Analytical model of optical force on supercavitating plasmonic nanoparticles.

Optical manipulation of nanoparticles (NPs) in liquid has garnered increasing interest for various applications, ranging from biological systems to nanofabrication. A plane wave as an optical source has recently been shown to be capable of pushing or pulling an NP when the NP is encapsulated by a nanobubble (NB) in water. However, the lack of an accurate model to describe the optical force on NP-in-NB systems hinders a comprehensive understanding of NP motion mechanisms. In this study, we present an analytical model using vector spherical harmonics to accurately capture the optical force and the resultant trajectory of an NP in an NB. We test the developed model using a solid Au NP as an example. By visualizing the vector field line of the optical force, we reveal the possible moving paths of the NP in the NB. This study can provide valuable insights for designing experiments to manipulate supercaviting NPs using plane waves.

Treatment patterns, healthcare resource utilization, and costs in patients with moderate-to-severe psoriasis treated with systemic therapy in Japan: A retrospective claims database study.

The real-world treatment landscape for patients with moderate-to-severe psoriasis receiving systemic therapies in Japan is not well understood. This study describes the demographic and clinical characteristics, treatment patterns, healthcare resource utilization, and psoriasis-associated costs in these patients. This retrospective observational study used data from the Japan Medical Data Center database between January 2016 and December 2020. Eligible patients had a confirmed diagnosis of psoriasis, ≥1 claim for a systemic treatment of interest, medical history for ≥6 months, and follow-up data for ≥12 months. Systemic therapies comprised biologics (tumor necrosis factor and interleukin inhibitors) and oral treatments (a phosphodiesterase-4 inhibitor, immunosuppressants, and vitamin A). Patient demographics and clinical characteristics, treatment patterns, healthcare resource utilization, and costs were evaluated. The study identified 1770 patients satisfying all inclusion criteria. The mean age was 49.0 years, with 68% of patients aged 20-54 years. Overall, 90.6% and 9.4% of patients received oral medications and biologics as index treatment, respectively. Treatment patterns, healthcare resource utilization, and costs were assessed for treatments received by ≥20 patients (n = 1730). During the 12-month follow-up period, 1102/1730 patients (63.7%) discontinued index treatment, of whom 9.9% switched to alternative systemic treatments. The persistence rate was ≥70% for most biologics and <50% for oral systemic treatments. All 1730 patients had ≥1 all-cause outpatient visit (2.0 visits per person per month) and hospitalization frequency was ≤0.01 per person per month. Persistent patients incurred inflation-adjusted costs of Japanese Yen (JPY) 88 667 per person per month. Treatment switching was associated with an increase in total cost: JPY 128 039 per person per month after switching versus JPY 117 504 before switching. This study of Japanese patients with moderate-to-severe psoriasis demonstrated low persistence, high discontinuation, and low rates of treatment switching with systemic therapies. Switching was associated with increased total cost. These results indicate unmet needs for new treatments.

Characteristic parameters of photonic nanojets of single dielectric microspheres illuminated by focused broadband radiation.

Herein, we report the theoretical investigation on the photonic nanojets (PNJs) of single dielectric microspheres illuminated by focused broadband radiation (polychromatic light) from a Halogen lamp, supercontinuum source, light-emitting diode, and Hg arc lamp. The role of incident beam waist, refractive index of the surrounding medium, and radius of the microsphere on the characteristic parameters such as the electric field intensity enhancement, effective width, and length of the PNJ is studied. Interestingly, the characteristic parameters of the PNJs of solid microspheres obtained for the above-mentioned broadband radiation sources are found close to those observed for the focused monochromatic radiation of wavelengths which are near to the central wavelengths of the sources. Moreover, the characteristic parameters of PNJs of the core-shell microspheres of different thicknesses (t) illuminated by polychromatic radiation from most commonly used sources such as Halogen and Hg arc lamps are studied. For each t value, a suitable wavelength of monochromatic radiation has been found to generate the PNJ with characteristic parameters which are close to those obtained in the case of polychromatic radiation. We believe that the analytical theory and the theoretical simulations reported here would be useful for researchers who work in the fields such as PNJ assisted photoacoustic spectroscopy, white light nanoscopy, low-coherence phase-shifting interference microscopy, and Mirau interferometry.

Indium nanoparticle-based surface enhanced fluorescence from deep ultraviolet to near-infrared: A theoretical study.

Herein, for the first time, we report a theoretical investigation on Indium nanoparticle-based surface enhanced fluorescence (SEF) from deep ultraviolet (UV) to near-infrared (NIR). In the beginning, the far- and near-field plasmonic properties of the Indium nanospheres of different sizes are studied to extract the wavelengths of lower and higher-order localized surface plasmon modes and the corresponding local electric field enhancement (EFE) values. Later, the dependence of the SEF enhancement with the separation between the fluorophore and nanoparticle (d), fluorescence, and excitation wavelengths is studied systematically. The role of the surrounding medium on plasmon mode wavelength and the SEF enhancement is also shown. Moreover, the effect of d and fluorescence wavelength on the average SEF enhancement is investigated. Finally, the variation in the plasmonic properties after thin dielectric coating on the surface of single Indium nanospheres is studied.