7,220 research outputs found
Competition between Electromagnetically Induced Transparency and Raman Processes
We present a theoretical formulation of competition among electromagnetically
induced transparency (EIT) and Raman processes. The latter become important
when the medium can no longer be considered to be dilute. Unlike the standard
formulation of EIT, we consider all fields applied and generated as interacting
with both the transitions of the scheme. We solve Maxwell equations
for the net generated field using a fast-Fourier-transform technique and obtain
predictions for the probe, control and Raman fields. We show how the intensity
of the probe field is depleted at higher atomic number densities due to the
build up of multiple Raman fields.Comment: 3.5 pages, 7 figure
Nucleosomes in colorectal cancer patients during radiochemotherapy
Apoptotic markers and tumor-associated antigens might be suitable to indicate the response to radiochemotherapy early. We analyzed the courses of nucleosomes, CEA, CA 19-9 and CYFRA 21-1 in 25 colorectal cancer patients during radiochemotherapy (4 postoperative, 13 preoperative, 8 local relapse therapy). Blood was taken before therapy, daily during the first week, once weekly during the following weeks, and at the end of the radiochemotherapy. After a temporary decline 6 h after the first irradiation, nucleosomes rose in most patients rapidly reaching a maximum during the first days which was followed by a subsequent decrease. In patients receiving postoperative therapy after complete resection of tumor, nucleosome levels generally were lower than in patients with preoperative or relapse therapy. Correspondingly, CEA, CA 19-9 and CYFRA 21-1 levels of postoperatively treated patients were the lowest whereas those with tumor relapse had the highest ones. During preoperative therapy, lower nucleosome concentrations were found in patients with response to therapy resulting in a smaller area under the curve of days 1-3 (AUC) than in those with progressive disease (p = 0.028). The other parameters did not indicate the response to therapy at the initial treatment phase. In conclusion, the course of nucleosomes (AUC) might be valuable for the early prediction of therapy response in preoperatively treated colorectal cancer patients. Copyright (c) 2006 S. Karger AG, Basel
Dielectric measurements of nanoliter liquids with a photonic crystal resonator at terahertz frequencies
Data supporting Hanham SM, Watts C, Otter WJ, LucyszynS and Klein N (2015) Dielectric measurements of nanoliter liquids with a photonic crystal resonator at terahertz frequencies. Applied Physics Letters, 107 (3), Article number: 032903Data supporting Hanham SM, Watts C, Otter WJ, LucyszynS and Klein N (2015) Dielectric measurements of nanoliter liquids with a photonic crystal resonator at terahertz frequencies. Applied Physics Letters, 107 (3), Article number: 03290
High-dimensional quantum cryptography with twisted light
Quantum key distributions (QKD) systems often rely on polarization of light
for encoding, thus limiting the amount of information that can be sent per
photon and placing tight bounds on the error that such a system can tolerate.
Here we describe a proof-of-principle experiment that indicates the feasibility
of high-dimensional QKD based on the transverse structure of the light field,
allowing for the transfer of more than 1 bit per photon. Our implementation
uses the orbital angular momentum (OAM) of photons and the corresponding
mutually unbiased basis of angular position (ANG). Our experiment uses a
digital micro-mirror device for the rapid generation of OAM and ANG modes at 4
kHz, and a mode sorter capable of sorting single photons based on their OAM and
ANG content with a separation efficiency of 93\%. Through the use of a
7-dimensional alphabet encoded in the OAM and ANG bases, we achieve a channel
capacity of 2.05 bits per sifted photon. Our experiment shows that, in addition
to having an increased information capacity, QKD systems based on spatial-mode
encoding will be more tolerant to errors and thus more robust against
eavesdropping attacks
Assessment of a Pharmacist-Led Antibiotic Time-out for Transition of IV Vancomycin to Oral Linezolid
Introduction: Intravenous (IV) vancomycin requires therapeutic drug monitoring and line placement and may prolong hospital stay. Linezolid requires less monitoring, is orally bioavailable, and may expedite transitions of care. This study assessed the impact of a pharmacist-led antibiotic timeout for the transition from IV vancomycin to oral linezolid. Methods: This single-center, quasi-experimental study included admitted adult patients receiving IV vancomycin for over 48 hours. Patients receiving vasopressors, of immunocompromised status, or with specific antibiotic indications were excluded. The primary outcome was the pharmacist intervention acceptance rate. Secondary outcomes included median hospital length of stay, median antibiotic treatment days, and incidence of adverse effects. Results: Of the 317 screened patients, 94 were eligible for the antibiotic time-out assessment, of which 66 met the criteria for oral linezolid. Of those meeting the criteria, 27 interventions were made, of which 20 (74%) were accepted. The median length of antibiotic treatment days was six days between both groups (p = .352). No differences in safety outcomes were observed. Discussion: A pharmacist-led antibiotic timeout for IV vancomycin to oral linezolid resulted in a high intervention acceptance rate and increased oral linezolid use without impacting safety outcomes. These results support the use of this strategy for antimicrobial stewardship. Conclusion: This study illustrates the impact of a pharmacist-led antibiotic timeout for the transition from IV vancomycin to oral linezolid therapy as an antimicrobial stewardship tool
Collisionless shock acceleration of narrow energy spread ion beams from mixed species plasmas using 1 m lasers
Collisionless shock acceleration of protons and C ions has been
achieved by the interaction of a 10 W/cm, 1 m laser with a
near-critical density plasma. Ablation of the initially solid density target by
a secondary laser allowed for systematic control of the plasma profile. This
enabled the production of beams with peaked spectra with energies of 10-18
MeV/a.m.u. and energy spreads of 10-20 with up to 3x10 particles within
these narrow spectral features. The narrow energy spread and similar velocity
of ion species with different charge-to-mass ratio are consistent with
acceleration by the moving potential of a shock wave. Particle-in-cell
simulations show shock accelerated beams of protons and C ions with
energy distributions consistent with the experiments. Simulations further
indicate the plasma profile determines the trade-off between the beam charge
and energy and that with additional target optimization narrow energy spread
beams exceeding 100 MeV/a.m.u. can be produced using the same laser conditions.Comment: Accepted for publication in Physical Review Accelerators and Beam
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Palbociclib plus letrozole as first-line therapy in estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with extended follow-up.
PurposeIn the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.MethodsIn this double-blind, phase 3 study, post-menopausal women with ER+/HER2- ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).ResultsAfter a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib-letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib-letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients' quality of life was maintained.ConclusionsWith approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2- ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427
Two-colour generation in a chirped seeded Free-Electron Laser
We present the experimental demonstration of a method for generating two
spectrally and temporally separated pulses by an externally seeded, single-pass
free-electron laser operating in the extreme-ultraviolet spectral range. Our
results, collected on the FERMI@Elettra facility and confirmed by numerical
simulations, demonstrate the possibility of controlling both the spectral and
temporal features of the generated pulses. A free-electron laser operated in
this mode becomes a suitable light source for jitter-free, two-colour
pump-probe experiments
Stillbirth rate by maternal HIV serostatus and antiretroviral use in pregnancy in South Africa: An audit
No abstract
Granular spirals on erodible sand bed submitted to a circular fluid motion
An experimental study of a granular surface submitted to a circular fluid
motion is presented. The appearance of an instability along the sand-water
interface is observed beyond a critical radius . This creates ripples with
a spiral shape on the granular surface. A phase diagram of such patterns is
constructed and discussed as a function of the rotation speed of the
flow and as a function of the height of water above the surface. The study
of as a function of , and parameters is reported.
Thereafter, is shown to depend on the rotation speed according to a power
law. The ripple wavelength is found to decrease when the rotation speed
increases and is proportional to the radial distance . The azimuthal angle
\az of the spiral arms is studied. It is found that \az scales with . This lead to the conclusion that \az depends on the fluid momentum.
Comparison with experiments performed with fluids allows us to state that the
spiral patterns are not the signature of an instability of the boundary layer.Comment: 7 pages, 10 figures, 1 table, using RevTeX4, submitted for
publication (2002
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