186 research outputs found
Induction of rifampicin metabolism during treatment of tuberculous patients with daily and fully intermittent regimens containing the drug
Self-induction of rifampicin metabolism during daily and intermittent
chemotherapy was studied by monitoring the changes in the serum half-life
of the drug over a 4-week period in patients with pulmonary tuberculosis.
Rifampicin 450 mg was administered to 8 patients who received treatment
daily, 7 on thrice-weekly and 7 others on twice-weekly treatment. Serum
half-life was computed from concentrations of the drug determined at 3, 4½
and 6 hours after drug administration, on admission and at 1, 2 and 4 weeks
after start of treatment. In the daily series, the mean serum half-life
decreased from 4.9 hours on admission to 3.6 hours at 1 week (P = 0.02),
and treatment beyond this had no further effect. In the thrice-weekly series,
maximal induction was observed at the 2nd week, the mean values on
admission and at 2 weeks being 5.8 and 3.7 hours, respectively (P < 0.01). In
the twiceweekly series, maximal induction was observed only at the 4th
week, the mean values on admission and at 4 weeks being 4.9 and 3.7 hours,
respectively (P < 0.01).
Serum activity of gamma glutamyl transferase was not found to be a suitable
in vivo marker to monitor induction of the hepatic microsomal enzymes as
no significant changes were observed in the activity of this enzyme in any of
the 3 series during the 4-week period
Optimal phase estimation in quantum networks
We address the problem of estimating the phase phi given N copies of the
phase rotation u(phi) within an array of quantum operations in finite
dimensions. We first consider the special case where the array consists of an
arbitrary input state followed by any arrangement of the N phase rotations, and
ending with a POVM. We optimise the POVM for a given input state and fixed
arrangement. Then we also optimise the input state for some specific cost
functions. In all cases, the optimal POVM is equivalent to a quantum Fourier
transform in an appropriate basis. Examples and applications are given.Comment: 9 pages, 2 figures; this is an extended version of
arXiv:quant-ph/0609160. v2: minor corrections in reference
Quantum search on graphene lattices
We present a continuous-time quantum search algorithm on a graphene lattice. This provides the sought- after implementation of an efficient continuous-time quantum search on a two-dimensional lattice. The search uses the linearity of the dispersion relation near the Dirac point and can find a marked site on a graphene lattice faster than the corresponding classical search. The algorithm can also be used for state transfer and communication
Search for the Flavor-Changing Neutral-Current Decays and
We report the results of a search for the flavor-changing neutral-current
decays and in
data from Fermilab charm hadroproduction experiment E791. No signal above
background is found, and we obtain upper limits on branching fractions,
and
, at the 90\% confidence
level.Comment: nine pages with figures; compressed, uuencoded postscrip
Fermilab E791
Fermilab E791, a very high statistics charm particle experiment, recently
completed its data taking at Fermilab's Tagged Photon Laboratory. Over 20
billion events were recorded through a loose transverse energy trigger and
written to 8mm tape in the the 1991-92 fixed target run at Fermilab. This
unprecedented data sample containing charm is being analysed on many-thousand
MIP RISC computing farms set up at sites in the collaboration. A glimpse of the
data taking and analysis effort is presented. We also show some preliminary
results for common charm decay modes. Our present analysis indicates a very
rich yield of over 200K reconstructed charm decays.Comment: 4 pages, 1 figure, LaTe
Measurement of the Ds Lifetime
We report the results of a precise measurement of the Ds meson lifetime based
on 1662 +/- 56 fully reconstructed Ds -> phi pi decays, from the charm
hadroproduction experiment E791 at Fermilab. Using an unbinned maximum
likelihood fit, we measure the Ds lifetime to be 0.518 +/- 0.014 +/- 0.007 ps.
The ratio of the measured Ds lifetime to the world average D0 lifetime is 1.25
+/- 0.04. This result differs from unity by six standard deviations, indicating
significantly different lifetimes for the Ds and the D0.Comment: 12 pages, 3 figures, 2 table. LaTe
Effect of doping on the dielectric properties of cerium oxide in the microwave and far-infrared frequency range
Cerium oxide (CeO2) has been prepared as a ceramic dielectric resonator by a conventional solid-state ceramic route. The sintered CeO2 has a high dielectric quality factor (Q×f), Q value of 10 000 at 6 GHz with a relative permittivity (ε′) of 23, and temperature coefficient of resonant frequency (τf of -53 ppm/°C. The Q value increases to 20 000 at 6 GHz when the CeO2 is doped with 1 mol% CaCO3. Higher levels of CaCO3 doping lowers the Q and ε′ values and simultaneously decreases τf. TiO2 doping decreases τf and slightly increases ε′, but deceases the Q value. The Q value of pure CeO2 increases to 105 000 at a frequency of 5.58 GHz when it is cooled to 30 K, whereas Q ≈ 85 000 at 5.48 GHz for 1-mol%-CaCO3-doped CeO2 at 30 K
Study of the decay and measurement of masses and widths
From a sample of 848 44 decays, we find
. Using a Dalitz plot analysis of this
three body decay, we find significant contributions from the channels
, , , , and
. We present also the values obtained for masses and widths of
the resonances and .Comment: 10 pages, 3 eps figure
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