Geraniin, a typical ellagitannin isolated from Phyllanthusurinaria Linn, has been reported to have anti-inflammatory effect. The aim of the study is to investigate the therapeutic effects of geraniin ...on LPS-induced acute lung injury (ALI) in mice. The mice were intranasal adminisration of LPS for 12 h. Geraniin was intra-peritoneal injection 1 h after LPS treatment. The results showed that geraniin significantly attenuated LPS-induced pathological changes in the lung. Geraniin also inhibited LPS-induced macrophages and neutrophils infiltration in the lung. Geraniin significantly attenuated LPS-induced elevation of MPO level. LPS-induced TNF-α, IL-6 and IL-1β production were markedly suppressed by treatment of geraniin. Furthermore, geraniin inhibited NF-κB activation in LPS-induced ALI. In addition, geraniin was found to up-regulate the expression of Nrf2 and HO-1. In conclusion, these data suggested that geraniin had therapeutic effects in LPS-induced ALI by inhibiting NF-κB and activating Nrf2 signaling pathways.
Due to its exceptional advantages, such as high specific strength, high specific modulus, and good fatigue resistance, carbon-fiber-reinforced plastic (CFRP) is frequently utilized in aerospace, ...aviation, automotive, rail transportation, and other areas. Composite components typically need to be joined and integrated. In the equipment manufacturing industry, the most used methods for processing composite components are cutting, drilling, and surface treatment. The quality of CFRP is significantly impacted by traditional mechanical processing, causing flaws like delamination, burrs, and tears. Laser processing technology has emerged as a crucial method for processing CFRP for its high quality, non-contact, simple control, and automation features. The most recent research on the laser processing of CFRP is presented in this paper, supporting scientists and engineers who work in the field in using this unconventional manufacturing technique. This paper gives a general overview of the key features of laser processing technology and the numerous machining techniques available. The concepts and benefits of laser processing technology are discussed in terms of the material properties, mode of operation, and laser characteristics, as well as the methods to achieve high efficiency, low damage, and high precision. This paper reviews the research development of laser processing of carbon-fiber-reinforced plastics, and a summary of the factors affecting the quality of CFRP laser processing. Therefore, the research content of this article can be used as a theoretical basis for reducing thermal damage and improving the processing quality of laser-processed composite materials, while, on this basis, we analyze the development trend of CFRP laser processing technology.
Novel theoretical model based on rate equations considering re-absorption is set up to deal with the output characteristics of continuous wave (CW) Tm: YAP laser for the first time. Compared with the ...model that ignore the reabsorption of thulium ion at all (Model 1) or only takes it as a fixed loss (Model 2), the simulation results of the new model (Model 3) can reflect the entire process of reabsorption more accurately and obtain numerical simulation results that are closer to experimental results. Laser characteristics of LD end-pumped CW Tm: YAP crystal is achieved experimentally, which can demonstrate the accuracy of the model. Output power of 7.1 W at 1936 nm is obtained with resonator length of 78 mm under the incident pump power of 27.13 W. While the simulation results on output power of Tm: YAP laser under incident pump power of 27.13 W and cavity length of 78 mm are 17.2 W, 2.76 W, 7.36 W for Model 1, 2, 3. The finding indicates that the new model can evaluate the output performance of Tm: YAP lasers in precise.
The 2 μm wavelength belongs to the eye-safe band and has a wide range of applications in the fields of lidar, biomedicine, and materials processing. With the rapid development of military, wind ...power, sensing, and other industries, new requirements for 2 μm solid-state laser light sources have emerged, especially in the field of lidar. This paper focuses on the research progress of 2 μm solid-state lasers for lidar over the past decade. The technology and performance of 2 μm pulsed single longitudinal mode solid-state lasers, 2 μm seed solid-state lasers, and 2 μm high power solid-state lasers are, respectively, summarized and analyzed. This paper also introduces the properties of gain media commonly used in the 2 μm band, the construction method of new bonded crystals, and the fabrication method of saturable absorbers. Finally, the future prospects of 2 μm solid-state lasers for lidar are presented.
We report a narrow linewidth continuous wave Tm:YLF laser with a Volume Bragg Grating. The Tm:YLF laser was operated at 1908.1 nm with FWHM of 0.14 nm. The maximum output power of 15.5 W with the ...absorbed pump power of 37.6 W, corresponding to the slope efficiency and optical-to-optical conversion efficiency were 46.5% and 41.3%, respectively.
In this paper, a multi-segment bonded crystal model of YAG/Tm:YAG/ YAG/Tm:YAG/YAG structure is proposed firstly and the thermal effect of LD double-end pumped multi-segment bonded Tm:YAG crystal is ...investigated. The thermal distribution is simulated and the thermal focal length of the multi-segment bonding is calculated and measured, which confirms that it can effectively alleviate the thermal effect. In experiment, when the absorbed power is 26 W the laser with a center wavelength of 2014.52 nm and an output power of 8.27 W is obtained, simultaneously optical-to-optical conversion efficiency is 31.8% and the slope efficiency is 38%.
•In this paper, a multi-segment bonded crystal model of YAG/Tm:YAG/ YAG/Tm:YAG/YAG structure is proposed firstly and the thermal effect of LD double-end pumped multi-segment bonded Tm:YAG crystal is investigated.•The thermal distribution is simulated and the thermal focal length of the multi-segment bonding is calculated and measured, which confirms that it can effectively alleviate the thermal effect.•In experiment, when the absorbed power is 26 W, the laser with a center wavelength of 2014.52 nm and an output power of 8.27 W is obtained, simultaneously optical-to-optical conversion efficiency is 31.8% and the slope efficiency is 38%.
This paper presented a single-frequency Ho:YAP ring laser, whose wavelength was variable and the pump source was the Tm fiber laser. Through rotating the Faraday rotator and the half-wave plate, we ...achieved 307 mW single-frequency Ho:YAP laser and the slope efficiency was 21.5% and the wavelength was 2118.45 nm. The M2 factor was about 1.1. In addition, the single-frequency laser 2117.05–2119.25 nm was realized through rotating the Fabry–Perot etalon with a bandwidth of 150 GHz.
A 3–5 μm mid-infrared band is a good window for atmospheric transmission. It has the advantages of high contrast and strong penetration under high humidity conditions. Therefore, it has important ...applications in the fields of laser medicine, laser radar, environmental monitoring, remote sensing, molecular spectroscopy, industrial processing, space communication and photoelectric confrontation. In this paper, the application background of mid-infrared laser is summarized. The ways to realize mid-infrared laser output are described by optical parametric oscillation, mid-infrared solid-state laser doped with different active ions and fiber laser doped with different rare earth ions. The advantages and disadvantages of various mid-infrared lasers are briefly described. The technical approaches, schemes and research status of mid-infrared lasers are introduced.
Glycoprotein VI (GPVI) is the major collagen receptor on the platelet surface and is important in mediating granule secretion and atherothrombosis. Sulforaphane (SFN), a dietary isothiocyanate ...enriched in cruciferous vegetables, exerts multiple biological activities. This study aimed to investigate the efficacy of SFN on GPVI-mediated signaling and platelet granule secretion in vitro. We herein demonstrated that SFN greatly attenuated granule secretion in human gel-filtered platelets in response to collagen, including inhibiting CD62P and CD63 expression and PF4, CCL5, and ATP release. Mechanistically, these inhibitory effects of SFN were mainly mediated by its attenuation of cytosolic phospholipase A
2
(cPLA
2
) phosphorylation and thromboxane A
2
(TxA
2
) generation. Moreover, SFN did not further decrease the inhibitory effects of p38 MAPK inhibitor SB203580 on cPLA
2
phosphorylation, TxA
2
generation and granule secretion. Thus, SFN attenuates platelet granule secretion via down-regulating GPVI-mediated p38 MAPK/cPLA
2
/TxA
2
signaling, which may play important preventive roles in cardiovascular diseases.
The thermal effects model of slab crystal was established based on the practical operating conditions of the solid-state laser. To our knowledge, this is the first time to use the simulation software ...of COMSOL Multiphysics to investigate the thermal model of slab crystal with the complex boundary conditions in detail. And this is also the first time to use this theoretical method to a slab Tm:YLF laser. The results showed that thermal effects of Tm:YLF crystal were enhanced with the increase of the pump power. And the thermal effects increased sharply with the decrease of the size of the pump light along the Y-axis or the increase of the crystal doping concentration. Thermal deformation which produced by thermal lens effect played a leading role of Tm:YLF crystal. Finally, under the premise of elevated the laser output efficiency and ameliorated thermal effects, the optimized parameters were chosen which were the pump size of ω
1
×ω
2
=1mm × 6mm and doping concentration of 2.5at.%.
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