125 research outputs found

    Contribución al conocimiento cariológico del género Centaurea L. (Asteraceae) en la Península Ibérica. Grupo Jacea-Lepteranthus

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    Se da a conocer el número cromosómico de 21 táxones del género Centaurea L. pertenecientes al grupo Jacea-Lepteranthus. En particular, se han estudiado 10 táxones de la sect. Jacea (Miller) DC., de los que C. jacea subsp vinyalsii (Sennen) O. Bolòs lo ha sido al parecer por vez primera. De la sect. Lepteranthus (Neck.)DC. se han estudiado 11 táxones, siendo probablemente nuevos los recuentos de C. pectinata var. acutifolia (Jord.) Briq., C. janeri Graells subsp. janeri y C. janeri subsp. babiana M. Laínz. En ambos grupos el número básico encontrado ha sido x = 11. Los números son en casi todos los casos 2n = 22 o 2n = 44, el último correspondiéndose con plantas tetraploides diploidizadas. En el caso de C. janeri subsp gallaecica, el número encontrado (2n = 66) indica el carácter hexaploide de las poblaciones estudiadas.A karyological study of 21 taxa of the Jacea-Lepteranthus group of genus Centaurea L. is reported. Within Centaurea sect. Jacea (Miller)DC. we have studied 10 taxa but only the report for C. jacea subsp vinyalsii (Sennen) O. Bolòs is given for the fi rst time. Within Centaurea sect. Lepteranthus (Neck.)DC. we have studied the chromosome number of 11 taxa and the reports for some of them are given probably for the fi rst time: C. pectinata var. acutifolia (Jord.) Briq., C. janeri Graells subsp. janeri and C. janeri subsp. babiana M. Laínz. In both groups we have found the basic number x = 11. The chromosome numbers are usually 2n = 22 or 2n = 44, the last one corresponding with diploidized tetraploids. In the case of C. janeri subsp gallaecica the cromosome number found (2n = 66) indicates the hexaploid level of the populations studied

    Gomphocarpus R. Br. (Apocynaceae sufma. Asclepiadoideae) en Andalucía Occidental

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    Se da a conocer la presencia en Andalucía Occidental de Gomphocarpus physocarpus E. Mey., un neófi to originario del E y S de África. Se comenta la fenología de la fl oración y fructifi cación, así como la capacidad de dispersión de las plantas en las poblaciones naturalizadas, y se comparan con las de G. fruticosus (L.) T.W. Aiton, también presente en el territorio. Se discute el carácter invasor de las tres especies de Asclepiadaceae citadas en el texto.In this article the neophyte Gomphocarpus physocarpus E.Mey., widely distributed in SE Africa, is fi rst cited in western Andalucía (southern Spain). The flowering and fruit ripening phenology and dispersal potential of plants in different naturalized populations are described and compared with that of G. fruticosus (L.) T.W. Aiton also present in this territory. The invasive potential of the three Asclepiadaceae species here considered is also discussed.Fundación MIGRE

    High prevalence of secondary resistance mutations in Venezuelan HIV-1 isolates.

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    The genetic variability was studied in HIV-1 from Venezuelan patients with and without treatment, in order to evaluate the presence of polymorphisms and drug resistance mutations. Proviral DNA from peripheral blood mononuclear cells or viral RNA from plasma was extracted from the blood of 30 patients. Two regions from the polymerase gene, protease (Pr) and reverse transcriptase (RT) and one genomic fragment from the envelope (Env) gene were amplified and sequenced. All HIV-1 samples analyzed were classified as subtype B, without evidence of recombination. Although no primary protease mutations were detected, a high frequency of secondary mutations (86%, 19/22), associated to restoration of viral replicative fitness, was observed in strains circulating both in treated and non-treated patients. Resistance mutations to nucleoside RT inhibitors (NRTI) and non-nucleoside RT inhibitors (NNRTI) were detected in 35% (6/17) and 12% (2/17) of the viruses circulating in treated patients, respectively. Resistance mutations were also present in the virus infecting one antiretroviral naive individual (7.7%), suggesting that local screening for resistant mutation in naive patient might be important to minimize therapy failure. Future studies are warranted to assess the role of secondary mutation in the success of viral infection

    Identification of a novel quinoxaline-isoselenourea targeting the STAT3 pathway as a potential melanoma therapeutic

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    The prognosis for patients with metastatic melanoma remains very poor. Constitutive signal transducer and activator of transcription 3 (STAT3) activation has been correlated to metastasis, poor patient survival, larger tumor size, and acquired resistance against vemurafenib (PLX-4032), suggesting its potential as a molecular target. We recently designed a series of isoseleno- and isothio-urea derivatives of several biologically active heterocyclic scaffolds. The cytotoxic effects of lead isoseleno- and isothio-urea derivatives (compounds 1 and 3) were studied in a panel of five melanoma cell lines, including B-RAFV600E-mutant and wild-type (WT) cells. Compound 1 (IC50 range 0.8–3.8 µM) showed lower IC50 values than compound 3 (IC50 range 8.1–38.7 µM) and the mutant B-RAF specific inhibitor PLX-4032 (IC50 ranging from 0.4 to >50 µM), especially at a short treatment time (24 h). These effects were long-lasting, since melanoma cells did not recover their proliferative potential after 14 days of treatment. In addition, we confirmed that compound 1 induced cell death by apoptosis using Live-and-Dead, Annexin V, and Caspase3/7 apoptosis assays. Furthermore, compound 1 reduced the protein levels of STAT3 and its phosphorylation, as well as decreased the expression of STAT3-regulated genes involved in metastasis and survival, such as survivin and c-myc. Compound 1 also upregulated the cell cycle inhibitor p21. Docking studies further revealed the favorable binding of compound 1 with the SH2 domain of STAT3, suggesting it acts through STAT3 inhibition. Taken together, our results suggest that compound 1 induces apoptosis by means of the inhibition of the STAT3 pathway, non-specifically targeting both B-RAF-mutant and WT melanoma cells, with much higher cytotoxicity than the current therapeutic drug PLX-4032

    Effectiveness and safety of sofosbuvir‐based regimens plus an NS5A inhibitor for patients with HCV genotype 3 infection and cirrhosis: results of a multicenter real‐life cohort

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    [Abstract] Patients with HCV genotype 3 (GT3) infection and cirrhosis are currently the most difficult to cure. We report our experience with sofosbuvir+daclatasvir (SOF+DCV) or sofosbuvir/ledipasvir (SOF/LDV), with or without ribavirin (RBV) in clinical practice in this population. This was a multicenter observational study including cirrhotic patients infected by HCV GT3, treated with sofosbuvir plus an NS5A inhibitor (May 2014‐October 2015). In total, 208 patients were included: 98 (47%) treatment‐experienced, 42 (20%) decompensated and 55 (27%) MELD score >10. In 131 (63%), treatment was SOF+DCV and in 77 (37%), SOF/LDV. Overall, 86% received RBV. RBV addition and extension to 24 weeks was higher in the SOF/LDV group (95% vs 80%, P=.002 and 83% vs 72%, P=.044, respectively). A higher percentage of decompensated patients were treated with DCV than LDV (25% vs 12%, P=.013). Overall, SVR12 was 93.8% (195/208): 94% with SOF+DCV and 93.5% with SOF/LDV. SVR12 was achieved in 90.5% of decompensated patients. Eleven treatment failures: 10 relapses and one breakthrough. RBV addition did not improve SVR (RR: 1.08; P=.919). The single factor associated with failure to achieve SVR was platelet count <75×10E9/mL (RR: 3.50, P=.019). In patients with MELD <10, type of NS5A inhibitor did not impact on SVR12 (94% vs 97%; adjusted RR: 0.49). Thirteen patients (6.3%) had serious adverse events, including three deaths (1.4%) and one therapy discontinuation (0.5%), higher in decompensated patients (16.7% vs 3.6%, P<.006). In patients with GT3 infection and cirrhosis, SVR12 rates were high with both SOF+DCV and SOF/LDV, with few serious adverse events

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

    A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector

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    A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance

    Combination of searches for Higgs boson pairs in pp collisions at \sqrts = 13 TeV with the ATLAS detector

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    This letter presents a combination of searches for Higgs boson pair production using up to 36.1 fb(-1) of proton-proton collision data at a centre-of-mass energy root s = 13 TeV recorded with the ATLAS detector at the LHC. The combination is performed using six analyses searching for Higgs boson pairs decaying into the b (b) over barb (b) over bar, b (b) over barW(+)W(-), b (b) over bar tau(+)tau(-), W+W-W+W-, b (b) over bar gamma gamma and W+W-gamma gamma final states. Results are presented for non-resonant and resonant Higgs boson pair production modes. No statistically significant excess in data above the Standard Model predictions is found. The combined observed (expected) limit at 95% confidence level on the non-resonant Higgs boson pair production cross-section is 6.9 (10) times the predicted Standard Model cross-section. Limits are also set on the ratio (kappa(lambda)) of the Higgs boson self-coupling to its Standard Model value. This ratio is constrained at 95% confidence level in observation (expectation) to -5.0 &lt; kappa(lambda) &lt; 12.0 (-5.8 &lt; kappa(lambda) &lt; 12.0). In addition, limits are set on the production of narrow scalar resonances and spin-2 Kaluza-Klein Randall-Sundrum gravitons. Exclusion regions are also provided in the parameter space of the habemus Minimal Supersymmetric Standard Model and the Electroweak Singlet Model. For complete list of authors see http://dx.doi.org/10.1016/j.physletb.2019.135103</p
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