MARGRET CHANDIRA RAJAPPA, GRACY GLADIN SOLOMON, NAGASUBRAMANIAN VENKATASUBRAMANIAM
et al.
Objective: This study aims to develop an in-situ gel formulation incorporating Ofloxacin-loaded nanoparticles to enhance ocular residence time and therapeutic efficacy of drug. Methods: The formulation process included pre-formulation studies such as solubility and UV analysis of Ofloxacin. A pH-triggered in-situ gel was prepared using Poloxamer 407, chitosan, and Eudragit L-100. Various post-formulation parameters were evaluated, including pH, viscosity, drug content, and in-vitro drug release kinetics. Results: Nanoparticles were confirmed using DLS with a particle size of 688 nm. The viscosity of in-situ gel formulations followed a shear thinning process before contact with simulated tear fluid (STF). The viscosity reduced significantly (p<0.05, two-way ANOVA) for the in-situ formulations after contact with STF. the formulation containing 4% Poloxamer 407 and 0.8% Gellan Gum (OFX3) demonstrated acceptable viscosity behavior and sustained drug release. OFX3 achieved a drug release of 97.81% over 6 h, adhering to Higuchi release models and expressing quasi-Fickian diffusion. The HET-CAM test confirmed the formulation non-irritant nature, while stability studies demonstrated no significant changes over a 3-month period. Conclusion: The developed pH-sensitive in-situ gel effectively enhances the solubility of Ofloxacin, providing a promising treatment option for bacterial conjunctivitis. The developed ofloxacin-loaded nanoparticulate in-situ gel successfully integrates controlled release through prolonged ocular residence. Future in-vivo studies will further consolidate its potential as a pioneering candidate for translational ophthalmic applications.
M. S. J. Barson, T. J. Christie, J. P. Duff
et al.
By using an ensemble of nitrogen-vacancy (NV) centers, the vector components of a time-varying (AC) magnetic field are measured in a phase sensitive manner. This allows for the determination of the magnetic field's polarization. This polarization contains useful information about the nearby magnetic environment, such as the response of lossy or anisotropic materials, or the reactance of electrical currents.
Use is made of rigorous definitions for the terms normal, natural, and harmonic to reveal a number of unfamiliar aspects about them. The Gaussian distribution is not sufficient to determine who is normal, and fluctuations above or below a natural-growth curve may or may not be natural. A recipe for harmonically sustained natural growth requires that the overlap during the substitution process must be limited. As a consequence the overall growth process must experience good as well as bad 'seasons'.
Harry Cook, Yulia Bezsudnova, Lari M. Koponen
et al.
We realise an intrinsic optically pumped magnetic gradiometer based on non-linear magneto-optical rotation. We show that our sensor can reach a gradiometric sensitivity of 18 $\text{fT}/\text{cm}/\sqrt{\text{Hz}}$ and can reject common mode homogeneous magnetic field noise with up to 30 dB attenuation. We demonstrate that our magnetic field gradiometer is sufficiently sensitive and resilient to be employed in biomagnetic applications. In particular, we are able to record the auditory evoked response of the human brain, and to perform real-time magnetocardiography in the presence of external magnetic field disturbances. Our gradiometer provides complementary capabilities in human biomagnetic sensing to optically pumped magnetometers, and opens new avenues in the detection of human biomagnetism.
Robert Nevels, Steven Scully, Francisco Espinal
et al.
A proof of the resonant property of linear periodically loaded antennas with subwavelength elements is obtained by applying a Lagrangian formalism. A Lagrangian is developed by modeling the antenna with lumped inductance and capacitance elements on a single line, thereby physically similar to the antenna and thus avoiding the inaccurate two parallel conductor transmission line model. An equation for the antenna current driven by an incident electromagnetic field is obtained via vector and scalar potentials. It is shown that periodic loading provides a means to shorten the resonant length while the antenna pattern remains unchanged. The Lagrangian model is validated through a calculation showing the loaded resonant length is determined by a product of a resonant half-wavelength dipole with the ratio of the free space velocity and the longitudinal traveling wave velocity. A periodically loaded disk-on-rod antenna example with simulations and measurements provides further validation of the mathematics.
Rhys Mackintosh, Jadon Y. Lin, Michael S. Wheatland
et al.
Lightsails using Earth-based lasers for propulsion require passive stabilization to stay within the beam. This can be achieved through the sail's scattering properties, creating optical restoring forces and torques. Undamped restoring forces produce uncontrolled oscillations, which could jeopardize the mission, but it is not obvious how to achieve damping in the vacuum of space. Using a simple two-dimensional model we show that the Doppler effect and relativistic aberration of the propelling laser beam create damping terms in the optical forces and torques. The effect is similar to the Poynting-Robertson effect causing loss of orbital momentum of dust particles around stars, but can be enhanced by design of the sail's geometry.
Mariana Ferreira Ramos, Marie-Christine Slater, Michael Hentschel
et al.
We investigate the co-existence of 852-nm and 1550-nm QKD with carrier-grade 4x25-Gb/s/$λ$ LANWDM over a short-reach interconnect. Shortwave QKD yields a higher key rate and is insensitive to Raman noise, as opposed to 1550-nm QKD.
Electric propulsion requires exhaustive ground test campaigns to obtain an accurate characterization of the propulsion devices, or thrusters, used by the spacecraft. Among the many plasma parameters, accurately measured during the tests, that of the ion velocity is key, and can be measured using non-intrusive tools such as Laser-Induced Fluorescence (LIF) diagnostics. The ion velocity is inferred by Doppler shift measurements that presupposes a precise and accurate knowledge of the wavelength of excitation of the ions at rest. Today electric propulsion is moving towards the use of Krypton as a propellant, due to the dramatic increase in cost of the more advantageous Xenon gas propellant, commonly used until now. In this work the 4d$^4D_{7/2}\rightarrow$5p$^4P^\circ_{5/2}$ transition of Kr II is used for LIF diagnostic in hollow cathode discharge.
Discovered and reported exactly 40 years ago, microwave plasma assisted chemical vapor deposition (MPACVD) pointed out an economic technology that could potentially produce lab-grown diamond stones at scale. After this breakthrough discovery, demonstrating that diamond can be growth at low pressure and temperature, the progress quickly curbed and synthetic single crystal diamond (SCD) size and quality could not be improved toward attaining requirements critical in solid-state electronics. This led to the early promise of MPACVD to not come true and slowed the level of investments, thereby further stalling the progress in diamond syntheses. With the invention of a few novel homo- and hetero-epitaxy growth techniques, the diamond research and technology has recently reinvigorated. This mini review attempts to capture the momentum of recent progress in diamond MPACVD that could finally bring scalable manufacturing of high quality large size wafers for future electronics and optics.
This paper summarizes the state of the art of photocathode based on III-V semiconductors for spin polarized electron beam production. The limitations preventing this class of material to provide the long term reliability at the highest average beam currents necessary for some of the new accelerator facilities or proposed upgrades of existing ones are illustrated. Promising alternative classes of materials are identified showing properties that can be leveraged to synthesize photocathode structures that can outperform III-V semiconductors in the production of spin polarized electron beams and support the operating conditions of advanced electron sources for new facilities.
Here, a physical formalism is proposed for an unconditional microwave quantum teleportation of Gaussian states via two-mode squeezed states in lossy environments. The proposed formalism is controllable to be used in both the fridge and free space in case of entanglement between two parties survives. Some possible experimental parameters are estimated for the teleportation of microwave signals with a frequency of 5GHz based on the proposed physical framework. This would be helpful for superconducting inter- and intra-fridge quantum communication as well as open-air quantum microwave communication, which can be applied to quantum local area networks (QLANs) and distributed quantum computing protocols.
Both exposure of stratum corneum to neutral pH buffers and blockade of acidification mechanisms disturb cutaneous permeability barrier homeostasis and stratum corneum integrity/cohesion, but these approaches all introduce potentially confounding variables. To study the consequences of stratum corneum neutralization, independent of hydration, we applied two chemically unrelated superbases, 1,1,3,3-tetramethylguanidine or 1,8-diazabicyclo [5,4,0] undec-7-ene, in propylene glycol:ethanol (7:3) to hairless mouse skin and assessed whether discrete pH changes alone regulate cutaneous permeability barrier function and stratum corneum integrity/cohesion, as well as the responsible mechanisms. Both 1,1,3,3-tetramethylguanidine and 1,8-diazabicyclo [5,4,0] undec-7-ene applications increased skin surface pH in parallel with abnormalities in both barrier homeostasis and stratum corneum integrity/cohesion. The latter was attributable to rapid activation (<20 min) of serine proteases, assessed by in situ zymography, followed by serine-protease-mediated degradation of corneodesmosomes. Western blotting revealed degradation of desmoglein 1, a key corneodesmosome structural protein, in parallel with loss of corneodesmosomes. Coapplication of serine protease inhibitors with the superbase normalized stratum corneum integrity/cohesion. The superbases also delayed permeability barrier recovery, attributable to decreased beta-glucocerebrosidase activity, assessed zymographically, resulting in a lipid-processing defect on electron microscopy. These studies demonstrate unequivocally that stratum corneum neutralization alone provokes stratum corneum functional abnormalities, including aberrant permeability barrier homeostasis and decreased stratum corneum integrity/cohesion, as well as the mechanisms responsible for these abnormalities.