342 research outputs found
Secondary somatic mutations restoring RAD51C and RAD51D associated with acquired resistance to the PARP inhibitor rucaparib in high-grade ovarian carcinoma
High-grade epithelial ovarian carcinomas (OC) containing mutated BRCA1 or BRCA2 (BRCA1/2) homologous recombination (HR) genes are sensitive to platinum-based chemotherapy and poly(ADP-ribose) polymerase inhibitors (PARPi), while restoration of HR function due to secondary mutations in BRCA1/2 has been recognized as an important resistance mechanism. We sequenced core HR pathway genes in 12 pairs of pre-treatment and post-progression tumor biopsy samples collected from patients in ARIEL2 Part 1, a phase 2 study of the PARPi rucaparib as treatment for platinum-sensitive, relapsed OC. In six of 12 pre-treatment biopsies, a truncation mutation in BRCA1, RAD51C or RAD51D was identified. In five of six paired post-progression biopsies, one or more secondary mutations restored the open reading frame. Four distinct secondary mutations and spatial heterogeneity were observed for RAD51C. In vitro complementation assays and a patient-derived xenograft (PDX), as well as predictive molecular modeling, confirmed that resistance to rucaparib was associated with secondary mutations
Desempenho do inhame (taro) em plantio direto e no consórcio com crotalária, sob manejo orgânico.
Estudaram-se os efeitos do plantio direto em cobertura morta de aveia-preta e do consórcio com Crotalaria juncea, em sistema orgânico de produção de inhame, em ensaio na EE de Nova Friburgo(Pesagro-Rio), região serrana do estado do Rio de Janeiro. Utilizouse o delineamento de blocos ao acaso com quatro repetições, em esquema fatorial 2 x 2, onde os tratamentos corresponderam ao: modo de plantio (direto ou convencional) e modo de cultivo (monocultivo ou consórcio com crotalária). O cultivo consorciado com a
leguminosa promoveu maior altura nas plantas do inhame, assim como reduziu a queima de folhas pelos raios solares. A população infestante de ervas espontâneas foi mais efetivamente controlada com a combinação entre consórcio e plantio direto. Nenhum dos tratamentos influenciou a produtividade do inhame, que foi considerada satisfatória, indicando o potencial do manejo orgânico adotado
Production and Decay of D_1(2420)^0 and D_2^*(2460)^0
We have investigated and final states and
observed the two established charmed mesons, the with mass
MeV/c and width MeV/c and
the with mass MeV/c and width
MeV/c. Properties of these final states, including
their decay angular distributions and spin-parity assignments, have been
studied. We identify these two mesons as the doublet predicted
by HQET. We also obtain constraints on {\footnotesize } as a function of the cosine of the relative phase of the two
amplitudes in the decay.Comment: 15 pages in REVTEX format. hardcopies with figures can be obtained by
sending mail to: [email protected]
Measurement of the branching fraction for
We have studied the leptonic decay of the resonance into tau
pairs using the CLEO II detector. A clean sample of tau pair events is
identified via events containing two charged particles where exactly one of the
particles is an identified electron. We find . The result is consistent with
expectations from lepton universality.Comment: 9 pages, RevTeX, two Postscript figures available upon request, CLNS
94/1297, CLEO 94-20 (submitted to Physics Letters B
Measurement of the Decay Asymmetry Parameters in and
We have measured the weak decay asymmetry parameters (\aLC ) for two \LC\
decay modes. Our measurements are \aLC = -0.94^{+0.21+0.12}_{-0.06-0.06} for
the decay mode and \aLC = -0.45\pm 0.31 \pm
0.06 for the decay mode . By combining these
measurements with the previously measured decay rates, we have extracted the
parity-violating and parity-conserving amplitudes. These amplitudes are used to
test models of nonleptonic charmed baryon decay.Comment: 11 pages including the figures. Uses REVTEX and psfig macros. Figures
as uuencoded postscript. Also available as
http://w4.lns.cornell.edu/public/CLNS/1995/CLNS95-1319.p
Measurement of the Charge Asymmetry in
We report on a search for a CP-violating asymmetry in the charmless hadronic
decay B -> K*(892)+- pi-+, using 9.12 fb^-1 of integrated luminosity produced
at \sqrt{s}=10.58 GeV and collected with the CLEO detector. We find A_{CP}(B ->
K*(892)+- pi-+) = 0.26+0.33-0.34(stat.)+0.10-0.08(syst.), giving an allowed
interval of [-0.31,0.78] at the 90% confidence level.Comment: 7 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Observation of the Charmed Baryon Decays to , , and
We have observed two new decay modes of the charmed baryon into
and using data collected with the
CLEO II detector. We also present the first measurement of the branching
fraction for the previously observed decay mode . The branching fractions for these three modes relative to
are measured to be , , and , respectively.Comment: 12 page uuencoded postscript file, postscript file also available
through http://w4.lns.cornell.edu/public/CLN
Study of the q^2-Dependence of B --> pi ell nu and B --> rho(omega)ell nu Decay and Extraction of |V_ub|
We report on determinations of |Vub| resulting from studies of the branching
fraction and q^2 distributions in exclusive semileptonic B decays that proceed
via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson
pairs collected at the Y(4S) resonance with the CLEO II detector. We measure
B(B0 -> pi- l+ nu) = (1.33 +- 0.18 +- 0.11 +- 0.01 +- 0.07)x10^{-4} and B(B0 ->
rho- l+ nu) = (2.17 +- 0.34 +0.47/-0.54 +- 0.41 +- 0.01)x10^{-4}, where the
errors are statistical, experimental systematic, systematic due to residual
form-factor uncertainties in the signal, and systematic due to residual
form-factor uncertainties in the cross-feed modes, respectively. We also find
B(B+ -> eta l+ nu) = (0.84 +- 0.31 +- 0.16 +- 0.09)x10^{-4}, consistent with
what is expected from the B -> pi l nu mode and quark model symmetries. We
extract |Vub| using Light-Cone Sum Rules (LCSR) for 0<= q^2<16 GeV^2 and
Lattice QCD (LQCD) for 16 GeV^2 <= q^2 < q^2_max. Combining both intervals
yields |Vub| = (3.24 +- 0.22 +- 0.13 +0.55/-0.39 +- 0.09)x10^{-3}$ for pi l nu,
and |Vub| = (3.00 +- 0.21 +0.29/-0.35 +0.49/-0.38 +-0.28)x10^{-3} for rho l nu,
where the errors are statistical, experimental systematic, theoretical, and
signal form-factor shape, respectively. Our combined value from both decay
modes is |Vub| = (3.17 +- 0.17 +0.16/-0.17 +0.53/-0.39 +-0.03)x10^{-3}.Comment: 45 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance
We have made a first measurement of the lepton momentum spectrum in a sample
of events enriched in neutral B's through a partial reconstruction of B0 -->
D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the
Upsilon(4S) resonance by the CLEO II detector, is compared directly to the
inclusive lepton spectrum from all Upsilon(4S) events in the same data set.
These two spectra are consistent with having the same shape above 1.5 GeV/c.
From the two spectra and two other CLEO measurements, we obtain the B0 and B+
semileptonic branching fractions, b0 and b+, their ratio, and the production
ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950
(+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57
+- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes,
tau+/tau0.Comment: 14 page, postscript file also available at
http://w4.lns.cornell.edu/public/CLN
Search for CP Violation in D^0--> K_S^0 pi^+pi^-
We report on a search for CP violation in the decay of D0 and D0B to Kshort
pi+pi-. The data come from an integrated luminosity of 9.0 1/fb of e+e-
collisions at sqrt(s) ~ 10 GeV recorded with the CLEO II.V detector. The
resonance substructure of this decay is well described by ten quasi-two-body
decay channels (K*-pi+, K*0(1430)-pi+, K*2(1430)-pi+, K*(1680)-pi+, Kshort rho,
Kshort omega, Kshort f0(980), Kshort f2(1270), Kshort f0(1370), and the ``wrong
sign'' K*+ pi-) plus a small non-resonant component. We observe no evidence for
CP violation in the amplitudes and phases that describe the decay D0 to K_S^0
pi+pi-.Comment: 10 pages, 3 figures, also available at
http://w4.lns.cornell.edu/public/CLNS/, submitted to PR
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