135 research outputs found

    A phase I trial of the selective oral cyclin-dependent kinase inhibitor seliciclib (CYC202; R-Roscovitine), administered twice daily for 7 days every 21 days

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    Seliciclib (CYC202; R-roscovitine) is the first selective, orally bioavailable inhibitor of cyclin-dependent kinases 1, 2, 7 and 9 to enter clinical trial. Preclinical studies showed antitumour activity in a broad range of human tumour xenografts. A phase I trial was performed with a 7-day b.i.d. p.o. schedule. Twenty-one patients (median age 62 years, range: 39–73 years) were treated with doses of 100, 200 and 800 b.i.d. Dose-limiting toxicities were seen at 800 mg b.i.d.; grade 3 fatigue, grade 3 skin rash, grade 3 hyponatraemia and grade 4 hypokalaemia. Other toxicities included reversible raised creatinine (grade 2), reversible grade 3 abnormal liver function and grade 2 emesis. An 800 mg portion was investigated further in 12 patients, three of whom had MAG3 renograms. One patient with a rapid increase in creatinine on day 3 had a reversible fall in renal perfusion, with full recovery by day 14, and no changes suggestive of renal tubular damage. Further dose escalation was precluded by hypokalaemia. Seliciclib reached peak plasma concentrations between 1 and 4 h and elimination half-life was 2–5 h. Inhibition of retinoblastoma protein phosphorylation was not demonstrated in peripheral blood mononuclear cells. No objective tumour responses were noted, but disease stabilisation was recorded in eight patients; this lasted for a total of six courses (18 weeks) in a patient with ovarian cancer

    The stellar and sub-stellar IMF of simple and composite populations

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    The current knowledge on the stellar IMF is documented. It appears to become top-heavy when the star-formation rate density surpasses about 0.1Msun/(yr pc^3) on a pc scale and it may become increasingly bottom-heavy with increasing metallicity and in increasingly massive early-type galaxies. It declines quite steeply below about 0.07Msun with brown dwarfs (BDs) and very low mass stars having their own IMF. The most massive star of mass mmax formed in an embedded cluster with stellar mass Mecl correlates strongly with Mecl being a result of gravitation-driven but resource-limited growth and fragmentation induced starvation. There is no convincing evidence whatsoever that massive stars do form in isolation. Various methods of discretising a stellar population are introduced: optimal sampling leads to a mass distribution that perfectly represents the exact form of the desired IMF and the mmax-to-Mecl relation, while random sampling results in statistical variations of the shape of the IMF. The observed mmax-to-Mecl correlation and the small spread of IMF power-law indices together suggest that optimally sampling the IMF may be the more realistic description of star formation than random sampling from a universal IMF with a constant upper mass limit. Composite populations on galaxy scales, which are formed from many pc scale star formation events, need to be described by the integrated galactic IMF. This IGIMF varies systematically from top-light to top-heavy in dependence of galaxy type and star formation rate, with dramatic implications for theories of galaxy formation and evolution.Comment: 167 pages, 37 figures, 3 tables, published in Stellar Systems and Galactic Structure, Vol.5, Springer. This revised version is consistent with the published version and includes additional references and minor additions to the text as well as a recomputed Table 1. ISBN 978-90-481-8817-

    Functional ultrastructure of the plant nucleolus

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    Measurement of C ⁣PC\!P asymmetries and branching-fraction ratios for B±DK±B^\pm \to DK^\pm and Dπ±D\pi^\pm with DKS0K±πD\to K^0_{\rm S} K^\pm\pi^\mp using Belle and Belle II data

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    We measure C ⁣PC\!P asymmetries and branching-fraction ratios for B±DK±B^\pm \to DK^\pm and Dπ±D\pi^\pm decays with DKS0K±πD\to K^0_{\rm S} K^\pm\pi^\mp, where DD is a superposition of D0D^0 and Dˉ0\bar{D}^0. We use the full data set of the Belle experiment, containing 772×106 BBˉ772\times 10^6~B\bar{B} pairs, and data from the Belle~II experiment, containing 387×106 BBˉ387\times 10^6~B\bar{B} pairs, both collected in electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance. Our results provide model-independent information on the unitarity triangle angle ϕ3\phi_3.Comment: 26 pages, 8 figure

    Tests of light-lepton universality in angular asymmetries of B0DνB^0 \to D^{*-} \ell \nu decays

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    We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic \Bz-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral \B is fully reconstructed in \PUpsilonFourS{} \to\B\overline{B} decays in data corresponding to \lumion integrated luminosity from electron-positron collisions collected with the \belletwo detector. We find no significant deviation from the standard model expectations

    Observation of BD()KKS0{B\to D^{(*)} K^- K^{0}_S} decays using the 2019-2022 Belle II data sample

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    We present a measurement of the branching fractions of four B0,D()+,0KKS0B^{0,-}\to D^{(*)+,0} K^- K^{0}_S decay modes. The measurement is based on data from SuperKEKB electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance collected with the Belle II detector and corresponding to an integrated luminosity of 362 fb1{362~\text{fb}^{-1}}. The event yields are extracted from fits to the distributions of the difference between expected and observed BB meson energy to separate signal and background, and are efficiency-corrected as a function of the invariant mass of the KKS0K^-K_S^0 system. We find the branching fractions to be: B(BD0KKS0)=(1.89±0.16±0.10)×104, \text{B}(B^-\to D^0K^-K_S^0)=(1.89\pm 0.16\pm 0.10)\times 10^{-4}, B(B0D+KKS0)=(0.85±0.11±0.05)×104, \text{B}(\overline B{}^0\to D^+K^-K_S^0)=(0.85\pm 0.11\pm 0.05)\times 10^{-4}, B(BD0KKS0)=(1.57±0.27±0.12)×104, \text{B}(B^-\to D^{*0}K^-K_S^0)=(1.57\pm 0.27\pm 0.12)\times 10^{-4}, B(B0D+KKS0)=(0.96±0.18±0.06)×104, \text{B}(\overline B{}^0\to D^{*+}K^-K_S^0)=(0.96\pm 0.18\pm 0.06)\times 10^{-4}, where the first uncertainty is statistical and the second systematic. These results include the first observation of B0D+KKS0\overline B{}^0\to D^+K^-K_S^0, BD0KKS0B^-\to D^{*0}K^-K_S^0, and B0D+KKS0\overline B{}^0\to D^{*+}K^-K_S^0 decays and a significant improvement in the precision of B(BD0KKS0)\text{B}(B^-\to D^0K^-K_S^0) compared to previous measurements

    Measurement of branching fractions and direct CPCP asymmetries for BKπB \to K\pi and BππB\to\pi\pi decays at Belle II

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    We report measurements of the branching fractions and direct CP\it{CP} asymmetries of the decays B0K+πB^0 \to K^+ \pi^-, B+K+π0B^+ \to K^+ \pi^0, B+K0π+B^+ \to K^0 \pi^+, and B0K0π0B^0 \to K^0 \pi^0, and use these for testing the standard model through an isospin-based sum rule. In addition, we measure the branching fraction and direct CP\it{CP} asymmetry of the decay B+π+π0B^+ \to \pi^+\pi^0 and the branching fraction of the decay B0π+πB^0 \to \pi^+\pi^-. The data are collected with the Belle II detector from e+ee^+e^- collisions at the Υ(4S)\Upsilon(4S) resonance produced by the SuperKEKB asymmetric-energy collider and contain 387×106387\times 10^6 bottom-antibottom meson pairs. Signal yields are determined in two-dimensional fits to background-discriminating variables, and range from 500 to 3900 decays, depending on the channel. We obtain 0.03±0.13±0.04-0.03 \pm 0.13 \pm 0.04 for the sum rule, in agreement with the standard model expectation of zero and with a precision comparable to the best existing determinations

    Sarilumab in patients admitted to hospital with severe or critical COVID-19: a randomised, double-blind, placebo-controlled, phase 3 trial

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    Background: Elevated proinflammatory cytokines are associated with greater COVID-19 severity. We aimed to assess safety and efficacy of sarilumab, an interleukin-6 receptor inhibitor, in patients with severe (requiring supplemental oxygen by nasal cannula or face mask) or critical (requiring greater supplemental oxygen, mechanical ventilation, or extracorporeal support) COVID-19. Methods: We did a 60-day, randomised, double-blind, placebo-controlled, multinational phase 3 trial at 45 hospitals in Argentina, Brazil, Canada, Chile, France, Germany, Israel, Italy, Japan, Russia, and Spain. We included adults (≥18 years) admitted to hospital with laboratory-confirmed SARS-CoV-2 infection and pneumonia, who required oxygen supplementation or intensive care. Patients were randomly assigned (2:2:1 with permuted blocks of five) to receive intravenous sarilumab 400 mg, sarilumab 200 mg, or placebo. Patients, care providers, outcome assessors, and investigators remained masked to assigned intervention throughout the course of the study. The primary endpoint was time to clinical improvement of two or more points (seven point scale ranging from 1 [death] to 7 [discharged from hospital]) in the modified intention-to-treat population. The key secondary endpoint was proportion of patients alive at day 29. Safety outcomes included adverse events and laboratory assessments. This study is registered with ClinicalTrials.gov, NCT04327388; EudraCT, 2020-001162-12; and WHO, U1111-1249-6021. Findings: Between March 28 and July 3, 2020, of 431 patients who were screened, 420 patients were randomly assigned and 416 received placebo (n=84 [20%]), sarilumab 200 mg (n=159 [38%]), or sarilumab 400 mg (n=173 [42%]). At day 29, no significant differences were seen in median time to an improvement of two or more points between placebo (12·0 days [95% CI 9·0 to 15·0]) and sarilumab 200 mg (10·0 days [9·0 to 12·0]; hazard ratio [HR] 1·03 [95% CI 0·75 to 1·40]; log-rank p=0·96) or sarilumab 400 mg (10·0 days [9·0 to 13·0]; HR 1·14 [95% CI 0·84 to 1·54]; log-rank p=0·34), or in proportions of patients alive (77 [92%] of 84 patients in the placebo group; 143 [90%] of 159 patients in the sarilumab 200 mg group; difference −1·7 [−9·3 to 5·8]; p=0·63 vs placebo; and 159 [92%] of 173 patients in the sarilumab 400 mg group; difference 0·2 [−6·9 to 7·4]; p=0·85 vs placebo). At day 29, there were numerical, non-significant survival differences between sarilumab 400 mg (88%) and placebo (79%; difference +8·9% [95% CI −7·7 to 25·5]; p=0·25) for patients who had critical disease. No unexpected safety signals were seen. The rates of treatment-emergent adverse events were 65% (55 of 84) in the placebo group, 65% (103 of 159) in the sarilumab 200 mg group, and 70% (121 of 173) in the sarilumab 400 mg group, and of those leading to death 11% (nine of 84) were in the placebo group, 11% (17 of 159) were in the sarilumab 200 mg group, and 10% (18 of 173) were in the sarilumab 400 mg group. Interpretation: This trial did not show efficacy of sarilumab in patients admitted to hospital with COVID-19 and receiving supplemental oxygen. Adequately powered trials of targeted immunomodulatory therapies assessing survival as a primary endpoint are suggested in patients with critical COVID-19. Funding: Sanofi and Regeneron Pharmaceuticals

    Measurement of the τ\tau-lepton mass with the Belle~II experiment

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    We present a measurement of the τ\tau-lepton mass using a sample of about 175 million e+eτ+τe^+e^- \to \tau^+\tau^- events collected with the Belle II detector at the SuperKEKB e+ee^+e^- collider at a center-of-mass energy of 10.579GeV10.579\,\mathrm{Ge\kern -0.1em V}. This sample corresponds to an integrated luminosity of 190fb1190\,\mathrm{fb^{-1}}. We use the kinematic edge of the τ\tau pseudomass distribution in the decay τππ+πντ{\tau^-\to\pi^-\pi^+\pi^-\nu_\tau} and measure the τ\tau mass to be 1777.09±0.08±0.11MeV ⁣/c21777.09 \pm 0.08 \pm 0.11 \,\mathrm{Me\kern -0.1em V\!/c^2}, where the first uncertainty is statistical and the second systematic. This result is the most precise to date

    Measurement of CPCP asymmetries in B0ϕKS0B^0\to \phi K^0_S decays with Belle II

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    We present a measurement of time-dependent rate asymmetries in B0ϕKS0B^0\to \phi K^0_S decays to search for non-standard-model physics in bqqsb\to q \overline{q}s transitions. The data sample is collected with the Belle II detector at the SuperKEKB asymmetric-energy e+ee^{+}e^{-} collider in 2019-2022 and contains (387±6)×106(387\pm 6)\times 10^6 bottom-antibottom mesons from Υ(4S)\Upsilon(4S) resonance decays. We reconstruct 162±17162\pm17 signal events and extract the charge-parity (CPCP) violating parameters from a fit to the distribution of the proper-decay-time difference of the two BB mesons. The measured direct and mixing-induced CPCP asymmetries are A=0.31±0.20±0.05A=0.31\pm0.20\pm0.05 and S=0.54±0.260.08+0.06S=0.54\pm0.26^{+0.06}_{-0.08}, respectively, where the first uncertainties are statistical and the second are systematic. The results are compatible with the CPCP asymmetries observed in bccsb\to c\overline{c} s transitions
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