Activation of aryl hydrocarbon receptor ameliorates rosacea-like eruptions in mice and suppresses the TLR signaling pathway in LL-37-induced HaCaT cells.

BACKGROUND: Toll-like receptor (TLR) 2, along with some chemokines, were found to be overexpressed in rosacea patients. Aryl hydrocarbon Receptor (AhR) activation inhibited the inflammatory responses triggered by TLR activation. The current study was conducted to evaluate the underlying mechanisms of AhR activation in rosacea models. MATERIALS AND METHODS: Seven-week-old female BALB/c mice received twice daily intradermal injections of LL-37 for 2 consecutive days. Thirty minutes after the second LL-37 injection, 1% or 0.5% AhR agonist benvitimod was administrated topically once per day for 3 consecutive days. HaCaT cells were treated with different concentrations of LL-37 and benvitimod, and were further infected with lentivirus to over-express TLR2. Expressions of TLR2, CCL5, CXCL9, CXCL10 and CXCL11 were evaluated using qRT-PCR, Western Blot or ELISA. RESULTS: AhR activation ameliorated LL-37-induced rosacea-like eruptions in mice by reductions in redness scores, redness areas and dermal inflammatory cell infiltrates. Elevated expressions of TLR2 and chemokines (CCL5, CXCL9, CXCL10 and CXCL11) following LL-37 treatment were decreased by AhR activation. In HaCaT cells receiving LL-37, TLR2 and the four chemokines were up-regulated, and levels of these chemokines were further enhanced after over-expressing TLR2. At 8 h after an administration of 10 µM benvitimod, gene expressions of TLR2 and the four chemokines in LL-37 treated HaCat cells were decreased, while their protein expressions were decreased for 24 h. CONCLUSION: AhR activation is beneficial in treating rosacea in a LL-37-induced rosacea mouse model and involves a suppression of the TLR signaling pathway in an HaCaT cell model of rosacea.

High power picosecond green and deep ultraviolet generations with an all-fiberized MOPA.

We demonstrate high power picosecond green and deep ultraviolet (DUV) lasers based on an all-fiberized master oscillator power amplifier (MOPA). The main power amplifier is fabricated with a highly Yb-doped large mode area (LMA) silicate glass fiber. It delivers 75.2-W laser output at 1029 nm with a pulse repetition rate of 10 MHz and a pulse duration of 70 ps. With a lithium triborate (LBO) crystal, a 43.0-W green output at 514.5 nm has been achieved with a pulse duration of 55 ps. With a caesium lithium borate (CLBO) crystal, a 14.5-W picosecond DUV output at 257 nm has been generated, which is the highest power for the all-fiber based DUV laser, to the best of our knowledge.

Single frequency tunable UV laser at 308†nm based on all-fiberized master oscillator power amplifiers.

A tunable narrow linewidth UV laser near 308 nm is necessary for highly sensitive hydroxyl (OH) radical measurement. We demonstrated a high-power fiber-based single frequency tunable pulsed UV laser at 308 nm. The UV output is generated from the sum frequency of a 515 nm fiber laser and a 768 nm fiber laser, which are harmonic generations from our proprietary high-peak-power silicate glass Yb- and Er-doped fiber amplifiers. A 3.50 W single frequency UV laser with 100.8 kHz pulse repetition rate, 3.6 ns pulse width, 34.7 µJ pulse energy, and 9.6 kW peak power has been achieved, which represents the first demonstration, to the best of our knowledge, of a high-power fiber-based 308 nm UV laser. With temperature control of the single frequency distributed feedback seed laser, the UV output is tunable for up to 792 GHz at 308 nm.

UVA influenced the SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in human skin primary fibroblasts.

Both SIRT1 and UVA radiation are involved in cellular damage processes such as apoptosis, senescence and ageing. MicroRNAs (miRNAs) have been reported to be closely related to UV radiation, as well as to SIRT1. In this study, we investigated the connections among SIRT1, UVA and miRNA in human skin primary fibroblasts. Our results showed that UVA altered the protein level of SIRT1 in a time point-dependent manner. Using miRNA microarray, bioinformatics analysis, we found that knocking down SIRT1 could cause up-regulation of miR-27a-5p and the latter could down-regulate SMAD2, and these results were verified by qRT-PCR or Western blot. Furthermore, UVA radiation (5 J/cm2 ), knocking down SIRT1 or overexpression of miR-27a-5p led to increased expression of MMP1, and decreased expressions of COL1 and BCL2. We also found additive impacts on MMP1, COL1 and BCL2 under the combination of UVA radiation + Sirtinol (SIRT1 inhibitor), or UVA radiation + miR-27a-5p mimic. SIRT1 activator resveratrol could reverse damage changes caused by UVA radiation. Besides, absent of SIRT1 or overexpression of miR-27a-5p increased cell apoptosis and induced cell arrest in G2/M phase. Taken together, these results demonstrated that UVA could influence a novel SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in skin primary fibroblasts, and may provide potential therapeutic targets for UVA-induced skin damage.

Focus issue introduction: advanced solid-state lasers.

This joint issue of Optics Express and Optical Materials Express features 28 state-of-the-art articles written by authors who participated in the international "Advanced Solid State Lasers" conference, held in Boston November 4-8, 2018. This review provides a summary of these articles that cover the spectrum of solid state lasers from materials research to sources and from design innovation to applications.

Feature issue introduction: Advanced Solid-State Lasers 2017.

The Advanced Solid State Lasers 2017 Conference (ASSL) was held from October 1 to 5, 2017. It was an extraordinary conference at the Nagoya Congress Center in Nagoya, Japan. ASSL 2017 again suggested an impressive platform where miscellaneous perceptions with a variety of approaches to optics, photonics, sensing, laser technology, laser systems, and solid state lasers were presented. This international meeting was highly selective, leading to high level contributions through one plenary conference, 17 invited presentations, 70 regular talks, and 121 posters. The present joint issue of Optics Express and Optical Materials Express features 27 articles written by ASSL 2017 authors and covering the spectrum of solid-state lasers from materials research to sources, and from design innovation to applications.

1.8 mJ, 3.5 kW single-frequency optical pulses at 1572 nm generated from an all-fiber MOPA system.

High-energy single-frequency optical pulses at 1572 nm were generated from an all-fiber MOPA system for atmospheric CO2 LIDAR system application. We report the experimental demonstration of 1.8 mJ, a peak power of 3.5 kW at the pulse repetition of 2.5 kHz, as well as 1.3 mJ, a peak power of 2.5 kW at the pulse repetition of 7.5 kHz single-frequency optical pulses at 1572 nm using single-mode large-core polarization-maintaining Er-Yb co-doped silicate glass fiber amplifiers pumped at 976 nm. To the best of our knowledge, this is the highest pulse energy of single frequency at 1572 nm from an all-fiber amplifier system.

Focus issue introduction: Advanced Solid-State Lasers (ASSL) 2016.

The editors introduce the focus issue on "Advanced Solid-State Lasers (ASSL) 2016", which is based on the topics presented at a conference of the same name held in Boston, USA, from October 30 to November 3, 2016. This focus issue, jointly prepared by Optics Express and Optical Materials Express, includes 20 contributed papers (14 for Optics Express and 6 for Optical Materials Express) selected from the voluntary submissions from attendees who presented at the conference and have extended their work into complete research articles. We hope this focus issue provides a useful link to the variety of topical discussions held at the conference and will contribute to the further expansion of the associated research areas.

Focus issue introduction: Advanced Solid-State Lasers (ASSL) 2015.

The editors introduce the focus issue on "Advanced Solid-State Lasers (ASSL) 2015", which is based on the topics presented at a congress of the same name held in Berlin, Germany, from October 4 to October 9, 2015. This focus issue, jointly prepared by Optics Express and Optical Materials Express, includes 23 contributed papers (17 for Optics Express and 6 for Optical Materials Express) selected from the voluntary submissions from attendees who presented at the congress and have extended their work into complete research articles. We hope this focus issue offers a good snapshot of a variety of topical discussions held at the congress and will contribute to the further expansion of the associated research areas.

The CDH1 -160C/A polymorphism is associated with breast cancer: evidence from a meta-analysis.

BACKGROUND: Numerous epidemiological studies have evaluated the association between the CDH1 -160C/A polymorphism and the risk of breast cancers. However, these studies have yielded conflicting results. To derive a more precise estimation of this association, this meta-analysis was conducted. METHODS: A comprehensive search using the keywords "CDH1," "E-Cadherin," "polymorphism," "SNP," and "variant" combined with "breast," "cancer," "tumor," or "carcinomas" was conducted. Pooled odds ratios (ORs) with 95 % confidence intervals (CIs) were appropriately calculated using a fixed effect or random effect model. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist was used for this meta-analysis. RESULTS: Four publications including five studies were identified. It was found that the CDH1 -160C/A polymorphism was significantly associated with breast cancer risk in the dominant model (CA + AA vs. CC: OR = 1.207, 95 % CI = 1.031-1.412, P = 0.019). CONCLUSIONS: Our meta-analysis demonstrated that the -160C/A polymorphism in the CDH1 gene might contribute to breast cancer susceptibility. Further investigations using a much larger sample including different ethnicities are still needed to verify this association.

Cascaded interferometers structure based on dual-pass Mach-Zehnder interferometer and Sagnac interferometer for dual-parameter sensing.

In this article, we propose and demonstrate a cascaded interferometers structure based on a dual-pass Mach-Zehnder interferometer (DP-MZI) and a Sagnac interferometer (SI) for simultaneous measurement of strain and lateral stress. The cascaded interferometers configuration consists of a SI structure following with a MZI setup. By inserting a section of polarization-maintaining photonic crystal fiber (PM-PCF) in the sensing loop of the SI structure, an inline interference between the two orthogonal polarization modes of PM-PCF, as well as the interference between the sensing arm and the reference arm of the DP-MZI, i.e., the cascaded interferometers with dual interference, are realized. Theoretical study shows that the reflection spectrum of such cascaded interferometers is consisted of two parts: the big spectrum envelope owing to the SI and the fine interference fringes as a result of the DP-MZI. Experimental results show that the SI achieves the sensitivity of lateral stress and strain 1.28 nm/kPa, 0.78 pm/µÎµ, respectively, while the DP-MZI achieves -0.009 nm/kPa and 5.65 pm/µÎµ, demonstrating the ability for dual parameters measurement with high accuracy.

Focus issue introduction: Advanced solid-state lasers (ASSL) 2014.

The editors introduce the focus issue on "Advanced Solid-State Lasers (ASSL) 2014," which is based on the topics presented at a congress of the same name held in Shanghai, China, from October 27 to November 1, 2014. This focus issue, jointly prepared by Optics Express and Optical Materials Express, includes 28 contributed papers (21 for Optics Express and 7 for Optical Materials Express) selected from the voluntary submissions by attendees who presented at the congress and have extended their work into complete research articles. We hope this focus issue offers a useful snapshot of the variety of topical discussions held at the congress and will contribute to the further expansion of the associated research areas.

Monolithic polarization maintaining fiber chirped pulse amplification (CPA) system for high energy femtosecond pulse generation at 1.03 µm.

A monolithic polarization maintaining fiber chirped pulse amplification system with 25 cm Yb(3+)-doped high efficiency media fiber that generates 62 µJ sub-400 fs pulses with 25 W at 1.03 µm has recently been demonstrated.

Focus issue introduction: Advanced Solid-State Lasers (ASSL) 2013.

The editors introduce the focus issue on "Advanced Solid-State Lasers (ASSL) 2013," which is based on the topics presented at a congress of the same name held in Paris, France, from October 27 to November 1, 2013. This focus issue, jointly prepared by Optics Express and Optical Materials Express, includes 21 contributed papers (18 for Optics Express and 3 for Optical Materials Express) selected from the voluntary submissions from attendees who presented at the congress and have extended their work into complete research articles. We hope this focus issue offers a good snapshot of a variety of topical discussions held at the congress and will contribute to the further expansion of the associated research areas.

High-efficiency ytterbium-free erbium-doped all-glass double cladding silicate glass fiber for resonantly-pumped fiber lasers.

A highly efficient ytterbium-free erbium-doped silicate glass fiber has been developed for high-power fiber laser applications at an eye-safe wavelength near 1.55 µm. Our preliminary experiments show that high laser efficiency can be obtained from a relatively short length of the gain fiber when resonantly pumped at 1535 nm in both core- and cladding-pumping configurations. With a core-pumping configuration as high as 75%, optical-to-optical efficiency and 4 W output power were obtained at 1560 nm from a 1 m long gain fiber. When using a cladding-pumping configuration, approximately 13 W output power with 67.7% slope efficiency was demonstrated from a piece of 2 m long fiber. The lengths of silicate-based gain fiber are much shorter than their silica-based counterparts used in other experiments, which is significantly important for high-power narrow-band and/or pulsed laser applications.

Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy.

A novel (to our best knowledge) optical fiber strain sensor using a fiber ring resonator based on frequency comb Vernier spectroscopy is proposed and demonstrated. A passively mode-locked optical fiber laser is employed to generate a phased-locked frequency comb. Strain applied to the optical fiber of the fiber ring resonator can be measured with the transmission spectrum. A good linearity is obtained between displacement and the inverse of wavelength spacing with an R(2) of 0.9989, and high sensitivities better than 40 pm/µÎµ within the range of 0 to 10 µÎµ are achieved. The sensitivity can be proportionally improved by increasing the length of the optical fiber ring resonator.

Single-frequency gain-switched Ho-doped fiber laser.

We demonstrate a single-frequency gain-switched Ho-doped fiber laser based on heavily doped silicate glass fiber fabricated in-house. A Q-switched Tm-doped fiber laser at 1.95 µm was used to gain-switch the Ho-doped fiber laser via in-band pumping. Output power of the single-frequency gain-switched pulses has been amplified in a cladding-pumped Tm-Ho-codoped fiber amplifier with 1.2 m active fiber pumped at 803 nm. Two different nonlinear effects, i.e., modulation instability and stimulated Brillouin scattering, could be seen in the 10 µm-core fiber amplifier when the peak power exceeds 3 kW. The single-frequency gain-switched fiber laser was operated at 2.05 µm, a popular laser wavelength for Doppler lidar application. This is the first demonstration of this kind of fiber laser.

High-spectral-flatness mid-infrared supercontinuum generated from a Tm-doped fiber amplifier.

Broadband mid-infrared supercontinuum pulses were generated directly from a short piece of active fiber in a single-mode Tm-doped fiber amplifier. The broadband mid-infrared pulses have an extremely high spectral flatness with ~600 nm FWHM bandwidth (from 1.9 µm to 2.5 µm), >15 kW peak power, and >20 GW/cm(2) laser peak intensity. This new approach exhibits a significantly different physical mechanism from other supercontinuum generation demonstrations in the literature, in which usually a piece of passive fiber was used for nonlinear spectral broadening. The physical mechanism for the broadband mid-infrared supercontinuum generation in this approach has been attributed to a combined effect of two superradiative processes of Tm(3+) ions (i.e., the (3)F(4)-(3)H(6) transition covering the 1.8~2.1 µm spectral region and the (3)H(4)-(3)H(5) transition covering the 2.2~2.5 µm spectral region), and also nonlinear optical processes as well in the Tm-doped gain fiber. The spectra of the mid-infrared supercontinuum pulses were further broadened in a 2 m chalcogenide fiber with 20 dB bandwidth ~1100 nm and a 3 m fluoride fiber with 20 dB bandwidth ~2600 nm.

Metasurface Micro/Nano-Optical Sensors: Principles and Applications.

Metasurfaces are 2D artificial materials consisting of arrays of metamolecules, which are exquisitely designed to manipulate light in terms of amplitude, phase, and polarization state with spatial resolutions at the subwavelength scale. Traditional micro/nano-optical sensors (MNOSs) pursue high sensitivity through strongly localized optical fields based on diffractive and refractive optics, microcavities, and interferometers. Although detections of ultra-low concentrations of analytes have already been demonstrated, the label-free sensing and recognition of complex and unknown samples remain challenging, requiring multiple readouts from sensors, e.g., refractive index, absorption/emission spectrum, chirality, etc. Additionally, the reliability of detecting large, inhomogeneous biosamples may be compromised by the limited near-field sensing area from the localization of light. Here, we review recent advances in metasurface-based MNOSs and compare them with counterparts using micro-optics from aspects of physics, working principles, and applications. By virtue of underlying the physics and design flexibilities of metasurfaces, MNOSs have now been endowed with superb performances and advanced functionalities, leading toward highly integrated smart sensing platforms.

Laser-Induced Fast Assembly of Wettability-Finely-Tunable Superhydrophobic Surfaces for Lossless Droplet Transfer.

Rose-petal-like superhydrophobic surfaces with strong water adhesion are promising for microdroplet manipulation and lossless droplet transfer. Assembly of self-grown micropillars on shape-memory polymer sheets with their surface adhesion finely tunable was enabled using a picosecond laser microprocessing system in a simple, fast, and large-scale manner. The processing speed of the wettability-finely-tunable superhydrophobic surfaces is up to 0.5 cm2/min, around 50-100 times faster than the conventional lithography methods. By adjusting the micropillar height, diameter, and bending angle, as well as superhydrophobic chemical treatment, the contact angle and adhesive force of water droplets on the micropillar-textured surfaces can be tuned from 117.1° up to 165° and 15.4 up to 200.6 µN, respectively. Theoretical analysis suggests a well-defined wetting-state transition with respect to the micropillar size and provides a clear guideline for microstructure design for achieving a stabilized superhydrophobic region. Droplet handling devices, including liquid handling tweezers and gloves, were fabricated from the micropillar-textured surfaces, and lossless liquid transfer of various liquids among various surfaces was demonstrated using these devices. The superhydrophobic surfaces serve as a microreactor platform to perform and reveal the chemical reaction process under a space-constrained condition. The superhydrophobic surfaces with self-assembled micropillars promise great potential in the fields of lossless droplet transfer, biomedical detection, chemical engineering, and microfluidics.