherapy appears to be active and well tolerated as first line chemotherapy in AGC patients. The 6-bp deletion in TS-3'UTR might be a candidate to select patients who are likely to benefit from 5-FU based modified FOLFOX-6 in future large scale trial.</p

    Recent progress towards development of effective systemic chemotherapy for the treatment of malignant brain tumors

    Get PDF
    Systemic chemotherapy has been relatively ineffective in the treatment of malignant brain tumors even though systemic chemotherapy drugs are small molecules that can readily extravasate across the porous blood-brain tumor barrier of malignant brain tumor microvasculature. Small molecule systemic chemotherapy drugs maintain peak blood concentrations for only minutes, and therefore, do not accumulate to therapeutic concentrations within individual brain tumor cells. The physiologic upper limit of pore size in the blood-brain tumor barrier of malignant brain tumor microvasculature is approximately 12 nanometers. Spherical nanoparticles ranging between 7 nm and 10 nm in diameter maintain peak blood concentrations for several hours and are sufficiently smaller than the 12 nm physiologic upper limit of pore size in the blood-brain tumor barrier to accumulate to therapeutic concentrations within individual brain tumor cells. Therefore, nanoparticles bearing chemotherapy that are within the 7 to 10 nm size range can be used to deliver therapeutic concentrations of small molecule chemotherapy drugs across the blood-brain tumor barrier into individual brain tumor cells. The initial therapeutic efficacy of the Gd-G5-doxorubicin dendrimer, an imageable nanoparticle bearing chemotherapy within the 7 to 10 nm size range, has been demonstrated in the orthotopic RG-2 rodent malignant glioma model. Herein I discuss this novel strategy to improve the effectiveness of systemic chemotherapy for the treatment of malignant brain tumors and the therapeutic implications thereof

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

    Get PDF
    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
    corecore