130 research outputs found
Capnography for Assessing Nocturnal Hypoventilation and Predicting Compliance with Subsequent Noninvasive Ventilation in Patients with ALS
BACKGROUND: Patients with amyotrophic lateral sclerosis (ALS) suffer from hypoventilation, which can easily worsen during sleep. This study evaluated the efficacy of capnography monitoring in patients with ALS for assessing nocturnal hypoventilation and predicting good compliance with subsequent noninvasive ventilation (NIV) treatment. METHODS: Nocturnal monitoring and brief wake screening by capnography/pulse oximetry, functional scores, and other respiratory signs were assessed in 26 patients with ALS. Twenty-one of these patients were treated with NIV and had their treatment compliance evaluated. RESULTS: Nocturnal capnography values were reliable and strongly correlated with the patients' respiratory symptoms (R(2) = 0.211-0.305, p = 0.004-0.021). The duration of nocturnal hypercapnea obtained by capnography exhibited a significant predictive power for good compliance with subsequent NIV treatment, with an area-under-the-curve value of 0.846 (p = 0.018). In contrast, no significant predictive values for nocturnal pulse oximetry or functional scores for nocturnal hypoventilation were found. Brief waking supine capnography was also useful as a screening tool before routine nocturnal capnography monitoring. CONCLUSION: Capnography is an efficient tool for assessing nocturnal hypoventilation and predicting good compliance with subsequent NIV treatment of ALS patients, and may prove useful as an adjunctive tool for assessing the need for NIV treatment in these patients
Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays
We report the observation of a narrow charmonium-like state produced in the
exclusive decay process B+ -> K+ pi+pi- J/psi. This state, which decays into
pi+pi- J/psi, has a mass of 3872.0+-0.6(stat)+-0.5(syst) MeV, a value that is
very near the M_D + M_D* mass threshold. The results are based on an analysis
of 152M B-Bbar events collected at the Upsilon(4S) resonance in the Belle
detector at the KEKB collider. The statistical significance of the signal is in
excess of 10 sigma.Comment: 10 pages 4 figures, submitted to Physical Review Letter
Measurement of the Branching Fraction for B->eta' K and Search for B->eta'pi+
We report measurements for two-body charmless B decays with an eta' meson in
the final state. Using 11.1X10^6 BBbar pairs collected with the Belle detector,
we find BF(B^+ ->eta'K^+)=(79^+12_-11 +-9)x10^-6 and BF(B^0 ->
eta'K^0)=(55^+19_-16 +-8)x10^-6, where the first and second errors are
statistical and systematic, respectively. No signal is observed in the mode B^+
-> eta' pi^+, and we set a 90% confidence level upper limit of BF(B^+->
eta'pi^+) eta'K^+- decays is
investigated and a limit at 90% confidence level of -0.20<Acp<0.32 is obtained.Comment: Submitted to Physics Letters
Evidence for B0->pi0pi0
We report evidence for the decay B0->pi0pi0. The analysis is based on a data
sample of 152million BBbar pairs collected at the Upsilon(4s) resonance with
the Belle detector at the KEKB e+e- storage ring. We find
25.6+9.3/-8.4(stat)+1.6/-1.4(syst) B0->pi0pi0 signal events with a significance
of 3.4 standard deviations. We measure the branching fraction to be
(1.7+-0.6(stat)+-0.2(syst))*10^{-6}.Comment: Submitted to PR
Observation of Cabibbo-suppressed and W-exchange Lambda_c^+ baryon decays
We present measurements of the Cabibbo-suppressed decays Lambda_c^+ -->
Lambda0 K+ and Lambda_c^+ --> Sigma0 K+ (both first observations), Lambda_c^+
--> Sigma+ K+ pi- (seen with large statistics for the first time), Lambda_c^+
--> p K+ K- and Lambda_c^+ --> p phi (measured with improved accuracy).
Improved branching ratio measurements for the decays Lambda_c^+ --> Sigma+ K+
K- and Lambda_c^+ --> Sigma+ phi, which are attributed to W-exchange diagrams,
are shown. We also present the first evidence for Lambda_c^+ --> Xi(1690)^0 K+
and set an upper limit on the non-resonant decay Lambda_c^+ --> Sigma+ K+ K-.
This analysis was performed using 32.6 fb^{-1} of data collected by the Belle
detector at the asymmetric e+ e- collider KEKB.Comment: Submitted to Phys. Lett. B. v2: A small correction to the Authorlist
was made. An earlier version of this analysis was released as
BELLE-CONF-0130, hep-ex/010800
Observation of
We report the first observation of the flavor-changing neutral current decay
and an improved measurement of the decay , where represents an electron or a muon, with a data
sample of 140 fb accumulated at the resonance with the
Belle detector at KEKB. The results for the branching fractions are and
, where the first error is statistical, the second is systematic and
the third is from model dependence.Comment: 11 pages, 2 figures, submitted to PR
Mesurement of the B0 - anti-B0 Mixing Parameter Delta m_d using Semileptonic B0 Decays
We present a measurement of the B^0-B^0bar mixing parameter Delta m_d using
neutral B meson pairs in a 29.1 fb^{-1} data sample collected at the
Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy
e^+e^- collider. We exclusively reconstruct one neutral B meson in the
semileptonic B^0 \to D^{*-}\ell^+\nu decay mode and identify the flavor of the
accompanying B meson from its decay products. From the distribution of the time
intervals between the two flavor-tagged B meson decay points, we obtain Delta
m_d = (0.494 +- 0.012 +- 0.015) ps^{-1}, where the first error is statistical
and the second error is systematic.Comment: 10 pages, 3 figures, Published in Phys.Rev.Lett. 89, 251803 (2002
Measurements of Branching Fractions and Decay Amplitudes in B-> J/\psi K^* decays
The branching fractions and the decay amplitudes of B -> J/psi K^* decays are
measured in a 29.4/fb data sample collected with the Belle detector at the KEKB
electron-positron collider. The decay amplitudes of helicity states of the
J/psi K^* system are determined from the full angular distribution of the final
state particles in the transversity basis. The branching fractions are measured
to be (1.29\pm0.05\pm0.13) \times 10^{-3} for neutral mesons and
(1.28\pm0.07\pm0.14) \times 10^{-3} for charged mesons. The measured
longitudinal and transverse (perpendicular to the transversity plane)
amplitudes are |A_0|^2 = 0.62\pm0.02\pm0.03 and |A_{\perp}|^2 =
0.19\pm0.02\pm0.03, respectively. The value of |A_{\perp}|^2 shows that the CP
even component dominates in the B^0 \to J/\psi K^{*0}(K_S\pi^0) decay.Comment: 17 pages, 3 figures, 5 tables, to appear in Phys. Lett.
Observation of the eta_c(2S) in exclusive B-->K KsK-pi+ decays
We report the observation of a narrow peak in the KsK-pi+ invariant mass
distribution in a sample of exclusive B-->K KsK-pi+ decays collected with the
Belle detector at the KEKB asymmetric energy e+e- collider. The measured mass
of the peak is M=3654+-6(stat)+-8(syst) MeV/c^2 and we place a 90% confidence
level upper limit on the width of Gamma<55 MeV/c^2. The properties agree with
heavy-quark potential model expectations for the eta_c(2S), the n=2 singlet S
charmonium state.Comment: 10 pages, 3 figures, submitted to Physical Review Letter
Charmless Hadronic Two-Body B Meson Decays
We report the results of a study of two-body B meson decays to the complete
set of K pi, pi pi, and K K final states. The study is performed on a data
sample of 31.7 +/- 0.3 million B B-bar events recorded on the Upsilon(4S)
resonance by the Belle experiment at KEKB. We observe significant signals in
all K pi final states and in the pi+ pi- and pi+ pi0 final states. We set
limits on the pi0 pi0 and K K final states. A search is performed for
partial-rate asymmetries between conjugate states for flavor-specific final
states.Comment: Submitted to PR
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