Unripe Pear Extract Suppresses UVB-Induced Skin Photoaging in Hairless Mice and Keratinocytes.

Our study aimed to investigate whether unripe pear extract (UP) could provide protection against UVB-induced damage to both mouse skin and keratinocytes. We observed that UVB exposure, a common contributor to skin photoaging, led to wrinkle formation, skin dryness, and inflammation in mice. Nevertheless, these effects were mitigated in the groups of UVB-irradiated mice treated with UP. Moreover, UP treatment at 400 µg/mL increased the antioxidant enzyme activities (sodium dodecyl sulfate, 2.22-fold higher; catalase, 2.91-fold higher; GPx, 1.96-fold higher) along with sphingomyelin (1.58-fold higher) and hyaluronic acid (1.31-fold higher) levels in UVB-irradiated keratinocytes. In the keratinocytes irradiated with UVB, UP 400 µg/mL resulted in reduced cytokine production (TNF-α, 33.2%; IL-1ß, 45.3%; IL-6, 33.4%) and the expression of inflammatory pathway-related proteins. The findings indicate that UP has a direct protective effect on UVB-irradiated keratinocytes and is also able to shield against photoaging induced by UVB. Hence, it is suggested that UP could contribute to improved skin health by averting skin photoaging.

Fabrication of ultra-high aspect ratio silicon grating using an alignment method based on a scanning beam interference lithography system.

The high-aspect-ratio silicon grating (HARSG) is an important X-ray optical device that is widely used in X-ray imaging and spectrum detection systems. In this paper, we propose a high-precision alignment method based on the scanning beam interference lithography (SBIL) system to realize precise alignment between the <111> orientation on the (110) wafer plane and the grating lines direction, which is an essential step in HARSG manufacture to obtain the high-aspect-ratio grating structure. After the location of the <111> orientation through fan-shaped mask etching and reference grating fabrication, a two-step method that combines static preliminary alignment and dynamic precision alignment is used to align the reference grating lines direction with the interference field fringes of the SBIL system through the interference of the diffracted light from the reference grating near the normal direction, which can realize a minimal alignment error of 0.001°. Through the overall alignment process, HARSGs with groove densities of 500 gr/mm, 1800 gr/mm, and 3600 gr/mm were fabricated through anisotropic wet etching in KOH solution, producing ultra-high aspect ratios and etch rate ratios greater than 200.

Reconstruction design method of an aspherical recording optical system for the varied line-space grating.

A reconstruction design method for an aspherical recording system for varied line-space gratings is introduced. This method converts the recording system design from achieving specific groove distribution coefficients within the expansion model into reconstruction of the auxiliary mirror surface via the ray-tracing method. The effects of higher-order expansion terms in the expansion model are investigated and more accurate design of the varied line-space grating recording structure is achieved. By varying the surface reconstruction target, this method can be used to design aspherical recording structures with any auxiliary mirror surface shapes.

Polarization-modulated grating interferometer by conical diffraction.

The grating interferometer in the Littrow configuration uses quarter wave plates (QWPs) to modulate the polarization in the measurement system to determine the autocollimation optical path. Fabrication errors and mounting errors of the QWPs lead to phase changes in the grating interferometer that generate measurement errors. As an alternative, we propose a grating interferometer that produces conical diffraction. Using the grating instead of QWPs to modulate the beam's polarization bypasses this source of error. A 45 mm range experiment was performed that yielded a repeated measurement error of 40 nm. Experiments show that the system has a simple structure and good repeatability and is capable of high-precision displacement measurements.

Geometric Aberration Theory of Offner Imaging Spectrometers.

A third-order aberration theory has been developed for the Offner imaging spectrometer comprising an extended source; two concave mirrors; a convex diffraction grating; and an image plane. Analytic formulas of the spot diagram are derived for tracing rays through the system based on Fermat's principle. The proposed theory can be used to discuss in detail individual aberrations of the system such as coma, spherical aberration and astigmatism, and distortion together with the focal conditions. It has been critically evaluated as well in a comparison with exact ray tracing constructed using the commercial software ZEMAX. In regard to the analytic formulas, the results show a high degree of practicality.

[Study on the Effects and Compensation Effect of Recording Parameters Error on Imaging Performance of Holographic Grating in On-Line Spectral Diagnose].

To making the high resolution grating, a numerical calculation was used to analyze the effect of recording parameters on groove density, focal curve and imaging performance of the grating and their compensation. Based on Fermat' s principle, light path function and aberration, the effect on imaging performance of the grating was analyzed. In the case of fixed using parameters, the error of the recording angle has a greater influence on imaging performance, therefore the gain of the weight of recording angle can improve the accuracy of the recording angle values in the optimization; recording distance has little influence on imaging performance; the relative errors of recording parameters cause the change of imaging performance of the grating; the results indicate that recording parameter errors can be compensated by adjusting its corresponding parameter. The study can give theoretical guidance to the fabrication for high resolution varied-line-space plane holographic grating in on-line spectral diagnostic and reduce the alignment difficulty by analyze the main error effect the imaging performance and propose the compensation method.