610 research outputs found

    Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0

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    Using 58 million J/psi and 14 million psi' decays obtained by the BESII experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous measurements.Comment: 9 pages, 8 figures, RevTex

    First observation of psi(2S)-->K_S K_L

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    The decay psi(2S)-->K_S K_L is observed for the first time using psi(2S) data collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC); the branching ratio is determined to be B(psi(2S)-->K_S K_L) = (5.24\pm 0.47 \pm 0.48)\times 10^{-5}. Compared with J/psi-->K_S K_L, the psi(2S) branching ratio is enhanced relative to the prediction of the perturbative QCD ``12%'' rule. The result, together with the branching ratios of psi(2S) decays to other pseudoscalar meson pairs (\pi^+\pi^- and K^+K^-), is used to investigate the relative phase between the three-gluon and the one-photon annihilation amplitudes of psi(2S) decays.Comment: 5 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let

    The Migration of Elites in a Borderless World: Citizenship as an Incentive for Professionals and Managers?

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    Der Artikel geht der Frage nach, inwiefern die geöffneten Türen für die Immigration Hochqualifizierter in den OECD-Ländern tatsächlich zu einer verstärkten Migrationsbewegung führen. Die Analyse von Daten zu Eliten- und Hochqualifiziertenmigration in Ostasien, Europa und den USA führt zu dem Ergebnis, dass diese dem Muster einer „brain circulation“ folgt und die Staatsbürgerrechte dabei keine entscheidende Rolle spielen

    Fabrication of Porous TiO2 Hollow Spheres and Their Application in Gas Sensing

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    In this work, porous TiO2 hollow spheres with an average diameter of 100 nm and shell thickness of 20 nm were synthesized by a facile hydrothermal method with NH4HCO3 as the structure-directing agent, and the formation mechanism for this porous hollow structure was proved to be the Ostwald ripening process by tracking the morphology of the products at different reaction stages. The product was characterized by SEM, TEM, XRD and BET analyses, and the results show that the as-synthesized products are anatase phase with a high surface area up to 132.5 m2/g. Gas-sensing investigation reveals that the product possesses sensitive response to methanal gas at 200°C due to its high surface area

    A Comparison of Red Fluorescent Proteins to Model DNA Vaccine Expression by Whole Animal In Vivo Imaging

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    DNA vaccines can be manufactured cheaply, easily and rapidly and have performed well in pre-clinical animal studies. However, clinical trials have so far been disappointing, failing to evoke a strong immune response, possibly due to poor antigen expression. To improve antigen expression, improved technology to monitor DNA vaccine transfection efficiency is required. In the current study, we compared plasmid encoded tdTomato, mCherry, Katushka, tdKatushka2 and luciferase as reporter proteins for whole animal in vivo imaging. The intramuscular, subcutaneous and tattooing routes were compared and electroporation was used to enhance expression. We observed that overall, fluorescent proteins were not a good tool to assess expression from DNA plasmids, with a highly heterogeneous response between animals. Of the proteins used, intramuscular delivery of DNA encoding either tdTomato or luciferase gave the clearest signal, with some Katushka and tdKatushka2 signal observed. Subcutaneous delivery was weakly visible and nothing was observed following DNA tattooing. DNA encoding haemagglutinin was used to determine whether immune responses mirrored visible expression levels. A protective immune response against H1N1 influenza was induced by all routes, even after a single dose of DNA, though qualitative differences were observed, with tattooing leading to high antibody responses and subcutaneous DNA leading to high CD8 responses. We conclude that of the reporter proteins used, expression from DNA plasmids can best be assessed using tdTomato or luciferase. But, the disconnect between visible expression level and immunogenicity suggests that in vivo whole animal imaging of fluorescent proteins has limited utility for predicting DNA vaccine efficacy

    Cooperation of p300 and PCAF in the Control of MicroRNA 200c/141 Transcription and Epithelial Characteristics

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    Epithelial to mesenchymal transition (EMT) not only occurs during embryonic development and in response to injury, but is an important element in cancer progression. EMT and its reverse process, mesenchymal to epithelial transition (MET) is controlled by a network of transcriptional regulators and can be influenced by posttranscriptional and posttranslational modifications. EMT/MET involves many effectors that can activate and repress these transitions, often yielding a spectrum of cell phenotypes. Recent studies have shown that the miR-200 family and the transcriptional suppressor ZEB1 are important contributors to EMT. Our previous data showed that forced expression of SPRR2a was a powerful inducer of EMT and supports the findings by others that SPRR gene members are highly upregulated during epithelial remodeling in a variety of organs. Here, using SPRR2a cells, we characterize the role of acetyltransferases on the microRNA-200c/141 promoter and their effect on the epithelial/mesenchymal status of the cells. We show that the deacetylase inhibitor TSA as well as P300 and PCAF can cause a shift towards epithelial characteristics in HUCCT-1-SPRR2a cells. We demonstrate that both P300 and PCAF act as cofactors for ZEB1, forming a P300/PCAF/ZEB1 complex on the miR200c/141 promoter. This binding results in lysine acetylation of ZEB1 and a release of ZEB1 suppression on miR-200c/141 transcription. Furthermore, disruption of P300 and PCAF interactions dramatically down regulates miR-200c/141 promoter activity, indicating a PCAF/P300 cooperative function in regulating the transcriptional suppressor/activator role of ZEB1. These data demonstrate a novel mechanism of miRNA regulation in mediating cell phenotype

    Direct Measurement of B(D0->phiX0) and B(D+->phiX+)

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    The first measurement of B(0->phi X0) and an upper limit for B(D+->phi X+) are determined from 22.3 pb-1 of e+e- annihilation data at a C. M. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied for the first time to charm threshold data to determine the charge of the D meson in the recoil from 9054+-309+-416 reconstructed D0, D+ mesons. The branching fractions B(D->phiX0) =(1.71+0.76-0.71+-0.17)%, and B(D+->phiX+) <1.8% are determined from 10 events with a reconstructed D and a recoiling phi. In addition, a 90% C.L. upper limit of B(D+->phi e+X0)<1.6% is determined from a search for semileptonic decays of the D+.Comment: Submitted to Phys. Rev.

    TGFbeta induces apoptosis and EMT in primary mouse hepatocytes independently of p53, p21Cip1 or Rb status

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    Melville Trust for the Care and Cure of Cancer to SP and SS.Background: TGF beta has pleiotropic effects that range from regulation of proliferation and apoptosis to morphological changes and epithelial-mesenchymal transition (EMT). Some evidence suggests that these effects may be interconnected. We have recently reported that P53, P21(Cip1) and pRB, three critical regulators of the G1/S transition are variably involved in TGF beta-induced cell cycle arrest in hepatocytes. As these proteins are also involved in the regulation of apoptosis in many circumstances, we investigated their contribution to other relevant TGF beta-induced effects, namely apoptosis and EMT, and examined how the various processes were interrelated. Methods: Primary mouse hepatocytes deficient in p53, p21 and/or Rb, singly or in combination were treated with TGF beta for 24 to 96 hours. Apoptosis was quantified according to morphology and by immunostaining for cleavedcapsase 3. Epithelial and mesenchymal marker expression was studied using immunocytochemistry and real time PCR. Results: We found that TGF beta similarly induced morphological changes regardless of genotype and independently of proliferation index or sensitivity to inhibition of proliferation by TGF beta. Morphological changes were accompanied by decrease in E-cadherin and increased Snail expression but the mesenchymal markers (N-cadherin, SMA alpha and Vimentin) studied remained unchanged. TGF beta induced high levels of apoptosis in p53-/-, Rb-/-, p21(cip1)-/- and control hepatocytes although with slight differences in kinetics. This was unrelated to proliferation or changes in morphology and loss of cell-cell adhesion. However, hepatocytes deficient in both p53 and p21(cip1)were less sensitive to TGF beta-induced apoptosis. Conclusion: Although p53, p21(Cip1) and pRb are well known regulators of both proliferation and apoptosis in response to a multitude of stresses, we conclude that they are critical for TGF beta-driven inhibition of hepatocytes proliferation, but only slightly modulate TGF beta-induced apoptosis. This effect may depend on other parameters such as proliferation and the presence of other regulatory proteins as suggested by the consequences of p53, p21(Cip1) double deficiency. Similarly, p53, p21(Cip1) and pRB deficiency had no effect on the morphological changes and loss of cell adhesion which is thought to be critical for metastasis. This indicates that possible association of these genes with metastasis potential would be unlikely to involve TGF beta-induced EMT.Publisher PDFPeer reviewe

    Deficiency of G1 regulators P53, P21Cip1 and/or pRb decreases hepatocyte sensitivity to TGFβ cell cycle arrest

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    <p>Abstract</p> <p>Background</p> <p>TGFβ is critical to control hepatocyte proliferation by inducing G1-growth arrest through multiple pathways leading to inhibition of E2F transcription activity. The retinoblastoma protein pRb is a key controller of E2F activity and G1/S transition which can be inhibited in viral hepatitis. It is not known whether the impairment of pRb would alter the growth inhibitory potential of TGFβ in disease. We asked how <it>Rb</it>-deficiency would affect responses to TGFβ-induced cell cycle arrest.</p> <p>Results</p> <p>Primary hepatocytes isolated from <it>Rb-floxed </it>mice were infected with an adenovirus expressing CRE-recombinase to delete the <it>Rb </it>gene. In control cells treatment with TGFβ prevented cells to enter S phase via decreased cMYC activity, activation of P16<sup>INK4A </sup>and P21<sup>Cip </sup>and reduction of E2F activity. In <it>Rb</it>-null hepatocytes, cMYC activity decreased slightly but P16<sup>INK4A </sup>was not activated and the great majority of cells continued cycling. <it>Rb </it>is therefore central to TGFβ-induced cell cycle arrest in hepatocytes. However some <it>Rb</it>-null hepatocytes remained sensitive to TGFβ-induced cell cycle arrest. As these hepatocytes expressed very high levels of P21<sup>Cip1 </sup>and P53 we investigated whether these proteins regulate pRb-independent signaling to cell cycle arrest by evaluating the consequences of disruption of <it>p53 </it>and <it>p21</it><sup><it>Cip1</it></sup>. Hepatocytes deficient in <it>p53 or p21</it><sup><it>Cip1 </it></sup>showed diminished growth inhibition by TGFβ. Double deficiency had a similar impact showing that in cells containing functional pRb; P21<sup>Cip </sup>and P53 work through the same pathway to regulate G1/S in response to TGFβ. In <it>Rb</it>-deficient cells however, <it>p53 </it>but not <it>p21</it><sup><it>Cip </it></sup>deficiency had an additive effect highlighting a pRb-independent-P53-dependent effector pathway of inhibition of E2F activity.</p> <p>Conclusion</p> <p>The present results show that otherwise genetically normal hepatocytes with disabled <it>p53</it>, <it>p21</it><sup><it>Cip1 </it></sup>or <it>Rb </it>genes respond less well to the antiproliferative effects of TGFβ. As the function of these critical cellular proteins can be impaired by common causes of chronic liver disease and HCC, including viral hepatitis B and C proteins, we suggest that disruption of pRb function, and to a lesser extend P21<sup>Cip1 </sup>and P53 in hepatocytes may represent an additional new mechanism of escape from TGFβ-growth-inhibition in the inflammatory milieu of chronic liver disease and contribute to cancer development.</p

    Family history of cancer and risk for esophageal and gastric cancer in Shanxi, China

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    <p>Abstract</p> <p>Background</p> <p>Family history (FH) by different relative types and risk of upper gastrointestinal (UGI) cancers has been only rarely reported; the data on UGI cancer survival are sparse.</p> <p>Methods</p> <p>600 esophageal squamous cell carcinoma (ESCC) cases, 598 gastric cardia adenocarcinoma cases, and 316 gastric non-cardia adenocarcinoma cases, and 1514 age-, gender-, and neighborhood-matched controls were asked for FH in first degree relatives and non-blood relatives. Odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regressions, and hazard ratios (HRs) from Cox proportional hazard regressions were estimated.</p> <p>Results</p> <p>Increased ESCC risk was associated with FH of any cancer (OR = 1.72, 95% CI = 1.39–2.12), FH of any UGI cancer (OR = 2.28, 95%CI = 1.77–2.95) and FH of esophageal cancer (OR = 2.84, 95%CI = 2.09–3.86), but not FH of non-UGI cancer. Individuals with two or more affected first-degree relatives had 10-fold increased ESCC risk. FH of gastric cardia cancer was associated with an increased risk of all three cancers. Cancer in non-blood relatives was not associated with risk of any UGI cancer. FH of UGI cancer was associated with a poorer survival rate among younger ESCC cases (HR = 1.82, 95%CI = 1.01–3.29).</p> <p>Conclusion</p> <p>These data provide strong evidence that shared susceptibility is involved in esophageal carcinogenesis and also suggest a role in prognosis.</p
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