500 research outputs found
Frequency-Domain Coherent Control of Femtosecond Two-Photon Absorption: Intermediate-Field vs. Weak-Field Regime
Coherent control of femtosecond two-photon absorption in the
intermediate-field regime is analyzed in detail in the powerful frequency
domain using an extended 4th-order perturbative description. The corresponding
absorption is coherently induced by the weak-field non-resonant two-photon
transitions as well as by four-photon transitions involving three absorbed
photons and one emitted photons. The interferences between these two groups of
transitions lead to a difference between the intermediate-field and weak-field
absorption dynamics. The corresponding interference nature (constructive or
destructive) strongly depends on the detuning direction of the pulse spectrum
from half the two-photon transition frequency. The model system of the study is
atomic sodium, for which both experimental and theoretical results are
obtained. The detailed understanding obtained here serves as a basis for
coherent control with rationally-shaped femtosecond pulses in a regime of
sizable absorption yields.Comment: 25 pages, 5 figure
Application of Shaken Lattice Interferometry Based Sensors to Space Navigation
High-sensitivity shaken lattice interferometry (SLI) based sensors have the
potential to provide deep space missions with the ability to precisely measure
non-gravitational perturbing forces. This work considers the simulation of the
OSIRIS-REx mission navigation in the vicinity of Bennu with the addition of
measurements from onboard SLI-based accelerometers. The simulation is performed
in the Jet Propulsion Laboratory's (JPL) Mission Analysis, Operations and
Navigation Toolkit (MONTE) and incorporates OSIRIS-REx reconstructed trajectory
and attitude data from the Navigation and Ancillary Information Facility (NAIF)
database. The use of the reconstructed data from NAIF provides realistic true
dynamical errors and JPL's MONTE software allows for a high-fidelity simulation
of a nominal reference for the filter. The navigation performance and reduction
of tracking and complex modeling enabled by the onboard SLI-based sensor are
presented for two orbital phases of the OSIRIS-REx mission. Overall, the
results show that the addition of SLI-based accelerometer measurements improves
navigation performance, when compared to a radiometric tracking only
configuration. In addition, results demonstrate that highly-precise
accelerometer measurements can effectively replace at least one day of DSN
passes over a three-day period, thereby reducing tracking requirements.
Furthermore, it is shown that lower-fidelity surface force modeling and
parameter estimation is required when using onboard SLI-based accelerometers.Comment: 30 pages, 8 figure
Optical markers of magnetic phase transition in CrSBr
Here, we investigate the role of the interlayer magnetic ordering of CrSBr in
the framework of calculations and by using optical
spectroscopy techniques. These combined studies allow us to unambiguously
determine the nature of the optical transitions. In particular,
photoreflectance measurements, sensitive to the direct transitions, have been
carried out for the first time. We have demonstrated that optically induced
band-to-band transitions visible in optical measurement are remarkably well
assigned to the band structure by the momentum matrix elements and energy
differences for the magnetic ground state (A-AFM). In addition, our study
reveals significant differences in electronic properties for two different
interlayer magnetic phases. When the magnetic ordering of A-AFM to FM is
changed, the crucial modification of the band structure reflected in the
direct-to-indirect band gap transition and the significant splitting of the
conduction bands along the direction are obtained. In addition,
Raman measurements demonstrate a splitting between the in-plane modes
/, which is temperature dependent and can be assigned to
different interlayer magnetic states, corroborated by the DFT+U study.
Moreover, the mode has not been experimentally observed before.
Finally, our results point out the origin of interlayer magnetism, which can be
attributed to electronic rather than structural properties. Our results reveal
a new approach for tuning the optical and electronic properties of van der
Waals magnets by controlling the interlayer magnetic ordering in adjacent
layers.Comment: 33 pages, 15 figure
Azimuthal and polar anchoring energies of aligning layers structured by nonlinear laser lithography
In spite of the fact that there are different techniques in the creation of
the high-quality liquid crystals (LCs) alignment by means of various surfaces,
the azimuthal and polar anchoring energies as well as the pre-tilt angle are
important parameters to all of them. Here, the modified by a certain manner
aligning layers, previously formed by nonlinear laser lithography (NLL), having
high-quality nano-periodic grooves on Ti surfaces, recently proposed for LC
alignment was studied. The change of the scanning speed of NLL in the process
of nano-structured Ti surfaces and their further modification by means of
ITO-coating, and deposition of polyimide film has enabled different aligning
layers, whose main characteristics, namely azimuthal and polar anchoring
energies, were measured. For the modified aligning layers, the dependencies of
the twist and pre-tilt angles for LC cells filled by nematic E7
({\Delta}{\epsilon} > 0) and MLC-6609 ({\Delta}{\epsilon} < 0) were obtained.
Also the contact angle for droplets of isotropic liquid (glycerol), and nematic
LCs was measured for the various values of the scanning speed during the laser
processing.Comment: 49 pages, 18 figure
Purification of Human Plasma/Cellular Fibronectin and Fibronectin Fragments
A method is described for the purification of plasma fibronectins based on a combination of gelatin- and arginine-Sepharose chromatography steps. Cellular fibronectin can be purified from an osteosarcoma fibroblast cell line by affinity chromatography using a monoclonal antibody anti-fibronectin as ligand. Furthermore, we also provide a protocol for the purification of fibronectin domains obtained by fractionation of thermolysin-digested plasma fibronectin on ion-exchange/gel filtration chromatography columns. Assessment of the fibronectin purity is performed by SDS-PAGE, while the ligand binding activities of specific fibronectin domains are determined by ELISA
Efficacy and Safety of Tedizolid Phosphate versus Linezolid in a Randomized Phase 3 Trial in Patients with Acute Bacterial Skin and Skin Structure Infection
Tedizolid phosphate is approved for the treatment of acute bacterial skin and skin structure infection (ABSSSI) caused by Gram-positive bacteria in the United States, Europe, and other countries. In this multicenter, double-blind, phase 3 study, 598 adult ABSSSI patients in China, Taiwan, the Philippines, and the United States were randomized to receive 200 mg of tedizolid, intravenously (i.v.)/orally (p.o.), once daily for 6 days or 600 mg of linezolid, i.v./p.o. twice daily for 10 days. The primary endpoint was early clinical response rate at 48 to 72 h. Secondary endpoints included programmatic and investigator-assessed outcomes at end-of-therapy (EOT) and posttherapy evaluation (PTE) visits. Safety was also evaluated. In the intent-to-treat (ITT) population, 75.3% of tedizolid-treated patients and 79.9% of linezolid-treated patients were early responders (treatment difference, –4.6%; 95% confidence interval [CI], –11.2, 2.2). After exclusion of patients who never received the study drug (tedizolid, n = 8; linezolid, n = 1; modified ITT), comparable early response rates were observed (tedizolid, 77.4%; linezolid, 80.1%; treatment difference, –2.7%; 95% CI, –9.4, 3.9). Secondary endpoints showed high and similar clinical success rates in the ITT and clinically evaluable (CE) populations at EOT and PTE visits (e.g., CE-PTE for tedizolid, 90.4%; for linezolid, 93.5%). Both drugs were well tolerated, and no death occurred. Eight patients experienced phlebitis with tedizolid while none did with linezolid; hence, drug-related treatment-emergent adverse events were reported in a slightly higher proportion in the tedizolid (20.9%) arm than in the linezolid arm (15.8%). The study demonstrated that tedizolid in a primarily Asian population was an efficacious and well-tolerated treatment option for ABSSSI patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT02066402.
Short interfering RNA against STAT1 attenuates cisplatin-induced ototoxicity in the rat by suppressing inflammation
Cisplatin is widely used for treating various solid tumors. However, this drug produces dose-limiting ototoxicity and nephrotoxicity, which significantly reduce the quality of life of cancer patients. While nephrotoxicity could be alleviated by diuresis, there is currently no approved treatment for hearing loss. Previous studies show that the ROS and inflammation are major contributors to cisplatin-induced hearing loss. In this study, we show that ROS trigger the inflammatory process in the cochlea by activating signal transducer and activator of transcription-1 (STAT1). Activation of STAT1 activation was dependent on ROS generation through NOX3 NADPH oxidase, knockdown of which by siRNA reduced STAT1 activation. Moreover, STAT1 siRNA protected against activation of p53, reduced apoptosis, reduced damage to OHCs and preserved hearing in rats. STAT1 siRNA attenuated the increase in inflammatory mediators, such as TNF-α, inhibition of which protected cells from cisplatin-mediated apoptosis. Finally, we showed that trans-tympanic administration of etanercept, a TNF-α antagonist, protected against OHC damage and cisplatin-induced hearing loss. These studies suggest that controlling inflammation by inhibition of STAT1-dependent pathways in the cochlea could serve as an effective approach to treat cisplatin ototoxicity and improve the overall quality of life for cancer patients
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