624 research outputs found
The Influence of Anterior Root Stimulation (S2) in Deafferented Spinal Cord Injury Men on Cavernous Electrical Activity
The QED Structure of the Photon
Measurements of the QED structure of the photon based on the reaction ee -->
ee \gamma(*)(P^2)\gamma*(Q^2) --> ee mumu are discussed.
This review is an update of the discussion of the results on the QED
structure of the photon presented in Refs.[1], and covers the published
measurements of the photon structure functions F_2, F_A nd F_B and of the
differential cross-section dsig/dx for the exchange of two virtual photons.Comment: Invited talk given at the 7th International Workshop on Deep
Inelastic Scattering and QCD, April 19 to 23, 1999, Zeuthen, to appear in the
proceedings. 8pages 4 figure
Lipolytic sensitivity to catecholamines in patients with human immunodeficiency virus infection
Lipolysis is higher in patients with acquired immunodeficiency syndrome (AIDS) than in healthy control subjects. To evaluate whether this increase in lipolysis is related to increased beta-adrenergic sensitivity, we compared the lipolytic response to epinephrine (approximately 15 ng x kg(-1) x min(-1)) of six AIDS patients with that of six matched control subjects. Lipolysis was measured by infusion of [2H2]glycerol and [2H2]palmitate. The baseline rates of appearance of palmitate (2.06 +/- 0.21 compared with 1.45 +/- 0.07 micromol x kg(-1) x min(-1)) and glycerol (2.35 +/- 0.16 compared with 1.35 +/- 0.06 micromol x kg(-1) x min(-1)) were higher in AIDS patients (P <0.05). The absolute increase in lipolysis, an indicator of the responsiveness to epinephrine, was not different between groups for the rate of appearance of palmitate (86 +/- 14 compared with 75 +/- 7 micromol x L(-1) x min(-1)) or glycerol (79 +/- 13 compared with 59 +/- 6 micromol x L(-1) x min(-1)). Plasma concentrations of epinephrine were not different between groups. Lipolysis was higher whereas the lipolytic response to epinephrine was normal in AIDS patients. Increased lipolytic sensitivity to catecholamines is not the cause of increased lipolysis in AID
RENO, a European Postmarket Surveillance Registry, confirms effectiveness of coronary brachytheraypy in routine clinical practice.
Purpose: To assess, by a European registry trial, the clinical event rate in patients with discrete stenotic lesions of coronary arteries (de novo or restenotic) in single or multiple vessels (native or bypass grafts) treated with -radiation.
Methods and Materials: Between April 1999 and September 2000, 1098 consecutive patients treated in 46 centers in Europe and the Middle East with the Novoste Beta-Cath System were included in Registry Novoste (RENO).
Results: Six-month follow-up data were obtained for 1085 patients. Of 1174 target lesions, 94.1% were located in native vessels and 5.9% in a bypass graft; 17.7% were de novo lesions, 4.1% were restenotic, and 77.7% were in-stent restenotic lesions. Intravascular brachytherapy was technically successful in 95.9% of lesions. Multisegmental irradiation, using a manual pullback stepping maneuver to treat longer lesions, was used in 16.3% of the procedures. The in-hospital rate of major adverse cardiac events was 1.8%. At 6 months, the rate was 18.7%.
Angiographic follow-up was available for 70.4% of the patients. Nonocclusive restenosis was seen in 18.8% and total occlusion in 5.7% of patients. A combined end point for late (30–180 days) definitive or suspected target vessel closure was reached in 5.4%, but with only 2% of clinical events. Multivariate analysis was performed for major adverse cardiac events and late thrombosis.
Conclusion: Data obtained from the multicenter RENO registry study, derived from a large cohort of unselected consecutive patients, suggest that the good results of recent randomized controlled clinical trials can be replicated in routine clinical practice. © 2003 Elsevier Science Inc
Applied Remote Sensing Program (ARSP)
There are no author-identified significant results in this report
Interference of circulating azathioprine but not methotrexate or sulfasalazine with measurements of interleukin-6 bioactivity
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Two-Tone Optomechanical Instability and Its Fundamental Implications for Backaction-Evading Measurements
While quantum mechanics imposes a fundamental limit on the precision of
interferometric measurements of mechanical motion due to measurement
backaction, the nonlinear nature of the coupling also leads to parametric
instabilities that place practical limits on the sensitivity by limiting the
power in the interferometer. Such instabilities have been extensively studied
in the context of gravitational wave detectors, and their presence has recently
been reported in Advanced LIGO. Here, we observe experimentally and describe
theoretically a new type of optomechanical instability that arises in two-tone
backaction-evading (BAE) measurements, designed to overcome the standard
quantum limit, and demonstrate the effect in the optical domain with a photonic
crystal nanobeam, and in the microwave domain with a micromechanical oscillator
coupled to a microwave resonator. In contrast to the well-known oscillatory
parametric instability that occurs in single-tone, blue-detuned pumping, which
is characterized by a vanishing effective mechanical damping, the parametric
instability in balanced two-tone optomechanics is exponential, and is a result
of small detuning errors in the two pump frequencies. Its origin can be
understood in a rotating frame as the vanishing of the effective mechanical
frequency due to an optical spring effect. Counterintuitively, the instability
occurs even in the presence of perfectly balanced intracavity fields, and can
occur for both signs of detuning. We find excellent quantitative agreement with
our theoretical predictions. Since the constraints on tuning accuracy become
stricter with increasing probe power, it imposes a fundamental limitation on
BAE measurements, as well as other two-tone schemes. In addition to introducing
a new limitation in two-tone BAE measurements, the results also introduce a new
type of nonlinear dynamics in cavity optomechanics
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